Title:

Light source coupler, illuminant device, patterned conductor, and method for manufacturing light source coupler

Document Type and Number:

United States Patent 7380961

Abstract:

To provide a light source assembly that does not use a printed circuit board and can be manufactured at a low cost even when produced in small quantities, a light source assembly according to the present invention comprises a plurality of light sources and a connective conductor structure extending in a direction of arrangement of the light sources to join the light sources, wherein the connective conductor structure is formed by cutting off parts of a substantially plate-like patterned conductor as required, the patterned conductor being provided with a prescribed pattern. Thus, by changing the parts to be cut off in the patterned conductor, it is possible to manufacture light source assemblies having various light source connection patterns in a single manufacturing line, allowing efficient and low cost manufacture of the light source assemblies to be achieved even when the light sources are manufactured in small quantities.

Inventors:

Moriyama, Hideo (Tokyo, JP)
Yanagita, Munehiko (Tokyo, JP)

Plaque It!

TECHNICAL FIELD

The present invention relates to a light source assembly formed by electrically connecting a plurality of light sources, a light emitting apparatus using the light source assembly, a patterned conductor for forming the light source assembly and a method for forming the light source assembly.

BACKGROUND OF THE INVENTION

Light emitting apparatuses having a plurality of light sources arranged on a surface of a holder are used not only in general illumination but also in various usages such as advertisement, decoration, signaling and the like. In order to form such a light emitting apparatus, it may be conceived to use bullet-type LED light sources having lead wires and a printed circuit board formed with through-holes into which the lead wires of the light sources are inserted and a conductor pattern for transmitting electric power to the light sources, and to connect the lead wires of the light sources to the conductor pattern of the printed circuit board by means of flow soldering.

Such a structure that utilizes a printed circuit board as a holder of the light sources can bring about an economic benefit when manufactured on a large scale. However, in a case that a variety of light emitting apparatuses having different light source arrangements and connection patterns are produced in small quantities, it can rather lead to a higher manufacturing cost. Further, contact with the molten solder in the soldering process will expose the printed circuit board to a high temperature, and this is undesirable to LEDs, which can be easily damaged by heat. Further, the solder typically contains lead, and thus the use thereof necessitates environmental measures. It may be conceived to use a leadless solder, but the leadless solder is higher in price as well as in melting temperature, which can worsen the detrimental effects of heat against the LEDs. Furthermore, the printed circuit board makes it difficult to arrange the light sources on a curved surface. In the case that flexible conductive wires are used to connect light sources, the process of connection may become cumbersome and this can lead to a higher manufacturing cost. The printed circuit board also has a problem that recycling thereof is quite difficult because the printed circuit board has unitary wirings and support board.

To provide a light emitting module without a printed circuit board and solder, Japanese Patent Application Laid-Open No. 7-106634 has disclosed to connect a plurality of LEDs between an anode bus bar and cathode bus bar by means of mechanical engagement. Further, Japanese Patent Application Laid-Open No. 8-316531 has disclosed a light emitting module comprising a plurality of bus bar pairs, a plurality of LEDs attached between each bus bar pair, and flexible joints for electrically and mechanically connecting adjacent bus bar pairs, so that a three-dimensional configuration of the light emitting module is possible. In these laid-open publications, however, there is no disclosure regarding a light source assembly that can allow easy selection of various light source connection patterns and yet can be manufactured with high production efficiency, nor is there a disclosure regarding a manufacturing method therefor.

BRIEF SUMMARY OF THE INVENTION

The present invention was made to solve the above prior art problems, and a primary object of the present invention is to provide a light source assembly comprising a plurality of light sources that can be manufactured with high efficiency and at low cost without using a printed circuit board, and to provide a manufacturing method therefor.

A second object of the present invention is to provide a light source assembly that can eliminate or considerably reduce an amount of solder used therein, and to provide a manufacturing method therefor.

A third object of the present invention is to provide a light source assembly that can easily achieve various arrangements of light sources, and to provide a manufacturing method therefor.

A fourth object of the present invention is to provide a light source assembly as mentioned above and utilizing a chip-type LED as a light source, and to provide a manufacturing method therefor.

A fifth object of the present invention is to provide a light emitting apparatus using a light source assembly as mentioned above.

A sixth object of the present invention is to provide a tape-shaped conductor for use in forming a light source assembly as mentioned above.

In order to accomplish such objects, according to one aspect of the present invention, there is provided a light source assembly comprising: a plurality of electrically connected light sources; and a connective conductor structure extending in a direction of arrangement of the light sources to join the light sources, wherein the connective conductor structure is formed by cutting off parts of a substantially plate-like patterned conductor as required, the patterned conductor being provided with a prescribed pattern. The patterned conductor can be formed by press working a conductive plate material. According to such a structure, because the light source assembly can be manufactured without using a printed circuit board, the solder used for attachment with the printed circuit board is no longer necessary. This can eliminate concern about environmental problems as well as a possibility that LEDs may be damaged due to heat generated in use of solder. Further, by varying the parts to be cut off in the patterned conductor, it is possible to form connective conductor structures having various light source connection patters by using the same patterned conductor in a single manufacturing line, and thus efficient and low cost manufacture is possible even when light source assemblies having various light source connection patterns are manufactured in small quantities. The light source assembly can be made deformable into a desired shape by providing an appropriate flexibility to the patterned conductor when forming it from a conductive plate material, so that various arrangement of light sources can be attained easily. The nonuse of the printed circuit board also allows easy recycling of the light source assembly when it is no longer used. Further, if the patterned conductor is of a longitudinal tape-like shape, it is possible to conduct various processes such as attachment of the light sources and press working of the patterned conductor while transporting the patterned conductor in a manufacturing line, to thereby allow continuous fabrication of the light source assembly. It can be also easily attained to provide a light source assembly of a desired length by cutting the patterned conductor at an appropriate length.

According to one embodiment of the present invention, the plurality of light sources comprise a chip-type LED, and a socket for receiving the chip-type LED is attached to the connective conductor structure by insert molding. Typically, the socket comprises a bottom wall and a side wall defining a cavity having an upper opening, and the chip-type LED is received in the cavity. In this way, even when a chip-type LED without lead wires is used as a light source, it is possible to easily attach the chip-type LED to the connective conductor structure to obtain a light source assembly.

Preferably, the bottom wall of the socket is formed with a hole so that the LED received in the socket can be pushed through the hole and thereby removed from the socket. This can allow quick replacement of a malfunctioning LED with a normal one. It will be also preferable in view of quick installment of the LED into the socket if a portion of the connective conductor structure is exposed in the cavity of the socket so as to contact electric terminals of the chip-type LED received in the socket. Further preferably, the portion of the connective conductor structure exposed in the cavity of the socket has projections for contacting the electric terminals of the LED. This can ensure electric connection between the LED and the connective conductor. If a portion of the connective conductor structure is bent so as to engage with the LED received in the socket to thereby prevent removal of the LED from the socket, inadvertent removal of the LED can be preferably prevented even when the light source assembly is placed upside-down.

In another embodiment of the present invention, the chip-type LED is of a side-view type having a light emitting portion on its side, and at least part of the side wall of the socket has an opening for allowing light from the light emitting portion of the LED to pass through the side wall. Thus, it is possible to use side-view LEDs

According to yet another embodiment of the present invention, the plurality of light sources comprise a light source having a lead wire, and the connective conductor structure has a hole corresponding to the lead wire of the light source. Preferably, a portion of the connective conductor structure defining the hole comprises projections extending into the hole. Typically, the lead wire of the light source is inserted into the hole of the connective conductor structure, whereby electrical/mechanical connection between the light source and the connective conductor structure is achieved. Further, it will be favorable in view of preventing inadvertent removal of the light sources if the lead wire is cramped by a portion of the connective conductor structure near the hole of the connective conductor structure to achieve attachment of the light source to the connective conductor structure. Instead of directly inserting the lead wire of the light source into the hole of the connective conductor structure, it may be possible that a pin portion of a socket pin is inserted into the hole of the connective conductor structure, and the lead wire is inserted into a socket portion of the socket pin.

According to yet another embodiment of the present invention, each of the plurality of light sources has a pair of lead wires extending substantially in parallel to each other, and the plurality of light sources are arranged in a direction substantially perpendicular to the lead wires, wherein the connective conductor structure is disposed such that its principal surface extends substantially along the lead wires, and attached to the lead wires to join the light sources. In such a case, it is preferable that the patterned conductor is of a longitudinal tape-like shape, and comprises a plurality of connection parts for the lead wires of the light sources, the connection parts being arranged corresponding to an arrangement of the light sources held by a radial taping. This can allow the attachment of the light sources to the patterned conductor to be carried out in a state where the plurality of light sources are unitarily held by the radial taping, and thus improve the work efficiency. After attaching the light sources to the patterned conductor, the lead wires are cut at a predetermined position and parts of the patterned conductor are cut off as required to form a connective structure, to thereby obtain a light source assembly. Further, it will be preferred if a cross-sectional shape of the connective conductor structure taken along a plane perpendicular to the longitudinal direction is bent. This can prevent undesirable contact between the connective conductor structure and the lead wires and thus avert inadvertent short-circuit even in a simple configuration that the connective conductor structure is exposed without being coated with insulating material. The exposed connective conductor structure without insulating coating provides improved heat dissipation and thus can favorably cope with high density arrangement of the light sources. Further, because the longitudinal flexion is limited, the light source assembly can be easily handled when attaching it to the holder.

Preferably, the patterned conductor is of a longitudinal tape-like shape, and comprises: a plurality of light source attachment portions arranged in a longitudinal direction for electrical connection with the light sources; an interconnection path for connecting the light source attachment portions in the longitudinal direction; at least one trunk path widthwise spaced from the interconnection path and the light source attachment portions and extending in the longitudinal direction; and a plurality of branch paths widthwise connecting the trunk path to the interconnection path. Thus, by cutting off prescribed portion of the branch paths, interconnection path or trunk path, a connective conductor structure for connecting the light sources in any of various connection patterns can be formed. In the light source assembly having the connective conductor structure thus formed, the trunk path can be used to connect the light sources to a power supply, favorably eliminating the need for additional wirings. In a case where parts of the trunk path are cut off so that the connective conductor structure connects the light sources in series, remaining parts of the trunk path can be connected to the light source attachment portions via the branch paths so that they can serve as heat dissipating portions for dissipating heat generated from the light sources, to thereby contribute preventing excessive increase in the temperature around the light sources.

In the light source assembly manufactured by using such a patterned conductor, it is possible that a resistor is connected between at least one pair of adjoining light sources, and the interconnection path is cut at a position between the pair of adjoining light sources. Thus, a resistor for preventing an excessive voltage from being applied to a light source, for example, can be connected to the light source.

Further preferably, the light source assembly may comprise a joint member extending in a widthwise direction of the connective conductor structure to hold the interconnection path and the trunk path in a unit. In this way, when pats of patterned conductor are cut off as required to form the connective conductor structure, it is possible to prevent the parts of the resulting connective conductor structure from being separated apart. Further, the joint member improves the mechanical strength of the connective conductor structure. Such a joint member can be preferably formed by insert molding. In the case that the joint member is formed by insert molding, it is favorable that the trunk path is formed with a widthwise recess of through-hole, and the joint member extends through the widthwise recess or through-hole because this can firmly engage the joint member to the trunk path. Further preferably, the joint member is formed with a hole at a position aligned with the interconnection path such that the hole exposes the interconnection path, thereby allowing a part of the interconnection path exposed by the hole to be cut off. In this way, it is possible to form a connective conductor structure having a desired light source connection pattern by cutting the interconnection path after forming the joint member. The part of the interconnection path exposed by the hole of the joint member may have a smaller width than the other part of the interconnection path so that it can be cut off easily. The joint member may comprise one or a plurality of insulating sheets. A plurality of insulating sheets may extend widthwise at predetermined positions or alternatively, a single insulating sheet may extend substantially a whole length of the connective conductor structure. By using such insulating sheets, the resultant light source assembly can be smaller (or thinner) compared with that manufactured using the joint member formed by insert molding. If the insulating sheet is attached to a light source attachment surface of the connective conductor structure, it is prevented that a part applied with the power supply voltage is exposed on the light source attachment surface where a personnel may touch with a relatively high possibility, and thus the safety is improved. Further, since the insulating sheet can reflect the light from the light sources, illumination efficiency can be increased.

When the light source assembly does not have insert molded joint members or when such joint members are removed after the light sources are attached to the connective conductor structure, it is possible that the branch paths connecting the trunk path to the interconnection path are bent such that a principal surface of the trunk path is substantially perpendicular to a principal surface of the interconnection path. In this way, by inserting the trunk path into an aligned recess or hole formed in the holder, the light source assembly can be easily attached to the holder.

In place of the joint member or in addition to the joint member, it is possible to provide a socket for receiving a chip-type LED, such that the socket extends in a widthwise direction of the connective conductor structure to hold the interconnection path and the trunk path in a unit.

In the case where the plurality of light sources comprise a chip-type LED, a light source attachment portion associated with the chip-type LED may have terminal connection parts corresponding to terminals of the chip-type LED, and at least one of the terminal connection parts may have an extension which is bent to form a wall for positioning or holding the chip-type LED. Preferably the terminal connection parts of the light source attachment portion associated with the chip-type LED have a pair of extensions opposing to each other. This can eliminate the need for a socket formed by insert molding or the like.

It is not necessary to attach a light source to every light source attachment portion, and it is possible that at least one of the light source attachment portions is not attached with a light source. This can flexibly vary the interval between the light sources. When the light sources are connected in series or in series-parallel connections, for example, such non-attachment of the light source can be achieved by coupling the terminal connection parts in each light source attachment portion when the patterned conductor is formed (primary processing), and in the secondary processing of the patterned conductor, separating the terminal connection parts only in the light source attachment portions where the light sources are actually attached.

When at least one of the plurality of light sources consists of a light source having a pair of terminals, the pair of terminals of the light source may be arranged in a widthwise direction of the light source assembly. In this way, when the light source assembly is flexed in the longitudinal direction, there is no force produced for urging the terminals of the light sources away from the connective conductor structure, and thus undesirable removal of the light sources from the connective conductor structure can be prevented. This can be preferably realized by that the light source attachment portion to which the light source having a pair of terminals is attached has a pair of terminal connection parts corresponding to the pair of terminals, and the pair of terminal connection parts are arranged in the widthwise direction of the patterned conductor.

When each of the light sources has a pair of terminals, it is preferable that the patterned conductor is provided with a pattern that can be commonly used in connecting the light sources in series, parallel or series-parallel connection. This can allow a light source assembly having light sources connected in any of series, parallel or series-parallel connections to be formed from the same patterned conductor, and thus can achieve increase in the production efficiency and decrease in the manufacturing cost. According to a preferred embodiment of the present invention, the patterned conductor is of a longitudinal tape-like shape, and comprises: a plurality of light source attachment portions arranged in a longitudinal direction for electrical connection with the light sources; an interconnection path for connecting the light source attachment portions in the longitudinal direction; a pair of trunk paths disposed on either side of the patterned conductor so as to interpose the interconnection path and the light source attachment portions therebetween and extending in the longitudinal direction; and a plurality of branch paths widthwise connecting the trunk paths to the interconnection path. In such a structure, it is possible to cut off a portion of the branch paths, interconnection path or trunk paths as required to form connective conductor structures having various light source connection patterns from the common patterned conductor in a single manufacturing line easily and efficiently, and thus the manufacturing cost can be reduced even when the light source assemblies are manufactured in small quantities. Preferably, each of the light source attachment portions has a pair of terminal connection parts corresponding to the pair of terminals of the light sources, and the interconnection path comprises a plurality of connection paths each connecting the terminal connection parts contained in adjoining light source attachment portions.

When the plurality of light sources comprise a three-pole LED lamp having two different color LED chips and three terminals, it will be preferable if the patterned conductor is of a longitudinal tape-like shape, and comprises: a plurality of light source attachment portions arranged in a longitudinal direction for electrical connection with the light sources; an interconnection path for connecting the light source attachment portions in the longitudinal direction; a pair of trunk paths disposed on either side of the patterned conductor so as to interpose the interconnection path and the light source attachment portions therebetween and extending in the longitudinal direction; and a plurality of branch paths widthwise connecting the trunk paths to the interconnection path, wherein each of the light source attachment portions has three widthwise arranged terminal connection parts corresponding to the three terminals of the three-pole LED lamp, and the interconnection path comprises a plurality of connection paths each connecting the widthwise aligned terminal connection parts contained in adjoining light source attachment portions. In this way, a light source assembly using three-pole LED lamps as light sources can be realized, which, when connected to an appropriate power supply and switches, can variously change the color of the illuminated light.

When the plurality of light sources comprise a four-pole LED lamp having first and second LED chips of different colors and four terminals, and two of the four terminals are connected to the first LED chip while the remaining two are connected to the second LED chip, it will be preferable if the patterned conductor is of a longitudinal tape-like shape, and comprises: a plurality of light source attachment portions arranged in a longitudinal direction for electrical connection with the light sources; an interconnection path for connecting the light source attachment portions in the longitudinal direction; a pair of trunk paths disposed on either side of the patterned conductor so as to interpose the interconnection path and the light source attachment portions therebetween and extending in the longitudinal direction; and a plurality of branch paths widthwise connecting the trunk paths to the interconnection path, wherein each of the light source attachment portions has four terminal connection parts corresponding to the four terminals of the four-pole LED chip, two of the four terminal connection parts corresponding to the terminals connected to the first LED chip being aligned in the longitudinal direction of the patterned conductor while two of the four terminal connection parts corresponding to the terminals connected to the second LED chip being aligned in the longitudinal direction of the patterned conductor and spaced from the other two terminal connection parts in a widthwise direction of the patterned conductor, wherein the interconnection path comprises a plurality of connection paths each connecting the widthwise aligned connection parts contained in adjoining light source attachment portions, and longitudinally aligned ones of the plurality of connection paths are connected by widthwise extending branch paths, and wherein the patterned conductor further comprises a third trunk path disposed at a widthwise outer side of one of the first and second trunk paths and extending in the longitudinal direction, and branch paths for widthwise connecting the third trunk path to the one of the first and second trunk paths. In this way, a light source assembly using four-pole LED lamps as light sources can be realized, which, when connected with an appropriate power supply and switches, can variously change the color of the illuminated light.

Preferably, the patterned conductor is essentially made of aluminum. It will be preferable if the light sources are attached to the connective conductor structure by laser welding because the attachment can be highly reliable. Further, a resistor for forming a prescribed circuit together with the light sources may be connected to the connective conductor structure by laser welding. Typically, the light source attached to the connective conductor structure by laser welding consists of a chip-type LED (or surface-mount type LED), and the resistor consists of a chip-type resistor (or surface-mount type resistor), but they may not be limited to the chip-type devices, and the laser welding may be applied to the light source having lead wires as terminals for electric connection.

It is also possible that at least one of the plurality of light sources consists of a light emitting element assembly comprising a plurality of light emitting elements. Further, it will be convenient if the patterned conductor comprises projections for defining attachment positions of the light sources.

In yet another preferred embodiment of a light source assembly according to the present invention, the patterned conductor comprises a pair of trunk paths extending substantially in parallel in a longitudinal direction and a plurality of branch paths connecting the pair of trunk paths to each other, the light sources are connected between the pair of trunk paths, and the cut-off parts of the patterned conductor include the branch paths. This embodiment is particularly suitable for embodying a light source assembly in which the plurality of light sources are connected in parallel between the pair of trunk paths. Since the pair of trunk paths are connected to each other by the branch paths, the patterned conductor can be handled quite easily, which can improve the production efficiency. If a gap between the pair of trunk paths is not straight (for example, bent in a rectangular wave), the attachment positions of the light sources (LEDs) connected between the pair of trunk paths can be adjusted not only in the longitudinal direction but also in the widthwise direction. Thus, in a case that the light source assemblies are used in forming automobile lamps, for example, it is possible to cope with a situation where different LED arrangement patterns are required for different vehicle types. This can lead to parts sharing and bring about significant economic benefits.

When each of the light sources consists of an LED having a plate-shaped cathode terminal and anode terminal, it is preferred that a portion of the patterned conductor to which the cathode terminal of each LED is attached has a larger area than a portion of the same to which the anode of each LED is attached. This is because that in such an LED, an LED chip encapsulated within a package is usually mounted on the cathode terminal and connected to the anode terminal via thin lead wire, and thus the heat generated from the LED chip is mainly discharged via the cathode terminal. When a portion of the patterned conductor to which the cathode terminal of each LED is attached has a larger area, the heat discharged via the cathode terminals can be efficiently dissipated. In the case where the patterned conductor comprises a pair of trunk paths extending substantially in parallel in a longitudinal direction, and the LEDs are connected between the pair of trunk paths, the trunk path to which the cathode terminals of the LEDs are attached may preferably have a larger width than the trunk path to which the anode terminals of the LEDs are attached.

According to another aspect of the present invention, there is provided a light emitting apparatus comprising a light source assembly having a plurality of electrically connected light sources and a holder for holding the light source assembly, wherein the light source assembly comprises a connective conductor structure extending in a direction of arrangement of the light sources to join the light sources, the connective conductor structure being formed by cutting off parts of a substantially plate-like patterned conductor as required, the patterned conductor being provided with a prescribed pattern, wherein the patterned conductor is of a longitudinal tape-like shape, and comprises: a plurality of light source attachment portions arranged in a longitudinal direction for electrical connection with the light sources; an interconnection path for connecting the light source attachment portions in the longitudinal direction; a pair of trunk paths disposed on either side of the patterned conductor so as to interpose the interconnection path and the light source attachment portions therebetween and extending in the longitudinal direction; and a plurality of branch paths widthwise connecting the trunk path to the interconnection path, and wherein the branch paths connecting the trunk paths to the interconnection path are bent such that a principal surface of each trunk path is substantially perpendicular to a principal surface of the interconnection path, and the trunk paths are inserted into corresponding holes or recesses provided to the holder to achieve attachment of the light source assembly to the holder. In this light emitting apparatus, the light source assembly can be attached to the holder by just inserting the trunk paths into the recesses or holes of the holder, and thus the efficiency of process of attaching can be improved.

According to another embodiment, there is provided a light emitting apparatus comprising a light source assembly having a plurality of electrically connected light sources each having lead wires and a holder for holding the light source assembly, the light sources being arranged in a direction substantially perpendicular to the lead wires, wherein the light source assembly comprises a connective conductor structure extending in the direction of arrangement of the light sources to join the light sources, and wherein one or both of the lead wires and the connective conductor structure protrude toward the holder and are inserted into holes or recesses provided to the holder to achieve attachment of the light source assembly to the holder. In such a light emitting apparatus, it is only necessary for the holder to be formed with holes or recesses, and thus no complicated processes are needed. This makes it possible to easily manufacture various light emitting apparatuses having different light source arrangements, and thus can reduce the cost when various light emitting apparatuses are manufactured in small quantities. Further, the light emitting apparatus can be securely attached to the holder with a simple structure. Also, since the connective conductor structure is disposed between the holder and the light source bodies, the light source bodies can be held spaced apart from a surface of the holder, which improves heat dissipation.

According to yet another aspect of the present invention, there is provided a tape-shaped patterned conductor having a prescribed pattern and used for forming a light source assembly by electrically connecting a plurality of light sources, comprising: a plurality of light source attachment portions arranged in a longitudinal direction for connection with the light sources; an interconnection path connecting the light source attachment portions in the longitudinal direction; at least one trunk path widthwise spaced from the interconnection path and the light source attachment portions and extending in the longitudinal direction; and a plurality of branch paths widthwise connecting the trunk path to the interconnection path. By using such a tape-shaped patterned conductor, it is possible to manufacture a light source assemblies efficiently without using a printed circuit board. Further, by cutting off a portion of the branch paths and/or interconnection path as required, light source assemblies having light sources connected in various connection patterns can be formed easily.

The cutting (secondary processing) of the patterned conductor can be achieved efficiently and at low cost if it is done by press working using a progressive press machine. Therefore, it is preferable that the trunk path is formed with a plurality of holes (pilot holes) arranged in the longitudinal direction at a predetermined interval for use in transportation or positioning of the patterned conductor in a progressive press machine. When each of the light sources has a pair of terminals for electrical connection, each of the light source attachment portions should have a pair of terminal connection parts for connection with the pair of terminals of a corresponding light source. In such a case, the interconnection path may comprise a plurality of connection paths each connecting the terminal connection parts contained in adjoining light source attachment portions. It is also possible that at least one of the connection paths and/or trunk path is formed with a hole for inserting a lead wire of a resistor having lead wires. If the pair of terminal connection parts in each light source attachment portion are spaced from each other, the number of parts need to be cut off in the secondary processing of the patterned conductor can be reduced while if the pair of terminal connection parts in each light source attachment portion are connected to each other, the part connecting the pair of terminal connection parts can be selectively cut off as needed, and thus the flexibility is improved. Further, a resistor attachment portion may be provided between at least one adjoining pair of light source attachment portions. It may be also possible that at least one of the branch paths may be replaced with a resistor. In this way, a resistor can be easily incorporated in the circuit. The trunk path may have a widthwise convexly curved portion. By bending the convexly curved portion at its root, it can be used in attachment to the holder. When a progressive press machine is used in attaching a plurality of light sources held by the radial taping to an unwound portion of the tape-shaped patterned conductor wound in a coil, the trunk path of the patterned conductor may interfere with main bodies of the light-sources. In such a case, however, if the trunk path is formed with convexly curved portions, the interference between the trunk path of the tape-shaped patterned conductor and the main bodies of the light sources can be prevented by bending the convexly curved portions in the unwound portion of the tape-shaped patterned conductor.

Further preferably, a pair of trunk paths may be disposed on either side of the patterned conductor so as to interpose the interconnection path and the light source attachment portions therebetween. In such a configuration, it is possible to form a light source assembly connecting the light sources in any of serial-parallel, parallel or series connections by cutting off a prescribed portion of the branch path and/or interconnection path. Thus, light source assemblies having various connection patters can be manufactured from the same patterned conductor in a single manufacturing line, advantageously improving the production efficiency and reducing the manufacturing cost.

According to another embodiment of the present invention, there is provided a tape-shaped patterned conductor having a prescribed pattern and used for forming a light source assembly by electrically connecting a plurality of light sources, wherein parts of the patterned conductor are to be cut off by a progressive press machine as required to form a connective conductor structure for connecting the light sources, and wherein the patterned conductor is formed with a plurality of holes arranged in a longitudinal direction at a predetermined interval for use in transportation or positioning of the patterned conductor in the progressive press machine. According to still another embodiment, there is provided a tape-shaped patterned conductor having a prescribed pattern and used for forming a light source assembly by electrically connecting a plurality of light sources each having lead wires, the light sources being arranged in a direction substantially perpendicular to the lead wires, the patterned conductor comprising: a plurality of connection parts arranged in a longitudinal direction for connection with the lead wires of the plurality of light sources; and an interconnection path for connecting the connection parts in the longitudinal direction, wherein the interconnection path is formed with pilot holes for engagement with pilot pins of a progressive press machine. Thus, by providing the patterned conductor with a plurality of holes used for transportation or positioning of the patterned conductor in the progressive press machine, the handling of the patterned conductor by the progressive press machine can be facilitated and the production efficiency of the light source assembly using the patterned conductor can be improved.

According to still another aspect of the present invention, there is provided a manufacturing method of a light source assembly comprising a plurality of light sources and a connective conductor structure for electrically connecting the plurality of light sources, the method comprising the steps of: forming a substantially plate-like patterned conductor having a prescribed pattern; attaching the patterned conductor to the light sources; and cutting off parts of the patterned conductor as required to form the connective conductor structure. In this way, by changing the parts to be cut out in the patterned conductor, it is possible to form a light source assembly comprising a connective conductor structure having various light source connection patterns. Also this manufacturing method can eliminate use of solder which is usually used in a printed circuit board or for connection with the printed circuit board.

Preferably, the step of forming the tape-shaped patterned conductor comprises a step of press working a conductive plate material. It will be further preferable in view of work efficiency if the step of cutting off parts of the patterned conductor and/or attaching the patterned conductor to the light sources is carried out by a progressive press machine. If the manufacturing method further comprises a step of attaching a joint member to the patterned conductor so as to hold parts of the connective conductor structure made from the patterned conductor, and the step of cutting off parts of the patterned conductor is carried out after the step of attaching the joint member, it is possible to prevent the parts of the connective conductor structure from being separated apart. In such a case, it is preferable that the joint member is formed with at least one hole to expose a part of the patterned conductor to be cut off, whereby allowing the part of the patterned conductor exposed by the hole can be cut as required. If the light sources comprise a chip-type LED, and the present method comprises a step of attaching a socket to the patterned conductor for receiving the chip-type LED, the step of cutting off parts of the patterned conductor can be carried out after the step of attaching the socket.

If the light sources comprise a light source having lead wires, the step of attaching the patterned conductor to the light sources may comprise a step of inserting the lead wires of the light source into corresponding holes provided to the connective conductor structure.

It may be also possible that the step of cutting off parts of the patterned conductor is carried out after the step of attaching the patterned conductor to the light sources. This can prevent the parts of the connective conductor structure, which is formed by cutting off parts of the patterned conductor as required, from being separated apart without using the joint member. Further, if each of the light sources has a pair of lead wires for electric connection, the step of attaching may preferably comprise step of cramping the lead wires with prescribed portions of the patterned conductor, to thereby eliminate use of solder. The engagement by cramping is also preferred for the reason that it is suitable to be carried out by progressive press working. The method may further comprise the step of bending the patterned conductor along a bending line extending in the longitudinal direction, so as to prevent undesirable contact between the patterned conductor (or the connective conductor structure made therefrom) and the lead wires of the light sources.

According to a further embodiment of the present invention, there is provided a manufacturing method of a light source assembly having a plurality of light sources each having lead wires, wherein the light sources are arranged in a direction substantially perpendicular to the lead wires, comprising the steps of: supplying the plurality of light sources arranged in the direction perpendicular to the lead wires and held by a carrier tape for radial taping; and electrically connecting the light sources in a state that the light sources are held by the carrier tape to thereby continuously obtain the light sources. In this method, the connecting of the light sources is conducted while the light sources are held unitarily, and thus the workability in the manufacture of the light source assembly can be improved.

According to another aspect of the present invention, there is provided a light emitting apparatus comprising: a light source assembly having a plurality of electrically connected light sources, a light transmissive tubular member for accommodating the light source assembly therein; and a pair of cap members attached to either end of the tubular member, wherein the light source assembly comprises a connective conductor structure for connecting the light sources, and the connective conductor structure is formed by cutting off parts of a substantially plate-like patterned conductor as required, the patterned conductor being provided with a prescribed pattern. In such a light emitting apparatus, the connective conductor structure can be significantly thicker (0.1-0.3 mm) than a circuit-forming copper film (typically 35 μm) of a printed circuit board to thereby improve heat conducting property. Thus, it is possible to transfer heat generated from the light sources or other elements (resistors) quickly and prevent excessive increase in temperature around the light sources or other elements to thereby prevent damage to them.

According to yet another aspect of the present invention, there is provided a light emitting apparatus comprising a light source assembly having a plurality of electrically connected light sources, wherein the light source assembly comprises a connective conductor structure for connecting the light sources, and the connective conductor structure is formed by cutting off parts of a substantially plate-like patterned conductor as required, the patterned conductor being provided with a prescribed pattern, and wherein the light emitting apparatus comprises: a housing for accommodating the light source assembly therein; and a heat transmission member contacting the connective conductor structure of the light source assembly and an inner surface of the housing to transmit heat therebetween. In such a configuration, the heat generated from the light sources or the like is transmitted from the connective conductor structure to the housing, and then dissipated to outside from the housing, and therefore, it is possible to suppress increase in the temperature within the housing, and thus prevent damage to the light sources or other elements or performance decrease of the same. In other words, the use of heat transmission member can make the housing work as a heat sink.

The heat transmission member can also serve as a support member for supporting the light source assembly in the housing, and this can make an additional support member unnecessary. Preferably, the heat transmission member is elastic, and pressed against the inner surface of the housing because this can improve the heat transmission to the housing as well as securely support the light source assembly without undesirable play. The housing is preferably made of a material having a favorable heat transmission property such as glass. If the patterned conductor is of a longitudinal tape-like shape, and comprises: a plurality of light source attachment portions arranged in a longitudinal direction for electrical connection with the light sources; an interconnection path for connecting the light source attachment portions in the longitudinal direction; at least one trunk path widthwise spaced from the interconnection path and the light source attachment portions and extending in the longitudinal direction; and a plurality of branch paths widthwise connecting the trunk path to the interconnection path, the heat transmission member can be connected to the trunk path.

According to another aspect of the present invention, there is provided a light emitting apparatus comprising a light source assembly having a plurality of electrically connected light sources and a holder for holding the light source assembly, wherein the light source assembly comprises a connective conductor structure extending in a direction of arrangement of the light sources to join the light sources, the connective conductor structure being formed by cutting off parts of a substantially plate-like patterned conductor as required, the patterned conductor being provided with a prescribed pattern, wherein the patterned conductor is of a longitudinal tape-like shape, and comprises: a plurality of light source attachment portions arranged in a longitudinal direction for electrical connection with the light sources; an interconnection path for connecting the light source attachment portions in the longitudinal direction; a pair of trunk paths disposed on either side of the patterned conductor so as to interpose the interconnection path and the light source attachment portions therebetween and extending in the longitudinal direction; and a plurality of branch paths widthwise connecting the trunk path to the interconnection path, and wherein at least one surface of the holder is formed with a channel having opposing side walls in which longitudinally extending guide grooves are formed corresponding to the pair of trunk paths so that the light source assembly is attached to the holder by sliding the pair of the trunk paths into the guide grooves. In such a light emitting apparatus, the attachment of the light source assembly to the holder can be achieved readily.

If both surfaces of the holder are formed with a channel, and opposing side walls of each channel are formed with longitudinally extending guide grooves corresponding to the pair of trunk paths, it is possible that each surface of the holder is attached with the corresponding light source assembly with the pair of trunk paths slid into the guide grooves, so that the light can be emitted on both sides of the holder.

According to yet another aspect of the present invention, there is provided a tape-shaped patterned conductor having a prescribed pattern and used for forming a light source assembly by electrically connecting a plurality of light sources, comprising: more than two trunk paths extending in a longitudinal direction and mutually spaced apart in a widthwise direction; a plurality of light source attachment portions for electrical connection with the light sources, the light source attachment portions being arranged in the longitudinal direction between adjoining trunk paths; interconnecting paths for connecting the plurality of light source attachment portions in the longitudinal direction; and a plurality of branch paths for widthwise connecting each of the interconnection paths to the trunk paths interposing the interconnection path therebetween. By using such a patterned conductor, it is possible to easily form a light source assembly having light sources arranged in a plurality of lines, and thus improve production efficiency.

According to still another aspect of the present invention, there is provided a light emitting apparatus comprising a plurality of light source assemblies each having a plurality of electrically connected light sources, wherein each of the light source assemblies comprises a connective conductor structure extending in a direction of arrangement of the light sources to join the light sources, the connective conductor structure being formed by cutting off parts of a substantially plate-like patterned conductor as required, the patterned conductor being provided with a prescribed pattern, and wherein the plurality of light sources are arranged in the widthwise direction, and adjoining light sources are connected to each other so that the plurality of light source assemblies are connected in series. Thus, it is possible to use light source assemblies to constitute a light emitting apparatus in which light sources are connected in a matrix pattern. Such a light emitting apparatus is suitable for a traffic light, for example, because even if a single light source breaks down and stops current conduction, its influence on the other light sources is small.

When each of the light sources consists of an LED and each LED is connected in series with a resistor, if a single LED suffers a short-circuiting malfunction, the voltage can be maintained by the resistor connected in series to the malfunctioning LED, and therefore, the LEDs connected in parallel with the malfunctioning LED can continue emitting light so that a significant decrease in the amount of emitted light can be avoided.

According to another aspect of the present invention, there is provided a light source assembly comprising a plurality of electrically connected light sources, wherein the light source assembly comprises a connective conductor structure extending in a direction of arrangement of the light sources to join the light sources, the connective conductor structure being formed by cutting off parts of a substantially plate-like patterned conductor as required, the patterned conductor being provided with a prescribed pattern, wherein the patterned conductor is of a longitudinal tape-like shape, and comprises: a plurality of light source attachment portions arranged in a longitudinal direction for electrical connection with the light sources; an interconnection path for connecting the light source attachment portions in the longitudinal direction; a pair of trunk paths disposed on either side of the patterned conductor so as to interpose the interconnection path and the light source attachment portions therebetween and extending in the longitudinal direction; and a plurality of branch paths widthwise connecting the trunk path to the interconnection path, and wherein parts of the interconnection path are cut off to form a plurality of light source parallel connections each comprising a plurality of light sources connected in parallel between the pair of trunk paths, and further, parts of the trunk paths are cut such that the light source parallel connections are connected in series. This can provide a light source assembly comprising light sources spatially arranged in a line and electrically connected in a matrix pattern.

When each of the light sources consists of an LED, the above light source assembly can be easily embodied if orientations of the LEDs contained in adjoining light source parallel connections are opposite to each other so that cathodes of the LEDs contained in an electrically upstream one of the adjoining light source parallel connections are connected to anodes of the LEDs contained in a downstream one via one of the pair of trunk paths, and if the pair of trunk paths are cut such that anodes of the LEDs contained in the upstream one of the adjoining parallel connections are separated from cathodes of the LEDs contained in the downstream one and that ends of each LED are not short-circuited.

Alternatively, the above light source assembly can be embodied by connecting portions of the pair of trunk paths to each other via the branch paths and the light source attachment portions such that cathodes of the LEDs contained in an electrically upstream one of the adjoining light source parallel connections are connected to anodes of the LEDs contained in a downstream one, and cutting the pair of trunk paths such that anodes of the LEDs contained in the upstream one of the adjoining parallel connections are separated from cathodes of the LEDs contained in the downstream one and that ends of each LED are not short-circuited.

According to yet another aspect of the present invention, there is provided a light emitting apparatus comprising a plurality of light source assemblies each having a plurality of electrically connected light sources, wherein the plurality of light source assemblies are each arranged to form a spiral extending toward a central portion from their respective starting points which are circumferentially spaced substantially evenly from each other in a periphery of a light emitting surface of the light emitting apparatus. In this way, a surface light emitting body can be made easily by using light source assemblies each constituted by joining a plurality of light sources arranged in a line. Particularly, if the plurality of light source assemblies comprise at least two light source assemblies emitting lights of different colors, the light sources of different colors can be mixedly arranged substantially evenly.

According to yet another aspect of the present invention, there is provided a light emitting apparatus, comprising a plurality of LED parallel connections each having a plurality of parallel connected LEDs, wherein the plurality of LED parallel connections are connected in series, and wherein each LED is connected to an associated resistor in series. In this light emitting apparatus, if a single LED suffers a short-circuiting malfunction, a voltage is produced across the resistor connected in series to the malfunctioning LED, and therefore, the ends of the LEDs connected in parallel with the malfunctioning LED are kept from short-circuiting and thus the light emission can be maintained. Thus, if a single LED suffers a short-circuiting malfunction, significant decrease in the amount of emitted light can be prevented.

According to still another aspect of the present invention, there is provided a patterned conductor having a prescribed pattern and used for forming a light source assembly by electrically connecting a plurality of light sources, wherein the patterned conductor comprises an expandable portion at a prescribed longitudinal position. In this way, even after the light source assembly is fabricated, arrangement positions of the light sources can be adjusted by deforming the expandable portion. Further, it is possible to easily achieve various light source arrangements. For example, the arrangement of the light sources may not be limited to straight and the direction of light source arrangement may be bent or offset. The patterned conductor preferably comprises a deformation prohibiting portion for selectively allowing deformation of the expandable portion. It is preferred that the expandable portion and the deformation prohibiting portion are formed by blanking (or punching) because this can allow easy and efficient fabrication of these portions. In such a case, it is desirable that deformation of the expandable portion is enabled by cutting off the deformation prohibiting portion so that the enabling can be easily done. In a case where the patterned conductor further comprises a pair of trunk paths extending substantially in parallel in the longitudinal direction, and the plurality of light sources are connected between the pair of trunk paths, the expandable portion and the deformation prohibiting portion can be formed by blanking a portion of the pair of trunk paths. Alternatively, the expandable portion may have at least one crease extending in a widthwise direction of the patterned conductor.

Other and further objects, features and advantages of the invention will appear more fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Now the present invention is described in the following with reference to the appended drawings, in which:

FIG. 1 is a cross-sectional view showing a light emitting apparatus according to the present invention;

FIG. 2 is a cross-sectional view along the lines II-II in FIG. 1;

FIG. 3 is a perspective view of a light source assembly shown in FIG. 1;

FIGS. 4 a and 4 b are front views each showing an embodiment of a tape-shaped patterned conductor;

FIG. 5 is a view for showing a state of the light emitting apparatus of FIG. 1 under fabrication;

FIG. 6 shows a way of secondary processing of the tape-shaped patterned conductor for achieving a light emitting apparatus of a serial-parallel connection type;

FIG. 7 shows a way of secondary processing of the tape-shaped patterned conductor for achieving a light emitting apparatus of a parallel connection type;

FIG. 8 shows a way of secondary processing of the tape-shaped patterned conductor for achieving a light emitting apparatus of a serial connection type;

FIG. 9 is a cross-sectional view showing a light emitting apparatus in that the light source assembly of a serial connection type obtained by the secondary processing shown in FIG. 8 is attached to a mounting board (holder);

FIG. 10 shows another embodiment of the secondary processing of the tape-shaped patterned conductor to form a light emitting apparatus of a serial connection type;

FIGS. 11 a and 11 b are cross-sectional views for showing different ways of attaching the light source assembly to the holder;

FIG. 12 is a front view showing an embodiment in which the light sources are arranged on a flat surface;

FIG. 13 is a cross-sectional view showing an embodiment in which the light sources are arranged on a curved surface;

FIG. 14 is a front view showing an embodiment of a tape-shaped patterned conductor suitable for achieving a light emitting apparatus of a serial connection type;

FIG. 15 shows a way of secondary processing of the patterned conductor shown in FIG. 14;

FIG. 16 is a perspective view showing an embodiment of a light source assembly according to the present invention;

FIG. 17 a is a cross-sectional view taken along the lines XVII-XVII in FIG. 16, and FIG. 17 b is a cross-sectional view corresponding to FIG. 17 a and showing an embodiment utilizing a socket pin;

FIG. 18 is a plan view of a patterned conductor used in forming a light source assembly shown in FIG. 16;

FIG. 19 shows a way of secondary processing of the patterned conductor of FIG. 18 to form a light source assembly in which the light sources are connected in series-parallel connection;

FIG. 20 shows a way of secondary processing of the patterned conductor of FIG. 18 to form a light source assembly in which the light sources are connected in parallel;

FIG. 21 shows a way of secondary processing of the patterned conductor of FIG. 18 to form a light source assembly in which the light sources are connected in series;

FIG. 22 is a perspective view showing another embodiment of a light source assembly according to the present invention;

FIG. 23 is a top view of a socket without an LED;

FIG. 24 is a cross-sectional view showing the socket with the LED installed therein;

FIG. 25 is a plan view of a patterned conductor used in forming the light source assembly shown in FIG. 16;

FIG. 26 shows a way of secondary processing of the patterned conductor shown in FIG. 25 to form a light source assembly in which the light sources are connected in series-parallel connection;

FIG. 27 shows a way of secondary processing of the patterned conductor shown in FIG. 25 to form a light source assembly in which the light sources are connected in parallel;

FIG. 28 shows a way of secondary processing of the patterned conductor shown in FIG. 25 to form a light source assembly in which the light sources are connected in series;

FIG. 29 is a perspective view showing a modified embodiment of the light source assembly shown in FIG. 22;

FIG. 30 a perspective view showing another modified embodiment of the light source assembly shown in FIG. 22;

FIG. 31 a perspective view showing a yet another modified embodiment of the light source assembly shown in FIG. 22;

FIG. 32 is a plan view of a patterned conductor used in forming the light source assembly shown in FIG. 31;

FIG. 33 is a plan view showing a modified embodiment of the patterned conductor of FIG. 18 suitable for forming a light source assembly having light sources connected in series;

FIG. 34 is a plan view showing a modified embodiment of the patterned conductor of FIG. 25 suitable for forming a light source assembly having light sources connected in series;

FIG. 35 is a perspective view similar to FIG. 16 and shows another embodiment of a joint member;

FIG. 36 is a perspective view similar to FIG. 16 and shows yet another embodiment of a joint member;

FIG. 37 is an underside view of the light source assembly of FIG. 36;

FIG. 38 is a perspective view showing an embodiment in which the light source assembly of FIG. 36 is attached to a holder;

FIG. 39 is a perspective view of a light emitting apparatus using the light source assembly of FIG. 36;

FIG. 40 is a cross-sectional view taken along the lines XL-XL in FIG. 39;

FIG. 41 is a top plan view for schematically showing the light emitting apparatus of FIG. 39;

FIG. 42 a is a perspective view showing an embodiment of a light source assembly that uses a light emitting element assembly as a light source, and FIG. 42 b is a circuit diagram of the light emitting element assembly shown in FIG. 42 a;

FIG. 43 a is a perspective view showing another embodiment of a light source assembly that uses a light emitting element assembly as a light source, and FIG. 43 b is a circuit diagram of the light emitting element assembly shown in FIG. 43 a;

FIG. 44 is a plan view showing another embodiment of a tape-shaped patterned conductor according to the present invention;

FIG. 45 is a perspective view showing a light source assembly using the patterned conductor of FIG. 44 together with a holder for supporting the light source assembly;

FIG. 46 is a schematic view showing the light source assembly of FIG. 45 flexed in a longitudinal direction;

FIG. 47 a is a partial plan view showing another embodiment of a tape-shaped patterned conductor according to the present invention, FIG. 47 b is a cross-sectional view taken along the lines A-A in FIG. 47 a , and FIG. 47 c is a partial plan view of a light source assembly formed by attaching chip-type LEDs and chip-type resistors to the connective conductor structure which in turn is formed by cutting off parts of the patterned conductor of FIG. 47 a as required;

FIG. 48 a is a front view of a three-pole LED lamp, and FIG. 48 b is a circuit diagram of the three-pole LED lamp shown in FIG. 48 a;

FIG. 49 is a plan view of a tape-shaped patterned conductor suitable for forming a light source assembly by connecting a plurality of three-pole LED lamps shown in FIGS. 48 a and 48 b;

FIG. 50 is a plan view showing an example of a way of cutting off in the secondary processing of the patterned conductor shown in FIG. 49 to form a connective conductor structure having a prescribed circuit pattern;

FIG. 51 is a circuit diagram of a light source assembly formed by using the connective conductor structure that is made following the way of secondary processing shown in FIG. 50;

FIG. 52 a is an upper perspective view of a four-pole LED lamp, FIG. 52 b is a lower perspective view of the four-pole LED lamp of FIG. 52 a , and FIG. 52 c is a circuit diagram thereof;

FIG. 53 is a plan view of a tape-shaped patterned conductor suitable for forming a light source assembly by connecting a plurality of four-pole LED lamps shown in FIGS. 52 a - 52 c;

FIG. 54 is a plan view showing an example of a way of cutting off in the secondary processing of the patterned conductor shown in FIG. 49 to form a connective conductor structure having a prescribed circuit pattern;

FIG. 55 is a circuit diagram of a light source assembly formed by using the connective conductor structure that is made following the way of secondary processing shown in FIG. 54;

FIG. 56 is a partial plan view showing another embodiment of a patterned conductor according to the present invention;

FIG. 57 shows a way of secondary processing of the patterned conductor shown in FIG. 25 for forming a light source assembly in that the light sources are connected in series and the trunk paths can be used for heat dissipation;

FIG. 58 a is a plan view showing a patterned conductor suitable for forming a light source assembly having a reduced width, and FIG. 58 b is a plan view showing an end conductor for allowing conductive pins to an end of the patterned conductor shown in FIG. 58 a;

FIG. 59 is a perspective view showing a light source assembly having an insulating sheet attached to its surface on which the light sources are mounted;

FIG. 60 a is a partial perspective view showing a way of attaching the light source assembly to a holder, and FIG. 60 b is a cross-sectional view of the light source assembly attached to the holder;

FIG. 61 is a cross-sectional view showing another embodiment of attaching the light source assembly to the holder;

FIGS. 62 a - 62 c schematically show a manufacturing process of the patterned conductor and light source assembly using photo-etching;

FIG. 63 a is a partial plan view of a patterned conductor suitable for forming a light source assembly having light sources arranged in two rows, and FIG. 63 b is a partial plan view showing an example of secondary processing of the patterned conductor;

FIG. 64 is a partial plan view suitable for forming a light source assembly having light sources arranged in four rows;

FIG. 65 is a circuit diagram showing a preferred embodiment of an LED circuit suitable for use as a traffic light;

FIG. 66 is a circuit diagram showing another preferred embodiment of an LED circuit suitable for use as a traffic light;

FIG. 67 is a schematic view showing a way of using a light source assembly to form a surface light emitting apparatus having an electric connection as shown in FIG. 66;

FIG. 68 is a schematic partial plan view showing an embodiment of a light source assembly having an electric connection as shown in FIG. 65 and adapted to provide a linear light emitting apparatus containing LEDs arranged in a line;

FIG. 69 is a schematic partial plan view showing another embodiment of a light source assembly having an electric connection as shown in FIG. 65 and adapted to provide a linear light emitting apparatus containing LEDs arranged in a line;

FIG. 70 is a partial plan view showing another embodiment of a patterned conductor;

FIG. 71 is a partial plan view showing an example of a light source assembly formed by using the patterned conductor shown in FIG. 70;

FIG. 72 a is a schematic view of a light emitting apparatus formed by using the light source assembly shown in FIG. 71, and FIG. 72 b is a cross-sectional view taken along the lines b-b in FIG. 72 a;

FIG. 73 is a partial plan view showing another example of a secondary processing of the patterned conductor shown in FIG. 56;

FIG. 74 is a partial plan view of a light source assembly formed by using the patterned conductor applied with the secondary processing shown in FIG. 73;

FIG. 75 is a schematic partial plan view showing an embodiment of a light source assembly for providing a linear light emitting body containing two rows of LEDs each having electric connection as shown in FIG. 65;

FIG. 76 is a schematic diagram showing a preferred arrangement of a plurality of light source assemblies used for forming a surface light emitting body;

FIG. 77 is a schematic diagram showing another preferred arrangement of a plurality of light source assemblies used for forming a surface light emitting body;

FIG. 78 is a schematic diagram showing yet another preferred arrangement of a plurality of light source assemblies used for forming a surface light emitting body;

FIG. 79 is a schematic view showing an exemplary state of light source assembly in use;

FIG. 80 is a perspective view showing an embodiment of a light emitting apparatus using a light source assembly according to the present invention and adapted for forming an automobile lamp;

FIG. 81 is a perspective view showing the light source assembly used in the light emitting apparatus, the light source assembly being shown in a state before bending;

FIG. 82 is an end view of the light source assembly shown in FIG. 81;

FIG. 83 is a partial plan view of an embodiment of a patterned conductor suitable for forming the light source assembly shown in FIG. 81;

FIG. 84 a is a partial plan view showing another embodiment of a patterned conductor for allowing adjustment of the position of LEDs, and FIG. 84 b is a view similar to FIG. 84 a and illustrates the parts to be removed in a used state by hatching lines;

FIGS. 85 a and 85 b are partial plan views showing examples of deformed states of the light source assembly formed by using the patterned conductor shown in FIG. 84 a;

FIG. 86 a is a partial plan view showing another embodiment of a patterned conductor having an extendable portion, and FIG. 86 b is a partial plan view showing an example of a deformed state of a light source assembly using the patterned conductor;

FIG. 87 a is a partial plan view showing yet another embodiment of a patterned conductor having an extendable portion, FIG. 87 b is a front view of the patterned conductor shown in FIG. 87 a , and FIG. 87 c is a partial plan view showing an example of a deformed state of a light source assembly using the patterned conductor;

FIG. 88 a is a partial plan view showing still another embodiment of a patterned conductor having an extendable portion, FIG. 88 b is a front view of the patterned conductor shown in FIG. 88 a , and FIG. 88 c is a partial plan view showing an example of a deformed state of a light source assembly using the patterned conductor; and

FIG. 89 a is a partial plan view showing yet another embodiment of a patterned conductor, and FIG. 89 b is a partial plan view showing a light source assembly using the patterned conductor of FIG. 89 a.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, embodiments of the present invention are explained with reference to the drawings.

FIG. 1 is a front cross-sectional view showing a preferred embodiment of a light emitting apparatus according to the present invention. As shown, the light emitting apparatus comprises a plurality of light emitting diodes (LEDs) 1 as light sources, and each LED 1 consists of a bullet-type LED (or lamp-type LED) having a pair of parallel lead wires 3 functioning as electric connection terminals and a packaging part (or main body) 1 a shaped like a bullet. The light sources 1 are arranged in a row along a surface of a mount board (holder) 2 in a direction perpendicular to the lead wires 3 . The light sources 1 are series-parallel connected by a connective conductor structure 4 that extends in a direction of arrangement of the light sources 1 , i.e., series connections of multiple light sources 1 are connected in parallel with each other, to form a light source assembly 6 . The series-parallel connection has a benefit that it can be connected to a commercial power source without using a step-down transformer by suitably adjusting a number of light sources connected in series as well as that an arbitrary number of light sources can be utilized by parallel-connecting a plurality of series connections of light sources (or series blocks).

As shown in the drawing, the connective conductor structure 4 comprises a first and second trunk paths 11 , 12 supplied with a power voltage and each connected to the lead wires 3 of prescribed light sources 1 , and a plurality of coupling pieces 5 for coupling between the lead wires 3 of adjacent light sources 1 . Each coupling piece 5 has a pair of connection parts 9 and engages base portions 3 a of the lead wires 3 of adjacent light sources 1 via the pair of connection parts 9 . The first and second trunk paths 11 , 12 are connected to the base portions 3 a of the lead wires 3 of associated light sources 1 via branch paths 13 , 14 , respectively, and the connection parts 9 coupled to the branch paths. The first trunk path 11 , which is closer to the main body 1 a of the light sources 1 , is formed with cuttings (or slits) 15 extending in a widthwise direction and whereby the first trunk path 11 assumes a tortuous shape. In other words, portions of the first trunk path 11 longitudinally aligned with the light source mount positions curve convexly. To secure the light source assembly 6 constructed as above to the mount board 2 , end portions 3 b of the lead wires 3 are inserted into mount holes 7 formed in the mount board 2 .

FIG. 2 is a cross-sectional view taken along the lines II-II in FIG. 1, and FIG. 3 is a perspective view showing the light source assembly 6 of FIG. 1. In FIG. 3, the main bodies 1 a of the light sources 1 are shown in broken lines for ease of illustration. Also in this drawing, a tape-shaped patterned conductor 16 , from which the connective conductor structure 4 is made as described in detail below, is shown in broken lines.

As best shown in FIG. 3, in this embodiment, each connection part 9 has a plate-shaped member such that the connection part 9 can be engaged to the associated lead wire 3 by cramping the lead wire 3 or bending the connection part 9 to sandwich the lead wire 3 . The securing of the connection part 9 to the lead wire 3 may be achieved by various means other than cramping, such as spot welding or engagement using elastic engaging pieces, but it should be noted that cramping can bring about such benefits as allowing continuous processing using a progressive press machine, eliminating use of solder, or eliminating concern about the heat deteriorating the light sources (LEDs) 1 .

As shown in FIGS. 2 and 3, the connective conductor structure 4 is bent at positions substantially corresponding to a bottom of the cuttings 15 of the first trunk path 11 and at positions substantially corresponding to an intersection between the branch paths 14 and the coupling pieces 5 along bending lines extending in a longitudinal direction. This places the first and second trunk paths 11 , 12 at an angle with respect to the connection parts 9 , which extend along the lead wires 3 , when seen in the cross-sectional view of FIG. 2. Thus, by bending the widthwise cross-sectional shape (i.e., a cross-sectional shape taken along a plane perpendicular to the longitudinal direction) of the connective conductor structure 4 , it is possible not only to prevent interference between the light source main bodies 1 a and the first trunk path 11 but also to achieve a simple structure with no insulating treatment applied to the connective conductor structure 4 while preventing the first and second trunk paths 11 , 12 from contacting the lead wires 3 of the light sources 1 to inadvertently make a short-circuit. The connective conductor structure 4 not covered by an insulating material and hence exposed to the air can improve heat dissipation and thus favorably allows high-density arrangement of the light sources 1 . The bending of the connective conductor structure 4 can limit longitudinal flexion thereof, and thus allows an easier handling when attaching it to the mount board 2 . Further, the bending can cause the end portions 3 b of the lead wires 3 to protrude towards the mount board 2 so that they can be easily inserted into the mount holes 7 of the mount board 2 .

According to the present invention, the connective conductor structure 4 described above can be obtained by carrying out secondary processing of a tape-shaped patterned conductor 16 , i.e., cutting off parts of the tape-shaped patterned conductor 16 as required when the patterned conductor 16 is attached to the light sources 1 , in which the patterned conductor 16 is beforehand formed with a circuit pattern that can be used commonly in series, parallel and series-parallel connections, preferably by press working (blanking) a conductive plate material. As described in detail later, by changing the parts to be cut off in the tape-shaped patterned conductor 16 , it is possible to connect the light sources 1 in any of series, parallel or series-parallel connections.

FIG. 4 a is a front view showing an embodiment of the tape-shaped patterned conductor 16 before the secondary processing. In this drawing, parts corresponding to those of the connective conductor structure 4 shown above are denoted with same reference numerals. In FIG. 4 a , the connection parts 9 to be engaged with the lead wires 3 of the light sources 1 are shown in a state before being bent to engage with the lead wires 3 . The connection parts 9 are connected by a longitudinally extending interconnection path 10 , and the first and second trunk paths 11 , 12 are disposed on either side of the tape-shaped patterned conductor 16 so as to interpose the interconnection path 10 and the connection parts 9 therebetween. The first and second trunk paths 11 , 12 are connected to the interconnection path 10 in a widthwise direction by the plurality of branch paths 13 , 14 .

As mentioned above, the tape-shaped patterned conductor 16 is applied with a secondary processing of cutting off parts as required depending on various usages to make the connective conductor structure 4 that realizes a circuit with a desired connection pattern. It, will be preferable if such a secondary processing is carried out at the same time when the tape-shaped patterned conductor 16 and the light sources 1 , which are held in a radial taping, are attached together by a progressive press machine because it can simplify the manufacturing process. For this reason, in the tape-shaped patterned conductor 16 shown in FIG. 4 a , the second trunk path 12 , which is away from the light source main bodies 1 a , is formed with pilot holes 18 for engaging pilot pins of the progressive press machine (not shown) to thereby align the tape-shaped patterned conductor 16 with the light sources 1 and thus ensure that the light sources 1 are mounted at predetermined positions on the tape-shaped patterned conductor 16 . Alternatively, as in a tape-shaped patterned conductor 16 shown in FIG. 4 b , it is possible to provide a side frame 19 connected to the second trunk path 12 via joints 20 , and form the pilot holes 18 for engaging the pilot pins of the progressive press machine in the side frame 19 , although the additional side frame 19 will necessitate a larger amount of material compared with the embodiment of FIG. 4 a.

The tape-shaped patterned conductor 16 can be obtained by press working (more specifically, blanking) a conductive plate material. Specifically, cut-out holes 21 are first formed such that the cut-out holes 21 define the connection parts 9 projecting from the interconnection path 10 in a direction along the lead wires 3 , divide the first trunk path 11 from the interconnection path 10 , and define the branch paths 13 connecting therebetween. The cut-out holes 21 also provide a space into which a tool for bending the connection parts 9 can be inserted. Then the first trunk path 11 is formed with the cuttings 15 . Further, cut-out holes 22 for dividing the interconnection path 10 from the second trunk path 12 as well as defining the branch paths 14 connecting between them are formed. The branch paths 13 , 14 for connecting the first and second trunk paths 11 , 12 to the interconnection path 10 are preferably formed at positions offset from the lead wires 3 so that inadvertent cutting of the lead wires 3 can be prevented when cutting off the branch paths 13 , 14 . This can allow a proper length of the lead wires 3 to project toward the mount board 2 , for example, whereby when the light source assembly 6 is attached to the mount board 2 , the lead wires 3 can be inserted into the mount holes 7 in the mount board 2 to achieve a secure mounting of the light source assembly 6 (see FIG. 1).

The tape-shaped patterned conductor 16 is flexible and can be curved or bent, and this allows the patterned conductor 16 to be wound in a coil or folded in an accordion fashion so that it can be easily stored, transported or packaged.

FIG. 5 shows a state of the light emitting apparatus of FIG. 1 during a manufacturing process. The light sources 1 each consist of a bullet-type LED lamp having a pair of lead wires 3 extending in the same direction, and are held in the radial taping so as to be arranged in a direction perpendicular to the direction of extension of the lead wires 3 . A carrier tape 25 for the radial taping consists of a pair of tape members 25 a , 25 b which are stuck together, and the lead wires 3 are held between the pair of tape members 25 a , 25 b to retain the light sources 1 . Like the tape-shaped patterned conductor 16 , the carrier tape 25 is formed with pilot holes 26 so that aligning the pilot holes 18 , 26 of the tape-shaped patterned conductor 16 and carrier tape 25 can achieve an axial alignment of the connection parts 9 formed in the patterned conductor 16 and the lead wires 3 of the light sources 1 held by the carrier tape 25 . The connection parts 9 are brought into engagement with the lead wires 3 held by the tape 25 , and then, the secondary processing of the tape-shaped patterned conductor 16 is carried out. It should be noted, that when the lead wires 3 and the connection parts 9 are engaged, the tape-shaped patterned conductor 16 need be bent along the longitudinal bending line so as to prevent the first trunk path 11 of the patterned conductor 16 from interfering with the main bodies 1 a of the light sources 1 .

It will be preferable in view of high production efficiency and easy handling to prepare the tape-shaped patterned conductor 16 wound in a coil, and then carry out the above described engagement between the patterned conductor 16 and the light sources 1 while unwinding the patterned conductor 16 in the progressive press machine. Since the first trunk path 11 of the tape-shaped patterned conductor 16 of the present invention is formed with the widthwise cuttings 15 so that the first trunk path 11 comprises a plurality of convexly curved portions, it is possible that the convexly curved portions in an unwound part of the tape-shaped patterned conductor 16 can be bent individually although the rest of the patterned conductor 16 is still wound in coil, to thereby avoid interference between the main bodies 1 a of the light sources 1 and the first trunk path 11 of the patterned conductor 16 .

FIG. 6 shows a way of secondary processing of the tape-shaped patterned conductor 16 for forming the light emitting apparatus of a series-parallel connection type shown in FIG. 1. In this drawing, the parts to be cut off are shown by hatching. As shown, parts 27 of the interconnection path 10 located between respective pairs of connection parts 9 each corresponding to a pair of lead wires 3 of a same light source 1 are removed. Further, the branch paths 13 , 14 except for those located at ends of a range corresponding to each series connection of the light sources 1 (series block) are cut off. Also, parts 28 of the interconnection path 10 between adjoining series blocks are-cut off. It will be understood that in this way, the coupling pieces 5 of the connective conductor structure 4 , for example, can be formed from the interconnection path 10 of the tape-shaped patterned conductor 16 . As described above, in the secondary processing, the tape-shaped patterned conductor 16 (or connective conductor structure 4 ) is bent along the longitudinal bending lines on either side of the interconnection path 10 and secured to the lead wires 3 preferably by cramping them with the connection parts 9 . In order to facilitate the bending, it may be possible to beforehand provide the tape-shaped patterned conductor 16 with a notch extending along the bending line. The tape-shaped patterned conductor 16 can be severed at appropriate points such that the resulting light source assembly 6 has a proper length that is easy to handle. The secondary processing of the tape-shaped patterned conductor 16 that can comprise the steps of cutting off, bending, cramping and severing as described above can be carried out by a progressive press machine. It should be noted that the bending of the tape-shaped patterned conductor 16 on a side of the second trunk path 12 that is formed with the pilot holes 18 for engaging the pilot pins of the progressive press machine should be done at a final stage of the progressive press machine. Alternatively, the bending may be done after the light source assembly 6 has been removed from the progressive press machine.

The parts 27 of the interconnection path 10 located between respective pairs of connection parts 9 each for a pair of lead wires 3 of a same light source 1 need be cut off in any connection pattern, and therefore, the tape-shaped patterned conductor 16 may not comprise the parts 27 . However, with the parts 27 , the connection parts 9 can be steadily supported when engaging the connection parts 9 with the lead wires 3 .

FIG. 7 shows a way of secondary processing of the tape-shaped patterned conductor 16 for making a light source assembly of a parallel connection type. As in the above example, the parts to be cut off are shown by hatching. In addition to the parts 27 of the interconnection path 10 located between respective pairs of connection parts 9 each corresponding to a pair of lead wires 3 of a same light source 1 , parts 29 of the interconnection path 10 between connection parts 9 corresponding to the lead wires 3 of adjoining light sources 1 are removed. Further, in a similar manner as in the above example, the patterned conductor 16 is bent along the longitudinal bending lines on either side of the interconnection path 10 , and the connection parts 9 are engaged to the lead wires 3 by cramping. In this connection pattern, the branch paths 13 , 14 are left without being cut off.

FIG. 8 shows a way of secondary processing of the tape-shaped patterned conductor 16 for making a light source assembly of a series connection type. As in the above examples, the parts to be cut off are shown by hatching. As seen, all the parts 27 of the interconnection path 10 located between respective pairs of connection parts 9 each for a pair of lead wires 3 of a same light source 1 are cut off, and further, all the branch paths 13 , 14 as well as the pair of trunk paths 11 , 12 are cut off, leaving the mutually separate coupling pieces 5 behind. Each coupling piece 5 comprises a main body extending in the direction perpendicular to the lead wires 3 , and the pair of connection parts 9 extend from either end portions of the main body in the direction along the lead wires 3 . The lead wires 3 of each light source 1 are electrically and mechanically connected to the lead wires 3 of the adjacent light source 1 via the coupling pieces 5 to form the light source assembly. Thus, in this embodiment; the connective conductor structure 4 is formed only by the coupling pieces 5 ;

FIG. 9 is a cross-sectional view showing a light emitting apparatus in that a series connection type light source assembly 32 obtained by the secondary processing shown in FIG. 8 is attached to the mount board (holder) 2 . In this embodiment, the lead wires 3 at both ends are not engaged with the coupling piece 5 , and the other lead wires 3 are cut at the same time when the coupling pieces 5 are separated so that the lead wires 3 do not protrude toward the mount board 2 . The lead wires 3 at both ends are cut at a desired length and inserted into mount holes 33 formed in the mount board 2 and connected to a power supply.

FIG. 10 shows another way of secondary processing of the tape-shaped patterned conductor 16 for making a light emitting assembly of a series connection type. As in the above embodiment, the parts to be cut off are shown by hatching. As shown, the parts 27 of the interconnection path 10 located between respective pairs of lead wires 3 of a same light source 1 are removed. Further, in this embodiment, the branch paths 13 connected to the first trunk path 11 are cut off except for the one located at one end (right end in this drawing). Also, the branch paths 14 connected to the second trunk path 12 are cut off except for the one located at the other end (left end in the drawing). In contrast to the above embodiment, this embodiment retains the first and second trunk paths 11 , 12 to which the supply voltage may be applied.

FIG. 11 a is a cross-sectional view showing a different example of an attachment of the light source assembly to the holder. In this embodiment, coupling pieces 35 of a light source assembly 37 are formed on either end thereof with a protrusion extending toward the mount board 2 such that each protrusion is aligned with the end of an associated lead wire 3 . The end of the lead wire 3 and the protrusion of the coupling piece 35 are together inserted into an associated mount hole 36 formed in the mount board 2 to thereby support the light source assembly 37 on the mount board 2 . Such a coupling piece 35 can be formed by providing the branch paths 14 of the tape-shaped patterned conductor 16 of FIG. 4 a not only for one, but for both of the pair of connection parts 9 associated with each light source 1 so as to be aligned in the longitudinal direction, and in the secondary processing of the tape-shaped patterned conductor, cutting the branch paths 14 at their root portion near the second trunk path 12 together with the lead wires of the light sources 1 attached to the tape-shaped patterned conductor. It may be possible that one for every several lead wires 3 may protrude to be inserted into the mount holes 36 , and in such a case, the number of lead wires 3 inserted in the mount holes 36 can be determined so as to ensure proper support of the light source assembly 37 on the mount board 2 taking into account the rigidity of the lead wires 3 and coupling pieces 35 . Further, as shown in FIG. 11 b , the mount holes 36 may be recesses 36 ′ instead of through-holes. Such recesses 36 ′ can be formed at a unitary part when the mount board 2 is made by molding, for example, or can be formed by drilling after the molding of the mount board 2 . Or the recesses 36 ′ can be formed by providing a plurality of projections on the mount board 2 .

FIGS. 12 and 13 show examples of arrangement of the light sources 1 on the holder. FIG. 12 shows an example in which the light sources are arranged on a plane. Specifically, on a surface of a flat holder (mount board) 41 , a light source assembly 42 having a plurality of light sources 1 connected by the above-mentioned connective conductor structure 4 are bent at appropriate portions to form a loop such that the line of the light sources of the light source assembly 42 represents a profile of a letter. FIG. 13 shows an example in that the light sources 1 are arranged on a curved surface, and specifically, a light source assembly 52 having a plurality of light sources 1 connected by the above-mentioned connective conductor structure 4 is wound around a holder 51 having a closed shape in cross-section. It is also possible to form a surface light emitting body by arranging light sources densely on a surface of a holder.

FIG. 14 is a front view showing a modified embodiment of the patterned conductor suitable for forming a series connection of light sources, and FIG. 15 shows a way of secondary processing carried out when attaching the patterned conductor to the light sources (parts to be cut off are shown by hatching). In these drawings, parts similar to those in FIG. 4 a or FIG. 6 are denoted with same numerals and detailed explanation thereof is omitted. As shown in the drawings, a patterned conductor 16 ″ for forming a series connection of light sources comprises an interconnection path 10 ′ formed with pilot holes 18 ′ for alignment or transportation in the manufacturing line, and does not poses the first and second trunk paths 11 , 12 and the branch paths 13 , 14 for connecting the first and second trunk paths 11 , 12 to the interconnection path 10 as shown in FIG. 4, and accordingly has a narrower width. In this way, an amount of material not used in the final light source assembly can be reduced to significantly lower the manufacturing cost.

In the above embodiments, LEDs are used as light sources. However, the present invention should not be limited to them, and may be similarly applied to the lamps having lead wires such as cap-less miniature lamps.

As described above, according to the embodiments of the present invention, various light source assemblies having different light source connection patterns can be formed in the same manufacturing line by using a tape-shaped patterned conductor formed with a commonly usable prescribed circuit pattern, whereby advantageously reducing the manufacturing cost of the light emitting apparatus using such a light source assembly. The light sources are unitarily connected in the light source assembly before being attached to the holder, and thus various light source arrangements can be easily achieved. Further, since no complicated machining processes are required in preparing the holder a, it is possible to suppress increase in the manufacturing cost even when a small amount of light source assemblies of various types are manufactured.

In the above embodiments, each light source has a pair of substantially parallel lead wires, which extend along a primary surface of the connective conductor structure (or patterned conductor). However, there may be a case where it is desired to attach the light sources such that the lead wires extend substantially perpendicular to the primary surface of the connective conductor structure or where the light source consists of a so-called chip-type LED having no lead wires. The embodiments below are suitable for such cases.

FIG. 16 is a partial perspective view showing another preferred embodiment of a light source assembly according to the present invention. As shown, the light source assembly 101 uses a plurality of light emitting diodes (LEDs) 102 as light sources, and each LED 102 consists of a bullet-type LED (or lamp-type LED) having a pair of parallel extending lead wires 103 . The LEDs 102 are arranged in a direction perpendicular to the lead wires 103 , and electrically connected by a substantially plate-like connective conductor structure

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