BEST MODE FOR CARRYING OUT INVENTION

[0040] Embodiments of the present invention will be described hereinafter with reference to the drawings.

[0041] FIG. 1 is a block diagram showing a constitution of a first embodiment of a cellular phone according to the present invention.

[0042] In FIG. 1 , the cellular phone is constituted of a cellular phone main body 1 , and an attachable/detachable operation key 2 which is an operation keyboard attachable/detachable with respect to the cellular phone main body 1 .

[0043] The cellular phone main body 1 includes: a controller 11 for executing a control inside the cellular phone main body 1 ; a transmitter/receiver 12 for transmitting/receiving information with respect to the attachable/detachable operation key 2 ; a voice communication section 13 for making the call with voice by a user; an information communication section 14 which has a modem function to perform information communication of an internet homepage, and the like; a first display memory 15 for a first display section 16 ; the first display section 16 ; a second display memory 17 for a second display section 18 ; the second display section 18 ; and a cellular phone function section 19 which has a phone function required for the cellular phone, such as a battery (not shown).

[0044] The controller 11 executes a whole control inside the cellular phone main body 1 including a general process in the cellular phone, a browser process for browsing an internet homepage, a process similar to that of a usual personal computer, a communication process, and the like.

[0045] Moreover, the first display section 16 is a standard display section for checking a phone number or a small amount of characters of a communication destination, and the second display section 18 is an enlarged display part for watching the internet homepage with an enlarged highly fine image. Furthermore, the first display memory 15 and second display memory 17 are disposed to store information displayed in the first display section 16 and second display section 18 .

[0046] On the other hand, the attachable/detachable operation key 2 is constituted of: a key input section 101 for inputting a phone number or various types of information in accordance with various types of operation keys; a code converter 102 for pressing a key button of the operation key to convert a key action into data; and a transmitter/receiver 103 for transmitting a signal converted by the code converter 102 to a cellular phone main body 1 side.

[0047] It is to be noted that although not shown in FIG. 1 , the attachable/detachable operation key 2 side includes a small CPU because of a small processing amount, or a structure in which a processable control is executed without disposing the CPU.

[0048] Moreover, a wire such as a cable or radio is used in transmitting a key input signal between the cellular phone main body 1 and attachable/detachable operation key 2 .

[0049] FIGS. 2A and 2B show an appearance of the cellular phone according to the present embodiment, FIG. 2A is a side view showing that the attachable/detachable operation key 2 is attached to the cellular phone main body 1 , and FIG. 2B is a side view showing that the attachable/detachable operation key 2 is detached from the cellular phone main body 1 .

[0050] As shown in FIG. 2 A, in the state in which the attachable/detachable operation key 2 is attached to the cellular phone main body 1 , the first display section 16 which is a standard display monitor for the call is disposed in one surface of the cellular phone main body 1 on the same plane as that of the attachable/detachable operation key 2 . The second display section 18 which is an enlarged display monitor is disposed in the cellular phone main body 1 , and is prevented from being seen from the outside while the attachable/detachable operation key 2 is attached to the cellular phone main body 1 .

[0051] Moreover, as shown in FIG. 2 B, when the attachable/detachable operation key 2 is detached from the cellular phone main body 1 , the second display section 18 is exposed to the outside. The second display section 18 is constituted of the enlarged display monitor, for example, in which an internet homepage, and the like can be browsed by an image size of a video graphics array (VGA; 640×480 dots or more resolution), or a super video graphics array (SVGA; 800×600 dots or more resolution).

[0052] The enlarged display generally has a looking-into style, and the user brings the cellular phone main body 1 close to his/her eyes. Therefore, in general, when the information is browsed in the enlarged display, to perform a key operation while looking at enlarged display information is a style difficult to operate. For example, when the user holds the cellular phone main body in his left hand while looking at the enlarged display, and operates the keys with his right hand, the cellular phone should be separated for ease of use.

[0053] To solve the problem, as shown in FIG. 2 B, the attachable/detachable operation key 2 can be detached from the cellular phone main body 1 . Detailed information is seen in the enlarged display. Therefore, the attachable/detachable operation key 2 is detached from the cellular phone main body 1 so that the second display section 18 can visually be recognized. Moreover, while watching the second display section 18 , the key is operated by the detached attachable/detachable operation key 2 .

[0054] Moreover, the input operation of the phone number before making the call is performed in the operation key while watching the first display section 16 as the standard display monitor in the state in which the attachable/detachable operation key 2 is attached to the cellular phone main body 1 .

[0055] Next, a second embodiment of the present invention will be described.

[0056] FIGS. 3A and 3B show the appearance of the cellular phone according to the second embodiment of the present invention, FIG. 3A is a side view showing that the attachable/detachable operation key 2 is attached to a cellular phone main body 1 a , and FIG. 3B is a side view showing that the attachable/detachable operation key 2 is detached from the cellular phone main body 1 a.

[0057] It is to be noted that in the embodiment described hereinafter, the same part as that of the above-described first embodiment is denoted with the same reference numerals and the description is omitted.

[0058] As shown in FIG. 3 A, the first display section 16 which is the standard display monitor for the call is disposed in one surface of the cellular phone main body 1 a on the same plane as that of the attachable/detachable operation key 2 in the state in which the attachable/detachable operation key 2 is attached to the cellular phone main body 1 a . The second display section 18 which is the enlarged display monitor is disposed in a main body movable section 21 of the cellular phone, and is prevented from being seen from the outside in the state in which the attachable/detachable operation key 2 is attached to the cellular phone main body 1 a.

[0059] Moreover, as shown in FIG. 3 B, when the attachable/detachable operation key 2 is detached from the cellular phone main body 1 , the second display section 18 is exposed to the outside. In addition, the main body movable section 21 is disposed so as to pop up in an arrow A ₁ direction using an attaching section (not shown) in the cellular phone main body 1 a as an axis, when the attachable/detachable operation key 2 is detached from the cellular phone main body 1 a.

[0060] Accordingly, as shown in FIG. 3 A, the input operation of the phone number before making the call is performed with the operation key while watching the first display section 16 as the standard display monitor in the state in which the attachable/detachable operation key 2 is attached to the cellular phone main body 1 a.

[0061] On the other hand, to see the detailed information by the enlarged display, as shown in FIG. 3 B, the attachable/detachable operation key 2 is detached from the cellular phone main body 1 a , and further the main body movable section 21 is popped up in the shown arrow A ₁ direction, and is set in a bent state from the surface part of the cellular phone main body 1 a . Therefore, the second display section 18 can be easily seen. Subsequently, while watching the second display section 18 , the key operation by the detached attachable/detachable operation key 2 is performed.

[0062] Next, a third embodiment of the present invention will be described.

[0063] FIGS. 4A and 4B show the appearance of the cellular phone according to the third embodiment of the present invention, FIG. 4A is a perspective view showing that the attachable/detachable operation key 2 is detached from a cellular phone main body 1 b and a magnification reflective mirror part 24 is contained, and FIG. 4B is a side view showing that the attachable/detachable operation key 2 is detached from the cellular phone main body 1 b and the magnification reflective mirror section 24 is opened.

[0064] In FIG. 4 A, the first display section 16 which is the standard display monitor for the call, and a speaker 26 for outputting sound are disposed in one surface of the cellular phone main body 1 b on one plane of the cellular phone main body 1 b . As shown by an arrow B, the magnification reflective mirror section 24 turned out in a shown arrow A ₂ direction is contained in a part to which the detached attachable/detachable operation key 2 is to be attached on the cellular phone main body 1 b . Moreover, in general, the magnification reflective mirror section 24 is disposed so as to open in the shown arrow A ₂ direction using the attaching part (not shown) in the cellular phone main body 1 b as the axis, when the attachable/detachable operation key 2 is detached from the cellular phone main body 1 b.

[0065] Furthermore, a projection display section 23 for displaying information in the magnification reflective mirror section 24 , and a microphone 27 for inputting voice are disposed in the cellular phone main body 1 b . Concave section 28 and a holder 29 for mounting the attachable/detachable operation key 2 are formed. These concave sections 28 and holder 29 engage with engaging pawls 105 and an engagement section 106 , respectively, so that the attachable/detachable operation key 2 is prevented from being detached from the cellular phone main body 1 b.

[0066] The input operation of the phone number before making the call is performed with the operation key while watching the first display section 16 as the standard display monitor in either the state in which the attachable/detachable operation key 2 is attached to the cellular phone main body 1 b or the state in which the key is detached.

[0067] On the other hand, the detailed information displayed by the enlarged display is seen as shown in FIG. 4B . That is, when the engagement between the holder 29 and the engagement section 106 of the attachable/detachable operation key 2 is released, and the attachable/detachable operation key 2 is detached from the cellular phone main body 1 b , the magnification reflective mirror section 24 is opened in the shown arrow A ₂ direction of FIG. 4A . In this state, light projected by the projection display section 23 is reflected by a primary reflective mirror section 25 disposed in the cellular phone main body 1 b , and subsequently guided into the magnification reflective mirror section 24 . Subsequently, the light reflected again by the magnification reflective mirror part 24 is taken into user's eyes 3 .

[0068] Therefore, the detailed information displayed by the enlarged display can easily be browsed by the projection display section 23 , primary reflective mirror section 25 , and magnification reflective mirror section 24 . Subsequently, while watching the detailed information displayed in the magnification reflective mirror section 24 , the key operation by the detached attachable/detachable operation key 2 is performed.

[0069] It is to be noted that in the third embodiment, when the cellular phone main body 1 b is grasped with the right hand and with the left hand, a vertical direction of the image (information) displayed in the magnification reflective mirror section 24 is inverted. Therefore, the image (information) displayed in the projection display section 23 has to be vertically inverted. For this technique, for example, a technique disclosed in Jpn. Pat. Appln. KOKAI Publication No 10-340073 can be used.

[0070] FIGS. 5A and 5B show the appearance of the cellular phone according to a fourth embodiment of the present invention, FIG. 5A is a perspective view showing that the attachable/detachable operation key 2 is detached from a cellular phone main body 1 c and a magnification optical section 31 is contained, and FIG. 5B is a side view showing that the attachable/detachable operation key 2 is detached from the cellular phone main body 1 c and the magnification optical section 31 and second display section 18 are popped up.

[0071] In FIG. 5 A, the first display section 16 which is the standard display monitor for the call is disposed in one surface of the cellular phone main body 1 c on one plane of the cellular phone main body 1 c . As shown by an arrow B, the magnification optical section 31 popped up in a shown arrow A ₃ direction and the second display section 18 for the enlarged display (see FIG. 5B ) are contained in a part to which the detached attachable/detachable operation key 2 is to be attached on the cellular phone main body 1 c.

[0072] The magnification optical section 31 and second display section 18 are generally disposed so as to pop up using the attaching part (not shown) in the cellular phone main body 1 c as the axis as shown in FIG. 5 B, when the attachable/detachable operation key 2 is detached from the cellular phone main body 1 c . Moreover, the magnification optical part 31 and second display section 18 are fixed in a position where the parts extend in parallel with each other on popping up.

[0073] It is to be noted that the magnification optical section 31 includes a lens which has a predetermined refractive index, and the transmitter/receiver 12 is constituted of display devices such as an LCD.

[0074] Moreover, the input operation of the phone number before making the call is performed with the operation key while watching the first display section 16 as the standard display monitor in either the state in which the attachable/detachable operation key 2 is attached to the cellular phone main body 1 c or the detached state.

[0075] On the other hand, to see the detailed information by the enlarged display, the attachable/detachable operation key 2 is detached from the cellular phone main body 1 c . Then, the magnification optical section 31 and second display section 18 pop up in the shown arrow A ₃ direction of FIG. 5A . In this state, the detailed information displayed in the second display section 18 is enlarged by the magnification optical section 31 , and taken into user's eyes 3 .

[0076] Therefore, by the second display section 18 and magnification reflective mirror section 24 , the detailed information by the enlarged display is reflected in a position where the user can easily browse the information. Moreover, while watching the detailed information displayed in the second display section 18 via the magnification optical section 31 , the key operation is performed by the detached attachable/detachable operation key 2 .

[0077] It is to be noted that, needless to say, the constitutions of the magnification optical section 31 and second display section 18 are not limited to the structures shown in FIGS. 5A and 5B , and can be constituted using another optical system.

[0078] For example, instead of the magnification optical part 31 of FIGS. 5A and 5B , the optical system disclosed in Jpn. Pat. Appln. KOKAI Publication No. 09-113801 and shown in FIG. 6A may also be used. This optical system includes three planes of a first plane 33 , second plane 34 , and third plane 35 , and is filled with a medium whose refractive index is larger than 1.

[0079] Moreover, a display light from an image display device 36 , which is incident upon the optical system via the third plane 35 as a transmission plane disposed opposite to the image display device 36 , is reflected by the first plane 33 disposed between the second plane 34 and observer's pupils 38 on an observer visual axis 37 . Next, the light is incident upon the second plane 34 of a reflective plane eccentrically disposed opposite to the observer's pupils 38 on the observer visual axis 37 , and reflected. This reflected light is transmitted through the first plane 33 and emitted from the optical system to proceed along the observer visual axis 37 , and is incident upon the observer's pupils 38 without forming any intermediate image to form a display image on an observer's retina.

[0080] It is to be noted that in the drawing, reference numeral 39 denotes axes of the first plane 33 and second plane 34 which form an anamorphic plane, and reference numeral 40 denotes a center of a plane shape.

[0081] Needless to say, in addition to the optical system shown in FIG. 6 A, various optical systems disclosed in the above-described publications can be applied.

[0082] Moreover, the magnification optical section and second display section may separately be rotated/operated as shown in FIG. 6B . Furthermore, for example, with respect to the cellular phone main body 1 c , an angle at which a magnification optical section 31 a is popped up may be set to be larger than that at which the second display section 18 is popped up.

[0083] Furthermore, for the optical system shown in FIG. 6 A, the constitution is integrally held so that an optical positional relation between the optical system and display section does not change, and this integral constitution may be rotated/operated.

[0084] Next, a fifth embodiment of the present invention will be described.

[0085] FIGS. 7A and 7B show the appearance of the cellular phone according to the fifth embodiment of the present invention, FIG. 7A is a perspective view showing that the attachable/detachable operation key 2 is detached from a cellular phone main body 1 d and a magnification optical section 42 is contained, and FIG. 7B is a side view showing that the attachable/detachable operation key 2 is detached from the cellular phone main body 1 d and the magnification optical section 42 are turned out.

[0086] In FIG. 7 A, the first display section 16 which is the standard display monitor for the call is disposed in one surface of the cellular phone main body 1 c on one plane of the cellular phone main body 1 d . As shown by the arrow B, the magnification optical section 42 turned out in a shown arrow A ₄ direction is contained in a part to which the detached attachable/detachable operation key 2 is to be attached on the cellular phone main body 1 d.

[0087] As shown in FIG. 7 B, the second display section 18 for the enlarged display monitor is disposed in the cellular phone main body 1 d . While the magnification optical section 42 is contained in the cellular phone main body 1 d , the second display section 18 is disposed in a position which is not seen from the outside. Moreover, the magnification optical section 41 is fixed in a position where the part extends opposite to and in parallel with the second display section 18 , when the attachable/detachable operation key 2 is detached from the cellular phone main body 1 d and the magnification optical section 42 is turned out.

[0088] It is to be noted that the magnification optical section 42 includes a lens which has a predetermined refractive index, and the second display section 18 is constituted of a display device such as an LCD.

[0089] Moreover, the input operation of the phone number before making the call is performed with the operation key while watching the first display section 16 as the standard display monitor in either the state in which the attachable/detachable operation key 2 is attached to the cellular phone main body 1 d or the detached state.

[0090] On the other hand, to see the detailed information by the enlarged display, the attachable/detachable operation key 2 is detached from the cellular phone main body 1 d . Then, the magnification optical section 42 is turned out in the shown arrow A ₄ direction of FIG. 7A . In this state, the detailed information displayed in the second display section 18 is enlarged by the magnification optical section 42 , and taken into user's eyes 3 .

[0091] Therefore, by the second display section 18 and magnification optical section 42 , the detailed information by the enlarged display is reflected in the position where the user can easily browse the information. Moreover, while watching the detailed information displayed in the second display section 18 via the magnification optical section 42 , the key operation is performed by the detached attachable/detachable operation key 2 .

[0092] It is to be noted that, needless to say, the constitutions of the magnification optical section 42 and second display section 18 are not limited to the structures shown in FIGS. 7A and 7B , and can be constituted using another optical system.

[0093] Next, a sixth embodiment of the present invention will be described.

[0094] FIGS. 8A and 8B show the appearance of the cellular phone according to the sixth embodiment of the present invention, FIG. 8A is a side view showing that the attachable/detachable operation key 2 is attached on the surface side of a cellular phone main body 1 e , and FIG. 8B is a side view showing that the attachable/detachable operation key 2 is attached to the cellular phone main body 1 e on the rear surface side.

[0095] As shown in FIG. 8 A, the first display part 16 which is the standard display monitor for the call is disposed on the surface side as one surface of the cellular phone main body 1 e on the same plane as that of the attachable/detachable operation key 2 in the state in which the attachable/detachable operation key 2 is attached to the cellular phone main body 1 e . The second display section 18 which is the enlarged display monitor is disposed in the cellular phone main body 1 e , and is not seen from the outside in the state in which the attachable/detachable operation key 2 is attached to the cellular phone main body 1 e.

[0096] Moreover, as shown in FIG. 8 B, when the attachable/detachable operation key 2 is detached from the cellular phone main body 1 e , the second display section 18 is exposed to the outside. In this case, the detached attachable/detachable operation key 2 is mounted on the rear surface side which is the other surface of the cellular phone main body 1 e.

[0097] FIGS. 9A and 9B show the constitution of the sixth embodiment of the cellular phone according to the present invention, FIG. 9A is a block diagram showing a constitution in which an attachable/detachable operation key 2 a is detached from the cellular phone main body 1 e , and FIG. 9B is a block diagram showing the constitution in which the attadchable/detachable operation key 2 a is attached to the cellular phone main body 1 e on the rear surface side.

[0098] The cellular phone main body 1 e is constituted of the controller 11 , the transmitter/receiver 12 , a cellular phone function section 19 , a switch section 44 , a rear surface attachment detector 45 , and a code allocation change section 46 . The attachable/detachable operation key 2 a is constituted of the key input section 101 , code converter 102 , and transmitter/receiver 103 .

[0099] The switch section 44 is a switch which turns on/off depending on whether or not the attachable/detachable operation key 2 a is attached to the cellular phone main body 1 e on the rear surface side. In accordance with an on/off state of the switch section 44 , it is judged in the rear surface attachment detector 45 whether or not the attachable/detachable operation key 2 a is attached to the cellular phone main body 1 e on the rear surface side. Furthermore, the code allocation change section 46 changes a code allocation function of the horizontal cursor arrow direction key from the signal from the rear surface attachment detector 45 .

[0100] Now, as shown in FIG. 9 A, when the attachable/detachable operation key 2 a is not attached to the cellular phone main body 1 e on the rear surface side, that is, when the attachable/detachable operation key 2 a is attached to the cellular phone main body 1 e on the surface side or when the key is detached but is not attached on the rear surface side, the cellular phone main body 1 e transmits/receives the signal with respect to the attachable/detachable operation key 2 a by a cable or by radio.

[0101] Moreover, as shown in FIG. 9 B, when the attachable/detachable operation key 2 a is attached to the cellular phone main body 1 e on the rear surface side, the switch part 44 turns off. Accordingly, the rear surface attachment detector 45 detects that the attachable/detachable operation key 2 a is attached to the cellular phone main body 1 e on the rear surface side.

[0102] When the rear surface attachment detector 45 detects that the attachable/detachable operation key 2 a is attached to the cellular phone main body 1 e on the rear surface side, a change process of the code allocation functions of two horizontal cursor arrow direction keys (not shown) in the attachable/detachable operation key 2 a is performed. That is, by the signal from the rear surface attachment detector, the code allocation change section 46 changes the code allocation function as shown in the following table 1. 1

[0103] Here, in a moving direction of a cursor or pointer on the display, “code 25h=left”, “code 27h=right” are represented. In a stage of mode setting, these may also be set so that function setting is impossible. Moreover, “H” of a detection signal indicates that the key is not attached to the rear surface, and “L” of the detection signal indicates that the key is attached to the rear surface.

[0104] With the use of the second display section 18 which is the enlarged display monitor, when the user looks into and operates the second display section 18 with one hand, the attachable/detachable operation key 2 a may be attached to the cellular phone main body 1 e on the rear surface side. However, in this case, the left and right of the display direction are reversed. Therefore, only in this case, when the left and right of the code allocation of the horizontal cursor arrow direction key are reversed, the main body can be operated in a usual process.

[0105] The code allocation change section 46 is disposed to perform this process, mechanically detects that the attachable/detachable operation key 2 is attached to the cellular phone main body 1 e on the rear surface side, and changes the code allocations of the left and right horizontal cursor arrow direction keys, when the key is attached. For the code allocation change of these horizontal cursor arrow direction keys, the pattern of the operation key is switched in accordance with a user's choice.

[0106] Next, a seventh embodiment of the present invention will be described.

[0107] FIGS. 10A and 10B show the constitution of the seventh embodiment of the cellular phone according to the present invention, FIG. 10A is a block diagram showing the constitution in which an attachable/detachable operation key 2 b is attached to a cellular phone main body 1 f , and FIG. 10B is a block diagram showing the constitution in which the attachable/detachable operation key 2 b is detached from the cellular phone main body 1 f.

[0108] The cellular phone main body 1 f is constituted of the controller 11 , the transmitter/receiver 12 , the cellular phone function section 19 , the switch section 44 , an input key allocation change section 49 , various function controllers 50 , and an attachment detector 51 . The attachable/detachable operation key 2 b is constituted of the key input section 101 , code converter 102 , and transmitter/receiver 103 .

[0109] The switch section 44 is a switch which turns on/off depending on whether or not the attachable/detachable operation key 2 a is attached to the cellular phone main body 1 f . In accordance with the on/off state of the switch section 44 , it is judged in the attachment detector 51 whether or not the attachable/detachable operation key 2 b has been attached to the cellular phone main body 1 f . Furthermore, the input key allocation change section 49 changes an information allocation function of the input key by the signal from the attachment detector 51 .

[0110] Now, as shown in FIG. 10 A, when the attachable/detachable operation key 2 b is attached to the cellular phone main body 1 f , the switch section 44 turns off, and the attachment detector 51 outputs a signal “L” indicating that the attachable/detachable operation key 2 b is attached to the input key allocation change section 49 . On receiving this, the input key allocation change section 49 judges that the input key is for usually inputting numerals or characters, and transmits character data corresponding to the input key to the controller 11 . The controller 11 controls the character data.

[0111] On the other hand, as shown in FIG. 10 B, when the attachable/detachable operation key 2 b is detached from the cellular phone main body 1 f , the switch section 44 turns on, and the attachment detector 51 outputs a signal “H” indicating that the attachable/detachable operation key 2 b is detached to the input key allocation change section 49 . Accordingly, the attachment detector instructs various function controllers 50 to change the key allocation so that the use of the input key is changed to that as the function key as an enlarged display viewer from that for inputting the text, and the corresponding function controller 50 controls this.

[0112] It is to be noted that the user is assumed to use the phone without watching the vicinity of the operation key. Therefore, it is assumed that the key functions as a function key so that one key is associated with one operation driving.

[0113] Here, the following are examples of various functions of the function key.

[0114] F1: ESC

[0115] F2: Select

[0116] F3: Down scroll

[0117] F4: Up scroll

[0118] F5: Left scroll

[0119] F6: Right scroll

[0120] F7: Open menu

[0121] F8: Close menu

[0122] F9: Open browser

[0123] Fa: Select bookmark

[0124] Fb: Close browser

[0125] Moreover, menu examples by the function key F7 are as follows.

[0126] a: Select standard display/enlarged display

[0127] b: Select energy saving mode

[0128] c: Select call

[0129] d: Switch external speaker

[0130] e: Convert resolution

[0131] f: Open menu

[0132] g: User custom 1

[0133] h: User custom 2

[0134] i: User custom 3

[0135] j: Return

[0136] Next, an eighth embodiment of the present invention will be described.

[0137] FIGS. 11A and 11B show the appearance of the cellular phone according to the eighth embodiment of the present invention, FIG. 11A is a side view showing that the attachable/detachable operation key 2 b is attached to a cellular phone main body 1 g , and FIG. 11B is a side view showing that the attachable/detachable operation key 2 b is detached from the cellular phone main body 1 g.

[0138] As shown in FIG. 11 A, in the state in which the attachable/detachable operation key 2 b is attached to the cellular phone main body 1 g , the first display section 16 which is the standard display monitor for the call is disposed in one surface of the cellular phone main body 1 g on the same plane as that of the attachable/detachable operation key 2 b . The second display section 18 which is the enlarged display monitor is disposed in the cellular phone main body 1 g , and is not seen from the outside, while the attachable/detachable operation key 2 b is attached to the cellular phone main body 1 g.

[0139] Moreover, as shown in FIG. 11 B, when the attachable/detachable operation key 2 b is detached from the cellular phone main body 1 g , the second display section 18 is exposed to the outside. In the same manner as the second display section 18 , a display switch 52 exposed to the outside in the state in which the attachable/detachable operation key 2 b is detached from the cellular phone main body 1 g is disposed in the cellular phone main body 1 g.

[0140] It is to be noted that the display switch 52 switches first and second power supplies in the cellular phone main body 1 g not shown in FIGS. 11A and 11B .

[0141] FIGS. 12A and 12B show the constitution of the eighth embodiment of the cellular phone according to the present invention, FIG. 12A is a block diagram showing the constitution in which the attachable/detachable operation key 2 b is attached to the cellular phone main body 1 g , and FIG. 12B is a block diagram showing the constitution in which the attachable/detachable operation key 2 b is detached from the cellular phone main body 1 g.

[0142] The cellular phone main body 1 g is constituted of the controller 11 , transmitter/receiver 12 , voice communication section 13 , information communication section 14 , first display memory 15 , first display section 16 , second display memory 17 , second display section 18 , cellular phone function section 19 , attachment detector 51 , display switch 52 , and first and second power supplies 53 and 54 which are power supplies mainly for the first display section 16 and second display section 18 . The attachable/detachable operation key 2 b is constituted of the key input section 101 , code converter 102 , and transmitter/receiver 103 .

[0143] The display switch 52 is a switch which turns on/off depending on whether or not the attachable/detachable operation key 2 b is attached to the cellular phone main body 1 g . In accordance with the on/off state of the display switch 52 , it is judged in the attachment detector 51 whether or not the attachable/detachable operation key 2 b has been attached to the cellular phone main body 1 g . Furthermore, the controller 11 controls so as to turn on/off the first power supply 53 for the first display section 16 and the second power supply 54 for the second display section 18 in response to the signal from the attachment detector 51 , and also controls the voice communication section 13 and information communication section 14 .

[0144] As shown in FIG. 12 A, when the attachable/detachable operation key 2 b is attached to the cellular phone main body 1 g , the display switch 52 turns off. Accordingly, the attachment detector 51 supplies the signal “L” indicating that the attachable/detachable operation key 2 b is attached to the controller 11 .

[0145] On receiving this, the controller 11 turns on the first power supply 53 so as to use the first display section 16 which is the standard display section for the call. Additionally, the voice communication section 13 is also turned on to obtain a use state. At this time, the second power supply 54 for the second display section 18 which is the enlarged display monitor and the information communication section 14 are not used and are therefore turned off.

[0146] On the other hand, as shown in FIG. 12 B, when the attachable/detachable operation key 2 b is detached from the cellular phone main body 1 g , the display switch 52 turns on, and the attachment detector 51 supplies the signal “H” indicating that the attachable/detachable operation key 2 b is detached from the attachment detector 51 to the controller 11 .

[0147] Next, the controller 11 turns on the second power supply 54 so as to use the second display section 18 which is the enlarged display section for information. Additionally, the communication section for information 14 is turned on so that the communication section is brought into the use state to start obtaining the information. At this time, the first power supply 53 for the first display section 16 and the voice communication section 13 are not used and are therefore turned off.

[0148] That is, when the cellular phone is used as the apparatus for the call, the attachable/detachable operation key 2 b is in the attached state with respect to the cellular phone main body 1 g , and the first power supply 53 for the first display section 16 which is a standard display and the voice communication section 13 are turned on. The second power supply 54 for the second display section 18 which is an enlarged display and the information communication section 14 are turned off.

[0149] On the other hand, when the cellular phone is used as an apparatus for the information, the attachable/detachable operation key 2 b is in the detached state from the cellular phone main body 1 g . The second power supply 54 for the second display section 18 which is the enlarged display and the information communication section 14 are turned on. The first power supply 53 for the first display section 16 which is the standard display and the voice communication section 13 are turned off.

[0150] When the enlarged display is used in this manner, the information data of the internet homepage is obtained, and the standard display section for the call is not used. Therefore, in the display switch 52 and attachment detector 51 , an attaching/detaching event of the attachable/detachable operation key 2 b is detected, and a signal indicating this is transmitted to the controller 11 . Accordingly, the first power supply 53 is turned off and the first display section 16 is turned off. Additionally, the second power supply is turned on and the second display section 18 is turned off under the control of the controller 11 . Furthermore, simultaneously with the turning-on/off of the first and second power supplies 53 and 54 , the information communication section 14 is controlled to be operated to start obtaining the information.

[0151] It is to be noted that when the attachable/detachable operation key 2 b is again attached to the cellular phone main body 1 g , the above-described operation for the call is performed, and the alternate operation is performed in accordance with the output of the display switch 52 .

[0152] Furthermore, in the eighth embodiment, the first power supply 53 for the first display section 16 operates opposite to the second power supply 54 for the second display section 18 , but a simultaneously operating mode can also be provided. It is similarly possible to provide a mode in which the communication for the call and the communication for the information can arbitrarily be switched and used.

[0153] Next, a ninth embodiment of the present invention will be described.

[0154] FIG. 13 shows the constitution of the ninth embodiment of the cellular phone according to the present invention, and is a block diagram showing the constitution in which the attachable/detachable operation key 2 is detached from a cellular phone main body 1 h.

[0155] The cellular phone main body 1 h is constituted of the controller 11 , transmitter/receiver 12 , first display memory 15 , first display section 16 , second display memory 17 , second display section 18 , and cellular phone function section 19 , and a text processor 55 and character edition memory 56 . The attachable/detachable operation key 2 is constituted of the key input section 101 , code converter 102 , and transmitter/receiver 103 .

[0156] In the ninth embodiment, the characters of a section of a document inputted from the attachable/de