JP2000209660A - Communication unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption by detecting whether or not communication is available and inhibiting all indications of a display panel section when disabled communication is judged so as to prevent useless dialing. SOLUTION: A control section 5 that controls an entire portable telephone set 11 judges whether or not a reception level of a control channel sent from a radio base station is a prescribed level or over and judges disabled communication when the reception level is the prescribed level or below. In this case, the disabled communication results from the portable telephone set 11 at the outside of a service zone off the base station. Moreover, when the reception level is the prescribed level or over, enable/disable communication is judged on the basis of contents of the received control channel. Moreover, when the communication is disabled, display of a dial key in a display section 6 is inhibited, that is, display of the dial key in the display section 6 is turned out to allow an operator to understand disabled communication at a glance and useless dialing and call transmission can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a communication device having a display panel, and more particularly to a communication device such as a portable telephone.

[0002]

2. Description of the Related Art Conventionally, portable telephones perform radio communication via a repeater called a radio base station. The mobile phone cannot communicate unless the radio wave from the base station is within a range (this range is called a service area).

[0003] Therefore, in current mobile phones,
Japanese Unexamined Patent Publication No. 3-203417 discloses a technology for displaying whether the service is outside or within a service area so that an operator can recognize whether the service is within a service area (service area) of the wireless base station.

[0004]

However, in the above method, when the user overlooks a display indicating that communication is not possible (for example, out of the service area of the radio base station), the user cannot communicate outside the service area. In some cases, the caller may perform a useless call operation, giving the operator an unpleasant sensation. In addition, there is a problem that the battery runs out early due to excessive power consumption. Was.

SUMMARY OF THE INVENTION The present invention provides a communication device with an excellent man-machine interface that prevents useless calling operation by inhibiting display related to calling operation when communication is disabled and reduces power consumption. It is.

[0006]

According to the present invention, claim 1 is provided.
Has a display panel unit that can be input, in a communication device that displays a dial key on the display panel unit, a detection unit that detects whether communication is possible, and when it is determined that communication is impossible by the detection unit, Display control means for prohibiting all display on the display panel unit.

According to a second aspect of the present invention, there is provided a communication device having a display panel capable of inputting and displaying dial keys on the display panel, and a detecting means for detecting whether a current position is within a service area of a radio base station. And display control means for prohibiting all display on the display panel when the detection means determines that the service area is out of the service area.

According to a third aspect of the present invention, there is provided a communication device having a display panel portion capable of inputting and displaying dial keys on the display panel portion, wherein a detecting means for detecting whether or not the current position is within a communication range with the master device. A display control unit for prohibiting all display on the display panel unit when the detection unit determines that the display is out of the master unit communication range.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which a communication device of the present invention is a portable telephone will be described with reference to the drawings.

FIG. 1 is a functional block diagram showing an embodiment of the mobile phone according to the present invention.

In FIG. 1, a portable telephone 11 is provided with an antenna 10 and a duplexer 1 having a coupler and a filter.
And a receiving unit 2 having a mixer and a demodulator, a transmitting unit 4 having a modulator and a power amplifier, a frequency synthesizer 3 for switching a frequency and setting a use channel, and a control unit 5 for controlling the entire mobile phone. An input unit 7 for inputting a dial number necessary for making a call and performing various operations;
It comprises a display unit 6 such as a CD or LED, a receiving unit 8 and a transmitting unit 9 necessary for a call. The antenna 10 is formed so as to be built in the housing or connected to the outside.
In addition, the display unit 6 is also provided with a speaker for audio output as audio display means.

In this embodiment, as shown in FIG. 2, the display unit 6 and the input unit 7 shown in FIG. 1 are provided on an LCD (display unit 6) on a pressure-sensitive type, a capacitance type, and an electromagnetic induction type. The transparent digitizer (input unit 7), which is a coordinate input means, is stacked. In the case of the electromagnetic induction type, a configuration may be adopted in which an LCD (display unit 6) is stacked on an electromagnetic induction type digitizer (input unit 7). Also, Japanese Patent Application Laid-Open No. 5-53726
Japanese Patent Application Laid-Open Publication No. HEI 9-205, in which a display-integrated tablet is provided, that is, the display unit 6 and the input unit 7 may be integrated. The display unit 6 and the input unit 7 are collectively referred to as a display panel unit capable of inputting. In this embodiment, LC
It is assumed that a pressure-sensitive touch panel is laminated on D, and the input is performed by hand (finger) input. When an electromagnetic induction type digitizer is used, an input is made using a dedicated input pen.

The control unit 5 determines whether the reception level of the control channel transmitted from the radio base station is equal to or higher than a predetermined value. If the reception level is equal to or lower than the predetermined value, it determines that communication is impossible. In this case, it is because the mobile phone is out of the service area of the base station. Further, when the reception level is equal to or higher than the predetermined value, it is determined whether communication is possible or not based on the content of the received control channel. Usually, when communication is not possible,
The reason is also detected.

The operation of the mobile phone according to the first embodiment of the present invention will be described below with reference to FIGS. FIG.
5 is a flowchart showing an operation of the mobile phone according to the first embodiment of the present invention. FIG. 4 is a schematic diagram showing a display operation according to the first embodiment of the present invention.
Numeric keypad 15 used for dial number input to digitizer
(Dial key) is displayed. Further, a selection key 16 (memo, FAX, TEL in the present embodiment) for selecting a menu screen of various function modes, and a status display 17 for displaying whether communication is possible or not, are displayed. .

In the standby state of the portable telephone, in step S101, a control channel from the base station is detected to determine whether communication is possible, and it is determined whether the communication enabled / disabled state has changed. I do. If there is no change, it is determined in step S102 whether or not communication is currently possible.
If it is determined that it is impossible, the process returns to step S101. On the other hand, if it is determined in step S102 that communication is possible, it is determined in step S103 whether or not there is a call request from the operator, that is, whether or not the operator is trying to make a call. It is determined whether there is an incoming signal from.

On the other hand, when an operator's calling instruction is received via input unit 7 in step S103, a calling operation is performed according to a calling sequence in step S105, and a call is made from portable telephone 11 to the wireless base station. Is performed.

When an incoming signal is received in step S104, an incoming call operation is performed in step S106 according to an incoming sequence, and the display unit 6 notifies the operator of the incoming call through a ring tone or an incoming call display.

On the other hand, if it is determined in step S101 that the communication is enabled / disabled, the flow advances to step S107 to determine whether communication is currently possible. If it is determined that it is impossible, the display of the dial key 15 on the display unit 6 is turned off in step S108 (FIG. 4B), and step S1 is performed.
At 09, acceptance of the dial key is prohibited. If it is determined that communication is possible, the dial key 15 is displayed in step S110 (FIG. 4A), and acceptance of the dial key is permitted in step S111.

Therefore, when communication is not possible, the display of the dial keys on the display panel is prohibited, that is, by extinguishing the display of the dial keys on the display panel, the operator cannot understand at a glance that communication is not possible, and the dial operation is prohibited. This eliminates unnecessary dialing and calling operations. Further, since no dial key is displayed, power consumption can be reduced.

In the first embodiment, when communication is not possible, the dial key display is turned off (dial key display is turned off). However, the dial key display is turned off, and the reason for the transmission failure and the current state are displayed. Message may be displayed. The display of this message may be performed on, for example, a display panel in the display unit 6, or a display (not shown) such as an LED in the display unit 6 may be used. In this case, in the flowchart of FIG.
8 is "dial key display off and communication disabled message display on", and step S110 is "dial key display on and communication disabled message display off". Therefore, when communication is not possible, the dial key on the display panel is turned off (display is prohibited), so that the operator can understand at a glance that communication cannot be performed, the dial operation is prohibited, and a message such as the reason for the communication failure or the current state is displayed. Is displayed, the operator can understand at a glance why communication cannot be performed, and it is possible to prevent useless calling operation. Further, since no dial key is displayed, power consumption can be reduced.

In the first embodiment, when communication is not possible, the dial key display is turned off (dial key display off) in step S108. However, the dial key display mode may be changed. Good. For example, as shown in FIG. 5, when communication is not possible, the size of the dial key is set smaller than that of the normal state (FIG. 5A).
(B)) and display. As another example, a method of blinking a dial key when communication is not possible is also conceivable. As another example, when communication is not possible, the display unit 6
In the case where a monochrome display panel for binary display is used, dial keys are displayed in reverse (FIG. 5 (c)).
When a monochrome panel of multi-value display is used for the display unit 6, the dial keys are changed to a predetermined gradation color to perform display. When a color panel is used for the display unit 6, the dial keys are used. May be changed to a predetermined color for display. In this case, in the flowchart of FIG. 3, step S108 is "change dial key display form". Therefore, the operator can understand at a glance that communication cannot be performed, and by prohibiting dial operation, unnecessary dial operation and calling operation are not performed.

In the first embodiment, when communication is possible, a normal dial is displayed in S110, but a reception level (communication level) indicating the strength of a radio wave is detected in S107. Then, in S110, the display may be changed to a dial key display mode corresponding to the reception level. For example, the size of the dial key is changed according to the reception level (when the reception level is high, the key display is large, and as the reception level is low, the key display is small) and displayed. As another example, the flashing speed of the flashing display of the dial key is changed according to the reception level (if the reception level is high, the flashing speed is slow, and as the reception level becomes low, the flashing speed is increased). As another example, when a multi-value display monochrome panel is used for the display unit 6, the gradation color of the dial key is changed according to the reception level (when the reception level is high, the color close to the normal display is used). If the color level panel is used for the display unit 6, the tone color of the dial key is changed according to the reception level. The display may be performed in such a manner that the display is green (when the reception level is high, the color is green, and as the reception level is low, the color is changed from green to yellow, and from yellow to red). In this case, in the flowchart of FIG. 3, step S110 is "change the display mode of the dial keys according to the reception level". The reception level is detected by the reception unit 2 in the functional block diagram of FIG. Therefore, a dedicated area for displaying the communication level state used in a conventional mobile phone or the like is not required, and the usable area of the panel is increased.

In the first embodiment, communication is possible /
Although it is determined that the reception is not possible, only the determination whether the reception level of the control channel transmitted from the wireless base station is equal to or higher than a predetermined value may be performed, and the determination may be made as to whether the reception level is within the service area of the wireless base station. In this case, in the flowchart of FIG. 3, step S101 is set to "change in service area / out of service area?", Step S102 is set to "service area?", And step S107 is set to "out of service area?" Similarly to the above, when communication is not possible, the dial key display is turned off (display is prohibited). However, the dial key display may be turned off and the out-of-service display may be performed. This out-of-service display may be performed, for example, on a display panel in the display unit 6, or the L in the display unit 6.
A display (not shown) such as an ED may be used. In this case, step S108 is set to "dial display off and out of service area display on", and step S110 is set to "dial display on and out of service area display off". Therefore, when the user is out of the service area, by prohibiting the display of the dial keys on the display panel, it is possible to understand at a glance that the operator cannot perform communication. Also, by prohibiting the dial operation and performing the out-of-service display, the operator cannot perform the communication. The reason can be understood at a glance, and useless calling operation can be prevented. Further, since no dial key is displayed, power consumption can be reduced.

In the first embodiment, communication is possible /
Although the determination of impossibility is made, only the determination whether the reception level of the signal transmitted from the master unit is equal to or higher than a predetermined value may be performed, and it may be determined whether or not the reception level is within the communication range of the master unit. In this case, FIG.
In the flowchart of step S101, it is determined that "there is a change in the communication range of the base unit / out of service area?"
2 is set to “the communication range of the base unit?”, And step S107 is set to “out of the communication range of the base unit”. As described above, when communication is not possible, the dial key display is turned off (display is prohibited). However, the dial key display may be turned off and the display outside the base station communication area may be performed. The display outside the communication range of the master unit may be performed on, for example, a display panel in the display unit 6 or a display (not shown) such as an LED in the display unit 6.
May be used. In this case, step S108 is set to "dial key display off and display outside base unit communication area on", and step S110 is set to "dial key display on and display outside base unit communication area off". Therefore, by prohibiting the display of the dial keys on the display panel when outside the base station communication area, the operator can understand at a glance that communication cannot be performed, and by prohibiting the dial operation and performing the display outside the base station communication area, The reason why the operator cannot communicate can be understood at a glance, and useless calling operation can be prevented. Further, since no dial key is displayed, power consumption can be reduced.

Further, in the first embodiment, the dial key display is turned off when communication is not possible, outside the service area, or outside the base station communication area. Is also good. For example, the display of operation keys related to calling, such as a call key and a one-touch key, instead of the dial key display, is turned off. As a method for selectively deleting the display, a process (selection screen: not shown) for selecting and setting a key to be deleted when communication is not possible is provided in advance, and an arbitrary key to be deleted is selected. For example, when the display of the transmission key is to be erased when communication is not possible, the transmission key is selected by pressing the transmission key on the display selection screen described above, and the transmission key is erased when communication is not possible (display prohibited state). Can be Alternatively, the display area may be arbitrarily specified in advance, and the display of the specified display area may be turned off. In this case, in the flowchart of FIG.
Is "selective display off", and step S110 is "selective display on". Therefore, when communication is not possible, by selectively prohibiting the display on the display panel, the operator can understand at a glance that communication is not possible, making a call operation impossible, and consequently performing an unnecessary call operation. Disappears. In addition, since the display is not selectively performed, power consumption can be reduced.

In the first embodiment, the dial key display is turned off (display is prohibited) when communication is not possible, when the mobile phone is out of the service area, and when the mobile phone is out of the base station communication area. The message may be displayed together with the message indicating the reason for the transmission failure or the current state. The display of this message may be performed on, for example, a display panel in the display unit 6, or a display device such as an LED in the display unit 6 may be used. In this case, in the flowchart of FIG. 3, if communication is not possible, step S108 is “selective display off and communication disabled message display on”, and step S108 is performed.
110 is "selective display ON and communication disabled message display OFF", and if the service is out of service area, step S1
08 is “selective display off and out of service area display on”
Step S110 is “selective display on and out of service area display off”, and when out of the parent device communication area, step S108 is “selective display off and out of parent device communication area display on”, and step S110 is “selection display off”. Display on and display outside base station communication area off ". Therefore, when communication is not possible, by selectively prohibiting the display on the display panel, the operator can understand at a glance that communication is not possible, call operation cannot be performed, and a message such as the reason for communication failure or the current state is displayed. By doing so, it is possible for the operator to understand the reason why communication cannot be performed, and it is possible to prevent useless calling operation. In addition, since the display is not selectively performed, power consumption can be reduced.

In the first embodiment, the dial key display is turned off (display is prohibited) when communication is not possible, when the mobile phone is out of the service area, and when the mobile phone is out of the base station communication area. May be turned off. In this case, in the flowchart of FIG.
Is "all display off", and step S110 is "all display on". In this case, as all the display-off processing, nothing is displayed on the display unit 6 (see FIG. 1), the power supply to the display unit 6 is cut off (off), or the LCD of the display unit 6 is turned off. For example, the power supply of the backlight used is cut off. Therefore, if communication is not possible,
By prohibiting all displays on the display panel,
The operator can understand at a glance that communication cannot be performed, and cannot perform a call operation. As a result, it is possible to prevent useless call operation. Further, since not all displays are performed, power consumption can be reduced. When all the display on the display section 6 is turned off, a power lamp (not shown) or the like is turned on.
It is possible to prevent erroneous recognition that the battery is dead. The display unit 6
Not only may be erased, but also a message such as the reason for the transmission failure or the current state may be displayed. The display of this message may be performed on, for example, a display panel in the display unit 6, or a display device such as an LED in the display unit 6 may be used. In this case, in the flowchart of FIG. 3, step S108 is "all display off and communication disabled message display on", and step S110 is "all display on and communication disabled message display off".
And Therefore, when communication is not possible, by prohibiting all display on the display panel, the operator can understand at a glance that communication cannot be performed, call operation cannot be performed, and a message indicating the reason for communication failure or the current state is displayed. This makes it possible for the operator to understand the reason why communication cannot be performed, and to prevent useless calling operation. Further, since not all displays are performed, power consumption can be reduced.

Next, the operation of the mobile phone according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 6 is a flowchart showing the operation of the mobile phone according to the second embodiment of the present invention.

The second embodiment is an example of a multifunctional portable telephone. The multifunctional portable telephone has functions such as a memo function, a telephone directory function, a calculation function, and a facsimile function.
It is common to operate with menus and icons. Here, the operation of the menu processing one stage before the communication menu will be described.

In step S201, in a standby state of the menu screen one stage before the communication menu, a control channel from the base station is detected, whether communication is possible or not, and the state of communication enabled / disabled is changed. It is determined whether or not it has been performed.

If there is no change in step S201, it is determined in step S202 whether or not there is a key input. If there is a key input, the next menu screen (for example, pressing a calculator icon is pressed based on the key information). (Step S2).
03). If there is no key input in step S202, the process returns to step S201 to determine whether the communication enabled / disabled state has changed.

If it is determined in step S201 that the communication is enabled / disabled, it is determined in step S204 whether communication is currently possible. If it is determined that communication is not possible, the display of the communication icon on the display unit 6 is turned off in step S205, and acceptance of the communication icon key is prohibited in step S206. That is, the communication processing menu is not displayed, that is, the processing does not proceed to the communication processing menu. If it is determined in step S204 that communication is possible, a communication icon is displayed in step S207, and acceptance of a communication icon key is permitted in step S208.

Therefore, when communication is not possible, by prohibiting the display of the communication icon on the display panel, the operator can understand at a glance that communication cannot be performed, and the operation does not shift to the communication menu. Nothing to do.

In the second embodiment, when communication is not possible, the display of the communication icon on the display panel is prohibited. However, the display of the communication icon is turned off, and the reason for the transmission failure and the current state are displayed. A message may be displayed. The display of this message may be performed, for example, on a display panel in the display unit 6, or the L in the display unit 6.
A display such as an ED may be used. In this case, in the flowchart of FIG. 6, step S205 is “communication icon display off and communication disabled message display on”, and step S207 is “communication icon display on and communication disabled message display off”. Therefore, when communication is not possible, by prohibiting the display of the communication icon on the display panel, the operator can understand at a glance that communication is not possible, without shifting to the communication menu, and further displaying a message such as the reason for the communication failure or the current state. By displaying the message, the operator can understand the reason why communication cannot be performed and can prevent useless calling operation.

In the second embodiment, communication is possible /
Although it is determined that the reception is not possible, only the determination whether the reception level of the control channel transmitted from the wireless base station is equal to or higher than a predetermined value may be performed, and the determination may be made as to whether the reception level is within the service area of the wireless base station. In this case, in the flowchart of FIG. 6, step S201 is set to "change in service area / out of service area?", And step S204 is set to "out of service area?" Therefore, when the user is out of the service area, by prohibiting the display of the communication icon on the display panel, the operator can understand at a glance that communication cannot be performed, and the operation does not shift to the communication menu, thereby preventing unnecessary dial operation and calling operation. be able to. Further, in the second embodiment, when the user is out of the service area, the communication icon display is turned off. However, the communication icon display may be turned off and the display outside the service area may be performed. This out-of-service display may be performed, for example, on a display panel in the display unit 6 or a display device such as an LED in the display unit 6 may be used. In this case, in the flowchart of FIG. 6, step S205 is “communication icon display off and out of service area display on”, and step S207 is “communication icon display on and out of service area display off”. Therefore, when the user is out of the service area, by prohibiting the display of the communication icon on the display panel, the operator can understand at a glance that the communication cannot be performed. It is possible to understand the reason why communication cannot be performed, and prevent useless calling operation.

In the second embodiment, communication is possible /
Although it is determined that the reception level of the signal transmitted from the master unit is equal to or higher than a predetermined value, it is determined whether or not the reception level is within the communication range of the master unit. Is performed. In this case, in the flowchart of FIG.
In step S201, "there is a change in the base station communication area / out of service area?", In step S204, "out of the base station communication area?", In step S205, "communication icon display off and display outside the base station communication area on", and in step S207, It is assumed that “communication icon display is on and display outside base station communication area is off”. Therefore, by prohibiting the display of the communication icon on the display panel when the communication is out of the communication area of the base unit, the operator can understand at a glance that communication cannot be performed. Accordingly, the reason why the operator cannot communicate can be understood, and useless calling operation can be prevented.

Next, the operation of the mobile phone according to the third embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a flowchart showing the operation of the mobile phone according to the third embodiment of the present invention.

In the standby state of the mobile phone, in step S301, a control channel from the base station is detected to determine whether communication is possible, and it is determined whether the communication enabled / disabled state has changed. I do. If there is no change, it is determined in step S302 whether or not communication is currently possible.
If it is determined that it is impossible, the process returns to step S301. On the other hand, if it is determined in step S102 that communication is possible, it is determined in step S303 whether or not there is a call request from the operator, that is, whether or not the operator is trying to make a call. It is determined whether there is an incoming signal from.

On the other hand, when an operator's call instruction is received via input unit 7 in step S303, a call operation is performed in accordance with a call sequence in step S305, and a call is made from portable telephone 11 to the wireless base station. Is performed.

When an incoming signal is received in step S304, an incoming call is performed in accordance with an incoming sequence in step S306, and the display unit 6 notifies the operator of the incoming call with a ring tone or an incoming call display.

On the other hand, if it is determined in step S301 that the communication is enabled / disabled, the flow advances to step S307 to determine whether communication is currently possible. If it is determined that it is impossible, the buzzer is called in step S308, and acceptance of the dial key is prohibited in step S309. If it is determined that communication is possible, the buzzer call is stopped in step S310, and the flow proceeds to step S310.
At 311, the acceptance of the dial key is permitted. Note that the buzzer is provided on the display unit 6.

Therefore, when communication is not possible, the operator can understand that the communication is not possible without looking at the display panel by calling the buzzer. No calling operation is performed.

In the third embodiment, if communication is not possible, the buzzer is called in step S308, but the reception unit 8 may notify by voice that the communication is not possible. Good. Note that the notification voice data is stored in a memory (not shown) managed by the control unit 5 in advance. In this case, in the flowchart of FIG. 7, step S308 is set to “turn on the sound display from the handset” and step S310 is set to “turn off the sound display from the handset”. Therefore, when communication is not possible, by notifying the communication disabled state by voice from the handset, the operator can understand that the communication is not possible without looking at the display panel, and by prohibiting dial operation, In addition, useless dialing and calling operations can be prevented.

In the third embodiment, when communication is not possible, the buzzer is called in step S308, but the fact that communication is not possible by not generating a call permission tone from the receiver 8 is described. The notification may be made. In this case, in the flowchart of FIG.
08 is "call tone off from the handset", and step S310 is "call tone on from the handset". Therefore, when communication is not possible, by not generating a call tone from the handset, the operator can understand that communication is not possible without looking at the display panel, and by prohibiting dial operation, wasteful dial operation and dialing can be prevented. Call operation can be prevented.

[0045]

According to the present invention, according to the first aspect, when communication is not possible, all displays on the display panel are prohibited, so that the operator can recognize at a glance that communication cannot be performed, Is not displayed, so that the power consumption can be significantly reduced.

According to the second aspect, all display on the display panel is prohibited, so that the operator can recognize at a glance whether or not the area is within the service area of the radio base station, and further, all display on the display panel is not performed. Thus, the power consumption can be significantly reduced.

According to the third aspect, all display on the display panel is prohibited, so that the operator can recognize at a glance whether or not the user is within the communication range with the master unit. Further, since all display on the display panel is not performed, Significant reduction in power consumption can be achieved.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an embodiment when a communication device of the present invention is a mobile phone.

FIG. 2 is a schematic diagram showing an embodiment of an arrangement configuration of an input unit and a display unit when a communication device of the present invention is a mobile phone.

FIG. 3 is a flowchart showing an operation of the mobile phone according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram showing a display example of the mobile phone according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram showing a display example of the mobile phone according to the first embodiment of the present invention.

FIG. 6 is a flowchart showing an operation of the mobile phone according to the second embodiment of the present invention.

FIG. 7 is a flowchart showing an operation of the mobile phone according to the third embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 transmission / reception duplexer 2 reception unit 3 frequency synthesizer 4 transmission unit 5 control unit 6 display unit 7 input unit 8 reception unit 9 transmission unit 10 antenna 11 mobile phone

Claims (3)

[Claims] 1. A communication device having a display panel unit capable of inputting and displaying dial keys on the display panel unit, detecting means for detecting whether communication is possible, and determining that communication is impossible by the detecting means. And a display control means for prohibiting all display on the display panel when the communication is performed. 2. A communication device having a display panel capable of inputting and displaying a dial key on the display panel, comprising: a detecting unit for detecting whether a current position is within a service area of a wireless base station; And a display control means for prohibiting all display on the display panel when it is determined that the display panel is out of the service area. 3. A communication device having a display panel portion capable of inputting and displaying dial keys on the display panel portion, wherein a detection means for detecting whether or not a current position is within a communication range with a master device, And a display control unit for prohibiting all display on the display panel unit when it is determined that the display is outside the communication range of the base unit.