Portable device and method for defining restricted area within touch panel

A portable phone device includes a display, a touch panel superimposed on the display and configured to detect a touch operation, an area defining module configured to define within the touch panel a restricted area in which acceptance of the touch operation is restricted, and a determination module configured to determine whether or not a screen being displayed on the display is a target screen for defining the restricted area. The area defining module defines the restricted area based on that the screen being displayed on the display is determined to be a target screen by the determination module.

FIELD

The present disclosure relates to a portable device such as a portable phone, a PDA (Personal Digital Assistant), a tablet PC, an e-book terminal, a portable music player, a portable television or a portable navigation system, and in particular relates to a portable device provided with a touch panel. Furthermore, the present disclosure relates to a method for defining a restricted area within a suitable touch panel used in such portable device.

BACKGROUND

Heretofore, such a portable phone that has a touch panel arranged on a display is known. The portable phone may adopt such a configuration that an invalid area for a touch operation is defined at an inner peripheral edge of the touch panel to invalidate the touch operation performed within the inner peripheral edge.

SUMMARY

A portable device according to a first aspect of the present disclosure may be configured to include a display, a touch panel superimposed on the display and configured to detect a touch operation, an area defining module configured to define within the touch panel a restricted area in which acceptance of the touch operation is restricted, and a determination module configured to determine whether or not a screen being displayed on the display is a target screen for defining the restricted area. The area defining module defines the restricted area based on that the screen being displayed on the display is determined to be a target screen by the determination module.

In a portable device according to the present disclosure, the restricted area may be defined within at least a part of an inner peripheral edge of the touch panel.

The portable device according to the present disclosure may further include an acceleration detection module configured to detect a dynamic acceleration generated in the portable device. In this case, the area defining module defines the restricted area based on that the screen being displayed on the display is determined to be a target screen by the determination module and that the dynamic acceleration is greater than a predetermined value.

The portable device with the abovementioned configuration may further include an imaging module configured to image the face of a user facing the display. In this case, the area defining module defines the restricted area based on that the screen being displayed on the display is determined to be a target screen by the determination module, and that the dynamic acceleration is greater than the predetermined value, and that the face of a user is not being imaged by the imaging module.

Alternatively or additionally, the portable device with the abovementioned configuration may further include an illuminance detection module configured to detect an environmental brightness of the portable device. In this case, the area defining module defines the restricted area based on that the screen being displayed on the display is determined to be a target screen by the determination module, and that the dynamic acceleration is greater than the predetermined value, and that the environmental brightness of the portable device is significantly lower than a predetermined amount.

The portable device according to the present disclosure may include a remaining amount detection module configured to detect a remaining battery amount. In this case, the acceleration detection module is activated to detect the dynamic acceleration when the remaining battery amount detected by the remaining amount detection module is greater than a predetermined amount.

A second aspect of the present disclosure relates to a method for defining a restricted area, in which acceptance of a touch operation is restricted, within a touch panel which is superimposed on a display and configured to detect the touch operation. The method for defining a restricted area according to the present aspect includes a step of determining whether or not a screen being displayed on the display is a target screen for defining the restricted area and a step of defining the restricted area based on the determination that the screen being displayed on the display is a target screen.

Effects and significance of the present disclosure will become more apparent from the description of the embodiments given below. It should be noted that each of the following embodiments is given for the purpose of illustration and example only and is not to be taken by way of limiting the present disclosure.

DETAILED DESCRIPTION

On a display of a portable device such as a portable phone, various screens are displayed in accordance with application programs (hereinafter, simply referred to as “application”) in operation. The screens to be displayed on the display may include screens on which frequent operations will be performed by a user such as a mail creation screen for creating an e-mail, and screens on which less operation will be performed by the user such as a TV viewing screen. Thus, in the case where an invalid area is defined regardless of the screen to be displayed on the display, the operability of the portable device may be deteriorated unnecessarily.

Therefore, a portable device and a method for defining a restricted area within a touch panel, which can provide a satisfactory prevention of any erroneous operation by a user, are desired.

FIGS. 1(a), 1(b) and 1(c)illustrate a front view, a rear view and a right side view of a portable phone1, respectively. Hereinafter, for the convenience of explanation, as illustrated inFIGS. 1(a) to 1(c), the longer direction of a cabinet2is defined as the vertical direction, and the shorter direction of cabinet2is defined as the lateral direction.

As illustrated inFIG. 1, portable phone1can include cabinet2, a display3, a touch panel4, a microphone5, and a conversation speaker6, and an external speaker7.

Cabinet2can have a profile of substantially rectangular shape when viewed from the front surface. Display3can be arranged on the front side of cabinet2. Display3is configured to display a variety of images (screens). Display3can be a liquid crystal display, for example. Display3may be another type of display such as an organic EL display or the like.

Touch panel4can be arranged to cover display3. Touch panel4can be formed into a transparent sheet. Touch panel4may be implemented by any of various types of touch panels such as an electrostatic capacitance type touch panel, an ultrasonic touch panel, a pressure sensitive touch panel, a resistive film type touch panel or an optical detection type touch panel.

Microphone5can be disposed inside cabinet2near a lower end thereof. Conversation speaker6can be disposed inside cabinet2near an upper end thereof. Microphone5is configured to receive sound passed through a microphone hole5aformed on the front surface of cabinet2. Microphone5is further configured to generate an electric signal in response to the received sound. Conversation speaker6is configured to output sound. The output sound is broadcasted to the outside of cabinet2through an output hole6aformed on the front surface of cabinet2. During a call, any phonetic sound received from a device (portable phone or the like) of a communication partner is output from conversation speaker6, any phonetic sound issued by the user is input to microphone5. The sound may include a variety of sounds such as voice, alarming sound and the like.

External speaker7can be disposed inside cabinet2. An output hole7acan be formed in an area on the back surface of cabinet2opposite to external speaker7. The sound output from external speaker7can be broadcasted to the outside of cabinet2through output hole7a.

A frame member2asurrounding display3in cabinet2can be constituted by an upper frame, a lower frame, a left frame and a right frame. As described in the above, a space for disposing conversation speaker6can be provided in the upper part of cabinet2, and a space for disposing microphone5can be provided in the lower part of cabinet2. Thereby, the widths W1and W2of the respective left and right frames are configured narrower than the widths W3and W4of the upper and lower frames. The width W1of the left frame is the same as the width W2of the right frame, and the width W3of the upper frame is wider than the width W4of the lower frame.

FIG. 2is a block diagram illustrating the overall configuration of portable phone1.

As illustrated inFIG. 2, portable phone1can include a control module11, a memory module12, an image output module13, a touch detection module14, a sound input module15, a sound output module16, a sound processing module17, an input key module18, a communication module19, an acceleration detection module20, and a power supply module21.

Memory module12can include a ROM, a RAM, and an external memory. Memory module12can store various programs. In addition to a control program for controlling each module in portable phone1, the programs stored in memory module12can include various applications (for example, home, telephone, e-mail, web browser, maps, games, and schedule management). Such programs may be preliminarily stored by the manufacturer in memory module12at the time of manufacturing portable phone1or may be stored in memory module12thereafter via a communication network or a memory medium such as a memory card or a CD-ROM.

Moreover, memory module12can be provided with a working area for temporarily storing data to be used or to be generated during execution of a program.

Control module11can include a CPU. Control module11is configured to control each of the modules (such as memory module12, image output module13, touch detection module14, sound input module15, sound output module16, sound processing module17, input key module18, communication module19and acceleration detection module20) constituting portable phone1in accordance with the programs stored in memory module12.

Image output module13can include display3as illustrated inFIG. 1. Image output module13is configured to display an image (screen) on display3based on a control signal and an image signal from control module11.

Touch detection module14can include touch panel4as illustrated inFIG. 1. Touch detection module14is configured to detect a touch operation by a user on display3illustrated inFIG. 1via touch panel4. Specifically, when the user touches an area of display3, touch detection module14can detect a position which the user has touched (hereinafter, referred to as a “touch position”) by using touch panel4. Touch detection module14can output a position signal which is generated based on the detected touch position to control module11.

Owing to the provision of touch panel4, a user can perform various touch operations by touching display3, i.e., touch panel4with a finger. Examples of touch operations include a tap operation, a flick operation, a slide operation and the like. In a tap operation, a user touches touch panel4with a finger, and then releases the finger from touch panel4after a short time. In a flick operation, a user touches touch panel4with a finger, and then flips touch panel4with the finger toward an optional direction. In a slide operation, a user touches touch panel4with a finger, and moves the finger toward an optional direction with the finger touched on touch panel4.

For example, if a touch position is detected by touch detection module14, and the touch position is no longer detected within a predetermined first time period thereafter, control module11can determine that a tap operation has been performed. If a touch position is detected, and the touch position is moved by a predetermined first distance or more within a predetermined second time period, and thereafter the touch position is no longer detected, control module11can determine that a flick operation has been performed. If a touch position is detected and the touch position is moved by a predetermined second distance or more thereafter, control module11can determine that a slide operation has been performed.

Sound input module15can include microphone5. Sound input module15is configured to output an electrical signal from microphone5to sound processing module17.

Sound output module16can include conversation speaker6and external speaker7. Sound output module16is configured to receive an electric signal from sound processing module17and output a sound through conversation speaker6or external speaker7.

Sound processing module17is configured to perform an A/D conversion or the like on an electric signal from sound input module15so as to convert the electric signal into a digital sound signal, and output the digital audio signal to control module11. Sound processing module17is also configured to perform a decoding process and a D/A conversion or the like on a digital sound signal from control module11so as to convert the digital sound signal to an electric signal, and output the electric signal to the sound output module16.

Input key module18can include at least one or more hardware keys. For example, input key module18can include a power key or the like for turning on portable phone1. Input key module18is configured to output a signal to control module11in response to a pressed hardware key.

Communication module19can include a circuit for converting signals, an antenna for interchanging electric waves, and the like so as to provide conversations or communications. Communication module19is configured to convert a conversation signal or a communication signal received from control module11into a radio signal, and transmit the converted radio signal to a communication partner such as a base station or another communication device through the antenna. Furthermore, communication module19is configured to convert the radio signal received through the antenna into a signal in a form that can be used by control module11, and output the converted signal to control module11.

Acceleration detection module20can include a triaxial acceleration sensor. Acceleration detection module20is configured to detect a static acceleration for portable phone1when portable phone1is in a static state, in other words, the acceleration of gravity through the triaxial acceleration sensor, and output a detection signal to control module11in response to the detected acceleration of gravity. Acceleration detection module20is also configured to detect a dynamic acceleration for portable phone1when portable phone1is in motion through the triaxial acceleration sensor, and output a detection signal to control module11in response to the detected dynamic acceleration.

Power supply module21can include a battery21aand a remaining amount detection module21b. Power supply module21is configured to supply power from battery21ato control module11and the other modules. Power supply module21is also configured to supply power from an external power source to battery21aso as to charge battery21a. Furthermore, power supply module21is configured to output a detection signal to control module11in response to the remaining amount of battery21adetected by remaining amount detection module21b.

FIG. 3is a diagram illustrating a home screen which is an example of a screen to be displayed on display3.

The home screen can include activation icons IC for activating various applications. A tap operation on an activation icon IC lunches a corresponding application. A number of screens such as the home screen and the like to be displayed on display3in correspondence to an application include a notification bar101located at the top and an operation key group102located at the bottom.

Notification bar101can include current time101a, a strength meter101bindicating the strength of radio waves, a remaining amount meter101cindicating the remaining battery amount, and the like. Operation key group102can include a setting key102a, a home key102b, a return key102cand the like. Setting key102ais mainly configured to invoke a setting screen to be displayed on display3so as to perform various settings. Home key102bis mainly configured to bring display3from any other screen back to the home screen. Return key102cis mainly configured to return a working process back to its prior step.

It should be noted that depending on the conditions of the screen, at least one of notification bar101and operation key group102may not be provided.

In portable phone1according to one embodiment, when a user is holding portable phone1, the user may touch display3, i.e., the inner peripheral edge of touch panel4with a finger without an intention of performing an operation, resulting in an erroneous operation. Thus, portable phone1is provided with a function to define within touch panel4a restricted area where acceptance of the touch operation is restricted by control module11(hereinafter, referred to as “restricted area defining function”).

However, the definition of a restricted area will accordingly reduce the area where the touch operation is not restricted in touch panel4, and thereby deteriorate the operability of the user to some extent. In addition, the screens to be displayed on display3may include screens on which frequent operations will be performed by a user such as a mail creation screen for creating an e-mail, and screens on which less operation will be performed by the user such as a TV viewing screen. Thus, in the case where a restricted area is defined regardless of the screen to be displayed on display3, the operability of portable device1may be deteriorated unnecessarily.

Thus, the restricted area defining function provided in portable phone1according to one embodiment is configured to define a restricted area within touch panel4in accordance with a screen to be displayed on display3. A restricted area defining process for implementing the restricted area defining function is performed by control module11.

As illustrated inFIG. 2, memory module12is stored with a target screen list12a. Target screen list12acan be utilized by the restricted area defining process as information to determine whether or not a screen being displayed on display3is a target screen for defining a restricted area within touch panel4.

FIG. 4is a diagram illustrating the configuration of target screen list12a. Target screen list12ais registered with a number of target screens for defining the restricted area. A target screen is such a screen that although it is displayed on display3, there is a relatively low possibility that the touch operation will be performed thereon by the user. For example, the home screen, the television viewing screen, the video replay screen and the like may be given as examples of target screens. The home screen is an initial screen, and it is quite common that a user may return display3to the home screen after shutting down an application and thereafter quit the use of portable phone1. In addition, when a user is watching a TV program on the television viewing screen or watching a video on the video replay screen, the user may seldom perform any operation. It should be noted that a mail creation screen or a web screen where touch operations are relatively frequently performed is not registered into target screen list12a.

In addition, an application may be registered into target screen list12a. The registration of an application means that all the screens of the application is registered, and thereby, all the screens of the registered application will be the target screen for defining the restricted area.

Memory module12is further stored with location information (coordinate information) serving as area information for defining a restricted area.

Control module11can function as an area defining module and a determination module, and is configured to define a restricted area based on the determination that a screen being displayed on display3is a target screen. More specifically, control module11can define the restricted area based on that the screen being displayed on display3is determined to be a target screen and that the dynamic acceleration detected by acceleration detection module20is greater than a predetermined value.

FIGS. 5A and 5Bare diagrams for explaining the restricted area defining function.FIG. 5Ais a flowchart illustrating a restricted area defining process, andFIG. 5Bis a diagram illustrating an example of a restricted area RA defined within touch panel4.

While portable phone1is in operation, control module11can repeatedly execute the restricted area defining process. A screen is displayed on display3in correspondence to an application that is being executed in foreground. Control module11, based on target screen list12a, determines whether or not a screen that is being displayed on display3is a target screen for defining restricted area RA (S101). If the screen that is being displayed is registered in target screen list12a, control module11determines that the screen that is being displayed is a target screen (S101: YES). In this case, control module11continues to determine whether or not the dynamic acceleration detected by acceleration detection module20is greater than a predetermined value (S102). The predetermined value may be obtained in such a manner that the dynamic acceleration generated when using portable phone1is measured in experiments, for example, and the predetermined value is derived from the measured values.

In the case where a user is holding and using portable telephone1in hand, portable phone1will not be remained stationary for all the time, and portable phone1may be moved to some extent. When such movement occurs in accordance with the use of portable phone1, the dynamic acceleration that occurs in portable phone1may exceed the predetermined value. Thus, when a user is holding portable phone1, the user may have a finger touched on touch panel4without an intention of performing an operation, resulting in an erroneous operation. At this time, if the screen that is being displayed on display3is a target screen, it is relatively unlikely to perform the touch operation on that screen by the user. Therefore, the definition of restricted area RA within touch panel4hardly deteriorate the operability of portable phone1.

Thus, in the case where the dynamic acceleration is greater than the predetermined value (S102: YES), control module11can define restricted area RA within touch panel4(S103). According to one embodiment, as illustrated by the dot chain line inFIG. 5B, control module11can define restricted area RA along the entire inner peripheral edge of touch panel4.

Control module11can perform a time counting through a timer built inside control module11, and determine whether or not a predetermined time (for example, 30 seconds) has elapsed from the definition of restricted area RA (S104). If the predetermined time has elapsed (S104: YES), control module11releases restricted area RA (S105), and ends the restricted area defining process. Even in the case where portable phone1recovers immediately the stationary state after being moved, as mentioned in the above, restricted area RA will not be immediately released but continue to exist for the predetermined time.

In the case where portable phone1is not in use and is being placed on a desk or the like, since portable phone1is being kept stationary, the dynamic acceleration of portable phone1will not exceed the predetermined value. Since portable phone1is not being held by the user, erroneous operation will not be caused by the user through touching touch panel4with his/her fingers. Thus, there is no need to define restricted area RA within touch panel4.

Thus, in the case where control module11determines that the dynamic acceleration is not greater than the predetermined value at step S102(S102: NO), restricted area RA will not be defined within touch panel4, and the restricted area defining process is ended.

On the other hand, in the case where the screen that is being displayed on display3is not a target screen, it is likely that the touch operations will be performed on the screen frequently by the user. Therefore, when a screen that is not a target screen is being displayed on display3, if restricted area RA is defined within touch panel4, the operability of portable phone1may be deteriorated significantly.

In the case where control module11determines that the screen that is being displayed is not a target screen at step S101(S101: NO), restricted area RA will not be defined within touch panel4, and the restricted area defining process is ended.

Immediately after a cycle of the restricted area defining process is ended, control module11restarts another cycle of the restricted area defining process. As long as the target screen is being displayed on display3and portable phone1is being held, immediately after the dynamic acceleration is detected greater than the predetermined value, restricted area RA is defined within touch panel4(S101: YES→S102: YES→S103).

As mentioned in the above, during the period when the target screen is being displayed on display3and portable phone1is being held, restricted area RA can be defined within touch panel4by repeating the restricted area defining process over substantially the whole period.

On the other hand, during the period when a screen that is not a target screen is being displayed on display3or during the period when a screen that is a target screen is being displayed on display3but portable phone1is not being held, restricted area RA will not be defined within touch panel4.

Portable phone1according to one embodiment is provided with such a function that can determine whether portable phone1is being held along the lateral direction or the vertical direction based on the acceleration of gravity detected by acceleration detection module20and change the display direction of a screen being displayed on display3accordingly. Thus, while portable phone1is in operation, the acceleration sensor of acceleration detection module20is in constant working. In the case where it is not necessary to make the acceleration sensor work constantly, for example when portable phone1is not provided with the function of changing the display direction in response to its orientation, control module11may be configured to control acceleration detection module20in the restricted area defining process to activate the acceleration sensor in need of detecting an acceleration, and to stop the acceleration sensor after the acceleration detection is finished.

FIG. 6is a flowchart illustrating a process of executing a function based on a touch operation performed after restricted area RA is defined. As long as portable phone1is in operation, the function execution process illustrated inFIG. 6will be executed repeatedly.

Control module11can determine whether or not a touch operation has been performed on display3(S201). In the case where a touch operation has been performed on display3(S201: YES), control module11can refer to the area information stored in memory module12and determine whether the touch position detected from touch panel4is inside restricted area RA (S202).

In the case where the touch position is not inside restricted area RA (S202: NO), control module11can determine whether or not the touch operation performed at the touch position has been assigned with any function (S203). If a function is assigned (S203: YES), control module11can execute the assigned function (S204). For example, in the case where a tap operation has been performed at the position of one of activation icons IC in the home screen as illustrated inFIG. 3, control module11can activate an application related to the tapped activation icon IC.

On the other hand, in the case where the touch position is inside restricted area RA (S202: YES), control module11can invalidate the touch operation, and will not perform the assigned function (S205).

As mentioned in the above, according to one embodiment, restricted area RA can be defined within touch panel4based on that the screen being displayed on display3is such a screen that no frequent operation will be performed by a user thereon. Therefore, it is possible to prevent the erroneous operation from being performed on portable phone1while suppressing the deterioration in the operability of portable phone1.

Furthermore, according to one embodiment, in the case where the screen being displayed on display3is such a screen that no frequent operation will be performed by a user thereon, and portable phone1is considered as being held by the user, restricted area RA can be defined within touch panel4. Thereby, it is further possible to prevent the erroneous operation from being performed on portable phone1while suppressing the deterioration in the operability of portable phone1.

An embodiment of the present disclosure has been described in the above, however, the present disclosure is not restricted in any means by the abovementioned embodiment, and may include various modifications other than the described embodiment.

FIG. 7is a block diagram illustrating the overall configuration of portable phone1according to a first modification.

As illustrated inFIG. 7, portable phone1of the present modification can include an imaging module22in addition to the configurations of the abovementioned embodiment.

Imaging module22can include an in-camera arranged on the front side of cabinet2. The in-camera is configured to photograph a subject present in the front direction of portable phone1. Imaging module22can perform various image processing on image data of an image photographed by the in-camera, and output the processed image data to control module11.

FIG. 8is a flow chart illustrating a restricted area defining process according to the first modification. Hereinafter, the description will be carried out on the restricted area defining process of the present modification with reference toFIG. 8.

In the case where a screen that is being displayed on display3is a target screen for defining restricted area RA (S301: YES) and the dynamic acceleration detected by acceleration detection module20is greater than the predetermined value (S302: YES), control module11can control imaging module22to activate the in-camera (S303). Control module11can perform a face detection process (S304), and determine whether or not a face has been photographed by the in-camera (S305).

As a user's face is directed to face portable phone1, the face will be photographed by the in-camera. In this case, it is likely that the user is using portable phone1, and in other words, portable phone1is being operated. Thus, in the case where control module11determines that the face is being photographed by the in-camera (S305: YES), control module11can stop the in-camera (S306), and end the restricted area defining process. Thereby, restricted area RA will not be defined within touch panel4.

On the other hand, in the case where the face is not being photographed by the in-camera, it is likely that the user is not using portable phone1. If the user is not using portable phone1, there is no possibility that portable phone1is operated. Thus, in the case where control module11determines that the face is not being photographed by the in-camera (S305: NO), control module11can define restricted area RA within touch panel4(S307).

Control module11can perform the face detection process (S308), and determine whether or not a face has been photographed by the in-camera (S309). In the case where a face is not being photographed by the in-camera (S309: NO), control module11can determine whether or not a predetermined time has elapsed (S310). After the predetermined time has elapsed (S310: YES), control module11can release restricted area RA (S311).

Unless the predetermined time has elapsed (S310: NO), control module11can repeat the processing from step S308and step S309.

In the case where a face is being photographed by the in-camera, it is likely that the user has started to use portable phone1. In the case where control module11determines that a face is being photographed before the predetermined time has elapsed (S309: YES), control module11can unlock restricted area RA without waiting for the predetermined time to elapse (S311).

After releasing restricted area RA (S311), control module11can stop the in-camera (S312), and end the restricted area defining process.

As mentioned in the above, according to the present modification, restricted area RA is defined in the case where portable phone1is considered as not being used. Therefore, it is possible to further suppress the deterioration in the operability of portable phone1.

Further, according to the present modification, after restricted area RA is defined, when it is considered that the use of portable phone1is started again, restricted area RA is released without waiting for the predetermined time to elapse. Therefore, it is possible to further suppress the deterioration in the operability of portable phone1.

It is acceptable that the restricted area defining process of the present modification is further modified in such a manner that the processing from step S308and step S309is dispensed so that no face detection will be performed after restricted area RA is defined.

FIG. 9is a block diagram illustrating the overall configuration of portable phone1according to a second modification.

As illustrated inFIG. 9, portable phone1of the present modification can include an illuminance detection module23in addition to the configurations of the abovementioned embodiment.

Illuminance detection module23can include an illuminance sensor. Illuminance detection module23is configured to detect the environmental brightness of portable phone1by using the illuminance sensor, and output to control module11a detection signal in accordance with the detected illuminance. Although not shown in the drawings, the illuminance sensor may be arranged, for example, at the right side relative to conversation speaker6with a sensing component thereof exposed to the outside.

FIG. 10is a flow chart illustrating a restricted area defining process according to the second modification. Hereinafter, the description will be carried out on the restricted area defining process of the present modification with reference toFIG. 10.

In the case where a screen that is being displayed on display3is a target screen for defining restricted area RA (S401: YES) and the dynamic acceleration detected by acceleration detection module20is greater than the predetermined value (S402: YES), control module11can control illumination detection module23to detect the illuminance (S403). Control module11is configured to determine whether or not the detected illuminance is significantly lower than a predetermined amount based on a comparison between the currently detected illuminance and a previously detected illuminance stored in memory module12(S404). The predetermined amount may be obtained in such a manner that the changes in the illuminance occurred when putting portable phone1into a bag or the like are measured in experiments, for example, and the predetermined amount is derived from the measured values.

In the case where the user is using portable phone1, normally it is unlikely that the outer environment of portable phone1suddenly becomes dark, causing the illuminance to decrease significantly. Thus, in the case where the illuminance is determined not to be significantly lower than the predetermined amount (S404: NO), control module11can store the currently detected illuminance in memory module12(S405) and end the restricted area defining process. Thereby, restricted area RA will not be defined within touch panel4.

In the case where the illuminance detection is performed for the first time and thus there is no previously detected illuminance stored in memory module12, control module11can determine that the illuminance is not significantly lower than the predetermined amount at step S404.

On the other hand, in the case where the user stops using portable phone1and puts it back into a pocket or a bag, the outer environment of portable phone1suddenly becomes dark, causing the illuminance to decrease significantly. Thus, in the case where the illuminance is determined to be significantly lower than the predetermined amount (S404: YES), control module11can define restricted area RA within touch panel4(S406).

After storing the detected illuminance in memory module12at step S403(S407), control module11can detect the illuminance again (S408). Control module11is configured to determine whether or not the detected illuminance is significantly greater than the predetermined amount based on a comparison between the currently detected illuminance and a previously detected illuminance stored in memory module12(S409). In the case where the illuminance is not significantly greater than the predetermined amount (S409: NO), control module11can determine whether or not a predetermined time has elapsed (S410). In the case where the predetermined time has elapsed (S410: YES), control module11can release restricted area RA (S411).

Unless the predetermined time has elapsed (S410: NO), control module11can repeat the processing from step S407to step S409.

In the case where the user takes portable phone1out of a bag or the like and starts to use portable phone1, the outer environment of portable phone1suddenly becomes bright, causing the illuminance to increase significantly. In the case where control module11determines that the illuminance is significantly greater than the predetermined amount before the predetermined time has elapsed (S409: YES), control module11can release restricted area RA without waiting for the predetermined time to elapse (S411).

After releasing restricted area RA (S411), control module11can end the restricted area defining process.

Thus, according to the present modification, restricted area RA is defined in the case where portable phone1is considered as not being used. Therefore, it is possible to further suppress the deterioration in the operability of portable phone1.

Further, according to the present modification, after restricted area RA is defined, when it is considered that the use of portable phone1is started again, restricted area RA is released without waiting for the predetermined time to elapse. Therefore, it is possible to further suppress the deterioration in the operability of portable phone1.

It is acceptable that the restricted area defining process of the present modification is further modified in such a manner that the processing from step S407to step S409is dispensed so that no illuminance detection will be performed after restricted area RA is defined.

FIG. 11is a block diagram illustrating the overall configuration of portable phone1according to a third modification.

In the present modification, the processing from step S111and step S112is added to the restricted area defining process illustrated inFIG. 5A.

The present modification is different from any of the abovementioned embodiments in that acceleration detection module20is not configured to work constantly while portable phone1is in operation. In the present modification, the acceleration sensor of acceleration detection module20operates in accordance with the remaining battery amount of portable phone1.

As illustrated inFIG. 11, control module11, after determining that a screen being displayed on display3is a target screen for defining restricted area RA (S101: YES), determines whether or not the remaining battery amount is greater than a predetermined amount (20% for example) (S111).

In the case where the remaining battery amount is determined to be greater than the predetermined amount (S111: YES), control module11can control acceleration detection module20to activate the acceleration sensor so as to detect the dynamic acceleration (S112). After the detection of the dynamic acceleration, control module11can stop the acceleration sensor. On the other hand, in the case where the remaining battery amount is not more than the predetermined amount (S111: NO), control module11can end the restricted area defining process without activating the acceleration sensor.

According to the present modification, since the acceleration sensor will not be activated when the remaining battery amount is low, it is possible to suppress the power consumption when the battery is running low. Thereby, it is possible to reserve the electric power for performing primary functions such as making a call or the like.

The configuration of the present modification can also be applied to the first modification and the second modification.

In any of the above embodiments, the width of restricted area RA is not particularly limited in both the vertical direction and the lateral direction. However, as mentioned in the above, the widths W1and W2of the respective left and right frames may be configured narrower than the widths W3and W4of the upper and lower frames. As such, when portable phone1is being held, it is easier for a finger to touch the central part of touch panel4from the left and right edges than from the upper and lower edges thereof. Thus, as illustrated inFIG. 12(a), restricted area RA may be configured to have the right and left widths W5and W6wider than the upper and lower widths W7and W8. Furthermore, frame member2amay be configured to have the width W4of the lower frame narrower than the width W3of the upper frame. Thus, as illustrated inFIG. 12(b), restricted area RA may be configured to have the left and right widths W5and W6wider than the upper and lower widths W7and W8, and the lower width W8wider than the upper width W7.

In the case where the width W3of the upper frame is sufficiently wide for a user to hold portable phone1and thereby it is unlikely for a finger to touch the upper edge of touch panel4, as illustrated inFIG. 12(c), restricted area RA may be configured to dispense the upper area. Similarly, in the case where the widths W3, W4of the upper and lower frames are sufficiently wide for a user to hold portable phone1, as illustrated inFIG. 12(d), restricted area RA may be configured to dispense the upper and lower areas. In other words, restricted area RA is not necessarily to be provided surrounding the entire periphery of the inner peripheral edge of touch panel4, and may be provided along at least a part of the inner peripheral edge of touch panel4.

Thus, restricted area RA can be provided in accordance with the width of each frame of frame member2a, which makes it possible to further suppress the deterioration in the operability of portable phone1.

In addition, portable phone1may be configured to have restricted area RA visibly displayed on display3, making the user aware of the presence of such area that the touch operation will be restricted therein.

In any of the above embodiments, it is configured that all of the touch operations are invalidated in restricted area RA, but it is acceptable to invalidate some types of touch operations such as some tap operations or some longer tap operations which may readily result in erroneous operations due to accidental finger touches on touch panel4.

In any of the above embodiments, the present disclosure is applied to a portable phone represented by a smartphone but not limited thereto, the present disclosure may be applied to any other types of portable phones such as a bar phone, a flip phone, a slider phone and the like.

Furthermore, the present disclosure may be applied to various portable devices such as a PDA (Personal Digital Assistant), a tablet PC, an e-book terminal, a portable music player, a portable television and a portable navigation system without being limited to a portable phone.

Although embodiments of the present disclosure has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation. Any embodiment may be modified within the scope of the present disclosure interpreted by the terms of the appended claims.