JP4811861B2 - Display terminal device - Google Patents

Description

  The present invention relates to a display terminal device, and more particularly, to an improvement in a display terminal device such as a mobile phone that controls a viewing angle of a display screen on which various types of information are displayed to suppress peeping. In particular, the present invention relates to a display terminal device that improves the confidentiality of screen display when a viewing angle is controlled using a liquid crystal panel different from a liquid crystal panel that displays information.

  In recent years, as an example of a display terminal device, mobile phones having various functions such as transmission / reception of e-mails, browsing of websites, management of schedules, and the like have become widespread. In this type of mobile phone, personal information of the user is often displayed on the screen, and thus it is necessary to improve the confidentiality when the user views the display screen.

Therefore, a technique for narrowing the viewing angle of the display screen as necessary has been proposed (for example, Patent Document 1). The portable terminal device described in Patent Document 1 includes a display device that displays information and a liquid crystal panel for viewing angle control provided on a display surface of the display device, and displays by changing the orientation of the liquid crystal in the liquid crystal panel. The viewing angle of the surface is narrowed. Patent Document 2 describes a liquid crystal display device that increases the luminance of a backlight in order to suppress deterioration in image quality caused by viewing angle control that narrows the viewing angle of a display screen.
JP 2004-62094 A JP 2001-147673 A

  In general, in a display terminal device such as a mobile phone, the screen display tends to have high contrast and the display screen illumination tends to have high brightness from the viewpoint of improving the visibility of the screen display. For this reason, it is difficult to completely prevent peeping on a screen display in a conventional display terminal device that attempts to suppress peeping by narrowing the viewing angle using a liquid crystal panel for viewing angle control. There was a problem. In other words, despite the narrowing of the viewing angle of the display screen, the screen display can be seen through the viewing angle control liquid crystal panel, and the display content can be identified even outside the viewing angle. There was a problem that.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a display terminal device that improves the confidentiality of screen display when the viewing angle is controlled using a liquid crystal panel for viewing angle control. It is said. In particular, even when a high-contrast screen display is performed, a viewing angle control liquid crystal panel that is different from a liquid crystal panel that displays information despite being out of the viewing angle when the viewing angle is narrowed. An object of the present invention is to provide a display terminal device that suppresses the screen display from being seen through.

A display terminal device according to the present invention controls a liquid crystal panel that displays information on a display screen, a backlight that emits light from the back side to the display screen of the liquid crystal panel, and a viewing angle of the display screen. A viewing angle control means for switching between a wide viewing mode for viewing the display screen at a wide viewing angle and a narrow viewing mode for viewing the display screen at a narrow viewing angle; and a backlight control means for controlling the backlight. Based on the angle switching instruction, the viewing angle control means switches from the wide viewing mode to the narrow viewing mode, and the backlight control means reduces the brightness of the backlight, thereby reducing the viewing angle and the viewing angle. It is configured to make the display screen appear darker than the wide-viewpoint mode for the out-of-corner viewpoint .

In this display terminal device, switching from the wide viewing mode to the narrow viewing mode is performed based on the viewing angle switching instruction, and the luminance of the backlight that irradiates the liquid crystal panel with light is changed . With such a configuration, the backlight brightness mode is automatically switched in conjunction with the switching of the viewing mode. In the narrow viewing mode, the backlight brightness is reduced, so the screen display on the LCD panel display screen is reduced. Contrast can be reduced.

  In addition to the above configuration, the display terminal device according to the present invention includes image display means for displaying a photographed image on the display screen of the liquid crystal panel. When the mode is switched, the backlight brightness is set to the low brightness mode in conjunction with the switching of the visual field mode, and the backlight low brightness mode is canceled while the captured image is displayed. In this display terminal device, the luminance of the backlight is set to the low luminance mode in conjunction with the switching of the viewing mode, and the low luminance mode is canceled while the captured image is displayed. According to such a configuration, since the low-brightness mode of the backlight is canceled while the captured image is displayed, it is possible to suppress a decrease in contrast of the captured image in the narrow field mode. In particular, in the case of a color image, the color reproducibility of the subject in the captured image can be improved.

  In addition to the above configuration, the display terminal device according to the present invention includes display restriction information storage means for storing display restriction information indicating whether or not the screen display is secret data in association with user data, and Display mode designation information storage means for rewritably storing display mode designation information for designating any one of a non-secret mode in which secret data is not displayed by display restriction information and a secret mode in which secret data is to be displayed, and the display mode designation described above Application execution means for selecting user data to be displayed based on the information and displaying the user data on a screen, and the backlight control means sets the backlight brightness to the low brightness mode during the secret mode. Configured. According to such a configuration, by specifying user data with high secrecy as secret data in advance, the user data is appropriately displayed according to the non-secret mode in which the secret data is not displayed and the secret mode to be displayed. Can be displayed. Here, data stored in the terminal based on an operation input by the user is referred to as user data. During the secret mode for displaying such secret data, the viewing angle is set to the narrow viewing mode and the backlight luminance is set to the low luminance mode, thereby effectively improving the confidentiality of the screen display. it can.

  According to the display terminal device of the present invention, the wide viewing mode and the narrow viewing mode are switched to each other based on the viewing angle switching instruction, and the backlight brightness is automatically changed. Since the brightness of the light is reduced, the contrast of the screen display on the display screen of the liquid crystal panel can be reduced. Therefore, even when a high-contrast screen display is performed, the screen display is performed via a viewing angle control liquid crystal panel that is different from the liquid crystal panel that displays information despite being out of the viewing angle in the narrow viewing mode. Can be suppressed, and the concealment of the screen display can be effectively improved when the viewing angle is controlled using the viewing angle control liquid crystal panel.

Embodiment 1 FIG.
1A and 1B are external views showing an example of a display terminal device according to Embodiment 1 of the present invention, in which a mobile phone 1 is shown as an example of a display terminal device. The mobile phone 1 is a so-called foldable mobile phone, in which a display housing 100 and an operation housing 200 are connected via a hinge part 300, and are folded with one surface of the display housing 100 and the operation housing 200 facing each other. be able to. FIG. 1A shows a state of a terminal state in which both housings are expanded, and FIG. 1B shows a state of a folded terminal state.

  In the display housing 100, a main display 101 and a receiver 103 are disposed on the inner housing surface when folded, and a sub display 102 and a camera 104 are disposed on the outer housing surface. In the operation housing 200, various operation keys 201, a “field-of-view switching” key 202, and a transmission microphone 203 are arranged on the inner housing surface when folded.

  Such a foldable mobile phone 1 can be carried in a compactly folded state, and if both housings are unfolded, the operation key 201 can be pressed while viewing the display on the main display 101. . That is, main information display is performed using the main display 101, and main operation input is performed using the operation keys 201.

  The main display 101 has a display screen having a vertically long rectangular shape, and various information including personal information is displayed in the display screen. In order to prevent such a display from being viewed by a third party, the main display 101 can variably control the viewing angle in the left-right direction.

  Specifically, by operating the “view switching” key 202, a wide viewing mode as an operation state for browsing the display screen with a wide viewing angle and a narrow viewing mode as an operation state for browsing the display screen with a narrow viewing angle are operated. Can be switched. In general, the main display of a mobile phone has a smaller display area than a television receiver or a stationary information terminal device, and the positional relationship between the user's eyes and the display screen is generally small because it is used in a hand. Since it is constant, it is suitable for viewing angle control. Further, since the cellular phone is used with the main display standing to some extent, the peeping can be effectively prevented by narrowing the viewing angle in the left-right direction.

  In the present embodiment, control for switching the luminance of the main display 101 is performed in conjunction with such switching of the visual field mode in order to further improve the confidentiality of the screen display in the narrow visual field mode.

  In this embodiment, an example in which the viewing angle control is performed on the main display 101 will be described, but it is needless to say that the same viewing angle control can be applied to the sub display 102. In this embodiment, an example in which the viewing angle in the left-right direction is variably controlled will be described, but similarly, the viewing angle in the up-down direction can be variably controlled.

  FIG. 2 is a cross-sectional view showing a configuration example of a main part of the mobile phone of FIG. 1, and shows a state of the main display 101 cut along line AA. The main display 101 includes a viewing angle control liquid crystal panel 2 and a display device 5. The display transmission surface of the viewing angle control liquid crystal panel 2 is disposed on the display screen of the display device 5, and the viewing angle control liquid crystal panel 2 switches the viewing angle of the display transmission surface, whereby the main display 101. The viewing angle can be switched.

  The display device 5 is a known display device including the display liquid crystal panel 3 and the backlight 4. In the liquid crystal panel for display (first liquid crystal panel) 3, a liquid crystal 34 is sealed between two insulating transparent substrates (for example, glass substrates) 32a and 32b. Further, polarizing plates 31a and 31b are disposed on the outer surfaces of the substrates 32a and 32b, respectively, and transparent electrodes (for example, ITO electrodes) 33a and 33b are disposed on the inner surfaces, respectively. For example, in the case of a general TFT display device, a common electrode is formed as the front electrode 33a, and a large number of pixel electrodes are formed as the back electrode 33b.

  The backlight 4 is a light source device that supplies light from the back side to the transmissive display liquid crystal panel 3. Here, the backlight 4 is made of a light emitting element such as an LED (Light Emitting Diode), and when the display surface of the display liquid crystal panel 3 is irradiated with light, the entire display surface is uniformly illuminated. Shall be able to. The display liquid crystal panel 3 displays characters and images by controlling the potential of each pixel electrode and controlling whether or not the incident light from the backlight 4 is transmitted for each pixel. That is, an area on the substrate 32b where the pixel electrode is arranged becomes a display area, and information including characters and figures is displayed by changing the light transmittance according to the position in the display area.

  On the other hand, the viewing angle control liquid crystal panel (second liquid crystal panel) 2 realizes variable control of the viewing angle by varying the transmittance according to the traveling direction of light. A region through which light from the display device 5 is transmitted, that is, a region on the viewing angle control liquid crystal panel 2 corresponding to the display area of the display device 5 is referred to as a display transmission surface.

  In this viewing angle control liquid crystal panel 2, a liquid crystal 24 is sealed between two insulating transparent substrates (for example, glass substrates) 22a and 22b, and a polarizing plate 21 is disposed on the outer surface of the front substrate 22a. ing. Transparent electrodes (for example, ITO electrodes) 23a and 23b are disposed on the inner surfaces of the substrates 22a and 22b, respectively. That is, if the polarizing plate 31 a of the display liquid crystal panel 3 is added, the configuration is the same as that of the display liquid crystal panel 3.

  The polarizing plates 21 and 31a are arranged so that their transmission axes coincide with each other, and the incident light from the display liquid crystal panel 3 has a viewing angle as long as the polarization plane (also referred to as a deflection plane) does not change in the liquid crystal 24. The liquid crystal panel 2 for control can be transmitted. In the liquid crystal 24, the polarization plane of the transmitted light rotates in accordance with the angle formed by the optical axis of the transmitted light with the front direction, so that the incident light traveling obliquely in the liquid crystal 24 toward the outside of a predetermined viewing angle. Is blocked at the polarizing plate 21.

  The viewing angle control liquid crystal panel 2 changes the viewing angle in the left-right direction of the display screen by controlling the potential of the transparent electrodes 23 a and 23 b and controlling the orientation of the liquid crystal 24.

  3 (a) and 3 (b) are diagrams showing an operation example by the mobile phone of FIG. 1. FIG. 3 (a) shows a main display having a wide viewing angle from a viewpoint within a viewing angle in the wide viewing mode. 3B shows an image when the main display with a narrow viewing angle is viewed from a viewpoint outside the viewing angle in the narrow viewing mode.

  In the wide viewing mode, the viewing angle of the display screen is widened, so that the screen display can be viewed even from a certain oblique direction. The wide viewing mode is a viewing mode that reproduces the original viewing angle of the display device, and is used for normal information display. On the other hand, when the visual field mode is switched to the narrow visual field mode by the user operating the “visual field switching” key, the visual field angle of the display screen is narrowed. This narrow visual field mode is used when displaying specific information that is not desired to be seen by others, and is in a state where the visible range of the screen display is reduced. If the “view switching” key is operated again in the narrow viewing mode, the narrowing of the viewing angle is canceled and the wide viewing mode is set.

  In the wide viewing mode (wide viewing angle), if the main display is viewed from the viewpoint within the viewing angle, it is natural that the screen display can be viewed well. Similarly, even in the narrow viewing mode, the screen display can be viewed well if the main display is viewed from the viewpoint within the viewing angle. On the other hand, in the narrow viewing mode (narrow viewing angle), the viewing angle is within the viewing angle in the wide viewing mode, but in the narrow viewing mode, if the main display is viewed from the viewpoint that is outside the viewing angle, (b) in FIG. As shown, the contrast of the original screen display is low, and the display contents are not easily identified.

  However, when a high-contrast screen display is performed, the screen display can be seen through the viewing angle control liquid crystal panel despite the fact that the viewing angle of the display screen is narrowed. Even if it exists, the display content can be identified. Therefore, in the present embodiment, the brightness of the backlight is changed in accordance with the switching of the viewing mode, and the brightness is reduced in the narrow viewing mode. As a result, even when a high-contrast screen display is performed, the entire screen becomes darker and the contrast of the screen display decreases. Thus, it is possible to prevent the screen display from being seen through, and it is possible to make the display content difficult to read.

  FIG. 4 is a block diagram showing an example of the internal configuration of the mobile phone shown in FIG. The cellular phone 1 includes an operation input unit 11, a viewing angle switching unit 12, a viewing angle control liquid crystal panel 2, a backlight control unit 13, a backlight 4, a display control unit 14, and a display liquid crystal panel 3. The operation input unit 11 performs an operation of generating an input signal based on the operation of the operation key. The display control unit 14 drives the display liquid crystal panel 3 based on an operation input by the user and performs an operation of displaying information on the display screen.

  The viewing angle switching unit 12 performs an operation of switching the viewing mode based on an operation input by the user. Specifically, the wide viewing mode and the narrow viewing mode are switched by changing the voltage applied to the viewing angle control liquid crystal panel 2 and switching the orientation of the liquid crystal in the liquid crystal panel.

  The backlight control unit 13 drives the backlight 4 based on the operation input by the user and the terminal state, and performs control to change the luminance of the backlight 4 based on the switching of the visual field mode when the backlight 4 is turned on. ing. Specifically, a high luminance mode in which the backlight 4 is lit at a high luminance and a low luminance mode in which the backlight 4 is lit at a low luminance are switched in conjunction with the switching of the visual field mode. Control is performed.

  Here, if the visual field mode is switched to the narrow visual field mode while the backlight 4 is lit, the luminance of the backlight 4 is lowered in accordance with the switching of the visual field mode, and the low luminance mode is switched until the visual field mode is switched again. Shall be assumed. Further, when the backlight 4 is turned on during the narrow field mode, the backlight 4 is turned on in the low luminance mode, and the low luminance mode is set until the backlight 4 is turned off.

  In addition, the brightness of the backlight 4 in the high brightness mode, that is, the brightness of the display screen is adjustable. For example, the output range of the backlight 4 is divided into a plurality of luminance levels, and one of the luminance levels is selected according to the user's preference. In the low luminance mode, the lowest luminance level among the plurality of divisions is assumed regardless of the luminance level selected and designated by the user.

  Steps S101 to S112 in FIG. 5 are flowcharts illustrating an operation example in the mobile phone in FIG. First, when an instruction (signal) for switching to the narrow viewing mode is input by pressing the “view switching” key, the viewing angle switching unit 12 controls the viewing angle control liquid crystal panel 2 to change the viewing angle of the display screen. The field of view mode is reduced to a narrow field of view mode (steps S101 and S102).

  Next, if the backlight 4 is on, the backlight control unit 13 switches to the low luminance mode by reducing the luminance of the backlight 4 (steps S103 and S104). If the “view switching” key is pressed again after shifting to the low luminance mode, the backlight control unit 13 cancels the luminance reduction and switches the backlight 4 to the high luminance mode (steps S105 and S106). ). Then, the viewing angle switching unit 12 cancels the narrowing of the viewing angle, and the viewing mode shifts to the wide viewing mode (step S107).

  On the other hand, the backlight control unit 13 turns on the backlight 4 with low brightness if the backlight 4 is turned on by an operation input by the user after shifting to the narrow field mode (steps S108 and S109). When the backlight 4 is turned off after the backlight 4 is turned on, the backlight 4 is turned off (steps S110 and S111).

  When the “view switching” key is pressed after the backlight 4 is turned off, the viewing angle switching unit 12 cancels the narrowing of the viewing angle and sets the viewing mode to the wide viewing mode (steps S112 and S107).

  In step S110, if the backlight 4 is not turned off after the backlight 4 is turned on with low brightness, the processing from step S105 to step S107 is performed. In step S108, if the backlight 4 is not turned on after shifting to the narrow field mode, the narrow field mode is maintained until the “field switching” key is input, and the “field switching” key is pressed. Then, the narrowing of the viewing angle is released, and the viewing mode shifts to the wide viewing mode (steps S112 and S107).

  According to the present embodiment, the luminance mode of the backlight 4 is automatically switched in conjunction with the switching of the visual field mode, and the luminance of the backlight 4 is reduced in the narrow visual field mode. The contrast of the screen display on the display screen can be reduced. Therefore, even when a high-contrast screen display is performed, it is possible to prevent the screen display from being seen through the viewing angle control liquid crystal panel 2 even though it is outside the viewing angle. The confidentiality of display can be effectively improved.

  In the present embodiment, an example in which the luminance mode of the backlight 4 is switched in accordance with the switching of the visual field mode has been described, but the present invention is not limited to this. For example, when a specific application program is launched in the narrow field mode, the luminance mode of the backlight 4 may be switched in conjunction with the program launch.

  Specifically, when user authentication is performed at the time of activation, an application program that allows activation only when the authentication is successful is designated in advance by the user, and when such an application program is launched after user authentication, the program The brightness mode is switched to the low brightness mode in accordance with the start-up. In this way, since the brightness of the backlight 4 is reduced in accordance with the activation of the application program by specifying in advance an application program that performs screen display with high confidentiality, Can be effectively prevented.

Embodiment 2. FIG.
In the first embodiment, an example in which the luminance mode of the backlight is switched in conjunction with the switching of the visual field mode has been described. On the other hand, in this embodiment, the visual field mode is switched to the narrow visual field mode based on the startup of an application program that requires user authentication at startup, and the luminance mode is switched to the low luminance mode in accordance with the switching of the visual field mode. The case will be described.

  FIG. 6 is a block diagram showing an example of a display terminal device according to Embodiment 2 of the present invention, and shows the internal configuration of the mobile phone 40. The mobile phone 40 is different from the mobile phone 1 of FIG. 4 in that it includes a user authentication unit 41, an application execution unit 42, and a program storage unit 43. In the mobile phone 40 according to the present embodiment, the viewing mode is automatically changed from the wide viewing mode to the narrow viewing mode in conjunction with the start of a specific application program in order to effectively prevent peeping of the screen display. In addition to switching, an operation of switching the luminance mode from the high luminance mode to the low luminance mode is performed.

  Specifically, user authentication is performed at the time of activation, and an application program that permits activation only when the authentication is successful is designated in advance by the user. Here, the application program whose activation is restricted in this way is called a PIM (Personal Information Manager) lock target application, and is distinguished from other application programs (non-PIM lock target applications). When such a PIM lock target application is launched after user authentication, the viewing angle of the display screen is narrowed and the luminance of the backlight 4 is lowered.

  The user authentication unit 41 performs user authentication based on an instruction from the application execution unit 42. Here, a method of performing authentication by inputting a password (identification code) such as a personal identification number is used.

  The program storage unit 43 is a non-volatile memory that stores a plurality of different application programs 43a that realize various functions, such as an application program that performs screen display. For example, a browser that accesses a web server on a communication network such as the Internet and displays various contents provided via the web server on the screen is stored as the application program 43a. In addition, a Java (trademark or registered trademark) application provided via a web server, an application for displaying a moving image such as an animation, an application for operating a camera and displaying a captured image on the screen, and the like are stored as the application program 43a. The

  In the program storage unit 43, data necessary for executing the application program 43a is also stored. In such a program storage unit 43, a lock designation flag 43b indicating whether or not the application is a PIM lock target application is stored in a rewritable manner in association with each application program 43a.

  The application execution unit 42 starts up and executes the application program 43 a based on an input signal from the operation input unit 41. The application program 43a is started based on the lock designation flag 43b. That is, in the case of an application program (PIM lock target application) designated in advance as a PIM lock target, user authentication is instructed and the program is started up and executed only when the authentication is successful. On the other hand, in the case of a non-PIM lock target application, it is immediately started up and executed.

  The viewing angle switching unit 12 narrows the viewing angle of the display screen based on the startup of the PIM lock target application, and sets the viewing mode to the narrow viewing mode until the PIM lock target application is terminated. The backlight control unit 13 reduces the luminance of the backlight 4 in conjunction with such switching of the visual field mode, and sets the luminance mode to the low luminance mode.

  In general, it is desirable to perform user authentication from the viewpoint of improving safety when starting an application program that displays a highly confidential screen. By specifying such an application program as a PIM lock target in advance, the viewing angle of the display screen is narrowed and the luminance of the backlight 4 is reduced during execution of the application program. Therefore, the confidentiality of the screen display can be effectively improved.

Embodiment 3 FIG.
In the first embodiment, an example in which the luminance mode of the backlight is switched in conjunction with the switching of the visual field mode has been described. On the other hand, in the present embodiment, a case will be described in which the luminance mode of the backlight is switched in conjunction with the switching of the visual field mode and the luminance reduction is canceled based on the screen display of the captured image.

  FIG. 7 is a block diagram showing an example of a display terminal device according to Embodiment 3 of the present invention, in which the internal configuration of the mobile phone 50 is shown. This cellular phone 50 differs from the cellular phone 1 of FIG. 4 in that it includes a captured image storage unit 52 and an imaging unit 53. In the mobile phone 50 according to the present embodiment, the luminance mode of the backlight 4 is switched in conjunction with the switching of the visual field mode in order to prevent peeping on the screen display without reducing the contrast of the captured image, and the imaging is performed. When the image is displayed on the screen, an operation for canceling the low luminance is performed.

  The imaging unit 53 is a camera that shoots a subject and generates image data. The generated image data is stored in the captured image storage unit 52. Here, pixel data including luminance data and color difference data is generated as image data. That is, a color image is generated as a captured image. The display control unit 51 performs an operation of displaying such a captured image on the display screen of the display liquid crystal panel 3 based on a user operation.

  The backlight control unit 13 performs an operation of switching the luminance mode of the backlight 4 based on the switching of the visual field mode and canceling the luminance reduction based on the screen display of the captured image. Specifically, when the captured image is displayed on the display screen in the narrow-field mode, the lowering of the luminance of the backlight 4 is released in conjunction with the screen display, and the luminance mode is changed to the high luminance mode. Transition. That is, even if the viewing mode is the narrow viewing mode, the high brightness mode is set while the captured image is displayed, and the contrast of the captured image is prevented from being lowered.

  According to the present embodiment, the reduction in brightness of the backlight 4 is canceled during display of the captured image, so that it is possible to prevent a decrease in contrast of the captured image in the narrow field mode. In particular, when viewing the screen display of a captured image within the viewing angle in the narrow field mode, the confidentiality of the screen display can be improved without reducing the color reproducibility of the subject in the screen display.

Embodiment 4 FIG.
In the first embodiment, an example in which the luminance mode of the backlight is switched in conjunction with the switching of the visual field mode has been described. In contrast, in the present embodiment, a case will be described in which the visual field mode is switched in conjunction with the switching of the display mode, and the luminance mode is switched in accordance with the switching of the visual field mode.

  FIG. 8 is a block diagram showing an example of a display terminal device according to Embodiment 4 of the present invention, in which the internal configuration of the mobile phone 60 is shown. Compared with the mobile phone 1 of FIG. 4, the mobile phone 60 includes a user authentication unit 41, a display mode switching unit 61, a display mode designation flag storage unit 62, an application execution unit 63, and a data storage unit 64. It is different. In the cellular phone 60 according to the present embodiment, when the display mode is switched to the secret mode in order to effectively prevent the peeping of the screen display, the viewing mode is switched from the wide viewing mode to the narrow viewing mode, and the luminance mode is switched. Is switched from the high luminance mode to the low luminance mode.

  The user authentication unit 41 performs user authentication based on an instruction from the display mode switching unit 61. Here, a method of performing authentication by inputting a password (identification code) such as a personal identification number is used.

  The display mode switching unit 61 performs an operation of switching the display mode to either the secret mode or the non-secret mode. The display mode is switched based on an operation input by the user. When switching from the non-secret mode to the secret mode, the user authentication unit 41 is instructed to perform user authentication.

  The secret mode is a display mode that displays all user data including specific user data, and the non-secret mode is a display mode that does not display the specific user data (hereinafter referred to as secret data). is there. Here, data stored in the terminal based on an operation input by the user is referred to as user data.

  Switching to the secret mode is permitted only when the user authentication is successful, and when the user authentication fails, the secret mode is not switched. The secret data is displayed only in such a secret mode, and is not displayed in the non-secret mode. That is, in order to display secret data, since it is necessary to succeed in user authentication, the confidentiality of specific user data (secret data) is maintained.

  Here, when the display mode is switched from the non-secret mode to the secret mode, the display mode designation flag is turned on. When the display mode is switched from the secret mode to the non-secret mode, the display mode designation flag is turned off. The display mode designation flag is display mode designation information indicating whether the display mode is a secret mode or a non-secret mode, and is stored in the display mode designation flag storage unit 62 in a rewritable manner. That is, whether or not the display mode of the main display is the secret mode is determined by whether or not the display mode designation flag is in an on state.

  The application execution unit 63 performs an operation of executing an application based on an input signal from the operation input unit 11. The application execution unit 63 selects user data to be displayed based on the display mode designation flag and displays the user data on the screen. Specifically, with reference to the display mode designation flag in the display mode designation flag storage unit 62, if the display mode designation flag is in an on state, all user data to be processed are set as display targets. On the other hand, if the display mode designation flag is in the OFF state, each user data excluding the secret data among all the user data is displayed. That is, when the display mode designation flag is in an off state, specific user data designated in advance as secret data is not displayed on the screen.

  As such an application, for example, a list of user data registered in advance as phone book data is displayed on the display screen, and new phone book data is registered or registered contents are changed. In addition, it is possible to display user data registered in advance as schedule data on the display screen and to register new schedule data or change registered contents.

  The data storage unit 64 is a non-volatile memory that stores a plurality of user data 64a to be processed by an application. In the data storage unit 64, a display restriction designation flag 64b is stored in a rewritable manner in association with each user data 64a as display restriction information indicating whether or not the screen display is secret data. Here, it is assumed that whether or not the user data associated with the flag is secret data is determined based on whether or not the display restriction designation flag 64b is on.

  When the display mode is switched to the secret mode, the viewing angle switching unit 12 performs an operation of switching the viewing mode from the wide viewing mode to the narrow viewing mode based on the switching of the display mode. The backlight control unit 13 reduces the luminance of the backlight 4 in conjunction with such switching of the visual field mode, and sets the luminance mode to the low luminance mode. That is, during the secret mode, the viewing angle is narrowed and the luminance of the backlight 4 is reduced.

  According to the present embodiment, by specifying user data with high confidentiality as secret data in advance, the viewing angle of the display screen is automatically adjusted in conjunction with switching to the secret mode for displaying the secret data. The brightness of the backlight 4 is reduced. Therefore, it is possible to effectively improve the confidentiality of the screen display including the secret data and having high confidentiality.

Embodiment 5 FIG.
In Embodiments 1 to 4, a mobile phone has been described as an example of a display terminal device, but the scope of application of the present invention is not limited to a mobile phone. In general, a portable information terminal device such as a mobile phone is suitable for the present invention because it is often used outdoors where it is easy for a third party to look around. However, the scope of the present invention is as follows. It is not limited only to a portable terminal device. That is, any terminal device that is required to prevent peeping by a nearby third party can be applied regardless of whether it is portable or stationary. For example, the present invention can also be applied to a financial terminal device such as an automatic teller machine or an automatic cash lending repayment machine that displays personal information on a screen in an environment where there are others around.

  FIG. 9 is a block diagram showing an example of a display terminal device according to Embodiment 5 of the present invention, and shows an internal configuration of an automatic teller machine 70 as an example of the display terminal device. This automatic teller machine 70 is a so-called ATM (Automatic Teller Machine) and is different from the mobile phone 1 of FIG. 4 in that it includes a main control unit 71, a person detection unit 72, and an ATM unit 73. The ATM unit 73 includes a depositing unit 73a, a dispensing unit 73b, a passbook handling unit 73c, and a card handling unit 73d.

  The main control unit 71 controls the entire automatic teller machine 70. The person detection unit 72 includes an infrared sensor or an ultrasonic sensor, and detects whether or not there is a person in front of the automatic teller machine 70. The depositing unit 73a is a mechanism for receiving deposit of bills or coins. The withdrawal unit 73b is a mechanism for dispensing banknotes or coins. The bankbook handling unit 73c performs processing for printing the transaction contents on the customer's bankbook. The card handling unit 73d is a card reader / writer for reading data from a customer's cash card and writing data.

  Steps S201 to S210 in FIG. 10 are flowcharts illustrating an operation example in the automatic teller machine 70 in FIG. In this example, when there is no person in front of the automatic teller machine 70, the backlight 4 is turned off and the display screen is set as a standby screen. When the person detecting unit 72 detects that there is a person in front of the automatic teller machine 70, the backlight control unit 13 turns on the backlight 4 with high luminance to enter the high luminance mode, and also changes the viewing angle switching unit. 12 controls the viewing angle control liquid crystal panel 2 to set the wide viewing mode (steps S201 and S202).

  After that, when an instruction (signal) for switching to the narrow field mode is input by pressing the “field switching” key, the backlight control unit 13 reduces the luminance of the backlight 4 to enter the low luminance mode, When the viewing angle switching unit 12 controls the viewing angle control liquid crystal panel 2 to enter the narrow viewing mode, the viewing angle and the luminance of the backlight 4 are reversed (steps S203 and S204).

  Also, when an operation for inputting a password is performed, an instruction (signal) for switching to the narrow-field mode is input, and the backlight control unit 13 reduces the luminance of the backlight 4 to reduce the luminance mode. In addition, the viewing angle switching unit 12 controls the viewing angle control liquid crystal panel 2 to enter the narrow viewing mode, so that the viewing angle and the luminance of the backlight 4 are reversed (step S205, S206).

  In this case, the low luminance mode and the narrow field mode are maintained until the input of the password is completed. When the input of the personal identification number is completed, the backlight control unit 13 turns on the backlight 4 with high luminance to enter the high luminance mode, and the viewing angle switching unit 12 controls the liquid crystal panel 2 for viewing angle control. By setting the wide viewing mode, the viewing angle and the luminance of the backlight 4 are reversed (steps S207 and S208).

  In this way, while the operation on the automatic teller machine 70 is being performed, the control in steps S203 to S209 is repeated. When the operation on the automatic teller machine 70 is completed and the person detecting unit 72 detects that no person is present in front of the automatic teller machine 70, the backlight 4 is turned off, and the display screen is changed to the standby screen. Is done.

  However, the standby screen is not limited to the configuration in which the backlight 4 is turned off and the power consumption is reduced as in this example, and the backlight control unit 13 turns on the backlight 4 with high luminance and the high luminance mode. In addition, an advertisement display may be performed on the display screen in a state where the viewing angle switching unit 12 controls the viewing angle control liquid crystal panel 2 to enter the wide viewing mode.

  As described above, when the high brightness mode and the wide viewing mode are set while the standby screen is displayed, the backlight control unit 13 is detected when the person detecting unit 72 detects that there is a person in front of the automatic teller machine 70. However, the luminance of the backlight 4 may be lowered to the low luminance mode, and the viewing angle switching unit 12 may control the viewing angle control liquid crystal panel 2 to be in the narrow viewing mode. In this case, the input signal from the person detection unit 72 acts as an instruction (signal) for switching to the narrow field mode.

  Note that the viewing angle switching instruction is not limited to the configuration in which the viewing angle of the display screen is automatically narrowed and the luminance of the backlight 4 is reduced based on the viewing angle switching instruction. In addition, a confirmation screen for confirming to the user whether to change the brightness of the backlight 4 may be displayed on the display screen. In this case, the luminance of the backlight 4 is changed based on an operation for changing the luminance of the backlight 4 by the user.

  Further, based on the viewing angle switching instruction, the display screen viewing angle switching and the luminance change of the backlight 4 are not limited to be performed at the same time. May be performed prior to the other.

BRIEF DESCRIPTION OF THE DRAWINGS It is the external view which showed an example of the display terminal device by Embodiment 1 of this invention, and the mobile telephone 1 is shown as an example of a display terminal device. It is sectional drawing which showed the structural example in the principal part of the mobile telephone of FIG. 1, and the mode of the main display 101 cut | disconnected by the AA line | wire is shown. It is the figure which showed the operation example by the mobile telephone of FIG. FIG. 2 is a block diagram illustrating an example of an internal configuration of the mobile phone in FIG. 1. 3 is a flowchart showing an operation example in the mobile phone of FIG. 1. FIG. 6 is a block diagram showing an example of a display terminal device according to Embodiment 2 of the present invention, and shows an internal configuration of a mobile phone 40; FIG. 5 is a block diagram showing an example of a display terminal device according to Embodiment 3 of the present invention, and shows an internal configuration of a mobile phone 50. FIG. 10 is a block diagram showing an example of a display terminal device according to Embodiment 4 of the present invention, and shows an internal configuration of a mobile phone 60. It is the block diagram which showed an example of the display terminal device by Embodiment 5 of this invention, and the internal structure of the automatic teller machine 70 is shown as an example of a display terminal device. It is the flowchart which showed the operation example in the automatic teller machine 70 of FIG.

Explanation of symbols

1, 40, 50, 60 Mobile phone 2 Viewing angle control liquid crystal panel 3 Display liquid crystal panel 4 Backlight 5 Display device 11 Operation input unit 12 Viewing angle switching unit 13 Backlight control unit 14, 51 Display control unit 21, 31a , 31b Polarizing plates 22a, 22b, 32a, 32b Insulating transparent substrates 23a, 23b, 33a, 33b Transparent electrodes 24, 34 Liquid crystal 41 User authentication unit 42 Application execution unit 43 Program storage unit 43a Application program 43b Lock designation flag 52 Storage unit 53 Imaging unit 61 Display mode switching unit 62 Display mode designation flag storage unit 63 Application execution unit 64 Data storage unit 64a User data 64b Display limit designation flag 70 Automatic teller machine 71 Main control unit 72 Person detection unit 73 ATM unit 73a Deposit Department 7 3b Withdrawal unit 73c Passbook handling unit 73d Card handling unit 100 Display case 101 Main display 102 Sub display 103 Receiver for receiver 104 Camera 200 Operation case 201 Operation key 202 "View switching" key 203 Speaking microphone 300 Hinge part

Claims (3)

A liquid crystal panel for displaying information on the display screen;
A backlight that emits light from the back side to the display screen of the liquid crystal panel;
A viewing angle control means for controlling the viewing angle of the display screen and switching between a wide viewing mode for viewing the display screen at a wide viewing angle and a narrow viewing mode for viewing the display screen at a narrow viewing angle;
A backlight control means for controlling the backlight,
Based on the viewing angle switching instruction, the viewing angle control means switches from the wide viewing mode to the narrow viewing mode, and the backlight control means reduces the brightness of the backlight, thereby reducing the viewing angle and the viewing angle. A display terminal device characterized in that a display screen is viewed darker than a wide viewing mode for a viewpoint outside the viewing angle . Image display means for displaying a photographed image on the display screen of the liquid crystal panel;
When the visual field mode is switched from the wide visual field mode to the narrow visual field mode, the backlight control means sets the backlight luminance to the low luminance mode in conjunction with the switching of the visual field mode. The display terminal apparatus according to claim 1 , wherein the low-brightness mode of the backlight is canceled. Display restriction information storage means for storing display restriction information indicating whether or not screen data is secret data restricted in association with user data;
Display mode designation information storage means for storing rewritable display mode designation information for designating any one of a non-secret mode in which secret data is not displayed by the display restriction information and a secret mode in which secret data is displayed;
Application execution means for selecting user data to be displayed based on the display mode designation information and displaying the user data on a screen;
The display terminal device according to claim 1 , wherein the backlight control means sets the luminance of the backlight to the low luminance mode during the secret mode.

Images