JP4911225B2 - Display system and display method - Google Patents

Description

  The present invention relates to an information display technique for displaying information and preventing leakage of the displayed information.

  In recent years, transactions such as Internet banking and Internet shopping can be performed using an information terminal connected to the Internet, such as a notebook computer, a personal digital assistant (PDA), and a mobile phone. These transactions require individuals to be identified so that only the identified individuals can conduct transactions. In general, personal authentication using a personal authentication character string (including a personal identification number composed only of numerals) is used to identify an individual.

  Transactions using small and portable information terminals are routinely performed in public places such as vehicles such as trains and airplanes and various public facilities. However, in such public places, when a character string is input to an information terminal using a keyboard or a numeric keypad, there is a risk that the personal authentication character string may be seen by others by looking into the terminal. How to conceal the personal authentication character string is an important issue in the future ubiquitous information society.

  In addition, not only the portable information terminal but also a similar problem occurs when using an information terminal installed in a public place. For example, in an ATM (Automatic Teller Machine) used in a bank, a selection key, a numeric keypad, etc. for various services are displayed on an LCD (Liquid Crystal Display) with a touch panel. The user touches the screen according to the display and receives services such as transfer, cash withdrawal, and personal authentication character string change.

  When receiving these services, personal authentication using a personal authentication character string is performed. The user inserts the card into the ATM and inputs a personal authentication character string using the numeric keypad. The user is permitted to use the service only when the entered personal authentication character string matches the personal authentication character string of the card. At the time of this input, there is a risk that the personal authentication character string can be seen by others.

  Various investigations have been made on countermeasures against such personal authentication character strings being known to others. As one of such related techniques, for example, a technique of randomly changing the numeric keypad layout every time the user changes is known (see Japanese Patent Application Laid-Open No. 8-069502 (hereinafter referred to as Document 1)).

  FIG. 1 is a diagram illustrating a display example according to a related technique disclosed in Document 1. In FIG. FIG. 2 is a schematic configuration diagram of an apparatus according to the related art disclosed in Document 1. A related technique described in Document 1 will be described with reference to FIGS.

  In the first embodiment of Document 1, the key information display device generates a random number when the power is turned on, determines a key arrangement from the random number, and displays a numeric keypad (for example, FIG. 1A) on the screen. The first operator inputs a personal authentication character string according to the first displayed numeric keypad and receives, for example, an ATM service. When the service ends, the numeric keypad image returns to the start mode.

  When returning to the start mode, the key information display device again generates a random number to change the arrangement of the numeric keys. When the next operator starts the service, the changed numeric keypad (for example, FIG. 1B) is displayed on the screen. The next operator inputs a personal authentication character string in accordance with the changed numeric keypad.

  According to this technique, since the arrangement of the numeric keys is changed every time the operator changes, it is impossible for another person to infer the personal authentication character string from the movement of the finger of the operator.

  Further, in the numeric keypad information display device according to the second embodiment of Document 1, as shown in FIG. 2, a polarizing plate 40A is disposed above the LCD 3A and away from the LCD 3A. In general, the polarizing plate is disposed on the surface of the LCD, but by disposing the polarizing plate 40A away from the LCD 3A, the display contents of the LCD 3A can be understood only by the operator. Therefore, the other person cannot look into the display screen through the polarizing plate 40A and cannot see the numeric keypad arrangement. By combining this with the first embodiment shown in FIG. 1, the confidentiality of the personal authentication character string can be further improved.

  Further, as another technique related to the secrecy of the personal authentication character string, there is a technique in which the key layout is randomly changed every time one character of the personal authentication character string is input (Japanese Patent Laid-Open No. 2004-102460 (hereinafter referred to as Reference 2) reference). According to this, since the arrangement of the numeric keys is changed for each character, the other person cannot infer the personal authentication character string from the movement of the finger of the operator.

  Further, as a technique for concealing a specific image (for example, a numeric keypad arrangement), there is a technique that combines high-speed switching of an image and opening / closing of an optical shutter (see JP-A-6-110403 (hereinafter referred to as Document 3)). A plurality of images are switched and displayed, and the optical shutter is opened and closed in synchronization with the switching.

  FIG. 3 is a diagram for explaining the related art disclosed in Document 3. As shown in FIG. 3, an image to be originally displayed (normal image 11B) and an image obtained by inverting the normal image 11B (reverse image 12B) are alternately switched at high speed and displayed on the display panel 14B. At the same time, the optical shutter 15B disposed in front of the user's eyes is opened and closed. The opening and closing of the optical shutter 15B is performed in synchronization with image switching so that light is transmitted when the normal image 11B is displayed and light is blocked when the reverse image 12B is displayed.

  By doing so, a user viewing the image through the optical shutter 15B can see the same image 16B as the normal image 11B. On the other hand, the other person who sees the image without passing through the optical shutter 15B sees the halftone (for example, gray) image in which the secret image 11B and the reverse image 12B are superimposed. It cannot be read.

  Another technique for concealing a specific image is to display a secret image in a distributed manner (see Japanese Patent Application Laid-Open No. 2001-255844 (hereinafter referred to as Document 4)).

  FIG. 4 is a diagram for explaining the technique disclosed in Document 4. FIG. FIG. 5 is a diagram for explaining switching of images in the technique disclosed in Document 4. In FIG.

  As shown in FIG. 4, it is assumed that a character “A” that is a secret image (original image) is represented by a plurality of pixels 54C. In the technique of Reference 4, the secret image is distributed over three divided screens 58C, 59C, and 60C as shown in FIG. 5, so that the secret image can be inferred even when the individual divided images 58C, 59C, and 60C are viewed. Make sure you can't.

  Then, the three divided images 58C, 59C, 60C and the masking image are sequentially switched and displayed at a high speed. Further, the optical shutter is opened and closed to transmit light when the divided images 58C, 59C, and 60C are displayed, and to block light when the masking image is displayed. As a result, the secret image can be seen by the user who is viewing the image through the optical shutter, but the secret image cannot be seen by others who are viewing the image without passing through the optical shutter.

  The techniques disclosed in Documents 1 to 4 exhibit certain effects in preventing others from stealing personal authentication information by looking into the user's screen operation and observing the movement of fingers. However, these techniques are vulnerable to methods in which others use a camera or video camera to obtain personal authentication information. In any of the techniques disclosed in any of the documents 1 to 4, the character selected by the finger on the touch panel or the character pointed by the mouse on the screen always matches the character to be input by the user. It is.

  In Document 1 and Document 2, even if the key arrangement changes randomly, if the camera is used to photograph the numeric keypad image displayed on the LCD screen and the finger selecting the key on the LCD screen, Others can easily know the personal authentication character string.

  Reference 2 also shows an example in which the polarizing plate is separated from the apparatus. However, if the polarizing plate is installed in the lens portion of the camera, the other person can know the personal authentication character string.

  In the techniques disclosed in Document 3 and Document 4, it is difficult for others to discriminate the key layout as compared with Document 1 or Document 2 in which the key layout is completely exposed. However, these techniques have similar problems.

  FIG. 6A is a diagram illustrating an example of a typical numeric keypad display according to the technique of Document 3. FIG. 6B is a diagram illustrating an example of a typical numeric keypad display according to the technique of Document 4.

  In FIG. 6A, the numeric keypad layout is displayed as it is as the secret image 51. Although the reverse image 52 has the black and white of the secret image 51 reversed, the display content represents a numeric keypad arrangement. When the input scene of the personal authentication character string is photographed by another person with the camera, if the shutter timing of the camera is entered when the secret image 51 or the reverse image 52 is displayed, the numeric keypad arrangement and the user's finger are together. It will be filmed. As a result, the personal authentication character string is known to others who do not use the optical shutter.

  In FIG. 6B, since the secret image is divided into a plurality of divided images, it is difficult to determine the numeric keypad arrangement as compared with FIG. 6A. FIG. 6B shows an example in which an image is divided in units of keys. However, since one key is actually further divided, it is more difficult to discriminate the numeric keypad arrangement and the numeric keypad characters themselves. However, if the shutter timing of the camera is entered while the divided image or its inverted image is displayed, the divided image or its inverted image is taken by another person, and the numeric keypad arrangement can be inferred from the image. Further, when a plurality of images are continuously photographed by the video camera and these images are synthesized later, the ten key arrangement and the ten keys selected by the finger are known to others.

  In addition, although the example which inputs a character string with a touch panel is explained here, there is a keyboard separately from a display screen, and also when inputting a character string with a keyboard, it is personally authenticated to others using a photography device similarly. Information is acquired. Furthermore, in the case of a keyboard, there is a risk that key press history information will be leaked.

  Nowadays, the sophistication and generalization of photography technology has progressed, and photography equipment has become small and capable of high-speed photography, and mobile phones are also equipped with a function for photographing moving images. Therefore, a technique with high secrecy is demanded even for a method of acquiring personal authentication information using a photographing device such as a camera or a video camera.

  An object of the present invention is to provide a technique for preventing secret information such as a personal authentication character string from being revealed to another person even if the other person looks into the screen or is photographed with a photographing device.

In order to achieve the above object, a display system according to an aspect of the present invention is a display system that displays an image on a screen,
Display information control means for generating a plurality of display information including effective display information to be recognized by the user, and dummy display information of the same type and different content.
Image display control means for displaying the plurality of display information including the effective display information and the dummy display information generated by the display information control means on the screen;
Visual control means for controlling the arrival of light from the image to the user so that only the user can specify the effective display information among the display information displayed on the screen by the image display control means, have.

A display method according to an aspect of the present invention is a display method for displaying an image viewed through an optical shutter on a screen,
Generating a plurality of display information including effective display information to be recognized by the user and dummy display information of the same type and different content from the effective display information;
Displaying the plurality of display information including the effective display information and the dummy display information on the screen;
The arrival of light from the screen to the user is controlled so that only the user can specify the effective display information among the display information displayed on the screen.

10 is a diagram illustrating a display example according to a related technique disclosed in Literature 1. FIG. 1 is a schematic configuration diagram of an apparatus according to related technology disclosed in Document 1. FIG. It is a figure for demonstrating the related art disclosed by literature 3. FIG. 10 is a diagram for explaining a technique disclosed in Document 4. FIG. 10 is a diagram for describing image switching in the technique disclosed in Literature 4. FIG. It is a figure which shows the example of the typical numeric keypad display by the technique of the literature 3. FIG. It is a figure which shows the example of the typical numeric keypad display by the technique of the literature 4. FIG. It is a block diagram which shows the structure of the display system of 1st Embodiment. It is a figure which shows the state in which the user is using the display system of 1st Embodiment. It is a flowchart which shows an example of operation | movement of the display system by 1st Embodiment. It is a figure which shows the specific example of the keyboard layout displayed by the display system of 1st Embodiment. It is a block diagram which shows the other structural example of the display system by 1st Embodiment. It is a figure which shows the specific example of the keyboard layout displayed by the display system of 2nd Embodiment. It is a block diagram which shows the structure of the display system by 3rd Embodiment. It is a flowchart which shows an example of operation | movement of the display system by 3rd Embodiment. It is a figure which shows the specific example of the keyboard layout displayed by the display system of 3rd Embodiment. It is a flowchart which shows an example of a part of operation | movement of the display system by 4th Embodiment. It is a figure which shows the specific example of the keyboard layout displayed by the display system by 4th Embodiment. It is a figure which shows the specific example of the keyboard layout displayed by the display system of 5th Embodiment. It is a figure which shows the example of an external appearance of the display apparatus by 6th Embodiment. It is a figure which shows a specific example of the keyboard layout displayed by the display system of 6th Embodiment. It is a figure which shows the other specific example of the keyboard layout displayed by the display system of 6th Embodiment. It is a figure which shows a specific example of the keyboard layout displayed by the display system of 7th Embodiment. It is a figure which shows the other specific example of the keyboard layout displayed by the display system of 7th Embodiment. It is a figure which shows the specific example of the keyboard layout displayed by the display system of 8th Embodiment. It is a figure which shows the 1st specific example of the display apparatus which assumed ATM. It is a figure which shows the 2nd specific example of the display apparatus which assumed ATM. It is a figure which shows the 3rd specific example of the display apparatus which assumed ATM. It is a figure which shows the 4th specific example of the display apparatus which assumed ATM. It is a figure which shows the 5th specific example of the display apparatus which assumed ATM. It is a figure which shows the 6th specific example of the display apparatus which assumed ATM. It is a figure for demonstrating the example which applied the display apparatuses 7 of 1st Embodiment etc. to the public panel. It is a figure for demonstrating the example which applied the display apparatuses 7 of 1st Embodiment etc. to the mobile telephone. It is a figure for demonstrating the example which applied the display apparatuses 7 of 1st Embodiment etc. to the computer.

  Embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 7 is a block diagram illustrating a configuration of the display system according to the first embodiment. Referring to FIG. 7, the display system includes a display device 7 and an optical shutter 8. The display device 7 includes a display unit 1 and a processing unit 2. As a specific example, an example in which the processing unit 2 is a computer and the display unit 1 is a display is assumed.

  The display unit 1 includes a display screen 102 and an image driving unit 103. The processing unit 2 includes a pressed position determination unit 201, a main processing unit 202, an optical shutter control signal generation unit 203, a key control unit 3, an image display control unit 4, and a mode selection unit 5. The key control unit 3 includes a key arrangement generation unit 301, a key arrangement memory 302, a key arrangement selection unit 303, a key arrangement transfer unit 304, a scan code correspondence unit 305, and a key arrangement correspondence table 306. If a computer is assumed as the processing unit 2, each unit included in the processing unit 2 is various processing means realized by a processor executing a software program.

  The image display control unit 4 includes an image composition unit 401, an image memory 402, a mode switching unit 403, and a synchronization signal generation unit 404. The mode selection unit 5 includes an input personal authentication character string memory 601 and a character string comparison unit 602 that operate in the personal authentication mode in the personal authentication mode unit 6.

  In the display unit 1, the image driving unit 103 displays an image on the display screen 102 under the control of the image display control unit 4. For example, a key layout 101 is displayed on the display screen 102. The display screen 102 is, for example, a touch panel display device, displays an image by driving from the image driving unit 103, detects a touch, and notifies the pressed position determining unit 201 of information indicating the pressed position.

  The optical shutter 8 is disposed between the display screen 102 and the position where the user's eyes come, and is used from the display screen 102 by opening and closing according to control from the optical shutter control signal generation unit 203 of the display device 7. Transmits or blocks light toward the person's eyes.

  The mode selection unit 5 determines the operation mode. The mode selection unit 5 may determine the operation mode according to the user's selection by key input or the like, for example. One of the operation modes is a personal authentication mode. The personal authentication mode is an operation mode in which the key layout is displayed in a state that only the user can see and is kept secret from others.

  In the state of the personal authentication mode, the mode selection unit 5 stores the key input character string in the input personal authentication character string memory 601. The mode selection unit 5 is preset with a user's personal authentication character string, and the character string comparison unit 602 includes a character string stored in the input personal authentication character string memory 601 and a preset personal authentication. User authentication is performed by comparing the character string.

  The pressed position determination unit 201 determines the pressed position based on the information notified from the display screen 102 and notifies the key control unit 3 of information indicating the determined position.

  In the key control unit 3, the key arrangement generation unit 301 generates a plurality of different key arrangements when the personal authentication mode is activated, and stores them in the key arrangement memory 302. The key arrangement is an example of display information to be concealed. In the present embodiment, this key layout is a secret object. The number of key arrays to be generated may be determined in advance according to the required confidentiality.

  The key arrangement selection unit 303 selects one key arrangement from the key arrangements generated by the key arrangement generation unit 301 and stored in the key arrangement memory 302, and sets the other key arrangements as dummy key arrangements. To do. The effective key arrangement is an effective key arrangement used when determining a key input by the user, and is a key arrangement that allows the user to recognize the display screen 102 through the optical shutter 8. The dummy key array is a key array for preventing an effective key array from being specified by others. Therefore, the dummy key array is display information that is the same type as the effective key array and has different display contents. In the present embodiment, the dummy key array displays a key array of the same type as the effective key array, and the actual key arrangement as the display content is different from the effective key array. Although the present embodiment is an example in which the key arrangement is used as display information, a character string or a product group may be used as display information as another example.

  If the display information is a character string, the valid display information and the dummy display information both display the same type of character string, but the dummy display information has a different character from the effective display information. If the display information is a product group, the effective display information and the dummy display information both display the same type of product group, but the dummy display information is different from the effective display information for the displayed product.

  The scan code correspondence unit 305 associates the valid key arrangement selected by the key arrangement selection unit 303 with the scan code, and stores correspondence information indicating the association in the key arrangement correspondence table 306. This key arrangement correspondence table 306 is used to convert information notified from the pressed position determination unit 201 into a scan code.

  The key arrangement transfer unit 304 transfers the key arrangement generated by the key arrangement generation unit 301 and stored in the key arrangement memory 302 to the image display control unit 4 in a predetermined order or a random order.

  In the present embodiment, the valid key array and the dummy key array are newly updated every time the personal authentication mode is switched. For this reason, when one personal authentication mode ends, the key arrangement generation unit 301 generates the key arrangement again, and the key arrangement selection unit 303 reselects the valid key arrangement.

  Here, it is assumed that confidentiality is not required in a state other than the personal authentication mode. Therefore, in a state other than the personal authentication mode, a general key arrangement may be used in consideration of usability. In this case, when the personal authentication mode ends, the key arrangement is restored to the general key arrangement, and when the personal authentication mode is newly activated, the key arrangement generation unit 301 regenerates the key arrangement, and the key arrangement selection unit 303 becomes effective. The key layout should be selected again.

  For example, if the key arrangement selection unit 303 randomly selects an effective key arrangement, the key arrangement transfer unit 304 only needs to transfer the key arrangement in a predetermined order. In addition, for example, the key arrangement selection unit 303 determines that the first generated key arrangement is an effective key arrangement, and the key arrangement transfer unit 304 transfers the key arrangement in a predetermined order or a completely random order. It may be.

  In the image display control unit 4, the mode switching unit 403 switches the operation of the image display control unit 4 according to the operation mode determined by the mode selection unit 5. In the personal authentication mode, images of a plurality of key arrays including an effective key array and a dummy key array are sequentially switched and displayed. In other operation modes, an image of one key arrangement is continuously displayed.

  The image memory 402 stores an image to be displayed on the display unit 1.

  The synchronization signal generation unit 404 is a synchronization signal that defines reference timings for both image switching in the image display control unit 4 and generation of the optical shutter control signal by the optical shutter control signal generation unit 203 in the state of the personal authentication mode. And the synchronization signal is provided to the image display control unit 4 and also to the optical shutter control signal generation unit 203.

  In the personal authentication mode, the image composition unit 401 sequentially fits the key layout image transferred from the key layout transfer unit 304 of the key control unit 3 into the image in the image memory 402. The image memory 402 stores an authentication image for prompting the user to input a personal authentication character string, and the authentication image has a portion for displaying a key arrangement. The image composition unit 401 inserts the key layout image transferred by the key layout transfer unit 304 into a portion where the key layout of the authentication image is displayed.

  The optical shutter control signal generation unit 203 uses the synchronization signal from the synchronization signal generation unit 404 to transmit the optical shutter at a timing when the effective key array is displayed in synchronization with the switching of the image displayed on the display unit 1. An optical shutter control signal is generated and sent to the optical shutter 8.

  The main processing unit 202 performs control of each unit and basic processing as a device based on the state of each unit and key information input by the user.

  In this example, the display screen 102 of the display unit 1 is an example of a touch panel type display device. However, key input using another configuration may be used. In this example, the key layout is a numeric keypad, but other key layouts such as a key layout including characters and special symbols may be used. Furthermore, the key input may be pointing with a mouse or an optical element in addition to touching the touch panel or pressing a key on the keyboard.

  In addition, not all display images need be stored in the image memory 402 in advance. For example, only the base image may be stored in the image memory 402, and another display image may be generated based on the image. Further, an image input from the outside instead of the image stored in the image memory 402 may be used for display.

  Further, instead of the key arrangement transfer unit 304, the image display control unit 4 may determine the display order of the key arrangement.

  In addition, the same display operation may always be used without specifying an operation mode. Each unit may always perform the operation in the personal authentication mode described above. In that case, the mode switching unit 403 is unnecessary.

  FIG. 8 is a diagram illustrating a state in which the user is using the display system according to the first embodiment.

  An optical shutter 8 is disposed between the display screen 102 provided in the display device 7 and the user's eye 85. The optical shutter 8 is connected to the display device 7 via a control cable 81 and opens and closes according to an optical shutter control signal received from the display device 7 via the control cable 81. The optical shutter control signal is a signal for controlling the optical shutter 8 so that the optical shutter 8 is in a transmissive state at a timing when an image having an effective key arrangement is displayed on the display screen 102. Thereby, only the user who is looking at the display screen 102 via the optical shutter 8 can visually recognize the image of the effective key arrangement from the sequentially displayed images.

  In FIG. 8, the display device 7 is shown as being similar to an ATM, but may have other shapes and configurations. As another example, the display device 7 may be a desktop computer or a notebook computer. The display device 7 may be a mobile phone. Further, the display device 7 may be a public panel arranged in an open environment. The public panel is a panel device that displays, for example, a catalog and allows a user who views the display to select and purchase a desired product by key input. The purchase price is paid by the combined use of an ID card such as a magnetic card or a portable terminal having a function corresponding thereto and an input of a personal authentication character string. The input of the personal authentication character string may be input by a touch panel method, may be input from a keyboard installed in the vicinity of the panel in advance, or may be input from a keyboard of a portable terminal.

  In FIG. 8, the display device 7 and the optical shutter 8 are connected by a control cable 81. However, as another example, a wireless communication link such as an RF link or an infrared link may be used. In this case, the control cable 81 is not necessary. However, when a wireless communication link is used, it is desirable to consider that the opening / closing timing of the optical shutter 8 by the optical shutter control signal does not leak. For example, the optical shutter control signal may be encrypted.

  FIG. 9 is a flowchart illustrating an example of the operation of the display system according to the first embodiment. When starting the display, the display device 7 selects an operation mode from an input by the user or the like (step S101). The display device 7 determines whether or not the selected operation mode is the personal authentication mode (step S102).

  In the personal authentication mode, the display device 7 generates a plurality of key arrays (step S103). Subsequently, the display device 7 determines whether or not the generated key arrangement is appropriate (step S104). Whether or not the key arrangement is appropriate is determined, for example, based on whether or not a duplicate key arrangement is generated. If the generated key arrangement is not proper, the display device 7 returns to step S103 to generate the key arrangement again.

  If the key arrangement is appropriate, the display device 7 stores the key arrangement (step S105). When the key arrangement is stored, the display device 7 selects an effective key arrangement from the plurality of key arrangements (step S106), and creates a key arrangement correspondence table indicating the correspondence between the effective key arrangement and the scan code (step S106). Step S107).

  The display device 7 sequentially transfers the generated plurality of key arrays from the key array memory 302 to the image display control unit 4 by the key array transfer unit 304 (step S108). The order of transfer may be a predetermined order or random.

  The image display control unit 4 generates a synchronization signal (step S112). The image display control unit 4 takes out the image stored in the image memory 402 (step S109), combines it with the image transferred from the key control unit 3 (step S110), and sequentially switches the display screen 102 according to the synchronization signal. (Step S111).

  The display device 7 generates an optical shutter control signal based on the synchronization signal (step S113), and controls the opening and closing of the optical shutter 8 by transmitting the optical shutter control signal (step S114).

  Since the user who is viewing the display screen 102 through the optical shutter 8 can visually recognize the effective key arrangement that matches the scan code, the user can key-in the personal authentication character string using the effective key arrangement.

  The display device 7 determines whether or not the number of determinations is equal to or less than a predetermined number (N times) (step S115), and returns to step S101 if it exceeds N times. If N times or less, the display device 7 receives an input of a personal authentication character string from the user on the input screen (step S116), and stores the personal authentication character string (step S117).

  Further, the display device 7 performs personal authentication by comparing the personal authentication character string input by the user with a personal authentication character string registered in advance (step S118). The success or failure of the personal authentication determines whether or not the user is permitted to perform subsequent operations.

  If the personal authentication is not successful, the display device 7 returns to step S115. If the number of determinations is N or less, the display device 7 starts again from the input of the personal authentication character string on the input screen.

  If the personal authentication is successful, the display device 7 performs the subsequent operation by receiving a predetermined screen display and receiving a key input by the user (step S119). When all the operations are completed, the display device 7 ends the series of operations (step S120). If all the operations are not completed, the display device 7 returns to step S101 and repeats a series of operations.

  In the example of FIG. 9, if it is not the personal authentication mode in step S102, the mode selection is returned to step S101. However, if it is not the personal authentication mode, an operation that does not require personal authentication may be executed.

  Further, in the example of FIG. 9, when the input error of the personal authentication character string exceeds N times in step S115, the example returns to step S101 to exclude the user from the personal authentication mode. However, instead of returning to step S101, other operations such as stopping the operation or issuing a warning may be executed.

  In the example of FIG. 9, after the input of the personal authentication character string is completed in steps S116 and S117, the personal authentication is determined in step S118. However, the determination may be made every time a certain number of characters are input. For example, if it is determined for each character, the personal authentication character string may not be stored in the memory. However, even in that case, the success or failure of the personal authentication may be displayed after the input of the personal authentication character string is completed.

  The configuration and operation of the above-described embodiment are merely examples, and the present invention can be applied to various configurations and operations.

  FIG. 10 is a diagram illustrating a specific example of a key arrangement displayed by the display system according to the first embodiment. As shown in FIG. 10, a key layout 101 is displayed on the display screen 102 of the display device 7. At that time, a plurality of key arrays each including an effective key array and a dummy key array are sequentially switched and displayed at a high speed.

  (A) in the figure shows the display switching of the display screen 102 as it is. Multiple key sequences are displayed repeatedly in a certain cycle. (B) shows the open / close state of the optical shutter 8. The optical shutter 8 is in a transmissive state at a timing when an effective key arrangement is displayed on the display screen 102, and is in a blocked state at other timings. The optical shutter 8 is in a transmission state once per cycle. (C) shows an image (shutter user perceived image) visually recognized when viewing the display screen 102 through the optical shutter 8. A user viewing the display screen 102 through the optical shutter 8 visually recognizes the effective key arrangement. On the other hand, another person who views the display screen 102 without passing through the optical shutter 8 perceives an image in which a plurality of key arrangements are combined.

  The display device 7 recognizes the correspondence between the effective key arrangement and the scan code, and inputs a character with a key arrangement (effective key arrangement) that the user using the optical shutter 8 can visually recognize on the display screen 102. Then, the display device 7 can acquire correct characters.

  Also, since there are multiple key layouts including valid key layouts and dummy key layouts, the keys entered by the user are unique even if another person shoots the display screen and the user's hand or finger with a video camera or camera. Cannot be estimated.

  For example, in FIG. 10A, it is assumed that the user presses the “4” key at the upper left of the numeric keypad. At this time, when another person shoots with a high frame rate video camera, the photographed image is pressed as if the "4" key is pressed, the "7" key is pressed, or another key is pressed. It looks like Therefore, it cannot be specified which key is pressed.

  Increasing the number of key arrays included in one cycle improves the confidentiality accordingly. Considering the visibility of the user who views the display screen 102 through the optical shutter 8, it is not preferable to make one cycle longer than a certain length. Therefore, it is preferable to shorten the display time per image and increase the number of key arrays included in one cycle. For example, if the resolution of the display screen 102 is lowered to shorten the time taken for display per image, the number of key arrays included in one cycle can be increased. The same is true even if the resolution is reduced in a pseudo manner by simultaneously selecting a plurality of gate lines and data lines. Further, the number of key arrays included in one cycle can also be increased by using a self-luminous display device having a high response speed such as an LED display or an organic EL display.

  Further, the display device 7 according to the present embodiment is not limited to the above-described one, and may be a projection type or FED type display device such as a projector.

  In the present embodiment, the numeric keypad layout is shown as an example of the key layout displayed on the display screen 102. However, the present invention is not limited to this. For example, the display device 7 may display a keyboard key layout on the display screen 102.

  In addition, the display order of the key arrangement to be displayed by switching sequentially may be the same as the generated order or may be different.

  The first embodiment can also be applied to display systems having other configurations. FIG. 11 is a block diagram illustrating another configuration example of the display system according to the first embodiment. Referring to FIG. 11, the display system includes a display device 7, an optical shutter 8, and an external server 9. 7 is different from the configuration of FIG. 7 in that the external server 9 is included in the display system.

  In the display system of FIG. 7, the display device 7 performs personal authentication by comparing personal authentication character strings. In the display system of FIG. 11, the external server 9 performs personal authentication. Therefore, the display device 7 in FIG. 11 includes the input personal authentication character string memory 1001 included in the mode selection unit 5 in FIG. 7 and a communication unit 1002 for communicating with the external server 9.

  The communication unit 1002 transmits the personal authentication character string stored in the input personal authentication character string memory 1001 to the external server 9.

  The external server 9 has a mode selection unit 901 and a communication unit 905. The mode selection unit 901 includes a personal authentication mode unit 902, and the personal authentication mode unit 902 includes an authentication image generation unit 903 and a character string comparison unit 904.

  The external server 9 transmits the authentication image generated by the authentication image generation unit 903 to the display device 7 via the communication unit 905.

  This authentication image is stored in the image memory 402 by the display device 7. The display device 7 synthesizes and displays the key layout image on the authentication image, stores the personal authentication character string input by the user in the input personal authentication character string memory 1001, and then passes the external server 9 via the communication unit. Send to.

  The external server 9 compares the personal authentication character string received from the display device 7 by the communication unit 905 with a personal authentication character string set in advance by the character string comparison unit 904 to authenticate the user. Do.

  11 illustrates a configuration in which only the external server 9 has the personal authentication mode unit 902 and the display device 7 has no personal authentication mode unit. However, both the display device 7 and the external server 9 have personal authentication. There may be a mode part. If the display device 7 is, for example, a computer, it is preferable to provide a personal authentication mode unit for performing personal authentication for logging in to the computer.

  According to the present embodiment, different key arrangements are sequentially displayed, and only the person using the optical shutter 8 can visually recognize an effective key arrangement among the key arrangements. Also, even if another person shoots the input scene of the user's personal authentication character string, the captured image is the same key layout with a different arrangement pattern, so the other person cannot specify the key layout from the captured image, and the individual The authentication string cannot be identified. In addition, when the user performs an input operation, even if another person peeks at or takes a picture, the key arrangement is not known, so the input information cannot be uniquely estimated from the movement of the user's fingers.

  The greater the number of key layouts displayed in one cycle of image display repetition, the higher the confidentiality of the personal authentication character string. Therefore, it is desirable that the key array generated by the key array generation unit 301 is as many different arrays as possible. However, if there is a sufficient key layout pattern, there may be overlap.

  In order to increase the number of key arrays in one cycle, it is conceivable to increase the number of display images per cycle. Therefore, the display screen may be dedicated to personal authentication, the resolution may be reduced, and the display period per image may be shortened.

  Even when the personal authentication character string is not input, the image may be displayed by a process of switching images at high speed. In that case, the same image may be displayed repeatedly. Then, it is not necessary to change the display operation mode of the display unit between when the personal authentication character string is input and when it is not.

(Second Embodiment)
In the second embodiment, by devising the operations of the key arrangement transfer unit 305 and the optical shutter control signal generation unit 203 in the first embodiment, the effective key arrangement can be achieved without changing the key arrangement display cycle. This is an embodiment in which the period in which the appears is changed. A display cycle of the key arrangement is referred to as an image cycle, and a period in which the effective key arrangement appears, that is, a period from when the optical shutter 8 enters the transmission state to the next transmission state is referred to as a shutter cycle.

  The basic configuration and operation of the display system according to the second embodiment are the same as those of the first embodiment. The order of display on the display screen 102 of a plurality of key arrays including an effective key array, and the optical shutter 8 Is different from the first embodiment in terms of the timing at which the light is made transparent.

  FIG. 12 is a diagram illustrating a specific example of a key arrangement displayed by the display system according to the second embodiment. In FIG. 12, only the portion of the numeric keypad arrangement is shown as the display image. Here, it is assumed that one image cycle is constituted by images of D key arrangements.

  FIG. 12A shows display switching of the display screen 102 according to the first embodiment. This is the same as that shown in FIG. The shutter cycle is equal to the image cycle, and D key arrangements are displayed therebetween. The order of the key arrangement displayed in all the image cycles is the same. Specifically, the key layout pattern displayed in the Kth image cycle is the same as the key layout pattern displayed in the (K + 1) th cycle.

  FIG. 12B shows an example of display screen display switching according to the second embodiment. In this example, the image cycle remains the same as in FIG. 12A, and the shutter cycle is doubled in FIG. 12A. The order in which the key arrangements appear in the image cycle is changed for each image cycle. Specifically, the key arrangement pattern of the Kth image cycle is different from the key arrangement pattern of the (K + 1) th image cycle.

  As a result, in FIG. 12B, the shutter cycle is doubled, and the number of key arrays appearing during the shutter cycle is increased to [2 × D]. Similarly, the shutter cycle can be lengthened within a range in which visibility by the user is ensured, and the number of key arrays appearing during that period can be increased to [3 × D], [4 × D],. .

  FIG. 12C shows another example of display screen display switching according to the second embodiment. In this example, the position where the valid key arrangement appears in the image cycle is shifted for each image cycle. Thus, the shutter cycle can be arbitrarily set instead of an integer multiple of the image cycle. FIG. 12C shows an example in which the number of key arrays included in the image cycle is set to 3, and the shutter cycle is set to four key arrays obtained by adding one key array to the image cycle.

  In this way, by increasing the shutter cycle and changing the key arrangement order, the number of dummy key arrays displayed between the effective key array and the effective key array is increased while the display period per image remains the same. Can be made. If the number of dummy key arrays displayed between the effective key array and the effective key array is increased, the confidentiality of the personal authentication character string is improved.

  Setting the opening / closing cycle of the optical shutter 8 to N times the normal cycle can be realized only by increasing the cycle of the optical shutter control signal by N times without changing the device configuration. Further, changing the order of the key arrangement does not require changing the display time per image, and can be easily realized by using the configuration of the display control system as it is.

  If the opening / closing cycle of the optical shutter 8 is lengthened, flickering occurs and the visibility of the user is lowered. In general image display, image degradation due to flicker is a serious problem. However, in image display for the purpose of inputting a personal authentication character string, confidentiality is more important than image quality. The work time for inputting the personal authentication character string is relatively short. The image of the key arrangement is a relatively simple image, and the key can be visually recognized even if there is a certain degree of deterioration. For these reasons, the allowable range of flicker is wider when inputting a personal authentication character string than when viewing and displaying general images.

(Third embodiment)
The third embodiment is different from the first embodiment in that the key arrangement is updated with a key input as a trigger. FIG. 13 is a block diagram showing a configuration of a display system according to the third embodiment. Referring to FIG. 13, the display system according to the third embodiment includes a trigger generation unit 204 in the processing unit 2 of the display device 1 in addition to the configuration illustrated in FIG. 7.

  The trigger generation unit 204 generates a trigger signal and inputs it to the key control unit 3 when the key of the character pressed by the pressed position determination unit 201 is determined in the personal authentication mode. The confirmation of the key pressed in the personal authentication mode means that a character included in the personal authentication character string has been input, so that a trigger signal is generated each time a character is input. However, the trigger generation unit 204 does not generate a trigger signal even when a key that cannot be used as a character of a personal authentication character string, such as a Shift key, a Ctrl key, or an escape key from the authentication mode, is pressed in the case of key input by a keyboard. .

  The key control unit 3 updates the key arrangement when a trigger signal is input from the trigger generation unit 204. At that time, the key arrangement generation unit 301 regenerates a plurality of different key arrangements, and the key arrangement selection unit 303 reselects an effective key arrangement. The scan code corresponding unit 305 stores correspondence information between the valid key array newly selected by the key array selecting unit 303 and the scan code in the key array correspondence table 306.

  FIG. 14 is a flowchart illustrating an example of the operation of the display system according to the third embodiment. For the operation of the display system according to the third embodiment shown in FIG. 14, steps S201 to S203 are used instead of steps S116 and S117 in the operation of the display system according to the first embodiment shown in FIG. S204 is newly included.

  The display device 7 according to the third embodiment receives characters of the personal authentication character string from the user through the input screen (step S201) and stores the characters in the input personal authentication character string memory 601 (step S201). S202). Subsequently, the display device 7 determines whether or not the input of the personal authentication character string has been completed (step S203). If the input has not been completed, the display device 7 returns to step S201 and receives the input of the next character. If the input has been completed, the display device 7 proceeds to step S118.

  Further, in the operation of the display system according to the third embodiment shown in FIG. 14, when the character of the personal authentication character string is input in step S201, the trigger generation unit 204 generates a trigger signal in step S204. Then, there is an operation of shifting to generation of the key arrangement in step S103. As a result, the key layout is updated each time a character of the personal authentication character string is input.

  In this example, when the personal authentication in step S118 is not successful, the process returns to step S115, and only the characters of the personal authentication character string are input again without updating the key layout. However, if the personal authentication is not successful, the personal authentication character string may be input again after updating the key layout.

  In the example of FIG. 14, after the personal authentication mode is activated, generation of a key arrangement by the key arrangement generation unit 301 and selection of an effective key arrangement by the key arrangement selection unit 303 are performed. However, the key layout may be generated and the valid key layout selected in advance, and the key layout may be applied when the personal authentication mode is activated.

  Further, in the example of FIG. 14, the key layout is updated every time the character of the personal authentication character example is input. However, a certain number or a necessary and sufficient number of key arrangement patterns are generated in advance and stored in the memory, and when a character of a personal authentication character example is inputted, a new key arrangement pattern is read from the memory. May be used. In addition, a key layout pattern is generated, and an image of the key layout is generated in advance. When a character of a personal authentication character is input, a new correspondence between the effective key layout and the scan code is constructed, and the key It is also conceivable to simply transfer the array image.

  The configuration and operation of the above-described embodiment are merely examples, and the present invention can be applied to various configurations and operations.

  FIG. 15 is a diagram illustrating a specific example of a key arrangement displayed by the display system according to the third embodiment. For simplicity, only the display image in which the key arrangement is repeatedly displayed in the personal authentication mode and the open / closed state of the optical shutter are illustrated.

  When characters of the personal authentication character string are input in the display state of FIG. 15A, a plurality of key arrays are newly generated, and a valid key array is newly selected. As a result, the display by the display device 7 shifts to a display state different from FIG. 15A as shown in FIG.

  A user who views the display screen 102 through the optical shutter 8 can visually recognize and use the effective key arrangement as a perceptual image. On the other hand, others who see the display screen 102 without passing through the optical shutter 8 perceive an image in which a plurality of key arrangements are combined. Even if another person photographs the movement of the user's hand or finger with a video camera or a camera, the personal authentication character string cannot be uniquely estimated because there are a plurality of different key arrangements.

According to the present embodiment, when a series of images is repeated in one cycle and the number of key arrangements displayed in one cycle is the same as in the first embodiment, the other person sets the personal authentication character string. The number of effective combinations of personal authentication character strings that are candidates for estimation is raised to the power [(number of key arrangements displayed in one cycle) ^ (number of characters of personal authentication character string)] and the first implementation. Compared with the form, it is greatly increased and the confidentiality is remarkably improved. For example, when a magnetic card with a four-digit password is used for ATM, if there are five types of key arrays in one cycle, there are 625 (= 5 ⁴ ) combinations of candidate passwords.

  From the point of view of confidentiality, it is desirable that the key layout generated when updating the key layout does not match the pattern of the key layout used so far, but there may be some overlap.

  When generating a plurality of key arrangements, one key arrangement may be determined at random, and another key arrangement may be determined based on the key arrangement. A plurality of key arrays may be generated by repeating generation of a new key array. Alternatively, all of the plurality of key arrays may be determined randomly.

  In the present embodiment, an example is shown in which the key layout is updated every time one character of the personal authentication character string is input. However, the key layout is updated every time a certain number of characters are input. Good. In addition, the number of characters leading up to the key layout update may change during the operation of inputting the personal authentication character string.

(Fourth embodiment)
In the fourth embodiment, a trigger signal is generated every time a character of a personal authentication character string is input, as in the third embodiment, but the operation according to the trigger signal is different from that in the third embodiment. . The display device 7 according to the fourth embodiment changes the effective key arrangement without generating a plurality of key arrangements again when a trigger signal is generated.

  The display system according to the fourth embodiment has the same configuration as the display system according to the third embodiment shown in FIG. However, the key arrangement selection unit 303 is activated in the key control unit 3 by the trigger signal from the trigger generation unit 204.

  When a trigger signal is input, the key array selection unit 303 reselects an effective key array from a plurality of key arrays stored in the key array memory 302. The scan code corresponding unit 305 stores correspondence information between the valid key array newly selected by the key array selecting unit 303 and the scan code in the key array correspondence table 306. Further, since the timing at which the optical shutter 8 is set to the transmissive state is changed by changing the effective key arrangement, the optical shutter control signal generation unit 203 generates a new optical shutter control signal.

  FIG. 16 is a flowchart illustrating an example of part of the operation of the display system according to the fourth embodiment. FIG. 16 shows only a part different from the third embodiment shown in FIG. 13 in the operation of the display system according to the fourth embodiment.

  Referring to FIG. 16, the display device 7 according to the fourth embodiment generates a trigger signal in step S204 when a character of the personal authentication character string is input in step S201. The input character is stored in the input personal authentication character string memory 601 (step S202). Subsequently, the display device 7 determines whether or not the input of the personal authentication character string has been completed (step S203). If the input has not been completed, the display device 7 returns to step S201 and receives the input of the next character. If the input has been completed, the display device 7 proceeds to step S118.

  Based on the trigger signal generated in step S204, in the key control unit 3, the key arrangement selection unit 303 reselects a new valid key arrangement (step S106), and the scan code correspondence unit 305 associates the valid key arrangement with the scan code. A key arrangement correspondence table indicating the relationship is created again (step S107).

  In step S106, when the effective key arrangement is changed, an optical shutter control signal that causes the optical shutter control signal generating unit 203 to transmit the optical shutter 8 at a timing when a new effective key arrangement is displayed. Generate (step S113), and control the opening and closing of the optical shutter 8 by transmitting the optical shutter control signal (step S114).

  FIG. 17 is a diagram illustrating a specific example of a key layout displayed by the display system according to the fourth embodiment. For simplicity, only the display image in which the key arrangement is repeatedly displayed in the personal authentication mode and the open / closed state of the optical shutter are illustrated.

  When the character of the personal authentication character string is input in the display state of FIG. 17A, the valid key arrangement is newly selected. As a result, the display by the display device 7 shifts to the display state of FIG. In FIG. 17B, there is no change in the plurality of key arrangements that are repeatedly displayed, but since the effective key arrangement is changed, the shutter state controlled by the optical shutter control signal is changed.

  According to the present embodiment, the effective key arrangement is changed without changing the plurality of key arrangements, and the opening / closing timing of the optical shutter 8 is changed according to the change. As a result, in the fourth embodiment, the number of key sequences appearing in one cycle is the same as in the first embodiment, but when another person estimates a personal authentication character string, The number of effective combinations of personal authentication character strings is greatly increased to a power of up to [(number of key arrangements displayed in one cycle) ^ (number of characters of personal authentication character string)], which significantly improves confidentiality. To do.

For example, when a magnetic card with a four-digit password is used for ATM, if there are five types of key arrays in one cycle, there are 625 (= 5 ⁴ ) combinations of candidate passwords.

  Note that the various methods for increasing the number of combinations of the personal authentication character strings described above may be used not only independently but also in combination.

(Fifth embodiment)
In the fifth embodiment, not only the dummy key array when the optical shutter 8 is in a shut-off state, but also an inverted image of an image obtained by synthesizing a plurality of key arrays, and some image for allowing the public or others to visually recognize The point of inserting is different from the first embodiment.

  FIG. 18 is a diagram illustrating a specific example of a key arrangement displayed by the display system according to the fifth embodiment. For the sake of simplicity, only the display image in which the key arrangement is repeatedly displayed and the open / close state of the optical shutter in the personal authentication mode are shown.

  FIG. 18A shows images sequentially displayed on the key arrangement portion of the display screen 102 of the display device 7. In addition to the effective key array 3001 and the plurality of dummy key arrays 3002, an inverted image 3003 of an image obtained by combining the effective key array 3001 and the plurality of dummy key arrays 3002 and a public image 3004 are sequentially displayed. (B) shows the shutter state. The optical shutter 8 is in the transmissive state at the timing when the valid key array 3001 is displayed.

  As a result, the perceived image of the user viewing the display screen 102 through the optical shutter 8 is the image 3101 shown in (c). The perceived image of the other person who sees the display screen 102 without passing through the optical shutter is obtained by placing the public image 3202 on the halftone image 3201 obtained by combining the effective key array 3001, the dummy key array 3002, and the reverse image 3003. It becomes an image.

  According to the present embodiment, the key arrangement is halftoned by adding an inverted image of an image obtained by combining the plurality of key arrangements to the image of the plurality of key arrangements, so that others cannot perceive the key arrangement. can do. Further, by including a public image, it is possible to make another person perceive a public image unrelated to the key arrangement, for example.

  FIG. 18 shows an example in which an inverted image of an image obtained by combining all the key arrangements for one cycle is inserted. As another example, a reverse image may be inserted at a rate of a predetermined number of key arrays in one cycle. The timing for inserting the reverse image need not be fixed with respect to the cycle, and the timing for inserting the reverse image and the number of key arrays included in the reverse image may be changed for each cycle.

  Further, the public image may be continuously displayed so as to overlap the display of the key arrangement, or may be displayed after displaying the reverse image.

  Further, as in the present embodiment, the inverted image of the image obtained by synthesizing a plurality of key arrangements and the public image may be separated, or the inverted image of the image obtained by synthesizing the key arrangement is placed on the public image. One image may be used.

  Alternatively, the key layout may be displayed in the area where the key layout is to be displayed, and some image and its reverse image may be displayed in the other area.

(Sixth embodiment)
In the sixth embodiment, in the display device, a display screen for displaying a key arrangement and a keyboard for inputting keys are separately configured. The configuration for realizing the display of the key arrangement is the same as that of the first embodiment shown in FIG. In the first embodiment, the input character is determined from the position determined by the pressed position determination unit 103 and the correspondence information stored in the key arrangement correspondence table 306. However, in the sixth embodiment, information indicating the correspondence between the actual keyboard key arrangement and the effective key arrangement is stored in the key arrangement correspondence table 306, and characters input from the keyboard are stored in the effective key arrangement. The input character is determined by replacing it with a character.

  FIG. 19A is a diagram illustrating an appearance example of a display device according to the sixth embodiment. Referring to FIG. 19A, the display device 3303 includes a display screen 3301 and a keyboard 3302 separately.

  In the state of the personal authentication mode, a plurality of key arrays generated by the key array generating unit 301 are sequentially displayed on the display screen 3301. Since the optical shutter 8 enters the transmissive state at the timing when the effective key array is displayed, the user can perceive only the effective key array among the plurality of key arrays. When the user inputs the personal authentication character string, the user presses a key at a corresponding position on the keyboard 3302 based on the key layout of the perceptual image on the display screen 3301.

  FIG. 19B is a diagram illustrating a specific example of a key arrangement displayed by the display system according to the sixth embodiment. On the display screen 3301, a plurality of key arrays including a valid key array and a dummy key array are sequentially displayed. When viewed through the optical shutter 8, the effective key arrangement can be perceived. In the perceptual image, keys are arranged at positions corresponding to the keys of the keyboard 3302 according to the effective key arrangement. The user compares the effective key arrangement of the display image 3301 with the keys of the keyboard 3302 and presses the keys on the keyboard 3302. For example, in the case of the effective key arrangement of FIG. 19B, when the 4-digit password is “4567”, “1234” on the keyboard 3302 is pressed.

  FIG. 19C is a diagram illustrating another specific example of the key arrangement displayed by the display system according to the sixth embodiment. On the display screen 3301, an array 3304 of the keyboard 3302 and an effective key array 3305 of the display device 3303 are displayed side by side. The user can easily determine which key of the keyboard 3302 should be pressed by looking at the perceived image on the display screen 3301.

  In FIG. 19C, since the key arrangement and effective key arrangement of the keyboard 3302 are displayed side by side, the display of individual keys is smaller than that in FIG. 19B, but the user can easily correspond to the keys. On the other hand, in FIG. 19B, since only the effective key arrangement is displayed on the display screen 3301, the keys on the keyboard 3302 must be compared. can get.

  Although the numeric keypad is illustrated in both FIGS. 19B and 19C, the present invention is not limited to this. For example, a general keyboard key layout having many types of keys can be displayed on the display screen 3301.

  Moreover, the key input in each description mentioned above is an example, and in this invention, other input methods, such as pointing with a mouse | mouth or an optical element, can be used widely.

(Seventh embodiment)
The seventh embodiment is an example in which the display position or display shape of the key arrangement on the display screen 102 is changed in addition to the operations of the first embodiment and the like. This makes it more difficult for others to obtain the personal authentication character string.

  FIG. 20A is a diagram illustrating a specific example of a key arrangement displayed by the display system according to the seventh embodiment. FIG. 20A shows a display image of a key arrangement in which the display position changes sequentially. In this example, the next key arrangement is displayed at a position shifted by one column from the previous display position. However, this shifting method is merely an example, and other shifting methods may be used. For example, the shift amount is not limited to an integral multiple, and may be continuously moved like a moving image.

  The timing for changing the position where the key layout is displayed may be matched with the timing of the change when the key layout changes due to the update when characters of the personal authentication character string are input as in the third embodiment. Alternatively, the display position may be changed while displaying the same key layout pattern.

  When the display position is changed in accordance with the change of the key arrangement pattern, the change amount of the display position may be increased. By doing so, it is possible to remove the line of sight of others looking from the surroundings and the shooting range of the camera. Further, when the display position is changed while displaying the same key arrangement, it is desirable that the change amount of the display position is not large in consideration of user operability.

  Further, it is desirable that the display position of a certain key layout is not the same in repeated display. This is to prevent the effective key arrangement from being estimated by others from the position of the user's hand or finger.

  FIG. 20B is a diagram illustrating another specific example of the key arrangement displayed by the display system according to the seventh embodiment. FIG. 20B shows a display image of a key arrangement whose display shape changes sequentially. In this example, the display shape of the key arrangement is changed from 4 rows × 3 columns to 2 rows × 6 columns. However, this is only an example, and other shape changes may be used. The display shape may not be a matrix key arrangement.

  The timing of the change in the display shape of the key arrangement may be matched with the timing of the change when the key arrangement changes due to the input of characters of the personal authentication character string, for example. Alternatively, the display shape may be changed while displaying the same key layout pattern.

  When the display shape is changed in accordance with the change in the key arrangement pattern, the amount of change in the display shape may change greatly. By doing so, it is possible to remove the line of sight of others looking from the surroundings and the shooting range of the camera. Further, when changing the display shape while displaying the same key arrangement, it is desirable that the change amount of the display shape is not large in consideration of the operability of the user.

  Further, it is desirable that the display shape of a certain key layout is not the same in repeated display. This is to prevent another person from estimating the effective key arrangement from the position of the user's hand or finger, as in the case of the display position change.

Further, both the display position and the display shape of the key arrangement may be changed. If the key input is a touch panel type, no special measures are required for changes in the display position and display shape. However, in the case of key input using a keyboard, no action is required even if the display position changes, but a change in the display shape may be required. Since the shape of the keyboard itself does not change, it is necessary to display the correspondence between the keys on the display screen and the keys on the keyboard.
(Eighth embodiment)
The eighth embodiment is an example in which a plurality of the same characters are included in one key layout for display. FIG. 21 is a diagram illustrating a specific example of a key layout displayed by the display system according to the eighth embodiment. (A) shows a display image obtained by extracting only the key arrangement area. (B) shows the open / closed state of the optical shutter 8. (C) shows a perceived image of the user who views the display screen 102 through the optical shutter 8. In (d), the key of the input character when the number “4” in the effective key array is input is shown.

  In this example, there are two all characters in one key layout. However, such a key arrangement is only an example, and all the characters may exist three by three or more. Further, for example, the number of keys may be different depending on the character, such as two keys for the character “1”, three keys for the character “2”, and one key for the character “3”. In either case, the number of keys in the key array increases by the number of duplicates of the same character, but the inherent key types are not shorted. In addition, when any key that is duplicated with the same character is pressed, the character is input.

  As a result, there are a plurality of the same characters in one key arrangement, and it is possible to input characters with all of them, so that the user can widen the key selection when inputting characters, and at the same time, input becomes easy. Thus, it is possible to prevent the effective key arrangement from being estimated by another person from the position of the user's hand or finger.

  However, in the keyboard input, there is no key corresponding to the duplicated character on the keyboard, so this embodiment cannot be applied to the keyboard input.

  As described above, the configurations and operations of various methods for changing the position, shape, and number of overlapping characters of the key arrangement are not only used alone, but may be used in combination. Furthermore, you may combine with the various methods for increasing the combination of the personal authentication character string mentioned above.

(Ninth embodiment)
The ninth embodiment is a specific example of the optical shutter 8 in the first embodiment and the like. The shape of the optical shutter 8 is preferably a glasses type or a card type.

  The glasses type includes shapes such as glasses, goggles, and visors, as well as shapes that are used by attaching to normal glasses.

  In the case of a card type, the shape of the optical shutter 8 does not have to be a square. Moreover, it does not need to be a planar shape and may be a curved surface shape. The card-type optical shutter 8 may be in the form of a film, for example.

  These optical shutters 8 may have any configuration as long as light transmission and shielding can be switched at high speed. The optical shutter 8 may have a configuration using liquid crystal, for example, or may be a mechanical type.

  The optical shutter 8 may be portable or may be fixed to the display device 7. As long as it is portable, the optical shutter 8 may exist alone, or may be attached to or incorporated in a mobile phone or the like.

(Tenth embodiment)
The tenth embodiment is an example in which the optical shutter 8 in the first embodiment or the like is provided with a cover for preventing peeping. This prevents leakage of the effective key arrangement by looking into the surroundings of the optical shutter 8 and photographing the transmission state of the optical shutter 8 and the display of the key arrangement at the same time with a video camera or camera, thereby improving confidentiality. Can be made.

  For the same reason, it is desirable to set the size, the installation position, and the installation angle of the optical shutter 8 in consideration of the peeping of others and voyeurism using a video camera or camera.

  As a result, it is possible to prevent leakage of the effective key arrangement due to peeping from the periphery of the optical shutter 8 and leakage of the effective key arrangement due to simultaneous photographing of the key arrangement and the open / closed state of the optical shutter 8. Can be improved.

(Eleventh embodiment)
The eleventh embodiment is an example in which the optical shutter 8 in the first embodiment or the like is attached to the display device 7. This eliminates the need for the user to bring the optical shutter 8 for personal authentication.

  Further, the optical shutter 8 may be fixed to the display device 7. This eliminates the need for the user to wear the glasses-type optical shutter 8 or hold the card-type optical shutter 8 by hand during personal authentication.

  Further, the optical shutter 8 attached to the display device 7 may be other shapes besides the glasses type and the card type.

(Twelfth embodiment)
The twelfth embodiment is a specific configuration example of the display device 7 assuming ATM. The basic configuration and operation are the same as those in the first embodiment described above. In the present embodiment, attention is particularly paid to the installation method of the optical shutter 8.

  FIG. 22A is a diagram showing a first specific example of a display device assuming ATM. A glasses-type optical shutter 8 is attached to the display device (ATM body) 7.

  FIG. 22B is a diagram showing a second specific example of a display device assuming ATM. A card-type optical shutter 8 is fixed to the display device (ATM body) 7.

  FIG. 22C is a diagram showing a third specific example of the display device assuming ATM. A movable support bar 4002 is connected to the display device (ATM body) 7. The card-type optical shutter 8 is supported by a support bar 4002. The support bar 4002 may be configured to change the length as well as the angle. Further, the angle of the optical shutter 8 with respect to the display screen 102 may be changeable.

  FIG. 22D is a diagram showing a fourth specific example of a display device assuming ATM. Two movable support bars 4202 are connected to the display device (ATM main body) 7. The card-type optical shutter 8 is supported by two support bars 4202. The length of the support bar 4202 may be changed along with the angle. Further, the angle of the optical shutter 8 with respect to the display screen 102 may be changeable.

  FIG. 22E is a diagram showing a fifth specific example of a display device assuming ATM. A fixed column 4403 is provided outside the display device (ATM body) 7. A movable support bar 4402 is connected to the fixed column 4403. The card-type optical shutter 8 is supported by the support rod 4402. Support rod 4402 may be variable in length with angle. Further, the angle of the optical shutter 8 with respect to the display screen 102 may be changeable.

  FIG. 22F is a diagram illustrating a sixth specific example of a display device assuming ATM. In this example, the glasses-type optical shutter 8 brought by the user is connected to the plug 4404 of the display device (ATM main body) 7 and used.

  In this way, the personal identification number can be concealed against peeping around the optical shutter 8 and voyeurism of ATM. In this example, ATM is shown, but the configuration of the present embodiment is not limited to ATM but can be applied to other devices.

(Thirteenth embodiment)
The thirteenth embodiment is various specific configuration examples of the display device 7. In particular, in the thirteenth embodiment, attention is paid to the display device 7 used in a situation where a personal authentication character string is input in an environment open to the surroundings.

  FIG. 23A is a diagram for describing an example in which the display device 7 according to the first embodiment described above is applied to a public panel. FIG. 23A shows the front surface of the public panel 48, which includes a display screen 4801, a key layout display screen 4802, and a card reader 4803.

  A product catalog is displayed on the display screen 4801, and the user selects and purchases a desired product. At the time of purchase, the card reader 4803 reads the ID card and inputs a personal authentication character string from the key layout display screen 4802.

  In the present embodiment, the key layout display screen 4802 corresponds to the display screen 102 of the first embodiment, and a plurality of key layouts are sequentially switched and displayed there. The plurality of key arrays include an effective key array. When the key arrangement display screen 4802 is viewed through the optical shutter 8, the effective key arrangement can be perceived.

  Further, on the display screen 4801, similarly to the display screen 102 of the first embodiment, a plurality of images may be sequentially switched and repeatedly displayed. By sequentially switching and displaying images of a plurality of products, it is possible to prevent other users from finding out the products that the user intends to purchase. Further, when a key layout is included in the display screen 4801, a plurality of key layouts may be sequentially switched and repeatedly displayed in that portion. An image of the purchased product and its reverse image may be displayed so that the product to be purchased is not revealed to others.

  Further, the public panel 48 of this example includes a card reader 4803 for personal authentication. However, for example, authentication information may be transmitted from the mobile terminal, and in that case, the public panel 48 includes means for receiving the authentication information. Further, the public panel 48 may use, for example, personal authentication by keying in a personal ID such as a membership number.

  Further, the input of the personal authentication character string on the public panel 48 may be input using a touch panel, a keyboard previously installed near the panel, or a keyboard of a portable terminal.

  Further, an advertisement unrelated to others may be visually recognized on the public panel 48, and a user using the optical shutter 8 may be allowed to visually recognize a desired image.

  Further, the above-described key layout display method may be applied to a display device that is installed at an entrance of a condominium or a private house and opens a door by inputting a personal identification number. By doing so, the personal identification number can be concealed.

  FIG. 23B is a diagram for explaining an example in which the display device 7 according to the first embodiment described above is applied to a mobile phone. Referring to FIG. 23B, the mobile phone 49 that is the display device 7 includes a display screen 4901 and a keyboard 4903. In this example, the display screen 4901 of the cellular phone 49 displays only the key layout 4902 that can be sequentially switched according to the first embodiment or the like. However, the same key arrangement as that of the keyboard 4903 may be displayed side by side with the key arrangement 4902 that is sequentially switched.

  FIG. 23C is a diagram for describing an example in which the display device 7 according to the first embodiment described above is applied to a computer. FIG. 23C shows a display screen 50 of a computer that is the display device 7. As an example, the display in FIG. 23C is a login screen. However, some keys are omitted.

  The display screen 50 shown in FIG. 23C has a portion for displaying the key arrangement 5001, and the key arrangement displayed in the portion is sequentially switched. In this example, as in FIG. 23B, only the key array 5001 that is sequentially switched is displayed. However, the key arrangement of a keyboard (not shown) used in the computer may be displayed side by side with the key arrangement 5001.

  In addition, the key layout display may be switched sequentially only when the password is input on the login screen, and the key layout may be switched and displayed in the same manner when the user name is input. In that case, it is desirable that the character display portion of the user name is also concealed by a “*” symbol or the like.

  Thereby, even if someone looks into the screen or is photographed with a photographing device, it is possible to prevent others from knowing secret information such as a personal authentication character string.

  Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the embodiments. Various changes that can be understood by those skilled in the art can be made to the configurations and details of the present invention defined in the claims within the scope of the present invention.

This application claims the benefit of priority based on Japanese Patent Application No. 2007-212166 filed on Aug. 16, 2007, the entire disclosure of which is incorporated herein by reference.

Claims (13)

A display system for displaying an image on a screen,
Display information control means for generating a plurality of display information including effective display information to be recognized by the user, and dummy display information of the same type and different content.
Image display control means for displaying the plurality of display information including the effective display information and the dummy display information generated by the display information control means on the screen;
Visual control means for controlling the arrival of light from the screen to the user so that only the user can specify the effective display information among the display information displayed on the screen by the image display control means, I have a,
The image display control means sequentially switches the display information to display on the screen,
The visual control means transmits light from the screen to the user at a timing when the effective display information of the plurality of display information is displayed on the screen by the image display control means, and the timing is displayed at other timings. Block the light from the screen to the user,
The visual control means includes:
An optical shutter control signal generating means for generating an optical shutter control signal indicating a timing at which the effective display information of the plurality of display information is displayed on the screen by the image display control means;
An optical shutter indicated by the optical shutter control signal generated by the optical shutter control signal generation means, which is in a transmitting state at a timing when the effective display information is displayed on the screen and is in a blocking state at other timings. Have
The image display control means increases the number of times the dummy display information is displayed while repeatedly displaying the effective display information when the generated plurality of display information is sequentially switched and displayed on the screen. Increase the period in which the effective display information appears,
The display system , wherein the dummy display information is significant display information that is the same type and different in content from the effective display information . An input means for the user to input information;
The display system according to claim 1, further comprising: input information confirmation means for confirming the input information input by the user from the input to the input means by the user and the effective display information. The display system according to claim 2 , wherein when the input information determination unit determines the input information, the display information control unit changes the effective display information. When the input information confirmation means confirms the input information, the display information control means regenerates a plurality of display information, and reselects the valid display information from the display information. The display system according to claim 3 , wherein the display system is changed. 4. The display according to claim 3 , wherein when the input information confirmation means confirms the input information, the display information control means changes the effective display information in the display information using the plurality of display information as they are. system. In addition to the effective display information and the dummy display information, the image display control means includes an inverted image of the effective display information and an inverted image of the dummy display information, or an image obtained by combining the effective display information and the dummy display information. The display system according to claim 1, wherein an inverted image of the image is displayed on the screen. The display system according to claim 2 , wherein the input unit is a touch panel type capable of inputting input information from the screen. Wherein the display information is the key sequence, the display information control unit generates a plurality of key sequences, select a valid key sequence from the plurality of key array, and the dummy key sequence the remainder, claim 1 7. The display system according to any one of 6 . Said image display control means, when said sequentially switch and a plurality of keys arranged to be displayed on the screen, changing the one or both of the display form of the display position and the key array of the key sequence, in claim 8 Display system described. The display according to claim 8 or 9 , wherein the display information control means generates a key arrangement in which a plurality of keys representing the same character exist and all keys representing the same character can be used for input of input information. system. The input means is a keyboard having a plurality of keys;
11. The display system according to claim 2 , wherein the display information control unit generates a plurality of key arrays corresponding to keys of the keyboard. The display system according to claim 2 , further comprising personal authentication means for performing personal authentication of the user from information input by the user.   When the effective display information is a character string, the dummy display information is a character string but a character string different from the effective display information, and when the effective display information is a product group, The display system according to any one of claims 1 to 12, wherein the dummy display information is a product group, but is different from the product indicated by the effective display information.

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