JP2000310965A - Display security securing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily prevent information displayed on a display screen from leaking out. SOLUTION: Spectacles (2-2) with liquid crystal shutters are connected to a notebook-sized PC (2-1) equipped with a display and the notebook PC (2-1) when displaying information on the display makes a white display on the display screen in predetermined timing and also closes the liquid crystal shutters of the spectacles while the white display is made. Thus, the 'white' display is generated fast and then a person who does not put on the spectacles with the liquid crystal shutters recognizes that a white picture is displayed flickering because of an afterimage phenomenon. The person who puts on the spectacles with the liquid crystal shutters can see the contents which are originally displayed since the white picture is hidden.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for preventing information displayed on a display from leaking to the outside.

[0002]

2. Description of the Related Art In recent years, with the development of a mobile computing environment, a usage form in which an information terminal such as a personal computer is used in public transportation such as a train or an aircraft has become widespread. In such a situation, there is a growing concern that confidential information such as a company is leaked because information displayed on a screen is accidentally or intentionally viewed by an unspecified number of unintended users.

In order to cope with such a situation, it is conceivable to use an eyeglass-type personal display device. However, since the device is expensive and visual information other than the display is cut off, it is difficult to use such a device. Inconveniences such as a dangerous situation in which the user cannot grasp the situation and a gap between the visual information and the acceleration experienced in the actual situation are remarkably intense as compared to when the vehicle is not in use, which may cause motion sickness.

[0004] On the other hand, it is expected that the need for similar security improvement will increase in terminals installed in public places and connected to a display (for example, terminals in financial institutions and terminals installed in government offices).

[0005]

As described above, information displayed on a display screen may be accidentally or intentionally seen by an unspecified number of unintended users. There is a problem that confidential information is leaked.

An object of the present invention is to provide a display security ensuring device which can easily prevent information displayed on a display screen from leaking to the outside.

[0007]

According to the present invention, there is provided an information processing apparatus having a display and a control device for controlling the display, wherein the control device is connected to glasses with a liquid crystal shutter, The control device has a first unit that performs white display on the display screen at a predetermined timing, and a second unit that closes a shutter of the glasses with the liquid crystal shutter during the white display. A display security assurance device is obtained.

By generating the "white" display at a high speed in this way, anyone other than the wearer of the glasses with the liquid crystal shutter recognizes that the white screen is flickering due to the afterimage phenomenon. On the other hand, the wearer of the glasses with the liquid crystal shutter hides the white screen, so that the contents originally displayed can be viewed.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

First, the principle of the present invention will be described with reference to FIG. Glasses 1-2 with a liquid crystal shutter are connected to the information terminal with a display 1-1, and the glasses 1-2 with a liquid crystal shutter are controlled by the information terminal with a display 1-1. The control software displays “white” on the screen at a predetermined timing, and closes the shutter of the glasses 1-2 during the “white” display. By generating the "white" display at a high speed, anyone other than the wearer of the glasses with the liquid crystal shutter recognizes that the white screen is flickering due to the afterimage phenomenon. On the other hand, since the white screen is concealed, the wearer of the glasses with the liquid crystal shutter can see the contents originally displayed.

Here, a first example of the present invention will be described with reference to FIG. Glasses 2-2 with a liquid crystal shutter connected to the notebook PC 2-1 by a control signal transmission interface (RS-232 is used in the illustrated example).
Is connected. The glasses 2-2 with the liquid crystal shutter receive the specific input from the interface, close the liquid crystal shutters of both eyes, and open the liquid crystal shutters at predetermined time intervals.

The notebook PC includes a CPU 3-1 shown in FIG. 3, a chipset 3-3, a memory 3-6, a display controller 3-5, a standard I / O unit 3-8, and a bus 3-2 connecting these. 3-4, 3-7.

The display controller 3-5 is shown in FIG.
Controller 4-2, RAMDAC4-
2, 4 or more frame buffers (hereinafter referred to as A and B, respectively) 4-4.

In addition to the above, control software for controlling the display screen and the glasses 2-2 with a liquid crystal shutter on the notebook PC side according to the following flow, and receiving predetermined commands from the control software and setting in advance And a device driver for a display controller to which a function of displaying the selected screen is added. Before the start of the control software, the display unit of the notebook PC uses only the frame buffer A and performs a display operation in the same manner as a normal PC.

Referring to FIG. 5, the started control software instructs a device driver for controlling display controller 3-5 to perform initialization for use of the present apparatus. As shown in FIG. 6, the device driver that has received the initialization instruction sets data corresponding to the “white” screen in the frame buffer B through the controller in the display controller unit 3-5. Subsequently, the control software sets 0 to tn-1 as an initial value of time.

T is the maximum value of the preset time interval for starting the display of the "white" screen, and Ti (<T) is the preset time interval for continuously displaying the "white" screen.
Next, a uniform random number between Ti and T is generated and set to a variable Tr.

The current time tn is obtained, and it is compared whether the time interval from tn-1 is greater than Tr. If it is less than Tr, return to time acquisition. If it is larger than Tr, a “white” screen display operation is performed.

In the "white" screen display operation, the device driver of the display controller is instructed to display the "white" screen, and then the glasses with liquid crystal shutter are instructed to close the liquid crystal shutter.

Referring to FIG. 7, the device driver of display controller unit 3-5 that has received the instruction passes through controller 4-2 of display controller unit 3-5, and RAMDAC 4-3 outputs the frame as the original data to be output. A change instruction is issued to change the buffer to B. After that, the device driver counts the clock by the controller 4-2 of the display controller, and instructs the RAMDAC via the controller to change the frame buffer to be the original data of the output to A when Ti has elapsed.

Referring to FIG. 8, glasses 2-2 with a liquid crystal shutter that has received the instruction make a transition to a state in which the shutter is closed. The glasses with the liquid crystal shutter open the shutter after the lapse of Tis with reference to a built-in timer. Here, Tis is a value obtained by adding a time in which the afterimage time unique to an individual depending on the phosphor of the display device is added to Ti. Then, as shown in FIG. 5, after giving the instruction, the control software sets tn to tn-1 and returns to the operation of setting a new Tr. Thereafter, the above operation is repeated.

In the above example, the variable time is an appropriate value preset in a table inside the control software, with the minimum time unit obtained from the clock of the notebook PC via the OS being the minimum. is there. In order for the user to make fine adjustments, the control software has an adjustment mode that can be changed within a predetermined range for each of these values. In the adjustment mode, the control software changes a value in a table in which each variable is stored when a numerical value in a predetermined range is input for each of these values.

Next, a second example of the display security ensuring device according to the present invention will be described.

A CRT-based display realizes a two-dimensional display by moving a scanning line from side to side and repeating this from the top to the bottom of the display unit. At this time, a method prevailing on a television implements an interlaced operation in which every other line is scanned in one vertical cycle. In the computer display, one of them is used depending on the relationship between the resolution of the interlaced scanning method and the capability of each hardware, and the method of performing the sequential scanning. In the second example, it is not necessary to add a function to the display controller of the PC main body in the case of performing the interlaced scanning as compared with the first example.

Referring to FIG. 9, in the illustrated example, PC 9-
A display 9-5 is connected to the distributor 9-4, and a glasses controller 9-with a liquid crystal shutter is connected to the distributor 9-4.
6 are connected. The glasses controller 9-6 with a liquid crystal shutter is further directly connected to the PC 9-1. Glasses 9-7 with a liquid crystal shutter are connected to the glasses controller 9-6 with a liquid crystal shutter.

The distributor 9-4 receives the display output 9-2 of the PC 9-1 and branches the vertical synchronizing signal into two systems.
The vertical synchronization signal is output to the glasses controller 9-6 with the liquid crystal shutter. The distributor 9-4 outputs all input signals to the display. The glasses controller 9-6 with the liquid crystal shutter receives the vertical synchronizing signal and receives the signal (RS-
232 output 9-3) is obtained, and the ON instruction / OF is sent to the glasses with the liquid crystal shutter at the start of the vertical synchronization cycle.
Send F command alternately. Then, the glasses controller 9-6 with the liquid crystal shutter skips the ON instruction / OFF instruction for one cycle by the notification via the RS-232 from the control software on the main body. The glasses 9-7 with the liquid crystal shutter close the liquid crystal shutters of both eyes when receiving the ON instruction, and open the liquid crystal shutter when receiving the OFF instruction. In the above-described example, the HW includes the above-described HW and control software for instructing the HW.

In the above-described second example, a "white" screen is displayed during one of the scans by utilizing the fact that interlaced even-line scanning and odd-line scanning are alternately performed at high speed. By closing the liquid crystal shutter during that time, it is intended to restrict the contents from being viewed by other than the wearer of the glasses with the liquid crystal shutter due to the visual afterimage phenomenon.

Referring to FIG. 10 as well, when the control software is started (step 10-1), a random time Tr that is longer than a predetermined vertical scanning cycle Ts and shorter than the maximum even-odd inversion interval T is generated (step 10-1). 10-2).
Next, the glasses controller with the liquid crystal switch is notified that the even and odd lines are to be inverted (step 10-3),
A white line is drawn on an odd-numbered scanning line in a portion corresponding to the uppermost layer of the virtual screen (step). After that, it waits until the time Tr has elapsed (steps 10-5 and 10-
6). After a lapse of the time Tr, a random number is set in the Tr (step 10-7), and the glasses controller with a liquid crystal switch is notified that the even / odd line is to be inverted (step 1).
0-8). A white line is drawn on the even-numbered scanning line of the portion corresponding to the uppermost layer of the virtual screen (step 10-9).
After that, it waits until the time Tr elapses (step 10).
-10 and 10-11). After a lapse of time Tr, T
r is generated, and the above operation is repeated. That is, the process returns to step 10-7.

Glasses controller 9 with liquid crystal switch
6 receives, from the control software, the first "notification of inverting the even / odd line to the glasses controller with a liquid crystal switch", and transmits an ON instruction to the glasses with a liquid crystal shutter 9-7 at the start of the next vertical synchronization signal. And
ON command alternately at the start of the next vertical synchronization signal cycle /
An OFF instruction is performed.

Upon receiving the next "notice of the glasses controller with liquid crystal switch inverting the even / odd line", the glasses controller with liquid crystal switch 9-6 sends an ON instruction / OFF instruction at the start of the next vertical synchronization. Skipping is performed, and at the start of the next vertical synchronization, the previously skipped instruction is transmitted, and thereafter, the ON instruction / OFF instruction is alternately repeated.

In addition, the control software accepts an interrupt from the user during execution of the loop from step 10-7 to step 10-11 shown in FIG.
After waiting for the vertical synchronization period or more, the controller notifies the glasses controller 9-6 with the liquid crystal switch to invert the even / odd line. Thereafter, the operation is restarted from step 10-7 shown in FIG.

In the second example described above, compared to the first example,
By using the afterimage effect of human vision without adding special functions to the PC itself, it is only for specific users who do not see the display when scanning the "white" line using glasses with a liquid crystal shutter The regular display screen is shown, and other people can only see the white screen without information.

Thus, it is possible to inexpensively perform the operation of safely displaying information on the display while ensuring security against prying eyes only by a specific user.

Next, a third example of the display security ensuring device according to the present invention will be described.

Up to the second example described above, the glasses with the liquid crystal shutter by the wired connection have been described. However, in an actual use environment, a wireless type may be desired. Thus, in a third example, an example using infrared communication will be described. In the case of the wireless system, if there is only an instruction to close the liquid crystal shutter, there is a risk of eavesdropping on the wiretapping signal, and therefore, a dummy instruction for not closing the shutter is transmitted.

In the third example, in addition to the RS-232 connection part described in the first example being an infrared communication device, the glasses with the liquid crystal shutter can decode the received signal by a predetermined decryption procedure. The shutter is closed when there is an instruction to close the shutter according to the decoding result. The HW and control software to which a function of transmitting data encoded by a predetermined procedure and random data are added.

Numerical data (decryption key) randomly generated from the control software as an initialization signal
To the glasses with LCD shutter. Since this numerical data is used as a decryption key, work is performed in an environment where the data is not stolen. The control software continues to transmit random data at predetermined intervals while performing the operation described in the first example. And
When the liquid crystal shutter instruction scanning is to be performed, a numerical value indicating a specific value is generated by calculation with an initially set numerical value and transmitted. Each time the liquid crystal shutter needs to be closed or in advance, a new numerical value satisfying the above condition is generated and transmitted. In the glasses with a liquid crystal shutter, an initially set numerical value and a specific operation are performed for all transmitted numerical values, and when the numerical values match a preset numerical value, the shutter is closed.

In the third example, in addition to the effects of the first example,
Unless an observer having a similar liquid crystal shutter has a decryption key to set / transfer at the time of initialization, the liquid crystal shutter cannot be closed in synchronization with the white screen.
As a result, the transmission interval of the random numerical data that is transmitted periodically is made sufficiently short so that the liquid crystal shutter remains closed and is displayed on the screen with the liquid crystal shutter that does not have the decryption key set / transferred at initialization. You will not be able to see what you are doing.

Next, a fourth embodiment of the display security ensuring device according to the present invention will be described with reference to FIG.

In a fourth example, an example in which infrared communication is applied to the second example will be described. In the third example, the RS of the first example
-232 connection only needs to be replaced with infrared communication, but the distributor 9-4 which does not exist in the first and third examples.
Therefore, it is not possible to simply replace with an infrared communication device as in the first and second examples.

In the illustrated example, a distributor 11-4 is connected to a display output 11-2 of the PC 11-1, and a display 11-5 is connected to the distributor 11-4. -8 is connected. The infrared communication device 11-8 is further directly connected to the RS-232 output 11-3 of the PC 11-1. And
The infrared communication device 11-8 is connected to the glasses controller with liquid crystal shutter 11-6 via a wireless line, and the glasses controller with liquid crystal shutter 11-6 is connected to glasses 9-7 with liquid crystal shutter.

The infrared communication device 11-8 transmits the RS-232 signal input as it is, and the vertical synchronization signal input transmits a signal indicating the beginning of the cycle. The glasses controller 11-6 with the liquid crystal shutter receives the signal indicating the beginning of the cycle and uses it as a trigger for the operation. Thus, the second example can be realized wirelessly. In addition to this, by adding a part that realizes the same security function as that described in the third example to the control software and the glasses controller with a liquid crystal shutter,
The second example can be made wireless while maintaining the same level of security as the third example.

If a plurality of glasses with liquid crystal shutters of the third example are prepared and the encryption key is transferred to the glasses with liquid crystal shutters, it is possible to use a projector, for example, without being known to a plurality of specific persons. It is also possible to display a projection on the screen (fifth example).

Further, in the first example, the frame buffer B
The data corresponding to the "white" screen is set on the entire surface of the frame buffer, but the data corresponding to the "white" screen is set in the corresponding portion of the frame buffer B only in a specific portion such as a specific window on the screen that is not desired to be shown. By setting the data corresponding to the “black” screen in the part, it is possible to make only a part of the screen invisible to anyone other than the specific person (sixth example).

Further, in the second example, by whitening even / odd lines only in a specific portion, it is possible to make only a part of the screen invisible to anyone other than the specific person (seventh example). ).

In addition, in the first example, a frame buffer for two screens is provided, but this is increased by one more screen (hereinafter referred to as a frame buffer C). Set white areas that do not match. The control software controls the RAMD through the device driver so that the frame buffer B and the frame buffer C are alternately displayed at the white screen display timing.
Give an instruction to AC. Two exclusive encryption keys (encryption keys B and C) described in the third example are set, and both or one of the encryption keys is transferred according to the viewing authority of the user of the glasses with the liquid crystal shutter. .

When displaying the frame buffer B, the control software displays one numerical value out of the numerical value group B which can be decrypted with the encryption key B, and displays the frame buffer C with the numerical value group which can be decrypted with the encryption key C. One numerical value is transmitted from C. Thereby, the encryption key B
The user of the glasses with the liquid crystal shutter having the above cannot view the information hidden by the frame buffer C, but can view the portion hidden by the frame buffer B.

Similarly, the user of the glasses with the liquid crystal shutter having the encryption key C cannot view the information hidden by the frame buffer B, but can view the portion hidden by the frame buffer C. In addition, a user of the glasses with the liquid crystal shutter having both the encryption keys B and C can browse all of them (eighth example).

Similarly, by increasing the number of planes of the frame buffer and the encryption key to four or more, it becomes possible to divide the frame buffer into a large number of groups and to grant browsing authority according to security.

Using the method described in the eighth example, it is possible to display another screen in each frame buffer and show a completely different screen according to the user (ninth example). . In addition, a mechanism that can be arbitrarily selected by the user among the encryption keys of the glasses with the liquid crystal shutter can be added, and only the screen that matches the encryption key can be displayed. This makes it possible to construct a system in which a plurality of movies can be projected on a common screen in an aircraft, for example, and the passenger can select the movie.

[0050]

As described above, in the present invention, a specific user who does not see the display on the "white" screen using the glasses with the liquid crystal shutter by utilizing the afterimage effect of human vision. Only a normal display screen is displayed, and other people can see only a white screen without information.

Thus, it is possible to inexpensively perform the operation of safely displaying information on the display while ensuring security against prying eyes only by a specific user.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the principle of a display security ensuring device according to the present invention.

FIG. 2 is a diagram for describing a first example of a display security ensuring device according to the present invention.

FIG. 3 is a diagram illustrating a configuration of the notebook PC illustrated in FIG. 2;

FIG. 4 is a diagram illustrating a configuration of a display controller unit illustrated in FIG. 2;

FIG. 5 is a flowchart for explaining the operation of control software in FIG. 2;

FIG. 6 is a flowchart for explaining an initialization operation of a display controller unit in FIG. 2;

FIG. 7 is a flowchart for explaining the operation of the display controller unit in FIG. 2;

FIG. 8 is a flowchart for explaining the operation of the glasses with a liquid crystal shutter in FIG. 2;

FIG. 9 is a diagram for explaining another example of the display security ensuring device according to the present invention.

FIG. 10 is a flowchart for explaining the operation of the display security ensuring device shown in FIG. 9;

FIG. 11 is a view for explaining still another example of the display security ensuring device according to the present invention.

[Explanation of symbols]

1-1 Information terminal with display 1-2, 2-2, 9-7, 11-7 Glasses with liquid crystal shutter 2-1 Notebook PC 3-1 CPU 3-2 CPU bus 3-3 Chipset 3-4 I / O bus 3-5 Display controller unit 3-6 Memory 3-7 Memory bus 3-8 Standard I / O unit 4-2 Controller 4-3 RAMDAC 4-4 Frame buffer 9-1, 11-1 PC 9-4, 11-4 Distributor 9-5, 11-5 Display 9-6, 11-6 Glasses Controller with Liquid Crystal Shutter 11-8 Infrared Communication Device

Claims (6)

[Claims] 1. An information processing apparatus having a display and a control device for controlling the display, wherein the control device is connected to glasses with a liquid crystal shutter, and the control device has a predetermined timing. And a second means for closing the shutter of the glasses with a liquid crystal shutter during the white display. 2. An information processing apparatus having a display and a control device for controlling the display. The control device is connected to glasses with a liquid crystal shutter, and the control device stores display data. A first frame buffer, a second frame buffer storing white screen data corresponding to a white screen, and a controller performing a white screen display operation at a preset time interval,
The controller, at the time of the white screen display operation, instructs the display to display a white screen on the display, and instructs the glasses with the liquid crystal shutter to close the liquid crystal shutter, and displays the display on the display. In response to the instruction, the white screen data is obtained from the second frame buffer and displayed on the screen, and the first screen data is displayed when a predetermined time elapses after displaying the white screen data.
Display means for obtaining the display data from the frame buffer and displaying the screen, and wherein the glasses with a liquid crystal shutter respond to the closing instruction to close the liquid crystal shutter for a preset closing time. Characteristic display security device. 3. The display security securing device according to claim 1, wherein the control device and the glasses with a liquid crystal shutter are wirelessly connected,
The controller sends a decryption key to the glasses with liquid crystal shutters, and the glasses with liquid crystal shutters perform decryption according to a predetermined decryption procedure, and close the shutter when there is an instruction to close the shutter according to the decryption result. A display security assurance device characterized in that: 4. The display security ensuring device according to claim 2, further comprising at least one third frame buffer, wherein said third frame buffer does not completely match said second frame buffer. The white screen data is stored, and the controller alternately displays the contents of the second and third frame buffers on the display during the white screen display operation. A display security ensuring device, wherein different encryption keys are set corresponding to the third frame buffer and sent to glasses with liquid crystal shutters. 5. An information processing apparatus having a display and a control device for controlling the display, wherein an on-instruction and an off-instruction are alternately generated at each start of a vertical synchronizing cycle based on a vertical synchronizing signal output from the display. A controller that skips the ON instruction and the OFF instruction for one cycle when receiving a notification from the control device,
A display security assuring device, comprising: glasses with a liquid crystal shutter connected to the controller to open and close a liquid crystal shutter in response to the on instruction and the off instruction. 6. The display security ensuring device according to claim 5, wherein the control device is connected to the controller by a wireless communication device.