JP2005172843A - Display apparatus, display method and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a display content not to be kept after power off after displaying documents which is security protected in a continually rewritable display equipped with a memory function such as an electronic paper. <P>SOLUTION: The apparatus is equipped with; a storing medium for storing density bit of one or more bits that represents density for each pixel to be displayed and one-bit security bit that indicates existence of security for each pixel to be displayed in a display part of the display apparatus; a means for detecting a status of the security bit; a means for detecting a status of a power switch of the display apparatus; a means for rewriting the density bit of the pixel to be displayed; and a control means for controlling power supply to the display apparatus. When it is detected that the power switch of the display apparatus is cut off, the status of the security bit is examined and if it is ON, the power supply to the display part of the display apparatus is stopped after a rewriting operation of the density bit of the pixel. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a display device, a display method, and a computer program, and is particularly suitable for use in a display method on electronic paper having memory properties.

  Conventionally, electronic paper has been developed as a display medium replacing paper. Electronic paper as used herein refers to a thin film display having flexibility in which a display layer and a control thin film layer are integrated. Examples of the display layer method include a microcapsule electrophoresis method and a twist ball method. An outline of the electronic paper is described in Patent Document 1, for example.

  The characteristics of the above-mentioned electronic paper include high resolution comparable to a printing apparatus using an electrophotographic development method, and memory characteristics in the display layer, and once displayed information, until the next rewrite operation is performed Has the property of being preserved.

  A display control device that performs display control on electronic paper as described above aims to reduce power consumption by rewriting only the dots that require rewriting operation, taking advantage of the memory characteristics of the display layer. It was.

  On the other hand, PDF is a page description technique for displaying on a display device or a printing device. A document defined in PDF can have an attribute that prohibits printing from the viewpoint of security even if it can be displayed on a display device.

JP 2003-123559 A

  However, if a security-protected document is displayed on the electronic paper as described above so that printing is not permitted, the electronic paper is rewritable at any time. There was a problem that the contents were retained.

  In view of the above-described problems, the present invention prevents display contents from being retained after a power-off after displaying a secure document on a display device having a memory property such as electronic paper. Objective.

  The present invention is a display device having memory characteristics, and should be rewritten according to the determination by the determination unit when determining the security state of the display content and stopping the power supply to the display device Display updating means for rewriting the display of the area.

  Further, the present invention is a display method for a display device having a memory property, and includes a determination step for determining a security state of display contents, and a determination in the determination step when power supply to the display device is stopped. And a display update step of rewriting the display of the area to be rewritten.

  Further, the present invention is a computer program for causing a computer to execute a display method of a display device having a memory property, and a determination step of determining a security state of display contents, and when power supply to the display device is stopped. The computer is caused to execute a display method including a display update step of rewriting a display of an area to be rewritten according to the determination in the determination step.

  According to the present invention, for display contents with security protection displayed on a display device having a memory property, the display contents are displayed after rewriting the area before the power supply to the display device is stopped. Since the power supply to the apparatus is stopped, it is possible to prevent the display contents protected by the security from being held even after the power is turned off.

  According to the present invention, it is possible to prevent display contents with security protection from being held after power supply to a display device having a memory property is stopped.

The display device, display method, and computer program of the present invention will be described below with reference to the accompanying drawings.
(First embodiment of the present invention)
FIG. 1 is a block diagram showing a schematic configuration of an electronic paper apparatus and an electronic paper controller to which the present invention is applicable.
In FIG. 1, 1000 denotes an electronic paper controller, and 1100 denotes an electronic paper device.

  The electronic paper controller 1000 includes a CPU 1001 and executes control software stored in the ROM 1002 to control each device connected to the system bus 1004 in an integrated manner. Each process of the display method of the present embodiment is executed by the program stored in the ROM 1002.

  Reference numeral 1003 denotes a RAM which functions as a main memory, work area, and the like for the CPU 1001. An operation panel controller 1005 controls input from the operation panel 1101. Reference numeral 1006 denotes an electronic paper display controller which controls screen display of the electronic paper display unit 1102. Reference numeral 1007 denotes a network interface card, which is connected to the LAN 1200 as necessary, and performs bidirectional data exchange with other network devices.

  The computer system comprising the CPU 1001, the ROM 1002, and the RAM 1003, the switch state detecting means (step) of the present embodiment, the security register means (step) for storing the coordinate information of the rectangular area, the security state detecting means (step), pixel rewriting A means (process), a pixel density setting means (process), a security attribute assigning means (process), a security area detecting means (process), and the like are configured.

FIG. 2 is a conceptual diagram showing an example of a frame memory and a security bit memory secured as an area in the RAM 1003.
The frame memory 2001 is a memory area having a size capable of expressing all the pixels of the electronic paper display unit 1102 with 1 bit of each pixel.
The security bit memory 2002 is a memory area having a size of 1 bit indicating whether or not security protection is required for all the pixels of the electronic paper display unit 1102.

  Normally, when drawing is performed in the frame memory 2001, first, a viewer application in the ROM 1002 is activated to secure a certain rectangular area on the display screen as a viewer window. The viewer application is an application for displaying a document file having security attributes such as a PDF document on the electronic paper display unit 1102. Thereafter, the viewer application draws the document file loaded into the RAM 1003 via the LAN 1200.

FIG. 3 is a flowchart showing a drawing process of the electronic paper controller 1000 according to the present embodiment.
The security bit 2002 in the electronic paper controller 1000 is initialized with “0”.

  Then, when the display of the document file is instructed by the user, the viewer application is activated in step S301. At this time, the viewer application occupies a logical rectangular area on the frame memory 2001 corresponding to the application window display area on the electronic paper as a display area, and the position information of the rectangular area is retained during execution of the application. The

  Next, when the document file is read in step S302, the viewer application confirms the security attribute in the document file in step S303. If “not printable” is set in the security attribute, the process advances to step S304 to change the security bit corresponding to the window area occupied by the application to “1”.

  Thereafter, the viewer application draws the document information in the viewer application window area on the frame memory 2001 in step S305. Thereafter, in step S306, the electronic paper display controller 1006 performs a rewriting process on the pixels that need to be redrawn on the electronic paper display unit 1102.

FIG. 4 is a flowchart illustrating processing performed when the power is turned off.
In step S401, the user instructs to turn off the power. This instruction is given by the operation panel controller 1005 on the electronic paper controller 1000.

  Next, in step S402, processing for checking the leading state of the security bit 2002 is performed. Next, in step S403, it is determined whether or not the result of the check in step S402 is security. If the result of determination in step S403 is that there is security, the corresponding pixel on the frame memory 2001 is set to a density “0” state in step S404.

  Thereafter, in step S405, the presence or absence of an unchecked security bit is inspected. If there is an unchecked security bit, the state of the unchecked security bit is confirmed in step S406. After this confirmation, the process returns to step S403, and the above-described processing is repeated.

  When the inspection of all the security bits and the erasure of the pixels with security are completed in this way, the process proceeds to step S407, and the electronic paper display controller 1006 sets the pixels that need to be redrawn on the electronic paper display unit 1102. On the other hand, a rewriting process is performed. Thereafter, the process proceeds to step S408, and the power-off process is performed on the electronic paper display unit 1102 from the electronic paper display controller 1006.

  By performing the above processing, the display of the area where the non-printable file contents are displayed in the display area of the electronic paper is erased when the power of the electronic paper is turned off. Note that the display contents of the area where the non-printable file is displayed remain displayed due to the memory property of the electronic paper.

(Second embodiment of the present invention)
In the first embodiment, the RAM 1003 can secure a frame memory capacity corresponding to all pixels of the electronic paper display unit 1102 and a memory capacity for security bits.

On the other hand, in the second embodiment, an embodiment in a system with a limited RAM capacity is shown.
As shown in FIG. 7, in the second embodiment, the security bit 2002 does not exist, and instead has a security register 2003 that stores coordinate information of a rectangular area that needs security protection.

FIG. 5 is a flowchart showing a drawing process of the electronic paper controller according to the present embodiment.
When the display of the document file is instructed by the user, the viewer application is activated in step S501. At this time, coordinate information indicating an application window display area on the electronic paper display unit 1102 is held during execution of the viewer application.

  Next, when the document file is read in step S502, the viewer application confirms the security attribute in the document file in the next step S503. As a result of the confirmation, if “printing impossible” is set in the security attribute, the process proceeds to step S504, and the coordinate information of the window area occupied by the viewer application is stored in the security register 2003.

  Thereafter, the viewer application renders the drawing object in the document in step S505, and then causes the electronic paper display controller 1006 to perform rewrite processing for each pixel in step S506. In step S506, the display of the corresponding pixel on the electronic paper display unit 1102 is updated.

  Thereafter, in step S507, it is confirmed whether or not all objects have been drawn. If all the objects have not been drawn, the process returns to step S505 to repeat the above-described processing, and drawing of all the drawing objects is completed. Until the drawing operation is repeated.

FIG. 6 is a flowchart illustrating processing performed when the electronic paper device 1100 is turned off.
In the first step S601, the user instructs to turn off the power. This instruction is made by operating the operation panel controller 1005 on the electronic paper controller 1000.

  Next, in step S602, the state of the security register 2003 is checked. Based on the check result, it is determined in step S603 whether or not there is a security area. If the result of this determination is that there is an area with security, the process proceeds to step S604, where the corresponding rectangular area is rendered with “density 0”, and the corresponding pixel is displayed to the electronic paper display controller 1006. To be rewritten. As a result, the display of the rectangular area on the electronic paper device 1102 is updated, and the corresponding pixel is rewritten so as not to be displayed.

  Thereafter, in step S605, it is determined whether or not an unchecked security area exists in the security register 2003. If it is determined that there is an unchecked security area, that is, if all the security registers 2003 have not been checked, the process proceeds to step S606 to check the coordinate information of the security area. Thereafter, the process returns to step S603 and the above-described processing is repeated to erase the display of all security-protected areas on the display screen.

  If all the security registers 2003 have been checked as a result of the determination in step S605, the process proceeds to step S607, and processing for turning off the power of the electronic paper display unit 1102 from the electronic paper display controller 1006 is performed. In the above-described embodiment, the security register 2003 is described as being provided in the RAM 1003. However, the security register 2003 may be provided in the CPU 1001.

  By performing the above processing, also in the present embodiment, the display of the electronic paper display area where the file contents that cannot be printed are displayed when the electronic paper is turned off. The display contents in the area where the erased and non-printable file is displayed remain displayed due to the memory property of the electronic paper.

(Another embodiment of the present invention)
A software program for realizing the functions of the above-described embodiment for a computer in an apparatus or system connected to the various devices so that the various devices are operated to realize the functions of the above-described embodiments. What was implemented by supplying the code and operating the various devices according to a program stored in a computer (CPU or MPU) of the system or apparatus is also included in the scope of the present invention.

  Further, in this case, the program code of the software itself realizes the functions of the above-described embodiment, and the program code itself and means for supplying the program code to the computer, for example, the program code The stored recording medium constitutes the present invention. As a recording medium for recording the program code, for example, a flexible disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

  Further, by executing the program code supplied by the computer, not only the functions of the above-described embodiments are realized, but also the OS (operating system) or other application software in which the program code is running on the computer. The program code is also included in the embodiment of the present invention even when the functions of the above-described embodiment are realized in cooperation with the above.

  Further, after the supplied program code is stored in the memory provided in the function expansion board of the computer or the function expansion unit connected to the computer, the CPU provided in the function expansion board or function expansion unit based on the instruction of the program code Etc. perform part or all of the actual processing, and the functions of the above-described embodiment are realized by the processing.

It is a block diagram which shows schematic structure of the electronic paper apparatus and electronic paper controller which can apply this invention. It is a conceptual diagram which shows an example of the frame memory and security bit memory which are ensured as an area | region in RAM. FIG. 6 is a flowchart showing drawing processing of the electronic paper controller of the present embodiment. It is a flowchart which shows the process performed when a power supply is turned off. It is a flowchart which shows the drawing process of the electronic paper controller of this Embodiment. It is a flowchart which shows the process performed when the power supply of an electronic paper apparatus is turned off. It is a figure which shows the concept of the frame memory and security register which are ensured as an area | region in RAM.

Explanation of symbols

1000 Electronic Paper Controller 1001 CPU
1002 ROM
1003 RAM
1004 System Bus 1005 Operation Panel Controller 1006 Operation Panel Controller 1006 Electronic Paper Display Controller 1007 Network Interface Card 1100 Electronic Paper Device 1101 Operation Panel 1102 Electronic Paper Display Unit 1200 LAN

Claims (7)

A display device having memory characteristics,
A discriminating means for discriminating the security state of the display content;
Display updating means for rewriting the display of the area to be rewritten according to the determination by the determination means when stopping the power supply to the display device;
A display device comprising: In claim 1,
Density storage means for storing density information representing the density of each pixel to be displayed;
Security information storage means for storing security information indicating the presence or absence of security for each pixel to be displayed;
Security status detection means for detecting the status of security information stored in the security information storage means;
Switch state detecting means for detecting the state of the power switch of the display device;
Power supply control means for controlling power supply to the display device;
Display means for performing display based on the concentration information,
When the switch state detection unit detects that the power switch of the display device is turned off, the determination unit checks the state of the security information stored in the security information storage unit by the security state detection unit. The display update means rewrites the density information in the density storage means according to the security information state, updates the display contents by the display means, and then the power supply control. The power supply to the display part of the said display apparatus is stopped by a means, The display apparatus characterized by the above-mentioned. In claim 2,
A display device, wherein density information for each pixel and security information for each pixel are stored correspondingly. In claim 1,
Density storage means for storing density information representing the density of each pixel in the region to be displayed;
Security attribute giving means for giving an attribute indicating the presence or absence of security to a specific area in the area to be displayed;
Switch state detecting means for detecting the state of the power switch of the display device;
Power supply control means for controlling power supply to the display device;
Display means for performing display based on the concentration information,
When the switch state detection means detects that the power switch of the display device is turned off, the determination means detects the specific area having the security attribute by the security area detection means and determines the security state of the display content. The display update means rewrites density information corresponding to the pixels in the specific region having the determination result and the security attribute, updates the display content by the display means, and then updates the display device by the power supply control means. A display device characterized by stopping power supply to the display unit. In claim 1,
The display update means erases the display of the area to be rewritten according to the determination by the determination means. A display method for a display device having memory characteristics,
A discriminating step for discriminating the security state of the display content;
A display update step of rewriting the display of the region to be rewritten according to the determination in the determination step when stopping the power supply to the display device;
A display method characterized by comprising: A program for causing a computer to execute a display method of a display device having memory characteristics,
A discriminating step for discriminating the security state of the display content;
A display update step of rewriting the display of the region to be rewritten according to the determination in the determination step when stopping the power supply to the display device;
A computer program for causing a computer to execute a display method including:

Images