JP2006011201A - Device, method, and program for driving image display medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a device, method, and program for driving an image display medium that can excellently display an image while suppressing an influence of noise generated when the image display device with a memory function is driven. <P>SOLUTION: A sequence controller 28 instructs an image converting circuit 38 not to output image data to a column electrode driving circuit 30 in a period wherein noise generated when a voltage from a power unit 26 is applied to a column electrode 24 appears on a signal line between the image converting circuit 38 and a column electrode driving circuit 30. Namely, data communication between the image converting circuit 38 and column electrode driving circuit 30 is stopped. In other periods, i.e. periods wherein no noise is generated, the data communication between the image converting circuit 38 and column electrode driving circuit 30 is permitted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image display medium driving apparatus, a driving method, and a driving program, and more particularly, to an image display medium driving apparatus, a driving method, and a driving program having a memory property.

  Conventionally, as a so-called electronic paper that can be repeatedly rewritten, an image display medium having a memory property such as rotating colored particles (Twisting Ball Display), electrophoresis, thermal rewritable, liquid crystal having a memory property, electrochromy, etc. Those using technology are known.

  Among these, as an image display medium to be displayed using particles (toner), an image display medium in which black particles and white particles having different charging characteristics are enclosed between facing sheets has been proposed (for example, Patent Documents). 1). Such an image display medium displays an image as a contrast between black particles and white particles by applying a voltage between sheets to form an electric field and moving the particles.

  In an image display medium using such particles, a voltage is applied between the substrates in order to form a high electric field (in MV / m unit) between the substrates in order for the particles to move between the substrates according to image information. Therefore, it is necessary to apply a voltage in units of 100 V between the electrodes. For this reason, frequent switching of the high voltage during driving of the image display medium causes noise due to ripples and the like, which causes disturbance of image information transferred to the drive circuit of the image display medium, and causes noise in the display image. There was a problem that may occur.

  When displaying a moving image on an image display medium such as a liquid crystal display, a plasma display panel (PDP), or a cathode ray tube (CRT), even if a frame image with noise generated in one frame is displayed, the next frame image is instantaneously displayed. Since the display is switched, the noise is not easily recognized and there is no problem.

  However, in an image display medium having a memory property, the voltage necessary for image display is applied only once, and once an image with noise is displayed, the image is displayed and held. It is not preferable because it remains.

For example, in the case of an image display medium using cholesteric liquid crystal, in order to solve the above-described problem, the phase of the reset pulse voltage applied to each electrode in the reset period before image display is changed to flow to the power supply line. A technique for reducing the inrush current itself and suppressing noise has been proposed (see, for example, Patent Document 2).
JP 2001-31225 A Japanese Patent Laid-Open No. 2001-100196

  However, in the image display medium using particles, when the applied voltage is reversed, the display color is changed. Therefore, the above-described conventional technique cannot be directly applied to the image display medium using particles. In the case of a large-screen image display medium, it is difficult to reduce the inrush current generated when a voltage is applied due to the structure of flat plates placed in parallel.

  The present invention has been made in consideration of the above facts, and an image display medium driving device capable of displaying an image satisfactorily while suppressing the influence of noise generated when driving an image display medium having a memory property, It is an object to obtain a driving method and a driving program.

  In order to achieve the above object, the drive device for an image display medium according to claim 1 drives the image display medium for displaying an image corresponding to the image information by applying a voltage corresponding to the image information. An image information output means for outputting image information, a voltage applying means for inputting the image information and applying a voltage corresponding to the inputted image information to the image display medium, and application of the voltage Control means for controlling the image information output means to prohibit the output of the image information for at least the first predetermined period of the period.

  A drive device according to the present invention is a drive device that drives an image display medium that displays an image corresponding to image information by applying a voltage according to the image information, and includes an image information output unit that outputs image information. I have.

  The voltage application unit inputs the image information output from the image information output unit, and applies a voltage corresponding to the input image information to the image display medium. As described above, when a voltage is applied to the image display medium while inputting image information, a large current instantaneously flows when the potential is switched, and a signal line for image information communication that connects the image information output means and the voltage application means. In some cases, noise is generated, and this is erroneously recognized as image information. In such a case, an image displayed on the image display medium has a defect.

  Therefore, the control unit controls the image information output unit so as to prohibit the output of the image information during at least the first predetermined period of the application period in which the voltage is applied to the image display medium by the voltage application unit. The predetermined period is set to a time sufficient for the noise to disappear.

  Thus, during the period when noise occurs, the output of image information from the image information output means is prohibited, that is, the voltage application of the image display medium is stopped by stopping the data communication between the image information output means and the voltage application means. It is possible to prevent the display image from being defective due to the influence of noise that is sometimes generated.

  Note that, as described in claim 2, the predetermined period may be set according to a level of the voltage. Thereby, the predetermined period can be optimally set according to the level of the voltage applied to the image display medium, and defects in the display image can be effectively prevented.

  According to a third aspect of the present invention, the voltage applying unit may apply the voltage to the image display medium by simple matrix driving. In the case of such a configuration, the voltage applying means applies the voltage to the image display medium while inputting the image information line by line, so that the effect of the present invention becomes remarkable.

  According to a fourth aspect of the present invention, the image display medium may be a memory image display medium. In the case of such an image display medium having a memory property, a still image is often displayed, and once an image is displayed by applying a voltage, the image is retained. In this case, the effect of the present invention becomes remarkable.

  As the image display medium having a memory property, as described in claim 5, the image display medium is disposed so as to face at least a part of the display substrate having translucency and the display substrate with a gap therebetween. A plurality of types having different colors and charging characteristics enclosed between a back substrate, the display substrate, and the back substrate and movably sealed according to an electric field formed by a voltage applied between the electrode pairs A particle group can be used.

  Since such an image display medium needs to apply a high voltage to move the particles, the effect of the present invention becomes remarkable when such an image display medium is used.

  The invention according to claim 6 is a driving method for driving an image display medium that displays an image corresponding to the image information by applying a voltage according to the image information, and outputting the image information; The image information is input and a voltage corresponding to the input image information is applied to the image display medium, and the output of the image information is prohibited during at least a first predetermined period of the voltage application period. And a step.

  By driving the image display medium by such a driving method of the image display medium, it is possible to prevent the display image from being defective.

  According to a seventh aspect of the present invention, there is provided a driving program for causing a computer to execute a driving method for driving an image display medium that displays an image corresponding to the image information when a voltage corresponding to the image information is applied. And outputting the image information; inputting the image information; applying a voltage according to the input image information to the image display medium; and at least a first predetermined period of the voltage application period. By causing the computer to execute a process including the step of prohibiting the output of the image information, the computer can function as a drive device for the image display medium.

  As described above, according to the present invention, there is an effect that an image can be displayed satisfactorily while suppressing the influence of noise generated when driving an image display medium having a memory property.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an image display apparatus 10 according to the present embodiment.

  The image display device 10 includes an image display medium 12, a power supply device 26, a sequence control device 28, a column electrode drive circuit 30, a row electrode drive circuit 32, a power supply control circuit 34, an image information storage device 36, and an image conversion circuit 38. It consists of

  As shown in FIG. 2, the image display medium 12 includes a display side substrate 14 having translucency, and a back side substrate 16 disposed to face the display side substrate 14 with a gap therebetween. The gap between the display-side substrate 14 and the back-side substrate 16 is held at a minute and constant interval by a gap holding member (not shown), and black particles 18 and white particles 20 having different charging characteristics are enclosed in the gap. (For example, the black particles 18 are positively charged and the white particles 20 are negatively charged).

  The black particles 18 and the white particles 20 are made of, for example, insulating particles. However, the present invention is not limited to this, and conductive particles may be used. As the black particles 18 and the white particles 20, for example, the types of particles described in Patent Document 1 can be used.

  Further, on the surface of the display-side substrate 14 facing the back-side substrate 16, a line-shaped (band-shaped) transparent electrode 22 extending in the first direction (the left-right direction in FIGS. 1 and 2) is a first electrode. A plurality of lines are formed along a second direction (vertical direction in FIG. 1, direction perpendicular to the paper surface in FIG. 2) perpendicular to the direction. A plurality of line-shaped electrodes 24 extending in the second direction are formed along the first direction on the surface of the back side substrate 16 facing the display side substrate 14. Thus, the transparent electrode 22 and the electrode 24 are arranged so that the image display medium 12 can be driven by a simple matrix method.

  When the image display medium 12 is driven by a simple matrix system, the intersection position of the transparent electrode 22 and the electrode 24 functions as a pixel of the image display medium 12 and is applied between the transparent electrode 22 and the electrode 24 at each intersection position. The movement of the black particles 18 and the white particles 20 at each crossing position, that is, the display density at each crossing position, is controlled according to the magnitude of the voltage (the electric field generated by). Hereinafter, the transparent electrode 22 is referred to as a “row electrode 22”, and the electrode 24 is referred to as a “column electrode 24”.

  The power supply device 26 generates, for example, a plurality of types of voltages with a single power supply. For example, the power supply voltage is divided by a plurality of voltage dividing resistors, and a smoothing capacitor provided corresponding to each voltage dividing resistor. Is configured to generate a plurality of types of stable voltages, and select and output a voltage having a desired potential from these voltages. The output voltage is output separately to the column electrode drive circuit 30 and the row electrode drive circuit 32. The power supply device 26 is controlled by the power supply control circuit 34, and the potential is selected by the sequence control device 28 instructing the power supply control circuit 34.

  The sequence controller 28 controls the power supply control circuit 34, the image conversion circuit 38, the column electrode drive circuit 30 and the row electrode drive circuit 32, and instructs the image conversion circuit 38 to transfer image information to the selected row. While outputting to the drive circuit 30, the power supply control circuit 34 is instructed to select an output voltage. As a result, a voltage corresponding to the image information is applied to the row electrode 22 and the column electrode 24, the particles move, and an image is displayed.

  As shown in FIG. 3, the column electrode drive circuit 30 stores the same number of switching elements as the number of column electrodes 24 provided in the image display medium 12 and one line of image data from the image conversion circuit 38. IC 40 having a shift register or the like is provided. By turning on / off the switching element, application of the output voltage HV from the power supply device 26 to the column electrode 24 can be turned on / off. Each switching element is turned on / off by a control signal corresponding to the image information of the line image supplied from the sequence controller 28.

  Note that when one line of image data cannot be stored in one shift register, a configuration in which a plurality of shift registers are connected may be employed.

  As shown in FIG. 4, the column electrode drive circuit 30 is attached to the back side substrate 16 of the image display medium 12, and individual switching elements of the column electrode drive circuit 30 are individually formed on the back side substrate 16. It is connected to the column electrode 24. Therefore, the application of voltage to each column electrode 24 of the image display medium 12 is turned on / off according to the on / off state of the connected switching element.

  Although not shown, the row electrode drive circuit 32 has the same number of switching operations as the number of row electrodes 22 provided in the image display medium 12, and the row electrodes 22 are turned on and off by turning on and off the switching elements. The application of the output voltage HV from the power supply device 26 is turned on / off. The individual switching elements are sequentially turned on from the switching element corresponding to the first row electrode to the switching element corresponding to the last row electrode by the control signal supplied from the sequence controller 28.

  As shown in FIG. 4, the row electrode driving circuit 32 is attached to the display side substrate 14 of the image display medium 12, and each switching element of the row electrode driving circuit 32 is an individual switching element formed on the display side substrate 14. Connected to the row electrode 22. Therefore, the application of voltage to the individual row electrodes 22 of the image display medium 12 is turned on / off according to the on / off state of the connected switching elements.

  The image information storage device 36 stores image data to be displayed on the image display medium 12, and the image data is output to the image conversion circuit 38.

  The image conversion circuit 38 performs processing such as compression or expansion on the image data output from the image information storage device 36 according to the number of pixels of the image display medium 12 or the like. Then, as shown in FIG. 5, the image data is output to the column electrode drive circuit 30 for each line in synchronization with the reference clock signal.

  In FIG. 5, one clock corresponds to one pixel, and pixel data is sequentially stored in the IC 40 of the column electrode driving circuit 30 every clock. Here, image data is stored by one signal line, but a plurality of pixel data may be stored simultaneously by using a plurality of signal lines.

  Incidentally, the output voltage HV output from the power supply device 26 when driving the image display medium 12 is a high voltage of 50 V or higher, and a large current instantaneously flows to the column electrode drive circuit 30 and the row electrode drive circuit 32. . For this reason, while the IC 40 of the column electrode drive circuit 30 outputs the voltage corresponding to the image data for one line to the column electrode 24, the image data of the next line output by the image conversion circuit 38 is captured. Then, noise is generated in the signal line of the image data connecting the image conversion circuit 38 and the column electrode drive circuit 30. Thereby, noise may be misrecognized as image data, and a display image may be defective. That is, as shown in FIG. 6A, in the data communication period in which image data is communicated between the image conversion circuit 38 and the IC 40 of the column electrode drive circuit 30, the output voltage HV from the power supply device 26 passes through the IC 40. When applied to the column electrode 24, the noise 42 indicated by the dotted line is recognized as image data, and a defect occurs in the display image.

  Such noise is likely to occur in the capacitive image display medium 12, but the generation period may end within a relatively short time when the potential is changed in the drive period for driving the image display medium 12. Many. For example, the generation period of a large drive current when driving the image display medium 12 ends in several tens of μsec to 1 msec. Therefore, the display image defect can be prevented by stopping the data communication for the first part of the period in which the potential is switched in the driving period for driving the image display medium 12.

  For this reason, as shown in FIG. 6B, the sequence control device 28 is a predetermined period when the output voltage HV is applied to the column electrode 24 from the power supply device 26, that is, a period in which a drive current is generated and noise is generated. Instructs the image conversion circuit 38 not to output the image data from the image conversion circuit 38 to the column electrode drive circuit 30. That is, the data communication between the image conversion circuit 38 and the column electrode drive circuit 30 is stopped. In other periods, that is, periods in which noise does not occur, data communication between the image conversion circuit 38 and the column electrode drive circuit 30 is permitted.

  By controlling in this way, even if the noise 42 is generated, it is not erroneously recognized as image data, and it is possible to prevent the display image from being defective due to the influence of the noise generated by the potential switching. .

  Note that the period during which data communication is stopped may be set according to the magnitude of the drive voltage (drive current). For example, table data representing the correspondence relationship between the magnitude of the drive voltage and the period during which data communication is stopped is stored in advance in the sequence controller 28, and data communication corresponding to the magnitude of the drive voltage is performed based on this table data. What is necessary is just to obtain and set the stop period. As a result, the data communication stop period can be set optimally according to the magnitude of the drive voltage, and defects in the display image due to the occurrence of noise can be effectively prevented.

  Further, in order to stabilize the voltage and absorb the surge voltage even when the output voltage from the power supply device 26 varies, the signal line connecting the image conversion circuit 38 and the column electrode drive drive circuit 30 and the ground of the power supply device 26 are used. You may provide a capacitor | condenser, a filter, etc. between lines.

  The sequence controller 28 can be configured by a computer. In this case, the computer can be caused to function as the sequence control device 28 by causing the computer to read a drive program that performs the above-described processing.

  In the present embodiment, the image display medium 12 provided with electrodes having a structure premised on driving in the simple matrix system has been described as an example. However, the present invention is not limited to this, and the active matrix system is used. Needless to say, the present invention can also be applied to an image display medium having a structure on the premise of driving in the above. The image display medium according to the present invention may be another known image display medium such as a liquid crystal display having a memory property.

It is a schematic block diagram of the image display apparatus which concerns on this embodiment. It is sectional drawing of the image display medium along the AA line of FIG. It is a figure which shows the schematic structure of a part of image display apparatus. It is a top view which shows the connection state of each electrode and drive part of an image display medium. It is a wave form diagram which shows the waveform of a clock signal and image data. (A) is a waveform diagram of conventional image data, drive voltage supplied to the image display medium, and drive current, and (B) is a waveform diagram of image data, drive voltage supplied to the image display medium, and drive current according to the present invention. It is.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image display apparatus 12 Image display medium 14 Display side board | substrate 16 Back side board | substrate 18 Black particle 20 White particle 22 Row electrode 24 Column electrode 26 Power supply device 28 Sequence control apparatus (control means)
30 column electrode drive circuit (voltage application means)
32 row electrode drive circuit 34 power supply control circuit 36 image information storage device 38 image conversion circuit

Claims (7)

A driving device that drives an image display medium that displays an image corresponding to the image information by applying a voltage according to the image information,
Image information output means for outputting image information;
A voltage applying means for inputting the image information and applying a voltage corresponding to the input image information to the image display medium;
Control means for controlling the image information output means so as to prohibit the output of the image information during at least the first predetermined period of the voltage application period;
An apparatus for driving an image display medium, comprising:   The image display medium driving device according to claim 1, wherein the predetermined period is set according to a level of the voltage.   3. The image display medium driving device according to claim 1, wherein the voltage applying unit applies the voltage to the image display medium by simple matrix driving.   4. The image display medium driving device according to claim 1, wherein the image display medium is an image display medium having a memory property.   The image display medium is sealed at least partially between a display substrate having translucency, a back substrate disposed opposite to the display substrate with a gap, and between the display substrate and the back substrate, 5. A plurality of types of particle groups having different colors and different charging characteristics that are movably enclosed in accordance with an electric field formed by a voltage applied between the electrode pairs. Image display medium drive apparatus. A driving method for driving an image display medium that displays an image corresponding to the image information by applying a voltage according to the image information,
Outputting image information;
Inputting the image information and applying a voltage corresponding to the input image information to the image display medium;
Prohibiting output of the image information for at least a first predetermined period of the voltage application period; and
A method for driving an image display medium, comprising: A drive program for causing a computer to execute a drive method for driving an image display medium that displays an image corresponding to the image information by applying a voltage according to the image information,
Outputting image information; and
Inputting the image information and applying a voltage corresponding to the input image information to the image display medium;
Prohibiting output of the image information for at least a first predetermined period of the voltage application period; and
A program for driving an image display medium, which causes a computer to execute a process including:

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