JP2006267327A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device for realizing sufficient contrast for display pixels by applying a voltage to a column electrode and a line electrode by adopting a simple matrix driving system. <P>SOLUTION: In an image display device 10, a driving device 14 successively applies E as a scanning voltage to one of a plurality of display side electrode 20 and a back side electrode 22, and applies ±1/4E as a data voltage to the other electrode, and carries out the first scanning to a whole image display medium 12, and successively applies -1/2E as a scanning voltage to one electrode, and re-applied ±-1/4E as a data voltage to the other electrode. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides an electrophoretic display medium that performs display by selectively moving a group of charged electrophoretic particles encapsulated between an opposing display substrate and a back substrate to the display substrate side and the back substrate side for each pixel. The present invention relates to the image display device used.

  From the viewpoint of reducing power consumption or reducing the burden on the eyes, expectations for reflective display devices are increasing, and as one of them, image display devices using electrophoretic display media are known.

  In this type of display medium, two types of migrating particles having charging characteristics of different polarities are mixed so as to be movable in a dispersion medium (liquid / gas). Each of the migrating particles has a positive charge or a negative charge on the surface in the dispersion medium.

  An image display device using this type of electrophoretic display medium has a configuration in which the above display medium is sealed between electrodes provided facing each other. In the above two types of migrating particles, when a positive charge is given to one of the electrodes provided opposite to each other and a negative charge is given to the other, the migrating particles carrying a negative charge move to one electrode. In addition, electrophoretic particles having a positive charge move to the other electrode.

  If these two types of electrophoretic particles with positive and negative charges are colored in different colors, a specific color is observed from one side of the electrode, thereby enabling image display. .

  As for the display medium as described above and a display device using the display medium, there are proposals such as Japanese Patent Application Laid-Open No. 2001-33833 (Patent Document 1) or Japanese Patent Application Laid-Open No. 2001-31225 (Patent Document 2).

  Here, the above two patent documents describe an image display device that drives an image display medium by so-called simple matrix driving.

  In an image display device that performs simple matrix driving, a plurality of line-shaped display-side electrodes are provided on the display substrate side, and a plurality of line-shaped back-side electrodes are provided on the back substrate side in a direction orthogonal to the longitudinal direction of the display-side electrodes. Is provided.

  Then, for example, while sequentially changing the back side electrode to which the voltage is applied, the voltage is applied to all the display side electrodes corresponding to the pixels to which the migrating particles need to be moved in synchronization with this. Thereby, it is possible to display a desired image by moving only the electrophoretic particles of the necessary pixels.

  As described above, in the simple matrix drive, since the drive is performed for each line, not for each pixel, an electric field acts on the migrating particles also in the non-image writing unit. Therefore, in order to implement the simple matrix driving, it is necessary that the display characteristics of the image display medium are not displayed up to a certain applied voltage value, and sufficient display is required at a voltage higher than that.

  However, if a voltage exceeding the maximum particle stop voltage is applied to the display substrate, the display density does not change abruptly, and the display density gradually changes according to the change in the applied voltage. In other words, the voltage applied to the image non-display pixel does not exceed the particle stop maximum voltage, but the voltage applied to the image display pixel is not so large and the difference from the stop maximum voltage is small, the display density is sufficient. Cannot be obtained, resulting in a display mode in which the display gradation is halftone and blurred.

  Therefore, in order to obtain a clear image with sufficient display contrast, it is necessary to increase the ratio between the voltage applied to the image non-display pixel and the voltage applied to the image display pixel as much as possible. .

  Since the above requirements are the same for liquid crystal display devices, a number of voltage application methods have been proposed for liquid crystal display devices. One of them is a method called “voltage averaging method” (Non-Patent Document 1: “Introduction to Liquid Crystal Display” written by Nikkan Kogyo Shimbun, 1998, written by Yasuji Suzuki).

In a normal simple matrix, the ratio of the voltage applied to the image non-display pixel and the voltage applied to the image display pixel is 1: 2, but in the voltage averaging method, the ratio may be 1: 3. Is possible.
JP 2001-33833 A JP 2001-31225 A "Introduction to Liquid Crystal Display", pages 128-131, published by Nikkan Kogyo Shimbun, published by Hachiji Suzuki (1998)

  When displaying the display example shown in FIG. 12 using a specific conventional image display device, a case will be described in which a voltage is applied to the column electrodes and the row electrodes by a simple matrix based on the voltage averaging method.

  In this case, in each pixel, a pixel displaying “black” is hatched, and a pixel displaying “white” is shown as not hatched. In this display example, the voltages applied to the column electrodes a and the row electrodes b are as shown in FIGS. “E” is a reference voltage (value). For example, 2E and 3E represent twice and three times E.

  As shown in FIGS. 13 and 14, in the column electrode a, 0 (= 0E) is applied to the display unit and 2E is applied to the non-display unit, and in the row electrode b, 3E is applied to the display unit and E is applied to the non-display unit. Therefore, the ratio of the voltage applied to the display pixel and the voltage applied to the non-display pixel is 1: 3. In this case, the potential difference between the row electrode and the column electrode in the display pixel is 3E.

  However, if the voltage averaging method is used in this way, the ratio of the voltage applied to the display pixel and the non-display pixel in the conventional simple matrix drive is improved from 1: 2 to 1: 3. It has been a limitation of the prior art to set the voltage to be three times that of the non-display pixels.

  The present invention has been made in view of the above problems, and in an image display device using electrophoretic particles, a simple matrix driving method is applied to a display pixel by applying a voltage to a column electrode and a row electrode. An object of the present invention is to provide an image display device capable of realizing sufficient contrast.

  The present invention relates to an image display apparatus.

  The image display device of the present invention moves between the substrates by a display substrate having at least translucency, a rear substrate facing the display substrate, and an electric field formed between the display substrate and the rear substrate. At least one kind of particle group enclosed in a possible manner, a plurality of line-shaped display side electrodes provided on the display substrate side and arranged in parallel, and provided on the back substrate side, and the display side electrode A scanning voltage is applied to one of the display-side electrode and the back-side electrode on an image display medium comprising a plurality of line-like back-side electrodes arranged in a direction crossing the longitudinal direction of In the image display device for displaying the image information so as to be visible from the display substrate side by moving and stopping the particles for each pixel by applying a data voltage corresponding to the image information to the other electrode. A voltage value that enables movement of substantially the whole of at least one kind of particles between the plate and the back substrate is set as a reference voltage E, and is sequentially applied to one of the plurality of display side electrodes and the back side electrode as a scanning voltage. It has a display medium driving means for applying E and applying ± 1 / 4E as a data voltage to the other electrode.

  In the image display device of the present invention, the display medium driving means sequentially applies E as the scanning voltage to one of the plurality of display side electrodes and the back side electrode, respectively, and the data voltage to the other electrode. ± 1 / 4E is applied to the entire image display medium for the first time, −1 / 2E is sequentially applied to the one electrode as a scanning voltage, and the data voltage is applied to the other electrode as ± It is preferable to apply −1 / 4E again.

  In the image display device of the present invention, it is preferable that ± 1 / 4E is equal to or less than a dead voltage at which particles do not move even when the voltage is applied to one of the display side electrode and the back side electrode. is there.

  According to the image display device of the present invention, the voltage value that enables the movement of substantially the whole of at least one kind of particles between the display substrate and the back substrate is set as the reference voltage E, and each of the display sides by the display medium driving means. Since E is sequentially applied to one of the electrodes and the back side electrode as a scanning voltage and ± 1 / 4E is applied to the other electrode as a data voltage, a potential difference of 5 / 4E is applied to the display pixel. In addition, the image can be displayed with good contrast by reliably moving the particles to the display side electrode or the back side electrode.

  Further, in the present invention, after the first scan, -1 / 2E is sequentially applied to the one electrode as the scan voltage by the second scan, and ± -1 as the data voltage is applied to the other electrode. By applying / 4E again (Claim 2), the difference between -1 / 2E of the scanning voltage and ± -1 / 4E of the data voltage becomes -1 / 4E or -3 / 4E.

  Accordingly, a potential difference of −1 / 4E is applied to the pixel (display pixel) in which particles are moved for display in the first scan by the second scan. It is preferable that -1 / 4E of the potential difference is equal to or less than the insensitive voltage of the particle (Claim 3), whereby the particle does not move and the display pixel moved by the first scanning moves. The display does not change.

  On the other hand, the potential difference between the scan voltage and the data voltage is also 3 / 4E to the pixel (non-display pixel) in which the particle is not moved for non-display in the first scan, and thus the particle moves to some extent. In other words, the pixels may have an intermediate display with no clear contrast. If the particles are black, the display is gray. On the other hand, as described above, it is preferable to apply a potential difference of −3 / 4E to the non-display pixel between the electrodes by the second scanning. This potential difference is a reverse voltage of 3 / 4E of the potential difference by the first scan described above, and the particles moved by the first potential difference are pulled back by applying a reverse voltage of the same absolute value. It can be clarified with good contrast that it is not displayed.

  Hereinafter, embodiments (embodiments) of the present invention will be described with reference to the accompanying drawings.

  1 to 11 are examples of embodiments of the present invention. In the drawings, the same reference numerals denote the same components.

  FIG. 1 is an explanatory diagram showing the overall configuration of an image display device according to an embodiment of the present invention, and FIGS. 2A and 2B are vertical cross-sectional descriptions along the row and column directions of the image display medium (display element). FIG. 3, FIG. 3 is a threshold characteristic diagram of reflectance with respect to external light with respect to an applied voltage of ink in which migrating particles are mixed in a dispersion medium, FIG. 4 is an explanatory diagram of a display example of a display medium, and FIGS. 5 to 7 are display media FIG. 8 is an explanatory diagram of the first voltage application to the column electrode and the row electrode, FIG. 8 is an explanatory diagram of the display state by the migrating particles after the first voltage application in the display medium, and FIG. 9 to FIG. FIG. 11 is an explanatory diagram of the second voltage application to the column electrode and the row electrode, and FIG. 11 is an explanatory diagram of the display state by the migrating particles after the second voltage application in the display medium.

  As shown in FIGS. 1 and 2, an image display apparatus 10 according to the present embodiment includes an image display medium (image display element) 12 that displays an image based on an image signal, and a drive apparatus that drives the image display medium 12. (Display medium driving means) 14.

  The image display medium 12 includes a transparent display substrate 16 made of resin or glass on the image display side, and a back substrate 18 disposed opposite to the display substrate 16 and spaced apart from the display substrate 16 by a thickness of the image display medium 12. It is provided on the front surface and back surface. A space between the display substrate 16 and the back substrate 18 accommodates migrating particles.

  The image display medium 12 is driven by a so-called simple matrix driving method, and a plurality of line-shaped electrodes (hereinafter referred to as “column electrodes”) 20 are provided on the surface of the display substrate 16 facing the back substrate 18. Similarly, a plurality of line-shaped electrodes (hereinafter referred to as “row electrodes”) 22 are also provided on the surface of the back substrate 18 facing the display substrate 16.

  The display substrate 16 and the back substrate 18 are arranged to face each other with a space portion therebetween so that the line directions of the column electrodes 20 and the row electrodes 22 provided to each other are orthogonal to each other. Insulating layers 24 and 26 are provided on the surfaces of the display substrate 16 and the back substrate 18 facing the respective spaces so that the column electrodes 20 and the row electrodes 22 do not directly contact the migrating particles.

  In the present embodiment, the image display medium 12 has a 4 × 4 simple matrix configuration for simplification of description, and the four column electrodes 20 of the display substrate 16 are indicated by a, b, c, and d, respectively. The row electrodes 22 of the back substrate 18 are indicated by (1), (2), (3), and (4), respectively.

  Further, the image display medium according to the present invention is not limited to the configuration of this embodiment, and the number of electrodes corresponding to the vertical and horizontal pixel lines necessary for image display can be formed on each substrate.

  In the present embodiment, the line-shaped electrode of the display substrate 16 is a column electrode, and the line-shaped electrode of the back substrate 18 forms a row electrode. A configuration in which row electrodes are provided and column electrodes are provided on the back substrate 18 may be employed.

  Further, the column electrode 20 and the row electrode 22 may be embedded in the display substrate 16 and the back substrate 18, and are formed on the surface opposite to the surface on the opposite side of the display substrate 16 and the back substrate 18. Alternatively, the display substrate 16 and the rear substrate 18 may be disposed separately and independently.

  Here, in the space between the display substrate 16 and the back substrate 18 in the image display medium 12, there are particle groups having different charging characteristics, that is, positively charged white particles 28 and negatively charged black particles 32. And are enclosed. The two types of particles, the white particles 28 and the black particles 32, correspond to particles that are moved between the display-side electrode and the back-side electrode of the present invention. In the present invention, one type of white particles, for example, may be used. In this case, one type of white particle is used, and the medium is colored with a dye or the like, and the white particle moves to the back substrate side to reveal an image, while moving to the display substrate side. This can be realized by selecting a medium in which the particles migrate so that the image becomes invisible.

  In addition, a gap member 30 is provided between the display substrate 16 and the back substrate 18, thereby keeping a constant distance between the display substrate 16 and the back substrate 18.

  As shown in FIG. 1, the image display medium 12 is connected to a driving device 14.

  In the present embodiment, the sequencer 44 of the drive device 14 has a central processing unit (CPU), a temporary storage device (RAM), and a nonvolatile storage device (ROM) (not shown) in the ROM. Then, E is sequentially applied to one of the plurality of display-side electrodes and the back-side electrode, and ± 1 / 4E is applied to the other electrode as a data voltage to the entire image display medium. After the first scan, there is a program that realizes a function of sequentially applying -1 / 2E to the one electrode as a scan voltage and re-applying ± -1 / 4E as a data voltage to the other electrode. It is remembered.

  Specifically, the column electrode 20 of the display substrate 16 and the row electrode 22 of the rear substrate 18 are connected to a column electrode drive circuit 40 and a row electrode drive circuit 42, respectively. Reference numeral 42 denotes a sequencer 44 and an external power supply 46. The sequencer 44 is connected to the image input device 48 and outputs an image information signal (image data signal) to the column electrode drive circuit 40 and the row electrode drive circuit 42 in accordance with arbitrary image information input from the image input device 48. .

  In simple matrix driving, an image writing signal (scanning signal) for each row is sent from the sequencer 44 to the row electrode driving circuit 42, and the image writing signals are sequentially pressed from the row electrode driving circuit 42 to the row electrodes 22 of the rear substrate 18. The

  At the same time, an image information signal corresponding to the row to which the image writing voltage is applied is sent from the sequencer 44 to the column electrode driving circuit 40 in synchronization with the image writing signal sequentially applied to the row electrodes 22 of the back substrate 18. Image write voltages corresponding to the write rows are applied simultaneously from the column electrode drive circuit 40 to the column electrodes 20 of the display substrate 16.

  Simultaneous application of an image writing voltage to the column electrode 20 corresponding to the writing row of the row electrode 22 (for example, application of a voltage of 1 / 4E to the column electrode 20 corresponding to the black display pixel, column output corresponding to the white display pixel) 20 is applied in order from the first line to the last line, and a desired image is displayed.

  Even when the application of voltage is stopped, the white particles 28 or the black particles 32 remain attached to the display substrate 16 or the back substrate 18 due to the mirror image force, and the image display is maintained.

  The column electrode 20 of the embodiment corresponds to the display side electrode of the present invention, the row electrode 22 corresponds to the back side electrode of the present invention, and the column electrode drive circuit 40, the row electrode drive circuit 42, and the sequencer 44 are This corresponds to the display medium driving means (voltage applying means) of the present invention.

  The operation of the image display apparatus according to the embodiment will be described below.

  The display characteristic of the image display medium 12 is that, with respect to the positively charged white particles 28, a voltage lower than the negative side particle maximum stop voltage (a voltage having a large absolute value) is applied to the column electrode 20 (display side electrode) of the display substrate 16. When applied, the white particles 28 on the back substrate 18 side start moving to the display substrate 16 side. The “negative particle maximum stop voltage” is a voltage having a maximum absolute value in a voltage range in which it is possible to maintain that the white particles 28 are stopped on the back substrate 18 side.

  Further, the display characteristic is that the black particles 32 on the back substrate 18 side are displayed when a voltage exceeding the maximum positive particle stop voltage is applied to the column electrode 20 of the display substrate 16 with respect to the negatively charged black particles 32. The movement starts to the substrate 16 side. The “positive particle stop maximum voltage” is the maximum voltage among the voltages that can maintain the state where the black particles 32 are stopped on the back substrate 18 side.

  Similarly, in the row electrode 22 of the back substrate 18, when a voltage lower than or exceeding the negative / positive particle maximum stop voltage is applied, the white particles 28 and the black particles 32 on the display substrate 16 side are applied. Starts to move to the back substrate 18 side.

FIG. 3 shows the ink threshold characteristics illustrating the particle maximum stop voltage.
In this case, the ink includes white particles charged with a positive charge and black particles charged with a negative charge, and these particles are mixed in a medium.
An example of an ink composition exhibiting such characteristics is as follows: black particles are carbon black-containing acrylic copolymer fine particles, white particles are organic titanate-treated titanium dioxide particles, and the medium is a normal paraffin based particle dispersant and charge control. Each is mainly composed of an agent, but the ink used in the present invention is not limited to this.
For example, a one-particle ink using one kind of particle that dissolves a dye in a medium and develops ink threshold characteristics only on the negative side or only on the positive side may be used as the ink for the present invention.

In the measurement according to the graph of FIG. 3, the ink is sealed between the display substrate and the back substrate of the embodiment, a positive voltage is applied to the display-side electrode, and the applied voltage and the reflectance of the ink with respect to external light are measured. Is measured.
This graph plots the reflectivity of the ink with respect to the applied voltage while changing (increasing) the applied voltage (absolute value).

That is, the reflectance of 50% is apparently white (so-called pure white), and the reflectance of 5 to 0% is when the reflected light is almost lost and apparently black (so-called pure black). .
When the voltage applied to the display-side electrode is increased, the reflectance does not change from 0 to 15 (v) and remains white. The maximum value in the voltage range in which the particles do not move even when this is applied and the color does not appear to change is called “particle maximum stop voltage”.
Further, when it exceeds 15 (v), the reflectance gradually decreases, and approaches white through gray through black. However, as can be seen from the graph of FIG. 3, the change to black is not abrupt, and the reflectance gradually decreases in the range of 15 to 60 (v). This is because black particles increase with increasing applied voltage. It will move more and will become clearer with voltage.
When the applied voltage exceeds 60 (v), it becomes black (black) by applying the voltage, and the blackness does not change even if it is increased beyond 60 (v).

In the example of FIG. 3, the particle maximum stop voltage was −15 (v) for the negative particle maximum stop voltage for black particles. The white particles also had the opposite characteristics of reflectance, and the positive particle maximum stop voltage was +15 (v).
Therefore, the particle maximum stop voltage is plus / minus (±) 15 (v).

  When a voltage equal to or lower than the value (absolute value) of the particle maximum stop voltage is applied to the electrode, the particle does not move, and this voltage value is regarded as a dead voltage.

  In the case of FIG. 3, when the voltage is 15 (v) or less, the reflectivity does not change, and the voltage value of 15 (v) or less is a dead voltage in the characteristic of FIG.

  As a specific example, a case of displaying as shown in FIG. In the present invention, the voltage applied to the column electrode is applied to FIG. 5 when the reference voltage E is a voltage value that enables at least substantially the entire black particles to move between the display substrate 16 and the back substrate 18. The voltage corresponding to the image information (image data) to be set is -1 / 4E and 1 / 4E. Then, as described below, scanning for applying a voltage to the column electrode 20 and the row electrode 22 is performed twice according to the image information.

  6 to 10, for the sake of easy understanding, the voltage values corresponding to the image information −1 / 4E and ¼E are quadrupled as a whole to be displayed as −E and E. Therefore, in the following description, the reference voltage is 4E.

  First, when applied in the first scan, the column voltage of the portion corresponding to the display pixel is −E, and the column voltage of the portion corresponding to the non-display pixel is E. The row voltage of the scanning row is 4E, and the row voltage of the non-scanning row is 0.

  As a result of scanning to the last row, 5E is applied to the display pixels in the display row. That is, the potential difference between the applied voltage 4E of the row electrode 22 and the applied voltage −E of the column electrode 20 is 5E (= 4E − (− E)).

  In addition, 3E is applied to the non-display pixels in the display row. That is, the potential difference between the applied voltage 4E of the row electrode 22 and the applied voltage E of the column electrode 20 is 3E (= 4E−E).

  Further, -E or E is applied to the non-display row.

  When E = 15 (v) (reference voltage 4E = 60 (v)), since the dead voltage is 25E as described above, the particles do not move even when -E or E is applied. Therefore, there is no influence of the applied voltage in the non-display row, and as a result of the application to the last row, 5E (75 (v) in the case of FIG. 3) is applied to the display pixel and 3E is applied to the non-display pixel. The particles move according to the voltage, and the result is as shown in FIG.

  Next, application is performed in the second scan.

  In the second scan, as shown in FIGS. 9 to 10, the column voltage of the portion corresponding to the display pixel is −E, and the column voltage of the portion corresponding to the non-display pixel is the same as the first scan described above. Is E, but the row voltage is -2E for the display row and 0 for the non-display row.

  The voltage applied to the image display medium 12 is −E for display pixels in the display row, −3E for non-display pixels in the display row, and −E or + E for non-display rows.

  Here, ± E is a dead voltage, and as a result of scanning up to the last row, −3E is applied only to the non-display pixels.

  As a result of scanning twice to the last row, 5E, which is the maximum drive voltage, is applied to the display pixel, -E or + E is applied to the non-display pixel, and the ratio of the applied voltage between the display pixel and the non-display pixel Becomes 1: 5.

  Therefore, as shown in FIG. 11, a clear image having an unprecedented display contrast can be obtained.

  According to the embodiment, a clear image having a sufficient display contrast can be obtained even when the image display medium is driven by a simple matrix driving method.

  Of course, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, with respect to the reference voltage E (shown as “4E” in FIG. 5 and the like), E (the voltage having the same value as the reference voltage) is applied to the row voltage at the time of the first scan in the above case. In the second application, −1 / 2E (indicated as “−2E” in FIG. 9 or the like) is applied, but this is limited to a display medium that digitally moves particles (electrophoretic particles).

  However, since E, -1 / 2E, and ± 1 / 4E have an error in the actual image display apparatus, the voltage range including the error is substantially within the range of the applied voltage in the present invention. .

  In addition, when particles have different movement characteristics on the + side and the − side, a method of applying a bias to one side can be employed. For example, when it is assumed that the movement is easier on the negative side, there is a method in which only the row voltage is slightly increased (for example, 1.05E). The width for increasing the voltage is considered to be approximately ± 25%, although it depends on the ink characteristics.

  Therefore, it is within the scope of the present invention that the voltage applied to each electrode changes within the range of ± 25%.

  In addition to the above black and white, the particles may be colored in various colors such as red, blue, and yellow.

It is explanatory drawing which shows the whole structure of the image display apparatus which concerns on embodiment of this invention. (A), (b) is sectional drawing along the II-II line | wire and III-III line | wire of FIG. 1, Comprising: It is explanatory drawing along the row direction and column direction of an image display medium (display element). FIG. 6 is a threshold characteristic diagram of reflectance of external light with respect to an applied voltage of ink in which migrating particles are mixed in a dispersion medium. It is explanatory drawing of the example of a display of a display medium. FIG. 9 is an explanatory diagram of voltage application in the first scan to the column electrode and the row electrode of the display medium, where E is the reference voltage. It is explanatory drawing of the voltage application in the 1st scan to the column electrode and row electrode of a display medium, Comprising: The reference voltage is set to 4E. FIG. 7 is an explanatory diagram of voltage application in the first scan to the column electrode and the row electrode of the display medium following FIG. 6. It is explanatory drawing of the display state by the electrophoretic particle after the voltage application by the 1st scan in a display medium. It is explanatory drawing of the voltage application in the 2nd scan to the column electrode and row electrode of a display medium. FIG. 10 is an explanatory diagram of voltage application in the second scan to the column electrode and the row electrode of the display medium following FIG. 9. It is explanatory drawing of the display state by the electrophoretic particle after the voltage application by the 2nd scan in a display medium. It is explanatory drawing of the example of a display shown with the conventional image display apparatus. It is explanatory drawing of the voltage applied to the column electrode and row electrode of the conventional image display apparatus. It is explanatory drawing of the voltage applied to the column electrode and row electrode of the conventional image display apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image display apparatus 12 Image display medium 14 Drive apparatus 16 Display board 18 Back board 20 Column electrode (display side electrode)
22 row electrode (back side electrode)
24 Insulating layer 28 Black particles (particles, migrating particles)
30 Gap member 32 White particles (particles, migrating particles)
40 column electrode drive circuit 42 row electrode drive circuit 44 sequencer 46 external power supply 48 image input device

Claims (3)

At least one kind of a display substrate having at least translucency, a rear substrate facing the display substrate, and an electric field formed between the display substrate and the rear substrate so as to be movable between the substrates. In a direction intersecting with the longitudinal direction of the display-side electrode provided on the back substrate side, and a plurality of line-like display-side electrodes provided on the display substrate side and arranged in parallel In an image display medium provided with a plurality of line-shaped backside electrodes arranged,
By applying a scanning voltage to one of the display side electrode and the back side electrode, and applying a data voltage corresponding to image information to the other electrode, the particles are moved and stopped for each pixel. In the image display device that displays the image information so as to be visible from the display substrate side,
The reference voltage E is a voltage value that enables movement of substantially the whole of at least one kind of particles between the display substrate and the rear substrate.
A display medium driving means for sequentially applying E as a scanning voltage to one of a plurality of display side electrodes and a back side electrode, and applying ± 1 / 4E as a data voltage to the other electrode; A characteristic image display device. The display medium driving means sequentially applies E as a scanning voltage to one of the plurality of display side electrodes and the back side electrode, and applies ± 1 / 4E as a data voltage to the other electrode. After the first scan of the entire image display medium,
2. The image display device according to claim 1, wherein -1 / 2E is sequentially applied to the one electrode as a scanning voltage and ± -1 / 4E is applied again as a data voltage to the other electrode. 3. The image display according to claim 1, wherein ± 1 / 4E is equal to or less than a dead voltage at which particles do not move even when the voltage is applied to one of the display side electrode and the back side electrode. apparatus.

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