WO2017115645A1

WO2017115645A1 - Display device, drive method, and electronic apparatus

Info

Publication number: WO2017115645A1
Application number: PCT/JP2016/087085
Authority: WO
Inventors: 安倍　浩信
Original assignee: ソニー株式会社
Priority date: 2015-12-28
Filing date: 2016-12-13
Publication date: 2017-07-06
Also published as: JP2017120315A

Abstract

A display device provided with: a pixel part including an electrophoresis element and having a plurality of pixels; and a drive part for performing drive by applying a voltage waveform for switching at least two values to each pixel of the pixel part, extending over multiple frames, and causing the display state of the pixel to change. When adjacent first and second pixels out of the plurality of pixels have mutually different display states, the drive part performs drive using such a combination of voltage waveforms applied to the first and second pixels that the difference between the voltage values applied to the first and second pixels is smaller than in other combinations.

Description

Display device, driving method, and electronic apparatus

The present disclosure relates to a display device using an electrophoretic element, a driving method, and an electronic apparatus.

In an active matrix display device using an electrophoretic element, when an image is rewritten, it is applied to each pixel based on the information of the image that has been displayed so far and the information of the image that is to be displayed next. A voltage waveform (Waveform) is determined, and each pixel is driven to display using this voltage waveform.

However, in a display device using such an electrophoretic element, a phenomenon in which a part of the previous image remains in the rewritten image (afterimage) occurs, or a phenomenon in which the image quality of the contour portion of the image deteriorates (edge ghost). May occur.

Therefore, for example, Patent Document 1 proposes a method for correcting an edge ghost generated in an image. In this method, by applying a voltage that cancels the edge ghost to the portion where the edge ghost has occurred, the display state of the portion can be changed to make the edge ghost inconspicuous.

JP 2012-93406 A

However, in the method of Patent Document 1, it takes time to further apply (overwrite) a voltage in order to correct the edge ghost. For this reason, when the edge ghost is strong, the correction takes a long time or the correction itself becomes difficult. In addition, a new edge ghost may occur due to overwriting. As described above, with the method of correcting the generated edge ghost afterwards, it is difficult to sufficiently suppress image quality deterioration due to the edge ghost.

Therefore, it is desirable to provide a display device, a driving method, and an electronic device that can suppress image quality deterioration.

A display device according to an embodiment of the present disclosure includes a pixel unit including an electrophoretic element and having a plurality of pixels, and applying a voltage waveform for switching at least two values to each pixel of the pixel unit over a plurality of frames. A driving unit that performs driving to change the display state of the pixel. When the first and second pixels adjacent to each other among the plurality of pixels have different display states, the driving unit includes first and second voltage waveforms as combinations of the voltage waveforms applied to the first and second pixels. The driving is performed using a combination in which the difference between the voltage values applied to the two pixels is smaller.

A driving method according to an embodiment of the present disclosure performs driving for changing a display state of a pixel by applying a voltage waveform for switching at least two values over a plurality of frames to each of a plurality of pixels including an electrophoretic element. When adjacent first and second pixels of the plurality of pixels have different display states, combinations of voltage waveforms applied to the first and second pixels are applied to the first and second pixels. On the other hand, a combination in which the difference between the applied voltage values becomes smaller is used.

An electronic apparatus according to an embodiment of the present disclosure includes the display device according to the embodiment of the present disclosure.

In the display device, the driving method, and the electronic device according to the embodiment of the present disclosure, each voltage waveform applied to the first and second pixels when the adjacent first and second pixels have different display states. As the combination, the combination in which the difference between the voltage values applied to the first and second pixels becomes smaller is used. Thereby, the electric field generated in the horizontal direction between the adjacent first and second pixels is reduced, and the occurrence of edge ghost is suppressed.

According to the display device, the driving method, and the electronic device according to the embodiment of the present disclosure, when the first and second pixels adjacent to each other have different display states, each applied to the first and second pixels As a combination with the voltage waveform, a combination in which the difference between the voltage values applied to the first and second pixels is smaller is used. Thereby, when adjacent first and second pixels have different display states, the occurrence of edge ghost can be suppressed. Therefore, it is possible to suppress image quality deterioration.

The above content is an example of the present disclosure. The effects of the present disclosure are not limited to those described above, and may be other different effects or may include other effects.

1 is a functional block diagram illustrating an overall configuration of a display device according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view illustrating a main configuration of a pixel array unit illustrated in FIG. 1. It is a schematic diagram for demonstrating a display drive operation | movement. It is a figure showing an example of the voltage waveform which drives each pixel. It is a cross-sectional schematic diagram showing a black display state. It is a cross-sectional schematic diagram showing a white display state. It is a cross-sectional schematic diagram showing the boundary area | region of a black display state and a white display state. It is a figure showing an example of the image displayed on a pixel array part. It is the figure which expanded the one part area | region of FIG. 6 is a schematic diagram illustrating an image written by a driving method according to Comparative Example 1. FIG. 12 is a schematic diagram illustrating an image displayed by a driving method according to Comparative Example 1. FIG. 10 is a schematic diagram for explaining a driving method according to Comparative Example 2. FIG. It is a schematic diagram of the voltage waveform used for the driving method according to the present embodiment. FIG. 6 is a schematic diagram illustrating an image written by the driving method according to the first embodiment. 6 is a schematic diagram illustrating an image displayed by the driving method according to Embodiment 1. FIG. 6 is a diagram illustrating an example of a voltage waveform according to Modification 1. FIG. It is a figure showing the example of substitution of the combination of each voltage waveform of the pixel holding a white display state, and the pixel which a display state changes from white to gray. It is a figure showing the example of substitution of the combination of each voltage waveform of the pixel holding a black display state, and the pixel holding a gray display state. 10 is a schematic diagram illustrating an image written by a driving method according to Comparative Example 3. FIG. 10 is a schematic diagram illustrating an image displayed by a driving method according to Comparative Example 3. FIG. 6 is a schematic diagram illustrating an image written by a driving method according to Embodiment 2. FIG. FIG. 10 is a schematic diagram illustrating an image displayed by a driving method according to a second embodiment. 10 is a schematic diagram for explaining a display body according to Modification 2. FIG. 14 is a perspective view illustrating an appearance of application example 1. FIG. FIG. 24B is a perspective view illustrating another example of the electronic book illustrated in FIG. 24A. 12 is a perspective view illustrating an appearance of application example 2. FIG. 12 is a perspective view illustrating an appearance of application example 3. FIG. FIG. 26B is a perspective view illustrating another display example of the electronic timepiece illustrated in FIG. 26A.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The order of explanation is as follows.
1. Embodiment (an example of an electrophoretic display device that is driven by applying voltage waveforms in a predetermined combination to adjacent pixels)
2. Modification 1 (Driving example of a pixel having a gray display state)
3. Modification 2 (example when a porous layer is used for the display body)
4). Application examples (examples of electronic devices)

<Embodiment>
[Constitution]
FIG. 1 illustrates an overall configuration of a display device (display device 1) according to a first embodiment of the present disclosure. The display device 1 is a reflective display device that displays an image using, for example, an electrophoretic element.

The display device 1 includes, for example, a pixel array unit 10, a panel control unit 51, a gate drive unit 52, a source drive unit 53, a data replacement unit 54, and a central control unit 50. The display device 1 further includes LUTs (look-up tables) 55A and 55B, a contour (edge) detection unit 56, and

storage units

57A and 57B. The panel control unit 51, the gate drive unit 52, the source drive unit 53, the data replacement unit 54, and the central control unit 50 in the present embodiment correspond to a specific example of “drive unit” in the present disclosure. Further, the

LUTs

55A and 55B correspond to specific examples of “first holding unit” and “second holding unit” of the present disclosure.

The pixel array unit 10 includes, for example, a plurality of pixels P arranged in a matrix, and is driven to display by an active matrix driving method using a thin film transistor (TFT: Thin Film Transistor). As will be described in detail later, the pixel array unit 10 includes, for example, an electrophoretic element, and displays an image (such as text) by changing the light reflectance for each pixel P. The pixel array unit 10 is connected to the gate drive unit 52 and the source drive unit 53. A plurality of gate lines (gate voltage supply lines) 110G extending from the gate drive unit 52 along the row direction, and a plurality of source lines (source voltage supply lines) extending from the source drive unit 53 along the column direction. ) A pixel P is formed at each intersection with 110S.

The panel control unit 51 generates signals necessary to display and drive the pixel array unit 10, and includes, for example, a timing controller and a display signal generation unit. The panel control unit 51 can supply a common potential (ground potential or offset potential) to each pixel P, for example, via the common voltage supply line 110C. The panel control unit 51 is configured to perform gradation display for each pixel P by, for example, a pulse width modulation (PMW: Pulse Width Modulation) method in units of frames. That is, display driving of the pixel array unit 10 is performed by switching and applying at least two values to each pixel P over a plurality of frames and changing the display state of each pixel P.

The gate driving unit 52 sequentially selects a plurality of pixels P by sequentially applying gate signals (scanning signals) to the plurality of gate lines 110G in accordance with a control signal supplied from the panel control unit 51. The source driving unit 53 generates an analog signal corresponding to the image signal in accordance with a control signal supplied from the panel control unit 51, and applies the analog signal to each source line 110S. Signals for display (signals corresponding to voltage waveforms Dp and Dpa described later) applied to each source line 110S by the source drive unit 53 are applied to the pixel P selected by the gate drive unit 52. It is like that.

The data replacement unit 54 replaces the signal of the pixel corresponding to the contour portion of the image display signal (signal corresponding to the voltage waveform Dp) based on information about the voltage waveform (voltage waveform Dpa) held in advance. The process which performs is performed. Specifically, the data replacement unit 54 converts a part of the plurality of types of voltage waveforms Dp held in the LUT 55A as image display signals (voltage waveforms given to adjacent two pixels corresponding to the contour portion) into the LUT 55B. The replacement process is performed using the information held in.

The LUT 55A (first holding unit) holds information about the voltage waveform Dp (first voltage waveform) of the image display signal. In display driving using an electrophoretic element, a voltage waveform (Waveform) applied to a pixel in response to a change in the display state of the pixel, for example, a change from black to white, white to black, black to black, or white to white. Can take various patterns. In other words, when rewriting an image, information on the image that has been displayed so far (image information held in the storage unit 57A) and information on an image that is to be displayed next (image information held in the storage unit 57B). ) And the voltage waveform Dp applied to each pixel is set. Information about a plurality of types of voltage waveforms Dp corresponding to changes in these display states is held in advance as an LUT 55A.

The LUT 55B (second holding unit) stores information on the voltage waveform Dpa (second voltage waveform) obtained by replacing a part of the voltage waveform Dp (voltage waveform held in the LUT 55A) of the image display signal. It is to hold. The voltage waveform Dpa held in the LUT 55B is to be applied to one or both of two adjacent pixels (pixels P1 and P2 described later) arranged in a region corresponding to the contour portion of the image.

The contour detection unit 56 (detection unit) detects a contour (edge) portion of the image displayed on the pixel array unit 10 by, for example, a predetermined calculation process. Specifically, it can be detected by a technique using differential calculation processing between data of adjacent pixels or a technique using an algorithm such as an edge detection filter. The contour detection unit 56 detects pixels (two adjacent pixels having different display states) arranged in the contour portion in the image to be displayed.

In the present embodiment, driving is performed to optimize the combination of applied voltage waveforms for two adjacent pixels having different display states. Specifically, when two adjacent pixels have different display states (white, black, gray, etc.), they are held in

LUTs

55A and 55B as a combination with each voltage waveform applied to these two pixels. Among a plurality of types of voltage waveforms, a combination in which the difference between the voltage values applied to these two pixels is smaller is used.

The central control unit 50 is a central part of the display device 1 that performs all processes including display control, for example, specifically, a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-). It consists of parts such as Programmable (Gate Array).

The storage unit 57A is an image memory that stores information on an image (written image) that has already been displayed on the pixel array unit 10, for example. The storage unit 57B is an image memory that stores information on an image to be displayed (image to be written) in the pixel array unit 10, for example. As described above, the pieces of information of the images before and after display are separately held here, but these pieces of information may be held in one storage unit.

(Detailed configuration example of the pixel array unit 10)
FIG. 2 illustrates a main configuration of the pixel array unit 10 of the display device 1. The pixel array unit 10 includes, for example, a TFT layer 12, a first electrode 13, a display body 14, a second electrode 15, and a second substrate 16 in this order on a first substrate 11. In the pixel array unit 10, the display body 14 may be separated for each predetermined region by a partition (not shown), or the partition may not be provided.

The first substrate 11 is made of, for example, an inorganic material, a metal material, or plastic. Examples of the inorganic material include silicon (Si), silicon oxide (SiO _x ), and silicon nitride (S
iN _x ) or aluminum oxide (AlO _x ). Silicon oxide includes, for example, glass or spin-on-glass (SOG). Examples of the metal material include aluminum (Al), nickel (Ni), and stainless steel. Examples of the plastic include polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyethyl ether ketone (PEEK).

The TFT layer 12 is a layer in which, for example, pixel circuits and various wirings including TFTs (Thin Film Transistors) are formed. Specifically, the TFT layer 12 includes, for example, a TFT, a capacitor, a gate line (110G), a source line (110S), a common voltage supply line (110C), and the like. The TFT is disposed for each pixel P and is electrically connected to the first electrode 13. As a result, a signal voltage corresponding to the display image can be applied to the first electrode 13 of each pixel P. The surface of the TFT layer 12 is covered with a planarization insulating film.

A plurality of first electrodes 13 are arranged in a matrix (arranged for each pixel P). The first electrode 13 includes, for example, at least one of conductive materials such as gold (Au), silver (Ag), and copper (Cu).

The display body 14 is configured such that the light reflectance (light reflection characteristics) changes (generates contrast) according to the voltage applied through the first electrode 13 and the second electrode 15. For example, in the example shown in FIG. 2, the display body 14 includes, for example, a plurality of types of migrating particles having different light reflectivities in the insulating liquid 140, for example, positive (+) charged black particles 141, and negative (− ) Charged white particles 142.

The insulating liquid 140 is a nonaqueous solvent such as an organic solvent, and is specifically paraffin or isoparaffin. It is preferable that the viscosity and refractive index of the insulating liquid 140 be as low as possible. This is because the mobility (response speed) of the migrating particles (the black particles 141 and the white particles 142) is improved, and the energy (power consumption) required for the migrating particles to move is accordingly reduced. The insulating liquid 140 may contain various materials as necessary. For example, the insulating liquid 140 may include a colorant, a charge control agent, a dispersion stabilizer, a viscosity adjusting agent, a surfactant, or a resin.

Electrophoretic particles (black particles 141 and white particles 142) are one or more charged particles that can move between the first electrode 13 and the second electrode 15, and are dispersed in the insulating liquid 140. The migrating particles are positively or negatively charged, and for example, any one or two of organic pigments, inorganic pigments, dyes, carbon materials, metal materials, metal oxides, glasses, polymer materials (resins), and the like. These particles (powder). The migrating particles 152 may be pulverized particles or capsule particles of resin solids containing the above-described particles. However, materials corresponding to carbon materials, metal materials, metal oxides, glass, or polymer materials are excluded from materials corresponding to organic pigments, inorganic pigments, or dyes. As the migrating particles 152, any one of the above may be used, or a plurality of types may be used.

The specific forming material of the migrating particles is selected according to, for example, the role of the migrating particles to cause contrast. For example, the material of the black particles 141 is a black material such as a carbon material or a metal oxide. The carbon material is, for example, carbon black, and the metal oxide is, for example, copper-chromium oxide, copper-manganese oxide, copper-iron-manganese oxide, copper-chromium-manganese oxide, or copper-iron. -Chromium oxide and the like. Among these, a carbon material is preferable. This is because excellent chemical stability, mobility and light absorption are obtained. On the other hand, the material of the white particles 142 is a white material, for example, a metal oxide such as titanium oxide, zinc oxide, zirconium oxide, barium titanate, or potassium titanate. Among these, titanium oxide is preferable. This is because it is excellent in electrochemical stability and dispersibility and has high reflectance.

Note that these electrophoretic particles are preferably easily dispersed and charged in the insulating liquid 140 over a long period of time. For this reason, in order to disperse the migrating particles by electrostatic repulsion, a dispersing agent (or charge adjusting agent) may be used, or the migrating particles may be subjected to a surface treatment. Moreover, you may use both together.

The second electrode 15 is made of, for example, a transparent conductive film. Examples of the transparent conductive film include indium oxide-tin oxide (ITO), antimony oxide-tin oxide (ATO), fluorine-doped tin oxide (FTO), and aluminum-doped zinc oxide (AZO). Here, the second electrode 15 is formed on one surface of the second substrate 16 as an electrode common to all the pixels P, for example. The second electrode 15 is connected to the common voltage supply line 110C.

The second substrate 16 is made of the same material as the first substrate 11. However, since an image is displayed through the second substrate 16, a material having optical transparency is used for the second substrate 16. A color filter (not shown) may be provided in contact with one surface of the second substrate 16, above the second substrate 16, or between the second substrate 16 and the second electrode 15.

[Driving method]
In the display device 1 according to the present embodiment, the gate drive unit 52 and the source drive unit 53 voltage drive each pixel P of the pixel array unit 10 based on the control signal from the panel control unit 51 shown in FIG. . Specifically, a predetermined voltage (voltage waveform Dp, Dpa) is applied between the first electrode 13 and the second electrode 15 for each pixel P by active matrix driving, and according to this applied voltage. Electrophoretic particles (black particles 141 and white particles 142) move between the first electrode 13 and the second electrode 15. As a result, the light reflectance in the display body 14 changes for each pixel P (the display state of the pixel P changes), and an image can be displayed (rewritten).

Here, in the display device 1 using an electrophoretic element, when performing the display driving as described above, a voltage waveform for switching, for example, binary or ternary is applied over a plurality of frames by a so-called pulse width modulation method. . That is, in order to express a desired display state (gradation), for example, a period corresponding to several frames to several tens of frames (hereinafter referred to as a writing period) is a unit for displaying (or rewriting) one image. As a period, a voltage waveform Dp of a signal applied to each pixel P is set. As described above, the voltage waveform Dp is preset as a plurality of types of patterns in accordance with the change in the display state, and is held in the LUT 55A.

For example, FIG. 3 shows an example of a signal voltage waveform applied to certain pixels P (m) and P (n). As described above, when displaying an image, for example, a signal voltage for switching three values of the voltage value V _H , the voltage value V _L, and 0 V is applied to each of the pixels P (m) and P (n). In addition, one writing period (period for black display) with respect to the pixel P (m) is further composed of several tens of frames, and the voltage value has a predetermined pattern (voltage waveform DPb) in these several tens of frames. Switched and applied. Similarly, one writing period (period for white display) with respect to the pixel P (n) is further composed of several tens of frames, and the voltage value is a predetermined pattern (voltage waveform DPw) in these several tens of frames. Switched and applied. The voltage waveforms DPb and DPw are shown as an array of frame periods, and the voltage values V _L , 0 V, and voltage value V _H are respectively shown in the periods with numerical values “−1”, “0”, and “1”. This corresponds to the application period. The voltage value V _L is a negative value, for example, and can be set to −15V as an example. Voltage V _H is, for example, a positive value, it is possible to + 15V as an example. Among these, the voltage value V _L corresponds to a specific example of “first voltage value” of the present disclosure, the voltage value V _H corresponds to a specific example of “second voltage value”, and 0 V corresponds to “first voltage value”. This corresponds to a specific example of “three voltage values”. However, the voltage value is merely an example. The first voltage value and the second voltage value may be values other than −15V and 15V. Further, the third voltage value is not limited to 0V, and may be a value shifted from 0V as long as it is an intermediate value between the first voltage value and the second voltage value. Further, instead of such three voltage values, the voltage waveform may be set by switching between the two voltage values V _{L and} V _H.

FIG. 4 shows an example of the voltage waveform Dp. The voltage waveform Dp11 is an example of a voltage waveform for switching the display state from white to white (holding the white display state), for example. The voltage waveform Dp12 is an example of a voltage waveform for switching the display state from white to black. In FIG. 4, numerical values (−1, 0, 1) representing voltage values are shown for each frame period (1 V) in the upper part of each voltage waveform. The lower part shows the shape of the corresponding voltage waveform. As in these examples, each of the three values of voltage values V _L, V _H, and 0 V may be applied continuously over two or more frames, or may be switched in units of frames. However, these are merely examples, and there are many voltage waveform patterns (combinations of voltage value, switching timing, etc.) for changing the display state. In the display device 1, information on a plurality of types of voltage waveforms Dp corresponding to changes in the display state is held in advance as an LUT 55A. Thereby, the LUT 55A is appropriately referred to according to the image to be displayed, and a voltage waveform corresponding to the display state can be applied to each pixel P.

By applying the voltage waveform Dp as described above to the first electrode 13 for each pixel P, black display, white display, and the like can be performed. At this time, for example, when the display body 14 includes positively charged black particles 141 and negatively charged white particles 142, the black particles 141 are secondly applied by applying the voltage value V _H to the first electrode 13. White particles 142 move to the first electrode 13 side toward the electrode 15 side, respectively. As a result, as shown in FIG. 5, the pixel region to which the voltage value V _H is applied (here, the region corresponding to the three pixels P is shown) is displayed in black. As described above, in the region where the black display pixels P are adjacent to each other, the black particles 141 are uniformly distributed on the second electrode 15 side, and good black (with little shading unevenness) is displayed. it can.

On the other hand, when the voltage value V _L is applied to the first electrode 13, the black particles 141 move to the first electrode 13 side, and the white particles 142 move to the second electrode 15 side. As a result, as shown in FIG. 6, the pixel region to which the voltage value V _L is applied (here, the region corresponding to the three pixels P is displayed) is displayed in white. As described above, in the region where the white display pixels P are adjacent to each other, the white particles 142 are uniformly distributed on the second electrode 15 side, and a good (small shading unevenness) white color is displayed. it can.

However, as shown in FIG. 7, in an area where pixels having different display states, here, a white display pixel P (referred to as pixel P1) and a black display pixel P (referred to as pixel P2) are adjacent to each other, an edge Image quality degradation called ghost is likely to occur. This is due to the following reasons.

That is, the voltage waveform Dp for displaying white and the voltage waveform Dp for displaying black often have almost symmetrical waveform patterns (inversion patterns) from the viewpoint of migration of electrophoretic particles. For this reason, the potential difference between the adjacent first electrodes 13 in the pixels P1 and P2 tends to increase. For example, −15V is applied to the pixel P1, and + 15V is applied to the pixel P2. As a result, a large potential difference (for example, 30 V) occurs in the lateral direction (direction parallel to the first substrate 11) between the pixels P1 and P2. Since the potential difference applied between the first electrode 13 and the second electrode 15 in each of the pixels P1 and P2 is at most 15V, a potential difference of 30V larger than that is applied in the lateral direction. Become. For this reason, the electrophoretic particles easily move between the pixels P1 and P2, and an edge ghost is easily generated.

Specifically, in the boundary region 14e, the black particles 141 and the white particles 142 are affected by the electric field in the lateral direction as described above, and move in an unintended direction (to adjacent pixels). Thereby, for example, in the boundary region 14e of the pixel P2, the black particles 141 on the second electrode 15 side are small, and the white particles 142 on the first electrode 13 side are small. As a result, the edge portion of the pixel P2 has a color that is mixed with white instead of the original black (a white outline-shaped edge ghost is generated at the edge portion). On the other hand, in the pixel P1, contrary to the pixel P2, black is mixed in the edge portion and an edge ghost with a black outline may be generated. The degree of occurrence of the edge ghost varies depending on the structure of the electrophoretic element, the number of black particles 141 and white particles 142, and the like.

Such a boundary region 14e between the pixels P1 and P2 exists in the contour portion of the display image. FIG. 8 shows an example of an image (image 30) displayed on the pixel array unit 10. FIG. 9 shows a part of the area A in FIG. 8 in an enlarged manner. As shown in FIG. 8, when the image 30 includes a black character region 30A representing “H” and a white background region 30B, the outline portion of the character region 30A (the character region 30A and the background region 30B Boundary). In the area A corresponding to the contour portion, as shown in FIG. 9, pixels (for example, pixels a11 to a17) constituting the white display background area 30B and pixels (for example, pixels) constituting the black display character area 30A. a21 to a25) are adjacent to each other in the X direction and the Y direction or in the oblique direction. In this example, the adjacent two pixels are, for example, a set of pixel a11 and pixel a21, a set of pixel a12 and pixel a22, a set of pixel a13 and pixel a23, a set of pixel a15 and pixel a23, and a set of pixel a16 and pixel a24. Examples include a set and a set of the pixel a17 and the pixel a25. However, in addition to this, the combination of two adjacent pixels may be two pixels adjacent in the oblique direction, such as a set of the pixel a11 and the pixel a22 or a set of the pixel a14 and the pixel a23.

Here, as a comparative example (comparative example 1), as shown in FIG. 10, after displaying an image 30 (left figure) having a character area 30A and a background area 30B, an entire white image 31 (right figure) is displayed. When writing, the above-described edge ghost occurs in an actually displayed image. That is, as shown in the right diagram of FIG. 11, the image 103 is such that only the outline portion (x1) of the character region 30A remains lightly on the white background.

Therefore, there is a method of performing correction to erase the generated edge ghost when such an edge ghost occurs. FIG. 12 is a schematic diagram for explaining a driving method according to the second comparative example. The upper diagram in FIG. 12 shows a written image and an actually displayed image in time series. The lower diagram shows the voltage (Vcom) to the common electrode and the voltage waveform applied to the pixels i, j, m, and k. In this example, the image 104 with the character “K” is rewritten to the image 107B with the character “H”. At this time, first, the entire screen is changed from the image 104 displaying “K” to the white image 105 (display reset period). After that, based on the contour information extracted in advance, the normal image 106A is written (black writing period) in the region (pixel i, m) where no edge ghost occurs. Subsequently, in the region (pixels j, k) where the edge ghost occurs, the correction image 107A is further written (monochrome overwriting period). As described above, in the method of Comparative Example 2, it takes time to apply (overwrite) a voltage separately from the normal display drive time for overwriting correction of the image 107A, that is, edge ghost correction.

Here, in the method of Comparative Example 2 described above, the overwriting correction as described above is performed in units of writing periods similar to the case of displaying normal white and black. As described above, when displaying one image, various voltage values are switched and applied over several tens of frames. In other words, this means that a period of overwriting the image 107A also requires a voltage waveform pattern of several tens of frames, as in other writing periods.

For this reason, when the edge ghost is strong, the correction takes a long time or the correction itself becomes difficult. In addition, a new edge ghost may occur due to overwriting. As described above, it is difficult to sufficiently suppress the edge ghost by the method of correcting the generated edge ghost afterwards.

On the other hand, in the display device 1 of the present embodiment, in the displayed image, when two adjacent pixels (pixels P1 and P2) have different display states, each voltage waveform applied to these pixels P1 and P2 As a combination, a combination in which a difference between the voltage values applied to these two pixels becomes smaller among a plurality of types of voltage waveforms held in advance is used.

Specifically, first, the contour detection unit 56 detects a contour portion of an image to be displayed, and extracts two adjacent pixels having different display states. Next, the data replacement unit 54 selects the voltage waveform Dpa for the pixels P1 and P2 held in the LUT 55B from among the signals for display corresponding to the voltage waveform Dp held in the LUT 55A. Replace based on the information. This replaces (optimizes) the signal corresponding to the contour portion of the normal image display signal, and outputs the replaced signal to the panel control unit 51. That is, two adjacent pixels corresponding to the contour portion are driven using the voltage waveform Dpa, and pixels other than the contour portion are driven using the voltage waveform Dp.

The voltage waveform Dpa is obtained by replacing a part of the voltage waveform Dp so that the difference between the respective voltage values becomes smaller in the combination of the voltage waveforms applied to the pixels P1 and P2. That is, when the voltage value V _H is “1” and the voltage value V _L is “−1”, the difference between the voltage values applied to the pixels P1 and P2 is the maximum value (−2 or 2). A part of the voltage value of the voltage waveform Dp is replaced with another voltage value so that the number of combinations is further reduced.

FIG. 13 shows an example of a voltage waveform Dp (voltage waveforms Dp11, Dp12) applied to the pixels P1, P2 and a voltage waveform Dpa (voltage waveforms Dp11a, Dp12a) formed by replacing a part thereof. As described above, in the combination of the voltage waveforms Dp11 and Dp12, there are many periods tw in which the difference between the voltage values applied to the pixels P1 and P2 is the maximum value (−2 or 2). In the combination of Dp11a and Dp12a, there is no period tw in which the difference between the voltage values applied to the pixels P1 and P2 is the maximum value (−2 or 2). It is also important to adjust the voltage value before and after this replacement so that the display state does not change (while maintaining the display state). For example, the voltage waveform Dp11 is a pattern applied to change the display state from white to white, and the voltage waveform Dp12 is changed from white to black. For this reason, the voltage waveform Dp11a after replacement has a pattern that changes the display state from white to white, and the voltage waveform Dp12a has a pattern that changes the display state from white to black. In this example, in the voltage waveform Dpa after replacement, the voltage value applied to the pixel P1 is the voltage value V _H , V _L or 0 V, and the voltage value applied to the pixel P2 is the voltage value V _H to the pixel P1. Or, when the voltage value V _L is applied, it is the same voltage or 0V as the pixel P1, and when 0V is applied to the pixel P1, it is one of the voltage values V _H , V _L and 0V. Further, the voltage waveform Dpa may be obtained by replacing only one of the combinations of the voltage waveforms Dp applied to the pixels P1 and P2, or may be obtained by replacing both.

As described above, in this embodiment, the combination of the voltage waveforms applied to two adjacent pixels P having different display states from each other is replaced with a combination in which the difference between the voltage values applied to each is reduced. A large potential difference is less likely to occur between adjacent pixels. Thereby, it is possible to suppress the occurrence of image quality degradation called edge ghost as described above. Here, what is important is not to correct the generated edge ghost afterwards as in the second comparative example, but to use a combination of voltage waveforms in which the edge ghost itself hardly occurs. That is, in the present embodiment, the voltage waveform Dpa for the contour portion is prepared in advance instead of performing the correction after the “writing period” unit as in the method of the comparative example 2, and thus the correction period. As a result, a desired display with little edge ghost can be achieved in a short time.

For example, as Example 1, FIG. 14 schematically shows a case where an image 30 having a character area 30A and a background area 30B (left figure) is displayed and then a white image 31 (right figure) is written. In this case, the signal corresponding to the outline portion of the character region 30A (the boundary portion between the character region 30A and the background region 30B) in the normal signal (voltage waveform Dp) for writing the entire white image 31 is described above. The voltage waveform Dpa is used for replacement. By writing the signal after the replacement into the pixel array unit 10, as shown in FIG. 15, the entire white image 31 with reduced edge ghost can be displayed.

[effect]
In the display device 1 of the present embodiment, when two adjacent pixels P have different display states, that is, with respect to the pixels P (P1, P2) arranged in the contour portion of the image, As the combination of the voltage waveforms to be applied, a combination in which the difference between the voltage values applied to the pixels P is smaller is used. Thereby, the electric field generated in the horizontal direction between two adjacent pixels P is reduced. As a result, movement of the migrating particles between the pixels P can be suppressed. When two adjacent pixels P such as a contour portion have different display states, it is possible to suppress the occurrence of image quality deterioration (edge ghost) that may occur near the boundary between the pixels P.

In the present embodiment, as described above, the display device 1 holds information about the voltage waveforms Dp and Dpa as

LUTs

55A and 55B in advance, and replaces the display image signal based on these information. However, the configuration of the display device 1 is not limited to this. For example, the display device 1 may have a function of generating information corresponding to the voltage waveforms Dp and Dpa as described above by arithmetic processing in real time. For example, instead of the data replacement unit 54, the display device 1 displays (rewrites) the voltage waveforms Dp and Dpa including the combination that reduces the difference value between the voltage values applied to the pixels P1 and P2 as described above. In this case, an arithmetic processing unit for calculating is provided. Further, when this arithmetic processing unit is provided, the

LUTs

55A and 55B may not be provided.

Hereinafter, modifications of the above embodiment will be described. In addition, the same code | symbol is attached | subjected about the component similar to the said embodiment, and the description is abbreviate | omitted suitably.

<Modification 1>
In the above embodiment, the case where the display state of each pixel P changes between black and white has been described as an example. However, a display showing a gray level (gray) between black and white is shown. The driving method described above can also be applied to a change to a state or a change from a gray display state to a white or black display state.

FIG. 16 shows an example of the voltage waveform Dp. The voltage waveform Dp21 is a pattern for changing the display state from white to white, the voltage waveform Dp22 is from white to black, the voltage waveform Dp23 is from black to white, and the voltage waveform Dp24 is from black to black. The voltage waveform Dp25 is a pattern for changing the display state from white to gray, and the voltage waveform Dp26 is a pattern for changing the display state from gray to gray.

Among these, as shown in FIG. 17, for example, when a voltage waveform Dp21 for changing from white to white and a voltage waveform Dp25 for changing from white to gray are applied to two adjacent pixels, There is a period tw in which the difference between the voltage values applied to each is the maximum value (-2 or 2) (upper stage). FIG. 17 shows the lower part of these combinations with partial replacement. Thus, for example, by replacing a part of the voltage value of the voltage waveform Dp21, the voltage waveform Dp21a for changing from white to white and the voltage waveform Dp25 for changing from white to gray are the same as before the replacement. Combinations can be set.

Further, as shown in FIG. 18, for example, when a voltage waveform Dp24 for changing from black to black and a voltage waveform Dp26 for changing from gray to gray are applied to two adjacent pixels, respectively. There is a period tw in which the difference between the applied voltage values is the maximum value (2) (upper stage). FIG. 18 shows the lower part of FIG. Thus, for example, by replacing a part of the voltage value of the voltage waveform Dp26, the voltage waveform Dp26a for changing from gray to gray as in the case before the replacement and the voltage waveform Dp24 for changing from black to black are the same. Combinations can be set.

Here, as a comparative example (comparative example 3), as shown in FIG. 19, after displaying an image 30 (left figure) having a character area 30A and a background area 30B, an entire gray image 32 (right figure) is displayed. When writing, an edge ghost as described above occurs in an actually displayed image. For example, as shown in the right diagram of FIG. 20, the image 108 is such that a blackish line and a whitish line (x2) are generated in a region corresponding to the outline of the character region 30A on a gray background.

On the other hand, as a second embodiment, FIG. 21 schematically shows a case where an image 30 (left figure) having a character area 30A and a background area 30B is displayed and then a full gray image 32 (right figure) is written. . In this case, the signal corresponding to the outline portion of the character region 30A (the boundary portion between the character region 30A and the background region 30B) out of the normal signal (voltage waveform Dp) for writing the entire gray image 32 is described above. The voltage waveform Dpa is used for replacement. By writing the signal after the replacement into the pixel array unit 10, as shown in FIG. 22, a full gray image 32 with reduced edge ghost can be displayed.

<Modification 2>
In the said embodiment, although the display body 14 of the electrophoretic element gave as an example what contained two types of electrophoretic particles (black particle 141, white particle 142), the structure of the display body 14 is limited to this. It is not a thing. For example, as shown in FIG. 23, a fibrous structure (porous layer 153) may be used. The display body 14 includes, for example, the porous layer 153 and the migrating particles 152 in the insulating liquid 140 as described above.

The migrating particles 152 are one or more charged particles that can move between the first electrode 13 and the second electrode 15, and are dispersed in the insulating liquid 140. The migrating particles 152 can move between the first electrode 13 and the second electrode 15 in the insulating liquid 140. The migrating particles 152 are, for example, any one kind or two or more kinds of particles (powder) such as an organic pigment, an inorganic pigment, a dye, a carbon material, a metal material, a metal oxide, glass, or a polymer material (resin). . The migrating particles 152 may be pulverized particles or capsule particles of resin solids containing the above-described particles. However, materials corresponding to carbon materials, metal materials, metal oxides, glass, or polymer materials are excluded from materials corresponding to organic pigments, inorganic pigments, or dyes. As the migrating particles 152, any one of the above may be used, or a plurality of types may be used.

The content (concentration) of the migrating particles 152 in the insulating liquid 140 is not particularly limited, and is, for example, 0.1 wt% to 10 wt%. This is because shielding (concealment) and mobility of the migrating particles 152 are ensured. In this case, when the amount is less than 0.1% by weight, the migrating particles 152 may hardly shield the porous layer 153. On the other hand, when the content is more than 10% by weight, the dispersibility of the migrating particles 152 is lowered, so that the migrating particles 152 are difficult to migrate, and in some cases, there is a possibility of aggregation.

The specific forming material of the migrating particles 152 is selected according to the role of the migrating particles 152 in order to generate contrast, for example. For example, the material in the case of dark display (black display) by the migrating particles 152 is a black material such as a carbon material or a metal oxide. The carbon material is, for example, carbon black, and the metal oxide is, for example, copper-chromium oxide, copper-manganese oxide, copper-iron-manganese oxide, copper-chromium-manganese oxide, or copper-iron. -Chromium oxide and the like. Among these, a carbon material is preferable. This is because excellent chemical stability, mobility and light absorption are obtained. On the other hand, the material in the case of bright display (white display) by the migrating particles 152 is a white material, for example, a metal oxide such as titanium oxide, zinc oxide, zirconium oxide, barium titanate or potassium titanate, Titanium oxide is preferred. This is because it is excellent in electrochemical stability and dispersibility and has high reflectance.

Note that it is preferable that the migrating particles 152 are easily dispersed and charged in the insulating liquid 140 for a long period of time and are not easily adsorbed by the porous layer 153. Therefore, a dispersing agent (or a charge adjusting agent) may be used to disperse the migrating particles 152 by electrostatic repulsion, or the migrating particles 152 may be subjected to a surface treatment. Moreover, you may use both together.

The porous layer 153 is, for example, a three-dimensional structure (irregular network structure such as a nonwoven fabric) formed by a fibrous structure 154 as shown in FIG. The porous layer 153 has a plurality of gaps (pores 156) through which the migrating particles 152 pass, at places where the fibrous structure 154 does not exist.

The fibrous structure 154 includes one or more non-migrating particles 155, and the non-migrating particles 155 are held by the fibrous structure 154. In the porous layer 153 that is a three-dimensional structure, one fibrous structure 154 may be entangled at random, or a plurality of fibrous structures 154 may be gathered and overlap at random. However, both may be mixed. In the case where there are a plurality of fibrous structures 154, each fibrous structure 154 preferably holds one or more non-migrating particles 155. Note that FIG. 23 illustrates a case where the porous layer 153 is formed of a plurality of fibrous structures 154.

The reason why the non-migrating particles 155 are included in the fibrous structure 154 is that the light reflectance of the porous layer 153 becomes higher because external light is more easily diffusely reflected. Thereby, contrast becomes higher.

The fibrous structure 154 is a fibrous substance having a sufficiently large length with respect to the fiber diameter (diameter). The fibrous structure 154 includes, for example, any one type or two or more types such as a polymer material or an inorganic material, and may include other materials. Polymer materials include, for example, nylon, polylactic acid, polyamide, polyimide, polyethylene terephthalate, polyacrylonitrile, polyethylene oxide, polyvinyl carbazole, polyvinyl chloride, polyurethane, polystyrene, polyvinyl alcohol, polysulfone, polyvinyl pyrrolidone, polyvinylidene fluoride, polyhexa Fluoropropylene, cellulose acetate, collagen, gelatin, chitosan or copolymers thereof. The inorganic material is, for example, titanium oxide. Among these, a polymer material is preferable as a material for forming the fibrous structure 154. This is because the reactivity (photoreactivity, etc.) is low (chemically stable), so that an unintended decomposition reaction of the fibrous structure 154 is suppressed. Note that in the case where the fibrous structure 154 is formed of a highly reactive material, the surface of the fibrous structure 154 is preferably covered with an arbitrary protective layer.

The shape (appearance) of the fibrous structure 154 is not particularly limited as long as it is a fibrous shape having a sufficiently large length with respect to the fiber diameter as described above. Specifically, it may be linear, may be curled, or may be bent in the middle. Moreover, you may branch to 1 or 2 or more directions on the way, not only extending in one direction. The formation method of the fibrous structure 154 is not particularly limited. For example, a phase separation method, a phase inversion method, an electrostatic (electric field) spinning method, a melt spinning method, a wet spinning method, a dry spinning method, a gel spinning method, A sol-gel method or a spray coating method is preferred. This is because a fibrous substance having a sufficiently large length with respect to the fiber diameter can be easily and stably formed.

The fibrous structure 154 preferably has an optical reflection characteristic different from that of the migrating particles 152. For example, when dark display is performed by the migrating particles 152, black migrating particles 152 and white fibrous structures 154 are used. When bright display is performed by the migrating particles 152, white migrating particles 152 and a black fibrous structure 154 are used.

Non-electrophoretic particles 155 are particles that are fixed to the fibrous structure 154 and do not migrate electrically. The material for forming the non-electrophoretic particles 155 is, for example, the same as the material for forming the electrophoretic particles 152, and is selected according to the role played by the non-electrophoretic particles 155. The non-migrating particles 155 have optical reflection characteristics different from those of the migrating particles 152.

The configuration of the display body 14 described above is an example, and other configurations may be used. For example, another configuration that does not have the porous layer 153, for example, a capsule shape, or an electrochromic display element may be used. As described above, the display device and the driving method thereof can be applied to various reflective display elements that can maintain a display state even when an external electric field is interrupted.

<Application example>
Next, application examples of the display device described in the above embodiments and modifications will be described. However, the configuration of the electronic device described below is merely an example, and the configuration can be changed as appropriate. The display device 1 can be applied to a part of various electronic devices or clothing, and the type of the electronic device is not particularly limited. The display device 1 can be mounted on, for example, the following electronic devices. However, the configuration of the electronic device or the like described below is merely an example, and the configuration can be changed as appropriate.

(Application example 1)
24A and 24B show the external configuration of an electronic book. The electronic book includes, for example, a display unit 110, a non-display unit 120, and an operation unit 130. Note that the operation unit 130 may be provided on the front surface of the non-display unit 120 as illustrated in FIG. 24A, or may be provided on the upper surface as illustrated in FIG. 24B. The display unit 110 includes the display device 1. The display device 1 may be mounted on a PDA (Personal Digital Assistants) having the same configuration as the electronic book shown in FIGS. 24A and 24B.

(Application example 2)
FIG. 25 shows the appearance of a tablet personal computer. The tablet personal computer has, for example, a touch panel unit 310 and a housing 320, and the touch panel unit 310 includes the display device 1.

The display device 1 described above can be applied to a part of clothing such as a watch (watch), a bag, clothes, a hat, glasses and shoes as a so-called wearable terminal. Below, an example of such an electronic device integrated with clothing is shown.

(Application example 3)
26A and 26B show the appearance of an electronic timepiece (a wristwatch integrated electronic device). The electronic timepiece has, for example, a dial (character information display portion) 410 and a band portion (color pattern display portion) 420, and the dial 410 and the band portion 420 include the display device 1. It is configured. For example, various characters and designs are displayed on the dial plate 410 as shown in FIGS. 26A and 26B by display driving using the above-described electrophoretic element. The band unit 420 is a part that can be attached to an arm or the like, for example. By using the display device 1 in the band unit 420, various color patterns can be displayed, and the design of the band unit 420 can be changed from the example of FIG. 26A to the example of FIG. 26B. . Electronic devices that are also useful in fashion applications can be realized.

Although the present disclosure has been described with reference to the embodiment, the present disclosure is not limited to the aspect described in the embodiment, and various modifications are possible. For example, it is not necessary to provide all the components described in the above embodiment, and other components may be included. Moreover, the material and thickness of the component mentioned above are examples, and are not limited to what was described.

In addition, the effect demonstrated in the said embodiment etc. is an example, The effect of this indication may be other effects and may also contain other effects.

Note that the present disclosure may be configured as follows.
(1)
A pixel portion including an electrophoretic element and having a plurality of pixels;
A drive unit that performs driving to change the display state of the pixel by applying a voltage waveform that switches at least two values over a plurality of frames to each pixel of the pixel unit;
With
In the case where the first and second pixels adjacent to each other among the plurality of pixels have different display states,
The driving is performed using a combination of smaller voltage values applied to the first and second pixels as a combination of voltage waveforms applied to the first and second pixels. Display device.
(2)
The drive unit is
Applying the first voltage waveform for image display to each pixel other than the first and second pixels to perform the driving,
The driving is performed by applying a second voltage waveform obtained by replacing a part of the first voltage waveform to one or both of the first and second pixels. Display device.
(3)
A first holding unit for holding the first voltage waveform;
The display device according to (2), further comprising: a second holding unit that holds the second voltage waveform.
(4)
The display device according to (2), wherein the driving unit generates the first and second voltage waveforms by arithmetic processing.
(5)
5. The display device according to any one of (1) to (4), further including a detection unit that detects a contour portion including the first and second pixels in an image displayed on the pixel unit.
(6)
The display device according to any one of (1) to (5), wherein the voltage waveform has a shape that switches between at least a negative first voltage value and a positive second voltage value.
(7)
Each of the voltage waveforms has a shape for switching the first voltage value, the second voltage value, and a third voltage value intermediate between the first voltage value and the second voltage value. Display device.
(8)
The combination of the voltage waveforms applied to the first and second pixels is such that one of the first and second pixels has the first voltage value and the other pixel has the second voltage value. The display device according to (6), wherein each frame is a combination in which relatively few frames are applied.
(9)
In each voltage waveform combination applied to the first and second pixels, in each frame,
One of the first voltage value, the second voltage value, and the third voltage value is applied to the first pixel,
When the first voltage value or the second voltage value is applied to the first pixel, the same voltage as the first pixel or the third voltage value is applied to the second pixel. When the third voltage value is applied to the first pixel, any one of the first voltage value, the second voltage value, and the third voltage value is applied. (7) The display device described.
(10)
The electrophoretic element is:
A first electrode provided for each pixel;
A second electrode disposed opposite to the plurality of first electrodes;
Any of the above (1) to (9), comprising: a display body that is sealed between the plurality of first electrodes and the second electrode, includes migrating particles, and changes light reflection characteristics according to an applied voltage. The display apparatus as described in any one.
(11)
For each of the plurality of pixels including the electrophoretic element, a voltage waveform for switching at least two values is applied over a plurality of frames to change the display state of the pixel,
When the first and second pixels adjacent to each other in the plurality of pixels have different display states, the first and second are combinations of voltage waveforms applied to the first and second pixels. A driving method in which the driving is performed using a combination in which the difference between the voltage values applied to the pixels is smaller.
(12)
Applying the first voltage waveform for image display to each pixel other than the first and second pixels to perform the driving,
The driving is performed by applying a second voltage waveform obtained by replacing a part of the first voltage waveform to one or both of the first and second pixels. Driving method.
(13)
The driving method according to (11) or (12), wherein a contour portion including the first and second pixels in the image is detected.
(14)
The driving method according to any one of (11) to (13), wherein the voltage waveform has a shape that switches between at least a negative first voltage value and a positive second voltage value.
(15)
Each of the voltage waveforms has a shape for switching the first voltage value, the second voltage value, and a third voltage value intermediate between the first voltage value and the second voltage value. Driving method.
(16)
The combination of the voltage waveforms applied to the first and second pixels is such that one of the first and second pixels has the first voltage value and the other pixel has the second voltage value. The driving method according to (14), wherein each of the frames is a combination in which relatively few frames are applied.
(17)
In each voltage waveform combination applied to the first and second pixels, in each frame,
One of the first voltage value, the second voltage value, and the third voltage value is applied to the first pixel,
When the first voltage value or the second voltage value is applied to the first pixel, the same voltage as the first pixel or the third voltage value is applied to the second pixel. When the third voltage value is applied to the first pixel, any one of the first voltage value, the second voltage value, and the third voltage value is applied. (15) The driving method described.
(18)
A pixel portion including an electrophoretic element and having a plurality of pixels;
A driving unit that performs driving to change a display state of the pixel by applying a voltage waveform that switches at least two values over a plurality of frames to each pixel of the pixel unit; and
In the case where the first and second pixels adjacent to each other among the plurality of pixels have different display states,
The drive is performed using a combination of smaller voltage values applied to the first and second pixels as a combination of voltage waveforms applied to the first and second pixels. Electronic equipment with a display device.

This application claims priority on the basis of Japanese Patent Application No. 2015-256653 filed on December 28, 2015 at the Japan Patent Office. The entire contents of this application are incorporated herein by reference. This is incorporated into the application.

Those skilled in the art will envision various modifications, combinations, subcombinations, and changes, depending on design requirements and other factors, which are within the scope of the appended claims and their equivalents. It is understood that

Claims

A pixel portion including an electrophoretic element and having a plurality of pixels;
A drive unit that performs driving to change the display state of the pixel by applying a voltage waveform that switches at least two values over a plurality of frames to each pixel of the pixel unit;
With
In the case where the first and second pixels adjacent to each other among the plurality of pixels have different display states,
The driving is performed using a combination of smaller voltage values applied to the first and second pixels as a combination of voltage waveforms applied to the first and second pixels. Display device.
The drive unit is
Applying the first voltage waveform for image display to each pixel other than the first and second pixels to perform the driving,
The display according to claim 1, wherein the driving is performed by applying a second voltage waveform obtained by replacing a part of the first voltage waveform to one or both of the first and second pixels. apparatus.
A first holding unit for holding the first voltage waveform;
The display device according to claim 2, further comprising: a second holding unit that holds the second voltage waveform.
The display device according to claim 2, wherein the driving unit generates the first and second voltage waveforms by arithmetic processing.
The display device according to claim 1, further comprising a detection unit that detects a contour portion including the first and second pixels in an image displayed on the pixel unit.
The display device according to claim 1, wherein the voltage waveform has a shape that switches at least between a negative first voltage value and a positive second voltage value.
The voltage waveform has a shape for switching the first voltage value, the second voltage value, and a third voltage value intermediate between the first voltage value and the second voltage value, respectively. Display device.
The combination of the voltage waveforms applied to the first and second pixels is such that one of the first and second pixels has the first voltage value and the other pixel has the second voltage value. The display device according to claim 6, wherein each frame is a combination in which relatively few frames are applied.
In each voltage waveform combination applied to the first and second pixels, in each frame,
One of the first voltage value, the second voltage value, and the third voltage value is applied to the first pixel,
When the first voltage value or the second voltage value is applied to the first pixel, the same voltage as the first pixel or the third voltage value is applied to the second pixel. The one of the first voltage value, the second voltage value, and the third voltage value is applied when the third voltage value is applied to the first pixel. Display device.
The electrophoretic element is:
A first electrode provided for each pixel;
A second electrode disposed opposite to the plurality of first electrodes;
The display device according to claim 1, further comprising: a display body that is sealed between the plurality of first electrodes and the second electrode, includes migrating particles, and changes light reflection characteristics according to an applied voltage.
For each of the plurality of pixels including the electrophoretic element, a voltage waveform for switching at least two values is applied over a plurality of frames to change the display state of the pixel,
When the first and second pixels adjacent to each other in the plurality of pixels have different display states, the first and second are combinations of voltage waveforms applied to the first and second pixels. A driving method in which the driving is performed using a combination in which the difference between the voltage values applied to the pixels is smaller.
Applying the first voltage waveform for image display to each pixel other than the first and second pixels to perform the driving,
The driving according to claim 11, wherein the driving is performed by applying a second voltage waveform obtained by replacing a part of the first voltage waveform to one or both of the first and second pixels. Method.
The driving method according to claim 11, wherein a contour portion including the first and second pixels in the image is detected.
The driving method according to claim 11, wherein the voltage waveform has a shape that switches at least a negative first voltage value and a positive second voltage value.
The voltage waveform has a shape for switching the first voltage value, the second voltage value, and a third voltage value intermediate between the first voltage value and the second voltage value, respectively. Driving method.
The combination of the voltage waveforms applied to the first and second pixels is such that one of the first and second pixels has the first voltage value and the other pixel has the second voltage value. The driving method according to claim 14, wherein each is applied in a combination of relatively few frames.
In each voltage waveform combination applied to the first and second pixels, in each frame,
One of the first voltage value, the second voltage value, and the third voltage value is applied to the first pixel,
When the first voltage value or the second voltage value is applied to the first pixel, the same voltage as the first pixel or the third voltage value is applied to the second pixel. The first voltage value, the second voltage value, or the third voltage value is applied when the third voltage value is applied to the first pixel. Driving method.
A pixel portion including an electrophoretic element and having a plurality of pixels;
A driving unit that performs driving to change a display state of the pixel by applying a voltage waveform that switches at least two values over a plurality of frames to each pixel of the pixel unit; and
In the case where the first and second pixels adjacent to each other among the plurality of pixels have different display states,
The driving is performed using a combination of smaller voltage values applied to the first and second pixels as a combination of voltage waveforms applied to the first and second pixels. Electronic equipment with a display device.