Electronic paper device and driving method thereof

Abstract

The present application discloses an electronic paper device and a driving method thereof, the driving method comprising the following steps: in the first stage, all n rows of pixels in a pixel area are adjusted to a black state; in the second stage, the n rows of pixels in the pixel area are simultaneously adjusted to an initial state; in the third stage, the n rows of pixels in the pixel area are simultaneously charged, and the charging time of the first row of pixels in the pixel area is shorter than the charging time of other rows of pixels in the pixel area; wherein n is a natural number greater than or equal to 2. Through the above design, the charging time of the electronic paper screen display can be improved to avoid abnormal screen display.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to an electronic paper device and a driving method thereof. Background Art

[0002] Electronic paper generally includes multiple microstructures and a first electrode and a second electrode arranged on opposite sides of each microstructure. Each microstructure is encapsulated with black and white electrophoretic particles. The electronic paper controls the regular movement of the electrophoretic particles in the microstructure by controlling the electric field generated by the first electrode and the second electrode, thereby reflecting ambient light so that the human eye can see the displayed pattern.

[0003] Since the electronic paper needs to go through the electrophoretic particle initialization stage when switching the screen display, the pixel charging time is very short. For small-sized electronic paper readers, a short charging time can also meet the display charging needs, such as electronic paper readers with a size of 320*640; but with the development of electronic paper display technology, the application market of electronic paper has gradually expanded to small and medium-sized products and large-sized products, such as electronic paper tablets with a size of 1920*1080. At this time, if the charging time cannot meet the display requirements, the screen display will be abnormal, such as horizontal stripes. Summary of the invention

[0004] The purpose of the present application is to provide an electronic paper device and a driving method thereof to improve the screen display charging time and avoid screen display abnormalities.

[0005] The present application discloses a driving method for an electronic paper device, wherein the electronic paper device comprises a plurality of pixel areas arranged in sequence, each of the pixel areas comprises n rows of pixels, and the driving method comprises the steps of:

[0006] In the first stage, all n rows of pixels in a pixel area are adjusted to a black state;

[0007] In the second stage, n rows of pixels in the pixel area are adjusted to an initial state at the same time;

[0008] In the third stage, n rows of pixels in the pixel area are charged simultaneously, and the charging time of the first row of pixels in the pixel area is shorter than the charging time of the other rows of pixels in the pixel area;

[0009] Wherein, n is a natural number greater than or equal to 2.

[0010] Optionally, the pixel includes a microcapsule and black particles and white particles located in the microcapsule. In the first stage, a first data voltage is applied to the pixel so that the black particles in the microcapsule move to the light-emitting side of the electronic paper device; in the second stage, a second data voltage is applied to the pixel so that the black particles and white particles in the microcapsule are evenly mixed; in the third stage, a third data voltage is applied to the pixel so that the pixel displays a picture; wherein the first data voltage is a negative voltage, the second data voltage is alternating positive and negative voltages, and the third data voltage is a positive voltage.

[0011] Optionally, the third data voltage includes a third pull-up voltage and a third display voltage, the third pull-up voltage and the third display voltage are both positive voltages, and the third pull-up voltage is greater than the third display voltage; wherein the pixel is first supplied with the third pull-up voltage and then with the third display voltage.

[0012] Optionally, in the pixel area, the starting time of the third pull-up voltage of each row of pixels is the same, and the starting time of the third display voltage of each row of pixels is the same.

[0013] Optionally, in the third stage, the duration of the third display voltage of the pixels in the pixel area increases row by row.

[0014] Optionally, the first data voltage is equal to a negative voltage of the second data voltage, and the positive voltage of the second data voltage is equal to the third display voltage.

[0015] Optionally, in the first stage, n rows of pixels in a pixel area are scanned simultaneously and adjusted to a black state at the same time.

[0016] Optionally, the time interval between the first stage and the second stage is shorter than the duration of the first stage.

[0017] Optionally, n is equal to 3.

[0018] The present application also discloses an electronic paper device, which is driven by the driving method of the electronic paper device as described above.

[0019] The beneficial effects of the present application are as follows: the screen display switching of the electronic paper needs to include three stages, namely: inversion, jitter and display, which correspond to the above-mentioned first stage, second stage and third stage respectively. Among them, inversion means that the whole screen is brushed black, so that the pixels become black after the previous frame; the jitter stage is that the black particles and white particles are evenly distributed in the microcapsule, so that the black particles and white particles are in the initial state; the display stage is that the black particles and white particles respond to the screen voltage at this time and display the graphics. That is, the response time of each frame of the screen can be calculated from the sum of the time of the three stages of inversion, jitter and display. After the screen is cut black, the black and white particles are jittered, and the screen is displayed, a frame of image display is completed. Through this design, the previous frame of the screen can quickly turn black after the end, preventing the problem of residual image and dragging; and before charging the pixel to enter the display stage, the black particles and white particles in the pixel will be mixed evenly, so that the electrophoretic particles are restored to the initial state, so as to shorten the time for the electrophoretic particles to enter the display state and improve the screen switching speed.

[0020] Moreover, the present application also adjusts at least two rows of pixels to the initial state at the same time in the second stage, so that when these pixels enter the third stage, the pixels in the following rows have a longer charging time, thereby solving the problem of short pixel charging time. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation methods of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0022] Figure 1 is a cross-sectional schematic diagram of an electronic paper device provided in an embodiment of the present application;

[0023] Figure 2 is a plan view of an electronic paper device provided in an embodiment of the present application;

[0024] Figure 3 is a flow chart of a driving method of an electronic paper device provided in an embodiment of the present application;

[0025] Figure 4 is a timing diagram of an electronic paper device driving process provided by an embodiment of the present application;

[0026] Figure 5 is a timing diagram of another electronic paper device driving process provided by an embodiment of the present application;

[0027] Figure 6 This is a timing diagram of an electronic paper device driving process provided by another embodiment of the present application.

[0028] Among them, 10, electronic paper device; 10A, pixel area; 100, array substrate; 110, pixel electrode; 200, color film substrate; 210, common electrode; 300, electrophoretic particle layer; 310, microcapsule; 311, black particles; 312, white particles. DETAILED DESCRIPTION

[0029] It should be understood that the terms used herein, the specific structures and functional details disclosed are only for describing specific embodiments and are representative, but the present application can be implemented in many alternative forms and should not be construed as being limited to only the embodiments described herein.

[0030] In addition, unless otherwise clearly specified or limited, "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internally connected between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] like Figure 1 As shown, an embodiment of the present application provides an electronic paper device, the electronic paper device 10 comprises an array substrate 100 and a color filter substrate 200 arranged opposite to each other, and an electrophoretic particle layer 300 arranged between the array substrate 100 and the color filter substrate 200, the array substrate 100 is provided with a data line, a scan line, a switch layer and a pixel electrode 110, the color filter substrate 200 is provided with a common electrode 210, and the electrophoretic particle layer 300 has a plurality of microcapsules 310, and the microcapsules 310 are filled with black particles 311 and white particles 312. The black particles 311 and the white particles 312 in the microcapsules 310 move under the action of the electric field between the pixel electrode 110 and the common electrode 210, so that the electronic paper device 10 displays a picture.

[0032] like Figure 2 As shown, in the electronic paper device 10, the entire display screen is divided into a plurality of pixel areas 10A, the plurality of pixel areas 10A are sequentially distributed along the length direction of the data line, and each pixel area 10A has n rows of pixels, wherein n is a natural number greater than or equal to 2.

[0033] like Figure 3 As shown, the embodiment of the present application further provides a driving method of an electronic paper device, which is used to drive the above electronic paper device. The driving method comprises the steps of:

[0034] S1: In the first stage, all n rows of pixels in a pixel area are adjusted to a black state;

[0035] S2: In the second stage, n rows of pixels in the pixel area are adjusted to an initial state at the same time;

[0036] S3: a third stage, charging n rows of pixels in the pixel area at the same time, and the charging time of the first row of pixels in the pixel area is shorter than the charging time of other rows of pixels in the pixel area.

[0037] It should be noted that the above driving method is based on driving within one pixel area 10A, and other pixel areas 10A are driven in sequence according to a row-by-row scanning order, which will not be elaborated herein.

[0038] In the embodiment of the present application, the screen display switching of the electronic paper needs to include three stages, namely: inversion, dithering and displaying, which correspond to the first stage, the second stage and the third stage mentioned above, respectively. Among them, inversion means that the whole screen is brushed black, so that the pixels become black after the previous frame; the dithering stage is that the black particles and white particles are evenly distributed in the microcapsules, so that the black particles and white particles are in the initial state; the display stage is that the black particles and white particles respond to the screen voltage at this time and display graphics. That is, the response time of each frame of the picture can be calculated from the sum of the time of the three stages of inversion, dithering and displaying. After the picture is cut to black, the black and white particles are dithered, and the picture is displayed, a frame of image display is completed.

[0039] Through this design, the previous frame of the picture can quickly turn black after it ends, preventing problems such as afterimages and ghosting. Moreover, before charging the pixels and entering the display stage, the black and white particles in the pixels will be mixed evenly to restore the electrophoretic particles to their initial state, thereby shortening the time it takes for the electrophoretic particles to enter the display state and improving the screen switching speed.

[0040] Considering that the pixel enters the third stage for display only after the first and second stages without affecting the refresh rate of the picture and without extending the scanning time of the pixel, resulting in a shorter charging time for the pixel, it may cause abnormal picture display. Based on this, the embodiment of the present application also adjusts at least two rows of pixels to the initial state at the same time in the second stage, so that when these pixels enter the third stage, the pixels in the following rows have a longer charging time, thereby solving the problem of the shorter charging time of the pixels.

[0041] Specifically, in the first stage, the first data voltage is applied to the pixel, and under the action of the electric field formed by the pixel electrode and the common electrode, the black particles in the microcapsule are moved to the light-emitting side of the electronic paper device, that is, the black particles are moved above the white particles, so that the pixel becomes black and does not reflect external light.

[0042] In the second stage, a second data voltage is applied to the pixel, and under the action of the electric field formed by the pixel electrode and the common electrode, the black particles and the white particles in the microcapsule are repeatedly moved to be evenly mixed.

[0043] In the third stage, a third data voltage is applied to the pixel, and under the action of the electric field formed by the pixel electrode and the common electrode, the white particles move to above the black particles, and the white particles reflect external light, so that the pixel displays a picture.

[0044] Among them, Figure 4 As shown, the first stage is represented by a, the second stage is represented by b, the third stage is represented by c, and the blanking period is represented by d. The first data voltage is a negative voltage, the second data voltage is an alternating positive voltage and negative voltage, and the third data voltage is a positive voltage.

[0045] As a specific example, the voltage of the common electrode is 0V, and the first data voltage is -15V at this time, and the pixel electrode also has a voltage of -15V. Since the black particles are negatively charged and the white particles are positively charged, the pixel electrode will attract the white particles to move downward, so that the black particles are all located above the white particles. At this time, the second data voltage is a voltage alternating between +15V and -15V. When the second data voltage is +15V, the pixel electrode will also have a voltage of +15V, and the pixel electrode will attract the black particles to move downward, so that the white particles are located above the black particles; when the second data voltage is -15V, the pixel electrode will also have a voltage of -15V, and the pixel electrode will attract the white particles to move downward, so that the black particles are located above the white particles. When the positive voltage and the negative voltage are switched at a very fast speed, the white particles and the black particles in the microcapsules will be evenly mixed together, and there will be no problem of stratification of the black particles and the white particles, so that when entering the third stage, the black particles and the white particles have a shorter moving path to speed up the switching of the screen. Likewise, the third data voltage is a positive voltage, so that the pixel electrode attracts the black particles to move downward, so that the white particles are located above the black particles, reflecting external light, causing the pixel to emit light, thereby generating a picture.

[0046] In the embodiment of the present application, in order to ensure that the black particles and the white particles are evenly mixed in the second stage, the inventors have found through experimental observation that when the second data voltage is a positive voltage and a negative voltage that alternate three times, that is, in the second stage, after the six voltages of +15V, -15V, +15V, -15V, +15V, and -15V are sequentially applied to the pixels, the black particles and the white particles are mixed more evenly.

[0047] As a further embodiment, Figure 5As shown, the first stage is represented by a, the second stage is represented by b, the third stage is represented by c, and the blanking period is represented by d. The third data voltage includes a third pull-up voltage and a third display voltage, the third pull-up voltage and the third display voltage are both positive voltages, and the third pull-up voltage is greater than the third display voltage; wherein, when the pixel enters the third stage, the third pull-up voltage is firstly applied, and then the third display voltage is applied.

[0048] Through this design, before the pixel displays the normal picture, a higher positive voltage is first applied to the pixel, so that the pixel electrode also has a higher positive voltage. At this time, a larger voltage difference is generated between the pixel electrode and the common electrode, which will attract the black particles to move downward very quickly, so that the pixel can quickly reflect the brightness and display the picture, thereby increasing the switching speed of the display picture. After the picture is switched, the charged voltage is replaced with a smaller normal display voltage to maintain the voltage required for normal display of the picture and avoid increasing the power consumption of the electronic paper device.

[0049] As a specific example, in combination with the previous example, the third pull-up voltage is +18V, and the third display voltage is +15V.

[0050] In the embodiment of the present application, the negative voltage of the first data voltage is equal to the negative voltage of the second data voltage, and the positive voltage of the second data voltage is equal to the third display voltage. Through this design, the data voltage is basically switched within a fixed range, the signal is more stable, and the force applied to the electrophoretic particles during the movement is also basically the same, so the movement of the electrophoretic particles is more stable.

[0051] In an embodiment of the present application, the duration of the first data voltage, the duration of the negative voltage in the second data voltage, and the duration of the positive voltage in the second data voltage are all the same, so that the distance moved by the electrophoretic particles each time is the same, ensuring that the electrophoretic particles achieve position change in the shortest time, thereby achieving the effect of pixel color change.

[0052] In an embodiment of the present application, in the pixel area, the starting time of the third pull-up voltage of each row of pixels is the same, the starting time of the third display voltage of each row of pixels is the same, and the duration of the third pull-up voltage of pixels in different rows is the same. It should be noted that the "start time" means the time when the pixel receives the signal, and the "duration" means the time when the pixel continues to receive the same signal. Through the above design, in the third stage, when the first row of pixels in the pixel area begins to enter the charging state, the pixels in other rows also begin to enter the charging state, and synchronously pull up the voltage first and then restore to the voltage required to maintain the normal display of the picture, so that multiple rows of pixels in the same pixel area can achieve the effect of simultaneous display, so as to improve the picture response speed and extend the charging time of non-first row pixels.

[0053] In the embodiment of the present application, in the third stage, the duration of the third display voltage of the pixels in the pixel area increases row by row. Specifically, the duration of the third display voltage of the first row of pixels in the pixel area is x, the duration of the third display voltage of the second row of pixels in the pixel area is 2x, and the duration of the third display voltage of the nth row of pixels in the pixel area is nx. The embodiment of the present application does not change the end time of the data signal in each row of pixels, but only advances the charging time of some pixels to achieve the purpose of pre-charging.

[0054] As a specific implementation, there are only 3 rows of pixels in each pixel area, that is, n is equal to 3. In the first stage, the first row of pixels, the second row of pixels and the third row of pixels are scanned row by row, so that the first row of pixels, the second row of pixels and the third row of pixels are adjusted to the black state in sequence. In the second stage, after the second row of pixels and the third row of pixels are adjusted to the black state, the second row of pixels and the third row of pixels are adjusted to the initial state quickly, so that the time interval between the black state and the initial state in the third row of pixels is the shortest, the time interval between the black state and the initial state in the second row of pixels is the second shortest, and the time interval between the black state and the initial state in the first row of pixels is the longest, so as to achieve the purpose of adjusting the first row of pixels, the second row of pixels and the third row of pixels to the initial state at the same time. In the third stage, there is no need to adjust the time interval between the initial state and the display state of the pixels. First, a higher pull-up voltage is provided to each row of pixels, and then it is quickly restored to the display voltage, so that the second row of pixels and the third row of pixels have a longer charging time.

[0055] This embodiment uses a data driving method that simultaneously shakes the three rows of pixels and precharges the last two rows of pixels through data voltage, so that the response time of each screen display is shortened, that is, the screen switching is smoother and the display effect is improved. Moreover, it can avoid the jitter state lasting longer, which affects the user experience.

[0056] When only 3 rows of pixels are set in each pixel area, after the first to third rows of pixels are brushed black, the 3 rows of pixels simultaneously shake the black and white particles. At this time, compared with the conventional driving scheme, the shaking time of every 3 rows of pixels is compressed to three-fifths of the original; the fourth to sixth rows of pixels...the m-2 to mth rows are repeated until the drive of one frame of the picture is completed. Moreover, the connection between the black state and the initial state in the third row of pixels will not be affected. Of course, according to specific needs, each pixel area can also contain only 2 rows of pixels or more than 4 rows of pixels, and it is not even necessary to make each pixel area contain the same row of pixels.

[0057] This embodiment only advances the jitter time of the second row of pixels and the third row of pixels to achieve the purpose of synchronization with the jitter time of the first row of pixels, but does not shorten the time between the charging and jittering processes in the second row of pixels and the third row of pixels to ensure that the black particles and white particles are mixed evenly in each pixel in the second stage.

[0058] like Figure 6 As shown, as another embodiment of the present application, the first stage is represented by a, the second stage is represented by b, and the third stage is represented by c. The black brushing process of all rows of pixels in the pixel area is carried out simultaneously, which can be specifically achieved by scanning all rows of pixels in the pixel area at the same time. At this time, in addition to being able to achieve the above-mentioned improvement in the charging time of the electronic paper screen display and avoid the problem of abnormal screen display, this implementation can also speed up the refresh rate of the electronic paper device, because the original refresh time of one frame of the electronic paper device is T, and m rows of pixels need to be scanned row by row, but now since n rows of pixels in each pixel area are scanned at the same time, that is, three rows of pixels are scanned each time, the refresh time of one frame of the electronic paper device is now only T / m, which greatly improves the display refresh rate of the electronic paper device.

[0059] In an embodiment of the present application, the jitter time of each row of pixels is further advanced so that the time interval between the first stage and the second stage is less than the duration of the first stage, or even directly enters the jitter stage after the pixels are brushed black without any transition time, so as to further increase the charging time of all rows of pixels.

[0060] Moreover, when the pixel enters the jitter stage directly after being brushed black, the number of alternations between the positive voltage and the negative voltage in the second stage can also be reduced, so that the first stage acts as a part of the second stage, which is equivalent to the pixel directly skipping the first stage and entering the second stage. At this time, the pixel directly starts charging after passing through the six stages of brushing black, brushing white, brushing black, brushing white, brushing black, and brushing white in sequence, or the pixel directly starts charging after passing through the five stages of brushing black, brushing white, brushing black, brushing white, and brushing black in sequence, so as to further increase the charging time of the pixel.

[0061] Similarly, the pixel area has three rows of pixels as an example for explanation. In the first stage, when the first row of pixels enters the black state, the second row of pixels and the third row of pixels also enter the black state; after completing the first stage, the second stage is immediately carried out, and there is almost no time transition between the two. At this time, it is equivalent to advancing the jitter time of the first row of pixels, the second row of pixels, and the third row of pixels. In this way, when entering the third stage, in addition to the second row of pixels and the third row of pixels having a longer charging time, the charging time of the first row of pixels is also increased, which can increase the charging time of all pixels in the entire display screen. Compared with the previous embodiment, the embodiment of the present application not only further increases the charging time of the second row and the third row of pixels, but also increases the charging time of the first row of pixels, which is conducive to improving the display effect of the entire screen.

[0062] It should be noted that the limitations on the various steps involved in this solution are not considered to limit the order of the steps without affecting the implementation of the specific solution. The steps written in front can be executed first, or later, or even simultaneously. The solutions of different implementation embodiments can be combined and applied without conflict. As long as this solution can be implemented, it should be regarded as belonging to the scope of protection of this application.

[0063] The above content is a further detailed description of the present application in combination with specific optional implementation methods, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, several simple deductions or substitutions can be made without departing from the concept of the present application, which should be deemed to fall within the scope of protection of the present application.

Claims

1. A driving method for an electronic paper device, wherein the electronic paper device comprises a plurality of pixel areas arranged in sequence, each of the pixel areas comprises n rows of pixels, characterized in that: The driving method comprises the steps of: In the first stage, all n rows of pixels in a pixel area are adjusted to a black state; In the second stage, n rows of pixels in the pixel area are adjusted to an initial state at the same time; In the third stage, n rows of pixels in the pixel area are charged simultaneously, and the charging time of the first row of pixels in the pixel area is shorter than the charging time of the other rows of pixels in the pixel area; Wherein, n is a natural number greater than or equal to 2.

2. The driving method of the electronic paper device according to claim 1, characterized in that: The pixel includes a microcapsule and black particles and white particles in the microcapsule. In a first stage, a first data voltage is applied to the pixel so that the black particles in the microcapsule move to the light-emitting side of the electronic paper device. In a second stage, a second data voltage is applied to the pixel so that the black particles and the white particles in the microcapsule are evenly mixed. In the third stage, a third data voltage is applied to the pixel so that the pixel displays a picture; The first data voltage is a negative voltage, the second data voltage is an alternating positive voltage and negative voltage, and the third data voltage is a positive voltage.

3. The driving method of the electronic paper device according to claim 2, characterized in that: The third data voltage includes a third pull-up voltage and a third display voltage, the third pull-up voltage and the third display voltage are both positive voltages, and the third pull-up voltage is greater than the third display voltage; The pixel is first supplied with the third pull-up voltage and then supplied with the third display voltage.

4. The driving method of the electronic paper device according to claim 3, characterized in that: In the pixel area, the starting time of the third pull-up voltage of each row of pixels is the same, and the starting time of the third display voltage of each row of pixels is the same.

5. The driving method of the electronic paper device according to claim 4, characterized in that: In the third stage, the duration of the third display voltage of the pixels in the pixel area increases row by row.

6. The driving method of the electronic paper device according to claim 3, characterized in that: The first data voltage is equal to a negative voltage of the second data voltage, and the positive voltage of the second data voltage is equal to the third display voltage.

7. The driving method of the electronic paper device according to claim 1, characterized in that: In the first stage, n rows of pixels in a pixel area are scanned simultaneously and adjusted to a black state at the same time.

8. The driving method of the electronic paper device according to claim 7, characterized in that: A time interval between the first phase and the second phase is smaller than a duration of the first phase.

9. The driving method of the electronic paper device according to claim 1, characterized in that: n is equal to 3.

10. An electronic paper device, characterized in that: The electronic paper device is driven by the driving method according to any one of claims 1 to 9.

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