Four-color electronic paper, afterimage elimination driving method based on four-color electronic paper and medium

Abstract

The invention provides four-color electronic paper, a ghost shadow elimination driving method based on the four-color electronic paper and a medium. The color developing method comprises a DC (direct current) balancing stage, a uniform driving stage, a first color developing stage and a second color developing stage. By adopting stepped voltage driving and performing specific waveform voltage construction based on four particles in stages, black, white, red and yellow particles are scattered, red and yellow particles are located in the middle, red and yellow are driven more conveniently, and the problem of ghost shadows in which various colors turn red and yellow is solved.

Description

Technical Field

[0001] The present invention relates to the field of electronic paper display driving, and particularly to a four-color electronic paper and a method and medium for eliminating afterimage driving based on the four-color electronic paper. Background Art

[0002] Electronic paper can display digital information in various ways. In fact, the possibilities of electronic paper applications are almost infinite. Among them, one of the best-known applications of electronic ink technology is e-book readers. Electronic ink screens can not only reduce eye fatigue but also provide a high-quality reading experience even in strong sunlight. Due to the low power consumption of electronic paper display technology, the battery life of e-book readers can last for several weeks.

[0003] However, currently, although the four-color electronic paper has the display ability and memory color mixing display ability of black, white, red, and yellow, the volumes of the four kinds of particles are inconsistent. Therefore, during the driving process of displaying one of the colors, there will be a problem of color mixing of the same-polarity particles. Since the degree of color mixing is different when switching from different colors to a certain color, afterimages will be formed. For example, when the red and yellow particles are over-driven to the lower layer, and when each color turns to red or yellow, some other particles will be doped when each color turns to red or yellow, and the afterimage effect is relatively poor, and the afterimage cannot be completely eliminated. Therefore, an effective method for eliminating afterimages is needed to achieve clearer color conversion. Summary of the Invention

[0004] Aiming at the deficiencies in the prior art, the present invention provides a four-color electronic paper and a method and medium for eliminating afterimage driving based on the four-color electronic paper, which mainly solves the problem that there is a lack of an effective method for eliminating afterimages in the prior art to achieve clearer color conversion.

[0005] The object of the present invention is achieved by the following solutions:

[0006] First aspect, according to an embodiment of the present invention, there is provided a driving method for eliminating afterimage based on a four-color electronic paper. The four-color electronic paper includes four kinds of particles: red, white, yellow, and black. The display driving method includes: DC balance stage: applying a first stepped voltage of opposite polarity for a first time period based on the total DC charge of all stages; Uniform driving stage: first applying a negative-polarity first stepped voltage for 2 frames, then applying a positive-polarity first stepped voltage for 2 frames, and repeating the above two steps for a first number of times, where the first number < 128; First color display stage: sequentially applying a zero voltage for a second time period, a negative-polarity first stepped voltage for a third time period, a zero voltage for a fourth time period, a positive-polarity second stepped voltage for a fifth time period, and repeating the above four steps for a second number of times, and then applying a zero voltage for a sixth time period, a positive-polarity first stepped voltage for a seventh time period, where 2 frames < the second time period, the third time period, the fourth time period, the fifth time period, the sixth time period, the seventh time period < 128 frames, and the second number < 128; Among them, the second color display stage: sequentially applying a negative-polarity second stepped voltage for an eighth time period, a positive-polarity first stepped voltage for 1 frame, and repeating the above two steps for a third number of times, and then sequentially applying a negative-polarity second stepped voltage for a ninth time period, a zero voltage for a tenth time period, a negative-polarity first stepped voltage for 1 frame, and repeating the above two steps for a fourth number of times, where 2 frames < the eighth time period, the ninth time period, the tenth time period < 128 frames, and the third number, the fourth number < 128.

[0007] According to an embodiment of the present invention, the first stepped voltage is 15V, and the second stepped voltage is any value in the range of 5 - 10V.

[0008] According to an embodiment of the present invention, any time period is in units of frames, and the driving frequency corresponding to each frame is any value in the range of 10 - 200Hz.

[0009] According to an embodiment of the present invention, 2 frames < the third time period < the fourth time period < the sixth time period, the seventh time period < the second time period < the fifth time period < 128 frames, and the second number < 128.

[0010] According to an embodiment of the present invention, 2 frames < the tenth time period < the ninth time period < the eighth time period < 128 frames, and the fourth number < the third number < 128.

[0011] In a second aspect, according to another embodiment of the present invention, a four-color electronic paper is provided, which includes four kinds of particles: red, white, yellow, and black, and is driven by a method for eliminating afterimage of a four-color electronic paper as described in the first aspect. The four-color electronic paper further includes: an electronic ink layer, which includes an ITO upper electrode layer, an upper ink layer, a middle-upper ink layer, a middle-lower ink layer, and a lower ink layer. Among them, the ITO upper electrode layer is located at the uppermost part of the electronic ink layer, and the upper ink layer, the middle-upper ink layer, the middle-lower ink layer, and the lower ink layer are all composed of black particles, white particles, yellow particles, and red particles. A TFT substrate is located below the electronic ink layer.

[0012] According to another embodiment of the present invention, when driven in the uniform driving stage in the method for eliminating afterimage, the upper ink layer in the four-color electronic paper is in a yellow-black mixed state with more black particles, the middle-upper ink layer is in a yellow-white-black mixed state with uniform distribution of yellow, white, and black, the middle-lower ink layer is in a red-white mixed state with uniform distribution, and the lower ink layer is in a red-white mixed state with more red particles.

[0013] According to another embodiment of the present invention, when driven in the first color display stage in the method for eliminating afterimage, the upper ink layer in the four-color electronic paper is in a red-black mixed state with more black particles, the middle-upper ink layer is in a red-white-black mixed state, the middle-lower ink layer is in a red-yellow-white mixed state, and the lower ink layer is in a white-yellow mixed state with more yellow particles.

[0014] According to another embodiment of the present invention, when driven in the second color display stage in the method for eliminating afterimage, the upper ink layer in the four-color electronic paper is in a white-yellow mixed state with more white particles, the middle-upper ink layer is in a state of uniform distribution of yellow, red, and white, the middle-lower ink layer is in a red-black mixed state with more red particles, and the lower ink layer is in a red-black mixed state with more black particles.

[0015] In a third aspect, according to still another embodiment of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, and the computer program can be executed by a processor to implement the steps of the method described in the first aspect.

[0016] Compared with the prior art, the present invention has the following beneficial effects: stepped voltage is adopted for driving, realizing targeted driving of particles of different sizes; through the separation of positive and negative particles, and for particles of the same polarity, those with larger volume are located above those with smaller volume, which is beneficial for further driving of various color particles and is a relatively stable state, especially suitable as the initial state for further driving and meeting the requirements of the afterimage elimination stage; in addition, it also realizes the dispersion of black, white, red, and yellow particles, with red and yellow particles in the middle, making it more convenient to drive red and yellow and improving the problem of afterimage of color conversion to red and yellow. Description of the Drawings

[0017] The embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0018] Figure 1 It is a voltage sequence diagram of the afterimage elimination driving method of the prior art;

[0019] Figure 2 It is a voltage sequence diagram of the afterimage elimination driving method of the embodiments of the present invention;

[0020] Figure 3 It is a flowchart of the afterimage elimination driving method of the embodiments of the present invention;

[0021] Figure 4 It is a particle state diagram of a four-color electronic paper adopting the afterimage elimination driving method of the embodiments of the present invention. Detailed implementation manners

[0022] Before proceeding with the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The terms "coupled", "connected" and their derivatives refer to any direct or indirect communication or connection between two or more elements, whether or not those elements are in physical contact with each other. The terms "transmit", "receive" and "communicate" and their derivatives cover both direct and indirect communication. The terms "comprise" and "include" and their derivatives mean including but not limited to. The term "or" is inclusive, meaning and / or. The phrase "associated with" and its derivatives mean including, included within, interconnected, containing, contained within, connected or connected to, coupled or coupled to, communicating with, cooperating with, interwoven with, juxtaposed, adjacent to, bound or bound to, having, having an attribute, having a relationship or having a relationship with, etc. The term "controller" refers to any device, system or part thereof that controls at least one operation. Such a controller can be implemented in hardware, or in a combination of hardware and software and / or firmware. The functions associated with any particular controller can be centralized or distributed, whether local or remote. The phrase "at least one", when used in conjunction with a list of items, means that different combinations of one or more of the listed items can be used, and it may only be necessary to have one item in the list. For example, "at least one of A, B, C" includes any one of the following combinations: A, B, C, A and B, A and C, B and C, A and B and C.

[0023] Definitions of other specific words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many cases, if not most cases, such definitions apply to the prior and future use of the words and phrases so defined.

[0024] In this patent document, the application combinations of modules and the hierarchical division of sub-modules are only for illustration purposes. Without departing from the scope of the present disclosure, the application combinations of modules and the hierarchical division of sub-modules can have different forms.

[0025] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below through specific embodiments with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] To better understand the present invention, first, recall the afterimage elimination technology in the prior art.

[0027] Figure 1 The driving waveform for realizing afterimage elimination in the prior art is shown. It includes a DC (direct current) balance stage, an afterimage clearing stage, an afterimage clearing stage 1 - particle mixing, an afterimage clearing stage 2 - yellow - white - red - white - black, and an afterimage clearing stage 3 - white - black - yellow - yellow - red. After these several stages, since the red and yellow particles are over-driven to the lower layer, when each color turns to red or each color turns to yellow, some other particles will be doped, and the afterimage effect is relatively poor, and the afterimage cannot be completely eliminated.

[0028] Regarding the above problems (as also described in the background art), as Figure 2 and Figure 3As shown, according to an embodiment of the present invention, a method for driving to eliminate afterimages based on a four-color electronic paper is provided. The four-color electronic paper includes four kinds of particles: red, white, yellow, and black. The display driving method includes: a DC balance stage: applying a first stepped voltage with opposite polarity for a first time period (n1, similarly, the Mth time period later is represented by nM) based on the total DC charge of all stages; a uniform driving stage: first applying a first stepped voltage with negative polarity for 2 frames, and then applying a first stepped voltage with positive polarity for 2 frames, repeating the above two steps for a first number of times, where the first number < 128; a first color display stage: sequentially applying a zero voltage for a second time period, a first stepped voltage with negative polarity for a third time period, a zero voltage for a fourth time period, a second stepped voltage with positive polarity for a fifth time period, and repeating the above four steps for a second number of times, and then applying a zero voltage for a sixth time period, a first stepped voltage with positive polarity for a seventh time period, where 2 frames < the second time period, the third time period, the fourth time period, the fifth time period, the sixth time period, the seventh time period < 128 frames, and the second number < 128; where, a second color display stage: sequentially applying a second stepped voltage with negative polarity for an eighth time period, a first stepped voltage with positive polarity for 1 frame, and repeating the above two steps for a third number of times, and then sequentially applying a second stepped voltage with negative polarity for a ninth time period, a zero voltage for a tenth time period, a first stepped voltage with negative polarity for 1 frame, and repeating the above two steps for a fourth number of times, where 2 frames < the eighth time period, the ninth time period, the tenth time period < 128 frames, and the third number and the fourth number < 128.

[0029] In the above solution, stepped voltages are adopted for driving, realizing targeted driving for particles of different sizes; through the separation of positive and negative particles, among particles of the same polarity, those with larger volume are located above those with smaller volume, which is conducive to further driving of particles of various colors and is a relatively stable state, especially suitable as the initial state for further driving and meeting the requirements of the afterimage elimination stage; in addition, it also realizes the dispersion of black, white, red, and yellow particles, with red and yellow particles in the middle, making it more convenient to drive red and yellow and improving the problem of afterimages when various colors turn to red and yellow.

[0030] The first step, the DC balance stage, is used to adjust the total charge amount of the entire group of waveforms to 0. The voltage polarity is opposite to that of the total DC charge of the remaining 3 driving stages, and the total amounts are the same, so as to achieve the DC balance of the entire waveform. The bistable characteristic of electronic ink is the result of the balance of various forces in its special electric field environment in the microcup. The first-stage DC balance stage applies a voltage with opposite polarity based on the total DC charge of all stages to neutralize the excess positive and negative electrons remaining in the electronic ink after driving through all stages, ensuring that the electric field state of the charged particles of various colors in the microcup of the electronic ink after each drive is not changed by the drive. Ensure that the bistable characteristic of the electronic ink is not affected by the drive.

[0031] In the second stage, the particle mixing stage, in order to make the distribution of charged particles of various colors in the electronic ink more uniform, the +15V and -15v voltages are alternately driven according to a specific structure, so that the smaller particles, the yellow and black charged particles, are evenly distributed in the micro-cups during the driving process, and the larger particles, the red and white particles, are evenly distributed in the central area of the micro-cups.

[0032] In order to drive different-sized particles specifically, a stepped voltage is adopted for driving. According to an embodiment of the present invention, the first stepped voltage is 15V, and the second stepped voltage is any value in the range of 5 - 10V. In addition, this also enables the positive and negative voltages of the four charged particles to reach balance by adjusting the driving voltage value, thereby ensuring the stable display of the electronic paper module. Moreover, these advantages make the driving method of the four-color electronic paper module highly versatile and applicable to various application scenarios.

[0033] In order to have stronger applicability to adapt to different application scenarios. According to an embodiment of the present invention, any time period is in units of frames, and the driving frequency corresponding to each frame is any value in the range of 10 - 200Hz. The driving frequency is independently selected by the operator, and 1 frame = 1 / driving frequency (seconds). The driving waveform is various combinations of driving voltages such as +15v, -15v, +5 - 10v, -5 - 10v, and idle for different numbers of frames.

[0034] Due to the charged characteristics of particles of different colors, the volumes of the four particles from largest to smallest are red, white, yellow, and black. Among them, the larger the volume, the slower the particle movement speed. In order to facilitate the driving of red and yellow and improve the problem of residual images of various colors turning to red and yellow, the black and red, and yellow and white are separated, with black and red on the upper layer and yellow and white on the lower layer. According to an embodiment of the present invention, 2 frames < the third time period < the fourth time period < the sixth time period, the seventh time period < the second time period < the fifth time period < 128 frames, and the second number < 128. The red particles and black particles are driven by positive pressure, and the white particles and yellow particles are driven by negative pressure. When voltages are applied to these electrodes, electrophoresis occurs. Specifically, if a positive voltage is applied to the top electrode and a negative voltage is applied to the bottom electrode, then the negatively charged white particles and yellow particles will be attracted upward, while the positively charged black particles and red particles will be repelled downward, so that the white particles will gather at the top of the capsule, making the area display white and yellow. On the contrary, if a negative voltage is applied to the top electrode and a positive voltage is applied to the bottom electrode, then the black particles and red particles will be attracted upward and gather at the top of the capsule, displaying red and black.

[0035] In detail, by alternately driving -15V and +5~10V voltages according to a specific structure, black and red, yellow and white can be accurately separated, with black and red on the upper layer and yellow and white on the lower layer. Then, driving the +15V voltage for a certain period of time drives black to the uppermost layer and white and yellow to the bottom layer. Finally, the charged particles in the microcup are distributed from top to bottom, with black and red mixed, red and yellow mixed, and yellow and white mixed.

[0036] In addition, further, in order to achieve the separation of positive and negative particles, the same polarity particles, the larger volume is located above the smaller volume. According to an embodiment of the present invention, 2 frames < the tenth time period < the ninth time period < the eighth time period < 128 frames, the fourth number < the third number < 128. Yellow particles with smaller particle volume are easier to drive than red and white particles, which is also the reason why yellow particles are easily doped during the afterimage elimination process. By alternately driving with -5~-10V and +15V voltages according to a specific structure, the black and red particles and the yellow and white particles are separated, the black particles and the white particles are driven to the surface layer, and the red and yellow particles are driven to the middle and lower layers. At this time, the yellow particles are driven to the upper layer by a -15V voltage according to a specific structure, and the black moves to the bottom layer under the influence of the -15v voltage. Finally, the charged particles of various colors in the microcup are distributed from top to bottom, white and yellow are mixed, white, yellow and red are mixed, and black. This state is conducive to further driving of particles of various colors and is a relatively stable state. It is particularly suitable as an initial state for further driving.

[0037] According to another embodiment of the present invention, Figure 4 As shown, a four-color electronic paper is provided, including four kinds of particles of red, white, yellow and black, and is driven by a residual image elimination driving method based on four-color electronic paper as described above. The four-color electronic paper also includes: an electronic ink layer, including an ITO (indium tin oxide) upper electrode layer 1, an upper ink layer 7, a middle-upper ink layer 8, a middle-lower ink layer 9 and a lower ink layer 10, wherein the ITO upper electrode layer is located at the top of the electronic ink layer, the upper ink layer, the middle-upper ink layer, the middle-lower ink layer and the lower ink layer are all composed of black particles 3, white particles 4, yellow particles 5 and red particles 6, and a TFT (thin film transistor) substrate 2 is located below the electronic ink layer.

[0038] In order to eliminate the residual image, firstly, the particles are made uniform. According to another embodiment of the present invention, Figure 4 When driven in the uniform driving stage of the afterimage elimination driving method, the upper ink layer in the four-color electronic paper is a yellow-black mixed state 11 with mostly black particles, the middle-upper ink layer is a yellow-black-white mixed state 12 with yellow, black and white evenly distributed, the middle-lower ink layer is a red-white mixed state 13 with even distribution, and the lower ink layer is a red-white mixed state 14 with mostly red particles.

[0039] Furthermore, in order to transition to the first color display stage, according to another embodiment of the present invention, referring again to Figure 4 , when driven in the first color display stage of the residual image elimination driving method, the upper ink layer in the four-color electronic paper is in a red-black mixed state 15 with more black particles, the upper-middle ink layer is in a red-white-yellow mixed state 16, the lower-middle ink layer is in a red-yellow-white mixed state 17, and the lower ink layer is in a white-yellow mixed state 18 with more yellow particles.

[0040] To further stabilize the residual image elimination and form white, referring again to Figure 4 , according to another embodiment of the present invention, when driven in the second color display stage of the residual image elimination driving method, the upper ink layer in the four-color electronic paper is in a white-yellow mixed state 19 with more white particles, the upper-middle ink layer is in a yellow-red-white evenly distributed state 20, the lower-middle ink layer is in a red-black mixed state 21 with more red particles, and the lower ink layer is in a red-black mixed state 15 with more black particles.

[0041] According to still another embodiment of the present invention, there is provided a computer-readable storage medium having stored thereon a computer program, which can be executed by a processor to implement the steps of a residual image elimination driving method based on a four-color electronic paper as described above.

[0042] The present invention may be a system, a method, and / or a computer program product. The computer program product may include a computer-readable storage medium having computer-readable program instructions thereon for causing a processor to implement various aspects of the present invention.

[0043] The computer-readable storage medium may be a tangible device that retains and stores instructions for use by an instruction execution device. The computer-readable storage medium may include, for example, but is not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), a memory stick, a floppy disk, a mechanically encoded device such as a punched card or raised structures in a groove having instructions stored thereon, and any suitable combination of the foregoing.

[0044] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is also not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to technologies in the market, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A method for eliminating afterimage based on four-color electronic paper, wherein the four-color electronic paper includes four particles of red, white, yellow and black, characterized in that: The afterimage elimination driving method comprises: DC balancing stage: applying a first step voltage of opposite polarity for a first time period based on the total amount of DC charges in all stages; Uniform driving stage: first apply a negative first step voltage for 2 frames, then apply a positive first step voltage for 2 frames, repeat the above two steps for a first number of times, wherein the first number of times is less than 128; A first color development stage and / or a second color development stage; Among them, the first color development stage: sequentially apply zero voltage for the second time period, the first step voltage of negative polarity for the third time period, zero voltage for the fourth time period, the second step voltage of positive polarity for the fifth time period, and repeat the above four steps for the second number, then apply zero voltage for the sixth time period, the first step voltage of positive polarity for the seventh time period, wherein 2 frames < the second time period, the third time period, the fourth time period, the fifth time period, the sixth time period, the seventh time period < 128 frames, and the second number of times < 128; Among them, the second color development stage: apply the second step voltage of negative polarity for the eighth time period, the first step voltage of positive polarity for 1 frame, and repeat the above two steps for the third time, then apply the second step voltage of negative polarity for the ninth time period, zero voltage for the tenth time period, the first step voltage of negative polarity for 1 frame, and repeat the above last two steps for the fourth time, among which, 2 frames < the eighth time period, the ninth time period, the tenth time period < 128 frames, and the third number and the fourth number < 128.

2. The afterimage elimination driving method based on four-color electronic paper according to claim 1, characterized in that: The first step voltage is 15V, and the second step voltage is any value between 5V and 10V.

3. The afterimage elimination driving method based on four-color electronic paper according to claim 1, characterized in that: Any time period is in frames, and the driving frequency corresponding to each frame is any value between 10 and 200 Hz.

4. The afterimage elimination driving method based on four-color electronic paper according to claim 1, characterized in that: 2 frames<third time period<fourth time period<sixth time period, seventh time period<second time period<fifth time period<128 frames, and the second number of times<128.

5. The afterimage elimination driving method based on four-color electronic paper according to claim 1, characterized in that: 2 frames<the tenth time period<the ninth time period<the eighth time period<128 frames, and the fourth number<the third number<128.

6. A four-color electronic paper, comprising four kinds of particles: red, white, yellow and black, characterized in that: The method for eliminating afterimages based on four-color electronic paper is used for driving according to any one of claims 1 to 5, wherein the four-color electronic paper further comprises: The electronic ink layer includes an ITO upper electrode layer, an upper ink layer, a middle-upper ink layer, a middle-lower ink layer and a lower ink layer, wherein the ITO upper electrode layer is located at the top of the electronic ink layer, and the upper ink layer, the middle-upper ink layer, the middle-lower ink layer and the lower ink layer are all composed of black particles, white particles, yellow particles and red particles. The TFT substrate is located below the electronic ink layer.

7. The four-color electronic paper according to claim 6, characterized in that: When driven in the uniform driving stage of the afterimage elimination driving method, the upper ink layer in the four-color electronic paper is a yellow-black mixed state with mostly black particles, the middle-upper ink layer is a yellow-black-white mixed state with yellow, black and white evenly distributed, the middle-lower ink layer is a red-white mixed state with evenly distributed red particles, and the lower ink layer is a red-white mixed state with mostly red particles.

8. The four-color electronic paper according to claim 6, characterized in that: When driven in the first color development stage of the afterimage elimination driving method, the upper ink layer in the four-color electronic paper is a red-black mixed state with mostly black particles, the middle-upper ink layer is a red-black-white mixed state, the middle-lower ink layer is a red-yellow-white mixed state, and the lower ink layer is a white-yellow mixed state with mostly yellow particles.

9. The four-color electronic paper according to claim 6, characterized in that: When driven in the second color development stage in the afterimage elimination driving method, the upper ink layer in the four-color electronic paper is a white-yellow mixed state with mostly white particles, the middle-upper ink layer is a yellow, red and white evenly distributed state, the middle-lower ink layer is a red-black mixed state with mostly red particles, and the lower ink layer is a red-black mixed state with mostly black particles.

10. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and the computer program can be executed by a processor to implement the steps of any method described in claims 1-5.

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