Electronic paper display driving method, chip and module

Abstract

An electronic paper display driving method, chip and module are provided, which are used for improving edge color difference, pixel points close to the edge N rows or M columns are driven by B driving waveform; center pixel points are driven by A driving waveform; color particle driving time of the B driving waveform is longer than that in the A driving waveform; or color particle driving voltage of the B driving waveform is higher than that in the A driving waveform. The technical scheme of the application can efficiently solve the problem of color deviation of the edge region and the center region.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of display devices, and particularly relates to an electronic paper display driving method and a display driving module. BACKGROUND

[0002] Electronic paper, also known as electronic ink screen, is a display screen made of electrophoretic display technology. A plurality of mixed electronic particles are arranged in the same ink capsule, and under the action of an electric current, the plurality of ink capsules are arranged and combined to form "electronic ink". Under the influence of positive and negative charges, these tiny ink capsules operate like a liquid to form various characters and patterns. Electronic paper has excellent characteristics such as ultra-low power consumption, continuous display without power consumption, eye protection, etc., and has the same display effect and visual experience as paper.

[0003] Electronic paper is driven by continuously applying a driving waveform voltage to each pixel point by a driving IC chip to drive electronic paper particles to achieve the effect of displaying images. Two-color, three-color and four-color electronic paper are all controlled by an external electric field to move up and down different charged black, white and red particles to display black, white, red and yellow display effects. The external electric field of the electronic price tag product made of electronic paper is composed of the electric field of the TFT pixel charged by the IC chip and the ITO of the electronic paper. The driving time of the electric field is controlled by a group of voltage driving waveforms controlled by the IC chip to achieve the display effect.

[0004] At present, the product market and customer requirements of electronic paper are becoming more and more strict, but due to process problems, raw material problems, water loss or other component loss of the edge of electronic paper affecting the display effect, the specific performance is that the edge display is abnormal. When the edge display is abnormal, the color of the screen around the edge is yellow or white (three-color electronic paper edge white, four-color electronic paper edge yellow) as shown in Figure 6

[0005] In the use of electronic paper, with time, the edge area is more prone to water loss and other problems, so the color deviation between the edge area and the center area will increase with time, thereby causing the problem of aggravated display color deviation.

[0006] How to efficiently and at low cost solve the above-mentioned edge display abnormality is a technical problem to be solved.

[0007] Glossary:

[0008] EPD is the abbreviation of English "electronic paper display", which means electronic paper master display. The meaning of electronic paper master in the application is electronic paper master display.

[0009] ​TFT is the abbreviation of English "Thin Film Transistor", the Chinese meaning is thin film transistor; each pixel point on the TFT display is driven by the integrated thin film transistor behind it.

[0010] PET is the abbreviation of English "Polyethylene terephthalate", the Chinese meaning is polyester resin film layer.

[0011] IC is the abbreviation of English "Integrated Circuit", the Chinese meaning is chip.

[0012] FPC is the abbreviation of English "Flexible Printed Circuit", the Chinese meaning is flexible circuit board.

[0013] PS is the abbreviation of English "Polystyrene", the Chinese meaning is polystyrene film.

[0014] FPL is the abbreviation of English "Front Plane Lamination", the Chinese meaning is front plane lamination display module.

[0015] ITO is the abbreviation of English "Indium Tin Oxide", the Chinese meaning is indium tin oxide. In this application, the ITO of electronic paper refers to the conductive film layer material of the transparent conductive film shielding glass, mainly ITO (indium tin oxide semiconductor) film. SUMMARY

[0016] The present application can avoid the same driving signal for different areas of electronic paper pixels in the prior art, and cannot solve the display color deviation problem of the edge area and the center area caused by various reasons. The driving method and module of the present application can solve the color deviation problem of the edge area and the center area.

[0017] The technical solution of the present application to solve the above technical problems is an electronic paper display driving method for improving edge color difference. The pixel points near the edge N rows or M columns are driven by B driving waveform; the center pixel points are driven by A driving waveform; the color particle driving time of the above B driving waveform is longer than that in the A driving waveform; or the color particle driving voltage of the B driving waveform is higher than that in the A driving waveform.

[0018] The above B driving waveform, when driving the edge N rows or N columns of pixels, the color particle driving time or driving voltage = set compensation coefficient-(edge distance x gradient compensation value).

[0019] The above set compensation coefficient is related to the running time. The longer the running time is, the larger the set compensation coefficient is.

[0020] The running time is the electronic paper starting running time, and the unit is day.

[0021] The compensation coefficient is related to the temperature value and humidity during the running.

[0022] The electronic paper can be black, white, red, yellow, and four-color electronic paper.

[0023] The electronic paper can be black, red, and yellow three-color electronic paper.

[0024] The electronic paper can be black and red two-color electronic paper.

[0025] The N rows or M columns of the edge can be set.

[0026] N can be equal to M.

[0027] The technical solution of the present application to solve the above technical problems can also be an electronic paper display driving chip.

[0028] The technical solution of the present application to solve the above technical problems can also be an electronic paper display driving module.

[0029] The technical solution of the present application to solve the above technical problems can also be an electronic paper display driving module.

[0030] One of the beneficial effects of the technical solution in the present application is that different driving waveforms are used in the edge area and the center area to compensate for the color difference between the edge area and the center area.

[0031] One of the beneficial effects of the technical solution in the present application is that the driving time is used in the driving waveform to facilitate control and compensate for color differences according to the driving time.

[0032] One of the beneficial effects of the technical solution in the present application is that the driving voltage adjustment is used in the driving waveform to facilitate control and compensate for color differences according to the driving voltage.

[0033] One of the beneficial effects of the technical solution in the present application is that the color particle driving time or driving voltage = set compensation coefficient-(edge distance x gradient compensation value), which can finely control according to the edge degree, so that the color difference between different pixels is smaller and the display is more balanced.

[0034] One of the beneficial effects of the technical solutions in this application is that the compensation coefficient is related to the running time, which can solve the problem of edge color difference caused by long-time running and aging.

[0035] One of the beneficial effects of the technical solutions in this application is that the running time is the starting running time of the electronic paper, which can be finely controlled according to the actual running time.

[0036] One of the beneficial effects of the technical solutions in this application is that the compensation coefficient is related to the temperature and humidity during running, which can solve the problem of edge color difference caused by environmental conditions.

[0037] One of the beneficial effects of the technical solutions in this application is that the electronic paper can be various different colored or non-colored electronic paper, which can solve the display difference between the edge and the center area. Especially the display deviation caused by water loss in the edge.

[0038] One of the beneficial effects of the technical solutions in this application is that the N and M values can be set respectively, which can be more flexible to adapt to actual use, and can flexibly set the compensation area according to actual needs. When the N and M values are equal, it is to control the square area.

[0039] One of the beneficial effects of the technical solutions in this application is that the electronic paper display driving chip can be integrated to solve, which is lower in cost.

[0040] One of the beneficial effects of the technical solutions in this application is that the electronic paper display driving module can be modularized to solve the problem, which is convenient to use. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is an electronic paper pixel array schematic diagram;

[0042] Figure 2 is an electronic paper display screen and driving module connection schematic diagram;

[0043] Figure 3 is an electronic paper pixel array schematic diagram;

[0044] Figure 4 is an electronic paper display driving chip module schematic diagram;

[0045] Figure 5 is an electronic paper display device schematic diagram;

[0046] Figure 6 is an electronic paper display device schematic diagram;

[0047] Figure 7 is a driving waveform schematic diagram;

[0048] Figure 8 is a driving waveform schematic diagram;

[0049] Figure 9 is a schematic diagram of a driving waveform. DETAILED DESCRIPTION

[0050] The embodiments of the present application will be further described in conjunction with the accompanying drawings.

[0051] It should be noted that the following description of the preferred embodiments of the present application is merely illustrative of the application and does not in any way point to limitations of the present application. The description of the preferred embodiments of the present application is merely illustrative of the general principles of the present application. The embodiments described in the present application are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0052] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are merely for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and technical features numbered with Arabic numerals 1, 2, 3, etc., and the numbering of "A" and "B" are for the purpose of description only, for the convenience of explanation, and do not represent the chronological or spatial sequence; cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited by "first", "second", and technical features numbered with Arabic numerals 1, 2, 3, etc. can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "several" is two or more, unless otherwise specifically limited.

[0053] As shown in Figure 6 , in the prior art, when the edge of the electronic paper shows abnormal, the color of the screen around the edge is yellow or white; for three-color electronic paper, the edge is white, and for four-color electronic paper, the edge is yellow.

[0054] As shown in Figure 2 , in an embodiment of an electronic paper display driving method for improving edge color difference, the pixel points near the edge N rows or M columns are driven by a B driving waveform; the center pixel points are driven by an A driving waveform; the color particle driving time of the B driving waveform is longer than that in the A driving waveform; or the color particle driving voltage of the B driving waveform is higher than that in the A driving waveform.

[0055] The meaning that the color particle driving voltage of the B driving waveform is higher than that in the A driving waveform is that the voltage for maintaining the target color particle driving is higher. Specifically, as shown in Figure 7 the driving voltage EB of the B driving waveform is greater than the driving voltage EA of the A driving waveform.

[0056] The meaning that the color particle driving time of the B driving waveform is longer than that in the A driving waveform is that the time for maintaining the target color particle driving is longer. Specifically, there are various embodiments. One of them is that, as shown in Figure 8 the square wave maintains the driving level for a longer time in the same period. Figure 8 In the embodiment, the time maintained by the driving period TB of the B driving waveform is greater than the time maintained by the driving period TA of the A driving waveform. One of them is that, as shown in Figure 9 the square wave maintains the driving level for a longer time in the same period or period. Thus, the total driving time is longer. Figure 9 In the embodiment, the time maintained by the driving period of the B driving waveform is determined by the product of the B frame number and the level maintenance; the time maintained by the driving period of the A driving waveform is determined by the product of the A frame number and the level maintenance; the time maintained by the driving period of the B driving waveform is greater than the time maintained by the driving period of the A driving waveform, and the corresponding frame number and square wave high level time can be adjusted. In the case of the same square wave high level time, only the frame number can be adjusted.

[0057] As shown in Figure 2 the electronic paper display driving module, the internal driving module includes two sub-modules, one for edge driving and one for center driving. The B driving waveform comes from the edge driving submodule and is used to drive the pixels of the edge; the A driving waveform comes from the center driving submodule and is used to drive the pixels of the center area.

[0058] In some embodiments not shown in the drawings, the above-mentioned B driving waveform, when driving N rows or N columns of edge pixels, the color particle driving time or driving voltage = set compensation coefficient-(edge distance x gradient compensation value).

[0059] For example: the set compensation coefficient is 10, the gradient compensation value is 1, the edge distance is 1, and the first edge compensation time is equal to 10-1x1=9. The first edge compensation time is used as the color particle driving time.

[0060] For example: the set compensation coefficient is 10, the gradient compensation value is 1, the edge distance is 2, and the second edge compensation time is equal to 10-2x1=8. The greater the edge distance value indicates that it is closer to the edge, the greater the degree of water loss, and the greater the compensation value. The second edge compensation time is used as the color particle driving time.

[0061] The color particle driving time and driving voltage can have different set compensation coefficients. It can be determined or selected according to the actual application.

[0062] The compensation coefficient and the gradient compensation value can be set according to the specific conditions of the electronic paper. The greater the difference gradient between the edge area and the center area, the greater the compensation coefficient and the gradient compensation value can be set.

[0063] In some embodiments not shown in the drawings, the setting of the compensation coefficient is related to the running time. The longer the running time, the greater the compensation coefficient is set. The running time is the running time of the electronic paper display module after starting, which is measured in days.

[0064] For example, after the electronic paper display module starts running, it is exposed to the air and ages over time, and the more moisture it loses, the greater the compensation value. For example, the compensation coefficient is set to 10 + running days x 0.01, and when running for 100 days, the compensation coefficient is set to 10 + 100 x 0.01 = 11.

[0065] In some embodiments not shown in the drawings, the setting of the compensation coefficient is related to the temperature value and humidity during the running time. After the electronic paper display module starts running, it is exposed to the air and experiences higher temperature values, and the more moisture it loses, the greater the degree of moisture loss. For example, the compensation coefficient is set to 10 + (the sum of the running temperature x the temperature compensation coefficient), and the temperature compensation coefficient is 0.0001. For example, if the module runs for 100 hours in an environment of 30 degrees, the compensation coefficient is 10 + (30 x 100 x 0.0001), and the compensation coefficient is 10 + 50 x 100 x 0.0001 = 10.3. For example, if the module runs for 100 hours in an environment of 50 degrees, the compensation coefficient is 10 + (50 x 100 x 0.0001), and the compensation coefficient is 10 + 50 x 100 x 0.0001 = 10.5. The running temperature range is usually 30-40 degrees, and some harsh environments may exceed this temperature range.

[0066] In some embodiments, the electronic paper described above is black, white, red, yellow, and four-color electronic paper; and the color particles include black particles, white particles, red particles, and yellow particles.

[0067] In some embodiments, the electronic paper described above is black, red, and yellow, and three-color electronic paper; and the color particles include black particles, red particles, and yellow particles.

[0068] In some embodiments, the electronic paper described above is black and red two-color electronic paper; and the color particles include black particles and white particles.

[0069] In some embodiments, in the edge N rows or M columns described above, the values of N and M can be set respectively. For example, as shown in the figure, the values of N and M are equal, which can be 8, i.e., 8 rows and 8 columns of pixels at the edge are driven for compensation. It can also be other multiples of 8, such as 16 rows and 16 columns of pixels at the edge are driven for compensation. In actual applications, the values of N and M can be different. Of course, other values can also be used. Figure 3 The values of N and M are equal, which can be 8, i.e., 8 rows and 8 columns of pixels at the edge are driven for compensation. It can also be other multiples of 8, such as 16 rows and 16 columns of pixels at the edge are driven for compensation. In actual applications, the values of N and M can be different. Of course, other values can also be used.

[0070] As Figure 4 , the embodiment of the electronic paper display driving chip is used to execute the above method. The electronic paper display driving chip comprises a Gate buffer zone for outputting a Gate driving signal, a Source buffer zone for outputing a Source driving signal, a Border for outputting a Border signal, a B driving waveform data module, an A driving waveform data module, a waveform selection module, a VCOM module, a waveform setting module and a RAM.

[0071] The waveform setting module is electrically connected with the B driving waveform data module and the A driving waveform data module; the waveform selection module controls the waveform selection according to the IC instruction, and can obtain the corresponding driving waveform data from the B driving waveform data module or the A driving waveform data module. The IC instruction control can select the corresponding driving waveform data according to the real-time set edge region or the pre-set edge region range. According to the different driving waveform data, the corresponding Gate driving signal, Source driving signal and Border signal are outputted, and the driving time control of the corresponding color particles is realized.

[0072] In an embodiment of the electronic paper display driving module, the above-mentioned electronic paper display driving module comprises at least two electronic paper display driving chips, one chip is used to drive the pixel points close to the edge, and one chip is used to drive the center pixel points.

[0073] In an embodiment of the electronic paper display driving module, the electronic paper display driving module can be a circuit module in a non-chip integrated manner; the electronic paper display driving module is used to execute the above method.

[0074] The method provided by the application can solve the difference of the screen color and ensure good display effect. The application is an efficient and economical solution based on the existing product architecture. In the use process, the display effect can be changed by adjusting the driving signal output by the driving chip, and the display imbalance problem of the center region and the edge region after long-term use and aging of the display can be solved.

[0075] The display effect of the electronic paper product is driven by the driving voltage waveform of the IC chip of the electronic paper module (EPD) to drive the particle color display effect in the electronic paper. The driving waveform is determined by the charging voltage time of the IC scanning control TFT. In the prior art, only one set of waveform such as A waveform can be outputted in the IC each time to control the color of the whole screen refresh, and the problem of inconsistent color of the screen itself cannot be compatible.

[0076] The application can select the way of driving the waveforms of the screen edge and the middle by 2 sets of waveforms, so as to reduce the optical difference between the screen edge and the middle, and achieve consistent display effect.

[0077] As Figure 1As shown, it is a schematic wiring diagram of TFT wiring and TFT pixel of electronic paper. When the edge area of G1-G16, Gm-Gm-16, S1-S16, Sn-S16 scanned by the IC chip, different driving waveforms, i.e. B driving waveforms are used to drive the corresponding TFT pixels to perform screen brushing, which can solve the problems of yellowing and whitening of the edge, and can completely improve the consistency of the effects of the middle area and the edge area of the screen.

[0078] As shown, Figure 4 As shown, it is an internal framework diagram of an electronic paper display driving chip. It can be seen that two different B driving waveform data and A driving waveform data can be placed in the IC chip. The B driving waveform only needs to modify the driving time (frame number) or voltage size of some target color particles on the basis of the A driving waveform. The target color particles can be red particles or any one or more of other color particles.

[0079] For example, in some embodiments, the optical L value of the middle of the screen is 24.15, and the A value is 36.5. The optical L value of the edge is 27.2, and the A value is 34.2. At this time, the optical difference between the edge and the middle of the screen is close to 3 points or so. At this time, the B driving waveform of the B region of the edge area only needs to increase the red voltage by about 0.6-1.2V, so as to reduce the L value to about 24.3 and the A value to about 36.7, so as to keep the optical of the middle and the edge consistent.

[0080] As shown, Figure 3 As shown, the method in the application can control the edge area and the center area by the IC chip, and does not limit the size of the edge area to G9 / S8 or G16 / S16. The IC can set the starting and ending positions of Gate and source to control the size of the edge position of the TFT pixel to the middle position to improve the whitening of the edge, and use the corresponding driving waveform voltage to brush the screen. The B region waveform needs to be fine-tuned by the A region waveform, so that the effect of brushing the screen of the whole screen is consistent, and the visual effect is not affected.

[0081] As shown, Figure 6 As shown, the electronic paper display has red edge whitening or yellowing. The effect after driving by the method of the application is shown in Figure 5 As shown, the red whole surface keeps consistent effect.

[0082] As shown in the drawings, the above embodiments are only examples of the application, and do not limit the patent scope of the application. Any equivalent structure or equivalent flow transformation using the contents of the application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. An electronic paper display driving method for improving edge color difference, characterized in that, pixels near the edge N rows or M columns are driven by a B driving waveform; the center pixel is driven by an A driving waveform; the color particle driving time of the B driving waveform is longer than that in the A driving waveform; or the color particle driving voltage of the B driving waveform is higher than that in the A driving waveform; when driving the edge N rows or N columns of pixels, the color particle driving time or driving voltage of the B driving waveform = set compensation coefficient - (edge distance x gradient compensation value); the set compensation coefficient is related to the running time, and the longer the running time, the greater the set compensation coefficient.

2. The electronic paper display driving method according to claim 1, characterized in that, the running time is the electronic paper start-up running time, and the unit is day.

3. The electronic paper display driving method according to claim 1, characterized in that, the set compensation coefficient is related to the temperature value and humidity during running.

4. The electronic paper display driving method according to claim 1, characterized in that, any one of the following technical features is included: TA1: the electronic paper is black, white, red, yellow, four-color electronic paper; the color particles include black particles, white particles, red particles, and yellow particles; TA2: the electronic paper is black, red, yellow, three-color electronic paper; the color particles include black particles, red particles, and yellow particles; TA3: the electronic paper is black, red two-color electronic paper; the color particles include black particles and white particles.

5. The electronic paper display driving method according to claim 1, characterized in that, any one of the following technical features is included: TB1: in the edge N rows or M columns, N and M values can be set respectively; TB2: N is equal to M.

6. An electronic paper display driving chip, characterized in that, the electronic paper display driving chip is used to execute the method of any one of claims 1 to 5.

7. An electronic paper display driving module, characterized in that, the electronic paper display driving module includes at least two electronic paper display driving chips as claimed in claim 6, one chip is used to drive the pixel point near the edge, and one chip is used to drive the center pixel.

8. An electronic paper display driving module, characterized in that, the electronic paper display driving module is used to execute the method of any one of claims 1 to 5.

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