A three-particle electrophoretic display driving method and display

Abstract

The application discloses a three-particle electrophoretic display driving method and a display. The method comprises the following steps: a driving signal is generated; when an erasing instruction is detected, the driving signal is controlled to provide an adjustable voltage for erasing an original image and direct current balance, and the brightness of black display is preliminarily adjusted; when an activating instruction is detected, the driving signal is controlled to provide a first driving voltage and a second driving voltage for activating white particles, black particles and red particles; when a black driving instruction is detected, the driving signal is controlled to provide a frequency-adjustable periodic voltage sequence for driving the red particles to move to the bottom of microcapsules and driving the black particles to move to the top of the microcapsules, so as to further adjust the brightness of black display; and when a red driving instruction is detected, the driving signal is controlled to provide a third driving voltage for driving the red particles. The application effectively improves the quality of black gray-scale display.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of three-particle electrophoretic display, and particularly to a three-particle electrophoretic display driving method and a display. BACKGROUND

[0002] Three-particle electrophoretic display (EPD) is a new type of electronic paper, which is stable in operation and has extremely low energy consumption, making up for the performance limitation of traditional electrophoretic electronic paper in colorization. However, due to the increase in particle types, the driving mechanism becomes more complex, and different types of particles in the microcapsule are more likely to mix and display, resulting in a decrease in display quality.

[0003] The production of three-particle electrophoretic display is mainly based on microcapsule technology, and its structure mainly consists of a common electrode, a pixel electrode, black particles, white particles, red particles and a non-polar solvent. The three types of particles have different types of charges and are encapsulated inside the microcapsule. The microcapsule is sandwiched between the common electrode and the pixel electrode. When a certain voltage is applied between the two electrodes, the charged particles will be subjected to the action of the electric field force to drift, thereby controlling the display color.

[0004] Three-particle electrophoretic display mainly adds red particles to the traditional black-and-white electrophoretic display, increasing the color diversity, but also increasing the complexity of driving. Among them, because the red particles and the black particles have the same charge polarity, when the pixel is driven to be black, part of the red particles will mix with the black particles, making the pixel display dark red, resulting in the inability to display the target darkness.

[0005] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0006] In view of the deficiencies of the prior art described above, the purpose of the present application is to provide a three-particle electrophoretic display driving method and a display to solve the problem that in the existing three-particle electrophoretic display, because the red particles and the black particles have the same charge polarity, when the pixel is driven to be black, part of the red particles will mix with the black particles, making the pixel display dark red, resulting in the inability to display the target darkness.

[0007] The technical solution of the present application is as follows:

[0008] A three-particle electrophoretic display driving method, comprising:

[0009] controlling a driving signal to be generated; the driving signal is used to realize an erasing stage, an activating stage, a black driving stage and a red driving stage in a three-particle display process;

[0010] when an erasing instruction is detected, controlling the driving signal to provide an adjustable voltage for erasing an original image and direct current balance, and preliminarily adjusting the brightness of black display;

[0011] when the activation instruction is detected, the driving signal is controlled to provide the first driving voltage and the second driving voltage for activating the white particles, the black particles and the red particles;

[0012] when the black driving instruction is detected, the driving signal is controlled to provide a periodic voltage sequence with adjustable frequency for driving the red particles to move to the bottom of the microcapsule and driving the black particles to move to the top of the microcapsule, so as to further adjust the black display brightness;

[0013] when the red driving instruction is detected, the driving signal is controlled to provide the third driving voltage for driving the red particles.

[0014] Further provided in the application, the step of controlling the driving signal to provide the periodic voltage sequence with adjustable frequency for driving the red particles to move to the bottom of the microcapsule and driving the black particles to move to the top of the microcapsule, so as to further adjust the black display brightness when the black driving instruction is detected comprises:

[0015] in one driving period, the fourth driving voltage with the first time length and the first amplitude is first applied to drive the red particles to move to the bottom of the microcapsule, and then the fifth driving voltage with the second time length and the second amplitude is applied to drive the black particles to move to the top of the microcapsule;

[0016] the multiple driving periods are cyclically driven until the pixel displays the target darkness.

[0017] Further provided in the application, the step of controlling the driving signal to provide the periodic voltage sequence with adjustable frequency for driving the red particles to move to the bottom of the microcapsule and driving the black particles to move to the top of the microcapsule, so as to further adjust the black display brightness when the black driving instruction is detected further comprises:

[0018] when the number of the driving periods is increased and the second time length is increased, the darkness displayed by the pixel is higher;

[0019] when the number of the driving periods is reduced and the size of the second time length is reduced, the brightness displayed by the pixel is higher.

[0020] Further provided in the application, the step of controlling the driving signal to provide the periodic voltage sequence with adjustable frequency for driving the red particles to move to the bottom of the microcapsule and driving the black particles to move to the top of the microcapsule, so as to further adjust the black display brightness when the black driving instruction is detected further comprises:

[0021] if the red particles in the display exist interference, the number of the driving periods is increased and / or the driving time length of the fourth driving voltage is increased;

[0022] If it is needed to reduce the overall driving period of the black driving stage, the number of driving periods is reduced and / or the driving duration of the fourth driving voltage is reduced.

[0023] Further provided in the application is that the adjustable voltage is between the second voltage and the fourth voltage.

[0024] When the adjustable voltage is increased, the duration of the erase stage is reduced and the driving period of the black driving stage is reduced.

[0025] When the adjustable voltage is reduced, the red particles are further driven to the bottom of the microcapsule.

[0026] Further provided in the application is that the first driving voltage and the second driving voltage have equal amplitude and equal driving duration.

[0027] Further provided in the application is that the third driving voltage has equal amplitude with the fourth driving voltage, and the fifth driving voltage has equal amplitude with the first driving voltage.

[0028] Further provided in the application is that the black driving stage is before the red driving stage.

[0029] A display for implementing the three-particle electrophoretic display driving method is provided.

[0030] A display panel is provided.

[0031] A driving circuit is provided, which is connected with the display panel and used for providing a driving signal to the display panel; wherein the driving signal is used for implementing an erase stage, an activation stage, a black driving stage and a red driving stage in a driving process.

[0032] Further provided in the application is that the display panel comprises:

[0033] An electrophoretic unit is provided, which comprises a microcapsule and black particles, white particles and red particles arranged in the microcapsule.

[0034] A pixel electrode is provided, which is arranged below the microcapsule and connected with the driving circuit.

[0035] A common electrode is provided, which is arranged above the microcapsule.

[0036] The application provides a three-particle electrophoretic display driving method and a display. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained according to the structures shown in the drawings without any creative effort.

[0038] Figure 1 Fig. 1 is a structural schematic diagram of a display in an embodiment of the present application.

[0039] Figure 2 Fig. 2 is a structural schematic diagram of an electrophoretic unit in an embodiment of the present application.

[0040] Figure 3 Fig. 3 is a flow schematic diagram of a three-particle electrophoretic display driving method in an embodiment of the present application.

[0041] Figure 4 Fig. 4 is a waveform diagram of a driving signal in an embodiment of the present application.

[0042] Figure 5 Fig. 5 is a waveform test system architecture diagram of a driving signal of a display in an embodiment of the present application.

[0043] Reference signs in the drawings: 100, display; 110, display panel; 111, microcapsule; 112, black particle; 113, white particle; 114, red particle; 115, pixel electrode; 116, common electrode; 120, drive circuit; 200, computer; 300, arbitrary waveform function generator; 400, voltage amplifier; 500, colorimeter. DETAILED DESCRIPTION

[0044] The present application provides a three-particle electrophoretic display driving method and display. In order to make the objectives, technical solutions and effects of the present application clearer and more explicit, the present application is further described in detail below with reference to the drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0045] In the embodiments and patent claims, unless the article is specifically limited, "an", "one", "said" and "the" also include plural forms. If the description in the embodiments of the present application involves "first", "second", etc., the description of "first", "second", etc. is only for the purpose of description and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features.

[0046] It should be further understood that the phrase "comprising" used in the specification of the present application means that the features, integers, steps, operations, elements and / or components exist, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we say that an element is "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can be intermediate elements. In addition, "connected" or "coupled" used herein can include wireless connection or wireless coupling. The phrase "and / or" used herein includes all or any single unit and all combinations of the associated listed items.

[0047] Those skilled in the art can understand that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as that generally understood by those skilled in the art to which the present application belongs. It should also be understood that terms such as those defined in a general dictionary should be understood as having meanings consistent with those in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as such.

[0048] In addition, the technical solutions in the various embodiments can be combined with each other, but it must be based on that a person skilled in the art can realize, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0049] Please refer to Figure 1 and Figure 2 The present application provides a preferred embodiment of a display.

[0050] As Figure 1 and Figure 2 shown, the present application provides a display 100, comprising a display panel 110 and a driving circuit 120, wherein the driving circuit 120 is connected with the display panel 110.

[0051] The display panel 110 comprises electrophoretic cells, pixel electrodes 115 and common electrodes 116. The electrophoretic cells comprise microcapsules 111, and black particles 112, white particles 113 and red particles 114 arranged in the microcapsules 111; the pixel electrodes 115 are arranged below the microcapsules 111 and connected with the driving circuit 120; the common electrodes 116 are arranged above the microcapsules 111. The driving circuit 120 is connected with the pixel electrodes 115, and the driving circuit 120 is used to provide driving signals to the pixel electrodes 115, wherein the driving signals are used to realize erasing stage, activating stage, black driving stage and red driving stage in the driving process.

[0052] Specifically, the microcapsules 111 are arranged with non-polar solvents, and the black particles 112, the white particles 113 and the red particles 114 are all arranged in the microcapsules 111. The microcapsules 111 are arranged between the common electrodes 116 and the pixel electrodes 115, wherein the common electrodes 116 and the pixel electrodes 115 are both transparent substrates covered with indium tin oxide (ITO). The driving circuit 120 is connected with the pixel electrodes 115, and can provide driving signals to the display panel 110 to drive the erasing stage, the activating stage, the black driving stage and the red driving stage of the three-particle electrophoretic display.

[0053] The black particles 112 and the red particles 114 are positively charged, and the white particles 113 are negatively charged. When the driving circuit 120 applies a positive voltage to the pixel electrode 115, the red particles 114 move to the common electrode 116 at a lower threshold voltage, and the display panel 110 displays red. When the driving circuit 120 applies a larger positive voltage to the pixel electrode 115, the black particles 112 move to the common electrode 116, and the display panel 110 displays black. When the driving circuit 120 applies a negative voltage to the pixel electrode 115, the white particles 113 move to the common electrode 116, and the display panel 110 displays white. Therefore, the driving circuit 120 controls the movement of the particles in the electrophoretic cell by controlling the application of different voltage sequences, thereby controlling the color display of the display 100. When no voltage is applied to the common electrode 116 and the pixel electrode 115, the three-particle electrophoretic display is in equilibrium, and the display 100 maintains the initial display state.

[0054] In the process of driving the three-particle electrophoretic display, the original image is erased by using an adjustable voltage in the erasing stage, and the direct current is balanced. The brightness of the black display is preliminarily adjusted. A frequency-adjustable periodic voltage sequence is provided in the black driving stage to drive the red particles to move to the bottom of the microcapsule and drive the black particles to move to the top of the microcapsule, so as to further adjust the brightness of the black display, so that the target darkness can be displayed, and the quality of the black gray scale display can be effectively improved.

[0055] Please refer to Figures 3 to 5 In some embodiments, the present application also provides a three-particle electrophoretic display driving method, which comprises the steps of:

[0056] S100, a driving signal is generated; the driving signal is used to realize an erasing stage, an activation stage, a black driving stage and a red driving stage in a three-particle display process;

[0057] Specifically, the waveform of the driving signal is designed on the computer, and then generated by using an arbitrary waveform function generator. The generated driving signal is amplified by a voltage amplifier and output to the driving circuit of the display. The driving circuit realizes the erasing stage, the activating stage, the black and white driving stage and the red driving stage of the display according to the driving signal. Since the brightness of the three-particle electrophoretic display can be obtained by the chromaticity coordinate value Y in the CIE Yxy color space, the performance of the driving waveform of the driving signal can be tested. By placing a colorimeter on the display and connecting it with the computer, the brightness of the display can be tested in real time when the driving signal is applied. The test data is given to the computer, and the performance of the driving waveform can be analyzed according to the recorded data.

[0058] Please refer to Figure 5 In actual implementation, the driving waveform of the driving signal is designed in the computer 200 by using MATLAB. The driving parameters are designed in combination with the actual driving requirements and the DC balance rule, and then output as a txt text format which is saved and converted into a tfw file which can be recognized by the arbitrary waveform function generator 300 by using AREXPRESS software. The computer 200 is connected with the arbitrary waveform function generator 300 through a USB interface, and can import the tfw waveform file into the arbitrary waveform function generator 300.

[0059] Each lead wire on the driving circuit of the display corresponds to the pixel electrode of each pixel, and the common electrode is grounded. The output end of the arbitrary waveform function generator 300 is connected with the input end of the voltage amplifier 400. The positive and negative electrodes of the voltage amplifier 400 are connected with the positive and negative ends of the driving circuit respectively, and the amplification multiple is adjusted. In an implementation manner, the voltage amplification multiple of the voltage amplifier 400 can be set to 10 times.

[0060] Then, the computer 200 is connected with the colorimeter 500, the colorimetric measurement software is opened, and the colorimeter is zeroed. Then, the colorimeter is placed on the display and fixed at a position to test the brightness of the same pixel point. The various parameters of the arbitrary waveform function generator which are consistent with the designed driving waveform are adjusted (the output amplitude voltage of the arbitrary waveform function generator is set to 1.5V, and the period is set to be consistent with the total period of the driving waveform), and the output switch is turned on. Then, the output switch of the voltage amplifier is turned on, and the electrophoretic display effect according to the set driving waveform can be observed on the display. Finally, the brightness change of the display after executing the driving waveform once is recorded on the computer measurement software.

[0061] S200, when the erasing instruction is detected, the adjustable voltage of the driving signal is provided for erasing the original image and DC balance, and the brightness of the black display is preliminarily adjusted;

[0062] Specifically, in the erasing stage, the adjustable voltage V0 is a direct current driving voltage with adjustable voltage value, mainly used for erasing original image and direct current balance. In the embodiment, by increasing the value of the adjustable voltage V0, the red particles can be further driven to the bottom of the microcapsule, so that the influence of the mixing of red particles and black particles on black display can be reduced.

[0063] S300, when the activation instruction is detected, the driving signal is controlled to provide the first driving voltage V1 and the second driving voltage V2 for activating the white particles, the black particles and the red particles;

[0064] Specifically, the amplitude of the first driving voltage V1 and the second driving voltage V2 is equal, and the driving time is equal to meet the direct current balance condition. In the activation stage, the first driving voltage V1 and the second driving voltage V2 can activate the white particles, the black particles and the red particles. In an implementation manner, the first driving voltage V1 can be set to 15V, and the second driving voltage V2 can be set to -15V.

[0065] S400, when the black driving instruction is detected, the driving signal is controlled to provide a periodic voltage sequence with adjustable frequency for driving the red particles to move to the bottom of the microcapsule and driving the black particles to move to the top of the microcapsule, so as to further adjust the brightness of black display;

[0066] Specifically, the black driving stage is before the red driving stage. In one driving period, the fourth driving voltage V4 with the first time length T3a and the first amplitude is first applied to drive the red particles to move to the bottom of the microcapsule, and then the fifth driving voltage V5 with the second time length T3b and the second amplitude is applied to drive the black particles to move to the top of the microcapsule. After the cyclic driving of multiple driving periods, the pixel displays the target darkness.

[0067] In some embodiments, according to the actual driving condition, in the black driving stage, the driving period n, the driving time T3a of the fourth driving voltage V4 and the driving time T3b of the fifth driving voltage V5 can be adjusted to meet the actual darkness display requirement, wherein the black driving time T3 = n (T3a + T3b), and the direct current balance condition is met, that is, the following formula is met:

[0068] ;

[0069] Wherein, T1 is the time length of the erasing stage, T2 is the time length of the activation stage, T3 is the time length of the black driving stage, and T4 is the time length of the red driving stage. The amplitude of the fifth driving voltage V5 is equal to the amplitude of the first driving voltage V1.

[0070] Specifically, when the darkness of the pixel display needs to be higher, the number of driving cycles n and the second duration T3b can be increased to achieve this; when the brightness of the pixel display needs to be higher, the number of driving cycles and the size of the second duration T3b can be reduced to achieve this.

[0071] In addition, in the black driving phase, if the red particles have more serious interference in the display, the number of driving cycles n and / or the driving duration of the fourth driving voltage V4 can be increased to reduce the red particle interference and reduce the case of being disturbed to display dark red when displaying black.

[0072] In some embodiments, the adjustable voltage V0 is between the second driving voltage V2 and the fourth driving voltage V4. When the adjustable voltage V0 is increased, the duration T1 of the erasing phase is reduced, and the driving cycle n of the black driving phase can be reduced. When the adjustable voltage V0 is reduced, the red particles can be further driven to the bottom of the microcapsule, thereby reducing the influence of the red particles on the display quality of the black gray scale.

[0073] S500, when the red driving signal is detected, the driving signal is controlled to provide a third driving voltage for driving the red particles.

[0074] Specifically, the red driving phase is located after the black display phase. In the red driving phase, the red particles are driven by the third driving voltage V3 to move to the top of the microcapsule to display red three-particle electrophoresis. The amplitude of the third driving voltage V3 is equal to the amplitude of the fourth driving voltage V4, that is, the size of the optimal driving voltage in the red driving phase is equal to the size of the fourth driving voltage V4 in the black driving phase.

[0075] In summary, the three-particle electrophoretic display driving method and display provided by the application, the method comprises: controlling a driving signal to be generated; the driving signal is used to realize an erasing stage, an activating stage, a black driving stage and a red driving stage in a three-particle display process; when an erasing instruction is detected, the driving signal is controlled to provide an adjustable voltage for erasing an original image and direct current balance and preliminarily adjusting a black display brightness; when an activating instruction is detected, the driving signal is controlled to provide a first driving voltage and a second driving voltage for activating white particles, black particles and red particles; when a black driving signal is detected, the driving signal is controlled to provide a frequency-adjustable periodic voltage sequence for driving the red particles to move to the bottom of a microcapsule and driving the black particles to move to the top of the microcapsule, so as to further adjust the black display brightness; and when a red driving signal is detected, the driving signal provides a third driving voltage for driving the red particles. In the process of driving the three-particle electrophoretic display, the original image and the direct current balance are erased by using the adjustable voltage in the erasing stage, the black display brightness is preliminarily adjusted, and the frequency-adjustable periodic voltage sequence is provided in the black driving stage to drive the red particles to move to the bottom of the microcapsule and drive the black particles to move to the top of the microcapsule, so as to further adjust the black display brightness, so that the target darkness can be displayed, and the black gray scale display quality can be effectively improved.

[0076] It should be understood that the application of the application is not limited to the above examples, and those of ordinary skill in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the application.

Claims

1. A three-particle electrophoretic display driving method, characterized by, The method comprises: controlling a driving signal to be generated; the driving signal is used to realize an erasing stage, an activating stage, a black driving stage and a red driving stage in a three-particle display process; when an erasing instruction is detected, controlling the driving signal to provide an adjustable voltage for erasing an original image and direct current balance, and preliminarily adjusting a black display brightness; when an activating instruction is detected, controlling the driving signal to provide a first driving voltage and a second driving voltage for activating white particles, black particles and red particles; when a black driving instruction is detected, controlling the driving signal to provide a frequency-adjustable periodic voltage sequence for driving the red particles to move to the bottom of the microcapsule and driving the black particles to move to the top of the microcapsule, so as to further adjust the black display brightness; the step of controlling the driving signal to provide the frequency-adjustable periodic voltage sequence for driving the red particles to move to the bottom of the microcapsule and driving the black particles to move to the top of the microcapsule, so as to further adjust the black display brightness when the black driving instruction is detected comprises: in one driving period, a fourth driving voltage with a first time length T3a and a first amplitude is first applied to drive the red particles to move to the bottom of the microcapsule, and then a fifth driving voltage with a second time length T3b and a second amplitude is applied to drive the black particles to move to the top of the microcapsule; the driving is cyclically performed for multiple driving periods until the pixel displays a target darkness; a black driving time length T3=n (T3a+T3b); when a red driving instruction is detected, controlling the driving signal to provide a third driving voltage for driving the red particles.

2. The three-particle electrophoretic display driving method according to claim 1, wherein the step of controlling the driving signal to provide the frequency-adjustable periodic voltage sequence for driving the red particles to move to the bottom of the microcapsule and driving the black particles to move to the top of the microcapsule, so as to further adjust the black display brightness when the black driving instruction is detected further comprises: when the number of the driving periods is increased and the second time length is increased, the pixel displays a higher darkness; when the number of the driving periods is reduced and the size of the second time length is reduced, the pixel displays a higher brightness.

3. The driving method of claim 1, wherein the three-particle electrophoretic display is a bistable display. the step of controlling the driving signal to provide the frequency-adjustable periodic voltage sequence for driving the red particles to move to the bottom of the microcapsule and driving the black particles to move to the top of the microcapsule, so as to further adjust the black display brightness when the black driving instruction is detected further comprises: if there is interference of the red particles in the display, the number of the driving periods is increased and / or the driving time length of the fourth driving voltage is increased; if it is required to reduce the overall driving period of the black driving stage, the number of the driving periods is reduced and / or the driving time length of the fourth driving voltage is reduced.

4. The driving method of claim 1, wherein the three-particle electrophoretic display is a bistable display. the adjustable voltage is between the second driving voltage and the fourth driving voltage; when the adjustable voltage is increased, the time length of the erasing stage is reduced, and the driving period of the black driving stage is reduced; when the adjustable voltage is reduced, the red particles are further driven to the bottom of the microcapsule.

5. The driving method of claim 1, wherein the driving method is a driving method of a three-particle electrophoretic display. the first driving voltage and the second driving voltage have equal amplitudes and equal driving time lengths.

6. The driving method of claim 1, wherein the driving method is a driving method of a three-particle electrophoretic display. The amplitude of the third driving voltage is equal to the amplitude of the fourth driving voltage; and the amplitude of the fifth driving voltage is equal to the amplitude of the first driving voltage.

7. The driving method of claim 6, wherein the driving method is a driving method of a three-particle electrophoretic display. The black driving stage is before the red driving stage.

8. A display for implementing the driving method of the three-particle electrophoretic display according to any one of claims 1 to 7, characterized by The display panel comprises: a display panel; a driving circuit connected with the display panel, the driving circuit being configured to provide a driving signal to the display panel; wherein the driving signal is configured to realize an erasing stage, an activating stage, a black driving stage and a red driving stage in a driving process.

9. The display of claim 8, wherein, The display panel comprises: an electrophoretic cell comprising a microcapsule and black particles, white particles and red particles arranged in the microcapsule; a pixel electrode arranged below the microcapsule and connected with the driving circuit; and a common electrode arranged above the microcapsule.

Images