Control method of display device and display device

Abstract

The present disclosure provides a control method for a display device, which relates to the display field, and in particular to the field of thin film transistor display technology. The specific implementation scheme is: in response to an image to be displayed having a predetermined shape, determining a display area of ​​the display device for displaying the image to be displayed; and based on the pixel data of the above-mentioned image to be displayed, applying a write signal to the pixel driving circuit of multiple pixel units in the display area to control the multiple pixel units in the display area to display the pixel data of the image to be displayed; wherein the write signal includes: a source drive signal and a common voltage signal; the voltage difference between the source drive signal and the common voltage signal is greater than or equal to the display switching voltage threshold of the pixel unit. The present disclosure also provides a display device.

Description

Technical Field

[0001] The present disclosure relates to the display field, and in particular to thin film transistor display technology. More specifically, the present disclosure provides a control method for a display device and a display device. Background Art

[0002] Traditional information display technology can no longer meet users' increasingly high requirements for environmental protection, health, energy saving and high efficiency. For example, traditional teaching writing blackboards produce a lot of dust, which seriously endangers the health of teachers and students. Electronic display devices can also be used in related technologies to replace traditional blackboards. For example, liquid crystal writing boards can be used to replace traditional blackboards.

[0003] For a large-sized writing board, when a user writes a large amount of content on the writing board, the time cost is high and it is easy to make mistakes. Summary of the invention

[0004] The present disclosure provides a control method, device, electronic device and storage medium of a display device.

[0005] According to a first aspect, a control method for a display device is provided, comprising: in response to an image to be displayed having a predetermined shape, determining a display area of ​​the display device for displaying the image to be displayed; and based on pixel data of the image to be displayed, applying a write signal to a pixel driving circuit of a plurality of pixel units in the display area to control the plurality of pixel units in the display area to display the pixel data of the image to be displayed; wherein the write signal comprises: a source drive signal and a common voltage signal; and a voltage difference between the source drive signal and the common voltage signal is greater than or equal to a display switching voltage threshold of the pixel unit.

[0006] According to certain embodiments of the present disclosure, based on pixel data of an image to be displayed, a write signal is applied to a pixel driving circuit of a plurality of pixel units in a display area to control the plurality of pixel units in the display area to display the pixel data of the image to be displayed, including: in a first stage, controlling the plurality of pixel units in the display area to be in a first display state; and in a second stage, controlling the first target pixel units in the display area to be in a second display state, the first target pixel units including pixel units in the display area that do not correspond to the pixel data of the image to be displayed.

[0007] According to certain embodiments of the present disclosure, each pixel unit includes a pixel electrode, a liquid crystal layer and a common electrode; the source drive signal includes a first source drive signal and a second source drive signal, and the common voltage signal includes a first common voltage signal and a second common voltage signal; in a first stage, the first common voltage signal is applied to the common electrode, and the gate control signal and the first source drive signal are applied row by row to each row of pixel units in the display area, so that the liquid crystal layer of the current row of pixel units is in a first state, wherein a first voltage difference between the first source drive signal and the first common voltage signal is greater than or equal to a display switching voltage threshold of the pixel unit; in a second stage, the second common voltage signal is applied to the common electrode, and the gate control signal and the second source drive signal are applied row by row to each row of pixel units in the display area, so that the liquid crystal layer of the first target pixel unit in the current row of pixel units is converted from the first state to the second state, wherein a second voltage difference between the second source drive signal and the second common voltage signal is greater than or equal to the display switching voltage threshold of the pixel unit.

[0008] According to certain embodiments of the present disclosure, the voltage value of the first common voltage signal is less than or equal to a preset common voltage reference value, wherein, when the voltage value of the first common voltage signal is less than the preset common voltage reference value, the first difference between the voltage value of the first source drive signal and the preset common voltage reference value is less than the second difference; the second difference is the difference between the voltage value of the first source drive signal and the preset common voltage reference value when the voltage value of the first common voltage signal is equal to the preset common voltage reference value.

[0009] According to some embodiments of the present disclosure, the voltage value of the source driving signal is symmetrically distributed relative to a preset common voltage reference value; the voltage value of the first common voltage signal is symmetrically distributed relative to the preset common voltage reference value.

[0010] According to certain embodiments of the present disclosure, a third difference between the voltage value of the first source drive signal and the voltage value of the first common voltage signal is greater than a fourth difference between the voltage value of the second source drive signal and the voltage value of the second common voltage signal; and a fifth difference between the voltage value of the second common voltage signal and a preset common voltage reference value is less than a sixth difference between the voltage value of the first common voltage signal and the preset common voltage reference value.

[0011] According to certain embodiments of the present disclosure, the voltage value of the second common voltage signal is a preset common voltage reference value, the voltage value of the first source drive signal is greater than the voltage value of the second source drive signal, and the voltage value of the gate control signal in the first stage is greater than or equal to the voltage value of the gate control signal in the second stage.

[0012] According to some embodiments of the present disclosure, in the second phase, the voltage value of the second source driving signal is symmetrically distributed relative to a preset common voltage reference value.

[0013] According to certain embodiments of the present disclosure, based on pixel data of an image to be displayed, a write signal is applied to a pixel driving circuit of a plurality of pixel units in a display area to control the plurality of pixel units in the display area to display the pixel data of the image to be displayed, including: controlling each second target pixel unit in the display area to be in a first display state, the second target pixel units including pixel units in the display area corresponding to the pixel data of the image to be displayed.

[0014] According to certain embodiments of the present disclosure, each pixel unit includes a pixel electrode, a liquid crystal layer and a common electrode; the source drive signal includes a third source drive signal, and the common voltage signal includes a third common voltage signal; the third voltage difference between the third source drive signal and the third common voltage signal is greater than or equal to the display switching voltage threshold of the pixel unit. Accordingly, controlling each second target pixel unit in the display area to be in the first display state includes: applying the third common voltage signal to the common electrode; applying the gate control signal and the third source drive signal to each row of pixel units in the display area row by row, so that the bistable liquid crystal of the second target pixel unit in the current row of pixel units is in the first state.

[0015] According to certain embodiments of the present disclosure, the voltage value of the third common voltage signal is less than or equal to a preset common voltage reference value, wherein, when the voltage value of the third common voltage signal is less than the preset common voltage reference value, the seventh difference between the voltage value of the third source drive signal and the preset common voltage reference value is less than the eighth difference; the eighth difference is the difference between the voltage value of the third source drive signal and the preset common voltage reference value when the voltage value of the third common voltage signal is equal to the preset common voltage reference value.

[0016] According to some embodiments of the present disclosure, the voltage value of the third source driving signal is symmetrically distributed relative to the preset common voltage reference value; and the voltage value of the third common voltage signal is symmetrically distributed relative to the preset common voltage reference value.

[0017] According to certain embodiments of the present disclosure, for multiple pixel units outside the display area of ​​the image to be displayed in the display device, the source drive signal also includes a fourth source drive signal, the common voltage signal also includes a fourth common voltage signal, and the voltage difference between the fourth source drive signal and the fourth common voltage signal is less than the display switching voltage threshold of the pixel unit.

[0018] According to some embodiments of the present disclosure, the source driving signal includes multiple square waves; wherein the pixel units corresponding to the peaks of each square wave in the multiple square waves are in the second display state, and the pixel units corresponding to the troughs of each square wave are in the first display state.

[0019] According to a second aspect, a control device for a display device is provided, the device comprising: a plurality of pixel units; and a control unit; wherein the control unit is configured to: determine a display area for displaying an image to be displayed in response to an image to be displayed having a predetermined shape; and based on pixel data of the image to be displayed, apply a write signal to a pixel driving circuit of a plurality of pixel units in the display area to control the plurality of pixel units in the display area to display the pixel data of the image to be displayed; wherein the write signal comprises: a first source drive signal and a first common voltage signal; a first voltage difference between the first source drive signal and the first common voltage signal is greater than or equal to a display switching voltage threshold of the pixel unit.

[0020] According to certain embodiments of the present disclosure, the display device is used for at least one of a light-energy blackboard, a light-energy business board, a billboard, a display board, and the like.

[0021] According to certain embodiments of the present disclosure, the pixel unit includes a liquid crystal layer located between a pixel electrode and a common electrode, and the liquid crystal layer includes a light-transmitting state and a light-reflecting state; the liquid crystal layer presents a light-transmitting state under a high voltage, and presents a light-reflecting state under a low voltage.

[0022] According to some embodiments of the present disclosure, the material of the liquid crystal layer includes bistable cholesteric liquid crystal.

[0023] According to some embodiments of the present disclosure, the liquid crystal layer further includes an optical rotator, and the bistable cholesteric liquid crystal includes cholesterol liquid crystal.

[0024] According to some embodiments of the present disclosure, a display area of ​​a display device includes a transparent area and a light absorbing portion located on a side of the transparent area close to a back shell.

[0025] According to some embodiments of the present disclosure, the light absorbing portion includes a common electrode.

[0026] According to a third aspect, an electronic device is provided, comprising: at least one processor; and a memory coupled to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can send an image to be displayed and its predetermined shape to a control unit, and control multiple pixel units in a display area of ​​the display device to display pixel data of the image to be displayed.

[0027] According to a fourth aspect, a non-transitory computer-readable storage medium storing computer instructions is provided, wherein the computer instructions are used to cause a computer to execute the method provided according to the present disclosure.

[0028] According to a fifth aspect, a computer program product is provided, comprising a computer program, which implements the method provided according to the present disclosure when executed by a processor.

[0029] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure.

[0031] Figure 1 A schematic diagram of a display device according to an embodiment of the present disclosure is shown.

[0032] Figure 2 Shows Figure 1 An example structural diagram of a gate driving circuit in a display device.

[0033] Figure 3A It is a schematic diagram of an application scenario of a control method of a display device and a display device that can be applied according to an embodiment of the present disclosure.

[0034] Figure 3B and Figure 3C It is for Figure 3A A partial enlarged schematic diagram of position A and position B in the figure.

[0035] Figure 4 A flow chart of a method for controlling a display device according to an embodiment of the present disclosure is shown.

[0036] Figure 5 A flowchart of displaying an image to be displayed in two stages according to an embodiment of the present disclosure is shown.

[0037] Figure 6 A schematic diagram of a write signal according to an embodiment of the present disclosure is shown.

[0038] Figure 7 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0039] Figure 8 A schematic diagram showing a switching voltage threshold according to an embodiment of the present disclosure is shown.

[0040] Fig. 9FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0041] Fig.10 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0042] Fig.11 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0043] Fig.12 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0044] Fig.13 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0045] Fig.14 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0046] Fig.15 A flowchart of displaying an image to be displayed in a single phase according to an embodiment of the present disclosure is shown.

[0047] Fig.16 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0048] Fig.17 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0049] Fig.18 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0050] Fig.19 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0051] Fig. 20 is a block diagram of a display device according to an embodiment of the present disclosure.

[0052] Fig.21 is a block diagram of an electronic device for executing a control method of a display device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0053] The following is a description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0054] Liquid crystal display (LCD) is favored by everyone due to its low power consumption, high image quality, small size and light weight, and has become the mainstream of current displays. Currently, liquid crystal displays are mainly thin film transistor (TFT) liquid crystal displays, and their display panels usually include color film substrates, TFT array substrates and a liquid crystal layer arranged between the two substrates.

[0055] The liquid crystal material of the liquid crystal layer of some types of liquid crystal displays is only in a monostable state. For example, it is in a light-transmitting state when an electric field is applied, and in a light-impermeable state when no electric field is applied. This results in the need to continuously supply power to these types of liquid crystal displays in order to display images.

[0056] In order to further reduce the energy consumption of the liquid crystal display, for application scenarios that do not require frequent refreshing, the liquid crystal layer can use a bistable liquid crystal material to form a bistable liquid crystal display. Specifically, the optical state of the liquid crystal layer can include a light-transmitting state and a light-reflecting state. The liquid crystal material in the light-transmitting state is converted to a light-reflecting state when subjected to pressure. The liquid crystal material in the light-reflecting state is converted to a light-transmitting state when subjected to an electric field. For example, the liquid crystal material includes but is not limited to cholesterol liquid crystal.

[0057] For the bistable liquid crystal writing board in the related art, the user can achieve manual writing by applying pressure to the liquid crystal writing board. When the user wants to write the content to be displayed on a large-sized liquid crystal writing board, and there is a lot of content to be written, it will take a long time. In addition, the user can also erase the liquid crystal writing board with one click. The writing range of the small-sized liquid crystal writing board is small, and the one-click erase operation has little effect on the writing experience. However, the writing range of the large-sized liquid crystal writing board is large, and the one-click erase operation has a greater impact on the user's writing experience. For example, when the user makes a mistake in writing, all written content needs to be erased.

[0058] The disclosed embodiment utilizes the characteristics of bistable liquid crystal to realize voltage-driven writing on the basis of pressure writing, effectively reducing the time spent when there is a lot of content to be written. In addition, the disclosed embodiment can also "erase" the content you want to write by high-voltage large-area writing and low-voltage line-by-line local erasing, thereby realizing active writing. Since the erase voltage is lower than the write voltage, the erase operation is easier to implement than the write operation and has lower power consumption.

[0059] In the technical solution disclosed herein, the acquisition, storage and application of the image information involved are in compliance with the provisions of relevant laws and regulations and do not violate public order and good morals.

[0060] Figure 1 A schematic diagram of a display device according to an embodiment of the present disclosure is shown.

[0061] like Figure 1 As shown, the display device 100 includes a plurality of pixel units P, which are arranged in an N×M array in an xy plane, where N and M are both integers greater than 1. Each pixel unit P may include one or more sub-pixels.

[0062] The display device 100 may further include a gate driving circuit (also referred to as a gate control circuit or a scanning driving circuit, etc.) 10, and the gate driving circuit 10 is connected to a plurality of pixel units P. The gate driving circuit 10 may be configured to drive the pixel units P in a first direction ( Figure 1 A plurality of gate signal lines extending in the direction (in the x direction) are respectively connected to N rows of sub-pixels, for example, the first row of pixel units P are connected through the first gate signal line to provide the first row of pixel units P with the first gate drive signal G1, and the second row of pixel units P are connected through the second gate signal line to provide the second row of pixel units P with the second gate drive signal G2, and so on. The first row of pixel units P are turned on in response to receiving the first gate drive signal G1, and the second row of pixel units P are turned on in response to receiving the second gate drive signal G2, and so on.

[0063] In some embodiments, the gate drive circuit 10 may scan N rows of pixel units P one by one or more rows. For example, the gate drive circuit 10 may scan one row of sub-pixels at a time, for example, sequentially generate N gate drive signals G1, G2, ... GN to sequentially turn on the first row of pixel units P, the second row of pixel units P ... the Nth row of pixel units P. The gate drive circuit 10 may also scan two or more rows of pixel units P at a time. For example, the gate drive circuit 10 may simultaneously generate the first gate drive signal G1 and the second gate drive signal G2 to simultaneously turn on the first row of pixel units P and the second row of pixel units P, then the gate drive circuit 10 may simultaneously generate the third gate drive signal G3 and the fourth gate drive signal G4 to simultaneously turn on the third row of pixel units P and the fourth row of pixel units P, and so on. In some embodiments, the gate drive circuit 10 may scan N rows of pixel units P with at least one row interval to sequentially turn on pixel units P in some rows. For example, the gate driving circuit 10 can sequentially turn on the odd-numbered rows of pixel cells P (for example, sequentially turn on the first row of pixel cells P, the third row of pixel cells P, the fifth row of pixel cells P, and so on), or sequentially turn on the even-numbered rows of pixel cells P (for example, sequentially turn on the second row of pixel cells P, the fourth row of pixel cells P, the sixth row of pixel cells P, and so on).

[0064] The display device 100 may further include a source driving circuit 20, and the source driving circuit 20 is connected to the plurality of pixel units P. For example, the source driving circuit 20 may be connected along the second direction ( Figure 1 The plurality of data lines extending in the direction (in the y direction) are respectively connected to the M columns of pixel units P. For example, the source driving circuit 20 may be connected to the first column of pixel units P through the first data line to provide the first data signal D1 to the first column of pixel units P, and may be connected to the second column of pixel units P through the second data line to provide the second data signal D2 to the second column of pixel units P, and so on.

[0065] For example, when the first row of pixel units P is turned on, the source driving circuit 20 can provide M data signals D11, D12, ..., D1M for the first row of sub-pixels to the M pixel units P in the first row through M data lines; when the second row of pixel units P is turned on, the source driving circuit 20 can provide M data signals D21, D22, ..., D2M for the second row to the M pixel units P in the second row through multiple data lines, and so on. Of course, the embodiments of the present disclosure are not limited to this, and this will be further described in detail below.

[0066] In some embodiments, the display device 100 may further include a timing controller 30, which is connected to the gate drive circuit 10 and the source drive circuit 20 and may provide relevant control signals to the gate drive circuit 10 and the source drive circuit 20. For example, the timing controller 30 may provide a data control signal TP to the source drive circuit 20, and the source drive circuit 20 may output data signals for each row, such as a source drive signal, under the control of the data control signal TP. The timing controller 30 may also provide other control signals to the source drive circuit 20, including but not limited to a row data start signal, a data synchronization signal, a data inversion signal, and the like. The timing controller 30 may also provide various control signals to the gate drive circuit 10, including but not limited to a start signal, a clock signal, and the like required by the gate drive circuit 10.

[0067] It should be noted that the source driving circuit 20 may be integrated on the display panel of the display device 100. The source driving circuit 20 may also be a source driver disposed on a circuit board.

[0068] Figure 2 Shows Figure 1 An example structural diagram of a gate driving circuit in a display device.

[0069] like Figure 2 As shown, the gate driving circuit 10 includes a plurality of cascaded shift register units GOA1, GOA2, ..., GOAN. Figure 2 For the sake of simplicity, the first to tenth stage shift register units GOA1 to GOA10 are shown. Figure 2 It can be seen that the input terminal IN of the n-th shift register unit GOAn is connected to the output terminal of the n-4-th shift register unit GOA(n-4)-th shift register unit, and the reset terminal RST of the n-th shift register unit GOAn is connected to the output terminal OUT of the n+5-th shift register unit GOA(n+5), where 5≤n≤N-5. The input terminals IN of the first to fourth shift register units GOA1 to GOA4 are connected to the start signal terminal STV1. Figure 2 The gate drive circuit 10 uses 10 clock signals CLK1 to CLK10, wherein the clock signal terminal CLK of the first-stage shift register unit GOA1 is connected to receive the first clock signal CLK1, the clock signal terminal CLK of the second-stage shift register unit GOA2 is connected to receive the second clock signal CLK2, and so on, the clock signal terminal CLK of the 10th-stage shift register unit GOA10 is connected to receive the 10th clock signal CLK10. In a similar manner, the eleventh to twentieth-stage shift register units GOA11 to GOA20 are respectively connected to receive the first to tenth clock signals CLK1 to CLK10. Each stage of the shift register unit GOA1, GOA2, ..., GOAN also has a total reset terminal STV, which is connected to receive the total reset signal STV0. Each stage of the shift register unit GOA1, GOA2, ..., GOAN can generate an output signal as a gate drive signal at its output terminal OUT under the control of the signal at its clock signal terminal CLK and the input terminal IN. For example, the first stage shift register unit GOA1 generates a first gate drive signal G1, the second stage shift register unit GOA2 generates a second gate drive signal G2, and so on. By cascading, the gate drive signal generated by one stage shift register unit can be shifted relative to the gate drive signal generated by another stage shift register unit.

[0070] It should be noted that the gate driving circuit 10 may be integrated on the display panel of the display device 100. The gate driving circuit 10 may also be a gate driver disposed on a circuit board.

[0071] The above is only an example of the display device of the embodiment of the present disclosure. The structure of the display device of the embodiment of the present disclosure is not limited thereto, and may have other structures as needed. For example, the display device may be a display device based on liquid crystal display (LCD) technology, or a display device based on organic light emitting diode (OLED) display technology. The gate drive circuit of the display device may adopt different Figure 2 The cascading method shown, for example, can use 8 or 12 clock signals to cascade in different ways.

[0072] Figure 3AIt is a schematic diagram of an application scenario of a control method of a display device and a display device that can be applied according to an embodiment of the present disclosure.

[0073] like Figure 3A As shown, the user hopes to display the image "Do Business" on the bistable liquid crystal display device serving as a blackboard. In the related art, the user can manually write the image "Do Business" on the bistable liquid crystal display device. However, when the user needs to manually write a lot of content in the image, it takes a lot of the user's time. In the disclosed embodiment, the user can input the image to be displayed on the blackboard in the host computer, and the host computer sends the image to be displayed and the predetermined shape of the image and other information to the display device, so that the display device displays the image to be displayed under the control of the electrical signal. Compared with the method of manually writing images, it can greatly improve the efficiency of information input.

[0074] In addition, if Figure 3A As shown, a method of writing a solid color in a display area b corresponding to an image to be displayed having a predetermined shape a, and then erasing the solid color in a blank area in the display area b can be adopted to realize the display of the image to be displayed. A method of directly writing an image in the display area b corresponding to an image to be displayed having a predetermined shape a can also be adopted to realize the display of the image. Since the display area b corresponding to the image to be displayed is determined, it is not necessary to refresh all the display areas of the bistable liquid crystal display device, which can help users retain the content they want to retain and improve the user experience.

[0075] Figure 3B and Figure 3C It is for Figure 3A A partial enlarged schematic diagram of position A and position B in the figure. Figure 3B A first target pixel unit 310 is shown, Figure 3C A second target pixel unit 320 is shown. Figure 3B The first target pixel unit 310 in FIG. 3 is a pixel unit in a light-transmitting state. Figure 3C The second target pixel unit 320 in the embodiment is a pixel unit in a light-reflecting state. Each pixel unit may include a first electrode c, a second electrode d, and a liquid crystal layer e between the first electrode c and the second electrode d. The electric field applied between the first electrode c and the second electrode d may affect the state of the liquid crystal layer e, so that the pixel unit is in a light-transmitting state or a light-reflecting state. The first electrode c may be a pixel electrode of the pixel unit, and the second electrode d may be a common electrode.

[0076] For example, Figure 3B After the incident light l reaches the first target pixel unit 310, the incident light l passes through the liquid crystal layer e from one side of the pixel unit to the other side of the pixel unit, so that the first target pixel unit 310 is in a light-transmitting state. Figure 3CAfter the incident light l reaches the second target pixel unit 320, the incident light l is reflected by the liquid crystal layer e in the pixel unit, and the incident light l cannot reach the other side of the pixel unit from one side of the pixel unit, so that the second target pixel unit 320 is in a light reflecting state. It should be noted that Figure 3B and Figure 3C The state of the liquid crystal layer e shown in FIG. 1 is merely an example and should not be construed as limiting the present disclosure.

[0077] Figure 4 A flow chart of a method for controlling a display device according to an embodiment of the present disclosure is shown.

[0078] like Figure 4 As shown, the control method 400 of the display device may include operations S410 to S420.

[0079] In operation S410, in response to an image to be displayed having a predetermined shape, a display area of ​​a display device for displaying the image to be displayed is determined.

[0080] In some embodiments, the image to be displayed may include at least one of a picture, text, etc. The image to be displayed has a certain shape. In order to display the image to be displayed on the display device, a display area on the display device for displaying the image to be displayed may be determined first. The display area may be a regular shape such as a rectangle, a square, a circle, or an irregular shape similar to the outer contour of the image to be displayed, which is not limited here. For example, a rectangular area may be represented by the coordinates of the diagonal vertices of the rectangle, or the rectangular area may be represented by the coordinates of a vertex, length information, and width information.

[0081] For example, first, the screen to be transmitted is set in the software of the host computer, and the screen resolution can be consistent with the resolution of the display device. After the display device is connected to the host computer (such as through a USB interface), the host computer transmits the image to be displayed to the display device. Before the image to be displayed is transmitted or during the transmission of the image to be displayed, the host computer can also transmit the attribute information of the image to be displayed to the display device, such as the display range information required by the display device to display the image to be displayed. The display range information can be coordinate information or coordinate information and size information. This makes it easy for the display device to determine the display area for displaying the image to be displayed from all display areas or part of the display area. For the display area outside the display area for displaying the image to be displayed, there is no need to erase the display image that is already displayed.

[0082] In operation S420, based on the pixel data of the image to be displayed, a write signal is applied to the pixel driving circuit of the plurality of pixel units in the display area to control each pixel unit in the display area to display the pixel data of the image to be displayed.

[0083] The write signal includes: a source driving signal and a common voltage signal. The voltage difference between the source driving signal and the common voltage signal is greater than or equal to the display switching voltage threshold of the pixel unit.

[0084] The image to be displayed can be realized by changing the reflective state of multiple pixel units in the display device. For example, the pixel unit corresponding to the image area in the image to be displayed can be set to a reflective state, and the pixel unit corresponding to the blank area in the image to be displayed can be set to a light-transmitting state. The transmitted light is absorbed by the display device, so that the user's eyes can see the reflected light of the pixel unit in the reflective state and see the image to be displayed. It should be noted that it can also be set as follows: the pixel unit corresponding to the image area in the image to be displayed can be set to a light-transmitting state, and the pixel unit corresponding to the blank area in the image to be displayed can be set to a reflective state.

[0085] In some embodiments, the display device may include a first substrate and a protective structure disposed opposite to each other, and a liquid crystal layer located between the first substrate and the protective structure. A first electrode is disposed on a side of the first substrate close to the liquid crystal layer.

[0086] The liquid crystal layer includes a liquid crystal material, and the liquid crystal layer includes a light-transmitting state and a light-reflecting state. The liquid crystal in the light-transmitting state is converted to a light-reflecting state when subjected to pressure. The liquid crystal in the light-reflecting state is converted to a light-transmitting state when subjected to an electric field. For example, the initial state of the liquid crystal may be a light-transmitting state, and when pressed by pressure or subjected to a low-voltage electric field, the light-transmitting state is converted to a light-reflecting state. The liquid crystal in the light-reflecting state reflects the external ambient light to achieve display. When the liquid crystal in the light-reflecting state is driven by a high-voltage electric field, it restores the initial state, such as converting from a light-reflecting state to a light-transmitting state. Specifically, the first substrate may also include a base substrate, and the first electrode is located on a side of the base substrate facing the liquid crystal. For example, the material of the base substrate is glass or a transparent organic resin. For example, the first electrode may be a transparent electrode, and the material of the first electrode includes but is not limited to indium tin oxide (ITO), indium zinc tin oxide, etc. For example, the protective structure may be a protective film, which is relatively soft and easy to conduct the pressure applied to the liquid crystal by a pressing object (for example, a finger or a pen). For example, the material of the protective film includes but is not limited to at least one of polyethylene (PE), polyethylene terephthalate (PET), and polyvinyl chloride (PVC). For example, the protective structure may be a transparent protective structure.

[0087] In some embodiments, when handwriting input display is required, the user can press the surface of the display device so that the liquid crystal deflects when pressed, and reflects the external ambient light, thereby realizing display. When it is necessary to erase the content displayed by the display device, the second electrode is pressurized so that a high-voltage electric field is formed in the area opposite to the second electrode and the first electrode, thereby restoring the liquid crystal to an initial state, thereby realizing partial erasure of the display device. The second electrode can be arranged on a side of the liquid crystal layer close to the protective structure, such as on one side of the protective structure. For example, the first electrode can be a pixel electrode, and the second electrode can be a common electrode.

[0088] In some embodiments, the liquid crystal material of the liquid crystal layer can be a bistable cholesteric phase liquid crystal, such as cholesterol liquid crystal. In addition, the liquid crystal layer can also include an optical rotator. Specifically, the optical rotator can be covered on the liquid crystal, and the liquid crystal is deflected, and the optical rotator reflects a certain band of light and absorbs the rest of the bands of light to achieve the reflection of light in a specific band. For example, the optical rotator reflects green light and absorbs light in bands other than green light. Among them, the molecular arrangement of cholesterol liquid crystal (Cholesteric Liquid Crystal) has two stable states: focal conic texture state (H state for short) and planar texture state (P state for short), so it has a bistable characteristic. That is, cholesterol liquid crystal does not need to provide additional energy from the outside to maintain the original liquid crystal molecular arrangement state. When an electric field is applied, the arrangement state of the liquid crystal molecules can be controlled to switch between the two stable states of the focal conic texture state and the planar texture state. When the cholesterol liquid crystal presents a planar texture state, it will reflect light of a specific wavelength in combination with an optical rotator. On the contrary, when the cholesterol liquid crystal presents a focal conic texture arrangement state, light will penetrate the cholesterol liquid crystal and then be absorbed by the light absorption structure. Therefore, the voltage applied to the cholesterol liquid crystal can control the cholesterol liquid crystal to be penetrated by light, or to reflect light of a specific wavelength in combination with an optical rotator.

[0089] In some embodiments, the display device is used for at least one of a light-powered blackboard, a light-powered business board, a billboard, a display board, and the like.

[0090] For example, actual application scenarios include classroom multimedia blackboard applications, conference blackboards, and other application sites for bistable liquid crystal display devices that require active writing and do not need frequent refreshing. When used as a classroom blackboard, it can be used with a computer in the classroom. Teachers can import the content to be written or the last written data as courseware into the matching software in advance, and import the courseware into the display device, saving time for writing over a large area. When used with a conference machine, the PPT text to be displayed can be imported into the software in advance, and the wipe and handwriting functions can be used to enhance the interactive experience for data analysis. In other fields of application, it can be used as a low-power display, such as store advertisements, exhibition stands, etc. It can be used with software when writing, and the power supply can be removed after writing is completed. After the display device loses power, the display content is not lost and can be maintained for a long time.

[0091] The following is an exemplary description of a method for displaying an image to be displayed and a write signal corresponding to the image to be displayed.

[0092] In some embodiments, this may be achieved by writing a pure color in a display area corresponding to the image to be displayed, and then erasing the pure color in a blank area.

[0093] Figure 5 A flowchart of displaying an image to be displayed in two stages according to an embodiment of the present disclosure is shown.

[0094] like Figure 5 As shown, based on the pixel data of the image to be displayed, applying a write signal to the pixel driving circuit of the plurality of pixel units in the display area to control the plurality of pixel units in the display area to display the pixel data of the image to be displayed may include operations S501 to S502.

[0095] In operation S501, in a first stage, a plurality of pixel units in a display area are controlled to be in a first display state.

[0096] The first display state may be a reflective state or a transparent state. As shown above, the display device may include a plurality of pixel units. For example, the first stage may be a writing stage, and the first display state is a reflective state.

[0097] For example, the host computer software sends the minimum rectangular range coordinate data of the image to be displayed to the MCU, and the MCU will start the timing controller synchronously after receiving it. The MCU can determine the display area of ​​the image to be displayed based on the minimum rectangular range coordinate data, such as a vertex of the display area can correspond to the pixel column of a row of the display device.

[0098] In operation S502, in the second stage, first target pixel units in the display area are controlled to be in a second display state, the first target pixel units including pixel units in the display area that do not correspond to pixel data of the image to be displayed.

[0099] The second display state may be a state different from the first display state in a reflective state and a transparent state. For example, in the first stage, all pixel units in the display area are controlled to be in a reflective state; in the second stage, pixel units corresponding to blank pixels of the image to be displayed in the display area are controlled to be converted from the reflective state to the transparent state. For example, the second stage is an erasing stage, and the second display state is a transparent state.

[0100] For example, when the light-energy blackboard is used, the images to be displayed, such as text, patterns, etc., can be written into the blackboard in advance, which saves the time of manual writing and improves writing efficiency.

[0101] In a specific embodiment, each pixel unit includes a pixel electrode, a liquid crystal layer and a common electrode; the source driving signal includes a first source driving signal and a second source driving signal, and the common voltage signal includes a first common voltage signal and a second common voltage signal.

[0102] In the above-mentioned first stage, first, a first common voltage signal is applied to the common electrode. Then, a gate control signal and a first source drive signal are applied row by row to each row of pixel units in the display area, so that the liquid crystal layer of the current row of pixel units is in a first state, wherein the first voltage difference between the first source drive signal and the first common voltage signal is greater than or equal to the display switching voltage threshold of the pixel unit. The first source drive signal can be a pixel electrode applied to the pixel unit. The voltage between the common electrode and the pixel electrode forms an electric field to control the liquid crystal state.

[0103] In the above-mentioned second stage, first, a second common voltage signal is applied to the common electrode. Then, a gate control signal and a second source drive signal are applied row by row to each row of pixel units in the display area, so that the liquid crystal layer of the first target pixel unit in the current row of pixel units is converted from the first state to the second state, wherein the second voltage difference between the second source drive signal and the second common voltage signal is greater than or equal to the display switching voltage threshold of the pixel unit. The display switching voltage threshold is a voltage threshold at which the state of the bistable liquid crystal changes.

[0104] In some embodiments, the voltage value of the first common voltage signal is less than or equal to a preset common voltage reference value. Wherein, when the voltage value of the first common voltage signal is less than the preset common voltage reference value, the first difference between the voltage value of the first source drive signal and the preset common voltage reference value is less than the second difference. The second difference is the difference between the voltage value of the first source drive signal and the preset common voltage reference value when the voltage value of the first common voltage signal is equal to the preset common voltage reference value.

[0105] Since the liquid crystal morphology transformation voltages of different products are different, there are at least two theoretical waveforms. In some embodiments, when the liquid crystal driving voltage of the display device cannot be directly generated by the driving circuit, the first difference between the voltage value of the first source driving signal and the preset common voltage reference value can be adjusted by adjusting the voltage value of the common voltage signal.

[0106] Figure 6 A schematic diagram of a write signal according to an embodiment of the present disclosure is shown.

[0107] like Figure 6 , which shows a schematic diagram of a write signal in the first stage when the voltage value of the first common voltage signal Vcom in the first stage t1 is less than the preset common voltage reference value. Figure 6 In FIG. 1 , the horizontal axis represents voltage (Votage), and the vertical axis represents reflectance (Reflectance). The voltage value of the first common voltage signal Vcom is less than the preset common voltage reference value (reference Figure 6 The preset common voltage reference value may be 0V, 1V, 3V, 4V, 4.5V, 5V, 5.5V, 6V or 8V. The gate control signal Vg may be between 20V and 35V in the on state, such as 20V, 21V, 23V, 24V, 25V, 26V, 28V, 30V or 35V. The gate control signal Vg may be between -8V and -3V in the off state, such as -8V, -7V, -6.5V, -6V, -5.5V, -5V, -4.5V, -4V or -3V. The difference between the first source drive signal Vs and the first common voltage signal Vcom may be greater than or equal to the display switching voltage threshold. The display switching voltage threshold corresponds to the threshold voltage value at which the state of the bistable liquid crystal can be converted. Since the voltage value of the first common voltage signal Vcom is adjusted to a smaller value, such as a negative value, the difference between Vs and Vcom can be greater than or equal to the display switching voltage threshold while the first source drive signal Vs is kept unchanged or the specific amplitude is reduced. The specific amplitude is less than the adjustment amplitude of the voltage value of the first common voltage signal Vcom. In addition, the difference between the preset common voltage reference value and the voltage value of the first common voltage signal Vcom can be less than the display switching voltage threshold, so as to avoid the voltage between the pixel electrode and the common electrode being always greater than the display switching voltage threshold.

[0108] For example, the Vcom voltage can be grounded, while Figure 6 The Vcom in the display is adjusted to a negative voltage, which is less than the display switching voltage threshold (reference Figure 8V1 in the display area). The first source driving signal applied to the pixels within the display area (such as the rectangular range) is a positive high voltage, which works together with the negative Vcom voltage to change the liquid crystal within the rectangular range to the H state. The pixels within other ranges outside the rectangular range make the voltage of the liquid crystal layer less than V1 due to the change of Vcom, and the liquid crystal layer will not switch its form. After the liquid crystal within the rectangular range becomes a light-transmitting state, the voltage is quickly removed (such as making both Vcom and Vs become a preset common voltage reference value), so that the liquid crystal changes from the H state to the P state. When the liquid crystal in the rectangular range is in the P state and no voltage is applied or the voltage is lower than V1, it will reflect light (such as emitting green light in combination with a specific optical rotator), and the color of the substrate or the original display content will still be displayed outside the range.

[0109] In some embodiments, when the liquid crystal driving voltage of the display device can be directly generated by the driving circuit, the second difference between the voltage value of the first source driving signal and the preset common voltage reference value can be adjusted by adjusting the voltage value of the first source driving signal.

[0110] Figure 7 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0111] like Figure 7 , which shows a schematic diagram of a write signal in the first stage t1' when Vcom in the first stage t1' is equal to a preset common voltage reference value. The voltage value of the first common voltage signal Vcom is equal to the preset common voltage reference value (reference Figure 7 The preset common voltage reference value may be 0V, 1V, 3V, 4V, 4.5V, 5V, 5.5V, 6V or 8V. The gate control signal Vg may be between 20V and 35V in the on state, such as 20V, 21V, 23V, 24V, 25V, 26V, 28V, 30V or 35V. The gate control signal Vg may be between -8V and -3V in the off state, such as -8V, -7V, -6.5V, -6V, -5.5V, -5V, -4.5V, -4V or -3V. The difference between the first source drive signal Vs and the preset common voltage reference value may be greater than or equal to the display switching voltage threshold.

[0112] In some embodiments, for a plurality of pixel units outside the display area of ​​the image to be displayed in the display device, the source drive signal further includes a fourth source drive signal, the common voltage signal further includes a fourth common voltage signal, and the voltage difference between the fourth source drive signal and the fourth common voltage signal is less than the display switching voltage threshold of the pixel unit. In this embodiment, it is possible to display the above-mentioned image to be displayed in a specific display area without erasing the displayed image in the display area outside the display area corresponding to the image to be displayed. This effectively improves the convenience of teachers updating the displayed image in a specific area on a blackboard where a lot of content has been written, for example.

[0113] For example, at stage t1', the host computer software sends the coordinate data of the minimum rectangular range of the screen to be displayed to the MCU. After receiving the data, the MCU will start the timing controller synchronously. Figure 7 The Vcom voltage is always kept consistent with the preset common voltage reference value, such as 0V. The pixels within the rectangular range are applied with a positive high voltage ( Figure 7 The voltage value of medium and high voltage is greater than Figure 6 The voltage value of medium and low voltage is used to change the liquid crystal of the pixel unit within the rectangular range to the H state. The pixel units in other ranges are not affected, so they will not switch states. After the liquid crystal of the pixel unit within the rectangular range changes to the H state, the voltage is quickly removed, causing the liquid crystal of the pixel unit within the rectangular range to change from the H state to the P state. At this time, the light of a specific band (such as green light) will be reflected within the rectangular range, and the pixel units outside the range will still retain the original display state, such as the display substrate color (such as black, etc.).

[0114] Figure 8 A schematic diagram showing a switching voltage threshold according to an embodiment of the present disclosure is shown.

[0115] like Figure 8 As shown, the vertical axis represents the reflectance and the horizontal axis represents the voltage. Figure 8 Two curves are shown in the figure, one of which corresponds to the H state and the other corresponds to the P state, such as the curve with the marked information V1. The initial state of the liquid crystal can be in the H state. When a high voltage (such as greater than 30V) is applied to the liquid crystal in the H state, the liquid crystal changes to the H state. The liquid crystal in the H state will change to the P state after the high voltage is quickly removed. When no voltage is applied to the liquid crystal in the P state or the voltage is less than V1, the liquid crystal is in a reflective state. When the applied voltage exceeds the display switching voltage threshold V1, as the voltage gradually increases, the liquid crystal layer gradually changes from the reflective state to the light-transmitting state. In addition, the initial state of the liquid crystal can also be in the P state, and the liquid crystal state transition process is similar to the above process and will not be described in detail.

[0116] For example, when the liquid crystal is in the P state, when the voltage between the pixel electrode and the common electrode is less than the display switching voltage threshold V1, the state of the liquid crystal layer between the pixel electrode and the common electrode is the reflective state. When the voltage between the pixel electrode and the common electrode is greater than or equal to the display switching voltage threshold V1, the state of the liquid crystal layer between the pixel electrode and the common electrode will change, such as from the reflective state to the light-transmitting state. It should be noted that Figure 8 The values ​​of the curve shown are only for illustrative purposes, and there are differences in the display switching voltage thresholds V1 of different types of liquid crystals.

[0117] In some embodiments, the first source driving signal (reference Fig. 9 Vs in the middle t1 segment, Fig.10 The voltage value of Vs in the t1' segment is the same as the first common voltage signal (reference Fig. 9 Vcom in the middle t1 segment, Fig.10 The third difference between the voltage values ​​of Vcom in the middle t1' segment) is greater than the second source drive signal (reference Fig. 9 Vs in the middle t3 segment, Fig.10 The voltage value of Vs in the t3' segment is the same as the voltage value of the second common voltage signal (reference Fig. 9 Vcom in the middle t3 segment, Fig.10 A fourth difference between the voltage values ​​of Vcom in the middle t3' segment and Vcom in the middle t3' segment. Moreover, a fifth difference between the voltage value of the second common voltage signal and Vcom is less than a sixth difference between the voltage value of the first common voltage signal and the preset common voltage reference value. The voltage value of the second common voltage signal may be equal to the preset common voltage reference value.

[0118] Fig. 9 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0119] like Fig. 9As shown, a schematic diagram of the write signal in the first stage t1 and the second stage t3 is shown when the Vcom in the first stage t1 is less than the preset common voltage reference value. In the second stage t3, a row-by-row erasing operation is performed to "erase" the image to be displayed. The Vcom voltage in the second stage t3 can be 0V, and the pixels in the rectangular range begin to be erased row by row. The voltage value of the second source drive signal Vs applied to the pixel unit corresponding to the blank screen in the row is a low voltage, and the voltage value of the second source drive signal Vs applied to the pixel unit corresponding to the image screen in the row is 0V. The voltage value of the second source drive signal Vs applied to the pixel unit outside the rectangular range in the row is 0V. In this way, the blank pixels in the rectangular range and the pixel units outside the rectangle are all changed to the substrate color, and only the pixel units that need to be displayed in a row of pixel units will become the color that reflects a specific wavelength (such as green). After the first row of pixel units is finished, the second row of pixel units will be erased until the last row of pixel units in the rectangular range is completely erased, and the writing process is completed.

[0120] Fig.10 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0121] like Fig.10 As shown, the write signal of the first stage t1' is Fig. 9 The write signal in the first phase t1' is different. However, Fig.10 The write signal of the second phase t3' is Fig. 9 The write signal in the second phase t3 is the same. Fig.10 The Vcom voltage in the second stage t3' can be 0V, and the pixels in the rectangular range begin to be erased row by row, and the voltage value of Vs applied to the pixel units in the row corresponding to the blank screen is a low voltage. The voltage value of Vs applied to the pixel units in the row corresponding to the image screen, and the voltage value of Vs applied to the pixel units outside the rectangular range in the row are all 0V. In this way, the blank pixels in the rectangular range and the pixel units outside the rectangular range are all changed to the substrate color, and only the pixels that need to be displayed in a row will be changed to the color that reflects a specific wavelength (such as green). The above operation is performed for each row in the rectangular range until the last row completes the above operation.

[0122] In some embodiments, the voltage value of the source drive signal is symmetrically distributed relative to the preset common voltage reference value. The voltage value of the first common voltage signal is symmetrically distributed relative to the preset common voltage reference value. The above-mentioned symmetrical distribution means that the voltage value of at least part of the signal (such as the source drive signal) in the write signal can be voltage-reversed (also referred to as polarity reversal) based on the preset common voltage reference value. For example, within a cycle, the preset common voltage reference value is 0V, then the voltage value of the source drive signal can be 20V or -20V at different time periods of the cycle. Voltage reversal can reduce the probability of liquid crystal polarization.

[0123] Fig.11 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0124] like Fig.11 As shown, a third stage t2 is further provided after the first stage t1. The voltage value of the first common voltage signal in the third stage t2 and the voltage value of the first common voltage signal in the first stage t1 are symmetrically distributed relative to the preset common voltage reference value. The voltage value of the first source driving signal in the third stage t2 and the voltage value of the first source driving signal in the first stage t1 are symmetrically distributed relative to the preset common voltage reference value. In addition, the voltage value of the gate driving signal in the third stage t2 remains unchanged so as to turn on the thin film transistor.

[0125] In some embodiments, in the second phase, the voltage value of the second source driving signal is symmetrically distributed relative to a preset common voltage reference value.

[0126] Fig.12 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0127] like Fig.12 As shown, if the preset common voltage reference value is 0V, in the third stage t2', the Vs voltage and the Vcom voltage are opposite to the corresponding values ​​in the first stage t1', and the value of the Vg voltage remains unchanged. At this moment, the liquid crystal also maintains the state of the t1 stage, but the polarity of the driving voltages on both sides is opposite, which can prevent the liquid crystal from polarizing. The rectangular range still reflects light of a specific wavelength, and the pixel units outside the rectangular range display the substrate color.

[0128] Fig.13 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0129] like Fig.13 , which is a schematic diagram showing write signals in the first stage t1 , the second stage t3 , the third stage t2 and the fourth stage t4 when the Vcom in the first stage t1 is less than the preset common voltage reference value. Fig.13 As shown in the write signal, the voltage values ​​of the source driving signal Vs and the common voltage signal Vcom in the third stage t2 are opposite in polarity to the voltage values ​​of the source driving signal Vs and the common voltage signal Vcom in the first stage t1. In addition, the voltage values ​​of the source driving signal and the common voltage signal in the fourth stage t4 are opposite in polarity to the voltage values ​​of the source driving signal and the common voltage signal in the second stage t3.

[0130] Fig.14 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0131] like Fig.14 , which is a schematic diagram showing write signals in the first stage t1 ′, the second stage t3 ′, the third stage t2 ′ and the fourth stage t4 ′ when Vcom in the second stage t3 ′ is equal to the preset common voltage reference value. Fig.14 As shown in the write signal, the voltage values ​​of the source driving signal Vs and the common voltage signal Vcom in the third stage t2' are opposite in polarity to the voltage values ​​of the source driving signal and the common voltage signal in the first stage t1'. In addition, the voltage values ​​of the source driving signal and the common voltage signal in the fourth stage t4' are opposite in polarity to the voltage values ​​of the source driving signal and the common voltage signal in the second stage t3'.

[0132] In some embodiments, the voltage value of the second common voltage signal is a preset common voltage reference value, the voltage value of the first source drive signal is greater than the voltage value of the second source drive signal, and the voltage value of the gate control signal in the first stage is greater than or equal to the voltage value of the gate control signal in the second stage.

[0133] refer to Fig.13 and Fig.14 As shown, the first stage t1, t1' and the second stage t3, t3' respectively have corresponding stages with opposite polarity: the third stage t2, t2' and the fourth stage t4, t4'. Among them, the absolute value of the voltage value of the second source drive signal in the second stage t3, t3' is less than the absolute value of the voltage value of the first source drive signal in the first stage t1, t1'. The absolute value of the voltage value of the second source drive signal in the fourth stage t4, t4' is less than the absolute value of the voltage value of the first source drive signal in the third stage t2, t2'. The second stage and the fourth stage form the image to be displayed by erasing, and the erasing voltage is lower than the writing voltage. The erasing operation is easier to implement than the writing operation and has lower power consumption.

[0134] It should be noted that during the writing process, due to the differences in the liquid crystal characteristics of different products, the writing waveform and the erasing waveform can also be performed multiple times, that is, multiple square waves can be performed in each stage of t1, t1', t2, t2', t3, t3', t4, and t4' to improve the writing success rate. Since the bistable liquid crystal needs to be quickly reduced to 0v after the t1, t1', t2, and t2' stages before it can enter the reflective state, the voltage when Vs drops (at the trough of the square wave) can be set to -2v or lower, thereby accelerating the discharge speed of the two ends of the liquid crystal and more successfully entering the writing state.

[0135] The disclosed embodiments utilize the characteristics of bistable liquid crystals, and on the basis of pressure-driven writing, voltage-driven writing can be further realized. The bistable liquid crystal is driven to undergo a morphological transformation using a given voltage, so that a preset image to be displayed can be quickly displayed. By writing over a large area with high voltage and erasing locally line by line with low voltage, the desired content is "erased", thereby realizing voltage-driven writing based on a write signal. In addition, the voltage required for the erase operation (erase voltage) is lower than the voltage required for the write operation (write voltage), so the erase operation is easier to implement than the write operation and has lower power consumption.

[0136] In some embodiments, the image can be directly written into the display area corresponding to the image to be displayed.

[0137] Fig.15 A flowchart of displaying an image to be displayed in a single phase according to an embodiment of the present disclosure is shown.

[0138] like Fig.15 As shown, based on the pixel data of the image to be displayed, applying a write signal to the pixel driving circuit of the plurality of pixel units in the display area to control the plurality of pixel units in the display area to display the pixel data of the image to be displayed may include operation S1501.

[0139] In operation S1501, each second target pixel unit in the display area is controlled to be in a first display state, and the second target pixel units include pixel units in the display area corresponding to pixel data of an image to be displayed.

[0140] In some embodiments, each pixel unit includes a pixel electrode, a liquid crystal layer, and a common electrode. The source drive signal includes a third source drive signal, and the common voltage signal includes a third common voltage signal. A third voltage difference between the third source drive signal and the third common voltage signal is greater than or equal to a display switching voltage threshold of the pixel unit.

[0141] Accordingly, controlling each second target pixel unit in the display area to be in the first display state may include the following operations.

[0142] A third common voltage signal is applied to the common electrode, and a gate control signal and a third source drive signal are applied row by row to each row of pixel units in the display area, so that the bistable liquid crystal of the second target pixel unit in the current row of pixel units is in the first state.

[0143] The pixel electrode, the liquid crystal layer and the common electrode may refer to the relevant parts of the above embodiments and will not be described in detail here.

[0144] In some embodiments, the voltage value of the third common voltage signal is less than or equal to the preset common voltage reference value. For example, when the voltage value of the third common voltage signal Vcom is less than the preset common voltage reference value, the seventh difference between the voltage value of the third source driving signal Vs and the preset common voltage reference value is less than the eighth difference. The eighth difference is the difference between the voltage value of the third source driving signal Vs and the preset common voltage reference value when the voltage value of the third common voltage signal Vcom is equal to the preset common voltage reference value.

[0145] Fig.16 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0146] like Fig.16 As shown, the voltage value of the third common voltage signal Vcom is less than the preset common voltage reference value.

[0147] like Fig.16 , which shows a schematic diagram of a write signal in the first stage T1 when the first common voltage signal Vcom in the first stage T1 is less than the preset common voltage reference value. The voltage value of the first common voltage signal Vcom is less than the preset common voltage reference value (reference Figure 6 The preset common voltage reference value, the voltage value of the first source driving signal Vs, the voltage value of the first gate control signal Vg and the voltage value of the first common voltage signal Vcom can be referred to as Figure 6 The relevant contents shown will not be repeated here.

[0148] The difference between the first source drive signal Vs and the first common voltage signal Vcom may be greater than or equal to the display switching voltage threshold. Since the voltage value of the first common voltage signal Vcom is adjusted to a smaller value, such as a negative value, the difference between Vs and Vcom can still be greater than or equal to the display switching voltage threshold while the first source drive signal Vs is kept unchanged or reduced by a smaller amplitude. The difference between the preset common voltage reference value and the voltage value of the first common voltage signal Vcom may be less than the display switching voltage threshold.

[0149] Fig.17 FIG. 4 is a schematic diagram showing a write signal according to another embodiment of the present disclosure.

[0150] like Fig.17 As shown, the voltage value of the third common voltage signal is equal to the preset common voltage reference value.

[0151] like Fig.17, which shows a schematic diagram of a write signal in the first stage T1' when Vcom in the first stage T1' is equal to a preset common voltage reference value. The voltage value of the first common voltage signal Vcom is equal to the preset common voltage reference value (reference Figure 7 The preset common voltage reference value, the voltage value of the first source driving signal Vs, the voltage value of the first gate control signal Vg and the voltage value of the first common voltage signal Vcom can be referred to as Figure 7 The relevant contents shown will not be repeated here.

[0152] In some embodiments, the voltage value of the third source driving signal is symmetrically distributed relative to the preset common voltage reference value, and the voltage value of the third common voltage signal is symmetrically distributed relative to the preset common voltage reference value.

[0153] Fig.18 A schematic diagram of a write signal according to another embodiment of the present disclosure is shown. When the liquid crystal drive voltage of the display device cannot be directly generated by the drive circuit, a Fig.18 The write signal is shown.

[0154] like Fig.18 As shown, in the T1 stage, the Gate of the transistor of the first row of pixel units is turned on, the voltage of the third source driving signal Vs of the pixel units to be displayed in the row is higher, and the voltage of the third common voltage signal Vcom takes a negative value (less than Figure 8 The positive high voltage of Vs and the negative voltage of Vcom act together on the liquid crystal between the pixel electrode and the common electrode, causing the liquid crystal to change to the H state. The voltage of the source drive signal of the liquid crystal that does not need to be displayed in the row is 0, and the voltage difference caused by the change of Vcom is less than V1, so the liquid crystal maintains its original state.

[0155] In the T2 phase, the gate control signal Vg turns off the transistor, the voltage of the source drive signal Vs and the voltage of the common power signal Vcom can both be 0V, and the liquid crystal changes from the H state to the P state. At this time, the voltage of the liquid crystal in the P state is less than V1, and the liquid crystal is in a reflective state, reflecting light of a specific wavelength, such as green light.

[0156] In the T3 stage, the action of the T1 stage is repeated, but the driving voltage polarity is opposite to prevent the liquid crystal from polarizing and write again to improve the writing success rate. After the T3 stage is completed, the Vs voltage and the Vcom voltage become 0V again.

[0157] Fig.19 A schematic diagram of a write signal according to another embodiment of the present disclosure is shown. When the liquid crystal driving voltage of the display device can be directly generated by the driving circuit, it can be used Fig.19 The write signal is shown.

[0158] like Fig.19 As shown, in the T1' stage, the third gate control signal Vg is a positive high voltage, and the thin film transistor is turned on. The voltage of the third source drive signal Vs of the pixel unit that needs to be displayed is relatively high, and the positive high voltage acts on the liquid crystal between the pixel electrode and the common electrode, so that the liquid crystal changes to the H state. The voltage of the third source drive signal Vs of the pixel unit that does not need to be displayed in the row is 0, and these liquid crystals maintain their original state.

[0159] In the T2' stage, the gate control signal Vg turns off the transistor (such as Vg is a negative voltage), the voltage of the third source drive signal Vs and the voltage of the third common voltage signal Vcom are both 0V, and the liquid crystal changes from the H state to the P state. The voltage of the liquid crystal in the P state is less than V1, and it is in a reflective state, reflecting light of a set wavelength.

[0160] In the T3' stage, the action of T1' is repeated, but the driving voltage (such as Vs) has the opposite polarity to prevent the liquid crystal from polarizing. Writing is performed again in the T3' stage to improve the writing success rate. After the T3' stage ends, the voltage of Vs and the voltage of Vcom become 0V again.

[0161] It should be noted that Fig.15 The method shown in the flowchart is Figure 5 Compared with the method in the flowchart shown in the figure, the implementation is simpler, with only two writing processes. However, each writing process requires the use of a higher Vs voltage, which consumes more power. During the writing process, due to the differences in the liquid crystal characteristics of different products, the writing waveform and the erasing waveform can also be performed multiple times, that is, multiple square waves are performed in the T1 and T1' stages and the T3 and T3' stages to improve the writing success rate. In addition, the voltage when Vs is at the trough of the square wave in the T1 and T1' stages and the T3 and T3' stages can also be adjusted to -2V or lower to speed up the discharge speed.

[0162] Another aspect of the present disclosure further provides a control device for a display device.

[0163] Fig. 20 is a block diagram of a display device according to an embodiment of the present disclosure.

[0164] like Fig. 20 As shown, the control device 2000 of the display device may include a plurality of pixel units; and a control unit.

[0165] The control unit is configured to: determine a display area for displaying an image to be displayed in response to an image to be displayed having a predetermined shape; and apply a write signal to a pixel driving circuit of a plurality of pixel units in the display area based on pixel data of the image to be displayed, so as to control the plurality of pixel units in the display area to display the pixel data of the image to be displayed.

[0166] The write signal includes: a first source driving signal and a first common voltage signal; a first voltage difference between the first source driving signal and the first common voltage signal is greater than or equal to a display switching voltage threshold of the pixel unit.

[0167] The above-mentioned display device is applicable to the following product types: light-energy blackboards, light-energy business boards, and other bistable liquid crystal display devices using TFT display technology.

[0168] In some embodiments, the control unit may include a gate driver and a source driver. The source driver is used to generate a first source drive signal, a second source drive signal, or a third source drive signal. The gate driver is used to generate a gate control signal. As shown above, the gate driver may include a plurality of shift registers.

[0169] In addition, the display device 2000 may further include a processor, a signal amplifier OP and a power supply circuit. The processor may be a microprocessor (MCU) or the like, and is used to determine a predetermined shape of an image to be displayed. The power supply circuit may supply power to a gate driver and a source driver. The signal amplifier OP is used to amplify a signal.

[0170] In some embodiments, a display device may include at least one processor, at least one memory, a gate driver, and a source driver.

[0171] The gate driver may also be referred to as a gate driving circuit, which is configured to output a scanning signal to the display device under the control of at least one processor to control the gating of each row of pixels. It may be provided in the display panel or in the display device, which is not limited in this embodiment, and the gate driver is provided in the display control device as an example.

[0172] The source driver may also be referred to as a source driving circuit, which is configured to output a data driving signal to the display device under the control of at least one processor to control the color displayed by each pixel.

[0173] For example, the gate driver and / or the source driver may send a BUSY signal (busy state signal) to the processor to inform the processor of the state of itself (gate driver and / or source driver). The processor may determine whether to send a command or data to the gate driver and / or source driver based on the BUSY signal. The processor sends a CLK (clock) signal to the gate driver and the source driver to provide the gate driver and the source driver with the clock required for their operation. In addition, the processor may also send a direct current (DC) signal to the gate driver and the source driver to inform the gate driver and / or the source driver whether the next command or data is to be sent. The source driver may include a plurality of source driver subcircuits, and the processor may send a chip select (CS) signal to one of the plurality of source driver subcircuits to select this source driver subcircuit for signal transmission. For example: the processor may send a start scan command to the gate driver to start scanning the first row of gate lines of the display device; and may also send a data drive signal (i.e., data) to the source driver.

[0174] The memory can store computer programs and data, which may include high-speed random access memory, and may also include non-volatile memory, such as disk storage devices, flash memory devices, etc. It can also be read-only memory (ROM) or other types of static storage devices that can store static information and instructions, random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or one-time programmable memory (OTP), electrically erasable programmable read only memory (EEPROM), disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store program codes in the form of instructions or data structures and can be accessed by a computer, but is not limited to this. The memory can exist independently and be connected to the processor through a communication line. The memory can also be integrated with the processor.

[0175] At least one processor is connected to the gate driver, the source driver and at least one memory, and by running or executing a computer program stored in the memory, the data in the memory is called to control the gate driver and the source driver to output corresponding signals. At least one processor 21 may be one or more general-purpose central processing units (CPUs), microcontroller units (MCUs), logic devices (Logic), application specific integrated circuits (ASICs), or integrated circuits for controlling the execution of programs in some embodiments of the present disclosure; wherein the CPU may be a single-core processor (single CPU) or a multi-core processor (multi CPU). A processor 21 here may refer to one or more devices, circuits, or processing cores for processing data (such as computer program instructions, etc.).

[0176] According to an embodiment of the present disclosure, the above-mentioned control unit is used to: in a first stage, control multiple pixel units in the display area to be in a first display state; and in a second stage, control a first target pixel unit in the display area to be in a second display state, the first target pixel unit including a pixel unit in the display area that does not correspond to pixel data of an image to be displayed.

[0177] According to an embodiment of the present disclosure, in the first stage, a first common voltage signal is applied to the common electrode; a gate control signal and a first source drive signal are applied row by row to each row of pixel units in the display area, so that the liquid crystal layer of the current row of pixel units is in the first state, wherein the first voltage difference between the first source drive signal and the first common voltage signal is greater than or equal to the display switching voltage threshold of the pixel unit. In the second stage, a second common voltage signal is applied to the common electrode; and a gate control signal and a second source drive signal are applied row by row to each row of pixel units in the display area, so that the liquid crystal layer of the first target pixel unit in the current row of pixel units is converted from the first state to the second state, wherein the second voltage difference between the second source drive signal and the second common voltage signal is greater than or equal to the display switching voltage threshold of the pixel unit.

[0178] According to an embodiment of the present disclosure, the voltage value of the first common voltage signal is less than or equal to a preset common voltage reference value, wherein, when the voltage value of the first common voltage signal is less than the preset common voltage reference value, the first difference between the voltage value of the first source drive signal and the preset common voltage reference value is less than the second difference; the second difference is the difference between the voltage value of the first source drive signal and the preset common voltage reference value when the voltage value of the first common voltage signal is equal to the preset common voltage reference value.

[0179] According to an embodiment of the present disclosure, the voltage value of the source driving signal is symmetrically distributed relative to the preset common voltage reference value; the voltage value of the first common voltage signal is symmetrically distributed relative to the preset common voltage reference value.

[0180] According to an embodiment of the present disclosure, the third difference between the voltage value of the first source drive signal and the voltage value of the first common voltage signal is greater than the fourth difference between the voltage value of the second source drive signal and the voltage value of the second common voltage signal; and the fifth difference between the voltage value of the second common voltage signal and the preset common voltage reference value is less than the sixth difference between the voltage value of the first common voltage signal and the preset common voltage reference value.

[0181] According to an embodiment of the present disclosure, the voltage value of the second common voltage signal is a preset common voltage reference value, the voltage value of the first source drive signal is greater than the voltage value of the second source drive signal, and the voltage value of the gate control signal in the first stage is greater than or equal to the voltage value of the gate control signal in the second stage.

[0182] According to an embodiment of the present disclosure, in the second stage, the voltage value of the second source driving signal is symmetrically distributed relative to the preset common voltage reference value.

[0183] According to an embodiment of the present disclosure, the control unit is configured to: control each second target pixel unit in the display area to be in a first display state, the second target pixel unit including the pixel unit in the display area corresponding to the pixel data of the image to be displayed.

[0184] According to an embodiment of the present disclosure, each pixel unit includes a pixel electrode, a liquid crystal layer and a common electrode; the source drive signal includes a third source drive signal, and the common voltage signal includes a third common voltage signal; a third voltage difference between the third source drive signal and the third common voltage signal is greater than or equal to a display switching voltage threshold of the pixel unit; the above-mentioned control unit is used to apply the third common voltage signal to the common electrode; and to each row of pixel units in the display area, a gate control signal and a third source drive signal are applied row by row to make the bistable liquid crystal of the second target pixel unit in the current row of pixel units in the first state.

[0185] According to an embodiment of the present disclosure, the voltage value of the third common voltage signal is less than or equal to the preset common voltage reference value, wherein, when the voltage value of the third common voltage signal is less than the preset common voltage reference value, the seventh difference between the voltage value of the third source drive signal and the preset common voltage reference value is less than the eighth difference; the eighth difference is the difference between the voltage value of the third source drive signal and the preset common voltage reference value when the voltage value of the third common voltage signal is equal to the preset common voltage reference value.

[0186] According to an embodiment of the present disclosure, the voltage value of the third source driving signal is symmetrically distributed relative to the preset common voltage reference value; and the voltage value of the third common voltage signal is symmetrically distributed relative to the preset common voltage reference value.

[0187] According to an embodiment of the present disclosure, for multiple pixel units outside the display area of ​​the image to be displayed in the display device, the source drive signal also includes a fourth source drive signal, the common voltage signal also includes a fourth common voltage signal, and the voltage difference between the fourth source drive signal and the fourth common voltage signal is less than the display switching voltage threshold of the pixel unit.

[0188] Another aspect of the present disclosure provides an electronic device.

[0189] Fig.21 1 is a block diagram of an electronic device for executing a control method of a display device according to an embodiment of the present disclosure. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present disclosure described and / or required herein.

[0190] like Fig.21 As shown, the device 2100 includes a computing unit 2101, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 2102 or a computer program loaded from a storage unit 2108 into a random access memory (RAM) 2103. In the RAM 2103, various programs and data required for the operation of the device 2100 can also be stored. The computing unit 2101, the ROM 2102, and the RAM 2103 are connected to each other via a bus 2104. An input / output (I / O) interface 2105 is also connected to the bus 2104.

[0191] A number of components in the device 2100 are connected to the I / O interface 2105, including: an input unit 2106, such as a keyboard, a mouse, etc.; an output unit 2107, such as various types of displays, speakers, etc.; a storage unit 2108, such as a disk, an optical disk, etc.; and a communication unit 2109, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 2109 allows the device 2100 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0192] The computing unit 2101 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 2101 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 2101 performs the various methods and processes described above, such as a control method for a display device. For example, in some embodiments, the control method for a display device may be implemented as a computer software program, which is tangibly included in a machine-readable medium, such as a storage unit 2108. In some embodiments, part or all of the computer program may be loaded and / or installed on the device 2100 via the ROM 2102 and / or the communication unit 2109. When the computer program is loaded into the RAM 2103 and executed by the computing unit 2101, one or more steps of the control method for the display device described above may be performed. Alternatively, in other embodiments, the computing unit 2101 may be configured to execute the control method of the display device in any other appropriate manner (for example, by means of firmware).

[0193] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0194] The program code for implementing the method of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0195] In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, 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), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0196] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0197] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0198] A computer system may include clients and servers. Clients and servers are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship to each other.

[0199] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0200] The above specific implementations do not constitute a limitation on the protection scope of the present disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A method for controlling a display device, comprising: In response to an image to be displayed having a predetermined shape, determining a display area of ​​a display device for displaying the image to be displayed; as well as Applying a write signal to a pixel driving circuit of a plurality of pixel units in the display area based on the pixel data of the image to be displayed, so as to control the plurality of pixel units in the display area to display the pixel data of the image to be displayed; The write signal includes: a source drive signal and a common voltage signal; the voltage difference between the source drive signal and the common voltage signal is greater than or equal to the display switching voltage threshold of the pixel unit, Wherein, applying a write signal to a pixel driving circuit of a plurality of pixel units in the display area based on the pixel data of the image to be displayed to control the plurality of pixel units in the display area to display the pixel data of the image to be displayed comprises: In the first stage, a plurality of pixel units in the display area are controlled to be in a first display state; and In the second stage, controlling the first target pixel unit in the display area to be in a second display state, the first target pixel unit including the pixel unit in the display area that does not correspond to the pixel data of the image to be displayed; Each pixel unit includes a pixel electrode, a liquid crystal layer and a common electrode; the source driving signal includes a first source driving signal and a second source driving signal, and the common voltage signal includes a first common voltage signal and a second common voltage signal; In the first stage, applying the first common voltage signal to the common electrode; Applying a gate control signal and the first source driving signal to each row of pixel units in the display area row by row, so that the liquid crystal layer of the pixel units in the current row is in a first state, wherein a first voltage difference between the first source driving signal and the first common voltage signal is greater than or equal to a display switching voltage threshold of the pixel unit; In the second stage, applying the second common voltage signal to the common electrode; and A gate control signal and a second source drive signal are applied row by row to each row of pixel units in the display area so that the liquid crystal layer of the first target pixel unit in the current row of pixel units is converted from a first state to a second state, wherein a second voltage difference between the second source drive signal and the second common voltage signal is greater than or equal to a display switching voltage threshold of the pixel unit.

2. The method according to claim 1, wherein: The voltage value of the first common voltage signal is less than or equal to a preset common voltage reference value, Among them, when the voltage value of the first common voltage signal is less than the preset common voltage reference value, the first difference between the voltage value of the first source drive signal and the preset common voltage reference value is less than the second difference; the second difference is the difference between the voltage value of the first source drive signal and the preset common voltage reference value when the voltage value of the first common voltage signal is equal to the preset common voltage reference value.

3. The method according to claim 2, wherein: The voltage value of the source driving signal is symmetrically distributed relative to the preset common voltage reference value; the voltage value of the first common voltage signal is symmetrically distributed relative to the preset common voltage reference value.

4. The method according to claim 3, wherein: A third difference between a voltage value of the first source driving signal and a voltage value of the first common voltage signal is greater than a fourth difference between a voltage value of the second source driving signal and a voltage value of the second common voltage signal; And a fifth difference between the voltage value of the second common voltage signal and the preset common voltage reference value is smaller than a sixth difference between the voltage value of the first common voltage signal and the preset common voltage reference value.

5. The method according to claim 4, wherein: The voltage value of the second common voltage signal is the preset common voltage reference value, the voltage value of the first source drive signal is greater than the voltage value of the second source drive signal, and the voltage value of the gate control signal in the first stage is greater than or equal to the voltage value of the gate control signal in the second stage.

6. The method according to claim 3 or 4, wherein: In the second stage, the voltage value of the second source driving signal is symmetrically distributed relative to the preset common voltage reference value.

7. The method according to claim 1, wherein: The applying a write signal to a pixel driving circuit of a plurality of pixel units in the display area based on the pixel data of the image to be displayed so as to control the plurality of pixel units in the display area to display the pixel data of the image to be displayed comprises: Each second target pixel unit in the display area is controlled to be in a first display state, wherein the second target pixel unit includes a pixel unit in the display area corresponding to the pixel data of the image to be displayed.

8. The method according to claim 7, wherein: Each pixel unit includes a pixel electrode, a liquid crystal layer and a common electrode; The source driving signal includes a third source driving signal, and the common voltage signal includes a third common voltage signal; A third voltage difference between the third source driving signal and the third common voltage signal is greater than or equal to a display switching voltage threshold of the pixel unit; The controlling each second target pixel unit in the display area to be in the first display state comprises: applying the third common voltage signal to the common electrode; A gate control signal and the third source driving signal are applied row by row to each row of pixel units in the display area, so that the bistable liquid crystal of the second target pixel unit in the current row of pixel units is in the first state.

9. The control method according to claim 8, wherein: The voltage value of the third common voltage signal is less than or equal to a preset common voltage reference value, wherein, when the voltage value of the third common voltage signal is less than the preset common voltage reference value, the seventh difference between the voltage value of the third source drive signal and the preset common voltage reference value is less than the eighth difference; the eighth difference is the difference between the voltage value of the third source drive signal and the preset common voltage reference value when the voltage value of the third common voltage signal is equal to the preset common voltage reference value.

10. The control method according to claim 8 or 9, wherein: The voltage value of the third source driving signal is symmetrically distributed relative to a preset common voltage reference value; and the voltage value of the third common voltage signal is symmetrically distributed relative to the preset common voltage reference value.

11. The control method according to any one of claims 1 to 5 and 7 to 9, wherein: For multiple pixel units outside the display area of ​​the image to be displayed in the display device, the source drive signal also includes a fourth source drive signal, the common voltage signal also includes a fourth common voltage signal, and the voltage difference between the fourth source drive signal and the fourth common voltage signal is less than the display switching voltage threshold of the pixel unit.

12. The control method according to any one of claims 1 to 5 and 7 to 9, wherein: The display device is used for at least one of a light-energy blackboard, a light-energy business board, a billboard, and a display board.

13. The control method according to claim 1 or 8, wherein: The material of the liquid crystal layer includes bistable cholesteric liquid crystal.

14. The control method according to claim 13, wherein: The liquid crystal layer further includes an optical rotator, and the bistable cholesteric liquid crystal includes cholesterol liquid crystal.

15. A display device, comprising: A plurality of pixel units; as well as Control unit; Wherein, the control unit is configured as: In response to an image to be displayed having a predetermined shape, determining a display area for displaying the image to be displayed; and Applying a write signal to a pixel driving circuit of a plurality of pixel units in the display area based on the pixel data of the image to be displayed, so as to control the plurality of pixel units in the display area to display the pixel data of the image to be displayed; The write signal includes: a first source driving signal and a first common voltage signal; a first voltage difference between the first source driving signal and the first common voltage signal is greater than or equal to a display switching voltage threshold of the pixel unit, Wherein, applying a write signal to a pixel driving circuit of a plurality of pixel units in the display area based on the pixel data of the image to be displayed to control the plurality of pixel units in the display area to display the pixel data of the image to be displayed comprises: In the first stage, a plurality of pixel units in the display area are controlled to be in a first display state; and In the second stage, controlling the first target pixel unit in the display area to be in a second display state, the first target pixel unit including the pixel unit in the display area that does not correspond to the pixel data of the image to be displayed; Each pixel unit includes a pixel electrode, a liquid crystal layer and a common electrode; the source driving signal includes a first source driving signal and a second source driving signal, and the common voltage signal includes a first common voltage signal and a second common voltage signal; In the first stage, applying the first common voltage signal to the common electrode; Applying a gate control signal and the first source driving signal to each row of pixel units in the display area row by row, so that the liquid crystal layer of the pixel units in the current row is in a first state, wherein a first voltage difference between the first source driving signal and the first common voltage signal is greater than or equal to a display switching voltage threshold of the pixel unit; In the second stage, applying the second common voltage signal to the common electrode; and A gate control signal and a second source drive signal are applied row by row to each row of pixel units in the display area so that the liquid crystal layer of the first target pixel unit in the current row of pixel units is converted from a first state to a second state, wherein a second voltage difference between the second source drive signal and the second common voltage signal is greater than or equal to a display switching voltage threshold of the pixel unit.

Images