Cholesteric liquid crystal multi-gray-scale display method and cholesteric liquid crystal display device

Abstract

The invention discloses a cholesteric liquid crystal multi-gray-scale display method and a cholesteric liquid crystal display device, and relates to the technical field of display. In the multi-gray-scale display method, all the pixel units use the same driving voltage, and multi-gray-scale display is realized by adjusting the duration of the driving voltage instead of changing the voltage, so that when the multi-gray-scale display is realized, the requirement on voltage precision is reduced, and voltage debugging does not need to be performed on each pixel unit independently; the complexity of realizing multi-gray-scale display is reduced; moreover, the method is applied to the cholesteric liquid crystal display device, the cholesteric liquid crystal display device comprises a pixel driving unit and a pixel unit, and the pixel driving unit comprises a driving transistor and a capacitor; the capacitor is connected in parallel with the pixel unit. A capacitor exists in the pixel driving unit and can store voltage, so that the pixel unit can keep previous gray scale display even if voltage is stopped being applied to the driving transistor, and the gray scale display duration is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a cholesteric liquid crystal multi-gray scale display method and a cholesteric liquid crystal display device. BACKGROUND

[0002] Since single brightness display cannot meet the perception needs of human eyes for picture light and dark details and level transitions, content details are lost and visual effects are monotonous, so different gray scales need to be realized to improve the information carrying capacity and visual restoration degree of a displayed picture.

[0003] In related different gray scale display methods, the reflectivity is usually changed by changing the voltage, so as to achieve the effect of displaying different gray scales. Figure 1 A cholesteric liquid crystal reflectivity-voltage curve. Figure 1 When the voltage is in a range from Vth to 15V or so, the slope of the curve is large, that is, when the voltage changes slightly, the reflection intensity changes greatly, so when different gray scales are displayed by changing the voltage, the output precision of the voltage is required to be high; and the material uniformity of different screens is different, so the characteristics of the same driving voltage are different, and the driving voltage of the pixel needs to be adjusted and programmed one by one, so the process of realizing different gray scale outputs is complex. t When the voltage is in a range from Vth to 15V or so, the slope of the curve is large, that is, when the voltage changes slightly, the reflection intensity changes greatly, so when different gray scales are displayed by changing the voltage, the output precision of the voltage is required to be high; and the material uniformity of different screens is different, so the characteristics of the same driving voltage are different, and the driving voltage of the pixel needs to be adjusted and programmed one by one, so the process of realizing different gray scale outputs is complex.

[0004] Therefore, under the condition of reducing the requirement for the output precision of the voltage and the complexity of the gray scale output, it is an urgent technical problem for those skilled in the art to realize the output of different gray scales. SUMMARY

[0005] The present application aims to provide a cholesteric liquid crystal multi-gray scale display method and a cholesteric liquid crystal display device to solve the technical problems that the output precision of the voltage is required to be high and the complexity is high when different gray scales are displayed by changing the voltage.

[0006] To solve the above technical problems, the present application provides a cholesteric liquid crystal multi-gray scale display method applied to a cholesteric liquid crystal display device, wherein the cholesteric liquid crystal display device comprises a pixel driving unit and a pixel unit, the pixel driving unit comprises a driving transistor and a capacitor, the first end of the driving transistor is used for receiving a selection signal, the second end is connected with a power supply, the third end is connected with the first end of the capacitor and the first end of the pixel unit, the second end of the capacitor is connected with the second end of the pixel unit, and the method comprises the following steps:

[0007] obtaining a uniform driving voltage and gray scale data of each pixel unit corresponding to RGB pixel data of a to-be-displayed image;

[0008] According to a pre-established mapping relationship between the gray scale data and the applied voltage duration, a target applied voltage duration corresponding to the gray scale data of each pixel unit is determined; wherein the gray scale data and the applied voltage duration are negatively correlated;

[0009] According to the target applied voltage duration, the uniform driving voltage is applied to the driving transistor connected to the corresponding pixel unit, and is transmitted to the cholesteric liquid crystal in each pixel unit;

[0010] Based on the uniform driving voltage of the target applied voltage duration, the molecular arrangement state of the cholesteric liquid crystal in the pixel unit is regulated, so that each pixel unit presents a corresponding gray scale display.

[0011] Exemplarily, before the uniform driving voltage is applied to the driving transistor according to the target applied voltage duration, the method further comprises:

[0012] Based on the gray scale data, the number of gray scales to be achieved is determined;

[0013] The corresponding relationship between the preset frame number and the number of gray scales achieved by the frame number is obtained;

[0014] According to the corresponding relationship, the frame number corresponding to the number of gray scales to be achieved is determined;

[0015] The frame period is obtained, and based on the frame period and the target applied voltage duration, the target frame number of the applied voltage corresponding to the gray scale data of each pixel unit is determined;

[0016] The duration corresponding to the target frame number is taken as the target applied voltage duration.

[0017] Exemplarily, the uniform driving voltage adopts a bipolar symmetric configuration.

[0018] Exemplarily, obtaining the uniform driving voltage comprises:

[0019] Obtaining the relationship between the voltage, reflectivity and time corresponding to the cholesteric liquid crystal;

[0020] Based on the relationship, the reflectivity threshold range of the cholesteric liquid crystal display device is determined;

[0021] The first voltage is applied to the cholesteric liquid crystal, and the first reflectivity range of the cholesteric liquid crystal after the first voltage is applied for a preset duration is obtained;

[0022] In the case where it is detected that the first reflectivity range does not cover the reflectivity threshold range, the uncovered reflectivity range is determined according to the reflectivity threshold range and the first reflectivity range;

[0023] a second voltage is selected to be applied to the cholesteric liquid crystal, and a second reflectivity range of the cholesteric liquid crystal after the second voltage is applied for a preset time length is obtained; in a case where the second reflectivity range covers the uncovered reflectivity range, the first voltage and the second voltage are both taken as the uniform driving voltage;

[0024] applying the uniform driving voltage to the driving transistor connected to the corresponding pixel unit according to the target application voltage time length includes:

[0025] applying a first voltage to the driving transistor connected to the corresponding pixel unit in the first pixel unit group according to the target application voltage time length; the first pixel unit group is a pixel unit whose gray scale data is in a gray scale range corresponding to the first reflectivity range;

[0026] applying a second voltage to the driving transistor connected to the corresponding pixel unit in the second pixel unit group according to the target application voltage time length; the second pixel unit group is a pixel unit whose gray scale data is in a gray scale range corresponding to the uncovered reflectivity range.

[0027] After the pixel unit presents the corresponding gray scale display by regulating the molecular arrangement state of the cholesteric liquid crystal in the pixel unit based on the uniform driving voltage of the target application voltage time length, the method further includes:

[0028] obtaining a total time length corresponding to the frame number corresponding to the to-be-implemented gray scale number;

[0029] obtaining a time difference value between the total time length and the target application voltage time length;

[0030] determining a remaining frame based on the time difference value;

[0031] stopping applying voltage to the driving transistor after the target application voltage time length since the uniform driving voltage is applied to the driving transistor connected to the corresponding pixel unit;

[0032] in the remaining frame, maintaining the voltage of the corresponding pixel unit by using the capacitor connected to the driving transistor, so that the pixel unit maintains the current gray scale display state in the remaining frame; the current gray scale display state is the gray scale display state presented by the pixel unit after the target application voltage time length of the uniform driving voltage is applied to the pixel unit by the driving transistor.

[0033] After the time length corresponding to the target frame number is taken as the target application voltage time length, the method further includes:

[0034] determine driving time sequence corresponding to each to-be-implemented gray scale based on the frame number corresponding to the to-be-implemented gray scale number and the target frame number; wherein in each gray scale driving time sequence, the target frame number is used to implement gray scale display by applying a uniform driving voltage to a driving transistor; the remaining frame number is used to keep the gray scale display by the driving transistor in a state of not applying voltage, and the capacitor connected with the driving transistor is used to keep the gray scale display; the remaining frame number is the difference between the frame number corresponding to the to-be-implemented gray scale number and the target frame number;

[0035] apply the uniform driving voltage to the corresponding pixel unit according to the driving time sequence corresponding to each to-be-implemented gray scale, so that each pixel unit presents corresponding gray scale display.

[0036] Exemplarily, before obtaining the uniform driving voltage and the gray scale data of each pixel unit corresponding to the RGB pixel data of the to-be-displayed image, the method further comprises:

[0037] apply a preset voltage to the driving transistor connected with all pixel units and transmit the preset voltage to the cholesteric liquid crystal in each pixel unit, so that each pixel unit presents a dark state;

[0038] start from detecting that all pixel units present a black state, reduce the voltage from the preset voltage to 0V within a preset time, so that all pixel units present a bright state.

[0039] Exemplarily, after each pixel unit presents corresponding gray scale display, the method further comprises:

[0040] measure the actual reflectivity of each pixel unit by a spectrometer;

[0041] substitute each actual reflectivity into a pre-calibrated gray scale-gamma curve to determine the actual gray scale value presented by each pixel unit;

[0042] compare the actual gray scale value presented by each pixel unit with the to-be-displayed gray scale data;

[0043] in the case of detecting that the comparison result is within a preset range, determine that the pixel unit has displayed according to the to-be-displayed gray scale data;

[0044] in the case of detecting that the comparison result is not within the preset range, output prompt information for indicating that the gray scale display of the pixel unit is deviated from the preset range.

[0045] In order to solve the above technical problems, the present application further provides a cholesteric liquid crystal display device, comprising:

[0046] a memory for storing a computer program;

[0047] A processor is configured to implement the steps of the cholesteric liquid crystal multi-gray scale display method when executing the computer program.

[0048] To solve the above technical problems, the application further provides a computer readable storage medium, wherein the computer readable storage medium stores a computer program, and the computer program is configured to implement the steps of the cholesteric liquid crystal multi-gray scale display method when executed by a processor.

[0049] The cholesteric liquid crystal multi-gray scale display method provided by the application first determines the target applied voltage duration corresponding to the gray scale data of each pixel unit according to the mapping relationship between the gray scale data and the applied voltage duration, wherein the gray scale data and the applied voltage duration are negatively correlated; then a uniform driving voltage is applied to the driving transistor connected to the corresponding pixel unit according to the target applied voltage duration, and is transmitted to the cholesteric liquid crystal in each pixel unit; finally, the molecular arrangement state of the cholesteric liquid crystal in the pixel unit is regulated based on the uniform driving voltage of the target applied voltage duration, so that each pixel unit presents corresponding gray scale display. In the gray scale display method, the same driving voltage is used for all pixel units, and multi-gray scale display is realized by adjusting the duration of the driving voltage instead of changing the voltage, so that the requirement for voltage precision is reduced and voltage adjustment for each pixel unit is not required, thereby reducing the complexity of realizing multi-gray scale display. Moreover, the method is applied to a cholesteric liquid crystal display device, which comprises a pixel driving unit and a pixel unit, the pixel driving unit comprises a driving transistor and a capacitor, the first end of the driving transistor is configured to receive a selection signal, the second end is connected to a power supply, the third end is connected to the first end of the capacitor and the first end of the pixel unit, and the second end of the capacitor is connected to the second end of the pixel unit. The capacitor in the pixel driving unit can store voltage, so that the pixel unit can maintain the previous gray scale display even if the voltage is stopped being applied to the driving transistor, thereby prolonging the gray scale display duration.

[0050] In addition, the application further provides a cholesteric liquid crystal display device and a computer readable storage medium, which have the same or corresponding technical features as the cholesteric liquid crystal multi-gray scale display method mentioned above, and have the same effects. BRIEF DESCRIPTION OF DRAWINGS

[0051] To make the application embodiments clearer, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort.

[0052] Figure 1 Cholesteric liquid crystal reflectivity-voltage curve;

[0053] Figure 2 A schematic diagram of a cholesteric liquid crystal display device provided by an embodiment of the present application is shown in the following figure:

[0054] Figure 3 A flow chart of a cholesteric liquid crystal multi-gray scale display method provided by an embodiment of the present application is shown in the following figure:

[0055] Figure 4 A pixel gray scale diagram provided by an embodiment of the present application is shown in the following figure:

[0056] Figure 5 A timing diagram of frame number driving partial gray scale provided by an embodiment of the present application is shown in the following figure:

[0057] Figure 6 A structural diagram of a cholesteric liquid crystal display device provided by an embodiment of the present application is shown in the following figure. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0059] The core of the present application is to provide a cholesteric liquid crystal multi-gray scale display method and a cholesteric liquid crystal display device, so as to solve the technical problems of high requirement for voltage output precision and high complexity when different gray scales are displayed by changing voltage.

[0060] In order for those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0061] Cholesteric liquid crystal (Cholesteric Liquid Crystal) under different conditions will present a variety of states, including the commonly seen homeotropic state (Homeotropic State, referred to as H state), planar state (Planar State, referred to as P state) and focal conic state (Focal conic, referred to as FC state). In the H state, the liquid crystal molecular helical texture is dis-helical, and a nematic phase vertical arrangement is presented, and the liquid crystal layer is a uniform refractive index medium, so the liquid crystal cell presents a transparent state. In the P state, the liquid crystal molecules present a helical arrangement around the helical axis perpendicular to the substrate surface, and when the light is incident on the liquid crystal surface, the liquid crystal molecules selectively reflect the light of a specific wavelength, and the reflection wavelength is controlled by the pitch, and a chiral dopant / optical agent can be used to control the pitch of the cholesteric liquid crystal, and different colors are reflected. In the FC state, the liquid crystal molecules are in a multi-domain state, and the helical structure still exists in each domain, and the helical axes of different domains are randomly oriented in space and have different directions. Due to the continuous change of the refractive index of light on the domain boundary, strong light scattering occurs, the substrate reflects the scattered light, and then the color of the display substrate is displayed (then a dark state is formed).

[0062] Since a single brightness display cannot meet the perception needs of the human eye for picture light and dark details and level transitions, content details are lost and visual effects are monotonous, so different gray scales need to be realized to improve the information carrying capacity and visual restoration degree of the displayed picture. However, when multiple gray scales are displayed by changing the voltage, the voltage output precision is high and the complexity is high, so the present embodiment of the application realizes the effect of brushing gray scales by applying different voltages to the cholesteric liquid crystal screen.

[0063] Figure 2 A schematic diagram of the cholesteric liquid crystal display device provided by the present embodiment is shown in Figure 2 , which includes a pixel driving unit 1 and a pixel unit 2. The pixel driving unit 1 includes a driving transistor (such as a TFT) and a capacitor Cp. The first end of the driving transistor is used to receive a selection signal, the second end is connected to a power supply, the third end is connected to the first end of the capacitor and the first end of the pixel unit, and the second end of the capacitor is connected to the second end of the pixel unit. The driving transistor can be a thin-film transistor (Thin-Film Transistor, TFT) or the like. Taking a thin-film transistor as an example, the gate of the thin-film transistor is used to receive a selection signal, and when the gate input is high, the thin-film transistor is turned on, and vice versa. The source of the thin-film transistor is connected to a power supply, the drain of the thin-film transistor is connected to the first end of the capacitor, and the second end of the capacitor is connected to the second end of the pixel unit. The cholesteric liquid crystal multi-gray scale display method provided by the present application is applied to the cholesteric liquid crystal display device. Figure 3 A flow chart of a cholesteric liquid crystal multi-gray scale display method provided by the present embodiment is shown in Figure 3 , which includes:

[0064] S10: Obtain the unified driving voltage and the grayscale data of each pixel unit corresponding to the RGB pixel data of the image to be displayed;

[0065] S11: Based on the pre-established mapping relationship between grayscale data and applied voltage duration, determine the target applied voltage duration corresponding to the grayscale data of each pixel unit; wherein, there is a negative correlation between grayscale data and applied voltage duration;

[0066] S12: Apply a uniform driving voltage to the driving transistor connected to the corresponding pixel unit according to the target applied voltage duration, and transmit it to the cholesteric liquid crystal in each pixel unit;

[0067] S13: Based on the uniform driving voltage of the target applied voltage duration, the molecular arrangement state of cholesteric liquid crystal in the pixel unit is adjusted so that each pixel unit presents the corresponding grayscale display.

[0068] Since multi-grayscale display is achieved based on the same voltage, a uniform driving voltage is described in this invention. The choice of driving voltage is not limited and can be determined based on the conventional voltage characteristics of cholesteric liquid crystals, measured values, or empirical values.

[0069] The image to be displayed is not limited and is determined based on actual display requirements. The grayscale data of each pixel unit corresponding to the RGB pixel data of the image to be displayed is obtained. First, the RGB components of the input image are read; each pixel unit contains brightness values ​​for the red, green, and blue channels. Then, according to a preset grayscale conversion algorithm, the three channel values ​​of each pixel unit are converted into a single grayscale value. Finally, this grayscale value is mapped to the grayscale range supported by the display panel to obtain the grayscale data corresponding to each pixel unit. Figure 4 This is a pixel grayscale diagram provided in an embodiment of the present invention. Figure 4 The image displays grayscale levels 0, 48, 207, 223, and 255. A pixel is at its darkest state at grayscale 0 and at its brightest state at grayscale 255.

[0070] After obtaining the grayscale data of each pixel unit corresponding to the RGB pixel data of the image to be displayed, the target applied voltage duration corresponding to the grayscale data of each pixel unit is determined according to the pre-established mapping relationship between grayscale data and applied voltage duration. It is worth noting that there is a negative correlation between grayscale data and applied voltage duration. That is, the larger the grayscale data, the shorter the applied voltage duration; the smaller the grayscale data, the longer the applied voltage duration.

[0071] After determining the applied voltage duration for each pixel unit, a uniform driving voltage is applied to the cholesteric liquid crystal within the driving transistor connected to the pixel unit, and the applied voltage duration is maintained. Based on the uniform driving voltage with the target applied voltage duration, the molecular arrangement state of the cholesteric liquid crystal within the pixel unit is adjusted to achieve the corresponding grayscale display for each pixel unit.

[0072] The cholesteric liquid crystal multi-grayscale display method provided in this embodiment firstly determines the target applied voltage duration corresponding to the grayscale data of each pixel unit based on a pre-established mapping relationship between grayscale data and applied voltage duration; wherein, the grayscale data and applied voltage duration have a negative correlation; a uniform driving voltage is applied to the driving transistor connected to the corresponding pixel unit according to the target applied voltage duration, and transmitted to the cholesteric liquid crystal in each pixel unit; finally, based on the uniform driving voltage of the target applied voltage duration, the molecular arrangement state of the cholesteric liquid crystal in the pixel unit is adjusted, so that each pixel unit presents the corresponding grayscale display. In this grayscale display method, all pixel units use the same driving voltage. Multi-grayscale display is achieved by adjusting the duration of the driving voltage, rather than changing the voltage itself. Therefore, the voltage accuracy requirements are reduced, and individual voltage adjustments for each pixel unit are unnecessary, thus lowering the complexity of multi-grayscale display. Furthermore, this method is applied to cholesteric liquid crystal display devices, which include pixel driving units and pixel units. The pixel driving unit includes a driving transistor and a capacitor. The first terminal of the driving transistor receives a gating signal, the second terminal is connected to a power supply, and the third terminal is connected to the first terminal of the capacitor and the first terminal of the pixel unit. The second terminal of the capacitor is connected to the second terminal of the pixel unit. The presence of a capacitor in the pixel driving unit allows for voltage storage; therefore, even if the voltage applied to the driving transistor is stopped, the pixel unit can maintain its previous grayscale display, increasing the grayscale display duration.

[0073] Based on the above embodiments, the method of applying a uniform driving voltage to the driving transistor according to the target applied voltage duration further includes:

[0074] The number of gray levels to be implemented is determined based on the grayscale data;

[0075] Obtain the correspondence between the preset number of frames and the number of gray levels achieved by the number of frames;

[0076] The number of frames corresponding to the number of gray levels to be implemented is determined based on the correspondence.

[0077] Obtain the frame period, and determine the target frame number corresponding to the applied voltage for each pixel unit based on the frame period and the duration of the applied voltage to the target.

[0078] The duration corresponding to the target frame number is taken as the duration for which the target voltage is applied.

[0079] If the desired number of gray levels is 16, the correspondence between the number of frames and the number of gray levels achieved by each frame is not limited. For example, if there are 10 frames, each frame corresponds to one gray level, resulting in 16 gray levels. If there are 100 frames, every two frames correspond to one gray level, resulting in 50 gray levels. Based on this correspondence, after determining the desired number of gray levels based on the gray level data, the corresponding number of frames can be determined. The frame period is not limited, such as 10ms per frame. Based on the frame period, the duration of the target voltage application corresponding to each pixel unit is represented by the duration of the target frame number. For example, the target voltage application duration corresponds to the duration of 3 frames.

[0080] In the method provided in this embodiment, the target frame duration is used to characterize the target voltage application duration of each pixel unit, which can directly anchor the display frame period and simplify the synchronous control logic of the driving timing. Relying on the inherent time reference of the frame period, the consistency and accuracy of the voltage application duration of different pixel units can be improved, ensuring the stability of grayscale display effect.

[0081] In some embodiments, the uniform drive voltage employs a bipolar symmetrical configuration. For example, if the uniform drive voltage is 20V, then +20V and -20V are used alternately for power supply.

[0082] In the method provided in this embodiment, the uniform driving voltage adopts a bipolar symmetrical configuration, which can effectively counteract the polarization fatigue of cholesteric liquid crystal molecules caused by unidirectional electric field and extend the service life of liquid crystal devices.

[0083] The above description uses a uniform driving voltage to achieve multi-grayscale display. In practice, the number of grayscale levels that a single uniform driving voltage can achieve may be limited; for example, a single uniform driving voltage, by changing the application duration, may only achieve 20 grayscale levels. To achieve more grayscale displays, in some embodiments, obtaining the uniform driving voltage includes:

[0084] The relationship between voltage, reflectivity, and time for cholesteric liquid crystals was obtained.

[0085] The reflectance threshold range of the cholesteric phase liquid crystal display device is determined based on the relationship;

[0086] A first voltage is selected and applied to the cholesteric liquid crystal, and the first reflectance range of the cholesteric liquid crystal after the first voltage is applied for a preset duration is obtained;

[0087] If the first reflectivity range is detected to not cover the reflectivity threshold range, the uncovered reflectivity range is determined based on the reflectivity threshold range and the first reflectivity range.

[0088] A second voltage is selected and applied to the cholesteric liquid crystal, and the second reflectivity range of the cholesteric liquid crystal after the second voltage is applied for a preset duration is obtained; if it is detected that the second reflectivity range covers the uncovered reflectivity range, both the first voltage and the second voltage are used as a unified driving voltage.

[0089] For example, if the screen's highest reflectivity is 23% and its lowest reflectivity is 3%, applying a 6V voltage for 2 seconds will only result in a reflectivity of 8%, indicating that it cannot display grayscale levels between 3% and 8% under 6V conditions. Applying a 20V voltage will reduce the reflectivity to 5% since the screen's frame rate is 10ms per frame and 20V is applied for one frame. It can reach 3% for two frames (20ms), but it cannot achieve the reflectivity corresponding to high grayscale levels. Therefore, multiple voltage combinations are needed to achieve multi-grayscale display.

[0090] After obtaining multiple uniform driving voltages, the uniform driving voltages are applied to the driving transistors connected to the corresponding pixel units according to the target applied voltage duration, including:

[0091] The first voltage is applied to the driving transistor connected to the corresponding pixel unit in the first pixel unit group according to the target voltage application duration; wherein, the first pixel unit group consists of pixel units with grayscale data in the grayscale range corresponding to the first reflectivity range;

[0092] The second voltage is applied to the driving transistor connected to the corresponding pixel unit in the second pixel unit group according to the target voltage application duration; wherein, the second pixel unit group is the pixel unit in the grayscale range corresponding to the grayscale data in the uncovered reflectivity range.

[0093] In the method provided in this embodiment, multiple uniform driving voltages are selected, and the duration of application of each uniform driving voltage is used to achieve partial grayscale display requirements. In this way, the display requirements of all grayscale levels are met by multiple uniform driving voltages.

[0094] In traditional (passive) grayscale displays, scanning occurs line by line. After a line is scanned, no voltage is applied to the pixel unit, causing grayscale display failure and poor grayscale display stability. Therefore, to improve grayscale display performance, some embodiments, after adjusting the molecular arrangement of cholesteric liquid crystal within the pixel unit using a uniform driving voltage based on the target applied voltage duration to ensure each pixel unit presents the corresponding grayscale display, further include:

[0095] Get the total duration corresponding to the number of frames corresponding to the number of gray levels to be implemented;

[0096] Obtain the time difference between the total duration and the duration of the target applied voltage;

[0097] The remaining frames are determined based on the time difference;

[0098] Starting from applying a uniform driving voltage to the driving transistor connected to the corresponding pixel unit, after the target applied voltage duration, the application of voltage to the driving transistor is stopped;

[0099] In the remaining frames, the voltage of the corresponding pixel unit is maintained by a capacitor connected to the driving transistor, so that the pixel unit maintains the current grayscale display state in the remaining frames; wherein, the current grayscale display state is the grayscale display state presented by the pixel unit after a uniform driving voltage of the target applied voltage duration is applied to the pixel unit by the driving transistor.

[0100] In the method provided in this embodiment, a uniform driving voltage is applied to the driving transistor connected to the corresponding pixel unit. After the target voltage application time, the voltage application to the driving transistor is stopped. Then, the multi-frame charge retention capability of the capacitor is used to allow the pixel unit to stably maintain the corresponding grayscale brightness within the multi-frame frame cycle, ensuring the grayscale display consistency of the entire image without flickering, and improving the grayscale display effect.

[0101] To achieve a rapid grayscale refresh effect, in some embodiments, after using the duration corresponding to the target frame number as the target voltage application duration, the method further includes:

[0102] The driving timing for each gray level to be implemented is determined based on the number of frames corresponding to the number of gray levels to be implemented and the target number of frames. In each gray level driving timing, gray level display is achieved within the target number of frames using a uniform driving voltage applied to the driving transistor. Within the remaining number of frames, the driving transistor is in a state without applied voltage, and gray level display is maintained by the capacitor connected to the driving transistor. The remaining number of frames is the difference between the number of frames corresponding to the number of gray levels to be implemented and the target number of frames.

[0103] A uniform driving voltage is applied to the corresponding pixel unit according to the driving timing of each gray level to be implemented, so that each pixel unit can present the corresponding gray level display.

[0104] To avoid the influence of previous grayscale values, before obtaining the uniform driving voltage and the grayscale data of each pixel unit corresponding to the RGB pixel data of the image to be displayed, the following steps are also included:

[0105] A preset voltage is applied to the driving transistors connected to all pixel units and transmitted to the cholesteric liquid crystal in each pixel unit so that each pixel unit presents a dark state;

[0106] Once all pixel units are detected to be in a black state, the voltage will be reduced from a preset voltage to 0V within a preset time so that all pixel units are in a bright state.

[0107] The preset time is not limited, such as 1ms. To enable those skilled in the art to better understand this process, the following description continues with reference to the accompanying drawings and specific embodiments.Figure 5 This is a timing diagram of grayscale for a frame-driven portion provided in an embodiment of the present invention. Figure 5 In this process, the total frame rate is 16 frames per second, achieving 16 grayscale levels. First, the entire screen is refreshed to brighten (i.e., the screen is reset, changing from H state (black state) to P state (bright state). Specifically, a large voltage (e.g., 40V) is applied to all pixel units, causing them to become H state (black state), and then the voltage is reduced to 0V within 1ms (becoming P state). Then, pixel blackening begins, following... Figure 5 The timing sequence shown (taking 16 grayscale as an example) will output 16 sets of positive and negative voltages of about 20V during the scanning phase (it can output one set of positive and negative voltages, or separate positive and negative voltages for each frame); the highest grayscale 255 (i.e., L255) will not have any high voltage output and will remain in a bright state during the 16 sets of grayscale timing; grayscale 223 (i.e., L223) will output 3 sets of voltages; the lower the grayscale, the more sets of voltages will be output, and at the lowest grayscale 0 (i.e., L0), all 16 sets will output grayscale voltages.

[0108] In the method provided in this embodiment, by applying the same brushing voltage (i.e., uniform driving voltage) at different times to achieve the effect of rapid grayscale brushing, the active cholesteric liquid crystal screen can achieve the effect of rapid grayscale brushing by applying the same brushing voltage at different times according to the driving timing corresponding to each grayscale to be realized.

[0109] In some embodiments, after each pixel unit presents its corresponding grayscale display, the method further includes:

[0110] The actual reflectance of each pixel unit is measured using a spectrometer.

[0111] Substitute each actual reflectance into the pre-calibrated gray-gamma curve to determine the actual gray value presented by each pixel unit;

[0112] The actual grayscale value of each pixel unit is compared with the grayscale data to be displayed.

[0113] If the comparison result is detected to be within the preset range, it is determined that the pixel unit has been displayed according to the grayscale data to be displayed;

[0114] If the comparison result is detected to be outside the preset range, a prompt message is output to indicate that there is a deviation in the grayscale display of the pixel unit whose comparison result is outside the preset range.

[0115] In the method provided in this embodiment, after each pixel unit presents the corresponding grayscale display, the grayscale display effect is verified. If there is a deviation between the actual grayscale value and the grayscale data to be displayed, a prompt is given, so that the user can intuitively understand the grayscale display effect.

[0116] In the above embodiments, the cholesteric liquid crystal multi-grayscale display method has been described in detail. This invention also provides embodiments of a cholesteric liquid crystal multi-grayscale display system and a cholesteric liquid crystal display device. It should be noted that this invention describes the device portion of the embodiments from two perspectives: one based on functional modules, and the other based on hardware.

[0117] The cholesteric phase liquid crystal multi-grayscale display system provided in this embodiment of the invention, based on the functional modules, includes:

[0118] The acquisition module is used to acquire the unified driving voltage and the grayscale data of each pixel unit corresponding to the RGB pixel data of the image to be displayed;

[0119] The determination module is used to determine the target applied voltage duration corresponding to the grayscale data of each pixel unit based on the pre-established mapping relationship between grayscale data and applied voltage duration; wherein, there is a negative correlation between grayscale data and applied voltage duration.

[0120] The voltage application module is used to apply a uniform driving voltage to the driving transistor connected to the corresponding pixel unit according to the target application voltage duration, and transmit it to the cholesteric liquid crystal in each pixel unit;

[0121] The control and display module is used to control the molecular arrangement state of cholesteric liquid crystal in the pixel unit based on a uniform driving voltage that is applied to the target for a certain duration, so that each pixel unit can present the corresponding grayscale display.

[0122] Since the embodiments of the apparatus and the embodiments of the method correspond to each other, please refer to the description of the embodiments of the method for the embodiments of the apparatus, which will not be repeated here.

[0123] Figure 6 This is a structural diagram of a cholesteric phase liquid crystal display device provided in an embodiment of the present invention. This embodiment is based on a hardware perspective, such as... Figure 6 As shown, the cholesteric liquid crystal display device includes:

[0124] Memory 20 is used to store computer programs;

[0125] The processor 21 is used to execute a computer program to implement the steps of the cholesteric liquid crystal multi-grayscale display method mentioned in the above embodiments.

[0126] The processor 21 may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor 21 may be implemented using at least one of the following hardware forms: Digital Signal Processor (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor, also known as the Central Processing Unit (CPU), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 21 may integrate a Graphics Processing Unit (GPU), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor 21 may also include an Artificial Intelligence (AI) processor, which handles computational operations related to machine learning.

[0127] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In this embodiment, the memory 20 is used to store at least the following computer program 201, which, after being loaded and executed by the processor 21, is capable of implementing the relevant steps of the cholesteric liquid crystal multi-grayscale display method disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202 and data 203, and the storage method may be temporary or permanent storage. The operating system 202 may include Windows, Unix, Linux, etc. The data 203 may include, but is not limited to, the data involved in the cholesteric liquid crystal multi-grayscale display method mentioned above.

[0128] In some embodiments, the cholesteric liquid crystal display device may further include a display screen 22, an input / output interface 23, a communication interface 24, a power supply 25, and a communication bus 26.

[0129] Those skilled in the art will understand that Figure 6 The structure shown does not constitute a limitation on the cholesteric liquid crystal display device and may include more or fewer components than shown.

[0130] The cholesteric liquid crystal display device provided in this embodiment of the invention includes a memory and a processor. When the processor executes the program stored in the memory, it can implement the following method: a cholesteric liquid crystal multi-grayscale display method, with the same effect as above.

[0131] Finally, the present invention also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, performs the steps described in the above method embodiments.

[0132] It is understood that if the methods in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0133] The computer-readable storage medium provided by this invention includes the above-mentioned cholesteric liquid crystal multi-grayscale display method, with the same effect.

[0134] The cholesteric liquid crystal multi-grayscale display method and cholesteric liquid crystal display device provided by the present invention have been described in detail above. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the invention, and these improvements and modifications also fall within the protection scope of the present invention.

[0135] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for displaying multiple grayscale levels of cholesteric liquid crystal, characterized in that, An application is made in a cholesteric liquid crystal display device, the cholesteric liquid crystal display device including a pixel driving unit and a pixel unit, the pixel driving unit including a driving transistor and a capacitor; a first terminal of the driving transistor is used to receive a gating signal, a second terminal is connected to a power supply, a third terminal is connected to the first terminal of the capacitor and the first terminal of the pixel unit, and the second terminal of the capacitor is connected to the second terminal of the pixel unit, the method comprising: Obtain the uniform driving voltage and the grayscale data of each pixel unit corresponding to the RGB pixel data of the image to be displayed; Based on the pre-established mapping relationship between grayscale data and applied voltage duration, the target applied voltage duration corresponding to the grayscale data of each pixel unit is determined; wherein, there is a negative correlation between grayscale data and applied voltage duration. The uniform driving voltage is applied to the driving transistor connected to the corresponding pixel unit according to the target applied voltage duration, and transmitted to the cholesteric liquid crystal in each pixel unit; Based on a uniform driving voltage applied for a specific duration to the target, the molecular arrangement of cholesteric liquid crystals within a pixel unit is controlled so that each pixel unit can display the corresponding grayscale.

2. The cholesteric liquid crystal multi-grayscale display method according to claim 1, characterized in that, Before applying the uniform driving voltage to the driving transistor according to the target applied voltage duration, the method further includes: The number of gray levels to be implemented is determined based on the gray level data; Obtain the correspondence between the preset number of frames and the number of gray levels achieved by the number of frames; The number of frames corresponding to the number of gray levels to be implemented is determined based on the correspondence. Obtain the frame period, and determine the target frame number corresponding to the applied voltage for each pixel unit based on the frame period and the duration of the applied voltage to the target; The duration corresponding to the target frame number is taken as the duration for which the voltage is applied to the target.

3. The cholesteric liquid crystal multi-grayscale display method according to claim 2, characterized in that, The unified driving voltage adopts a bipolar symmetrical configuration.

4. The cholesteric liquid crystal multi-grayscale display method according to claim 3, characterized in that, Obtaining the unified driving voltage includes: The relationship between voltage, reflectivity, and time for cholesteric liquid crystals was obtained. The reflectance threshold range of the cholesteric liquid crystal display device is determined based on the aforementioned relationship; A first voltage is selected and applied to the cholesteric liquid crystal, and the first reflectance range of the cholesteric liquid crystal after the first voltage is applied for a preset duration is obtained; If it is detected that the first reflectivity range does not cover the reflectivity threshold range, the uncovered reflectivity range is determined based on the reflectivity threshold range and the first reflectivity range; A second voltage is selected and applied to the cholesteric liquid crystal, and a second reflectance range of the cholesteric liquid crystal after applying the second voltage for a preset duration is obtained; if it is detected that the second reflectance range covers the uncovered reflectance range, both the first voltage and the second voltage are used as the unified driving voltage; The step of applying the uniform driving voltage to the driving transistor connected to the corresponding pixel unit according to the target applied voltage duration includes: The first voltage is applied to the driving transistor connected to the corresponding pixel unit in the first pixel unit group according to the target voltage application duration; wherein, the first pixel unit group consists of pixel units whose grayscale data is within the grayscale range corresponding to the first reflectivity range; The second voltage is applied to the driving transistor connected to the corresponding pixel unit in the second pixel unit group according to the target voltage application duration; wherein, the second pixel unit group consists of pixel units whose grayscale data are within the grayscale range corresponding to the uncovered reflectivity range.

5. The cholesteric liquid crystal multi-grayscale display method according to claim 4, characterized in that, After adjusting the molecular arrangement state of cholesteric liquid crystal within a pixel unit using a uniform driving voltage based on the duration of the applied voltage to the target, so that each pixel unit presents a corresponding grayscale display, the method further includes: Obtain the total duration corresponding to the number of frames corresponding to the number of gray levels to be implemented; Obtain the time difference between the total duration and the duration of the applied voltage to the target. The remaining frames are determined based on the time difference; Starting from the time the uniform driving voltage is applied to the driving transistor connected to the corresponding pixel unit, the voltage application to the driving transistor stops after the target applied voltage duration. In the remaining frames, the voltage of the corresponding pixel unit is maintained by a capacitor connected to the driving transistor, so that the pixel unit maintains the current grayscale display state in the remaining frames; wherein, the current grayscale display state is the grayscale display state presented by the pixel unit after a uniform driving voltage of the target applied voltage duration is applied to the pixel unit by the driving transistor.

6. The cholesteric liquid crystal multi-grayscale display method according to claim 2, characterized in that, After using the duration corresponding to the target frame number as the target voltage application duration, the method further includes: The driving timing sequence for each gray level to be implemented is determined based on the number of frames corresponding to the number of gray levels to be implemented and the target number of frames. In each gray level driving timing sequence, gray level display is achieved within the target number of frames using a uniform driving voltage applied to the driving transistor. Within the remaining number of frames, the driving transistor is in a state without applied voltage, and gray level display is maintained using a capacitor connected to the driving transistor. The remaining number of frames is the difference between the number of frames corresponding to the number of gray levels to be implemented and the target number of frames. The uniform driving voltage is applied to the corresponding pixel unit according to the driving timing of each gray level to be implemented, so that each pixel unit presents the corresponding gray level display.

7. The cholesteric liquid crystal multi-grayscale display method according to any one of claims 1 to 6, characterized in that, Before acquiring the uniform driving voltage and the grayscale data of each pixel unit corresponding to the RGB pixel data of the image to be displayed, the process also includes: A preset voltage is applied to the driving transistors connected to all pixel units and transmitted to the cholesteric liquid crystal in each pixel unit so that each pixel unit presents a dark state; Once all pixel units are detected to be in a black state, the voltage is reduced from the preset voltage to 0V within a preset time period so that all pixel units are in a bright state.

8. The cholesteric liquid crystal multi-grayscale display method according to any one of claims 1 to 6, characterized in that, After each pixel unit displays its corresponding grayscale, the process also includes: The actual reflectance of each pixel unit is measured using a spectrometer. Substitute the actual reflectance of each pixel into the pre-calibrated gray-gamma curve to determine the actual gray value of each pixel unit. The actual grayscale value of each pixel unit is compared with the grayscale data to be displayed. If the comparison result is detected to be within a preset range, it is determined that the pixel unit has been displayed according to the grayscale data to be displayed; If the comparison result is detected to be outside the preset range, a prompt message is output to indicate that there is a deviation in the grayscale display of the pixel unit whose comparison result is outside the preset range.

9. A cholesteric liquid crystal display device, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the cholesteric liquid crystal multi-grayscale display method as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the cholesteric liquid crystal multi-grayscale display method as described in any one of claims 1 to 8.

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