Display driving method, display driver and display device

Abstract

This invention discloses a display driving method, a display driver, and a display device. The display driving method includes: determining a touch area of ​​a bistable liquid crystal display panel; determining a refresh area and a non-refresh area based on the touch area; wherein the refresh area includes the touch area, and the non-refresh area is connected to the refresh area; in a first refresh stage, providing a sustaining voltage to a common electrode of the bistable liquid crystal display panel, providing the sustaining voltage to pixel electrodes of the bistable liquid crystal display panel in the non-refresh area; and providing a refresh voltage to the pixel electrodes of the refresh area to restore the current image in the refresh area to the original image. Embodiments of this invention can reduce power consumption during the process of eliminating touch traces.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a display driving method, a display driver, and a display device. Background Technology

[0002] Bistable liquid crystal display panels can still display images normally after power is cut off, have extremely low power consumption, and have important applications in the display field.

[0003] Due to the characteristics of the liquid crystals inside bistable liquid crystal displays, touch marks are left on the display panel after being touched or pressed. These marks cannot be automatically erased, affecting the display effect. Related technologies require power-on refresh of the entire screen to remove the touch marks, and refreshing the entire screen requires a large voltage, resulting in high power consumption for bistable liquid crystal displays. Summary of the Invention

[0004] The present invention provides a display driving method, a display driver, and a display device to reduce power consumption during the process of eliminating touch traces.

[0005] According to one aspect of the present invention, a display driving method is provided for driving a bistable liquid crystal display panel, the display driving method comprising: Determine the touch area of ​​the bistable liquid crystal display panel; A refresh area and a non-refresh area are determined based on the touch area; wherein the refresh area includes the touch area, and the non-refresh area is adjacent to the refresh area; In the first refresh phase, a sustaining voltage is provided to the common electrode of the bistable liquid crystal display panel, and the sustaining voltage is also provided to the pixel electrodes of the bistable liquid crystal display panel in the non-refresh area; a refresh voltage is provided to the pixel electrodes in the refresh area to restore the current image in the refresh area to the original image.

[0006] Optionally, providing a refresh voltage to the pixel electrode in the refresh area includes: Provide a focal cone state pulse control voltage to the pixel electrode in the refresh area that corresponds to the original image in a focal cone state; The sustaining voltage is provided to the pixel electrodes in the refresh area that correspond to the original image in a planar state.

[0007] Optionally, providing a focal-cone pulse control voltage to the pixel electrode in the refresh area that corresponds to the original image in a focal-cone state includes: In the first sub-stage, a first voltage is provided to the pixel electrode; In the second sub-stage, a second voltage is provided to the pixel electrode; the second voltage has the same absolute value as the first voltage, but the voltage polarity is opposite. In the third sub-stage, the sustaining voltage is provided to the pixel electrode.

[0008] Optionally, prior to the first refresh phase, the display driving method further includes: Only the display data corresponding to the original screen of the refreshed area is obtained.

[0009] Optionally, the display driving method further includes: If it is not determined that there is no touch area on the bistable liquid crystal display panel, the current screen of the bistable liquid crystal display panel is refreshed in the second refresh stage; wherein the number of frames in the second refresh stage is greater than the number of frames in the first refresh stage.

[0010] Optionally, the second refresh phase includes a first sub-refresh phase and a second sub-refresh phase; In the second refresh phase, refreshing the current screen of the bistable liquid crystal display panel includes: During the first sub-refresh phase, planar pulse control voltages are provided to all pixel electrodes; During the second sub-refresh stage, a sustaining voltage is provided to the pixel electrode of the corresponding planar state, and a focal conic state pulse control voltage is provided to the pixel electrode of the corresponding focal conic state. The number of frames in the first refresh phase is the same as the number of frames in the second sub-refresh phase.

[0011] Optionally, determining the refresh area and non-refresh area based on the touch area includes: The boundary contour of the touch area is extended by a predetermined distance in a direction away from the center of the touch area to form an extended contour; The area enclosed by the extended contour is defined as the refresh area; the area outside the refresh area in the bistable liquid crystal display panel is defined as the non-refresh area.

[0012] According to another aspect of the present invention, a display driver is provided, the display driver being used to perform the display driving method as described above, the display driver comprising: A touch determination module is used to determine the touch area of ​​the bistable liquid crystal display panel; The region segmentation module is used to determine the refresh region and non-refresh region based on the touch region; The control module is configured to provide a sustaining voltage to the common electrode of the bistable liquid crystal display panel during the first refresh phase, provide the sustaining voltage to the pixel electrode of the bistable liquid crystal display panel in the non-refresh area, and provide a refresh voltage to the pixel electrode in the refresh area, so as to restore the current image in the refresh area to the original image.

[0013] Optionally, the control module is further configured to refresh the current screen of the bistable liquid crystal display panel in the second refresh stage if it is determined that there is no touch area on the bistable liquid crystal display panel; wherein the number of frames in the second refresh stage is greater than the number of frames in the first refresh stage.

[0014] According to another aspect of the present invention, a display device is provided, the display device comprising a display driver and a bistable liquid crystal display panel as described above; the display driver is used to drive the bistable liquid crystal display panel.

[0015] The technical solution of this invention employs a display driving method comprising: determining a touch area of ​​a bistable liquid crystal display panel; determining a refresh area and a non-refresh area based on the touch area; wherein the refresh area includes the touch area, and the non-refresh area is connected to the refresh area; in a first refresh stage, providing a sustaining voltage to the common electrode of the bistable liquid crystal display panel, providing a sustaining voltage to the pixel electrodes of the bistable liquid crystal display panel in the non-refresh area; and providing a refresh voltage to the pixel electrodes of the refresh area to restore the current image in the refresh area to the original image. By refreshing only the refresh area and not refreshing the non-refresh area, touch traces can be eliminated with lower power consumption. Furthermore, by applying sustaining voltages to both the pixel electrodes and the common electrode in the non-refresh area, a charge discharge path is provided for the bistable liquid crystal molecules in the non-refresh area, thereby avoiding the problem of display state changes and improving the display effect.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart of a display driving method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a bistable liquid crystal display panel provided in an embodiment of the present invention; Figure 3 A schematic diagram illustrating the principle of three-state transformation of cholesterol liquid crystal molecules provided in an embodiment of the present invention; Figure 4 A timing diagram of a first refresh stage provided in an embodiment of the present invention; Figure 5 A timing diagram of a second refresh stage provided in an embodiment of the present invention; Figure 6 This is a schematic diagram illustrating the positions of the refreshed area and the non-refreshed area provided in an embodiment of the present invention; Figure 7 A schematic diagram of the structure of a display driver provided in an embodiment of the present invention; Figure 8 A flowchart illustrating yet another display driving method provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of a display device provided in an embodiment of the present invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] Figure 1 This is a flowchart of a display driving method provided in an embodiment of the present invention. The display driving method is used to drive a bistable liquid crystal display panel and can be executed by a controller. (Refer to...) Figure 1 The display driver methods include: Step S110: Determine the touch area of ​​the bistable liquid crystal display panel; Specifically, Figure 2 This is a schematic diagram of the structure of a bistable liquid crystal display panel provided in an embodiment of the present invention, with reference to... Figure 2First, a brief introduction to the structure of the bistable liquid crystal display panel: The bistable liquid crystal display panel includes a first substrate 210 and a second substrate 220 disposed opposite to each other. A pixel electrode layer 230 is disposed on the side of the first substrate 210 closest to the second substrate 220, and a common electrode layer 240 is disposed on the side of the second substrate 220 closest to the first substrate 210. A liquid crystal layer 260 is disposed between the pixel electrode layer 230 and the common electrode layer 240. The pixel electrode layer 230 contains multiple pixel electrodes, each corresponding to one pixel. When driving the bistable liquid crystal display panel to display, by applying a common voltage to the common electrode layer 240 and applying corresponding data voltages to different pixel electrodes, the bistable liquid crystal display panel can achieve display.

[0022] The liquid crystal layer is a bistable liquid crystal, such as cholesteric liquid crystal molecules. Cholesteric liquid crystal molecules have three textures: P-state (planar texture, reflective state), FC-state (focal conic), and H-state (transparent state). Both the FC and H states are transparent. In the P-state, the reflection spectrum of cholesteric liquid crystal molecules is in the visible spectrum, reflecting bright colored light. The specific color of the reflected light can be set according to the pitch of the cholesteric liquid crystal. Under a certain electric field, these three states can interconvert. The P-state and FC-state are stable textures and do not require voltage to maintain, while the H-state requires voltage to maintain.

[0023] In detail, such as Figure 3 As shown, Figure 3This is a schematic diagram illustrating the principle of three state transitions of cholesteric liquid crystal molecules according to an embodiment of the present invention. A common voltage is applied to the common electrode layer 240, and a pixel voltage is applied to the pixel electrode layer 230. When there is a voltage difference of 20V between the pixel voltage and the common voltage, the cholesteric liquid crystal molecules are under a strong vertical electric field, causing them to rotate and remain stationary in the H state. If the pixel voltage is slowly reduced to the same level as the common voltage, a strong vertical electric field initially exists between the common electrode layer 240 and the pixel electrode layer 230, and then the vertical electric field slowly disappears, causing the cholesteric liquid crystal molecules to rotate and be in the FC state, which is a scattering state and has a light-scattering effect. When the voltage difference between the pixel voltage and the common voltage is approximately 30V, and the pixel voltage rapidly decreases to the same level as the common voltage, a strong vertical electric field is initially formed between the pixel electrode layer 230 and the common electrode layer 240. Then the vertical electric field rapidly disappears, causing the cholesteric liquid crystal molecules to rotate and be in the P state. The different arrangement directions of the cholesteric liquid crystal molecules result in different reflected visible light spectra, while the remaining spectrum is transmitted. The reflection spectral band (Δλ) of cholesteric liquid crystal molecules is proportional to the pitch (Po) and birefringence (Δn) of the cholesteric liquid crystal molecules, with the formula: Δλ = PoΔn; the reflection spectral wavelength (λ) of cholesteric liquid crystal molecules is proportional to the pitch (Po) and average birefringence (n) of the cholesteric liquid crystal molecules, with the formula: λ = nPo. Therefore, cholesteric liquid crystal molecules with different pitches can reflect different colors of light in the reflective state. Preferably, the thickness of the liquid crystal layer is set to an integer multiple of the pitch (Po) of the cholesteric liquid crystal molecules.

[0024] Bistable liquid crystal displays (LCDs) can be used in applications such as outdoor billboards and smart tags. In these applications, LCDs need to display the same content for extended periods, i.e., static images, without frequent refreshes. LCDs can maintain their displayed content even after power is off, resulting in extremely low power consumption. However, when touched or pressed, the FC (focal-joint) state of the bistable liquid crystal molecules changes to the P (phasic-state), and the P state cannot recover on its own, leaving touch marks on the LCD panel.

[0025] In this embodiment, the touch area of ​​the bistable liquid crystal display panel can be detected by the touch chip; that is, the touch area can be determined by the touch chip through touch control of the touch electrode layer 250. The controller can obtain the specific location of the touch area from the touch chip. FC-state bistable liquid crystal molecules in the touch area are pressed into the P-state.

[0026] Step S120: Determine the refresh area and non-refresh area based on the touch area; wherein, the refresh area includes the touch area, and the non-refresh area is adjacent to the refresh area. Specifically, the refresh area includes at least the touch area determined in step S110. In the refresh area, bistable liquid crystal molecules that were originally in the FC state change to the P state due to pressing, while bistable liquid crystal molecules that were originally in the P state remain in the P state. The non-refresh area is the area in the bistable liquid crystal display panel other than the refresh area. The bistable liquid crystal molecules in the non-refresh area are not pressed, so the bistable liquid crystal molecules that were originally in the FC state in the non-refresh area remain in the FC state, and the bistable liquid crystal molecules that were originally in the P state in the non-refresh area remain in the P state. In other words, for the original image before the touch action, the image formed after the touch action does not change in the non-refresh area, but changes in the refresh area. Therefore, it is only necessary to restore the image in the refresh area to the original image.

[0027] In step S130, during the first refresh phase, a sustaining voltage is provided to the common electrode of the bistable liquid crystal display panel, a sustaining voltage is provided to the pixel electrode of the bistable liquid crystal display panel in the non-refresh area, and a refresh voltage is provided to the pixel electrode of the refresh area to restore the current image in the refresh area to the original image.

[0028] Specifically, the first refresh stage corresponds to the situation where the current image needs to be restored to the original image, that is, an unwanted touch action has occurred on the bistable liquid crystal display panel. The image on the bistable liquid crystal display panel should not change, but a touch action has created a touch mark. The first refresh stage is used to eliminate this touch mark, thereby restoring the original image. The common electrode of the bistable liquid crystal display panel, also known as the common electrode layer, uses a sustaining voltage to maintain the current state of the bistable liquid crystal molecules; that is, if the original state is P, it remains P; if the original state is FC, it remains FC. After determining the refresh area and the non-refresh area, the controller generates corresponding instructions. Under the control of the corresponding instructions, for the non-refresh area, both the pixel electrode and the common electrode are subjected to sustaining voltages, so the voltage difference across the bistable liquid crystal molecules in the non-refresh area is 0, and the state of the bistable liquid crystal molecules remains unchanged. For the refresh area, the common electrode is also subjected to a sustaining voltage, but the pixel electrode is subjected to the corresponding refresh voltage, thus restoring only the image in the refresh area. In this embodiment, since only the refreshed area is refreshed and the non-refreshed area is not refreshed, a large voltage does not need to be supplied to the bistable liquid crystal display panel during the first refresh stage, thus reducing power consumption. Furthermore, for the non-refreshed area, the same voltage is applied to both ends of the bistable liquid crystal molecules, rather than applying voltage to only one electrode. This provides a discharge path for the charge accumulated on the bistable liquid crystal molecules, thereby avoiding the problem of charge accumulation due to prolonged display or other reasons causing changes in the display state, ensuring that the bistable liquid crystal display panel has a better display effect.

[0029] The technical solution of this embodiment employs a display driving method including: determining the touch area of ​​a bistable liquid crystal display panel; determining a refresh area and a non-refresh area based on the touch area; wherein the refresh area includes the touch area, and the non-refresh area is connected to the refresh area; in a first refresh stage, providing a sustaining voltage to the common electrode of the bistable liquid crystal display panel, providing a sustaining voltage to the pixel electrodes of the bistable liquid crystal display panel in the non-refresh area; and providing a refresh voltage to the pixel electrodes of the refresh area to restore the current image in the refresh area to the original image. By refreshing only the refresh area and not refreshing the non-refresh area, touch traces can be eliminated with lower power consumption. Furthermore, by applying sustaining voltages to both the pixel electrodes and the common electrode in the non-refresh area, a charge discharge path is provided for the bistable liquid crystal molecules in the non-refresh area, thereby avoiding the problem of display state changes and improving the display effect.

[0030] Optionally, in some embodiments, before determining the refresh area and non-refresh area based on the touch area, the display driving method further includes: if a new touch area is determined within a preset time after the touch area is determined; then determining the refresh area and non-refresh area based on the touch area includes: determining the refresh area and non-refresh area based on all touch areas. That is, after a touch action occurs, the refresh area is not determined immediately; instead, a common refresh area is determined after a series of touches within a short period. During continuous touches within a short period, multiple refreshes are unnecessary, thereby further reducing the power consumption of the bistable liquid crystal display panel. For example, the preset time can be 2 seconds, 3 seconds, or 4 seconds, etc.

[0031] Further optionally, in some embodiments, if there are multiple refresh areas, the refresh area located at the center of the bistable liquid crystal display panel can be refreshed first, followed by the refresh areas located at the edge of the bistable liquid crystal display panel.

[0032] Optionally, in some implementations, determining the refresh area and non-refresh area based on the touch area includes: if the proportion of pixels in the original image that are in a focal cone state in the touch area is less than a preset value, then the touch area is determined to be a non-refresh area.

[0033] Specifically, in this embodiment, a touch area is a complete region whose outer contour is a closed shape. After determining the touch area, the original image corresponding to the touch area is first detected. If the proportion of pixels originally in a focal cone state is less than a preset value, it indicates that fewer cholesteric liquid crystal molecules change state after being pressed, and this touch area can be classified as a non-refresh area. This reduces the size of the refresh area, thereby reducing power consumption, without affecting the overall display effect. The preset value can be 5%, 6%, 7%, 8%, 9%, or 10%, etc.

[0034] Optionally, such as Figure 2 As shown, in some embodiments, the touch electrode layer 250 is located between the first substrate 210 and the second substrate 220, in which case the bistable liquid crystal display panel is an in-cell touch architecture. Of course, in other embodiments, the bistable liquid crystal display panel can also be an on-cell touch architecture. The bistable liquid crystal display panel can be a self-capacitive touch panel or a mutual-capacitive touch panel, etc. The corresponding touch electrode layer 250 can be a single layer or a double layer. This embodiment does not limit the specific implementation of the touch, and the specific principle of the touch is well known to those skilled in the art and will not be described in detail here.

[0035] Optionally, in some implementations, the sustaining voltage can be a ground voltage. That is, during the first refresh phase, the common electrode controlling the bistable liquid crystal display panel and the pixel electrodes in the non-refreshing areas are both grounded, which can result in lower power consumption.

[0036] Optionally, providing a refresh voltage to the pixel electrodes in the refresh area includes: Provide a focal cone state pulse control voltage to the pixel electrode in the refresh area that is in the original focal cone state, i.e., the FC state; A sustaining voltage is provided to the pixel electrode in the refresh area that corresponds to the original image in a planar state, i.e., a P state.

[0037] Specifically, in this embodiment, the original state corresponding to the pixel electrode refers to the original state of the bistable liquid crystal molecule corresponding to the pixel electrode. That is, the pixel electrode corresponding to the original state of focal conic state refers to the pixel electrode corresponding to the bistable liquid crystal molecule in the original state of focal conic state; the pixel electrode corresponding to the original state of planar state refers to the pixel electrode corresponding to the bistable liquid crystal molecule in the original state of planar state. Figure 3 As shown, Figure 3This is a timing diagram of a first refresh stage provided in an embodiment of the present invention. The voltage applied to the common electrode is defined as the common voltage ACVCOM; the voltage applied to the pixel electrode corresponding to the bistable liquid crystal molecule desired to be in a focal conic state is defined as the first control voltage Source-FC, which is a focal conic state pulse control voltage; the voltage applied to the pixel electrode corresponding to the bistable liquid crystal molecule desired to be in a planar state is defined as the second control voltage Source-P. In this embodiment, the common voltage ACVCOM is a sustaining voltage, i.e., grounded. The first control voltage Source-FC is a pulse voltage. In this embodiment, the second control voltage Source-P is a sustaining voltage, i.e., grounded. In summary, this embodiment only requires providing a pulse voltage to the pixel electrode in the refresh region where the bistable liquid crystal molecule's initial state is FC, while the other pixel electrodes of the entire bistable liquid crystal display panel and the common electrode are all grounded. Therefore, fewer pixel electrodes require pulse voltage, significantly reducing power consumption.

[0038] For example, continue to refer to Figure 2 Providing a focal-cone pulse control voltage to the pixel electrode in the refresh area that corresponds to the original image in a focal-cone state includes: In the first sub-stage T11, a first voltage is provided to the pixel electrode; In the second sub-stage T12, a second voltage is provided to the pixel electrode; the absolute value of the second voltage is equal to that of the first voltage, but the voltage polarity is opposite. In the third sub-stage T13, a sustaining voltage is provided to the pixel electrode.

[0039] Specifically, the first refresh stage T1 includes a first sub-stage T11, a second sub-stage T12, and a third sub-stage T13 performed sequentially. Neither the first voltage nor the second voltage is zero; if one is positive, the other is negative. For example, in the first sub-stage T11, a first voltage, such as -15V, is provided to the pixel electrode; in the second sub-stage T12, a second voltage, such as +15V, is provided to the pixel electrode; and in the third sub-stage T13, a sustaining voltage, i.e., grounding, is provided to the pixel electrode. The setting of the focal cone pulse control voltage in this embodiment ensures that the bistable liquid crystal molecules that have changed to the P-state due to touch pressure can be restored to the FC-state.

[0040] Optionally, prior to the first refresh phase, the display driving method further includes: acquiring only the display data corresponding to the original screen of the refresh area.

[0041] Specifically, the display data corresponding to the original image includes display data for all pixels, resulting in a large data volume. In this embodiment, since only the refresh area needs to be refreshed, and the non-refresh area does not need to be refreshed, only the display data corresponding to the pixels in the refresh area needs to be acquired; however, it is not necessary to acquire the display data corresponding to the pixels in the non-refresh area. Therefore, the display data reading time can be greatly shortened, thereby shortening the refresh time.

[0042] Optionally, in some embodiments, the display data corresponding to the original image can be stored in a second memory, and can be stored in bin format. In some embodiments, the second memory can be divided into multiple storage blocks, with each storage block storing display data corresponding to a portion of the original image. For example, the original image can be divided into multiple sub-regions, and the display data corresponding to each sub-region can be stored in one storage block. With this configuration, when subsequently reading the display data corresponding to the refresh area, it can be directly read from the corresponding storage block, thereby further shortening the display data reading time and thus shortening the refresh time.

[0043] Optionally, the display driving method further includes: If it is determined that there is no touch area on the bistable liquid crystal display panel, the current screen of the bistable liquid crystal display panel is refreshed in the second refresh stage; wherein the number of frames in the second refresh stage is greater than the number of frames in the first refresh stage.

[0044] Specifically, the second refresh stage corresponds to scenarios requiring a complete refresh of the displayed image, such as when a new display image needs to be shown, or when the current display image has been displayed for too long and needs to be updated. It can detect touch actions on the LCD panel in real time. When a touch action occurs, it enters the first refresh stage. When no touch action occurs, it can enter the second refresh stage at a set time or based on image update control. In the second refresh stage, all bistable liquid crystal molecules need to be adjusted to the P-state first, and then different bistable liquid crystal molecules are selected to be in the P-state or FC-state according to the needs of the image. Therefore, the second refresh stage requires more frames for a complete refresh. In contrast, in the first refresh stage, since only the refresh area is updated, the bistable liquid crystal molecules in the refresh area are already in the P-state after being pressed. Therefore, the P-state bistable liquid crystal molecules can be directly selected to be in the FC-state or P-state, meaning the first refresh stage requires fewer frames, thus greatly improving the speed of eliminating touch traces and enhancing the display effect.

[0045] Optionally, Figure 5 A timing diagram for a second refresh stage provided in an embodiment of the present invention, with reference to... Figure 5 The second refresh phase includes a first sub-refresh phase T21 and a second sub-refresh phase T22. During the second refresh phase, the current image of the bistable liquid crystal display panel is refreshed, including: In the first sub-refresh stage T21, planar pulse control voltage is provided to all pixel electrodes; in the second sub-refresh stage T22, sustaining voltage is provided to the corresponding plateau state pixel electrodes, and focal cone state pulse control voltage is provided to the corresponding focal cone state pixel electrodes; wherein, the number of frames in the first refresh stage is the same as the number of frames in the second sub-refresh stage.

[0046] Specifically, the first sub-refresh stage T21 corresponds to the stage where all bistable liquid crystal molecules in the bistable liquid crystal display panel are adjusted to the P state. In this stage, a strong voltage is first applied to the bistable liquid crystal molecules, then the voltage is immediately reversed, and subsequently, the voltage across the bistable liquid crystal molecules is set to 0. The first sub-refresh stage T21 includes the sequentially performed fourth sub-stage T211, fifth sub-stage T212, and sixth sub-stage T213. In the fourth sub-stage T211, the common voltage ACVCOM can be +25V, while the voltage applied to each pixel electrode can be -15V. The bistable liquid crystal molecules are driven by a strong electric field, causing all bistable liquid crystal molecules to enter an ordered and unified state. In the fifth sub-stage T212, the common voltage ACVCOM can be -25V, while the voltage applied to each pixel electrode can be +15V, achieving DC balance. In the sixth sub-stage T213, both the common voltage ACVCOM and the voltage on the pixel electrodes are grounded, at which point each bistable liquid crystal molecule automatically evolves to the P state.

[0047] The second sub-refresh stage T22 corresponds to the stage where each bistable liquid crystal molecule selects to enter the P state or FC state. It includes the sequentially performed seventh sub-stage T221, eighth sub-stage T222, and ninth sub-stage T223. The principle of the seventh sub-stage T221 is the same as that of the first sub-stage, the principle of the eighth sub-stage T222 is the same as that of the second sub-stage, and the principle of the ninth sub-stage T223 is the same as that of the third sub-stage, and will not be repeated here. In this embodiment, the number of frames in the seventh sub-stage T221 is the same as that in the first sub-stage, the number of frames in the eighth sub-stage T222 is the same as that in the second sub-stage, and the number of frames in the ninth sub-stage T223 is the same as that in the third sub-stage. That is, compared to the second refresh stage, the first refresh stage eliminates the first sub-refresh stage, thus reducing the number of frames in the first refresh stage and allowing for partial reuse of timing, reducing the difficulty of display control.

[0048] Optionally, the number of frames in the first refresh sub-stage T21 can be 20 frames, and the number of frames in the second refresh sub-stage T22 can be 30 frames.

[0049] Optionally, determining the refresh area and non-refresh area based on the touch area includes: The boundary contour of the touch area is extended by a preset distance away from the center of the touch area to form an extended contour; the area enclosed by the extended contour is defined as the refresh area; the area outside the refresh area in the bistable liquid crystal display panel is defined as the non-refresh area.

[0050] Specifically, such as Figure 6 As shown, Figure 6 This is a schematic diagram illustrating the positions of a refresh area and a non-refresh area according to an embodiment of the present invention. After obtaining a touch area A1 based on touch detection, the touch area A1 is expanded outward to form a refresh area A2. The preset expansion distance can be a preset number of pixels. The preset distance can be related to the size of the touch area, and is the preset distance corresponding to a certain point on the boundary contour, for example, less than or equal to one-tenth of the distance between that point and the center of the touch area. By expanding the touch area A1 outward, it can be ensured that the refresh area A2 includes all touched positions, that is, to avoid the situation where some areas are touched but not detected and are included in the non-refresh area A3. It should be noted that the touch area A1 can be obtained from the coordinates of the detected touch. There can be one or more touch areas A1. When there are multiple touch areas A1, each touch area A1 has its own corresponding boundary contour, and the refresh areas formed also include multiple areas.

[0051] Based on the same inventive concept, the present invention also provides a display driver, such as... Figure 7 As shown, Figure 7 A schematic diagram of a display driver provided in an embodiment of the present invention. The display driver includes: Touch determination module 31 is used to determine the touch area of ​​the bistable liquid crystal display panel; The region division module 32 is used to determine the refresh region and non-refresh region based on the touch region; The control module 33 is used to provide a sustaining voltage to the common electrode of the bistable liquid crystal display panel, a sustaining voltage to the pixel electrode of the bistable liquid crystal display panel in the non-refresh area, and a refresh voltage to the pixel electrode in the refresh area during the first refresh phase, so as to restore the current image in the refresh area to the original image.

[0052] For details on the working principle of the display driver, please refer to the description of the display driving method section of this invention. The display driver has the same beneficial effects as the display driving method, and will not be repeated here.

[0053] Optionally, the control module is further configured to refresh the current screen of the bistable liquid crystal display panel in the second refresh stage if it is determined that there is no touch area on the bistable liquid crystal display panel; wherein the number of frames in the second refresh stage is greater than the number of frames in the first refresh stage.

[0054] Optionally, such as Figure 8As shown, Figure 8 This is a flowchart of another display driving method provided by an embodiment of the present invention. The display driving method includes: step S210, a touch chip detects a touch area; step S220, a controller determines the touch area of ​​the bistable liquid crystal display panel; that is, the touch chip sends the detected touch area to the controller. Step S230, the controller determines a refresh area and a non-refresh area based on the touch area; step S270, the controller reads the display data of the original image corresponding to the refresh area, and defines the refresh voltage of the pixel electrode according to the timing diagram of the first refresh stage; wherein, before step S270, the display driving method further includes steps S240, S250 and S260. Step S240 is to convert the original image into bin data using software. The bin data is the aforementioned display data. Step S250 is to burn the bin data into a second memory. Step S260 is to store the timing diagram of the first refresh stage in the first memory. The timing diagram of the first refresh stage includes tables for FC state and P state, that is, data that needs to form FC state and data that needs to form P state. After step S270, step S280 is performed on the refresh area, that is, a refresh voltage is provided to the pixel electrodes of the refresh area, and a sustaining voltage is provided to the common electrode; the image in the refresh area is refreshed. After step S270, step S290 is performed on the non-refresh area, that is, a common voltage is provided to the pixel electrodes of the non-refresh area, and a sustaining voltage is provided to the common electrode. The image in the non-refresh area remains unchanged.

[0055] Based on the same inventive concept, the present invention also provides a display device, such as... Figure 9 As shown, Figure 9This is a schematic diagram of a display device provided in an embodiment of the present invention. The display device includes a display driver and a bistable liquid crystal display panel 41. The touch determination module may include a touch chip 42 and a touch electrode layer 250. The area division module and the control module may be integrated into the controller 46. The display device also includes a power module 45, a source driver 43, and a gate driver 44. The power module 45 is used to supply power to the various modules in the display device and provides a common voltage ACVCOM. The touch chip 42 determines the touch area and transmits it to the controller 46. The controller 46 controls the source driver 43 to provide the corresponding refresh voltage or sustain voltage according to the touch area. The controller 46 can also control the gate driver 44 to provide a line scan signal to the bistable liquid crystal display panel, so that the pixel electrodes write signals line by line. The controller may be an MCU (Microcontroller Unit), a CUP (Central Processing Unit), an FPGA (Field-Programmable Gate Array), or a TCON (Timing Controller), etc.

[0056] The display device of the present invention can be applied to outdoor advertising, electronic price tags and other scenarios, and has the same beneficial effects as the display driving method, which will not be described in detail here.

[0057] For example, the following is a brief description of the operation of the display device. When a touch action occurs, the touch chip 42 determines the touch area and sends it to the controller 46. The controller 46 expands the touch area to form a refresh area and determines the non-refresh area based on the refresh area. In the first refresh stage, the ACVCOM outputs a ground voltage. For the non-refresh area, the controller 46 controls the source driver 43 to output a ground voltage. For the refresh area, the controller 46 controls the source driver 43 to output a focal cone pulse control voltage to the bistable liquid crystal molecules in their original FC state, and outputs a ground voltage to the bistable liquid crystal molecules in their original P state. For the non-refresh area, the controller 46 controls the source driver 43 to output a ground voltage. Ultimately, the image corresponding to the bistable liquid crystal molecules in their original FC state in the refresh area is refreshed, while the image corresponding to the bistable liquid crystal molecules in their original P state is not refreshed. The image in the non-refresh area is not refreshed.

[0058] Optionally, in some embodiments, the timing diagram of the first refresh stage can be stored in the first memory of the display device in the form of a table, such as a flash memory. The image displayed by the bistable liquid crystal display panel can be stored in the second memory of the display device, such as a flash memory. The image can also be converted to bin format and burned into the second memory. The controller 46 controls the source driver 43 to output a focal cone state pulse control voltage to the bistable liquid crystal molecules in their original FC state, including: the controller can read the data corresponding to the refresh area from the second memory and define the data output by the source driver, i.e., the focal cone state pulse control voltage, by referring to the table stored in the first memory. Of course, it is understood that the timing diagram corresponding to the second refresh stage can also be stored in the first memory, and the timing diagram of the second sub-refresh stage can be reused as the timing diagram of the first refresh stage, meaning that it is no longer necessary to additionally store the timing diagram of the first refresh stage.

[0059] Optionally, in some implementations, the second memory can be divided into multiple storage blocks, with each storage block storing display data corresponding to a portion of the original screen. For example, the original screen can be divided into multiple sub-regions, with the display data corresponding to each sub-region stored in a storage block. With this configuration, when subsequently reading display data corresponding to the refresh area, it can be directly read from the corresponding storage block, thereby further shortening the display data reading time and reducing the refresh time.

[0060] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0061] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A display driving method, characterized in that, The display driving method for driving a bistable liquid crystal display panel includes: Determine the touch area of ​​the bistable liquid crystal display panel; A refresh area and a non-refresh area are determined based on the touch area; wherein the refresh area includes the touch area, and the non-refresh area is adjacent to the refresh area; In the first refresh phase, a sustaining voltage is provided to the common electrode of the bistable liquid crystal display panel, and the sustaining voltage is also provided to the pixel electrodes of the bistable liquid crystal display panel in the non-refresh area; a refresh voltage is provided to the pixel electrodes in the refresh area to restore the current image in the refresh area to the original image.

2. The display driving method according to claim 1, characterized in that, Providing a refresh voltage to the pixel electrode in the refresh area includes: Provide a focal cone state pulse control voltage to the pixel electrode in the refresh area that corresponds to the original image in a focal cone state; The sustaining voltage is provided to the pixel electrodes in the refresh area that correspond to the original image in a planar state.

3. The display driving method according to claim 2, characterized in that, Providing a focal-cone pulse control voltage to the pixel electrode in the refresh area that corresponds to the original image in a focal-cone state includes: In the first sub-stage, a first voltage is provided to the pixel electrode; In the second sub-stage, a second voltage is provided to the pixel electrode; the second voltage has the same absolute value as the first voltage, but the voltage polarity is opposite. In the third sub-stage, the sustaining voltage is provided to the pixel electrode.

4. The display driving method according to claim 1, characterized in that, Prior to the first refresh phase, the display driving method further includes: Only the display data corresponding to the original screen of the refreshed area is obtained.

5. The display driving method according to claim 1, characterized in that, The display driving method further includes: If it is determined that there is no touch area on the bistable liquid crystal display panel, then in the second refresh stage, the current screen of the bistable liquid crystal display panel is refreshed; wherein, the number of frames in the second refresh stage is greater than the number of frames in the first refresh stage.

6. The display driving method according to claim 5, characterized in that, The second refresh phase includes a first sub-refresh phase and a second sub-refresh phase; In the second refresh phase, refreshing the current screen of the bistable liquid crystal display panel includes: During the first sub-refresh phase, planar pulse control voltages are provided to all pixel electrodes; During the second sub-refresh stage, a sustaining voltage is provided to the pixel electrode of the corresponding planar state, and a focal conic state pulse control voltage is provided to the pixel electrode of the corresponding focal conic state. The number of frames in the first refresh phase is the same as the number of frames in the second sub-refresh phase.

7. The display driving method according to claim 1, characterized in that, Determining the refresh area and non-refresh area based on the touch area includes: The boundary contour of the touch area is extended by a predetermined distance in a direction away from the center of the touch area to form an extended contour; The area enclosed by the extended contour is defined as the refresh area; the area outside the refresh area in the bistable liquid crystal display panel is defined as the non-refresh area.

8. A display driver, characterized in that, The display driver is configured to perform the display driving method according to any one of claims 1-7, the display driver comprising: A touch determination module is used to determine the touch area of ​​the bistable liquid crystal display panel; The region segmentation module is used to determine the refresh region and non-refresh region based on the touch region; The control module is configured to provide a sustaining voltage to the common electrode of the bistable liquid crystal display panel during the first refresh phase, provide the sustaining voltage to the pixel electrode of the bistable liquid crystal display panel in the non-refresh area, and provide a refresh voltage to the pixel electrode in the refresh area, so as to restore the current image in the refresh area to the original image.

9. The display driver according to claim 8, characterized in that, The control module is further configured to refresh the current screen of the bistable liquid crystal display panel in the second refresh stage if it is determined that there is no touch area on the bistable liquid crystal display panel; wherein the number of frames in the second refresh stage is greater than the number of frames in the first refresh stage.

10. A display device, characterized in that, The display device includes the display driver and bistable liquid crystal display panel as described in claim 8 or 9; the display driver is used to drive the bistable liquid crystal display panel.

Images