Display device and driving method thereof

Abstract

The application provides a display device and a driving method thereof. The driving method of the display device comprises the following steps: determining whether a Nth frame display picture reaches a compensation condition according to gray scale information of the Nth frame display picture and gray scale information of an (N-1)th frame display picture; and compensating a driving voltage corresponding to the Nth frame display picture in the case that the Nth frame display picture reaches the compensation condition; wherein the gray scale information comprises a gray scale value and a voltage value corresponding to the gray scale value. By compensating the driving voltage corresponding to the Nth frame display picture, at least the technical problem that a short-time sudden excessive liquid crystal driving force can cause domain error of the liquid crystal, and the liquid crystal deviates from a correct direction, and the improvement effect is poor is solved, so that the dynamic display effect of the display device avoids the liquid crystal deviating from the correct direction caused by the excessive driving voltage on the premise of shortening the response time, and the display effect is effectively improved.

Description

Technical Field

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

[0002] Due to the inherently slow response time of liquid crystals, LCD monitors often exhibit motion blur or trailing when displaying dynamic images. Overdriving (OD) technology can be used to improve response time, thereby enhancing the display of dynamic images.

[0003] However, a sudden, excessive driving force on the liquid crystal can cause domain faults, leading to the liquid crystal tilting off the correct direction and resulting in poor improvement. Summary of the Invention

[0004] Embodiments of this application provide a display device and its driving method to solve the problem of poor screen display effect caused by long liquid crystal response time in related technologies.

[0005] To solve the above problems, the technical solution provided in this application is as follows:

[0006] In a first aspect, this application provides a driving method for a display device, comprising:

[0007] Based on the grayscale information of the Nth frame and the (N-1)th frame, determine whether the Nth frame meets the compensation condition.

[0008] When the Nth frame of the display meets the compensation condition, the driving voltage corresponding to the Nth frame of the display is compensated.

[0009] The grayscale information includes grayscale values ​​and the voltage values ​​corresponding to the grayscale values.

[0010] In one embodiment, determining whether the Nth frame of the displayed image meets the compensation condition based on the grayscale information of the Nth frame and the grayscale information of the (N-1)th frame includes:

[0011] Obtain the first grayscale value of the Nth frame of the display and the first voltage value corresponding to the first grayscale value;

[0012] Obtain the second grayscale value of the N-1th frame of the display and the second voltage value corresponding to the second grayscale value;

[0013] If the difference between the first voltage value and the second voltage value is greater than or equal to the first threshold, it is determined whether the Nth frame of the display has met the compensation condition.

[0014] In one embodiment, determining whether the Nth frame of the displayed image meets the compensation condition based on the grayscale information of the Nth frame and the grayscale information of the (N-1)th frame includes:

[0015] If the first voltage value is in the first voltage range, the second voltage value is in the second voltage range, and the difference between the first voltage value and the second voltage value is greater than or equal to the first threshold, it is determined whether the Nth frame of the display has met the compensation condition.

[0016] In one embodiment, the first voltage range is the voltage value corresponding to grayscale values ​​of 240 to 255, and the second voltage range is the voltage value corresponding to grayscale values ​​of 0 to 8.

[0017] In one embodiment, before compensating the driving voltage corresponding to the Nth frame of the display, the method further includes:

[0018] A first lookup table is generated based on the driving voltage corresponding to different grayscale values ​​and the compensation voltage corresponding to different grayscale differences, or based on the driving voltage corresponding to different grayscale values ​​and the compensation coefficient corresponding to different grayscale differences.

[0019] In one embodiment, compensating for the driving voltage corresponding to the Nth frame of the display includes:

[0020] Based on the grayscale information of the Nth frame and the (N-1)th frame, the compensated driving voltage corresponding to the Nth frame is obtained from the first lookup table.

[0021] In one embodiment, before compensating the driving voltage corresponding to the Nth frame of the display, the method further includes:

[0022] A second lookup table is generated based on the driving voltage corresponding to different grayscale values;

[0023] A third lookup table is generated based on the compensation voltage corresponding to different grayscale differences or the compensation coefficient corresponding to different grayscale differences.

[0024] In one embodiment, compensating for the driving voltage corresponding to the Nth frame of the display includes:

[0025] Based on the grayscale information of the Nth frame and the grayscale information of the (N-1)th frame, the first target driving voltage and the second target driving voltage corresponding to the Nth frame are obtained from the second lookup table and the third lookup table, respectively.

[0026] The compensated driving voltage corresponding to the Nth frame of the display is obtained by adding the first target driving voltage and the second target driving voltage.

[0027] In one embodiment, the method further includes:

[0028] If the compensation condition is not met in the Nth frame of the display, the driving voltage corresponding to the Nth frame of the display is obtained from the second lookup table.

[0029] Secondly, this application provides a display device, comprising:

[0030] The determination module is used to determine whether the Nth frame of the display meets the compensation condition based on the grayscale information of the Nth frame and the grayscale information of the (N-1)th frame of the display.

[0031] The compensation module is used to compensate the driving voltage corresponding to the Nth frame of the display when the compensation condition is met.

[0032] The grayscale information includes grayscale values ​​and the voltage values ​​corresponding to the grayscale values.

[0033] This application provides a display device and its driving method. The driving method determines whether the Nth frame of the display meets the compensation condition based on the grayscale information of the Nth frame and the (N-1)th frame. If the Nth frame meets the compensation condition, the driving voltage corresponding to the Nth frame is compensated. By compensating the driving voltage corresponding to the Nth frame, the technical problem of domain faults in the liquid crystal caused by a sudden excessive driving force in a short period is at least solved, leading to liquid crystal tilting and a poor display effect. This allows the dynamic display effect of the display device to be improved by avoiding liquid crystal tilting due to excessive driving voltage while shortening the response time. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Appendix Figure 1 This is a schematic diagram of the overall process of the display device driving method in the embodiments of this application;

[0036] Appendix Figure 2 This is a schematic flowchart of an optional display device driving method in an embodiment of this application;

[0037] Appendix Figure 3This is a schematic diagram illustrating the specific process of another optional display device driving method in the embodiments of this application;

[0038] Appendix Figure 4 This is a schematic diagram illustrating the specific process of another optional display device driving method in the embodiments of this application;

[0039] Appendix Figure 5 This is a schematic diagram of an optional first lookup table in an embodiment of this application;

[0040] Appendix Figure 6 This is a schematic diagram illustrating the specific process of another optional display device driving method in the embodiments of this application;

[0041] Appendix Figure 7 This is a schematic diagram comparing the effects of the embodiments of this application with those of the comparative examples;

[0042] Appendix Figure 8 This is a waveform diagram showing the response time of the photodiode at different gray levels in the embodiments of this application;

[0043] Appendix Figure 9 This is a schematic diagram of a module of an optional display device in an embodiment of this application;

[0044] Appendix Figure 10 This is a schematic diagram of another optional display device in the embodiments of this application.

[0045] Explanation of the reference numerals in the figure:

[0046] 1. Display device; 100. Determining module; 200. Compensation module; 210. First compensation module; 220. Second compensation module; 230. Third compensation module; 300. Encoder; 400. Frame buffer; 500. Decoder. Detailed Implementation

[0047] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0048] It will be understood that although the terms “first,” “second,” etc., may be used in this document to describe various components, these components should not be limited by these terms. These terms are used only to distinguish one component from another.

[0049] With the continuous development of display technology, users have increasingly higher requirements for display effects. In most usage scenarios, display devices display dynamic images, making the quality of dynamic display a major criterion for user selection. Due to the inherently slow response speed of liquid crystals, problems such as trailing or motion blur occur when displaying dynamic images. To address these issues, overdrive technology is used to effectively improve response time and enhance the display effect of dynamic images. The principle of overdrive technology is to apply a voltage higher than the target grayscale to the first frame of the display image, giving the liquid crystal a greater driving force during rotation. However, a sudden and excessive driving force can cause domain faults in the liquid crystal, meaning that the liquid crystal molecules become unevenly aligned under excessive driving voltage, resulting in inconsistent colors or brightness in the displayed image, affecting image quality. Furthermore, the liquid crystal molecules need time to return to their normal state, and this does not significantly improve the long response time problem.

[0050] Reference Figure 1 As shown, according to a first aspect of the embodiments of this application, a method for driving a display device is provided, comprising:

[0051] S100: Based on the grayscale information of the Nth frame and the grayscale information of the (N-1)th frame, determine whether the Nth frame meets the compensation condition.

[0052] It should be noted that in this embodiment, the grayscale information includes grayscale values ​​and the corresponding voltage values. Each grayscale value corresponds to a specific voltage value. By controlling this voltage, the arrangement of liquid crystal molecules can be changed, thereby altering the light transmittance and achieving different brightness levels. Furthermore, the relationship between grayscale values ​​and voltage values ​​can be linear. In some embodiments of this application, the grayscale value and its corresponding voltage value are linearly related, with the voltage value ranging from 0 to 5V. Therefore, the voltage values ​​corresponding to grayscale values ​​0, 1, 2, 3...127...253, 254, and 255 can be 0.00V, 0.02V, 0.04V, 0.06V...2.50V...4.96V, 4.98V, and 5.00V. In other embodiments of this application, the grayscale value and its corresponding voltage value can also be non-linear. Specific designs can be implemented according to actual conditions, and this application does not impose any limitations on this.

[0053] Based on this, refer to Figure 2 As shown, in some more specific embodiments of this application, step S100 includes:

[0054] S110: Obtain the first grayscale value of the Nth frame of the display and the first voltage value corresponding to the first grayscale value;

[0055] S120: Obtain the second grayscale value of the N-1th frame of the display and the second voltage value corresponding to the second grayscale value;

[0056] S130: If the difference between the first voltage value and the second voltage value is greater than or equal to the first threshold, determine whether the Nth frame of the display has met the compensation condition.

[0057] Since the improvement focuses on the dynamic display effect of the liquid crystal, N is an integer greater than 1. By comparing the grayscale and voltage changes between consecutive frames, the transition of the displayed image between frames can be analyzed. If the difference in grayscale or voltage between the Nth frame and the (N-1)th frame is too large, compensation is required. In some embodiments of this application, the value of the first threshold can range from 10mV to 50mV, specifically, it can be 10mV, 15mV, 20mV, 25mV, 30mV, 35mV, 40mV, 45mV, or 50mV, etc. In practical applications, the value of the first threshold depends on the panel characteristics of the display device and the desired display effect. For faster response times to reduce motion blur, a smaller first threshold might be chosen to allow for more frequent compensation. However, a smaller first threshold could lead to over-compensation, meaning frequent compensation even when unnecessary. Conversely, for more stable compensation, a larger first threshold might be chosen. This reduces unnecessary variations and may lower the overall power consumption of the display device, improving reliability and lifespan. However, an excessively large first threshold could prevent timely compensation when needed. Therefore, the first threshold must be selected based on the specific characteristics of the display device and the application scenario to ensure optimal display performance and device capabilities.

[0058] More specifically, refer to Figure 3 As shown, in some embodiments of this application, S100 may also include:

[0059] S140: If the first voltage value is in the first voltage range, the second voltage value is in the second voltage range, and the difference between the first voltage value and the second voltage value is greater than or equal to the first threshold, determine whether the Nth frame of the display meets the compensation condition.

[0060] It should be noted that in some embodiments of this application, the first voltage range corresponds to the voltage values ​​of grayscale values ​​from 240 to 255, and the second voltage range corresponds to the voltage values ​​of grayscale values ​​from 0 to 8. In other embodiments, the first voltage range may also be the voltage values ​​corresponding to grayscale values ​​from 0 to 8, and the second voltage range may be the voltage values ​​corresponding to grayscale values ​​from 240 to 255. Since grayscale values ​​from 0 to 8 and grayscale values ​​from 240 to 255 represent near-complete darkness and complete brightness, respectively, the voltage change from the second voltage range to the first voltage range is relatively large, which is more likely to cause visual artifacts. Therefore, monitoring the voltage change between these two voltage ranges is more helpful in improving display quality.

[0061] S300: When the compensation condition is met in the Nth frame of the display, the driving voltage corresponding to the Nth frame of the display is compensated.

[0062] Specifically, refer to Figure 4 As shown, in some embodiments of this application, the method further includes the following steps before step S300:

[0063] S200: Generate a first lookup table based on the driving voltage corresponding to different grayscale values ​​and the compensation voltage corresponding to different grayscale differences, or based on the driving voltage corresponding to different grayscale values ​​and the compensation coefficient corresponding to different grayscale differences.

[0064] Optional, refer to Figure 5 As shown, a specific embodiment of the first lookup table is provided. Rows represent the grayscale values ​​of the Nth frame of the displayed image, and columns represent the grayscale values ​​of the (N-1)th frame of the displayed image. Each cell in the table, V(i, j), can contain multiple values. Specifically, it can contain the required driving voltage and compensation voltage for the transition from grayscale value i to grayscale value j; it can also contain the required driving voltage and compensation coefficient for the transition from grayscale value i to grayscale value j. When the table records a compensation coefficient, the required compensation voltage can be obtained by multiplying the driving voltage and the compensation coefficient. In this case, the compensation coefficient ranges from 0 to 1, specifically 0.7, 0.8, or 0.9, etc. Furthermore, it can also contain the required driving voltage and compensation value for the transition from grayscale value i to grayscale value j. The required compensation voltage can be obtained by the difference between the driving voltage and the compensation value.

[0065] Based on this, in step S300, compensating the driving voltage corresponding to the Nth frame of the display screen includes: obtaining the compensated driving voltage corresponding to the Nth frame of the display screen from the first lookup table according to the grayscale information of the Nth frame of the display screen and the grayscale information of the (N-1)th frame of the display screen.

[0066] It should be noted that in the aforementioned embodiments, when the Nth frame of the display does not meet the compensation conditions, the driving voltage required for the Nth frame of the display can be directly obtained from the first lookup table.

[0067] Optional, refer to Figure 6 As shown, in some other embodiments of this application, before compensating the driving voltage corresponding to the Nth frame of the display screen, the method may further include:

[0068] S200: Generate a second lookup table based on the driving voltage corresponding to different grayscale values; generate a third lookup table based on the compensation voltage corresponding to different grayscale differences or the compensation coefficient corresponding to different grayscale differences.

[0069] It should be noted that the second lookup table can be similar to the first lookup table in the aforementioned embodiments, except that the second lookup table only records the driving voltage corresponding to the grayscale value of the Nth frame and the grayscale value of the (N-1)th frame. Correspondingly, the third lookup table records the compensation voltage, compensation coefficient, or compensation value corresponding to the grayscale value of the Nth frame and the grayscale value of the (N-1)th frame.

[0070] Based on this, step S300 may specifically include:

[0071] S310: Based on the grayscale information of the Nth frame and the grayscale information of the (N-1)th frame, obtain the first target driving voltage and the second target driving voltage corresponding to the Nth frame from the second lookup table and the third lookup table, respectively.

[0072] It should be noted that when the record in the third lookup table is a compensation voltage, the second target driving voltage is a compensation voltage with the opposite polarity to the first target driving voltage. In this case, the absolute value of the second target driving voltage is less than the absolute value of the first target driving voltage. The compensation value of the second target driving voltage can be obtained by testing the response time waveform or by observing changes in the dark patterns of the pixels.

[0073] In some embodiments, when the contents of the third lookup table include a compensation coefficient, the second target driving voltage can be calculated based on the first target driving voltage and the compensation coefficient. In this case, the value of the compensation coefficient is between -1 and 0. Specifically, the value of the compensation coefficient can be -0.1, -0.2 or -0.3.

[0074] S320: The compensated driving voltage corresponding to the Nth frame of the display screen is obtained by adding the first target driving voltage and the second target driving voltage.

[0075] In this step, it should be noted that the second target driving voltage and the first target driving voltage are connected in series with opposite polarities. When the first target driving voltage is too large, the second target driving voltage can be added to the first target voltage to output a driving voltage smaller than the first target voltage.

[0076] Furthermore, in this embodiment, if the compensation condition is not met in the Nth frame of the display, the driving voltage corresponding to the Nth frame of the display is obtained from the second lookup table.

[0077] In conjunction with the above, in some embodiments of this application, the grayscale value of the previous frame is first recorded during the driving process of the display device. Then, based on the relationship between the grayscale value and voltage, the grayscale voltage of the previous frame is obtained. Next, the grayscale value of the current frame is recorded, and the grayscale voltage of the current frame is obtained based on the grayscale value. In this embodiment, a voltage threshold 'a' is set for the previous frame, where 'a' is within the voltage range corresponding to grayscale values ​​of 0-8, and a voltage threshold 'b' is set for the current frame, where 'b' is within the voltage range corresponding to grayscale values ​​of 240-255. Simultaneously, a threshold 'c' is set to represent the difference between 'a' and 'b', the specific value of 'c' being flexibly set according to the panel conditions. Afterward, the display device compares the recorded data of the previous and next frames with the thresholds 'a', 'b', and 'c'. If all three conditions are met, compensation is performed.

[0078] During the compensation process, different compensation values ​​are set based on the recorded grayscale differences between consecutive frames. There are two ways to set the compensation values. One is to add compensation coefficients or compensation values ​​to a single first lookup table, setting different compensation coefficients or compensation values ​​for different grayscale changes. Alternatively, a third lookup table can be added to a second lookup table, where the third lookup table stores the compensation coefficients or compensation values.

[0079] Of course, compensation coefficients or compensation values ​​can also be set only for a portion of the set area, that is, only for a portion of the drive voltage in the second lookup table.

[0080] Reference Figure 7 The image shown is a display screen obtained after simulating the display device according to the driving method of this application embodiment, and a comparison image of the display screen obtained by the driving method in related technologies. As can be seen in the image, dark lines exist inside the pixels in both the comparative example and the first frame of the display screen in this application embodiment. However, in the second and third frames of the display screen in this application embodiment, the dark lines inside the pixels have almost disappeared. In the comparative example, some dark lines still exist inside the pixels in the second frame of the display screen, and the dark lines only nearly disappear in the third frame. Therefore, it can be seen that the liquid crystal response time is significantly improved in the embodiment of this application.

[0081] More specifically, refer to Figure 8 As shown, the response time waveform between different gray levels can be measured using a photodiode. The final liquid crystal response time of this embodiment is approximately 10ms. Compared to the 25ms response time in the comparative example, the driving method of this embodiment effectively improves the response time.

[0082] Reference Figure 9 and Figure 10 As shown, according to a second aspect of this application, a display device 1 is provided for implementing the aforementioned driving method. The display device 1 includes a determination module 100 and a compensation module 200.

[0083] The determining module 100 is used to determine whether the Nth frame of the display meets the compensation condition based on the grayscale information of the Nth frame and the (N-1)th frame of the display. The compensation module 200 is used to compensate the driving voltage corresponding to the Nth frame of the display if the compensation condition is met. It should be noted that the grayscale information includes the grayscale value and the voltage value corresponding to the grayscale value.

[0084] Furthermore, in some embodiments of this application, the display device 1 further includes a frame signal acquisition module, used to input the grayscale information of the Nth frame and the grayscale information of the (N-1)th frame of the display image to the determination module 100. More specifically, refer to... Figure 9 and Figure 10 As shown, the frame signal acquisition module includes an encoder 300, a frame buffer 400, and a decoder 500. The encoder 300 receives and encodes the frame signal, the frame buffer 400 stores the encoded and compressed frame signal, and the decoder 500 reads the compressed data from the frame buffer 400, decodes the compressed data into a frame signal, and transmits it to the determination module 100. Based on this, the determination module 100 can directly acquire the grayscale information of the Nth frame of the display image, while the grayscale information of the (N-1)th frame of the display image can be obtained through the decoder 500.

[0085] More specifically, refer to Figure 9 As shown, in some embodiments of this application, the compensation module 200 includes a first compensation module 210, which at least includes a first storage unit storing a first lookup table. The first storage unit may be a register or the like.

[0086] More specifically, refer to Figure 10 As shown, in some other embodiments of this application, the compensation module 200 may also include a second compensation module 220 and a third compensation module 230, with the determination module 100 electrically connected to the third compensation module 230. The second compensation module 220 includes at least a second storage unit storing a second lookup table, and the third compensation module 230 includes at least a third storage unit storing a third lookup table.

[0087] In addition, in some embodiments of this application, the compensation module 200 may also include a control unit or a calculation unit, etc., for performing calculations to compensate the driving voltage corresponding to the Nth frame of the display screen.

[0088] In summary, although the present application has disclosed the preferred embodiments as described above, the above preferred embodiments are not intended to limit the present application. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be determined by the scope defined in the claims.

Claims

1. A driving method for a display device, characterized in that, include: Based on the grayscale information of the Nth frame and the (N-1)th frame, determine whether the Nth frame meets the compensation condition. When the Nth frame of the display meets the compensation condition, the driving voltage corresponding to the Nth frame of the display is compensated. The grayscale information includes grayscale values ​​and voltage values ​​corresponding to the grayscale values. Determining whether the Nth frame of the display meets the compensation condition based on the grayscale information of the Nth frame and the (N-1)th frame includes: acquiring a first grayscale value of the Nth frame and a first voltage value corresponding to the first grayscale value; acquiring a second grayscale value of the (N-1)th frame and a second voltage value corresponding to the second grayscale value; and determining that the Nth frame meets the compensation condition when the first voltage value is within a first voltage range, the second voltage value is within a second voltage range, and the difference between the first voltage value and the second voltage value is greater than or equal to a first threshold. Before compensating the driving voltage corresponding to the Nth frame of the display, the method further includes: generating a second lookup table based on the driving voltage corresponding to different grayscale values; generating a third lookup table based on the compensation voltage corresponding to different grayscale differences or the compensation coefficient corresponding to different grayscale differences; the compensation of the driving voltage corresponding to the Nth frame of the display includes: obtaining the first target driving voltage and the second target driving voltage corresponding to the Nth frame of the display from the second lookup table and the third lookup table respectively, based on the grayscale information of the Nth frame of the display and the grayscale information of the (N-1)th frame of the display; adding the first target driving voltage and the second target driving voltage to obtain the compensated driving voltage corresponding to the Nth frame of the display; the second target driving voltage is a compensation voltage with a polarity opposite to the first target driving voltage.

2. The driving method according to claim 1, characterized in that, The first voltage range is the voltage value corresponding to grayscale values ​​of 240 to 255, and the second voltage range is the voltage value corresponding to grayscale values ​​of 0 to 8.

3. The driving method according to claim 1, characterized in that, The method further includes: If the compensation condition is not met in the Nth frame of the display, the driving voltage corresponding to the Nth frame of the display is obtained from the second lookup table.

4. A display device, characterized in that, include: The determination module is used to determine whether the Nth frame of the display meets the compensation condition based on the grayscale information of the Nth frame and the grayscale information of the (N-1)th frame of the display. The compensation module is used to compensate the driving voltage corresponding to the Nth frame of the display when the compensation condition is met. The grayscale information includes grayscale values ​​and the voltage values ​​corresponding to the grayscale values; The determining module is further configured to obtain the first grayscale value of the Nth frame of the display and the first voltage value corresponding to the first grayscale value; obtain the second grayscale value of the (N-1)th frame of the display and the second voltage value corresponding to the second grayscale value; and determine that the Nth frame of the display has reached the compensation condition when the first voltage value is in the first voltage range, the second voltage value is in the second voltage range, and the difference between the first voltage value and the second voltage value is greater than or equal to the first threshold. The compensation module is further configured to generate a second lookup table based on the driving voltage corresponding to different grayscale values; generate a third lookup table based on the compensation voltage corresponding to different grayscale differences or the compensation coefficient corresponding to different grayscale differences; and obtain the first target driving voltage and the second target driving voltage corresponding to the Nth frame of the display from the second lookup table and the third lookup table respectively, based on the grayscale information of the Nth frame of the display and the grayscale information of the (N-1)th frame of the display; add the first target driving voltage and the second target driving voltage to obtain the compensated driving voltage corresponding to the Nth frame of the display; the second target driving voltage is a compensation voltage with a polarity opposite to the first target driving voltage.

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