Display panel driving method and display device

Abstract

The present application relates to a method for driving a display panel and a display device, wherein the method includes: a timing controller detecting the current display mode; when the display mode is a variable refresh rate mode, the timing controller detecting the refresh frequency of the image; when the timing controller detects a change in the refresh frequency of the previous frame, the timing controller calls a pixel brightness correction table and a gamma voltage table corresponding to the refresh frequency of the previous frame at the beginning of the current frame; and a microcontroller driving the display panel to display the image using the pixel brightness correction table and gamma voltage called by the current frame when displaying the next frame. This application solves the problem in the prior art of a long delay in calling the corresponding pixel brightness correction table after the refresh frequency is switched, resulting in noticeable flickering in the switching image.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a driving method for a display panel and a display device. Background Art

[0002] VRR (Variable Refresh Rate) mode allows the display to refresh at a frequency of 48Hz-144Hz in gaming mode. This means that the screen refresh rate can be matched to the game frame rate in real time, avoiding stuttering and tearing caused by different frequencies. The conventional debugging method in related art is to debug the pixel brightness correction table corresponding to ACC (Accurate Color Capture) at 48&144Hz frequencies. That is, the corresponding pixel brightness correction table is called at different frequencies to make the brightness at different frequencies similar, thereby meeting the Free-Sync standard. However, this debugging method in related art has the following problems: when the VRR frequency switches, it takes at least 2 to 3 frames for the corresponding pixel brightness correction table to switch. During this at least 2 to 3 frame time, the pixel brightness correction table of the previous frame is still used, which will cause the brightness difference to become larger and form a more obvious flicker.

[0003] There is currently no effective solution to the above problems in the prior art. Summary of the Invention

[0004] The present application provides a display panel driving method and a display device to solve the problem of noticeable flickering of the switching screen due to a large number of delayed frames in calling a corresponding pixel brightness correction table after the refresh frequency is switched.

[0005] In a first aspect, the present application provides a method for driving a display panel, comprising:

[0006] The timing controller detects the current display mode;

[0007] When the display mode is the variable refresh rate mode, the timing controller detects the refresh frequency of the picture;

[0008] When the timing controller detects that the refresh frequency of the previous frame has changed, the timing controller starts to call the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame in the current frame;

[0009] When displaying the next frame, the microcontroller drives the display panel to display the picture through the pixel brightness correction table and gamma voltage called by the current frame.

[0010] In the second aspect, the present application provides a display device, comprising: a timing controller, a gamma chip, a microcontroller and a display panel; wherein the microcontroller is electrically connected to the timing controller, and the timing controller and the microcontroller are both electrically connected to the gamma chip; the timing controller is used to detect the current mode, and when the display mode is a variable refresh rate mode, the timing controller detects the refresh frequency of the picture; when the timing controller detects that the refresh frequency of the previous frame has changed, the timing controller starts to call the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame stored in the gamma chip at the beginning of the current frame; the microcontroller is used to drive the display panel to display the picture through the pixel brightness correction table and gamma voltage called by the current frame when the next frame is displayed.

[0011] The above technical solution provided by the embodiment of the present application has the following advantages compared with the related art:

[0012] Through the embodiments of the present application, in the present application, the timing controller can further detect the refresh frequency of the picture by detecting that the current display mode is a variable refresh rate. When the timing controller detects that the refresh frequency of the previous frame has changed, the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame are called at the beginning of the current frame, and then the microcontroller drives the display panel to display the picture through the pixel brightness correction table and gamma voltage called by the current frame when the next frame is displayed. That is to say, in the present application, the pixel brightness correction table and gamma voltage of the previous frame are directly called in the current frame to drive the display of the next frame. That is, when the refresh frequency changes, the corresponding data of the display drive is delayed by only one frame (that is, the time for calling the corresponding data in the current frame). Compared with the situation in the prior art where a delay of at least 2 to 3 frames is required, the flicker of the display panel is reduced through the present application, and the problem in the prior art that the call of the corresponding pixel brightness correction table after the refresh frequency is switched is delayed by a large number of frames, resulting in obvious flickering of the switching screen is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0015] Figure 1 A schematic flow chart of a method for driving a display panel provided in an embodiment of the present application;

[0016] Figure 2 A schematic diagram of monitoring the vertical blanking zone provided in an embodiment of the present application;

[0017] Figure 3 This is a schematic structural diagram of a display device of the present application;

[0018] Figure 4 This is a schematic structural diagram of another display device of the present application;

[0019] Figure 5 This is a structural diagram of another display device of the present application.

[0020] Among them, 11-operational amplifier circuit, T1-previous frame, T2-current frame, T3-next frame, S-vertical blanking time. DETAILED DESCRIPTION

[0021] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] Figure 1 Schematic diagram of a method for driving a display panel provided in an embodiment of the present application. Figure 1 As shown, the steps of the method include:

[0023] Step 101, the timing controller detects the current display mode;

[0024] Step 102, when the display mode is a variable refresh rate mode, the timing controller detects the refresh frequency of the image;

[0025] Step 103 , when the timing controller detects that the refresh rate of the previous frame has changed, the timing controller starts to call the pixel brightness correction table and gamma voltage table corresponding to the refresh rate of the previous frame in the current frame;

[0026] Step 104 : When displaying the next frame of picture, the microcontroller drives the display panel to display the picture by using the pixel brightness correction table and gamma voltage called by the current frame of picture.

[0027] It can be seen from the above steps 101 to 104 that in the present application, the timing controller can further detect the refresh frequency of the picture by detecting that the current display mode is a variable refresh rate. When the timing controller detects that the refresh frequency of the previous frame has changed, the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame are called at the beginning of the current frame, and then the microcontroller drives the display panel to display the picture through the pixel brightness correction table and gamma voltage called by the current frame when the next frame is displayed. That is to say, in the present application, the pixel brightness correction table and gamma voltage corresponding to the refresh frequency of the previous frame can be called to drive the display of the next frame, that is, only one frame needs to be delayed, that is, when the refresh frequency changes, the corresponding data of the display drive is only delayed by one frame (that is, the time for calling the corresponding data in this frame). Compared with the situation in the prior art where at least 2 to 3 frames need to be delayed, the flicker of the display panel is reduced by the present application, and the problem of the prior art that the calling of the corresponding pixel brightness correction table after the refresh frequency is switched is delayed for a large number of frames, resulting in obvious flickering of the switching screen is solved.

[0028] In an optional implementation of the embodiment of the present application, the method for the timing controller involved in step 103 to call the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame image at the beginning of the current frame image can be further:

[0029] Step 11: When the current frame is displayed, the timing controller reads the vertical blanking duration of the previous frame;

[0030] In step 12, when it is determined that the vertical blanking duration of the previous frame is different from the vertical blanking duration of the previous frame, the timing controller reads the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame in the current frame, so that the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame are used when the next frame is displayed.

[0031] For the above steps 11 to 12, it should be noted that the vertical blanking time of the previous frame refers to the interval between the previous frame and the current frame, and the vertical blanking time of the previous frame refers to the interval between the previous frame and the previous frame. In the specific example, Figure 2As shown, after reading the vertical blanking duration of the previous frame, the timing controller compares it with the vertical blanking duration of the previous frame. If the two are different, it indicates that the refresh frequency of the picture is changing, and it is necessary to adjust the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency in time to maintain the brightness of the displayed picture unchanged and reduce the degree of picture flicker as much as possible. In this application, the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame are used when displaying the next frame, that is, only one frame needs to be delayed (that is, the time for the corresponding data called by this frame). Compared with the prior art where a delay of at least 2 to 3 frames is required, the flicker of the display panel is reduced through this application.

[0032] In an optional implementation manner of the embodiment of the present application, the manner in which the timing controller reads the pixel brightness correction table and the gamma voltage table corresponding to the refresh frequency of the previous frame image in the current frame image involved in step 12 may further include:

[0033] Step 21, the data port between the timing controller and the flash memory is switched to SPI (Serial Peripheral Interface);

[0034] Step 22: At the beginning of the vertical blanking period of the current frame, the timing controller reads the pixel brightness correction table and the gamma voltage table corresponding to the refresh frequency of the previous frame from the flash memory via SPI.

[0035] It should be noted that the SPI is a high-speed, full-duplex, synchronous communication bus. Through the SPI, the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame can be quickly read from the memory, reducing the delay in displaying the next frame through the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame, thereby reducing the degree of flicker.

[0036] Because the vertical blanking period of the current frame is very short, and the data in the pixel brightness correction table and gamma voltage table is relatively large, it is necessary to ensure that the data of the pixel brightness correction table and gamma voltage table are fully read during the vertical blanking period of the current frame. Therefore, the data port of the timing controller and flash memory is selected to be SPI. To further ensure complete data reading, it is preferred to set two data ports for the timing controller and flash memory, and both data ports are SPI; one data port is used to transmit the pixel brightness correction table, and the other data port is used to transmit the gamma voltage table. This can fully ensure complete data reading in a short time.

[0037] In an optional implementation manner of an embodiment of the present application, the pixel brightness correction table in the embodiment of the present application includes multiple preset refresh frequencies, and grayscale compensation values ​​mapped one-to-one with each preset refresh frequency; the gamma voltage table includes multiple preset refresh frequencies, and gamma voltages mapped one-to-one with each refresh frequency.

[0038] It should be noted that in the embodiment of the present application, the multiple preset refresh frequencies can be 48Hz, 60Hz, and 144Hz. Different refresh frequencies can correspond to different grayscale compensation values. The grayscale compensation values ​​can be set accordingly according to different needs, as shown in Tables 1 and 2 in specific examples.

[0039]

[0040] Table 1

[0041]

[0042] Table 2

[0043] In addition, in the specific example, the gamma voltage table and the gamma voltage mapped one-to-one to each refresh frequency can be set accordingly according to actual conditions, as long as different refresh frequencies correspond to different gamma voltages, and the gamma voltage can meet the consistency of the brightness of the current display panel at the current refresh frequency and the low degree of flicker.

[0044] Furthermore, in an embodiment of the present application, the gamma voltage table also includes a gamma binding point code provided in the timing controller and a gamma binding point voltage provided in the gamma chip. The gamma binding point code and the refresh frequency are mapped one-to-one. The gamma binding point voltage includes at least two. The gamma voltage is obtained by calculating the gamma binding point code and the gamma binding point voltage. That is, the gamma chip receives the gamma binding point code of a certain refresh frequency, and the gamma chip obtains the gamma voltage by combining the gamma binding point voltage and the gamma binding point voltage.

[0045] However, under existing circumstances, occasional flickering occurs when the refresh rate changes; therefore, further improving the accuracy of the gamma voltage can further reduce flickering when the refresh rate changes. The gamma binding point voltage generally includes a first gamma binding point voltage to a fourteenth gamma binding point voltage, that is, there are 14 gamma binding point voltages. In the present application, the gamma binding point voltage includes at least two, and it can be any two or any three of them. The specific number of gamma binding point voltages and the specific gamma binding point voltage can be set accordingly according to actual conditions. In addition, in the embodiment of the present application, the gamma voltage is obtained based on the gamma voltage encoding at different refresh frequencies and the corresponding gamma binding point voltage, making the calculation of the gamma voltage more accurate.

[0046] Furthermore, in the present application, the gamma voltage coding can be taken as a corresponding value according to the actual refresh frequency. Specifically, if the refresh frequency is low, the corresponding gamma voltage coding value is large, and if the refresh frequency is high, the corresponding gamma voltage coding value is small, so as to ensure that the brightness of the display panel is consistent at high refresh frequency or low refresh frequency to avoid flickering.

[0047] In this embodiment, to obtain more accurate gamma voltages, at least one gamma tie-point voltage is adjusted to achieve a more refined gamma voltage. Therefore, in theory, by adjusting each gamma tie-point voltage in the gamma tie-point voltage group, each gamma voltage output is more accurate, thereby maintaining constant brightness and reducing flicker when the refresh rate switches.

[0048] However, the applicant discovered that adjusting every gamma tie voltage would complicate the circuit and significantly increase costs. To balance circuit simplification with lower cost, the inventor discovered that optimizing some gamma tie voltages could also reduce screen flicker when the refresh rate changes.

[0049] In the embodiment of the present application, the gamma binding point voltage includes at least a first gamma binding point voltage and a fourteenth gamma binding point voltage, the first gamma binding point voltage is a positive polarity binding point voltage value corresponding to the white grayscale, and the fourteenth gamma binding point voltage is a negative polarity binding point voltage value corresponding to the white grayscale; therefore, it is selected to adjust the size of the first gamma binding point voltage and the fourteenth gamma binding point voltage to adjust the accuracy of the gamma voltage; at this time, the flicker can be significantly reduced, and the circuit structure is also relatively simple, and the cost is also lower.

[0050] In a specific example, the process of adjusting the gamma voltage accuracy can be: when the timing controller detects that the vertical blanking (V-blank) area of ​​the previous frame reaches a certain length (that is, when the refresh frequency occurs), the timing controller will give instructions to adjust the gamma voltage through the I2C (Inter-Integrated Circuit) connected to the gamma chip in the current frame to make the brightness of the corresponding frequencies close, thereby reducing screen flicker in VRR mode.

[0051] When the refresh rate changes, the steps of adjusting the gamma voltage with higher precision are as follows: finding a voltage point adjacent to the gamma binding point voltage, wherein the voltage value of the adjacent voltage point is close to the voltage value of the gamma binding point voltage; providing a variable resistor between the gamma binding point corresponding to the gamma binding point voltage and the adjacent voltage point, wherein two ends of the variable resistor are respectively connected to the gamma binding point and the adjacent voltage point, and an output end of the variable resistor is connected to a microcontroller;

[0052] The gamma chip receives the gamma binding point code and the gamma binding point voltage outputted from the output end of the variable resistor, and obtains the gamma voltage by multiplying the gamma binding point code and the gamma binding point voltage.

[0053] In a specific embodiment, because the voltage value of the ground point is very close to the fourteenth gamma binding point of the gamma chip, the fourteenth gamma binding point of the gamma chip is connected to the ground point. A variable resistor or multiple resistors of equal value are provided between the fourteenth gamma binding point and the ground point. The variable resistor is connected to a microcontroller, and the microcontroller controls the size of the variable resistor to output a fourteenth gamma binding point voltage with varying precision. In addition, the first gamma binding point of the gamma chip is connected to the output terminal of the microcontroller to receive AVDD (digital voltage); a variable resistor or multiple resistors of equal value are provided between the first gamma binding point of the gamma chip and the output terminal of the microcontroller; the variable resistor is connected to the microcontroller, and the microcontroller controls the size of the variable resistor to output a first gamma binding point voltage with varying precision.

[0054] Since the first gamma binding point voltage is a positive polarity voltage corresponding to the 255 grayscale of white, and the fourteenth gamma binding point voltage is a negative polarity voltage corresponding to the 255 grayscale of white; adjusting the gamma voltage of the 255 grayscale of white, compared with adjusting the gamma voltage of other grayscales, adjusting the gamma voltage of the 255 grayscale of white can more obviously reduce brightness fluctuations and flicker, and can obtain a better display effect.

[0055] In this embodiment, more preferably, Figure 4 The microcontroller controls the gamma binding point voltage corresponding to the gamma binding point voltage group according to the difference between the previous frame refresh frequency and the current frame refresh frequency. If the difference is greater than a preset threshold, the microcontroller does not adjust the gamma binding point voltage; if the difference is less than or equal to the preset threshold, the microcontroller adjusts the resistance of the variable resistor to adjust the gamma binding point voltage. This may further include:

[0056] Step 31 : when the difference is greater than a preset threshold, the microcontroller does not adjust the first gamma binding point voltage;

[0057] Step 32 : When the difference is less than or equal to the preset threshold, the microcontroller adjusts the resistance of the variable resistor to adjust the first gamma binding point voltage.

[0058] It should be noted that when the constant frequency display mode is selected, the gamma voltage output can be directly adjusted using an equivalent resistor circuit based on the predetermined required debugging accuracy. When the variable refresh rate mode is selected, the refresh rate is constantly changing, and considering the different situations of refresh rate changes, the gamma voltage output accuracy may need to be adjusted, so a variable resistor circuit is selected. At this time, based on the change in refresh frequency, the decision on whether to adjust the variable resistor is made, thereby adjusting the gamma voltage output accuracy, taking into account both control circuit stability and flicker control, thereby further improving the display effect.

[0059] Based on this, when the variable refresh rate mode is selected, for the above steps 31 to 32, taking the preset threshold of 60Hz as an example in the specific example, it can be: obtain the refresh frequency of the previous frame and the current frame, and calculate the difference B between the refresh frequency A1 of the previous frame and the refresh frequency A2 of the current frame; if the difference B is greater than 60Hz, the microcontroller does not adjust the fourteenth gamma binding point voltage and / or the first gamma binding point voltage; at this time, due to the large change in refresh rate, the gamma voltage values ​​corresponding to the same brightness of the low refresh rate and the high refresh rate are quite different. At this time, the slightly lower gamma voltage adjustment accuracy has less effect on the brightness fluctuation of the picture, so it is chosen not to adjust the binding point voltage to maintain the consistent stability of the circuit, which is less conducive to reducing the flicker of the display for smaller fluctuations in the display. If the difference is less than 60Hz, the microcontroller adjusts the fourteenth gamma binding point voltage and / or the first gamma binding point voltage to improve the output accuracy of the fourteenth gamma voltage and / or the first gamma binding point voltage; since the refresh frequency changes little at this time, the difference in gamma voltage values ​​corresponding to the same brightness at low refresh rate and high refresh rate is also small. Since the gamma voltage changes, if the gamma voltage adjustment accuracy is too low at this time, the picture fluctuation is easily perceived by the human eye. At this time, choosing to improve the accuracy of the gamma voltage can effectively ensure that the output gamma voltage after adjustment is closer to the actual required value (if the accuracy of the gamma voltage is reduced, the brightness change after the gamma voltage is switched will increase, thereby deepening the human eye's perception of flicker). The brightness is more in line with actual needs, effectively avoiding the display brightness fluctuation caused by the refresh frequency switching, making it difficult for the human eye to perceive picture flicker.

[0060] In an optional implementation manner of the embodiment of the present application, Figure 4 A variable resistor or multiple resistors of equivalent value are provided between the fourteenth binding point of the gamma chip and ground. Voltage division by the variable resistor or resistors of equivalent value can improve the debugging accuracy of the gamma voltage. In a specific example, if the variable resistor is a variable resistor, the fourteenth gamma binding point voltage is output by the output end of the variable resistor, and the variable resistor is electrically connected to the microcontroller. Based on this, the method for the microcontroller involved in this application to control the gamma binding point voltage corresponding to the gamma binding point voltage group based on the difference between the previous frame refresh frequency and the current frame refresh frequency can further include:

[0061] Step 41 , when the difference is greater than the preset threshold, the microcontroller does not adjust the voltage of the fourteenth gamma binding point;

[0062] Step 42 : When the difference is less than or equal to the preset threshold, the microcontroller adjusts the resistance of the variable resistor to adjust the fourteenth gamma-binding point voltage.

[0063] For steps 41 and 42 above, taking a preset threshold of 60 Hz as an example, when the refresh frequency variation difference B is greater than 60 Hz, an equivalent resistor circuit is directly used to output the gamma voltage. When the refresh frequency variation value is less than 60 Hz, a variable resistor circuit is directly used to output the gamma voltage. In this case, the variable resistor can be preset to a value different from the equivalent resistor, and the gamma voltage output accuracy of the variable resistor circuit is higher than that of the equivalent resistor. In this case, the resistance does not change, and the circuit remains as stable as possible, while being able to adapt to the different refresh frequency variations. The gamma voltage output accuracy is adjusted, which not only ensures circuit stability but also reduces the human eye's perception of flicker according to the different refresh frequency variations, further improving the display effect. Of course, although the variable resistor is preset to a value, the value of the variable resistor can still be changed by the microcontroller if needed. Although this sacrifices a small amount of circuit stability, when the refresh frequency variation value is less than 60 Hz, the further subdivision of the refresh frequency variation value further controls the different gamma voltage accuracy, which is conducive to further effectively controlling brightness changes or fluctuations, thereby more effectively reducing flicker and improving display effects.

[0064] Figure 4 The variable resistor in can also be replaced with multiple resistors of equal value, such as Figure 5 shown.

[0065] Without a variable resistor or multiple resistors of equal value, when the timing controller detects that the vertical blanking (V-blank) area has reached a certain length, it will issue instructions through the I2C (Inter-Integrated Circuit) connected to the gamma chip to adjust the gamma voltage to make the brightness of the corresponding frequency close, reducing screen flicker in VRR mode. Its debugging accuracy is output voltage / 256 (grayscale value). If the output voltage is 16V, the debugging accuracy is 0.06V. If the current gamma voltage to be adjusted is 0.08V, the debugging accuracy of 0.06V cannot meet further requirements. After setting a variable resistor or multiple resistors of equal value, the debugging accuracy can be higher, that is, the debugging accuracy will be further reduced to less than 0.06V. Taking multiple equal-value resistors as an example, if the current number of equal-value resistors is 5, then after the 5 resistors divide the voltage, the adjustment accuracy is 0.06 / 5 = 0.012V. Compared with the previous adjustment without adjusting a single grid, the voltage change is smaller. In other words, the corresponding brightness change is smaller after adjusting a single grid, making the flickering during frequency switching relatively less noticeable. Of course, the above equal-value resistor values ​​are only examples and can be further adjusted according to actual conditions. For example, the number of equal-value resistors can be 4, 8, 10, 15, etc.

[0066] The above is only for the first gamma binding point voltage and the fourteenth gamma binding point voltage, and the next step of processing is performed after judging according to the difference in refresh frequency. In fact, for all gamma voltage binding points, the microcontroller can adjust the gamma binding point voltage group according to the difference between the previous frame refresh frequency and the current frame refresh frequency. Specifically, when the difference is greater than the preset threshold, the microcontroller does not adjust the gamma binding point voltage; when the difference is less than or equal to the preset threshold, the microcontroller adjusts the resistance of the variable resistor to adjust the gamma binding point voltage. The microcontroller can control the gamma binding point voltage corresponding to the gamma binding point voltage group according to the difference between the previous frame refresh frequency and the current frame refresh frequency, that is, the gamma binding point voltage is not adjusted when the refresh frequency changes, but is controlled according to the difference in refresh frequency changes. Because if the refresh rate changes too much, the brightness of the original low refresh rate and the gamma voltage of the high refresh rate will change significantly. At this time, the slightly lower gamma voltage adjustment accuracy will have a smaller impact on the brightness fluctuation of the picture. Therefore, it is possible to choose not to adjust the binding point voltage to maintain the consistent stability of the circuit. For smaller display fluctuations, it is more conducive to reducing display flicker. When the refresh rate changes little, the brightness of the original low refresh rate and the gamma voltage of the high refresh rate will also change less. At this time, the gamma binding point voltage is adjusted to improve the precision of the gamma binding point voltage to improve the precision of the output gamma voltage. This can effectively ensure that the adjusted output gamma voltage is closer to the actual required value (if the gamma voltage accuracy is reduced, the brightness change after the gamma voltage is switched will increase, thereby deepening the human eye's perception of flicker). The brightness is more in line with actual needs (that is, when the brightness remains the same, the fluctuation is smaller), effectively avoiding the display brightness fluctuation caused by the refresh rate switching, making it less likely for the human eye to perceive screen flicker.

[0067] In an optional implementation manner of the embodiment of the present application, the display mode in the embodiment of the present application includes a constant refresh rate mode and a variable refresh rate mode;

[0068] The constant refresh rate mode includes a first preset refresh rate and a first gamma voltage table corresponding to the preset refresh rate; the first gamma voltage table is a pre-stored fixed value. The variable refresh rate mode has multiple second preset refresh rates and a second gamma voltage table that maps each refresh rate one-to-one; the second gamma voltage table is a real-time value calculated based on the detected refresh rate.

[0069] That is, if the refresh rate is constant, the corresponding gamma voltage table also contains pre-stored fixed values. If the current refresh rate is variable, the voltage values ​​in the gamma voltage table are real-time values ​​calculated based on the detected refresh rate. In other words, in this application, the corresponding gamma voltage table can be selected according to different situations to ensure consistent brightness of the display panel and low flicker.

[0070] Corresponding to the above Figure 1 The present application also provides a display device, such as a driving method of a display panel. Figure 3 As shown, the display device includes: a timing controller, a gamma chip, a microcontroller and a display panel;

[0071] Among them, the microcontroller is electrically connected to the timing controller, and the timing controller and the microcontroller are both electrically connected to the gamma chip; the timing controller is used to detect the current mode, and when the display mode is a variable refresh rate mode, the timing controller detects the refresh frequency of the picture; when the timing controller detects that the refresh frequency of the previous frame has changed, the timing controller starts to call the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame stored in the gamma chip at the beginning of the current frame; the microcontroller is used to drive the display panel to display the picture through the pixel brightness correction table and gamma voltage called by the current frame when the next frame is displayed.

[0072] It should be noted that the timing controller, gamma chip, and microcontroller constitute a driving device for driving the display panel.

[0073] In an optional implementation manner of an embodiment of the present application, when the current frame is displayed, the timing controller is also used to read the vertical blanking duration of the previous frame; when it is determined that the vertical blanking duration of the previous frame is different from the vertical blanking duration of the previous frame, the timing controller is also used to read the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame in the current frame, so that the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame are used when the next frame is displayed.

[0074] In an optional implementation manner of an embodiment of the present application, the timing controller is also used to switch the data port between the flash memory to a serial peripheral interface SPI, and at the beginning of the vertical blanking period of the current frame, read the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame from the flash memory through the SPI.

[0075] like Figure 5 As shown, the display device further includes an operational amplifier circuit, namely, an OP (Operational Amplifier) ​​circuit; the operational amplifier circuit is connected between the variable resistor and the output end of the gamma tie point voltage; Figure 5 As shown, the gamma tie point voltage output terminal is between two equal-value resistors close to the ground, and the operational amplifier circuit is arranged between the node of the two equal-value resistors close to the ground and the gamma tie point voltage output terminal; the OP circuit stabilizes the gamma tie point voltage, which can make the circuit more stable after the variable resistor / equivalent resistor is connected, thereby ensuring the stable output of the gamma tie point voltage.

[0076] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the display panel driving method provided in any of the aforementioned method embodiments are implemented.

[0077] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0078] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is intended to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for driving a display panel, characterized in that: include: The timing controller detects the current display mode; When the display mode is the variable refresh rate mode, the timing controller detects the refresh frequency of the picture; When the timing controller detects that the refresh frequency of the previous frame has changed, the timing controller starts to call the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame in the current frame; When the next frame is displayed, the microcontroller drives the display panel to display the picture through the pixel brightness correction table and gamma voltage called by the current frame; When the current frame is displayed, the timing controller reads the vertical blanking duration of the previous frame; When it is determined that the vertical blanking duration of the previous frame is different from the vertical blanking duration of the previous frame, the timing controller reads the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame in the current frame, so that the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame are used when displaying the next frame; wherein the gamma voltage table also includes a gamma binding point code provided in the timing controller and a gamma binding point voltage provided in the gamma chip; The steps of calculating the gamma voltage using the gamma binding point code and the gamma binding point voltage include: finding a voltage point adjacent to the gamma binding point voltage, wherein the voltage value of the adjacent voltage point is close to the voltage value of the gamma binding point voltage; setting a variable resistor between the gamma binding point corresponding to the gamma binding point voltage and the adjacent voltage point, wherein the two ends of the variable resistor are respectively connected to the gamma binding point and the adjacent voltage point, and the output end of the variable resistor is connected to a microcontroller; the gamma chip receives the gamma binding point code and the gamma binding point voltage output by the output end of the variable resistor, and obtains the gamma voltage by multiplying the gamma binding point code and the gamma binding point voltage.

2. The method according to claim 1, characterized in that The timing controller reads a pixel brightness correction table and a gamma voltage table corresponding to the refresh frequency of the previous frame of the current frame, including: The data port between the timing controller switch and the flash memory is a serial peripheral interface SPI; At the beginning of the vertical blanking period of the current frame, the timing controller reads the pixel brightness correction table and the gamma voltage table corresponding to the refresh frequency of the previous frame from the flash memory through the SPI.

3. The method according to claim 1, characterized in that The pixel brightness correction table includes multiple preset refresh frequencies and grayscale compensation values ​​mapped one-to-one with each preset refresh frequency; the gamma voltage table includes multiple preset refresh frequencies and the gamma voltage mapped one-to-one with each refresh frequency.

4. The method according to claim 3, characterized in that The gamma binding point codes and the refresh frequencies are mapped one to one, the gamma binding point voltages include at least two, and the gamma voltage is calculated using the gamma binding point codes and the gamma binding point voltages.

5. The method according to claim 1, wherein The gamma binding point voltage includes a fourteenth gamma binding point voltage. The fourteenth gamma binding point of the gamma chip is connected to a ground point. A variable resistor is provided between the fourteenth gamma binding point and the ground point. The variable resistor is connected to a microcontroller. The microcontroller controls the size of the variable resistor to output the fourteenth gamma binding point voltage with different precision.

6. The method according to claim 1, characterized in that The gamma binding point voltage includes a first gamma binding point voltage. The first gamma binding point of the gamma chip is connected to the output end of the microcontroller to receive the AVDD digital voltage. A variable resistor is provided between the first gamma binding point of the gamma chip and the output end of the microcontroller. The variable resistor is connected to the microcontroller, and the microcontroller controls the size of the variable resistor to output the first gamma binding point voltage with different accuracy.

7. The method according to claim 1, characterized in that The display mode includes a constant refresh rate mode and a variable refresh rate mode; The constant refresh rate mode includes a first preset refresh frequency and a first gamma voltage table corresponding to the first preset refresh frequency; The variable refresh rate mode includes a plurality of second preset refresh frequencies and a second gamma voltage table mapped one-to-one with each of the second preset refresh frequencies; The first gamma voltage table is a pre-stored fixed value; The second gamma voltage table is a real-time value calculated according to the detection refresh rate.

8. A display device applied to the method according to any one of claims 1 to 7, characterized in that: include: Timing controller, gamma chip, microcontroller and display panel; Among them, the microcontroller is electrically connected to the timing controller, and the timing controller and the microcontroller are both electrically connected to the gamma chip; the timing controller is used to detect the current mode, and when the display mode is a variable refresh rate mode, the timing controller detects the refresh frequency of the picture; when the timing controller detects that the refresh frequency of the previous frame has changed, the timing controller starts to call the pixel brightness correction table and gamma voltage table corresponding to the refresh frequency of the previous frame stored in the gamma chip at the beginning of the current frame; the microcontroller is used to drive the display panel to display the picture through the pixel brightness correction table and gamma voltage called by the current frame when the next frame is displayed.

Images