Driving method for a display panel and driving device for a display panel

Abstract

The present application relates to a driving method for a display panel and a driving device for a display panel. The method includes: a timing controller detecting a refresh rate of a previous frame and a refresh rate of a current frame of the display panel; when the refresh rate of the current frame is different from the refresh rate of the previous frame, a microcontroller controlling at least one gamma binding point voltage in a gamma binding point voltage group; a gamma chip determining a gamma voltage based on the gamma voltage coding corresponding to the gamma binding point voltage group and the refresh rate of the current frame, and delivering the gamma voltage to the display panel; the display panel driving a next frame display of a display image through the gamma voltage; wherein, the timing controller stores multiple groups of preset frequencies and multiple groups of gamma voltage codings mapped one-to-one with the preset frequencies. Through the present application, the problem in the prior art that when adjusting the gamma voltage at different refresh rates, the brightness change is relatively large during the debugging process, resulting in obvious flickering, is solved.

Description

Technical Field

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

[0002] Variable Refresh Rate (VRR) can enable the entire game process to achieve refresh display from low frequency to high frequency, that is, the screen refresh rate can be matched with the game frame rate in real time, avoiding game screen stuttering and tearing caused by different frequencies. The conventional debugging method in the prior art is to debug the Gamma voltage at different frequencies, so that different Gamma voltages are called at different frequencies, so as to keep the brightness as constant as possible during the display process to ensure the display effect. However, the existing Gamma voltage debugging process is not fine enough, which will cause a large change in brightness during the debugging process, making the flicker more obvious.

[0003] Regarding the above problems in the related art, there is currently no effective solution. Summary of the Invention

[0004] The present application provides a driving method and a driving device for a display panel to solve the problem that when adjusting the Gamma voltage at different refresh rates in the prior art, the brightness changes greatly during the debugging process, making the flicker more obvious.

[0005] In a first aspect, the present application provides a driving method for a display panel, including: a timing controller detecting the refresh frequency of the previous frame and the current frame of the display panel; when the current frame refresh frequency is different from the previous frame refresh frequency, a microcontroller controlling at least one Gamma binding point voltage in the Gamma binding point voltage group; a Gamma chip determining a Gamma voltage based on the Gamma voltage encoding corresponding to the Gamma binding point voltage group and the current frame refresh frequency, and delivering the Gamma voltage to the display panel; the display panel driving the display of the next frame of the display screen through the Gamma voltage; wherein, the timing controller stores multiple groups of preset frequencies and multiple groups of Gamma voltage encodings mapped one-to-one with the preset frequencies.

[0006] Second aspect, the present application provides a driving device for a display panel, including: a timing controller, configured to detect a refresh rate of a display screen of the display panel, and call a corresponding gamma voltage encoding according to a change in the refresh rate and transmit it to a gamma chip; a gamma chip, configured to calculate a gamma voltage according to the gamma voltage encoding and gamma voltage binding points transmitted by the timing controller, and deliver the gamma voltage to the display panel; a microcontroller, configured to adjust at least one of the gamma binding point voltages in a gamma binding point voltage group; the microcontroller is electrically connected to the timing controller, the timing controller and the microcontroller are both electrically connected to the gamma chip, and the timing controller, the gamma chip, and the microcontroller are all electrically connected to the display panel; wherein, the timing controller stores multiple groups of preset frequencies, and multiple groups of gamma voltage encodings that are mapped one-to-one with the preset frequencies.

[0007] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0008] In the present application, the microcontroller controls at least one of the gamma binding point voltages in the gamma binding point voltage group, making the accuracy of the gamma binding point voltage finer. Therefore, the accuracy of the gamma voltage generated and output by the gamma chip based on the gamma binding point voltage and the gamma voltage encoding is finer, that is, the gamma voltage error required for the output gamma voltage to actually maintain a constant brightness is smaller, and the gamma voltage delivered to the display panel is closer to the actually required gamma voltage. Furthermore, when the refresh rate changes, the brightness change is smaller during the process of maintaining the brightness of the screen, thereby reducing the flicker when displaying the screen. Description of the Drawings

[0009] The drawings here are incorporated into the specification and constitute a part of this specification, showing embodiments that conform to the present invention, and are used together with the specification to explain the principles of the present invention.

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0011] Figure 1 It is a flowchart of a driving method for a display panel provided by the present application.

[0012] Figure 2 It is a schematic structural diagram of a driving device for a display panel provided by the present application;

[0013] Figure 3 It is a schematic structural diagram of another driving device for a display panel provided by the present application;

[0014] Figure 4 The structural schematic diagram of another driving device for a display panel provided by this application.

[0015] Among them, 11 - arithmetic amplifier circuit. Specific embodiments

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the scope of protection of this application.

[0017] This application provides a driving method for a display panel, as Figure 1 shown. The steps of this method include:

[0018] Step 101, the timing controller detects the refresh frequency of the previous frame and the refresh frequency of the current frame of the display panel;

[0019] Step 102, when the refresh frequency of the current frame is different from that of the previous frame, the microcontroller controls at least one gamma binding point voltage in the gamma binding point voltage group;

[0020] Step 103, the gamma chip determines the gamma voltage based on the gamma voltage encoding corresponding to the gamma binding point voltage group and the refresh frequency of the current frame, and delivers the gamma voltage to the display panel;

[0021] Step 104, the display panel drives the display of the next frame of the display image through the gamma voltage; among them, the timing controller stores multiple groups of preset frequencies and multiple groups of gamma voltage encodings mapped one - to - one with the preset frequencies.

[0022] It can be seen that in the embodiments of this application, when the refresh frequency of the current frame is different from that of the previous frame, the microcontroller controls at least one gamma binding point voltage in the gamma binding point voltage group, making the accuracy of the gamma binding point voltage finer. Therefore, the accuracy of the gamma voltage generated and output by the gamma chip based on the gamma binding point voltage and the gamma voltage encoding is finer, that is, the error of the gamma voltage actually required to maintain the brightness unchanged for the output gamma voltage is smaller, and the gamma voltage delivered to the display panel is closer to the actually required gamma voltage. Furthermore, when the refresh rate changes and the screen maintains the same brightness, the brightness change is smaller, thereby reducing the flicker when displaying the display image.

[0023] In the existing gamma chip, a set of gamma binding point voltage groups is set. Among them, the gamma binding point voltage group includes multiple gamma binding point voltages. When the timing controller detects a certain refresh frequency, it will transmit the gamma voltage code corresponding to the refresh frequency to the gamma chip. The gamma chip calculates by combining the gamma binding point voltage and the gamma voltage code, outputs a set of gamma voltages, and transmits the gamma voltages to the display panel. The display panel drives the display of the next frame of the display image through the adjusted gamma voltages.

[0024] The gamma binding point voltage group includes at least two gamma binding point voltages, namely the first gamma binding point voltage and the fourteenth gamma binding point voltage. Among them, the first gamma binding point voltage is the positive voltage corresponding to the 255 gray level of white, and the fourteenth gamma binding point voltage is the negative voltage corresponding to the 255 gray level of white.

[0025] In an alternative embodiment of the present application, for the step in which the microcontroller controls at least one gamma binding point voltage in the gamma binding point voltage group in step 102 above, it may further include: finding a neighboring voltage point of the gamma binding point voltage, where the voltage value of the neighboring 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 neighboring voltage point, with both ends of the variable resistor connected to the gamma binding point and the neighboring voltage point respectively, and the output end of the variable resistor connected to the microcontroller.

[0026] It should be noted that the neighboring voltage point may be a ground point, or AVDD (the digital-analog voltage of the microcontroller), or other voltages close to a certain gamma binding point voltage; in addition, the voltage value of the neighboring voltage point being close to the voltage value of the gamma binding point voltage means that the voltage difference between the two is less than a preset threshold, and the threshold may be 1V, 3V, etc., which can be set accordingly according to the actual situation. In this way, the adjusted gamma binding point voltage output through the variable resistor is more refined than the original gamma binding point voltage before adjustment. Therefore, the gamma voltage output by the gamma chip is closer to the gamma voltage value actually required, thereby reducing the flicker caused by the adjustment of the gamma voltage when the refresh frequency changes.

[0027] In this embodiment, in order to obtain a more accurate gamma voltage, at least one gamma binding point voltage is selected for adjustment to obtain a more refined gamma voltage. Therefore, theoretically, each gamma binding point voltage in the gamma binding point voltage group is adjusted to ensure that the output of each gamma voltage is more accurate, and further, when the refresh frequency switches, the brightness remains unchanged and the flicker is less.

[0028] However, the applicant found that if each gamma binding point voltage is adjusted, the circuit will be more complex and the cost will be increased significantly. In order to balance circuit simplification and lower improvement costs, the inventor found that selecting some gamma binding point voltages for adjustment and optimization can also reduce the flicker of the screen when the refresh frequency changes.

[0029] Specifically, the voltage value of the first gamma bonding point is close to that of AVDD. Therefore, a variable resistor is provided between the first bonding point of the gamma chip and the digital-analog voltage of the microcontroller. The voltage of the first gamma bonding point is output from the output terminal of the variable resistor, and the variable resistor is electrically connected to the microcontroller.

[0030] Furthermore, the voltage value of the fourteenth gamma bonding point is close to the voltage value of the ground. Therefore, a variable resistor is provided between the fourteenth bonding point of the gamma chip and the ground. The voltage of the fourteenth gamma bonding point is output from the output terminal of the variable resistor, and the variable resistor is electrically connected to the microcontroller.

[0031] Since the voltage of the first gamma bonding point is the positive-polarity voltage corresponding to the 255 gray level of white, and the voltage of the fourteenth gamma bonding point is the negative-polarity voltage corresponding to the 255 gray level of white; adjusting the gamma voltage of the 255 gray level of white can reduce the brightness fluctuation and flicker more significantly compared with the adjustment of the gamma voltage of other gray levels, and a better display effect can be obtained.

[0032] In this application, at different refresh frequencies of the display panel, the corresponding gamma voltage coding can be matched based on the timing controller. Then, the gamma chip can multiply the gamma voltage coding and the corresponding gamma bonding point voltage to obtain the corresponding gamma voltage. That is to say, the gamma voltage is obtained based on the gamma voltage coding and the corresponding gamma bonding point voltage at different refresh frequencies, making the calculation of the gamma voltage more accurate. Moreover, after the timing controller detects the refresh frequency of the display panel, it immediately triggers the gamma chip to calculate the gamma voltage, and the calculation process is also relatively fast.

[0033] In an alternative embodiment of the embodiment of this application, a variable resistor or multiple equal-value resistors are provided between the first bonding point of the gamma chip and the digital-analog voltage of the microcontroller. By dividing the voltage of the variable resistor or equal-value resistors, the debugging accuracy of the gamma voltage can be higher. In a specific example, if it is a variable resistor, the voltage of the first gamma bonding point is output from the output terminal of the variable resistor, and the variable resistor is electrically connected to the microcontroller.

[0034] For the method in the embodiment of this application in which the microcontroller controls the gamma bonding point voltage corresponding to the gamma bonding point voltage group according to the difference between the refresh frequency of the previous frame and the refresh frequency of the current frame, when the difference is greater than the preset threshold, the microcontroller does not adjust the gamma bonding point voltage; when the difference is less than or equal to the preset threshold, the microcontroller adjusts the resistance value of the variable resistor to adjust the gamma bonding point voltage. Further, it may include:

[0035] Step 21, when the difference is greater than the preset threshold, the microcontroller does not adjust the first gamma binding point voltage;

[0036] Step 22, when the difference is less than or equal to the preset threshold, the microcontroller adjusts the resistance value of the variable resistor to adjust the first gamma binding point voltage.

[0037] It should be noted that when the constant frequency display mode is selected, the equivalent resistance circuit can be directly selected to adjust the output of the gamma voltage according to the predetermined debugging accuracy required. When the variable refresh rate mode is selected, since the refresh rate is constantly changing, considering different situations of the refresh rate change, it may be necessary to adjust the accuracy of the gamma voltage output. Therefore, the variable resistor circuit is selected; at this time, after judging according to the change value of the refresh frequency, it is decided whether to adjust the variable resistor, so as to adjust the output accuracy of the gamma voltage, taking into account the stability of the control circuit and the flicker control, and further improving the display effect.

[0038] Based on this, when the variable refresh rate mode is selected, for the above steps 21 to 22, in a specific example, taking the preset threshold as 60Hz, it can be: obtain the refresh frequencies 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, since the refresh rate changes too much, the gamma voltage values corresponding to the same brightness of the original low refresh rate and high refresh rate are quite different. At this time, a slightly lower gamma voltage adjustment accuracy has little impact on the fluctuation of the picture brightness. Therefore, it is chosen not to adjust the binding point voltage to maintain the consistency of the circuit stability, and the fluctuation of the display is smaller, which is more conducive to reducing the flicker of 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 at this time, the refresh rate changes little, the gamma voltage values corresponding to the same brightness of the original low refresh rate and high refresh rate are also relatively 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 will increase after the gamma voltage is switched, thus deepening the human eye's perception of the flicker), and the brightness is more in line with the actual requirements, effectively avoiding the display brightness fluctuation caused by the refresh rate switching, making it difficult for the human eye to perceive the picture flicker.

[0039] In an alternative embodiment of the present application, a variable resistor or multiple equal-value resistors are provided between the fourteenth bonding point of the gamma chip and the ground. By the voltage division of the variable resistor or equal-value resistors, the debugging accuracy of the gamma voltage can be higher. In a specific example, if it is a variable resistor, the fourteenth gamma bonding point voltage is output from the output terminal of the variable resistor, and the variable resistor is electrically connected to the microcontroller. Based on this, for the method in which the microcontroller involved in the present application controls the gamma bonding point voltage corresponding to the gamma bonding point voltage group according to the difference between the previous frame refresh frequency and the current frame refresh frequency, it may further include:

[0040] Step 31, when the difference is greater than the preset threshold, the microcontroller does not adjust the fourteenth gamma bonding point voltage;

[0041] Step 32, when the difference is less than or equal to the preset threshold, the microcontroller adjusts the resistance value of the variable resistor to adjust the fourteenth gamma bonding point voltage.

[0042] For the above steps 31 and 32, taking the preset threshold as 60Hz as an example, when the change difference B of the refresh frequency is greater than 60Hz, an equal-value resistor circuit is directly selected for the output of the gamma voltage; when the change value of the refresh frequency is less than 60Hz, a variable resistor circuit is directly selected for the output of the gamma voltage. At this time, the variable resistor can be preset to another value different from the equal-value resistor, and the output accuracy of the gamma voltage through the variable resistor circuit is higher than that of the equal-value resistor; at this time, the resistor does not change, and the circuit is kept as stable as possible, but it can also meet the adjustment of the output accuracy of the gamma voltage when the change of the refresh frequency is different. It not only ensures the stability of the circuit, but also can reduce the human eye's perception of flicker according to different changes in the refresh frequency, further improving the display effect. Of course, although a value is preset for the variable resistor, if necessary, the size of the variable resistor can still be changed through the microcontroller. At this time, although a small part of the circuit stability is sacrificed, when the change value of the refresh frequency is less than 60Hz, according to the further subdivision of different change values of the refresh frequency, the different accuracies of the gamma voltage are further controlled, which is beneficial to the effective control of the brightness change or fluctuation, and further effectively reduces the flicker and improves the display effect.

[0043] In the case where no variable resistor or multiple equal-value resistors are set, when the timing controller detects that the area of vertical blanking (V-blank) reaches a certain length, the timing controller will give an instruction through I2C (Inter-Integrated Circuit) connected to the gamma chip to adjust the gamma voltage, so as to make the brightness of the corresponding frequency close and reduce the screen flicker in the VRR mode. Its debugging accuracy is the output voltage / 256 (gray scale 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. However, after setting the variable resistor or multiple equal-value resistors, its debugging accuracy can be higher, that is, the debugging accuracy will be further less than 0.06V. As Figure 2 shown, taking multiple equal-value resistors as an example, if the current number of equal-value resistors is 5, after voltage division by 5 resistors, the debugging accuracy is 0.06 / 5 = 0.012V, which is smaller than the voltage change per grid before debugging. That is to say, the brightness change corresponding to debugging one grid is smaller, so that the flicker is relatively less obvious when the frequency changes. Of course, the values of the above equal-value resistors are only examples and can be further adjusted according to the actual situation. For example, the number of equal-value resistors can be 4, 8, 10, 15, etc.

[0044] The above is only for the first gamma binding point voltage and the fourteenth gamma binding point voltage. After judging according to the difference in the refresh rate, the next step is processed. In fact, for all gamma voltage binding points, the microcontroller can adjust the gamma binding point voltage group according to the difference between the refresh rate of the previous frame and the current frame. 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 value 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 refresh rate of the previous frame and the current frame, that is, it does not adjust the gamma binding point voltage when the refresh rate changes, but controls according to the difference in the refresh rate change. Because if the refresh rate changes too much, the brightness of the original low refresh rate and the gamma voltage change of the high refresh rate will be large. At this time, the slightly lower gamma voltage adjustment accuracy has little impact on the screen brightness fluctuation. Therefore, it is possible to choose not to adjust the binding point voltage to maintain the consistency of the circuit. For the display, the fluctuation is small, which is more conducive to reducing the display flicker. When the refresh rate changes little, the brightness of the original low refresh rate and the gamma voltage change of the high refresh rate are also small. At this time, it is selected to adjust the gamma binding point voltage to improve the fineness of the gamma binding point voltage, so as to improve the fineness of the output gamma voltage, which 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 will increase after the gamma voltage is switched, thus deepening the perception of flicker by the human eye), and the brightness is more in line with the actual requirements (that is, when the brightness is maintained the same, the fluctuation is smaller), effectively avoiding the display brightness fluctuation caused by the refresh rate switching, making it difficult for the human eye to perceive the screen flicker.

[0045] In addition, the embodiment of the present application also provides a display device, as Figure 2 shown. The display device includes: a timing controller, a gamma chip, a microcontroller, and a display panel; the microcontroller is electrically connected to the timing controller, the timing controller and the microcontroller are both electrically connected to the gamma chip, and the timing controller, the gamma chip, and the microcontroller are all electrically connected to the display panel;

[0046] The timing controller is configured to detect the refresh rate of the display screen of the display panel, and call the corresponding gamma voltage coding according to the change of the refresh rate and transmit it to the gamma chip;

[0047] The gamma chip is configured to calculate the gamma voltage according to the gamma voltage coding transmitted by the timing controller and the gamma voltage binding point, and deliver the gamma voltage to the display panel;

[0048] The microcontroller is configured to adjust at least one gamma binding point voltage in the gamma binding point voltage group;

[0049] The microcontroller and the timing controller are electrically connected. The timing controller and the microcontroller are both electrically connected to the gamma chip. The timing controller, the gamma chip, and the microcontroller are all electrically connected to the display panel. Among them, the timing controller stores multiple groups of preset frequencies, and multiple groups of gamma voltage encodings that are mapped one-to-one with the preset frequencies.

[0050] In the embodiment of the present application, when the timing controller detects that the refresh frequency of the current frame is different from that of the previous frame, the timing controller matches the gamma voltage encoding corresponding to the refresh frequency of the current frame and sends the gamma voltage encoding to the gamma chip.

[0051] Based on this, in a specific example, the timing controller detects the refresh frequency of the display panel and matches the gamma voltage encoding corresponding to the refresh frequency. The gamma chip stores a gamma binding point voltage group. The gamma chip receives the gamma voltage encoding and multiplies the gamma voltage encoding by the gamma binding point voltage corresponding to the gamma binding point voltage group to obtain the gamma voltage. The gamma chip transmits the gamma voltage to the display panel, and the display panel is driven by the gamma voltage to display the picture.

[0052] It should be noted that in the present application, the gamma binding voltage group includes multiple gamma binding point voltages, such as the first gamma binding point voltage, the second gamma binding point voltage, etc. Generally, the gamma binding point voltage group includes 14 gamma binding point voltages. In a specific application scenario, corresponding selection and setting can be made according to actual needs. For example, if only the first gamma binding point voltage is required for the calculation of the current gamma voltage, then only multiply the gamma voltage encoding at the current refresh frequency by the gamma binding point voltage corresponding to the first gamma binding point voltage to obtain the gamma voltage.

[0053] It can be seen that in the present application, corresponding gamma voltage encodings can be matched based on the timing controller at different refresh frequencies of the display panel. Furthermore, the gamma chip can multiply the gamma voltage encoding by the corresponding gamma binding point voltage to obtain the corresponding gamma voltage. That is to say, the gamma voltage is obtained based on the gamma voltage encoding and the corresponding gamma binding point voltage at different refresh frequencies, making the calculation of the gamma voltage more accurate. Moreover, after the timing controller detects the refresh frequency of the display panel, it immediately triggers the gamma chip to calculate the gamma voltage, and the calculation process is also relatively fast, solving the problem in the prior art that when directly debugging the gamma voltage at different frequencies, the accuracy of the calculated gamma voltage is relatively low and the debugging process is slow, resulting in obvious flickering of the display panel.

[0054] The microcontroller can be a PMIC (Power Management IC), other microprocessors, etc. In this embodiment, the microcontroller has a built-in AVDD, and the AVDD is close to the voltage of the first gamma bonding point. For example, when the microcontroller is selected as the PMIC, the microcontroller has an interface to output the AVDD, and the AVDD is close to the voltage of the first gamma bonding point. As Figure 4 shown, the microcontroller is connected to the output terminal of the variable resistor. The microcontroller controls the sliding position of the output terminal to control the size of the variable resistor connected, and further controls the size of the gamma bonding point voltage output from the output terminal of the variable resistor. The gamma bonding point voltage is led out from the output terminal of the variable resistor.

[0055] Optionally, the display panel can include at least two display modes, including a constant frequency display mode and a variable refresh rate mode. When displaying at a constant frequency, the refresh rate of the display panel remains unchanged, the brightness remains unchanged, there is basically no flicker, and the power consumption is low; when displaying at a variable refresh rate, since the refresh rates of different frames or time periods are different, the brightness may change at this time, causing display flicker; with the driving device of this display panel, by accurately outputting or regulating the gamma voltage, the display flicker of the display panel can be effectively reduced, thereby improving the display effect.

[0056] In an alternative embodiment of the present application, the timing controller stores multiple groups of preset frequencies (such as 48Hz, 60Hz, 90Hz, 120Hz, 144Hz, etc.), and multiple groups of gamma voltage encodings mapped one-to-one with the preset frequencies (that is, each refresh rate corresponds to a group of gamma voltage encodings). In addition, in the embodiment of the present application, the gamma bonding point voltage group includes at least two gamma bonding point voltages. The gamma bonding point voltage includes at least a first gamma bonding point voltage and a fourteenth gamma bonding point voltage. The first gamma bonding point voltage is the positive voltage corresponding to the 255 gray scale of white, and the fourteenth gamma bonding point voltage is the negative voltage corresponding to the 255 gray scale of white.

[0057] It should be noted that in the embodiment of the present application, the multiple groups of preset frequencies can be 48Hz, 90Hz, 120Hz, 144Hz, etc. The values and quantities of the frequencies in the multiple groups of preset frequencies can be set according to actual needs. In addition, in the present application, the gamma voltage encoding can be correspondingly valued according to the actual frequency. Specifically, the gamma voltage corresponding to the actual frequency is obtained through experiments, debugging, or existing gamma voltage correction technologies, etc., to ensure that the display panel brightness is consistent at high or low refresh frequencies and avoid flicker.

[0058] In an alternative embodiment of the present application, a variable resistor or a plurality of equivalent resistors are provided between the fourteenth gamma tie point and the ground. The voltage of the fourteenth gamma tie point is output via the output terminal of the variable resistor. The variable resistor is electrically connected to the microcontroller. The size of the variable resistor is controlled by the microcontroller, so as to control the voltage of the fourteenth gamma tie point, and further control the output accuracy of the fourteenth gamma voltage. When equivalent resistors are connected between the fourteenth gamma tie point and the ground, at this time, according to the fixed design accuracy, a plurality of equivalent resistors are inserted between the fourteenth gamma tie point and the ground, and the voltage of the fourteenth gamma tie point is obtained by voltage division between adjacent two equivalent resistors, thereby controlling the voltage of the fourteenth gamma tie point, and controlling the output accuracy of the fourteenth gamma voltage. In theory, it is easier to adjust the variable resistor according to the actual situation, which is more convenient. However, when most parameters such as design data, accuracy, display accuracy, and calibration can be determined in the design stage, directly inserting appropriate equivalent resistors during design is also relatively convenient, and the cost of equivalent resistors is lower than that of variable resistors. Therefore, choosing equivalent resistors also has some advantages. Since the voltage of the fourteenth gamma tie point is very close to the voltage of the ground, it is the most convenient and simple to adjust the accuracy of the voltage of the fourteenth gamma tie point. Moreover, the voltage of the fourteenth gamma tie point is the negative voltage corresponding to the 255 gray scale of white. Improving the accuracy of the voltage of the fourteenth gamma tie point enables the actual demand system of the fourteenth gamma voltage. Therefore, adjusting the voltage of the fourteenth gamma tie point is more significant for reducing flicker and improving the display effect.

[0059] In another alternative embodiment of the present application, a variable resistor is provided between the first gamma tie point and the digital-to-analog voltage output terminal of the microcontroller. The voltage of the first gamma tie point is output from the output terminal of the variable resistor. The variable resistor is electrically connected to the microcontroller. The size of the variable resistor is controlled by the microcontroller. In the display device, the microcontroller is connected to the gamma chip and inputs digital-to-analog voltages such as AVDD to the gamma chip. The AVDD is relatively close to the voltage of the first gamma tie point. Therefore, a variable resistor is selected to be inserted between the AVDD and the first gamma tie point, and the output accuracy of the voltage of the first gamma tie point is adjusted by adjusting the variable resistor. Similar to the voltage of the fourteenth gamma tie point, a plurality of equivalent resistors can also be inserted between the first gamma tie point and the digital-to-analog voltage output terminal of the microcontroller. The principle and advantages here are the same as those of the voltage of the fourteenth gamma tie point above, and will not be elaborated here.

[0060] When adjusting the first gamma bonding point voltage, the microprocessor inputs an AVDD close to the first gamma bonding point voltage to the gamma chip. Therefore, it is relatively convenient to adjust the first gamma bonding point voltage. Moreover, the fourteenth gamma bonding point voltage is the positive voltage corresponding to the 255 gray level of white. Improving the accuracy of the first gamma bonding point voltage enables the actual demand system of the first gamma voltage. Therefore, adjusting the first gamma bonding point voltage also has a significant effect on reducing flicker and improving the display effect.

[0061] It should be noted that theoretically, adjusting multiple bonding point voltages to improve the output accuracy of multiple bonding point voltages will enable the display panel to obtain a more accurate gamma voltage during driving and reduce display flicker. However, the applicant found that although adjusting the accuracy of multiple gamma bonding points can obtain a better display effect, in actual application and production, the adjustment of other bonding points is relatively complex or the cost increases significantly. Merely adjusting the first gamma bonding point voltage and / or the fourteenth gamma bonding point voltage can not only effectively improve the display effect, but also the adjustment is relatively simple and convenient, the circuit design structure changes little, and the cost can be taken into account. Therefore, adjusting the first gamma bonding point voltage and / or the fourteenth gamma bonding point voltage is the optimal solution for reducing flicker by adjusting the gamma voltage accuracy.

[0062] It can be seen that in the embodiment of the present application, a variable resistor or multiple equivalent resistors can be provided between the first gamma bonding point voltage and the ground, and / or between the fourteenth gamma bonding point voltage and the ground. The voltage division of the variable resistor can make the debugging accuracy of the gamma voltage higher.

[0063] In the case where no variable resistor or multiple equivalent resistors are provided, when the timing controller detects that the vertical blanking (V-blank) area of a frame of display screen reaches a certain length, the timing controller will give an instruction through the I2C (Inter-Integrated Circuit) connected to the gamma chip to adjust the gamma voltage so that the brightness of the corresponding frequency is close and reduce the screen flicker in the VRR mode. Taking the fourteenth gamma bonding point voltage as an example, its debugging accuracy is the output voltage / 256 (gray scale value). If the output voltage is 16V, the debugging accuracy is 0.06V. If the current output voltage to be adjusted is greater than 6V, the debugging accuracy of 0.06V cannot meet further requirements, while after setting the variable resistor or multiple equivalent resistors, its debugging accuracy can be higher, that is, the debugging accuracy will be further less than 0.06V. For example Figure 2As shown, taking multiple equal-value resistors as an example, if the current number of equal-value resistors is 5, then after voltage division by 5 resistors, the debugging accuracy is 0.06 / 5 = 0.012V. Compared with the previous voltage change per grid before debugging, it is smaller. That is to say, the corresponding brightness change per grid is smaller, so that the flicker is relatively less obvious when the frequency changes. Of course, the values of the above equal-value resistors are only for illustration and can be further adjusted according to the actual situation. For example, the number of equal-value resistors can be 4, 8, 10, 15, etc.

[0064] To further illustrate the beneficial effects of the above embodiments, assume that the required value of the first gamma voltage is 10.1V. When the variable resistor is not inserted, assume that the first gamma binding point voltage is 0.01V and the first gamma code is 1122. Then the first gamma voltage output by the gamma chip at this time is 11.22V; if the variable resistor is inserted at this time and the first gamma binding point voltage is adjusted to 0.09V, then the first gamma voltage output by the gamma chip at this time is 10.098V; it can be seen that when the variable resistor is inserted, the first gamma voltage is closer to its actual required value, and the brightness change is smaller when the first gamma voltage is output to drive the display panel. By further controlling the accuracy, the display flicker can be effectively reduced.

[0065] In addition, the values of the equal-value resistors in the embodiments of the present application can be set according to actual needs. For example, the equal-value resistor values are 5 ohms, 10 ohms, etc.

[0066] In another alternative embodiment of the embodiments of the present application, as Figure 3 shown, the display device further includes an operational amplifier circuit, that is, an OP (Operational Amplifier) circuit; the operational amplifier circuit is connected between the variable resistor and the output end of the gamma binding point voltage; as Figure 3 shown, the gamma binding point voltage output end 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 binding point voltage output end; the OP circuit stabilizes the gamma binding point voltage, which can make the circuit more stable after the variable resistor / equal-value resistor is connected and ensure the stable output of the gamma binding point voltage.

[0067] The embodiments of the present application also provide a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the display panel driving method provided in any one of the foregoing method embodiments are implemented.

[0068] It should be noted that in this text, relational terms such as "first" and "second" are only used 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 term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0069] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A driving method for a display panel, characterized in that, a timing controller detects the refresh frequency of the previous frame and the current frame of the display panel; wherein, when the timing controller detects that the refresh frequency of the current frame is different from that of the previous frame, the timing controller matches the gamma voltage encoding corresponding to the current frame refresh frequency and transmits the gamma voltage encoding to the gamma chip; when the current frame refresh frequency is different from the previous frame refresh frequency, a microcontroller controls at least one gamma binding point voltage in the gamma binding point voltage group; wherein, the gamma binding point voltage group includes at least two gamma binding point voltages, and the gamma binding point voltage at least includes a first gamma binding point voltage and a fourteenth gamma binding point voltage, the first gamma binding point voltage is the positive voltage corresponding to the 255 gray level of white, and the fourteenth gamma binding point voltage is the negative voltage corresponding to the 255 gray level of white; the gamma chip determines the gamma voltage by multiplying at least one gamma binding point voltage in the gamma binding point voltage group by the gamma voltage encoding corresponding to the current frame refresh frequency, and transmits the gamma voltage to the display panel; the display panel drives the display of the next frame of the display image through the gamma voltage; wherein, the timing controller stores multiple groups of preset frequencies and multiple groups of gamma voltage encodings mapped one-to-one with the preset frequencies; wherein, the step of the microcontroller controlling at least one gamma binding point voltage in the gamma binding point voltage group includes: finding a neighboring voltage point of the gamma binding point voltage, the voltage value of the neighboring 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 neighboring voltage point, both ends of the variable resistor are respectively connected to the gamma binding point and the neighboring voltage point, and the output end of the variable resistor is connected to the microcontroller, and the size of the variable resistor is controlled by the microcontroller.

2. The method according to claim 1, characterized in that, a variable resistor is provided between the first binding point of the gamma chip and the digital-to-analog voltage of the microcontroller, the first gamma binding point voltage is output from the output end of the variable resistor, and the variable resistor is electrically connected to the microcontroller.

3. The method according to claim 1, characterized in that, a variable resistor is provided between the fourteenth binding point of the gamma chip and the ground, the fourteenth gamma binding point voltage is output from the output end of the variable resistor, and the variable resistor is electrically connected to the microcontroller.

4. A driving device for a display panel, characterized in that, comprising: a timing controller, configured to detect the refresh frequency of the display image of the display panel and call the corresponding gamma voltage encoding according to the change of the refresh frequency and transmit it to the gamma chip; a gamma chip, configured to calculate the gamma voltage by multiplying the gamma voltage encoding transmitted by the timing controller by the gamma voltage binding point and transmit the gamma voltage to the display panel; a microcontroller, configured to adjust at least one of the gamma binding point voltages in the gamma binding point voltage group when the current frame refresh frequency is different from the previous frame refresh frequency; The microcontroller and the timing controller are electrically connected. The timing controller and the microcontroller are both electrically connected to the gamma chip. The timing controller, the gamma chip, and the microcontroller are all electrically connected to the display panel. Among them, the timing controller stores multiple groups of preset frequencies and multiple groups of gamma voltage encodings that are mapped one-to-one with the preset frequencies. Among them, when the timing controller detects that the refresh frequency of the current frame is different from that of the previous frame, the timing controller matches the gamma voltage encoding corresponding to the refresh frequency of the current frame and sends the gamma voltage encoding to the gamma chip. Among them, the gamma binding point voltage group includes at least two gamma binding point voltages. The gamma binding point voltage at least includes a first gamma binding point voltage and a fourteenth gamma binding point voltage. The first gamma binding point voltage is the positive voltage corresponding to the 255 gray level of white, and the fourteenth gamma binding point voltage is the negative voltage corresponding to the 255 gray level of white. Among them, a variable resistor is provided between the first binding point of the gamma chip and the digital-analog voltage of the microcontroller. The first gamma binding point voltage is output from the output end of the variable resistor. The variable resistor is electrically connected to the microcontroller, and the size of the variable resistor is controlled by the microcontroller.

5. The driving device of the display panel according to claim 4, characterized in that a variable resistor is provided between the fourteenth binding point of the gamma chip and the ground. The fourteenth gamma binding point voltage is output from the output end of the variable resistor. The variable resistor is electrically connected to the microcontroller, and the size of the variable resistor is controlled by the microcontroller.

6. The driving device of the display panel according to claim 5, characterized in that the driving device of the display panel further includes an operational amplifier circuit. The operational amplifier circuit is connected between the variable resistor and the output end of the gamma binding point voltage. The operational amplifier circuit stabilizes the gamma binding point voltage.

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