Driving method of display panel, driving chip, display device and electronic equipment

Abstract

The invention discloses a driving method of a display panel, a driving chip, a display device and electronic equipment, and the driving method comprises the steps: calculating the first high level time of a PWM signal of a current display frame according to the display brightness value of the current display frame; obtaining second high level time of each row according to the first high level time and the minimum change unit; determining the number of display frames in one compensation period according to the display precision; a compensation value and the number of compensation frames are obtained according to the second high level time, the display precision and the compensation lookup table, inter-frame compensation is conducted on the compensation frames in the compensation period, and the number of the compensation frames is smaller than the number of the display frames in the compensation period. According to the driving method of the display panel, the driving chip, the display device and the electronic equipment, one compensation period is determined according to the corresponding second high level time and display precision of each row under the current display brightness value, and compensation of the display frame is completed in the compensation period.

Description

Technical Field

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

[0002] Since the popularization of organic electroluminescence display (OLED) screens in the mobile phone industry, the improvement in screen display effects has been obvious to all, such as high refresh rate, low blue light, high dynamic range imaging (HDR), etc., which have brought users a better screen viewing experience.

[0003] Currently, the OLED screens on the market mainly have DC dimming and PWM dimming. PWM dimming, the full name of which is Pulse Width Modulation, controls the brightness of the screen by controlling the time ratio of the screen being bright and dark in a unit cycle. On a PWM dimming screen, the screen keeps flickering from "bright → dark → bright" to control the amount of light emitted by the screen, but because of the residual vision of the human eye, the screen is always bright.

[0004] Due to the physical characteristics of the panel, PWM has a minimum change unit, which limits the dimming accuracy of PWM. For example, if the panel resolution is 2920, at a certain brightness, the lighting time is expected to account for 50%, that is, 1460 lines, but the minimum unit of panel change is 8 lines, so only 1456 / 2920=49.8% can be achieved. This slight deviation will lead to a loss of dimming accuracy, which in turn affects the overall display quality.

[0005] In addition, PWM dimming will have different dimming frequencies under different display brightness. For example, under high brightness (1000nit), there is only one pulse per unit time, and under low brightness (50nit), there are multiple pulses. This rapid switching from a single pulse to multiple pulses is often accompanied by slight fluctuations in brightness. This phenomenon will also weaken the user's visual experience and reduce the stability of the display.

[0006] Therefore, improving the accuracy and stability of PWM dimming is a key link in current display brightness technology. Summary of the invention

[0007] In view of the above problems, the object of the present invention is to provide a driving method, a driving chip, a display device and an electronic device for a display panel, wherein the second high level time of each corresponding row is obtained through the first high level time and the minimum change unit under the current display brightness value, and then a compensation period is determined according to the second high level time and the display accuracy, and the compensation of the display frame is completed within the compensation period.

[0008] According to one aspect of the present invention, a method for driving a display panel is provided, which includes: calculating a first high level time of a PWM signal of a current display frame according to a display brightness value of the current display frame; obtaining a second high level time of each row according to the first high level time and a minimum change unit; determining the number of display frames of a compensation cycle according to display accuracy; obtaining a compensation value and the number of compensation frames according to the second high level time, the display accuracy and a compensation lookup table, performing inter-frame compensation on the compensation frames within the compensation cycle, the number of compensation frames being greater than or equal to 1 and less than the number of display frames of the compensation cycle.

[0009] Optionally, the second high level time includes an integer part and a decimal part, and the compensation value is obtained according to the decimal part of the second high level time.

[0010] Optionally, according to the display brightness value of the current display frame, the step of calculating the first high level time of the PWM signal of the current display frame includes: obtaining the maximum value and the minimum value of the interval in which the display brightness value is located; obtaining the first high level time of the PWM signal according to the maximum value and the minimum value of the interval and an interpolation algorithm, wherein the maximum value and the minimum value of the interval include the maximum value of the brightness display value of the interval and its corresponding PWM signal duty cycle, and the minimum value of the brightness display value and its corresponding PWM signal duty cycle.

[0011] Optionally, the minimum change unit is the minimum change unit when a pixel row in the display panel emits light under the control of a PWM signal.

[0012] Optionally, the second high level time of each row is the quotient of the first high level time and the minimum change unit.

[0013] Optionally, the number of display frames in one compensation cycle is: 1 divided by the value of the display accuracy.

[0014] Optionally, the compensation value and the number of compensation frames are obtained according to the second high level time, the display accuracy and the compensation lookup table, and the step of performing inter-frame compensation on the compensation frames within the compensation period includes: searching the compensation lookup table according to the decimal part of the second high level time and the number of display frames of the compensation period to obtain the compensation value; searching the compensation lookup table according to the decimal part of the second high level time and the display accuracy to obtain the number of compensation frames; and compensating the compensation value to the corresponding compensation frame according to the minimum compensation value.

[0015] Optionally, the compensation value is the product of a fractional part of the second high level time and the number of display frames of the compensation period, and the compensation value includes an integer part and a fractional part.

[0016] Optionally, the number of compensation frames is the quotient of a fractional part of the second high level time and the display accuracy.

[0017] Optionally, the value of the integer part of the compensation value is equal to the value of the number of compensation frames.

[0018] Optionally, when the integer part of the compensation value is equal to the minimum compensation value, the compensation value is added to a display frame within the compensation period; when the integer part of the compensation value is greater than the minimum compensation value, the compensation value is divided into multiple minimum compensation values ​​and added to multiple corresponding compensation frames within the compensation period.

[0019] Optionally, the position of the compensation frame is determined according to the priority of the display frame and the number of the compensation frames in the compensation period, and the display frame with a higher priority is more likely to be used as a compensation frame.

[0020] Optionally, after obtaining the compensation value and the number of compensation frames according to the second high level time, the display accuracy and the compensation lookup table, and performing inter-frame compensation on the compensation frames within the compensation period, the method further includes: obtaining a first frequency corresponding to a current display brightness value and a second frequency corresponding to a next display brightness value; determining whether the second frequency is a jump increase compared to the first frequency, the jump increase indicating that among all frequencies arranged from large to small or from small to large, there is another frequency between the two frequencies; when the second frequency is not a jump increase compared to the first frequency, displaying according to the PWM signal of the second frequency; when the second frequency is a jump increase compared to the first frequency, generating a transition frequency according to the first frequency, and displaying according to the transition frequency and the second frequency in sequence, wherein the value of the transition frequency is greater than the first frequency and less than the second frequency.

[0021] Optionally, the step of generating a transition frequency according to the first frequency includes: acquiring a PWM signal of the first frequency; and increasing the number of pulses to obtain the transition frequency while keeping the pulse position of the PWM signal of the first frequency unchanged.

[0022] Optionally, the transition frequency includes at least one.

[0023] According to another aspect of the present invention, a driving chip is provided, wherein the driving chip is used to execute the above-mentioned display panel driving method.

[0024] According to another aspect of the present invention, a display device is provided, comprising a display panel and the above-mentioned driving chip.

[0025] Preferably, the display panel emits light when the PWM signal is at a low level, and the display panel includes an OLED display panel.

[0026] According to another aspect of the present invention, there is provided an electronic device, comprising the above-mentioned display device.

[0027] The driving method, driving chip, display device and electronic device of the display panel provided by the present invention obtain the first high level time at the current brightness by interpolation method, and then obtain the second high level time of each row according to the first high level time and the minimum change unit, the second high level time includes an integer part and a decimal part, the number of display frames in a compensation cycle is determined according to the display accuracy, and then the compensation value is determined according to the number of display frames and the decimal part of the second high level time, and the compensation of the display frame is completed within the compensation cycle according to the compensation lookup table, so as to improve the accuracy of PWM dimming in a time domain compensation manner.

[0028] Furthermore, in the display panel driving method, driving chip, display device and electronic device provided by the present invention, during the PWM signal dimming process, if the pulse frequency of the PWM signal jumps and increases, on the basis of the original first frequency (low frequency), the pulse position is preferentially kept unchanged, and then the number of pulses is gradually increased on this basis to obtain the transition frequency, thereby increasing the pulse frequency and finally reaching the second frequency, thereby achieving the smoothness of the frequency jump of the PWM signal through the transition frequency, thereby improving the display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0030] Figure 1 A flow chart showing a method for driving a display panel according to an embodiment of the present invention is shown;

[0031] Figure 2A schematic comparison table of display brightness and PWM signal frequency according to an embodiment of the present invention is shown;

[0032] Figure 3 A flow chart of a method for driving a display panel during frequency hopping according to an embodiment of the present invention is shown;

[0033] Figure 4 A waveform diagram corresponding to a method for driving a display panel during frequency hopping according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0034] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by the same or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale.

[0035] It should be understood that in the following description, a "circuit" may include a single or multiple combined hardware circuits, programmable circuits, state machine circuits, and / or elements capable of storing instructions executed by programmable circuits. When an element or circuit is said to be "connected to" another element or an element or circuit is said to be "connected between" two nodes, it may be directly coupled or connected to another element or there may be an intermediate element, and the connection between the elements may be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected to" another element, it means that there is no intermediate element between the two.

[0036] At the same time, certain words are used in this patent specification and claims to refer to specific components. It should be understood by those skilled in the art that hardware manufacturers may use different terms to refer to the same component. This patent specification and claims do not use differences in names as a way to distinguish components, but rather use differences in components' functions as the criteria for distinction.

[0037] In addition, it should be noted that, in this article, 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 such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the statement "comprise one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0038] The specific implementation of the present invention is further described in detail below in conjunction with the drawings and examples.

[0039] Figure 1 A flow chart showing a method for driving a display panel according to an embodiment of the present invention is shown; Figure 2 A schematic comparison table of display brightness and PWM signal frequency according to an embodiment of the present invention is shown; Figure 3 A flow chart of a method for driving a display panel during frequency hopping according to an embodiment of the present invention is shown; Figure 4 A waveform diagram corresponding to a method for driving a display panel during frequency hopping according to an embodiment of the present invention is shown.

[0040] refer to Figure 1 The driving method of the display panel of the present application improves the accuracy of PWM dimming by time domain compensation through inter-frame compensation. Specifically, the driving method includes the following steps:

[0041] Step S110: calculating the first high level time of the PWM signal of the current display frame according to the display brightness value of the current display frame.

[0042] In this step, the display brightness value DBV (Display Brightness Value) of the current display frame is first obtained, and then an interpolation algorithm is performed according to the maximum and minimum values ​​of the interval in which the display brightness value DBV is located to obtain the first high level time H1 of the PWM signal of the current display frame corresponding to the display brightness value.

[0043] The display brightness value DBV is a parameter used to indicate the brightness of the OLED display panel. Its value range is usually limited to the interval [0, 4095]. The larger the DBV value, the higher the brightness, which can be equivalent to the brightness bar on a mobile phone. However, the value range is divided into multiple small intervals, and the pulse frequency of the PWM signal corresponding to different small intervals is different. Figure 2 As shown, for example, the frequency of the PWM signal pulse corresponding to the brightness interval DBV(1)-DBV(2) is PWM(1), and the frequency of the PWM signal pulse corresponding to the brightness interval DBV(2)-DBV(3) is PWM(2). If the difference between the maximum value and the minimum value in the brightness interval is small, there is also a situation where the corresponding PWM signal pulse frequencies between two adjacent small intervals are the same, but in general, the larger the display brightness value, the smaller the corresponding PWM signal frequency.

[0044] In practical applications, each display brightness value DBV corresponds to a gamma parameter, which includes the corresponding PWM duty cycle of the light-emitting control signal (EM Duty). Therefore, in this step, since the PWM duty cycle of the light-emitting control signal corresponding to the maximum and minimum values ​​of the interval where the current display brightness value DBV is located can be obtained by looking up the table, the PWM duty cycle of the light-emitting control signal corresponding to the current display brightness value DBV can be obtained according to the interpolation algorithm. The duty cycle (Duty Cycle) describes the ratio of the duration of the "high level" in the periodic waveform to the entire cycle time. Therefore, knowing the PWM duty cycle of the light-emitting control signal corresponding to the current display brightness value DBV is equivalent to knowing the first high level time H1 of the PWM signal of the current display frame.

[0045] Step S120: Obtain the second high level time of each row according to the first high level time and the minimum change unit.

[0046] In this step, the first high level time H1 corresponding to the current frame is divided by the minimum change unit of the PWM signal, so as to obtain the second high level time H2 of each row.

[0047] The minimum change unit is limited by the physical characteristics of the panel. It is the minimum change unit when the PWM signal dims the display panel's pixel rows to emit light. For example, in a display panel, the minimum change unit of the PWM signal is 8 rows, which means that each time the PWM signal controls the display panel to emit light, 8 rows will emit light at the same time, and no other number of pixel rows will emit light.

[0048] In addition, the second high level time H2 actually represents the theoretical average brightness contribution of each row under the current display brightness value DBV and the minimum change unit.

[0049] The second high level time H2 includes an integer part and a decimal part, the integer part represents the display brightness value that the display panel can display under the minimum change unit, and the decimal part represents the display brightness value that the display panel cannot display under the minimum change unit.

[0050] Step S130: Determine the number of display frames in a compensation cycle according to the display accuracy.

[0051] In this step, the length of a compensation cycle is determined according to the display accuracy, wherein the number of display frames in a compensation cycle is a value obtained by dividing 1 by the display accuracy.

[0052] In one embodiment, if the display accuracy is 0.1step, the number of display frames in one compensation cycle is 10 frames; if the display accuracy is 0.2step, the number of display frames in one compensation cycle is 5 frames; if the display accuracy is 0.01step, the number of display frames in one compensation cycle is 100 frames.

[0053] In the present application, the display accuracy can be changed by setting the register as needed.

[0054] Step S140: obtaining a compensation value and the number of compensation frames according to the second high level time, display accuracy and the compensation lookup table, and performing inter-frame compensation on the compensation frames within the compensation period.

[0055] In this step, the compensation lookup table is searched according to the fractional part of the second high level time H2 and the number of display frames of the compensation cycle to obtain the compensation value under the minimum change unit, and the preset compensation lookup table is searched according to the fractional part of the second high level time H2 and the display accuracy to obtain the number of corresponding compensation frames in the compensation cycle under the minimum change unit, and the compensation value is added to the corresponding compensation frame according to the minimum compensation value. Among them, the preset compensation lookup table gives the compensation value and the number of compensation frames corresponding to the fractional part of the second high level time H2 of various display accuracies and different values.

[0056] The specific calculation method of the compensation value and the number of compensation frames is as follows: the compensation value is, for example, the product of the fractional part of the second high level time H2 and the number of display frames in one compensation cycle, and the compensation value includes an integer part and a fractional part; the number of compensation frames is, for example, the quotient of the fractional part of the second high level time H2 and the display accuracy. In one compensation cycle, the number of compensation frames is greater than or equal to 1 and less than the number of display frames in the compensation cycle.

[0057] Since the compensation frame can only complete the compensation of the integer part of the compensation value, when the compensation value includes a valid decimal part, the decimal part cannot be compensated within the compensation cycle. The value of the integer part of the compensation value is equal to the value of the number of compensation frames.

[0058] In addition, when the integer part of the compensation value is equal to the minimum compensation value, the compensation value is added to a display frame within the compensation period; when the integer part of the compensation value is greater than the minimum compensation value, the integer part of the compensation value is divided into multiple minimum compensation values ​​and added to multiple corresponding compensation frames within the compensation period.

[0059] When the compensation frame includes multiple compensation frames, the multiple compensation frames are evenly distributed in one compensation cycle. In other embodiments, the display frames in a compensation cycle can also be set as the priority of the compensation frames. The higher the priority, the easier it is to be selected as the compensation frame, so that the display frames in the compensation cycle can be judged as compensation frames according to the priority. For example, the number of display frames in a compensation cycle is 5 frames, and the priority is set from large to small. Then, when the compensation frame is one frame, the first display frame in the compensation cycle is the compensation frame; when the compensation frame is three frames, the first three frames in the compensation cycle are the compensation frames; if the priority is set to 3, 5, 2, 4, and 1 (for example, the larger the value, the higher the priority), then when the compensation frame is one frame, the second display frame in the compensation cycle is the compensation frame; when the compensation frame is three frames, the first frame, the second frame, and the fourth frame in the compensation cycle are compensation frames.

[0060] In this embodiment, the display frames within the compensation period are compensated according to the minimum compensation value, which can minimize the inter-frame display quality problem within the compensation period, and at the same time, the brightness compensation of the display frames can be completed, thereby improving the display brightness. The minimum compensation value is the minimum display brightness value that can be achieved by the display panel under the limitation of the minimum change unit, and the minimum compensation value is an integer.

[0061] In one embodiment, if the value of the second high level time H2 is 12.2, the display accuracy is 0.2step, the minimum compensation value is 1, and the priority of the compensation frame is from low to high, the number of display frames in one compensation cycle is 5 frames, and the compensation value calculated and obtained according to the compensation lookup table is 1, and the number of compensation frames is 1. Before compensation, the high level time of the minimum change unit of the display frames of these 5 frames is [12, 12, 12, 12, 12], and the high level time of the minimum change unit of the display frames of the 5 frames after compensation is, for example, [12, 12, 12, 12, 13], thereby achieving the purpose of improving the accuracy of PWM signal dimming by time domain compensation.

[0062] In another embodiment, if the value of the second high level time H2 is 12.3, the display accuracy is 0.2step, the minimum compensation value is 1, and the priority of the compensation frame is from low to high, the number of display frames in one compensation cycle is 5 frames, and the compensation value calculated and obtained according to the compensation lookup table is 1.5, and the number of compensation frames is 1. Before compensation, the high level time of the minimum change unit of the display frames of these 5 frames is [12, 12, 12, 12, 12], and the high level time of the minimum change unit of the display frames of the 5 frames after compensation is [12, 12, 12, 12, 13].

[0063] In another embodiment, if the value of the second high level time H2 is 12.7, the display accuracy is 0.1step, the minimum compensation value is 1, and the priority of the compensation frame is from low to high, the number of display frames in one compensation cycle is 10 frames, and the compensation value calculated and obtained according to the compensation lookup table is 7, and the number of compensation frames is 7. Before compensation, the high level time of the minimum change unit of the display frames of these 10 frames is [12, 12, 12, 12, 12, 12, 12, 12, 12], and the high level time of the minimum change unit of the display frames of the 10 frames after compensation is [12, 12, 12, 13, 13, 13, 13, 13, 13, 13].

[0064] In this embodiment, the corresponding inter-frame compensation is performed on the display frames within the compensation period, which is actually the adjustment of the duty cycle of the corresponding display frame, and does not affect the frequency of the PWM signal. The following will introduce a technical solution for adjusting the frequency of the PWM signal on this basis. This technical solution is completed by a micro control unit in the display device, for example, after the inter-frame compensation is completed.

[0065] refer to Figure 3 The PWM signal pulse dimming method when the PWM signal frequency jumps includes the following steps:

[0066] Step S210: obtaining a first frequency corresponding to a current display brightness value and a second frequency corresponding to a next display brightness value.

[0067] Since different display brightness intervals correspond to different PWM signal frequencies, when the current display brightness value and the next display brightness value are obtained, the corresponding first frequency and second frequency can be obtained.

[0068] Generally, the larger the display brightness value, the smaller the corresponding PWM signal frequency. Therefore, when the display brightness value changes greatly, the difference between the first frequency and the second frequency will also be large. If there is at least one frequency gap between the first frequency and the second frequency, when the display panel changes from the current display brightness value to the next display brightness value, the jump of the accompanying frequency will reduce the user's visual experience and reduce the stability of the display image.

[0069] Step S220: whether the second frequency is a jump increase compared to the first frequency.

[0070] In this step, it is determined whether the second frequency is a jump increase compared to the first frequency. A jump increase means that in the display panel, when all frequencies of the PWM signal that can be realized are arranged from large to small or from small to large, there is another frequency between the two frequencies.

[0071] Among them, reference Figure 2It can be seen that the frequency of the PWM signal increases step by step as the display brightness value of the display panel gradually decreases. It is normal for the frequency to increase or decrease step by step as the display brightness value changes. However, when the frequency jumps and increases, the user's visual experience is reduced. This problem can be improved.

[0072] In one embodiment, the frequencies of the PWM signal are 10 Hz, 20 Hz, 30 Hz, 60 Hz, 120 Hz, etc. from small to large. When the frequency of the PWM signal changes from 10 Hz to 30 Hz, the frequency jumps and increases because there is a 20 Hz gap in between.

[0073] When the second frequency increases by a jump compared to the first frequency, step S240 is executed; when the second frequency does not increase by a jump compared to the first frequency, step S230 is executed.

[0074] Step S230: display according to the PWM signal of the second frequency.

[0075] In this step, since the second frequency does not increase in a jump compared to the first frequency, the display panel performs brightness display according to the PWM signal of the second frequency.

[0076] Step S240: generating a transition frequency according to the first frequency, and displaying according to the PWM signals of the transition frequency and the second frequency in sequence.

[0077] In this step, since the second frequency jumps and increases compared with the first frequency, the process of changing from the first frequency to the second frequency also includes at least one transition frequency, thereby improving the display stability of the display panel when the brightness jumps.

[0078] In this embodiment, the transition frequency is obtained by keeping the original pulse position in the PWM signal of the first frequency unchanged and then increasing the number of some pulses on the basis of the PWM signal corresponding to the first frequency. Therefore, the transition frequency is greater than the first frequency but less than the second frequency. Figure 4 For example, when the display brightness value changes from 1000nit to 100nit, the corresponding first frequency jumps to the second frequency. The transition frequency can be regarded as the corresponding frequency at 200nit. At this time, the transition frequency is obtained by increasing the number of pulses on the basis of the first frequency.

[0079] In addition, compared with the PWM signal of the first frequency, the period of the PWM signal with the transition frequency may be different, and even if the period is the same, the duty cycle may be different. Figure 4As shown in the accompanying drawings, for example, when the display brightness value changes from 1000 nit to 100 nit, the corresponding first frequency jumps to the second frequency, and the transition frequency can be regarded as the corresponding frequency at 200 nit. At this time, the period and duty cycle of the PWM signal in the transition frequency may be different.

[0080] In the OLED display panel, since it emits light under low-level conditions, when the display brightness value jumps from high to low, the frequency of the PWM signal jumps from low to high, and the transition frequency increases the number of pulses on the basis of the first frequency, thereby increasing the duty cycle of the PWM signal and reducing the light-emitting time of the OLED display panel, thereby achieving the purpose of lowering the display brightness value.

[0081] The display panel driving method of the present application can be implemented through the existing structure inside the display panel, for example, through a micro control unit, without the need for additional registers.

[0082] Furthermore, the present application provides a driving chip for executing the above-mentioned display panel driving method.

[0083] Furthermore, the present application also provides a display device, comprising a display panel and the above-mentioned driving chip, wherein the display panel is a display panel that emits light under a low-level PWM signal, such as an OLED display panel.

[0084] Furthermore, the present application also provides an electronic device, which includes the above-mentioned display device.

[0085] The driving method, driving chip, display device and electronic device of the display panel provided by the present invention obtain the first high level time at the current brightness by interpolation method, and then obtain the second high level time of each row according to the first high level time and the minimum change unit, the second high level time includes an integer part and a decimal part, the number of display frames in a compensation cycle is determined according to the display accuracy, and then the compensation value is determined according to the number of display frames and the decimal part of the second high level time, and the display frame is compensated within the compensation cycle according to the compensation lookup table, so as to improve the accuracy of PWM signal dimming in a time domain compensation manner.

[0086] Furthermore, in the display panel driving method, driving chip, display device and electronic device provided by the present invention, during the PWM signal dimming process, if the pulse frequency of the PWM signal jumps and increases, on the basis of the original first frequency (low frequency), the pulse position is preferentially kept unchanged, and then the number of pulses is gradually increased on this basis to obtain the transition frequency, thereby increasing the pulse frequency and finally reaching the second frequency, thereby achieving the smoothness of the frequency jump of the PWM signal through the transition frequency, thereby improving the display effect.

[0087] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for driving a display panel, wherein: include: Calculate the first high level time of the PWM signal of the current display frame according to the display brightness value of the current display frame; Obtaining the second high level time of each row according to the first high level time and the minimum change unit; According to the display accuracy, the number of display frames in a compensation cycle is determined; The compensation value and the number of compensation frames are obtained according to the second high level time, the display accuracy and the compensation lookup table, and inter-frame compensation is performed on the compensation frames within the compensation period. The number of compensation frames is greater than or equal to 1 and less than the number of display frames in the compensation period.

2. The driving method according to claim 1, wherein: The second high level time includes an integer part and a decimal part, and the compensation value is obtained according to the decimal part of the second high level time.

3. The driving method according to claim 2, wherein: The step of calculating the first high level time of the PWM signal of the current display frame according to the display brightness value of the current display frame comprises: Obtaining the maximum and minimum values ​​of the interval in which the display brightness value is located; The first high level time of the PWM signal is obtained according to the maximum value and the minimum value of the interval and the interpolation algorithm. The maximum value and the minimum value of the interval include the maximum value of the brightness display value of the interval and its corresponding PWM signal duty cycle, and the minimum value of the brightness display value and its corresponding PWM signal duty cycle.

4. The driving method according to claim 3, wherein: The minimum change unit is the minimum change unit when a pixel row in the display panel emits light under the control of the PWM signal.

5. The driving method according to claim 4, wherein: The second high level time of each row is the quotient of the first high level time and the minimum change unit.

6. The driving method according to claim 5, wherein: The number of display frames in one compensation cycle is: 1 divided by the value of the display accuracy.

7. The driving method according to claim 6, wherein: The step of obtaining the compensation value and the number of compensation frames according to the second high level time, the display accuracy and the compensation lookup table, and performing inter-frame compensation on the compensation frames within the compensation period includes: Searching the compensation lookup table according to the fractional part of the second high level time and the number of display frames of the compensation period to obtain the compensation value; Search the compensation lookup table according to the fractional part of the second high level time and the display precision to obtain the compensation frame quantity; The compensation value is compensated to the corresponding compensation frame according to the minimum compensation value.

8. The driving method according to claim 7, wherein: The compensation value is the product of the fractional part of the second high level time and the number of display frames of the compensation period, and the compensation value includes an integer part and a fractional part.

9. The driving method according to claim 7, wherein: The number of compensation frames is the quotient of the fractional part of the second high level time and the display accuracy.

10. The driving method according to claim 9, wherein: The value of the integer part of the compensation value is equal to the value of the compensation frame number.

11. The driving method according to claim 10, wherein: When the integer part of the compensation value is equal to the minimum compensation value, adding the minimum compensation value to a display frame within the compensation period; When the integer part of the compensation value is greater than the minimum compensation value, the integer part of the compensation value is divided into a plurality of minimum compensation values, which are added to a plurality of corresponding compensation frames within a compensation period.

12. The driving method according to claim 11, wherein: The position of the compensation frame is determined according to the priority of the display frame in the compensation period and the number of the compensation frames. The display frame with a higher priority is more likely to be used as a compensation frame.

13. The driving method according to claim 1, wherein: After the step of obtaining the compensation value and the number of compensation frames according to the second high level time, the display accuracy and the compensation lookup table, and performing inter-frame compensation on the compensation frames within the compensation period, the method further includes: Obtaining a first frequency corresponding to a current display brightness value and a second frequency corresponding to a next display brightness value; Determine whether the second frequency is a jump increase compared to the first frequency, where the jump increase means that among all frequencies arranged from large to small or from small to large, there is another frequency between the two frequencies; When the second frequency does not jump and increase compared with the first frequency, displaying according to the PWM signal of the second frequency; When the second frequency jumps and increases compared to the first frequency, a transition frequency is generated according to the first frequency, and the PWM signals of the transition frequency and the second frequency are displayed in sequence. The transition frequency has a value greater than the first frequency and less than the second frequency.

14. The driving method according to claim 13, wherein: The step of generating a transition frequency according to the first frequency comprises: Acquire a PWM signal of the first frequency; When the pulse position of the PWM signal of the first frequency remains unchanged, the pulse number is increased to obtain the transition frequency.

15. The driving method according to claim 14, wherein: The transition frequency includes at least one.

16. A driver chip, wherein: A method for driving a display panel as claimed in any one of claims 1 to 15.

17. A display device, wherein: The device comprises a display panel and a driving chip as claimed in claim 16.

18. The display device according to claim 17, wherein: The display panel emits light when the PWM signal is at a low level, and the display panel includes an OLED display panel.

19. An electronic device, wherein: Comprising the display device as claimed in claim 17 or 18.

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