Backlight control circuit, brightness adjustment circuit, pixel driving circuit and display device

Abstract

The present disclosure relates to a backlight control circuit, a brightness adjustment circuit, a pixel driving circuit and a display device. The backlight control circuit comprises: a plurality of first gamma voltage determination modules, each of which is used to determine and output a first search group when the brightness value of a display panel changes; a second gamma voltage determination module, which is electrically connected to each of the first gamma voltage determination modules and is used to determine a second search group according to the first search group, and to determine and output a gamma voltage value corresponding to each pixel unit in the display panel according to the second search group and a grayscale value corresponding to each pixel point in an input image of the display panel; since the backlight control circuit provided by the present disclosure can determine a plurality of first search groups through a plurality of parallel first gamma voltage determination modules, it can improve the calculation speed of the gamma voltage, thereby making the brightness transition of the display panel delicate.

Description

Technical Field

[0001] The present disclosure relates to the field of display panels, and in particular to a backlight control circuit, a brightness adjustment circuit, a pixel driving circuit and a display device. Background Art

[0002] In the prior art, the user can adjust the brightness of the display panel to the user's expected brightness by adjusting the display brightness value (i.e., display brightness value, DBV) of the display panel. The display brightness value of the display panel is usually achieved by adjusting the duty cycle of the PWM signal, the cathode voltage value, and the gamma voltage value. However, in the prior art, the display panel is prone to the problem that the duty cycle of the PWM signal and the cathode voltage value have been updated according to the current display brightness value, while the gamma voltage value has not been successfully updated. Then, when the DBV is updated to the current DBV, the user can clearly feel that the brightness of the display panel has changed twice (i.e., the brightness of the display panel is excessively rough), thereby reducing the user's experience.

[0003] In view of this, there is an urgent need to provide a backlight control circuit that can make the brightness of a display panel smooth and delicate. Summary of the invention

[0004] In view of this, the present disclosure proposes a backlight control circuit, a brightness adjustment circuit, a pixel driving circuit and a display device.

[0005] The present disclosure provides a backlight control circuit, which is applied to a display panel. The backlight control circuit includes: a plurality of first gamma voltage determination modules, each of which is used to determine and output a first search group when the brightness value of the display panel changes; wherein the first search group includes each brightness value within a preset interval corresponding to each first gamma voltage determination module, and a gamma voltage value corresponding to each brightness value at a preset grayscale value, and there are non-overlapping parts in the preset intervals corresponding to different first gamma voltage determination modules; a second gamma voltage determination module, which is electrically connected to each first gamma voltage determination module, and is used to determine a second search group according to the first search group, and determine and output a gamma voltage value corresponding to each pixel unit in the display panel according to the second search group and the grayscale value corresponding to each pixel point in an input image of the display panel; wherein the second search group includes each grayscale value at a current brightness value of the display panel, and a gamma voltage value corresponding to each grayscale value, and the pixel unit is used to display the pixel point.

[0006] In a possible implementation, the first gamma voltage determination module includes: a storage unit, used to store a first preset corresponding group; wherein the first preset corresponding group includes at least two preset brightness values ​​within a preset interval corresponding to each of the first gamma voltage determination modules, and a gamma voltage value at a preset grayscale value corresponding to each of the preset brightness values; and an interpolation calculation unit, electrically connected to the storage unit, used to determine and output the first search group to the second gamma voltage determination module based on an interpolation method and the first preset corresponding group.

[0007] In a possible embodiment, the second gamma voltage determination module includes: a first determination unit, used to determine the gamma voltage value at the preset grayscale value corresponding to the current brightness value of the display panel according to the first search group; a second determination unit, electrically connected to the first determination unit, used to determine the second search group according to the gamma voltage value at the preset grayscale value corresponding to the current brightness value of the display panel, and the gamma curve corresponding to the current brightness value; a third determination unit, electrically connected to the second determination unit, used to determine the gamma voltage value corresponding to each pixel unit in the display panel according to the grayscale value of each pixel point of the input image of the display panel and the second search group; a gamma voltage value output unit, electrically connected to the third determination unit, used to output the gamma voltage value corresponding to each pixel unit in the display panel.

[0008] In a possible implementation, the backlight control circuit further includes: a PWM duty cycle determination module, used to determine the duty cycle of the PWM signal of the display panel at the current brightness value according to the current brightness value of the display panel and a preset third search group; wherein the PWM control signal is used to control the light-emitting time of each pixel unit in the display panel, and the third search group includes the PWM duty cycle and the brightness value corresponding to each PWM duty cycle; and a PWM duty cycle output module, electrically connected to the PWM duty cycle determination module, used to output the duty cycle of the PWM signal corresponding to the current brightness value.

[0009] In a possible embodiment, the backlight control circuit also includes: a cathode voltage value determination module, which is used to determine the cathode voltage value under the current brightness value of the display panel based on the current brightness value of the display panel and a preset fourth search group, wherein the fourth search group includes the cathode voltage value and the brightness value corresponding to each cathode voltage; and a cathode voltage value output module, which is electrically connected to the cathode voltage value determination module and is used to output the cathode voltage value corresponding to the current brightness value.

[0010] In a possible implementation, when the brightness value of the display panel increases, the gamma voltage value corresponding to each pixel unit in the display panel decreases, the duty cycle of the PWM signal increases, and the cathode voltage value increases; when the brightness value of the display panel decreases, the gamma voltage value corresponding to each pixel unit in the display panel increases, the duty cycle of the PWM signal decreases, and the cathode voltage value decreases.

[0011] According to another aspect of the present disclosure, a brightness adjustment circuit is further provided. The brightness adjustment circuit is applied to a display panel, and the brightness adjustment circuit includes: a backlight control circuit according to any one of claims 1-6.

[0012] In a possible embodiment, the brightness adjustment circuit also includes: a gamma voltage generation circuit, electrically connected to the backlight control circuit, for generating multiple groups of gamma voltage signals according to the gamma voltage value corresponding to each pixel unit in the display panel output by the backlight control circuit; wherein the gamma voltage signal is used to drive at least one pixel unit in the display panel.

[0013] According to another aspect of the present disclosure, a pixel driving circuit is further provided, and the pixel driving circuit includes: a brightness adjustment circuit as described in any one of the above.

[0014] According to another aspect of the present disclosure, a display device is further provided, comprising a plurality of display units and at least one pixel driving circuit as described above.

[0015] In a possible embodiment, the display unit includes a display panel, and the display panel includes at least one of a liquid crystal display panel, a micro light emitting diode display panel, a light emitting diode display panel, a mini light emitting diode display panel, a quantum dot light emitting diode display panel, an organic light emitting diode display panel, a cathode ray tube display panel, a digital light processing display panel, a field emission display panel, a plasma display panel, an electrophoretic display panel, an electrowetting display panel and a small pitch display panel.

[0016] The backlight control circuit provided by the present disclosure outputs the first search group corresponding to the current brightness value in parallel through the first gamma voltage determination module, and determines the second search group corresponding to the current brightness value through the second gamma voltage determination module, thereby determining the gamma voltage value corresponding to each pixel unit in the display panel. Since the backlight control circuit provided by the present disclosure includes multiple parallel first gamma voltage determination modules, it can quickly determine the gamma voltage value corresponding to each grayscale value under the current brightness value compared to the backlight control circuit in the prior art, thereby improving the calculation speed of the gamma voltage value. Figure 2As shown, when the brightness value of the display panel changes, since the backlight control circuit can quickly determine the gamma voltage value corresponding to each pixel unit at the current brightness value, the duty cycle, cathode voltage value and gamma voltage value of the PWM signal can be updated at the same time, thereby making the brightness of the display panel more delicate and improving the user experience.

[0017] Further features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.

[0019] Figure 1 Schematic diagram of gamma voltage values, PWM signals and cathode voltage value update time in a display panel in the prior art.

[0020] Figure 2 A schematic diagram of the gamma voltage value, PWM signal and cathode voltage value update time in the display panel provided by the present disclosure.

[0021] Figure 3 A schematic diagram of the structure of a backlight control circuit provided by the present invention.

[0022] Figure 4 A schematic diagram of the structure of a backlight control circuit provided by the present invention.

[0023] Figure 5 A schematic diagram of a second search group provided by the present disclosure when the brightness value is X3.

[0024] Figure 6 A schematic diagram of the structure of a backlight control circuit provided by the present invention.

[0025] Figure 7 A schematic diagram of the structure of a backlight control circuit provided by the present invention.

[0026] Figure 8 A schematic diagram of the structure of a backlight control circuit provided by the present invention. DETAILED DESCRIPTION

[0027] Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0028] In the description of the present disclosure, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0029] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0030] In the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0031] The term "and / or" herein is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" herein represents any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set consisting of A, B, and C.

[0032] See also Figure 1 As shown, to implement the low frame rate refresh technology, only one frame out of every four frames of the display panel is refreshed, and the remaining three frames are not refreshed. For example: Figure 1In the first cycle, A is the refresh area, and B1-B3 are non-refresh areas. Taking the display panel with low frame rate refresh in the prior art as an example, when the host of the display panel indicates that the display brightness value (i.e., displaybrightness value, DBV) of the display panel changes, the display panel will adjust the duty cycle of the internal PWM signal, the cathode voltage value (i.e., ELVSS) and the gamma voltage value, and then adjust the brightness of the display panel to the brightness corresponding to the current display brightness value. However, since the calculation process of the gamma voltage is relatively complicated, it is easy to cause the duty cycle of the PWM signal and the cathode voltage value in the display panel to be updated according to the current display brightness value, while the gamma voltage value has not yet been updated according to the current display brightness value. For example: Figure 1 When the current frame is in the B1 area in the first cycle, the display panel adjusts the display brightness value from 255 to 55 (i.e., the brightness is reduced). Since the duty cycle of the PWM signal and the determination process of the cathode voltage value are relatively simple, the duty cycle of the PWM signal and the cathode voltage value can be updated at the first time (i.e., the PWM signal can be updated from PWM1 to PWM2 within the first time, and the cathode voltage value can also be updated from ELVSS1 to ELVSS2 within the first time), so that the brightness of the display panel changes to the brightness corresponding to the display brightness value A, wherein the display brightness value A is between the display brightness value 255 and the display brightness value 55. Since the calculation process of the gamma voltage value is relatively complicated, the display panel can only update the gamma voltage value to the gamma voltage value corresponding to the current display brightness (i.e., update Gamma1 to Gamma2) when it is in the A area of ​​the second cycle, thereby adjusting the brightness of the display panel to the brightness corresponding to the display brightness value 55. It can be seen from this that when the display brightness value is updated, the user can clearly feel that the brightness of the display panel has changed twice (i.e., the problem of excessive and rough brightness of the display panel occurs), thereby reducing the user's use experience.

[0033] In view of this, see Figure 2-Figure 3 As shown, the present disclosure provides a backlight control circuit 1, which can solve technical problems such as excessive brightness of the display panel and poor user experience. The backlight control circuit 1 provided by the present disclosure is applied to the display panel, and the backlight control circuit 1 includes: a plurality of first gamma voltage determination modules 11 and a second gamma voltage determination module 12.

[0034] Exemplarily, each first gamma voltage determination module 11 is used to determine and output a first search group when the brightness value of the display panel changes. The first search group includes each brightness value within a preset interval corresponding to each first gamma voltage determination module 11, and a gamma voltage value corresponding to each brightness value at a preset grayscale value, and there are non-overlapping parts in the preset intervals corresponding to different first gamma voltage determination modules 11.

[0035] For example, see Figure 4 As shown, the backlight control circuit 1 includes: a first gamma voltage determination module A, a first gamma voltage determination module B and a first gamma voltage determination module C. The brightness value of the display panel (equivalent to the display brightness value of the display panel described above) ranges from 0 to X n The preset interval corresponding to the first gamma voltage determination module A is the preset interval A (i.e., 0-A1), the preset interval corresponding to the first gamma voltage determination module B is the preset interval B (i.e., A2-A3), and the preset interval corresponding to the first gamma voltage determination module C is the preset interval C (i.e., A4-X n ) as an example, when the brightness value of the display panel changes from X1 to X2, the first gamma voltage determination module A is used to determine the first search group A (i.e., each brightness value in the preset interval A, and the gamma voltage value corresponding to each brightness value at the preset grayscale value), the first gamma voltage determination module B is used to determine the first search group B (i.e., each brightness value in the preset interval B, and the gamma voltage value corresponding to each brightness value at the preset grayscale value), and the first gamma voltage determination module C is used to determine the first search group C (i.e., each brightness value in the preset interval C, and the gamma voltage value corresponding to each brightness value at the preset grayscale value). Among them, the total coverage range of the preset intervals corresponding to each first gamma voltage determination module 11 in the backlight control circuit 1 includes the value range of the brightness value of the display panel, that is, the total coverage range of the preset interval A, the preset interval B and the preset interval C includes the value range of the brightness value of the display panel (i.e., 0-X n The preset interval corresponding to each first gamma voltage determination module 11 can be determined according to actual conditions, and the present disclosure does not make any specific limitation on this.

[0036] Exemplarily, when the number of first gamma voltage determination modules 11 is determined, in order to improve the calculation speed of multiple first gamma voltage determination modules 11 and reduce their calculation pressure, the value range of the brightness value of the display panel can be divided into multiple intervals, the number of intervals is equal to the number of first gamma voltage determination modules, and the preset interval of each first gamma voltage determination module 11 corresponds to an interval (that is, each first gamma voltage determination module 11 is used to calculate the first search group within an interval). For example: the number of the first gamma voltage determination modules 11 is 2, and the value range of the brightness value of the display panel is an integer of 0-255, then the value range of the brightness value of the display panel can be divided into interval A (i.e., 0-127) and interval B (i.e., 128-255), the preset interval corresponding to the first first gamma voltage determination module is interval A (i.e., 0-127), and the preset interval corresponding to the second first gamma voltage determination module is interval B (i.e., 128-255), so that the calculation contents between the first first gamma voltage determination module and the second first gamma voltage determination module will not overlap (for example: repeatedly calculating the gamma voltage value corresponding to a certain brightness value at a preset grayscale value), and at the same time, the calculation time required for the first first gamma voltage determination module can be equal to the calculation time required for the second first gamma voltage determination module, so that each first gamma voltage determination module can be fully utilized, preventing the occurrence of a situation where one first gamma voltage determination module is working while another first gamma voltage determination module has stopped working.

[0037] Exemplarily, the preset grayscale value mentioned above may be a maximum grayscale value. The preset grayscale value may be determined according to actual conditions, and the present disclosure does not make any specific limitation on this.

[0038] Exemplarily, the second gamma voltage determination module 12 is electrically connected to each first gamma voltage determination module 11, and the second gamma voltage determination module 12 is used to determine the second search group according to the first search group, and determine and output the gamma voltage value corresponding to each pixel unit in the display panel according to the second search group and the grayscale value corresponding to each pixel point in the input image of the display panel. The second search group includes each grayscale value under the current brightness value of the display panel, and the gamma voltage value corresponding to each grayscale value, and the pixel unit is used to display the above pixel point.

[0039] For example, see Figure 4As shown, the second gamma voltage determination module 12 is electrically connected to the first gamma voltage determination module A, the first gamma voltage determination module B and the first gamma voltage determination module C respectively. The second gamma voltage determination module 12 is used to receive the first search group A output by the first gamma voltage determination module A, the first search group B output by the first gamma voltage determination module B and the first search group C output by the first gamma voltage determination module C, which is equivalent to the second gamma voltage determination module 12 obtaining the gamma voltage value corresponding to each brightness value of the display panel under the preset gray scale through each first gamma voltage determination module 11. In the case where the second gamma voltage determination module 12 obtains the first search group output by each first gamma voltage determination module 11, the second gamma voltage determination module 12 can determine the second search group. Figure 5 As shown, Figure 5 When the brightness value of the display panel is X3, the gamma voltage value corresponding to each grayscale value is X3. Taking the current brightness value of the display panel as an example, when the grayscale value of the pixel point A of the input image of the display panel is H1, according to Figure 5 It can be seen that the gamma voltage value corresponding to pixel point A should be V1. When the grayscale value of pixel point B of the input image of the display panel is H2, according to Figure 5 It can be known that the gamma voltage value corresponding to the pixel point B should be V2, and then the gamma voltage value corresponding to each pixel unit in the display panel can be determined, so that the display panel can display the input image.

[0040] The backlight control circuit provided by the present disclosure outputs the first search group corresponding to the current brightness value in parallel through the first gamma voltage determination module, and determines the second search group corresponding to the current brightness value through the second gamma voltage determination module, thereby determining the gamma voltage value corresponding to each pixel unit in the display panel. Since the backlight control circuit provided by the present disclosure includes multiple parallel first gamma voltage determination modules, it can quickly determine the gamma voltage value corresponding to each grayscale value under the current brightness value compared to the backlight control circuit in the prior art, thereby improving the calculation speed of the gamma voltage value. Figure 2 As shown, when the brightness value of the display panel changes, since the backlight control circuit can quickly determine the gamma voltage value corresponding to each pixel unit at the current brightness value, the duty cycle, cathode voltage value and gamma voltage value of the PWM signal can be updated at the same time, thereby making the brightness of the display panel more delicate and improving the user experience.

[0041] In one possible implementation, see Figure 6 As shown, the first gamma voltage determination module 11 includes: a register unit 111 and an interpolation calculation unit 112 .

[0042] Exemplarily, the register unit 111 is used to store a first preset corresponding group, wherein the first preset corresponding group includes at least two preset brightness values ​​within a preset interval corresponding to each first gamma voltage determination module, and a gamma voltage value at a preset grayscale value corresponding to each preset brightness value.

[0043] Exemplarily, taking the first gamma voltage determination module A in the above text as an example, when the preset interval corresponding to the first gamma voltage determination module A is the preset interval A (i.e., 0-A1), the first preset corresponding group corresponding to the first gamma voltage determination module A includes gamma voltage values ​​corresponding to any two brightness values ​​in 0-A1 and at the preset grayscale value. For example: the first preset corresponding group corresponding to the first gamma voltage determination module A includes brightness value a and gamma voltage value v1 corresponding to brightness value a and at the preset grayscale value, and brightness value b and gamma voltage value v2 corresponding to brightness value b and at the preset grayscale value.

[0044] Exemplarily, the interpolation calculation unit 112 is electrically connected to the register unit 111 , and the interpolation calculation unit 112 is used to determine and output the first search group according to the interpolation method and the first preset corresponding group.

[0045] Exemplarily, also taking the first gamma voltage determination module A as an example, when the first preset corresponding group corresponding to the first gamma voltage determination module A includes brightness value a, gamma voltage value v1, brightness value b and gamma voltage value v2, the interpolation calculation unit can determine the gamma voltage value corresponding to each brightness value in the preset interval A and at the preset grayscale according to the linear interpolation method, and then determine the first search group corresponding to the first gamma voltage determination module A. The present disclosure does not limit the above interpolation method to the linear interpolation method, which can be adjusted according to the actual situation of the display panel, and the present disclosure does not limit this.

[0046] In one possible implementation, see Figure 6 As shown, the second gamma voltage determination module 12 includes: a first determination unit 121 , a second determination unit 122 , a third determination unit 123 and a gamma voltage value output unit 124 .

[0047] Exemplarily, the first determination unit 121 is used to determine the gamma voltage value at a preset grayscale value corresponding to the current brightness value of the display panel according to the first search group. The second determination unit 122 is electrically connected to the first determination unit 121, and is used to determine the second search group according to the gamma voltage value at a preset grayscale value corresponding to the current brightness value of the display panel, and the gamma curve corresponding to the current brightness value. The third determination unit 123 is electrically connected to the second determination unit 122, and is used to determine the gamma voltage value corresponding to each pixel unit in the display panel according to the grayscale value of each pixel point of the input image of the display panel, and the second search group. The gamma voltage value output unit 124 is electrically connected to the third determination unit 123, and is used to output the gamma voltage value corresponding to each pixel unit in the display panel.

[0048] Exemplarily, when determining the current brightness value of the display panel, the first determination unit 121 selects the gamma voltage value corresponding to the current brightness value (i.e., the gamma voltage value under the preset grayscale value when the brightness value is the current brightness value) from the multiple first search groups output by the multiple first gamma voltage determination modules 11. For example, if the current brightness value of the display panel is 255, the first determination unit 121 determines the gamma voltage value under the preset grayscale value when the brightness value is 255 according to the multiple first search groups, and outputs it to the second determination unit 122. The second determination unit 122 can determine the second search group according to the gamma voltage value under the preset grayscale value corresponding to the current brightness value and the gamma curve corresponding to the current brightness value (such as: the relationship curve between the brightness value and the grayscale value when the gamma value is equal to 2.2). Exemplarily, when the preset grayscale value is the maximum grayscale value, the grayscale value corresponding to the current brightness value 255 can be determined according to the gamma curve, and the gamma voltage value corresponding to the current brightness value 255 can be determined according to the first search group, so the gamma voltage value corresponding to the grayscale value can be determined. The second search group can also be determined according to a preset relationship curve between grayscale value and gamma voltage value. The process here can refer to the relevant technology, and the present disclosure will not elaborate on it here. The third determination unit 123 determines the gamma voltage value corresponding to each pixel unit according to the grayscale value corresponding to each pixel point in the input image of the display panel. Taking the current brightness value of the display panel as X3 as an example, refer to Figure 5 As shown, when the grayscale value of pixel A of the input image of the display panel is H1, the gamma voltage value corresponding to pixel A should be V1. When the gamma voltage value corresponding to each pixel unit in the display panel is determined, the gamma voltage value output unit 124 outputs the gamma voltage value of each pixel unit in the display panel to a designated circuit, which may be a gamma voltage generating circuit hereinafter.

[0049] In one possible implementation, see Figure 7As shown, the backlight control circuit further includes: a PWM duty cycle determining module 13 and a PWM duty cycle output module 14 .

[0050] Exemplarily, the PWM duty cycle determination module 13 is used to determine the duty cycle of the PWM signal of the display panel at the current brightness value according to the current brightness value of the display panel and the preset third search group. The PWM control signal is used to control the light-emitting time of each pixel unit in the display panel, and the third search group includes the PWM duty cycle and the brightness value corresponding to each PWM duty cycle.

[0051] Exemplarily, the preset third search group may be stored in the PWM duty cycle determination module 13 , wherein the preset third search group may be determined according to an actual application scenario of the display panel, which is not limited in the present disclosure.

[0052] Exemplarily, the PWM duty cycle output module 14 is electrically connected to the PWM duty cycle determination module 13, and the PWM duty cycle output module 14 is used to output the duty cycle of the PWM signal corresponding to the current brightness value of the PWM duty cycle. The larger the duty cycle of the PWM signal, the longer the light emission time of the pixel unit of the display panel, and thus the brighter the brightness of the display panel.

[0053] Exemplarily, the PWM duty cycle output module 14 can output the duty cycle of the PWM signal corresponding to the current brightness value to the PWM signal generation circuit. The PWM signal generation circuit is used to generate a PWM signal according to the duty cycle of the PWM signal output by the PWM duty cycle output module 14 to control the light emission time of each pixel unit in the display panel.

[0054] In one possible implementation, see Figure 8 As shown, the backlight control circuit 1 further includes: a cathode voltage value determining module 15 and a cathode voltage value output module 16 .

[0055] Exemplarily, the cathode voltage value determination module 15 is used to determine the cathode voltage value under the current brightness value of the display panel according to the current brightness value of the display panel and a preset fourth search group, wherein the fourth search group includes the cathode voltage value and the brightness value corresponding to each cathode voltage value.

[0056] Exemplarily, the preset fourth search group may be stored in the cathode voltage value determination module 15 , wherein the preset fourth search group may be determined according to an actual application scenario of the display panel, which is not limited in the present disclosure.

[0057] Exemplarily, the cathode voltage value output module 16 is electrically connected to the cathode voltage value determination module 15 , and the cathode voltage value output module 16 is used to output the cathode voltage value corresponding to the current brightness value.

[0058] Exemplarily, the cathode voltage value output module 16 can output the cathode voltage value corresponding to the current brightness value to the cathode power supply, wherein the cathode power supply is used to adjust the output voltage value according to the cathode voltage value, thereby adjusting the cathode voltage of each pixel unit.

[0059] In a possible implementation, when the brightness value of the display panel increases, the gamma voltage value corresponding to each pixel unit in the display panel decreases, the duty cycle of the PWM signal increases, and the cathode voltage value increases. When the brightness value of the display panel decreases, the gamma voltage value corresponding to each pixel unit in the display panel increases, the duty cycle of the PWM signal decreases, and the cathode voltage value decreases.

[0060] Exemplarily, when the brightness value of the display panel increases from 25 to 255, the gamma voltage value corresponding to each pixel in the display panel will decrease, the duty cycle of the PWM signal will increase, and the cathode voltage value will increase. For example: when the brightness value of the display panel is 25, the gamma voltage value corresponding to the pixel unit A is 10v, the duty cycle of the PWM signal is 20%, and the cathode voltage value is -2v. Then, when the brightness value of the display panel is 255, the gamma voltage value corresponding to the pixel unit A is 5v, the duty cycle of the PWM signal is 80%, and the cathode voltage value is -5v.

[0061] Exemplarily, when the brightness value of the display panel decreases from 200 to 30, the gamma voltage value corresponding to each pixel in the display panel will increase, the duty cycle of the PWM signal will decrease, and the cathode voltage value will decrease. For example: when the brightness value of the display panel is 200, the gamma voltage value corresponding to the pixel unit A is 6v, the duty cycle of the PWM signal is 70%, and the cathode voltage value is -4v. When the brightness value of the display panel is 30, the gamma voltage value corresponding to the pixel unit A is 8v, the duty cycle of the PWM signal is 30%, and the cathode voltage value is -3v.

[0062] In a possible implementation, when the display panel is in the front and rear corridor areas (ie, the Proch area), the backlight control circuit 1 is used to determine the gamma voltage value, the duty cycle of the PWM signal, and the cathode voltage value corresponding to the current brightness value of the display panel.

[0063] In one possible implementation, the gamma voltage generating circuit, PWM signal generating circuit and cathode power supply in the display panel are used to output updated gamma voltage, PWM signal and cathode voltage to the pixel unit according to the output value of the backlight control circuit 1 when a vertical synchronization signal (i.e., a sync synchronization signal in the VSYNC Vertical direction) is received.

[0064] In a possible implementation, the present disclosure further provides a brightness adjustment circuit, which includes the backlight control circuit 1 described above.

[0065] In a possible implementation manner, the brightness adjustment circuit further includes: a gamma voltage generating circuit.

[0066] Exemplarily, the gamma voltage generating circuit is electrically connected to the backlight control circuit, and is used to generate multiple sets of gamma voltage signals according to the gamma voltage value corresponding to each pixel unit in the display panel output by the backlight control circuit 1. The gamma voltage signal is used to drive at least one pixel unit in the display panel.

[0067] Exemplarily, the gamma voltage generating circuit is used to output the gamma voltage to the pixel unit according to the vertical synchronization signal (ie, the sync synchronization signal in the VSYNC Vertical direction), wherein the gamma voltage generating circuit can output the gamma voltage to a row of pixel units at the same time.

[0068] In a possible implementation, the brightness adjustment circuit further includes: a PWM signal generating circuit and a cathode power supply.

[0069] Exemplarily, the PWM signal generating circuit is electrically connected to the PWM duty cycle output module mentioned above, and is used to receive the duty cycle of the PWM signal output by the PWM duty cycle output module, generate a PWM signal according to the duty cycle of the PWM signal, and output the PWM signal to the pixel unit according to the vertical synchronization signal.

[0070] Exemplarily, the cathode power supply is electrically connected to the cathode voltage value output module mentioned above, and is used to receive the cathode voltage value output by the cathode voltage value output module, and update the cathode voltage value of the pixel unit to the cathode voltage value output by the cathode voltage value output module according to the vertical synchronization signal.

[0071] In a possible implementation, the present disclosure further provides a pixel driving circuit, the pixel driving circuit comprising: a brightness adjustment circuit as described in any one of the foregoing.

[0072] In a possible implementation, the present disclosure further provides a display device, which includes a plurality of display units and at least one pixel driving circuit as described above.

[0073] In a possible embodiment, the display unit includes a display panel, and the display panel includes at least one of a liquid crystal display panel, a micro light emitting diode display panel, a light emitting diode display panel, a mini light emitting diode display panel, a quantum dot light emitting diode display panel, an organic light emitting diode display panel, a cathode ray tube display panel, a digital light processing display panel, a field emission display panel, a plasma display panel, an electrophoretic display panel, an electrowetting display panel and a small pitch display panel.

[0074] In a possible implementation, the present disclosure further provides a driver chip, which includes the brightness adjustment circuit described above.

[0075] Exemplarily, the at least one reset signal inside the chip includes, but is not limited to, at least one of a power-on reset signal, a software reset signal, an ESD reset signal, a watchdog reset signal, and an abnormal power-off reset signal.

[0076] It should be noted that the chip reset circuit provided in the embodiment of the present invention can actually be integrated into any chip with a reset function to realize the reset function of the internal circuit of the chip. The present invention does not limit this.

[0077] It is worth noting that the driving chip according to the embodiment of the present disclosure can be formed as a universal driving chip, which can be applicable to display panels with different sub-pixel arrangements, thereby reducing design costs and manufacturing costs.

[0078] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A backlight control circuit, the backlight control circuit being applied to a display panel, characterized in that: The backlight control circuit comprises: A plurality of first gamma voltage determination modules, each of which is used to determine and output a first search group when the brightness value of the display panel changes; wherein the first search group includes each brightness value within a preset interval corresponding to each first gamma voltage determination module, and a gamma voltage value corresponding to each brightness value at a preset grayscale value, and there are non-overlapping parts in the preset intervals corresponding to different first gamma voltage determination modules; a second gamma voltage determination module, electrically connected to each of the first gamma voltage determination modules, for determining a second search group according to the first search group, and determining and outputting a gamma voltage value corresponding to each pixel unit in the display panel according to the second search group and the grayscale value corresponding to each pixel point in the input image of the display panel; wherein the second search group includes each grayscale value under the current brightness value of the display panel, and the gamma voltage value corresponding to each grayscale value, and the pixel unit is used to display the pixel point; The second gamma voltage determination module comprises: A first determining unit, configured to determine, according to the first search group, a gamma voltage value at the preset grayscale value corresponding to a current brightness value of the display panel; The second determining unit is electrically connected to the first determining unit, and is used to determine a second search group according to the gamma voltage value at the preset grayscale value corresponding to the current brightness value of the display panel and the gamma curve corresponding to the current brightness value.

2. The backlight control circuit according to claim 1, characterized in that: The first gamma voltage determination module comprises: A register unit, configured to store a first preset corresponding group; wherein the first preset corresponding group includes at least two preset brightness values ​​within a preset interval corresponding to each of the first gamma voltage determination modules, and a gamma voltage value at a preset grayscale value corresponding to each of the preset brightness values; and The interpolation calculation unit is electrically connected to the register unit, and is used to determine and output the first search group to the second gamma voltage determination module according to the interpolation method and the first preset corresponding group.

3. The backlight control circuit of the display panel according to claim 1, characterized in that: The second gamma voltage determination module further includes: a third determining unit, electrically connected to the second determining unit, and configured to determine a gamma voltage value corresponding to each pixel unit in the display panel according to a grayscale value of each pixel point of the input image of the display panel and the second search group; The gamma voltage value output unit is electrically connected to the third determination unit and is used to output the gamma voltage value corresponding to each pixel unit in the display panel.

4. The backlight control circuit of the display panel according to claim 1, characterized in that: The backlight control circuit further includes: a PWM duty cycle determination module, configured to determine the duty cycle of the PWM signal of the display panel at the current brightness value according to the current brightness value of the display panel and a preset third search group; wherein the PWM signal is used to control the light-emitting time of each pixel unit in the display panel, and the third search group includes the PWM duty cycle and the brightness value corresponding to each PWM duty cycle; and The PWM duty cycle output module is electrically connected to the PWM duty cycle determination module and is used to output the duty cycle of the PWM signal corresponding to the current brightness value.

5. The backlight control circuit of the display panel according to claim 4, characterized in that: The backlight control circuit further includes: a cathode voltage value determination module, configured to determine the cathode voltage value of the display panel at the current brightness value according to the current brightness value of the display panel and a preset fourth search group, wherein the fourth search group includes the cathode voltage value and the brightness value corresponding to each cathode voltage; and The cathode voltage value output module is electrically connected to the cathode voltage value determination module and is used to output the cathode voltage value corresponding to the current brightness value.

6. The backlight control circuit of the display panel according to claim 5, characterized in that: When the brightness value of the display panel increases, the gamma voltage value corresponding to each pixel unit in the display panel decreases, the duty cycle of the PWM signal increases, and the cathode voltage value increases; When the brightness value of the display panel decreases, the gamma voltage value corresponding to each pixel unit in the display panel increases, the duty cycle of the PWM signal decreases, and the cathode voltage value decreases.

7. A brightness adjustment circuit, applied to a display panel, characterized in that: The brightness adjustment circuit comprises: a backlight control circuit according to any one of claims 1-6.

8. The brightness adjustment circuit of the display panel according to claim 7, characterized in that: The brightness adjustment circuit also includes: A gamma voltage generating circuit is electrically connected to the backlight control circuit and is used to generate multiple sets of gamma voltage signals according to the gamma voltage value corresponding to each pixel unit in the display panel output by the backlight control circuit; wherein the gamma voltage signal is used to drive at least one pixel unit in the display panel.

9. A pixel driving circuit, characterized in that: The pixel driving circuit comprises: a brightness adjustment circuit according to any one of claims 7-8.

10. A display device, characterized in that: The display device comprises a plurality of display units and at least one pixel driving circuit according to claim 9.

11. The display device according to claim 10, characterized in that The display unit includes a display panel, and the display panel includes at least one of a liquid crystal display panel, a micro light emitting diode display panel, a light emitting diode display panel, a mini light emitting diode display panel, a quantum dot light emitting diode display panel, an organic light emitting diode display panel, a cathode ray tube display panel, a digital light processing display panel, a field emission display panel, a plasma display panel, an electrophoretic display panel, an electrowetting display panel and a small pitch display panel.

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