Gamma circuit and display panel

Abstract

The embodiment of the present application discloses a gamma circuit and a display panel, comprising a voltage output module, the voltage output module is used for outputting first gamma voltage and second gamma voltage according to received power voltage, the first gamma voltage and the second gamma voltage are used as reference voltage of data signal to adjust gray scale value of the data signal, the data signal is used for controlling pixel unit of display area to perform image display. The gamma circuit further comprises a voltage adjustment module, the voltage adjustment module is electrically connected to the voltage output module, the voltage adjustment module is used for receiving the first gamma voltage and the second gamma voltage from the voltage output module, and the second gamma voltage is synchronously controlled to change along the first direction when the first gamma voltage changes along the first direction, and the voltage difference between the first gamma voltage and the second gamma voltage is controlled to be within a preset range, so as to eliminate the horizontal crosstalk phenomenon caused by inconsistent positive and negative polarity gamma voltage pressure drop.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a gamma circuit and a display panel. Background Art

[0002] Currently, crosstalk, the phenomenon of parallel horizontal lines appearing on a white frame, often occurs when large-scale display panels display images. This crosstalk phenomenon is primarily caused by the data voltage changing from low to high, which pulls the AVDD power supply of the data driver circuit, causing a voltage drop in the AVDD voltage. Since the AVDD voltage is the input power supply for the gamma circuit, this AVDD voltage drop also causes a gamma voltage drop. The data driver circuit generates a data signal based on the gamma voltage and outputs the data signal to the data line. The data voltage signal is then output to each sub-pixel through the data line to control the brightness of each pixel. Due to the inconsistent voltage drops of the positive and negative gamma voltages, the changes in the positive and negative data signals are inconsistent, which in turn leads to inconsistent pixel brightness, thus causing horizontal crosstalk. Therefore, adjusting the gamma voltage to eliminate horizontal crosstalk is an urgent problem that needs to be solved. Summary of the Invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present application proposes a gamma circuit and a display panel that can effectively prevent the lateral crosstalk phenomenon.

[0004] The present application provides a gamma circuit, comprising a voltage output module, the voltage output module being configured to output a first gamma voltage and a second gamma voltage based on a received power supply voltage, the first gamma voltage and the second gamma voltage being used as reference voltages for a data signal to adjust the grayscale value of the data signal, the data signal being used to control pixel units in a display area to display an image. The gamma circuit also includes a voltage adjustment module, the voltage adjustment module being electrically connected to the voltage output module, the voltage adjustment module being configured to receive the first gamma voltage and the second gamma voltage from the voltage output module, and synchronously controlling the second gamma voltage to vary along the first direction when the first gamma voltage varies along the first direction, and controlling the voltage difference between the first gamma voltage and the second gamma voltage to be within a preset range.

[0005] Optionally, the first gamma voltage is a reference voltage of the data signal with a positive polarity, the second gamma voltage is a reference voltage of the data signal with a negative polarity, and the first gamma voltage and the second gamma voltage are symmetrical about a central reference voltage.

[0006] Optionally, the voltage adjustment module includes a detection unit and a control unit. The detection unit is electrically connected to the first gamma voltage output end and the control unit, and is used to detect changes in the first gamma voltage. When it is detected that the first gamma voltage changes along the first direction, the detection unit outputs a control signal to the control unit. The control unit controls the second gamma voltage to change along the first direction according to the control signal.

[0007] Optionally, the voltage adjustment module further includes a comparison unit, which is electrically connected to the detection unit and the control unit. When the detection unit detects that the first gamma voltage changes along the first direction, the detection unit transmits the first gamma voltage to the comparison unit. The comparison unit is used to compare the received first gamma voltage with a preset reference voltage. When the first gamma voltage is less than or equal to the reference voltage, the comparison unit outputs a control signal to the control unit. The control unit controls the second gamma voltage to change along the first direction to a preset voltage value according to the control signal.

[0008] Optionally, the comparison unit includes a comparator, the non-phase end of the comparator is electrically connected to the detection unit, the inverting end of the comparator is electrically connected to the preset reference voltage end, the output end of the comparator is electrically connected to the control unit, and the comparator is used to compare the first gamma voltage with the preset reference voltage. When the first gamma voltage is less than or equal to the preset reference voltage, the comparator outputs a first level signal to the control unit; when the first gamma voltage is greater than the preset reference voltage, the comparator outputs a second level signal to the control unit, and the first level signal is the control signal.

[0009] Optionally, the control unit includes a switching tube and a delay resistor, the control end of the switching tube is electrically connected to the output end of the comparator, the first end of the switching tube is electrically connected to the second gamma voltage output end, the second end of the switching tube is electrically connected to the first end of the delay resistor, and the second end of the delay resistor is electrically connected to the ground end. The switching tube is used to be turned on under the control of the control signal to transmit the second gamma voltage to the delay resistor, and transmit it to the ground end through the delay resistor to control the second gamma voltage to change along the first direction to the preset voltage value.

[0010] Optionally, the control unit also includes a delay capacitor, the first end of the delay capacitor is electrically connected to the second end of the switching tube, and the second end of the delay capacitor is electrically connected to the ground end, and the delay capacitor is used to adjust the time for the second gamma voltage to change along the first direction to the preset voltage value.

[0011] Optionally, the voltage output module further outputs a third gamma voltage and a fourth gamma voltage, the third gamma voltage being a reference voltage of the data signal of positive polarity, the fourth gamma voltage being a reference voltage of the data signal of negative polarity, the third gamma voltage and the fourth gamma voltage being symmetrical about the center reference voltage, the first gamma voltage and the third gamma voltage corresponding to positive polarity data signals of a plurality of different gray scales, the second gamma voltage and the fourth gamma voltage corresponding to negative polarity data signals of a plurality of different gray scales.

[0012] Optionally, the voltage output module comprises a plurality of resistors connected in series, the resistors being used to divide the received power supply voltage to output the first gamma voltage, the second gamma voltage, the third gamma voltage and the fourth gamma voltage.

[0013] The embodiment of the present application further provides a display panel comprising the foregoing gamma circuit and a data driving circuit and a plurality of pixel units, the data driving circuit being used to output a plurality of different gray scale data signals according to the first gamma voltage and the second gamma voltage output by the gamma circuit, and transmit the data signals to the pixel units to drive the pixel units to display images.

[0014] Compared with the prior art, the embodiment of the present application sets the voltage adjustment module, which is used to detect the change of the first gamma voltage, and when detecting that the first gamma voltage appears voltage drop, synchronously controls the second gamma voltage to also drop in the same direction, so that the voltage difference between the first gamma voltage and the second gamma voltage is within the preset range, thereby effectively eliminating the horizontal crosstalk phenomenon caused by the asymmetry of the gamma voltage. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0016] Figure 1 A structural schematic diagram of a display device provided in the embodiment of the present application is shown in FIG. 1.

[0017] Figure 2 A structural schematic diagram of a display device provided in the embodiment of the present application is shown in FIG. 1. Figure 1 A planar layout schematic diagram of a display panel in the embodiment of the present application is shown in FIG. 2.

[0018] Figure 3 A planar layout schematic diagram of a display panel in the embodiment of the present application is shown in FIG. 2. Figure 2 A gamma voltage generation logic schematic diagram in the embodiment of the present application is shown in FIG. 3.

[0019] Figure 4 A gamma voltage generation logic schematic diagram in the embodiment of the present application is shown in FIG. 3. Figure 3 Schematic diagram of equivalent circuit of gamma circuit and data driving circuit;

[0020] Figure 5 Schematic diagram of gamma voltage change;

[0021] Figure 6 A circuit block diagram of a gamma circuit provided in the second embodiment of the present application;

[0022] Figure 7 for Figure 6 Circuit diagram of the medium voltage adjustment module;

[0023] Figure 8 A circuit block diagram of a voltage adjustment module provided in the third embodiment of the present application;

[0024] Figure 9 for Figure 8 Schematic diagram of mid-gamma voltage adjustment.

[0025] Reference numerals:

[0026] Display device 100, display panel 10, power module 30, display area 10a, power management circuit 11, timing control circuit 12, gamma circuit 13, data driver circuit 14, scan driver circuit 15, pixel unit P, power supply voltage AVDD, analog operating voltage DVDD, VGL-off voltage, VGH-on voltage, clock signal CLK, reference voltage GM0, first gamma voltage GM1, second gamma voltage GM2, third gamma voltage GM3, fourth gamma voltage GM4, resistor R, voltage output module 131, voltage adjustment module 132, detection unit 1321, comparison unit 1322, control unit 1323, comparator U, reference voltage Vref, switch tube T, delay resistor Rx, delay capacitor C, control node Q, ground terminal GND, data signal Data, first time period t1, second time period t2. DETAILED DESCRIPTION

[0027] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0028] The following descriptions of the embodiments are with reference to the attached diagrams to illustrate specific embodiments that the present application can be used to implement. The serial numbers of the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in the present application include direct and indirect connections (couplings) unless otherwise specified. The directional terms mentioned in the present application, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", etc., are only with reference to the directions of the attached drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the present application, rather than indicating or implying 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 application.

[0029] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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; it can be directly connected, or indirectly connected through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances. It should be noted that the terms "first", "second", etc. in the description, claims, and drawings of this application are used to distinguish different objects, rather than to describe a specific order.

[0030] In addition, the terms "include", "may include", "include", or "may include" used in this application indicate the existence of the corresponding functions, operations, elements, etc. disclosed, and do not limit one or more other functions, operations, elements, etc. In addition, the terms "include" or "include" indicate the existence of the corresponding features, numbers, steps, operations, elements, components, or combinations thereof disclosed in the specification, and do not exclude the existence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, and are intended to cover non-exclusive inclusions. In addition, when describing the embodiments of the present application, "may" is used to indicate "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0032] See also Figure 1 , Figure 1 This is a schematic diagram of the structure of a display device provided in an embodiment of the present application. Figure 1 As shown, the display device 100 includes a display panel 10 and a power module 30. The power module 30 is disposed on the back side of the display panel 10, i.e., the non-display side of the display panel 10. The power module 30 is used to provide a power supply voltage for the display panel 10 to display images. In the embodiment of the present application, the display device 100 can be a portable electronic device, such as a mobile phone, a tablet computer, etc.

[0033] See also Figure 2 , Figure 2 for Figure 1 A schematic diagram of the floor plan layout of the display panel is shown in FIG.

[0034] like Figure 2 As shown, the display panel 10 includes a power management circuit 11, a timing control circuit 12, a gamma circuit 13, a data driving circuit 14 and a scan driving circuit 15. The power management circuit 11 is electrically connected to the timing control circuit 12, the gamma circuit 13, the data driving circuit 14 and the scan driving circuit 15. The power management circuit 11 is used to output a power supply voltage AVDD to the timing control circuit 12, the gamma circuit 13, the data driving circuit 14 and the scan driving circuit 15, and output an analog operating voltage DVDD to the data driving circuit 14 and the scan driving circuit 15, so as to provide an operating voltage for the timing control circuit 12, the gamma circuit 13, the data driving circuit 14 and the scan driving circuit 15.

[0035] Among them, the timing control circuit 12 is used to generate a clock signal CLK, a data control signal and a scan control signal (not marked) based on the initial data signal received from the outside and the power supply voltage AVDD provided by the power management circuit 11, wherein the data control signal is used to cooperate with the data driving circuit 14 to output the data signal, and the clock signal CLK and the scan control signal are used to cooperate with the scan driving circuit 15 to output the scan signal.

[0036] The gamma circuit 13 is also electrically connected to the data driving circuit 14. The gamma circuit 13 is used to generate a gamma voltage based on the received power supply voltage AVDD and transmit the gamma voltage to the data driving circuit 14 under the control of the timing control circuit 12. The data driving circuit 14 is used to use the gamma voltage as a reference voltage and generate voltages of all grayscales, i.e., data signals, based on the received power supply voltage AVDD and the analog operating voltage DVDD, and transmit the required grayscale voltages to the pixel units P in the display area 10a to control the pixel units P to display images.

[0037] The scan driving circuit 15 is used to receive the power supply voltage AVDD, the turn-on voltage VGH and the turn-off voltage VGL from the power management circuit 11, and to output a scan signal to the pixel units P in the display area 10a according to the clock signal CLK and the turn-on voltage VGH and the turn-off voltage VGL. The pixel units P receive the data signals output by the data driving circuit 14 under the control of the scan signal.

[0038] Please also refer to Figure 3 and Figure 4 , Figure 3 for Figure 2 Schematic diagram of the logic of gamma voltage generation. Figure 4 for Figure 3 Schematic diagram of the equivalent circuit of the gamma circuit and data driver circuit.

[0039] like Figure 3 and Figure 4 As shown, the gamma circuit 13 outputs a first gamma voltage GM1, a second gamma voltage GM2, a third gamma voltage GM3, and a fourth gamma voltage GM4 based on the power supply voltage AVDD. The first gamma voltage GM1 and the second gamma voltage GM2 are respectively the positive and negative voltages when the display panel 10 displays full white, corresponding to grayscale 255. The third gamma voltage GM3 and the fourth gamma voltage GM4 are respectively the positive and negative voltages when the display panel 10 displays full black, corresponding to grayscale 0. The other grayscales, i.e., grayscales 1 to 254, are generated by the data driving circuit 14 based on the first gamma voltage GM1 to the fourth gamma voltage GM4. The first gamma voltage GM1 and the second gamma voltage GM2 are symmetrical about the center reference voltage GM0, and the third gamma voltage GM3 and the fourth gamma voltage GM4 are symmetrical about the center reference voltage GM0.

[0040] Specifically, the gamma circuit 13 includes a plurality of resistors R connected in series, and is used to divide the received power supply voltage AVDD into the required gamma voltages, i.e., the first gamma voltage GM1 to the fourth gamma voltage GM4, through the plurality of resistors R. The data driving circuit 14 includes a plurality of resistors R connected in series, and is used to divide the received gamma voltages into the plurality of resistors R to generate a plurality of different grayscale voltages, wherein a positive polarity grayscale voltage of 0 to 255 is generated according to the first gamma voltage GM1 and the second gamma voltage GM2, and a negative polarity grayscale voltage of 0 to 255 is generated according to the third gamma voltage GM3 and the fourth gamma voltage GM4, that is, n data signals Data1 to Datan are generated.

[0041] For example, taking the 64th gray scale as an example, the 64th gray scale of positive polarity is equal to (GM1-GM3)*(R1+R2+…R64) / Rt+GM3, and the 64th gray scale of negative polarity is equal to (GM4-GM2)*(R254+R253+…R64) / Rt+GM2, wherein R1+R2+…R64 represents 64 resistors R connected in series, R254+R253+…R64 represents 190 resistors R connected in series, and Rt represents the total resistance of the 254 series resistors.

[0042] When the data voltage output by the data driving circuit 14 changes from low to high, the power management circuit 11 outputting the power supply voltage AVDD will have a load change, thereby causing the power supply voltage AVDD provided to the gamma circuit 13 to have a voltage drop.

[0043] As shown in Figure 5 , Figure 5 is a schematic diagram of gamma voltage change. Since the power supply voltage AVDD is the input voltage of the gamma circuit 13, when the power supply voltage AVDD has a voltage drop, the gamma voltage output by the gamma circuit 13 will also have a voltage drop, for example, the first gamma voltage GM1 and the second gamma voltage GM2 will also have a voltage drop, but the voltage drops of the first gamma voltage GM1 and the second gamma voltage GM2 are different, resulting in that the first gamma voltage GM1 and the second gamma voltage GM2 are asymmetric in the case of positive and negative polarities, thereby causing the display panel to have a horizontal crosstalk phenomenon. As can be seen from the formula V=√(V1-cfvcom)2+(V2-CFCOM)2) / 2, wherein V1 and V2 are respectively the positive and negative polarity voltages at the same gray scale, and V is the pixel voltage of the liquid crystal driven by the positive and negative polarities, when V1 / V2 simultaneously decreases and the decrease amplitude is the same, the total pixel voltage V of the liquid crystal driven changes less, thereby avoiding the horizontal crosstalk phenomenon of the display panel.

[0044] Based on this, the application provides a gamma circuit for eliminating the above horizontal crosstalk phenomenon.

[0045] Please refer to Figure 6 , Figure 6 is a circuit block diagram of a gamma circuit provided by the second embodiment of the application.

[0046] As Figure 6As shown, the gamma circuit 13 includes a voltage output module 131 and a voltage adjustment module 132. The voltage output module 131 is electrically connected to the data driving circuit 14 and is used to output a first gamma voltage GM1, a second gamma voltage GM2, a third gamma voltage GM3, and a fourth gamma voltage GM4 to the data driving circuit 14 according to the received power supply voltage AVDD. The voltage adjustment module 132 is electrically connected to the first gamma voltage output terminal and the second gamma voltage output terminal, and is used to receive the first gamma voltage GM1 and the second gamma voltage GM2 from the voltage output module 131. When it is detected that the first gamma voltage GM1 changes along the first direction, the second gamma voltage GM2 is synchronously controlled to change along the first direction. That is, when it is detected that the first gamma voltage GM1 has a voltage drop, the second gamma voltage GM2 is synchronously controlled to drop, so as to control the voltage difference between the first gamma voltage GM1 and the second gamma voltage GM2 to be within a preset range. Among them, the voltage output module 131 and the second gamma voltage GM2 are electrically connected to the first gamma voltage output terminal and the second gamma voltage output terminal. Figure 4 The middle gamma circuit 13 has the same configuration, ie, includes a plurality of resistors R connected in series, for dividing the power supply voltage AVDD and outputting a first gamma voltage GM1 , a second gamma voltage GM2 , a third gamma voltage GM3 and a fourth gamma voltage GM4 .

[0047] See also Figure 7 , Figure 7 for Figure 6 Circuit block diagram of the medium voltage regulation module.

[0048] like Figure 7 As shown, the voltage adjustment module 132 includes a detection unit 1321 and a control unit 1323, wherein the detection unit 1321 is electrically connected to the first gamma voltage output terminal and the control unit 1323, and is used to receive the first gamma voltage GM1 from the first gamma voltage output terminal and detect changes in the first gamma voltage GM1. When a voltage drop is detected in the first gamma voltage GM1, the detection unit 1321 outputs a control signal to the control unit 1323.

[0049] The control unit 1323 is also electrically connected to the second gamma voltage output terminal. When the control unit 1323 receives a control signal, the control unit 1323 pulls down the second gamma voltage GM2 to a preset voltage value so that the difference between the first gamma voltage GM1 and the second gamma voltage GM2 is within a preset range.

[0050] See also Figure 8 , Figure 8 This is a circuit block diagram of a voltage adjustment module provided in the third embodiment of the present application. Figure 8As shown, the voltage adjustment module 132 comprises a detection unit 1321, a comparison unit 1322 and a control unit 1323, wherein the detection unit 1321 is electrically connected to the first gamma voltage output end and the comparison unit 1322, for receiving the first gamma voltage GM1 from the first gamma voltage output end and detecting the change of the first gamma voltage GM1, when detecting that the first gamma voltage GM1 appears voltage drop, the detection unit 1321 transmits the first gamma voltage GM1 to the comparison unit 1322, when the detection unit 1321 does not detect that the first gamma voltage GM1 appears voltage drop, the detection unit 1321 does not transmit the first gamma voltage GM1 to the comparison unit 1322.

[0051] The comparison unit 1322 is also electrically connected to the control unit 1323, and the comparison unit 1322 is used to compare the received first gamma voltage GM1 with the preset reference voltage Vref, when the first gamma voltage GM1 is less than or equal to the preset reference voltage Vref, the comparison unit 1322 outputs the first control signal to the control unit 1323, when the first gamma voltage GM1 is greater than the preset reference voltage Vref, the comparison unit 1322 outputs the second control signal to the control unit 1323.

[0052] The control unit 1323 is also electrically connected to the second gamma voltage output end, for receiving the second gamma voltage GM2 from the second gamma voltage output end of the voltage output module 131, when the control unit 1323 receives the first control signal, the control unit 1323 pulls down the second gamma voltage GM2, when the control unit receives the second control signal, the control unit 1323 stops pulling down the second gamma voltage GM2 to the preset voltage value.

[0053] Specifically, the comparison unit 1322 comprises a comparator U, the positive phase end of the comparator U is electrically connected to the detection unit 1321, the reverse end of the comparator U is electrically connected to the reference voltage end, and the output end of the comparator U is electrically connected to the control unit 1323.

[0054] The control unit 1323 comprises a switch tube T, a delay resistance Rx and a delay capacitor C, wherein the control end of the switch tube T is electrically connected to the comparison unit 1322, the first end of the switch tube T is electrically connected to the second gamma voltage output end, the second end of the switch tube T is electrically connected to the control node Q, the switch tube T is turned on when receiving the first control signal and is turned off when receiving the second control signal, and the second gamma voltage GM2 is transmitted to the control node Q through the switch tube T when the switch tube T is turned on. The first end of the delay resistance Rx is electrically connected to the control node Q, the second end of the delay resistance Rx is electrically connected to the ground end GND, the first end of the delay capacitor C is electrically connected to the control node Q, and the second end of the delay capacitor C is electrically connected to the ground end GND, wherein the delay resistance Rx and the delay capacitor C constitute a delay circuit, for adjusting the falling time and the voltage value of the second gamma voltage GM2.

[0055] The specific adjustment process is as follows: when the power supply voltage AVDD drops due to the load caused by the data voltage, the first gamma voltage GM1, the second gamma voltage GM2, the third gamma voltage GM3 and the fourth gamma voltage GM4 are also pulled down. When the detection unit 1321 detects that the first gamma voltage GM1 drops, the detection unit 1321 transmits the first gamma voltage GM1 to the comparison unit 1322. The comparison unit 1322 compares the first gamma voltage GM1 with the preset reference voltage Vref. When the first gamma voltage GM1 is less than or equal to the preset reference voltage Vref, the comparison unit 1322 outputs a first control signal to the switch tube Q to control the switch tube Q to turn on. At this time, the second gamma voltage GM1 is turned off. GM2 is transmitted to the control node Q through the switch tube Q and discharged to the ground terminal GND through the delay resistor Rx. At this time, the second gamma voltage GM2 is continuously pulled down. The delay resistor Rx is used to control the difference between the voltage value of the second gamma voltage GM2 and the voltage value of the first gamma voltage GM1 to be within a preset range. The delay capacitor C is used to adjust the speed at which the second gamma voltage GM2 is pulled down to be similar to the speed at which the first gamma voltage GM1 is dropped, and is used to control the falling speeds and falling voltage values ​​of the first gamma voltage GM1 and the second gamma voltage GM2 to be similar, thereby eliminating the lateral crosstalk phenomenon caused by the large change in the voltage difference between the first gamma voltage GM1 and the second gamma voltage GM2, and effectively improving the display effect.

[0056] See also Figure 9 , Figure 9 for Figure 8 Schematic diagram of mid-gamma voltage adjustment.

[0057] like Figure 9 As shown, in the first time period t1, when the data signal Data increases from the 64th gray scale to the 255th gray scale, the power supply voltage AVDD causes a voltage drop due to voltage loading. In the second time period t2, the power supply voltage AVDD gradually recovers to the initial voltage, and the first gamma voltage GM1 and the second gamma voltage GM2 also recover to the preset voltage.

[0058] During the first period t1, the first gamma voltage GM1 and the second gamma voltage GM2 also experience different degrees of voltage drops due to the change of the power supply voltage AVDD. At this time, the detection unit 1321 transmits the first gamma voltage GM1 to the comparison unit 1322. The comparison unit 1322 compares the first gamma voltage GM1 with the preset reference voltage Vref. When the first gamma voltage GM1 is less than or equal to the preset reference voltage Vref, the comparison unit 1322 controls the switch tube T to turn on, so as to control the second gamma voltage GM2 to be transmitted to the control node Q. The delay circuit composed of the delay resistor Rx and the delay capacitor C is used to pull down the second gamma voltage GM2. The voltage value of the gamma voltage GM2 is such that the voltage dropped by the second gamma voltage GM2 is the same as or close to the voltage dropped by the first gamma voltage GM1, so that the voltage difference between the second gamma voltage GM2 and the first gamma voltage GM1 is controlled within a preset range, so that the first gamma voltage VH1 and the second gamma voltage GM2 are symmetrical about the central reference voltage GM0. When the voltage difference between the second gamma voltage GM2 and the first gamma voltage GM1 is within the preset range, the display panel 10 does not experience lateral crosstalk due to data voltage pumping, that is, the lateral crosstalk caused by data voltage pumping is eliminated, thereby improving image display effects.

[0059] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A gamma circuit, characterized in that: The device includes a voltage output module, the voltage output module being configured to output a first gamma voltage and a second gamma voltage based on a received power supply voltage, the first gamma voltage and the second gamma voltage being used as reference voltages for a data signal to adjust a grayscale value of the data signal, the data signal being used to control a pixel unit in a display area to display an image, wherein the first gamma voltage is a reference voltage for the data signal of positive polarity, the second gamma voltage is a reference voltage for the data signal of negative polarity, and the first gamma voltage and the second gamma voltage are symmetrical about a central reference voltage; The gamma circuit further includes a voltage adjustment module, the voltage adjustment module being electrically connected to the voltage output module, the voltage adjustment module being configured to receive a first gamma voltage and a second gamma voltage from the voltage output module, and synchronously controlling the second gamma voltage to change along the first direction when the first gamma voltage changes along the first direction, and controlling a voltage difference between the first gamma voltage and the second gamma voltage to be within a preset range; The voltage adjustment module includes a detection unit and a control unit. The detection unit is electrically connected to the first gamma voltage output terminal and the control unit, and is used to detect changes in the first gamma voltage. When it is detected that the first gamma voltage changes along the first direction, the detection unit outputs a control signal to the control unit. The control unit controls the second gamma voltage to change along the first direction according to the control signal.

2. The gamma circuit according to claim 1, wherein The voltage adjustment module also includes a comparison unit, which is electrically connected to the detection unit and the control unit. When the detection unit detects that the first gamma voltage changes along the first direction, the detection unit transmits the first gamma voltage to the comparison unit. The comparison unit is used to compare the received first gamma voltage with a preset reference voltage. When the first gamma voltage is less than or equal to the reference voltage, the comparison unit outputs a control signal to the control unit. The control unit controls the second gamma voltage to change along the first direction to a preset voltage value according to the control signal.

3. The gamma circuit according to claim 2, wherein: The comparison unit includes a comparator, a non-phase terminal of the comparator is electrically connected to the detection unit, an inverting terminal of the comparator is electrically connected to a preset reference voltage terminal, an output terminal of the comparator is electrically connected to the control unit, and the comparator is used to compare the first gamma voltage with the preset reference voltage. When the first gamma voltage is less than or equal to the preset reference voltage, the comparator outputs a first level signal to the control unit. When the first gamma voltage is greater than the preset reference voltage, the comparator outputs a second level signal to the control unit. The first level signal is the control signal.

4. The gamma circuit according to claim 3, wherein: The control unit includes a switching tube and a delay resistor, the control end of the switching tube is electrically connected to the output end of the comparator, the first end of the switching tube is electrically connected to the second gamma voltage output end, the second end of the switching tube is electrically connected to the first end of the delay resistor, and the second end of the delay resistor is electrically connected to the ground end. The switching tube is used to be turned on under the control of the control signal to transmit the second gamma voltage to the delay resistor, and then transmit it to the ground end through the delay resistor, so as to control the second gamma voltage to change along the first direction to the preset voltage value.

5. The gamma circuit according to claim 4, wherein: The control unit also includes a delay capacitor, a first end of the delay capacitor is electrically connected to the second end of the switch tube, and a second end of the delay capacitor is electrically connected to the ground end. The delay capacitor is used to adjust the time for the second gamma voltage to change along the first direction to the preset voltage value.

6. The gamma circuit according to any one of claims 1 to 5, wherein: The voltage output module also outputs a third gamma voltage and a fourth gamma voltage, the third gamma voltage being a reference voltage for the data signal with a positive polarity, and the fourth gamma voltage being a reference voltage for the data signal with a negative polarity, the third gamma voltage and the fourth gamma voltage being symmetrical about the central reference voltage, a plurality of positive polarity data signals of different grayscales corresponding to the first gamma voltage and the third gamma voltage, and a plurality of negative polarity data signals of different grayscales corresponding to the second gamma voltage and the fourth gamma voltage.

7. The gamma circuit according to claim 6, wherein: The voltage output module includes a plurality of resistors connected in series, and the resistors are used to divide the received power voltage to output the first gamma voltage, the second gamma voltage, the third gamma voltage, and the fourth gamma voltage.

8. A display panel, characterized in that: It includes a gamma circuit as described in any one of claims 1 to 7, a data driving circuit and a plurality of pixel units, wherein the data driving circuit is used to output a plurality of data signals of different gray levels according to a first gamma voltage and a second gamma voltage output by the gamma circuit, and transmit the data signals to the pixel units to drive the pixel units to display images.

Images