CN107452354B - Gray scale control circuit, display driving circuit and display device - Google Patents
Gray scale control circuit, display driving circuit and display device Download PDFInfo
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- CN107452354B CN107452354B CN201710872734.2A CN201710872734A CN107452354B CN 107452354 B CN107452354 B CN 107452354B CN 201710872734 A CN201710872734 A CN 201710872734A CN 107452354 B CN107452354 B CN 107452354B
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
- G09G3/3607—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
- G09G3/3611—Control of matrices with row and column drivers
- G09G3/3685—Details of drivers for data electrodes
- G09G3/3688—Details of drivers for data electrodes suitable for active matrices only
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- Theoretical Computer Science (AREA)
- Control Of Indicators Other Than Cathode Ray Tubes (AREA)
Abstract
The embodiment of the invention provides a gray scale control circuit, a display driving circuit and a display device, relates to the technical field of display, and is used for reducing the deviation between a data voltage on a data line and a set value. The gray scale control circuit comprises a reference voltage generator and a gray scale compensator; the gray scale compensator is connected with the reference voltage generator and the source driver; the gray scale compensator is used for acquiring a voltage difference between a reference gray scale voltage output by the reference voltage generator and a data voltage fed back by the source driver and compensating the voltage difference in the reference gray scale voltage input to the source driver. The gray scale control circuit is used for providing reference gray scale voltage for the source driver.
Description
Technical Field
The invention relates to the technical field of display, in particular to a gray scale control circuit, a display driving circuit and a display device.
Background
A TFT-LCD (Thin Film Transistor-Liquid Crystal Display) is used as a flat panel Display device, and has the characteristics of small size, low power consumption, no radiation, relatively low manufacturing cost, and the like, so that it is increasingly applied to the field of high-performance Display.
The TFT-LCD comprises grid lines and data lines which are crossed transversely and longitudinally. In the display process, scanning the grid line by line to gate the sub-pixels in the TFT-LCD line by line; then, a data voltage is input to the strobed row of sub-pixels through the data lines, respectively, thereby charging the sub-pixels. At this time, the liquid crystal molecules corresponding to the sub-pixel position are deflected, so that the gray scale value displayed by the sub-pixel is matched with the gray scale value output to the sub-pixel.
A Source IC (Source driver) for outputting a data voltage to the data line is generally provided in the TFT-LCD. Due to the influence of the self line resistance of the wiring on the display Panel (Panel) of the TFT-LCD, the RC Delay effect and the Noise (Noise) interference signal, the data voltage on the data line has larger deviation with a set value, thereby reducing the display effect.
Disclosure of Invention
Embodiments of the present invention provide a gray scale control circuit, a display driving circuit and a display device for reducing a deviation between a data voltage on a data line and a set value.
In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:
in one aspect of the embodiments of the present invention, a gray scale control circuit is provided, where the gray scale control circuit includes a reference voltage generator and a gray scale compensator; the gray scale compensator is connected with the reference voltage generator and the source driver; the gray scale compensator is used for acquiring a voltage difference between a reference gray scale voltage output by the reference voltage generator and a data voltage fed back by the source driver and compensating the voltage difference in the reference gray scale voltage input to the source driver.
Optionally, the gray scale control circuit further comprises a data selector, a first compensation module and a second compensation module; the data selector is connected with a polarity inversion control signal end, the source electrode driver and the gray scale compensator; the data selector is used for outputting the positive polarity or negative polarity data voltage fed back by the output end of the source driver to the gray scale compensator under the control of the polarity inversion control signal end; the first compensation module is connected with a positive polarity voltage output end of the reference voltage generator and the source driver; the first compensation module is used for acquiring a voltage difference between the voltage of the positive polarity voltage output end and the positive polarity data voltage fed back by the source driver and compensating the voltage difference into a reference gray scale positive polarity voltage input to the source driver; the second compensation module is connected with a negative polarity voltage output end of the reference voltage generator and the source driver; the second compensation module is used for acquiring a voltage difference between the voltage of the negative polarity voltage output end and the negative polarity data voltage fed back by the source driver and compensating the voltage difference in the reference gray scale negative polarity voltage input to the source driver.
Optionally, the first compensation module includes a first subtractor and a first adder; the reverse input end of the first subtracter is connected with the data selector, the same-direction input end of the first subtracter is connected with the positive-polarity voltage output end of the reference voltage generator, and the output end of the first subtracter is connected with the same-direction input end of the first adder; the same-direction input end of the first adder is also connected with the positive-polarity voltage output end of the reference voltage generator.
Optionally, the first compensation module further includes a first operational amplifier; the same-direction input end of the first operational amplifier is connected with the output end of the first adder, and the output end of the first operational amplifier is connected with the source electrode driver.
Optionally, the second compensation module includes a second subtractor and a second adder; the reverse input end of the second subtracter is connected with the data selector, the homodromous input end of the second subtracter is connected with the negative polarity voltage output end of the reference voltage generator, and the output end of the second subtracter is connected with the homodromous input end of the second adder; the same-direction input end of the second adder is also connected with the negative-polarity voltage output end of the reference voltage generator.
Optionally, the second compensation module further includes a second operational amplifier; the same-direction input end of the second operational amplifier is connected with the output end of the second adder, and the output end of the second operational amplifier is connected with the source electrode driver.
Further optionally, the data selector is further connected to the first power supply voltage terminal and the second power supply voltage terminal; the data selector includes: a first transistor, a second transistor, a third transistor, and a fourth transistor; the grid electrode of the first transistor is connected with the polarity inversion control signal end, the first pole of the first transistor is connected with the source electrode driver, and the second pole of the first transistor is connected with the first compensation module; the first pole of the second transistor is connected with the source driver, and the second pole of the second transistor is connected with the second compensation module; the grid electrode of the third transistor is connected with the polarity inversion control signal end, the first pole of the third transistor is connected with the first power supply voltage end, and the second pole of the third transistor is connected with the grid electrode of the second transistor; the grid electrode of the fourth transistor is connected with the polarity inversion control signal end, the first pole of the fourth transistor is connected with the grid electrode of the second transistor, and the second pole of the fourth transistor is connected with the second power supply voltage end.
In another aspect of the embodiments of the present invention, a display driving circuit is provided, which includes any one of the above gray scale control circuits, and the display driving circuit further includes a source driver; and the gray scale compensator in the gray scale control circuit and the reference voltage generator are connected with the source driver.
Optionally, the source driver includes a timing controller and a plurality of driving channels, each driving channel is used for driving one data line; the driving channel comprises a digital-to-analog conversion module and an operational amplification module; the digital-to-analog conversion module is connected with the gray scale compensator, the reference voltage generator, the time sequence controller and the operational amplification module; the digital-to-analog conversion module is used for generating a plurality of gray scale voltages according to the reference gray scale positive polarity voltage and the reference gray scale negative polarity voltage provided by the gray scale compensator and the gray scale reference value except the reference gray scale positive polarity voltage and the reference gray scale negative polarity voltage provided by the reference voltage generator, and selecting one of the plurality of gray scale voltages to output to the operational amplification module according to the digital signal output by the time schedule controller; the operational amplification module is further connected with a data line, and is used for amplifying the gray scale voltage output by the digital-to-analog conversion module so as to output the gray scale voltage to the data line as the data voltage.
In a further aspect of the embodiments of the present invention, there is provided a display device including any one of the display driving circuits described above.
The embodiment of the invention provides a gray scale control circuit, a display driving circuit and a display device. The gray scale compensator in the gray scale control circuit is connected with the reference voltage generator and the source driver. The gray scale compensator is used for acquiring a voltage difference between a reference gray scale voltage output by the reference voltage generator and a data voltage fed back by the source driver and compensating the voltage difference in the reference gray scale voltage input to the source driver. At this time, the voltage provided by the gray scale control circuit to the source driver is the sum of a reference gray scale voltage output by the reference voltage generator and the voltage difference. In this case, after the compensated reference gray scale voltage is received by the source driver, the actually output data voltage can be adjusted to be closer to the theoretical value, thereby improving the display effect.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a display driving circuit according to an embodiment of the present invention;
FIG. 2 is a waveform diagram of an uncompensated data voltage and an ideal data voltage;
FIG. 3 is a schematic diagram of another display driving circuit according to an embodiment of the present invention;
FIG. 4 is a schematic structural diagram of the first compensation module and the second compensation module in FIG. 3;
FIG. 5 is a schematic structural diagram of the source driver in FIG. 3;
FIG. 6 is a waveform diagram illustrating a compensated data voltage, an uncompensated data voltage and an ideal data voltage;
fig. 7 is a schematic diagram of a specific structure of the data selector in fig. 4.
Reference numerals:
01-a gray scale control circuit; 02-source driver; 03-a time schedule controller; 10-a reference voltage generator; 20-a gray scale compensator; 201-a first compensation module; 211-a first subtractor; 212-first adder; 213-a first operational amplifier; 202-a second compensation module; 221-a second subtractor; 222-a second adder; 223-a second operational amplifier; 30-a data selector; 40-a drive channel; 401-digital to analog conversion module; 402-operational amplification module.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In an embodiment of the present invention, as shown in fig. 1, a gray scale control circuit 01 is provided, where the gray scale control circuit 01 includes a reference voltage generator 10 and a gray scale compensator 20.
The reference voltage generator 10 is used for generating a plurality of reference gray scale voltages (Vgam1, Vgam2 … … Vgamn), N is not less than 2, and N is a positive integer. For example, N-14.
The gray scale compensator 20 is connected to the reference voltage generator 10 and the source driver 02. The gray scale compensator 20 is configured to obtain a voltage difference Δ V between a reference gray scale voltage (e.g., Vgam1) output by the reference voltage generator 10 and a data voltage Vdata Fed Back (FB) by the source driver 02, and compensate the voltage difference Δ V in the reference gray scale voltage input to the source driver 02. At this time, the voltage supplied from the gray scale control circuit 01 to the source driver 02 is the sum of a reference gray scale voltage Vgam1 output from the reference voltage generator 10 and the voltage difference Δ V, i.e., Vgam1+ Δv. In this case, after the source driver 02 receives the compensated reference gray scale voltage, the actually output data voltage Vdata may be adjusted to be closer to the theoretical value Vdata, thereby facilitating to improve the display effect.
When the display panel displays a picture, particularly a static picture, the light transmittance of the sub-pixels on the display panel remains unchanged during the process of displaying the static picture. In this case, if the data voltage Vdata charged to the sub-pixel through the data line DL is also kept constant, the liquid crystal molecules at the sub-pixel position maintain a certain deflection angle for a long time. This tends to cause degradation of the liquid crystal molecules and makes them unable to deflect. In order to solve the above problem, the data voltage Vdata input to the same sub-pixel in two adjacent frames needs to have polarity inversion, as shown in fig. 2, that is, the waveform of the data voltage Vdata input to the sub-pixel in the previous frame is above the common voltage Vcom with respect to the common voltage Vcom, and is positive polarity (+). The waveform of the data voltage Vdata inputted to the sub-pixel in the next frame is negative (-) below the common voltage Vcom with respect to the common voltage Vcom. The example in which the reference voltage generator 10 generates 14 reference grayscale voltages (Vgam1, Vgam2 … … Vgam14) is given. Among them, the first 7 reference gray scale voltages (Vgam1, Vgam2 … … Vgam7) are positive polarity. The source driver 02 may output a data voltage of a positive polarity according to the first 7 reference gray scale voltages; the last 7 reference gray-scale voltages (Vgam8, Vgam9 … … Vgam14) are negative polarity, and the source driver 02 can output data voltages of negative polarity according to the last 7 reference gray-scale voltages.
However, due to the influence of the line resistance of the data line itself and noise interference, as shown in fig. 2, the waveform of the data voltage Vdata' actually charged into the sub-pixel by the data line has a certain deviation from the ideal waveform Vdata. In the waveform of the actual data voltage Vdata', the positive polarity voltage and the negative polarity voltage are not symmetrical with respect to the common voltage Vcom, and a defect such as an Image Sticking is formed.
In this case, the data voltage Vdata' actually output by the source driver 02 is closer to the theoretical value Vdata. Not only the positive polarity voltage of the actual data voltage Vdata 'but also the negative polarity voltage of the actual data voltage Vdata' needs to be adjusted.
Accordingly, the gray scale control circuit 01 further includes a data selector 30 as shown in fig. 3.
The data selector 30 is connected to the polarity inversion control signal terminal POL, the source driver 02, and the gray scale compensator 20.
Specifically, the polarity inversion control signal terminal POL is connected to the timing controller (Tcon) 03. The timing controller 03 is configured to provide a square wave to the polarity inversion control signal terminal POL as a polarity inversion signal. For example, when the polarity inversion control signal terminal POL outputs a low level, the source driver 02 feeds back the positive polarity data voltage; when the polarity inversion control signal terminal POL outputs a high level, the source driver 02 feeds back a negative polarity data voltage. Or, when the polarity inversion control signal terminal POL outputs a low level, the source driver 02 feeds back a negative polarity data voltage; when the polarity inversion control signal terminal POL outputs a high level, the source driver 02 feeds back the positive polarity data voltage.
Accordingly, the data selector 30 is configured to output the positive polarity data voltage or the negative polarity data voltage fed back from the output terminal of the source driver 02 to the gray-scale compensator 20 under the control of the polarity inversion control signal terminal POL, so that the gray-scale compensator 20 can compensate the positive polarity data voltage or the negative polarity data voltage, respectively.
On this basis, the gray scale compensator 20, as shown in fig. 3, includes: a first compensation module 201 and a second compensation module 202.
Specifically, the first compensation module 201 is connected to the positive polarity voltage output terminal of the reference voltage generator 10, for example, Vgam1 and the input terminal of the source driver 02.
It should be noted that the reference voltage generator 10 can output 7 positive reference gray-scale voltages (Vgam1, Vgam2 … … Vgam7), wherein the reference voltage generator 10 can adjust the remaining reference gray-scale voltages (Vgam2, Vgam3 … … Vgam7) according to the value of the reference gray-scale voltage Vgam 1. The optional first compensation module 201 is connected to a voltage output terminal of the reference voltage generator 10 capable of outputting the reference gray scale voltage Vgam 1.
In this case, the first compensation module 201 is configured to obtain a voltage difference (Δ V1 ═ Vgam1-Vdata) between the voltage Vgam1 at the positive polarity voltage output terminal and the positive polarity data voltage Vdata fed back by the source driver, and compensate the voltage difference Δ V1 in the reference gray scale positive polarity voltage input to the source driver 02, that is, input Vgam1 +/Δ V1 to the source driver 02.
In addition, the second compensation module 202 is connected to the negative polarity voltage output terminal of the reference voltage generator 10, for example, Vgam14 and the source driver 20.
The reference voltage generator 10 can output 7 negative reference grayscale voltages (Vgam8, Vgam9 … … Vgam14), wherein the reference voltage generator 10 can adjust the remaining reference grayscale voltages (Vgam8, Vgam9 … … Vgam13) according to the value of the reference grayscale voltage Vgam 14. The optional second compensation module 202 is therefore connected to the voltage output of the reference voltage generator 10 capable of outputting the reference grayscale voltage Vgam 14.
In this case, the second compensation module 202 is configured to obtain a voltage difference (Δ V2 ═ Vgam14- (-Vdata)) between the voltage Vgam14 at the negative polarity voltage output terminal and the negative polarity data voltage-Vdata fed back by the source driver 20, and compensate the voltage difference Δ V2 in the reference gray scale negative polarity voltage input to the source driver 20, that is, input Vgam14 +/Δ V2 to the source driver 02.
The specific configurations of the first compensation module 201 and the second compensation module 202 will be described in detail below. As shown in fig. 4, the first compensation module includes a first subtractor 211 and a first adder 212.
The inverting input terminal of the first subtractor 211 is connected to the data selector 30, the inverting input terminal thereof is connected to the positive polarity voltage output terminal Vgam1 of the reference voltage generator 10, and the output terminal of the first subtractor 211 is connected to the inverting input terminal of the first adder 212. In this case, the output voltage of the output terminal of the first subtractor 211 is Δ V1 ═ Vgam 1-Vdata.
The non-inverting input terminal of the first adder 212 is also connected to the positive polarity voltage output terminal Vgam1 of the reference voltage generator 10. In this case, the output voltage of the first adder 212 is Vgam1 +. DELTA.V 1.
On this basis, the first compensation module 201 further includes a first operational amplifier 213. The same-direction input terminal of the first operational amplifier 213 is connected to the output terminal of the first adder 212, and the output terminal of the first operational amplifier 213 is connected to the source driver 02. The voltage output from the first adder 212 can be amplified by the first operational amplifier 213.
In addition, the second compensation module 202 includes a second subtractor 221 and a second adder 222. The inverting input terminal of the second subtractor 221 is connected to the data selector 30, the non-inverting input terminal thereof is connected to the negative polarity voltage output terminal Vgam14 of the reference voltage generator 10, and the output terminal of the second subtractor 221 is connected to the non-inverting input terminal of the second adder 222. In this case, the output voltage of the output terminal of the second subtractor 221 is Δ V2 ═ Vgam12- (-Vdata).
The non-inverting input terminal of the second adder 222 is also connected to the negative polarity voltage output terminal Vgam14 of the reference voltage generator 10. In this case, the output voltage of the second adder 222 is Vgam14 +. DELTA.V 2.
On this basis, the second compensation module 202 further comprises a second operational amplifier 223. The non-inverting input terminal of the second operational amplifier 223 is connected to the output terminal of the second adder 222, and the output terminal of the second operational amplifier 223 is connected to the source driver 02. The voltage output from the second adder 222 can be amplified by the second operational amplifier 223.
Based on this, as shown in fig. 5, the source driver 02 includes a plurality of driving channels 40. Each driving channel is used to drive one data line DL. The driving channel 40 includes a digital-to-analog conversion module 401 and an operational amplification module 402.
The digital-to-analog conversion module 401 is connected to the output ends of the first operational amplifier 213 and the second operational amplifier 223, and in addition, the digital-to-analog conversion module 401 is further connected to the reference voltage generator 10 and the operational amplification module 402.
The dac module 401 is configured to generate a plurality of gray scale voltages, for example, 256 gray scale voltages under the voltage dividing action of the voltage dividing resistors in the dac module 401, according to the reference gray scale positive polarity voltage Vgam1 +. DELTA.V 1 amplified and outputted by the first operational amplifier 213, the reference gray scale positive polarity voltage Vgam14 +. DELTA.V 2 amplified and outputted by the second operational amplifier 223, and the gray scale reference values (Vgam2, Vgam3 … … Vgam13) provided by the reference voltage generator 10, except for the reference gray scale positive polarity voltage and the reference gray scale negative polarity voltage.
In addition, the digital-to-analog conversion module 401 is also connected to the timing controller 03 as shown in fig. 5. In this case, under the control of the digital signal (for example, 8Bit) output from the timing controller 03, a part of the switches in the digital-to-analog conversion module 401 are closed and a part of the switches are opened, so that one gray-scale voltage among the 256 gray-scale voltages can be selected and output to the operational amplification module 402.
The operational amplification module 402 is further connected to the data line DL, and the operational amplification module 402 is configured to amplify the gray scale voltage output by the digital-to-analog conversion module 401, so as to output the gray scale voltage as the data voltage Vdata to the data line DL. The operational amplifier module 402 may be an operational amplifier.
In this case, since the reference gray scale voltages inputted to the driving channel 40 of the source driver 02 are the compensated reference gray scale positive polarity voltage Vgam1 +. DELTA.V 1 and the reference gray scale positive polarity voltage Vgam14 +. DELTA.V 2, the positive polarity data voltage and the negative polarity data voltage supplied from the source driver 02 to the data lines DL are also compensated accordingly. Thus, as shown in fig. 6, the compensated data voltage Vdata "is closer to the reference value Vdata than the uncompensated data voltage Vdata'.
In addition, as shown in fig. 7, the data selector 30 is also connected to a first power supply voltage terminal Vcc and a second power supply voltage terminal Vss. The first power supply voltage terminal Vcc is used to output a constant high level. The second supply voltage terminal Vss is used to output a constant low level or ground.
The data selector 30 includes: a first transistor M1, a second transistor M2, a third transistor M3, and a fourth transistor M4.
The gate of the first transistor M1 is connected to the polarity inversion control signal terminal POL, the first pole is connected to the source driver 02, and the second pole is connected to the first compensation module 201.
The first pole of the second transistor M2 is connected to the source driver 02, and the second pole is connected to the second compensation module 202.
The gate of the third transistor M3 is connected to the polarity inversion control signal terminal POL, the first pole is connected to the first power supply voltage terminal Vcc, and the second pole is connected to the gate of the second transistor M2.
The gate of the fourth transistor M4 is connected to the polarity inversion control signal terminal POL, the first pole is connected to the gate of the second transistor M2, and the second pole is connected to the second power supply voltage terminal Vss.
Specifically, as shown in fig. 7, the first transistor M1, the second transistor M2, and the third transistor M3 are P-type transistors, and the fourth transistor M4 is an N-type transistor. In this case, when the polarity inversion control signal terminal POL outputs a low level, the first transistor M1 is turned on. The positive polarity data voltage fed back by the source driver 02 at this time may be output to the first compensation module 201 through the first transistor M1. At this time, the third transistor M3 is turned on, thereby transmitting the high level output from the first power supply voltage terminal Vcc to the gate of the second transistor M2, so that the second transistor M2 is in a turn-off state.
When the polarity inversion control signal terminal POL outputs a high level, the first transistor M1 and the third transistor M3 are turned off, and the fourth transistor M4 is turned on. The low level of the second power supply voltage terminal Vss output is transmitted to the second transistor M2, and the second transistor M2 is turned on. At this time, the negative polarity data voltage fed back by the source driver 02 may be output to the second compensation module 202 through the second transistor M2.
The embodiment of the invention provides a display driving circuit, which comprises the gray scale control circuit 01 as described in any one of the above. The display driver circuit further comprises a source driver 02 as shown in fig. 3. The gray scale compensator 20 and the reference voltage generator 10 in the gray scale control circuit 01 are connected to the source driver 02.
In addition, the source driver 02 has a structure as shown in fig. 5, a timing controller, and a plurality of driving channels 40, each driving channel 40 is used for driving one data line DL. The driving channel 40 includes a digital-to-analog conversion module 401 and an operational amplification module 402 as shown in fig. 3. The specific structures and connection manners of the digital-to-analog conversion module 401 and the operational amplification module 402 are the same as those described above, and are not described herein again.
It should be noted that the display driving circuit described above has the same technical effects as the gray scale control circuit 01 provided in the foregoing embodiment, and the details are not repeated herein.
An embodiment of the invention provides a display device, which includes the display driving circuit as described above, and has the same technical effects as the display driving circuit provided in the foregoing embodiment, and details are not repeated here.
In the embodiment of the present invention, the display device may specifically include a liquid crystal display device, for example, the display device may be any product or component with a display function, such as a display, a television, a digital photo frame, a mobile phone, or a tablet computer.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (9)
1. The gray scale control circuit is characterized by comprising a reference voltage generator and a gray scale compensator;
the gray scale compensator is connected with the reference voltage generator and the source driver; the gray scale compensator is used for acquiring a voltage difference between a reference gray scale voltage output by the reference voltage generator and the data voltage fed back by the source driver, and compensating the voltage difference between the reference gray scale voltage output by the reference voltage generator and the data voltage fed back by the source driver in the reference gray scale voltage input to the source driver;
the gray scale control circuit also comprises a data selector, a first compensation module and a second compensation module;
the data selector is connected with a polarity inversion control signal end, the source electrode driver and the gray scale compensator; the data selector is used for outputting the positive polarity or negative polarity data voltage fed back by the output end of the source driver to the gray scale compensator under the control of the polarity inversion control signal end;
the first compensation module is connected with a positive polarity voltage output end of the reference voltage generator and the source driver; the first compensation module is used for acquiring a voltage difference between the voltage of the positive polarity voltage output end and the positive polarity data voltage fed back by the source driver, and compensating the voltage difference between the voltage of the positive polarity voltage output end and the positive polarity data voltage fed back by the source driver into a reference gray scale positive polarity voltage input to the source driver;
the second compensation module is connected with a negative polarity voltage output end of the reference voltage generator and the source driver; the second compensation module is used for acquiring a voltage difference between the voltage of the negative polarity voltage output end and the negative polarity data voltage fed back by the source driver, and compensating the voltage difference between the voltage of the negative polarity voltage output end and the negative polarity data voltage fed back by the source driver into the reference gray scale negative polarity voltage input to the source driver.
2. The gray scale control circuit of claim 1, wherein the first compensation module comprises a first subtractor and a first adder;
the reverse input end of the first subtracter is connected with the data selector, the same-direction input end of the first subtracter is connected with the positive-polarity voltage output end of the reference voltage generator, and the output end of the first subtracter is connected with the same-direction input end of the first adder;
the same-direction input end of the first adder is also connected with the positive-polarity voltage output end of the reference voltage generator.
3. The gray scale control circuit of claim 2, wherein the first compensation module further comprises a first operational amplifier;
the same-direction input end of the first operational amplifier is connected with the output end of the first adder, and the output end of the first operational amplifier is connected with the source electrode driver.
4. The gray scale control circuit of claim 1, wherein the second compensation module comprises a second subtractor and a second adder;
the reverse input end of the second subtracter is connected with the data selector, the homodromous input end of the second subtracter is connected with the negative polarity voltage output end of the reference voltage generator, and the output end of the second subtracter is connected with the homodromous input end of the second adder;
the same-direction input end of the second adder is also connected with the negative-polarity voltage output end of the reference voltage generator.
5. The gray scale control circuit of claim 4, wherein the second compensation module further comprises a second operational amplifier;
the same-direction input end of the second operational amplifier is connected with the output end of the second adder, and the output end of the second operational amplifier is connected with the source electrode driver.
6. The gray scale control circuit of any one of claims 1-5, wherein the data selector is further connected to a first supply voltage terminal and a second supply voltage terminal; the data selector includes: a first transistor, a second transistor, a third transistor, and a fourth transistor;
the grid electrode of the first transistor is connected with the polarity inversion control signal end, the first pole of the first transistor is connected with the source electrode driver, and the second pole of the first transistor is connected with the first compensation module;
the first pole of the second transistor is connected with the source driver, and the second pole of the second transistor is connected with the second compensation module;
the grid electrode of the third transistor is connected with the polarity inversion control signal end, the first pole of the third transistor is connected with the first power supply voltage end, and the second pole of the third transistor is connected with the grid electrode of the second transistor;
the grid electrode of the fourth transistor is connected with the polarity inversion control signal end, the first pole of the fourth transistor is connected with the grid electrode of the second transistor, and the second pole of the fourth transistor is connected with the second power supply voltage end.
7. A display driving circuit comprising the gray scale control circuit according to any one of claims 1 to 6, further comprising a source driver; and the gray scale compensator and the reference voltage generator in the gray scale control circuit are connected with the source driver.
8. The display driving circuit according to claim 7, wherein the source driver comprises a timing controller and a plurality of driving channels, each driving channel for driving one data line;
the driving channel comprises a digital-to-analog conversion module and an operational amplification module;
the digital-to-analog conversion module is connected with the gray scale compensator, the reference voltage generator, the time sequence controller and the operational amplification module; the digital-to-analog conversion module is used for generating a plurality of gray scale voltages according to the reference gray scale positive polarity voltage and the reference gray scale negative polarity voltage provided by the gray scale compensator and the gray scale reference value except the reference gray scale positive polarity voltage and the reference gray scale negative polarity voltage provided by the reference voltage generator, and selecting one of the plurality of gray scale voltages to output to the operational amplification module according to the digital signal output by the time schedule controller;
the operational amplification module is further connected with a data line, and is used for amplifying the gray scale voltage output by the digital-to-analog conversion module so as to output the gray scale voltage to the data line as the data voltage.
9. A display device comprising the display drive circuit according to claim 7 or 8.
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| CN108154857B (en) * | 2017-12-29 | 2019-12-13 | 深圳市华星光电半导体显示技术有限公司 | gamma reference voltage generating circuit, driving circuit and method of liquid crystal display panel |
| CN108231000B (en) * | 2018-04-04 | 2020-03-17 | 深圳市华星光电半导体显示技术有限公司 | OLED display unit driving compensation circuit, OLED display circuit and OLED display |
| CN109254695A (en) * | 2018-11-23 | 2019-01-22 | 京东方科技集团股份有限公司 | The driving method of touch-control display panel, display device and touch-control display panel |
| CN109672478B (en) * | 2019-01-02 | 2021-03-02 | 合肥京东方光电科技有限公司 | Display device, signal transmission anti-interference method thereof and time sequence controller |
| CN109584831B (en) * | 2019-01-08 | 2020-10-16 | 合肥京东方显示技术有限公司 | Display compensation method and device and display device |
| CN110033728B (en) * | 2019-04-24 | 2022-10-11 | 京东方科技集团股份有限公司 | Crosstalk eliminating method and device, display equipment and storage medium |
| CN110322852B (en) * | 2019-06-14 | 2020-10-16 | 深圳市华星光电技术有限公司 | Gamma voltage output circuit, step-down repairing method thereof and source driver |
| CN113160768B (en) * | 2021-04-15 | 2022-08-23 | 惠州市华星光电技术有限公司 | Display panel, control method thereof and storage medium |
| CN115798430B (en) * | 2022-12-02 | 2024-05-28 | Tcl华星光电技术有限公司 | Display device and driving method thereof |
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| KR100768047B1 (en) * | 2005-11-30 | 2007-10-18 | 엘지.필립스 엘시디 주식회사 | OLED display apparatus and drive method thereof |
| JP2008083399A (en) * | 2006-09-27 | 2008-04-10 | Lg Philips Lcd Co Ltd | Reference voltage circuit for liquid crystal display device |
| CN103544927B (en) * | 2013-11-07 | 2015-07-22 | 京东方科技集团股份有限公司 | Display drive circuit, display device and display drive method |
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