TWI796006B - Source driving circuit and display apparatus - Google Patents

Abstract

The present disclosure relates to a source driving circuit and an electronic apparatus. The source driving circuit includes gamma resistor strings, a digital to analog converting (DAC) circuit and an output buffer circuit. The DAC circuit selects a gamma voltage from the gamma resistor strings based on data signal. The output buffer circuit outputs a driving voltage to a corresponding data line based on the gamma voltage. The output buffer circuit includes an input stage module, a gain stage module, and an output stage module. At a switching period, an auxiliary input stage unit of the input stage module, the gain stage module, and the output stage module cooperate with each other to form a first unity gain amplifier for outputting the driving voltage based on the received gamma voltage. In a steady period, a major input stage unit of the input stage module, the gain stage module, and the output stage module cooperate with each other to form a second unity gain amplifier for outputting the driving voltage based on the received gamma voltage.

Description

Source driving circuit and display device

The invention relates to a source drive circuit and a display device.

With the continuous development of electronic technology, most consumer electronic products such as mobile phones, portable computers, personal digital assistants (PDAs), tablet computers, and media players use displays as input and output devices to make the products more user-friendly. machine dialogue mode. Generally, a display includes a display panel and a driving circuit for driving the display panel to display images. The display panel includes a plurality of pixel units. The drive circuit includes a timing control circuit, a gamma correction reference voltage circuit, a gate drive circuit and a source drive circuit. The source driving circuit includes a gamma resistor string, a digital to analog converter (Digital to Analog, DAC) and an output buffer circuit. The DAC converts the received image data into an analog signal based on the gamma voltage provided by the gamma correction reference voltage circuit and outputs it to the pixel unit through the output buffer circuit. When the timing control circuit transmits image data to the source drive circuit, the DAC will select the corresponding gamma voltage in the gamma resistor string according to the received image data, that is, convert the received image data into an analog signal ( The gamma voltage) is transmitted to the output buffer circuit, and then the output buffer circuit generates a driving voltage and outputs it to the pixel unit to generate display gray scale changes. When the display panel is displaying an image, the timing control circuit continuously transmits and updates the image data to the source drive circuit according to the change of the displayed image, and the DAC will select and update the gamma voltage to the output buffer according to the received image data circuit, so when the image data is different, the external gamma correction reference voltage needs to charge or discharge the input terminal of the output buffer circuit. But since the source drive The existence of parasitic capacitance and parasitic resistance in the dynamic circuit causes a delay in the transmission of the gamma voltage, which in turn affects the output slew rate of the output buffer circuit.

The main purpose of the present invention is to provide a source driving circuit and a display device, aiming at solving the problem of slow gamma voltage response in the prior art.

A source drive circuit that receives a gamma correction reference voltage and is electrically connected to a data line; the source drive circuit includes: a gamma resistor string that receives the gamma correction reference voltage and generates a gamma voltage; digital analog A conversion circuit, electrically connected to the gamma resistor string, for selecting and outputting a corresponding gamma voltage from the gamma resistor string according to the data signal; and an output buffer circuit, for receiving the gamma voltage and Output driving voltage to the data line; the output buffer circuit includes an input stage module, a gain stage module and an output stage module; the input stage module includes a main input stage unit and an auxiliary input stage unit; the main The size of the components in the input stage unit is larger than the size of the components in the auxiliary input stage unit; the input stage module works alternately in the switching stage and the stable stage; in the switching stage, the auxiliary input stage unit, the gain the stage module and the output stage module form a first unity gain amplifier to output the driving voltage according to the gamma voltage, and the output stage module provides the driving voltage to the main input stage unit ; In the stable stage, the main input stage unit, the gain stage module and the output stage module form a second unity gain amplifier to output the driving voltage according to the gamma voltage.

A display device, comprising a plurality of scanning lines and a plurality of data lines, the two are intersected; the display device also includes: The gamma correction reference voltage circuit is used to output the gamma correction reference voltage according to the gamma correction curve; and the source drive circuit is used to convert the data signal into a drive voltage; the source drive circuit includes a gamma resistor string, a digital An analog conversion circuit and an output buffer circuit; the gamma resistor string receives the gamma correction reference voltage and generates a gamma voltage; the digital-to-analog conversion circuit is used to select the corresponding gamma resistor string from the gamma resistor string according to the data signal and output the gamma voltage; the output buffer circuit is used to receive the gamma voltage and output the driving voltage to the data line; the output buffer circuit includes an input stage module, a gain stage module and an output stage Module; the input stage module includes a main input stage unit and an auxiliary input stage unit; the size of the components in the main input stage unit is larger than the component size in the auxiliary input stage unit; the input stage modules work alternately In the switching phase and the stabilization phase; in the switching phase, the auxiliary input stage unit, the gain stage module and the output stage module form a first unity gain amplifier to output the driving voltage, and the output stage module provides the driving voltage to the main input stage unit; in the stable phase, the main input stage unit, the gain stage module and the output stage module A second unity gain amplifier is formed to output the driving voltage according to the gamma voltage.

A source drive circuit that receives a gamma correction reference voltage and is electrically connected to a data line; the source drive circuit includes: a gamma resistor string that receives the gamma correction reference voltage and generates a gamma voltage; digital analog A conversion circuit, electrically connected to the gamma resistor string, for selecting and outputting a corresponding gamma voltage from the gamma resistor string according to the data signal; and an output buffer circuit, for receiving the gamma voltage and Output driving voltage to the data line; the output buffer circuit includes an input stage module, a gain stage module and an output stage module; the input stage module includes a main input stage unit and an auxiliary input stage unit; the main The input stage unit is directly electrically connected to the gain stage module, and the auxiliary input stage unit is directly electrically connected to the gain stage module. connected; the size of the components in the main input stage unit is greater than the size of the components in the auxiliary input stage unit; the input stage module works alternately in the switching phase and the stable phase; in the switching phase, the auxiliary input stage The unit, the gain stage module and the output stage module form a first unity gain amplifier to output the driving voltage according to the gamma voltage, and the output stage module provides the driving voltage to the the main input stage unit; during the stabilization phase, the main input stage unit, the auxiliary input stage, the gain stage module, and the output stage module form a second unity gain amplifier to function according to the gamma The ma voltage outputs the driving voltage.

The above-mentioned source drive circuit and display device use an auxiliary input stage unit with a small component size to receive the gamma voltage during the switching phase, which reduces the parasitic capacitance on the transmission path of the gamma voltage, and therefore can reduce the delay of the gamma voltage Time, and then improve the output conversion rate of the output buffer circuit, and at the same time, the output stage module provides the driving voltage to the main input stage unit, which can precharge the parasitic capacitance in the input stage unit. Therefore, when the output buffer circuit switches back to the stabilization stage, the gamma voltage becomes received by the main input stage unit, since the driving voltage is close to the gamma voltage, the gamma voltage does not require re-stabilization time, It can ensure the stability of subsequent system operation.

1: Display device

100: display panel

SL: scan line

DL: data line

200: timing control circuit

300: Gate drive circuit

400: source drive circuit

500: Gamma correction reference voltage circuit

IMAGE: image data

CONT: input control signal

CONT1: the first control signal

CONT2: Second control signal

DATA: data signal

410: shift temporary storage circuit

420: the first latch circuit

430: the second latch circuit

440: level conversion circuit

450: Digital to analog conversion circuit

460: output buffer circuit

470: Gamma resistor string

CLK: the first clock signal

SET: start signal

MCLK: the second clock signal

RESET: reset signal

461: Input stage module

462: Gain stage module

463: Output stage module

464: Output control module

4610: Main Input Stage Unit

4611: Auxiliary Input Stage Unit

4612: The first switch unit

4613: Second switch unit

VIN: input terminal

IN1: the first input terminal

IN2: the second input terminal

IN3: The third input terminal

IN4: The fourth input terminal

OUT1: the first output terminal

OUT2: the second output terminal

OUT3: the third output terminal

OUT4: the fourth output terminal

S1: first switching element

S2: second switching element

S3: the third switching element

S4: the fourth switching element

VOUT: output terminal

S5: fifth switching element

LD: the first output control signal

T1: switching stage

T2: stable stage

FIG. 1 is a schematic diagram of a module of a display device in a preferred embodiment.

FIG. 2 is a schematic diagram of a module of the source driving circuit in FIG. 1 .

FIG. 3 is a block diagram of the output buffer circuit of the first embodiment in FIG. 2 .

FIG. 4 is a schematic circuit diagram of the input stage module and the output stage module in FIG. 3 .

5 is a timing schematic diagram of the output terminal, the first switch control signal received by the first switch element, the second switch control signal received by the second switch element, the first node and the data line in FIG. 4 .

FIG. 6 is a block diagram of the output buffer circuit of the second embodiment in FIG. 2 .

FIG. 7 is a schematic circuit diagram of the input stage module and the output stage module in FIG. 6 .

In order to enable those skilled in the art to better understand the solutions of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only It is an embodiment of a part of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

The terms "first", "second" and "third" in the description of the present invention and the above-mentioned drawings are used to distinguish different items, rather than to describe a specific sequence. Furthermore, the term "comprise", as well as any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the listed steps or modules, but optionally also includes steps or modules that are not listed, or optionally It also includes other steps or modules inherent to these processes, methods, products or devices.

The specific implementation manner of the display device of the present invention will be described below with reference to the accompanying drawings.

Please refer to FIG. 1 . FIG. 1 is a schematic diagram of an equivalent module of a display device 1 according to an embodiment of the present invention. The display device 1 includes a display panel 100 disposed in a display area and a timing control circuit 200 , a gate drive circuit 300 , a source drive circuit 400 and a gamma correction reference voltage circuit 500 disposed in a non-display area.

The display panel 100 includes a plurality of scan lines SL and a plurality of data lines DL. The plurality of scanning lines SL extend along the first direction X and are arranged parallel to each other, the plurality of data lines DL extend along the second direction Y and are arranged parallel to each other, the plurality of scanning lines SL and the plurality of data lines The DLs are insulated from each other and intersected in a grid to define a plurality of pixel units arranged in a matrix (not shown in the figure). In at least one embodiment of the present invention, the first direction X is perpendicular to the second direction Y. In other implementation manners, the first direction X and the second direction Y may intersect at other angles. The pixel units in each row are electrically connected to the gate drive circuit 300 through one scan line SL, and the pixel units in each column are connected to the source drive circuit 400 through one data line DL. electrical connection. The timing control circuit 200 is electrically connected to the gate driving circuit 300 and the source driving circuit 400 respectively. The timing control circuit 200 generates a first control signal CONT1 to the gate drive circuit 300 according to the received input control signal CONT, generates a data signal DATA and a second control signal CONT2 to the source according to the received image data IMAGE drive circuit 400. The control signals may include periodic control signals and aperiodic control signals. The plurality of control signals include a vertical sync signal, a horizontal sync signal and a data enable signal. The gate driving circuit 300 provides scan signals to the plurality of scan lines SL to scan the pixel units. The source driving circuit 400 is used to convert the data signal DATA into a driving voltage and provide it to the plurality of data lines DL for displaying images. The gamma correction reference voltage circuit 500 is used for outputting a gamma correction reference voltage according to a gamma correction curve.

Please also refer to FIG. 2 , which is a schematic diagram of a module of the source driving circuit 400 . The source driver circuit 400 includes a shift register circuit 410, a first latch circuit 420, a second latch circuit 430, a level conversion circuit 440, a digital-to-analog conversion circuit 450, an output buffer circuit 460 and a gamma resistor string 470.

The shift register circuit 410 receives the start signal SET and the first clock signal CLK provided by the timing control circuit 200 , and generates a sampling pulse signal with the said timing control circuit 200 .

The first latch circuit 420 is electrically connected to the shift register circuit 410 . The first latch circuit 420 receives the data signal DATA provided by the timing control circuit 200 and the sampling pulse signal output by the shift register circuit 410 . The first latch circuit 420 samples the data signal DATA according to the sampling pulse signal to obtain a sampling signal.

The second latch circuit 430 is electrically connected to the first latch circuit 420 and the timing control circuit 200 . The second latch circuit 430 receives the second clock signal MCLK and the reset signal RESET output by the timing control circuit 200, and performs the sampling of the sampling signal according to the second clock signal MCLK and the reset signal RESET. to buffer.

The level conversion circuit 440 is electrically connected to the second latch circuit 430 . The level conversion circuit 440 performs amplitude modulation on the sampling signal.

The digital-to-analog conversion circuit 450 is electrically connected to the level conversion circuit 440 and the gamma resistor string 470 . The digital-to-analog conversion circuit 450 selects the corresponding gamma voltage in the gamma resistor string 470 according to the modulated sampling signal and outputs it to the output buffer circuit 460 .

The output buffer circuit 460 is electrically connected to the digital-to-analog conversion circuit 450 and the plurality of data lines DL. The output buffer circuit 460 is used for receiving the gamma voltage and outputting the driving voltage to the data line DL. The output buffer circuit 460 works alternately in the switching phase T1 and the stable phase T2. Wherein, in the switching phase T1, the output buffer circuit 460 quickly responds to the adjustment of the driving voltage by the digital-to-analog conversion circuit 450 . In the stabilization phase T2, the output buffer circuit 460 provides the adjusted driving voltage to the data line DL.

Please also refer to FIG. 3 , which is a schematic circuit diagram of the output buffer circuit 460 . The output buffer circuit 460 includes an input stage module 461 , a gain stage module 462 , an output stage module 463 and an output control module 464 .

The input stage module 461 is electrically connected between the digital-to-analog conversion circuit 450 and the gain stage module 462 . The input stage module 461 is used for buffering the driving voltage. The input stage module 461 includes a main input stage unit 4610 , an auxiliary input stage unit 4611 , a first switch unit 4612 and a second switch unit 4613 .

Please also refer to FIG. 4 , which is a schematic circuit diagram of the input stage module 461 and the output control module 464 . The main input stage unit 4610 is electrically connected to the digital-to-analog conversion circuit 450 through the first switch unit 4612 . The main input stage unit 4610 is used for converting the received gamma voltage into a differential current and outputting it to the gain stage module 462 in the stable stage T2. The main input stage unit 4610 may be a differential input pair circuit. The size of the components in the main input stage unit 4610 is N times the size of the components in the auxiliary input stage unit 4611 . Wherein, N may or may not be an integer. In at least one embodiment of the present invention, the size of the elements in the main input stage unit 4610 is three times the size of the elements in the auxiliary input stage unit 4611 . In other implementations, the size of the components in the main input stage unit 4610 is more than 40 times the size of the components in the auxiliary input stage unit 4611 . The main input stage unit 4610 includes a first input terminal IN1, a second input terminal IN2, a first output terminal OUT1 and a second output terminal OUT2. In at least one embodiment of the present invention, the first input terminal IN1 is a positive input terminal, the second input terminal IN2 is a negative input terminal, and the first output terminal OUT1 is a reverse output terminal, so The second output terminal OUT2 is a forward output terminal.

The auxiliary input stage unit 4611 is electrically connected to the gain stage module 462 through the second switch unit 4613 . The auxiliary input stage unit 4611 has a small parasitic capacitance, and is used to convert the received gamma voltage into a differential current and output it to the gain stage module 462 in the switching phase T1. The auxiliary input stage unit 4611 may be a differential input pair circuit. The auxiliary input stage unit 4611 includes a third input terminal IN3, a fourth input terminal IN4, a third output terminal OUT3 and a fourth output terminal OUT4. In at least one embodiment of the present invention, the third input terminal IN3 is a positive input terminal, the fourth input terminal IN4 is a negative input terminal, and the third output terminal OUT3 is a reverse output terminal, so The fourth output terminal OUT4 is a forward output terminal.

The first switch unit 4612 is electrically connected to the digital-to-analog conversion circuit 450 and the main input stage unit 4610 . The first switch unit 4612 controls the main input stage unit 4610 is electrically connected to the digital-to-analog conversion circuit 450 . During the switching phase T1, the first switch unit 4612 disconnects the electrical connection between the digital-to-analog conversion circuit 450 and the main input stage unit 4610, and controls the first input terminal IN1 and the The second input terminal IN2 is connected to the output terminal VOUT of the output stage module 463 . In the stable phase T2, the first switch unit 4612 establishes the electrical connection between the digital-to-analog conversion circuit 450 and the main input stage unit 4610, and disconnects the first input terminal IN1 from the Electrical connection between the second input terminals IN2. The first switch unit 4612 includes a first switch element S1 and a second switch element S2. One end of the first switch element S1 is electrically connected to the digital-to-analog conversion circuit 450 through the input terminal VIN, and the other end is electrically connected to the first input terminal IN1 of the main input stage unit 4610 . One end of the second switch element S2 is electrically connected to the first input end IN1 of the main input stage unit 4610 , and the other end is electrically connected to the second input end IN2 of the main input stage unit 4610 . The first switch element S1 is controlled by a first switch control signal, and the second switch element S2 is controlled by a second switch control signal. Wherein, the first switch control signal and the second switch control signal are pulse signals. The pulse widths of the first switch control signal and the second switch control signal can be adjusted according to the time required for the voltage of the output terminal VOUT of the output stage module 463 to reach a stable state. At any moment, the level states of the first switch control signal and the second switch control signal are opposite. That is, when the first switch control signal is at high level, the second switch control signal is at low level; when the first switch control signal is at low level, the second switch control signal is at high level flat. In at least one embodiment of the present invention, the first switching element S1 and the second switching element S2 are electrical switches. In other implementation manners, the first switch element S1 and the second switch element S2 may also be transistor structures.

The second switch unit 4613 is connected between the auxiliary input stage unit 4611 and the gain stage module 462 . The second switch unit 4613 is used to establish an electrical connection between the auxiliary input stage unit 4611 and the gain stage module 462 during the switching phase T1, The electrical connection between the auxiliary input stage unit 4611 and the gain stage module 462 is disconnected when the stage T2 is determined. The second switch unit 4613 includes a third switch element S3 and a fourth switch element S4. One end of the third switching element S3 is electrically connected to the third output end OUT3 of the auxiliary input stage unit 4611 , and the other end is electrically connected to the gain stage module 462 . One end of the fourth switch element S4 is electrically connected to the fourth output end OUT4 , and the other end is electrically connected to the gain stage module 462 . The third switch element S3 and the fourth switch element S4 are controlled by the second switch control signal. In at least one embodiment of the present invention, the third switch element S3 and the fourth switch element S4 are electrical switches. In other implementation manners, the third switching element S3 and the fourth switching element S4 may also be transistor structures.

The gain stage module 462 is electrically connected between the input stage module 461 and the output stage module 463 . The gain stage module 462 is used to convert the differential current output by the input stage module 461 into a voltage and transmit it to the rear end output stage module 463 . The gain stage module 462 can be an active load circuit.

The output terminal VOUT of the output stage module 463 is electrically connected to the data line DL through the output control module 464 , and the output terminal VOUT is electrically connected to the input stage module 461 . During the switching phase T1, the output stage module 463 charges or discharges the main input stage unit 4610 . During the stable phase T2, the output stage module 463 outputs the driving voltage to the data line DL through the output terminal VOUT and the output control module 464, so as to load image data into the The above data line DL.

Please refer to FIG. 4 again, which is a schematic circuit diagram of the output control module 464 . The output control module 464 is electrically connected to the output stage module 463 through the output terminal VOUT. The output control module 464 is used for establishing or disconnecting the electrical connection between the output stage module 463 and the data line DL according to the output control signal. During the switching phase T1, the output control module 464 disconnects the electrical connection between the output stage module 463 and the data line DL. said The auxiliary input stage unit 4611 , the gain stage module 462 and the output stage module 463 form a first unity gain amplifier to receive the gamma voltage output by the gamma resistor string 470 . During the stable phase T2, the output control module 464 establishes an electrical connection between the output stage module 463 and the data line DL to provide the driving voltage to the data line DL. The main input stage unit 4610 , the gain stage module 462 and the output stage module 463 form a second unity gain amplifier to receive the gamma voltage output by the gamma resistor string 470 . In at least one embodiment of the present invention, the output control module 464 may be a transmission gate structure, and the output control module 464 includes a fifth switching element S5. The control end of the fifth switch element S5 receives the first output control signal LD, the first connection end of the fifth switch element S5 is electrically connected to the output end VOUT, and the second end of the fifth switch element S5 The connection end is electrically connected with the data line DL.

The gamma resistor string 470 is electrically connected to the gamma correction reference voltage circuit 500 and the digital-to-analog conversion circuit 450 . The gamma resistor string 470 is used to provide a gamma voltage to the digital-to-analog conversion circuit 450 . The gamma resistor string 470 can also adjust the gamma voltage according to the gamma correction reference voltage.

Please also refer to FIG. 5, which shows the output terminal VOUT, the first switch control signal received by the first switch element S1, the second switch control signal received by the second switch element S2, the output terminal VOUT and data Timing diagram of line DL.

The specific working method of the output buffer circuit 460 is as follows: in the switching phase T1, the first switch control signal is at a low level, and the first switching element S1 is turned off to cut off the digital-to-analog conversion The electrical connection between the circuit 450 and the main input stage unit 4610 . The second switch control signal is at a high level, and the second switch element S2 is closed to establish a connection between the first input terminal IN1 and the second input terminal IN2 and the output terminal VOUT of the output stage module 463 electrical connection between. According to the high level of the second switch control signal, the third switch element S3 and the fourth switch element S4 are closed to establish an electrical connection between the auxiliary input stage unit 4611 and the gain stage module 462, so that the auxiliary The input stage unit 4611 , the gain stage module 462 and the output stage module 463 form a first unit gain amplifier to output the driving voltage according to the gamma voltage. Since the size of the components in the auxiliary input stage unit 4611 is smaller than the size of the components in the main input stage unit 4610, the driving voltage is quickly provided to the output terminal VOUT. In addition, the first output control signal LD is at a low level, and the output control module 464 disconnects the electrical connection between the output stage module 463 and the data line DL.

During the stable phase T2, the first switch control signal is at a high level, and the first switch element S1 is closed to establish an electrical connection between the digital-to-analog conversion circuit 450 and the main input stage unit 4610. sexual connection. The second switch control signal is at a low level, and the second switch element S2 is turned off, so as to disconnect the electrical connection between the first input terminal IN1 and the second input terminal IN2. According to the second switch control signal at a low level, the third switch element S3 and the fourth switch element S4 are turned off, so as to disconnect the auxiliary input stage unit 4611 from the gain stage module 462 electrical connection between. The main input stage unit 4610, the gain stage module 462 and the output stage module 463 form a second unity gain amplifier to output the driving voltage according to the gamma voltage. When the first output control signal LD is switched to a high level (may be after the second switch control signal is switched to a low level), the output control module 464 establishes the output stage module 463 and the data The electrical connection between the lines DL is used to output the driving voltage to the data line DL. In at least one embodiment of the present invention, the first switch control signal and the second switch control signal have the same pulse width, and the pulse width may be different from the pulse width of the first output control signal LD, It can also be the same. For example, the pulse width of the first output control signal LD may be greater than the pulse widths of the first switch control signal and the second switch control signal.

Please refer to FIG. 6 and FIG. 7 , which are schematic diagrams of modules and circuits of the output buffer circuit 460 in the second embodiment. The output buffer circuit 460 of the second embodiment has a similar structure to the output buffer circuit 460 of the first embodiment. That is to say, the description of the output buffer circuit 460 described in the first embodiment can basically be applied to the output buffer circuit 460 in the second embodiment, the main difference between the two lies in: the output The buffer circuit 460 does not include the second switch unit 4613 . The main input stage unit 4610 and the auxiliary input stage unit 4611 are directly electrically connected to the gain stage module 462 .

With the source drive circuit 400 and the display device 1 with the above structure, the auxiliary input stage unit 4611 with a small component size is used to receive the gamma voltage in the switching phase T1, so as to reduce the transmission path of the gamma voltage. Therefore, the delay time of the gamma voltage can be reduced, thereby improving the output conversion rate of the output buffer circuit 460, while the output stage module 463 provides the driving voltage to the main input stage unit 4610, which can be used for The parasitic capacitance in the main input stage unit 4610 is pre-charged. When the output buffer circuit switches back to the stable stage, the gamma voltage is received by the main input stage unit 4610. Since the driving voltage is close to the gamma voltage, the gamma voltage does not require a re-stabilization time, and can be Ensure the stability of the system operation.

As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still understand the foregoing The technical solutions recorded in each embodiment are modified, or some of the technical features are replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

In summary, the present invention meets the requirements of an invention patent, and a patent application is filed according to law. However, what is described above is only a preferred embodiment of the present invention, and those who are familiar with the technology of this case, Equivalent modifications or changes made according to the creative spirit of this case shall be included in the scope of the following patent application.

450: Digital to analog conversion circuit

461: Input stage module

4610: Main Input Stage Unit

4611: Auxiliary Input Stage Unit

4612: The first switch unit

4613: Second switch unit

462: Gain stage module

463: Output stage module

464: Output control module

DL: data line

VIN: input terminal

VOUT: output terminal

Claims (10)

A source drive circuit that receives a gamma correction reference voltage generated by a gamma correction reference voltage circuit and is electrically connected to a data line; the improvement is that the source drive circuit includes: a gamma resistor string that receives the gamma Gamma corrects the reference voltage and generates a Gamma voltage; a digital-to-analog conversion circuit is electrically connected to the Gamma resistor string, and is used to select and output a corresponding Gamma voltage from the Gamma resistor string according to a digital signal; and output The buffer circuit is used to receive the gamma voltage and output the drive voltage to the data line; the output buffer circuit includes an input stage module, a gain stage module and an output stage module; the input stage module includes a main The input stage unit and the auxiliary input stage unit; the size of the components in the main input stage unit is larger than the element size in the auxiliary input stage unit; the input stage module works alternately in the switching stage and the stable stage; in the switching stage, the auxiliary input stage unit, the gain stage module and the output stage module form a first unity gain amplifier to output the drive voltage according to the gamma voltage; in the stabilization stage, the The main input stage unit, the gain stage module and the output stage module form a second unity gain amplifier to output the driving voltage according to the gamma voltage. The source drive circuit according to claim 1, wherein the input stage module further includes a first switch unit and a second switch unit; the main input stage unit uses the first switch unit and the digital The analog conversion circuit is electrically connected; in the switching phase, the first switch unit disconnects the electrical connection between the digital-to-analog conversion circuit and the main input stage unit; in the stabilization phase, the first A switch unit establishes an electrical connection between the digital-to-analog conversion circuit and the main input stage unit; the second switch unit is electrically connected between the auxiliary input stage unit and the gain stage module; The second switch unit is used to establish an electrical connection between the auxiliary input stage unit and the gain stage module during the switching phase, and disconnect the auxiliary input stage unit from the gain stage module during the stabilization phase. The electrical connection between the above-mentioned gain stage modules. The source drive circuit according to claim 2, wherein the first switch unit includes a first switch element and a second switch element; the main input stage unit includes a first input terminal and a second input terminal; in the In the switching stage, the first switching element disconnects the electrical connection between the first input end of the main input stage unit and the digital-to-analog conversion circuit, and the second switching element establishes the first input end electrical connection with the second input terminal; in the stable phase, the first switching element establishes electrical connection between the first input terminal of the main input stage unit and the digital-to-analog conversion circuit connected, the second switch element disconnects the electrical connection between the first input end and the second input end. The source drive circuit according to claim 1, wherein the output buffer circuit further includes an output stage control module; the output stage control module is used to establish or disconnect the output stage module from the data The electrical connection between the wires; in the switching phase, the output stage control module cuts off the electrical connection between the output stage module and the data line; in the stabilization phase, the output A stage control module establishes an electrical connection between the output stage module and the data line. The source driver circuit according to claim 1, wherein the size of the elements in the main input stage unit is N times the size of the elements in the auxiliary input stage unit; wherein, N is an integer or not an integer. A display device, comprising a plurality of scanning lines and a plurality of data lines, the two are arranged crosswise; the improvement is that the display device further includes: a gamma correction reference voltage circuit, used to output a gamma correction reference voltage circuit according to a gamma correction curve voltage; and a source drive circuit for converting data signals into drive voltages; the source drive circuit includes a gamma resistor string, a digital-to-analog conversion circuit, and an output buffer circuit; the gamma resistor string receives the gamma correcting the reference voltage and generating a gamma voltage; the digital-to-analog conversion circuit is used to select and output the corresponding gamma voltage from the gamma resistor string according to the data signal; the output buffer A circuit for receiving the gamma voltage and outputting the driving voltage to the data line; the output buffer circuit includes an input stage module, a gain stage module and an output stage module; the input stage module includes The main input stage unit and the auxiliary input stage unit; the size of the components in the main input stage unit is larger than the element size in the auxiliary input stage unit; the input stage module works alternately in the switching stage and the stable stage; in the In the switching stage, the auxiliary input stage unit, the gain stage module and the output stage module form a first unity gain amplifier to output the driving voltage according to the gamma voltage, and the output stage module providing the drive voltage to the main input stage unit; during the stabilization phase, the main input stage unit, the gain stage module and the output stage module form a second unity gain amplifier to be used according to the The gamma voltage outputs the driving voltage. The display device as described in claim 6, wherein the input stage module further includes a first switch unit and a second switch unit; the main input stage unit communicates with the digital analog through the first switch unit The conversion circuit is electrically connected; in the switching phase, the first switch unit disconnects the electrical connection between the digital-to-analog conversion circuit and the main input stage unit; in the stabilization phase, the first The switch unit establishes the electrical connection between the digital-to-analog conversion circuit and the main input stage unit; the second switch unit is electrically connected between the auxiliary input stage unit and the gain stage module; The second switch unit is used to establish an electrical connection between the auxiliary input stage unit and the gain stage module in the switching stage, and disconnect the auxiliary input stage unit from the gain stage module in the stable stage Electrical connections between gain stage modules. The display device as described in claim 7, wherein the first switch unit includes a first switch element and a second switch element; the main input stage unit includes a first input end and a second input end; in the In the switching phase, the first switching element disconnects the electrical connection between the first input end of the main input stage unit and the digital-to-analog conversion circuit, and the second switching element establishes the connection between the first input end and the digital-to-analog conversion circuit. an electrical connection between the second input terminals; during the stabilization phase, the first switching element establishes the first input terminal of the main input stage unit with the digital class The electrical connection between the ratio conversion circuits, the second switching element disconnects the electrical connection between the first input end and the second input end. The display device as described in claim 6, wherein the output buffer circuit further includes an output stage control module; the output stage control module is used to establish or disconnect the output stage module and the data line electrical connection between; in the switching phase, the output stage control module cuts off the electrical connection between the output stage module and the data line; in the stabilization phase, the output stage The control module establishes the electrical connection between the output stage module and the data line. A source drive circuit that receives a gamma correction reference voltage generated by a gamma correction reference voltage circuit and is electrically connected to a data line; the improvement is that the source drive circuit includes: a gamma resistor string that receives the gamma Gamma corrects the reference voltage and generates a Gamma voltage; a digital-to-analog conversion circuit is electrically connected to the Gamma resistor string, and is used to select and output a corresponding Gamma voltage from the Gamma resistor string according to a digital signal; and output The buffer circuit is used to receive the gamma voltage and output the drive voltage to the data line; the output buffer circuit includes an input stage module, a gain stage module and an output stage module; the input stage module includes a main An input stage unit and an auxiliary input stage unit; the main input stage unit is directly electrically connected to the gain stage module, and the auxiliary input stage unit is directly electrically connected to the gain stage module; the main input stage The size of the components in the unit is larger than the size of the components in the auxiliary input stage unit; the input stage module works alternately in the switching stage and the stable stage; in the switching stage, the auxiliary input stage unit, the gain stage module group and the output stage module form a first unity gain amplifier to output the driving voltage according to the gamma voltage; in the stable stage, the main input stage unit, the auxiliary input stage unit, the The gain stage module and the output stage module form a second unity gain amplifier to output the driving voltage according to the gamma voltage.

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