CN101707054A - Liquid crystal display device and driving method thereof - Google Patents

Abstract

A liquid crystal display device comprises a reference voltage generator, a voltage selector, a time schedule controller, a voltage level shifter, a grid drive circuit and a pixel array. The reference voltage generator is used for providing a first high reference voltage and a second high reference voltage. The voltage selector is used for selecting the first high reference voltage or the second high reference voltage as the high reference voltage. The time schedule controller is used for providing scanning control signals. The voltage level shifter generates a pre-driving signal according to a scan control signal and a high reference voltage. The gate driving circuit provides a plurality of gate signals according to the pre-driving signal. The pixel array is used for displaying images according to a plurality of grid signals.

Description

Liquid crystal display device and driving method thereof

technical field

The invention relates to a liquid crystal display device and a driving method thereof, in particular to a liquid crystal display device and a driving method thereof with an adjustable reference voltage.

Background technique

A liquid crystal display (Liquid Crystal Display; LCD) is a flat panel display widely used at present, which has the advantages of light and thin appearance, power saving and no radiation. The working principle of the liquid crystal display device is to change the alignment state of the liquid crystal molecules in the liquid crystal layer by changing the voltage difference between the two ends of the liquid crystal layer to change the light transmittance of the liquid crystal layer, and then cooperate with the light source provided by the backlight module or ambient light to display image. FIG. 1 is a schematic diagram of a known liquid crystal display device. As shown in FIG. 1 , the liquid crystal display device 100 includes a reference voltage generator 110 , a timing controller (Timing Controller) 140 , a voltage level shifter 150 , a source driving circuit 160 , a gate driving circuit 170 and a pixel array unit 180 . The reference voltage generator 110 is used to provide a high reference voltage Vgh and a low reference voltage Vgl. The timing controller 140 is used to provide the scan control signal Sx required for the operation of the gate driving circuit 170 .

The voltage level shifter 150 is used to generate the pre-drive signal Si according to the scan control signal Sx, the high reference voltage Vgh and the low reference voltage Vgl to feed to the gate driving circuit 170 . The gate driving circuit 170 provides a plurality of gate signals according to the pre-driving signal Si. The source driving circuit 160 is used to provide a plurality of data signals, and the pixel array unit 180 drives a plurality of pixels PX according to the plurality of gate signals and the plurality of data signals to display images. In the design of the liquid crystal display device 100, in order to reduce the manufacturing cost, the gate driver circuit 170 is integrated into the display panel 185 including the pixel array unit 180, which is based on the GOA (Gate-driver On Array) architecture, which has gradually developed into the mainstream. technology. However, in the GOA structure, the multi-stage shift registers SR1˜SRn of the gate driving circuit 170 are sequentially arranged in a relatively long and narrow frame area of the display panel 185 corresponding to the plurality of gate lines 175, that is, they are not accumulated in the within a small chip area. Therefore, the high-level voltage of the gate signal generated by the last-stage shift register SRn may be significantly lower than the high-level voltage of the gate signal generated by the first-stage shift register SR1, so that the last-stage shift The gate signal generated by the register SRn may not be able to effectively drive the corresponding plurality of pixels PX to perform the data signal writing operation normally. Generally speaking, the gate signal generated by the shift register of the last number of stages may have a high-level voltage that is too low. In addition, when the liquid crystal display device 100 is just turned on, the above-mentioned high-level voltage of the gate signal is too low. In addition, since the turn-on speed of the thin film transistor will be slowed down due to the temperature drop, when the liquid crystal display device 100 is turned on at a low temperature, the above-mentioned high-level voltage of the gate signal is too low and the situation is even more serious. In other words, the pixel array unit 180 may not be able to work normally immediately when the liquid crystal display device 100 is turned on at a low temperature.

Contents of the invention

According to an embodiment of the present invention, it discloses a liquid crystal display device capable of adjusting a reference voltage. This liquid crystal display device includes a reference voltage generator, a voltage selector, a control unit, a timing controller, a voltage level shifter, a gate The driving circuit and the pixel array unit. The reference voltage generator is used to provide a first high reference voltage and a second high reference voltage lower than the first high reference voltage. The voltage selector is electrically connected to the reference voltage generator to receive the first high reference voltage and the second high reference voltage are used to select the first high reference voltage or the second high reference voltage as the high reference voltage according to the control signal. The control unit is electrically connected to the voltage selector to provide the control signal. The timing controller is used to provide the scanning The control signal. The voltage level shifter is electrically connected to the timing controller and the voltage selector, and is used to generate the pre-drive signal according to the scanning control signal and the high reference voltage. The gate drive circuit is electrically connected to the voltage level shifter, and is used for To provide multiple gate signals according to the pre-drive signal. The pixel array unit is electrically connected to the gate drive circuit and used to display images according to multiple gate signals. In the operation of the liquid crystal display device, when the liquid crystal display device is turned on After a predetermined time elapses, the high reference voltage is changed from the first high reference voltage to the second high reference voltage.

According to the embodiment of the present invention, it also discloses a liquid crystal display device with adjustable reference voltage. The liquid crystal display device includes a reference voltage generator, an adjustable power supply module, a timing controller, a voltage level shifter, a gate driving circuit, and a pixel array unit. The reference voltage generator is used to provide a high reference voltage and a low reference voltage according to the power supply voltage. The adjustable power module is electrically connected to the reference voltage generator and used to provide the power supply voltage. When the liquid crystal display device is turned on for a predetermined time, the power supply voltage provided by the adjustable power supply module is changed from the first voltage to a second voltage lower than the first voltage. The timing controller is used to provide scanning control signals. The voltage level shifter is electrically connected to the timing controller and the reference voltage generator, and is used to generate the pre-drive signal according to the scanning control signal, the high reference voltage and the low reference voltage. The gate driving circuit is electrically connected to the voltage level shifter for providing multiple gate signals according to the pre-drive signal. The pixel array unit is electrically connected to the gate driving circuit for displaying images according to a plurality of gate signals.

The present invention also discloses a method for driving a liquid crystal display device, which includes: providing a high reference voltage and a low reference voltage within a predetermined time after the liquid crystal display device is turned on, wherein the high reference voltage is the first high reference voltage; , driving the pixel array unit of the liquid crystal display device according to the first high reference voltage and the low reference voltage to perform an image display operation; after a predetermined time, changing the high reference voltage from the first high reference voltage to lower than the first high reference voltage the second high reference voltage; and after a predetermined time, drive the pixel array unit according to the second high reference voltage and the low reference voltage to perform image display operation.

Description of drawings

FIG. 1 is a schematic diagram of a known liquid crystal display device.

FIG. 2 is a schematic structural diagram of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 3 is a schematic structural diagram of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 4 is a schematic structural diagram of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 5 is a schematic structural diagram of a liquid crystal display device according to a fourth embodiment of the present invention.

FIG. 6 is a flowchart of a method for driving a liquid crystal display device according to an embodiment of the present invention.

[Description of main component labels]

100, 200, 300, 400, 500  Liquid crystal display device 110, 210, 410   Reference Voltage Generator 140, 240, 340, 440, 540 timing controller 150, 250, 450 Voltage level shifter

100, 200, 300, 400, 500  Liquid crystal display device 160, 260, 460 Source drive circuit 170, 270, 470 Gate drive circuit 180, 280, 480 Pixel Array Unit 185, 285, 485 display panel 220 voltage selector 221 first switch 222 Second switch 230, 330, 430, 530 control unit 231, 431 timer 265 data cable 275 Gate line 341, 541 frame counter 420, 520 Adjustable Power Module 425, 525 Power supply voltage generation unit 900 process PX pixel S910～S940 steps Sc control signal Si Pre-drive signal Sn count signal

100, 200, 300, 400, 500  Liquid crystal display device SR1, SRn Shift Register Sx Scan control signal Vck1 first clock signal Vck2 Second clock signal Vdd voltage Vgh High reference voltage Vgh1 The first high reference voltage Vgh2 Second Highest Reference Voltage Vgl low reference voltage Vst Start pulse signal

Detailed ways

In the following, according to the liquid crystal display device and its driving method of the present invention, specific embodiments will be described in detail in conjunction with the accompanying drawings. However, the provided embodiments are not intended to limit the scope of the present invention, and the method flow step numbers are not In order to limit the order of execution, any method with equivalent functions produced by recombining the execution flow of the method steps is within the scope of the present invention.

FIG. 2 is a schematic structural diagram of a liquid crystal display device according to a first embodiment of the present invention. As shown in FIG. 2 , the liquid crystal display device 200 includes a reference voltage generator 210, a voltage selector 220, a control unit 230, a timing controller 240, a voltage level shifter 250, a source driving circuit 260, a gate driving circuit 270, and a pixel array unit 280 . The pixel array unit 280 includes a plurality of pixels PX, is electrically connected to the source driving circuit 260 through a plurality of data lines 265 , and is electrically connected to the gate driving circuit 270 through a plurality of gate lines 275 . The gate driving circuit 270 can be integrated into the display panel 285 including the pixel array unit 280 .

The reference voltage generator 210 is used to provide a first high reference voltage Vgh1, a second high reference voltage Vgh2 lower than the first high reference voltage Vgh1, and a low reference voltage Vgl. The voltage selector 220 is electrically connected to the reference voltage generator 210 for Receive the first high reference voltage Vgh1 and the second high reference voltage Vgh2 for selecting the first high reference voltage Vgh1 or the second high reference voltage Vgh2 as the high reference voltage Vgh according to the control signal Sc. The control unit 230 is electrically connected to the voltage selector 220, used to provide a control signal Sc. During the operation of the liquid crystal display device 200, after a predetermined time has elapsed after power-on, the voltage selector 220 is used to change the high reference voltage Vgh from the first high reference voltage Vgh1 to the second high reference voltage Vgh according to the control signal Sc. Second high reference voltage Vgh2.

The timing controller 240 is used to provide the scan control signal Sx required for the operation of the gate driving circuit 270 . The voltage level shifter 250 is electrically connected to the timing controller 240 , the voltage selector 220 and the reference voltage generator 210 for generating the pre-drive signal Si according to the scan control signal Sx, the high reference voltage Vgh and the low reference voltage Vgl. The pre-drive signal Si may include a start pulse signal Vst, a first clock signal Vck1, and a second clock signal Vck2 opposite to the first clock signal Vck1, and the gate drive circuit 270 generates multiple clock signals according to the pre-drive signal Si. Gate signals to scan a plurality of gate lines 275. The source driving circuit 260 is used to provide a plurality of data signals, which are fed into the pixel array unit 280 through a plurality of data lines 265 . The pixel array unit 280 is used to control the writing operation of multiple data signals according to multiple gate signals, so as to drive multiple pixels PX to display images.

In the embodiment shown in FIG. 2 , the voltage selector 220 includes a first switch 221 and a second switch 222 , and the control unit 230 includes a timer 231 . The first switch 221 is electrically connected to the control unit 230 , the reference voltage generator 210 and the voltage level shifter 250 for outputting the first high reference voltage Vgh1 as the high reference voltage Vgh according to the control signal Sc. The second switch 222 is electrically connected to the control unit 230 , the reference voltage generator 210 and the voltage level shifter 250 for outputting the second high reference voltage Vgh2 as the high reference voltage Vgh according to the control signal Sc. In the operation of the liquid crystal display device 200, when the control signal Sc is in the first state, the second switch 222 is in the off state, and the first switch 221 is in the on state, which is used to output the first high reference voltage Vgh1 as a high reference Voltage Vgh. Alternatively, when the control signal Sc is in the second state, the first switch 221 is in the off state, and the second switch 222 is in the on state for outputting the second high reference voltage Vgh2 as the high reference voltage Vgh. The timer 231 is used to automatically perform a timing operation to generate a timing signal after the liquid crystal display device 200 is turned on, and the control unit 230 provides a control signal Sc according to the timing signal.

It can be seen from the above that after the liquid crystal display device 200 is turned on for a predetermined time, the control unit 230 switches the control signal Sc from the first state to the second state according to the timing signal, so that the first switch 221 is switched from the on state to the off state. , and switch the second switch 222 from the off state to the on state, thereby changing the high reference voltage Vgh from the first high reference voltage Vgh1 to the second high reference voltage Vgh2. That is, when the liquid crystal display device 200 is turned on, the voltage selector 220 first selects the first high reference voltage Vgh1 as the high reference voltage Vgh, so that the pixel array unit 280 can operate normally in real time to display high-quality images. , the voltage selector 220 selects the second high reference voltage Vgh2 as the high reference voltage Vgh to save power consumption. In addition, by setting the first high reference voltage Vgh1 suitable for a low-temperature environment, when the liquid crystal display device 200 is turned on at low temperature, the pixel array unit 280 can still operate normally immediately to display high-quality images.

Fig. 3 is the structure diagram of the liquid crystal display device of the second embodiment of the present invention. As shown in Fig. 3, the structure of the liquid crystal display device 300 is similar to the liquid crystal display device 200 shown in Fig. 2, and the main difference is that the control unit 230 is replaced by The control unit 330, and the timing controller 240 is replaced by a timing controller 340. The timing controller 340 includes a frame counter 341 electrically connected to the control unit 330. The frame counter 341 is used to automatically perform frame counting after the liquid crystal display device 300 is turned on Operate to generate the count signal Sn. The control unit 330 then provides the control signal Sc to the voltage selector 220 according to the count signal Sn. Sc is switched from the first state to the second state, so that the first switch 221 is switched from the on state to the off state, and the second switch 222 is switched from the off state to the on state, and then the high reference voltage Vgh is changed from the first state to the second state. A high reference voltage Vgh1 is changed to a second high reference voltage Vgh2, wherein the time required for displaying a predetermined number of frames corresponds to the predetermined time for the operation of the above-mentioned liquid crystal display device 200. The remaining functional operations of the liquid crystal display device 300 are the same as those of the liquid crystal display device. device 200, so when the liquid crystal display device 300 is turned on, even at low temperature, the pixel array unit 280 can still operate normally immediately to display high-quality images.

FIG. 4 is a schematic structural diagram of a liquid crystal display device according to a third embodiment of the present invention. As shown in FIG. 4, the liquid crystal display device 400 includes a reference voltage generator 410, an adjustable power supply module 420, a timing controller 440, a voltage level shifter 450, a source driving circuit 460, a gate driving circuit 470, and a pixel array Unit 480. The pixel array unit 480 includes a plurality of pixels PX, is electrically connected to the source driving circuit 460 through a plurality of data lines 465 , and is electrically connected to the gate driving circuit 470 through a plurality of gate lines 475 . The gate driving circuit 470 can be integrated into the display panel 485 including the pixel array unit 480 .

The adjustable power module 420 is used to provide the power voltage Vdd to the reference voltage generator 410 . The reference voltage generator 410 is electrically connected to the adjustable power module 420 for providing a high reference voltage Vgh and a low reference voltage Vgl according to the power voltage Vdd. In the operation of the liquid crystal display device 400, after a predetermined time has elapsed after starting up, the adjustable power supply module 420 can change the power supply voltage Vdd from the first voltage to a second voltage lower than the first voltage, and the reference voltage generator 410 provides The high reference voltage Vgh also changes from the first high reference voltage to a second high reference voltage lower than the first high reference voltage.

The timing controller 440 is used to provide the scan control signal Sx required for the operation of the gate driving circuit 470 . The voltage level shifter 450 is electrically connected to the timing controller 440 and the reference voltage generator 410 for generating the pre-drive signal Si according to the scan control signal Sx, the high reference voltage Vgh and the low reference voltage Vgl. The pre-drive signal Si may include a start pulse signal Vst, a first clock signal Vck1, and a second clock signal Vck2 opposite to the first clock signal Vck1, and the gate drive circuit 470 generates multiple clock signals according to the pre-drive signal Si. Gate signals to scan a plurality of gate lines 475. The source driving circuit 460 is used to provide a plurality of data signals, which are fed into the pixel array unit 480 through a plurality of data lines 465 . The pixel array unit 480 is used to control the writing operation of a plurality of data signals according to a plurality of gate signals, so as to drive a plurality of pixels PX to display images.

In the embodiment shown in FIG. 4 , the adjustable power module 420 includes a control unit 430 and a power voltage generating unit 425 . The control unit 430 is used for providing a control signal Sc. The supply voltage generating unit 425 is electrically connected to the control unit 430 and the reference voltage generator 410 for generating the supply voltage Vdd according to the control signal Sc. In the operation of the liquid crystal display device 400, when the control unit 430 provides the control signal Sc with the first state, the power supply voltage Vdd generated by the power supply voltage generating unit 425 is the first voltage, and the high voltage Vdd provided by the reference voltage generator 410 is The reference voltage Vgh is the first high reference voltage. Alternatively, when the control unit 430 provides the control signal Sc with the second state, the power voltage Vdd generated by the power voltage generating unit 425 is the second voltage, and the high reference voltage Vgh provided by the reference voltage generator 410 is the first voltage. Two high reference voltages. The control unit 430 includes a timer 431. The timer 431 is used to automatically perform a timing operation to generate a timing signal after the liquid crystal display device 400 is turned on, and the control unit 430 provides a control signal Sc according to the timing signal.

It can be seen from the above that after the liquid crystal display device 400 is turned on for a predetermined time, the control unit 430 switches the control signal Sc from the first state to the second state according to the timing signal, so that the power supply voltage Vdd is changed from the first voltage to the second voltage. , and then change the high reference voltage Vgh from the first high reference voltage to the second high reference voltage. That is, when the liquid crystal display device 400 is turned on, the reference voltage generator 410 first provides the first high reference voltage as the high reference voltage Vgh, so that the pixel array unit 480 can operate normally in real time to display high-quality images. , the reference voltage generator 410 provides a second high reference voltage as the high reference voltage Vgh to save power consumption. In addition, by setting the first high reference voltage suitable for a low-temperature environment, when the liquid crystal display device 400 is turned on at low temperature, the pixel array unit 480 can still operate normally immediately to display high-quality images.

FIG. 5 is a schematic structural diagram of a liquid crystal display device according to a fourth embodiment of the present invention. As shown in FIG. 5 , the structure of a liquid crystal display device 500 is similar to that of the liquid crystal display device 400 shown in FIG. It is replaced by an adjustable power supply module 520, and the timing controller 440 is replaced by a timing controller 540. The adjustable power supply module 520 includes a control unit 530 and a power supply voltage generation unit 525. The control unit 530 is used to provide control signals Sc. Power supply voltage generation The unit 525 is electrically connected to the control unit 530 and the reference voltage generator 410, and is used to generate the power supply voltage Vdd according to the control signal Sc.

The timing controller 540 includes a frame counter 541 electrically connected to the control unit 530 . The frame counter 541 is used to automatically perform a frame counting operation to generate a counting signal Sn after the liquid crystal display device 500 is turned on. The control unit 530 provides a control signal Sc to the power voltage generation unit 525 according to the count signal Sn. When the liquid crystal display device 500 is turned on to display a predetermined number of screens, the control unit 530 switches the control signal Sc from the first state to the second state according to the count signal Sn, so that the power supply voltage Vdd is changed from the first voltage to the second voltage. , and then change the high reference voltage Vgh from the first high reference voltage to the second high reference voltage, wherein the time required to display a predetermined number of frames corresponds to the predetermined time for the operation of the above-mentioned liquid crystal display device 400 . The remaining functions of the liquid crystal display device 500 are the same as those of the liquid crystal display device 400 , so when the liquid crystal display device 500 is turned on, even at low temperature, the pixel array unit 480 can still operate normally immediately to display high-quality images.

FIG. 6 is a flowchart of a method for driving a liquid crystal display device according to an embodiment of the present invention. The process 900 shown in FIG. 6 is a liquid crystal display device driving method based on the liquid crystal display device 200 of FIG. 2 , the liquid crystal display device 300 of FIG. 3 , the liquid crystal display device 400 of FIG. 4 , or the liquid crystal display device 500 of FIG. 5 . The liquid crystal display device driving method shown in the process 900 includes the following steps:

Step S910: providing a high reference voltage and a low reference voltage within a predetermined time after a liquid crystal display device is turned on, wherein the high reference voltage is a first high reference voltage;

Step S920: within the predetermined time, drive a pixel array unit of the liquid crystal display device according to the first high reference voltage and the low reference voltage to perform an image display operation;

Step S930: changing the high reference voltage from the first high reference voltage to a second high reference voltage lower than the first high reference voltage after the predetermined time elapses; and

Step S940: After the predetermined time elapses, drive the pixel array unit according to the second high reference voltage and the low reference voltage to perform an image display operation.

In the liquid crystal display device driving method based on the liquid crystal display device 300 in FIG. 3 or the liquid crystal display device 500 in FIG. 5 , the predetermined time described in the process 900 is the time required for the liquid crystal display device to display a predetermined number of frames. In the liquid crystal display device driving method based on the liquid crystal display device 400 of FIG. 4 or the liquid crystal display device 500 of FIG. The second high reference voltage of the reference voltage is for changing a power supply voltage from a first voltage to a second voltage lower than the first voltage, whereby the high reference voltage is changed from the first high reference voltage to The second high reference voltage is lower than the first high reference voltage.

To sum up, the liquid crystal display device of the present invention performs a driving operation according to the first high reference voltage within a predetermined time after starting up to display high-quality images in real time, and then after a predetermined time, according to the first high reference voltage lower than the first high reference voltage Two high reference voltages perform driving operation to save power consumption. In addition, by setting the first high reference voltage corresponding to the low temperature of the environment, the liquid crystal display device of the present invention can still operate normally immediately to display high-quality images even when it is turned on at low temperature.

Although the present invention has been disclosed above with embodiments, it is not intended to limit the present invention. Any person with ordinary knowledge in the technical field of the present invention can make various changes and modifications without departing from the spirit and scope of the present invention. Modification, therefore, the scope of protection of the present invention should be defined by the scope of the appended claims.

Claims (19)

1. A liquid crystal display device comprising: a reference voltage generator, configured to provide a first high reference voltage and a second high reference voltage lower than the first high reference voltage; A voltage selector, electrically connected to the reference voltage generator to receive the first high reference voltage and the second high reference voltage, for selecting the first high reference voltage or the second high reference voltage as a high reference according to a control signal Voltage; a control unit, electrically connected to the voltage selector, for providing the control signal; a timing controller for providing scan control signals; a voltage level shifter, electrically connected to the timing controller and the voltage selector, for generating a pre-drive signal according to the scanning control signal and the high reference voltage; a gate drive circuit, electrically connected to the voltage level shifter, for providing a plurality of gate signals according to the pre-drive signal; and a pixel array unit, electrically connected to the gate driving circuit, and used to display images according to the plurality of gate signals; The high reference voltage is changed from the first high reference voltage to the second high reference voltage after the liquid crystal display device is turned on for a predetermined time. 2. The liquid crystal display device according to claim 1, wherein the voltage selector comprises: a first switch, electrically connected to the control unit, the reference voltage generator and the voltage level shifter, for outputting the first high reference voltage as the high reference voltage according to the control signal, and a second switch, electrically connected to the control unit, the reference voltage generator and the voltage level shifter, for outputting the second high reference voltage as the high reference voltage according to the control signal; Wherein when the control signal is in the first state, the first switch is turned on to output the first high reference voltage as the high reference voltage; when the control signal is in the second state, the second switch is turned on to output The second high reference voltage output is the high reference voltage. 3. The liquid crystal display device according to claim 2, wherein the control signal is switched from the first state to the second state after the liquid crystal display device is turned on for the predetermined time. 4. The liquid crystal display device according to claim 2, wherein when the liquid crystal display device is turned on to display a predetermined number of screens, the control signal is switched from the first state to the second state, and the predetermined time is for displaying the predetermined number of screens. the time required for the screen. 5. The liquid crystal display device according to claim 1, wherein the control unit comprises: A timer is used to automatically perform a timing operation to generate a timing signal after the liquid crystal display device is turned on; Wherein the control unit provides the control signal according to the timing signal. 6. The liquid crystal display device according to claim 1, wherein the timing controller comprises: The frame counter is electrically connected to the control unit, and the frame counter automatically executes the frame counting operation to generate a counting signal after the liquid crystal display device is turned on; Wherein the control unit provides the control signal according to the count signal. 7. The liquid crystal display device according to claim 1, wherein the gate driving circuit and the pixel array unit are integrated into a display panel. 8. The liquid crystal display device according to claim 1, further comprising: a source driving circuit, electrically connected to the pixel array unit, for providing multiple data signals to display images; Wherein the pixel array unit controls writing operation of the plurality of data signals according to the plurality of gate signals. 9. A liquid crystal display device comprising: a reference voltage generator for providing a high reference voltage and a low reference voltage according to the power supply voltage; An adjustable power supply module, electrically connected to the reference voltage generator, is used to provide the power supply voltage, wherein when the liquid crystal display device is powered on for a predetermined time, the power supply voltage is changed from a first voltage to a second voltage lower than the first voltage Two voltages; a timing controller for providing scan control signals; a voltage level shifter, electrically connected to the timing controller and the reference voltage generator, for generating a pre-drive signal according to the scanning control signal, the high reference voltage and the low reference voltage; a gate drive circuit, electrically connected to the voltage level shifter, for providing a plurality of gate signals according to the pre-drive signal; and The pixel array unit is electrically connected to the gate driving circuit and used for displaying images according to the plurality of gate signals. 10. The liquid crystal display device according to claim 9, wherein the adjustable power module comprises: a control unit for providing a control signal; and The power supply voltage generation unit is electrically connected to the control unit and the reference voltage generator, and is used for generating the power supply voltage according to the control signal. 11. The liquid crystal display device according to claim 10, wherein when the liquid crystal display device is turned on and the predetermined time passes, the control signal is switched from the first state to the second state, so that the power supply voltage changes from the first voltage to changed to the second voltage. 12. The liquid crystal display device according to claim 10, wherein when the liquid crystal display device is turned on and displays a predetermined number of screens, the control signal is switched from the first state to the second state, so that the power supply voltage changes from the first The voltage is changed to the second voltage, and the predetermined time is the time required to display the predetermined number of frames. 13. The liquid crystal display device according to claim 10, wherein the control unit comprises: A timer is used to automatically perform a timing operation to generate a timing signal after the liquid crystal display device is turned on; Wherein the control unit provides the control signal according to the timing signal. 14. The liquid crystal display device according to claim 10, wherein the timing controller comprises: The frame counter is electrically connected to the control unit, and the frame counter automatically executes the frame counting operation to generate a counting signal after the liquid crystal display device is turned on; Wherein the control unit provides the control signal according to the count signal. 15. The liquid crystal display device according to claim 9, wherein the gate driving circuit and the pixel array unit are integrated into a display panel. 16. The liquid crystal display device according to claim 9, further comprising: a source driving circuit, electrically connected to the pixel array unit, for providing multiple data signals to display images; Wherein the pixel array unit controls writing operation of the plurality of data signals according to the plurality of gate signals. 17. A method for driving a liquid crystal display device, comprising: providing a high reference voltage and a low reference voltage within a predetermined time after the liquid crystal display device is turned on, wherein the high reference voltage is the first high reference voltage; within the predetermined time, drive the pixel array unit of the liquid crystal display device to perform image display operation according to the first high reference voltage and the low reference voltage; changing the high reference voltage from the first high reference voltage to a second high reference voltage lower than the first high reference voltage after the predetermined time elapses; and After the predetermined time passes, the pixel array unit is driven according to the second high reference voltage and the low reference voltage to perform an image display operation. 18. The method for driving a liquid crystal display device according to claim 17, wherein the predetermined time is the time required for the liquid crystal display device to display a predetermined number of frames. 19. The liquid crystal display device driving method according to claim 17, wherein changing the high reference voltage from the first high reference voltage to the second high reference voltage lower than the first high reference voltage is to change the power supply voltage Changing from a first voltage to a second voltage lower than the first voltage, whereby the high reference voltage is changed from the first high reference voltage to the second high reference voltage lower than the first high reference voltage.

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