TWI448885B - Common voltage supply circuit of display, method of supplying common voltage and liquied crystal display thereof - Google Patents

Description

Shared voltage supply circuit of display, supply method and liquid crystal display thereof

The present invention relates to a voltage supply circuit, a supply method, and a display device thereof, and more particularly to a common voltage supply circuit, a supply method, and a liquid crystal display thereof.

In the current design of the common voltage supply circuit, the power consumption can be reduced by a Capacitance Coupling Driver (CCD) technology. The principle of the capacitive coupling driver technology is to divide the common voltage of the pixels of each column into an AC common voltage (AC VCOM) and a DC common voltage (DC VCOM). After each data writing is completed, after the pixel film transistor is turned off, the AC VCOM signal is flipped again. At this time, the capacitive coupling effect will push or lower the pixel voltage to the correct level, thus, the data The write voltage only needs to be 1/2 of the original (for example, from 5V to -5V to 5V~0V), so the power saving effect can be achieved.

Since different process thin film transistors have their own advantages and disadvantages, how to choose a suitable thin film transistor to make a common voltage supply circuit that meets the design requirements is also considered by researchers. For example, the uniformity of an amorphous germanium film transistor (abbreviated as α-TFT) is good, but the electron mobility of the α-TFT is poor. If a common voltage supply circuit is to be fabricated using an α-TFT, the required circuit layout area is required. Larger, it is more difficult to meet the design requirements of narrowing the width of the border. Therefore, the current capacitively coupled driver technology is applied to low temperature polycrystalline germanium (LTPS) products, but low temperature polycrystalline germanium thin film transistors (LTPS-TFT) have higher electron mobility, but are limited by the crystallization process. However, it is impossible to make a large area, and in particular, the number of masks required for the LTPS-TFT process is large, and the relative manufacturing cost is high.

In addition, since the amorphous indium gallium zinc oxide thin film transistor (abbreviated as α-IGZO TFT) has a high electron mobility, it is generally about 10 times that of hydrogen-containing amorphous germanium (abbreviated as α-Si:H). The α-IGZO TFT is also more uniform than LTPS-TFTF, and because the process is similar to α-Si:H, it is easy to produce in the current α-Si:H production line. However, in the current common voltage supply circuit designed with an α-IGZO TFT, 0 volts is usually regarded as the turn-off voltage of the TFT. However, sometimes a serious leakage path may occur due to the drifting of the shutdown voltage, which may cause the output voltage of the shared voltage supply circuit to fail.

The invention provides a common voltage supply circuit, a supply method and a liquid crystal display thereof for a display, which utilize a switching circuit with a dual voltage supply to improve the output failure of the common voltage supply circuit due to the drift of the closing voltage of the transistor.

Therefore, the common voltage supply circuit of the display of the present invention includes: a common voltage supply unit, a first switching unit, and a second switching unit. The shared voltage supply unit may receive the first common voltage and provide a first storage voltage according to the first control signal to control whether to provide the first common voltage to the output. The first switching unit is electrically coupled to the common voltage supply unit. The first switching unit receives the first voltage and the second voltage, respectively. The second switching unit is electrically coupled to the common voltage supply unit. The second switching unit receives the first voltage and the second voltage respectively, wherein the first switching unit and the second switching unit respectively conduct the electrical paths of the first switching unit and the second switching unit by the first storage voltage, Correspondingly outputting the second voltage and the first voltage to the common voltage supply unit, and enabling the common voltage supply unit to output a first common voltage of one frame, wherein the first voltage is different from the second voltage.

In addition, the shared voltage supply method of the display of the present invention includes the following steps: first, providing a first storage voltage according to the first control signal to control output of the first common voltage; and then, respectively, turning on the first storage voltage a switching unit and a second switching unit to respectively receive the first voltage and the second voltage, and respectively provide the first voltage and the second voltage to the switching element that affects the output; and according to the received first voltage and the second voltage The resulting differential voltage turns off the switching element such that the output first common voltage can sustain one frame, wherein the first voltage is greater than the second voltage.

In addition, the common voltage supply circuit of the display of the present invention includes a common voltage supply unit, a first switching unit, and a second switching unit. The common voltage supply unit has a control stage that receives the first control signal and an output stage that receives the first common voltage. The control stage provides a first storage voltage according to the first control signal to control the output stage to output the first common voltage. The first switching unit is electrically coupled to the control stage, and the first switching unit receives the first voltage and the second voltage, respectively. The second switching unit is electrically coupled to the control stage, and the second switching unit receives the first voltage and the second voltage, respectively. The control stage has a first output end and a second output end, and the output stage is electrically coupled to the first output end and the second output end, respectively. The first switching unit and the second switching unit respectively conduct electrical paths of the first switching unit and the second switching unit by the first storage voltage, so that the first output end of the control stage outputs the second voltage to the An output stage, which in turn causes the output stage to output a first common voltage, wherein the first voltage is different from the second voltage.

In addition, the liquid crystal display of the present invention includes a plurality of scan lines, a plurality of data lines, a plurality of display pixel units, and a plurality of common voltage supply units. The plurality of scan lines and the plurality of data lines span each other. The plurality of display pixel units are electrically coupled to the scan line and the data line, respectively. The plurality of common voltage supply units are electrically coupled to the scan line and the display pixel unit, respectively. Each of the common voltage supply units receives the common voltage and provides a storage voltage according to the control signal provided by the scan line to control whether to output the shared voltage, wherein each of the common voltage supply units is electrically coupled with the first The switching unit and the second switching unit respectively receive the first voltage and the second voltage, and the first switching unit and the second switching unit respectively turn on the electrical path of the first switching unit and the second switching unit by the first storage voltage And correspondingly outputting the second voltage and the first voltage to the common voltage supply unit, and enabling the common voltage supply unit to output a common voltage of one frame, wherein the first voltage is different from the second voltage.

In summary, the common voltage supply circuit, the supply method, and the liquid crystal display of the display of the present invention utilize a switching circuit having a dual voltage supply, and respectively apply the double voltage to the transistor that affects the output of the common voltage supply circuit. Both ends of the element such that the gate voltage difference of the transistor element is negative. Thereby, in order to reduce or solve the problem that the transistor element may cause a floating voltage of the off voltage, the output voltage of the common voltage supply circuit may be invalid, thereby improving the stability of the common voltage supply circuit.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

Please refer to FIG. 1. FIG. 1 is a block diagram of a circuit according to an embodiment of the present invention. As shown in FIG. 1, the common voltage supply circuit 100 of the display of the embodiment of the present invention includes a common voltage supply unit 10, a first switching unit 20, and a second switching unit 30.

The common voltage supply unit 10 can be substantially constituted by the control stage 10a and the output stage 10b. The control stage 10a includes a switching element T5, a switching element T6, a switching element T9, a switching element T10, a switching element T11, a switching element T12, a switching element T13, a switching element T14, a switching element T15, a switching element T16, and a switching element. T17, first energy storage element C1, second energy storage element C2, energy storage element C4 and energy storage element C5. The output stage 10b includes a switching element T7, a switching element T8 and a third energy storage element C3. The switching element T5, the switching element T6 and the switching elements T9~T17 may be NMOS type thin film transistor switches, but not limited thereto. The first energy storage element C1, the second energy storage element C2, the third energy storage element C3, the energy storage element C4 and the energy storage element C5 may be capacitors.

More specifically, in the control stage 10a of the common voltage supply unit, the 汲 terminal of the switching element T5 is electrically coupled to the source terminal of the switching element T1 and the source terminal of the switching element T2, respectively.

The gate terminal of the switching element T6 is electrically coupled to the second output terminal 14 , and the source terminal of the switching element T5 is also electrically coupled to the second output terminal 14 . The 汲 terminal of the switching element T6 is electrically coupled to the 汲 terminal of the switching element T3 and the 汲 terminal of the switching element T4, respectively.

The gate terminals of the switching element T9 are electrically coupled to each other and receive the second clock signal Vclk2. The 汲 terminal of the switching element T10 is electrically coupled to the source terminal of the switching element T9. The gate terminal of the switching element T11 is electrically coupled to the source terminal of the switching element T10. The 汲 terminal of the switching element T12 is electrically coupled to the source terminal of the switching element T11. The gate terminal of the switching element T12 is electrically coupled to the gate terminal of the switching element T10 and receives the first control signal GATE(n-1).

The gate terminals of the switching element T13 are electrically coupled to each other and receive the first clock signal Vclk1. The 汲 terminal of the switching element T14 is electrically coupled to the source terminal of the switching element T13. The gate terminal of the switching element T14 is electrically coupled to the gate terminal of the switching element T10. The gate terminal of the switching element T15 is electrically coupled to the source terminal of the switching element T14. The source terminal of the switching element T16 is electrically coupled to the source terminal of the switching element T15. The gate terminal of the switching element T16 is electrically coupled to the gate terminal of the switching element T12. The 汲 terminal of the switching element T16 is electrically coupled to the source terminal of the switching element T12 and receives the first voltage VSS1. The gate terminals of the switching element T17 are electrically coupled to each other and receive the second control signal GATE(n). The source terminals of the switching element T17 are electrically coupled to the 汲 terminal of the switching element T15 and the 汲 terminal of the switching element T11, respectively.

The first ends of the first energy storage device C1 are electrically coupled to the gate terminal of the switching element T7 and the gate terminal of the switching element T5, respectively. The second end of the first energy storage device C1 is electrically coupled to the first end of the energy storage device C4, the source terminal of the switching element T11, and the 汲 terminal of the switching element T12.

The first ends of the second energy storage device C2 are electrically coupled to the gate terminal of the switching element T6 and the gate terminal of the switching element T8, respectively. The second end of the second energy storage component C2 is electrically coupled to the first end of the energy storage component C5, the source terminal of the switching component T15, and the source terminal of the switching component T16. The second end of the energy storage component C5 is electrically coupled to the second end of the energy storage component C4.

In the output stage 10b of the common voltage supply unit, the switching element T7 receives the first common voltage VcomH and is electrically coupled to the switching element T6 and the switching element T5, respectively. When the switching element T7 is turned on, the output terminal Vcom_out outputs the first The common voltage VcomH.

The source terminal of the switching element T8 receives the second common voltage VcomL. The switching element T8 is electrically coupled to the switching element T6 and the switching element T5, respectively. Furthermore, the gate terminal of the switching element T8 is electrically coupled to the second output terminal 14 , and the gate terminal of the switching element T6 and the source terminal of the switching element T5 are also electrically coupled to the second output terminal 14 . When the switching element T8 is turned on, the second common voltage VcomL is outputted by the output terminal Vcom_out.

The first end of the third energy storage device C3 is electrically coupled to the first output end 12 , and the first end of the first energy storage device C1 is also electrically coupled to the first output end 12 . The second end of the third energy storage device C3 is electrically coupled to the second output end 14 , and the first end of the second energy storage device C2 is also electrically coupled to the second output end 14 . It is worth mentioning that the third energy storage component C3 cooperates with the first energy storage component C1 to provide the first storage voltage QH, and the third energy storage component C3 and the second energy storage component C2 jointly provide the The second storage voltage QL.

The first switching unit 20 is electrically coupled to the common voltage supply unit 10 . The first switching unit 20 receives the first voltage VSS1 and the second voltage VSS2, respectively. The first switching unit 20 includes a switching element T1 and a switching element T2. The switching element T1 receives the first voltage VSS1 and the second storage voltage QL, respectively. Further, the 汲 terminal of the switching element T1 receives the first voltage VSS1, and the gate terminal thereof receives the second storage voltage QL (or the gate terminal of the switching element T1 is electrically coupled to the second output terminal 14). The switching element T2 is electrically coupled to the switching element T1. The switching element T2 receives the second voltage VSS2 and the first storage voltage QH, respectively. Further, the 汲 terminal of the switching element T2 receives the second voltage VSS2, and the gate terminal thereof receives the first storage voltage QH (or the gate terminal of the switching element T2 is electrically coupled to the first output terminal 12), the source thereof. The electrical connection is extremely electrically coupled to the source terminal of the switching element T1.

The second switching unit 30 is electrically coupled to the common voltage supply unit 10 . The second switching unit 30 receives the first voltage VSS1 and the second voltage VSS2, respectively. The second switching unit 30 includes a switching element T3 and a switching element T4. The switching element T3 receives the first voltage VSS1 and the first storage voltage QH, respectively. Further, the source terminal of the switching element T3 receives the first voltage VSS1, and the gate terminal thereof receives the first storage voltage QH (or the gate terminal of the switching element T3 is electrically coupled to the first output terminal 12). The switching element T4 is electrically coupled to the switching element T3, and the switching element T4 receives the second voltage VSS2 and the second storage voltage QL, respectively. Further, the source terminal of the switching element T4 receives the second voltage VSS2, and the gate terminal thereof receives the second storage voltage QL (or the gate terminal of the switching element T4 is electrically coupled to the second output terminal 14). The electrical connection is extremely electrically coupled to the 汲 terminal of the switching element T3. Further, the switching element used in the common voltage supply unit 10, the first switching unit 20, and the second switching unit 30 is preferably an Indium Gallium Zinc Oxide (IGZO) thin film transistor.

Next, please refer to FIG. 1 and FIG. 2A together. FIG. 2A is a schematic diagram of a partial signal waveform according to an embodiment of the present invention. The operation principle of the common voltage supply circuit 100 is first described in the following. First, the first switching unit 20 and the second switching unit 30 respectively turn on the electrical paths of the first switching unit 20 and the second switching unit 30 from the first storage voltage QH. To output the second voltage VSS2 and the first voltage VSS1 to the common voltage supply unit 10, and to enable the common voltage supply unit 10 to output the first common voltage VcomH of one frame, wherein the first voltage VSS1 is different from the second voltage VSS2. Please refer to FIG. 2B. FIG. 2B is a schematic diagram of signal waveforms of a first voltage and a second voltage according to an embodiment of the present invention. As shown in FIG. 2B, the voltage value of the first voltage VSS1 is preferably a voltage value greater than the second voltage VSS2, and the voltage value of the first voltage VSS1 and the voltage value of the second voltage VSS2 are both less than 0 volts.

In another aspect, control stage 10a has a first output 12 and a second output 14. The output stage 10b is electrically coupled to the first output end 12 and the second output end 14, respectively. The first switching unit 20 and the second switching unit 30 respectively turn on the electrical paths of the first switching unit 20 and the second switching unit 30 by the first storage voltage QH, so that the first output end 12 of the control stage 10a outputs the second The voltage VSS2 to the output stage 10b further causes the output terminal Vcom_out of the output stage 10b to output the first common voltage VcomH.

For example, the output stage 10b of the shared voltage supply unit 10 can be used to receive the first common voltage VcomH, and the control stage 10a provides the first storage voltage QH to the first switching unit 20 according to the first control signal GATE(n-1). And the second switching unit 30 to control whether the output stage 10b provides the first common voltage VcomH to the output terminal Vcom_out. Similarly, the output stage 10b of the common voltage supply unit 10 also receives the second common voltage VcomL, and the control stage 10a provides the second storage voltage QL to the first switching unit 20 and the second switching according to the second control signal GATE(n). The unit 30 controls whether the output stage 10b provides the second common voltage VcomL to the output terminal Vcom_out.

More specifically, when the control stage 10a of the common voltage supply unit 10 receives the level rise of the first control signal GATE(n-1), the switching elements T9, T10, T11, T12, the switching element T5, and the switching element T7 To be conductive. The second clock signal Vclk2 passes through the switching elements T9 and T10 to charge the third energy storage element C3 and the first energy storage element C1, thereby starting to store the third energy storage element C3 and the first energy storage element C1. can. When the level of the first control signal GATE(n-1) received by the control stage 10a of the common voltage supply unit 10 decreases, the first energy storage element C3 and the first energy storage element C1 jointly provide the first Storage voltage QH.

Next, the first storage voltage QH turns on the switching element T2 of the first switching unit 20, and passes the second voltage VSS2 to the gate terminal of the switching element T6. The first storage voltage QH can also turn on the third switching element T3 of the second switching unit 30, and pass the first voltage VSS1 to reach the source terminal of the sixth switching element T6. Thereby, when the common voltage supply unit 10 outputs the first common voltage VcomH, the gate voltage difference of the switching element T6 is the second voltage VSS2 minus the first voltage VSS1, and the gate voltage difference of the switching element T6 is negative. The gate voltage difference may be, for example, a voltage difference between the gate terminal and the source terminal of the switching element T6. As a result, the switching element T6 can be prevented from being affected by the drift of the off voltage, thereby causing leakage, which in turn causes the output of the common voltage supply unit 10 to fail.

Further, when the control stage 10a of the common voltage supply unit 10 receives the level rise of the second control signal GATE(n), the switching elements T13, T14, T15, T16, T17, the switching element T6, and the switching element T8 are turned on. The first clock signal Vclk1 passes through the switching elements T13 and T14 to charge the third energy storage element C3 and the second energy storage element C2, thereby starting to store the third energy storage element C3 and the second energy storage element C2. can. When the level of the first control signal GATE(n) received by the control stage 10a of the common voltage supply unit 10 decreases, the second storage voltage is provided by the third energy storage element C3 and the second energy storage element C2. QL.

Next, the second storage voltage QL turns on the switching element T1 of the first switching unit 20, and passes the first voltage VSS1 to the source terminal of the switching element T5. The second storage voltage QL can also turn on the switching element T4 of the second switching unit 30, and pass the second voltage VSS2 to the gate terminal of the switching element T5. Thereby, when the common voltage supply unit 10 outputs the second common voltage VcomL, the gate voltage difference of the switching element T5 is the second voltage VSS2 minus the first voltage VSS1, and the gate voltage difference of the switching element T5 is negative. The gate voltage difference may be, for example, a voltage difference between the gate terminal and the source terminal of the switching element T5. As a result, the switching element T5 can be prevented from being affected by the drift of the off voltage, thereby causing leakage, which in turn causes the output of the common voltage supply unit 10 to fail.

Please refer to FIG. 1 and FIG. 3 together. FIG. 3 is a schematic diagram of partial signal waveform simulation according to an embodiment of the present invention. As shown in FIG. 3, when the level of the first control signal GATE(n-1) rises, the switching elements T9, T10, T11, T12, the switching element T5, and the switching element T7 are turned on. The second clock signal Vclk2 passes through the switching elements T9 and T10 to charge the third energy storage element C3 and the first energy storage element C1, thereby starting to store the third energy storage element C3 and the first energy storage element C1. The time during which the first stored voltage QH rises and maintains one frame. It can be known from the simulation that although the first storage voltage QH in FIG. 2 still has a partial leakage, the common voltage supply unit 10 can output the first common voltage VcomH of one frame without causing the output. The output of the terminal Vcom_out is invalid.

Please refer to FIG. 4. FIG. 4 is a schematic circuit diagram of a liquid crystal display according to an embodiment of the present invention. As shown in FIG. 4, the liquid crystal display 400 includes a scan line SL, a data line DL, a display pixel unit 40, a display pixel unit 42, a first switching unit 20, a first switching unit 22, a second switching unit 30, The second switching unit 32, the common voltage supply unit 10, and the common voltage supply unit 11. The common voltage supply unit 10 is electrically coupled to the scan line SL and the display pixel unit 40, respectively. The common voltage supply unit 11 is electrically coupled to the scan line SL and the display pixel unit 42 respectively. The shared voltage supply unit 10 and the common voltage supply unit 11 may have the same or similar circuit architectures as each other. Similarly, the first switching unit 20 and the first switching unit 22 may have the same or similar circuit architectures, and the second switching unit 30 and the second switching unit 32 may have the same or similar circuit architectures as each other. The display pixel unit 40 and the display pixel unit 42 may have the same or similar circuit architectures as each other.

Referring to the embodiment shown in FIG. 4, the data line DL crosses the scan line SL. The display pixel unit 40 is electrically coupled to the scan line SL and the data line DL, respectively. Further, the display pixel unit 40 includes a transistor element TFT1, a transistor element TFT2, a storage capacitor Cst, and a liquid crystal capacitor Clc. The storage capacitor Cst and the first end of the liquid crystal capacitor Clc are electrically coupled to the 汲 terminal of the transistor element TFT2, respectively. The storage capacitor Cst and the second end of the liquid crystal capacitor Clc are electrically coupled to the common electrode terminals Vcom1 and Vcom2, respectively. The gate terminals of the transistor elements TFT1 and TFT2 in the display pixel unit 40 are electrically coupled to the scan line SL. The source terminal of the TFT element TFT2 is electrically coupled to the 汲 terminal of the transistor element TFT1. The source terminal of the TFT element TFT1 is electrically coupled to the data line DL. In addition, the circuit architecture and the number of the components listed in the liquid crystal display 400 in the embodiment of the present invention are merely examples, and are not limited thereto.

The principle of circuit operation of the common voltage supply unit 10, the first switching unit 20, and the second switching unit 30 has been described above, and will not be described herein. The common voltage supply unit 10 is electrically coupled to the display pixel unit 40, and further outputs a common voltage to the common electrode terminals Vcom1 and Vcom2 of the display pixel unit 40 according to the control signal provided by the scan line SL. The common electrode terminal Vcom1 can receive the common voltage of the AC type, and the common electrode terminal Vcom2 can receive the common voltage of the DC mode.

Please refer to FIG. 1 and FIG. 5 together. FIG. 5 is a flow chart showing the steps of the shared voltage supply method according to an embodiment of the present invention. As shown in FIG. 5, first, in step S501, the common voltage supply unit 10 pairs the first energy storage device C1 and the third energy storage device according to the first control signal GATE(n-1) and the second clock signal Vclk2. The component C3 is charged to provide the first storage voltage QH to the first switching unit 20 and the second switching unit 30 to control the output terminal Vcom_out to output the first common voltage VcomH. In addition, the common voltage supply unit 10 charges the energy storage component C2 and the energy storage component C3 according to the second control signal GATE(n) and through the first clock signal Vclk1 to provide the second storage voltage QL to the first switching. The unit 20 and the second switching unit 30 output a second common voltage VcomL with the control output terminal Vcom_out.

Next, in step S503, the switching element T2 of the first switching unit 20 and the switching element T3 of the second switching unit 30 are respectively turned on by the first storage voltage QH, so that the second voltage VSS2 received by the switching element T2 is supplied to The switching element T6 that affects the output, and the first voltage VSS1 received by the switching element T3 are supplied to the switching element T6 that affects the output, and the reason for affecting the output has been described above, and will not be described herein. It is worth mentioning that the gate voltage difference of the switching element T6 described at this time is a negative value.

In addition, when the common voltage supply unit 10 charges the second energy storage element C2 and the third energy storage element C3 according to the second control signal GATE(n) and through the first clock signal Vclk1 to provide the second storage voltage QL. When the first switching unit 20 and the second switching unit 30 are connected, the switching element T1 of the first switching unit 20 and the switching element T4 of the second switching unit 30 are respectively turned on by the second storage voltage QL to be received by the switching element T1. The first voltage VSS1 is supplied to the switching element T5 that affects the output, and the second voltage VSS2 received by the switching element T4 is supplied to the switching element T5 that affects the output. Similarly, the reason for affecting the output has been described as before. Let me repeat. It is worth mentioning that the gate voltage difference of the switching element T5 described at this time is also a negative value.

Next, in step S505, the common voltage supply circuit 100 turns off the switching element T6 according to the voltage difference formed by the received first voltage VSS1 and the second voltage VSS2, so that the first common output of the common voltage supply circuit 100 is output. The voltage VcomH can maintain one frame, wherein the first voltage VSS1 is greater than the second voltage VSS2.

As described above, the common voltage supply circuit 100 also turns off the switching element T5 according to the voltage difference formed between the received first voltage VSS1 and the second voltage VSS2, so that the outputted second common voltage VcomL can be maintained for one frame. For example, the switching element T5 and the switching element T6 are turned off according to the voltage difference formed by subtracting the first voltage VSS1 from the received second voltage VSS2.

In summary, the common voltage supply circuit, the supply method, and the liquid crystal display of the display of the present invention utilize a switching circuit having a dual voltage supply, and respectively apply the double voltage to the transistor that affects the output of the common voltage supply circuit. Both ends of the element such that the gate voltage difference of the transistor element is negative. Thereby, in order to reduce or solve the problem that the transistor element may cause a floating voltage of the off voltage, the output voltage of the common voltage supply circuit may be invalid, thereby improving the stability of the common voltage supply circuit.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

10. . . Shared voltage supply unit

11. . . Shared voltage supply unit

10a. . . Control level

10b. . . Output stage

100. . . Shared voltage supply circuit

12. . . First output

14. . . Second output

20. . . First switching unit

twenty two. . . First switching unit

30. . . Second switching unit

32. . . Second switching unit

400. . . LCD Monitor

40. . . Display pixel unit

42. . . Display pixel unit

C1. . . First energy storage component

C2. . . Second energy storage component

C3. . . Third energy storage component

C4~C5. . . Energy storage component

Cst. . . Storage capacitor

Clc. . . Liquid crystal capacitor

DL. . . Data line

GATE(n-1). . . First control signal

GATE(n). . . Second control signal

QH. . . First storage voltage

QL. . . Second storage voltage

SL. . . Sweep line

T1~T17. . . Switching element

TFT1. . . Transistor element

TFT2. . . Transistor element

VSS1. . . First voltage

VSS2. . . Second voltage

Vclk1. . . First clock signal

Vclk2. . . Second clock signal

Vcom1. . . Common electrode end

Vcom2. . . Common electrode end

Vcom_out. . . Output

VcomH. . . First common voltage

VcomL. . . Second common voltage

S501~S505. . . Method step description

FIG. 1 is a block diagram of a circuit according to an embodiment of the present invention.

FIG. 2A is a schematic diagram of a partial signal waveform according to an embodiment of the present invention.

2B is a schematic diagram showing signal waveforms of a first voltage and a second voltage according to an embodiment of the invention.

FIG. 3 is a schematic diagram of signal waveform simulation according to an embodiment of the present invention.

4 is a schematic circuit diagram of a liquid crystal display according to an embodiment of the present invention.

FIG. 5 is a flow chart showing the steps of a shared voltage supply method according to an embodiment of the present invention.

10. . . Shared voltage supply unit

10a. . . Control level

10b. . . Output stage

100. . . Shared voltage supply circuit

12. . . First output

14. . . Second output

20. . . First switching unit

30. . . Second switching unit

C1. . . First energy storage component

C2. . . Second energy storage component

C3. . . Third energy storage component

C4~C5. . . Energy storage component

GATE(n-1). . . First control signal

GATE(n). . . Second control signal

QH. . . First storage voltage

QL. . . Second storage voltage

T1~T17. . . Switching element

VSS1. . . First voltage

VSS2. . . Second voltage

Vclk1. . . First clock signal

Vclk2. . . Second clock signal

Vcom_out. . . Output

VcomH. . . First common voltage

VcomL. . . Second common voltage

Claims (17)

A common voltage supply circuit for a display includes: a common voltage supply unit, receiving a first common voltage, and providing a first storage voltage according to a first control signal to control whether to provide a first common voltage to a An output terminal; a first switching unit electrically coupled to the common voltage supply unit, the first switching unit respectively receiving a first voltage and a second voltage; and a second switching unit electrically coupled to the The first switching unit and the second switching unit respectively receive the first voltage and the second voltage; wherein the first switching unit and the second switching unit respectively turn on the first switching unit and the first energy storage voltage An electrical path of the second switching unit to correspondingly output the second voltage and the first voltage to the common voltage supply unit, and enable the common voltage supply unit to output the first common voltage of one frame, wherein the first The voltage is different from the second voltage. The shared voltage supply circuit of claim 1, wherein the common voltage supply unit further receives a second common voltage and provides a second storage voltage according to a second control signal to control whether the second is provided. Sharing the voltage to the output end, and the first switching unit and the second switching unit respectively turn on the electrical path of the first switching unit and the second switching unit by the second storage voltage to correspondingly output the first And a voltage and the second voltage to the common voltage supply unit, and enabling the common voltage supply unit to output the second common voltage of one frame. The shared voltage supply circuit of claim 2, wherein the first switching unit comprises: a first switching element respectively receiving the first voltage and the second storage voltage; and a second switching element Electrically coupled to the first switching element, the second switching element respectively receiving the second voltage and the first storage voltage; wherein the second switching unit comprises: a third switching element, respectively receiving the a voltage and the first storage voltage; and a fourth switching element electrically coupled to the third switching element, the fourth switching element receiving the second voltage and the second storage voltage, respectively, and the A voltage is greater than the second voltage. The common voltage supply unit of claim 3, wherein the common voltage supply unit comprises: a fifth switching element electrically coupled to the first switching element and the second switching element; a sixth switching element electrically coupled to the fifth switching element, the third switching element, and the fourth switching element; a seventh switching element receiving the first common voltage and electrically coupled to the first a sixth switching element and the fifth switching element, when the seventh switching element is turned on, outputting the first common voltage; a first energy storage element electrically coupled to the seventh switching element and the fifth switching element respectively An eighth switching element receives the second common voltage and is electrically coupled to the sixth switching element and the fifth switching element, respectively, and outputs the second common voltage when the eighth switching element is turned on; The second energy storage component is electrically coupled to the sixth switching component and the eighth switching component respectively; and a third energy storage component is electrically coupled to the first energy storage component and the second energy storage component respectively And the third energy storage The component provides the first stored voltage with the first energy storage component, and the third energy storage component and the second energy storage component together provide the second stored voltage. The common voltage supply circuit of claim 4, wherein when the common voltage supply unit outputs the first common voltage, the gate voltage difference of the sixth switching element is the second voltage minus the first a voltage, and when the common voltage supply unit outputs the second common voltage, a gate voltage difference of the fifth switching element is the second voltage minus the first voltage. The common voltage supply circuit according to claim 1, wherein the common voltage supply unit, the switching element used in the first switching unit and the second switching unit are indium gallium zinc oxide (IGZO) thin film Crystal. A common voltage supply method for a display includes the steps of: providing a first storage voltage according to a first control signal to control outputting a first common voltage; and electrically conducting a first switching unit by the first storage voltage And a second switching unit to respectively receive a first voltage and a second voltage, and respectively provide the first voltage and the second voltage to a switching element that affects the output; and according to the received first voltage and the first The voltage difference formed by the two voltages turns off the switching element, wherein the first voltage is greater than the second voltage. The method of claim 7, wherein the step of providing a first storage voltage according to a first control signal to control outputting a first common voltage further comprises: The control signal provides a second stored voltage to control the step of outputting a second common voltage. The shared voltage supply method of claim 8, wherein a first switching unit and a second switching unit are respectively turned on by the first storage voltage to respectively receive a first voltage and a second voltage. And providing the first voltage and the second voltage respectively to a switching element that affects the output, and further comprising the step of separately providing the first voltage and the second voltage to a further switching element that affects the output. The shared voltage supply method of claim 9, wherein the switching element is turned off according to a voltage difference formed between the received first voltage and the second voltage, so that the outputted first common voltage can be Maintaining a frame, wherein the step of the first voltage being greater than the second voltage further comprises: closing the another switching element according to a voltage difference formed between the received first voltage and the second voltage, so that the output is The second common voltage can maintain one frame. The shared voltage supply method of claim 10, wherein the switching element and the other switching element are turned off according to a voltage difference formed by subtracting the first voltage from the received second voltage. A common voltage supply circuit for a display includes: a common voltage supply unit having a control stage for receiving a first control signal and an output stage for receiving a first common voltage, the control stage being provided according to the first control signal a first storage voltage to control the output stage to output the first common voltage; a first switching unit electrically coupled to the control stage, the first switching unit respectively receiving a first voltage and a second voltage And a second switching unit electrically coupled to the control stage, the second switching unit respectively receiving the first voltage and the second voltage; wherein the control stage has a first output end and a second output end The output stage is electrically coupled to the first output end and the second output end, respectively, the first switching unit and the second switching unit respectively turn on the first switching unit and the first by the first energy storage voltage Switching the electrical path of the unit such that the first output of the control stage outputs the second voltage to the output stage, thereby causing the output stage to output the first common voltage, wherein the first voltage is different from the first Voltage. The shared voltage supply circuit of the display of claim 12, wherein the control stage further receives a second control signal, the output stage further receives a second common voltage, the control stage is provided according to the second control signal a second storage voltage to control the output stage to output the second common voltage, and the first switching unit and the second switching unit respectively turn on the first switching unit and the second switching unit by the second storage voltage The electrical path is such that the second output of the control stage outputs the first voltage to the output stage, thereby causing the output stage to output the second common voltage. The common voltage supply circuit of the display of claim 12, wherein the common voltage supply unit, the switching element used in the first switching unit and the second switching unit is indium gallium zinc oxide (IGZO) Thin film transistor. A liquid crystal display includes: a plurality of scan lines; a plurality of data lines spanning the scan lines; and a plurality of display pixel units electrically coupled to the scan lines and the data lines The plurality of common voltage supply units are electrically coupled to the scan lines and the display pixel units, and each of the common voltage supply units receives a common voltage and is provided according to the control signals provided by the scan lines. a storage voltage to control whether to output the common voltage; wherein each of the common voltage supply units is electrically coupled to a first switching unit and a second switching unit to respectively receive a first voltage and a second voltage, and The first switching unit and the second switching unit respectively conduct electrical paths of the first switching unit and the second switching unit by the first storage voltage to correspondingly output the second voltage and the first voltage to the The voltage supply unit is shared and enables the common voltage supply unit to output the common voltage of one frame, wherein the first voltage is different from the second voltage. The liquid crystal display of claim 15, wherein the first voltage is greater than the second voltage. The liquid crystal display according to claim 15, wherein each of the common voltage supply unit, the switching element used in the first switching unit and the second switching unit is an indium gallium zinc oxide (IGZO) thin film transistor. .