# US 11,908,411 B1 · Display panel and pixel driving method

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- Number: US 11,908,411 B1
- Document ID: US11908411B1
- Status: Granted
- Kind: B1
- Application number: 18/329,036
- Filed: 2023-06-05
- Granted: 2024-02-20
- Earliest claimed: 2022-12-01
- Assignees: Hkc Corporation Limited
- Applicants: Hkc Corporation Limited
- Inventors: Tao Fan; Rongrong Li
- Web page: https://patentgrep.com/patent/US11908411B1

## CPC

- G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element
- G09G 3/3291: in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
- G09G 2300/0426: Layout of electrodes and connections
- G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing
- G09G 2310/0251: Precharge or discharge of pixel before applying new pixel voltage
- G09G 2310/0256: with the purpose of reversing the voltage across a light emitting or modulating element within a pixel
- G09G 2310/0262: The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
- G09G 2320/0233: Improving the luminance or brightness uniformity across the screen
- G09G 2320/043: Preventing or counteracting the effects of ageing
- G09G 2330/021: Power management, e.g. power saving
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)

## Abstract

A display panel includes a plurality of pixel driving circuits arranged in an array along a row direction and a column direction. The display panel further comprises a plurality of first control lines, a plurality of second control lines, a plurality of data lines, and a plurality of power lines. Each of the pixel driving circuits is correspondingly connected to the first control line, the second control line, the data line, and two power lines, and the two power lines comprises a first power line and a second power line. The pixel driving circuit includes: a driving transistor, a storage capacitor, a sampling compensation assembly, a first switch assembly, a second switch assembly and a light emitting device.

## Claims

### Claim 1

A display panel, comprising:
a plurality of pixel driving circuits arranged in an array along a row direction and a column direction;
wherein the display panel further comprises a plurality of first control lines, a plurality of second control lines, a plurality of data lines, and a plurality of power lines;
wherein each of the pixel driving circuits is correspondingly connected to the first control line, the second control line, the data line, and two power lines, and the two power lines comprises a first power line and a second power line;
wherein the pixel driving circuit, comprises:
a driving transistor having a control terminal connected to a point G, a first terminal connected to a point D, and a second terminal connected to ground;
a storage capacitor having a first terminal connected to the point G, and a second terminal connected to ground;
a sampling compensation assembly, comprising a first response terminal connected to the point G, a first connection terminal connected to a point A, and a second connection terminal connected to a point B, the first response terminal being configured to respond to a level signal at the point G to control an on-off state between the first connection terminal and the second connection terminal;
a first switch assembly, comprising a second response terminal connected to the first control line, a third connection terminal connected to the first power line of the two power lines, and a fourth connection terminal connected to the point B, the second response terminal being configured to respond to a level signal provided by the first control line to control an on-off state between the third connection terminal and the fourth connection terminal;
a second switch assembly, comprising a third response terminal connected to the second control line, a data writing terminal connected to the data line, a fifth connection terminal connected to the point A, a sixth connection terminal connected to the point B, and a seventh connection terminal connected to the point G, the third response terminal being configured to respond to a level signal provided by the second control line to control an on-off state between the data writing terminal and the fifth connection terminal and an on-off state between the sixth connection terminal and the seventh connection terminal; and
a light emitting device having a cathode connected to the point D and an anode connected to the second power line of the two power lines, the second power line being configured to provide a high level signal during a displaying light emitting stage and a low level signal in other stages;
wherein the power lines extend in a row direction, and the power lines and the pixel driving circuit each comprises N rows;
wherein in a first row of the pixel driving circuit, the anode of the light emitting device is connected to a first row of the power line, and the third connection terminal of the first switch assembly is connected to an N-th row of the power line, wherein the first row of the power line is the second power line of the two power lines, and the N-th row of the power line is the first power line of the two power lines;
wherein in an n-th first row of the pixel driving circuit, the anode of the light emitting device is connected to the n-th row of the power line, and the third connection terminal of the first switch assembly is connected to an n-1-th row of the power line;
wherein the n-th row of the power line is the second power line of the two power lines, and the n-1-th row of the power line is the first power line of the two power lines;
wherein n and N are positive integers, and 1<n≤N;
wherein the sampling compensation assembly comprises a sampling compensation transistor having a control terminal serving as the first response terminal, a first terminal serving as the first connection terminal, and a second terminal serving as the second connection terminal;
the first switch assembly comprising a first switch transistor having a control terminal serving as the second response terminal, a first terminal serving as the third connection terminal, and a second terminal serving as the fourth connection terminal;
the second switch assembly comprising a second switch transistor and a third switch transistor having control terminals of the second switch transistor and the third switch transistor connected to the third response terminal, a first terminal of the second switch transistor serving as the data writing terminal, a second terminal of the second switch transistor serving as the fifth connection terminal, a first terminal of the third switch transistor serving as the sixth connection terminal, and a second terminal of the third switch transistor serving as the seventh connection terminal;
wherein the types of the driving transistor, the sampling compensation transistor, the first switch transistor, the second switch transistor, and the third switch transistor are the same;
wherein the control terminal of the sampling compensation transistor and the control terminal of the driving transistor are arranged on the same layer; wherein the first terminal of the sampling compensation transistor is arranged on the same layer as the first terminal of the driving transistor, and the second terminal of the sampling compensation transistor is arranged on the same layer as the second terminal of the driving transistor.

### Claim 2 (depends on 1)

The display panel according to claim 1, wherein the first power line is configured to provide a same level signal in each stage.

### Claim 3 (depends on 2)

The display panel according to claim 2, wherein the driving transistor, the sampling compensation transistor, the first switch transistor, the second switch transistor, and the third switch transistor each are N-type transistors.

### Claim 4 (depends on 1)

The display panel according to claim 1, wherein the parameters of the sampling compensation transistor are consistent with the parameters of the driving transistor.

### Claim 5 (depends on 4)

The display panel according to claim 4, wherein the position of the sampling compensation transistor is provided to be closer to the driving transistor than positions of the first switch transistor, the second switch transistor, and the third switch transistor.

### Claim 6 (depends on 5)

The display panel according to claim 5, wherein the parameters comprises threshold voltage, mobility and gate capacitance of the transistor.

### Claim 7 (depends on 1)

The display panel according to claim 1, wherein the control terminal of the first switch transistor and the control terminal of the driving transistor are arranged on the same layer, the first terminal of the first switch transistor and the first terminal of the driving transistor are arranged on the same layer, and the second terminal of the first switch transistor and the second terminal of the driving transistor are arranged in the same layer.

### Claim 8 (depends on 1)

The display panel according to claim 1, wherein the control terminals of the second switch transistor and the third switch transistor and the control terminal of the driving transistor are arranged on the same layer, the first terminals of the second switch transistor and the third switch transistor and the first terminal of the driving transistor are be arranged on the same layer, and the second terminals of the second switch transistor and the third switch transistor and the second terminal of the driving transistor are arranged on the same layer.

### Claim 9 (depends on 1)

The display panel according to claim 1, wherein the driving transistor, the sampling compensation transistor, the first switch transistor, the second switch transistor, and the third switch transistor each are bottom-gate type.

### Claim 10 (depends on 1)

The display panel according to claim 1, wherein power provided by the second power line is AC power, and the second power line is configured to provide a high level signal during the displaying light emitting stage, and provide a low level signal during other periods.

### Claim 11 (depends on 1)

The display panel according to claim 1, wherein the light emitting device is a current-driven light emitting device, which is controlled by the current flowing through the driving transistor to emit light.

### Claim 12

A pixel driving method for driving a display panel, the pixel driving method comprising:
an initialization stage, a sampling compensation stage, and a displaying light emitting stage;
wherein the initialization stage comprises: providing a low level signal to an anode of a light emitting device through a second power line, while providing a first level signal to a second response terminal through a first control line, providing a second level signal to a third response terminal through a second control line, providing a third level signal to a third connection terminal through a first power line, and providing a fourth level signal to a data writing terminal through a data line, so as to have the third connection terminal and the fourth connection terminal turned on, the data writing terminal and the fifth connection terminal turned on, and the sixth connection terminal and the seventh connection terminal turned on;
wherein the sampling compensation stage comprises: providing a low level signal to the anode of the light emitting device through the second power line, while providing a fifth level signal to the second response terminal through the first control line, providing a sixth level signal to the third response terminal through the second control line, providing a seventh level signal to the third connection terminal through the first power line, and providing an eighth level signal to the data writing terminal through the data line, so as to have the third connection terminal and the fourth connection terminal turned off, the data writing terminal and the fifth connection terminal turned on, and the sixth connection terminal and the seventh connection terminal turned on; and
wherein the displaying light emitting stage comprises: providing a high level signal to the anode of the light emitting device through the second power line, while providing a ninth level signal to the second response terminal through the first control line, providing a tenth level signal to the third response terminal through the second control line, providing an eleventh level signal to the third connection terminal through the first power line, and providing a twelfth level signal to the data writing terminal through the data line, so as to have the third connection terminal and the fourth connection terminal turned off, the data writing terminal and the fifth connection terminal turned off, and the sixth connection terminal and the seventh connection terminal turned off;
wherein the display panel comprises: a plurality of pixel driving circuits arranged in an array along a row direction and a column direction;
wherein the display panel further comprises a plurality of first control lines, a plurality of second control lines, a plurality of data lines, and a plurality of power lines;
wherein each of the pixel driving circuits is correspondingly connected to the first control line, the second control line, the data line, and two power lines, and the two power lines comprises the first power line and the second power line;
wherein the pixel driving circuit comprises:
a driving transistor having a control terminal connected to a point G, a first terminal connected to a point D, and a second terminal connected to ground;
a storage capacitor having a first terminal connected to the point G, and a second terminal connected to ground;
a sampling compensation assembly, comprising a first response terminal connected to the point G, a first connection terminal connected to a point A, and a second connection terminal connected to a point B, the first response terminal being configured to respond to a level signal at the point G to control an on-off state between the first connection terminal and the second connection terminal;
a first switch assembly, comprising the second response terminal connected to the first control line, the third connection terminal connected to the first power line of the two power lines, and the fourth connection terminal connected to the point B, the second response terminal being configured to respond to a level signal provided by the first control line to control an on-off state between the third connection terminal and the fourth connection terminal; and
a second switch assembly, comprising the third response terminal connected to the second control line, the data writing terminal connected to the data line, the fifth connection terminal connected to the point A, the sixth connection terminal connected to the point B, and the seventh connection terminal connected to the point G, the third response terminal being configured to respond to a level signal provided by the second control line to control an on-off state between the data writing terminal and the fifth connection terminal and an on-off state between the sixth connection terminal and the seventh connection terminal;
wherein the light emitting device has a cathode connected to the point D and the anode is connected to the second power line of the two power lines, the second power line being configured to provide a high level signal during the displaying light emitting stage and a low level signal in other stages;
wherein the power lines extend in a row direction, and the power lines and the pixel driving circuit each comprises N rows;
wherein in a first row of the pixel driving circuit, the anode of the light emitting device is connected to a first row of the power line, and the third connection terminal of the first switch assembly is connected to an N-th row of the power line, wherein the first row of the power line is the second power line of the two power lines, and the N-th row of the power line is the first power line of the two power lines;
wherein in an n-th first row of the pixel driving circuit, the anode of the light emitting device is connected to the n-th row of the power line, and the third connection terminal of the first switch assembly is connected to an n-1-th row of the power line;
wherein the n-th row of the power line is the second power line of the two power lines, and the n-1-th row of the power line is the first power line of the two power lines;
wherein n and N are positive integers, and 1<n≤N;
wherein in the sampling compensation stage, the light emitting device is in a reversed-biased state;
wherein in the displaying light emitting stage, the light emitting device switches to a forward-biased state.

### Claim 13 (depends on 12)

The pixel driving method according to claim 12, wherein the first level signal provided by the first control line is a high level signal, and the fifth level signal and the ninth level signal are both low level signals;
wherein the second level signal and the sixth level signal provided by the second control line are both high level signals, and the tenth level signal is a low level signal;
wherein the third level signal, the seventh level signal, and the eleventh level signal provided by the first power line each are high level signals; and
wherein the fourth level signal and the eighth level signal provided by the data line are both high level signals, and the twelfth level signal is a low level signal.

### Claim 14 (depends on 12)

The pixel driving method according to claim 12, wherein in the displaying light emitting stage, threshold voltages of the driving transistor and the sampling compensation transistor are controlled to be equal.

### Claim 15 (depends on 14)

The pixel driving method according to claim 14, wherein a driving current of the light emitting device is calculated by:
IOLED=½×μ×W/L×CGI×(VData)2
where IOLED denotes the driving current of the light emitting device, μ denotes electron mobility, CGI denotes capacitance per unit area of the light emitting device, which is a transistor, W/L denotes a ratio of a channel width to the length of the transistor, Vdata denotes data voltage provided by the data signal.

### Claim 16 (depends on 12)

The pixel driving method according to claim 12, wherein the sampling compensation assembly comprises a sampling compensation transistor having a control terminal serving as the first response terminal, a first terminal serving as the first connection terminal, and a second terminal serving as the second connection terminal;
the first switch assembly comprising a first switch transistor having a control terminal serving as the second response terminal, a first terminal serving as the third connection terminal, and a second terminal serving as the fourth connection terminal;
the second switch assembly comprising a second switch transistor and a third switch transistor having control terminals of the second switch transistor and the third switch transistor connected to the third response terminal, a first terminal of the second switch transistor serving as the data writing terminal, a second terminal of the second switch transistor serving as the fifth connection terminal, a first terminal of the third switch transistor serving as the sixth connection terminal, and a second terminal of the third switch transistor serving as the seventh connection terminal;
wherein the types of the driving transistor, the sampling compensation transistor, the first switch transistor, the second switch transistor, and the third switch transistor are the same.