# US 12,223,887 B2 · Gate drive circuit and display panel

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- Number: US 12,223,887 B2
- Document ID: US12223887B2
- Status: Granted
- Kind: B2
- Application number: 18/502,076
- Filed: 2023-11-05
- Published: 2025-01-02
- Granted: 2025-02-11
- Earliest claimed: 2023-06-27
- Assignees: Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd.
- Applicants: Wuhan China Star Optoelectronics Semiconductor Display Technology Co., Ltd.
- Inventors: Feixiang Sun; Hongyan Liu; Yi Liu
- Web page: https://patentgrep.com/patent/US12223887B2

## CPC

- G09G 3/32: semiconductive, e.g. using light-emitting diodes [LED]
- G09G 3/20: for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters}
- G11C 19/28: using semiconductor elements (G11C19/14, G11C19/36 take precedence)
- G11C 19/287: {Organisation of a multiplicity of shift registers}
- G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing
- G09G 2300/0852: being a dynamic memory with more than one capacitor
- G09G 2310/0267: Details of drivers for scan electrodes, other than drivers for liquid crystal, plasma or OLED displays
- G09G 2310/0286: Details of a shift registers arranged for use in a driving circuit
- G09G 2310/08: Details of timing specific for flat panels, other than clock recovery
- 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)
- G11C: STATIC STORES (semiconductor memory devices H10B)

## Abstract

A gate drive circuit and a display panel. The gate drive circuit includes one or more shift register groups. Each of the shift register groups includes N shift adjacent registers that output in sequence, with N being an integer greater than or equal to 3. Each of the shift registers includes a first output stage and a frequency division control module. The first output stage is configured to output a gate drive signal. The frequency division control module is configured to control outputting of the gate drive signal based on a refresh frequency. A control end of each frequency division control module in each of the shift register groups receives a control signal with a different phase and a same frequency, respectively, to adjust a pulse width of the gate drive signal and maintain a same pulse width at different refresh frequencies.

## Claims

### Claim 1

A gate drive circuit, wherein the gate drive circuit comprises one or more shift register groups, each of the shift register groups comprises N adjacent shift registers that output in sequence, N being an integer greater than or equal to 3, each of the shift registers comprises:
a first output stage configured to output a gate drive signal;
a frequency division control module configured to control outputting of the gate drive signal based on a refresh frequency,
wherein a control end of each frequency division control module in each of the shift register groups receives a control signal with a different phase and a same frequency, respectively, to adjust a pulse width of the gate drive signal and maintain a same pulse width at different refresh frequencies.

### Claim 2 (depends on 1)

The gate drive circuit of claim 1, wherein each of the shift register groups comprises a first shift register, a second shift register, a third shift register that output gate drive signals with sequentially lagged phases;
the control signal comprise a first control signal, a second control signal, and a third control signal, and a frequency of the first control signal, a frequency of the second control signal, and a frequency of the third control signal are the same, and a phase of the first control signal, a phase of the second control signal, and a phase of the third control signal are lagged sequentially;
in each of the shift register groups, the control end of the frequency division control module in the first shift register receives the first control signal, the control end of the frequency division control module in the second shift register receives the second control signal, and the control end of the frequency division control module in the third shift register receives the third control signal.

### Claim 3 (depends on 2)

The gate drive circuit of claim 2, wherein an interval exists between a pulse start edge of the first control signal and a pulse start edge of the second control signal, and the interval exists between a pulse start edge of the second control signal and a pulse start edge of the third control signal.

### Claim 4 (depends on 3)

The gate drive circuit of claim 3, wherein the pulse width of the gate drive signal is a product of N and the interval.

### Claim 5 (depends on 3)

The gate drive circuit of claim 3, wherein the first shift register outputs a first gate drive signal, the second shift register outputs a second gate drive signal, and the third shift register outputs a third gate drive signal; and
the interval exists between a pulse start edge of the first gate drive signal and a pulse start edge of the second gate drive signal, and the interval exists between a pulse start edge of the second gate drive signal and a pulse start edge of the third gate drive signal.

### Claim 6 (depends on 5)

The gate drive circuit of claim 5, wherein the pulse start edge of the first control signal is located at a same time as the pulse start edge of the first gate drive signal, the pulse start edge of the second control signal is located at a same time as the pulse start edge of the second gate drive signal, and the pulse start edge of the third control signal is located at a same time as the pulse of the third gate drive signal.

### Claim 7 (depends on 1)

The gate drive circuit of claim 1, wherein the control signal is transmitted via a control line, and the control line comprises a first control line, a second control line and a third control line; each of the shift register groups comprises a first shift register, a second shift register, a third shift register that output gate drive signals with sequentially lagged phases; and the first control line is connected to the control end of the frequency division control module of the first shift register in each of the shift register groups, the second control line is connected to the control end of the frequency division control module of the second shift register in each of the shift register groups, and the third control line is connected to the control end of the frequency division control module of the third shift register in each of the shift register groups.

### Claim 8 (depends on 7)

The gate drive circuit of claim 7, wherein the control line further comprises a fourth control line, each of the shift register groups further comprises a fourth shift register, and the fourth control line is connected to the control end of the frequency division control module of the fourth shift register in each of the shift register groups.

### Claim 9 (depends on 8)

The gate drive circuit of claim 8, wherein the first control line, the second control line, the third control line, and the fourth control line sequentially transmit a first control signal, a second control signal, a third control signal, and a fourth control signal, respectively; a frequency of the first control signal, a frequency of the second control signal, a frequency of the third control signal, and a frequency of the fourth control signal are the same; and a phase of the first control signal, a phase of the second control signal, a phase of the third control signal, and a phase of the fourth control signal are lagged sequentially.

### Claim 10 (depends on 1)

The gate drive circuit of claim 1, wherein the gate drive circuit further comprises a signal generating module, the signal generating module comprises N cascaded signal generating units, and the N signal generating units generates, based on an initial control signal, N control signals with different phases and a same frequency.

### Claim 11 (depends on 10)

The gate drive circuit of claim 10, wherein the N signal generating units comprise a first signal generating unit, a second signal generating unit, and a third signal generating unit, wherein the first signal generating unit generates a first control signal based on the initial control signal, the second signal generating unit generates a second control signal based on the first control signal, and the third signal generating unit generates a third control signal based on the second control signal.

### Claim 12

A display panel, comprising:
a gate drive circuit comprising one or more shift register groups, wherein each of the shift register groups comprises N adjacent shift registers that output in sequence, N being an integer greater than or equal to 3, each of the shift registers comprises:
a first output stage configured to output a gate drive signal;
a frequency division control module configured to control outputting of the gate drive signal based on a refresh frequency,
wherein a control end of each frequency division control module in each of the shift register groups receives a control signal with a different phase and a same frequency, respectively, to adjust a pulse width of the gate drive signal and maintain a same pulse width at different refresh frequencies; and
a pixel circuit comprising a drive transistor, a compensation transistor, and a write transistor, wherein a first electrode of the compensation transistor is connected to a gate of the drive transistor, a second electrode of the compensation transistor is connected to a first electrode or a second electrode of the drive transistor, and a gate of the compensation transistor receives a gate drive signal; and a first electrode of the write transistor is connected to the first electrode or the second electrode of the drive transistor, a second electrode of the write transistor is connected to a data line, and a gate of the write transistor is connected to a scan line.