# US 11,443,687 B2 · Display device

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- Number: US 11,443,687 B2
- Document ID: US11443687B2
- Status: Granted
- Kind: B2
- Application number: 17/242,818
- Filed: 2021-04-28
- Published: 2021-12-02
- Granted: 2022-09-13
- Earliest claimed: 2020-05-28
- Assignees: Samsung Display Co., Ltd.
- Applicants: Samsung Display Co., Ltd.
- Inventors: Min Seong Son; Seung Kyu Lee; Sun Joon Hwang; Yun Seong Kim; Youn Woo Choe
- Web page: https://patentgrep.com/patent/US11443687B2

## CPC

- G09G 3/32: semiconductive, e.g. using light-emitting diodes [LED]
- G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element
- G09G 3/2022: {using sub-frames}
- G09G 2300/0426: Layout of electrodes and connections
- G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing
- G09G 2300/0842: forming a memory circuit, e.g. a dynamic memory with one capacitor
- G09G 2300/0861: with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
- 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 2310/0267: Details of drivers for scan electrodes, other than drivers for liquid crystal, plasma or OLED displays
- G09G 2310/027: Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
- G09G 2310/08: Details of timing specific for flat panels, other than clock recovery
- G09G 2320/0233: Improving the luminance or brightness uniformity across the screen
- G09G 2320/0247: Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
- G09G 2320/045: Compensation of drifts in the characteristics of light emitting or modulating elements
- G09G 2340/0435: Change or adaptation of the frame rate of the video stream
- 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 device includes a pixel including a first transistor coupled between a first node and a second node, an emission driver supplying an emission control signal at a first frequency to an emission control line, a scan driver supplying first to fourth scan signals respectively to first to fourth scan lines, a data driver supplying a data signal to a data line, and a timing controller. The first scan signal controls a timing at which a voltage of a first power source is supplied to the first node or the second node, and the second scan signal controls a timing at which a first electrode of the first transistor and a gate electrode of the first transistor are coupled to each other. The scan driver controls a bias state of the first transistor by supplying, plural times, the first and second scan signals in a non-emission period.

## Claims

### Claim 1

A display device comprising:
a pixel including a first transistor coupled between a first node and a second node to generate a driving current, the pixel being connected to a first scan line, a second scan line, a third scan line, a fourth scan line, an emission control line, and a data line;
an emission driver which supplies an emission control signal at a first frequency to the emission control line;
a scan driver which supplies first to fourth scan signals respectively to the first to fourth scan lines in a period in which the emission control signal is supplied;
a data driver which supplies a data signal to the data line; and
a timing controller which controls driving of the scan driver, the emission driver, and the data driver,
wherein the first scan signal controls a timing at which a voltage of a first power source is supplied to the first node or the second node,
the second scan signal controls a timing at which a first electrode of the first transistor and a gate electrode of the first transistor are coupled to each other, and
the scan driver controls a bias state of the first transistor by supplying, plural times, the first scan signal and the second scan signal in a non-emission period in which the emission control signal is supplied.

### Claim 2 (depends on 1)

The display device of claim 1, wherein the pixel further includes:
a light emitting device;
a second transistor coupled between the data line and the first node, the second transistor being turned on in response to the fourth scan signal supplied to the fourth scan line;
a third transistor coupled between the second node and a third node connected to the gate electrode of the first transistor, the third transistor being turned on in response to the second scan signal;
a fourth transistor turned on in response to the first scan signal supplied to the first scan line to apply the voltage of the first power source to the first transistor;
a fifth transistor coupled between a driving power source and the first node, the fifth transistor being turned off in response to the emission control signal supplied to the emission control line; and
a sixth transistor coupled between the second node and a first electrode of the light emitting device, the sixth transistor being turned off in response to the emission control signal supplied to the emission control line.

### Claim 3 (depends on 2)

The display device of claim 2, wherein, in a first period of the non-emission period, the scan driver supplies the second scan signal to the second scan line, and supplies the first scan signal to the first scan line.

### Claim 4 (depends on 3)

The display device of claim 3, wherein, in the first period, the fourth transistor is turned on after the third transistor is turned on.

### Claim 5 (depends on 4)

The display device of claim 4, wherein, in the first period, a time length during which the third transistor is turned on is longer than a time length during which the fourth transistor is turned on.

### Claim 6 (depends on 3)

The display device of claim 3, wherein the pixel further includes:
a seventh transistor coupled between the third node and a second power source, the seventh transistor being turned on in response to the third scan signal supplied to the third scan line.

### Claim 7 (depends on 6)

The display device of claim 6, wherein the scan driver:
supplies the third scan signal to the third scan line in a second period of the non-emission period; and
supplies the second scan signal to the second scan line in a third period of the non-emission period.

### Claim 8 (depends on 7)

The display device of claim 7, wherein the second period is started between the first period and the third period.

### Claim 9 (depends on 7)

The display device of claim 7, wherein, in the third period, the scan driver supplies the fourth scan signal to the fourth scan line while overlapping with a portion of the second scan signal.

### Claim 10 (depends on 7)

The display device of claim 7, wherein the scan driver again supplies the first scan signal to the first scan line in a fourth period after the third period.

### Claim 11 (depends on 10)

The display device of claim 10, wherein the supply of the first to fourth scan signals is suspended during a remained period of the non-emission period after the fourth period, and
wherein a time length of the remained period is greater than a pulse width of the first scan signal.

### Claim 12 (depends on 11)

The display device of claim 11, wherein the time length of the remained period is equal to or greater than about 10 microseconds.

### Claim 13 (depends on 12)

The display device of claim 12, wherein the scan driver supplies the third scan signal and the fourth scan signal at a second frequency corresponding to a frame frequency, and
wherein the second frequency is lower than the first frequency.

### Claim 14 (depends on 13)

The display device of claim 13, wherein a frame period includes a plurality of non-emission periods,
wherein the scan driver supplies the first scan signal in the plurality of non-emission periods, and
wherein the scan driver supplies the second scan signal, the third scan signal, and the fourth scan signal only in a first non-emission period among the plurality of non-emission periods.

### Claim 15 (depends on 6)

The display device of claim 6, wherein the pixel further includes:
an eighth transistor coupled between the first electrode of the light emitting device and a third power source, the eighth transistor being turned on in response to the first scan signal.

### Claim 16 (depends on 3)

The display device of claim 3, wherein one electrode of the fourth transistor is coupled to the first node.

### Claim 17 (depends on 3)

The display device of claim 3, wherein one electrode of the fourth transistor is coupled to the second node.

### Claim 18 (depends on 3)

The display device of claim 3, wherein the scan driver comprises:
a first scan driver which supplies a plurality of first scan signals to the first scan line during the non-emission period;
a second scan driver which supplies a plurality of second scan signals to the second scan line during the non-emission period;
a third scan driver which supplies the third scan signal to the third scan line between times at which the plurality of second scan signals is supplied; and
a fourth scan driver which supplies the fourth scan signal to the fourth scan line while overlapping with portions of the plurality of second scan signals.