Display device and method of driving the same

Patent metadata

Field	Value
Publication number	US-11423834-B2
Application number	US-202117142131-A
Country	US
Kind code	B2
Filing date	Jan 5, 2021
Priority date	Jun 26, 2020
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

A display device includes: a pixel configured to display an image based on image data and a reference voltage; a controller configured to generate reference voltage data corresponding to the reference voltage for restraining leakage current in the pixel based on a frame frequency; and a power supply configured to generate the reference voltage based on the reference voltage data and supply the reference voltage to the pixel.

First claim

What is claimed is:

1. A display device comprising:
a pixel configured to display an image based on image data and a reference voltage;
a controller configured to generate reference voltage data corresponding to the reference voltage for restraining leakage current in the pixel based on a frame frequency; and
a power supply configured to generate the reference voltage based on the reference voltage data and supply the reference voltage to the pixel,
wherein the controller further comprises a register configured to output a compensation factor in which a distribution of threshold voltages of a driving transistor of the pixel is reflected, and
wherein the power supply outputs the reference voltage based on the reference voltage data and the compensation factor.

2. The display device according to claim 1 , wherein the power supply comprises:
a variable resistor circuit configured to adjust a resistance value based on the reference voltage data, and change an input power voltage based on the resistance value.

3. A display device comprising:
a pixel configured to display an image based on image data and a reference voltage;
a controller configured to generate reference voltage data corresponding to the reference voltage for restraining leakage current in the pixel based on a frame frequency; and
a power supply configured to generate the reference voltage based on the reference voltage data and supply the reference voltage to the pixel,
wherein the controller determines the reference voltage data with further reference to a representative value of a grayscale of the image data.

4. The display device according to claim 3 , wherein the representative value is an average of grayscales included in the image data of a frame.

5. The display device according to claim 3 , wherein for the representative value being the same, the reference voltage changes as the frame frequency changes from a first frequency to a second frequency.

6. The display device according to claim 5 , wherein for the frame frequency being the same, the reference voltage changes as the representative value changes from a first value to a second value.

7. The display device according to claim 3 , wherein the controller comprises:
a frequency analyzer configured to determine the frame frequency based on at least one of a vertical synchronization signal and a data enable signal supplied from an external device;
a representative value determiner configured to determine the representative value based on grayscales included in the image data; and
a voltage data generator configured to generate the reference voltage data with reference to a lookup table that stores values of the reference voltage corresponding to the frame frequency and the grayscale.

8. The display device according to claim 7 , wherein the voltage data generator comprises:
a comparator configured to compare the frame frequency and a reference frequency; and
a data determiner configured to determine the reference voltage data based on a result of comparison of the comparator.

9. The display device according to claim 8 ,
wherein, for the frame frequency being equal to or greater than the reference frequency, the data determiner outputs a default value of the reference voltage data corresponding to a default value among the values of the reference voltage, and
wherein, for the frame frequency being less than the reference frequency, the data determiner determines the reference voltage data with reference to the lookup table.

10. The display device according to claim 8 , wherein the data determiner extracts a plurality of reference values from the lookup table based on the frame frequency and the representative value, and calculates the reference voltage data by interpolating the reference values.

11. A display device comprising:
a pixel configured to display an image based on image data and a reference voltage;
a controller configured to generate reference voltage data corresponding to the reference voltage for restraining leakage current in the pixel based on a frame frequency;
a power supply configured to generate the reference voltage based on the reference voltage data and supply the reference voltage to the pixel;
a data driver configured to supply a data voltage to the pixel through a data line based on the image data;
a scan driver configured to supply a first scan signal to the pixel through a first scan line, supply a second scan signal to a second scan line; and
an emission driver configured to supply a first emission control signal to the pixel through a first emission control line,
wherein the pixel comprises:
a light emitting element;
a first transistor configured to control driving current based on a voltage of a first node and being coupled between a second node and a third node;
a second transistor coupled between the data line and the second node, and configured to be turned on by the first scan signal supplied to the first scan line;
a third transistor and a fourth transistor coupled in series between the first node and the third node and configured to be turned on by the second scan signal supplied to the second scan line;
a fifth transistor configured to supply the reference voltage to a fourth node between the third transistor and the fourth transistor and to be turned off by the first emission control signal supplied to the first emission control line; and
a sixth transistor coupled between a first power supply voltage and the second node and configured to be turned off by the first emission control signal.

12. The display device according to claim 11 , wherein the scan driver is further configured to supply a third scan signal to the pixel through a third scan line and supply a fourth scan signal to the pixel through a fourth scan line, and
wherein the pixel further comprises:
a seventh transistor coupled between the third node and the light emitting element, and configured to be turned off by the first emission control signal;
an eighth transistor configured to supply an initialization voltage to the light emitting element and to be turned on by the third scan signal supplied to the third scan line;
a ninth transistor and a tenth transistor coupled in series between the first node and a power line for supplying the initialization voltage, and configured to be turned on by the fourth scan signal supplied to the fourth scan line; and
an eleventh transistor configured to supply the reference voltage to a fifth node between the ninth transistor and the tenth transistor, and to be turned off by the first emission control signal.

13. The display device according to claim 12 , wherein an identical scan signal is supplied to the first scan line and the second scan line.

14. The display device according to claim 11 , wherein the scan driver is further configured to supply a third scan signal to the pixel through a third scan line,
wherein the emission driver is further configured to supply a second emission control signal to the pixel through a second emission control line, and
wherein the pixel further comprises:
a seventh transistor coupled between the third node and the light emitting element, and configured to be turned off by the second emission control signal supplied to the second emission control line; and
an eighth transistor configured to supply an initialization voltage to the third node and to be turned on by the third scan signal supplied to the third scan line.

15. The display device according to claim 14 , wherein the second emission control signal is supplied later than the first emission control signal.

Assignees

• Samsung Display Co Ltd

Inventors

• Park Se Hyuk
• Kim Hong Soo
• Roh Jin Young
• Lee Hyo Jin
• Lim Jae Keun

Classifications

• G09G3/3291 Primary

  in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements · CPC title

• G09G3/2096

  Details of the interface to the display terminal specific for a flat panel (suitable for both CRT and flat panel G09G5/006; specific for a CRT G09G1/167) · CPC title

• G09G2320/045

  Compensation of drifts in the characteristics of light emitting or modulating elements · CPC title

• G09G2360/16

  Calculation or use of calculated indices related to luminance levels in display data · CPC title

• G09G2300/0819

  used for counteracting undesired variations, e.g. feedback or autozeroing · CPC title