Data driver, organic light emitting display device using the same, and method of driving the organic light emitting display device

Patent metadata

Field	Value
Publication number	US-10192491-B2
Application number	US-201715782780-A
Country	US
Kind code	B2
Filing date	Oct 12, 2017
Priority date	Aug 10, 2005
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

A data driver capable of displaying images with a substantially uniform brightness, an organic light emitting display device using the same, and a method of driving the organic light emitting display device. The data driver includes a plurality of current sink units for controlling predetermined currents to flow through data lines, a plurality of voltage generators for resetting values of gray scale voltages using compensation voltages generated when the predetermined currents flow, a plurality of digital-to-analog converters for selecting one gray scale voltage among the gray scale voltages as a data signal in response to bit values of the data supplied from the outside, and a plurality of switching units for supplying the data signal to the data lines. The predetermined currents may be set equal to pixel currents that correspond to a maximum brightness.

First claim

What is claimed is:

1. A data driver for an organic light emitting display device, the data driver comprising:
a precharging unit for supplying a precharging voltage to a pixel coupled to a data line;
a current sink unit for receiving a predetermined current from the pixel;
a voltage generator for resetting values of gray scale voltages using a compensation voltage generated when the predetermined current flows;
a digital-to-analog converter for selecting one gray scale voltage among the gray scale voltages as a data signal in response to a bit value of data supplied to the data driver from outside; and
a switching unit for supplying the data signal to the data line,
wherein the precharging unit is located between the digital-to-analog converter and the switching unit, and comprises:
a first transistor located between a precharging voltage source and the switching unit and for being turned on in a 0th period of each horizontal period; and
a second transistor located between the digital-to-analog converter and the switching unit and for being turned on in a second period of each horizontal period,
wherein each horizontal period includes the 0th period, a first period, and the second period.

2. The data driver as claimed in claim 1 , wherein a voltage value of the precharging voltage source is set so that the predetermined current flows through the pixel.

3. The data driver as claimed in claim 1 , wherein the current sink unit receives the predetermined current in the first period of each horizontal period.

4. The data driver as claimed in claim 3 , wherein the predetermined current is equal to a current that flows when the pixel emits light with a maximum brightness.

5. The data driver as claimed in claim 1 , wherein the switching unit comprises a transistor for electrically coupling the data line and the precharging unit to each other in the 0 th period and the second period.

6. A method of driving an organic light emitting display device, the method comprising:
supplying, by a precharging unit, a predetermined precharging voltage to a pixel selected by a scan signal;
supplying a predetermined current from the pixel to a data driver;
resetting values of gray scale voltages using compensation voltages generated when the predetermined current is supplied; and
selecting, by a digital-to-analog converter, one of the gray scale voltages as a data signal to correspond to bit values of the data supplied from outside for supplying the data signal to the pixel by a switching unit,
wherein the precharging unit is located between the digital-to-analog converter and the switching unit, and comprises:
a first transistor located between a precharging voltage source and the switching unit and for being turned on in a 0th period of each horizontal period; and
a second transistor located between the digital-to-analog converter and the switching unit and for being turned on in a second period of each horizontal period,
wherein each horizontal period includes the 0th period, a first period, and the second period.

7. The method as claimed in claim 6 , wherein the predetermined current is same as a current that flows when the pixel emits light with a maximum brightness.

8. The method as claimed in claim 7 , wherein the precharging voltage is set so that a predetermined current flows through the pixel.

Assignees

• Samsung Display Co Ltd
• Iucf Hyu

Inventors

• Ryu Do Hyung
• Chung Bo Yong
• Kim Hong Kwon
• Kwon Oh Kyong

Classifications

• G09G2352/00

  Parallel handling of streams of display data · CPC title

• G09G2310/0251

  Precharge or discharge of pixel before applying new pixel voltage · CPC title

• G09G2300/0819

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

• 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

• G09G3/3233

  with pixel circuitry controlling the current through the light-emitting element · CPC title