Display apparatus and method of driving the same

Patent metadata

Field	Value
Publication number	US-2016133191-A1
Application number	US-201514735484-A
Country	US
Kind code	A1
Filing date	Jun 10, 2015
Priority date	Nov 12, 2014
Publication date	May 12, 2016
Grant date	—

Abstract

A display apparatus includes pixels connected to scan lines, data lines, and emission control lines. Each include includes an organic light-emitting diode (OLED), a first transistor to transfer driving current to the OLED based on a data signal, a second transistor to transfer the data signal to the first transistor based on a first scan signal having a gate-on voltage level during a data writing period, a first capacitor connected between a gate electrode of the first transistor and a first power source, and a second capacitor connected between a drain electrode of the first transistor and the first power source.

First claim

What is claimed is:

1 . A display apparatus, comprising:
a display unit including a plurality of pixels connected to a plurality of scan lines, a plurality of data lines, and a plurality of emission control lines, wherein each of the pixels includes: an organic light-emitting diode (OLED); a first transistor to transfer driving current, based on a data signal, to the OLED; a second transistor to transfer the data signal to the first transistor based on a first scan signal having a gate-on voltage level during a data writing period; a first capacitor connected between a gate electrode of the first transistor and a first power source; and a second capacitor connected between a drain electrode of the first transistor and the first power source.

2 . The display apparatus as claimed in claim 1 , wherein:
the gate electrode of the first transistor is connected to a first node, and the first node connects the first transistor to the second transistor.

3 . The display apparatus as claimed in claim 1 , wherein each of the pixels includes a third transistor to supply an initialization voltage to the gate electrode of the first transistor, in order to initialize a characteristic of the first transistor based on a second scan signal having the gate-on voltage level during an initialization period.

4 . The display apparatus as claimed in claim 3 , wherein the second scan signal has the gate-on voltage level during a unit scan period immediately before the data writing period.

5 . The display apparatus as claimed in claim 3 , wherein the second scan signal has the gate-on voltage level during one or more unit scan periods before the data writing period.

6 . The display apparatus as claimed in claim 5 , wherein the first scan signal has the gate-on voltage level during a unit scan period before a unit scan period in which the second scan signal has the gate-on voltage level.

7 . The display apparatus as claimed in claim 3 , wherein:
the second scan signal has the gate-on voltage level during two or more unit scan periods before the data writing period, and the first scan signal has the gate-on voltage level during a unit scan period between two or more unit scan periods in which the second scan signal has the gate-on voltage level.

8 . The display apparatus as claimed in claim 3 , wherein:
the second scan signal has the gate-on voltage level during two or more unit scan periods before the data writing period, and a period between two or more unit scan periods in which the second scan signal has the gate-on voltage level is multiples of a unit scan period.

9 . The display apparatus as claimed in claim 3 , wherein:
the first scan signal has the gate-on voltage level during one or more unit scan periods before the data writing period, and the second scan signal has the gate-on voltage level during a unit scan period immediately before a unit scan period in which the first scan signal has the gate-on voltage level before the data writing period and/or a unit scan period immediately after a unit scan period in which the first scan signal has the gate-on voltage level.

10 . The display apparatus as claimed in claim 3 , wherein the initialization period is prior to the data writing period.

11 . The display apparatus as claimed in claim 1 , wherein each of the pixels includes a fourth transistor that diode-connects the first transistor based on the first scan signal having the gate-on voltage level during the data writing period.

12 . The display apparatus as claimed in claim 1 , wherein each of the pixels includes a fifth transistor to supply the initialization voltage to an anode electrode of the OLED based on a third scan signal.

13 . The display apparatus as claimed in claim 12 , wherein the third scan signal is equal to the first scan signal.

14 . The display apparatus as claimed in claim 1 , wherein each of the pixels includes sixth transistor to turn on based on a emission control signal, the sixth transistor connected to the second capacitor in parallel.

15 . The display apparatus as claimed in claim 1 , wherein each of the pixels includes a seventh transistor to connect the first transistor to the OLED based on an emission control signal.

16 . The display apparatus as claimed in claim 1 , further comprising:
a scan driver to transfer scan signals through the scan lines; a data driver to transfer data signals through the data lines; and an emission driver to transfer emission control signals through the emission control lines.

17 . A method for driving a display apparatus, the method comprising:
initializing a characteristic of the driving transistor; compensating for a threshold voltage of the driving transistor and transferring a data signal to the driving transistor; and emitting light from the OLED based on driving current corresponding to the data signal, wherein initializing the characteristic includes: transferring a first scan signal having a gate-on voltage level at least one time; and transferring a second scan signal having the gate-on voltage level at least one time.

18 . The method as claimed in claim 17 , wherein the first scan signal has the gate-on voltage level during a unit scan period before a unit scan period in which the second scan signal has the gate-on voltage level.

19 . The method as claimed in claim 17 , wherein the first scan signal has the gate-on voltage level during a unit scan period between two or more unit scan periods in which the second scan signal has the gate-on voltage level.

20 . The method as claimed in claim 17 , wherein:
the second scan signal has the gate-on voltage level during two or more unit scan periods, and a period between two or more unit scan periods in which the second scan signal has the gate-on voltage level is multiples of a unit scan period.

Assignees

• Samsung Display Co Ltd

Inventors

• Kang Hyungryul
• Kim Cheolmin

Classifications

• G09G2320/045

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

• G09G2310/0216

  Interleaved control phases for different scan lines in the same sub-field, e.g. initialization, addressing and sustaining in plasma displays that are not simultaneous for all scan lines · CPC title

• G09G2300/0876

  Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes · CPC title

• G09G2300/0871

  with level shifting · CPC title

• G09G2300/043

  Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver · CPC title