Organic light emitting display and method of driving the same

Patent metadata

Field	Value
Publication number	US-9437134-B2
Application number	US-77365810-A
Country	US
Kind code	B2
Filing date	May 4, 2010
Priority date	Oct 9, 2009
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

An organic light emitting display is capable of reducing power consumption. The organic light emitting display includes a scan driver for sequentially supplying scan signals to scan lines, a data driver for supplying data signals to data lines in synchronization with the scan signals, pixels located at crossing regions of the scan lines and the data lines, a timing controller for determining a normal driving mode for displaying a normal image and a standby driving mode displaying less information than the normal image, and a power source for supplying a first power and a second power to the pixels, wherein a voltage difference between the first power and the second power in the normal driving mode is a first voltage, and a voltage difference between the first power and the second power is a second voltage different from the first voltage.

First claim

What is claimed is:

1. An organic light emitting display, comprising:
a scan driver configured to sequentially supply scan signals to scan lines;
a data driver configured to supply data signals to data lines in synchronization with the scan signals;
a switch unit coupled directly to output terminals of the data driver and coupled directly to the data lines;
pixels located at crossing regions of the scan lines and the data lines, each of the pixels comprising a driving transistor;
a timing controller configured to determine a normal driving mode for displaying a normal image or a standby driving mode for displaying less information than the normal image; and
a power source configured to supply a first power and a second power to the pixels and a third power and a fourth power to the switch unit, wherein a voltage difference between the first power and the second power in the normal driving mode is a first voltage, and a voltage difference between the first power and the second power in the standby driving mode is a second voltage different from the first voltage,
wherein the data driver is configured to supply the data signals corresponding to a first plurality of gray levels having a first bit resolution (2 j ) in the normal driving mode and supply the data signals corresponding to a second plurality of gray levels having a second bit resolution (2 k ) in the standby driving mode,
wherein, in the standby driving mode, the switch unit is configured to transmit, selectively, the voltages of the third power and the fourth power to the data lines in accordance with the data signals corresponding to the second plurality of gray levels, and
wherein j is greater than k.

2. The organic light emitting display as claimed in claim 1 , wherein the first voltage is larger than the second voltage.

3. The organic light emitting display as claimed in claim 1 , wherein the data driver is configured to supply the data signals corresponding to various gray levels in the normal driving mode and supply the data signals determining emission or non-emission of the pixels in the standby driving mode.

4. The organic light emitting display as claimed in claim 1 , wherein each of the pixels comprises:
an organic light emitting diode (OLED) having a cathode electrode for receiving the second power; and
a pixel circuit receiving the first power and coupled to an anode electrode of the OLED and to control the amount of current supplied to the OLED.

5. The organic light emitting display as claimed in claim 4 , wherein the pixel circuit comprises the driving transistor, and wherein the power source is configured to set the voltages of the first power and the second power so that the driving transistor is driven in a saturation region in the normal driving mode.

6. The organic light emitting display as claimed in claim 4 , wherein the pixel circuit comprises the driving transistor, and wherein the power source is configured to set the voltages of the first power and the second power so that the driving transistor is driven in a linear region in the standby driving mode.

7. The organic light emitting display as claimed in claim 6 , wherein the data driver is configured to supply the data signals for turning the driving transistor on and off in the standby driving mode.

8. The organic light emitting display as claimed in claim 4 , wherein the power source is further configured to supply the third power at the same voltage value in the standby driving mode and in the normal driving mode and the fourth power a different voltage in the standby driving mode than in the normal driving mode.

9. The organic light emitting display as claimed in claim 8 , wherein the pixel circuit comprises the driving transistor, and
wherein the third power has a voltage that completely turns on the driving transistor.

10. The organic light emitting display as claimed in claim 9 , wherein the third power has a voltage less than or equal to the voltage of the lowermost data signal output from the data driver.

11. The organic light emitting display as claimed in claim 8 , wherein each of the pixel circuits comprises the driving transistor, and
wherein the fourth power is configured to have a voltage less than or equal to the voltage of the lowermost data signal supplied from the data driver in the normal driving mode and is configured to have a voltage that completely turns off the driving transistors in the standby driving mode.

12. An organic light emitting display, comprising:
a scan driver configured to sequentially supply scan signals to scan lines;
a data driver configured to supply data signals to data lines in synchronization with the scan signals;
pixels located at crossing regions of the scan lines and the data lines;
a timing controller configured to determine a normal driving mode for displaying a normal image or a standby driving mode for displaying less information than the normal image; and
a power source configured to supply a first power and a second power to the pixels, wherein a voltage difference between the first power and the second power in the normal driving mode is a first voltage, and a voltage difference between the first power and the second power in the standby driving mode is a second voltage different from the first voltage,
wherein the data driver is configured to supply the data signals corresponding to a first plurality of gray levels in the normal driving mode and supply the data signals determining a second plurality of gray levels in the standby driving mode,
wherein the number of gray levels in second plurality of gray levels is fewer than the number of gray levels in the first plurality of gray levels,
wherein each of the pixels comprises:
an organic light emitting diode (OLED) having a cathode electrode for receiving the second power; and
a pixel circuit receiving the first power and coupled to an anode electrode of the OLED and to control the amount of current supplied to the OLED,

wherein the power source is further configured to supply a third power that maintains the same voltage value in the standby driving mode as in the normal driving mode and a fourth power whose voltage in the standby driving mode is different from its voltage in the normal driving mode, and
wherein the organic light emitting display further comprises a switch unit coupled directly to output terminals of the data driver and coupled directly to the data lines, configured to transmit the data signals supplied from the output terminals of the data driver to the data lines in the normal driving mode period, and to transmit, selectively, the voltages of the third power and the fourth power to the data lines in accordance with the data signals supplied from the output terminals of the data driver in the standby driving mode period.

13. The organic light emitting display as claimed in claim 12 , wherein the switch unit comprises:
a first transistor located between an output terminal of the output terminals and a data line of the data lines, wherein the timing controller is configured to supply a first control signal to continuously turn on the first transistor in the normal driving mode and to turn off the first transistor in the standby driving mode;
a second transistor for receiving the fourth power and coupled to the data line of the data lines, wherein the data driver is configured to turn on and turn off the second transistor in the standby driving mode; and
a third transistor for receiving the third power and coupled to the data line of the data lines, wherein the timing controller is configured to supply a second control signal to repeatedly turn on and turn off the third tr

Assignees

• Choi Sang-Moo
• Kim Do-Youb
• Ahn Soon-Sung
• Jang Brent
• Samsung Display Co Ltd

Inventors

• Choi Sang-Moo
• Kim Do-Youb
• Ahn Soon-Sung
• Jang Brent

Classifications

• G09G2320/0626

  for control of overall brightness · CPC title

• G09G3/3233 Primary

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

• G09G2330/022

  in absence of operation, e.g. no data being entered during a predetermined time · CPC title

• G09G3/20

  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} · CPC title

• G09G3/30 Primary

  using electroluminescent panels · CPC title