Organic light emitting display apparatus

Patent metadata

Field	Value
Publication number	US-10551903-B2
Application number	US-201715817851-A
Country	US
Kind code	B2
Filing date	Nov 20, 2017
Priority date	Oct 29, 2014
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

A display apparatus includes a display panel and a power supply. The display panel displays an image at a first driving frequency in a normal mode and displays an image at a second driving frequency in a low power mode. The second driving frequency is lower than the first driving frequency. The power supply outputs a first initialization voltage at a first level to the display panel during an active period of the low power mode. The power supply outputs a second initialization voltage at a second level to the display panel during at least a portion of a blank period of the low power mode. The second level is higher than the first level.

First claim

What is claimed is:

1. A display apparatus, comprising:
a display panel to display a first image at a first driving frequency in a normal mode and to display a second image at a second driving frequency lower than the first driving frequency in a low power mode; and
a power supply to output a first initialization voltage at a first level to the display panel through an initialization voltage line during an active period of the low power mode and to output a second initialization voltage at a second level to the display panel through the initialization voltage line during at least a portion of a blank period of the low power mode, wherein the second level is higher than the first level, wherein
the display panel includes a plurality of pixels, each of the pixels including:
an organic light-emitting diode;
a first transistor to drive the organic light-emitting diode with a current corresponding to the first image and the second image; and
a second transistor including a first electrode connected to a gate electrode of the first transistor and a second electrode connected to the initialization voltage line, wherein the second transistor is to transfer the first initialization voltage and the second initialization voltage through the initialization voltage line to the gate electrode of the first transistor.

2. The display apparatus as claimed in claim 1 , wherein the power supply is to: output the first initialization voltage during a first period of the blank period of the low power mode, and output the second initialization voltage during a second period that is subsequent to the first period of the blank period.

3. The display apparatus as claimed in claim 2 , wherein a length of the first period is equal to a length of a blank period of the normal mode.

4. The display apparatus as claimed in claim 1 , wherein each of the pixels further includes: a capacitor connected between a first power voltage line and the gate electrode of the first transistor.

5. The display apparatus as claimed in claim 4 , wherein each of the pixels further includes: an auxiliary capacitor connected between the gate electrode of the first transistor and the second electrode of the second transistor.

6. The display apparatus as claimed in claim 5 , wherein the power supply is to: output the first initialization voltage during a first period of the blank period of the low power mode, and gradually increasingly output the second initialization voltage from the first level to the second level during a second period subsequent to the first period of the blank period.

7. The display apparatus as claimed in claim 1 , wherein the second initialization voltage is a value that is equal to a voltage of the gate electrode of the first transistor of each of the plurality of pixels or a value that is equal to an average of voltages of gate electrodes of a plurality of first transistors of the plurality of pixels.

8. The display apparatus as claimed in claim 1 , wherein: during the blank period of the low power mode, the first and second transistors are turned off.

9. The display apparatus of claim 1 , wherein the second initialization voltage is configured to change from the second level directly to the first level.

Assignees

• Samsung Display Co Ltd

Inventors

• An Taehyeong
• Park Suhyeong
• Yoon Soowan

Classifications

• G09G2310/0262

  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 · CPC title

• G09G3/3233

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

• G06F1/3265 Primary

  Power saving in display device · CPC title

• G09G2340/0435

  Change or adaptation of the frame rate of the video stream · CPC title

• G09G2300/0861

  with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes · CPC title