Method of driving organic light emitting display

• US 7,839,361 B2
• Filed: 12/05/2005
• Issued: 11/23/2010
• Est. Priority Date: 04/29/2005
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Mobile Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Lee, Jae-Sung
• Primary Examiner(s): Eisen; Alexander
• Assistant Examiner(s): LAM, NELSON C
• Application Number:
  US11/294,706
• Publication Number:
  US 20060244691A1
• Time in Patent Office: 1,814 Days
• Field of Search: 345 76- 83, 315/169.3
• US Class Current: 345/76
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0861 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 Class Codes: G09G 2330/022 in absence of operation, e.g. no data being entered during a predetermined time
• CPC Class Codes: G09G 2340/0428 Gradation resolution change
• CPC Class Codes: G09G 3/2014 by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

A method of driving an organic light emitting display is provided in which, during a standby mode, a display operation is performed using only eight colors. In the alternative, the luminance of a plurality of pixels is reduced by adjusting a duty ratio of the emission control signals. By reducing the luminance, power consumption and image sticking are reduced, and the life span of the pixels is increased.

Claims

1. A method of driving an organic light emitting display, the organic light emitting display having a plurality of data lines for transmitting data signals, a plurality of scan lines for transmitting scan signals, a plurality of emission control lines for transmitting emission control signals, and a plurality of pixels, the method comprising:

receiving the data signals that enable the plurality of pixels to operate in a normal mode;

shifting an initial emission control signal to generate a plurality of shift register signals;

generating the emission control signals by performing logical AND operation on consecutive ones of the shift register signals;

determining whether or not the plurality of pixels is receiving an operation signal within a first reference time;

switching to a standby mode if the operation signal is not received within the first reference time; and

after switching to the standby mode,

determining whether or not the plurality of pixels receives the operation signal within a second reference time; and

turning off the plurality of pixels if the plurality of pixels does not receive the operation signal within the second reference time,

wherein during the normal mode a display operation by the plurality of pixels is performed in full color, and during the standby mode, a duty ratio of the emission control signals is adjusted to reduce pixel luminance.

2. The method of claim 1, wherein during the standby mode the duty ratio of the emission control signals increases such that the plurality of pixels has a reduced luminance compared to their luminance during the normal mode.

3. The method of claim 1, wherein if the plurality of pixels receives the operation signal within the first reference time, the plurality of pixels returns to the normal mode.

4. The method of claim 1, wherein if the plurality of pixels receives the operation signal within the second reference time, the plurality of pixels returns to the normal mode.

7. The method of claim 1, wherein during the standby mode, the display operation is performed in restricted colors.

8. The method of claim 7, wherein, the display operation during the standby mode is performed in eight colors.

9. The method of claim 8, wherein the eight colors include black, red, green, blue, a mixed color of red and green, a mixed color of green and blue, a mixed color of red and blue, and white.

5. A method of driving an organic light emitting display having a plurality of data lines for transmitting data signals, a plurality of scan lines for transmitting scan signals, a plurality of emission control lines for transmitting emission control signals, and a plurality of pixels, the method comprising:

shifting an initial emission control signal to generate a plurality of shift register signals; and

generating the emission control signals by performing logical AND operation on consecutive ones of the shift register signals;

receiving the data signals such that the plurality of pixels performs a display operation in a normal mode;

determining whether or not the plurality of pixels receives an operation signal within a first reference time;

switching to a standby mode if the operation signal is not received within the first reference time;

determining whether or not the plurality of pixels receives the operation signal within a second reference time; and

turning off the plurality of pixels when the plurality of pixels does not receive the operation signal within the second reference time,

wherein during the standby mode, a duty ratio of the emission control signals is adjusted to reduce pixel luminance.

6. The method of claim 5, wherein during the standby mode, the plurality of pixels performs the display operation in a restricted group consisting of eight colors.