Method for improving display lifetime

• US 8,237,642 B2
• Filed: 07/14/2008
• Issued: 08/07/2012
• Est. Priority Date: 07/14/2008
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Inventors: Miller, Michael E.
• Primary Examiner(s): CERULLO, LILIANA P
• Application Number:
  US12/172,440
• Publication Number:
  US 20100007587A1
• Time in Patent Office: 1,485 Days
• Field of Search: 345 76- 77, 345 82- 83, 345690-699, 345211-214, 345/102, 315/169.3, 315/151, 382270-274, 348671-675
• US Class Current: 345/83
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 3/3216 using a passive matrix
• CPC Class Codes: G09G 3/3225 using an active matrix

Abstract

A method for adjusting the intensity values of colored pixels wherein each pixel has a first subpixel, a second subpixel, and a third subpixel, wherein each of the subpixels emits light of a different color and the lifetime of the first subpixel is lower than the lifetimes of the other colored subpixels, comprising: for each pixel, receiving intensity values corresponding to the intensity of each color subpixel in each pixel; and lowering the intensity value of the first subpixel in each pixel and still providing an acceptable pixel color to an observer.

Claims

1. A method for adjusting the intensity values of colored pixels wherein each pixel has a first subpixel, a second subpixel, and a third subpixel, wherein each of the subpixels emits light of a different color and the lifetime of the first subpixel is lower than the lifetimes of the other colored subpixels, comprising:

a. for each pixel, receiving intensity values corresponding to the intensity of each color subpixel in each pixel; and

b. adjusting by lowering the intensity value of the first subpixel in each pixel when producing saturated colors between green and red, with no-adjustment of the intensity of the first subpixel when producing neutral colors,

wherein

the subpixel colors are red, green, and blue,

the first subpixel is the blue subpixel,

the colored pixels are part of an electroluminescent display, and

the adjustment is based upon the blue, cyan or magenta color saturation of the pixel, where the color saturation is calculated as a difference between the intensity of the first subpixel and a function of the second subpixel intensity and the third subpixel intensity.

2. The method according to claim 1 wherein the intensity of the first subpixel is adjusted to be in a range of no adjustment to one-half the received intensity value.

3. The method of claim 2 wherein the adjustment is continuous within the range and depends upon intensity value of the second and third subpixels.

4. The method of claim 1 wherein the intensity of the first subpixel is adjusted to be in a range of no adjustment to one-quarter the received intensity value.

5. The method of claim 4 wherein the adjustment is continuous within the range and depends upon intensity value of the second and third subpixels.

6. The method of claim 1 wherein the color saturation is calculated as a function of the intensity value corresponding to the first subpixel and the minimum of the remaining intensity values.

7. The method of claim 1 wherein the color saturation is calculated as a function of the intensity value corresponding to the first subpixel and a weighted mean of the remaining intensity values.

8. The method of claim 1 wherein the electroluminescent display is an Organic Light-Emitting Diode (OLED) display.

9. The method of claim 1 wherein the electroluminescent display is a Coatable Inorganic Light-Emitting Diode (CILED) display.