OLED display system and method

• US 9,741,282 B2
• Filed: 12/05/2014
• Issued: 08/22/2017
• Est. Priority Date: 12/06/2013
• Status: Active Grant

• Current Assignee: IGNIS Innovation Incorporated
• Original Assignee: IGNIS Innovation Incorporated
• Inventors: Giannikouris, Allyson, Soni, Jaimal, Zahirovic, Nino, Ngan, Ricky Yik Hei, Chaji, Gholamreza'
• Primary Examiner(s): Abdin, Shaheda
• Application Number:
  US14/561,404
• Publication Number:
  US 20150161935A1
• Time in Patent Office: 991 Days
• Field of Search: None
• 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 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2320/0238 Improving the black level
• 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 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• 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 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

A method and system control an OLED display to achieve desired color points and brightness levels in an array of pixels in which each pixel includes at least three sub-pixels having different colors and at least one white sub-pixel. The method and system select a plurality of reference points in the pixel content domain with known color points and brightness levels. For each set of three sub-pixels of different colors, the method and system determine the share of each sub-pixel to produce the color point and brightness level of each selected reference point, and select the maximum share determined for each sub-pixel as peak brightness needed from that sub-pixel.

Claims

1. A method of controlling an OLED display to achieve desired color points and brightness levels in an array of pixels in which each pixel includes at least three sub-pixels having different colors and at least one white sub-pixel, said method comprising

selecting a plurality of reference points in a pixel content domain with known color points and brightness levels,

identifying all possible tri-color sets of three sub-pixels from the at least three sub-pixels having different colors and the at least one white sub-pixel;

for each tri-color set of three sub-pixels, determining a share of each sub-pixel to produce the color point and brightness level of each selected reference point, and

selecting the maximum share determined for each sub-pixel as the peak brightness needed for that sub-pixel.

2. The method of claim 1 wherein the at least three sub-pixels having different colors of each pixel comprises red, green and blue sub-pixels.

3. A system for controlling an OLED display to achieve desired color points and brightness levels in an array of pixels in which each pixel includes at least three sub-pixels having different colors and at least one white sub-pixel, said system comprising

a processor configured to

select a plurality of reference points in a pixel content domain with known color points and brightness levels,

identify all possible tri-color sets of three sub-pixels from the at least three sub-pixels having different colors and the at least one white sub-pixel,

determine, for each tri-color set of three sub-pixels, a share of each sub-pixel to produce the color point and brightness level of each selected reference point, and

select the maximum share determined for each sub-pixel as the peak brightness needed for that sub-pixel.

4. The system of claim 3 wherein the at least three sub-pixels having different colors of each pixel comprises red, green and blue sub-pixels.

5. A method of controlling an OLED display to achieve desired color points and brightness levels in an array of pixels in which each pixel includes at least three sub-pixels having different colors and at least one white sub-pixel, said method comprising

identifying two or more tri-color sets of three sub-pixels of different colors that encircle a desired color point,

for each identified tri-color set of sub-pixels, determining the brightness shares of the sub-pixels in that tricolor set to produce the desired color point,

for each identified tri-color set of sub-pixels, selecting a set of share factors based on at least one of a pixel operation point and display performance,

modifying said brightness shares based on said share factors, and

mapping the modified brightness shares to pixel input data.

6. The method of claim 5 which includes

determining the efficiencies of the identified tri-color sets,

increasing the set share factor of one of the tri-color sets with the highest efficiency,

decreasing the set share factor of one of the tri-color sets with the lowest efficiency, as the gray scale of the desired color point increases, and

decreasing the share factor of the tri-color set with the highest efficiency, and increasing the share factor of the tri-color set with the lowest efficiency, as the gray scale of the desired color point decreases.

7. The method of claim 5 in which each tricolor set of sub-pixels of different colors is a set of red, green and blue sub-pixels.

8. A system for controlling an OLED display to achieve desired color points and brightness levels in an array of pixels in which each pixel includes at least three sub-pixels having different colors and at least one white sub-pixel, said system comprising

a processor configured to

identify two or more tri-color sets of three sub-pixels of different colors that encircle a desired color point,

determine, for each identified tri-color set of sub-pixels, the brightness shares of the sub-pixels in that tricolor set to produce the desired color point,

select, for each identified tri-color set of sub-pixels, a set share factor based on at least one of:

a pixel operation point and display performance,

modify said brightness shares based on said set share factors, and

map the modified brightness shares to pixel input data.

9. The system of claim 8 which said processor is configured to:

determine the efficiencies of the identified tri-color sets,

increase the set share factor of one of the tri-color sets with the highest efficiency, and decrease the set share factor of one of the tri-color sets with the lowest efficiency, as the gray scale of the desired color point increases, and

decrease the set share factor of the tri-color set with the highest efficiency, and increase the set share factor of the tri-color set with the lowest efficiency, as the gray scale of the desired color point decreases.

10. The system of claim 8 in which each tri-color set of sub-pixels of different colors is a set of red, green and blue sub-pixels.

11. A method of controlling an OLED display to achieve desired color points and brightness levels in an array of pixels in which each pixel includes at least three sub-pixels having different colors and at least one white sub-pixel, said method comprising

determining the color point of an input signal for a selected pixel,

identifying all tri-color sets of three sub-pixels of different colors,

selecting two or more tri-color sets that encircle said color point of said input signal,

for each selected tri-color set of sub-pixels, determining brightness shares of the three sub-pixels of that tri-color set to produce said color point of said input signal,

selecting, for each identified tri-color set of sub-pixels, a set share factor based on at least one of:

a pixel operation point and display performance,

modifying said brightness shares based on said set share factors, and

mapping the modified brightness shares to pixel input data.

12. The method of claim 11 in which each tri-color set of sub-pixels of different colors is a set of red, green and blue sub-pixels.

13. An OLED display comprising

an array of pixels in which each pixel includes at least three sub-pixels having different colors and at least one white sub-pixel for displaying desired color points and brightness levels,

said sub-pixels having operating conditions that vary with the gray level displayed by the sub-pixel,

said pixel having at least two sub-pixels for displaying the same color but having operating conditions that vary differently with the gray level being displayed, and

a controller for selecting one of the two sub-pixels displaying the same color, in response to a gray level input to that pixel.

14. The OLED display of claim 13 wherein the at least three sub-pixels having different colors of each pixel comprises red, green and blue sub-pixels.