OLED DISPLAY SYSTEM AND METHOD

• US 20150161935A1
• Filed: 12/05/2014
• Published: 06/11/2015
• 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`
• Granted Patent: US 9,741,282 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 the pixel content domain with known color points and brightness levels,

for each set of three sub-pixels of different colors, determining the 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 from that sub-pixel.

2. The method of claim 1 in which each set of three sub-pixels of different colors is a set of 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 the pixel content domain with known color points and brightness levels,

determine, for each set of three sub-pixels of different colors, 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 the peak brightness needed from that sub-pixel.

4. The system of claim 3 in which each set of three sub-pixels of different colors is a set of 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 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,

selecting a set of share factors based on at least 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 share factor of the tri-color set with the highest efficiency, and decreasing the share factor of the tri-color set 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 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 a set of share factors based on at least a pixel operation point and display performance,

modify said brightness shares based on said 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 share factor of the tri-color set with the highest efficiency, and decrease the share factor of the tri-color set with the lowest efficiency, as the gray scale of the desired color point increases, and

decrease the share factor of the tri-color set with the highest efficiency, and increase the 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 the tri-color sets of three sub-pixels of different colors,

selecting the 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, and

selecting

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.

14. The OLED display 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,

each pixel including at least three sub-pixels having different colors and at least one white sub-pixel, 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.