OLED display with reduced power consumption

• US 8,466,856 B2
• Filed: 02/22/2011
• Issued: 06/18/2013
• Est. Priority Date: 02/22/2011
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Inventors: Hamer, John W., Miller, Michael E., Ludwicki, John
• Primary Examiner(s): Beck, Alexander S
• Assistant Examiner(s): STEINBERG, JEFFREY S
• Application Number:
  US13/032,074
• Publication Number:
  US 20120212515A1
• Time in Patent Office: 847 Days
• Field of Search: 345 76- 83, 345/204, 345/690, 315/169.3
• US Class Current: 345/76
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: G09G 2300/0443 with several sub-pixels for the same colour in a pixel, not specifically used to display gradations G09G3/364 takes precedence
• 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 2320/0666 for control of colour parameters, e.g. colour temperature
• 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 3/30 using electroluminescent panels
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: G09G 3/3216 using a passive matrix
• CPC Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127

Abstract

Methods for displaying an image on a color display having a target display white point luminance and chromaticity, and including three gamut-defining emitters defining a display gamut and two or more additional emitters which emit light within the display gamut; the method including receiving a three-component input image signal; transforming the three-component input image signal to a five-or-more component drive signal; and providing the drive signal to display an image corresponding to the input image signal. One method provides a reproduced luminance value higher than the sum of the respective luminance values of the three components of the input signal when reproduced with the gamut-defining emitters. Another method provides reduced power in an OLED display including a white-emitting layer with three color filters for gamut-defining emitters and two or more additional color filters for three additional within-gamut emitters.

Claims

1. A method for displaying an image on a color display, comprising:

a) providing the color display having a selected target display white point luminance and chromaticity, the color display including three gamut-defining emitters defining a display gamut and two or more additional emitters which emit light at respective different chromaticity coordinates within the display gamut, wherein each emitter has a corresponding peak luminance and chromaticity coordinate, the gamut-defining emitters produce a gamut-defining peak luminance at the target display white point chromaticity, and the gamut-defining peak luminance is less than the display white point luminance;

b) receiving a three-component input image signal corresponding to a chromaticity within a supplemental gamut defined by a combination of three emitters that includes at least one of the additional emitters;

c) transforming the three-component input image signal to a five-component drive signal such that when the transformed image signal is reproduced on the display, its reproduced luminance value is higher than the reproduced luminance value of a display with only gamut-defining emitters; and

d) providing the five-component drive signal to respective gamut-defining and additional emitters to display an image corresponding to the input image signal.

2. The method of claim 1, wherein step c further includes selecting the white point luminance based on the three-component input image signal.

3. A method for displaying an image on an OLED display with reduced power consumption, comprising:

a. an OLED display including;

i) a white-light emitting layer;

ii) three color filters for transmitting light corresponding to red, green and blue gamut-defining emitters, each emitter having respective chromaticity coordinates, wherein the chromaticity coordinates of the gamut-defining emitters together define a display gamut; and

iii) two or more additional color filters for filtering light corresponding to three additional within-gamut emitters having chromaticity coordinates within the display gamut, wherein the three additional emitters form an additional color gamut, each emitter has a corresponding radiant efficiency, and wherein the radiant efficiency of each additional emitter is greater than the radiant efficiency of each of the gamut-defining emitters;

b. receiving a three-component input image signal;

c. transforming the three-component input image signal to a six-component drive signal; and

d. providing the six components of the drive signal to respective emitters of the OLED display to display an image corresponding to the input image signal whereby there is a reduction in power.

4. The method of claim 3, wherein step a) includes providing only two additional color filters corresponding to two of the additional emitters, and wherein the third additional emitter is unfiltered.

5. The method of claim 4, wherein the third additional emitter has a correlated color temperature that is equal to or less than 6500K, the OLED display includes only two additional color filters, and the two additional color filters are a cyan and a magenta color filter.

6. The method of claim 4, wherein the third additional emitter has a correlated color temperature that is equal to or greater than 9000K, the OLED display includes only two additional color filters, and the two additional color filters are a yellow and a magenta color filter.

7. The method of claim 3, wherein step a) includes providing exactly three additional color filters corresponding to the respective additional emitters.

8. The method of claim 7, wherein the three color filters corresponding to the additional emitters include cyan, magenta and yellow.

9. The method of claim 3, wherein the three additional emitters respectively emit cyan, magenta and yellow light.

10. The method of claim 3, wherein the display additionally has a white point with defined chromaticity coordinates and wherein the chromaticity coordinates of the additional emitters form a triangle that includes the chromaticity coordinates of the defined white point.

11. The method of claim 3, wherein step c) includes transforming the three-component input signals such that input signals corresponding to chromaticity coordinates within the additional gamut are reproduced using the additional emitters.

12. The method of claim 11, wherein step c) includes transforming the three-component input signals such that input signals corresponding to chromaticity coordinates within the additional gamut are reproduced using only the additional emitters.

13. The method of claim 3, wherein step c) includes transforming the three-component input signals such that input signals corresponding to chromaticity coordinates within the display gamut but outside the additional gamut are reproduced using combinations of the gamut-defining and additional emitters.

14. The method of claim 13, wherein step c) includes transforming the three-component input signals such that input signals corresponding to chromaticity coordinates inside the display gamut but outside the additional gamut are reproduced using combinations of one of the gamut-defining and two of the additional emitters.

15. The method of claim 3, further comprising forming one or more of the color filters for the gamut-defining emitters from combinations of the color filters of the additional emitters.

16. The method of claim 3, wherein the display gamut and the additional color gamut have respective areas in the 1931 CIE chromaticity color diagram and the area of the additional color gamut is equal to or less than half the area of the display gamut.

17. The method of claim 3, further including providing power to the emitters, wherein the power is provided with a first voltage magnitude to the gamut-defining emitters and with a second voltage magnitude to the additional emitters, and the second voltage magnitude is different than the first voltage magnitude.

18. The method of claim 3, wherein step c) includes transforming at least one of the three-component input signals to a six-component drive signal such that the corresponding color is reproduced on a the display with a luminance that is higher than can be reproduced at the same chromaticity coordinates by a combination of the gamut-defining emitters alone.

19. The method of claim 3, wherein the OLED display has a white point luminance, and wherein step c) includes selecting the white point luminance of the display based on the three-component input image signals.

20. The method of claim 3, wherein the white-emitting layer includes at least three different light-emitting materials, each light-emitting material having a spectral emission that includes a peak intensity at a unique peak spectral frequency, and wherein the two or more additional color filters each have respective spectral transmission functions such that the spectral transmission of the two or more color filters is 50% or greater at spectral frequencies corresponding to the peak intensities of at least two of the light-emitting materials.