OLED display with improved power performance

• US 7,586,497 B2
• Filed: 12/20/2005
• Issued: 09/08/2009
• Est. Priority Date: 12/20/2005
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Eastman Kodak Company
• Inventors: Boroson, Michael L., Murdoch, Michael J., Ludwicki, John E.
• Primary Examiner(s): TRAN, MY CHAU T
• Application Number:
  US11/312,872
• Publication Number:
  US 20070139437A1
• Time in Patent Office: 1,358 Days
• Field of Search: 345/55, 345/76, 345/82, 345/83, 345/84, 345/87, 345/88, 345/90, 345/92, 345/204, 345/690, 345/581, 345/589, 345/590, 345/591, 345/593, 345/596, 345/597
• US Class Current: 345/590
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• 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 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 3/3225 using an active matrix
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/351 comprising more than three subpixels, e.g. red-green-blue-white [RGBW]

Abstract

An OLED display for producing a full color image, comprising a plurality of at least four different colored pixels including three different colored addressable gamut-defining pixels and a fourth addressable within-gamut pixel, each pixel having an organic light-emitting diode with first and second electrodes and one or more organic light-emitting layers provided between the electrodes; the OLED display having a selected display white point, display peak luminance, gamut-defining pixel peak luminances and within-gamut pixel peak luminance; and drive circuitry for regulating luminance of the organic light-emitting diode of each of the colored pixels wherein the sum of the gamut-defining pixel peak luminances is less than the display peak luminance.

Claims

1. A method for operating an OLED display for producing a full color image at reduced power, comprising:

a) providing a plurality of at least four different colored pixels including three different colored addressable gamut-defining pixels and a fourth addressable within-gamut pixel, each pixel having an organic light-emitting diode with first and second electrodes and one or more organic light-emitting layers provided between the electrodes;

b) selecting a display white point, display peak luminance, gamut-defining pixel peak luminances and within-gamut pixel peak luminance; and

c) regulating luminance of the organic light-emitting diode of each of the colored pixels wherein the sum of the gamut-defining pixel peak luminances is less than the display peak luminance.

2. The method of claim 1 wherein luminance regulation is provided by mapping a range of input signals, each corresponding to a gamut-defining pixel luminance, into a narrower range of gamut-defining pixel luminances.

3. The method of claim 1 wherein luminance regulation includes converting gamut-defining pixel signals to modified gamut-defining pixel signals and within-gamut pixel signals.

4. The method of claim 3 wherein the luminance regulation further includes scaling.

5. The method of claim 3 wherein the luminance regulation further includes clipping or non-linear mapping.

6. The method of claim 3 wherein the luminance regulation further includes a matrix operation.

7. The method of claim 1 wherein luminance regulation includes providing drive circuitry for applying a maximum voltage across the first and second electrodes of the at least four different colored pixels for regulating current through the organic light-emitting diode of each of the colored pixels wherein the maximum voltage is selected in accordance with the regulated luminance.

8. The method of claim 1 wherein the display peak luminance is provided by the within-gamut pixel or the within-gamut pixel and one or more of the gamut-defining pixels.

9. The method of claim 1 wherein the three different colored addressable gamut-defining pixels respectively produce red, green, and blue light and the fourth addressable within-gamut pixel produces white light.