High-performance emissive display device for computers, information appliances, and entertainment systems

• US 20050285822A1
• Filed: 12/17/2004
• Published: 12/29/2005
• Est. Priority Date: 06/29/2004
• Status: Abandoned Application

• Current Assignee: Leadin Technology Co., Ltd.
• Original Assignee: Leadin Technology Co., Ltd.
• Inventors: Reddy, Damoder, Naugler, Walter Edward
• Application Number:
  US11/016,357
• Publication Number:
  US 20050285822A1
• Time in Patent Office: Days
• US Class Current: 345/76
• CPC Class Codes: G06F 2203/04109 FTIR in optical digitiser, i.e. touch detection by frustrating the total internal reflection within an optical waveguide due to changes of optical properties or deformation at the touch location
• CPC Class Codes: G06F 3/03542 Light pens for emitting or receiving light
• CPC Class Codes: G06F 3/0386 for light pen
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2310/066 Waveforms comprising a gently increasing or decreasing portion, e.g. ramp
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/0295 by monitoring each display pixel
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2360/142 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 2360/147 the originated light output being determined for each pixel
• CPC Class Codes: G09G 2360/148 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3275 Details of drivers for data electrodes
• CPC Class Codes: G09G 3/3291 : in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
• CPC Class Codes: H01L 27/1446 : in a repetitive configuration
• CPC Class Codes: H10K 2102/3026 : Top emission
• CPC Class Codes: H10K 59/126 : Shielding, e.g. light-blocking means over the TFTs
• CPC Class Codes: H10K 59/13 : comprising photosensors that control luminance
• CPC Class Codes: H10K 59/40 : OLEDs integrated with touch screens
• CPC Class Codes: H10K 59/60 : OLEDs integrated with inorganic light-sensitive elements, e.g. with inorganic solar cells or inorganic photodiodes
• CPC Class Codes: H10K 65/00 : Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element and at least one organic radiation-sensitive element, e.g. organic opto-couplers organic image sensors integrated with organic light-emitting devices H10K39/34; OLED displays integrated with photosensors H10K59/13

Abstract

Information appliance device and method for operating display associated with information appliance. Information appliance includes display device comprising plurality of active-matrix pixels arranged as two-dimensional array, each pixel including a photon emitter, emitter drive circuit receiving input image data for each pixel and generating pixel drive signal intended to produce a corresponding target pixel luminance during frame time, and emitter luminance sensor and measurement circuit that measures electrical parameter indicative of actual luminance of each pixel over portion of measurement display frame time; and display logic coupled to display and receiving pixel luminance related electrical parameter for each pixel and generating correction for application subsequent time period to input image data for each pixel based on difference between target pixel luminance and measured pixel luminance. Photon emitter may be OLED, electroluminescent, plasma or other emissive device in flat panel display. Information appliance may include computer monitor, TV, or portable device.

Claims

1. An information appliance comprising:

a flat panel display device comprising a plurality of active-matrix pixels arranged as a two-dimensional array, each pixel including an organic light emitting diode emitter, an emitter drive circuit receiving an input image data for each pixel and generating a pixel drive signal intended to produce a corresponding target pixel luminance during a frame time, and an emitter luminance sensor and measurement circuit that measures an electrical parameter indicative of the actual luminance of each pixel over a portion of a measurement display frame time; and

a display logic subsystem coupled to the flat panel display device and receiving the pixel luminance related electrical parameter for each pixel and generating a correction to be applied during a frame time subsequent to the measurement display frame time to the input image data for each pixel based on a difference between the target pixel luminance and the measured pixel luminance.

2. An information appliance as in claim 1, wherein the information appliance farther comprises at least one of:

a television monitor, a television receiver, a CD player, a DVD player, a computer monitor, a computer system, an automobile instrument panel, an aircraft instrument display panel, a video game, a cellular telephone, a personal data assistant (PDA), a telephone, a graphics system, a printing system, a scoreboard system, an entertainment system, a domestic or home appliance, a copy machine, a global positioning system navigation display, a dynamic art display device, and combinations thereof.

3. An information appliance as in claim 1, wherein each of the pixels comprises:

a light emitting device;

a drive circuit generating a current to drive the light emitting device to a predetermined luminance corresponding to an image voltage and applying the drive current to the light emitting device during a frame time;

a photo sensor that exhibits a change in electrical characteristic in response to a change in incident photon flux disposed near the light emitting device to intercept a measurable photon flux when the light emitting device is in an emitting state;

a charge storage device coupled with the sensor for accumulating or releasing charges and exhibiting a capacitance charge and voltage proportional to the charge at a time;

a control circuit controlling the charging and discharging of the charge storage device in response to changes in the electrical characteristics of the sensor during at least a portion of the frame time;

a voltage reading circuit for measuring the voltage across the charge storage device at the end of the at least a portion of a display frame time, the measured voltage being an indication of a measured luminance of the pixel during the portion of the frame time; and

a feedback control circuit for applying a correction to the pixel drive circuit during a subsequent frame time so that the measured luminance during the subsequent frame time will have a smaller variation from the reference luminance than during the frame time of the measurement.

16. An information appliance as in claim 3, wherein the light emitting device comprises an organic light emitting diode (OLED).

17. An information appliance as in claim 16, wherein the organic light emitting diode (OLED) is a small molecule OLED.

18. An information appliance as in claim 16, wherein the organic light emitting diode (OLED) is a polymer OLED (PLED).

19. An information appliance as in claim 16, wherein the organic light emitting diode (OLED) is a phosphorescent OLED (PHOLED).

20. An information appliance as in claim 16, wherein the organic light emitting diode (OLED) is constructed from any organic material in any combination of single or multiple layers of organic materials and electrodes.

21. An information appliance as in claim 16, wherein the organic light emitting diode (OLED) is a active matrix OLED.

22. An information appliance as in claim 3, wherein the light emitting device is an electroluminescent device.

23. An information appliance as in claim 3, wherein the light emitting device is a plasma emission device.

24. An information appliance as in claim 3, wherein the light emitting device is any controllable photon emissive device.

25. An information appliance as in claim 3, wherein the display device is constructed from amorphous silicon.

26. An information appliance as in claim 3, wherein the display device is constructed from poly silicon.

27. An information appliance as in claim 3, wherein the display device is constructed from cadmium selenide.

28. An information appliance as in claim 3, wherein the display device is constructed from any type of semiconductor material.

4. A method of operating a display device of the type having a plurality of active-matrix pixels arranged as a two-dimensional array, each pixel including a light emitting diode emitter and an emitter drive circuit receiving an input image data for each pixel and generating a pixel drive signal intended to produce a corresponding target pixel luminance during each frame display time;

the method characterized in that the method further includes;

measuring a voltage indicative of a photon flux intercepted by an emitter luminance measurement circuit during at least a portion of a first frame time; and

comparing the measured voltage corresponding to a measured luminance with a reference voltage corresponding to a reference luminance to generate a difference signal and using the difference signal to modify the input image data for each pixel during a subsequent frame display time so that the pixel luminance during the subsequent display frame time will more nearly equal the reference luminance.

5. A method as in claim 4, wherein the portion of the frame time comprises the row address time or less.

6. A method as in claim 4, wherein the portion of the frame display time comprises substantially the entire frame time.

7. A method as in claim 4, wherein the portion of the frame display time comprises at least 50 percent of the entire frame time.

8. A method as in claim 4, wherein the portion of the frame display time comprises at least between 90 percent and 100 percent of the entire frame time.

9. A method as in claim 4, wherein the portion of the frame display time comprises at least 1 millisecond.

10. A method as in claim 4, wherein the subsequent frame display time is a frame display immediately following the first display time.

11. A method as in claim 4, wherein the portion of the frame time is equal to or less than the row address time.

12. A method as in claim 4, wherein the subsequent frame display time is a frame display a predetermined number of display frames following the first frame display time for which the luminance measurement was made, and wherein the predetermined number of frames is any integer number of frames N.

13. A method as in claim 4, wherein the subsequent frame display time is a frame display at the occurrence of a predetermined or dynamically determined event.

14. A method as in claim 13, wherein the occurrence of a predetermined or dynamically determined event is selected from a display initialization event, a display power-on event, a display time of operation event, a user initiated event, any automatic policy or rule based event, and combinations of these.

15. A method of operating a display device as in claim 4, wherein the display device comprises a flat panel display device that is a component in an overall system and wherein the system is selected from the set of systems consisting of:

any information appliance, a television monitor, a CD player, a DVD player, a computer monitor, a computer system, an automobile instrument panel, an aircraft instrument display panel, a video game, a cellular telephone, a personal data assistant (PDA), a telephone, a graphics system, a printing system, a scoreboard system, an entertainment system, a domestic or home appliance, a copy machine, a global positioning system navigation display, a dynamic art display device, and combinations thereof.