OLED display with aspect ratio compensation

• US 20060087588A1
• Filed: 10/22/2004
• Published: 04/27/2006
• Est. Priority Date: 10/22/2004
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Eastman Kodak Company
• Inventors: Cok, Ronald S.
• Granted Patent: US 7,400,345 B2
• Time in Patent Office: Days
• US Class Current: 348/556
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• 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 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2340/0442 Handling or displaying different aspect ratios, or changing the aspect ratio
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/3216 using a passive matrix
• CPC Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: H04N 7/0122 the input and the output signals having different aspect ratios

Abstract

A method for uniformly aging an OLED display device, the OLED display device including a display screen with a screen aspect ratio, the method comprising: receiving a first external video signal having a first signal aspect ratio different from the screen aspect ratio; illuminating a primary region of the OLED display in response to the first external video signal, whereby a secondary region of the OLED display is not illuminated in response to the first external video signal; receiving a second external video signal having a second signal aspect ratio different from the first external video signal aspect ratio, wherein the display area corresponding to the second signal aspect ratio includes at least a portion of each of the primary and of the secondary regions of the OLED display; generating a regional correction value corresponding to the primary and secondary regions of the OLED display; employing the regional correction value to correct the second external video signal to compensate for differential aging in the included portions of the primary and secondary regions of the OLED display resulting from differential illumination of the primary and secondary regions of the OLED display in response to the first external video signal; and illuminating the OLED display in response to the corrected second external video signal.

Claims

1. A method for uniformly aging an OLED display device, the OLED display device including a display screen with a screen aspect ratio, the method comprising:

receiving a first external video signal having a first signal aspect ratio different from the screen aspect ratio;

illuminating a primary region of the OLED display in response to the first external video signal, whereby a secondary region of the OLED display is not illuminated in response to the first external video signal;

receiving a second external video signal having a second signal aspect ratio different from the first external video signal aspect ratio, wherein the display area corresponding to the second signal aspect ratio includes at least a portion of each of the primary and of the secondary regions of the OLED display;

generating a regional correction value corresponding to the primary and secondary regions of the OLED display;

employing the regional correction value to correct the second external video signal to compensate for differential aging in the included portions of the primary and secondary regions of the OLED display resulting from differential illumination of the primary and secondary regions of the OLED display in response to the first external video signal; and

illuminating the OLED display in response to the corrected second external video signal.

2. The method of claim 1, further comprising recording the duration of illumination of the OLED display in response to the first external video signal, and wherein the regional correction value is generated in response to the duration of the first external video signal.

3. The method of claim 2, further comprising recording the duration of illumination of the OLED display in response to the corrected second external video signal, and wherein the regional correction value is generated in response to the durations of the first and corrected second external video signals.

4. The method of claim 3, wherein the regional correction value is generated based upon the relative durations of the first and corrected second external video signals.

5. The method of claim 3, further comprising the step of calculating and storing the average brightness of the first and corrected second external video signals, and wherein the regional correction value is generated in response to the stored average brightness and durations of the first and corrected second external video signals.

6. The method of claim 1, wherein the second signal aspect ratio is the same as the screen aspect ratio.

7. The method of claim 1, wherein the first signal aspect ratio is greater than the screen aspect ratio.

8. The method of claim 7, wherein the first signal aspect ratio is 16:

9 and the screen aspect ratio is 4;

3.

9. The method of claim 1, wherein the first signal aspect ratio is less than the screen aspect ratio.

10. The method of claim 9, wherein the first signal aspect ratio is 4:

3 and the screen aspect ratio is 16;

9.

11. The method of claim 1, wherein the OLED display device is an active-matrix device.

12. The method of claim 1, wherein the OLED display device is a passive-matrix device.

13. The method of claim 1, wherein the regional correction value is generated from a measurement of the relative performance of the OLED display in the primary and secondary regions.

14. The method of claim 13, wherein the relative performance is based upon the relative brightness of the primary and secondary regions in response to a uniform illumination signal.

15. The method of claim 14, further comprising the step of adjusting the brightness of the primary and secondary regions to provide a uniform brightness, storing the adjustments, and wherein the correction is based upon the stored adjustments.

16. The method of claim 15, further comprising the step of periodically repeating the adjustment.

17. The method of claim 15, wherein the adjustment is done by a viewer.

18. The method of claim 17, wherein the adjustment is done by providing an on-screen interactive adjustment.

19. The method of claim 14, further comprising the step of measuring the light output of the primary and secondary regions.

20. The method of claim 19, wherein the measurement is done using a photo-sensor integrated into the display and formed on the same substrate.

21. The method of claim 14, wherein a plurality of regional correction values are calculated at a corresponding plurality of brightness levels.

22. The method of claim 1, wherein the regional correction value is generated from a measurement of the relative performance of representative pixels for the primary and secondary regions of the OLED display wherein the representative pixels for the primary region and the secondary region are illuminated at an average brightness corresponding to the average brightness of the illumination of the corresponding region.

23. The method of claim 22, wherein a separate representative pixel is provided for each color of the OLED display device.

24. The method of claim 22, wherein the measurement is the brightness of the representative pixels.

25. The method of claim 24, wherein the measurement is the current used by the representative pixels.

26. The method of claim 1, wherein the regional correction value is generated from a measurement of the relative current used by the primary and secondary regions.

27. The method of claim 1, further comprising the step of receiving a third external video signal having a third aspect ratio different from the first and second external video signals, wherein the display area corresponding to the third signal aspect ratio comprises a tertiary region that excludes at least a portion of at least one of the primary and secondary regions of the OLED display, and generating a regional correction value corresponding to the tertiary region of the OLED display.

28. The method of claim 27, wherein the primary, secondary, and tertiary regions are not mutually exclusive.

29. An OLED display device including a display screen with a screen aspect ratio, comprising:

a video circuit for receiving a first external video signal having a first signal aspect ratio different from the screen aspect ratio and a second external video signal having a second signal aspect ratio different from the first external video signal aspect ratio, wherein the display area corresponding to the second signal aspect ratio includes at least a portion of each of the primary and of the secondary regions of the OLED display;

a controller for (i) illuminating a primary region of the OLED display in response to the first external video signal, whereby a secondary region of the OLED display is not illuminated in response to the first external video signal, (ii) generating a regional correction value corresponding to the primary and secondary regions of the OLED display, wherein the controller employs the regional correction value to correct the second external video signal to compensate for differential aging in the included portions of the primary and secondary regions of the OLED display resulting from differential illumination of the primary and secondary regions of the OLED display in response to the first external video signal, and (iii) illuminating the display area corresponding to the second signal aspect ratio in response to a corrected second external video signal.