ORGANIC LIGHT EMITTING DIODE BASED DISPLAY AGING MONITORING

• US 20140055500A1
• Filed: 08/23/2012
• Published: 02/27/2014
• Est. Priority Date: 08/23/2012
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: LAI, Jackson Chi Sun
• Granted Patent: US 8,922,599 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• 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 2320/048 using evaluation of the usage time
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 2330/12 Test circuits or failure detection circuits included in a display system, as permanent part thereof
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: G09G 3/3225 using an active matrix

Abstract

A multiple pixel display driving system and method. A display generator displays a plurality of images on a multiple pixel display. An aging monitor determines values of total electrical current consumed by the multiple pixel display while displaying the images, and determines electrical current value differences between baseline electrical currents total electrical currents associated with a test pattern image. A plurality of pixel aging characterization values indicating decreases in electrical current consumed by a pixels of the display is determined, and a display aging compensation matrix representing values by which pixel intensity values are to be compensated is determined based on the pixel aging characterization values.

Claims

1. A method for driving a multiple pixel display, the method comprising:

performing any of the following with a processor;

displaying a plurality of test pattern images on a multiple pixel display;

determining, while displaying each test pattern image of the plurality of test pattern images, a respective value of measured total electrical current consumed by the multiple pixel display;

determining, for each respective value of total electrical current, a plurality of electrical current value differences, each electrical current value difference within the plurality of electrical current value differences comprising a difference between a respective baseline electrical current and the respective value of total electrical current, wherein the respective baseline electrical current is associated with a test pattern image displayed while determining the respective value of total electrical current;

determining, based on the plurality of electrical current value differences and pixel intensity values of pixels in each test pattern image, a plurality of pixel aging characterization values, each pixel aging characterization value within the a plurality of pixel aging characterization values indicating a respective decrease in electrical current consumed by a respective group of at least one pixel of the multiple pixel display; and

determining, based upon the plurality of pixel aging characterization values, a display aging compensation matrix representing values by which pixel intensity values are to be compensated.

2. The method of claim 1, further comprising retrieving, from a data storage prior to the displaying, the plurality of test pattern images.

3. The method of claim 2, further comprising retrieving, prior to determining a respective electrical current value difference within the plurality of electrical current value differences, the respective baseline electrical current from a test pattern total current measurements storage.

4. The method of claim 2, further comprising calculating, prior to determining a respective electrical current value difference within the plurality of electrical current value differences, the respective baseline electrical current based upon combining empirical pixel electrical current consumption characterization data with intensity data of a respective test pattern image associated with the respective electrical current value difference.

5. The method of claim 1, further comprising:

receiving, through an image source interface, a plurality of operational images to be displayed on the multiple pixel display, and wherein the plurality of test pattern images comprises the plurality of operational images; and

calculating, prior to determining a respective electrical current value difference within the plurality of electrical current value differences, the respective baseline electrical current based upon combining empirical pixel electrical current consumption characterization data with intensity data of the respective operational image.

6. The method of claim 1, wherein the determining the plurality of pixel aging characterization values comprises:

solving for a characterization vector based upon a matrix equation,

the matrix equation expressing an equality of an electrical current value difference vector and a matrix product of the characterization vector and an intensity matrix representing pixel intensity values of pixels of each test pattern image within the plurality of test pattern images,

the electrical current value difference vector comprising the plurality of electrical current value differences,

the characterization vector comprising a plurality of entries each representing a respective reduction in electrical current consumption of at least one respective pixel in the multiple pixel display.

7. The method of claim 1,

wherein each pixel aging characterization value within the plurality of pixel aging characterization values characterizes aging of a respective subset plurality of pixels within the multiple pixel display.

8. The method of claim 7, wherein each respective subset plurality of pixels comprises contiguous pixels within the multiple pixel display.

9. A multiple pixel display driving system, comprising:

a display generator configured to display a plurality of test pattern images on a multiple pixel display; and

an aging monitor configured to;

determine, while the display generator is displaying each test pattern image of the plurality of test pattern images, a respective value of total electrical current consumed by the multiple pixel display;

determine, for each respective value of total electrical current, a plurality of electrical current value differences, each electrical current value difference within the plurality of electrical current value differences comprising a difference between a respective baseline electrical current and the respective value of total electrical current, wherein the respective baseline electrical current is associated with a test pattern image displayed while determining the respective value of total electrical current;

determine, based on the plurality of electrical current value differences and pixel intensity values of each test pattern image, a plurality of pixel aging characterization values, each pixel aging characterization value within the a plurality of pixel aging characterization values indicating a respective decrease in electrical current consumed by a respective group of at least one pixel of the multiple pixel display; and

determine, based upon the plurality of pixel aging characterization values, a display aging compensation matrix representing values by which pixel intensity values are to be compensated.

10. The multiple pixel display driving system of claim 9, further comprising a data storage configured to store the plurality of test pattern images, and

wherein the aging monitor is further configured to retrieve, from the data storage prior to the displaying, the plurality of test pattern images.

11. The multiple pixel display driving system of claim 10, further comprising a test pattern total current measurements storage configured to store a respective baseline electrical current for at least a subset plurality of test pattern images stored in the test pattern images, and

wherein the aging monitor is further configured to retrieve, prior to determining a respective electrical current value difference within the plurality of electrical current value differences, the respective baseline electrical current from the test pattern total current measurements storage.

12. The multiple pixel display driving system of claim 10, the aging monitor further configured to calculate, prior to determining a respective electrical current value difference within the plurality of electrical current value differences, the respective baseline electrical current based upon combining empirical pixel electrical current consumption characterization data with intensity data of a respective test pattern image associated with the respective electrical current value difference.

13. The multiple pixel display driving system of claim 9, further comprising:

an image source interface configured to receive a plurality of operational images to be displayed on the multiple pixel display, and wherein the plurality of test pattern images comprises the plurality of operational images, and

wherein the aging monitor is further configured to calculate, prior to determining a respective electrical current value difference within the plurality of electrical current value differences, the respective baseline electrical current based upon combining empirical pixel electrical current consumption characterization data with intensity data of the respective operational image.

14. The multiple pixel display driving system of claim 9, wherein the aging monitor is configured to determine the plurality of pixel aging characterization values by solving for a characterization vector based upon a matrix equation,

the matrix equation expressing an equality of an electrical current value difference vector and a matrix product of the characterization vector and an intensity matrix representing pixel intensity values of pixels of each test pattern image within the plurality of test pattern images,

the electrical current value difference vector comprising the plurality of electrical current value differences,

the characterization vector comprising a plurality of entries each representing a respective reduction in electrical current consumption of at least one respective pixel in the multiple pixel display.

15. The multiple pixel display driving system of claim 9, wherein each pixel aging characterization value within the plurality of pixel aging characterization values characterizes aging of a respective subset plurality of pixels within the multiple pixel display.

16. The multiple pixel display driving system of claim 15, wherein each respective subset plurality of pixels comprises contiguous pixels within the multiple pixel display.

17. A computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising instructions for:

displaying a plurality of test pattern images on a multiple pixel display;

determining, while displaying each test pattern image of the plurality of test pattern images, a respective value of measured total electrical current consumed by the multiple pixel display;

determining, for each respective value of total electrical current, a plurality of electrical current value differences, each electrical current value difference within the plurality of electrical current value differences comprising a difference between a respective baseline electrical current and the respective value of total electrical current, wherein the respective baseline electrical current is associated with a test pattern image displayed while determining the respective value of total electrical current;

determining, based on the plurality of electrical current value differences and pixel intensity values of pixels in each test pattern image, a plurality of pixel aging characterization values, each pixel aging characterization value within the a plurality of pixel aging characterization values indicating a respective decrease in electrical current consumed by a respective group of at least one pixel of the multiple pixel display; and

determining, based upon the plurality of pixel aging characterization values, a display aging compensation matrix representing values by which pixel intensity values are to be compensated.

18. The computer readable storage medium of claim 17, the computer readable program code further comprising instructions for retrieving, from a data storage prior to the displaying, the plurality of test pattern images.

19. The computer readable storage medium of claim 18, the computer readable program code further comprising instructions for retrieving, prior to determining a respective electrical current value difference within the plurality of electrical current value differences, the respective baseline electrical current from a test pattern total current measurements storage.

20. The computer readable storage medium of claim 18, the computer readable program code further comprising instructions for calculating, prior to determining a respective electrical current value difference within the plurality of electrical current value differences, the respective baseline electrical current based upon combining empirical pixel electrical current consumption characterization data with intensity data of a respective test pattern image associated with the respective electrical current value difference.

21. The computer readable storage medium of claim 17, the computer readable program code further comprising instructions for:

receiving, through an image source interface, a plurality of operational images to be displayed on the multiple pixel display, and wherein the plurality of test pattern images comprises the plurality of operational images; and

calculating, prior to determining a respective electrical current value difference within the plurality of electrical current value differences, the respective baseline electrical current based upon combining empirical pixel electrical current consumption characterization data with intensity data of the respective operational image.

22. The computer readable storage medium of claim 17, wherein the instructions for determining the plurality of pixel aging characterization values comprises instructions for:

solving for a characterization vector based upon a matrix equation,

the matrix equation expressing an equality of an electrical current value difference vector and a matrix product of the characterization vector and an intensity matrix representing pixel intensity values of pixels of each test pattern image within the plurality of test pattern images,

the electrical current value difference vector comprising the plurality of electrical current value differences,

the characterization vector comprising a plurality of entries each representing a respective reduction in electrical current consumption of at least one respective pixel in the multiple pixel display.

23. The computer readable storage medium of claim 17,

wherein each pixel aging characterization value within the plurality of pixel aging characterization values characterizes aging of a respective subset plurality of pixels within the multiple pixel display.

24. The computer readable storage medium of claim 23, wherein each respective subset plurality of pixels comprises contiguous pixels within the multiple pixel display.

25. An electronic display device comprising:

a multiple pixel display;

a display generator configured to display a plurality of test pattern images on a multiple pixel display; and

an aging monitor configured to;

determine, while the display generator is displaying each test pattern image of the plurality of test pattern images, a respective value of total electrical current consumed by the multiple pixel display;

determine, for each respective value of total electrical current, a plurality of electrical current value differences, each electrical current value difference within the plurality of electrical current value differences comprising a difference between a respective baseline electrical current and the respective value of total electrical current, wherein the respective baseline electrical current is associated with a test pattern image displayed while determining the respective value of total electrical current;

determine, based on the plurality of electrical current value differences and pixel intensity values of each test pattern image, a plurality of pixel aging characterization values, each pixel aging characterization value within the a plurality of pixel aging characterization values indicating a respective decrease in electrical current consumed by a respective group of at least one pixel of the multiple pixel display; and

determine, based upon the plurality of pixel aging characterization values, a display aging compensation matrix representing values by which pixel intensity values are to be compensated.