Organic light emitting diode based display aging monitoring

• US 8,922,599 B2
• Filed: 08/23/2012
• Issued: 12/30/2014
• 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
• Primary Examiner(s): Beck, Alexander S
• Assistant Examiner(s): WOOD, NEIL E
• Application Number:
  US13/592,602
• Publication Number:
  US 20140055500A1
• Time in Patent Office: 859 Days
• Field of Search: 345/690
• 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, sequentially in time, a plurality of test pattern images on a multiple pixel display,

wherein each test pattern image in the plurality of test pattern images defines respective intensity values for each of at least three pixels, wherein each respective intensity value of the each of the at least three pixels of each test pattern image is different from one another,

wherein the respective intensity value in each test pattern image for a particular pixel is different from the respective intensity value of the particular pixel in other test pattern images within the plurality of test pattern images;

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 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 measured 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 the different respective intensity values of each respective pixel of the at least three pixels, 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 corresponding respective pixel within the at least three pixels; and

determining, based upon the plurality of pixel aging characterization values, a display aging compensation matrix representing values by which pixel intensity values for the at least three pixels 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, subsequent to retrieving each test pattern image within the plurality of test pattern images and 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, wherein the plurality of operational images define a sequence of images to be presented to a user, and wherein the plurality of test pattern images comprises the plurality of operational images; and

calculating for each operational image received through the image source interface, subsequent to receiving each operational image within the plurality of operational images and 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:

forming electrical current value difference vector comprising the plurality of electrical current value differences;

forming an intensity definition matrix comprising values, arranged in a first dimension, corresponding to the respective intensity values of each pixel within the at least three pixel defined by each respective test pattern image, and

the intensity definition matrix further comprising values, arranged in a second dimension different than the first dimension, corresponding to the intensity values of different test pattern images within the plurality of test pattern images; and

solving for a characterization vector based upon a matrix equation

expressing an equality of the electrical current value difference vector and a matrix product of the characterization vector and the intensity definition matrix,

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.

25. The method of claim 5, wherein the plurality of operational images define a video to be presented to the user.

9. A multiple pixel display driving system, comprising:

a display generator configured to display, sequentially in time, a plurality of test pattern images on a multiple pixel display,

wherein each test pattern image in the plurality of test pattern images defines respective intensity values for each of at least three pixels, wherein each respective intensity value of the each of the at least three pixels of each test pattern image is different from one another,

wherein the respective intensity value in each test pattern image for a particular pixel is different from the respective intensity value of the particular pixel in other test pattern images within the plurality of test pattern images; 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 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 measured 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 the different respective intensity values of each respective pixel of the at least three pixels, 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 corresponding respective pixel within the at least three pixels; and

determine, based upon the plurality of pixel aging characterization values, a display aging compensation matrix representing values by which pixel intensity values for the at least three pixels 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

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,

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

11. The multiple pixel display driving system of claim 10, the aging monitor further configured to calculate, subsequent to retrieving each test pattern image within the plurality of test pattern images and 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.

12. 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, wherein the plurality of operational images define a sequence of images to be presented to a user, and wherein the plurality of test pattern images comprises the plurality of operational images, and

wherein the aging monitor is further configured to calculate for each operational image received through the image source interface, subsequent to receiving each operational image within the plurality of operational images and 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.

13. 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:

forming electrical current value difference vector comprising the plurality of electrical current value differences;

forming an intensity definition matrix comprising values, arranged in a first dimension, corresponding to the respective intensity values of each pixel within the at least three pixel defined by each respective test pattern image, and the intensity definition matrix further comprising values, arranged in a second dimension different than the first dimension, corresponding to the intensity values of different test pattern images within the plurality of test pattern images; and

solving for a characterization vector based upon a matrix equation expressing an equality of the electrical current value difference vector and a matrix product of the characterization vector and the intensity definition matrix,

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.

14. 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.

15. The multiple pixel display driving system of claim 14, wherein each respective subset plurality of pixels comprises contiguous pixels within the multiple pixel display.

16. A non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising instructions for:

displaying, sequentially in time, a plurality of test pattern images on a multiple pixel display,

wherein each test pattern image in the plurality of test pattern images defines respective intensity values for each of at least three pixels, wherein each respective intensity value of the each of the at least three pixels of each test pattern image is different from one another,

wherein the respective intensity value in each test pattern image for a particular pixel is different from the respective intensity value of the particular pixel in other test pattern images within the plurality of test pattern images;

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 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 measured 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 the different respective intensity values of each respective pixel of the at least three pixels, 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 corresponding respective pixel within the at least three pixels; and

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

17. The non-transitory computer readable storage medium of claim 16, the computer readable program code further comprising instructions for retrieving, from a data storage prior to the displaying, the plurality of test pattern images.

18. The non-transitory computer readable storage medium of claim 17, 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.

19. The non-transitory computer readable storage medium of claim 17, the computer readable program code further comprising instructions for calculating, subsequent to retrieving each test pattern image within the plurality of test pattern images and 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.

20. The non-transitory computer readable storage medium of claim 16, 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, wherein the plurality of operational images define a sequence of images to be presented to a user, and wherein the plurality of test pattern images comprises the plurality of operational images; and

calculating for each operational image received through the image source interface, subsequent to receiving each operational image within the plurality of operational images and 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.

21. The non-transitory computer readable storage medium of claim 16, wherein the instructions for determining the plurality of pixel aging characterization values comprises instructions for:

forming electrical current value difference vector comprising the plurality of electrical current value differences;

forming an intensity definition matrix comprising values, arranged in a first dimension, corresponding to the respective intensity values of each pixel within the at least three pixel defined by each respective test pattern image, and

the intensity definition matrix further comprising values, arranged in a second dimension different than the first dimension, corresponding to the intensity values of different test pattern images within the plurality of test pattern images; and

solving for a characterization vector based upon a matrix equation

expressing an equality of the electrical current value difference vector and a matrix product of the characterization vector and the intensity definition matrix,

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.

22. The non-transitory computer readable storage medium of claim 16,

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.

23. The non-transitory computer readable storage medium of claim 22, wherein each respective subset plurality of pixels comprises contiguous pixels within the multiple pixel display.

24. An electronic display device comprising:

a multiple pixel display;

a display generator configured to display, sequentially in time, a plurality of test pattern images on a multiple pixel display,

wherein each test pattern image in the plurality of test pattern images defines respective intensity values for each of at least three pixels, wherein each respective intensity value of the each of the at least three pixels of each test pattern image is different from one another,

wherein the respective intensity value in each test pattern image for a particular pixel is different from the respective intensity value of the particular pixel in other test pattern images within the plurality of test pattern images; 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 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 measured 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 the different respective intensity values of each respective pixel of the at least three pixels, 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 corresponding respective pixel within the at least three pixels; and

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