Method of more quickly calibrating display panels and calibration apparatus for performing the same

• US 9,754,545 B2
• Filed: 07/25/2014
• Issued: 09/05/2017
• Est. Priority Date: 01/03/2014
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Han, Jung-Suk, Moon, Hoi-Sik, Kim, Kang-Hyun, Na, Jong-Hee, Jung, Woo-Jin, Chung, Jae-Seob
• Primary Examiner(s): Lin, Hang
• Application Number:
  US14/341,590
• Publication Number:
  US 20150194105A1
• Time in Patent Office: 1,138 Days
• CPC Class Codes: G02F 1/1309 Repairing; Testing
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/068 for control of viewing angle adjustment
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A method of reducing a total, per device, measurements taking time in a calibration system that uses a sensor array that serially reports out its readings and a data processing unit that needs to receive the reported out readings in good order before allowing an under-measurement first display device to advance away from a measurements taking station includes the step of not driving the first display device with all of required full screen test images where each is a full screen display of only a respective one of a predetermined minimum number of grayscale values produced as a minimum number of needed full screen sample images and; in place of at least a first plurality of the not-produced full screen images, driving the under-measurement first display device with a partial screen multi-pattern that presents a plurality of different grayscale values including ones not presented by those of all of the full screen test images that are used to drive the under-measurement first display device. The serially reported out readings from the sensor array for the partial screen multi-pattern and for the full screen test images are obtained and used to generate virtual full screen sample images based on the obtained partial screen multi-pattern and for the full screen test images.

Claims

1. A machine implemented method of compensating an image of a display panel, the method comprising:

capturing a plurality of full pattern images corresponding to a plurality of full grayscales, each full pattern image being the image of an entire display area of the display panel;

measuring luminance and color of the plurality of full pattern images, each of the full pattern images including a single full grayscale of the full gray scales;

measuring luminance and color of a multi pattern image, the multi pattern image including a plurality of multi grayscales;

generating a first compensating value to displace a position of a multi grayscale region in the multi pattern image to a central portion of the multi pattern image; and

compensating luminance and color of the display panel based on the luminance and the color of the full pattern image, the luminance and the color of the multi pattern image and the first compensating value,

wherein the first compensating value is generated based on measurements taken from a high full image and a low full image, the high full image having a high full grayscale which is one of the full grayscales greater than and adjacent to a multi grayscale of the multi grayscale region, the low full image having a low full grayscale which is one of the full grayscales less than and adjacent to the multi grayscale of the multi grayscale region,

wherein the generating of the first compensating value comprises;

determining a first difference between a measured value of the high full grayscale at a first position and a measured value of the high full grayscale at a second position in the high full image and a second difference between a measured value of the low full grayscale at the first position and a measured value of the low full grayscale at the second position in the low full image, the first position being the central portion of the multi pattern image, the second position being the position of the multi grayscale region; and

linearly interpolating the first difference and the second difference using the high full grayscale, the multi grayscale of the multi grayscale region and the low full grayscale.

2. The method of claim 1, wherein the multi pattern image includes a common multi grayscale which is substantially the same as one of the full grayscales.

3. The method of claim 2, further comprising generating a second compensating value using a ratio between a measured value of the full grayscale which is substantially the same as the common multi grayscale and a measured value of the common multi grayscale in the multi pattern image.

4. The method of claim 3, wherein a measured position of the measured value of the full grayscale which is substantially the same as the common multi grayscale is substantially the same as a measured position of the measured value of the common multi grayscale in the multi pattern image.

5. The method of claim 1, wherein a number of the full pattern images is greater than or equal to three.

6. The method of claim 1, wherein a number of multi pattern images is two, and

a first multi pattern image among the multi pattern images corresponds to relatively low grayscales and a second multi pattern image among the multi pattern images corresponds to relatively high grayscales.

7. A method of compensating an image of a display panel, the method comprising:

capturing a plurality of full pattern images corresponding to a plurality of full grayscales, each full pattern image being the image of an entire display area of the display panel;

measuring luminance and color of a plurality of full pattern images corresponding to a plurality of full grayscales, each of the full pattern images including a single full grayscale of the full grayscales;

measuring luminance and color of a multi pattern image, the multi pattern image including a plurality of multi grayscales;

generating a first compensating value to displace a position of a multi grayscale region in the multi pattern image to a central portion of the multi pattern image;

compensating luminance and color of input image data based on the input image data, the luminance and the color of the full pattern image, the luminance and the color of the multi pattern image and the first compensating value to generate a data signal; and

displaying an image on the display panel based on the data signal,

wherein the first compensating value is generated using a high full image and a low full image, the high full image having a high full grayscale which is one of the full grayscales greater than and adjacent to a multi grayscale of the multi grayscale region, the low full image having a low full grayscale which is one of the full grayscales less than and adjacent to the multi grayscale of the multi grayscale region,

wherein the generating of the first compensating value comprises;

determining a first difference between a measured value of the high full grayscale at a first position and a measured value of the high full grayscale at a second position in the high full image and a second difference between a measured value of the low full grayscale at the first position and a measured value of the low full grayscale at the second position in the low full image, the first position being the central portion of the multi pattern image, the second position being the position of the multi grayscale region; and

linearly interpolating the first difference and the second difference using the high full grayscale, the multi grayscale of the multi grayscale region and the low full grayscale.

8. The method of claim 7, wherein the multi pattern image includes a common multi grayscale which is substantially the same as one of the full grayscales.

9. The method of claim 8, further comprising generating a second compensating value using a ratio between a measured value of the full grayscale which is substantially the same as the common multi grayscale and a measured value of the common multi grayscale in the multi pattern image.

10. The method of claim 7, wherein a number of the full pattern images is greater than or equal to three.

11. A display apparatus comprising:

a timing controller configured to compensate luminance and color of input image data to generate a data signal based on the input image data, luminance and color of a plurality of full pattern images corresponding to a plurality of full grayscales, luminance and color of a multi pattern image and a first compensating value to displace a position of a multi grayscale region in the multi pattern image to a central portion of the multi pattern image, each of the full pattern images including a single full grayscale of the full grayscales, the multi pattern image including a plurality of multi grayscales;

a data driver configured to convert the data signal into a data voltage having an analog type; and

a display panel configured to display an image based on the data voltage,

wherein each full pattern image is a captured image of an entire display area of the display panels,

wherein the first compensating value is generated using a high full image and a low full image, the high full image having a high full grayscale which is one of the full grayscales greater than and adjacent to a multi grayscale of the multi grayscale region, the low full image having a low full grayscale which is one of the full grayscales less than and adjacent to the multi grayscale of the multi grayscale region,

wherein, to generate the first compensating value, the timing controller is configured to;

determine a first difference between a measured value of the high full grayscale at a first position and a measured value of the high full grayscale at a second position in the high full image and a second difference between a measured value of the low full grayscale at the first position and a measured value of the low full grayscale at the second position in the low full image, the first position being the central portion of the multi pattern image, the second position being the position of the multi grayscale region, and

linearly interpolate the first difference and the second difference using the high full grayscale, the multi grayscale of the multi grayscale region and the low full grayscale.

12. The display apparatus of claim 11, wherein the multi pattern image includes a common multi grayscale which is substantially the same as one of the full grayscales.

13. The display apparatus of claim 12, wherein the timing controller is further configured to generate a second compensating value using a ratio between a measured value of the full grayscale which is substantially the same as the common multi grayscale and a measured value of the common multi grayscale in the multi pattern image.

14. The display apparatus of claim 11, wherein a number of the full pattern images is greater than or equal to three.

15. A machine implemented and automated method for quickly determining luminance and color compensation values for a display panel having a display area populated by a matrix of pixels, where each pixel is independently drivable over a predetermined range of grayscales, the method comprising:

first driving all the pixels with a first single full grayscale signal to thereby produce a corresponding first full screen image and using a sensor array to measure luminance and color attributes of the produced first full screen image;

second driving all the pixels with a different second single full grayscale signal to thereby produce a corresponding second full screen image and using the sensor array to measure luminance and color attributes of the produced second full screen image;

third driving only a subset of the pixels of the display area with a corresponding multi pattern signal to thereby produce a corresponding multi pattern image having a predetermined spatial arrangement of darker and lighter regions and using the sensor array to measure respective luminances and color attributes of the respective and spatially arranged darker and lighter regions of the multi pattern image corresponding to only the subset of the pixels;

using the measured luminances and color attributes of the multi pattern image and of the first and second full screen images to generate luminance and color calibrating factors for the display panel.