Method of compensating Mura of display apparatus and vision inspection apparatus performing the method

1. A method of compensating a Mura defect of a display apparatus which comprises a display area divided into an upper area and a lower area, which are driven independently of each other, the method comprising:

calculating a sharp grayscale correction value of a predetermined sample grayscale displayed on the display apparatus, wherein the sharp grayscale correction value is configured to compensate a sharp horizontal Mura in a boundary area between the upper and lower areas;

displaying a corrected sample grayscale on the display apparatus based on the predetermined sample grayscale and the sharp grayscale correction value;

sensing the corrected sample grayscale displayed on each of a plurality of sample areas, wherein the sample areas are defined on the display area based on a Mura type;

calculating an intensity profile of the corrected sample grayscale and a target intensity profile which is configured to compensate the intensity profile of the corrected sample grayscale;

calculating a grayscale correction value of the sample area using the intensity profile and the target intensity profile; and

applying the sharp grayscale correction value to the grayscale correction value.

2. The method of compensating Mura of claim 1 , wherein the calculating the sharp grayscale correction value displayed on the display apparatus comprises:

sensing the predetermined sample grayscale displayed on each sample area, and sensing an adjacent sample grayscale of the predetermined sample grayscale displayed on each sample area; and

calculating the sharp grayscale correction value of the predetermined sample grayscale using an intensity value of the predetermined sample grayscale, an intensity value of the adjacent sample grayscale, a piecewise gamma between the predetermined sample grayscale and the adjacent sample grayscale, and a target intensity value.

3. The method of compensating Mura of claim 2 , wherein the calculating the sharp grayscale correction value using the intensity value of the predetermined sample grayscale, the intensity value of the adjacent sample grayscale, the piecewise gamma between the predetermined sample grayscale and the adjacent sample grayscale, and the target intensity value comprises:

calculating a first sharp grayscale correction value corresponding to a last pixel row of the upper area by setting the target intensity value as an average intensity value of pixels in a pixel row of the upper area adjacent to the last pixel row of the upper area; and

calculating a second sharp grayscale correction value corresponding to the last pixel row of the upper area by setting the target intensity value as an average intensity value of pixels in a pixel row of the lower area adjacent to a first pixel row of the lower area.

4. The method of compensating Mura of claim 2 , wherein the calculating the sharp grayscale correction value using the intensity value of the predetermined sample grayscale, the intensity value of the adjacent sample grayscale, the piecewise gamma between the predetermined sample grayscale and the adjacent sample grayscale, and the target intensity value further comprises:

calculating a sharp grayscale correction value of another sample grayscale, which is different from the predetermined sample grayscale, using an adaptive offset ratio with respect to the predetermined sample grayscale.

5. The method of compensating Mura of claim 1 , wherein

the sample areas comprise a plurality of vertical sample areas and a plurality of horizontal sample areas, and

the sensing the corrected sample grayscale displayed on each of the sample areas comprises:

sensing the corrected sample grayscale displayed on each of the vertical sample areas; and

sensing the corrected sample grayscale displayed on each of the horizontal sample areas.

6. The method of compensating Mura of claim 5 , wherein the sharp grayscale correction value is calculated for each vertical sample area.

7. The method of compensating Mura of claim 5 , wherein

the calculating the intensity profile of the corrected sample grayscale and the target intensity profile comprises calculating a vertical intensity profile of the corrected sample grayscale sensed from each vertical sample area and a vertical target intensity profile which is configured to compensate the vertical intensity profile, and

the calculating the grayscale correction value of the sample area using the intensity profile and the target intensity profile comprises calculating a vertical grayscale correction value based on the vertical intensity profile and the vertical target intensity profile.

8. The method of compensating Mura of claim 7 , wherein

the vertical grayscale correction value comprises grayscale correction values of pixels in a pixel column, and

the applying the sharp grayscale correction value comprises:

adding a first sharp grayscale correction value to a grayscale correction value of a pixel in a last pixel row of the upper area; and

adding a second sharp grayscale correction value to a grayscale correction value of a pixel in a first pixel row of the lower area.

9. The method of compensating Mura of claim 5 , wherein

the calculating the intensity profile of the corrected sample grayscale and the target intensity profile comprises calculating a horizontal intensity profile of the corrected sample grayscale sensed from each horizontal sample area and the horizontal target intensity profile which is configured to compensate the horizontal intensity profile, and

the calculating the grayscale correction value of the sample area using the intensity profile and the target intensity profile comprises calculating a horizontal grayscale correction value based on the horizontal intensity profile and the horizontal target intensity profile.

10. The method of compensating Mura of claim 9 , wherein

a horizontal sample area adjacent to the boundary area between the upper and lower areas has a size smaller than a size of a horizontal sample area distant from the boundary area.

11. The method of compensating Mura of claim 10 , wherein the calculating the horizontal grayscale correction value based on the horizontal intensity profile and the horizontal target intensity profile comprises:

calculating horizontal grayscale correction values of a first horizontal sample area in the upper area adjacent to the boundary area and a second horizontal sample area in the lower area adjacent to the boundary area, based on a same horizontal target intensity profile,

wherein the horizontal grayscale correction value comprises grayscale correction values of pixels in a pixel row.

12. A vision inspection apparatus comprising:

a sensing part configured to sense a sample grayscale displayed on a display apparatus, wherein the display apparatus comprises a display area divided into an upper area and a lower area, which are driven independently of each other;

a sharp Mura compensation part configured to calculate a sharp grayscale correction value of a predetermined sample grayscale, wherein the sharp grayscale correction value is configured to compensate a sharp horizontal Mura in a boundary area between the upper and lower areas;

an inspection control part configured to control the sensing part to sense the sample grayscale displayed on each of a plurality of sample areas defined on the display area based on a Mura type and to display a corrected sample grayscale on the display apparatus based on the predetermined sample grayscale and the sharp grayscale correction value;

an intensity calculation part configured to calculate an intensity profile of the corrected sample grayscale and a target intensity profile which is configured to compensate the intensity profile of the corrected sample grayscale;

a correction calculation part configured to calculate a grayscale correction value of the sample area using the intensity profile and the target intensity profile; and

an addition part configured to add the sharp grayscale correction value to the grayscale correction value.

13. The vision inspection apparatus of claim 12 , wherein

the sharp Mura compensation part is configured to calculate the sharp grayscale correction value of the predetermined sample grayscale using an intensity value of the predetermined sample grayscale, an intensity value of the adjacent sample grayscale, a piecewise gamma between the predetermined sample grayscale and the adjacent sample grayscale, and a target intensity value.

14. The vision inspection apparatus of claim 13 , wherein

the sharp Mura compensation part is configured to calculate a first sharp grayscale correction value corresponding to a last pixel row of the upper area by setting the target intensity value as an average intensity value of pixels in a pixel row of the upper area adjacent to the last pixel row of the upper area, and

the sharp Mura compensation part is configured to calculate a second sharp grayscale correction value corresponding to the last pixel row of the upper area by setting the target intensity value as an average intensity value of pixels in a pixel row of the lower area adjacent to a first pixel row of the lower area.

15. The vision inspection apparatus of claim 14 , wherein

the sharp Mura compensation part is configured to calculate a sharp grayscale correction value of another sample grayscale, which is different from the predetermined sample grayscale, using an adaptive offset ratio with respect to the predetermined sample grayscale.

16. The vision inspection apparatus of claim 14 , wherein

the sample areas comprise a plurality of vertical sample areas,

the intensity calculation part is configured to calculate a vertical intensity profile of the corrected sample grayscale sensed from each vertical sample area and a vertical target intensity profile which is configured to compensate the vertical intensity profile ; and

the correction calculation part is configured to calculate a vertical grayscale correction value based on the vertical intensity profile and the vertical target intensity profile.

17. The vision inspection apparatus of claim 16 , wherein

the vertical grayscale correction value comprises grayscale correction values of pixels in a pixel column, and

the addition part is configured to add a first sharp grayscale correction value to a grayscale correction value of a pixel in a last pixel row of the upper area, and

add a second sharp grayscale correction value to a grayscale correction value of a pixel in a first pixel row in the lower area.

18. The vision inspection apparatus of claim 14 , wherein

the sample areas comprise a plurality of horizontal sample areas,

the intensity calculation part is configured to calculate a horizontal intensity profile of the corrected sample grayscale sensed from each horizontal sample area and the horizontal target intensity profile which is configured to compensate the horizontal intensity profile; and

the correction calculation part is configured to calculate a horizontal grayscale correction value based on the horizontal intensity profile and the horizontal target intensity profile.

19. The vision inspection apparatus of claim 18 , wherein

a horizontal sample area adjacent to the boundary area between the upper and lower areas has a size smaller than a size of a horizontal sample area distant from the boundary area.

20. The vision inspection apparatus of claim 18 , wherein

the correction calculation part is configured to calculate horizontal grayscale correction values of a first horizontal sample area of the upper area adjacent to the boundary area and a second horizontal sample area of the lower area adjacent to the boundary area, based on a same horizontal target intensity profile.