Method and apparatus for defect correction in a display

1 . A method for displaying an image on a display device having defective light-emitting elements, comprising the steps of:

a) providing a display having a plurality of light-emitting elements, comprising at least one light-emitting element that is defective and additional light-emitting elements;

b) providing a plurality of distinct image-content dependent defect-masking compensation computations, at least one of which includes the step of selectively modifying the light output of an additional light-emitting element;

c) analyzing an input image signal to determine a preferred defect-masking compensation computation for driving additional light-emitting elements in the vicinity of the defective light-emitting element;

d) compensating the input image signal with the determined preferred defect-masking compensation computation; and

e) driving the light-emitting elements of the display to display a defect-masked compensated image.

2 . The method of claim 1 wherein the determined preferred defect-masking compensation computation modifies the light output of at least one additional light-emitting element neighboring the defective light-emitting element.

3 . The method of claim 1 wherein the determined preferred defect-masking compensation computation modifies the light output of at least one additional light-emitting element that is not an immediate neighbor of the defective light-emitting element and wherein the light output of the immediate neighbors of the defective light-emitting element is not modified.

4 . The method of claim 1 wherein the light-emitting elements are organized into a plurality of pixel groups and wherein at least one image-content dependent defect-masking compensation computation selectively modifies the light output of at least one additional light-emitting element within the same pixel group as the defective light-emitting element and at least one additional light-emitting element not within the same pixel group as the defective light-emitting element.

5 . The method of claim 4 wherein the additional light-emitting element not within the same pixel group as the defective light-emitting element is designed to emit light of the same color as the defective light-emitting element.

6 . The method of claim 4 , wherein the pixel groups comprise at least red, green, blue, and white sub-pixels and the at least one image-content dependent defect-masking compensation computation employs light from the white sub-pixel of a pixel group to compensate for at least a portion of the light from a defective red, green, or blue sub-pixel of a pixel group.

7 . The method of claim 1 , wherein the plurality of distinct image-content dependent defect-masking compensation computations include a computation that makes no changes to the light output of any additional light-emitting elements.

8 . The method of claim 1 , wherein the plurality of distinct image-content dependent defect-masking compensation computations include a computation that modifies the light output of a single additional light-emitting element in the place of the defective light-emitting element and the light output by no other light-emitting elements is modified.

9 . The method of claim 1 , wherein the plurality of distinct image-content dependent defect-masking compensation computations include a computation that modifies the light output of a plurality of additional light-emitting elements in the neighborhood of the defective light-emitting element to minimize the error in the light output due to the defective light-emitting element.

10 . The method of claim 1 , wherein the analysis of the image signal determines whether the defective light-emitting element and surrounding additional light-emitting elements are to be driven to display a flat field.

11 . The method of claim 1 , wherein the analysis of the image signal determines whether the defective light-emitting element or its immediate neighbor are to be driven to display part of a luminance and/or a chrominance edge defining first and second image areas having a distinctive difference in luminance or chrominance.

12 . The method of claim 11 , wherein the preferred defect-masking compensation computation for driving additional light-emitting elements in the vicinity of the defective light-emitting element makes no changes to the light output of any additional light-emitting elements when the defective light-emitting element or its immediate neighbor are to be driven to display part of an irregular edge.

13 . The method of claim 11 , wherein the preferred defect-masking compensation computation for driving additional light-emitting elements in the vicinity of the defective light-emitting element modifies the light output from one or more neighboring additional elements in the same area as the defective light-emitting element, and makes no changes to the light output from any neighboring additional elements in the other area.

14 . The method of claim 1 , wherein the analysis of the image signal determines whether the defective light-emitting element is to be driven to display part of a luminance and/or a chrominance line separating first and second image areas.

15 . The method of claim 14 , wherein when analysis determines a defective light-emitting element is to be driven to display part of the edge on one side of a line that is more than one light-emitting element wide, the preferred defect-masking compensation computation for driving additional light-emitting elements in the vicinity of the defective light-emitting element modifies the light output from one or more additional elements on the opposite side of the line.

16 . The method of claim 14 , wherein when analysis determines a defective light-emitting element is to be driven to display part of a line that is one light-emitting element wide, the preferred defect-masking compensation computation for driving additional light-emitting elements in the vicinity of the defective light-emitting element modifies the light output from one or more additional elements to form a line circumventing the defective light-emitting element.

17 . The method of claim 14 , wherein the preferred defect-masking compensation computation for driving additional light-emitting elements in the vicinity of the defective light-emitting element makes no changes to the light output of any additional light-emitting elements when the defective light-emitting element or its immediate neighbor are to be driven to display part of an irregular line.

18 . The method of claim 1 , wherein the analysis of the image signal determines whether the defective light-emitting element is to be driven to display part of a random field having a range of output values.

19 . The method of claim 18 , wherein the preferred defect-masking compensation computation for driving additional light-emitting elements in the vicinity of the defective light-emitting element makes no changes to the light output of any additional light-emitting elements when the light output of the defective light-emitting element is within the range of output values in the random field.

20 . A display device, comprising:

a) a display having a plurality of light-emitting elements, comprising at least one light-emitting element that is defective and additional light-emitting elements; and

b) a controller having circuitry for computing a plurality of distinct image-content dependent defect-masking compensation computations, at least one of which selectively modifies the light output of an additional light-emitting element; for analyzing an input image signal to determine a preferred defect-masking compensation computation for driving light-emitting elements in the vicinity of the defective light-emitting element; for compensating the input image signal with the determined preferred defect-masking compensation computation; and for driving the light-emitting elements of the display to display a defect-masked compensated image.