Method of reducing the visual impact of defects present in a spatial light modulator display

A method of reducing the visual impact of defects present in an image display, the display being of the type which includes an array of pixels, each non-defective pixel being selectively operable, in response to input data provided by addressing facilities, between an "on" state in which light is directed onto a viewing surface, and an "off" state in which light is not directed onto the viewing surface;

• a defect being the result of a defective pixel which continuously remains in the "on" or "off" state regardless of the input data or the operation of the addressing facilities;
• each defective pixel being, in effect, a central defective pixel immediately surrounded by a first ring of compensation pixels adjacent to the central defective pixel with the first ring of compensation pixels being immediately surrounded by a second ring of reference pixels spaced from the central defective pixel;
• wherein the method comprises:
• (a) identifying a defect-producing defective pixel;
• and
• (b) changing the addressing circuit-determined value of at least one compensation pixel in the first ring surrounding the defective pixel to a corrective value to thereby reduce the visual impact of the defect, the corrective value given by:
• C.sub.NEW =C.sub.SINC (D.sub.ACT -R.sub.AVG)+D.sub.INT
• where C.sub.NEW is the intensity value assigned to the compensation pixel, C.sub.SINC is the value of the sine function evaluated for the compensation pixel, D.sub.ACT is the actual intensity value of the defective pixel, R.sub.AVG is the average value of at least one reference pixel, and D.sub.INT is the desired intensity value of the defective pixel.

A display system comprising:

• a modulator comprised of an array of pixels including at least one defective pixel, at least one compensation pixel adjacent to the defective pixel, and at least one reference pixel adjacent to said at least one compensation pixel and spaced apart from said defective pixel, the modulator for receiving a set of image data values corresponding to the array of pixels and for selectively activating the pixels to represent the set of image data values;
• and
• a processor for receiving an image signal and outputting the set of image data values to the modulator, wherein the processor alters the image data value corresponding to the compensation pixels according to the following:
• C.sub.NEW =C.sub.SINC (D.sub.ACT -D.sub.INT)+D.sub.INT
• where C.sub.NEW is the image data value assigned to the compensation pixel, C.sub.SINC is the value of the sinc function evaluated for the compensation pixel, D.sub.ACT is the actual intensity value of the defective pixel, and D.sub.INT is the desired intensity value of the defective pixel.

A display system comprising:

• a modulator comprised of an array of pixels including at least one defective pixel, at least one compensation pixel adjacent to the defective pixel, and at least one reference pixel adjacent to said at least one compensation pixel and spaced apart from said defective pixel, the modulator for receiving a set of image data values corresponding to the array of pixels and for selectively activating the pixels to represent the set of image data values;
• and
• a processor for receiving an image signal and outputting the set of image data values to the modulator, wherein the processor alters the image data value corresponding to the compensation pixels according to the following:
• C.sub.NEW =C.sub.SINC (D.sub.ACT -R.sub.AVG)+D.sub.INT
• where C.sub.NEW is the image date value assigned to the compensation pixel, C.sub.SINC is the value of the sinc function evaluated for the compensation pixel, D.sub.ACT is the actual intensity value of the defective pixel, R.sub.AVG is the average value of at least one of the reference pixels, and D.sub.INT is the desired intensity value of the defective pixel.