Color filter array with reference pixel to reduce spectral crosstalk
AssigneeOmniVision Technologies, Inc.
InventorsChen-Wei Lu, Jin Li, Yin Qian, Dyson H. Tai
Life of this patent
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Abstract
A color filter array includes a plurality of tiled minimal repeating units, each minimal repeating unit comprising an M×N set of individual filters. Each minimal repeating unit includes a plurality of imaging filters including individual filters having at least first, second, and third photoresponses, and at least one reference filter having a reference photoresponse, wherein the reference filter is positioned among the imaging filters and wherein the reference photoresponse transmits substantially the same percentage of wavelengths that remain unfiltered by filters of a different photoresponse than the incident wavelength. Other embodiments are disclosed and claimed.
Claims24
A color filter array comprising:
- a plurality of tiled minimal repeating units, wherein a minimal repeating unit is a repeating unit such that no other repeating unit has fewer individual filters, and wherein every one of the plurality of tiled minimal repeating units is an M×N set of individual filters including:
- a plurality of imaging filters including individual filters having at least first, second, and third photoresponses;
- and
- at least one reference filter having a reference photoresponse, wherein the reference filter is positioned among the imaging filters and wherein the reference photoresponse transmits substantially the same percentage of wavelengths that remain unfiltered by filters of a different photoresponse than the incident wavelength.
An image sensor comprising:
- a pixel array including a plurality of individual pixels;
- a color filter array positioned over and optically coupled to the pixel array, the color filter array comprising a plurality of tiled minimal repeating units, wherein a minimal repeating unit is a repeating unit such that no other repeating unit has fewer individual filters, and wherein every one of the plurality of tiled minimal repeating units is an M×N set of individual filters including:
- a plurality of imaging filters including individual filters having at least first, second, and third photoresponses, and
- at least one reference filter having a reference photoresponse, wherein the reference filter is positioned among the imaging filters and wherein the reference photoresponse transmits substantially the same percentage of wavelengths that remain unfiltered by filters of a different photoresponse than the incident wavelength;
- and
- readout circuitry coupled to the pixel array to read out signals from the individual pixels.
A process comprising:
- capturing an image comprising a plurality of imaging pixel values and a plurality of reference pixel values using a pixel array including a plurality of individual pixels optically coupled to a color filter array positioned over the pixel array, the color filter array comprising a plurality of tiled minimal repeating units, wherein a minimal repeating unit is a repeating unit such that no other repeating unit has fewer individual filters, and wherein every one of the plurality of tiled minimal repeating units is an M×N set of individual filters including:
- a plurality of imaging filters, each imaging filter optically coupled to an imaging pixel, wherein the plurality of imaging filters includes individual filters having at least first, second, and third photoresponses, and
- at least one reference filter optically coupled to a reference pixel, the reference filter having a reference photoresponse, wherein the reference filter is positioned among the imaging filters and wherein the reference photoresponse transmits substantially the same percentage of wavelengths that remain unfiltered by filters of a different photoresponse than the incident wavelength;
- adjusting imaging pixel values based on one or more reference pixel values to reduce or remove spectral crosstalk from the imaging pixel values.
Dependencies are inferred from the claim text.