Color filter array with reference pixel to reduce spectral crosstalk

Patent metadata

Field	Value
Publication number	US-9479745-B2
Application number	US-201414491039-A
Country	US
Kind code	B2
Filing date	Sep 19, 2014
Priority date	Sep 19, 2014
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

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 crosstalk spectrum that is not filtered from light incident on the color filter array by the plurality of imaging filters. Other embodiments are disclosed and claimed.

First claim

The invention claimed is:

1. A color filter array comprising:
a plurality of tiled minimal repeating units, each minimal repeating unit comprising an M×N set of individual filters, wherein each minimal repeating unit includes:
a plurality of imaging filters including individual filters having at least first, second, third, and fourth 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 crosstalk spectrum that is not filtered from light incident on the color filter array by the plurality of imaging filters;

wherein the first photoresponse is panchromatic (C), the second photoresponse is red (R), the third photoresponse is green (G), and the fourth photoresponse is blue (B), and wherein the minimal repeating unit is selected from a group consisting of a minimal repeating unit wherein M=N=4 and the minimal repeating unit is:

R
C
G
C

C
R
Re
G

G
C
B
C

C
G
C
B

and a minimal repeating unit wherein M=N=8 and the minimal repeating unit is:

R
C
G
C
R
C
G
C

C
R
Re
G
C
R
C
G

G
C
B
C
G
Re
B
C

C
G
C
B
C
G
C
B

R
C
G
C
R
C
G
C

C
R
C
G
C
R
Re
G

G
Re
B
C
G
C
B
C

C
G
C
B
C
G
C
B

wherein Re represents a filter with the reference photoresponse.

2. A color filter array comprising:
a plurality of tiled minimal repeating units, each minimal repeating unit comprising an M×N set of individual filters, wherein 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 crosstalk spectrum that is not filtered from light incident on the color filter array by the plurality of imaging filters;

wherein the first photoresponse is red (R), the second photoresponse is green (G), and the third photoresponse is blue (B), and wherein M=N=2 and the minimal repeating unit is:

Re
R

B
G

wherein Re represents a filter with the reference photoresponse.

3. 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, each minimal repeating unit comprising an M×N set of individual filters, wherein each minimal repeating unit includes:
a plurality of imaging filters including individual filters having at least first, second, third, and fourth 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 only the crosstalk spectrum that is not filtered from light incident on the color filter array by the plurality of imaging filters;

wherein the first photoresponse is panchromatic (C), the second photoresponse is red (R), the third photoresponse is green (G), and the fourth photoresponse is blue (B), wherein the minimal repeating unit is selected from a group consisting of a minimal repeating unit wherein M=N=4 and the minimal repeating unit is:

R
C
G
C

C
R
Re
G

G
C
B
C

C
G
C
B

Assignees

• Omnivision Tech Inc

Inventors

• Lu Chen-Wei
• Li Jin
• Qian Yin
• Tai Dyson H

Classifications

• H04N25/135 Primary

  based on four or more different wavelength filter elements · CPC title

• H04N25/70

  SSIS architectures; Circuits associated therewith · CPC title

• H04N25/60

  Noise processing, e.g. detecting, correcting, reducing or removing noise · CPC title

• H04N25/133

  including elements passing panchromatic light, e.g. filters passing white light · CPC title

• H04N25/78

  Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters · CPC title