US 8,045,029 B2Granted

CMOS image sensor for high speed signal processing

AssigneeIntellectual Ventures II LLC

InventorsNam-Ryeol Kim, Song-Yi Kim, Chang-Min Bae, Hack-Soo Oh

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Abstract

A CMOS image sensor includes: a plurality of CDS/PGAs (correlating double sampling/programmable gain amplifiers) for processing output signals of pixels corresponding to same colors on different paths; and an offset difference removing part for removing offset difference that occurs when the same color signals are processed on the different paths, wherein the offset difference removing part includes: a dummy pixel array where light is shielded; a unit for reading signals of the dummy pixel array through the CDS/PGAs and storing average offset values for each path; and a signal synthesizing unit for synthesizing the average offset values and signals of an effective pixel array, which are read through the respective CDS/PGAs, and outputting signals of which offset difference is removed.

Claims15

Dependent claims

A complementary metal-oxide semiconductor (CMOS) image sensor, comprising:

a pixel array including red (R) pixels, green (G) pixels, blue (B) pixels, an effective pixel array, and a dummy pixel array configured to be shielded from light;
a first analog signal processing path and configured to process analog signals output from the G pixels of the pixel array, wherein the first analog signal processing path is subdivided into a G sub-path and a G′ sub-path;
and
a second analog signal processing path configured to process analog signals output from both the B pixels and the R pixels of the pixel array, wherein the second analog signal processing path is subdivided into a BR sub-path and a B′R′ sub-path;
wherein each of the first and second analog signal processing paths includes:
a plurality of correlated double-sampling/programmable gain amplifiers (CDS/PGAs) configured to process output signals of pixels corresponding to same colors on different paths;
a digital signal processor (DSP) configured to generate a digital average offset value for each path using signals of the dummy pixel array;
a unit configured to convert each digital average offset value into at least one analog average offset value;
and
a signal synthesizing unit configured to synthesize the analog average offset value and signals of the effective pixel array, configured to output a synthesized signal;
wherein a first portion of the G pixel signals are processed on the G sub-path, a second portion of the G pixels are processed on the G′ sub-path, a first portion of the R pixels and a first portion of the B pixels are processed on the BR sub-path, and a second portion of the R pixels and a second portion of the B pixels are processed on the B′R′ sub-path.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/114,386Filed 25 Apr 2005
Priority: KR 10-2004-002876926 Apr 2004
Published: US 2005/0253947 A117 Nov 2005
Granted: 25 Oct 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H04N 25/767
Addressed sensors, e.g. MOS or CMOS sensors: horizontal readout lines, multiplexers or registers
H04N 25/134
Characterised by the spectral characteristics of the filter elements: based on three different wavelength filter elements
H04N 25/41
Extracting pixel data from image sensors by controlling scanning circuits, e.g. by modifying the number of pixels sampled or to be sampled:…
H04N 25/633
Applied to dark current: by using optical black pixels