Photoelectric conversion apparatus that amplifies reference voltages corresponding to pixel signals of different colors at different gains

Patent metadata

Field	Value
Publication number	US-9267840-B2
Application number	US-201313891911-A
Country	US
Kind code	B2
Filing date	May 10, 2013
Priority date	May 24, 2012
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

A photoelectric conversion apparatus has: a plurality of pixels having mutually different color filters, and generating pixel signals by a photoelectric conversion; a color selecting switch for selecting the pixel signals generated by the plurality of pixels having mutually different color filters; a first amplifier circuit for amplifying at mutually different gains the pixel signals generated by the pixels having mutually different color filters and selected by the color selecting switch; a reference voltage connecting switch for selecting a reference voltage; and a second amplifier circuit for amplifying at mutually different gains the reference voltages correspondingly to the pixel signals of mutually different colors.

First claim

What is claimed is:

1. A photoelectric conversion apparatus comprising:
a plurality of pixels each generating pixel signals by a photoelectric conversion, and including a first pixel and a second pixel, the first pixel having a first color filter of a first color, the second pixel having a second color filter of a second color different from the first color;
a first amplifier circuit configured to input the pixel signal of the first pixel and the pixel signal of the second pixel, amplify the pixel signal of the first pixel at a first gain, and amplify the pixel signal of the second pixel at a second gain different from the first gain; and
a second amplifier circuit configured to input a reference signal, amplify the reference signal at a third gain in correspondence with the pixel signal of the first pixel inputted to the first amplifier circuit, and amplify the reference signal at a fourth gain in correspondence with the pixel signal of the second pixel inputted to the first amplifier circuit.

2. The photoelectric conversion apparatus according to claim 1 , wherein the first gain and the third gain are same, and the second gain and the fourth gain are same.

3. The photoelectric conversion apparatus according to claim 2 , further comprising a difference detector configured to perform a difference processing between the pixel signal amplified by the first amplifier circuit at the first gain, and the reference signal amplified by the second amplifier circuit at the third gain, and a difference processing between the pixel signal amplified by the first amplifier circuit at the second gain, and the reference signal amplified by the second amplifier circuit at the fourth gain.

4. The photoelectric conversion apparatus according to claim 3 , further comprising a read out switch configured to read out the pixel signal amplified by the first amplifier circuit and the reference signal amplified by the second amplifier circuit in a time division manner to the same output line.

5. The photoelectric conversion apparatus according to claim 3 , wherein the reference signal is generated by an optical black pixel shielded from light.

6. The photoelectric conversion apparatus according to claim 2 , wherein the reference signal is generated by an optical black pixel shielded from light.

7. The photoelectric conversion apparatus according to claim 1 , further comprising a difference detector configured to perform a difference processing between the pixel signal amplified by the first amplifier circuit and the reference signal amplified by the second amplifier circuit.

8. The photoelectric conversion apparatus according to claim 1 , further comprising a read out switch configured to read out the pixel signal amplified by the first amplifier circuit and the reference signal amplified by the second amplifier circuit in a time division manner to the same output line.

9. The photoelectric conversion apparatus according to claim 1 , further comprising;
a first capacitor configured to hold an offset signal corresponding to initialization of the first amplifier circuit, and
a second capacitor configured to hold the pixel signal amplified by the first amplifier circuit.

10. The photoelectric conversion apparatus according to claim 9 , further comprising a read out switch configured to read out, to the different output lines, the offset signal held by the first capacitor and the pixel signal held by the second capacitor.

11. The photoelectric conversion apparatus according to claim 1 , wherein the reference signal is generated by an optical black pixel shielded from light.

Assignees

• Canon Kk

Inventors

• Kato Satoshi

Classifications

• G01J3/513 Primary

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  SSIS architectures; Circuits associated therewith · CPC title

• H04N25/134

  based on three different wavelength filter elements · CPC title

• H04N23/70

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