# US 8,786,723 B2 · Photoelectric-conversion device

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- Number: US 8,786,723 B2
- Document ID: US8786723B2
- Status: Granted
- Kind: B2
- Application number: 12/958,238
- Filed: 2010-12-01
- Published: 2011-06-09
- Granted: 2014-07-22
- Earliest claimed: 2009-12-07
- Assignees: Canon Kabushiki Kaisha
- Applicants: Tomohisa Kinugasa
- Inventors: Tomohisa Kinugasa
- Web page: https://patentgrep.com/patent/US8786723B2

## CPC

- H04N 25/65: applied to reset noise, e.g. KTC noise related to CMOS structures by techniques other than CDS
- H04N 23/672: {based on the phase difference signals}
- H04N 25/77: Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

A photoelectric-conversion device including at least two memory-cell units for a single sensor-cell unit is provided. A reset noise generated due to initialization of the sensor-cell unit is written into each of the memory-cell units at one time.

## Claims

### Claim 1

A focus-detection device comprising:
a pair of line-sensor units,
wherein each line-sensor unit includes a plurality of unit pixels each having a sensor-cell unit that outputs a signal obtained by photoelectric conversion, and a plurality of memory-cell units,
wherein the focus-detection device writes, in a temporally overlapped manner, a reset noise generated due to initialization of one of the sensor-cell units into each of the corresponding memory-cell units,
wherein the device further comprises a transfer unit configured to receive a signal from the unit pixel and to transfer the signal to the unit pixel, where the transfer unit performs a difference processing between the signal from the sensor-cell unit, and the reset noise written in the corresponding memory-cell unit and a noise generated in the transfer unit,
wherein, for a first region of each of the line-sensor units, the focus-detection device performs the difference processing using one of the memory-cell units of each of the unit pixels, and detects the defocusing amount from a second region of each of the line-sensor units, the second region being of a wider region of the line-sensor unit and performs the difference processing through a memory-cell unit different from the one of the memory-cell units of each of the unit pixels.

### Claim 2 (depends on 1)

An image pickup system comprising the focus-detection device according to claim 1.

### Claim 3 (depends on 2)

The image pickup system according to claim 2, wherein the focus-detection device is a phase-difference detection-type focus-detection device.

### Claim 4 (depends on 1)

The image pickup system according to claim 1, wherein a noise generated in the transfer unit is included in the reset noise.

### Claim 5 (depends on 1)

The focus-detection device according to claim 1, wherein each of the sensor-cell units includes a photoelectric-conversion unit and an amplifying unit configured to amplify and output a signal based on an electrical charge generated in the photoelectric-conversion unit.