Active pixel sensor with reduced fixed pattern noise

• US 20050127414A1
• Filed: 01/31/2005
• Published: 06/16/2005
• Est. Priority Date: 04/23/1999
• Status: Active Grant

• Current Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Original Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Inventors: Barna, Sandor L., Andersson, Anders
• Granted Patent: US 7,525,582 B2
• Time in Patent Office: Days
• US Class Current: 257/291
• CPC Class Codes: H01L 27/14603 Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14654 Blooming suppression
• CPC Class Codes: H01L 27/14656 Overflow drain structures
• CPC Class Codes: H04N 25/616 involving a correlated sampling function, e.g. correlated double sampling [CDS] or triple sampling
• CPC Class Codes: H04N 25/65 applied to reset noise, e.g. KTC noise related to CMOS structures by techniques other than CDS
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array

Abstract

An image sensor includes pixels each of which is designed to transfer charge, accumulated in a photoactive region of the pixel during a first period, through a second active region of the pixel to a power supply node, and to transfer charge, accumulated in the photoactive region during a second period, through the second active region to a sense node in the pixel. Passing charge through the second active region prior to transferring it either to the power supply node or the sense node can help reduce fixed pattern noise. The image sensor can be operated in snap-shot mode.

Claims

1. A method of operating a pixel, the method comprising:

transferring charge, accumulated in a photoactive region of the pixel during a first period, through a second active region of the pixel to a power supply node; and

transferring charge, accumulated in the photoactive region during a second period, through the second active region to a sense node in the pixel.

2-24. -24. (canceled)