Image capturing system for correcting signals output from defective pixels

• US 8,456,550 B2
• Filed: 10/18/2011
• Issued: 06/04/2013
• Est. Priority Date: 05/02/2007
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Takenaka, Shintaro, Sonoda, Kazuhiro, Kitani, Kazunari
• Primary Examiner(s): Hernndez Hernndez, Nelson D.
• Assistant Examiner(s): HOGUE, DENNIS A
• Application Number:
  US13/275,596
• Publication Number:
  US 20120033111A1
• Time in Patent Office: 595 Days
• Field of Search: None
• US Class Current: 348/246
• CPC Class Codes: H04N 25/63 applied to dark current
• CPC Class Codes: H04N 25/68 applied to defects

Abstract

An image capturing system includes a signal correction unit which corrects a signal output from a defective pixel in an optical black region based on a signal output from a normal pixel. The optical black region has a plurality of pixel blocks. Each of the plurality of pixel blocks has a plurality of pixels each including one or more elements which have the same functions as in the remaining pixels and which have relative positions different from the remaining pixels. The signal correction unit corrects the signal output from the defective pixel in the optical black region based on a signal output from a normal pixel which is included in another pixel block different from the pixel block of the defective pixel in the optical black region and includes one or more elements having the same functions and same relative positions as in the defective pixel.

Claims

1. An image capturing system comprising:

an optical black region having a plurality of pixel blocks, wherein each of the plurality of pixel blocks has a plurality of pixels in a column for outputting a dark reference signal, each pixel block including at least one transistor which performs, for each pixel of the pixel block, the same function, and each pixel having a relative position, which is a position within the pixel block to which that pixel belongs, different from that of the remaining pixels of the pixel block to which that pixel belongs; and

a signal correction unit which corrects a signal output from a defective pixel of a pixel block of the plurality of pixel blocks in accordance with only a signal output from a normal pixel of a pixel block of the plurality of pixel blocks, wherein the pixel block including the normal pixel is different from the pixel block including the defective pixel and in a same column as the pixel block including the defective pixel,

wherein the normal pixel, whose signal is used by the signal correction unit for the correction, has a relative position within the pixel block to which the normal pixel belongs, that is the same as a relative position of the defective pixel within the pixel block to which the defective pixel belongs.

2. The image capturing system according to claim 1, wherein the at least one transistor includes an amplification transistor.