IMAGER ROW-WISE NOISE CORRECTION

• US 20100020213A1
• Filed: 10/06/2009
• Published: 01/28/2010
• Est. Priority Date: 02/28/2005
• Status: Active Grant

• Current Assignee: Rick Mauritzson
• Original Assignee: Rick Mauritzson
• Inventors: Mauritzson, Rick
• Granted Patent: US 7,852,385 B2
• Time in Patent Office: Days
• US Class Current: 348/294
• CPC Class Codes: H01L 27/14603 Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 27/14623 Optical shielding
• CPC Class Codes: H04N 25/63 applied to dark current
• CPC Class Codes: H04N 25/68 applied to defects
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array

Abstract

An imager having optically and electrically black reference pixels in each row of the imager'"'"'s pixel array. Since the reference pixels of each row experience the same row-wise noise as active imaging pixels in the associated row, the signals from the reference pixels are used to cancel out row-wise noise from the row of imaging pixels. The reference pixels are designed such that their photosensors are physically or effectively removed from the row-wise noise correction, thus rendering them electrically black or dark. As such, the reference pixels can be used to provide row-wise noise correction without the adverse effects of warm and hot pixels.

Claims

1. An imaging device comprising:

an array of imaging pixels, said array being organized into a plurality of rows and columns;

a plurality of optically black pixels being arranged into a plurality of rows, said optically black pixels for generating optically black signals used for a black level pedestal; and

a plurality of reference pixels, said plurality of reference pixels being arranged into a plurality of rows, each row of reference pixels corresponding to a respective row of imaging pixels within said array, each reference pixel including a circuit for causing said reference pixel to output electrically black signals to be used in row-wise noise correction of signals from the imaging pixels from its associated row, each reference pixel has a different configuration than the optically black pixels and comprises a photosensor directly coupled to a floating diffusion region, said reference pixel being operable to output electrically black signals by resetting the photosensor and floating diffusion region prior to readout.

13. The device of claim 1, wherein said imaging pixels and reference pixels are CMOS pixels.

14. The device of claim 1, wherein said imaging pixels and reference pixels are CCD pixels.

15. The device of claim 1, wherein each reference pixel comprises a photosensor that does not have an accumulation region.

2-12. -12. (canceled)

16. A processor system comprising:

a processor; and

an imaging device coupled to said processor, said device comprising;

an array of imaging pixels, said array being organized into a plurality of rows and columns,

a plurality of optically black pixels being arranged into a plurality of rows, said optically black pixels for generating optically black signals used for a black level pedestal; and

a plurality of reference pixels, said plurality of reference pixels being arranged into a plurality of rows, each row of reference pixels corresponding to a respective row of imaging pixels within said array, each reference pixel including a circuit for causing said reference pixel to output electrically black signals to be used in row-wise noise correction of signals from the imaging pixels from its associated row, each reference pixel has a different configuration than the optically black pixels and comprises a photosensor directly coupled to a floating diffusion region, said reference pixel being operable to output electrically black signals by resetting the photosensor and floating diffusion region prior to readout.

28. The system of claim 16, wherein said imaging device is a CMOS imager.

29. The system of claim 16, wherein said imaging pixels and reference pixels are CMOS pixels.

30. The system of claim 16, wherein said imaging device is a CCD imager.

31. The system of claim 16, wherein each reference pixel comprises a photosensor that does not have an accumulation region.

17-27. -27. (canceled)

32-47. -47. (canceled)

48. An imaging device comprising:

an array of imaging pixels, said array being organized into a plurality of rows and columns;

a plurality of optically black pixels being arranged into a plurality of rows, said optically black pixels for generating optically black signals used for a black level pedestal; and

a plurality of reference pixels, said plurality of reference pixels being arranged into a plurality of rows, each row of reference pixels corresponding to a respective row of imaging pixels within said array, each reference pixel including a circuit for causing said reference pixel to output electrically black signals to be used in row-wise noise correction of signals from the imaging pixels from its associated row, each reference pixel has a different configuration than the optically black pixels and comprises a photosensor that does not have an accumulation region.