Patent US5198906A successfully refreshed from Google Patents.
← Back to Patent Explorer
US5198906A Expired / Lapsed US ⏱️ 0.0 years remaining

Defective pixel compensation with memory using interpolation via plural sample-and-hold circuits

Assignee: Sony Corp
•
Filing: 1991-10-21
•
Granted: 1993-03-30
•
Expires: 2011-10-21
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A defect correction circuit for a solid-state imaging device, made up of a large number of charge-coupled devices, is disclosed. The correcting circuit includes a storage circuit for storing position data indicating the position of a defective pixel among a number of pixels of the solid-state imaging device, a sampling pulse generator for generating a first sampling pulse timed to the pixels of the imaging device, a second sampling pulse phase-shifted by 180° with respect to the first sampling pulse, a first sample-and-hold circuit for sample-holding an imaging output signal from the imaging device by the first sampling pulse, and a second sample-and-hold circuit for sample-holding an output signal of the first sample-and-hold circuit by the second sampling pulse. The sampling pulse generator withholds the outputting of a first sampling pulse associated with the defective pixel among the pixels of the solid-state imaging device, based on the position data read out from the storage device. The sampling pulse generator also elongates the pulse width of a second sampling pulse associated with the defective pixel as far as at least the trailing edge of a first sampling pulse succeeding the second sampling pulse. The defect correction circuit may additionally include a third sample-and-hold circuit for oversampling the imaging output signal corrected for defect by the second sample-and-hold circuit by a third sampling pulse to eliminate noise contained in the imaging output signal.

Inventors

  • 👤 Masahiro Yamashita

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 20:29
CPC Classifications
H; H04; H04N; H04N25/00; H04N25/70; H04N25/71; H04N25/60; H04N25/616; H04N25/68

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 184 words
A defect correcting circuit for a solid-state imaging device comprising a storage circuit for storing position data indicating the position of a defective pixel among a number of pixels of the solid-state imaging device, a sampling pulse generator for generating a first sampling pulse timed to the pixels of the imaging device, and a second sampling pulse phase-shifted by 180° with respect to said first sampling pulse, a first sample-and-hold circuit for sample-holding an imaging output signal from the imaging device by said first sampling pulse, and a second sample-and-hold circuit for sample-holding an output signal of said first sample-and-hold circuit by said second sampling pulse, characterized in that said sampling pulse generator withholds the outputting of a first sampling pulse associated with the defective pixel among the pixels of the solid-state imaging device, based on said position data read out from said storage means, and in that said sampling pulse generator elongates the pulse width of a second sampling pulse associated with the defective pixel as far as at least the trailing edge of a first sampling pulse succeeding said second sampling pulse.
Claim 2
Dependent Claim 184 words
A defect correcting circuit for a solid-state imaging device comprising a storage circuit for storing position data indicating the position of a defective pixel among a number of pixels of the solid-state imaging device, a sampling pulse generator for generating a first sampling pulse timed to the pixels of the imaging device, and a second sampling pulse phase-shifted by 180° with respect to said first sampling pulse, a first sample-and-hold circuit for sample-holding an imaging output signal from the imaging device by said first sampling pulse, and a second sample-and-hold circuit for sample-holding an output signal of said first sample-and-hold circuit by said second sampling pulse, characterized in that said sampling pulse generator withholds the outputting of a first sampling pulse associated with the defective pixel among the pixels of the solid-state imaging device, based on said position data read out from said storage means, and in that said sampling pulse generator elongates the pulse width of a second sampling pulse associated with the defective pixel as far as at least the trailing edge of a first sampling pulse succeeding said second sampling pulse.
Claim 3
Dependent Claim 64 words
The defect correcting circuit as claimed in claim 1 characterized in that said first sample-and-hold circuit performs defect correction on an imaging output signal from the defective pixel of the imaging device by 0'th order holding interpolation, and in that said second sample-and-hold circuit performs defect correction on the imaging output signal, corrected for defect by said first sample-and-hold circuit, by a mean-value interpolation.
Claim 4
Dependent Claim 41 words
The defect correction circuit as claimed in claim 2 further comprising a third sample-and-hold circuit for oversampling an imaging output signal corrected for defect by said sample-and-hold circuit by a third sampling pulse for eliminating noise in said imaging output signal.
Claim 5
Dependent Claim 63 words
The defect correcting circuit as claimed in claim 1 characterized in that it is used with a color imaging device operating in accordance with a spatial pixel shift system in which a solid-state image sensor for green-color imaging and solid-state image sensors for blue-color and red-color imaging are arrayed with a horizontal shift by one-half the pixel pitch with respect to each other.

References Cited (Backward Citations)

US5095368A Cited
US5010408A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-03-29 1996-09-28 1997-03-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-03-29 2000-09-28 2001-03-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-03-29 2004-09-28 2005-03-30 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag