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US5659358A Expired / Lapsed US ⏱️ 0.0 years remaining

Image pickup device with digital signal processing for reducing signal distortion

Assignee: Canon Inc
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Filing: 1994-03-02
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Granted: 1997-08-19
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Expires: 2014-03-02
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Abstract

Abstract An image pickup device comprises variable gain control circuits 11-13 and 23-25 for respective channels of digital color signals and luminance signals to control the gains by a gain control signal SG. Since the gains are variable in the digital signal channels, the deterioration of the image quality is reduced. The number of input bits of the variable gain control circuits is larger than the number of output bits to minimize the deterioration of the signal due to the loss of digits in coefficient circuits in the variable gain control circuits.

Inventors

  • 👤 Teruo Hieda

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 17:25
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/646; H04N5/00; H04N5/14; H04N5/20

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 98 words
An image pickup device for digitally processing a digital image pickup signal which is analog-to-digital converted from an output signal of a color image pickup device to produce a video signal, comprising: variable gain control means for varying gains of channels of color signals separated from the digital image pickup signal and luminance signals; gain control signal generation means for generating a signal to control the gains of said variable gain control means; and bits control means for making the number of input bits of said variable gain control means larger than the number of output bits thereof.
Claim 2
Dependent Claim 98 words
An image pickup device for digitally processing a digital image pickup signal which is analog-to-digital converted from an output signal of a color image pickup device to produce a video signal, comprising: variable gain control means for varying gains of channels of color signals separated from the digital image pickup signal and luminance signals; gain control signal generation means for generating a signal to control the gains of said variable gain control means; and bits control means for making the number of input bits of said variable gain control means larger than the number of output bits thereof.
Claim 3
Dependent Claim 29 words
An image pickup device according to claim 1 wherein the number of input bits of said variable gain control means is larger than the number of output bits thereof.
Claim 4
Dependent Claim 61 words
An image pickup device comprising: a) image pickup means for generating a digital image signal; b) variable gain control means for controlling a gain of the digital image signal outputted from said image pickup means; and c) bits control means for making the number of input bits of said variable gain control means larger than the number of output bits thereof.
Claim 5
Dependent Claim 61 words
An image pickup device comprising: a) image pickup means for generating a digital image signal; b) variable gain control means for controlling a gain of the digital image signal outputted from said image pickup means; and c) bits control means for making the number of input bits of said variable gain control means larger than the number of output bits thereof.
Claim 6
Dependent Claim 17 words
An image pickup device according to claim 3 wherein said image pickup means includes an AD converter.
Claim 7
Dependent Claim 20 words
An image pickup device according to claim 3 further comprising a digital filter provided before said variable gain control means.
Claim 8
Dependent Claim 18 words
An image pickup device according to claim 5 wherein said digital filter includes round means for rounding digits.

References Cited (Backward Citations)

US4345270A Cited
US4620222A Cited
US5293225A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-08-18 2001-02-17 2001-08-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-08-18 2005-02-17 2005-08-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-08-18 2009-02-17 2009-08-19 $7700.00 Window Closed / Lapsed

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