Patent US5221963A successfully refreshed from Google Patents.
US5221963A
Expired / Lapsed
US
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Video camera having a video signal processing apparatus
Assignee: Minolta Co Ltd
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Filing: 1991-03-29
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Granted: 1993-06-22
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Expires: 2011-03-29
Abstract
Abstract A video camera comprising a taking lens, an image taking circuit which generates a video signal by receiving a light having passed through the taking lens, a knee correction circuit which compresses a video signal generated by the image taking circuit and having a level as high as or higher than a predetermined level, a detection circuit which detects a luminance distribution condition of a field, a pedestal adjusting circuit which adjusts a black level of the video signal generated by the image taking circuit and a control circuit which changes a compression method of a video signal in the knee correction circuit and an adjusting method of the black level in the pedestal adjusting circuit according to a luminance distribution condition of a field detected by the detection circuit. According to the present invention, it is possible to perform various controls in response to a luminance condition of a field.
Inventors
- 👤 Nobuo Hashimoto
- 👤 Hiroaki Kubo
- 👤 Yuuichi Kunisaki
- 👤 Yoshito Konishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:32
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/14; H04N5/20; H04N23/00; H04N23/70; H04N23/76; H04N23/71; H04N23/72
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
88 words
A video camera comprising: a taking lens; image taking means for generating a video signal by receiving a light having passed through said taking lens; knee correction means for compressing the video signal having a level higher than a predetermined level generated by said image taking means; detection means for detecting a luminance difference between a main subject and a background; and control means for changing a compression method of a video signal in said knee correction means according to the luminance difference detected by said detection means.
Claim 2
Dependent Claim
88 words
A video camera comprising: a taking lens; image taking means for generating a video signal by receiving a light having passed through said taking lens; knee correction means for compressing the video signal having a level higher than a predetermined level generated by said image taking means; detection means for detecting a luminance difference between a main subject and a background; and control means for changing a compression method of a video signal in said knee correction means according to the luminance difference detected by said detection means.
Claim 3
Dependent Claim
44 words
A video camera according to claim 1, wherein said detection means detect a luminance of a lower center of a taken image plane as a luminance of the main subject and detect an average luminance of the taken as a luminance of the background.
Claim 4
Dependent Claim
34 words
A video camera according to claim 1, wherein said detection means detect the luminance difference between a bright main subject and a dark background or between a dark main subject and a bright background.
Claim 5
Dependent Claim
36 words
A video camera according to claim 1, wherein said image taking means generate video signals of red, green and blue, respectively, and said knee correction means compress said video signals of red, green and blue, respectively.
Claim 6
Dependent Claim
33 words
A video camera according to claim 1, wherein said control means change a compression starting point (knee point) of said knee correction means according to the luminance difference detected by said detection means.
Claim 7
Dependent Claim
25 words
A video camera according to claim 5, wherein said control means lower the knee point as the luminance difference detected by said detection means increases.
Claim 8
Dependent Claim
30 words
A video camera according to claim 1, wherein said control means change a compression rate of said knee correction means according to the luminance difference detected by said detection means.
Claim 9
Dependent Claim
25 words
A video camera according to claim 7, wherein said control means increase a compression rate as the luminance difference detected by said detection means increases.
Claim 10
Dependent Claim
28 words
A video camera according to claim 1, wherein said knee correction means have a feedback loop and the video signal output from said correction means is input again.
Claim 11
Dependent Claim
84 words
A video camera comprising: a taking lens; image taking means for generating a video signal by receiving a light having passed through said taking lens; pedestal adjusting means for adjusting a black level of the video signal generated by said image taking means; detection means for detecting a luminance difference between a main subject and a background; and control means for changing an adjusting method of the black level by said pedestal adjusting means according to the luminance difference detected by said detection means.
Claim 12
Dependent Claim
84 words
A video camera comprising: a taking lens; image taking means for generating a video signal by receiving a light having passed through said taking lens; pedestal adjusting means for adjusting a black level of the video signal generated by said image taking means; detection means for detecting a luminance difference between a main subject and a background; and control means for changing an adjusting method of the black level by said pedestal adjusting means according to the luminance difference detected by said detection means.
Claim 13
Dependent Claim
46 words
A video camera according to claim 10, wherein said detection means detect a luminance of a lower center of a taken image plane as a luminance of the main subject and detect an average luminance of the taken image plane as a luminance of the background.
Claim 14
Dependent Claim
34 words
A video camera according to claim 10, wherein said detection means detect the luminance difference between a bright main subject and a dark background or between a dark main subject and a bright background.
Claim 15
Dependent Claim
35 words
A video camera according to claim 10, wherein said image taking means generate video signals of red, green and blue, respectively, and said pedestal adjusting means compress video signals of red, green and blue, respectively.
Claim 16
Dependent Claim
34 words
A video camera according to claim 10, wherein said control means change a reference voltage to the black level of said pedestal adjusting means according to the luminance difference detected by said detection means.
Claim 17
Dependent Claim
29 words
A video camera according to claim 14, wherein said control means increase the reference voltage to the black level as the luminance difference detected by said detection means increases.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-06-21 | 1996-12-21 | 1997-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-21 | 2000-12-21 | 2001-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-21 | 2004-12-21 | 2005-06-22 | $7700.00 | Window Closed / Lapsed |