Patent JPS6080307A successfully refreshed from Google Patents.
EP0137994A2
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EP
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Secondary beat signal cancel circuit for magnetic reproducing apparatus
Assignee: Sony Corp
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Filing: 1984-08-28
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Granted: —
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Expires: 2004-08-28
Abstract
Abstract A magnetic reproducing apparatus is provided with an improved secondary beat signal cancel circuit for reducing a secondary beat signal of a low-frequency converted chroma signal leaked into a reproduced luminance signal without deteriorating a vertical resolution at an edge portion of an oblique check signal.A secondary beat signal cancel operation is stopped during a period in which no vertical correlation exists between the edge portions of two succeeding horizontal lines of the oblique check signal.
Inventors
- 👤 Toshihiko C/O Sony Corporation Kitazawa
- 👤 Ichitaro C/O Sony Corporation Sato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 20:48
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/79; H04N9/7908; H04N9/7912
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
145 words
A circuit for reducing a secondary beat signal of a low-frequency converted chrominance signal leaked into a repro - duced luminance signal, said secondary beat signal being produced due to the transformation of said luminance and chrominance signals through a non-linear transmission medium comprising: (a) means for deriving a secondary beat signal and a non-correlation signal indicating a difference between succeeding horizontal line signals from said reproduced luminance signal which includes said secondary beat signals; (b) means for detecting an amplitude of said chrominance signal of a reproduced video signal; (c) means for controlling an amplitude of said secondary beat signal in response to said detected amplitude of said chrominance signal; (d) means for subtracting said controlled amplitude of said secondary beat signal from said reproduced luminance signal; and (e) means for controlling an operation of said subtracting means in response to said non-correlation signal.
Claim 2
Dependent Claim
145 words
A circuit for reducing a secondary beat signal of a low-frequency converted chrominance signal leaked into a repro - duced luminance signal, said secondary beat signal being produced due to the transformation of said luminance and chrominance signals through a non-linear transmission medium comprising: (a) means for deriving a secondary beat signal and a non-correlation signal indicating a difference between succeeding horizontal line signals from said reproduced luminance signal which includes said secondary beat signals; (b) means for detecting an amplitude of said chrominance signal of a reproduced video signal; (c) means for controlling an amplitude of said secondary beat signal in response to said detected amplitude of said chrominance signal; (d) means for subtracting said controlled amplitude of said secondary beat signal from said reproduced luminance signal; and (e) means for controlling an operation of said subtracting means in response to said non-correlation signal.
Claim 3
Dependent Claim
78 words
The circuit according to claim 1, in which said deriving means includes a separating circuit having two circuit paths, one of said two circuit paths for deriving said secondary beat signal having a band pass filter and a limiting amplifier circuit serially coupled to said first-mentioned controlling means and the other of said two circuit paths for deriving said non-correlation signal having an amplifier, a band-eliminating filter and a full-wave rectifier serially coupled to said last-mentioned controlling means.
Claim 4
Dependent Claim
60 words
The circuit according to claim 2, in which said last-mentioned controlling means includes two input terminals to which said full-wave rectified non-correlation signal and said detected amplitude signal are respectively supplied so that said detected amplitude signal is controlled so as to be applied to said first-mentioned controlling means during a period in which said full-wave rectified non-correlation signal occurs.
Claim 5
Dependent Claim
43 words
The circuit according to claim 3 further comprising delay line means connected between an input terminal of said luminance signal and said subtracting means, said delay line means having a time delay substantially equal to a time delay caused by said deriving means.
References Cited (Backward Citations)
No citation records indexed.
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