Claims
- 1. A circuit for reducing a secondary beat signal of a low-frequency converted chrominance signal leaked into a reproduced luminance signal, said secondary beat signal being produced because of the transmission of said luminance and chrominance signals through a non-linear transmission medium; said circuit comprising:
- means for deriving a non-correlation signal having a leakage chrominance signal component superimposed thereon and an edge signal indicating a difference between luminance signal levels of corresponding points of succeeding horizontal scan lines;
- means for detecting an amplitude of said chrominance signal;
- level control means responsive to said detected amplitude of said chrominance signal for controlling an amplitude of said non-correlation signal in response to said detected amplitude of said chrominance signal to produce a signal of controlled amplitude such that said chrominance signal and said leakage chrominance signal component have equal amplitudes;
- means responsive to said signal of controlled amplitude and said reproduced luminance signal for subtracting said signal of controlled amplitude from said reproduced luminance signal; and
- gate means for inhibiting output from said level control means in response to said edge signal.
- 2. 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 deriving said non-correlation signal and having a band pass filter and a limiting amplifier circuit serially coupled to said level control means and the other of said two circuit paths deriving said edge signal and having an amplifier, a band-eliminating filter and a full-wave rectifier serially coupled to said gate means, whereby the edge signal supplied to said gate means is full-wave rectified.
- 3. The circuit according to claim 2, in which said gate means includes two input terminals to which said full-wave rectified edge signal and said detected amplitude signal are respectively supplied so that said detected amplitude signal is inhibited from being applied to said level control means during a period in which said full-wave rectified edge signal occurs.
- 4. 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.
Priority Claims (1)
Number |
Date |
Country |
Kind |
58-159461 |
Aug 1983 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 06/643,371, filed Aug. 23, 1984, now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (2)
Number |
Date |
Country |
56-96590 |
Aug 1981 |
JPX |
57-3486 |
Aug 1982 |
JPX |
Non-Patent Literature Citations (2)
Entry |
Hobbs, M., Servicing Home Video Cassette Recorders, 1982, pp. 31-41. |
Sony Basic Video Recording Cource, Tape Formats, 1979, pp. 3-6 and 10-11. |
Continuations (1)
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Number |
Date |
Country |
Parent |
643371 |
Aug 1984 |
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