Video signal reproduction apparatus for chrominance signals
AssigneeSanyo Electric Co., Ltd.
InventorHiroshi Iizuka
Life of this patent
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Abstract
A video signal reproduction apparatus reproduces a chrominance signal which has been converted to a low frequency band and recorded on a magnetic tape. The low frequency chrominance signal read out from the magnetic tape is first subjected to phase recovery processing. Then, frequency conversion is carried out for the phase recovered chrominance signal to generate a reproduced chrominance signal. Thus, phase recovery is carried out prior to frequency conversion, and an oscillation signal can be directly supplied to the frequency converter from a voltage controlled oscillator in a phase controller, thereby achieving an accurate frequency conversion. This structure allows an extra frequency converter or a complicated band pass filter to be omitted.
Claims8
A video signal reproduction apparatus for a chrominance signal which has been converted to a low frequency band and recorded on a magnetic tape, said video signal reproduction apparatus comprising:
- a phase recovery circuit, the phase recovery circuit receiving a first frequency chrominance signal read out from the magnetic tape and recovering the phase of the first frequency chrominance signal to generate a phase recovered chrominance signal;
- a frequency converter, the frequency converter receiving the already phase recovered grist frequency chrominance signal that has passed through the phase recovery circuit and converting the frequency of the phase recovered first frequency chrominance signal to generate a second frequency reproduced chrominance signal,
- wherein the first frequency chrominance signal read out from the magnetic tape is received by the phase recovery circuit before passing through the frequency converter and the first frequency is lower than the second frequency an oscillator which oscillates at a burst signal frequency, and a phase controller including a phase comparator for comparing the phase of a burst component of the reproduced chrominance signal with the oscillation signal from the oscillator, a filter for smoothing the comparison signal form the phase comparator, and a voltage controlled oscillator having an oscillation frequency that varies in response to the output form the filter, the output of the voltage controlled oscillator controlling the frequency conversion in the frequency converter.
A video signal reproduction apparatus for a chrominance signal which has been converted to a low frequency band and recorded on a magnetic tape, said video signal reproduction apparatus comprising:
- a phase recovery circuit,
- a frequency converter,
- wherein a first frequency chrominance signal is read out from the magnetic tape, is passed through the phase recovery circuit before passing through the frequency converter in order to recover the phase of the first frequency chrominance signal, and is then passed through the frequency converter in order to convert the frequency of the first frequency chrominance signal, which has previously been phase recovered, to generate a second frequency reproduced chrominance signal the first frequency being lower than the second frequency an oscillator which oscillates at a burst signal frequency, and a phase controller including a phase comparator for comparing the phase of a burst component of the reproduced chrominance signal with the oscillation signal from the oscillator, a filter for smoothing the comparison signal form the phase comparator, and a voltage controlled oscillator having an oscillation frequency that varies in response to the output form the filter, the output of the voltage controlled oscillator controlling the frequency conversion in the frequency converter.
A video signal reproduction apparatus for a chrominance signal which has been converted to a low frequency band and recorded on a magnetic tape, said video signal reproduction apparatus comprising:
- an input terminal that receives a first frequency chrominance signal read out from the magnetic tape;
- a phase recovery circuit that recovers the phase of the first frequency chrominance signal to generate a phase recovered chrominance signal;
- a frequency converter that converts the frequency of the phase recovered first frequency chrominance signal to generate a second frequency reproduced chrominance signal;
- an output terminal that receives the second frequency reproduced chrominance signal,
- wherein the input terminal, the phase recovery circuit, the frequency converter, and the output terminal are coupled in series such that the chrominance signal passes through the phase recovery circuit before passing through the frequency converters so that the chrominance signal is phase recovered before reaching the frequency converter, the first frequency being lower than the second frequency an oscillator which oscillates at a burst signal frequency, and a phase controller including a phase comparator for comparing the phase of a burst component of the reproduced chrominance signal with the oscillation signal from the oscillator, a filter for smoothing the comparison signal form the phase comparator, and a voltage controlled oscillator having an oscillation frequency that varies in response to the output form the filter, the output of the voltage controlled oscillator controlling the frequency conversion in the frequency converter.
Dependencies are inferred from the claim text.