Recording and reproducing system
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsChojuro Yamamitsu, Ichiro Arimura, Hiroshi Taniguchi
Life of this patent
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Abstract
A video signal recording and reproducing system in which a video signal to be recorded is passed through preemphasis means and subsequently angular modulated so that it is recorded on a record medium. During playback operation, the video signal is angular demodulated and deemphasized through a deemphasis means. Preemphasis means comprises both a non-linear preemphasis circuit and a fixed preemphasis circuit. The deemphasis means similarly comprises a fixed deemphasis circuit and a non-linear deemphasis circuit. Each of the non-linear circuits is responsive to the amplitude of an input signal thereon.
Claims9
A video signal recording and reproducing system in which a video signal to be recorded is passed through preemphasis means and subsequently angular-modulated so that it is recorded on a record medium, and in playback operation the video signal to be reproduced is angular demodulated and then deemphasized through deemphasis means, wherein:
- said preemphasis means comprises a first non-linear preemphasis circuit having a frequency characteristic variable according to the amplitude of the video signal applied thereto for emphasizing the amplitude of high frequency components of the video signal to the extent of a first predetermined value, and a fixed preemphasis circuit connected to said non-linear preemphasis circuit for receiving and further emphasizing the amplitude of said high frequency components to the extent of a second predetermined value;
- said deemphasis means comprises a fixed deemphasis circuit for deemphasizing noises of the reproduced signal to the extent of the substantially same value as the second predetermined value of said fixed preemphasis circuit, and a non-linear deemphasis circuit connected to said fixed deemphasis circuit for receiving the deemphasized output and further deemphasizing the amplitude of high frequency components of the reproduced signal to the extent of the substantially same value as the first predetermined value of said non-linear preemphasis circuit;
- said non-linear deemphasis circuit including an amplifier having an input terminal to which a demodulation signal is applied and an output terminal, and a negative feedback circuit for negatively feeding the output of said amplifier back to the input terminal of said amplifier.
A video signal recording and reproducing system in which a video signal to be recorded is passed through preemphasis means and subsequently angular-modulated so that it is recorded on a record medium, and in playback operation the video signal to be reproduced is angular-demodulated and then deemphasized through deemphasis means, wherein:
- said preemphasis means comprises a non-linear preemphasis circuit having a frequency characteristic variable according to the amplitude of the video signal applied thereto for emphasizing the amplitude of high frequency components of the video signal to the extent of a first predetermined value, and a fixed preemphasis circuit connected to said non-linear preemphasis circuit for receiving and further emphasizing the amplitude of said high frequency components to the extent of a second predetermined value;
- and
- said deemphasis means comprises a fixed deemphasis circuit for deemphasizing noises of the reproduced signal to the extent of the substantially same value as the second predetermined value of said fixed preemphasis circuit, and a non-linear deemphasis circuit connected to said fixed deemphasis circuit for receiving the deemphasized output and further deemphasizing the amplitude of high frequency components of the reproduced signal to the extent of the substantially same value as the first predetermined value of said non-linear preemphasis circuit, said non-linear deemphasis circuit comprising an amplifier having an input terminal to which a demodulation signal is applied and an output terminal, and a negative feedback circuit for negatively feeding the output of said amplifier back to the input terminal of said amplifier.
Dependencies are inferred from the claim text.