KR940004605A - Recording and playback method and apparatus by frequency band compression - Google Patents

Abstract

The present invention relates to a method and apparatus for recording and reproducing by compressing a frequency band of a video signal. The method according to the present invention comprises the steps of: a frequency modulation step of an input video signal, a square vortexing step of a frequency modulated signal, obtaining a band-compressed square wave at which the square wave is triggered at an upper edge point and a falling edge point, respectively, and recording these square-compressed rectangular waves. Picking up each recorded signal to obtain each band compressed square wave, synthesizing these two band compressed square waves, and demodulating the synthesized square wave signals. This reduces the frequency band of the signal to be recorded to at least one half and simultaneously records and reproduces at least two channels, thereby allowing existing circuits and components to be used as they are and at the same time processing signals at the same drum rotation speed. This makes it possible to simplify the hardware design, which provides an excellent advantage.

Description

Recording and playback method and apparatus by frequency band compression

Since this is an open matter, no full text was included.

3 is a block diagram showing a recording system of a recording / playback apparatus according to the present invention;

4 is a waveform diagram of signals processed in respective parts of FIG.

5 is a block diagram showing a reproduction system of a recording / playback apparatus according to the present invention.

Claims (6)

A recording and reproducing method of a video signal, comprising: frequency modulating an input video signal; Square wave the frequency-modulated signal; Obtaining a band compression square wave at which the square wave is triggered at the rising edge point and the falling edge point, respectively; Recording the band-compressed square waves on a recording medium, respectively; Picking up each of the signals recorded on the recording medium to obtain each of the band-compressed square waves; Triggering at all rising and falling edge points of the two band compression square waves and synthesizing them into square waves of an original frequency-modulated signal; And demodulating a square wave of the frequency-modulated signal obtained by the synthesis. 2. The recording and reproducing method according to claim 1, wherein the square wave of the frequency modulated signal is obtained by detecting the frequency modulated signal at AC zero volt point. The method as claimed in claim 1 or 2, further comprising: triggering each of the band-compressed square waves at a rising edge point and a falling-edge point in a recording process to obtain a secondary band-compressed square wave, wherein the secondary band-compression is performed during a reproduction process. And synthesizing square waves to obtain the primary band-compressed square wave. A recording and reproducing apparatus of a video signal, comprising: a frequency modulator of an input video signal; A square wave generator for generating a square wave for a frequency modulated signal; A first trigger circuit for outputting a square wave triggered at all rising edge points of the square wave; A second trigger circuit for outputting a square wave triggered at all falling edge points of the square wave; A recording unit for recording the band compression square waves output by the first and second trigger circuits on a recording medium, respectively; A reproducing unit which picks up each of the recorded signals and outputs each of the band compressed square waves; A synthesizer that synthesizes square waves of the original frequency-modulated signal by triggering at all rising and falling edge points of the two band compression square waves; And a demodulator for demodulating square waves of the frequency modulated signal output from the synthesizer. 5. The recording and reproducing apparatus according to claim 4, wherein the square wave generator is a zero cross detector that detects the frequency modulated signal at a zero volt point AC to obtain a square wave. 6. The apparatus according to claim 4 or 5, wherein the first and second trigger circuits are respectively provided with trigger circuits for respectively triggering the respective band compression square waves at rising and falling edge points to generate secondary band compression square waves, respectively. And preliminary synthesizers for synthesizing the secondary band compressed square waves to obtain primary band compressed square waves, respectively, being transposed to the synthesizer. ※ Note: The disclosure is based on the initial application.