JPS6243994A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve the wave shape reproducibility by providing a trap circuit for improving a wave shape distortion by a low frequency conversion before the demodulator of a reproducing frequency modulating signal of B-Y. CONSTITUTION:A trap circuit 5 is added between a balance modulator 2 and a demodulator 4 and consists of an inductance 1, a capacitor C and a resistance R. A signal high frequency converted in a balance modulation and inputted to the trap circuit 5 has an oscillating frequency in the vicinity of the circuit 5 to attenuate and output it. The oscillating frequency of the circuit 5 is set in the vicinity of a modulating frequency of the balance modulation, thereby, the modulating frequency component of the balance modulation and a part of moire component of a signal band are attenuated. Thereby, the wave form reproducibility can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides recording/reproduction by frequency multiplexing RY and I'3-Y frequency modulation signals of color information signals. The present invention relates to a magnetic recording/reproducing device.

2. Description of the Related Art In a conventional circuit, color information signals of RY and I'3-Y are frequency-multiplexed and recorded and reproduced as shown in FIG.

A block diagram of the reproducing circuit is shown in FIG. First, when a frequency-multiplexed reproduced color information signal is input, a low-pass filter 1 separates R-Y modulation signal components. It is converted to a high frequency by a balanced modulator 2 of 7.16H1lz, and only the L side is extracted by a bandpass filter 3. The error is input to the demodulator 4 and demodulated.

Problems to be Solved by the Invention However, in the above configuration, when a wide band large amplitude signal is input, the [-Y frequency modulation signal separated by the low pass filter is It includes a folded component (referred to as jXX momoale) that occurs over and over again. Therefore, the demodulated signal has ringing and the like and waveform reproducibility is poor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording and reproducing device that attenuates moiré that impairs waveform reproducibility.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides R
In a magnetic recording and reproducing device that changes the frequency of -Y and performs frequency conversion of 8-Y between frequency intervals and low-line conversion, the frequency of 8-Y is multiplied, and the reproduction frequency of B-Y is recorded on a magnetic tape. A trap circuit for improving waveform distortion due to low-frequency conversion is provided before the demodulator f of the modulated signal.

Operation book 51 is based on the configuration described in F, and the balanced modulation r'c high-frequency conversion is performed. By inputting it to the trap circuit, the modulation frequency component of the balanced modulation and a part of the signal band component are obtained. This will result in a reduction in capital and improve waveform reproducibility.

Embodiment Below, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a reproducing circuit in an embodiment of the present invention. The trap circuit 5 is connected to the balanced modulator 2 as shown in the figure.
and the demodulator 4. As shown in FIG. 2, the trap circuit 5 includes an inductance (1) and a capacitor (C
) and a resistor (R). Furthermore, capacitor (C)
It is also possible to make the resonant frequency variable by making it variable.

The following describes the operation of the trap circuit 5 of this embodiment configured as described above.

The signal which has been converted into a high frequency band by balanced modulation and which has been input to the trap circuit 5 comes out with the vicinity of the resonant frequency of the circuit 5 attenuated. By setting the resonant frequency of this circuit 5 to the modulation frequency tllJMF of balanced modulation, the modulation frequency component of balanced modulation and a part of the moiré component of the signal band are attenuated, and the waveform reproducibility is improved. be able to.

EFFECTS OF THE INVENTION As is clear from the explanation in 1-1, according to the present invention, waveform reproducibility can be improved in the cylinder.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is its circuit diagram, Fig. 3 is a color information signal recording spectrum diagram, and Fig. 4 is a block diagram of an embodiment of the present invention.
The figure is a block diagram of a conventional example. 2... Balanced modulator, 4... Demodulator, 5... Trap circuit

Claims (1)

[Claims] 1. Frequency modulation of the color information signal R-Y and B-
A magnetic recording and reproducing device that performs frequency modulation of Y and low frequency conversion, and then frequency multiplexing and recording and reproducing on a magnetic tape,
1. A magnetic recording and reproducing apparatus characterized in that a trap circuit for improving waveform distortion caused by low frequency conversion is provided before a demodulator for a B-Y reproduction frequency modulation signal.