JPS58143689A - Video recording and playback device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a video recording and reproducing device.

Conventional q) The color signal processing circuit of the Eirin recording and reproducing device that records and reproduces the SICAM television signal has an independent recording system path and reproducing system N path, so the portable type video recording and reproducing device requires less board space. However, there was a drawback that the weight and power consumption increased.

Figure 1 is a block diagram of a conventional 81CAM video record playback device. Each component will be explained according to the block diagram. A small amount of the 81 CAM video signal is input to the input electron 4, and the low-pass filter 1 removes the dark color signal component, leaving only the brightness signal component. This signal is FM modulated through an FM modulator 1Qller 2Yt. FM
The modulated signal is passed through the bypass filter 5t, and is added to the color signal described below in the addition (9) path 11, and then sent to the head 1.
At step 2, the tape is placed on the magnetic tape. The color signal separated by the bandpass filter 5 is FMK tuned, and is 59Mt.
The 0 color signal in the band from lc to 475MHg has anti-pel filter characteristics t during transmission, so a bell filter 6t is used.
- Flatten the energy within the band by passing it through. Thereafter, the waveform is shaped through a limiter amplifier 7, and the frequency of the color signal is reduced to 1/4 by a 6th-order 174 frequency divider circuit 8, which makes the waveform easier to frequency divide. As a result, A9MHz ~ 475
The MHg color signal has a band of (L98 MHz to 1.19 MHg).The upper limit frequency is limited by the first-order low-pass filter 9, and after considering 8/N and color reversal development, it is recorded and reproduced by the recording equalizer 10. FM with characteristics suitable for
It is added to the t-tuned luminance signal in an adder circuit 11. As shown in the second factor, in the reproducing system, the output of the head 12 passes only the FM-modulated luminance signal component through the high-pass filter 15t, is sufficiently waveform-shaped by the limiter amplifier 14, and is then processed by the iPM demodulator 15. demodulated. The demodulated video signal is added to the demodulated color signal described below in an adder circuit 11, and a SECAM video signal is obtained at terminal 25. The output of the head 12 is passed through a low-pass filter 16t,
Obtain an FMfpl color signal. After this signal passes through a reproduction equalizer 171, it passes through a quadrupling circuit 18. It passes through a band pass filter 19t to obtain color signal components of 49 MHz to 475 MHg. Since the level is low up to 1, the SFiCAM color signal can be obtained by using the limiter amplifier 20° bandpass filter 21 and the antibell filter 22ta. The above method is the conventional method69, in which the recording system and the reproducing yarn are completely separated, and the circuit scale is large.

The present invention solves the above-mentioned problems and provides a compact and lightweight recording and reproducing apparatus by sharing the limiter amplification section of the recording color signal processing circuit and the reproduction color signal processing circuit.

The present invention aims at reducing costs by using the IJJ ivy amplification port used in the recording circuit in the SICAM type Eirin type Eirin recording and reproducing device as well as the 4x amplifier tube used during playback. as well as.

The goal is to reduce board space and weight.

FIG. 5 shows a color signal processing section of a video recording and reproducing apparatus based on the present invention. In the circuit No. 2, in the conventional circuit described above, a limiter increase of 1.20 mm is used in common for each of the recording system and the reproducing system.

This not only contributes to the reduction of rounding costs, but also has the effect of reducing the space and weight of the portable type video recording/producing device. This limiter amplifier 924 for both recording and reproduction has a frequency of 49MHz to 475MHz (2).
%Fmt increases the amplification, so it is good for recording and playback.
L number characteristic t - There is no need to change it, but due to the difference in gain distribution between the recording thread and the reproduction system, the recording/reproducing IJ mitter amplification 24
There are many cases where the gain of 1 is changed.

This implementation circuit example is shown as the fourth factor, and a limiter amplifier 24 for both recording and reproduction is activated by a switch 25 that is closed during recording or reproduction.
The gain t is changed by opening and closing the feedback circuit 26.

[Brief explanation of drawings]

First, FIG. 2 is a block diagram of a conventional magnetic recording and reproducing apparatus, and FIG. S is a block diagram of a video recording and reproducing apparatus of the present invention. Figure 4 is another lol II of the present invention.
1 is a block diagram illustrating an example. 1...Low pass filter 2...FM modulator 3...Bypass filter 4...SECAM video signal input 5...Band pass filter Patent attorney Susuki 1) Yukiri Toshi / Zuzai ZC! 1 Ya 3 Inzai 4 diagram

Claims (1)

[Claims] The color difference signal that has passed through the antibell filter is amplified and IJ j
A recording system color signal processing circuit is composed of a limiter amplifier that applies a filter, a branching circuit that divides its output, and a recording amplifier that sends one branched output to the head, and a head output multiplier circuit. In the SICAM type Eirin recording and reproducing apparatus, the reproduction color signal processing circuit is composed of an amplifier that amplifies the output, and an addition circuit that adds the luminance signal and the color signal through a bell filter. Video recording and playback II featuring a dual use of the limiter amplifier and the amplifier of the reproduced thread color signal processing circuit! Place.