JPS60103794A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve identification accuracy and to stabilize the simultaneity by deriving the difference between a demodulated color difference signal and a signal which makes the clolor difference signal delay, and by discriminating the color difference signal. CONSTITUTION:In simultaneous generation of a line-sequential color difference signal in a regeneration system, signal are inputted to a differential amplifier circuit 43, and DC level matching of line-sequential color difference signals R-Y and B-Y is executed after clamping the demodulated line sequential color difference signal (h) and the signal which is delayed by a delay circuit 40 respectively. In order to clamp only the blanking part of the color difference signals R-Y and B-Y, they are clamped by clamp pulses (p) and (q) every two horizontal scanning periods. The output (k) of the differential amplifier circuit 43 is compared with the prescribed DC in level, and only the falling pulse is taken out. An identifying signal (m), which indicates the beginning of the period of the R-Y signal, is obtained by gating by a gate circuit 48 according to a horizontal synchronizing signal (j).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a recording/reproducing apparatus such as an electronic still camera.

Conventional configuration and its problems The video signal is divided into a luminance signal and a color signal, and the color signal is further divided into two.
A recording and reproducing apparatus which divides the color difference signals into different types and performs time division multiplexing, so-called line sequential recording, for each horizontal period and performs FM recording is constructed as shown in FIG. In Figure 1, video camera 1
The video signal of
B-Y), and a composite synchronization signal S. The control circuit 5 is a circuit that generates a control signal for line-sequentializing color difference signals, and generates a signal 5a whose polarity is inverted every horizontal scanning period in synchronization with a horizontal synchronizing signal. With this, reswitch 3
1, the first color difference signal (R-Y) and the second color difference signal (B-Y) are time-division multiplexed alternately every horizontal scanning period, and are FM modulated by an FM modulator at 6°. Ru. On the other hand, the luminance signal Y is also FM modulated by the FM modulator 4, and after the two FM waves are mixed and amplified by the mixer 7, they are recorded on the magnetic sheet 9 by the head 8. FIG. 2 shows the level of recording signals. The color signal C is on the low frequency side, and during playback, the color difference signal of each horizontal scanning period is the first color difference signal to identify whether the first color difference signal (R-Y) is the second color difference signal (B-Y). Signal (R
-Y) carrier frequency is Fl, second color difference signal @(B-Y)
The carrier frequency of F2 is different from that of F2. The luminance signal Y is on the high frequency side, 1:3 indicates the carrier frequency of the sync chip, and F4 indicates the carrier frequency of the white beak.

FIG. 3 explains the configuration for reproducing this signal. The signal from the magnetic sheet 9 picked up by the video head 10 is amplified by a preamplifier 11, the 1I degree signal component is separated by a bypass filter 12, the color signal component is separated by a low pass filter 16, and the FMtI signal component is separated by a low pass filter 16 via limiters 13 and 17, respectively.
The FM demodulation is performed by the modulators 14 and 18, and the color signals are synchronized by the color difference signal processing circuit 19, and the two types of color difference signals are converted into quadrature two-phase modulated color signals by the encoder 20. This color signal and the luminance signal processing circuit The output signals of the FM demodulator 14 via the FM demodulator 15 are added together by a synthesizer 21, and the resulting signal is connected to a monitor or the like through a video signal output terminal 22 for display.

FIG. 4 shows the configuration of the color difference signal processing circuit. Input terminal 25
As shown in FIG. 5a, the FM demodulated line-sequential color difference signal a input to the FM demodulated line-sequential color difference signal a has different carrier waves, so when it is demodulated, the voltage level of the blanking part W changes to Vl and V2.
It makes a difference. By differentiating this with the differentiating circuit 26,
A differential signal is obtained. This differential signal @b is compared with a predetermined DC voltage level in the comparator circuit 27, and only the falling pulse C is extracted. An identification signal e indicating the start of the period -Y) can be obtained. Using the FM demodulated color signal and the signal processed one by one by the Chikanobu circuit 30, when the color signal signal a is a color difference signal (R-Y), it is a signal delayed by 1H period (B-Y). By selecting interpolation of the signals by the synchronization switch circuit 32, two consecutive color difference signals (RY) ([3-Y) are outputted to each output terminal 33, 34. The flip-flop circuit 31 controlling the synchronization switch circuit 32 uses the horizontal synchronizing signal d as a clock, and its polarity is inverted every horizontal scan, and is initialized by the identification signal 0.

When extracting the identification signal using a differentiating circuit, the frequency characteristics of the differentiating circuit are those of a high-pass filter shown in Figure 6, and the high frequency components have a high gain and the S/N of the differentiated signal becomes poor, making it difficult to reproduce. If the S/N of the color difference signal deteriorates, there is a risk that the identification will malfunction.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a recording and reproducing apparatus that can improve detection accuracy and obtain a normal reproduced video signal compared to extraction of an identification signal using a single differential constant path.

Composition of the Invention During recording, the recording/reproducing device of the present invention separates the color signal of a video signal into two types of color difference signals, converts the separated two types of color difference signals into line sequential signals, and generates signals that differ depending on the type of color difference signal. The 1Ali degree signal of the video signal is FM-modulated at a carrier wave frequency and mixed with the FM-modulated signal and recorded on a recording medium, and at the time of reproduction, the type of reproduced line-sequential color difference signal is identified and synchronized into 102 types. The demodulated color difference signal and the demodulated luminance signal are synthesized to form a reproduced video signal, and the demodulated line sequential color difference signal and the line sequential color difference signal are processed. The present invention is characterized in that the edge information of the difference with the extended signal is gated by a horizontal synchronizing signal to identify the type of color i signal in each horizontal period, thereby improving identification accuracy.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 7 to 9.

FIG. 7 is a block diagram of the color difference signal processing circuit of the reproduction system included in the recording and reproduction apparatus of the present invention, and FIG. 8 hr shows a waveform diagram of each part in FIG. 7. The FM demodulated line-sequential color signal is delayed by a delay circuit 40 by 1.2 μsJ, for example, and is clamped by clamp circuits 41 and 42, and then input to a differential amplifier circuit 43. Clamp circuit 4
1.42 is for adjusting the DC level of the line sequential color difference signals (R-Y) (B-Y) input to the differential amplifier circuit 43; In order to clamp only the blanking portion, clamping is performed using clamp pulses p and q every two horizontal scanning periods. This clamp pulse p is applied to the flip-flop circuit 4 clocked by the horizontal synchronizing signal j.
The clamp pulse q is obtained by detecting the AND of the output signal r of 4 and the horizontal synchronizing signal j by the AND circuit 4G, and the clamp pulse q is generated by delaying the clamp pulse p by the delay circuit 45. Here, the delay times of delay circuits 40 and 45 are almost the same.

The output of the differential amplifier circuit 43 is sent to a comparator circuit 47, which compares it with a predetermined DC level, extracts only the falling pulse, and further outputs a horizontal synchronizing signal j to a gate circuit 48.
to obtain an identification signal m indicating the beginning of the period (RY). The operation of synchronizing the FM demodulated line-sequential color difference signals is the same as that of the conventional method, so the explanation thereof will be omitted. FIG. 9 shows a 5-frequency characteristic diagram of the conventional differential circuit 26 and a frequency characteristic (2) of the delay element of the delay circuit 40.

When the identification signal is obtained using the delay circuit 40, unnecessary high-frequency components are not output, so that the S/N of the identification signal is good and malfunctions related to synchronization can be reduced.

Note that in the above embodiment, the demodulated line-sequential color signal is (R
Although it has been described that synchronization is performed by detecting and identifying the pulse when the signal becomes (-Y), it is also possible to perform synchronization by detecting the pulse when the signal becomes (B-Y).

As described in the detailed description of the invention, when the recording and reproducing apparatus of the present invention is used, the reproducing system receives the demodulated line sequential color difference signal and the demodulated line sequential color difference signal. The edge information obtained by taking the difference with the extended signal is gated with a horizontal synchronization signal, and in order to identify the type of τ color difference signal and make it into a synchronized color difference signal, a differentiating circuit is used as in the past. Compared to conventional methods, this method has less noise, improved identification accuracy, and can stably synchronize color difference signals.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of the recording system of an electronic still camera, Figure 2 is a frequency distribution diagram of recorded signals, Figure 3 is a configuration diagram of the reproduction system, Figure 4 is a configuration diagram of conventional color difference signal processing, and Figure 5 is a diagram of the configuration of the recording system of an electronic still camera. The figure is a conventional signal waveform diagram, Figure 6 is a frequency characteristic diagram of a differential circuit, and Figures 7-
FIG. 9 shows an embodiment of the present invention, FIG. 7 is a configuration diagram of a color difference signal processing circuit included in the recording/reproducing apparatus of the present invention, and FIG.
This figure is a signal waveform diagram of FIG. 7, and FIG. 9 is a frequency characteristic diagram of a delay circuit used for identification signal extraction and a frequency characteristic diagram of a differential circuit used for conventional identification. 30...1 horizontal scanning period delay circuit, 31...flip knob, 32...synchronization switch circuit, 40...
・Delay circuit, 41.42... Clamp circuit, 43...
・Differential amplifier circuit, 47...]] Amparator 48...
Goo 1-Circuit agent Yoshihiro Morimoto 1st drawing 2nd @ 3rd drawing 4th 'C34o S Q) ← Cylinder 6th diagram → Oka Nagao 7th drawing 3rd drawing q)

Claims (1)

[Claims] 1. At the time of recording, the color signal of the video signal is separated into two types of color difference signals, and the separated two types of color difference signals are line-sequentialized and used at different carrier frequencies depending on the type of color difference signal. The FM-modulated I[ill* signal of the video signal is mixed with the FM-modulated signal and recorded on a recording medium, and when reproduced, the type of reproduced line-sequential color difference signal is identified and two types are synchronized. The demodulated color difference signal and the demodulated luminance signal are synthesized to produce a reproduced video signal, and the synchronization is delayed between the demodulated line sequential color difference signal and the line sequential color difference signal. The recording/reproducing apparatus is configured to identify the type of color difference signal in each horizontal period by gating the edge information of the difference between the signal and the horizontal synchronization signal. 2. The invention is characterized in that the difference between the reproduced line-sequential color signal and the delayed color difference signal is determined by clamping the two signals every two horizontal scanning periods. The recording/reproducing device according to item 1.