JPS5951680A - Recording and reproducing system of information disc - Google Patents

Abstract

PURPOSE:To prevent the deterioration in picture quality, by recording a video luminance signal subject to frequency modulation and plural signals including a carrier video chroma signal with different frequency band in a video disc system. CONSTITUTION:A signal from a reproducer pickup device 71 is amplified and inputted to four band pass filters 73-76, and separated into four kinds of signal components. The carrier chroma signal extracted from a BPF 74 is inputted to a signal converting circuit 80, the frequency fluctuation component is cancelled with a formed control loop, resulting that the television carrier chroma signal eliminated with the frequency fluctuating component is obtained as an output signal of a frequency converting circuit 80. The output signal of the frequcncy converting circuit 80 is added to the luminance signal at an adder circuit 78 and outputted to a video output terminal 86.

Description

[Detailed description of the invention] The invention relates to a method for recording and reproducing information signals such as video information and audio information on a disk-shaped recording medium (hereinafter referred to as a disk), and is particularly novel and effective. It provides all information disc recording and reproducing methods.

Conventional configuration and its problems As a video disc system, Philips and M
VLP method developed by CA, CE developed by RCA
There are D format, VHD format developed by Victor Company of Japan, etc. However, other formats except VLP format cannot record and playback standard television video signals in one format due to the recording capacity of the system. Instead, the video signal band is limited to approximately 3 GB for recording. Therefore, the carrier ROMA signal is converted to a low frequency and superimposed on the luminance signal in a frequency interleaved manner, and is recorded and reproduced in a signal form called the Verirad-the-B carrier system. However, in this Verirad subcarrier system, since the luminance signal and the carrier ROMA signal share the frequency band, it is necessary to separate both signals using a comb-shaped filter means on the reproduction side, which only increases the cost of the reproduction equipment GI. However, at least the vertical resolution of the frequency band that Luminance No. 411 and the carrier Roma Shingetsu share is reduced, and since this common frequency band is a relatively high frequency region, the details of the reproduced image are reduced as a result. The disadvantage is that it is difficult to produce f, l+1. Furthermore, the comb-shaped filter means uses the high correlation of signals between horizontal scanning lines to perform error signal processing for adding or subtracting signals of a plurality of adjacent horizontal scanning lines. Since there is no correlation between horizontal scanning lines in the contours of the image in the direction, the contours of the image after the comb-shaped filter processing are difficult to see, resulting in a significant deterioration in image quality. are doing.

In view of these shortcomings, the first aspect of the invention is to provide a new recording + IJ: raw method that uses all comb-shaped filters, is inexpensive, and has little deterioration in image quality. 0 Structure of the Invention: Ratio 1: By recording a frequency-modulated video luminance signal and a plurality of signals including at least a carrier video chroma signal in a superimposed form with different frequency bands on a diode. , i'L is intended to avoid various causes of image quality deterioration caused by the comb-shaped filter means during reproduction.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 is a block diagram showing an example of an information recording apparatus according to the invention. NT input to input terminal 1
An i5C type television (hereinafter referred to as TV) video signal is input to a brightness/chroma separation circuit 2, where it is divided into a brightness Y signal and a carrier ROMA C signal. The TV video signal input to the input terminal 1 is also input to the burst gate pulse generation circuit 3, where the synchronization signal in the TV video signal is separated. A burst gate pulse signal is created based on this synchronization signal, and its output (Ff) is input to the burst gate circuit 4. The transmitted ROMA signal is input, and the ELIBURST signal is gated to the L1 burst gate pulse, and its output signal is sent to the phase comparator circuit 5.
Enter the following information. A signal from the voltage side slant oscillator 6 is also input to this phase comparator circuit 5, where a phase comparison is performed with the 01 engineering bust signal 1'L, and the error signal is sent to the voltage side slant oscillator 6. The input is reduced. By forming such a loop, it is possible to obtain, as the output signal of the voltage suppressing oscillator 6, a continuous wave signal whose frequency and phase match the burst signal of the carrier Roma signal inputted to the input terminal 1.

The output signal of the voltage side slant oscillator 6 is input to the 1o/7 multiplier circuit 7, and after its frequency is multiplied by γ by 1o/-r, it is input to the frequency conversion circuit 8nl. Here, from the YC separation circuit 2 Frequency conversion is performed on the carrier Roma signal. In this case,
However, the carrier wave frequency of the output carrier ROMA signal of the frequency conversion circuit 8 is fH-horizontal scanning frequency. The output signal of the frequency conversion circuit 8 is sent to a level adjuster 9.
It is inputted to the addition port Wr11 through. The luminance signal separated by the YC separation circuit 2 is input to a frequency modulation (hereinafter referred to as FM) circuit 10, where it is subjected to frequency modulation with a frequency deviation range of, for example, 5.3 to 7 degrees, and its output is The signal is input to an adder circuit 11. On the other hand, audio input terminal 12.1
The audio input signals of the two channels input to 3 are input to FM modulation circuits 14+15, which are provided independently from each other.
lHere, for example, the carrier frequency of
k(=716kHz, 115/2・fH(=90
5k)lZ), F with a frequency deviation range of ±50 kHz
Receives M modulation. The output signals of the FM modulation circuits 14 and 15 are respectively input to the adder circuit 11 via f level adjusters 16 and 17. In the adder circuit 11, the FM luminance signal,
7J113' when the signal level ratio of the carrier ROMA signal and the two types of FM audio signals is, for example, 10:2:1.
J: The output signal of the cutting head is the cutting head drive circuit 1.
The input to B is then increased to a signal level sufficient to drive the cutting node by 1, and then output terminal 19.2.
Output to 0. Cutting methods include a laser cutting method, an electron beam cutting method, a mechanical cutting method, etc., and FIG. 2 is a schematic diagram showing an example of a canting head for the mechanical cutting method. The structure of the head is a cantilever 31. Damping layer 32. Piezoelectric conversion element 33. Consists of 34 diamond hands,
Two lead wires 35 are connected to the piezoelectric transducer 33.
When the signals from the output terminals 19 and 20 of FIG. 34, signals can be recorded by sequentially cutting the surface of a rotatably driven copper master disk 37 whose surface has been mirror-polished.In this way, signals can be recorded on the copper master disk. An example of a spectrum diagram of the recorded γ signal is shown in FIG.

38 and 39 in Figure 3 are two-channel audio FM signals,
4o is the carrier ROMA signal, 41 is the luminance FM (q is omitted)
It's showing off. The process of making a disc from this copper master disc is similar to that of an audio record, in which a master → mother → stamper is created using electromagnetic technology.
The disc that is to be replaced with N Fl is created with an edge in the pressing process.

FIG. 4 is a schematic diagram of a mechanical type pink-up for reproducing signals from the pressed disk produced in this manner.

Its configuration is cantilever 51. Damping layer 52. Piezoelectric conversion element 53. Muffler rubber 54. Diamond needle 56. Composed of r
A mechanical pressure signal is applied to the piezoelectric transducer 63 according to the unevenness of the signal recorded on the surface of the disk 58, and the output terminal 56 is piezoelectrically converted.
, 57, electrical signals are taken out. FIG. 5 shows an outline of the format of the signals recorded on the disc, but here, for the sake of simplicity, we will use the FM luminance signal 69,
- of one of the plurality of signals superimposed on this FM luminance signal, for example, a signal on which the carrier ROMA signal 60 is superimposed.
The outline is shown as a shape. The signals 59 and 60 are recorded in a state in which they are superimposed and are brought into contact with the diamond stylus 55 of the mechanical pink-up device with a constant pressure, as shown in FIG. , a pressure signal corresponding to not only the unevenness of the FM luminance signal 69 but also the unevenness of the conveyed ROMA signal 6o is applied to the piezoelectric transducer 53 via the diamond needle 55, where it is piezoelectrically converted, thereby converting the FM luminance signal. It is possible to extract the electrical signal which is superimposed with the transmitted ROMA signal. Figure 6 shows a block ξ which picks up a signal from a disc on which multiple signals are recorded as described above, converts it to the original signal format, and reproduces the signal.
FIG. 2 is a block diagram showing an example of a second disc playback device.

The signal pinked up from the disc by the playback pick amplifier device 71 is input to a preamplifier circuit 72, where it is amplified to an appropriate level and then passed through four band pass filters (hereinafter referred to as BPF) 73, 74, 75 and 76
Now input f-L. The output signal of the preamplifier circuit 72 has a spectrum shown in the spectrum diagram of FIG. 3, for example, but these four types of signal components recorded by frequency division are separated and extracted by the four BPFs. SarLru. FM that has been engineered to BPF73
The luminance signal is input to an FM demodulation circuit 77, where it is subjected to FM demodulation and the output signal is input to an adder circuit 8 and a burst gate pulse generation circuit 79. The ROMA signal extracted by the BPF 74 is sent to the frequency conversion circuit 8o.
is input to nl, where its oscillation frequency is approximately fH/2×65
Using the signal from the voltage control oscillator 81 of 0, the carrier frequency is 9/2X650-fH/2X195 = 9/2X455
The frequency is converted so that it becomes (=3.58-). The output signal of the frequency conversion circuit 8o is input to an adder circuit 78, where the luminance signal and the power 11 are summed, and after being amplified by an output intensifier 85, it is output to a video output terminal 86. The output signal of the frequency conversion circuit 8o is also sent to the burst gate circuit 8.
2, here burst gate pulse generation circuit 7
The burst signal is gated by the burst gate signal from 9, and its output signal is input to the phase comparison circuit 83. The phase comparison circuit 83 also has an oscillation frequency of 9/
A signal from a reference crystal oscillator 84 of 2×465 is also input, and a phase comparison of both signals is performed.

The error signal generated in the phase comparison circuit 83 is input to the voltage side oblique oscillator 81, where the oscillation frequency of the oscillator 81 is suppressed. To construct such a side oblique loop)! :The output of the BPF 74 acts to cancel the frequency fluctuation component of the carrier wave signal of the carrier wave signal, and as a result, the output signal of the frequency conversion circuit 80 is the TV carrier Roma signal with the frequency fluctuation component removed. signal? :
Obtainable.

- The two types of FM audio signals carefully extracted by the BPFs 76 and 76 are then input to independent FM demodulation circuits 87 and 88, and after being LFM demodulated, It is output to output terminals 89 and 90 of.

Advantages of the Invention By adopting the disk recording and reproducing method as described in 2, not only can the reproducing device be constructed easily and inexpensively, but also the luminance signal and the carrier ROMA signal are not frequency multiplexed, so the comb-shaped By using a filter means, it is possible to avoid the causes of picture quality deterioration, and it is possible to record and reproduce information signals on and from discs at low cost and with little picture quality deterioration. Although the explanation has been given using the NTSC system as an example, it is clear that other TV systems can be processed in the same way.

[Brief explanation of drawings]

Fig. 1 shows an example of an information recording device according to the invention. 1 - Block diagram. Fig. 2 shows an example of a mechanical cutting type canting head. 1 - Schematic diagram. Fig. 3 shows an example of an information recording device according to the invention. First, a spectrum diagram of an example of a signal recorded on a disc, Figure 4 is a schematic diagram showing an example of a mechanical pickup, and Figure 6 is a schematic diagram of the shape of a signal recorded on a disc. FIG. 6 is a block diagram showing an embodiment of the screen reproduction apparatus according to the invention. 1...Input terminal, 2...Brightness/clama separation circuit, 3...Burst gate pulse generation circuit, 4...Burst gate circuit, 5... ...
・Phase comparison circuit, 6...Voltage needle oscillator, 7.
...multiplier circuit, 8...frequency conversion circuit,
9,16.17...Level adjuster, 1°...
... Frequency modulation circuit, 11 ... Addition circuit, 1
2゜13...Audio input terminal, 14.15...
...FM modulator, 18... Cutting head drive circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
figure

Claims (3)

[Claims] (1) Information disc recording characterized in that a frequency-modulated video luminance signal and a plurality of signals including at least a carrier video chroma signal are recorded and reproduced on a disc-shaped recording medium in a superimposed form with different frequency bands. Playback method. (2) The information disk recording and reproducing method according to claim 1, characterized in that one or more frequency-modulated audio signals are included as the plurality of signals superimposed on the frequency-modulated video luminance signal. . (3) Special IT characterized in that a mechanical recording and reproducing means using piezoelectric transducer is used as a means for recording and reproducing signals on a disk-shaped recording medium [Claim 1
Recording and reproducing method of information disk described in section.