JPS60171890A - Recording and reproducing system of television signal - Google Patents

Abstract

PURPOSE:To insert an instruction data, etc. of a special reproduction and an address number by changing a frequency or the inserting period of a color burst signal of a television signal. CONSTITUTION:A television signal subject to frequency modulation is detected by a detector 1 and the television signal of base band is obtained at an output terminal 11 through an amplifier 2, a limiter circuit 3 and an FM demodulator 4. A color burst signal is extracted by a color burst extracting device 5 and the signal is fed through an amplifier 6 and a limiter circuit 7, then a rectangular wave is converted and the pulse number is outputted to an output terminal. Then an address number, and a special reproduction instruction such as slow still are used as a digital value in a VTR and inserted to the color burst signal and then transmitted.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention adds new information to a color bust signal used as a reference signal when demodulating one-color decoding in a television signal without losing its original function. This invention relates to a method for recording and reproducing television signals.

[Technical background of the invention and its problems]

Conventional color television signals include NTSC system and PA
There are several methods such as L method, but these signals use 8-8 as a reference for the phase and frequency of the color subcarrier to demodulate the color signal.
Approximately 12 cycles of color bust signals are inserted. On the other hand, video tape V: I-ta (hereinafter referred to as VTR),
For video discs (hereinafter referred to as VD), etc., information such as TV frame numbers (addresses) or information for special playback such as slow and still is inserted into the TV signal to ensure reliable playback. By UTJVD
There is a demand to expand the usage of such materials.

[Purpose of the invention]

Therefore, an object of the present invention is to convert this information into two or more digital values, record it according to changes in the insertion period of the color burst signal, or according to the number of cycles of the color burst signal, and
After reproduction, envelope detection is performed for the former, and the information is reproduced from its duration.

For the latter, the information is reproduced by counting the number of cycles.

[Summary of the invention]

That is, the present invention records information by including information in the change in the number of cycles of a color burst signal, extracts the color bust signal from a television signal during playback, and transmits the color burst signal to the ig! After passing through a width transducer and a limiter circuit to form a rectangular wave, the pulse Vt+ is counted to reproduce digital information. or
Information is included in the change in the insertion period of the color burst signal, color burst No. 48 is extracted in the same way, and this is
By passing all the buses and filters (hereinafter referred to as P and F).

The envelope is detected and the digitized information is reproduced into two or more values.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a block diagram of a VD as an embodiment of the present invention. A frequency modulated (hereinafter referred to as FM) television signal is detected by a detector 1, and an amplifier 2. Limiter circuit 3. FM
As shown in FIG. 2(a) throughout the fIl regulator 4,
A baseband television signal is demodulated and obtained at an output terminal 11. Instead, the color burst extractor 5 extracts only the color burst signal. In this method, as known from J. J., the PI delays the water synchronization signal to a predetermined pulse width, opens the color burst signal period gate with this pulse, and extracts the entire color burst signal. be. The output of the color burst signal extractor 5 is as shown in FIG. 2(b), and when it passes through the amplifier 5 and limiter circuit 7, it is converted into a rectangular wave as shown in FIG. 2(C). The number of pulses is counted by the counter 8 and outputted to the output terminal 12.

Further, the horizontal synchronization signal separated by the horizontal synchronization signal separation circuit 91.c becomes as shown in FIG. 8g2 (d), thereby resetting the counter 8. Therefore, v'r
'In JVD etc., is it an address number or a special playback command ring such as slow still? , a digital value of two or more values and inserting it into a color burst signal as a change in the number of pulses, information can be transmitted.

[Other embodiments of the invention]

As another embodiment of the present invention, an N'J'SC type VD
A block diagram of the system is shown in Fig. 3. Its structure and operation are such that a frequency modulated (hereinafter referred to as FM) television signal is detected by a detector 17, an amplifier 18, a limiter 19, and so on. and FMfI! It passes through a modulator 20, demodulates a baseband television signal as shown in FIG. 4(a), and obtains it at an output terminal 25. From this, the color burst extractor 21 extracts all the color bursts. As is well known in the past, this method delays the horizontal synchronization signal,
A color burst signal is extracted by opening a gate during a color burst signal period with a predetermined pulse width. By doing this, the output of the color burst extraction 21 becomes as shown in FIG. 4(b).

In order to remove the carrier wave component, P, F, and 22 are all passed through one pulse as fCl in FIG. 4. Here, for example, in the length of the duration of a color burst signal, all of the 8-cycle durations are %O of the digital value, and the 12-cycle duration of the digital value is %O of the digital value.ゝ1] If recorded as 1, as above, P, F.

The length of the output pulse of 22 is IY' o *d11
．． The ratio is 1.5. This is used as an operation command pulse for the counter 23 to generate a 11φ carrier wave frequency of 3.5 for each color.
The pulse length can be easily detected by counting the output of the oscillator 24 which oscillates at 3MH2. In order to detect the pulse length, the counter 23 may be a limit register, a shift register, etc., and the frequency of the oscillator 24 may be of a frequency that allows the pulse ratio to be detected.

This frequency can be determined arbitrarily and does not need to be synchronized with the output color burst signal, but if the same frequency is used, a more accurate determination can be made. According to the present invention, for example, in the N T'SC system, one frame is composed of 525 lines, so when inserting about 20 bits of address data as binary digital data, a large number of If a majority decision is made on the playback side, even if a dropout occurs, it can be inserted more reliably.
It is possible to transmit information.

Another solid line example is shown in FIG. Components in the figure that are common to those in FIG. 3 are given the same numbers. The reproduced television signal is passed through the color burst signal extractor 21, and then the low
Pass through the entire pass filter 22. This allows digital data′
0 and '11 have waveforms as shown in (a) and fb) in FIG. 6, respectively, and these are input to the latch circuit 32. On the other hand, if the monostable multivibrator 31 generates a pulse (C1'e in FIG. The waveforms for the digital data are as shown in FIG. The data can be extracted.

Although this embodiment has been described using binary information, it is clear that two or more values may be used if more accurate detection is performed.

〔Effect of the invention〕

As described above, according to the present invention, by changing the cycle number, 1-i, and insertion period of the color burst signal of the television signal, it is possible to transmit new information.
It is possible to provide a recording and reproducing system for television program signals that can insert address numbers, special reproduction command data, etc. in 't, VD, etc., and can expand the range of applications.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a waveform diagram for explaining the operation of FIG. 1, FIG. 3 is a block diagram showing another embodiment of the present invention, and FIG. The figures are waveform diagrams for explaining the operation of FIG. 3, FIG. 5 is a block diagram showing still another embodiment of the present invention, and FIG. 6 is an operational waveform diagram. 1.17...Detector, 2,6.18 Amplifier, 3,7
．． 19...Limiter circuit, 4.20...FMfJ! !
Adjustment device, 5.21... Color burst signal extractor, 8
, 23 Counter, 9...Horizontal synchronization signal separation circuit, 1
0.31・Monostable multivibrator, 11,25.3
3... Reproduction TV signal output terminal 12.26.34 Reproduction digital signal output terminal, 24... Oscillator, 32 Latch circuit agent Patent attorney Kensuke Norichika (and one other person) Figure 1 Figure 2 (C) −Kamiho Kazuichiichi−−−−−−−−−−几■Tomohori−Figure 3 Figure 4

Claims (1)

[Claims] Ten Vision signal color 7th berth Hi! -@f, corresponding to information digitized into two or more values, recorded as a change in the insertion period or as a change in the insertion period of the signal,
After reproduction, the digital information is reproduced by counting the number of cycles of the signal for the former and detecting an insertion period for the latter, thereby reproducing the digital information.