JPS58196785A - Recording and reproducing system of television signal - Google Patents

Abstract

PURPOSE:To realize high-speed frame retrieval, etc., of a video signal, by recording an address signal in the interval of horizontal synchronizing signal. CONSTITUTION:A pulse generator 8 separates a synchronizing signal from an input signal and supplies the synchronizing signal to a timing signal generation circuit 9. The circuit 9 controls an RAM11 and outputs an address and a digital signals having a fixed pattern to the synchronizing signal part of the video signal. These signals are encoded in a coding circuit 12, inputted to a signal adder 5 via a switch S1 to be added to a frequency-converted chromaticity signal, and recorded in a proper memory medium. The address signal recorded in the section of the horizontal synchronizing signal is used to perform the frame retrieval, etc., of a video signal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for recording and reproducing television signals, and particularly to a method for recording and reproducing data signals such as address signals used for cueing, etc. together with television signals.

Conventionally, in video discs and the like, in order to locate the beginning of the information track, an address signal is superimposed on the blanking portion 4 of the vertical synchronization signal of the video signal and recorded as fV, thereby making it possible to search for the desired information track. It is being done. In this conventional method, the timing at which an address signal can be read is once every 1/60 second, and in order to shorten the search time, a pickup that reproduces the information signal scans a group of information tracks at high speed. It took a long time to search because the signals could not be read out frequently enough. Also, the amount of data in the address signal was small.

The present invention has been proposed in view of this point, and consists of converting the synchronization signal portion of a television signal into a digital signal (referred to as a 5YNC word) with a certain pattern, and an address indicating the address of the video information. It consists of data signals such as signals, and by encoding and recording them using an appropriate method, the location where the address signal is recorded is set up in a large mouse, which speeds up searches and increases the amount of data that can be used. be.

Hereinafter, one embodiment of the present invention will be described.

In FIG. 1, a chroma signal in a video signal to be recorded at terminal A is taken out, balanced modulated with the output of an oscillator 3 by a balanced modulator 2, and a frequency-converted chroma signal is obtained as the output of a low-pass filter 14. .

A luminance signal in the video signal is separated by a single pass filter 6, and frequency modulation is performed by a filter 7 into an FM signal.

A pulse generator 8 separates a synchronizing signal from the input video signal and supplies the synchronizing signal to a timing signal generating circuit 9. 10 is a read-only memory, which supplies data to the tying signal generator 9 and controls the random access memory circuit 11, and outputs N to the synchronizing signal portion of the video signal as the output of the random access memory circuit 11.
YNC word and address signals are generated.

12 is a code 4 encoding circuit which encodes the output of the random access memory circuit 11 using an encoding method suitable for the recording medium;
Supplied to switch S1. Here, the clock signal of the encoded output of the encoder circuit 12 can also maintain a synchronous relationship with the generator 3. The switch S1 is an electronic switch controlled by a timing signal generator 9, and as shown in FIG. It works like this. Sunawa
First, in FIG. 2, A is a luminance signal that is the output of the low-pass filter 4, which is frequency modulated by the frequency modulator 7 and converted into a signal shown at the mouth. On the other hand, encoding circuit 1
The encoded output of 2 is shown by C, and is combined with the frequency modulation signal port by switch S1 as shown by 2, and is input to the signal adder 5. Then, it is added to the frequency-converted chroma signal by an adder 6 and recorded on a suitable recording medium.

Next, the format of the digital signal recorded in the synchronization signal portion will be explained.

The horizontal synchronization signal period it is about 471581 and now S Y
12 bits as NC word, 20 bits as address signal
If bits are inserted (Fig. 2 E), 4μsec/
(12+20)=0.12611 stx/bi
t, which is a value that allows sufficient recording and reproduction.

Also, from the 20-bit address signal +=, 79999
It is possible to assign an address to each information track one by one.

Note that when recording in the form of bits on an optical disc, it is possible to provide an ε-tutter circuit after the signal adder 5 and record the chroma signal that is the output of the low-pass filter 4 as duty cycle modulation. can.

Next, the reproduction method will be described.

FIG. 3 is a block diagram showing one embodiment of the Nr5J: circuit.

Almost the same signal as recording signal 2 explained in Fig. 2 is recorded.
The signal is played back from the medium and input to terminal A.

The bandpass filter 30 passes the low-pass converted chroma signal and inputs it to the balanced modulator 31. This balanced modulator 31
The chroma burst signal being outputted is sent to the burst extraction circuit 3.
2, the phase comparator 33 inputs the phase comparison with the output of the reference signal generator 434 (3,58MHz), and the output of this phase comparator 33 passes through the low-pass filter 35 to the CO (voltage controlled oscillator), and its output is input to the balanced modulator 31, forming a so-called APC loop.

The frequency-modulated 14-degree signal component, excluding the chromatic component that has been low-frequency converted by the 29if 4-band filter, is supplied to the FMi modulation circuit 37, and the output of the FM demodulation circuit 37 is a luminance signal that does not include a synchronization signal. number is obtained.

40 is a comparator, which slices the encoded digital signal portion and sends the coded digital signal portion to the clock signal generator 41.
It is input together with the output of O36.

The clock signal generator 41 receives the output of the vC036,
A stable lock signal is generated from the clock signal of the encoded digital signal portion extracted from the output of the comparator 40.

A decoder 42 is used for decoding using the output of the comparator 4o and the clock signal of the clock signal generator 41. The NRZ signal is obtained as an output and sent to the shift register 43. This shift register 43 converts the 7 real output signals of the decoder 42 into parallel signals, and the data comparator 44 converts the 7 real output signals into parallel signals.
It is compared with the 5YNC word output of the word generator 46, and when they match, a pulse signal 'f' is generated.

Therefore, the output of the data comparator 44 becomes a pulse indicating the synchronization (g) of the video signal.
is played after 5 YNC words and communicated to another control circuit (not shown).

In addition, 46 is a control circuit, which controls the tie of the shift register 43 and the 5YNC word generator 46.

In addition, 46 is a control circuit, and the timing comparator 4 of the shift register 43 and the 5YNC word generator 45
The periodic signal pulse which is the output of 4 is input to the 5YNC generator 47, which generates a synchronization signal for the video signal, and input to the synchronization signal addition circuit 38.The output of this addition circuit 38 has a synchronization signal. (This becomes a luminance signal, and the chroma signal addition circuit 39 passes the output of the light modulator 31 to the bandpass filter 28.
By configuring as above, it is possible to record an address signal in the horizontal synchronization signal section. Using the signal, frame searches of video signals can be performed at extremely high speed.

In addition, in the case of NTSC television MM, one frame includes
Since there are 525 horizontal synchronization signals, data of 525 x 20 bits - 10,600 bits can be recorded in one frame. Therefore, it is of course possible to use not only address signals but also character information signals. In this case, in order to distinguish address signals from other information signals, an identification signal may be provided, They can be distinguished by their location.

[Brief explanation of drawings]

FIG. 1 shows one of the recording and reproducing systems for television signals according to the present invention.
FIG. 2 is a block diagram showing the recording system of the embodiment, FIG. 2 is a waveform diagram of the same operation, and FIG. 3 is a block diagram showing the reproduction system. 1...bandpass filter, 2...balanced modulator. 3...Oscillator, 4,6...Low pass filter, 5...Adder, 7...Frequency modulator, 8... Pulse generator, 9... Timing signal generation 111 path, 11... - Random access memory circuit. Fig. 1, 3 Fig. 2 Fig. 3

Claims (4)

[Claims] (1) At least the synchronization signal part of the television signal,
a data signal associated with the television signal is arranged in the form of a digital signal together with the pattern of digital signals, the digital signal part is encoded and the synchronization signal part is converted into a digital signal of a certain pattern; A recording and reproducing method for television signals, which is characterized in that the television signals are frequency modulated, recorded on a recording medium, and then reproduced. (2) The recording and reproducing method for a television signal according to claim 1, wherein the data signal related to the television signal is an address signal indicating a frame number of the television signal. (3) The television signal according to claim 1, characterized in that the subcarriers of the chroma signal included in the television signal are set to have a synchronous relationship with the clock signal of the encoded digital signal. Recording and playback method. (4) The chroma signal included in the television signal is
1. A recording and reproducing method for a television signal according to claim 1, wherein the frequency of the digital signal is converted using a signal having a synchronization relationship with a clock signal of a pi-encoded digital signal, and the resulting signal is recorded on a recording medium.