JPH0359504B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a recording method for recording and reproducing video and audio signals on a track in which an address signal indicating a position on a recording medium is recorded in advance on a part of the track. The present invention relates to a playback device.

Conventional configurations and their problems Currently, video discs and the like are being considered in which sequential addresses are assigned to each field or frame of a video signal to facilitate retrieval. As shown in FIG. 1, a code signal 2 indicating position information is inserted into a part of the vertical blanking period _Tv of the video signal 1. This method allows addresses to be assigned to recording tracks on which information is recorded, without damaging video or audio information, and, like video discs,
This method is very suitable for reproducing signals from a recording medium on which pre-edited signals have been continuously recorded. However, with this method, position information on the recording medium cannot be obtained unless the video signal is recorded, so it is not possible to search for an arbitrary position prior to the start of recording, and intermittent recording results in discontinuous addresses. As a recording device, it has the disadvantage of being extremely difficult to operate.

Therefore, in such a recording device, it is easier to operate if an address signal indicating position information is recorded in advance on a track provided on the recording medium, but with this method, the above-mentioned In the case of a method of inserting into the video signal, interference to the video signal or audio signal cannot be ignored, and especially in the case of a method that is inserted into the video signal, interference to the video signal or audio signal cannot be ignored. Interference with audio signals that do not have a certain duration causes a significant deterioration in the quality of the reproduced audio.

Purpose of the Invention The purpose of the invention is to form an address signal in advance on a part of a track on a recording medium so that the quality of the audio information will hardly deteriorate even when video information and audio information are recorded and reproduced. Therefore, it is an object of the present invention to provide a video and audio information recording and reproducing device with good insertability.

Structure of the Invention In the present invention, the address signal pre-formed on a part of the track on the recording medium is a signal recorded by modulating the address represented by a digital code signal, and its spectrum is From a physical perspective, it has peaks (mountains) and notches (troughs) based on the minimum inversion interval of the signal. The larger the spectral component of the recorded address signal, the greater the influence will be on the audio signal superimposed thereon. Therefore, in the present invention, in order to prevent the audio signal from being influenced by the address signal, the above-mentioned The relationship between the minimum inversion interval of the address signal and the audio signal carrier wave is set so that the audio signal is recorded in the "trough" region of the address signal spectrum, and the influence of the address signal on the audio signal is as follows:
It is made so that it can be practically ignored.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows an example of a signal spectrum recorded on a recording medium by multiplexing a video signal and an audio signal.The color signal 3 consists of a color carrier wave converted to a low frequency band, and for example, its subcarrier frequency is 630KHz
It has sideband waves that spread to ±500KHz around that point. The audio signal 4 is a frequency-modulated two-channel signal, and for example, its center frequencies are 1.3 MHz and 1.5 MHz, and the frequency is shifted by ±50 KHz around the center frequencies. Furthermore, the luminance signal 5 is a frequency-modulated signal, and for example, the modulation frequency range is from 5.2MHz to 6.7MHz.
It has a sideband that spreads to ±3.2MHz around that point.

On the other hand, the address signal is recorded in advance on a track on the recording medium so as to be located within the vertical retrace period of the video signal to be recorded.For example, as shown in FIG. , with a bit "1" corresponding to a reversal in one direction and a bit "0" corresponding to a reversal in the opposite direction, so that
So-called PE (Phase Encoding), which inverts the boundaries between bits as necessary.
Modulation is performed to create address signal b.

In PE modulation, as shown in Figure 3, data
For the reciprocal T of the bit transfer rate (hereinafter referred to as bit period), the minimum inversion interval T _nio = T/2, the maximum inversion interval T _nax = T, and as shown in FIG. The signal spectrum 8 with the minimum inversion interval T _nio has peaks and notches (valleys) as shown by solid lines, and the signal spectrum 9 with the maximum inversion interval T _nax has peaks and valleys as shown by broken lines. There are other transient intermediate states, but their spectral components are small in terms of the whole and can be ignored on the solid line, so the PE-modulated address signal has a frequency between 3/2T and 5/2T. There is a region with few spectral components, and signals in this frequency region are least affected by the address signal.

For example, the bit period T of the address signal is 1.43 μs.
, this address signal is 1.05MHz to 1.75M
There is a trough in the spectral components between Hz, and the address signal component in that frequency range is small, so the aforementioned audio signals with center frequencies of 1.3 MHz and 1.5 MHz are not easily affected by this, so there is no problem in practice. I can do it.

In this way, with respect to the period t of the audio carrier wave to be recorded, the minimum inversion period T _nio is from 3t/4 to 5t/
The address signal between 4 and 4 has little influence on the audio signal, and its influence becomes minimum when the minimum inversion period T _nio =t. Also, if the audio information is stereo or
If there are multiple voice carrier waves in multiple languages, the average of their periods is the minimum inversion period of the address signal.
When T _nio is equal, overall, the influence of the address signal on voice information is the smallest.

Effects of the Invention According to the present invention, even if an address signal is recorded in advance on a track on a recording medium, it can be made so that it has almost no effect on the video signal or audio signal to be recorded. An address signal can be recorded in advance on a part of the recording medium, so even if no video signal is recorded, any position on the recording medium can be searched freely, and the address signal can be freely moved to any position. It is possible to obtain a video/audio information recording and reproducing device that is extremely easy to operate and can record data on images.

[Brief explanation of drawings]

Figure 1 is a waveform diagram showing a conventional example in which address information is inserted into a part of a video signal, Figure 2 is a spectrum diagram of each signal recorded on a recording medium in an embodiment of the present invention, and Figure 3 is a waveform diagram of this example. FIG. 4 is a diagram showing an embodiment of the address signal in the invention, and FIG. 4 is a diagram showing the spectrum of the address signal in FIG. 3. 1...Video signal, 3...Color signal, 4...Audio signal, 5
...Brightness signal, 7...Address signal.

Claims (1)

[Claims] 1. An address signal having a minimum inversion interval longer than 3/4 times and shorter than 5/4 times the period of the audio signal carrier wave to be recorded is used as a vertical return of a video signal to be recorded on a part of the track. Record in advance to be located in the line period,
A video/audio information recording/reproducing apparatus characterized in that a video signal and an audio signal are multiplexed and recorded/reproduced on the track on which the address signal is recorded. 2. Video/audio information according to claim 1, in which the period of the audio signal carrier wave, or if there are multiple carrier waves, the average of those periods is equal to the minimum inversion interval of the address signal. Recording and playback device.