JPS6114712B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-density recording method, and more particularly to a high-density recording method that allows easy interlacing operations during reproduction, for example.

[Conventional technology]

The recently developed optical high-density recording signal reproducing device has the advantage that the recording medium, such as a disk or sheet, and the signal readout (detection) device are not in contact with each other. This advantage also creates a new function that allows skipping between recorded tracks during playback. With such functions, for example, when video signals are recorded on a disk, still image playback, slow motion playback, quick playback, etc. can be easily performed, greatly improving the functionality of the device as an image playback device. Ta.

FIG. 1 is an illustrative view showing an example of a disk which is the background of the present invention. Here, a video signal is frequency-modulated (or phase-modulated) and recorded on the disk 1 to form a track 2. On this track 2, the video signal is recorded so that one field per half cycle and one frame per cycle.
Therefore, the vertical synchronization signal is recorded every half cycle on the disk 1, and the vertical synchronization signals are A, A, and A in FIG.
They are recorded as B and C. Now, in order to reproduce, for example, a still image using such a disc 1, it is necessary to perform a track skipping operation every round. Further, such a skipping operation is usually performed during a vertical blanking period so that noise caused by the skipping operation does not appear on the playback screen. For example, the reproduction light beam reproduces from the vertical synchronization signal A part along track 2 (on track 2), but when it reaches the vertical synchronization signal C part, a skip operation is performed in this vertical synchronization signal C part. , returns to the vertical synchronization signal A section again. By repeating the interlacing operation in this way, a still image is obtained as a reproduced image.

FIG. 2 is an illustrative diagram showing the above-mentioned jumping operation, FIG. 2 a shows the movement of the light beam, and FIG. 2 b
indicates the envelope of the reproduced signal. That is, the light beam spot 3 is connected to the vertical synchronization signal C of the track.
When the vertical synchronization signal A section (indicated by reference numeral 2C) is reached, a jump operation is performed to the vertical synchronization signal A section (indicated by reference numeral 2A). In order to shorten this jumping time, the center of the light beam spot 3 is set at the point a in FIG.
is moved so as to draw a trajectory 4 shown by a broken line. In this manner, the optical beam spot 3 temporarily deviates from the track 2A during this jumping operation, so that the envelope 5 of the resulting reproduced signal becomes wavy as shown in FIG. 2b. Generally, such "wavyness" is not large enough to disturb the image;
Furthermore, as described above, this is performed during the vertical blanking period, so it does not appear on the screen.

[Problem that the invention seeks to solve]

In such a device, minute changes in the characteristics of the servo system that performs the interleaving operation or uneven pitch between the tracks 2 on the disk 1 are unavoidable. Therefore, if such a situation occurs, the fluctuations in the envelope 5 of the signal during the interlacing operation shown in FIG. There is a problem in that this special playback becomes unstable.

Therefore, the main object of the present invention is to provide a high-density recording method that eliminates the above-mentioned problems and allows stable interlacing operations.

[Means for solving problems]

In summary, the present invention forms a thick (wider) recording track in the vertical synchronization signal section (than the normal signal section), and for example, skips during special playback such as quick playback and still image playback. The apparatus is designed to capture a predetermined track without making a mistake during operation, and to obtain a reproduced image with less disturbance in the envelope (image) of the reproduced signal.

The above objects and other objects and features of the invention will become more apparent from the following detailed description with reference to the drawings.

〔Example〕

FIG. 3 is a functional block diagram showing an optical recording method as an embodiment of the present invention. A laser beam 16 emitted from a laser light source 6 such as an argon laser is modulated in intensity by an optical modulator 7 made of, for example, a ferroelectric material in accordance with the video signal to be recorded, and becomes a beam 16'. The light is focused on the surface of the disk 10 through the reflection mirror 8 and the condensing lens 9, and the photosensitive material (photoresift, silver salt, etc.) coated on the surface of the disk 10 is exposed to record the video signal.

On the other hand, the video signal is derived from the video signal source 13 and given to the FM modulator 12 and the vertical synchronization signal separation circuit 15. The vertical synchronization signal separation circuit 15 extracts a vertical synchronization signal from the input video signal and supplies it to the pulse width converter 14. The pulse width converter 14 is configured by, for example, a combination of a delay multi (monostable multi) and a pulse amplifier, and converts the input vertical synchronization signal into a pulse having an appropriate pulse (time) width and height. (hereinafter referred to as a "vertical synchronization pulse"). This vertical sync pulse and the
The FM modulator 12 output is given to the modulation amplifier 11. Therefore, a superimposed version of the two signals is applied to the optical modulator 7 via the modulation amplifier 11, and the laser beam 16 is adjusted accordingly.
change the transmittance of

FIG. 4 is a waveform diagram showing the operation of this embodiment. The operation of the embodiment shown in FIG. 3 will be explained below with reference to FIG. 4. First, the input voltage versus transmitted light amount characteristic of the optical modulator 7 made of a ferroelectric element is curve D.
It is indicated by.

Now, consider the timing when the signal from the video signal source 13 does not include the vertical synchronization signal, that is, the case other than the vertical synchronization signal portion. At this time, modulation amplifier 1
The input signal to FM modulator 1 is only the modulated video signal from FM modulator 12 . Therefore, the input signal voltage to the optical modulator 7 is as shown by the solid line waveform E, and
It is superimposed with the bias voltage V1. Therefore, the amount of transmitted light from the optical modulator 7 is as shown by a solid line waveform F.

Next, consider the timing at which the signal from the video signal source 13 includes the vertical synchronization signal, that is, the case near the vertical synchronization signal portion. At this time, the vertical synchronization pulse triggered by the vertical synchronization signal separated from the video signal from the video signal source 13 is
The signal is superimposed on the output signal from the FM modulator 12 and input to the modulation amplifier 11. Therefore, during the period during which this vertical synchronization pulse continues, the input signal voltage to the optical modulator 7 is a superposition of the bias voltage V1, the voltage V2 of the vertical synchronization pulse, and the signal waveform, as shown by the broken line waveform G. becomes. Therefore, the amount of light transmitted through the optical modulator 7 is, as shown by the broken line waveform H, compared to the amount of transmitted light F in the case of only the video signal described above.
Becomes large. Therefore, the photoresist coated on the surface of the disk 10 forms a wider recording track than in the case where the amount of transmitted light is F. In this way, the vertical synchronizing signal portion is recorded as a wide track for an appropriate period.

It should be noted that the above-mentioned portion with a large track width only needs to be long enough to perform a normal skipping operation as shown in FIG. This is desirable. Therefore, the length of the wide track is the length of the vertical sync signal section, the length of several horizontal sync signals from the vertical sync signal section until the image starts, or the length that includes the vertical sync signal section and the blanking sections before and after it. The length is preferably set by the pulse width converter 14, and the thickness ratio of the track width can be set by manipulating its height (output voltage).

Further, in the above embodiments, an optical disk recording device was explained, but the recording medium may be a sheet-shaped one in addition to a disk-shaped one.
The recording may be performed using pits instead of using a photosensitive material. Of course, the present invention can also be easily applied to recording using an electron beam or the like in addition to a light beam.

〔Effect of the invention〕

As described above, according to the present invention, since the recording track is made wider by the predetermined length of the vertical synchronization signal portion, stable skipping operations can be performed without any special modifications to the reproducing apparatus. Therefore, special playback such as still image playback and quick playback can be performed easily and stably.

[Brief explanation of the drawing]

FIG. 1 is an illustrative diagram showing an example of a recording pattern of an optical disk, which is the background of the present invention. Second
The figure shows the state of the jumping operation in Figure 1, and Figure 2 a shows the trajectory of the light beam spot,
FIG. 2b is a diagram showing the envelope of the reproduced signal. FIG. 3 is a functional block diagram showing an optical disk recording method as an embodiment of the present invention. FIG. 4 is a waveform example diagram showing the operation of the embodiment of FIG. 3. In the figure, 1 and 10 are disks, 2 and 2A,
2C is a track, 3 is a light beam spot, 6 is a laser light source, 7 is an optical modulator, 11 is a modulation amplifier, 1
2 is an FM modulator, 13 is a video signal source, 14 is a panel width converter, 15 is a vertical synchronization signal separation circuit, 1
6 and 16' indicate laser beams.

Claims (1)

[Scope of Claims] 1: means for providing a video signal including at least a vertical synchronization signal; means for generating a recording beam; means for modulating the recording beam in accordance with the video signal; A high-density recording device includes a recording medium that receives a recording beam modulated by a beam, and changes its recording track width depending on the intensity of the recording beam. and applying the pulse signal and the video signal to the modulation means in a weighted manner, thereby widening the recording track by a predetermined section in relation to the vertical synchronization signal section. Recording method. 2. A pulse signal having a predetermined time width in relation to the vertical synchronization signal: separates the vertical synchronization signal from the video signal, and has a predetermined time width and height in response to the separated vertical synchronization signal. 2. The high-density recording method according to claim 1, wherein the high-density recording method is obtained by converting into a pulse signal such as 3. The high-density recording method according to claim 1 or 2, wherein the recording beam is a light beam. 4. The high-density recording method according to claim 1 or 2, wherein the recording beam is an electron beam.