JPS6011870B2 - High density recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-density recording medium, and more particularly to a high-density recording medium that allows easy interlacing operations during reproduction, for example.

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 output (detection) device are not in contact with each other.

Furthermore, this advantage has created a new function in that it is possible to skip between recorded tracks during playback. For example, when a video signal is recorded on a disk, such a machine can easily perform still image playback, slow-motion playback, quick playback, etc., and its functionality as an image playback device has been greatly improved. . 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 disc 1, forming a track 2.
On this track 2, the video signal is recorded so that one field per half circle and 17 frames per round.
Therefore, the vertical synchronizing signal is recorded every half cycle on the disk 1, and is recorded as A, B, and C in FIG. 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 normally performed during the vertical planking period so that the resulting noise does not appear on the playback screen. For example, a reproduction light beam is reproduced along track 2 (on track 2) from the vertical sync signal A section, but when it reaches the vertical sync signal C section, an interlacing operation is performed in the vertical sync signal C section. Then, return to the vertical synchronizing signal A section again. By repeating the skipping operation in this manner, a still image is obtained as a reproduced image. FIG. 2 is an illustrative diagram showing the above-mentioned interlacing operation, in which FIG. 2a shows the movement of the light beam, and FIG. 2b shows the envelope of the reproduced signal.

That is, when the light beam spot 3 reaches the vertical synchronizing signal C section (indicated by the symbol 2c) of the track, it performs a jumping operation to the vertical synchronizing signal A section (indicated by the symbol 2^). In order to shorten this jumping time, the center of the light beam spot 3 is moved so as to draw a trajectory 4 shown by a broken line in FIG. 2a. In this way, the optical beam spot 3 temporarily deviates from the track 2^ during this jumping operation, so the envelope 5 of the obtained reproduced signal is as shown in Fig. 2b.
The result will be waves as shown in the figure. Generally, such "undulations" are not so large as to disturb the image, and as described above, they do not appear on the screen because they occur during the vertical planking period. However, in such an apparatus, minute changes in the characteristics of the servo system that performs the interlacing operation or pitch irregularities between the tracks 2 on the disk 1 are unavoidable.

Therefore, when 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 may cause a malfunction and the special playback becomes unstable. Therefore, the main object of the present invention is to provide a high-density recording medium that can perform stable interlacing operations while eliminating the above-mentioned problems.

In summary, the present invention forms a thick (wider) recording track in the vertical synchronization signal section (than the regular signal section), and for example, during special playback such as quick playback and still image playback. The present invention is designed to capture a predetermined track without making a mistake through a skipping 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. FIG. 3 is a functional block diagram showing a recording apparatus for optically recording on a high-density recording medium as an embodiment of this invention.

A laser beam 16 emitted from a laser light source 6, such as an argon laser, has its light intensity modulated by an optical modulator 7 made of, for example, a strong electrolyte according to the video signal to be recorded.
The beam 16' passes through the reflecting mirror 8 and the condensing lens 9 and is focused on the surface of the disk 10, and the photosensitive material (photoresist, silver salt, etc.) coated on the surface of the disk 10 is exposed to the image. Record the 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. This pulse-adjacent converter 14 is configured by, for example, a combination of a delay multi (monostable multi) and a pulse amplifier, etc., and converts the input vertical synchronization signal into a pulse (hereinafter referred to as "pulse") having an appropriate pulse (time) width and height. This is converted into a "vertical synchronization pulse"). This vertical synchronization pulse and the output of the FM modulator 12 are applied to a modulation amplifier 11. Therefore, the optical modulator 7 has the above two
A superimposed signal of two signals is applied via a modulation amplifier 11, and the transmittance of the laser beam 16 is changed accordingly. 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 shown by a curve ◯. Now, consider the timing when the signal from the video signal line 13 does not include a vertical synchronizing signal, that is, the case other than the vertical synchronizing signal portion.

At this time, the input signal to the modulation amplifier 11 is only the modulated video signal from the FM modulator 12. Therefore, the input signal voltage to the optical modulator 7 is shown by the solid broken line E.
It is superimposed with the bias voltage VI. 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 a vertical synchronization signal, that is, the case near the vertical synchronization signal portion.

At this time, a vertical synchronization pulse triggered and derived by a vertical synchronization signal separated from the video signal from the video signal source 13 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 becomes a superposition of the bias voltage VI, the voltage V2 of the vertical synchronization pulse, and the signal waveform, as shown by the broken line waveform G. . Therefore, as shown by the broken line waveform, the amount of light transmitted through the optical modulator 7 is larger than the amount F' of transmitted light in the case of only the video signal described above. 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 base/base synchronization signal portion is recorded as a wide track for an appropriate period. Note that the above-mentioned portion with a large track width is, for example, the second
It only needs to be long enough to perform a normal interlacing operation as shown in Figure a, and a range that does not affect the reproduced image (
time) is desirable.

Therefore, the length of the wide track is the length of the vertical sync signal section or 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. Its length is 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 embodiment, an optical disk recording device was explained, but the recording medium may be in the form of a disk or a sheet, and the recording may be performed using bits instead of using a photosensitive material. You can.

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. As described above, according to the present invention, since the recording track is formed wide by the predetermined length of the vertical synchronization signal portion,
Stable jumping operations can be performed without any special modifications to the playback device. Therefore, special playback such as still image playback and quick playback can be performed easily and stably.

[Brief explanation of drawings]

FIG. 1 is an illustrative diagram showing an example of a recording pattern of an optical disc, which is the background of the present invention. Figure 2 shows the state of the jumping operation in Figure 1;
Figure a shows the locus of the light beam spot, and Figure 2 b shows the envelope of the reproduced signal. FIG. 3 is a functional block diagram showing an optical disc recording device 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, 1,1 Kawama disk, 2,2~
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, 12 is an FM modulator, 13 is a video signal source, 14 is a pulse width converter, 15 is a vertical The synchronizing signal separation circuits 16 and 16' are laser beams. Takashi's picture Takayuki Inko's 3rd picture Hair Mu diagram

Claims (1)

[Claims] 1. A high-density recording medium having a track on which a video signal including at least a vertical synchronizing signal is recorded, characterized in that the recording track is widened only in a predetermined section in relation to the vertical synchronizing signal section. Density recording medium.