JPS6035735B2 - optical recording method - Google Patents

Description

[Detailed Description of the Invention] In recent years, there has been research and development into technology for recording various information signals at high density and reproducing them using disk-shaped information recording media (hereinafter sometimes referred to as disks). As a result of this active research, it has become possible to expect that a system for recording and reproducing information signals using disks will be put to practical use in the near future.

Now, when trying to record information signals on a master disk at high recording density, a typical conventional recording method is to use a minute laser beam modulated by the recording signal. A spot, or a minute spot of an electron beam modulated by an information signal, is projected onto a beam-sensitive material layer (for example, a photoresist layer) of a disk master. Since recording means using a beam requires the use of expensive equipment, recording means using an inexpensive laser is often adopted unless the rotation speed of the disk is kept low. . Incidentally, when optically recording information signals on a master disc, an argon laser (Ar+ laser) is generally used as a light source that can produce short wavelength light with low noise and high output. However, during use, an argon laser experiences a phenomenon in which its output decreases or stops several times an hour, each time lasting from several tens of microseconds to several hundred microseconds.

As mentioned above, the number of times that the argon laser output decreases or stops during use varies depending on the laser output, how long the laser tube has been used, and the manufacturer, but in any case, the argon laser When a laser is used, the phenomenon of a decrease in output or a stoppage of output is observed to occur to varying degrees during use.

It is not clear at present what causes the above-mentioned phenomenon in argon lasers, but it is probably caused by gas or fine dust released from the tube wall when ions and electrons collide with the tube wall due to discharge. It is assumed that there is no such thing.

As mentioned above, the argon laser can output low-noise, high-output, short-wavelength (4579 angstrom) light, so it is useful when recording minute bits corresponding to information signals on the master disc. It is used as the most suitable light source, but if the output decreases or stops as described above during use, the information signal that should be recorded will be missing. becomes a problem.

In particular, in the case of a disc in which a tracking control signal is recorded in addition to the main information signal (for example, a so-called VHD disc), this problem may occur due to the decrease in the laser output or the stoppage of the laser output as described above. The non-recording state of the tracking control signal is serious in that it greatly hinders the reproduction of information signals from the disc, and a solution to this problem has been desired. The present invention attempts to solve the above-mentioned problems by specializing the manner in which the recording trace by the tracking control signal is recorded adjacent to the recording trace by the main information signal. Hereinafter, specific contents of the present invention will be explained in detail with reference to the accompanying drawings.

FIG. 1 shows a disk-shaped information recording medium (hereinafter referred to as a disk) that has no guide grooves by recording traces of main information signals and traces of tracking control signals adjacent to each other. In Fig. 1, Da is a disk, T, , T2, 9, etc. are recording traces of main information signals. Record traces T,, T2...
is composed of an array of bits 1, 1, . . . each corresponding to a main information signal.

A tracking control signal f side is located between adjacent recording traces T, L, etc. due to the above-mentioned main information signals.
The recording trace Tt, .
, T upper milk, Tt, 2, etc., the recording trace of the main information signal is sandwiched on both sides by the recording trace of the tracking control signals fp, , fp2, each having a different frequency value. It has become a thing.

4 is a regeneration needle that detects changes in capacitance value, and 4a in the figure
indicates an electrode portion, and arrow X indicates the direction of movement of the disk.

Details of the above-mentioned non-grooved disc and the capacitance change detection type reproduction method using the non-grooved disc can be found in, for example, JP-A-52-123205 and JP-A-53-98814.
It is recommended that you refer to the publication and other documents.

Now, in the above-described disk, the recording traces T,, T2, T3, etc. of the main information signals, which are formed by the arrangement of bits 1, 1, etc. corresponding to the main information signals, correspond to the tracking control signals fp,, fp2. bits 2, 2..., 3
, 3... are recorded by the tracking control signals Tp, . , Tp, 2 ●・, Tpa, Tp2 are the light spot intensity-modulated by the main information signal and the light spot intensity-modulated by the tracking control signal on the beam-sensitive material layer of the rotating disk master. At that time, the tracking control signals fp, fp2 having different specific frequency values are switched and recorded every rotation of the master disc as shown in FIG. It is possible to optically record a recording pattern on a master disc to obtain a disc Da showing a recording trace pattern as described above, but in an optical recording device, one light source for recording is used. When the light obtained from one laser light source is divided, and each of the divided lights is intensity-modulated separately by a main information signal and a tracking control signal (for example, the above-mentioned Special Publication No. 52-123205, JP-A-53-
98814), if the optical power from the laser light source decreases or stops for a short period of time, recording of the main information signal and recording of the tracking control signal will not take place during that time. Needless to say, this will result in signal loss.

Signal loss due to the above causes is not desirable for the main information signal, but short-term loss of the main information signal can be repaired by a loss signal compensation circuit provided in the playback device. Although this is not a very serious problem, the loss of the tracking control signal cannot be repaired, so the loss of the signal causes disturbances in the tracking control operation during the playback operation, and the tracking control signal The lack of this will seriously impede the playback operation.

In other words, short-term laser output drops or stops in the laser light source occur randomly, about several times an hour. The aspect is that only the tracking control signal of one of the two tracking control signal recording traces sandwiching both sides of the main information signal is left in a non-recorded state, so that the tracking control operation during playback is disturbed. That's what happens.

The present inventor has discovered that even if the tracking control signals in the recording trace caused by the tracking control signals present on both sides of the recording trace caused by the main information signal are simultaneously deleted for a short period, it will cause a major hindrance to the tracking control operation during playback. The method of the present invention was completed by focusing on the fact that no

FIGS. 2 and 3 show a light spot 5 that is irradiated onto the master disk in order to form a bit corresponding to a main information signal on the master disk when carrying out the optical recording method of the present invention. 2 is a plan view for explaining the relative arrangement of two light spots 6 and 7 that are irradiated onto the master disc in order to form a bit corresponding to a tracking control signal on the master disc. , this second
In the figures and FIG. 3, the line A-A passes through the center of the recording trace of the main information signal formed by the arrangement of bits of the main information signal, and extends in the direction in which the recording trace extends. In the optical recording method of the present invention, the spot of light irradiated onto the master disc in order to form a bit corresponding to the tracking control signal on the master disc is shown in FIG. 3
As illustrated in the figure, two light spots 6 and 7 occupy positions that are approximately symmetrical with respect to the above-mentioned line A-A.
These are the two light spots 6 and 7, and the two light spots 6 and 7 are irradiated onto the master disc at the same time.

4 to 6 show the optical spot 5 for recording the main information signals and the optical spot 5 for recording the tracking control signal, which are arranged as shown in FIG. 2 or 3 above. FIG. 4 is a diagram showing an example of the structure of a recording pattern recorded on a master disk by two optical spots 6 and 7. First, FIGS. A recording is made which can form bits 1, 1 corresponding to the main information signal, and
The optical spot 6 for recording the tracking control signal is intensity-modulated by the tracking control signal fp,
This optical spot 6 performs recording that can form bits 2 and 2 corresponding to the tracking control signal fp.
Furthermore, a light spot 7 for recording a tracking control signal is provided.
is intensity-modulated by the tracking control signal fp2, and this light spot 7 performs recording that can form bits 3 and 3 corresponding to the tracking control signal fp2. 7, the recording pattern of the tracking control signal is intermittently performed every other revolution of the disc master, and for ease of understanding, the recording pattern for each revolution of the master disc is divided into figures a to d. The recording patterns shown in figures a to d are collectively shown in figure e.

It goes without saying that the recording pattern shown in FIG. 4e is the recording pattern formed on the master disk.

In Fig. 4, figure a is the 1st rotation of the n-th rotation of the master disk.
These are the recording patterns recorded on the master disk during rotation, and figures b, c, and d are (n11) of the master disk, respectively.
) rotation, (n+2) rotation, (n13) rotation, 1 each
This shows the recording pattern recorded on the master disc during rotation.

Next, FIG. 5 shows the optical spot 5 for recording the main information signal.
Recording is performed to form bits 1, 1, etc. corresponding to the main information signals, and one optical spot 6 for recording the tracking control signal is placed on the master disk of the disc as shown in FIGS. 5a to 5c. Two tracking control signals fp, , fp2 and corresponding bits 2, 2, . . . , 3 are generated for each rotation of
, 3, etc., the other optical spot 7 receives two tracking control signals fp2 for each rotation of the master disk as shown in FIGS. 5a to 5c. , fp, and the corresponding bits 3, 3..., 2,
In this example, each information signal is recorded in a recording pattern as shown in Fig. 5d on the master disc by performing recording such that one of the two... is formed. be.

Further, FIG. 6 shows that tracking control signals are recorded intermittently during the first rotation of the master disc in the recording mode explained with reference to FIG. This is an example in which tracking control signals are recorded in an interpolative manner for parts where no tracking control signals are recorded during one rotation of the light. This will be understood with reference to FIGS. 6a-d. In order to record the tracking control signal when the main information signal is a TV video signal according to the tracking control signal recording mode shown in FIG. 6, the intermittent recording mode may be selected every horizontal scanning period. (It is a desirable embodiment to make the recording position of the tracking control signal correspond to the horizontal line erasing period in the TV signal as shown in Japanese Patent Application Laid-Open No. 52-123205. 7 is a block diagram showing the configuration of an example of an optical recording device suitable for carrying out an optical recording method, and in this FIG. and is laterally transferred by a transfer mechanism (not shown).

An information recording medium ○ (disk master D) formed by adhering and forming a recording material layer on a substrate with a flat surface is fixed on the turntable 39, and the above-mentioned disc master D
Recording is performed by focusing three laser beam spots, each modulated by an information signal and having a desired cross-sectional shape, on the recording material layer formed thereon.
, in Figure 7, 4
0 is a laser light source, and the laser light beam emitted from this laser light source 40 is supplied to the light amount adjustment optical modulator 8 via the reflecting mirror 41, and is
After removing the drift of the laser beam and controlling the amount of light in the radial direction on the master disc D of the disc (for this point, please refer to Samurai Seki No. 52-76003), the laser beam is transmitted through the half mirror 9. One optical modulator for the main information signal is provided. Optical modulator 1 Kawakoha terminal 1
A recording signal of the main information signal is given to the optical modulator 1, and the laser light beam (first laser light beam) whose intensity is modulated by the main information signal is sent to the reflector 1.
2 and applied to the cylindrical lens 13.
The first laser beam emitted from the cylindrical lens 13 is focused by the cylindrical lens 14 which focuses the light in a direction substantially perpendicular to the focusing direction of the cylindrical lens 13, and then passes through the slit. Member 15 is provided. The slit member 15 has a slit S that is connected to the cylindrical lens 14.
It is placed at the focal point of the light.

The first laser beam, which is partially blocked by the slit S of the slit member 15, passes through the convex lens 16, the polarizing prism 17, the half mirror 18, the prism 19, and the recording lens 20, and is applied to the first laser beam on the master D of the disk. An image of the slit S is formed by the laser beam 21. That is, the convex lens 16 and the lens 20 described above are the slit member 1 placed at the focal point of the cylindrical lens 14.
The image of the slit S of No. 5 is formed on the master D of the disk 21
You can spend it.

Further, the laser beam reflected by the half mirror 9 described above is given to the optical modulator 22 for tracking control signals via the half mirror 36, and is also applied to the half mirror 36.
6 and a reflecting mirror 37 to the optical modulator 28 for tracking control signals, and in the optical modulators 22, 28 for tracking control signals, the signals are supplied from the signal generator 38 to the terminals 23, 29. The intensity is modulated by the tracking control signal. It goes without saying that depending on the form of the signal from the signal generator 38, recording can be performed in the recording manners shown in FIGS. 4 to 6. optical modulator 22,
The laser light beam {second (third) laser beam} outputted from 28 is transmitted through convex lenses 24 and 30, slit members 25 and 31, convex lenses 26 and 32, reflecting mirror 27, half mirror 33, polarizing prism 17, Through the half mirror 18, the prism 19, and the recording lens 20, the slits Sa in the slit sections 25 and 31 are formed on the master D of the disk.
A light image at the S22 position is formed 34 and 35. That is, the convex lenses 26 and 32 and the recording lens 20 described above have a slit member 25 placed at the focal point of the convex lenses 24 and 30.
, 31, the optical images at the slit S phantom and S22 positions are formed on the master D of the disk 34, 35. The polarizing prism 17 described above transmits the first laser beam and applies it to the half mirror 18 , and also reflects the second (third) laser beam and applies it to the half mirror 18 .

The half mirror 18 also includes the polarizing prism 17 described above.
The first and second laser beams incident from the direction are transmitted toward the prism 19, and the reflected light from the laser beam spots 21, 34, 45 on the master D of the disk and the surface of the prism 19 are transmitted. The reflected light is reflected towards the optical monitoring device PM. The position of the slit S of the slit member 15 provided in the optical path of the first laser beam and the slit S2 of the slit members 25 and 31 provided in the optical path of the second and third laser beams. ，
, S22 means those slits S,,S2,,
The relative positional relationship of the S mother image formation is set correctly so that the first, second, and third laser beam spots irradiated onto the master D of the disk have a predetermined positional relationship. has been done. Therefore, even if the traveling direction of the laser light emitted from the laser light source 40 changes due to a change in temperature, the slit sections 15, 25, 31 set as described above will remain the same.
The first and second slits S, , S2, , S22 of
, the relative positional relationship of the first, second, and third laser beam spots irradiated onto the disk master by the third laser beam is always maintained at a predetermined positional relationship.

To shift the positions of the spots 34 and 35 of the second and third laser beams with respect to the spot 21 of the first laser beam as shown in FIG. 2 or 6 and 7 shown in FIG. This can be easily realized by changing the arrangement of optical members in the optical paths of the second and third laser beams (for example, by changing the arrangement of optical members in the optical paths of the second and third laser beams). (You can do this by slightly changing the angle of the lens, or by slightly shifting the principal axis of the lens in parallel.)

As is clear from the above description, in the optical recording method of the present invention, when the laser light source used as a light source for recording information signals has a short-term decrease in laser output or a stoppage of laser output, As a result, the tracking control signal is made unrecorded on both sides of the main information signal at the same time, so that the above-mentioned conventional problems can be satisfactorily solved by implementing the method of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a part of the disk, FIGS. 2, 3, and 4 to 6 are explanatory diagrams of recording patterns, and FIG.
The figure is a block diagram of an example configuration of a recording device. Da● Disc, D... Disc master, 5... Light spot modulated by the main information signal, 6, 7...
a light spot modulated by a tracking control signal;
40...Laser light source. Scheme 1 Figure 2 Figure 3 Chrysanthemum diagram Chrysanthemum S Scheme Figure 6 Atsushi Figure 7

Claims (1)

[Scope of Claims] 1. Optical recording is performed on the surface of a disk-shaped information recording medium so that the recording trace of the main information signal and the recording trace of the tracking control signal form adjacent spiral or concentric recording traces. In order to record data, two light spots whose intensity is modulated by the tracking control signal pass through the center of the width of the recording trace created by the main information signal and form a line extending in the direction in which the recording trace extends. In an optical recording method, optical recording is performed using a main information signal and a tracking control signal so that the two optical spots are provided at positions approximately symmetrical to are intensity-modulated by tracking control signals having specific frequency values different from each other, and the recording of the tracking control signals by the two optical spots described above is performed on one of the disk-shaped information recording medium discs. An optical recording method in which data is recorded every rotation. 2. To optically record on the surface of a disk-shaped information recording medium so that the recording trace by the main information signal and the recording trace by the tracking control signal form adjacent spiral or concentric recording traces. , two light spots whose intensity is modulated by the tracking control signal are applied to positions approximately symmetrical to a line extending in the direction in which the recording trace by the main information signal is extended, thereby detecting the main information. In an optical recording method in which optical recording is performed using a signal and a tracking control signal, the intensity of the two optical spots described above is changed by tracking control signals having specific frequency values that are different from each other. In addition, the specific frequency value in the tracking control signal for intensity modulating the two optical spots is alternately switched for each revolution of the disc-shaped information recording medium. Optical recording method. 3. To optically record on the surface of a disc-shaped information recording medium so that the recording trace by the main information signal and the recording trace by the tracking control signal form adjacent spiral or concentric recording traces. , two light spots whose intensity is modulated by the tracking control signal are applied to positions approximately symmetrical to a line extending in the direction in which the recording trace by the main information signal is extended, thereby detecting the main information. In an optical recording method in which optical recording is performed using a signal and a tracking control signal, the intensity of the two optical spots described above is changed by tracking control signals having specific frequency values that are different from each other. The specific frequency value in the tracking control signal that modulates the intensity of the two optical spots is alternately switched each time the disc-shaped information recording medium rotates. The recording of the tracking control signal is performed intermittently so that the recording position in the circumferential direction by the tracking control signal is interrogated with each other for each successive rotation of the information recording medium of the shape. Optical recording method. 4. The optical recording method according to claim 3, wherein the intermittent recording is performed every horizontal scanning period.