JP3177505B2 - Disk, disk manufacturing method, and disk recording / reproducing apparatus - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk, a disk manufacturing method, and a disk recording / reproducing apparatus in which the conditions of the rotational speed of the disk are formed as an uneven array. 2. Description of the Related Art Conventionally, when information about the rotation speed of a disk is recorded on a recording disk represented by a magneto-optical disk, for example, as disclosed in JP-A-59-81671. Generally, such information is recorded for each disk after the disk is manufactured. However, recording such information for each disk requires a great amount of work and is not suitable for mass production. Further, if other information is erroneously recorded on a track on which the condition of the rotational speed of the disc is recorded, the condition of the rotational speed may be erased by overwriting. Therefore, there is a need for a disk manufacturing method which is excellent in mass productivity and free from erroneous erasure. Therefore, the disk of the present invention has a recording / reproducing track comprising a guide groove and a rotation of the disk determined before molding the disk substrate at a position preceding the recording / reproducing track. A read-only track including speed conditions is molded on the surface of a plastic disc base
Therefore , after formation, a re-recordable recording film is formed on the surfaces of the recording / reproducing track and the reproduction-only track. Further, the disk manufacturing method according to the present invention is directed to a read-only track including a recording / reproducing track comprising a guide groove and a condition of a rotational speed of the disk determined before molding the disk substrate at a position preceding the recording / reproducing track. After the tracks are formed on the surface of the plastic disk base by molding , a re-recordable recording film is formed on the surfaces of the recording / reproducing tracks and the read-only tracks. Further, the disk recording / reproducing apparatus according to the present invention provides a recording / reproducing track including a guide groove and a position preceding the recording / reproducing track, including a condition of a rotational speed of the disk determined before forming the disk substrate. The dedicated track is molded on the surface of the plastic disc base
A recording / reproducing apparatus for recording / reproducing information on / from a disk having a re-recordable recording film formed on the surface of the recording / reproducing track and the reproduction-only track. Then, the condition of the rotation speed of the disk is reproduced, and the rotation speed of the disk at the time of recording or reproduction is adjusted. An embodiment of the present invention will be described below with reference to the drawings. 1 is a plan view of an information recording medium, FIG. 4 is a perspective view, FIG. 2 shows a format in which information relating to recording and reproduction conditions is recorded, and FIGS. 3 and 5 use the information recording medium of the present invention. FIG. 1 is a block diagram of an information recording / reproducing apparatus to be used. In FIG. 1, reference numeral 1 denotes a magneto-optical disk (information recording medium). A through hole 2 is provided in a central portion, and the through hole 2 is clamped by an information recording / reproducing device.
The disk 1 is rotated. 3 is a magneto-optical recording part,
Its structure is as shown in FIG. That is, a perpendicular magnetization film 5 (shown by hatching) of GdTbFe, TbFeCo, or the like is provided on a plastic substrate (polycarbonate, acrylic) 4 on which a guide groove 4a (this portion becomes a recording track) is formed by evaporation or sputtering. . A protective layer 6 made of a dielectric is formed on the perpendicular magnetization film 5. Inside the magneto-optical recording section 3, there is provided a recorded section 7 in which information signals relating to recording and reproduction conditions are recorded. The method of recording the information signal on the recorded portion 7 is a method of recording as uneven pits 8 on the plastic substrate 4 like a compact disk, or removing the perpendicular magnetization film 5 like a write-once disk. The recording method can be considered. In the recorded portion, an aluminum reflection film may be formed instead of the perpendicular magnetization film. According to the above recording method, an already recorded information signal can be read by a change in the amount of reflected light from the disk 1. The method of recording in the form of uneven pits is advantageous because pits can be created when the guide groove 4a is formed, and there is no possibility of erasing.
The laser beam is emitted from the plastic substrate 4 as shown by the arrow A. As a format in which information relating to recording and reproduction conditions is recorded, in a device that can also use a compact disc, the subcode Q of the compact disc is used.
Use channel format. The format of the subcode Q channel is as shown in FIG. Of these, 0001, 001 in the four bits of the address
0,0011 is a significant pattern for compact discs, while other patterns are meaningless for compact discs. The recorded portion 7 of the magneto-optical disk 1 is
For example, 1000 patterns are recorded in the address portion of the format of the subcode Q channel. In the 72-bit data portion, information relating to recording (including erasure) and reproduction conditions of the magneto-optical disk is recorded. This information relates to, for example, laser power, linear velocity, intensity and direction of a bias magnetic field during recording, erasing, and reproducing. Alternatively, a specific pattern can be recorded to indicate the beginning of the magneto-optical recording portion 3 (or the end of the recorded portion 7). That is, the specific pattern is used as a mark indicating the reference position, and data on the number of rotations and time up to the start of the magneto-optical recording portion is recorded. The conditions for recording and reproduction are required for the following reasons. That is, as described above, GdFe, TbFe, Tb
There are FeCo and the like, but if the composition is different, the conditions of the laser power and the bias magnetic field are naturally different.
This is because, even in a material based on eCo, when the proportion of Co increases, the Curie point increases, so that the laser power for recording and erasing must be increased. Therefore, if the laser power at the time of recording, erasing, and reproducing, the intensity of the bias magnetic field at the time of recording and erasing, or the required linear velocity is written into the recorded portion 7, the information recording / reproducing apparatus can record the recording material. To different types of magneto-optical disks. Also, even if the recording material is the same, the magnetization direction of the magneto-optical recording portion in the non-recording state may differ depending on the standard, so that information for specifying the direction of the bias magnetic field at the time of recording and erasing is recorded. It is effective to be done. Next, a first embodiment of an information recording / reproducing apparatus using the above disc will be described with reference to FIG.
In FIG. 3, reference numeral 10 denotes a semiconductor laser as a laser light source;
11 is a collimator lens, 12 is a first polarizing beam splitter, 13 is an objective lens, 14 is a disk, and 15 is 1
/ 2 wavelength plate, 16 is a polarizing beam splitter, 17, 18
Is a photodetector, 19 and 20 are changeover switches for switching the outputs of the photodetectors 17 and 18, 21 is an adder (non-differential reproduction circuit), 22 is a differential amplifier (differential reproduction circuit), and 23 is A decoder 24 is a control circuit. Reference numeral 25 denotes a bias magnetic field applying means. When a disk (information recording medium) is mounted,
Since this disk has two possibilities, a magneto-optical disk and a compact disk, the information recording / reproducing apparatus is in a read state of a recorded portion of the magneto-optical disk or a lead-in portion of the compact disk. That is, each switch 1
9 and 20 are controlled to the a side, and the outputs of the photodetectors 17 and 18 are applied only to the adder 21. Then, since the pickup 26 is at the reading start position, the intensity of the reflected light from the disk changes in accordance with the information recorded in the lead-in portion or the recorded portion. Since the outputs of the photodetectors 17 and 18 change in accordance with the strength change, a reproduced HF signal is obtained by adding the outputs of the photodetectors 17 and 18 (using one photodetector having a large output change). May be). The reproduced HF signal is decoded by a decoder 23 and supplied to a control circuit 24. The control circuit 24 controls the device according to the read information signal. First, when the 4-bit address of the subcode Q channel is 1000 as described above, it is determined that the disk is a magneto-optical disk, and the changeover switches 19 and 20 are set.
Is controlled to select the b side. In the case of a magneto-optical disk,
Information related to recording and reproduction is read, and the control circuit controls the semiconductor laser 10, the bias magnetic field generating means 25, and the spindle motor for rotating the disk according to the information. That is, while information is being read from the recorded portion 7, the changeover switches 19 and 20 must select the a side. Therefore, in a medium in which a specific pattern is recorded at the end of the already-recorded portion 7, the changeover switches 19 and 20 may be switched to the b side by detecting this specific pattern. At the same time, the counter value indicating the position of the pickup 26 is cleared. When data relating to the time until the start of the magneto-optical recording portion 3 is recorded, the data may be read and switched to the b side after a predetermined time has elapsed. The above operation is easily realized by the control circuit 24 (comprising a microcomputer or the like). When a magneto-optical disk is mounted on the information recording / reproducing apparatus, the above-described determination is first performed. When a reproduction operation is designated, a predetermined power is supplied to the semiconductor laser 10 under the control of the control circuit 24. The light from the semiconductor laser 10 is collimated by the collimator lens, and is converted into linearly polarized light (P-polarized light) by reflecting the S-polarized light by the first polarizing beam splitter 12. The linearly polarized light is condensed by the objective lens 13 and applied to the magneto-optical recording portion of the magneto-optical disk 14, and the polarization plane of the reflected light is rotated according to the recorded information. In this reflected light, the P-polarized light component is changed by about ± 0.3 degrees (that is, the S-polarized light component is generated). When the light again enters the first polarization beam splitter 12, the P-polarized light component is reflected by about 30%, and the S-polarized light component is reflected by 100%, whereby the change in the rotation angle is enlarged. The reflected light in which the change in the rotation angle is enlarged is ２.
The polarization plane is rotated by the wave plate 15, and is separated into a P-polarized component and an S-polarized component by the second polarization beam splitter 16, and is incident on the corresponding photodetectors 17 and 18, respectively. The outputs of the photodetectors 17 and 18 are supplied to a differential amplifier 22, whereby a magneto-optical reproduction HF signal is obtained. On the other hand, when a recording or erasing operation is designated after the mounting of the magneto-optical disk, the laser power, the strength and direction of the magnetic field, and the state of the disk rotation control according to the mode are determined based on the read information. Set by the control circuit. Also, the start position of the magneto-optical recording part is set and used for subsequent access. Then, recording and erasing operations are performed. If 1000 is not recorded in the 4 bits of the address of the subcode Q channel, it is determined that a compact disc is loaded, and the changeover switch 1
In 9 and 20, the a side remains selected, and the HF signal of the compact disk is obtained from the adder 21. In the above embodiments, a magneto-optical disk was used as an information recording medium. Is also good. The information on the condition may be recorded in a portion other than the reading start portion. The configuration of the information recording / reproducing apparatus is shown in FIG.
Embodiment) can also be used. As described above, according to the present invention, the condition of the rotational speed of the disk can be recorded by a method suitable for mass production, and the condition is not erased by mistake. But it has an excellent effect.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view of a disk of the present invention. FIG. 2 is an explanatory diagram of a recording format of a disc of the present invention. FIG. 3 is a block diagram of a reproducing circuit of the disk recording / reproducing apparatus according to the first embodiment of the present invention. FIG. 4 is a cutaway perspective view of a main part of the present invention. FIG. 5 is a block diagram of a reproducing circuit of a disk recording / reproducing apparatus according to a second embodiment of the present invention. [Description of Signs] 1 magneto-optical disk 3 magneto-optical recording part 4 plastic substrate 4a guide groove 7 already recorded part 8 pit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification code FI G11B 11/105 581 G11B 11/105 581L 19/28 19/28 B (58) Investigated field (Int.Cl. ⁷ , DB name) ) G11B 7/00-7/013 G11B 11/105

Claims (1)

(57) [Claims] Molding and reproducing track consisting of a guide groove, and a reproduction-only track including the rotational speed of the conditions of the disc that is determined before the disc substrate molded in a position preceding the recording track on the surface of the disk substrate of the plastic properties By
And a recording film capable of re-recording is formed on the surface of the recording / reproducing track and the reproduction-only track. 2. Molding and reproducing track consisting of a guide groove, and a reproduction-only track including the rotational speed of the conditions of the disc that is determined before the disc substrate molded in a position preceding the recording track on the surface of the disk substrate of the plastic properties By
After formation I, disk manufacturing method characterized by forming the re-recording is possible recording film on the recording track and the surface of said reproduction-only track. 3. Molding and reproducing track consisting of a guide groove, and a reproduction-only track including the rotational speed of the conditions of the disc that is determined before the disc substrate molded in a position preceding the recording track on the surface of the disk substrate of the plastic properties By
A recording / reproducing apparatus for recording / reproducing information on / from a disk having a re-recordable recording film formed on the surface of the recording / reproducing track and the reproduction-only track. A disk recording / reproducing apparatus for reproducing the condition of the disk rotation speed and adjusting the disk rotation speed during recording or reproduction.