JPS6376124A - Optical information recording disk - Google Patents

Abstract

PURPOSE:To permit reading out of data pits of a reproduction part and the data clock corresponding thereto at all times during reproduction by forming guide track of a guide pit array corresponding to the data clock. CONSTITUTION:The guide track of an optical information recording disk preformatted with the concentrical or spiral guide tracks around the center of rotation are formed of the guide pit array 1 corresponding to the data clock. A laser spot is made to track by the guide pit array 1 corresponding to the data clock. The data pits 4 or the data clock corresponding to the inverted magnetic domain can, therefore, be read out at all times during the reproduction. The after-writing of the fresh data to the unrecorded region by the read-out data clock is thereby permitted and the simplification and miniaturization of a VFO circuit are permitted even with a disk driving device of a CLV or MCAV system.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical information recording disc that records and reproduces information by irradiating it with a laser beam, and more specifically relates to an optical information recording disc that records and reproduces information by irradiating it with a laser beam. This invention relates to a recording method of a preformatted data clock.

[Prior art]

In order to reproduce the data recorded on an optical information recording disk, the clock signal of the data must be reproduced. In this case, there is a modulation method that superimposes the clock signal on the data itself, but the recording density is low. Generally, data clock information is grouped into a specific block.

Also, a method is used in which data is separated into data fields and recorded.

A disk drive device applied to an optical information recording disk employing such a recording method includes a VFO circuit (variable frequency generation circuit) for distinguishing between data pulses and clock pulses.
It is necessary to prepare

[Problem that the invention seeks to solve]

For disk drive devices that record information while driving an optical information recording disk at a constant angular velocity (C: AV method), a single data clock is fixed regardless of the radial position of the playback area with respect to the center of rotation of the disk. For example, when new data is to be later written into an unrecorded area, the data clock at that time can be written by writing a VFO signal with a relatively simple structure.

However, there are disk drive devices that record information by adjusting the rotational speed of the optical information recording disk so that the beam spot moves at a constant linear velocity on the signal surface (CLV method), and the recording area of the optical information recording disk. is divided into multiple blocks in the radial direction.

A method of recording information in CAV mode for each block (
For disk drive devices using the MCAV method, the data clock changes depending on the radial position of the playback area with respect to the center of rotation of the disk, so in order to perform an operation such as writing new data into an unrecorded area, it is necessary to perform a complicated and complicated operation. The problem is that it requires a large VFO signal structure.
Ru.

[Means for solving problems]

By the way, for this type of optical information recording disc.

As shown in FIGS. 3(a) and 3(b), there is one in which a continuous guide track for guiding the laser spot is preformatted. That is, in the optical information recording disk of FIG. 3(a), rectangular groove-shaped recording pits 22 are formed overlappingly on the triangular groove-shaped guide track 21, and the optical information recording disk of FIG. 3(b) is formed. In the recording disk, recording pits 22 are formed between two adjacent guide tracks 21,21.

The guide track 21 and recording pit 22 are detected by optically reading the difference in depth dx and dz from the surface 23a of the disk 23 with a photodetector. Therefore,
By applying track servo so that the output of the photodetector is constant.

The laser spot can be tracked to the guide groove 21.

The guide track 21 described above merely functions as a signal supply source for guiding the laser spot, and the function necessary for tracking the laser spot as a guide track is merely to supply the necessary detection level within the servo band. No, therefore.

It is possible to superimpose other types of data outside the servo band.

The present invention has been made based on the above knowledge, and is aimed at reducing the size and simplification of the VF○ circuit of a disk drive device applied to optical information recording disks of the CLV system and MCAV system. This optical information recording disk is preformatted with a concentric or spiral guide track centered on the data clock, and is characterized in that the guide track is formed by a guide pit row corresponding to a data clock.

[Effect]

If the laser spot is tracked by the data clock and the corresponding guide pit row, the data clock corresponding to the relevant data pit or anti@magnetic domain can be read out at all times during playback, so the read data clock and the New data can be subsequently written into an unrecorded area, and the VFO circuit can be simplified and miniaturized even in a CLV or MCAV type disk drive device.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is an enlarged plan view of the signal pattern forming surface of the optical information recording disk of the present invention, in which 1 is a guide pit row corresponding to a data clock, and 2 is a data pit row corresponding to an information signal.

The guide pit rows 1 are formed concentrically or spirally with respect to the rotation center of the disk, although detailed illustrations are omitted, and the guide pit rows 1, 1 are adjacent to each other in the radial direction.
The interval (track pitch) p is written in H! They are formed at constant intervals from the inner circumference to the outer circumference of the area.

The clock frequency of each guide pit 3 constituting this guide pit row I is 1.5 of the 2-7 modulated data clock.
It is formed with a data period equal to the data clock or an integral multiple thereof, and the period from the rise to the fall of the data clock corresponds to the land portion 4 between each guide pit 3 constituting the guide pit 1-column 1. It looks like this. Also,
The pits ltiw of the guide pit 3 can be formed to have any width, but the track pitch P of the guide pit row 1
If it is 3/4 or more, the pit width of the data pit 2 that can be formed becomes small, and the S/N of the reproduced signal decreases.
If the track pitch p of the guide pit row 1 is set to 1/8 or less, the S/N of the tracking information will decrease and it will be difficult to guarantee a sufficient tracking operation. Formed in 8 to 3/4. Furthermore, data pit row 2 is placed between guide track row 1.1.
Since the structure records information, the depth of the guide pit 3 can be set to a depth 1 where the contrast of the readout light detected by the photodetector is the strongest, for example, 1/4 of the wavelength of the reproduction laser beam. . Further, the cross-sectional shape of the guide pit 3 is not limited to a triangular groove shape, but can be formed in any shape such as a rectangular groove shape.

The data pit row 2 is formed in the middle region of the guide pit row 1. The width of each data pit 4 constituting this data pit row 2 can be formed to any width as long as it does not interfere with the guide pit row 1, but it is wider than the width of each pit constituting the guide pit row 1. It is also preferable to form it with a large width.

The data pit 4 is set at a depth 1, for example, 1/4 of the wavelength of the reproduction laser beam, where the contrast of the readout light detected by the photodetector is the strongest.

The light ff! configured as above! When reproducing an information signal from an information recording disc, as shown in FIG. The light is received through the information recording disk by a photodetector 7 set at a position optically symmetrical with the objective lens 6. Data and a data clock are discriminated from the output of the photodetector 7 by a VFO circuit (not shown), and recording and reproduction are performed. Further, a tracking servo circuit (not shown) is activated due to fluctuations in the output of the photodetector 7.

The laser spot is tracked along the desired guide pit row 1.1.

In the optical information recording disk of the above embodiment, the laser spot is tracked by the guide pit row corresponding to the data clock, so that the corresponding data clock can always be read out along with the data pits of the playback part during playback. can. Therefore, regardless of the data clock of the playback area, operations such as writing new data into an unrecorded area can be easily performed, and the VFO circuit in a CLV type or MCAV type disk drive device can be simplified. Miniaturization can be achieved.

In addition, the clock frequency of each guide pit 3 constituting the guide pit row 1 is set to 1.5 of the 2-7 modulated data clock.
Since the data is formed at a data cycle equal to the data clock or an integral multiple thereof, the pit length of each guide pit 3 constituting the guide track is smaller than the length of the land portion 8 formed between each guide pit 3.3. Long and stable tracking characteristics.

In the optical information recording disk of the above embodiment, the clock frequency of each guide pit 3 constituting the guide pit row 1 is set to a data cycle equal to 1.5 data clocks of the 2-7 modulated data clock or an integral multiple thereof. However, the gist of the present invention is that the guide track is formed by a guide pit row corresponding to the data clock, and the relationship between the clock frequency of the guide pit and the data clock is as described above. For example, the clock frequency of each guide pit may be formed by a data cycle of one data clock of a 2-7 modulated data clock.

Further, it can also be formed with a data period that is an integral multiple of the 2-7 modulated data clock. In the former case, the data clock and data have a one-to-one correspondence, so the VFO
The circuit can be further simplified. In addition, in the latter case, the pit length of each guide pit constituting the guide track can be made much longer than the length of the land formed between each guide pit, resulting in even better tracking characteristics. can be improved. Furthermore, the data clock modulation method is not limited to 2-7 modulation, and any modulation method can be applied.

Further, in the optical information recording disk of the above embodiment, the data pit row 2 was formed between the guide pit rows 1 and 1, but the gist of the present invention is not limited to this. In optical information recording discs,
It is also possible to form data pit row 2 overlapping guide pit rows 1 and 1.

Further, in the above embodiment, the case where the information signal is formed in the form of data pits has been explained, but the gist of the present invention is not limited to this.1 For example, in the case of a magneto-optical recording medium, the information signal Of course, it is also possible to record the inversion in the form of wards.

In such a magneto-optical recording medium, since the guide pit array 1 and the reversal magnetic domain are read out by a separate reproduction mechanism, the presence or absence of the reversal magnetic domain has little effect on tracking performance, forming a more stable servo system. be able to.

〔Effect of the invention〕

As explained above, the optical information recording disk of the present invention has
The laser spot is tracked by the data glock and the corresponding guide pit row, so during playback,
It is possible to always read out the data pit and the corresponding data clock of the reproduction section. Therefore, regardless of the data clock of the playback area, operations such as writing new data into an unrecorded area can be easily performed, and the VFO circuit in a CLV type or MCAV type disk drive device can be simplified. Miniaturization can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a partially enlarged plan view of an optical information recording disk according to the present invention, FIG. 2 is a partially enlarged plan view of the optical information recording disk showing the tracking state of a reproduction laser beam, and FIG. 3 is a partially enlarged plan view of an optical information recording disk according to the present invention. FIG. 3 is an explanatory diagram of a guide track formed on an information recording disc. 1: Guide pit row, 2: Data pit row, 3: Guide pit, 4: Data pit (-15: Laser spot for reproduction,
6: Objective lens; 7: Photodetector; ) (b)

Claims (5)

[Claims] (1) An optical information recording disk in which a guide track is preformatted concentrically or spirally around the center of rotation of the disk, characterized in that the guide track is formed by a guide pit row corresponding to a data clock. Information recording disc. (2) A patent characterized in that the clock frequency of each guide pit constituting the guide pit row is formed with a data cycle equal to 1.5 data clocks of a 2-7 modulated data clock or an integral multiple thereof. An optical information recording disc according to claim 1. (3) The pit width of each guide pit constituting the guide pit row should be set to 1/8 to 3/ of the track pitch of the guide pit row.
4. The optical information recording disk according to claim 1, characterized in that the optical information recording disk is formed in a shape of 4. (4) The optical information recording disk according to any one of claims 1 to 3, characterized in that a data pit row corresponding to an information signal is formed between two adjacent guide pit rows. (5) An inverted magnetic domain array corresponding to an information signal is formed on the guide pit row or between two adjacent guide pit rows. Optical information recording disc.