JPH03237657A - Data recording track - Google Patents

Abstract

PURPOSE:To prevent the deterioration of a recording and reproducing characteristic of data to be written by previously forming clock information by means of width direction displacement information whose displacement is set to be smaller than width direction displacement information formed in a reproduction-only rack area in the pregroup of a recordable track area. CONSTITUTION:In a data recording track, width direction displacement information whose displacement in the direction of a width is comparatively large is previously formed in a ROM track area 1b which comes to the reproduction-only track as prescribed data and width direction displacement information whose displacement is smaller than width direction displacement information formed in the ROM track area 1b is formed in a RAM track area 1a which comes to the recordable track. Then, clock information or timing information is added by width direction displacement information. Consequently, track control data can be continuously obtained by the same signal processing and the control signal of recording data can be obtained based on said information at the time of recording. Width direction displacement information formed in the RAM track area 1a is set to be small displacement DELTAd2. Thus, the reproducing and recording characteristic of data to be written is not adversely influenced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data recording track applied to, for example, a write-once or rewritable optical disc.

[Summary of the Invention 1 The present invention provides a write-once optical disc, a rewritable optical disc, etc., in which a pre-groove forming a recording track has a first track area exclusively for reproduction, and data can be continuously recorded in the first track area. The first track area is pre-added with predetermined data formed by width direction pits displaced in the width direction of the pregroove, and the second track area is divided into a second track area. The clock information and/or timing information is formed by width direction pits having a smaller displacement width than the width direction pits formed in the first track area, and based on the information recorded on one optical disc. This allows other information to be written on the disc later.

[Prior art] Optical discs whose recording surface is a recording medium that is sensitive to light include
Generally, it has a recording track formed spirally or concentrically, and data is recorded along this recording track.
Or what is known to be played.

By the way, when using such a recording medium as an operating system, a basic dictionary disk, or an educational soft disk, it is necessary to allow the user to add or write desired data based on various program data recorded in advance. It is requested that the

In other words, it is preferable to provide a recordable area for the reproduction-only data recorded by the software supplier in which the user can write necessary data outside the recording area of the reproduction-only data.

FIG. 5 shows an example of such an optical disc.
In optical disks that use organic dye as a recording medium or have an interface that changes due to the magneto-optical effect as the recording surface,
A spiral pregroove is formed 1, and in this spiral pregroove, a reproduction-only track area IB in which data has already been recorded is provided, which is continuous with a signal recordable track area IA. .

It has been proposed that the playback-only recording track records control data such as synchronization signals and address information, as well as various data, and that data management is performed based on this control data. There is a system in which data is recorded in block units or sector units in consecutive recordable track areas @lA and then reproduced.

As a method for recording control data such as synchronization signals and address signals, recording is performed by forming sample pits, for example.

Furthermore, as another method for pre-recording control data such as address information, a technique has been proposed in which a wobbling track for detecting tracking errors is FM modulated using a time code to form a record.

In this case, for example, a sine wave carrier signal of 22.05KH2 is FM-modulated based on a time code signal with a frequency sufficiently lower than this carrier wave to form a wobbling track, and a tracking error signal is obtained during playback. At the same time, this time code is demodulated to obtain a time code as position information.

[Problem to be Solved by the Invention 1] By the way, if control data is detected by sample pits formed in a playback-only track area that is connected to a recordable track area, the formation of such pits Since the location is different from the data recording area of the disk, and a sampling method is used when applying tracking servo, there is a problem that continuous tracking servo cannot be applied using a single tracking method. Ta.

Furthermore, when pits are formed on a disk, crosstalk to adjacent tracks may occur, which may adversely affect signal reproduction from data recordable areas of adjacent tracks.

Furthermore, when control data is recorded by FM modulating the wobbling track with a time code, there is a problem in that it is difficult to specify the track position in detail using the control data, and the precision is not high.

[Means for Solving the Problems] The present invention has been made in view of these problems.
A first track area serving as a pre-groove playback-only track and a second track area serving as a recordable track are formed by a pre-groove having approximately the same track pitch, and the first track area includes: Predetermined data is written using irregularities displacing in the width direction (hereinafter referred to as widthwise pits), and in the second track area, irregularities displacing in the widthwise direction (hereinafter referred to as widthwise pits) are formed in the first track area. The width direction pits are formed with a smaller displacement than the width direction pits, and the clock information or timing information of the data written in the recordable area is provided by the width direction pits.

[Function] The recordable track in the pregroove and the track width that becomes the playback-only track are almost the same, but the recordable track has data recorded in advance in widthwise pits with relatively small displacement. Therefore, it is possible to prevent the recording/reproducing characteristics of data to be additionally written or written subsequently to this track from deteriorating.

In addition, predetermined data is recorded on the playback-only track in pits in the width direction that have relatively large displacements, but the crosstalk that occurs during playback of this track cannot be reduced because the track width is originally small. can.

[Example 1] In a recording medium according to an embodiment of the present invention, an organic dye is provided on the recording surface that is sensitive to light, and the dye and substrate are separated by irradiating the organic dye with a laser beam from a transparent substrate layer. The constituent polycarbonate is softened by heating, and interaction with the decomposed dye deforms the interface of the substrate, forming pits.

FIG. 1 shows an enlarged view of a pregroove formed on such a recording medium, and shows a first track area IB indicating a read-only track shown in FIG. 5, and a second track area IB which is a recordable track. This is an enlarged view of a part of the track near the boundary of track area IA.

In this figure, lb indicates the shape of the pregroove (hereinafter referred to as ROM track area) on the above-mentioned read-only track, and 1a indicates the shape of the pregroove on the recordable track (hereinafter referred to as R
The shape of the AM track area) is shown.

The pitch interval of each pregroove is set to, for example, approximately 1°6 μm, and the track width d1. dz is about 0.
It is said to be 6 to 0.8 μm.

A widthwise displacement Δd is given to the ROM track area during mastering of the optical disc, and the shape of the unevenness (hereinafter referred to as widthwise pit) of this widthwise displacement Δd1 indicates the recording data input to pre-mastering.

That is, in the above embodiment, a seek address, a sector mark, a synchronization signal, preamble data, etc. are formed as recorded data, but other necessary ROM
Data can also be recorded in the ROM track area 1b.

The displacement Δd in the width direction in this ROM track area is such that a sufficient detection signal can be obtained when the reflected light of the laser spot (1.6 to 2 μm) irradiated to this ROM track area is detected using a push-pull method. so about 0
．． It has an amplitude of 2 μm and is designed to reduce crosstalk from adjacent tracks.

The RAM track area 1a is a recording track on which data is additionally written using the recording method described above.
A similar displacement Δd2 in the width direction is also formed in the M track area.

However, the widthwise displacement Δd2 formed in this RAM track area can mainly provide clock information, and for example, the clock frequency (4,3218MH2) adopted in the CD format can be easily extracted. It is preferable to form pits in the width direction that are uneven in units of 17 bits.

Further, the amplitude of the displacement Δd2 in the width direction is approximately 0.04 to 0.0.
06 μm, which is a sufficiently small value compared to the ROMh rack area. However, since this RAM track area only needs to be able to reproduce clock information, it is possible to sufficiently extract the clock signal with such a small amplitude.

Further, by reducing the amplitude (Δd2) of the pits in the width direction, the recording and reproducing characteristics of data written in the pregroove are prevented from deteriorating.

FIG. 2 shows another embodiment of the RAMh rack area.

In this embodiment, width direction pits IIT%LIT are formed as a frame synchronization signal in units of one frame length (588 bits) adopted in the CD format, for example, and these width direction pits are
It is formed with the same displacement in the width direction (Δd2) as in the figure.

Except for the widthwise pits IIT and IIT, the track on which data is recorded has no widthwise pits up to the leading end of the next frame.

FIG. 3 shows yet another embodiment of the RAM)-rack area, and in this embodiment, as in the case of FIG. It is formed as.

However, the width direction pits IIT, IIT are configured to be displaced by the same amount in the vertical direction from both ends of the track width indicated by the dashed line.

Therefore, the track center of each frame can be positioned on a straight line.

In this embodiment, as shown in the figure, the rising point t0 of the synchronization signal of the odd-numbered frame and the falling point t of the width direction pit forming the frame synchronization signal of the even-numbered frame.
If the direction of the frame 6 is reversed, there is an advantage that whether the next frame will be an even number or an odd number can be detected from this width direction pit.

The frame synchronization signal may have other shapes as long as it indicates the frame unit of data to be additionally written in the RAM1-rack area.

Note that the track width d2 of the RAM track area and the ROM track area in FIG. If the distances d and d are different, a connection track whose track width gradually changes may be inserted in this connection area.

Further, the recording medium of the present invention is not limited to a disk, but can also be applied to an optical recording card type recording medium.

Furthermore, the RAM track area may be wobbled by a frequency modulated carrier signal in the circumferential direction, from which data indicating an absolute address of the disk may be read.

FIG. 4 shows an outline of an optical disk recording and reproducing apparatus having the above-mentioned recording medium. Reference numeral 1 denotes an optical disk on which the above-mentioned read-only track and recordable track are formed. The optical disc 1 is moved at a constant linear velocity (CLV) or a constant angular velocity (CAV) by a spindle motor 2.
). The laser beam from the laser light source 3 for recording and reproduction is made into a parallel light beam by a collimator lens 4, and then passed through a beam splitter 5 and an objective lens 6 of a so-called two-axis device for focusing and tracking. The optical disc l is irradiated with light. The reflected light from the optical disk 1 is separated by a beam splitter 5, and is incident on a polarizing beam splitter 8 via an optical device 7 such as a 1/2 wavelength plate, a converging lens, or a cylindrical lens. In this polarizing beam splitter 8, the P polarized light component and the S polarized light component are separated into a tracking error signal, a focus error signal, and an R polarized light component.
Fort detectors 9 and 10 for F-fold signal detection
is incident on the

Then, the outputs of the Fort detectors 8 and 10 are supplied to the differential amplifier 11, and the difference between the two outputs is taken by the differential amplifier 11, thereby extracting the recorded RF signal, and converting the extracted data signal into the differential amplifier 11. A signal is supplied to the recorded data reproducing circuit 12 and reproduced from the recordable track of the optical disk, and a signal is obtained at the terminal 13. Further, the fort detector 10 uses, for example, an element in which the light receiving section is divided into four parts, a push-pull detection circuit 14 detects a push-pull signal as a difference between the respective light receiving sections, and this push-pull signal is sent to the control data reproducing circuit 15.
The control data for the optical disc 1 is obtained at the terminal 16 by applying signal processing thereto.

Further, the push-pull signal output from the push-pull detection circuit 14 is supplied to a low-pass filter 17, servo information is extracted from the push-pull signal, and this servo signal is supplied to a servo control circuit 18. Then, this servo control circuit 18 controls the objective lens 6 based on the servo information, and performs tracking control and focus control.

By performing reproduction in this manner, the servo circuit 18 performs tracking control on both the control data recording track and the data recordable track of the optical disc l, and the reproduction-only track and the data recordable track are continuously controlled. Tracking control is performed. Moreover, there is no possibility that tracking will be lost due to pits in the width direction of the pregroove, and stable tracking control is performed during playback.

Note that the recording/reproducing device described above is related to a magneto-optical disk, but for write-once optical disks, C
A recording/reproducing device similar to that for the D disk can be used, and the device can be further simplified.

[Effects of the Invention] As explained above, in the data recording track of the present invention, widthwise pits having a relatively large widthwise displacement are formed in advance as predetermined data in the ROM track area which is a read-only track. R becomes a recordable track
In the AM track area, a widthwise pit having a smaller displacement than the widthwise pit formed in the ROM track area is formed, and clock information or timing information is added to this widthwise pit. Track control data and the like can be obtained continuously by the same signal processing, and control signals for recording data can be obtained during recording based on this information.

Further, since the width direction pits formed in this RAM track area are made to have a small displacement, there is an effect that the reproducing/recording characteristics of the written data can be prevented from being adversely affected.

[Brief explanation of drawings]

FIG. 1 is an enlarged view of the RAM1-rack area and ROM)-rack area showing one embodiment of the present invention, and FIGS. 2 and 3 are RAM)-enlarged view of the rack area showing another embodiment of the present invention. Figure 4 is a block diagram showing an overview of a disc recording/reproducing device that can read or write signals from a recording medium according to the present invention, and Figure 5 shows an example of an optical disc provided with a recordable track and a playback-only track. FIG. In the figure, IA indicates a data recordable track, IB indicates a read-only track, 1a indicates a RAM track area, and 1b indicates a ROM track area. Procedural amendment 1 sentence supervision (voluntary)

Claims (3)

[Claims] (1) A pregroove is formed in a recording medium on which data can be recorded and reproduced by optical means, and the pregroove is formed in a first track area that is a read-only track and in the first track area. The track area is continuously divided into a second track area that is a recordable track, pre-grooves of the first track area are pre-formed with predetermined data by width direction pits displaced in the track width direction, and A data recording track characterized in that clock information is previously formed in the pregroove of the track area by widthwise pits having a smaller displacement than the widthwise pits formed in the first track area. (2) A pregroove is formed on a recording medium on which data can be recorded and reproduced by optical means, and the pregroove is formed in a first track area that is a read-only track and in the first track area. The track area is continuously divided into a second track area that is a recordable track, pre-grooves of the first track area are pre-formed with predetermined data by width direction pits displaced in the track width direction, and The pre-groove serving as the track area is characterized in that a frame synchronization signal is formed in advance on a frame-by-frame basis by width direction pits whose displacement is smaller than the width direction pits formed in the first track area. data recording track. (3) The frame synchronization signal added on a frame-by-frame basis is formed by widthwise pits whose displacements in the track width direction are opposite between even and odd frames. 2) Data recording track described in section 2).