JPH03237631A - Recording medium - Google Patents

Abstract

PURPOSE:To obtain the control signal of recording data in accordance with clock information and timing information at the time recording by adding above- mentioned information by the information on the displacement in a transverse direction smaller in the displacement than the information on the displacement in the transverse direction. CONSTITUTION:Pregrooves (ROM tracks) 1b are formed in a reproduction only region 1B and pregrooves (ROM tracks) 1a are formed in a recordable region 1A. The displacement DELTAd1 in the transverse direction is applied to the ROM tracks 1b at the time of mastering of an optical disk and the ruggedness (the information on the displacement in the transverse direction) of the displacement DELTAd1 in this transverse direction is formed. The similar displacement DELTAd2 in the transverse direction is formed in the RAM tracks 1a as well. The displacement DELTAd2 in the transverse direction formed in the RAM tracks 1a can apply mainly the clock information and is preferably formed as the information on the displacement in the transverse direction to form ruggedness in 17 bit unit so as to allow the easy extraction of the clock frequency (4.3218 MHz) adopted in, for example, a CD format. The good tracking control is executed in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a recording medium applied to, for example, a write-once or rewritable optical disc.

[Summary of the Invention] The present invention provides a write-once optical disc, a rewritable optical disc, etc., in which a recording medium is divided into a first area that is used only for reproduction and a second area that is capable of recording data, and a second area that is used only for reproduction. 1 area and a pre-groove formed in a second area which is a recordable area, wherein the first area is a recordable area.
Predetermined data formed by widthwise pits displaced in the widthwise direction of the pregroove is added to the area in advance, and predetermined data is added to the second area from the widthwise pits formed in the first area. Clock information and/or timing information is formed by width direction pits with a small displacement width, so that other information can be written on one optical disc later based on the information recorded on the disc. This is what I did.

[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.
indicates an optical disk whose recording medium is an organic dye, or whose recording surface is an interface that changes due to the magneto-optical effect;
A is a signal recordable area, and IB is a reproduction-only area in which data has already been recorded.

In this case, for example, as described in Japanese Patent Application No. 1-247833, control data such as synchronization signals and address information and various data are recorded on the recording track, and data management etc. are performed based on this control data. Some systems have been proposed in which data is recorded and reproduced in blocks or sectors based on this control data.

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, a wobbling track is formed by FM modulating a sine wave carrier signal of, for example, 22.05 KH based on a time code signal with a sufficiently lower frequency compared to this carrier wave, and a tracking error signal is generated during playback. At the same time, this time code is demodulated to obtain a time code as position information.

[Problems to be Solved by the Invention] By the way, if control data is recorded by forming sample bits, it is necessary to apply a track servo to the place where such pits are formed, which is different from the data recording area of the disk. Continuous tracking servo cannot be applied using one tracking method, and the structure of the recording/reproducing apparatus for tracking becomes complicated. Furthermore, if a bit formation location is provided on the disk, crosstalk to adjacent tracks may occur, which may have an adverse effect on signal reproduction in the data recordable area of the adjacent track.

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 1 The present invention has been made in view of the above problems,
A first area serving as a read-only area and a second area serving as a recordable area are formed by a pregroove having approximately the same track pitch, and the first area has unevenness displacing in the width direction. (hereinafter referred to as width direction bit)
writing predetermined data, forming widthwise bits in the second region with a smaller displacement than the widthwise-displaced unevenness (widthwise bits) formed in the first region; The width direction bits provide clock information or timing information for data written in the recordable area.

[Operation] The width of the pregroove that becomes the recordable area and the pregroove that becomes the read-only area are almost the same, but data is recorded in advance in the recordable area using bits in the width direction with relatively small displacement. Therefore, it is possible to prevent the recording/reproducing characteristics of data additionally recorded or written into this pregroove from deteriorating.

In addition, in the pregroove of the playback-only area, predetermined data is recorded using bits in the width direction that have relatively large displacements, but the crosstalk that occurs during playback of this area is also small because the track width is originally small. be able to.

[Example] A recording medium that is an example of the present invention has an organic dye provided on the recording surface that is sensitive to light, and the dye and substrate are bonded 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 bits.

FIG. 1 shows an enlarged view of a pre-groove formed on such a recording medium, and shows a first area IB which is a reproduction-only area shown in FIG. 5, and a second area which is a recordable area. This is an enlarged view of a portion of the track near the IA border.

In this figure, lb and lb indicate the shape of the pregroove (hereinafter referred to as ROM track) in the above-mentioned playback-only area,
la and la are pre-grooves (hereinafter referred to as R) in the recordable area.
AM)-referred to as rack) is shown.

The pitch width of each pregroove is set to, for example, about 1.6 μm, and the track widths d, d, are both about 0.6 μm.
It is said to be 6 μm.

A widthwise displacement Δd1 is applied to the ROM track during mask ringing of the optical disk, and the shape of the unevenness (hereinafter referred to as widthwise bit) of this widthwise displacement Δd indicates recording data input to the mask ring. And this ROM
The displacement Δd1 in the width direction in the track has an amplitude of about 0.2 μm so that a sufficient detection signal can be obtained when the reflected light of the laser spot irradiated on this ROM track is detected by the push-pull method. This also reduces crosstalk from the tracks being used.

The RAM)-rack serves as a recording area in which data is additionally recorded using the above-described recording method, and a similar displacement Δd2 in the width direction is also formed in this RAM)-rack.

However, the displacement Δd2 in the width direction formed in this RAMh rack can mainly provide clock information, and for example, the clock frequency (4,3218MH) adopted in the CD format can be easily extracted. It is preferable to use bits 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 a ROM track. However, since this RAM track only needs to be able to reproduce clock information, the clock signal can be sufficiently extracted with such a small amplitude.

Furthermore, by reducing the widthwise bit amplitude (Δd2), the recording and reproducing characteristics of data written in the pregroove are prevented from deteriorating.

FIG. 2 shows another embodiment of the RAM track.

In this embodiment, the width direction bits IIT and IIT 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 bits are the same as those shown in FIG. It is formed with the same displacement in the width direction (Δd,) as in the case.

In the area where data is recorded except for the width direction bits lIT and 11T, no width direction bits exist until the leading edge of the next frame.

FIG. 3 shows yet another embodiment of the RAM track, and in this embodiment, as in the case of FIG. 2, widthwise bits consisting of IIT and 11T are formed at the leading edge of each frame as a frame synchronization signal. ing.

However, the width direction bits 11T and 11T 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 to of the synchronization signal of the odd-numbered frame and the falling point 1 of the widthwise bit forming the frame synchronization signal of the even-numbered frame.
If the direction of 1 is reversed, there is an advantage that it is possible to detect whether the next frame will be an even number or an odd number from this width direction bit.

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

In addition, the RAM shown in FIGS. 1, 2, and 3
Normally, sector marks, address data, etc. are recorded in the O frame of a track, but the width direction bits recorded in this O frame are width direction bits with a large displacement width, such as those formed in a ROM track. It is preferable.

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, it is also possible to wobble in the circumferential direction of the RAM (RAM) rack using a frequency-modulated carrier wave signal, and data indicating the absolute address of the disk may be read from this wobbling track.

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 area and recordable area are formed. This optical disk 1 is rotated by a spindle motor 2 at a constant linear velocity (CLV) or a constant angular velocity (CAV). Then, 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 is turned into a parallel light beam by a beam splitter 5.
, the so-called 2 for focusing and tracking
The light is irradiated onto the optical disc l via the objective lens 6 of the axis device. 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. The polarizing beam splitter 8 separates the light into a P-polarized component and an S-polarized component, and the light is input to Fort detectors 9 and 10 for detecting a tracking error signal, a focus error signal, and an RF signal.

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. The signal is supplied to the recorded data reproducing circuit 12 and reproduced from the recordable area 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, a push-pull detection circuit 14 detects a push-pull signal as a difference between each light receiving section, and supplies this push-pull signal to the control data reproducing circuit 15. Then, by performing signal processing, control data for the optical disk l is obtained at the terminal 16.

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 in both the control data recording area and the data recordable area of the optical disc l, and the reproduction-only area and the data recordable area are continuously controlled. Tracking control is performed. Moreover, there is no possibility that tracking will be lost due to the widthwise bits 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 recording medium of the present invention, widthwise pits having a relatively large displacement in the widthwise direction are formed in advance as predetermined data in the ROM1-rack in the read-only area, and recording A widthwise bit having a smaller displacement than the widthwise bit formed on the ROM track is formed in the RAM track in the possible area, and clock information or timing information is added to this widthwise pit. Therefore, a control signal for recording data can be obtained based on this information during recording.

Further, since the width direction pits formed in this RAM track are made to have small displacements, there is an effect that it is possible to prevent any adverse effects on the reproduction/recording characteristics of the written data.

[Brief explanation of drawings]

FIG. 1 shows a RAM l-rack and a R rack showing one embodiment of the present invention.
OM) - Enlarged view of the rack, Figures 2 and 3 are RAM) -
An enlarged view of a rack, FIG. 4 is a block diagram showing an overview of a disc recording/reproducing apparatus that can read or write signals from a recording medium of the present invention, and FIG. 5 is an optical disc having a recordable area and a read-only area. It is a figure showing an example. In the figure, IA is a data recordable area, IB is a playback-only area, 1
a indicates a RAM track, and lb indicates a ROM l-rack. Figure 15 procedural amendment (voluntary) October 26, 1990

Claims (3)

[Claims] (1) A pregroove is formed in a recording medium that can record and reproduce data by optical means, and the recording medium is divided into a first area that is a playback-only area and a second area that is a recordable area. Pre-grooves in the first area are pre-formed with predetermined data by widthwise pits displaced in the track width direction, and pre-grooves in the second area are formed in the first area. 1. A recording medium characterized in that clock information is formed in advance by widthwise pits whose displacement is smaller than that of the widthwise pits. (2) A pregroove is formed in a recording medium on which data can be recorded and reproduced by optical means, and the recording medium is divided into a first area which becomes a reproduction-only area and a second area which becomes a recordable area. The pre-groove of the first area is pre-formed with predetermined data by width-direction pits displaced in the track width direction, and the pre-groove of the second area is formed with the pre-groove of the first area. A recording medium characterized in that a frame synchronization signal is formed in advance in units of frames by width direction pits whose displacement is smaller than the width direction pits formed in the area. (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) Recording medium described in section 2).