JPS63263667A - Optical information recording disk - Google Patents

Abstract

PURPOSE:To obtain the data transfer speed and high density record equal to CAV and CLV by subjecting a data clock signal to preformat so that the frequency may become larger in proportion to a track radius at the time when a disk is rotated at fixed angle. CONSTITUTION:The guide track 2 of an optical information recording disk 1 is divided into plural sectors 6a, 6b... in the radial direction to form a clock pit line 3 by following the sector mark 7 of each sector 6a, 6b.... An address pit is subjected to a preformat so as to discriminate it on each guide track in succession to the pit line 3. The pit line 3 is made by the pit 3a in fixed length and a land part 3b irrespective of the radii R1, R2... from the rotary center P of the disk 1. Since the pit line 3 having fixed length and arrangement irrespective of the radii R1, R2... from the center P of the disk 1 is formed over the whole periphery of a recording zone, the frequency of the data clock to be read becomes higher in proportion to the radii R1, R2... in the case of rotating the disk 1 with CAV.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical information recording disk, and more particularly, to preformatting of address signals and data clock signals recorded at regular intervals along a guide track. .

[Prior Art] - In order to record information on an optical information recording disk and to reproduce information recorded on the optical information recording disk, it is necessary to provide a data clock signal that serves as a time base for data pulses.

In this case, there is a modulation method that superimposes a data clock signal on the data itself, but since this has the problem of lower recording density, it is generally used at the beginning of each sector divided into fixed intervals along the guide track. A method is adopted in which a data clock signal is recorded together with an address signal in the data field, and data is recorded separately in a data field following the data clock signal recording portion.

By the way, the conventional rotational drive methods for optical information recording devices include the constant angular velocity (CAV) method and the constant linear velocity (CLV) method. , ' A method (Modified CL V , M CLv) in which CAV is taken within each block has been proposed. In the C'AV and CLV type optical information recording disks, the data clock signal is preformatted so that a constant data clock frequency can be detected from all sectors, and in the MCLV type optical information recording disk, The data clock signal is preformatted so that a different data clock frequency can be detected for each block.

[Problem that the invention seeks to solve]

CAV has the feature that sector positions can be specified radially around the rotation center of the optical information recording disk, so it has excellent random access and can perform data transfer at high speed. However, on the other hand, the data clock frequency Since is fixed, there is a problem in that as the radius of the selected sector increases, the linear velocity increases in proportion to and the recording density decreases.

On the other hand, CLV controls the rotation speed of the optical information recording disk so that the linear velocity remains constant regardless of the radial position of the sector, so by fixing the data clock frequency, the recording density is made uniform over the entire surface. However, on the other hand, the seek speed is slow because the rotation speed of the disk drive motor must be controlled depending on the radial position of the sector, and it is difficult to control the sector position. Since it is not possible to specify an intermittent pattern, there are problems in that random access is poor and data transfer speed is slow.

Furthermore, MCLV can have features intermediate between the aforementioned CAV and CLV by setting the data clock frequency for each block divided in the radial direction, but the data clock frequency is set for each block. Therefore, there are multiple VFOs for playback that are subdivided by that number.
This requires a circuit, and the configuration and control are limited to IMm.

The purpose of the present invention is to solve the problems of the prior art described above,
Achieves data transfer speeds equivalent to CAV.

And is it as high as CLV? ! It is possible to record the degree, and it is also CA
A simple VFO for playback similar to that used for V and CL V
The purpose of the present invention is to provide an optical information recording disk that allows data to be streamed through a circuit.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides an optical information recording disk in which address signals and data clock signals are recorded at regular intervals along guide tracks, so that the address signals can be distinguished for each guide track. Along with preformatting.

The present invention is characterized in that the data clock signal is preformatted so that when the optical information recording disk is driven to rotate at a constant angular velocity, the frequency of the data clock signal increases in proportion to the track radius.

[Effect]

If the address signal is differentiated for each guide track, the address signal and data clock signal can be searched for each track in the same way as with conventional CAV optical information recording discs, so the seek speed can be lowered than before. It can be made similar to the CAV type optical information recording disk.

Further, if the optical information recording disk is preformatted so that when it is rotated at a constant angular velocity, the frequency of the data clock signal increases in proportion to the track radius,
Since the frequency of the data clock signal increases toward the outer circumference, the recording density is constant regardless of the inner circumference and outer circumference of the disk, and it is possible to obtain a recording density equivalent to that of CLV.

It also changes the frequency of the data clock signal in proportion to the radial position of the track (sector).

Data can be read with one VFO circuit.

〔Example〕

FIG. 1 is a plan view of an optical information recording disk showing an embodiment in which the number of sectors per track is fixed;
The figure is a plan view of a main part of an optical information recording disk showing an embodiment in which the storage capacity per l sector is constant, where l is the optical information recording disk.

2 is a guide track, and 3 is a clock bit string corresponding to a data clock signal.

As the optical information recording disk 1, any known optical information recording disk can be used, such as a read-only optical information recording disk, a write-once type optical information recording disk, and an erasable type optical information recording disk. Regarding the disk structure, for example, air sandwich #I structure,
Any structure can be used, such as a bonded structure 9 a double-sided recording structure 1 a single-sided recording structure.

The optical information recording disk 1 is mainly formed from a substrate 4 and a recording film or a reflective film (not shown).
The guide track 2 and the clock bit string 3 are recorded in a concave and convex manner on one side of the disk.

As means for forming the guide track 2 and the clock pit row 3 on one side of the substrate 4, an appropriate means can be used depending on the substrate material.For example, thermoplastics such as polycarbonate and polymethyl methacrylate may be used. Injection molding is suitable when the substrate 4 is formed.

When the substrate 4 is formed of ceramics such as glass, metals, and thermosetting plastics such as epoxy, the 2P method (photocurable resin method) is suitable.

The guide track 2 is formed in a spiral shape or a concentric circle shape in an area other than the innermost and outermost peripheries of the substrate 4. The interval (track pitch) between adjacent guide tracks 2.2 is adjusted to be constant, and the cross-sectional shape is formed in the shape of a groove with a constant depth. This guide track 2 is divided into a plurality of sectors 6a, eb, (3 cmφ) in the radial direction,
A clock bit string 3 is formed following a sector mark 7 indicating the start position of each sector 5a, 6b, 6e, . . . . Therefore, when this optical information recording disk l is viewed from the plane side, the sector marks 7 are radially IItrA as shown in FIG.

Note that detailed illustration of the address bits that indicate the address signal of each sector will be omitted.

Following the clock bit string 3, each guide track is preformatted to be distinguishable.

As shown in FIG. 2, the clock pit row 3 has radii Rx and R8 from the rotation center P of the optical information recording disk 1.
, Rs..., it is composed of a bit 3a of a constant length and a land portion 3b of a constant length. The bit 3a is formed in the shape of a groove with a constant depth and a different cross-sectional shape from the guide track 2. In addition, the 21st! I
Although the case where the clock bit string 3 is formed on the guide track 2 is illustrated in 9, the gist of the present invention is not limited to this. It is also possible to form

The optical information recording disk 1 of the embodiment has a certain degree of stability and arrangement throughout the entire circumference of the recording area, regardless of the radius Rx - R2, R3, Φ, from the rotation center P of the optical information recording disk 1. Since a clock pit row 3 is formed, when this is rotationally driven by a CAV, the guide track 3 becomes larger as the radius from the rotation center P of the optical information recording disk 1 becomes larger.
As the linear velocity of the data clock increases, the frequency of the data clock read from the clock pit row 3 increases. Therefore,
Information is recorded based on a data clock frequency that is higher toward the outer circumference, and the recording density becomes uniform over the entire circumference of the recording area. As a result, the recording density per optical information recording disk becomes equivalent to that of the conventional CLV.

FIG. 3 is a graph comparing the recording density of the optical information recording disk 1 of the above embodiment with conventional CAV, CLV, and MCLV, in which the horizontal axis is the disk radius and the vertical axis is the recording capacity per track. ing.

As is clear from this graph, in conventional CAV, the recording capacity per track is constant regardless of the track position, so the recording density is the lowest, whereas in CLV, the recording capacity per track increases towards the outer periphery. So note #
In MCLV, which has the highest I density, the recording capacity per track is constant for each block, and as the number of blocks increases, the recording density can approximate CLV.6 The optical information recording disk of the present invention has the following features: The recording density can be made equal to that of the conventional CLV as shown in FIG.

Further, the optical information recording disk of the present invention has the first [! l
As shown in ', sectors can be specified radially in the same way as with conventional CAV optical information recording disks, so data access time can be made the same as with conventional CAV optical information recording disks. .

Hereinafter, an example of a reproducing apparatus for reading information from the optical information recording disk 1 of the embodiment described above will be explained based on FIG. 4.

In FIG. 4, 1 is an optical information recording disk preformatted as described above, 11 is an optical head that is tracked along the guide track 2 and reads information from the optical information recording disk 1, and 12 is an optical head for reading information from the optical information recording disk 1. A scale for measuring the distance from the center of rotation of the information recording disk 1 to the optical head 11, 13 a clock separation circuit for separating a burst clock signal from data read by the optical head 11, and 14 a clock separation circuit for separating a burst clock signal from the data read by the optical head 11; Position information of the optical rad 11 and the clock separation circuit 13
A VFO circuit 15 generates a data reproduction clock by synchronizing the burst clock signal from the VFO circuit 14. Reference numeral 15 indicates a data reproduction device that reproduces data based on the data reproduction clock from the VFO circuit 14. In this figure, the drive mechanism of the optical information recording disk 1 and its control circuit are shown.

Portions that are not directly related to the gist of the present invention, such as a track servo circuit and a focus servo circuit of the optical head 11, are omitted from illustration.

When the optical information recording disk 1 is attached to the playback device configured as described above and rotated by the CAV, and a desired sector is selected by operating a control device (not shown), the optical head 11 accesses the sector. do. Optical head 1 at this time
The distance from the center of rotation of one optical information recording disk 1 is detected by a scale 12, and position information 16 proportional to the size is output.

Next, by emitting a laser beam 17 from the optical head 11 and detecting the reflected light from the optical information recording disk 1, the data clock signal and information signal recorded on the optical information recording disk 1 can be read out.

Read signal 1 read from optical information recording disk 1
8 is a clock pulse 1 by the clock separation circuit 13.
9 and data pulse 20.

The clock pulse 19 is also applied to the VFO circuit 14.

Data pulse 20 is input to data regeneration circuit 15 .

The VFO circuit 14 receives position information 1 from the scale 12.
6, the clock separation circuit 1
Regenerated clock 2 synchronized with clock pulse 19 from 3
Outputs 1. Note that the VFO circuit 14 can be tuned by controlling it with a variable capacitance diode or a diode that switches a time constant circuit.

In the data reproducing device ff15, the data pulse 20 from the clock separation circuit 13 is read out using the reproduced clock 21 outputted from the VFO circuit 14 as a reference.

In this way, since the playback device shown in FIG. 4 tunes the VFO circuit 14 using the position information 16 from the scale 12, it is sufficient to have only one VFO circuit.
Like the playback device applied to conventional MCLV, VFO
The circuit configuration and control do not become complicated.

In the above embodiment, the case where the clock pit is formed in the shape of a groove with a constant depth has been described, but the clock pit can be read out as a difference in some physical quantity between the part where the clock pit is present and the part where it is not. However, the present invention is not limited to the shape and forming means as in the above embodiments.

In a magneto-optical disk, the clock pits can be recorded in the form of magnetic domains on a magneto-optical recording film.

(Effect of the invention) As explained above, the optical information recording disk of the present invention has the following features:
Since it is basically a CAV system, it has excellent random access properties and can perform data transfer at high speed. In addition, since the optical information recording disk is preformatted so that the read data clock frequency increases in proportion to the radius from the rotation center, the recording density becomes uniform over the entire circumference of the recording area, making it similar to CLV. High-density recording can be achieved. Furthermore, since it is only necessary to add a scale for detecting positional information of the optical head from the center of rotation of the optical information recording disk, there is no need to use a plurality of subdivided VFO circuits.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a plan view showing the overall structure of the optical information recording disk according to the present invention, FIG. 2 is an enlarged plan view of the main parts of the optical information recording disk shown in FIG. 1, and FIG. 4 is a graph comparing the recording density of the optical information recording disk according to the present invention with that of a conventional optical information recording disk, and FIG. 4 is a circuit diagram of a reproducing device that reads information from the optical information recording disk of the present invention. 1: Optical information recording disk, 2: Guide track. 3: Data clock pit row, 3-a: Bit, 3b:
Land portion, 4: Board, 5a, 6b, 6e...: Sector,
11: Optical head, 12 scale. 13: RI0'/RI separation circuit, 14: VFOI circuit,
15: data reproducing device, 16: position information, 17: laser beam, 18: readout signal, 19: clock pulse,
20: Data pulse Fig. 1 1 2 Light fk'fLR%y-<xy 2: Home ＾ Doshi 7 f5a 6b 6c: c77 7: Begging mark Fig. 2 Fig. 3 Usage period Fig. 4

Claims (1)

[Claims] In an optical information recording disk in which an address signal and a data clock signal are recorded at regular intervals along a guide track, the address signal is preformatted so as to be distinguishable for each guide track, and the optical information recording disk is controlled at an angular velocity. 1. An optical information recording disk characterized in that the data clock signal is preformatted so that the frequency of the data clock signal increases in proportion to the track radius when the disk is rotated at a constant speed.