JPH09231575A - Optical disk and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk and an optical disk device of high reliability capable performing high density recording with a narrow track pitch in the optical disk and the optical disk device forming address information by a rugged bit. SOLUTION: The duty ratio (a ratio of bit length L3 to a bit interval L4) of the presence/absence of rugged bit representing the address information of an address information part 3 in an outer peripheral track 2 is made smaller than the duty ratio (a ratio of bit length L1 to a bit interval L2) of the presence/ absence of rugged bit representing the address information of an address information part in an inner peripheral track 1. Consequently, resin molding at the time of preparing the disk is surely performed and high reliability capable of surely reading out the address information is ensured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk and an optical disk apparatus for recording or reproducing a signal by irradiating light from a semiconductor laser.

[0002]

2. Description of the Related Art In recent years, optical disks and optical disk devices have been recording and reproducing computer data, audio, video, and the like, and are capable of recording and reproducing at a higher density so that a larger amount of data can be recorded and reproduced. Is required. In addition, since optical discs handling video and audio are searched for new scenes one after another, reproduced and output for use, those having a short search time are required. Since the disk has a large amount of video and audio data, a large disk having a diameter of 30 cm is used. If the control method of the disk is such that the linear velocity of the head is constant (CLV method) regardless of the position of the head from the inner circumference to the outer circumference on the disk, moving the head from the inner circumference to the outer circumference It takes time to move the head and change the rotation speed of the disk.
If the disk is large, it takes a long time to change the rotation speed, and the search time cannot be shortened. Therefore, when such a large optical disk is used, the search can be performed only by the moving time of the head, the search time is short, and the rotation of the disk can be performed regardless of the position of the head from the inner circumference to the outer circumference on the disk. A method in which the number is constant (CAV method) is adopted.

By the way, an optical disc has a guide groove for guiding a laser beam, and data is recorded in the guide groove portion or a track between the guide grooves and the data is reproduced from there. When data is recorded / reproduced on a track between the guide grooves, an address recording part is provided in a part of the track, and the address information is formed by uneven bits. Here, in order to increase the recording density, the recording track width is reduced,
You need to increase the number of tracks on the disc.

Structurally, the disc has a resin layer formed on the recording film. When this resin is molded on the recording film, it is necessary to fill the inside of the guide groove with the resin reliably. Since the address information of the address recording section is formed by uneven bits inside the track between the guide grooves, the resin is most difficult to fill between the uneven bits of the smallest address information and the guide grooves. .

FIG. 3 shows a track of a conventional optical disk. FIG. 4 is a block diagram showing a conventional optical disc device. In FIG. 3, 14 is the inner track, 15 is the outer track, 3 is the address information section, 4 is the data recording / reproducing section, L1 is the length of the address information bit of the inner track 14,
L2 is an interval of address information bits of the inner track 14, L9
Is the length of the address information bits of the outer track 15, L4 is the interval of the address information bits of the outer track 15, and L7 and L8 are the width dimensions of the address information bits of the outer track 14 and the guide groove.

In FIG. 4, 12 is an optical disk which is a recording medium, 5 is a disk motor for rotating the optical disk 12, 6 is an optical head for outputting a laser beam to record / reproduce a signal on the optical disk 12, and 70 is an optical head 6. A reproduction amplifier for amplifying the detected reproduction signal, 8 is a binarization circuit for binarizing the reproduction signal amplified by the reproduction amplifier 70, and 9 is a binarization circuit 8 for calculating the binarized reproduction signal to obtain data. A signal processing circuit that generates a recording signal from the output and input data, 10 is a recording circuit that records the recording signal generated by the signal processing circuit 9, and 11 is a track control circuit.

When the optical disk 12 rotates, the optical head 6 advances in the track counterclockwise, and the address information section 3,
The data recording / reproducing section 4 is alternately passed. At the time of recording, the address information of the address information section 3 on the track of the optical disk 12 is reproduced by the optical head 6 and the reproduction amplifier 70, and the binarization circuit 8 detects the reproduction amplifier output signal at the detection threshold level to obtain a digital signal. Is converted into a signal, which is detected by the signal processing circuit 9 and output to the track control circuit 11. The track control circuit 11 searches for the track of the target address to be recorded while detecting the address information from the signal processing circuit 9. After the search, the signal processing circuit 9 calculates the input data and outputs it to the recording circuit 10 as a recording signal. The recording circuit 10 records the recording signal from the signal processing circuit 9 in the data recording / reproducing unit 4 on the track.

At the time of reproduction, the address information of the address information section 3 on the track of the optical disk 12 is reproduced by the optical head 6 and the reproduction amplifier 70, and the reproduction amplifier output signal is detected by the binarization circuit 8 at the detection threshold level. By doing so, it is converted into a digital signal, detected by the signal processing circuit 9 and output to the track control circuit 11. The track control circuit 11
The track of the target address to be reproduced is searched while detecting the address information from the signal processing circuit 9. When the search is completed, the optical head 6 and the reproducing amplifier 70 reproduce the signal written in the data recording / reproducing unit 4 on the track, and the binarization circuit 8 detects the output signal from the reproducing amplifier 70 at the detection threshold level. Then, the signal processing circuit 9 binarizes the digital signal, and the signal processing circuit 9 calculates the digital signal from the binarizing circuit 8 and outputs the data.

In the CAV method, in order to make the frequency characteristics of the reproduced signal of the address information the same from the inner circumference to the outer circumference, the duty ratio of the presence or absence of the signal of the address information is the same from the inner circumference to the outer circumference. In FIG. 3, the duty ratio of the presence or absence of the address information signal of the inner track 14 (the ratio of the bit length L1 to the bit interval L2) and the duty ratio of the presence or absence of the address information signal of the outer track 15 (the bit to the bit interval L4) The ratio of the length L9) is the same. In this case, the uneven bit length of the address information on the outer circumference is longer than that on the inner circumference.

In order to perform higher density recording, it is necessary to narrow the track width and increase the number of tracks per disk. FIG. 5 shows a track having a narrow track width in the conventional optical disc. In FIG.
1 is an inner track with a narrow track width, 2 is an outer track with a narrow track width, 3 is an address information section, 4 is a data recording / reproducing section, L1 is the length of the address information bit of the inner track 1, L2 is the interval of the address information bits of the inner track 1, L9 is the length of the address information bits of the outer track 2,
L4 is the address information bit interval of the outer track 2, L5,
L6 is the width dimension of the address information bit of the outer peripheral track 2 and the guide groove.

[0011]

When the track width is narrowed, the dimensions L5 and L between the uneven bit of the address information and the guide groove are reduced.
6 becomes smaller and narrower, and especially at the outer circumference where the concavo-convex bit length L9 is long, a portion 13 where the resin molding of the address information portion 3 is uncertain is formed at the time of disc production. here,
If the resin is not reliably filled and air or the like remains inside the guide groove, the laser light is diffused by this and an error occurs in reproducing the address information. Therefore, at the time of reproduction, a track different from the track originally desired to be reproduced may be reproduced, or at the time of recording, it may be recorded on another track instead of the track to be recorded. In particular, at the time of recording, there arises a problem of destroying an important track that should not be erased.

Further, the yield at the time of making a disk is increased, the manufacturing cost of the disk is increased, and the disk cannot be provided at a low cost. If the concavo-convex bit length is long, it is necessary to widen the width of the bit and the guide groove in order to reliably fill the resin. The inability to narrow the track width causes a problem that high-density recording / reproduction cannot be performed and the amount of video and audio data that can be recorded / reproduced on the disk cannot be increased.

It is an object of the present invention to provide an inexpensive and highly reliable optical disk and optical disk device capable of reproducing address information without any erroneous detection, having a narrow track width and capable of high density recording.

[0014]

The optical disk of the present invention comprises:
An information track having a guide groove has an address information section in which address information is formed by uneven bits, and the duty ratio of the presence or absence of an uneven bit representing the address information of the address information section of the outer track (bit length L3 to bit interval L4 The ratio) is smaller than the duty ratio (ratio of bit length L1 to bit interval L2) of the presence / absence of a concavo-convex bit representing the address information of the address information section of the inner track, and the optical disk device is the optical disk device of the present invention. , Constant disk rotation speed (C
And a disk rotating means for rotating in the AV system, and a frequency characteristic extending to a high frequency range capable of sufficiently passing the reproduction signal of the address information at the outer circumference including a frequency component higher than the reproduction signal of the address information at the inner circumference. It is composed of a reproduction means.

As a result, it is possible to obtain an inexpensive and highly reliable optical disk and optical disk device which can reproduce the address information without erroneously detecting the address information and enable high density recording.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention has an address information section in which address information is formed by concave and convex bits in an information track having a guide groove, The duty ratio of the presence / absence of the concavo-convex bit representing the address information (the ratio of the bit length L3 to the bit interval L4) is the duty ratio of the presence / absence of the concavo-convex bit representing the address information in the address information part of the inner track (the bit length L relative to the bit interval L2.
1)), the resin molding of the address information section does not become uncertain when the disc is made, even if the track width is narrowed to achieve high-density recording. The yield is reduced, the disk manufacturing cost is reduced, and an inexpensive disk can be provided.

According to the second aspect of the present invention, the information track having the guide groove has an address information section in which the address information is formed by uneven bits, and represents the address information of the address information section of the outer peripheral track. The duty ratio of the presence / absence of the uneven bit (the ratio of the bit length L3 to the bit interval L4) represents the address information of the address information part of the inner circumferential track. The duty ratio of the presence / absence of the uneven bit (the ratio of the bit length L1 to the bit interval L2).
For smaller optical disks, keep the disk rotation speed constant (CA
(V method) and a disc rotating means for rotating the disc, and a frequency characteristic extending to a high range capable of sufficiently passing the reproduction signal of the address information at the outer circumference including a frequency component higher than the reproduction signal of the address information at the inner circumference. It is an optical disk device characterized by having a reproducing means, and even if the track width is narrowed for high density recording, at the time of creating the disk,
The resin molding of the address information section does not become uncertain, and the address information can be reproduced without any erroneous detection.

Hereinafter, embodiments of the present invention will be described. (Embodiment 1) FIG. 1 shows tracks of an optical disk according to an embodiment of the present invention. FIG. 2 is a block diagram showing an optical disk device according to one embodiment of the present invention. FIG.
, 1 is the inner track, 2 is the outer track,
3 is an address information section, 4 is a data recording / reproducing section, L1 is the length of the address information bits of the inner track 1, L2 is the interval of the address information bits of the inner track 1, and L3 is the address information bits of the outer track 2. The length, L4 is the space between the address information bits of the outer track 2, and L5 and L6 are the width dimensions of the address information bits of the outer track 2 and the guide groove. Duty ratio of the presence / absence of a concavo-convex bit representing the address information of the address information section 3 of the outer track 2 (the ratio of the bit length L3 to the bit interval L4)
Is smaller than the duty ratio (ratio of the bit length L1 to the bit interval L2) of the presence / absence bit indicating the address information of the address information section 3 of the inner track 1, and the uneven bit length L3 of the outer address information is Inner circumference uneven bit length L1
It is set to the same length as.

If the track width is narrowed in order to increase the recording density, the widths L5 and L6 of the address information bit and the guide groove of the outer track 2 are narrowed, but the length of the uneven bit (L1 at the inner circumference, Since L3) is sufficiently short at the outer circumference, resin molding can be reliably performed when the disc is made, and air etc. remains inside the guide groove, which causes the laser light to diffuse and errors in reproducing the address information. There is no problem such as causing In addition, the yield at the time of disc production does not deteriorate.

In FIG. 2, 12 is an optical disk as a recording medium, 5 is a disk motor for rotating the optical disk 12, 6 is an optical head for outputting a laser beam to record / reproduce a signal on the optical disk 12, and 7 is an optical head 6. A reproduction amplifier for amplifying the detected reproduction signal, 8 is a binarization circuit for binarizing the reproduction signal amplified by the reproduction amplifier 7, and 9 is a binarization circuit 8 for calculating the binarized reproduction signal to obtain data. A signal processing circuit that outputs and generates a recording signal from input data, 1
Reference numeral 0 is a recording circuit for recording the recording signal generated by the signal processing circuit 9, and 11 is a track control circuit.

When the optical disk 12 rotates, the optical head 6 advances the track counterclockwise, and the address information section 3,
The data recording / reproducing section 4 is alternately passed. At the time of recording, the address information of the address information section 3 on the track of the optical disk 12 is reproduced by the optical head 6 and the reproduction amplifier 7. In the case of the disk rotation speed constant method (CAV method), the outer track 2
The duty ratio of the presence / absence bit indicating the address information of the address information section 3 (the ratio of the bit length L3 to the bit interval L4) is the duty ratio of the presence / absence bit indicating the address information of the address information section 3 of the inner track 1 ( Since it is configured to be smaller than the ratio of the bit length L1 to the bit interval L2), the reproduced signal of the address information in the outer circumference contains a frequency component higher than that in the inner circumference. Therefore, the reproduction amplifier 7
Has a wide frequency characteristic up to a high range so that a reproduction signal of address information at the outer periphery can be sufficiently passed.
The address information reproduced by the reproduction amplifier 7 is converted into a digital signal by being detected by the binarization circuit 8 at the detection threshold level, detected by the signal processing circuit 9, and output to the track control circuit 11. The track control circuit 11 searches for the track of the target address to be recorded while detecting the address information from the signal processing circuit 9. After the search, the signal processing circuit 9 calculates the input data and outputs it to the recording circuit 10 as a recording signal. The recording circuit 10 records the recording signal from the signal processing circuit 9 in the data recording / reproducing unit 4 on the track.

During reproduction, the address information of the address information section 3 on the track of the optical disk 12 is reproduced by the optical head 6 and the reproduction amplifier 7, and the reproduction amplifier output signal is detected by the binarization circuit 8 at the detection threshold level. By doing so, it is converted into a digital signal, detected by the signal processing circuit 9 and output to the track control circuit 11. The track control circuit 11 searches for the track of the target address to be reproduced while detecting the address information from the signal processing circuit 9. After the search, the optical head 6 and the reproduction amplifier 7 are connected to the data recording / reproducing section 4 on the track.
, The binarization circuit 8 binarizes the output signal from the replay amplifier 7 at the detection threshold level to binarize it into a digital signal, and the signal processing circuit 9 outputs the binarization circuit 8 from the binarization circuit 8. The digital signal of is calculated and the data is output.

When the track width is narrowed to increase the recording density, the width dimension L between the address information uneven bit and the guide groove is reduced.
When 5 and L6 are narrow, resin molding at the time of making a disk becomes the most difficult. However, since the length of the address information concavo-convex bit is configured to be as short as the inner circumference on the outer circumference, the resin molding is reliably performed, and the address information is accurately detected by reproducing the resin molding.

[0024]

As described above, according to the present invention, even if the track width is narrowed, the resin molding in the address information portion is surely performed at the time of making a disc, the yield at the time of making a disc is reduced, and the disc is manufactured. The cost can be reduced, an inexpensive optical disk can be obtained, and the practical effect is great. According to the present invention, even if the track width is narrowed, resin molding is reliably performed in the address information portion at the time of making a disc, and the address information can be reproduced at the time of recording or reproduction without erroneous detection. You can
It is possible to obtain an optical disc and an optical disc device that ensure high reliability for high-density recording, and the practical effect thereof is great.

According to the present invention, in an optical disk and an optical disk device used as a CAV method with a constant number of revolutions, address information can be reproduced from the inner circumference to the outer circumference without any false detection, and high reliability is obtained. , Its practical effect is great.

[Brief description of drawings]

FIG. 1 is a diagram showing tracks of an optical disc according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an optical disc device according to an embodiment of the present invention.

FIG. 3 is a diagram showing tracks of a conventional optical disc.

FIG. 4 is a block diagram showing a conventional optical disc device.

FIG. 5 is a diagram showing a track having a narrow track width in a conventional optical disc.

[Explanation of symbols]

1 inner track 2 outer track 3 address information section 4 data recording / reproducing section L1 inner track 1 address information bit length L2 inner track 1 address information bit interval L3 outer track 2 address information bit length L4 Interval between address information bits of outer track 2 L5, L6 Width of address information bit of outer track and guide groove

Claims (2)

[Claims] 1. A duty ratio of presence / absence of a concavo-convex bit (bit interval L4), which has an address information section in which address information is formed by concavo-convex bits, in an information track having a guide groove, and represents the address information of the address information section of an outer peripheral track. Is smaller than the duty ratio (ratio of the bit length L1 to the bit interval L2) of the presence / absence bit representing the address information of the address information section of the inner track. 2. A duty ratio of presence / absence of a concavo-convex bit (bit interval L4), which has an address information section in which address information is formed of concavo-convex bits, in an information track having a guide groove, and which represents the address information of the address information section of the outer peripheral track. , The bit length L3 is smaller than the duty ratio (ratio of the bit length L1 to the bit interval L2) of the presence / absence bit indicating the address information of the address information section of the inner track, and the constant rotation speed of the disc ( (CAV system) has a disk rotating means for rotating and a frequency characteristic extending up to a high frequency range capable of sufficiently passing the reproduction signal of the address information at the outer circumference including a frequency component higher than the reproduction signal of the address information at the inner circumference. An optical disk device having a reproducing means.