JP3076759B2 - Optical disk and optical disk device - Google Patents

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.

[0003] In an optical disk that handles video and audio, new scenes are successively searched for, reproduced, output, and used.
Short search times are desired. Since the amount of video and audio data is large, 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.

An optical disc has a guide groove for guiding a laser beam, and data is recorded on the guide groove or a track between the guide grooves, and data is reproduced from the track. 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.

[0005] The disc is structurally formed with a resin layer 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. .

Here, when increasing the recording density of the disk by reducing the track width, the track width is narrowed in the data portion and the unevenness bit is formed in the address information portion with a wider track width, and the resin is filled. Is ensured. Thus, the guide groove widths of the address information section and the data recording / reproducing section are changed.

FIG. 5 shows a track of a conventional optical disk. FIG. 6 is a block diagram showing a conventional optical disk device.

In FIG. 5, 1 is an inner track, 2 is an outer track, 3 is an address information section, 4 is a data section, 5 is an intervening section existing between the address information section 3 and the data section 4, S Is a laser beam spot, 6 is an optical disk, L1, L2
Is the length of the track where the groove width at the inner and outer circumferences changes continuously, V1 is the linear velocity of the laser beam spot on the inner peripheral track, and V2 is the linear velocity of the laser beam spot on the outer peripheral track.

In FIG. 6, 6 is an optical disk, 8 is a disk motor for rotating the optical disk 6, 7 is an optical head that outputs a laser beam and records and reproduces a signal on the optical disk 6, and 9 is a reproduced signal detected by the optical head 7. , A reference numeral 11 denotes a binarization circuit for binarizing the reproduction signal amplified by the reproduction amplifier 9, and a reference numeral 12 calculates the reproduction signal binarized by the binarization circuit 11 and outputs data. A signal processing circuit for generating a recording signal from the generated data; 13 a recording circuit for recording the recording signal generated by the signal processing circuit 12;
Reference numeral 4 denotes a track control circuit.

[0010] As the optical disk 6 rotates, the laser beam spot S by the optical head 7 advances counterclockwise on the track and passes through the address information section 3 and the data section 4 alternately.

At the time of recording, the address information of the address information section 3 on the track of the optical disk 6 is read by the optical head 7 and the reproducing amplifier 9.
The digital signal is converted into a digital signal by detecting a reproduction amplifier output signal at a detection threshold level by a binarization circuit 11, detected by a signal processing circuit 12, and output to a track control circuit 14. The track control circuit 14 searches for a track at a target address to be recorded while detecting address information from the signal processing circuit 12. When the search is completed, the signal processing circuit 12 calculates the input data and outputs it to the recording circuit 13 as a recording signal. The recording circuit 13 records the recording signal from the signal processing circuit 12 in the data section 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 6 is reproduced by the optical head 7 and the reproduction amplifier 9, and the binarization circuit 11 detects the reproduction amplifier output signal at the detection threshold level. Then, the signal is converted into a digital signal, detected by the signal processing circuit 12 and output to the track control circuit 14. The track control circuit 14
While detecting address information from the signal processing circuit 12, a track at a target address to be reproduced is searched. Once you can search,
The optical head 7 and the reproduction amplifier 9 reproduce the signal written in the data section 4 on the track, and the binarization circuit 11 detects the output signal from the reproduction amplifier 9 at the detection threshold level to convert the digital signal into two. The signal processing circuit 12 calculates the digital signal from the binarization circuit 11 and outputs the data.

FIG. 7 shows a track shape and a reproduction signal waveform in an inner track of a conventional example. FIG. 8 shows a track shape and a reproduced signal waveform in a conventional outer track.

In FIG. 7, 1 is an inner track, 15 is a guide groove, S is a laser beam spot by an optical head,
L1 is the length of the track where the groove width on the inner circumference changes continuously, V1 is the linear velocity of the laser beam spot on the inner circumference track, and T1 is the track L1 where the groove width on the inner circumference changes continuously. It is time to play.

In FIG. 8, reference numeral 2 denotes an outer track, L1 denotes a length of a track in which a groove width on the outer circumference continuously changes,
V2 is the linear velocity of the laser beam spot on the outer track, and T3 is the time for reproducing the track L1 in which the groove width on the outer circumference changes continuously.

In the conventional optical disc, the length of the track where the groove width continuously changes at the boundary between the address information section and the data section is the same as L1 on the inner circumference and L1 on the outer circumference. The DC fluctuation frequency F1 of the reproduction signal due to the groove width change on the inner circumference is expressed by the following equation. F1 = 1 / (4 × T1) = V1 / (4 × L1) Further, the DC fluctuation frequency F3 of the reproduced signal due to the change in the groove width at the outer periphery is expressed by the following equation. F3 = 1 / (4 × T3) = V2 / (4 × L1) When the optical disk device operates in the CAV method, the rotation speed is constant, and therefore the linear velocity V2 of the laser beam spot on the outer track is linear in the inner circumference. It becomes larger than the speed V1. V2> V1 Accordingly, the DC fluctuation frequency F3 of the reproduction signal due to the groove width change at the outer periphery becomes the D value of the reproduction signal due to the groove width change at the inner periphery.
It becomes larger than the C fluctuation frequency F1. F3> F1

[0017]

As shown in FIG. 7, since the DC fluctuation frequency F1 of the reproduction signal due to the change in the groove width is smaller than the low-frequency cutoff frequency FC of the reproduction amplifier at the inner circumference, as shown in FIG. Does not exceed the detection threshold level, and the binarized output signal accurately outputs address information and data. However, as shown in FIG. 8, on the outer periphery, the DC fluctuation frequency F3 of the reproduced signal due to the groove width change is:
Since the frequency is higher than the low cutoff frequency FC of the reproduction amplifier, the reproduction amplifier output signal exceeds the detection threshold level, and the binarized output signal outputs an erroneous signal.

According to the present invention, address information and recording / reproduction data are
An object of the present invention is to provide a highly reliable optical disk and an optical disk device that can reproduce data without any erroneous detection.

[0019]

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 a data section, and the guide groove width of the address information section is different from the guide groove width of the data section. The groove width changes up to the portion, and the length of the track in the portion where the groove width changes is a length proportional to the radius of the optical disk.

From another point of view, the optical disk of the present invention is an optical disk having information tracks sandwiched by guide grooves, wherein the information tracks sandwiched by the guide grooves have a first width. An address information section in which information is formed by concave and convex bits, a data section in which data is added to a track having a second width in which the width of the information track sandwiched by the guide grooves is smaller than the first width, An intervening portion between the data portions, wherein the width of the information track changes from the first width to the second width, and the length of the intervening portion in the track direction goes toward the outer periphery in proportion to the radius of the optical disc. It is characterized in that it is made longer.

The embodiment of the optical disk of the present invention is characterized in that the track length at the portion where the groove width changes changes continuously or stepwise from the inner circumference to the outer circumference of the disk.

The optical disc device of the present invention has an address information section having address information formed by uneven bits on an information track having a guide groove, and a data section. The guide groove width of the address information section and the guide of the data section are provided. An optical disc reproducing apparatus for reproducing an optical disc in which the groove width is different, the groove width changes from the address information section to the data section, and the track length of the portion where the groove width changes is proportional to the radius of the optical disc. An optical head that irradiates light to a rotating optical disk, receives reflected light from the optical disk, and outputs an electric reproduction signal according to the received light; and a portion where the groove width changes from the reproduction signal. And filter means for removing a component having a predetermined frequency due to the above.

From another point of view, the optical disc apparatus of the present invention comprises an address information section in which address information is formed by concave and convex bits on a track having a first width of an information track sandwiched by guide grooves; A data section in which data is added to a track having a second width smaller than the first width and having an information track between the address information section and the data section; An optical disc reproducing apparatus for reproducing an optical disc having an intervening portion that changes from a first width to a second width, wherein the length of the intervening portion in the track direction becomes longer toward the outer periphery in proportion to the radius of the optical disc. An optical head that irradiates light to a rotating optical disk, receives reflected light from the optical disk, and outputs an electric reproduction signal according to the received light; Component having a predetermined frequency And it is characterized in that comprising a filter means for removing.

In the embodiment of the optical disk apparatus of the present invention, the predetermined frequency F is: F = Cω / 4, where C is (the length of the track of the interposed portion): (radius of the optical disk at the interposed portion) And ω is the angular velocity of the disk.

As a result, it is possible to obtain a high recording density and high reliability optical disk and optical disk apparatus capable of reproducing address information and data without any erroneous detection.

[0026]

Embodiments of the present invention will be described below. (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.

In FIG. 1, 1 is an inner track, 2 is an outer track, 3 is an address information section, 4 is a data section, 5 is an intervening section existing between the address information section 3 and the data section 4, S Is a laser beam spot, 6 is an optical disk, L1 is a portion where the groove width on the inner circumference changes continuously, that is, the track length of the interposed portion 5, V1 is the linear velocity of the laser beam spot on the inner circumference track, and L2 is A portion where the groove width at the outer periphery continuously changes, that is, the track length of the interposition portion 5;
V2 is the linear velocity of the laser beam spot on the outer track.

In FIG. 2, 6 is an optical disk, 8 is a disk motor for rotating the optical disk 6, 7 is an optical head for outputting a laser beam and recording and reproducing signals on the optical disk 6, and 9 is a reproduced signal detected by the optical head 7. , A high-pass filter (HPF) that cuts off unnecessary signals in the low frequency range of the reproduced signal, 11 a binarizing circuit that binarizes the reproduced signal low-frequency-corrected by the high-pass filter 10, and 12 A signal processing circuit that calculates the reproduced signal binarized by the binarization circuit 11 and outputs data, and generates a recording signal from the input data, and a recording circuit 13 that records the recording signal generated by the signal processing circuit 12 The circuit 14 is a track control circuit.

As the optical disk 6 rotates, the laser beam spot S from the optical head 7 advances counterclockwise on the track and passes through the address information section 3 and the data section 4 alternately.

At the time of recording, the address information of the address information section 3 on the track of the optical disk 6 is read by the optical head 7 and the reproducing amplifier 9.
The high-pass filter 10 cuts off unnecessary signals in the low frequency band, and the binarizing circuit 11 detects the reproduced amplifier output signal at a detection threshold level, converts the signal into a digital signal, and detects the signal by the signal processing circuit 12. Output to the track control circuit 14. The track control circuit 14 searches for a track at a target address to be recorded while detecting address information from the signal processing circuit 12. When the search is completed, the signal processing circuit 12 calculates the input data and outputs it to the recording circuit 13 as a recording signal. The recording circuit 13 records the recording signal from the signal processing circuit 12 in the data section 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 6 is reproduced by the optical head 7 and the reproduction amplifier 9, and the unnecessary signal in the low band is cut by the high-pass filter 10 to be binarized. The output signal of the reproduction amplifier is detected by the circuit 11 at the detection threshold level, converted into a digital signal, detected by the signal processing circuit 12 and output to the track control circuit 14. The track control circuit 14
While detecting address information from the signal processing circuit 12, a track at a target address to be reproduced is searched. Once you can search,
The optical head 7 and the reproducing amplifier 9 reproduce the signal written in the data section 4 on the track, the high-pass filter 10 cuts the unnecessary signal in the low band, and the binarizing circuit 11 outputs the output signal from the reproducing amplifier 9. Is binarized into a digital signal by detecting at the detection threshold level, and the signal processing circuit 12 calculates the digital signal from the binarization circuit 11 and outputs the data.

FIG. 3 shows a track shape and a reproduction signal waveform in the inner track of the present invention. FIG. 4 shows a track shape and a reproduced signal waveform in the outer track according to the present invention.

In FIG. 3, 1 is an inner track, 15 is a guide groove, S is a laser beam spot by an optical head,
L1 is the track length of the interposition portion 5 where the groove width on the inner circumference changes continuously, V1 is the linear velocity of the laser beam spot on the inner circumference track, and T1 is the interposition portion on the inner circumference where the track length is L1. 5 is the time to play. Inner track 1
If the radius of the optical disk 6 is r ₁ and the angular velocity of the optical disk 6 is ω, V ₁
= R ₁ ω holds.

In FIG. 4, reference numeral 2 denotes an outer track, L2 denotes a track length of the interposition portion 5 where the groove width at the outer circumference continuously changes, V2 denotes a linear velocity of a laser beam spot on the outer track, and T2 denotes a track length. Is the time to regenerate the intervening portion 5 on the outer circumference, which is L2. Assuming that the radius of the outer track 2 is r ₂ and the angular velocity of the optical disk 6 is ω, V ₂ = r ₂ ω
Holds.

The DC fluctuation frequency F1 of the reproduced signal due to the groove width change on the inner circumference is expressed by the following equation. F1 = 1 / (4 × T1) = V1 / (4 × L1) = r ₁ ω / (4
× L1) Further, the DC fluctuation frequency F2 of the reproduction signal due to the groove width change at the outer periphery is expressed by the following equation. F2 = 1 / (4 × T2) = V2 / (4 × L2) = r ₂ ω / (4
× L2) When the optical disk device operates in the CAV system, the linear speed V2 of the laser beam spot on the outer track is higher than the linear speed V1 on the inner track because the rotation speed is constant. V2> V1

In the optical disk of the present invention, the length of the track of the intervening part where the groove width continuously changes at the boundary between the address information part and the data part depends on the linear velocity of the optical head on the disk. It is configured to change continuously or stepwise from the inner circumference to the outer circumference, and the DC fluctuation frequency F2 of the reproduction signal due to the groove width change at the outer circumference is the DC fluctuation frequency of the reproduction signal due to the groove width change at the inner circumference. It becomes the same as the frequency F1. F1 = F2 _{i.e., L 1 / L 2 = r} 1 / r 2 is satisfied. Therefore, in the present invention, the length of the track of the interposition portion 5 where the groove width continuously changes is a length proportional to the radius. Further, in the optical disk device of the present invention, the low-pass cutoff frequency FC
Are the DC fluctuation frequencies F1 and F
It is configured to be larger than 2. FC> F1 = F2 The _{r 1 / L 1 = r 2} / L 2 = C (C is constant) is satisfied. That is, the high-pass filter 10 according to the present invention, the frequency _{F F = r 1 ω / 4L} 1 = Cω / 4 represented by the following formula, is a filter for removing from the reproduced signal.

Thus, on the inner circumference, as shown in FIG.
The DC fluctuation frequency F1 of the reproduction signal due to the groove width change in the interposition part 5 is lower than the low-pass cutoff frequency F of the high-pass filter.
Since it is smaller than C, the reproduction amplifier output signal does not exceed the detection threshold level, and the binarized output signal outputs address information and data accurately. Similarly, on the outer circumference,
As shown in FIG. 4, since the DC fluctuation frequency F2 of the reproduction signal due to the groove width change in the interposition portion 5 is also lower than the low-pass cutoff frequency FC of the high-pass filter, the reproduction amplifier output signal may not exceed the detection threshold level. Instead, the binarized output signal accurately outputs address information and data.

In the first embodiment, an example is described in which a high-pass filter having a low-frequency cutoff frequency of FC is connected after the reproduction amplifier. However, a reproduction amplifier having a low-frequency cutoff frequency of FC is used. The high-pass filter may be omitted.

[0039]

As described above, according to the present invention, even if the guide groove width changes between the address information section and the data recording / reproducing section, the track length of the interposition portion 5 where the groove width changes continuously is provided. Is a length proportional to the radius, so at the time of recording,
The address information and the data can be reproduced without any erroneous detection at the time of reproducing the address information and the data, and an optical disk and an optical disk device with high reliability can be obtained.

According to the present invention, in an optical disk and an optical disk apparatus for which high-density recording is desired, the track length of the interposition portion 5 where the groove width changes continuously is set to a length proportional to the radius. Can be reproduced without any false detection of address information or data,
High reliability is obtained and its practical effect is great.

According to the present invention, in the optical disk and the optical disk apparatus used as the CAV system with a constant rotation speed, the length of the track of the interposition portion 5 where the groove width changes continuously is made to be a length proportional to the radius. From the inner circumference to the outer circumference, address information and data can be reproduced without any erroneous detection, high reliability is obtained, and the practical effect is great.

[Brief description of the drawings]

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

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

FIG. 3 is a diagram showing a track shape and a reproduced signal waveform in an inner track according to the embodiment of the present invention.

FIG. 4 is a diagram showing a track shape and a reproduction signal waveform in an outer track according to the embodiment of the present invention.

FIG. 5 is a diagram showing tracks of an optical disc of a conventional example.

FIG. 6 is a block diagram showing a conventional optical disk device.

FIG. 7 is a diagram showing a track shape and a reproduction signal waveform in an inner track of a conventional example.

FIG. 8 is a diagram showing a track shape and a reproduction signal waveform in an outer peripheral track of a conventional example.

[Explanation of symbols]

Reference Signs List 1 inner track 2 outer track 3 address information section 4 data section 5 interposition section 6 optical disk 7 optical head 9 reproduction amplifier 10 high-pass filter 11 binarization circuit 12 signal processing circuit 13 recording circuit 14 track control circuit S laser beam spot L1 Length dimension of the track where the groove width on the inner circumference changes continuously V1 Linear velocity of the laser beam spot on the inner circumference track L2 Length dimension of the track where the groove width changes continuously on the outer circumference V2 On the outer track Linear velocity of laser beam spot

Claims (10)

(57) [Claims] An information track having a guide groove has an address information section in which address information is formed by uneven bits, and a data section. The guide groove width of the address information section is different from the guide groove width of the data section. An optical disc characterized in that the groove width changes from the address information section to the data section, and the length of the track in the portion where the groove width changes is proportional to the radius of the optical disc. 2. The optical disc according to claim 1, wherein:
An optical disc characterized in that the length of a track in a portion where the groove width changes continuously changes from the inner circumference to the outer circumference of the disc. 3. The optical disc according to claim 1, wherein
An optical disc, characterized in that the length of the track at the portion where the groove width changes changes stepwise from the inner circumference to the outer circumference of the disc. 4. An information track having a guide groove has an address information section in which address information is formed by concave and convex bits and a data section, and the guide groove width of the address information section is different from the guide groove width of the data section. An optical disc reproducing apparatus for reproducing an optical disk in which a groove width changes from an address information section to a data section and a track length of a portion where the groove width changes is proportional to a radius of the optical disk. An optical head for irradiating the optical disk with light, receiving reflected light from the optical disk, and outputting an electric reproduction signal according to the received light; and a predetermined signal caused by a portion where the groove width changes from the reproduction signal. An optical disc reproducing apparatus comprising: a filter for removing a component having a frequency. 5. The optical disk device according to claim 4, wherein the predetermined frequency F is: F = Cω / 4, where C is (the track length of a portion where the groove width changes continuously): An optical disc device characterized in that a constant expressed by (radius of the optical disc in the track) and ω are expressed by an angular velocity of the disc. 6. An optical disc having an information track sandwiched between guide grooves, wherein an address information section is formed by forming unevenness bits on address information on a track having a first width of the information track sandwiched between the guide grooves. A data section in which data is added to a track having a second width smaller than the first width, the data track being sandwiched between the guide grooves; and a data section existing between the address information section and the data section. An intervening portion having a width varying from the first width to the second width, wherein the length of the intervening portion in the track direction becomes longer toward the outer periphery in proportion to the radius of the optical disc. optical disk. 7. The optical disc according to claim 6, wherein:
An optical disk characterized in that the length of the interposed portion in the track direction changes continuously from the inner circumference to the outer circumference of the disk. 8. The optical disc according to claim 6, wherein:
An optical disk characterized in that the length of the interposed portion in the track direction changes stepwise from the inner circumference to the outer circumference of the disk. 9. An address information section in which address information is formed by concavo-convex bits on a track whose information track sandwiched by the guide grooves has a first width, and a width of the information track sandwiched by the guide grooves is a first width. A data portion in which data is attached to a track having a second width smaller than the data portion, wherein the data portion exists between the address information portion and the data portion;
An optical disc having an intervening portion in which the width of the information track changes from the first width to the second width, wherein the length of the intervening portion in the track direction becomes longer toward the outer periphery in proportion to the radius of the optical disc; An optical disk reproducing apparatus for reproducing light, irradiating a rotating optical disk with light, receiving reflected light from the optical disk, and outputting an electric reproduction signal according to the received light, An optical disc reproducing apparatus comprising: a filter for removing a component having a predetermined frequency caused by the intervening portion. 10. The optical disk device according to claim 9, wherein the predetermined frequency F is: F = Cω / 4, where C is (the length of the track of the intervening portion): An optical disc apparatus characterized in that a constant represented by (radius) and ω is represented by an angular velocity of the disc.