JP2002083461A - Device for discriminating kind of optical disk, and method for discriminating kind of optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for discriminating the kind of an optical disk which can discriminate a kind of a disk while avoiding position control of a pickup head having extremely high accuracy. SOLUTION: This device is provided with a detecting means (10, 11 detecting the number of header field consisting of emboss-bit per prescribed disk rotation angle in the prescribed radius distance range on an optical disk, and a discriminating means (12) discriminating it as a rewritable disk being relevant to a kind having first storage capacity when (n) pieces of header fields are detected, a discriminating means (12) discriminating it as a rewritable disk being relevant to a kind having second storage capacity being more than the first storage capacity when (m) (n<m) pieces of header fields are detected, and discriminating it as an optical disk for reproduction only when a header field is not detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical disk type determining apparatus and an optical disk type determining method for determining the type of an optical disk.

[0002]

2. Description of the Related Art In recent years, CDs (Compact Discs), D
VD (Digital Video Disk) -ROM and DVD-R
Research and development of an optical disk device capable of reproducing AM has been advanced. In such an optical disk device, after the disk is loaded, the type of the loaded disk is determined (CD, DVD-ROM, DVD-RAM type determination).
Is required.

Here, DVD-ROM and DVD-RA
An example of the type determination of M will be described. First, the position of the pickup head in the radial direction of the disk is controlled, and the laser irradiation position for signal reading is set to the radius of the disk 2.
3.5 mm to 23.996 mm. DVD-ROM
And DVD-RAM both have a disk radius of 23.5mm
The recording method of the physical signal between ２３23.996 mm is the same (the emboss data zone). By reading the data recorded in this section, the DVD-RO
M and DVD-RAM can be determined. At the time of data reading at this time, focus / track servo is executed in exactly the same manner as when reading data from a DVD-ROM.

[0004]

In the disk discrimination described above, it is necessary to control the position of the pickup head aiming at a common part of the recording method. This common part is extremely narrow, and requires extremely accurate position control of the pickup head.

[0005] If the laser irradiation position of the DVD-RAM is shifted outside the disk radius of 23.996 mm, the laser irradiation position becomes a rewritable data zone. Rewritable data zone is DVD-RAM
The recording method of the physical signal in the rewritable data zone is different from that of the DVD-ROM. Therefore, the data in this rewritable data zone is D
The data cannot be read by focus / track servo when reading data from the VD-ROM.

If the laser irradiation position is shifted inward from the disk radius of 23.5 mm with respect to the DVD-RAM,
The laser irradiation position becomes a BCA (burst cutting area). The data in this BCA is DVD-
It cannot be read by focus / track servo when reading data from ROM.

As described above, the conventional disk discrimination requires extremely accurate position control of the pickup head. As a result, there is a problem that the manufacturing cost of the optical disk device is increased.

SUMMARY OF THE INVENTION An object of the present invention has been made in view of the above-mentioned circumstances, and an optical disk type determining apparatus capable of determining a disk type by avoiding position control of a pickup head with extremely high accuracy. An object of the present invention is to provide an optical disk type determining method.

[0009]

In order to solve the above-mentioned problems and achieve the object, an optical disk type determining apparatus and an optical disk type determining method according to the present invention are configured as follows.

(1) An optical disc type determining apparatus according to the present invention comprises: a detecting means for detecting the number of header fields composed of embossed pits per predetermined disc rotation angle in a predetermined radial distance range on the optical disc; Is determined as a rewritable disc corresponding to the type having the first storage capacity, and when m (n <m) header fields are detected, the first field is detected. Determining means for determining that the disc is a rewritable disc corresponding to a type having a second storage capacity larger than the storage capacity, and for determining that the disc is a read-only optical disc when no header field is detected. .

(2) An optical disk type determining apparatus according to the present invention comprises: a driving unit for driving the optical disk to rotate; a rotation angle detecting unit for detecting a rotation angle of the optical disk; Converting means for detecting reflected light from the optical disc and converting the detected reflected light into an electric signal; irradiation point control means for controlling an irradiation point of the laser light in a radial direction of the optical disc; An irradiation point of the laser light is controlled to a predetermined radial distance on the optical disk by a point control means, and at this time, an emboss pit per rotation angle detected by the rotation angle detection means based on the electric signal converted by the conversion means. Header field detecting means for detecting the number of header fields, comprising: When n header fields are detected by the output unit, it is determined that the disc is a rewritable disc corresponding to the type having the first storage capacity, and m (n <m) header fields are detected. At this time, it is determined that the disc is a rewritable disc corresponding to a type having a second storage capacity larger than the first storage capacity, and if no header field is detected, it is determined that the disc is a read-only optical disc. Means.

(3) In the optical disc type determining method according to the present invention, a first step of detecting the number of header fields composed of embossed pits per predetermined disc rotation angle in a predetermined radial distance range on the optical disc, and the first step Thus, when n header fields are detected, it is determined that the disc is a rewritable disc corresponding to the type having the first storage capacity, and when m (n <m) header fields are detected, It is determined that the disc is a rewritable disc corresponding to a type having a second storage capacity larger than the first storage capacity, and is determined to be a read-only optical disc when no header field is detected. And steps.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

First, a DVD-R will be described with reference to FIGS.
A schematic configuration of the AM will be described. DVD-RAM has a storage capacity of 2.6 Gbytes / side and 4.7 Gb / side.
Some are ytes / side. FIG. 1 shows that both the DVD-ROM and the DVD-RAM (2.6 G, 4.7 G) between the radial positions 23.5 mm to 23.996 mm are emboss data zones. 2 and 3 show the data structure of the DVD-RAM (2.6 G). FIG. 4 shows a data structure of the DVD-RAM (4.7 G).

Here, a 2.6 Gbytes / side DVD-
The RAM will be described. Radius 2 of this DVD-RAM
Outside of 4 mm is a rewritable data zone.
The rewritable data zone includes a part of the lead-in area and a total of 24 zones of zones 0 to 23. The rewritable data zone includes a recording / reproducing area in which recording / reproducing can be performed by laser light, and a read-only area (header field) in which recording cannot be performed by laser light. One recording / reproducing area and one reproduction-only area are paired to form a unit called a sector. The number of sectors per track in the lead-in area and zone 0 is 17, the number of sectors per track in zone 1 is 18, and the number of sectors per track in zone n is (n + 17).

Subsequently, a 4.7 Gbytes / side DVD-
The RAM will be described. Radius 2 of this DVD-RAM
Outside of 4 mm is a rewritable data zone.
The rewritable data zone includes a part of the lead-in area and a total of 35 zones of zones 0 to 34. The rewritable data zone includes a recording / reproducing area in which recording / reproducing can be performed by laser light, and a read-only area (header field) in which recording cannot be performed by laser light. One recording / reproducing area and one reproduction-only area are paired to form a unit called a sector. The number of sectors per track in the lead-in area and zone 0 is 25, the number of sectors per track in zone 1 is 26, and the number of sectors per track in zone n is (n + 25).

In the above-mentioned read-only area, a PID (Phys
ical ID) is recorded. The physical signal recording method in the read-only area is the same as the signal recording method in the DVD-ROM. That is, the data recorded in the read-only area can be reproduced by the focus / track servo at the time of DVD-ROM reproduction. Further, a focus servo mechanism for reading data recorded in the read-only area can apply focus servo of laser light for reproducing data recorded in the recording / reproducing area.

Next, a schematic configuration of the optical disk device will be described with reference to FIG. The optical disk type determination device according to the present invention is applied to this optical disk device.

As shown in FIG. 5, the optical disk device has a C
Optical disk 1 such as D, DVD-ROM, DVD-RAM, etc.
To reproduce the data recorded in the. The optical disk apparatus includes a disk motor 2, a motor drive control unit 3, an optical pickup head (PUH) 4, a head motor 5, a motor drive control unit 6, a low-pass filter (LPF) 7, a comparison level generation unit 8, a comparison unit 9, a counter 10, a rotation angle detection unit 11, a determination unit 12, and a main control unit 13.

The disk motor 2 includes a motor drive control unit 3
Controls the disk 1 to rotate at a predetermined speed. The rotation of the disk motor 2 is monitored in real time by the rotation angle detector 11, and the rotation angle of the disk is calculated.

The optical pickup head 4 includes a laser irradiation section 4a, a light detection section 4b, a photoelectric conversion section 4c, and the like.
The laser irradiation unit 4a irradiates the optical disc 1 with a laser beam for reproduction. The light detection unit 4b detects reflected light from the optical disc 1, that is, reflected light on which data recorded on the optical disc 1 is reflected. The photoelectric conversion unit 4c converts the reflected light detected by the light detection unit 4b into an electric signal, and reproduces data recorded on the optical disc 1.

The head motor 5 moves the optical pickup head 4 to a predetermined radial position on the disk under the control of the motor drive control unit 6. As a result, the irradiation point of the laser beam emitted from the optical pickup head 4 is controlled in the radial direction of the disk.

The LPF 7 cuts high frequency components from the electric signal RF provided from the optical pickup head 4 (photoelectric conversion unit 4c). The comparison level generator 8 generates a reference level signal REF for comparison. The comparison unit 9 is LP
F7 from which the high-frequency component has been cut and the reference level signal R generated by the comparison level generator 8.
EF and a comparison result is output. This comparison will be described later in detail. The counter 10 counts the header field based on the comparison result and outputs a count value.

The rotation angle detector 11 detects the rotation angle of the disk motor and detects the number of header fields per rotation angle based on the count value provided by the counter. The determination unit 12 determines the type of the optical disc 1 based on the number of header fields per rotation angle.
This type determination will be described later in detail.

Next, the disk type determination processing will be described in detail. Here, as an example, the irradiation position of the signal reading laser is set at a radius of 24.18 mm to 2 mm on the disk.
It is assumed that the position of the optical pickup head 4 is controlled to be 5.40 mm. That is, as can be seen from FIG. 2, the position of the optical pickup head 4 is controlled so that the irradiation position of the laser is in zone 0.

At this position, laser focus servo for signal reading is performed. As shown in FIG. 6, the reproduced signal LPFO (signal output from the LPF 7) obtained at this time is composed of a recording / reproducing area recordable / reproducible by the laser and a reproduction-only area (header field) not recordable by the laser. Different levels. A reference level signal REF (a signal output from the comparison level generator 8) is set so that only the signal in the reproduction-only area can be detected from the reproduction signal LPFO, and the level of the reproduction signal LPFO is compared with the reference level signal REF. To count the number of read-only areas. Further, the number of appearances of the reproduction-only area per disk rotation angle can be detected from the disk rotation angle detected by the rotation angle detection unit 11. As a result, the number of header fields (= the number of sectors) per disk rotation angle can be detected.

In a 2.6 Gbytes / side DVD-RAM, one round of the track in zone 0 (during one rotation of the disk)
There are 17 header fields. Therefore, when the reproduction target is a 2.6 Gbytes / side DVD-RAM,
When the reproduction is performed for zone 0, the output of the comparator 9 is inverted about 17 times. That is, 17 per 360 degrees of disk rotation angle
When the number of header fields is detected, the disc to be reproduced is determined to be a 2.6 Gbytes / side DVD-RAM. The disk rotation angle is not limited to 360 degrees, but may be 180 degrees, 90 degrees, or the like. In that case, the number of header fields according to the rotation angle may be detected.

In the 4.7 Gbytes / side DVD-RAM, one round of the track in zone 0 (during one rotation of the disk)
There are 25 header fields. Therefore, when the reproduction target is a 4.7 Gbytes / side DVD-RAM,
When the reproduction is performed for zone 0, the output of the comparator 9 is inverted about 25 times. In other words, 25 per 360 degrees of disk rotation angle
When the header fields are detected, the disc to be reproduced is determined to be a 4.7 Gbytes / side DVD-RAM. The disk rotation angle is not limited to 360 degrees, but may be 180 degrees, 90 degrees, or the like. In that case, the number of header fields according to the rotation angle may be detected.

A DVD-ROM does not have a recording / reproducing area that can be recorded / reproduced by a laser and a read-only area that cannot be recorded by a laser (only a read-only area). Therefore, even if high-frequency components are cut from the reproduction signal obtained from the DVD-ROM, a clear level difference as in the case of the DVD-RAM cannot be obtained. Therefore, the output of the comparator 9 is not inverted, and the counter 10 does not count up. From this, the DVD-ROM can be determined.

Next, the determination of the type of the optical disk will be summarized with reference to FIG.

The rotation of the disk starts (ST1),
Focus servo is applied (ST2). Here, first, the types of the CD system and the DVD system are determined (ST3).
If it is determined to be a CD system (ST3, CD system),
It goes on to the processing of the system. When the optical pickup head is determined to be a DVD system (ST3, DVD system), the optical pickup head is moved to a predetermined radial position (ST4). Thereby, the irradiation position of the laser beam is directed to, for example, zone 0. Here, the number of header fields per disk rotation angle is detected (ST5). Disk rotation angle 3
If about 17 header fields are detected per 60 degrees (ST6, YES), it is determined that the reproduced disc is a 2.6 Gbytes / side DVD-RAM. If about 25 header fields are detected per 360 ° of disk rotation angle (ST7, YES),
The reproduced disc is a 4.7 Gbytes / side DVD-
It is determined that it is a RAM. When the header field is not detected (ST7, NO), it is determined that the reproduced disc is a DVD-ROM.

According to the disc type determination method of the present invention, the disc type can be determined without having to aim at the emboss data zone provided at a very narrow radius position common to DVD-ROM and DVD-RAM. . This eliminates the need for high-precision control for irradiating the laser irradiation position to an extremely narrow position.

It should be noted that the present invention is not limited to the above-described embodiment, and can be variously modified in an implementation stage without departing from the gist thereof. In addition, the embodiments may be implemented in appropriate combinations as much as possible, in which case the combined effects can be obtained. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriate combinations of a plurality of disclosed constituent elements. For example, even if some components are deleted from all the components shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effects described in the column of the effect of the invention can be solved. If you get
A configuration from which this configuration requirement is deleted can be extracted as an invention.

[0034]

According to the present invention, it is possible to provide an optical disk type determining apparatus and an optical disk type determining method capable of determining the type of a disk while avoiding the position control of the pickup head with extremely high accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a difference in data structure at a disc radial position between a DVD-ROM and a DVD-RAM.

FIG. 2 is a diagram showing a data structure of a 2.6 Gbytes / side DVD-RAM.

FIG. 3 is a diagram showing a data structure of a 2.6 Gbytes / side DVD-RAM.

FIG. 4 is a diagram showing a data structure of a 4.7 Gbytes / side DVD-RAM.

FIG. 5 is a block diagram showing a schematic configuration of an optical disk device to which the optical disk type determination device of the present invention is applied.

FIG. 6 shows a level difference of a signal obtained from each of a recording / reproducing area where recording / reproducing can be performed by a laser of a DVD-RAM and a read-only area (header field) which cannot be recorded by a laser, and uses the level difference FIG. 7 is a diagram for explaining a process of detecting a read-only area by using the process shown in FIG.

FIG. 7 is a flowchart illustrating an optical disc type determination method according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical disk 2 ... Disk motor 3 ... Motor drive control part 4 ... Optical pickup head (PUH) 4a ... Laser irradiation part 4b ... Light detection part 4c ... Photoelectric conversion part 5 ... Head motor 6 ... Motor drive control part 7 ... Low-pass filter (LPF) 8 ... Comparison level generator 9 ... Comparator 10 ... Counter 11 ... Rotation angle detector 12 ... Determination unit 13 ... Main control unit

Claims (7)

[Claims] A detecting means for detecting information in a header field comprising embossed pits in a recordable area on the optical disk; and a determining means for determining a type of the optical disk based on a detection result by the detecting means. An optical disc type determination device characterized by the following. 2. A detecting means for detecting information of a header field composed of embossed pits per predetermined disk rotation angle in a predetermined radial distance range on an optical disk, and determining the type of the optical disk based on a detection result by the detecting means. Means for determining the type of an optical disc, comprising: 3. A detecting means for detecting the number of header fields composed of embossed pits per a predetermined disk rotation angle in a predetermined radial distance range on an optical disk, and when the detecting means detects n header fields, When the disc is determined to be a rewritable disc corresponding to the type having the storage capacity of 1, and m (n <m) header fields are detected, the second storage capacity larger than the first storage capacity is determined. An optical disk type determination device, comprising: a determination unit that determines that the disk is a rewritable disk corresponding to the type of the optical disk and determines that the disk is a read-only optical disk when no header field is detected. 4. A driving means for driving the optical disc to rotate, a rotation angle detecting means for detecting a rotation angle of the optical disc, and a laser light for reproduction to the optical disc, and a reflected light from the optical disc to be detected. Conversion means for converting the detected reflected light into an electric signal; irradiation point control means for controlling an irradiation point of the laser light in a radial direction of the optical disc; irradiation point of the laser light by the irradiation point control means Is controlled to a predetermined radial distance on the optical disk, and at this time, a header for detecting information of a header field composed of embossed pits per rotation angle detected by the rotation angle detection means based on the electric signal converted by the conversion means. Field detecting means, based on a detection result by the header field detecting means, Optical disc type determination apparatus characterized by comprising determination means for determining the type of disc, the. 5. A driving means for driving the optical disc to rotate, a rotation angle detecting means for detecting a rotation angle of the optical disc, and a laser beam for reproducing the optical disc and detecting the reflected light from the optical disc. Conversion means for converting the detected reflected light into an electric signal; irradiation point control means for controlling an irradiation point of the laser light in a radial direction of the optical disc; irradiation point of the laser light by the irradiation point control means Is controlled to a predetermined radial distance on the optical disk, and at this time, a header field for detecting the number of header fields composed of embossed pits per rotation angle detected by the rotation angle detection means based on the electric signal converted by the conversion means. Detecting means; and n header fields by the header field detecting means. When detected, it determines that the rewritable disc corresponding to the type having a first storage capacity,
When m (n <m) header fields are detected,
Determining that the disc is a rewritable disc corresponding to a type having a second storage capacity larger than the first storage capacity,
Determining means for determining that the optical disk is a reproduction-only optical disk when a header field is not detected; 6. A first step of detecting information of a header field composed of embossed pits per a predetermined disk rotation angle in a predetermined radial distance range on an optical disk, and a type of the optical disk based on a result of the detection in the first step. And a second step of determining the type of the optical disk. 7. A first step of detecting the number of header fields consisting of emboss pits per predetermined disk rotation angle in a predetermined radial distance range on the optical disk, and n header fields are detected by the first step. Is judged to be a rewritable disk corresponding to the type having the first storage capacity, and m (n <n)
m) when the header field is detected, the disc is determined to be a rewritable disc corresponding to the type having the second storage capacity larger than the first storage capacity, and when the header field is not detected, the reproduction is performed. A second step of determining that the optical disk is a dedicated optical disk.