JP2006228364A - Optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk device having a discrimination means which can quickly discriminate a plurality of kinds of optical disks having approximately similar track pitches and different disk recording capacities. <P>SOLUTION: The optical disk device has a means (23) which moves an optical pickup to a prescribed position along the radial direction of a loaded optical disk to obtain the address information of the prescribed position beforehand recorded on the optical disk and a means (24) which compares the obtained address information with the reference address of the prescribed position and discriminates the plurality of the kinds of optical disks having different recording capacities in accordance with the discrimination result. Thus, the optical disk device having the discrimination means, which can quickly discriminate the plurality of the kinds of optical disks having approximately similar track pitches and different disk recording capacities, is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical disc apparatus, and more particularly to an optical disc apparatus that quickly discriminates a plurality of types of optical discs having different recording capacities.

In recent years, optical discs are widely used because various information signals such as audio information, video information, and computer data can be recorded at high density, and a desired track can be accessed at high speed during reproduction.
When optical discs are classified, a playback-only CD (Compact Disc) prerecorded with music information, a playback-only CD-ROM (CD-Read Only Memory) pre-recorded with computer data, and recording / playback that can record information signals only once There are CD groups such as possible CD-R (CD-Recordable), and these generally use a single disk substrate having a disk substrate thickness of 1.2 mm.

As the optical disk having a higher recording density than the CD, a reproduction-only DVD (Digital Versatile Disc) in which video and audio information is compressed and recorded in advance, and a reproduction-only DVD-ROM (DVD-Read Only Memory) in which computer data is recorded in advance. ), Recordable / reproducible DVD-R (DVD-Recordable) capable of recording information signals only once, recordable / reproducible DVD-RW (DVD-Rewritable) and DVD-RAM (DVD-Random) capable of recording information signals multiple times There are DVD groups such as Access Memory), and these are generally used by bonding two disk substrates having a disk substrate thickness of 0.6 mm.
More recently, “ultra-high density optical discs” (for example, Blu-ray Discs) that can record and reproduce information signals at ultra-high density with higher density than the DVD have been put into practical use.

Since the above-mentioned optical discs have substantially the same external shape, one optical disc apparatus can be designed so that a plurality of optical discs can be used with a common disc drive mechanism. In that case, it is necessary to automatically discriminate the type of the disc in the optical disc apparatus. As an example of the discriminating means, in Patent Document 1, the optical pickup in the optical disc device is moved in the radial direction of the disc surface. A technique is disclosed in which a track error signal is detected from reflected light of a disk by traversing a track and discriminating between a CD and a DVD based on the level of the tracking error signal.
Japanese Patent Laid-Open No. 11-250558 (page 6-7, FIG. 2)

  However, in the Blu-ray Disc of the ultra-high density optical disc, a plurality of types of discs having different recording capacities are created although they are optical discs having substantially the same track pitch. However, there is a problem that even if it is possible to discriminate between CDs, DVDs and ultra-high density optical discs, it is not possible to discriminate between different types of recording capacities at the same track pitch as described above.

For this reason, when such an optical disc is loaded, the type of the optical disc cannot be known until the capacity information recorded on the disc is read out in a normal playback state. There were problems such as being unable to pre-process according to the difference.
The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an optical disc apparatus provided with a means for quickly discriminating a plurality of types of optical discs having different disc recording capacities at substantially the same track pitch. There is.

  The present invention has the following configuration as means for solving the above problems. That is, in an optical disc apparatus that performs recording or reproduction of an optical disc by discriminating between a plurality of optical discs having substantially the same track pitch and different recording capacities, an optical pickup that irradiates a predetermined position on the optical disc with a laser beam, and the predetermined position Using the detection means for detecting address information from the return light of the optical disk and the relationship in which the address information at the predetermined position varies depending on the recording capacity of the plurality of optical disks, the reference address obtained in advance and the detection means are used. An optical disc apparatus comprising: a discriminating unit that discriminates a recording capacity of the optical disc by comparing the address information.

According to the present invention, it is possible to determine the recording capacity type of an optical disk loaded without reading the recording capacity information of the disk. As a result, it is possible to avoid an unstable state in which the recording capacity of the disk is not determined yet. In addition, since the process of reading the recording capacity information of the disc can be omitted, it is possible to speed up the startup process of the optical disc.
Furthermore, by using the discriminating means according to the present invention in combination with other optical disc discriminating means, it is possible to speed up and increase the accuracy of discriminating the type of optical disc.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of an optical disc apparatus according to the present invention, FIG. 2 is a diagram showing the relationship between radius and address for each recording capacity of a Blu-ray Disc, and FIG. FIG. 4 is a flow chart for explaining the discriminating operation of the optical disc apparatus according to the present invention.

In the present embodiment, the determination of the Blu-ray Disc (hereinafter abbreviated as BD) will be described as an example, and an outline of the BD will be described here.
According to the specification, the track pitch of the BD is determined to be 0.32 μm, and the data recording area is from a position of a radius of 24 mm to a position of 58 mm. Further, the recording capacity varies depending on the number of rotations and the recording mark length, and there are three types: 23 GB (gigabyte), 25 GB, and 27 GB.
In a single-layer BD, the address increases from the inner circumference to the outer circumference with reference to the position of a radius of 24 mm, which is the head of the data recording area. In addition, the layer 2 BD address increases from the inner periphery to the outer periphery on the basis of the position of the radius 24 mm in the layer 0 as in the single layer, and from the inner periphery to the outer periphery on the basis of the position of the radius 24 mm in the layer 1. The address is subtracted.
In the following description, when the recording capacity of the optical disc is determined, the reproduction laser beam is used, so that the description will focus on reproduction. Since the single layer and the two layers 0 have the same specifications, the BD single layer will be mainly described.

First, the configuration of the optical disk apparatus of this embodiment and the operation of each unit will be described with reference to FIG.
In the optical disk apparatus of the present embodiment, the BD 11 is rotatably mounted on the turntable 12, and an optical pickup 13 for recording or reproducing on the BD 11 is provided so as to be movable in a radial direction and a direction perpendicular to the surface of the BD 11. It has been.
The optical pickup 13 scans the signal surface of the BD 11 to obtain a detection signal. The detection signal is supplied to the preamplifier 14, and the preamplifier 14 amplifies the detection signal and supplies it to the focus error signal detection circuit 15, the tracking error signal detection circuit 16, the RF signal detection circuit 17, and the wobble signal detection circuit 18, respectively.

  The focus error signal detection circuit 15 generates a focus error signal based on the input detection signal and outputs the focus error signal to the focus control circuit 20. A focus control signal from the focus control circuit 20 is supplied to the optical pickup 13 to control the optical pickup 13 in the focus direction (perpendicular to the surface) with respect to the BD 11.

  Next, the tracking error signal detection circuit 16 generates a tracking error signal based on the input detection signal and outputs the tracking error signal to the tracking control circuit 21. A tracking control signal from the tracking control circuit 21 is supplied to the optical pickup 13 to control the optical pickup 13 in the tracking direction (radial direction) with respect to the BD 11.

  The method for generating the focus error signal and the tracking error signal can be performed by various known techniques such as the well-known knife edge method, SSD method, push-pull method, and three-beam method.

  Next, the RF signal detection circuit 17 obtains an RF signal based on the input detection signal, and inputs this RF signal to the reproduction signal processing circuit 22, where signal processing according to the format specification of the BD11 is performed. After that, the reproduction signal is output from the output terminal 25 to the outside.

Next, the wobble signal detection circuit 18 generates a wobble signal based on the input detection signal, and supplies the wobble signal to the clock generation circuit 19 and the address detection circuit 23.
The clock generation circuit 19 generates a clock signal based on the supplied wobble signal, and outputs this clock signal to the spindle motor drive control circuit 28. Then, by supplying a spindle motor control signal from the spindle motor drive control circuit 28 to the spindle motor 29, the rotation speed of the optical disk is controlled.

  Further, the address detection circuit 23 obtains an address based on the supplied wobble signal, outputs the address from the output terminal 26 to the outside, and supplies the address to the optical disc type determination circuit 24.

  The optical disc type discriminating circuit 24 compares the original address obtained for each recording capacity with the address obtained by the address detecting circuit 23 at a predetermined radial position of the optical pickup 13. Then, it is determined whether the address obtained by the address detection circuit 23 is an address obtained by a BD with a recording capacity of 23 GB, an address obtained by a BD of 25 GB, or an address obtained by a BD of 27 GB. The optical disc type discrimination result is output from the output terminal 27 to the outside. The optical disc type discriminating circuit 24 can also perform arithmetic processing using a known CPU.

Next, the operation of the optical disc type discriminating circuit 24 will be specifically described with reference to FIGS.
FIG. 2 is a diagram showing the relationship between the radial position and address of the three types of BDs. As shown in the figure, the physical address at the radius of 24 mm is 0x00100000 for any capacity disk, and the outermost circumference of the data recording area. The physical address at 58 mm is 0x00BDA25F for a BD with a recording capacity of 23 GB, 0x00CA73FF for 25 GB, and 0x00D950BF for 27 GB.
For this reason, in the BD, when the addresses are compared with the same radius and for each recording capacity, there is little difference in the addresses read on the inner circumference side, and there is a difference in the addresses read out toward the outer circumference.

On the other hand, the address read from the optical disc has an error with respect to the address calculated by the radial position due to the movement accuracy of the optical pickup and the influence of the eccentricity of the optical disc. Therefore, it is necessary to read the address of the optical disc at the radial position where the read address is sufficiently different due to the difference in recording capacity even if the detected address includes some errors, and to determine the recording capacity.
For example, assuming that the movement accuracy of the optical pickup and the influence of the eccentricity of the optical disk are ± 0.4 mm, as shown in FIG. 3, if the address is not read at least with a radius of 40 mm or more, the difference in recording capacity is determined. There is no address difference that can be generated.

Next, the operation flow of the optical disc type discrimination circuit 24 will be described with reference to the flowchart of FIG.
In this embodiment, the recording capacity of the BD 11 is determined by reading an address at a position having a radius of 40 mm. First, the tracking control circuit 21 is driven to move the optical pickup 13 to a radius of 40 mm (step S11). Next, the spindle motor 29 is driven at a reference rotational speed with a radius of 40 mm (step S12). Next, the signal surface of the BD 11 is reproduced by the optical pickup 13, and each servo drive of focus control (step S13), tracking control (step S14), and rotation speed control (step S15) is performed based on the obtained detection signal. .

Next, an address is acquired by the address detection circuit 23 (step S16). Next, the obtained address is input to the optical disc type discriminating circuit 24 for discrimination. In the determination, first, it is determined whether the address is 0x0052000 or less (step S17). If YES, it is determined that the recording capacity is a 23 GB BD (step S18). If NO, it is then determined whether the address is 0x00570000 or higher (step S19). If NO, it is determined that the recording capacity is 25 GB BD (step S20), and if YES, it is determined that the recording capacity is 27 GB BD (step S21).
Various settings are made according to the recording capacity of the disc using the optical disc type discrimination result thus obtained (step S22).

  In this embodiment, the position to be discriminated is set to a position having a radius of 40 mm. As described above, this position is the address difference at the same radius of various recording capacities of the BD, the movement accuracy of the optical pickup, and the optical disc. The value can be appropriately changed in consideration of the magnitude of the eccentricity. Similarly, the boundary address value for determining the recording capacity can be changed.

As described above in detail, according to the present invention, the recording capacity type of the loaded optical disk can be determined without reading the recording capacity information of the disk. Unstable conditions can be avoided early. In addition, since the process of reading the recording capacity information of the disc can be omitted, it is possible to speed up the startup process of the optical disc.
In addition, by using the discriminating means according to the present invention in combination with other optical disc discriminating means, it is possible to speed up and increase the accuracy of discriminating optical disc types.

It is a block diagram which shows the structure of the optical disk apparatus based on this invention. It is a figure which shows the relationship between the radius according to various recording capacities of Blu-ray Disc, and an address. It is a figure which shows the relationship between the radius for various recording capacities of Blu-ray Disc and the address in the vicinity of a radius of 40 mm. 5 is a flowchart for explaining a determination operation of the optical disc apparatus according to the present invention.

Explanation of symbols

11 ... BD (Blu-ray Disc)
DESCRIPTION OF SYMBOLS 12 ... Turntable 13 ... Optical pick-up 14 ... Preamplifier 15 ... Focus error signal detection circuit 16 ... Tracking error signal detection circuit 17 ... RF signal detection circuit 18 ... Wobble signal detection Circuit 19 ... Clock generation circuit 20 ... Focus control circuit 21 ... Tracking control circuit 22 ... Reproduction signal processing circuit 23 ... Address detection circuit 24 ... Optical disc type discrimination circuit 25, 26, 27 ... Output terminal 28 ... Spindle motor drive control circuit 29 ... Spindle motor

Claims (1)

In an optical disc apparatus for performing recording or reproduction of the optical disc by discriminating between a plurality of optical discs having substantially the same track pitch and different recording capacities,
An optical pickup for irradiating a predetermined position of the optical disc with a laser beam;
Detecting means for detecting address information from the return light from the predetermined position;
Using the relationship in which the address information at the predetermined position varies depending on the recording capacity of the plurality of optical discs, the reference address obtained in advance is compared with the address information obtained by the detecting means, and the optical disc Discriminating means for discriminating the recording capacity of
An optical disc apparatus comprising:

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