JP2713999B2 - Disk unit - Google Patents

Description

Description of the Invention [Object of the Invention] (Industrial application field) The present invention relates to a disk device for recording or reproducing information on an optical disk, for example.

2. Description of the Related Art As is well known, various disk devices have been developed which record information on an optical disk or read information recorded on an optical disk by using a laser beam output from a semiconductor laser, for example.

The optical disc has a characteristic data recording area provided outside the recording area (inner periphery), and mode information commonly assigned to the optical disc by any manufacturer is recorded in this area in the form of a bar code as characteristic data. Things are considered.

In the characteristic data recording area, information such as reflectance, laser power at the time of writing and reading, and the number of sectors in one revolution are recorded in order to determine the reading and reading modes.

Thus, the compatibility of the optical disk and the device is maintained by reading the information in the characteristic data recording area.

However, such a characteristic data recording area is only defined by the radial position on the optical disk. For this reason, there is a drawback that the apparatus cannot determine the access position by the laser beam with respect to the characteristic data recording area without any reference.

(Problems to be Solved by the Invention) The present invention eliminates the drawback that the access position cannot be determined by the light condensed by the optical head with respect to the characteristic data recording area. In addition, it is possible to provide a disk device capable of positioning the access position by the light condensed by the optical head at the center of the radial position of the characteristic data recording area without adding an extra sensor or circuit.

[Configuration of the Invention] (Means for Solving the Problems) According to the present invention, a recording track is formed, a data recording area in which data is recorded on the recording track, and the recording on the inner peripheral side of the data recording area. An optical head that is provided in an area where no tracks are formed and has a characteristic data recording area in which characteristic data at the time of manufacture is recorded; Moving means for moving in the direction, the optical head being located at an inner peripheral end of a range in which the optical head can move when accessing the data recording area, and being located at the radial center of the disc of the characteristic data recording area. To detect the abnormality of the moving means at the time of the access and the position at the time of standby, and Detecting means for detecting that the light condensing position of the optical head is in the characteristic data recording area on the disk in accordance with the movement of the means, and moving the optical head when accessing the characteristic data recording area. Moving in the radial direction of the disk by the means, when the detection signal from the detection means is recorded,
It is configured to stop the movement by the moving means so as to condense the light from the optical head to the characteristic data recording area.

(Operation) The present invention is provided in a data recording area in which a recording track is formed and data is recorded in the recording track, and in an area in which the recording track is not formed on an inner side of the data recording area. An optical head is used to condense and access light on a disk having a characteristic data recording area on which characteristic data at the time of manufacture is recorded, and the optical head is moved in a radial direction of the disk by a moving means. At the inner peripheral end of a range in which the optical head can move when the data recording area is accessed by the optical head, a detecting unit provided so as to be located at a radial center of the disc of the characteristic data area, In addition to performing an abnormality detection of the moving means at the time of the access and a position detection at the time of standby, the moving means is moved according to the movement of the moving means. Detecting that the focus position by the optical head is the characteristic data recording area on the disk, and moving the optical head in the radial direction of the disk by the moving means when accessing the characteristic data recording area;
When the detection signal is supplied from the detection means, the movement by the movement means is stopped so that the light from the optical head is focused on the characteristic data recording area.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 shows a disk device. A groove (recording track) is formed in a spiral shape on the surface of the optical disk (disk) 1, and the optical disk 1 is rotated at a constant speed by a motor 2, for example. The motor 2 is controlled by a motor control circuit 18.

In the optical disk 1, for example, a metal film layer such as tellurium or bismuth, that is, a recording film is coated in a donut shape on a surface of a substrate formed in a circle of glass or plastics, for example. Is provided with a notch, that is, a reference position mark.

On the optical disk 1, as shown in FIG. 3, a data recording area in which guide grooves (recording tracks) are formed.
1a and a characteristic data recording area 1b without a guide groove provided on the inner peripheral side of the data recording area 1a.

In the characteristic data recording area 1b, the same characteristic data is recorded in advance in the form of a bar code in the circumferential direction three times per rotation at the time of manufacture. As the characteristic data, the characteristics of the film of the optical disc 1 (reflectance), the power at the time of recording and reproduction of the semiconductor laser, the format type (the number of sectors in one round), and the like are recorded. As shown in FIG. 3, the characteristic data recording area 1b indicates information in a continuous or discontinuous pit sequence, and is recorded radially in the radial direction of the optical disk 1.
(See FIG. 3).

The characteristic data recording area 1b is composed of three sectors as shown in FIG. 4, and for each sector, a gap, a preamble, a synchronization signal, characteristic data, a sector,
It is composed of track address data, CRC check data, and the like.

As shown in FIG. 5, one bit of the data in the characteristic data recording area 1b is determined to be "0" when the pit string is in the first half of a continuous 82 pits, and when it is in the second half,
It is determined to be "1".

As shown in FIG. 6, when there are a plurality of pit strings in the first half 328 channel bits, the one bit of data in the characteristic data recording area 1b is determined to be “0”, and the second half 328 channel bits are determined. If there are a plurality of pit strings in a bit, it is determined to be "1".

The data recording area 1a is divided into a plurality of sectors based on the fiducial mark. Variable length information is recorded over a plurality of blocks on the optical disc 1, and 300,000 blocks are formed on 36,000 tracks on the optical disc 1.

Recording and reproduction of information on the optical disk 1 are performed by the optical head 3. The optical head 3 is fixed to a drive coil 13 constituting a movable portion of a linear motor, and the drive coil 13 is connected to a linear motor control circuit 17.

A linear motor position detector (not shown) is connected to the linear motor control circuit 17. The linear motor position detector (not shown) controls an optical scale (not shown) provided on the optical head 3. Upon detection, a position signal is output.

The linear motor control circuit 17 has a detector 3 for detecting that the linear motor is positioned at the inner end.
1, and a detector 32 for detecting that the linear motor is located at the outer end is connected, and the detector 3
Reference numerals 1 and 32 each include an optical sensor, and are configured to output a detection signal when light is shielded by a light shield 13a provided below the drive coil 13.

The detectors 31 and 32 detect both ends of the range in which the optical head 3 can move, and are used for detecting abnormality of the linear motor at the time of access and position detection at the time of standby. The position is set so as to match the center of the radial position of the characteristic data recording area 1b.

A permanent magnet (not shown) is provided at a fixed portion of the linear motor, and the drive coil 13 is excited by a linear motor control circuit 17 so that the optical head 3
Are moved in the radial direction of the optical disc 1.

An objective lens 6 is held by the optical head 3 by a wire or a leaf spring (not shown). The objective lens 6 is moved in a focusing direction (an optical axis direction of the lens) by a drive coil 5, and is moved by a drive coil 4. It is movable in a tracking direction (a direction orthogonal to the optical axis of the lens).

The laser light generated by the semiconductor laser 9 driven by the laser control circuit 14
a, the light is irradiated onto the optical disc 1 through the half prism 11b and the objective lens 6, and the reflected light from the optical disc 1 is
The light is guided to the half prism 11c via the objective lens 6 and the half prism 11b, and one of the light beams separated by the half prism 11c is guided to the pair of tracking position sensors 8 via the condenser lens 10.

The other light split by the herb prism 11c is guided to a pair of focus position sensors 7 via a condenser lens 11d and a knife edge 12.

The output signal of the tracking position sensor 8 is supplied to a tracking control circuit 16 via a differential amplifier OP1. The track difference signal output from the tracking control circuit 16 is supplied to the linear motor control circuit 17 and also to the drive coil 4 in the tracking direction via the amplifier 27.

The focus position sensor 7 outputs a signal relating to the focus point of the laser beam, and this signal is supplied to the focusing control circuit 15 via the differential amplifier OP2. The output signal of the focusing control circuit 15 is supplied to the focusing drive coil 5 via the amplifier 28, and is controlled so that the laser beam is always just focused on the optical disc 1.

The sum signal of the output of the tracking position sensor 8 in the state where focusing and tracking are performed as described above is
The unevenness of the pits (recorded information) formed on the track is reflected. This signal is supplied to the video circuit 19, where the image information and address information (track number, sector number, etc.) are reproduced.

The video signal reproduced by the video circuit 19 is output via an interface circuit 40 to an optical disk control device 41 as an external device.

The video signal of the video circuit 19 is supplied to the reading circuit 30. The reading circuit 30 outputs an envelope binarized signal corresponding to the recording data of the characteristic data recording area 1b according to the video signal from the video circuit 19, and includes an envelope detection circuit (not shown) and an envelope detection circuit. And a binarizing circuit.

That is, the video circuit 19 as shown in FIG.
Then, the envelope of the video signal is detected (see (b) in the figure), and the envelope detection signal is binarized to obtain an envelope binary signal (see (c) in the figure). This envelope binarized signal is used when the characteristic data recording area 1b is accessed.
This is output to the CPU 23 described later.

Further, the tracking control circuit 16 moves the objective lens 6 in accordance with a track jump signal supplied from the CPU 23 via the D / A converter 22, and moves the beam light for one track. .

The laser control circuit 14, the focusing control circuit 15,
The tracking control circuit 16, the linear motor control circuit 17, the motor control circuit 18, the video circuit 19, and the like are controlled by a CPU 23 via a bus line 20.
Reference numeral 23 performs a predetermined operation in accordance with control data supplied from the optical disk control device 41 and a program stored in the memory 24.

When accessing the characteristic data recording area 1b, the CPU 23 moves the laser beam from the innermost circumference of the optical disc 1 by the optical head 3, and thereafter, when a detection signal is supplied from the detector 31, the optical head 3 Is determined to be at the inner peripheral end (inner end), and the optical head 3
Is determined to be applied near the center of the radial position of the characteristic data recording area 1b, and the movement of the optical head 3 is stopped. At this time, the characteristic data of the characteristic data recording area 1b is read by checking the time interval between the high level and the low level of the envelope binarized signal supplied from the reading circuit 30, and the characteristic data corresponding to the read characteristic data is read. Control is performed. That is, control corresponding to the optical discs 1 having various specifications (company) can be performed.

The disk drive also includes an A / D converter 21 and a D / A converter 21 used for transmitting and receiving information between the focusing control circuit 15, the tracking control circuit 16, the linear motor control circuit 17 and the CPU 23, respectively. 22 are provided.

Next, in such a configuration, an access operation of the characteristic data recording area 1b in the characteristic data recording area 1b will be described with reference to a flowchart shown in FIG.
For example, now, an instruction to access the characteristic data recording area 1b is supplied to the CPU 23 from the optical disk control device 41. Then, the CPU 23 controls the linear motor control circuit 17 to move the optical head 3 outward from the innermost circumference of the optical disc 1. As the optical head 3 moves, the drive coil 13 also moves.

Then, when the detector 32 is shielded from light by the light shield 13a of the drive coil 13, a detection signal from the detector 32 is supplied to the CPU 23. Then, based on the detection signal, the CPU 23 determines that the moving position of the optical head 3 is located at the inner peripheral end, and irradiates the laser light from the optical head 3 near the center of the radial position of the characteristic data recording area 1b. Then, the movement of the optical head 3 is stopped.

Then, the CPU 23 reads the characteristic data of the characteristic data recording area 1b by examining the time interval between the high level and the low level of the envelope binarized signal from the reading circuit 30 at this time. Performs control corresponding to data. That is, control corresponding to the optical disc 1 having various specifications (company) is performed.

For example, the characteristics (reflectance) of the film of the optical disc 1, the power at the time of recording and reproduction of the semiconductor laser, the format type (the number of sectors in one round) and the like are controlled according to the corresponding specifications.

As described above, at the time of accessing the characteristic data recording area 1b, the optical head 3 is moved from the innermost circumference of the optical disc 1, and thereafter, by the detection signal supplied from the detector 31,
It is determined that the moving position of the optical head 3 is located at the inner peripheral end, and it is determined that the laser beam of the optical head 3 is applied to the center of the radial position of the characteristic data recording area 1b. Is to be stopped.

With this, the mounting position of the detector for detecting the inner peripheral end as the movable range of the optical head is aligned with the center of the radial position of the characteristic data recording area 1b of the optical head. The center of the radial position of the characteristic data recording area 1b can be accessed without adding a sensor or a circuit.

In the above-described embodiment, the case of moving from the innermost circumference when accessing the characteristic data recording area has been described. However, the present invention is not limited to this, and the movement may be started from the outermost circumference or an arbitrary position.

[Effects of the Invention] As described above in detail, according to the present invention, the access position by the light condensed by the optical head can be determined in the characteristic data recording area by a simple method and without adding an extra sensor or circuit. Can be provided at the center of the radial position.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a flowchart for explaining an operation of accessing a characteristic data recording area, FIG. 2 is a block diagram of a disk device, and FIG. FIGS. 4 and 5 are diagrams illustrating an example of the configuration of one bit in the characteristic data recording area, FIG. 6 is a diagram illustrating an exemplary configuration of the characteristic data recording area, and FIGS. The figure is a signal waveform diagram for explaining the operation of the main part in the recording / non-recording detection circuit. 1 optical disk (disk), 1a data recording area, 1b characteristic data recording area, 3 optical head,
17 …… Linear motor control circuit, 19 …… Video circuit, 23 ……
CPU, 24 ... memory, 30 ... reading circuit, 31, 32 ... detector.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-121633 (JP, A) JP-A-63-121130 (JP, A) JP-A-61-87282 (JP, A) JP-A-63 87648 (JP, A) JP-A-60-124070 (JP, A)

Claims (1)

(57) [Claims] A recording track is formed, and is provided in a data recording area where data is recorded in the recording track and in an area where the recording track is not formed on an inner side of the data recording area, and is provided at the time of manufacturing. An optical head for collecting and accessing light on a disk having a characteristic data recording area on which characteristic data is recorded, moving means for moving the optical head in a radial direction of the disk, and the optical head It is provided so as to be located at the inner peripheral end of the range in which the optical head can move when accessing the data recording area, and to be located at the center of the characteristic data recording area in the radial direction of the disc. In addition to detecting the abnormality of the moving means and detecting the position during standby, the optical head is moved according to the movement of the moving means. Detecting means for detecting that the light condensing position is a characteristic data recording area on the disk; and moving the optical head in the radial direction of the disk by the moving means when accessing the characteristic data recording area. Means for stopping the movement by the moving means when the detection signal is supplied from the detecting means, thereby condensing the light from the optical head to the characteristic data recording area. Disk device.