JP2000207812A - Optical disk reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the efficiently recognizable the kind of media. SOLUTION: This optical disk reproducing device is capable of reading out the information from the plural kinds of information recording media, and it is provided with a means 35 for outputting plural reference clocks corresponding to the kind of information recording media, plural reproduced signals demodulating means (PWM 1-7 demodulating circuit 31, PPM 2-7 demodulating circuit 32) corresponding to the kind of information recording media, and a setting means for setting the priority order of the operations of the plural reference clocks output means and the plural reproducing signals demodulating means based on the setting information from the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical disk reproducing apparatus for reading information from a magneto-optical disk (hereinafter simply referred to as a disk) as an information recording medium.

[0002]

2. Description of the Related Art In recent years, with the increase in disk capacity, existing disk capacities of 128 MB, 230 MB, and 540 have been used.
In addition to MB and 640 MB, a high-density disk such as 1.3 GB has been proposed. Of these, 128 MB, 2
For a 30 MB disk, a 2-7 demodulation method using PPM recording is used, and for a 540 MB, 640 MB, 1.3 GB disk, a 1-7 demodulation method using PWM recording is used. Thus, a plurality of demodulation methods are required depending on the type of the disk. In addition, since the recording density of each disk is different, it is necessary to select a different reference clock for recording and reproduction.

For such reasons, in an optical disk reproducing apparatus capable of reading information from various types of disks, it is necessary to identify the inserted disk and set a corresponding reference clock and demodulation circuit. In this case, first, the disk inserted into the drive is rotated to apply focus servo or track servo. After that, a demodulation circuit suitable for the reproduced signal is selected and an appropriate reference clock is searched. If an appropriate reference clock is found by this search, the address information of the control track can be known. Therefore, seek to the control track is performed, and the disc is identified by recognizing the contents of the control track (reproducing the control track information). .

[0004]

As described above, reproducing the control track information requires an operation of rotating the disk and applying focus servo or track servo to seek to the control track. In addition, in searching for a reference clock suitable for a reproduction signal for recognizing the address of a control track, it is necessary to reproduce a reference clock different for each band, even in the same disk, such as a ZCAV disk. Therefore, a search operation for this is also required. When a disc different from the disc assumed by the playback device (drive) is inserted into the drive, the above operation is repeated.

As described above, it takes a considerable amount of time since the search for the reference clock is repeatedly performed until the inserted disk is recognized.

[0006] Depending on the inserted disc, the number of revolutions of the disc may be changed. In this case, since it is necessary to recognize the content of the control track after the disc is inserted into the drive and set the disc to an optimum rotation speed, it takes a lot of time to complete disc identification. .

Japanese Patent Application Laid-Open No. 5-101400 discloses a method for identifying two types of disks. That is,
The type of the inserted disk is determined based on the disk type determination data in the lead-in subcode, and the rotation speed and LD power corresponding to the disk are set. However, since this publication does not describe which one of the two types of disks is to be preferentially searched, it does not overcome the problem that the search requires a lot of time.

The present invention has been made in view of such a problem, and an object of the present invention is to reduce the time required for searching for a reference clock corresponding to an inserted information recording medium and setting demodulation means. Accordingly, it is an object of the present invention to provide an optical disk reproducing apparatus capable of efficiently recognizing the type of a medium.

[0009]

In order to achieve the above object, an optical disk reproducing apparatus according to the first invention is an optical disk reproducing apparatus capable of reading information from a plurality of types of information recording media, A plurality of reference clock output means corresponding to the type of the information recording medium; a plurality of reproduction signal demodulation means corresponding to the type of the information recording medium; and an operation of the plurality of reference clock output means and the plurality of reproduction signal demodulation means. Setting means for setting priorities based on external setting information.

The optical disk reproducing apparatus according to a second aspect of the present invention is the optical disk reproducing apparatus according to the first aspect, wherein a specific one of the plurality of reference clock output means is selected based on a selection instruction from the setting means. A second selector for selecting a specific one from the plurality of reproduction signal demodulation units based on a selection instruction from the setting unit, and a PLL circuit for synchronizing the reproduction signal with a reference clock. It also has

Further, in the optical disk reproducing apparatus according to a third aspect of the present invention, in the first aspect, the setting means includes a plurality of disk rotation speeds corresponding to the type of the information recording medium, based on externally set information. Set priorities between

Further, the optical disc reproducing apparatus according to a fourth aspect of the present invention, according to the first aspect, further comprises a storage unit for storing external setting information in the apparatus.

[0015] In the optical disk reproducing apparatus according to a fifth aspect of the present invention, in the first aspect, the setting means includes a user interface which allows a user to select one of the priority disks from a plurality of disk types. Have.

[0014] In the optical disc reproducing apparatus according to a sixth aspect of the present invention, in the first aspect, the setting means includes a user interface that allows a user to set a priority order among a plurality of disc types. .

[0015]

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

(First Embodiment) First, a first embodiment of the present invention will be described. FIG. 1 is a diagram showing the configuration of an optical disk reproducing apparatus according to a first embodiment of the present invention. The optical head 2 reproduces information recorded on a disk 1 as an information recording medium, and the optical head 2 comprises: A readout circuit 3 for performing signal processing on the reproduced signal, a spindle motor 4 for rotatingly driving the disk 1, a CPU 5 for performing overall control, and a non-volatile as storage means for storing information set by a user. Memory (for example, EEP
ROM) 6. The present optical disk reproducing apparatus is connected to a host computer 8 via a SCSI interface 7, and can communicate with the host computer 8.

The host computer 8 has a user interface that allows the user to select one priority disk from among a plurality of disk types or to set a priority order among the plurality of disk types. This will be described later.

Various information about a recording medium is recorded on the disk 1 in advance. One of them is medium identification information for identifying the type of medium. This medium identification information is recorded on a control track of the disk 1. The control track also records the number of sectors and the number of bands of the logical track.

The optical head 2 includes a laser light source for outputting a reproduction laser beam, a focus actuator for applying focus servo to the reproduction laser beam from the laser light source, and a reproduction laser beam. A track actuator or the like for applying track servo to light is provided.

FIG. 2 is a diagram showing a configuration of the read circuit 3 shown in FIG. The reference clock output means 35 serves as a plurality of reference read clocks (reference clocks) corresponding to the type of recording medium or the difference in band in the same disk.
Is the part that outputs In this embodiment, 1.3 GB, 640 MB, 540 MB, 230 MB,
Assuming a 128 MB disk, a reference clock suitable for each of these disks is prepared. The 640 MB has 11 types of bands. 1.3 GB has 18 types,
There are 18 bands for 540 MB and 10 bands for 230 MB. The selector 34 switches a plurality of reference clocks based on a selection instruction from the CPU 5.

The above-described reference clock output means 35 and selector 34 can be specifically replaced by a circuit such as a frequency synthesizer.

FIG. 6 is a typical block diagram of a frequency synthesizer. In FIG. 6, the master clock is 1 /
The signal divided by 1 / N in the N divider 50 and a VCO (Voltage Co
The output of the ntrolled oscillator 53 is compared with a signal obtained by dividing the output by a 1 / M divider 54 by a phase comparator 51, and the difference is output as a voltage.

The voltage of this difference is input to the VCO 53 after passing through the charge pump and the filter 52. VC
In O53, the oscillation frequency is changed in accordance with the input voltage.
It operates so that the frequency of the output of No. 3 matches 1 / M.

Therefore, the output clock is represented by the following equation.

Output clock = M / N × master clock For example, when the master clock is 20 MHz, M = 3 and N = 4 to set the output clock to 15 MHz. To set the output clock to 18 MHz, M = 9 and N = 10. The values of M and N are set by the CPU 5. At the same time, the center frequency of the VCO 53 is also set by the CPU 5. In such a circuit,
The M and N values for generating the reference clock of each band of each disk are stored in a memory inside the CPU 5 and set as needed.

The readout circuit 3 further includes a demodulation circuit 31 for PWM recording 1-7 modulation as a reproduction signal demodulation means,
And a demodulation circuit 32 for PPM recording 2-7 modulation. The selector 33 switches between the two types of demodulation circuits 31 and 32 based on a selection instruction from the CPU 5. PLL
The (Phase Locked Loop) circuit 30 is a circuit for synchronizing the reproduction signal from the optical head 2 with the reference clock selected by the selector 34.

In this manner, the identification means including the optical head 2 and the read circuit 3 can read the medium identification information from the control track of the disk 1.

FIG. 3 shows an example of a SCSI driver setting screen on the CRT screen of the host computer 8. The user can use such a setting screen as a user interface for 1.3 GB, 640 MB, 540 M
Among the five types of disks B, 230 MB, and 128 MB, the disk with the highest priority can be set using a mouse or the like. In the figure, 640 MB is selected. If the user wants to update this setting, he can press the update button 80A, and if he wants to cancel the setting, he can press the cancel button 80B.

FIG. 4 is a diagram showing another example of the SCSI driver setting screen displayed on the CRT screen of the host computer 8. In this setting screen, the user inputs a number (1 to 5 in this case) from a keyboard or the like, and
3GB, 640MB, 540MB, 230MB, 128
The priority can be set among the five types of disks of MB.

FIG. 5 is a flowchart for explaining the operation of the first embodiment.

A disc is set in the playback device (step S
1) When this is done, the spindle motor 4 rotates (step S
2) Then, the disk 1 is rotationally driven at a predetermined rotational speed.
Next, the focus servo is applied by the focus actuator and the track servo is applied by the track actuator (step S3). Next, referring to the setting screen of the SCSI driver as shown in FIG. 3 or FIG. 4, the type of the disk to be prioritized is set (step S4). Here, it is assumed that the user has set the priority of the 640 MB disk with reference to the setting screen of FIG. As a result, a command (setting information) indicating that a 640 MB disk has priority is transferred from the host computer 8 to the CPU 5 of the playback device via the SCSI interface 7. CPU 5 as setting means
A selection instruction according to the setting information is sent to the selector 33 of the read circuit 3 to set the disc demodulation method (step S5). Here, since a 640 MB disk is selected, the PWM 1-7 demodulation circuit 31 is set as the corresponding demodulation circuit.

Next, 0 is substituted for a counter variable ZONE for reference clock search (step S6). Next, the CPU 5 sends a selection instruction according to the setting information to the selector 33 to set a reference clock for the ZONE value of the disk (step S7). Here, a reference clock corresponding to a 640 MB disk is set.

Next, reproduction is performed using the set modulation method and reference clock, and it is determined whether the address information has been read without error (step S8).
Here, as described above, in a 640 MB disk, 11
Since there are types of bands and the reference clocks of the respective bands are different, eleven types of reference clocks are sequentially set until the determination in step S8 becomes YES. Therefore, if the determination in step S8 is NO, the process proceeds to step S9 to determine whether or not the ZONE value is the MAX value of the disk for which the ZONE value has been set. If less than the above, the ZONE value is incremented (step S10), and the process returns to the setting of the reference clock for the ZONE value of the set disk. In this way, the above processing is repeated while the reference clock is sequentially incremented until the address information can be read without error.

Here, if the disk inserted in the reproducing apparatus in step S1 is 640 MB, the address information can be accurately recognized because there is a reference clock from which the address information can be read. On the other hand, other disks have different reference clocks, and
Since the MB uses the 2-7 demodulation method of the PPM recording, the address information cannot be accurately recognized. In this case, a similar search is performed using a reference clock and a demodulation circuit corresponding to another disk.

When the address information can be read without error, a seek operation to the control track becomes possible, and the optical head 2 moves to the control track (step S11). The control track stores information on the medium, and reads information on the type of the medium from the medium (step S12) to recognize the medium.

The setting information (640 MB in this embodiment) transferred from the host computer 8 is stored in the non-volatile memory 6, and when the power is turned on next, priority is given to the contents of the non-volatile memory 6. The search time can be reduced by performing the first search operation with the reference clock corresponding to the medium.

As can be seen from the above description, conventionally, the setting of the priority order of the disk is performed from 128 MB → 230 MB →
Although the processing was performed in the order of 540 MB → 640 MB → 1.3 GB, in the present embodiment, since a command from the host computer is received so that 640 MB is prioritized, for example, the setting of the disk type is changed from 640 MB → 128 MB.
→ 230 MB → 540 MB → 1.3 GB in this order, so that the inserted information recording medium (here, 64 MB)
Since the time required for searching for a reference clock corresponding to a 0 MB disc and setting demodulation means can be reduced, the type of medium can be recognized efficiently.

If there is no setting instruction from the user using the setting screen, the priority set by default, for example, 1.3 GB → 640 MB → 540 MB → 2
The search is performed in the order of 30 MB → 128 MB.

(Second Embodiment) Hereinafter, a second embodiment of the present invention will be described. In the second embodiment, when a disk to be prioritized is set using the setting screen as shown in FIG. 3 or 4 as a user interface, the rotation speed of the spindle motor corresponding to this setting information, that is, the rotation of the disk Switch to a number. Therefore the second
In the embodiment, a rotation speed switching circuit is provided which makes high-speed rotation of 128 MB and 230 MB for recording on a recording medium by PPM recording, and low-speed rotation of 540 MB, 640 MB and 1.3 GB for performing PWM recording. Other configurations are exactly the same as in the first embodiment.

In the above configuration, when setting information indicating that a 640 MB disk has priority is sent from the host computer 8, for example, the playback device specifies the specified 640 MB disk.
The spindle motor 4 is rotated at a low speed corresponding to the MB disk, and focus servo and track servo are applied. Next, the reference clock corresponding to 640 MB and P
A search is performed until the address information is read by the WM1-7 demodulation circuit. After the search operation is completed, a seek operation to the control track is performed, and the medium information of the control track is read to recognize the inserted medium.

At this time, if the address information cannot be reproduced without error with the corresponding reference clock,
If the search is performed again with another medium, for example, a reference clock corresponding to 540 MB, and the address information cannot be reproduced without an error even with the reference clock corresponding to 540 MB, the rotation speed of the disk is switched to high-speed rotation. Address information is reproduced by setting the reference clock and demodulation circuit (PPM2-7 modulation) corresponding to 230 MB.

According to the second embodiment, the time required for setting the rotation speed of the spindle motor corresponding to the inserted information recording medium can be shortened, so that the type of the medium can be recognized efficiently. Will be able to

[0043]

According to the present invention, the time required for searching for the reference clock corresponding to the inserted information recording medium and for setting the number of revolutions of the demodulation means and the spindle motor can be shortened. It is possible to provide an optical disk reproducing apparatus capable of efficiently recognizing a disc.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an optical disc reproducing device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a read circuit 3 shown in FIG.

FIG. 3 is a diagram showing S on the CRT screen of the host computer 8;
FIG. 4 is a diagram illustrating an example of a setting screen of a CSI driver.

FIG. 4 is a diagram showing another example of a SCSI driver setting screen displayed on the CRT screen of the host computer 8;

FIG. 5 is a flowchart for explaining the operation of the first embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of a frequency synthesizer as specific means of a reference clock output unit and a selector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Magneto-optical disk, 2 ... Optical head, 3 ... Readout circuit, 4 ... Spindle motor, 5 ... CPU, 6 ... Non-volatile memory, 7 ... SCSI interface, 8 ... Host computer, 30 ... PLL, 31 ... PWM1-7 Demodulation circuit, 32 ... PPM2-7 demodulation circuit, 33 ... selector, 34 ... selector.

Claims (6)

[Claims] 1. An optical disk reproducing apparatus capable of reading information from a plurality of types of information recording media, comprising: a plurality of reference clock output means corresponding to the type of information recording medium; A plurality of reproduction signal demodulation units; and a setting unit for setting the priority order of the operations of the plurality of reference clock output units and the plurality of reproduction signal demodulation units based on setting information from outside. Optical disk playback device. A first selector for selecting a specific one from the plurality of reference clock output units based on a selection instruction from the setting unit; and a plurality of first selectors for selecting a specific one from the plurality of reference clock output units. 2. The optical disc reproducing apparatus according to claim 1, further comprising a second selector for selecting a specific one from the reproduced signal demodulating means, and a PLL circuit for synchronizing the reproduced signal with a reference clock. 3. The apparatus according to claim 1, wherein said setting means sets a priority order among a plurality of disk rotation speeds corresponding to the type of the information recording medium, based on externally set information. Optical disc playback device. 4. The optical disk reproducing apparatus according to claim 1, further comprising a storage unit for storing external setting information in the apparatus. 5. The optical disk reproducing apparatus according to claim 1, wherein said setting means has a user interface that allows a user to select one priority disk from a plurality of disk types. 6. The optical disk reproducing apparatus according to claim 1, wherein said setting means has a user interface that allows a user to set a priority order among a plurality of disk types.