JPH07320388A - Optical disk device - Google Patents

Abstract

PURPOSE:To prevent unprepared readout from a written disk which is limited in number of reading-out times by discriminating written disks from unwritten disks. CONSTITUTION:An ATIP detecting device 4 detects absolute time information of a wobbling loop which is formed in advance on the recording surface of a writing type optical disk. A focus servo circuit 5 supplies a control signal for focus servo to the actuator 7 of an optical head device 3 based on a focus error signal fetched from the optical head device 3 and a tracking servo circuit 6 supplies a control signal for tracking servo to the actuator 7 based on a tracking error signal fetched from the optical head device 3. A control section 8 controls each servo circuit 5 and 6 by fetching detected absolute time information. An FFM demodulator 9 performs an EFM code demodulating process on reproduced signals fetched from the optical head disk 3 in accordance with a standard for compact disk.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk device, and more particularly, to discriminate between a writing groove disk and a disk which is not so that a writing groove disk having a limited number of read times is not read carelessly. Optical disk device.

[0002]

2. Description of the Related Art A conventional optical disk device (for example, CD-
In the ROM drive), after inserting the disc, the pause operation is performed in the standby state for the operation from the outside. As a publicly known document describing a conventional writable optical disc,
For example, there is JP-A-3-194778. According to this publication, the absolute time information is read from a writable disc-shaped recording medium in which a wobbling group having absolute time information is formed, and the continuity of the sequentially read absolute time information is detected. The tracking state is determined, and detrack detection is performed to detect when tracking is off. That is,
When the stop key is operated, the first music piece on the disc is searched for a pause state, and thereafter, if no operation command is given within a certain time, the laser light source of the pickup is turned off.

[0003]

The number of times of reading the written optical disc written in the information writable optical disc is guaranteed up to 1 million times in the Orange Book part II. Further reading may not be possible. In a conventional optical disk device (for example, a CD-ROM drive), after recognizing the disk after inserting the disk, it stands by in a pause state until the next operation command comes. In the discs specified by the Red Book and Yellow Book, there are about 10 sectors on the inner circumference, and if you make one pause to make one track return, 7.5 tracks per second.
Rotate. To read the same place 1 million times, 133
This can be achieved by leaving the disc in for 333 seconds ≈ 37 hours. This time is a time that can be achieved relatively quickly when the same disk is used many times, and in the case of a written disk, it may be impossible to read. "Red Book" and "Yellow Book"
Is a standardized CD system standard proposed by Philips of the Netherlands and is now a worldwide standard. Also, "Orange Book" is a similar CD-WO
It is the standard of the system.

The present invention has been made in view of such a situation, and discriminates between a written disk and a disk which has not been written, thereby dividing the subsequent operation to obtain a written disk with a limited number of read times. It is an object of the present invention to provide an optical disk device that prevents careless reading.

[0005]

In order to achieve the above object, the present invention provides (1) detection means for detecting absolute time information in a disc and presence or absence of absolute time information detected by the detection means. And a control means for making a judgment so that the CD that has been written does not perform the pause operation or the track is followed, and (2) the absolute time information is not present in the C.
If D is confirmed, perform a pause operation, and
(3) The feature is that the operation is stopped if the next operation is not performed for a certain period of time after the track is followed and the pause operation is performed.

[0006]

The optical disk device of the present invention having the above structure is
If the absolute time information signal is detected from the disc, and if it can be detected, it is judged as a written disc. In that case, after recognition after the disc is inserted, the track is made to follow that way and the number of times of reading the same sector is reduced. is there. Also,
If the absolute time information signal cannot be detected, it is determined that the disc has only the EFM (Eight to Fourteen Modulation) signal, not the written disc, and the disc is put in the pause state and maintained until the next operation command arrives. Further, even when the written disc is made to follow the track as it is, if the next operation command does not arrive for a certain period of time, the operation is stopped.

[0007]

Embodiments will be described below with reference to the drawings. FIG. 1 is a block diagram for explaining an embodiment of an optical disk device according to the present invention. In the figure, 1 is a disk, 2 is a spindle motor, 3 is an optical head device, 4 is absolute time information ATIP (Absolute Time in). Pregroove) detection device, 5 is a focus servo circuit, 6 is a tracking servo circuit, 7 is an actuator, 8 is a control unit, and 9 is an EF.
M (Eight to fourteen Modulation) demodulator, 10 is a decoder.

The disk 1 is rotated by a spindle motor 2 under CLV (Constant Linear Velocity) control. The ATIP detection device 4 detects absolute time information (ATIP information) from a wobbling probe previously formed on the recording surface of the write-type optical disc. The focus servo circuit 5 supplies a focus error signal extracted from the optical head device to a control signal for focus servo by the actuator of the optical head device 3. The tracking servo circuit 6 supplies the tracking error signal extracted from the optical head device 3 to the actuator 7 as a control signal for tracking servo. The control unit 8 takes in the detected absolute time information and controls each servo circuit.

The EFM demodulator 9 demodulates the reproduced signal taken out from the optical head device 3 into an EFM (Eight to Fourteen Modulation) code in accordance with the compact disc standard. The decoder 10 decodes the output of the demodulator. The decoder 10 reproduces the control data recorded on the information track of the disc 1 in 1-frame units by performing decoding processing such as descramble and error correction on the demodulated output. This data is given to the control unit 8.

FIG. 2 is a flow chart for explaining the operation of the optical disk device according to the present invention. Hereinafter, each step will be described in order. As preparation for playback, rotate the spindle 2 to rotate the disc (step 1),
The focus servo circuit 5 is started and a control signal is sent to the actuator 7 of the optical head to focus (st
ep2), the tracking servo circuit 6 is started, a control signal is sent to the actuator 7 of the optical head to perform tracking (step 3), and EFM servo which is rotation control capable of accurately demodulating the EFM is applied (step 4).

The EFM demodulated signal is passed through the decoder 10 to recognize the disc based on the control data reproduced in units of one frame (step 5). If the disc is a writable optical disc, there should be pre-formed ATIP information on the disc.
Perform the operation to follow the track as it is (step 6,
7). Wait until the next command arrives with the track following (step 8). If the disc is not a writable disc such as a compact disc, there is no ATIP information previously formed on the disc, and the pause operation starts (steps 6 and 9). Wait in the pause state until the next command comes (step 8).

FIG. 3 is a flow chart for explaining another operation of the optical disk device according to the present invention. Less than,
Each step will be described in order. In addition, step11-st
Since steps up to ep15 are the same as steps 1 to 5 in FIG. 2, step 16 and subsequent steps will be described. After checking the disk (step 15), start the timer (step 1)
6). This time can be set arbitrarily. If the disc is a writable disc, AT
Since there should be IP information, follow the track as it is (steps 17 and 18).
Perform a pause action (steps 17 and 21). When the timer set in step 16 times out, the focus and tracking servo circuits are stopped (step 19,
22). While checking the timeout, the next instruction is waited (steps 19 and 20).

[0013]

As is apparent from the above description, the present invention has the following effects. (1) Effect corresponding to claim 1: Whether or not a write-once disc has been written is determined by the presence / absence of ATIP information, and in the case of a written disc, the pause operation is not performed and the track is followed as it is. By doing so, it is possible to prevent the same portion from being read many times, and it is possible to extend the read life of the written disk in actual use. (2) Effect corresponding to claim 2: When the disc is judged to be a normal compact disc (not a written disc) by the presence or absence of ATIP information, the next command is waited in the pause state as in the conventional case. It is possible to make the access of the user faster. (3) Effect corresponding to claim 3: The disk is judged to be a written disk depending on the presence or absence of ATIP information, and the waiting of the next command is stopped at a certain time by keeping the track following the command for a certain time. If you do not operate for more than the period of time, you can stop the unnecessary read operation and extend the read life of the written disk further in actual use, and stop the pause operation on a disk that is not a written disk for a certain period of time. It is possible to extend the life of the optical head device.

[Brief description of drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of an optical disc device according to the present invention.

FIG. 2 is a flow chart for explaining the operation of the optical disc device according to the present invention.

FIG. 3 is a flowchart for explaining another operation of the optical disc device according to the present invention.

[Explanation of symbols]

1 ... Disk, 2 ... Spindle motor, 3 ... Optical head device, 4 ... Absolute time information ATIP (Absolute Time in P)
regroove) detection device, 5 ... focus servo circuit, 6 ...
Track King Servo Circuit, 7 ... Actuator, 8 ...
Controller, 9 ... EFM (Eight to fourteen Modelation)
Demodulator, 10 ... Decoder.

Claims (3)

[Claims] 1. A detection means for detecting absolute time information in a disc, and a control means for judging presence / absence of absolute time information detected by the detection means, wherein a pause operation is not performed on a written CD. The optical disk device is characterized by following the track. 2. The optical disk device according to claim 1, wherein a pause operation is performed when it is confirmed that the CD has no absolute time information. 3. The optical disk device according to claim 1, wherein the operation is stopped after the track is followed and after the pause operation is performed, unless the next operation is performed for a certain period of time.