JPH10228713A - Bca data reading method for optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately move a pickup to a BCA reading position and to eliminate the necessity of a special BCA reading means by moving the pickup to the BCA data reading position after temporarily moving it to a disk reference position. SOLUTION: A disk reference position is set to be the starting position of content information, a system controller is used to irradiate a disk with a laser light and, by detecting the fluctuation of high frequency signal obtained by detecting a reflection light from the disk, BCA data is read. In this case, for detecting the fluctuation of an RF signal in BCA in time, a disk rotating speed is switched to a speed lower than a prescribed standard speed. But the low speed range of the disk rotating speed is limited to one where focusing is not shifted. After the completion of BCA data reading, the rotating speed is returned to the standard speed before returning to the original position.

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 capable of reproducing an information recording medium, and more particularly to the reproduction of an optical disk on which content management information is recorded in a format different from the content information recorded on the optical disk. Related to the device.

[0002]

2. Description of the Related Art BCA not provided in conventional optical disks
The optical disc device needs to read the content management information from the (Burst Cutting Area) and transfer the written management information to the host computer.

[0003] The method of using the management information transferred to the host computer is left to the discretion of the content information creator of the optical disc. One example is the serial number of the optical disc on which the management information is written. When installing the content information, its serial number is also installed at the same time, and when the same serial number collides on the network, one of the content information is regarded as illegally copied and used to interrupt the subsequent operation .

[0004] BCA data is written later on an already completed optical disk, that is, the BCA write area is created in a write-once state, and the BCA write area is irradiated with a strong laser to skip the reflection surface. To form a burst part,
Data is formed according to the interval between the burst portions.

FIG. 1 shows a recording format of BCA on an optical disk. By detecting the interval between radially formed burst portions in BCA 101, management information recorded in BCA can be obtained.

FIG. 2 is a cross-sectional view of a portion 102 of FIG. 1 where there is no burst portion in the BCA, and there is no missing reflective surface.

FIG. 3 is a cross-sectional view of the portion 102 in FIG.
There is a missing reflective surface as indicated by the burst portion.

FIG. 4 is a cross-sectional view of the optical disk in the track direction at a position where the content information is recorded. Here, there is no lack of the reflection surface.

FIG. 5 is a cross-sectional view in the track direction of the optical disk at a position where the BCA exists, and there is a missing reflective surface in the burst portion.

As described above, as can be seen from FIGS. 1, 2, 3, 4, and 5, in the conventional method of reading out content information based on a change in the amount of reflected light on an optical disc, the BCA content management information cannot be read out. Obviously you can't.

[0011]

An object of the present invention is that, since content management information is recorded in a format different from that of content information, a means different from the content information reading means is required to read the content management information. An object of the present invention is to solve the problem that the price of the apparatus becomes high.

[0012]

In order to achieve the above object, the present invention provides a process for switching the rotation speed of a disk to a low speed so that the processing can be performed at a speed of a microcontroller for controlling the system of the optical disk device.
Processing to suppress fluctuations in the rotational speed of the disc, and RF
By providing a means for detecting the burst portion from the signal, the BCA data can be read without increasing the price of the apparatus, and the pickup can be moved to the BCA data reading position by preparing the movement to the reference position of the disk. Can be performed with high accuracy.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to one embodiment shown in the drawings.

FIG. 6 shows the flow of the simplest processing by the system controller in the BCA data reading method of the optical disk device according to the present embodiment.

In FIG. 1, an optical disk is inserted into an optical disk device at 601, discrimination processing of the optical disk is performed at 602, focus is set at 603, and 604 is set.
Reads out the ID information recorded on the optical disc,
At 605, the TOC information recorded on the optical disc is read, and at 606, the pickup is temporarily moved to the start position of the content information as the reference position of the optical disc, and then, at 607, the pickup is moved further inward than the start position of the content information. By moving the pickup to the BCA position located on the circumferential side, it becomes possible to move the pickup to the BCA position with higher precision than when moving directly to the BCA position without moving to the start position of the content information. Next, after moving the pickup to the BCA data reading position, the disk rotation speed is switched to low speed at 608. This is because if the disk rotation speed is switched to low speed and the pickup is moved to the BCA data reading position, In the state where the rotation speed is switched to a low speed, the burst portion of the BCA becomes longer in time, and when trying to move to the BCA position in this state, there is no track in the burst portion. Since the possibility of occurrence becomes very large, the risk of misreading the number of tracks can be avoided by the sequence in this embodiment. Next, the BCA data is read in 609 and the read data is stored in the optical disk device, the rotation speed of the disk is switched to the standard speed in 610 in the reverse order, and then the data is read in 611. By returning the pickup to the original position, the risk of misreading the number of tracks in a track jump can be avoided. Next, the apparatus is shifted to the pause state of 612, and the
BC that is read and stored in advance when A data request is received
The A data is transferred to the host computer at 613.

FIG. 7 is a diagram for explaining the detection of a burst portion in the BCA data reading method of the optical disk device according to the present embodiment.

In FIG. 1, the laser is the BC of the optical disk.
R output by return light when irradiating part A
The bottom level of the burst portion included in the F signal is V0, and the bottom level of the portion excluding the burst portion is V0.
If it is set to 1, V0 is almost the same level as when laser return light is not obtained, but V1 is not always at a constant level due to factors such as the reflectivity of the disk and the output of the laser. In order to detect the burst portion without increasing the price of the device, the RF signal can be taken into an A / D converter built in the system controller, and the burst portion can be detected from the level fluctuation. Assuming that a threshold for detecting a part is Vth, the following relationship is obtained.

V0 <Vth <V1 Here, in this embodiment, it is possible to detect the burst portion by sequentially monitoring the level of the RF signal with Vth = (V0 + V1) / 2, so that the burst interval can be detected. Can be easily done.

FIG. 8 shows a method of controlling the disk rotation speed in reading BCA data.

In FIG. 1, the time width of the burst portion of the RF signal when reading the BCA data of the optical disk is t1, and the burst portion detection processing cycle determined by the conversion time of the A / D converter built in the system controller is t0. In this case, ensuring the relationship of t1> t0 is the minimum condition for detecting the burst portion and reading out the BCA data.
That is, according to the standard, the disk rotation speed is equal to the standard speed (24
Hz), t1 = 3.0 ± 1.5 μs, so B
The disk rotation speed condition required for reading CA data is 2
Since it is less than 4 × (3.0−1.5) / t0, the conversion time of the A / D converter built in the system controller of the present embodiment is 8.4 μs, and the A / D conversion activation set time is 2 .
Since the period is 6 μs, the burst part detection processing cycle t0 is set to 8.8.
4 + 2.6 = 11.0 μs, the disk rotation speed condition required for reading BCA data is 24 × (3.0
−1.5) /11.0=3.27 Hz, but it is 2 Hz in view of the margin.

FIG. 9 shows the configuration of the head portion of the BCA, and FIG. 10 shows the RF signal waveform at that time in two stages.

In FIG. 10, assuming that the minimum value of the burst interval in the BCA is T, the BCA has T, 2T, and 3T burst intervals as a 4T synchronization signal and an information signal, and the preamble portion has a burst interval. Are present at 2T intervals. In this embodiment, the burst interval 2T in the preamble portion is fetched 32 times, and the total is shown in Table 1.
The burst interval classification threshold value shown in the burst interval classification table of 1.
5T, 2.5T, and 3.5T are obtained, and each time the burst interval of the BCA section is measured, the measurement result is compared with Table 1 each time to obtain T, 2T, 3T, and 4T.
And can be read as data of the BCA section. Here, when the burst interval 2T of the preamble portion is captured 32 times, the rotation control of the disk is in a free state, but the time required at this time is less than 10 ms and can be regarded as constant.

[0023]

[Table 1]

FIG. 11 shows a disk rotation control method during BCA data reading.

In the figure, a burst interval 4T of a synchronization signal existing everywhere in the BCA is measured, and a kick for accelerating the rotation of the disk motor or acceleration / deceleration of the rotation according to a disk motor control table of Table 2 prepared in advance is used. It is possible to minimize the change in the disk rotation speed by repeating the free operation or the brake for reducing the rotation until the burst interval 4T of the next synchronization signal is detected until the reading of the BCA data is completed. Thus, the BCA data can be read without correcting the burst interval classification threshold value obtained in FIG.

[0026]

[Table 2]

[0027]

As described above, according to the present invention, it is possible to accurately move the pickup to the BCA reading position where the content management information is recorded, and it is necessary to provide a special means for reading the BCA data. Therefore, an increase in the price of the apparatus can be suppressed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a recording form of BCA on an optical disc according to the present invention.

FIG. 2 is a diagram showing a cross section of the optical disc according to the present invention when there is no BCA burst portion.

FIG. 3 is a diagram showing a cross section of the optical disc when there is a BCA burst portion in the optical disc according to the present invention.

FIG. 4 is a diagram showing a cross section in a track direction of the optical disc at a position where content information is recorded on the optical disc according to the present invention.

FIG. 5 is a diagram showing a cross section in the track direction of the optical disc at a BCA position on the optical disc according to the present invention.

FIG. 6 shows an optical disk drive B according to an embodiment of the present invention.
FIG. 9 is a diagram showing a flow of processing by a system controller relating to a CA data reading method.

FIG. 7 illustrates an optical disk drive according to one embodiment of the present invention.
FIG. 7 is a diagram for describing detection of a burst portion related to a CA data reading method.

FIG. 8 illustrates an optical disk drive according to one embodiment of the present invention.
FIG. 4 is a diagram showing a disk rotation speed control method in BCA data reading related to the CA data reading method.

FIG. 9 is a diagram showing a configuration of a head portion of a BCA on an optical disc according to an embodiment of the present invention.

FIG. 10 is a diagram showing an RF signal waveform at the head of BCA on the optical disc according to one embodiment of the present invention.

FIG. 11 is a diagram showing a disk rotation control method during reading BCA data from the optical disk according to one embodiment of the present invention.

[Explanation of symbols]

101 BCA, 102 cross-sectional position, 301 burst part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuhiko Ono 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref.

Claims (16)

[Claims] 1. Burst Cutting Area
(Hereinafter abbreviated to BCA) a method of reading a BCA data of an optical disk device, wherein when moving a pickup to a data reading position, the pickup is first moved to a reference position of the disk and then to a BCA data reading position. . 2. The BCA of the optical disk device according to claim 1.
In the data reading method, the reference position of the disk is a start position of the content information, and the BCA data reading method of the optical disk device is characterized in that: 3. An optical disk device provided with a means for reading BCA data, wherein a high-frequency signal (hereinafter referred to as an RF signal and an RF signal) obtained by irradiating a disk with laser light and detecting reflected light from the disk using a system controller. Characterized in that the BCA data is read out by detecting the fluctuation of the BCA.
Data reading method. 4. The BCA of an optical disk device according to claim 3,
In the data reading method, an optical disc is characterized in that the BCA data reading process is performed with the disc rotation speed switched to a speed lower than a prescribed standard speed so that the detection process of the fluctuation of the RF signal in the BCA can be sufficiently performed. A method of reading BCA data of the device. 5. The BCA of the optical disk device according to claim 4.
A BCA data reading method for an optical disk device, wherein a low-speed range of a disk rotation speed is limited to a range in which focus is not deviated. 6. The BCA of an optical disk device according to claim 5,
In the data reading method, a BCA data reading method for an optical disc device, wherein a threshold for replacing bit data based on a burst interval is obtained from a burst cycle of a preamble portion of the BCA. 7. The BCA of an optical disk device according to claim 6,
In the data reading method, when the output time of the BCA synchronization signal becomes longer than a preset time during the reading of the BCA data, a kick of the disk motor is performed, and the BCA data reading of the optical disk apparatus is performed. Method. 8. The BCA of an optical disk device according to claim 7,
In the data reading method, the kick time of the disk motor is set to be the time until the next synchronization signal is output. 9. The BCA of an optical disk device according to claim 7,
In the data reading method, the kick time of the disk motor is set to a fixed time shorter than the time until the next synchronization signal is output.
A data reading method. 10. The BC of the optical disk device according to claim 6.
In the A data reading method, when the output time of the BCA synchronization signal becomes shorter than a preset time during the reading of the BCA data, the disc motor is braked.
Data reading method. 11. The optical disk drive according to claim 10, wherein
A method of reading BCA data of an optical disk device, wherein the CA data reading method is such that a brake time of a disk motor is set until a next synchronization signal is output. 12. The optical disk drive according to claim 10, wherein:
A method for reading BCA data of an optical disk device, wherein the CA data reading method is characterized in that the brake time of the disk motor is a fixed time shorter than the time until the next synchronization signal is output. 13. The method for reading BCA data of an optical disk device according to claim 1, wherein the operation of reading the BCA data is performed in an initial process performed when a disk is inserted. BCA data reading method. 14. The optical disk drive according to claim 13, wherein
In the CA data reading method, when a BCA data request is received from a host computer, the BCA data read and stored in advance by an initial process is transferred to the host computer, and the BCA data reading method for an optical disk device is provided. 15. The BC of the optical disk device according to claim 4.
In the A data reading method, the timing of switching the disk rotation speed to a low speed is after moving the pickup to a BCA data reading position. 16. The BC of the optical disk device according to claim 4.
In the A data reading method, after the BCA data is read while the disk rotation speed is switched to a low speed, the timing at which the disk rotation speed is returned to the original standard speed is set before the pickup is moved to the original position outside the BCA area. A BCA data reading method for an optical disk device, characterized by comprising: