JP3480959B2 - Absolute position detection method and optical disk device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absolute position detecting method for detecting an absolute position on an optical disk and an optical disk device for reproducing a signal using the optical disk.

[0002]

2. Description of the Related Art In recent years, optical discs having a large recording capacity and capable of easily repeating reproduction have been widely used. A so-called CD (Compact Disc) player or the like is commercially available as a device using this optical disc.

FIG. 4 shows the relationship between each area on the optical disk and the absolute time. Audio data such as music is recorded from the inside to the outside of the program area on the optical disc. Further, a lead-in area including the innermost 0 minute 0 second 0 frame is present inside the program area, and a lead-out area is present outside the program area. Recording of the absolute time of the so-called CD format on the optical disc is started from the program area.

In the lead-in area, a TOC (Table of Contents) is recorded in the subcode, that is, a table of contents for audio data recorded in the program area. This TOC is stored in the subcode. Using 72 bits of data in one frame 96 bits of the Q channel,
It is recorded in the format as shown in FIG.

In the TOC, the song number (track number) TNO of the music recorded in the program area, the point PO indicating the details in the song indicated by the song number TNO, and the song indicated by the song number Is the elapsed time of M
IN, second SEC, frame number FR in which audio data of this elapsed time is recorded, minute PMIN and second PSEC indicating absolute time of the position indicated by the point PO, and audio data of this absolute time are recorded. The frame number PFR is recorded in 8 bits.

When performing an operation including a seek operation such as a seek operation for detecting a predetermined position on the optical disk and moving the signal reading means and a seek operation for waiting for the next operation after the seek operation, the TOC The amount of movement by the seek operation is determined by obtaining the current absolute position and the absolute position of the desired seek destination from the absolute time of.

[0007]

By the way, the above TOC
Absolute position cannot be detected because no absolute time is recorded for the lead-in area itself. Therefore, a seek operation or an operation including a seek operation cannot be performed in the lead-in area in the same manner as in the program area.

In view of the above situation, it is an object of the present invention to provide an absolute position detecting method and an optical disk device capable of detecting the absolute position in the lead-in area.

[0009]

In the absolute position detecting method according to the present invention, a step of jumping the signal reading means from a predetermined position in a program area on an optical disk to a lead-in area by a predetermined amount at a predetermined timing. And a step of reading the relative time of the final position of the lead-in area by continuously reading the relative time from the current position in the lead-in area of the signal reading means jump-moved by the certain amount. , A step of determining whether or not the current position of the signal reading means is within the lead-in area during a seek operation, and the current position of the signal reading means is within the lead-in area based on the determination. If it is determined, the relative time is read out, and based on the read relative time, the current absolute position is calculated from the relative time of the final position. By providing the step of detecting, to solve the problems described above.

Further, the optical disk device according to the present invention is an optical disk device for reproducing a signal by using an optical disk, and is provided with a control section for controlling a seek operation on the optical disk. Means for jumping the signal reading means from a predetermined position in the program area on the optical disc to the lead-in area by a fixed amount, and the lead-in area of the signal reading means jumped by the fixed amount. Means for reading the relative time of the final position of the lead-in area by continuously reading the relative time from the current position within
Means for determining whether or not the current position of the signal reading means is within the lead-in area during seek operation;
If it is determined by the determination that the current position of the signal reading means is within the lead-in area, the relative time is read and the current absolute time is obtained from the relative time of the final position based on the read relative time. And a means for detecting a position.

Here, at least a program area, which is an area for recording audio data and the like, and a lead-in area, which serves as a guide portion to the program area, are provided on the optical disc. In the table, for example, table of contents information of the program area and the like are recorded.

Further, jumping means that the signal reading means including an optical system including a reproducing head jumps inward or outward over a plurality of tracks from the current position on the optical disk.

[0013]

In the present invention, the absolute position in the lead-in area on the optical disk can be detected, and the seek operation and the operation including the seek operation can be performed in the entire area on the optical disk.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram of an optical disk device according to the present invention. When the optical disc is loaded into the optical disc device and the operation is started, the information of the TOC is read. Next, in order to obtain the relative time in the lead-in area and the difference between this relative time and the absolute time in the program area, the signal reading means is controlled by the signal reading position control unit 2 to make the inside of the program area. After jumping to a predetermined position, a certain amount of jumping is further moved into the lead-in area.
The signal reading means continuously reads the information of the TOC from the jump-moved position in the lead-in area via the signal reading section 18 and the sub-code reading section 19, and the relative time of the final position of the lead-in area. To detect. Further, the difference between the relative time of the final position of the lead-in area and the absolute time of the program area is calculated.

Thereafter, when a seek operation or an operation command including a seek operation is input by a key operation or the like, the microcomputer 1 detects whether or not the current position of the signal reading means is within the lead-in area. . If the current position of the signal reading means is within the lead-in area, the current absolute position on the optical disc can be detected by the relative time of the final position of the lead-in area. Perform a seek operation.

First, in order to read the TOC information at the start of operation of the optical disk device, the optical system, which is a signal reading means, is jump-moved in the radial direction of the disk to the position of 0 minutes 2 seconds 0 frame in the program area. Further, the signal reading means is moved inward from the position, that is, jumping for 100 tracks to the lead-in area six times. At this time, the jump movement amount in the disc radial direction is about 1 mm, and the width of the lead-in area in the disc radial direction is about 2 mm. Therefore, the jumping movement causes the signal reading means to be located at a substantially middle position of the lead-in area. Will move. The TOC information is read from this position.

Next, in order to read the relative time information of the TOC, the optical system, which is the signal reading means, is again jump-moved to a predetermined position in the program area, for example, a position where the relative time is indicated by 0 minutes 2 seconds 0 frame. Let

When a jump movement position signal is supplied from the microcomputer 1 to the signal reading position control unit 2, a tracking signal is supplied from the signal reading position control unit 2 to the drive circuit 15 and the drive circuit 22. Is supplied with a slide control signal.

The drive circuit 15 controls the tracking actuator 17 based on the tracking signal to move the signal reading means on the optical disk 8. Here, the output from the position sensor 20 indicating the position of the objective lens 6 is sent to the drive circuit 22 via the phase compensation circuit 21, and the drive circuit 22 sleds so that the objective lens 6 does not move greatly and shifts. Control the feed 23. As a result, the signal reading means is accurately jumped to the predetermined position.

Further, the signal reading means is jump-moved from the predetermined position by a fixed amount to the lead-in area in the disk radial direction. Also at this time, the same movement as the jump movement as described above is performed, for example, the above-mentioned fixed amount is 5
Assuming 0 tracks, 5 jumps for 10 tracks
The signal reading means is moved by repeating the above steps.

After the signal reading means is moved by a certain amount, the light emitted by the laser diode 3 is converted into a parallel light beam by the collimation lens 4, and the beam splitter 5 and the objective of a so-called biaxial device for tracking are used. It is irradiated onto the optical disk 8 through the lens 6. The emitted light is reflected by the optical disc 8,
After being separated by the beam splitter 5 via the objective lens 6, it passes through a multi-lens 7 including a cylindrical lens, a condenser lens and the like, and is condensed and detected on a split photodetector 9.

The detected output is converted into a voltage by the head amplifier 10 and output to the matrix amplifier 11. The matrix amplifier 11 performs addition and subtraction of the outputs to obtain a focus error signal, a tracking error signal,
An RF signal, which is an output signal from the head, is generated and output.

The focus error signal is output to the drive circuit 14 via the phase compensation circuit 12. With this output, the drive circuit 14 controls the movement of the focus actuator 16 so as to keep the distance between the optical disk 8 and the objective lens 6 constant. Further, the tracking error signal is output to the drive circuit 15 via the phase compensation circuit 13. With this output, the drive circuit 15 accurately controls the tracking on the optical disk 8.

The RF signal is sent to the signal reading section 18, demodulated, and sent to the subcode reading section 19.
The sub-code reading unit 19 reads out relative time information, which is the elapsed time of the piece of music in the TOC.

The above-described operation is continuously performed from the position jumped by a fixed amount in the lead-in area to the final position of the lead-in area, which is the outermost circumference of the lead-in area. As a result, the relative time at the final position of the lead-in area can be read. Also, by adding one frame to the detected relative time of the final position, the deviation between the relative time of the final position and the absolute time of the program area is obtained. As a result,
When the signal reading means is in the lead-in area, the absolute position on the optical disc can be obtained by subtracting the deviation from the relative time of the current position. Further, the absolute position detection as described above may be performed at the time of the first seek operation after the optical disk is mounted in the optical disk apparatus or the operation including the seek operation, and the subsequent seek operation and the operation including the seek operation. Sometimes, the absolute position value obtained first may be used.

FIG. 2 is a flow chart for detecting the absolute position of the final position of the lead-in area described above. In step S1, the optical disc is mounted in the optical disc device, and in step S2, TOC information in the lead-in area on the optical disc is read. Next, step S3
Then, the signal reading means is jump-moved to the 0 minute 2 second 0 frame which is a predetermined position in the program area on the optical disk. Further, in step S4, the signal reading means is jump-moved in the direction of the lead-in area by a predetermined amount.

In step S5, the relative time in the TOC is continuously read from the position in the lead-in area where the signal reading means is jump-moved, and in step S5.
At 6, the relative time of the final position in the lead-in area is read. Using the relative time of the final position, step S7
Then, the deviation from the absolute time of the program area is obtained.

Thereafter, when a seek operation or an operation command including a seek operation is input by a key operation or the like, it is determined whether the current position of the signal reading means in the microcomputer 1 is within the lead-in area. To detect. If the current position of the signal reading means is within the lead-in area, the difference between the relative time of the current position and the absolute time of the program area is subtracted from the relative time of the current position to obtain the signal. The absolute time of the current position of the reading means on the optical disk 8 is calculated. This absolute time is the optical disk 8
It is the absolute position above, and the desired amount of movement during seek operation can be obtained based on this absolute time and the absolute time within the TOC of the position at the seek destination, and as described above using this amount of movement. The signal reading means is moved to and the seek operation is performed.

Also, if the current position of the signal reading means is within the program area, the absolute time of the Q channel in the subcode at the current position and the absolute time of the Q channel in the subcode at the seek destination position. The seek operation may be performed by obtaining the movement amount based on

FIG. 3 shows a procedure at the time of a seek operation by the optical disk device which realizes the above-mentioned absolute position detecting method.
In step S11, it is detected whether or not the current position of the signal reading means is in the lead-in area on the optical disc. If the signal reading means is in the lead-in area, the process proceeds to step S12, By using the absolute position detection method to obtain the relative time of the final position of the lead-in area and the absolute time of the program area, by subtracting the deviation from the relative time of the current position of the signal reading means, The absolute position of the signal reading means on the optical disk is obtained.

If the current position of the signal reading means is not within the lead-in area, the process proceeds to step S13 to read the absolute time indicated by the Q channel in the subcode of the current position. The absolute position of the signal reading means on the optical disk can be obtained.

In step S14, the amount of movement to the seek destination is obtained using the current absolute position of the signal reading means obtained by the above method, and in step S15 the signal reading means is jumped.

The above embodiment is an example of the present invention.
It goes without saying that various other configurations can be adopted without departing from the scope of the present invention.

[0035]

As is apparent from the above description, in the absolute position detecting method according to the present invention, the signal reading means is moved from the predetermined position in the program area on the optical disk to a predetermined amount in the lead-in area at a predetermined timing. The relative time of the final position of the lead-in area can be obtained by continuously reading the relative time from the current position in the lead-in area of the signal reading means that is jump-moved by a minute and jumped by a fixed amount. It is possible to detect the absolute position in the lead-in area by reading the relative time during the read and seek operations and detecting the current absolute position from the relative time of the final position based on the read relative time. it can. Further, the optical disk device according to the present invention is
By including the control unit that realizes the absolute position detection method, it is possible to perform a seek operation and an operation including a seek operation in the entire area on the optical disc by using the absolute position on the optical disc. It is also possible to perform an operation that could not be performed in the past, such as a pause operation on the 0 minute 0 second 0 frame.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an optical disk device according to the present invention.

FIG. 2 is a flowchart showing steps of an absolute position detecting method according to the present invention.

FIG. 3 is a flowchart showing a seek operation procedure by the optical disc device according to the present invention.

FIG. 4 is a diagram showing a relationship between each area on a conventional optical disc and absolute time.

FIG. 5 is a diagram showing a format of a TOC in a lead-in area on the optical disc according to the present invention.

[Explanation of symbols]

1 ... Microcomputer 2 ・ ・ ・ ・ ・ ・ ・ Signal reading position controller 3 ... Laser diode 8: Optical disc 10: Head amplifier 11: Matrix amplifier 12, 13, 21 ... Phase compensation circuit 14, 15, 22, ... Drive circuit 18: Signal reading section 19 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Subcode reading unit

Claims (2)

(57) [Claims] 1. A step of jump-moving a signal reading means from a predetermined position in a program area on an optical disc to a lead-in area by a predetermined amount at a predetermined timing, and the signal reading jumped by the predetermined amount. Reading the relative time of the final position of the lead-in area by continuously reading the relative time from the current position of the means in the lead-in area, and the current position of the signal reading means during the seek operation. If it is determined that the current position of the signal reading means is within the lead-in area, the relative time is read out and read out. Absolute position based on the relative time of the final position from the relative time of the final position. Detection method. 2. An optical disk device for reproducing a signal by using an optical disk, comprising a control section for controlling a seek operation on the optical disk, and the control section has a signal reading means at a predetermined timing. Relative time from the current position in the lead-in area of the signal reading means jumped by a fixed amount from a predetermined position in the upper program area to the lead-in area Means for reading the relative time of the final position of the lead-in area by continuously reading and the means for determining whether or not the current position of the signal reading means is in the lead-in area during seek operation. If it is determined by the above determination that the current position of the signal reading means is within the lead-in area, the relative position Reading between based on the read relative time the optical disk apparatus characterized by comprising a means for detecting a current absolute position than the relative time of the final position.