JPH10162377A - Device for reproducing disk and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To access a position of minimizing a track deviation due to eccentricity between two layered recording surfaces of a disk by calculating a pickup moving amt. with detection of a sector address and an access instruction and deciding a moving direction in terms of an actual moving amt. of a pickup from a calculated result. SOLUTION: After reproducing the disk, a sector address n' is detected and decided by a sector address detecting circuit 12, and by the sector address n' detected after issuing a focus changeover instruction and a reproducing starting sector address (m) comprised in the access instruction, k'=m-n is calculated by a pickup moving amt. calculating means 18. An absolute value of k' is converted into a moving amt. of the pickup 2, and also the moving direction is decided from the sign of + or - of k' by a moving amt. converting/direction deciding means 21, and the pickup 2 is moved to access a position of the sector address (m) by a pickup moving control circuit 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc reproducing apparatus and a disc reproducing method, and more particularly, to controlling the focus of a pickup on an optical disc having two or more recording surfaces in one disc. The present invention relates to a disk reproducing apparatus and a disk reproducing method for accessing a specific recording surface among two or more recording surfaces and starting reproduction from a sector requested by an access command.

[0002]

2. Description of the Related Art A conventional optical disk on which a digital signal in sector units is recorded is, for example, a CD-ROM.
(CD-Read Only Memory). This CD-R
OM is “Nikkei Byte” (Nikkei BP); September 1994
As in the technique described on page 146 of the month, a sector consisting of valid data, a sector address, and a synchronization signal is stored in a sector.
A plurality of pieces are arranged in the recording order, and are spirally recorded on the recording surface on the disk from the innermost circumference to the outer circumference.

[0003]

In recent years, in addition to the above-mentioned CD-ROM, a two-layered upper and lower recording surface formed by laminating disks has been recently developed. Discs having a four-layered disc that can be read from one side with the recording surface formed as described above have been developed and are beginning to be put to practical use. Access to a specific recording surface in these discs is performed by switching the focus of the pickup. For this type of disc (DVD), if necessary, for example,
"Nikkei Byte" (Nikkei BP); October 1993, pp. 129-130, "DVD standardization";"ElectronicMaterials" (Industry Research Council); June, 1996, p. Special features DVD and its elemental technology, double-sided tape used for bonding DVDs, etc. "

As described above, when a single disk has multiple recording surfaces readable from one surface over multiple layers, a spirally recorded track (a series of irregularities on which information is recorded) is recorded on each recording surface. It is difficult to make the positions of the (rows) coincide with each other in the upper and lower directions as the recording density of the disk becomes higher and the track pitch becomes narrower. In particular, in the case where one disk is formed by bonding disks together, it is easy for the disks to be misaligned on the bonding surface, and it is difficult to match the upper and lower tracks after bonding.

In the reproduction of such a disk, when a recording surface currently being reproduced is accessed by switching the focus of a pickup to another recording surface,
It is necessary to remove tracking at the moment of focus switching and perform tracking again to access the track on another recording surface at the access destination so that the track is focused.

However, in the disk of the above technique, even if the pickup is located at the same distance in the radial direction of the disk, since the sector addresses overlap on the upper and lower recording surfaces, the disk is currently accessed and reproduced. When the movement of the pickup is controlled from a sector on one recording surface to an access destination on another recording surface, there is a problem that the calculation of the movement amount of the pickup and the control of the movement direction are complicated.

Accordingly, it is an object of the present invention to reliably access a track on another recording surface due to focus switching, calculate a pickup moving amount to a sector of an access destination, and determine a moving direction. An object of the present invention is to provide a disk reproducing apparatus and a disk reproducing apparatus which can be easily performed.

[0008]

According to a feature of the present invention, there is provided a disk reproducing apparatus for solving the above-mentioned problem, a means for performing digital signal processing in a predetermined format recorded on a disk, and controlling the entire reproducing apparatus. Means, means for moving the pickup to a desired position on the disk, means for controlling the focus of the pickup to access a specific recording surface among the plurality of recording surfaces, and means for controlling the rotation speed of the disk motor, Means for detecting information contained in the lead-in area of the disk, means for detecting the rotation angle of the disk motor, and means for outputting a detection output; Setting means for executing focus switching of the pickup at an arbitrary disc rotation angle included in the detection output; Means for determining a rotation angle without deviation between tracks above and below the disc, means for storing the detected rotation angle, means for generating a focus switching command for the pickup, and a recording surface different from the sector address detection and access command. Means for judging that the access is over, means for calculating the pickup movement amount from the detection of the sector address and the access command, and means for determining the movement direction by converting the actual movement amount of the pickup from the calculation result, Have.

According to the above configuration, the focus of the pickup can be switched when the track coincidence point where there is no deviation between the tracks passes directly above the pickup, so that the recording surface between the two recording layers in the disc can be switched. Access can be made at a position where track deviation due to eccentricity is minimum. Further, it is possible to easily calculate the amount of movement of the pickup and determine the direction of movement when accessing over different recording surfaces.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a disk reproducing apparatus according to one embodiment of the present invention. In the figure, reference numeral 1 denotes an optical disk having a multilayer recording surface of two or more layers,
2 is a pickup (optical reading means) that can access a specific recording surface of the multilayer recording surface by switching focus, 3 is a preamplifier, 4 is a digital signal processing circuit, 5 is an interface circuit, 6 is a host computer, 7 is a disk Motor, 8 is CLV (Constant Linea
r Velocity) motor control circuit, 9 is a rotation encoding circuit that outputs a numerical code corresponding to the current rotation angle with respect to rotation of the disk (rotation of the disk motor 7), 10 is a focus control circuit, 11 is a pickup movement control circuit ,
12 is a sector address detecting circuit, 13 is a lead-in information detecting circuit, 14 is a track match detecting means for detecting a numerical code in which the upper and lower tracks of the disk coincide with the numerical code output continuously at 9, and 15 is Numerical code storage means, 16 is a focus switching instruction generating means, 1
7 is an access method determining means for determining an access method, 1
Reference numeral 8 denotes a pickup movement amount calculating means for calculating a pickup movement amount to an access destination; 19, a system controller for controlling the entire reproducing apparatus; and 20, a numerical value code for executing focus switching of the pickup by a track coincidence detecting means 14. The focus switching numerical code setting means 21 sets the actual movement amount of the pickup 2 based on the calculation result obtained by the pickup movement amount calculation means 18 to determine the movement direction.
It is a direction determining means.

The above means 14 to means 18, 20, 2
As described later, the processing performed by combining
The program is stored in a recording medium such as a (Read Only Memory) in the form of a program, and the system controller 19 can realize processing (each means) by reading from the recording medium.

In FIG. 1, a digital signal to be transferred to a host computer 6 is stored on an optical disk 1 in the form of a first digital signal.
Recording is performed over the second recording surface, and each recording surface can be read from one surface. This optical disk 1
Is rotated at a constant linear velocity by a disk motor 7 controlled by a CLV motor control circuit 8, and a digital signal is reproduced from the optical disk 1 by the pickup 2. At this time, the pickup movement control circuit 11
The movement of the pickup 2 in the radial direction of the disk is controlled, and the focus control circuit 10 performs focus control when the first or second recording surface is selectively accessed.

Here, the structure of a digital signal to be stored and a method of recording the digital signal on the optical disk 1 will be described with reference to FIG.

As shown in FIG. 6, the structure of one sector 601 which is the minimum unit to be recorded on the optical disk 1 is composed of a synchronization signal 602 indicating a boundary between sectors and a sector address 603 indicating the position of the sector on the optical disk 1. And data 604. When recording a sector having such a configuration on the optical disk 1, the number of sectors to be recorded on the disk is collected, and a series of numbers (0, 1, 2,... j-
1) up to j; j is a natural number). Then the first
In the order from the sector at sector address 0 to i (i is a natural number and 0 <i), and spirally recorded from the innermost circumference to the outer circumference. Further, the remaining sectors (sector addresses i + 1 to j) are shifted from the outer circumference to the inner circumference so that the second sector is continuous with the last sector address recorded last in the first disk in the radial direction of the disk. Record spirally in the direction up to the innermost circumference. Finally, the first and second disks are bonded together to form an optical disk 1 that can be read from one side.

Problems that occur when the optical disk described with reference to FIG. 6 is reproduced will be described with reference to FIG. FIG.
Reference numeral 201 denotes a first recording surface, 202 denotes a second recording surface, and 203 denotes a bonding surface between disks, which is a disk that can access a specific recording surface by switching the focus of a pickup from one surface. Reference numeral 206 denotes a displacement generated when the disks are bonded. Due to this shift, the track 204 spirally recorded on the first recording surface and the track 205 spirally recorded on the second recording surface do not completely overlap each other, and a deviation 207 between the tracks occurs. Occurs.
Also, in this case, a point where the tracks match always occurs,
For example, 208A and 208B in the figure correspond to this. For this reason, it is desirable to access another recording surface by switching the focus of the pickup when the vicinity of the point 208A or 208B where the upper and lower tracks coincide passes right above the pickup.

The operation of the reproducing apparatus for the track coincidence detection for executing the focus switching of the pickup for the optical disk in the above state will be described with reference to the block diagram of FIG. 1, the explanatory diagram of FIG. 2, and the flowchart of FIG. Will be explained. The operation of the reproducing apparatus in response to an access command from the host computer will be described with reference to the block diagram of FIG. 1 and the flowchart of FIG.

First, the operation of the reproducing apparatus for detecting track coincidence between the upper and lower tracks of the disk will be described. 1 and 3, when the optical disc 1 is inserted into the reproducing apparatus, the system controller 19 detects the disc insertion (step 301). Next, the innermost lead-in area of the first recording surface of the optical disc 1 is accessed by the pickup 2, and after reproduction, the digital signal processing circuit 4 performs predetermined signal processing. In step 13, lead-in information for the currently inserted optical disk 1 is detected (step 302). Among the detected information, information necessary for the host computer 6 to access is:
Host computer 6 through interface circuit 5
Sent to The information of the recording type of the optical disc 1 (identification information indicating that the disc is a single-sided readable disc) and the information of the last sector address i of the first recording face are included in the information.
It is sent to the system controller 19. The system controller 19 determines whether or not the disc is a single-sided readable disc based on the recording type identification information among these pieces of information (step 303).

Here, a method of outputting a numerical code corresponding to the rotation of the disk motor 7 of the rotation encoding circuit 9 in FIG. 1 will be described with reference to FIG. Reference numeral 209 in FIG. 2 is a detection position corresponding to the rotation angle of the disk motor 7, and a numerical code from (0) to (11) as shown in the drawing corresponds to each detection position. 21
0 is a reference corresponding to the rotation of the disk motor 7.
When the optical disk 1 is rotated by the disk motor 7, the reference 210 is rotated in the same rotation direction as the rotation direction of the disk motor 7.
Rotates, and the accompanying rotation angle 211 changes continuously,
It passes over a plurality of detection positions 209. That is, the detection position 209 that matches the reference 210 corresponding to the rotation of the disk motor 7 corresponds to the current rotation angle of the disk motor 7, and the numerical code for the detection position 209 at that time is output from the rotation encoding circuit 9. You. With such a method, the rotation of the disk motor 7 is
That is, the rotation angle corresponding to the rotation of the optical disc 1 is
You can know by the output numerical code.

If it is determined in step 303 that the disc is a single-sided read disc, the focus switching numerical code setting means 20 changes from (0) to (0) which are continuously output from the rotation encoding circuit 8 as the disc motor 7 rotates. Among the numerical codes of 11), for example, a numerical code (0) is set to the track coincidence detecting means 14 as a numerical code for executing focus switching (step 313). The reproduction of the disc is continued (step 304), and the track coincidence detecting means 14
In step 305, when it is determined that the numerical code continuously output from the rotation encoding circuit 9 matches the numerical code (0) set in step 313 (step 305), the focus switching instruction generating means 16 is controlled to execute the focus switching instruction. Is generated, and the focus of the pickup 2 is switched via the focus control circuit 10 (step 306).

After the focus switching, if the digital signal processing circuit 4 does not detect the synchronization signal and the sector address detecting circuit 12 does not detect the sector address (NO in step 307), the focus switching instruction generating means 16 Control to generate a focus switching command for the pickup 2, and the focus control circuit 10
To switch the focus (step 311) to access the track on the recording surface that was accessed first.
After the digital signal processing circuit 4 confirms the detection of the synchronization signal and the sector address detection circuit 12 confirms the detection of the sector address (step 312), the focus switching numerical code setting means 20 sets the numerical code currently set. (0) is changed to another numerical code (for example, numerical code (1)), set again for the track coincidence detecting means 14 (step 308), and again set for the numerical code (1) whose setting has been changed. The process is restarted from 304.

If a sector address is detected in step 307, the focus switching numerical code setting means 2
When 0 is output from the rotary encoder circuit 9 to the track coincidence detecting means 14, the coincidence point between the upper and lower tracks passes directly above the pickup 2. The numerical code at that time is stored in the numerical code storage means 15 (step 30).
9). Since there may be a plurality of places where the upper and lower tracks match, there is a possibility that there is a plurality of places. After performing the above-described track coincidence detection processing on all the numerical codes output from the rotation encoding circuit 9 (step 31).
0), and waits for an access command from the host computer.

Here, steps 303 to 313 described above are performed.
The processing up to this point is realized by a combination of the functions of the track coincidence detecting means 14, the numerical code storage means 15, the focus switching instruction generating means 16, and the focus switching numerical code setting means 20 in FIG. This step 303
To 313 are stored in the storage medium as described above, and the system controller 19 realizes the processing (each means) by reading the program from the storage medium.

Next, the operation of the reproducing apparatus in response to an access command from the host computer 6 will be described. FIG.
4 and FIG. 4, when the interface circuit 5 receives an access command (reproduction start sector address = m; m is a natural number) from the host computer 6 (step 40).
1) The reproduction of the optical disk 1 is resumed, and in the sector address detection circuit 12, the recording surface currently accessed by the pickup 2 and the reproduction sector address n at the current position of the pickup 2 in the disk radial direction (n is a natural number) ) Is detected (step 402).

The access method determining means 17 determines the last recording sector address i, the reproduction sector address n, and the reproduction sector address n of the first recording surface detected by the reproduction of the lead-in area after the disk is inserted by the lead-in information detection circuit 13. From the start sector address m, it is determined whether or not the sector corresponding to the address m exists on the same recording surface as the sector currently being reproduced (step 403).

If it is determined in step 403 that m and n are on the same recording surface, the pickup moving amount is calculated so that k = mn (k is a natural number) for sector addresses m and n. The means 18 is controlled (step 404). Then, the moving amount conversion / moving direction determining means 21
, The amount of movement of the pickup is converted from the absolute value of the operation result k, and the movement direction is determined from the sign of “+” or “−” of k (step 408). Is moved to the position where the sector having the sector address m is present, and reproduction is started (step 409). After digital signal processing, the reproduction data is sent to the host computer 6 through the interface circuit 5.

On the other hand, if it is determined in step 403 that m and n do not exist on the same recording surface, that is, in the case of accessing a different recording surface, the access method determination means 17 sets the focus switching numerical value. Code setting means 20
, An instruction is generated to start the track match detection processing. As a result, the focus switching numerical code setting means 20 reads the numerical code stored in the numerical code storage means 15 and
Is set to the numerical code (step 411). Then, after detecting the coincidence between the numerical code continuously output and the currently set numerical code by the rotation encoding circuit 9 (step 405), the rotation control circuit 9 controls the focus switching instruction generating means 16 to generate a focus switching instruction. Then, the focus of the pickup 2 is switched through the focus control circuit 10 (step 410), so that the focus of the pickup 2 is traced to a track on another recording surface.

After reproducing the disc, the sector address detection circuit 12 makes a detection determination of the sector address n '(n' is a natural number) (step 406). If the sector address n 'is detected, the pickup moving amount calculating means 18 determines , The sector address n ′ detected after the focus switch command
Then, k ′ = mn ′ (k ′ is a natural number) is calculated based on the reproduction start sector address m included in the access command (step 407). Then, the moving amount conversion / direction determining means 21 converts the moving amount of the pickup 2 from the absolute value of k 'and determines the moving direction from the sign of "+" or "-" of k' (step 408). ), The pickup 2 is moved by the pickup movement control circuit 11 to a position where the sector of the sector address m exists, and is accessed;
Playback is started (step 409), and after digital signal processing, playback data is sent to the host computer 6 through the interface circuit 5.

If it is determined in step 406 that the sector address n 'has not been detected, the original recording surface is accessed by switching the focus of the pickup 2, and the digital signal processing circuit 4 confirms the detection of the synchronization signal. After confirming the detection of the sector address by the sector address detection circuit 12 (step 412), if another numerical code already stored in the numerical code storage means 15 still exists (if NO in step 413), step 4 is executed.
The process is restarted from 11 and the focus switching of the pickup 2 is executed for another stored numerical code.
On the other hand, in step 413, the numerical code storage unit 1
If the above processing has been performed for all the numeric codes stored in step 5, an access error occurrence is sent to the host computer 6 through the interface circuit 5 (step 414).

Here, steps 403 to 414 described above are performed.
The processing up to this step is performed by the track coincidence detecting means 14, the numerical code storage means 15, the focus switching instruction generating means 16, the focus switching numerical code setting means 20, the access method determining means 17, the pickup moving amount calculating means 18, the moving amount shown in FIG. This is realized by a combination of functions in the conversion / direction determining means 21. The programs corresponding to the respective processes of steps 403 to 414 are stored in the storage medium as described above, and the system controller 19 realizes the processes (each means) by reading the program from the storage medium.

Next, FIG. 5 shows a method of selecting the movement control of the pickup 2 from k or k 'in step 408 according to the type of access. In FIG. 5, “1” and “2” indicate that the reproduction sector address n and the access start sector address m are the same as those in step 403 described above.
In the determination processing by the access method determination means 17 in
If it is determined that they exist on the same recording surface,
“3” and “4” are cases where it is determined that n and m are present on different recording surfaces. In the case of “1” and “2”, from the operation result k (= m−n) of n and m,
In the case of “3” and “4”, the operation result k ′ of n ′ and m
(= Mn ′), the actual movement amount of the pickup 2 in the radial direction of the disc is converted from the absolute value of k or k ′, respectively, and “+” or “+” of k or k ′. − ”
The moving direction of the pickup 2 from the current position is determined as shown in FIG.

As described above, in the present embodiment, the first and second
When playing back a bonded disc that can be read from one side of the disc when there is a recording surface, when the disc is inserted and after the lead-in playback, when the tracks of the first and second recording surfaces match up and down The output numerical code of the rotary encoder circuit corresponding to the rotation of the disk motor is determined, the numerical code is stored, and when accessing over different recording surfaces, the stored numerical code and the rotary encoder By switching the focus of the pickup when the output numerical code matches, it is possible to easily trace the focus of the pickup on a track on another recording surface and perform access reproduction. At this time, the operation of the sector address detected after the focus switching is performed and the access start sector address are executed, the pickup moving amount is determined from the absolute value of the operation result, and the moving direction is determined by the sign of the operation result. Is determined, it becomes easy to control the movement of the pickup when accessing a different recording surface of a single-sided readable disc.

FIG. 7 is a block diagram showing a configuration of a disk reproducing apparatus according to another embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a single-sided readable optical disk on which images, audio information, etc. are recorded; A circuit 23 is an audio decompression / interpolation circuit which also processes audio information, 24 is a reproduction time display means for converting a sector address detected during reproduction into a reproduction time display of the disk, and 25 is a recording on the disk. In order to make random access to each of the files such as images, sounds, etc., the cueing detection means for detecting cueing information for each file from the lead-in information detection circuit 13; This is a cueing selection circuit that generates an access instruction according to a cueing selection instruction. The parts corresponding to those in FIG. Omitted.

In FIG. 7, after detecting the insertion of the disk, the information recorded in the lead-in area of the disk 1 is read out, and after the digital signal processing circuit 4 performs predetermined signal processing, the lead-in information detection circuit 13 detects the information. From the read-in information obtained, in order to perform random access to each file such as image and sound recorded on the disk 1, a sector address m corresponding to a sector address m recorded at the head sector of each file is obtained. The cue information is detected by the cue information detecting means 25, and the detection result is output for displaying the cue information. After the detection of the cue information, detection of a numerical code corresponding to the rotation angle of the disk motor 7 having no track shift amount for executing the focus switching according to the above-described flow shown in FIG. 3 and waiting for an access command to be accepted. Become.

The detected cue information is output to display cue information and sent to the cue selection circuit 26. The cue selection circuit 26 sends an access command to the system controller 19 to start reproduction from the sector address m according to the cue information and the cue selection command. In accordance with the received access command, the system controller 19
The processing according to the above-described flow shown in FIG. 4 is performed, and the reproduction of the image or audio file starting from the sector address m is started. The reproduction is started, and the image data of the reproduced signal that has been subjected to the predetermined signal processing by the digital signal processing circuit 4 is converted into image information by the image decompression / interpolation circuit 22 and output as an image output. The audio information is converted into audio information by the audio decompression / interpolation circuit 23 and output as audio output.

The sector address detected after the start of the reproduction is converted into a reproduction time by the reproduction time display circuit 24 and output for displaying the reproduction time.

Therefore, in the present embodiment, even for a single-sided read-out two-layer disc on which image and audio information are recorded, it is possible to access and reproduce different recording surfaces. Further, the movement control of the pickup when accessing different recording surfaces is facilitated.

In the above embodiment, only one recording surface, the first and second recording surfaces, can be read from one side on one disk, but the number of recording surfaces readable from one side is three or The present invention is applicable to four or more surfaces. In this case, the detection target of the disk motor rotation angle without vertical track deviation for executing the focus switching of the pickup is the first and second recording surfaces, the first and third recording surfaces, and the first and fourth recording surfaces. It is easily understood by those skilled in the art that the operations are performed on the second and third recording surfaces, the second and fourth recording surfaces, and the third and fourth recording surfaces, respectively.

In the above embodiment, a case is described in which a single-sided readable disk in which the disks are bonded to each other is reproduced. However, a plurality of recordings are performed in one disk without performing the bonding. The present invention can be applied to a single-sided reading disk in which the surface is formed as it is.

The output of the rotation encoding circuit corresponding to the motor rotation angle is not limited to a numerical code, but may be any output format as long as the output signal is such that the motor rotation angle can be determined.

The detection accuracy of the rotation angle of the motor in the rotation encoding circuit is not limited to the above embodiment. The detection accuracy of the disk motor rotation angle without the gap is improved.

Further, as described above, 14 to 1 in FIG.
The processing performed by the means 8 and 21 is stored in a recording medium such as a ROM in the form of a program so that the processing can be performed by the system controller 19, but has the same function as the processing performed by executing the program. The playback device may be configured using hardware (circuits) to be realized.

The value of the address stored in the sector address is not limited to a continuous natural number from sector numbers 0 to j, but may be any value as long as the recording location of the sector on the disk becomes clear. In this case, the method of calculating the amount of movement of the pickup when accessing between different recording surfaces and the method of determining the direction of movement depend on the format of the sector address to be stored, which is apparent from the detection of the lead-in information. This is performed by controlling the moving amount conversion / direction determining means 21.

The calculation method of the pickup moving amount is as follows.
The present invention is not limited to the subtraction of the reproduction sector address n or n 'from the access start address, but may subtract m from n or n'. In this case, it is easily understood by those skilled in the art that the moving direction of the pickup is opposite to the moving direction described in the above-described embodiment.

[0044]

As described above, according to the present invention, it is possible to switch the focus of the pickup when the track coincidence point where there is no deviation between the tracks passes directly above the pickup, so that the focus of the disc can be changed. Access can be made at a position where track deviation due to eccentricity between the recording surfaces of the layers is minimized. Further, it is possible to easily calculate the amount of movement of the pickup and determine the direction of movement when accessing over different recording surfaces.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a disc reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration example of an optical disc to be reproduced by a disc reproducing apparatus according to the present invention.

FIG. 3 is a flowchart illustrating a process of determining a disk motor rotation angle when performing focus switching according to an embodiment of the present invention.

FIG. 4 is a flowchart illustrating a process of controlling pickup movement according to an access command in one embodiment of the present invention.

FIG. 5 is an explanatory diagram showing an access type, a pickup movement amount, and a movement direction in one embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a structure of a sector recorded on an optical disk and a method of recording a sector on the disk.

FIG. 7 is a block diagram showing a configuration of a disk reproducing apparatus according to another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 optical disk 2 pickup 3 preamplifier 4 digital signal processing circuit 5 interface circuit 6 host computer 7 disk motor 8 CLV control circuit 9 rotation encoding circuit 10 focus control circuit 11 pickup movement control circuit 12 sector address detection circuit 13 lead-in information detection circuit 14 track Coincidence detecting means 15 Numerical code storage means 16 Focus switching instruction generating means 17 Access method determining means 18 Pickup moving amount calculating means 19 System controller 20 Focus switching numerical code setting means 21 Moving amount conversion / direction determining means 22 Image expansion / interpolation circuit 23 Audio decompression / interpolation circuit 24 Playback time display means 25 Cueing information detecting means 26 Cueing selection circuit

Claims (7)

[Claims] 1. A first disk recording surface and a second disk recording surface have a two-layer structure in a depth direction as viewed from an optical pickup means, and each layer has an inner periphery to an outer periphery or an outer periphery. A disk rotating means for rotating the disk, a pickup means for extracting data and information from the disk, and a focus switch of the pickup means for reproducing a single-sided read double-layer disk spirally recorded in the inner circumferential direction. Focus control means for enabling access to the two-layer recording surface, pickup movement control means for controlling movement of the disc in the radial direction, and performing predetermined signal processing on digital signals recorded on the disc. A disc reproducing apparatus having digital signal processing means and system controller means for controlling the entire reproducing apparatus. Te, at least a sector address detection means for performing a sector address detection to detect the rotation angle of the disk rotation means, the detection output p
Rotation encoding means for outputting a rotation angle; a setting means for executing focus switching of the pickup means at a disk rotation angle q;
The amount of track deviation caused by the eccentricity between the first and second recording surfaces is detected from the address of the disk recording surface and the address of the second disk recording surface. Track coincidence detecting means for determining a rotation angle q; storage means for storing the determined rotation angle q; and focus switching instruction generating means for generating a focus switching instruction according to the track coincidence detecting means. Disc playback device. 2. The disc reproducing method for a disc reproducing apparatus according to claim 1, wherein the method of obtaining the rotation angle q without the track shift amount is at least after inserting the single-sided reading dual-layer disc. A first step of setting the rotation angle q for executing focus switching of the pickup means in the setting means; and establishing a relationship of p = q from the set rotation angle q and the detection output p of the rotation encoding means. A second step of generating a focus switching command of the pickup means in response to the establishment of the relationship of p = q, and determining sector address detection from the sector address detection means after the focus switching of the pickup means. And the rotation set in the first step according to the detection of the sector address. a fourth step of storing q, and setting of the rotation angle q for all the outputs p of the rotation encoding means. When the processing from the first step to the fourth step is completed, the processing ends. And a fifth step of reproducing the disc. 3. The apparatus according to claim 2, wherein when the sector address cannot be detected in the third step, at least a sixth step of generating a focus switching command, and a sector address after the focus switching of the pickup means. A seventh step of confirming detection, and, for the rotation angle q set in the first step, a rotation angle q ′ different from the rotation angle q among the rotation angles output from the rotation encoding means. An eighth step of setting. 4. The processing according to claim 3, wherein the setting of the rotation angle is not set for all the outputs p of the rotation encoding means, or the processing of the second, third, and fourth steps, or 2,3,6,7,
A disk reproducing method characterized by repeating the processing of the eighth step. 5. The disc reproducing method of the disc reproducing apparatus according to claim 1, wherein the disc reproducing method according to the access command received by the system controller means includes at least a reproduction start sector address included in the access command. m
(M is a natural number) and the detected sector address n (n is a natural number), a ninth step of determining that the access is over two layers in the disk, and a response to the determination of the ninth step. A tenth step of reading the rotation angle q stored in the storage means and setting the rotation angle q in the setting means; and p = from the set rotation angle q and the detection output p of the rotation encoding means. an eleventh step of detecting the establishment of a relationship of q and generating a focus switching command of the pickup unit in response to the establishment of a relationship of p = q; and, after switching the focus of the pickup unit, a sector from the sector address detection unit. Address n '(n'
A twelfth step of judging the detection; a thirteenth step of obtaining k ′ (k ′ is a natural number) from the operation of the reproduction start sector address m and the above detected sector address n ′; A fourteenth step of converting the amount of movement of the pickup means from the absolute value of (i) and determining the direction of movement from the k 'code. 6. The method according to claim 5, wherein in the twelfth step, when the detection of the sector address n ′ is not performed, at least a fifteenth step of generating a focus switching command, and a sector after the focus switching. A disk reproducing method, comprising: a sixteenth step of confirming address detection; and a seventeenth step of determining whether there is an unset rotation angle stored in the storage means. 7. A first disk recording surface and a second disk recording surface have a two-layer structure in a depth direction as viewed from an optical pickup means, and each layer has an inner periphery to an outer periphery or an outer periphery. A processor used in a reproducing apparatus for reproducing a single-sided readable double-layer disc spirally recorded in the inner circumferential direction includes a program section for detecting at least a disc rotation angle q with no track shift amount on a readable recording medium. A first program section for setting the disk rotation angle q for executing the focus switching of the pickup means in the setting means; a set rotation angle q; and a rotation encoding means for detecting the rotation angle of the disk rotation means. From the detection output p, p =
a second program section for detecting the establishment of the relationship of q and generating a focus switching command of the pickup means in response to the establishment of the relation of p = q; and a sector from the sector address detection means after the focus switching of the pickup means. A third program section for determining the address detection, a fourth program section for storing the rotation angle q set in the first step according to the sector address detection, and a fourth program section for storing the rotation angle q. The setting of the rotation angle q
Performed for all the outputs p of the rotation encoding means,
When the processing from the first program section to the fourth program section is completed, the processing ends.
A sixth program section for generating a focus switching command in response to the inability to detect a sector address in the third program section; and a confirmation of sector address detection after the focus switching of the pickup means. A seventh program section to be executed, and a rotation angle q ′ different from the rotation angle q among the rotation angles output from the rotation encoding means with respect to the rotation angle q set in the first program section. And a program section for performing disk playback in accordance with the access command received by the system controller means for controlling the entire playback apparatus, at least included in the access command. Playback start sector address m (M
Is a natural number) and a detected sector address n (n is a natural number), a ninth program section for determining that the access is over two layers in the disk, and a response to the determination of the ninth program section. A tenth program section for reading the rotation angle q stored in the storage means and setting the rotation angle q in the setting means, and the set rotation angle q and the detection output p of the rotation encoding means, an eleventh program section for detecting the establishment of the relationship of p = q and generating a focus switching command of the pickup means in response to the establishment of the relationship of p = q; and the sector address detection means after the focus switching of the pickup means. From the sector address n '(n'
Is a natural number) a twelfth program section for determining detection, a thirteenth program section for obtaining k ′ (k ′ is a natural number) by an operation of a reproduction start sector address m and a detected sector address n ′, and an operation result k In the fourteenth program section for converting the pickup movement amount from the absolute value of 'and determining the movement direction from the sign of k', and in the twelfth program section, the sector address n 'is detected. A fifteenth program section for generating a focus switching command in response to the absence of the focus, a sixteenth program section for confirming detection of a sector address after the focus switching, and an unset rotation stored in the storage means. And storing a program section including a seventeenth program section for determining the presence or absence of a corner. Disk playback method characterized by and.