JPH1079126A - Accessing method for optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To move an optical pick-up to a target position at a high speed, by moving an objective lens so as to focus on a target layer when a recording layer of target information differs, and then calculating the distance between two physical positions, that is, the current position and the target position. SOLUTION: First, the position of an optical pick-up for reading current position information recording on a disk is checked. Then, it is judged whether the recording position of target information is equal to the current recording layer. When the recording position of target information is not equal to the current recording layer, an objective lens is moved in a direction perpendicular to the disk so as to focus on the target layer. Then, the current position of the optical pick-up is checked. The current position and the target position are converted to physical positions on the disk, and the distance between the relative two points is calculated. Thus, the optical pick-up may be moved to the target position at a high speed without reading the position information recorded on the disk during moving. After the movement, the pick-up is caused to access the target information recording position while the position information recorded on the disk is checked. Thus, high-speed access is easily carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk apparatus capable of reproducing an optical disk having a plurality of information recording surfaces on one side of the disk.

[0002]

2. Description of the Related Art In an optical disc as a recording medium,
At present, a laser disk (LD) is widely used as a medium having a plurality of information recording surfaces. These recording media have an information recording surface of one layer each on both sides of the medium due to the physical structure. Therefore, when it is necessary to switch the information recording layer to be reproduced, the disc is generally flipped or replaced.

[0003]

In recent years, due to the increase in the capacity of computer data and the practical use of recording and reproducing digital moving picture information, it has been required to increase the recording density of optical discs, such as DVDs (digital versatile discs). The specification of a large-capacity optical disk has been devised, and an optical disk such as a double-layer disk has been standardized in addition to the conventional single-sided single-layer information recording. Since these optical discs have two information recording layers on one side, in an optical disc apparatus for reproduction, the information recording layer to be reproduced is switched, and depending on the form of the recorded information and the method of using the information, a conventional optical disc apparatus may be used. A different playback method from that of a single-layer disc is required. One is an access method and the other is a pause method.

In an optical disk device, when an optical pickup accesses a recording position of information to be read, usually on the same information recording layer, in order to realize high-speed access, first, current position information recorded on the disk is first read. Obtain the current position of the reading optical pickup. Next, the target position is obtained from the logical or physical address of the read target information. The position of the two points is converted from the information recording format of the disk into physical position information, the distance on the disk plane between the two points is determined, and the optical pickup is moved to the target position by means for controlling the slider on which the optical pickup is mounted. Is accessed.

However, in the case of an optical disk having a plurality of information recording layers on one side, if the read target information is present on another information recording layer, the track positions between the information recording layers do not always coincide with each other, and the current reproduction is performed. In the method in which the optical pickup is moved to the target position based on the position information of the existing information recording layer and then moved to the target information recording layer, there is a problem that the target position cannot be accessed quickly and accurately.

[0006] In addition, in a single-sided dual-layer DVD of a DVD, a Parallel Track Path having the same recording path (path) of the first layer and the second layer in FIG.
(Hereinafter referred to as PTP) and Opposite where the recording paths of the first layer and the second layer are opposite as shown in FIG.
There are two types, Track Path (hereinafter referred to as OTP). In the case of OTP, the physical address of the second layer is assigned irrespective of the physical address of the first layer. It is impossible to access other information layers based on it.

[0007] Also, with regard to the pause (pause) operation,
If the operation for the conventional single-sided single-layer disc playback is not changed,
There is a problem that the pause is not performed in the second layer of the TP disk.

An object of the present invention is to provide a method for accurately, quickly and easily controlling access to an optical pickup in reproducing a disk having a plurality of recording layers, and an accurate pause operation regardless of the type of the disk. Is to provide a way to do this.

[0009]

According to the present invention, when starting access control of an optical pickup across a plurality of recording layers, first, moving means to a recording layer in which target information is recorded is provided. The switching of the information recording layer during reproduction is performed by moving the beam focal point of the optical pickup using, and thereafter, the same control processing means as in the access between the same recording layers is used, on the information recording layer after the movement. The problem is solved by obtaining the distance on the disk plane between two points from the current position of the optical pickup and the target position of the read information, and performing access control of the optical pickup.
Also, the present invention relates to a pause operation, in which whether or not the disc being reproduced is a single-sided dual-layer disc is stored in an optical disc reproducing apparatus in advance, and when a pause operation command is issued during reproduction of the second layer on the OTP disc, the first layer is discarded. The solution was achieved by reversing the pickup's track jump direction.

[0010]

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

FIG. 1 is a block diagram of an optical disk apparatus which constitutes a constituent element of the present invention in a first embodiment of the present invention. The present optical disc reproducing apparatus includes a decoder block for performing signal reproduction, demodulation, error correction and the like for demodulating reproduced data, a system control block for controlling the entire optical disc apparatus, and an external information processing device. Interface blocks for interfacing, modulation for recording data, encoder blocks for error correction, etc., among these blocks, blocks that are not directly related to the present invention are described and described in the drawings. Omitted.

First, the function of each block in FIG.

The optical disk 1 is a compact disk (C
D), an optically readable information storage medium such as a digital versatile disk (DVD), and information is recorded on a signal recording surface thereof in a concave portion called a pit.

The optical pickup 2 is for reproducing information from the optical disk 1, and includes a semiconductor laser (not shown), optical components, a focus actuator 3, a tracking actuator 4, and a photodetector 5. Light emitted from the semiconductor laser is focused on the signal recording surface of the optical disc 1 to form a light spot. Since the amount of light reflected from the light spot changes depending on the presence or absence of pits, signal reproduction can be performed by detecting a change in the amount of light as a signal.

The photodetector 5 converts a change in the amount of light reflected from the optical disk 1 into a current signal. The output of the photodetector 5 is converted into a voltage signal by a current-voltage conversion circuit 6 and transmitted to a focus error detection circuit 7 and a tracking servo circuit 8, respectively.

The focus error signal 8 detected by the focus error detection circuit 7 is supplied to the phase compensation circuit 9 and the switch 1
0, through the drive circuit 11, the focus actuator 3
To form a focus servo loop for controlling the objective lens 12 in the focus direction.

The search signal generating circuit 13 is a circuit for generating a search signal 15 in response to a focus search control signal 14. By transmitting the search signal 15 to the drive circuit 11 and applying it to the focus actuator 3, the objective lens 12 can be moved in the focus direction separately from the focus servo loop.

The switch 10 switches in accordance with the state of the focus switching signal 16, and the operation of the focus servo loop can be started by switching the switch 10 so as to transmit the output of the phase compensation circuit 9 to the drive circuit 11. .

The tracking servo circuit 8 comprises a tracking error detecting circuit, a phase compensating circuit and the like.
To form a tracking servo loop for controlling the objective lens 12 in the tracking direction.

The switch 18 opens the tracking servo loop in response to the tracking control switching signal 19, and can move the objective lens 12 in the tracking direction by the output signal of the tracking actuator movement signal generation circuit 20.

The slide motor 21 is for moving the optical pickup 2. In a steady state, the output signal of the tracking servo circuit 8 is transmitted to the drive circuit 23 via the slide motor servo circuit 22 to form a slide motor servo loop. When the optical pickup is moved by an access operation or the like, the switch 25 is switched by the slide motor control switching signal 24, and the controller 27 moves the slide motor control signal 28 based on the speed / position information obtained from the output signal of the rotary encoder 26 to move the slide motor. The output to the signal generation circuit 29 and the drive of the drive motor 23 drive the slide motor 21.

Next, an example of an optical disk having two information recording layers on one side will be described. This optical disc playback device is C
D, a DVD single-layer disc, and a DVD dual-layer disc are to be reproduced. Here, a DVD double-layer disc is described as an example.

FIG. 2 shows the structure of a DVD double-layer disc.

A DVD dual-layer disc has two discs on one side of the disc.
The two information recording layers are arranged at a distance of about 55 μm in the disk thickness direction. These information recording layers are usually formed separately and mechanically stuck together.

In FIG. 2, the first layer is a translucent recording film, and the second layer is a reflective film formed by aluminum evaporation or the like. This 2
The reproduction of the layer disc is performed by irradiating a laser beam from the first layer side as shown in FIG. 2 and moving the objective lens 12 in a direction perpendicular to the disc to focus on the second layer of the first layer. Let's do it.

FIG. 3 shows the arrangement of physical sectors and the structure of address information of a DVD two-layer disc.

(1) PARALLEL TRACK
Called PATH (PTP), LAYER0 (first layer)
There is no relationship between the physical sector on the upper side and the physical sector on the LAYER1 (second layer) with respect to the address information.
Physical sectors of the same address incremented from the inner circumference to the outer circumference of the disk are present in each information recording layer.

(2) OPPOSITE TRACK
This is called PATH (OTP), and the address information of the start physical sector on LAYER1 (the second layer) is LAYER
It is represented as address information obtained by inverting each bit of the address information of the last physical sector on 0 (first layer).
The address information of R1 (second layer) is recorded by being incremented from the outer circumference to the inner circumference of the disk. That is, the address information of LAYER0 (first layer) is incremented from the inner circumference to the outer circumference of the disk, whereas the address information of LAYER1 (second layer) is incremented from the outer circumference of the disk to the inner circumference. I have.

In the case of a DVD disk, a single-sided single-layer disk, a single-sided dual-layer disk, and a PTP disk
The information as to whether the disc is an OTP disc is recorded as disc index information, and the sector address is LA.
Information as to whether it is YER0 (first layer) or LAYER1 (second layer) is recorded.

Therefore, in the optical disk reproducing apparatus, it is possible to know what disk is inserted by reading the index information,
By storing the P disk or the OTP disk in the optical disk reproducing device, it is possible to provide special reproduction.

In any of the discs (1) and (2), the optical pickup is moved from a certain physical sector A on LAYER0 (first layer) to a physical sector B on LAYER1 (second layer). When performing access between such information recording layers, in addition to the conventional optical pickup moving in the disk radial direction, it is necessary to move in the disk thickness direction to switch the information recording layer where the optical spot of the optical pickup focuses. become.

Next, a processing procedure for switching the information recording layer to be reproduced in the present optical disk device will be described. In the following processing procedure, a case where a CPU functioning as a system controller performs the processing by software is used as an example.

FIG. 4 is a diagram showing an outline of a procedure for switching the reproduction information recording layer.

At 401, it is determined whether the information recording layer at which the objective lens of the optical pickup is currently focusing and reproducing is the first or second layer based on the information in the sector address described above. The information recording layer on which information to be recorded is recorded is confirmed.

As a result of the processing in steps 401 and 402, if it is determined in 403 that the target information recording layer is another layer,
, A servo loop such as a focus servo and a tracking servo for maintaining the focus of the light spot at a target position on the information recording layer of the disk is turned off.

Thereafter, at 405, transmission of a focus search control signal for driving the objective lens in the moving direction to the target information recording layer is started. As a result, as the focus of the light spot gradually moves to the vicinity of the adjacent information recording layer, a focus error signal starts to be output.

At 406, while monitoring the focus error signal, the transmission of the focus search control signal is continued until the level exceeds a predetermined judgment level.

After exceeding the judgment level, at 407,
A signal having a phase opposite to that of the drive signal applied in 405 is output as a focus search control signal to stabilize pull-in of the focus servo loop thereafter, and a brake is applied to the focus actuator. At 408, by detecting the zero cross point of the focus error signal, it is determined that the focus error signal has reached the adjacent information recording layer.

Thereafter, at 409, the focus servo loop is turned on by switching the switch, and the other servo loops are sequentially turned on.

Now, a case will be described in which an optical disc having two information recording layers on one side actually accesses the information recording layer.

In general, in an optical disk such as a CD and a DVD, a logical current position and a target position at the start of access are converted into a physical position on the disk, and the relative difference is obtained by obtaining the difference. Calculate the distance on the disk plane between them, and move the optical pickup to the target position at high speed without reading the position information recorded on the moving disk by using the control means of the slider equipped with the optical pickup Is used.

As an example of a method of converting the current position and the target position into physical positions, the radius from the center of the disk of a certain sector number S0 as a reference on the disk is R0 (m).
And the linear velocity at which the information on the disc was recorded is CLV
(M / s), the track pitch is TP (m), and the time required for reproducing one sector is T0, the radius R of the sector number S1 existing in the same information recording layer from the center of the disk is obtained.
R12 = (CLV · TP · T0 (S1−S0) / π) +
R02. In the case of a two-layer disc, since the above-mentioned linear velocity and track pitch are different in each information recording layer in forming the disc, it is necessary to use the above formula for each information recording layer in which the sector is recorded.

When an access is made across the information recording layer, the physical sector of the PTP disk is LAYER0 (1).
Layer 2) and LAYER1 (second layer) are located in the same manner from the inner circumference to the outer circumference of the disc. Therefore, the target distance is moved based on the information of the information recording layer currently being reproduced, and the information being reproduced is recorded. There is a method of approaching the target sector while reading the current position information recorded on the layer, and then accessing the target sector across the information recording layer.
In YER0 and LAYER1, the track pitch, the linear velocity and the like do not always match, so that the access time to the final target sector is wasted.

In the case of an OTP disk, LAY
The physical sectors of ER0 and LAYER1 are completely different, and it is impossible to access the target sector of another information recording layer based on the information of the information recording layer currently being reproduced.

In this embodiment, the above problem is solved by the following processing.

FIG. 5 shows a processing flow of the system controller in the access control of the optical pickup according to the present invention.

In this embodiment, first, at 501, the current position information recorded on the optical disk is read to confirm the position of the optical pickup.

Next, at 502, it is determined whether or not the recording position of the target information to be accessed is the same as the current information recording layer.

If the information recording layers are not the same, 5
At 03, the beam focus of the optical pickup is moved to the target information recording layer by the focus moving means described with reference to FIG.

At 504 after the movement, the current position of the optical pickup on the information recording layer after the movement is confirmed by the same processing as 501.

In steps 505 and 506, the current position and the target position are converted into physical positions on the disk.

From the physical positions of the current position and the target position obtained by these methods, the distance between two relative points on the disk plane is calculated at 507, and the control of the slider on which the optical pickup is mounted is controlled at 508. The optical pickup is moved to the target position at high speed without reading the position information recorded on the moving disk by using the means.

After the movement, the optical pickup is made to access the target information recording position while confirming the position information recorded on the disk at 509.

In this series of processing, even in the case of access across the information recording layer, 502, 503,
By additionally performing only the processing of step 504, the same processing means as the conventional access processing in the same information recording layer after step 505 can be used, so that high-speed access is possible and easy. Processing can be performed.

Next, the pause operation of the present invention will be described with reference to FIGS. FIG. 6 shows a flow of the pause operation used in the conventional CD and LD, and FIG. 7 shows a flow of the pause operation of the present invention. In both the CD and LD, information is recorded along a spiral signal track from the inner circumference to the outer circumference of the disk. When a pause operation instruction is given in FIG.
The pause is realized by "jump one track toward the inner circumference at the designated pause position." This operation is repeated until there is a pause end command at 602. DVD
6 can be realized with the single-layer disk and the PTP disk of FIG. 6, but in the case of the OTP disk LAYER1 (second layer), the method of FIG.
No pause action.

In FIG. 7, the optical disc reproducing apparatus reads out the OTP disc from the index information and stores it. When a pause operation is instructed, first, at 703, "whether or not the disc is an OTP disc", "Layer 1 (second layer) or not" is checked from the sector address, and only when the layer is the LAYER 1 (second layer) on the OTP disk, 705 "jumps one track toward the outer circumference at the pause designated position" only in the case of LAYER 1 (second layer). A pause operation is realized.

Although the embodiment of the present invention has been described with reference to a two-layer disc, the access method and the pause method of the present invention can be applied to a disc reproducing apparatus having a plurality of information recording layers such as three layers and four layers. It goes without saying that it can be applied.

[0058]

According to the present invention, there is provided an optical disc apparatus which has a plurality of information recording layers to be reproduced on one side of an optical disc to be reproduced and which needs to switch these information recording layers to be reproduced during operation. Even when the recording position of the target information is located outside the information recording layer currently being reproduced,
The access control of the optical pickup can be performed accurately and at high speed and relatively easily using the same control processing means as the access between the same recording layers.
The pause operation can be realized with any OTP disk.

[Brief description of the drawings]

FIG. 1 is a block diagram of an optical disk device constituting a constituent element of the present invention in a first embodiment of the present invention.

FIG. 2 is a diagram schematically showing a structure of a DVD double-layer disc used in the present embodiment.

FIG. 3 is a diagram schematically showing an arrangement of physical sectors and a configuration of address information of a DVD double-layer disc used in the embodiment.

FIG. 4 is a flowchart illustrating a flow of a switching process of a reproduction information recording layer according to an embodiment of the present invention.

FIG. 5 is a flowchart showing a flow of an access control process of the optical pickup in one embodiment of the present invention.

FIG. 6 is a flowchart showing a flow of handling a conventional pause operation.

FIG. 7 is a flowchart showing a flow of processing of a pause operation according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical disk, 2 ... Optical pickup, 3 ... Focus actuator, 4 ... Tracking actuator, 5 ... Photodetector, 6 ... Current-voltage conversion circuit, 7 ... Focus error detection circuit, 8 ... Focus error signal, 9 ... Phase compensation Circuit, 10: switch, 11: drive circuit, 12: objective lens, 13: search signal generation circuit, 14: focus search control signal, 15: search signal, 16: focus switching signal, 17: drive circuit, 18: switch, 19: tracking control switching signal, 20: tracking actuator movement signal generation circuit, 21: slide motor, 22: slide motor servo circuit, 23: drive circuit, 24: slide motor control switching signal, 25: switch, 26: rotary encoder, 27 ... controller, 28 Slide motor control signal, 29 ... slide motor motion signal generation circuit.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akio Fukushima 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Yokohama, Japan Inside the Visual Information Media Division of Hitachi, Ltd. No. 1 in the Semiconductor Business Division of Hitachi, Ltd. (72) Inventor Shigeki Inoue 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture In the Visual Information Media Division of Hitachi, Ltd.

Claims (8)

[Claims] In an optical disc apparatus capable of reproducing an optical disc having a plurality of information recording surfaces on one side of a disc, the information recording layer to be reproduced can be switched during operation. An access method for an optical disk device, comprising: 2. The method according to claim 1, wherein the switching of the information recording layer to be reproduced is performed by moving a focal position of an objective lens in a thickness direction of the information recording medium and using a signal obtained from the information recording medium. An access method for an optical disk device, wherein the method is performed by: 3. An optical pickup according to claim 1, wherein, when accessing an information recording layer different from the information recording layer being reproduced, the optical pickup is moved to the information recording layer in which target information is recorded. An access method for the optical disk device, wherein the access is made later in the recording layer. 4. The optical pickup according to claim 3, wherein at least the focus servo and the tracking servo are turned off when the optical pickup is moved to the information recording layer on which the target information is recorded, and the movement to the information recording layer is completed. An access method for an optical disk, wherein a servo system is turned on in the order of a focus servo and a tracking servo at a point in time. 5. The method according to claim 3, wherein after the optical pickup is moved to the information recording layer on which the target information is recorded, the current position of the recording layer is confirmed, and then access is made on the recording layer. An access method for an optical disk device, comprising: 6. An optical disc apparatus capable of reproducing an optical disc having a plurality of information recording surfaces on one side of a disc, wherein at least an Opposite Track P is used.
ath (hereinafter, referred to as OTP) when reproducing a disc having OTP disc,
When a pause (pause) instruction is given during reproduction of a layer, the pickup jumps one track from the outer peripheral side to the inner peripheral side of the disc at the position where the pause is instructed to perform a pause operation. Optical disk device. 7. An optical disc apparatus capable of reproducing an optical disc having a plurality of information recording surfaces on one side of a disc, in a Parallel Track Path (hereinafter abbreviated as PTP) playback pause and opposition.
An optical disc apparatus characterized in that the direction of one track jump of a pickup is reversed in a pause during reproduction of a Track Path (hereinafter referred to as OTP). 8. The disc playback apparatus according to claim 7, wherein
During P playback, move the pickup from the outer circumference to the inner
An optical disc device characterized in that a pause operation is performed by jumping one track from the inner circumference to the outer circumference during P playback.