JP2005018945A - Optical disc device and control method for track jump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disc device which can reduce occurrences of read error. <P>SOLUTION: With respect to tracks on a spinning disc 1 the optical disc device is equipped with a thread motor 4 for moving an optical pickup 3 in a thread direction, a lens kick means 20 for shifting a lens system of the optical pickup 3 to the adjacent recording track position, and a system controller 15 for positioning the lens system of the pickup 3 to the designated recording track by driving selectively the thread motor 4 and the lens kick means 20. The system controller 15 decides the maximum shift quantity for the lens system of the pickup 3 shifted by the lens kick means 20 for each region of the disc 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical disc apparatus and a track jump control method.
[0002]
[Prior art]
Recently, the spread of optical discs has been remarkable, and various types of optical disc playback apparatuses have been developed. This type of optical disk has a plurality of recording tracks formed concentrically or spirally to record a signal digitally, and an optical disk reproducing apparatus has a pickup unit that faces the recording surface of the disk. A signal of a required recording track is optically reproduced while being moved in the direction.
[0003]
When the pickup unit is positioned at the designated recording track position, it is generally performed by selectively operating thread feed control and lens kick control according to the relationship between the current recording track position and the target recording track position. The Here, the thread feed control is a control for driving the thread motor to operate the feed screw mechanism and moving the pickup unit in the radial direction of the disk.
[0004]
The lens kick control is a control for displacing the lens system in the pickup unit by the track width, thereby positioning the lens system on the adjacent recording track. In this way, the search speed for the recording track is increased.
[0005]
Depending on the relationship between the current recording track position and the target recording track position, these controls are performed only by thread feed control when the number of moving tracks is large, and when the number of moving tracks is small. This is done by executing thread feed control and lens kick control in combination. Further, when only moving to an adjacent recording track, only lens kick control may be executed.
[0006]
Further, an optical disc device described in Patent Document 1 has been proposed as a technique for correcting lens shift in the optical disc device. According to the optical disk device described in Patent Document 1, the tangential phase difference is intentionally shifted, and after the lens shift amount is detected and corrected by the phase difference offset, the tracking error balance is adjusted. Alternatively, the initial lens shift is detected based on the reproduction signal, and the lens shift is corrected so that the reproduction signal characteristic is almost the best.
[0007]
[Patent Document 1]
JP, 2000-315327, A [Problems to be solved by the invention]
However, the lens kick control described above controls the displacement of the lens system in the pickup unit so that the lens system is positioned on the adjacent recording track. However, when the shift amount of the lens system in the pickup increases, The characteristic (ease of signal detection) is deteriorated and the performance of data read is deteriorated. As a result, there is a problem that data read errors such as ID detection impossible and correction impossible occur.
[0008]
Accordingly, the present invention has been made to solve these problems, and an object thereof is to provide an optical disc apparatus and a track jump control method capable of reducing the occurrence of reading errors.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, an optical disk apparatus according to the present invention includes a thread feeding means for moving a pickup in a thread direction with respect to a track on a rotating disk, and a lens system in the pickup at an adjacent recording track position. An optical disc apparatus comprising: a lens kick means for shifting; and a control means for selectively driving the thread feeding means and the lens kick means to position the lens system of the pickup on the designated recording track. It has a determining means for determining the maximum shift amount of the lens system of the pickup to be shifted by the lens kick means for each area.
[0010]
According to the present invention, since the maximum shift amount is determined for each area of the disk, it is possible to reduce the occurrence of reading errors according to the state of each area of the disk. Thereby, playability is securable. In addition, the reduction in reading errors leads to a reduction in data lead time.
[0011]
The present invention is characterized in that, in the optical disk apparatus, the determining means changes a maximum shift amount in a disk area where the error has occurred when a reading error of the disk occurs.
[0012]
According to the present invention, when a disk reading error occurs, the maximum shift amount in the disk area where the error has occurred is changed, so that even if a reading error occurs, the recurrence of the reading error can be prevented. Can do.
[0013]
In the optical disk apparatus according to the present invention, when a reading error occurs, the control means moves the pickup by the thread feeding means by an amount corresponding to a shift amount of the lens kick means at an error occurrence location. And
[0014]
According to the present invention, since the pickup is moved by the thread feeding means by the shift amount of the lens kick means at the error occurrence location, it is possible to prevent the data read error from recurring.
[0015]
The track jump control method according to the present invention includes a thread feeding means for moving a pickup in a thread direction with respect to a track on a rotating disk, and a lens kick for shifting the lens system of the pickup to an adjacent recording track position. Means for determining a maximum shift amount of the lens system of the pickup to be shifted by the lens kick means for each area of the disk in the track jump control method for positioning the lens system of the pickup on a designated track. It has one process.
[0016]
According to the present invention, since the maximum shift amount is determined for each area of the disk, it is possible to reduce the occurrence of reading errors according to the state of each area of the disk. Thereby, playability is securable. In addition, the reduction in reading errors leads to a reduction in data lead time.
[0017]
The track jump control method may further include a second step of changing a maximum shift amount in the disk area where the error has occurred when the disk read error occurs. To do.
[0018]
According to the present invention, when a disk reading error occurs, the maximum shift amount in the disk area where the error has occurred is changed, so that even if a reading error occurs, the recurrence of the reading error can be prevented. Can do.
[0019]
In the track jump control method according to the present invention, when the disk reading error occurs, the pick-up is performed by the thread feeding means by an amount corresponding to the shift amount of the lens kick means at the error occurrence location. It has the 3rd process to move, It is characterized by the above-mentioned.
[0020]
According to the present invention, since the pickup is moved by the thread feeding means by the shift amount of the lens kick means at the error occurrence location, it is possible to prevent the data read error from recurring.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a block diagram of an optical disc apparatus according to this embodiment. In FIG. 1, reference numeral 1 denotes an optical disk, which is placed on a turntable and rotationally driven at a predetermined rotational speed D to be used for signal reproduction. Further, a spiral track is formed on the recording surface of the optical disc 1 around the rotation axis.
[0022]
2 is a spindle motor that rotates the optical disk 1 at a predetermined linear velocity, 3 is an optical pickup that irradiates the optical disk 1 with a laser beam, and detects a signal recorded on the optical disk 1 from a reflected beam. A sled motor 5 for sending in the radial direction of the optical disk 1 is an RF amplifier that creates an RF signal, an EFM signal, a focus error signal FE, a tracking error signal TE, a CLV control signal, and the like from the detection signal of the optical pickup 3. The pickup 3 supports a lens system (not shown) via a spring or the like.
[0023]
Reference numeral 6 denotes a spindle servo circuit that controls the drive of the spindle motor 2 based on the CLV control signal, 7 denotes a focus servo circuit that controls the drive of the focus actuator of the optical pickup 3 based on the focus error signal FE, and 8 denotes a tracking error signal TE. Is a tracking servo circuit that controls the driving of the tracking actuator of the optical pickup 3, 8a is a loop filter that performs phase compensation, 8b is an adder, and 8c is an amplifier.
[0024]
Reference numeral 9 denotes a sled servo circuit that performs drive control of the sled motor 4 based on a signal input from the LPF 8a, 9a is a loop filter that performs phase compensation, 9b is an adder, and 9c is an amplifier.
[0025]
10 receives an instruction from a system controller 15 to be described later, inputs a predetermined lens kick signal to the adder 8b, kicks the objective lens in a predetermined direction by a predetermined amount, and performs a fine seek, or a predetermined thread feed signal. Is input to the adder 9b, the entire optical pickup is threaded in a predetermined direction by a predetermined amount, and coarse seek is performed, and is constituted by a microcomputer or the like.
[0026]
11 is a digital signal processing circuit that performs synchronization, deinterleaving, error correction, etc. on the EFM signal output from the RF amplifier 5 and demodulates audio sample data or subcode data, and 12 and 13 are digital signals. A D / A converter for D / A converting audio sample data output from the signal processing circuit for each channel, and 14 includes a PLAY key, a STOP key, a direct music selection key, a music advance key, a music return key, and the like. An operation unit 15 is a system controller composed of a microcomputer or the like that controls the entire system to perform a desired normal performance operation or music selection performance operation in accordance with an operation on the operation unit.
[0027]
When the optical disk 1 is set, the system controller 15 activates various servos, moves the optical pickup 3 to the lead-in area, and makes the optical pickup 3, the RF amplifier 5, and the digital signal processing circuit 11 perform TOC information. Is stored in a built-in memory (not shown). The system controller 15 corresponds to determination means and control means. In FIG. 1, reference numeral 20 denotes lens kick means.
[0028]
Next, a method for determining the maximum shift amount for each region will be described. FIG. 2 is a diagram showing a flow for determining the maximum shift amount for each disk area. FIG. 3 is a diagram illustrating a state in which a variable according to the maximum shift amount is assigned. In FIG. 3, the left side shows the inner circumference side of the disc, and the right side shows the outer circumference side of the disc. In the example shown in FIG. 3, the disk is divided into two areas, area A and area B. In the area A, a variable SA corresponding to the maximum shift amount is assigned, and in the area B, a variable SB corresponding to the maximum shift amount is assigned. The variables SA and SB can be changed as will be described later.
[0029]
As shown in FIG. 2, first, in step S11, the system controller 15 passes the optical pickup 3, the RF amplifier 5, and the digital signal processing circuit 11 from the inner circumference side of the disc toward the outer circumference side of the disc. The optical disc 1 is divided into a plurality of areas in the radial direction. In the example shown in FIG. 3, the disk is divided into an area A and an area B.
[0030]
In step S12, the system controller 15 determines the maximum shift amount for each of the areas divided in step S11, assigns variables SA and SB corresponding to the maximum shift amount, stores them in the memory, and ends the process.
[0031]
In this embodiment, the playback disc is divided into regions by disc radius and address, each region has a maximum shift amount as a variable, and the maximum shift amount of the pickup is changed according to the data reading position of the pickup according to each region. I am doing so. By providing the maximum shift amount as a variable for each region, playability can be ensured without slowing down the seek operation even when there are hard-to-read parts or easy-to-read parts. Note that the area in step S11 may be replaced with the environmental temperature of the mechanism or the vibration of the mechanism.
[0032]
Next, read processing of the optical disc apparatus according to the present embodiment will be described. FIG. 4 is a flowchart of the read process of the optical disc apparatus according to the present embodiment. First, in step S21, the system controller 15 detects whether the current position of the optical pickup 3 is in the area A of the optical disc 1 via the optical pickup, the RF amplifier 5, and the digital signal processing circuit 11, and the optical pickup 3 In step S22, the maximum shift amount is set in the variable SA, and the process proceeds to step S24.
[0033]
That is, the system controller 15 gives an instruction to the search control circuit 10, and the search control circuit 10 that has received the instruction sends a predetermined lens kick signal corresponding to the variable SA to the adder 8b in the area A of the optical disc 1. Input and kick the objective lens in a predetermined direction by a predetermined amount to perform fine seek.
[0034]
In step S21, if the pickup position is not in the area A, the system controller 15 proceeds to step S23, sets the maximum shift amount to the variable SB, and proceeds to step S24.
[0035]
That is, the system controller 15 gives an instruction to the search control circuit 10, and the search control circuit 10 receiving the instruction inputs a predetermined lens kick signal corresponding to the variable SB to the adder 8b in the area B of the optical disc 1. Then, the objective lens is kicked in a predetermined direction by a predetermined amount to perform fine seek.
[0036]
In step S24, the system controller 15 performs normal read processing via the optical pickup 3, the RF amplifier 5, and the digital signal processing circuit 11, and proceeds to step S25.
[0037]
In step S25, the system controller 15 refers to the output of the digital signal processing circuit 11 to detect whether or not the data read has been completed normally. Proceed to the lens shift correction flow. On the other hand, if the system controller 15 detects in step S25 that the data read has ended normally, it ends the process.
[0038]
Next, correction of the lens shift amount will be described. FIG. 5 is a flowchart of lens shift amount correction processing. As shown in FIG. 5, in step S31, the system controller 15 refers to the output of the digital signal processing circuit 11 and detects whether or not a read error has occurred. The process in step S31 corresponds to step S25 in FIG.
[0039]
If the read error has not occurred in step S31, the system controller 15 proceeds to step S33. In step S31, when the system controller 15 detects that a read error has occurred, the system controller 15 changes a variable corresponding to the maximum shift amount in step S32.
[0040]
That is, as shown in FIG. 3, the variable SA is assigned in correspondence with the maximum shift amount of the region A, and the variable SB is assigned in correspondence with the maximum shift amount of the region B, but when a reading error occurs, The maximum shift amount is changed so that the maximum shift amount becomes smaller than the previously assigned maximum shift amount, and a variable corresponding to the changed maximum shift amount is assigned in that area, and the assigned variable is stored in the internal memory. To store.
[0041]
When the system controller 15 next reads the area, the system controller 15 gives an instruction to the search control circuit 10, and the search control circuit 10 receiving the instruction in the area of the optical disc 1 performs a predetermined lens kick according to the changed variable. A signal is input to the adder 8b, and the objective lens is kicked in a predetermined direction by a predetermined amount to perform fine seek. In this way, when a reading error occurs, the maximum shift amount is reduced, so that the visual field specification at the time of data reading can always be kept in a good state.
[0042]
Next, in step S33, the system controller 15 performs an existing track search process according to the changed variable, and proceeds to step S14. In step S34, the system controller 15 performs the existing data read process and ends the process.
[0043]
As described above, the variable SA or SB is selected depending on the position of the optical pickup 3 on the optical disc 1, and if the read does not end normally, the variable corresponding to the maximum shift amount is changed. By performing the above, the optimum maximum shift amount in each region is selected.
[0044]
Next, an operation for canceling the lens shift amount will be described. FIG. 6 is a processing flowchart of the lens shift amount canceling operation. First, in step S41, the system controller 15 performs an existing track search process via the optical pickup 3, the RF amplifier 5, and the digital signal processing circuit 11, and proceeds to step S42.
[0045]
In step S42, the system controller 15 refers to the output level of the digital signal processing circuit to detect whether a read error has occurred. If no read error has occurred, the system controller 15 proceeds to step S44. On the other hand, if a read error has occurred in step S42, the system controller 15 proceeds to step S23 and moves the sled motor 4 to cancel the lens shift amount.
[0046]
In other words, the system controller 15 gives an instruction to the search control circuit 10, and the search control circuit 10 that has received the instruction inputs a predetermined thread feed signal corresponding to a predetermined lens kick signal to the adder 9b to input the optical pickup. The entire thread is fed in a predetermined direction by a predetermined amount.
[0047]
As described above, the shift amount of the lens is corrected by moving by the thread feeding means by the shift amount of the lens, so that the recurrence of the reading error can be reduced.
[0048]
In step S43, the system controller 15 performs the existing data read process and ends the process. According to the present embodiment, when a data read error such as ID detection impossible / correction occurs due to signal detection, the shift amount of the pickup lens is reduced as much as possible, and the visual field characteristics are improved. Since the recovery process of preventing the recurrence of the data read error is performed by re-executing the data read, playability is ensured. In addition, a high-speed seed operation can be realized.
[0049]
The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Deformation / change is possible. For example, in this embodiment, the determination of the maximum shift amount and the control of the thread feeding means and the lens kick means are performed by the system controller 15 shown in FIG. 1, but the present invention is not limited to this configuration. It can also be realized by other means.
[0050]
【The invention's effect】
As described above, according to the present invention, an optical disc apparatus and a track jump control method that can reduce the occurrence of reading errors are provided.
[Brief description of the drawings]
FIG. 1 is a block diagram of an optical disc apparatus according to an embodiment.
FIG. 2 is a diagram showing a flow of determining a maximum shift amount for each disk area.
FIG. 3 is a diagram illustrating a state in which a variable according to a maximum shift amount is assigned.
FIG. 4 is a flowchart of read processing of the optical disc apparatus according to the present embodiment.
FIG. 5 is a flowchart of lens shift amount correction processing;
FIG. 6 is a processing flowchart of a lens shift amount canceling operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Optical disk apparatus 2 Spindle motor 3 Optical pick-up 4 Thread motor 5 RF amplifier 7 Focus servo circuit 8 Tracking servo circuit 9 Thread servo circuit 10 Search control circuit 11 Digital signal processing circuit 15 System controller

Claims (6)

Thread feeding means for moving the pickup in the thread direction with respect to the track on the rotating disk, lens kick means for shifting the lens system in the pickup to an adjacent recording track position, the thread feeding means, and the lens kick An optical disc apparatus comprising: a control means for selectively driving the means to position the lens system of the pickup on the designated recording track;
An optical disc apparatus comprising: a determining unit that determines a maximum shift amount of the lens system of the pickup that is shifted by the lens kick unit for each area of the disc. 2. The optical disc apparatus according to claim 1, wherein the determination unit changes a maximum shift amount in a disc area where the error has occurred when a read error of the disc occurs. 3. The control device according to claim 1, wherein when the reading error occurs, the thread feeding device moves the pickup by an amount corresponding to a shift amount of the lens kick device at an error occurrence position. The optical disk device described. The lens system of the pickup is designated by a thread feeding means for moving the pickup in a thread direction with respect to a track on the rotating disk and a lens kick means for shifting the lens system of the pickup to an adjacent recording track position. In the method of controlling the track jump positioned on the track,
A track jump control method comprising a first step of determining a maximum shift amount of the lens system of the pickup to be shifted by the lens kick means for each area of the disc. 5. The track according to claim 4, wherein the track jump control method further includes a second step of changing a maximum shift amount in a disk area where the error has occurred when a read error of the disk occurs. Jump control method. The track jump control method further includes a third step of moving the pickup by the thread feeding means by an amount corresponding to the shift amount of the lens kick means at the error occurrence location when a reading error of the disk occurs. 6. The track jump control method according to claim 4, wherein the track jump is controlled.

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