JP2005267792A - Optical disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk device where a reproduction ability of an optical disk is improved by preventing the occurrence of sound jump when reproducing a damaged optical disk. <P>SOLUTION: In the case of judging that an optical pickup 3 is moved to an inner track 14 when passing through a damaged part 13, an offset 16 is added to tracking by adding an offset to a tracking drive signal output to a DSP 6 or adding an offset to an error signal input from an FEP, just before a reproduction position for acquiring an address just before passing through the damaged part 13 again. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical disc apparatus, and for example, relates to an optical disc apparatus capable of performing tracking control during reproduction of an optical disc.

  Conventionally, when reproducing information recorded on an optical disk, a laser beam spot is irradiated from an optical pickup along a track formed on the optical disk, and information recorded on the track is read from reflected light. .

  For this reason, it is necessary to control the pickup so that the beam spot is positioned directly above the track. As this control method, a tracking error signal corresponding to the deviation between the beam spot position and the track is generated, and servo control is performed using this error signal.

  By the way, if there are scratches or fingerprints on the surface of the optical disk, the tracking error signal becomes an incorrect control signal, and this false error signal causes a malfunction such as a light beam spot moving to an adjacent track. Need to prevent.

In order to prevent this kind of conventional malfunction, if a servo error signal contains a large fluctuation component immediately before a flaw detection signal is generated after a flaw is detected, the polar and negative polarities of the servo error signal are generated. The servo hold signal is generated immediately after generating the flaw detection signal, and the read operation of the optical pickup is controlled according to the servo hold signal instead of the servo drive signal during generation of the flaw detection signal. Even when a scratch on the recording medium is passed, there is one that can maintain the servo state immediately before passing the scratch (see, for example, Patent Document 1).
JP 2000-90467 A

  However, in the conventional servo control device, the reading operation of the optical pickup is controlled according to the servo hold signal instead of the servo drive signal during the generation of the flaw detection signal. If a false error signal is generated due to a flaw detection delay or reflected light disturbance, the servo is applied to the inner track after passing the flaw in response to this error signal. There was a risk of sound skipping due to a hold track condition.

  The present invention has been made to solve the conventional problems, and provides an optical disc apparatus capable of preventing the occurrence of sound skipping during reproduction of a damaged optical disc and improving the reproduction capability of the optical disc. Objective.

An optical disc apparatus according to the present invention outputs an optical beam toward an optical disc, reads information recorded on a track on the optical disc from reflected light from the optical disc, and the optical pickup along a radial direction of the optical disc. And detecting from the information read by the optical pickup that the optical pickup has passed through the scratch on the track of the optical disk and moved to the inner side in the radial direction with respect to the track. And an optical pickup hold detection means for generating an error signal.
The optical pickup control unit moves the optical pickup according to the error signal so that the optical pickup moves radially outward with respect to the track before the optical pickup passes the scratch next time. Consists of things to control.

  With this configuration, when the optical pickup moves to the radially inner peripheral side by passing through the scratch, the optical pickup moves to the radially outer peripheral side with respect to the track before the optical pickup passes the scratch next time. Therefore, the movement of the optical pickup is controlled, so that an unintended hold track can be released to prevent sound skipping, and the reproduction capability of the optical disk can be improved.

  Further, the optical disc apparatus of the present invention is configured such that the optical pickup control means adds an offset signal for moving the optical pickup to the outer peripheral side in the radial direction to the tracking drive signal output to the optical pickup. Is done.

  With this configuration, when the optical pickup moves to the radially inner peripheral side by passing through the scratch, the optical pickup moves to the radially outer peripheral side with respect to the track before the optical pickup passes the scratch next time. The optical pickup can be moved and controlled.

  In the optical disc apparatus of the present invention, the optical pickup control means adds an offset signal for moving the optical pickup to the outer peripheral side in the radial direction to the error signal input from the optical pickup hold detection means. Composed of things.

  With this configuration, when the optical pickup moves to the radially inner peripheral side by passing through the scratch, the optical pickup moves to the radially outer peripheral side with respect to the track before the optical pickup passes the scratch next time. The optical pickup can be moved and controlled.

  As described above, the present invention can provide an optical disc apparatus capable of improving reproduction capability by preventing sound skipping during reproduction of a damaged optical disc.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 are views showing an embodiment of an optical disk apparatus according to the present invention.

  First, the configuration will be described. In FIG. 1, an optical disk 1 such as a CD or DVD is driven to rotate by a spindle motor 2.

  The optical pickup 3 reads digital information recorded by the pits on the track of the optical disk 1 using a laser beam, and the driver motor moves the optical pickup 3 along the radial direction of the optical disk 1. It is composed of four. In the present embodiment, the traverse motor 4 constitutes an optical pickup moving means.

  A front-end processor (hereinafter simply referred to as FEP) 5 generates and outputs a focus error signal and a tracking error signal based on the read signal output from the optical pickup 3, and amplifies the read signal (RF signal). The scratches on the optical disk 1 are detected and output from these signals.

  A DSP (Digital Signal Processor) 6 shapes the RF signal output from the FEP 5 and performs processing such as demodulation, code error correction, and complementation as an EFM (Eight to Fourteen Modulation) signal of digital data.

  The DSP 6 also includes a DA converter that converts a digital signal into an analog signal, and an audio circuit that performs processing such as amplification and sound quality control on the analog signal output from the DA converter, via an audio output terminal 7. Output to an external speaker.

  The system controller 8 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) in which a program used in the CPU is stored, a data storage RAM (Random Access Memory), and an I / O (input / output) port. Consists of.

  The DSP 6 also has a servo controller circuit function. The focus error signal and tracking servo signal output from the FEP 5 under the control of the system controller 8 are used to control the focus servo and tracking servo of the optical pickup 3 and the traverse motor 4. A control signal is output to perform the traverse servo to be sent.

  The focus driver 9 uses the focus servo control signal output from the servo controller circuit of the DSP 6 so that the focus of the objective lens of the optical pickup 3 always matches the signal recording surface of the optical disc 1. Drive actuator.

  The tracking driver 10 drives the tracking servo actuator of the optical pickup 3 using the tracking servo control signal so that the laser beam output from the optical pickup 3 always traces on the track of the optical disc 1. The traverse driver 11 drives the traverse motor 4 using the traverse servo control signal output from the DSP 6 so that the laser beam output from the optical pickup 3 traces on the signal track of the predetermined optical disc 1.

  Further, the DSP 6 generates an error signal by detecting that the optical pickup 3 moves to the radially inner side with respect to the track on the optical disc 1, and has an optical pickup hold detecting means. .

  Further, the DSP 6 causes the optical pickup 3 to move radially outward with respect to the track before the optical pickup 3 passes the scratch next time when the optical pickup 3 moves to the radially inner periphery of the optical disc 1. The optical pickup 3 is moved and controlled, and has optical pickup control means.

  Next, a tracking control method will be described based on FIG. FIG. 2 is a conceptual diagram in which the scratched portion of the optical disk 1 is enlarged.

  First, when a damaged optical disk 1 is reproduced, when the laser beam 12 output from the optical pickup 3 reaches a scratched part (a part surrounded by a frame) 13 of the optical disk 1, tracking is performed until the DSP 6 detects the scratch. The servo may follow a false error signal and may be applied to the inner track 14 one lap before passing through the scratch, that is, the inner track 14 on the radially inner side of the optical disc 1. When this state is repeated, a hold track state is reached, so that the optical pickup 3 is 1 with respect to the target track 15 before the optical pickup 3 passes through the damaged portion 13 so that the target track 15 can be reached next time. An offset 16 is added to the tracking drive signal so as to move to the track after the circumference, that is, the outer circumference track 17 side in the radial direction outer circumference side.

  Specifically, the address information on the optical disk 1 is read from the optical disk 1 by the optical pickup 3, generated as an RF signal by the FEP 5 and digital data by the DSP 6, and sent to the system controller 8. Further, the address information progresses as it goes to the outer peripheral side.

  Using the above, the system controller 8 always compares the address before update with the address after update when updating the address information, and the address information after update is delayed from the address information before update during playback. If so, it is determined that it has moved to the inner track 14 by passing through the scratch.

  Here, in order to exclude the case where the address of a command such as a seek process is changed by an external operation, the address information update during reproduction is clarified using a flag or the like in the sysconfirm.

  The system controller 8 adds an offset to the tracking drive signal output to the DSP 6 immediately before the reproduction position for acquiring the address before passing the scratch again when it is determined that the movement is the inner peripheral movement by passing the scratch, or By adding an offset to the error signal input from the FEP 5, an offset 16 is added to the tracking (target track 15).

  These offset amounts are appropriately determined by the system at the time of design, and even when the hold track is moved to the inner track 14 without being released even by this value, the offset amount is incremented.

  As described above, in the present embodiment, when it is determined that the optical pickup 3 has moved to the inner track 14 side due to the passage of the scratched portion 13, immediately before the reproduction position for acquiring the address before the scratched portion 13 passes. Since the offset 16 is added to the tracking by adding an offset to the tracking drive signal output to the DSP 6 or adding an offset to the error signal input from the FEP 5, the unintended hold track is released. As a result, the occurrence of sound skipping can be prevented, and the reproduction capability of the optical disc 1 can be improved.

  As described above, the optical disc apparatus according to the present invention has the effect of preventing the occurrence of sound skipping during playback of a damaged optical disc and improving the playback capability of the optical disc. This is useful as an optical disk device or the like that can be controlled.

1 is a block diagram of an optical disc apparatus according to an embodiment of the present invention. The figure which shows a state when an optical pick-up passes the wound part of one Embodiment

Explanation of symbols

1 optical disk 3 optical pickup 4 traverse motor (optical pickup moving means)
6 DSP (optical pickup hold detection means, optical pickup control means)
13 Scratched part 14 Inner track 15 Target track 16 Offset 17 Outer track

Claims (3)

An optical pickup that outputs light toward an optical disc and reads information recorded on a track on the optical disc from reflected light from the optical disc;
Optical pickup control means for moving the optical pickup along the radial direction of the optical disc;
An optical pickup hold that generates an error signal by detecting that the optical pickup has passed through a flaw on the track of the optical disk and moved to the inner side in the radial direction with respect to the track from information read by the optical pickup. Detecting means,
The optical pickup control unit moves the optical pickup according to the error signal so that the optical pickup moves radially outward with respect to the track before the optical pickup passes the scratch next time. An optical disc apparatus characterized by controlling. 2. The optical disc according to claim 1, wherein the optical pickup control means adds an offset signal for moving the optical pickup to the outer peripheral side in the radial direction to the tracking drive signal output to the optical pickup. apparatus. 2. The optical pickup control unit adds an offset signal for moving the optical pickup to the outer peripheral side in the radial direction to the error signal input from the optical pickup hold detection unit. The optical disk device described.

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