JPH10320897A - Optical disk recording/reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk recording/reproducing device capable of performing an excellent recording/reproducing operation while performing stable and accurate multi-track jumping with an optical pickup even if there is damage, dust or stains in an optical disk. SOLUTION: Signal omission is detected by a control circuit when dust or stains are stuck to an optical disk and a defect signal is then produced, and if this defect signal is ON, a track count signal and acceleration and deceleration pulses for a driving signal are produced by a specified method and, by inserting these into the track count signal and the driving signal, the multi-track jumping of the optical pickup is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording / reproducing apparatus, and more particularly, to a means for an optical pickup to move a plurality of tracks collectively in a radial direction of an optical disk.

[0002]

2. Description of the Related Art Hitherto, in an optical disk recording / reproducing apparatus, means for moving a plurality of tracks together (hereinafter, referred to as "multi-track jump") has been used to move an optical pickup to a target track. . This conventional technique will be described with reference to FIGS. FIG. 3 is a schematic diagram of an optical disk recording / reproducing apparatus, and FIG. 4 is a timing chart of a multi-track jump. FIG. 5 is a timing chart of a conventional multi-track jump at the time of a defect, and FIG. 6 is a flowchart of a conventional multi-track jump.

First, an optical disk recording / reproducing apparatus will be described. As shown in FIG. 3, a spindle motor 2 for rotating an optical disk 1, an objective lens 4 for condensing a laser beam on the optical disk 1, and a focusing direction for the objective lens 4 An optical pickup 3 having a lens actuator 5 that moves in the tracking direction; a sled motor 7 that moves the optical pickup 3 in the radial direction of the optical disk 1 via an optical pickup drive shaft 6; a semiconductor laser (not shown); An optical component including elements and the like, and a control circuit 8 for controlling these members are provided.

First, a control circuit 8 controls a thread motor 7 in accordance with a target track instruction input from outside to move a light beam to a target track, and moves the optical pickup 3 in a radial direction. Next, a focus error signal and a tracking error signal are extracted from an output signal of the optical pickup 3 for adjusting a light beam to a target track. Based on the focus error signal and the tracking error signal, the control circuit 8 drives the lens actuator 5 of the optical pickup 3 to control the focus direction of the objective lens 4 (hereinafter, referred to as “focus servo”).
And a track direction control (hereinafter, referred to as “tracking servo”) to precisely control the position of the objective lens 4 so that the light beam matches the target track.

In the above-described control for matching the light beam to the target track, when the optical pickup 3 is moved to the target track by the thread motor 7, the optical pickup 3 is moved in a radial direction of the optical disc 1 to collectively collect a plurality of tracks. A moving, so-called multi-track jump is performed.

Next, control of the conventional multi-track jump will be described. The track count signal in FIG. 4 is a tracking error signal output from the optical pickup 3 or a crossing signal of the track generated in the control circuit 8 from the RF signal, and measures the target number of tracks and the time required to move between tracks. Used for The drive signal includes an acceleration pulse and a deceleration pulse, and is used for driving the lens actuator 5 and the sled motor 7. The drive signal is not limited to a pulse signal, but may be an analog signal.

At the start of a multi-track jump, first,
Stop (OFF) the tracking servo. Next, the acceleration pulse of the drive signal is output from the control circuit 8 to drive the sled motor 7. The larger the track jump amount,
A large number of acceleration pulses are generated to greatly accelerate the sled motor 7 to move the optical pickup 3 quickly.

When the time interval of the track count signal is set to a constant value, that is, the movement of the optical pickup 3 is performed at a predetermined speed. Output a lot,
When the track count time interval is short, the deceleration pulse is output more than the acceleration pulse and adjusted. When the count number of the track count signal reaches the number corresponding to the target track position, the output of the acceleration and deceleration pulses is stopped and the tracking servo is started (ON).

As described above, the multi-track jump enables the optical pickup 3 to move a plurality of tracks in a lump and quickly reach a target track. However, in the conventional multi-track jump, when a signal is lost (hereinafter, referred to as “defect”) when dust or dirt adheres to the optical disc, the number of moving tracks increases or the acceleration of the optical pickup 3 is excessive. There was a problem of running out of control.

This will be described with reference to a timing chart of a multi-track jump at the time of a defect shown in FIG. The defect is detected from the signal level of the optical pickup 3, and the ON of the defect signal means that the signal is missing. Since the signal is missing in this ON section, no track count signal is output even though the optical pickup 3 crosses the track. FIG.
The dashed line of the track count signal indicates a signal which is normally output unless it is in a defect state.

In this signal missing state, there is no track count signal, and therefore, it is determined that the moving speed of the optical pickup 3 is slow, and the generation of the acceleration pulse of the drive signal is increased. As a result, the moving speed of the optical pickup 3 increases as the signal missing time increases. Also, since the moving speed of the optical pickup 3 is high immediately after passing through the defect, the time interval of the track count signal becomes short, and accordingly, the generation of the deceleration pulse increases. However, it takes time to reduce the speed to the predetermined moving speed, and depending on the position of the defect, a target track may be exceeded, and further time for position control may be required.

Further, when the defect time is long,
The acceleration is so large that the moving speed becomes too fast, and it becomes a state close to runaway. If such a state occurs near the outer periphery of the optical disk 1, there is also a problem that the optical pickup 3 jumps out of the data area of the optical disk 1.

Next, the control flow of the conventional multi-track jump will be described with reference to the flowchart of FIG.

First, when a multi-track jump is commanded, the tracking servo is turned off (step S20).
1). At this time, the sled on which the optical pickup is mounted may be accelerated and kicked. Next, the time interval of the track count signal generated with the movement of the thread is measured (step S202), and it is determined whether the time interval is larger than a predetermined value (step S203). If the time interval is larger than the predetermined value, it is determined that the moving speed of the optical pickup 3 is slow, and an acceleration pulse is output (step S20).
4) On the other hand, if it is smaller than the predetermined value, it is determined that the moving speed is high, and a deceleration pulse is output (step S205).
Thereafter, the pulses of the track count signal are counted (step S206), and it is determined whether or not the count has reached a value N corresponding to the number of tracks to be jumped (step S207). If the value N has not been reached, step S2
02, and the subsequent steps are executed again. On the other hand, if the value has reached the value N, it is determined that the target track has been reached, and the tracking servo is turned on (step S20).
8), end the control of the multi-track jump. At this time, a deceleration kick may be performed to stop the thread.

As described above, the operation of the multi-track jump is controlled. If there is a defect, the track count signal is lost. Therefore, it is determined in step S203 that the time interval of the track count signal is larger than a predetermined value. As a result, the acceleration pulse is continuously output, which causes a problem such as runaway of the optical pickup.

[0016]

SUMMARY OF THE INVENTION Accordingly, the present invention provides an optical disc recording / reproducing apparatus which performs stable and accurate multi-track jumping even when an optical disc has scratches, dust, dust, etc. It is an object to provide a device.

[0017]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has at least a movement control means for controlling a radial movement of an optical pickup in an optical disk, and a movement of the optical pickup in a radial direction of the optical disk. At this time, it comprises a track crossing detecting means for detecting a track crossing, a first pseudo signal generating means for generating a pseudo signal for crossing a track, and a second pseudo signal generating means for controlling a moving speed. If a track-crossing signal cannot be obtained when traversing the track of the optical pickup, the signal generated by the first pseudo-signal generating means is interpolated into a portion where the track-crossing signal is missing, and the second pseudo signal is inserted. The signal generated by the signal generating means is inserted into the movement control means to constitute an optical disk recording / reproducing apparatus for controlling the movement of the optical pickup. To solve the serial problems.

According to the configuration of the present invention, even when a track crossing signal cannot be obtained when the optical pickup crosses a track, the signal generated by the pseudo signal generating means is interpolated into a portion where the track crossing signal is missing. Thus, stable movement control of the pickup can be performed.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to FIGS. FIG. 1 is a timing chart of a multi-track jump at the time of a defect according to the present invention, and FIG. 2 is a flowchart of a multi-track jump according to the present invention.

An optical disk recording / reproducing apparatus to which the multi-track jump control method according to the present invention is applied conforms to the conventional example described with reference to FIG. 3, and a detailed description of the configuration of this apparatus will be given. Is omitted. FIG. 3 is referred to as needed.

As shown in FIG. 1, the control circuit 8 (see FIG. 3) detects a signal loss when dust or dirt adheres to the optical disc 1, and generates a defect signal. When the defect signal is ON, a track count signal, an acceleration pulse and a deceleration pulse of the drive signal are generated by a predetermined method, and these are interpolated into the track count signal and the drive signal, thereby obtaining the optical pickup 3.
(See FIG. 3). The drive signal to be generated is not limited to a pulse, but may be an analog signal.

Next, the control flow of the multi-track jump of the present invention will be described with reference to the flowchart of FIG.

First, when a multi-track jump is commanded, the tracking servo is turned off (step S10).
1). At this time, the sled on which the optical pickup is mounted may be accelerated and kicked. Next, the time interval of the track count signal is measured (step S102), and it is determined whether or not the optical disc has a defect (step S103). If there is no defect, step S1
In step 04, control is performed in the same manner as in the related art. On the other hand, if there is a defect, the track count is waited for a predetermined time (step S108), and then the count number of the track count signal is increased by 1 (step S109). An acceleration / deceleration pulse is output (step S110). Thereafter, in step S111, it is determined whether or not the count has reached a value N corresponding to the number of tracks to be jumped. If the value N has not been reached, the process returns to step S102, and the subsequent steps are executed again. On the other hand, if the value N has been reached,
When it is determined that the target track has been reached, the tracking servo is turned on (step S112), and the multi-track jump control is terminated. At this time, a deceleration kick may be performed to stop the thread.

The predetermined time in step S108 may be a track count time at which a desired moving speed is obtained, or a time interval of a track count signal measured immediately before a defect. In addition, the relationship between the acceleration / deceleration pulse may be determined so that the predetermined acceleration / deceleration pulse in step S110 has a moving speed having a desired acceleration.
The ratio of the acceleration / deceleration pulses may be set to be the same so that the moving speed is kept constant.

As described above, by generating and interpolating the acceleration pulse and the deceleration pulse of the drive signal by a predetermined method at the time of a defect, it is possible to perform stable multi-track jump control without runaway. Also, the missing track count at the time of passing through the defect can be compensated by generating and interpolating the track count signal, and the moving distance to the target track can be estimated.

[0026]

As is apparent from the above description, according to the optical disk recording / reproducing apparatus of the present invention, the optical disk has scratches,
Even when there is a defect such as dust or dirt, the optical pickup can stably and accurately perform a multi-track jump, thereby preventing an increase in access time and runaway.

[Brief description of the drawings]

FIG. 1 is a timing chart of a multi-track jump at the time of a defect according to the present invention.

FIG. 2 is a flowchart of a multi-track jump according to the present invention.

FIG. 3 is a schematic diagram of an optical disk recording / reproducing apparatus.

FIG. 4 is a timing chart of a multi-track jump.

FIG. 5 is a timing chart of a conventional multi-track jump at the time of a defect.

FIG. 6 is a flowchart of a conventional multi-track jump.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk, 2 ... Spindle motor, 3 ... Optical pickup, 4 ... Objective lens, 5 ... Lens actuator,
6 ... optical pickup drive shaft, 7 ... thread motor, 8 ...
Control circuit

Claims (1)

[Claims] At least when the optical pickup moves in the radial direction of the optical disk, the movement control means controls the radial movement of the optical disk in the optical pickup.
A track crossing detecting means for detecting a track crossing, a first pseudo signal generating means for generating a pseudo signal for crossing a track, and a second pseudo signal generating means for controlling a moving speed; When a track crossing signal cannot be obtained when crossing a track, the signal generated by the first pseudo signal generation means is interpolated into a portion where the track crossing signal is missing, and the second pseudo signal generation means is inserted. Interpolating the signal generated by the movement control means,
An optical disc recording / reproducing apparatus for controlling movement of an optical pickup.