JP5066203B2 - Optical disk device - Google Patents

Description

  The present invention relates to an optical disc apparatus having an optical pickup, and more particularly to a track jump in an optical disc.

There has been proposed a track jump method for storing a scan position of a track when an abnormality occurs in the track jump of the optical disc and outputting a track jump command at a timing at which the track jump does not overlap. (Patent Document 1)
By using this method, when the rotation speed of the optical disk is low, the track jump can be performed so as not to overlap the PID portion.

Japanese Patent Laid-Open No. 5-205287

  In the above-described prior art of Patent Document 1, no consideration is given to the case where the rotational speed is increased and the PID portion cannot be avoided during the track jump.

  As DVD-RAM increases in speed, track jumps cannot be performed within one sector (between PID and PID), and track jumps must be performed across two sectors.

  The time required for track jumping is approximately 200 to 300 μs, but the time from passing the next PID to passing the next PID is approximately 300 μs at 5 × speed, and the recording / reproducing speed exceeds 5 × speed. This is because the PID is passed during the track jump.

  As shown in FIG. 2, if the PID is passed before the deceleration end threshold, the deceleration voltage end timing is incorrect, the deceleration is insufficient, the light spot cannot be drawn into the target track, the track jump fails, and the disk There is a possibility that the reproduction operation or recording operation of the system fails.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical disc apparatus that improves the stability of track jump .

The above object is achieved, for example, by the configurations described in the claims.

According to the present invention, it is possible to provide an optical disc apparatus that improves the stability of track jump .

Track jump basic operation explanatory diagram Track jump failure operation explanatory diagram Optical disk device Track jump operation explanatory diagram Track jump operation explanatory diagram Track jump operation explanatory diagram flowchart

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

  The optical disk apparatus of the present invention may be any of a reproduction-only apparatus, a recording-only apparatus, and a recording / reproducing apparatus as long as it can discriminate an optical disk.

Data is recorded on an optical disc having grooves and lands of a certain length for recording spiral or concentric data, and having a plurality of sectors consisting of a header portion consisting of address data and a data area where data is recorded. Alternatively, a DVD-RAM disc compatible optical disc device has been developed in which data recorded on an optical disc is reproduced and PID (Physical ID) as address data of the header portion is alternately formed for grooves and lands. ing.

  Further, in the optical disc apparatus, the track jump for moving the light spot to the adjacent track is controlled using the tracking error signal. As shown in FIG. 1, the waveform of the tracking error signal changes in accordance with the movement of the light spot between tracks. In the track jump control, the acceleration voltage and the deceleration voltage are synchronized with the timing when the light spot passes the track boundary. The control of is particularly important. By switching the acceleration voltage to the deceleration voltage at the timing when the track error signal crosses the acceleration / deceleration switching threshold, the track jump is realized by switching to the normal feedback control by terminating the application of the deceleration voltage at the timing crossing the deceleration end threshold. Because.

  However, in a DVD-RAM drive device or the like, if the light spot crosses the PID at the time of track jump, a tracking error signal is generated and switching between acceleration and deceleration by the tracking drive signal is not normally performed. It was necessary to perform a track jump so as not to cross.

  FIG. 3 is a block diagram showing the configuration of the optical disc apparatus according to the present invention.

  The optical disk 100 is read, erased, and written by irradiating laser light from the optical pickup 110, and rotated by a spindle motor 101 driven by a spindle motor driving means 121 that receives a signal from the system control means 120. The

  The laser light emitted from the laser light source 111 is condensed on the information recording surface of the optical disc 100 by the objective lens 113 moved in the radial direction of the optical disc 100 by the actuator 112, reflected, and detected by the photodetector 114. The tracking error signal generated by the error signal generation unit 122 from the signal detected by the photodetector 114 is input to the system control unit 120, and the actuator is driven by the tracking drive signal output from the system control unit based on the information. The means 123 drives the actuator 112 and moves the objective lens 113 in the radial direction of the optical disc 100.

FIG. 4 shows the movement of the light spot and the tracking error signal and the tracking drive signal during the track jump according to the present invention. The system control unit 120 outputs the acceleration voltage to the tracking drive signal, then moves the actuator in the jump direction while detecting the tracking error signal, and measures the acceleration time A until the tracking error signal crosses the acceleration / deceleration switching threshold. Then, the deceleration end threshold is not set, and the deceleration voltage is output only for the deceleration time B which is a certain ratio of the acceleration time A. When the ratio is α, the deceleration time B is expressed by the following equation.
B = α × A
As a result, even if the light spot crosses the PID during deceleration, deceleration can be performed for a certain time with respect to the acceleration time A without being affected by it. Although the deceleration end threshold is not set, the same applies if the deceleration end threshold is set to a level equal to or greater than the amplitude of the tracking error signal.

  Also, the timing for starting the track jump is adjusted by setting the wait process after passing the PID. The time for this wait process is set so that the light spot does not cross the PID during acceleration and crosses the PID at approximately the center of the deceleration time in order to cope with variations. Since the DVD-RAM has a larger number of PIDs on the outer periphery, assuming that the disk rotation method is constant angular velocity (hereinafter referred to as CAV), the time between the PID and the PID differs between the inner periphery and the outer periphery of the disk. To cope with this, the wait time may be set for each zone.

  By outputting an acceleration signal and a deceleration signal in the same manner, it can be applied to a half track jump from a land to a groove and from a groove to a land.

  FIG. 5 shows the movement of the light spot and the tracking error signal and the tracking drive according to the present invention when the appearance period of the PID is shorter than that of the first embodiment and it is difficult to cope with the method of the first embodiment. The signal is shown. The configuration of the optical disc apparatus of the present embodiment is the same as that of the first embodiment.

  As in the first embodiment, the deceleration time B is a certain ratio of the acceleration time A. The system control means 120 sets the wait processing time so that the light spot crosses the PID immediately after the start of acceleration.

  The system control unit 120 performs an error signal ignoring process P for ignoring even if the tracking error signal crosses the acceleration / deceleration switching threshold when acceleration starts, and then detects the tracking error signal, and the tracking error signal is detected by the acceleration / deceleration switching threshold. Detects crossing. The time for the error signal ignoring process P is set to the time required for the light spot to cross the PID and before the acceleration / deceleration switching threshold is crossed.

  Further, the system control means 120 performs error signal ignoring processing Q after switching the tracking drive voltage to deceleration, causes the tracking error signal to be ignored even if it crosses the deceleration end threshold, and sets the deceleration time B to a certain acceleration time A. Output only percentage. The time of the error signal ignoring process Q is set long enough to sufficiently cover the deceleration time B.

  By combining the first and second embodiments, the track jump is performed by the method of the first embodiment at the inner and middle circumferential portions of the optical disk 100 rotating at CAV, and the track jump is performed by the method of the second embodiment at the outer periphery. Can be used.

  FIG. 6 shows the movement of the light spot and the tracking error signal and the tracking drive signal at the time of track jump according to the present invention in the case where the appearance period of the PID is shorter than that of the first embodiment and the method of the first embodiment cannot cope. Show. The configuration of the optical disc apparatus of the present embodiment is the same as that of the first embodiment.

  In the present embodiment, the acceleration voltage X and the deceleration voltage Y are made larger than the acceleration voltage V and the deceleration voltage W of the first embodiment. For this reason, the moving speed of the objective lens 113 is increased, and the moving time can be shortened.

  If the method of this embodiment is used, the time set for each of the optical discs 100 in Embodiments 1 and 2 can be used for different rotational speeds. That is, even if the rotational speed is different, it is possible to cope with one wait time for one zone by changing the voltage level of acceleration / deceleration. Thus, if the wait time is set for each zone in the memory or the like of the optical disc apparatus, it is only necessary to change the voltage depending on the rotation speed, and a parameter table for the wait time is not required for each rotation speed.

  In this embodiment, a method in which the time set for each zone in the optical disc 100 in Embodiments 1 and 2 is used for different rotational speeds is shown. The configuration of the optical disc apparatus of the present embodiment is the same as that of the first embodiment.

  In both the first and second embodiments, the acceleration voltage and the deceleration voltage are constant regardless of the zone, and the wait time is set for each zone. When the rotational speeds are different, the time for crossing the PID changes, so it is necessary to set a wait time table for each rotational speed corresponding to the optical disc apparatus.

  Therefore, the wait time table is made to correspond to a plurality of rotation speeds by changing the voltage level as in the third embodiment. In the present embodiment, a method of making the wait time table correspond to a plurality of rotation speeds by adjusting the voltage level when the optical disc 100 is inserted into the optical disc apparatus will be described.

  A voltage level adjustment method will be described with reference to the flowchart of FIG.

  In step 1, both the acceleration voltage and deceleration voltage are set to the initial voltage level. This is stored in advance in the optical disk device.

  In step 2, a track jump is performed. At this time, the track jump may be performed in any zone, but is preferably performed in the inner peripheral portion because the inner peripheral portion has a smaller number of PIDs.

  In step 3, the time Ta required to accelerate the track jump is measured. Here, an appropriate time is stored in the optical disc device for the time required for acceleration suitable for the rotational speed. This is set as an allowable time Tx to Ty (Tx <Ty).

  In step 4, it is determined whether or not the measured acceleration time Ta is within the allowable time Tx to Ty.

  If Ta <Tx as a result of step 4, the voltage level is too high, so the voltage level is decreased in step 5 and the process returns to step 3.

  If Ta> Ty as a result of step 4, the voltage level is too small. Therefore, the voltage level is increased in step 6 and the process returns to step 3.

  If Tx ≦ Ta ≦ Ty as a result of step 4, the voltage level is assumed to be appropriate, and the level is set to step 7.

  By using the method of the present embodiment, unlike the third embodiment, it is possible to cope with variations in the sensitivity of the actuator, and even if the characteristics of the actuator differ due to the difference in temperature, the voltage level corresponding to the situation is changed. Can be set.

DESCRIPTION OF SYMBOLS 100 ... Optical disk, 101 ... Spindle motor, 110 ... Optical pick-up, 111 ... Laser light source, 112 ... Actuator, 113 ... Objective lens, 114 ... Optical detector, 120 ... System control means, 121 ... Spindle motor drive means, 122 ... Error Signal generating means, 123... Actuator driving means.

Claims (6)

An optical disc apparatus that has a plurality of address information recording units, reproduces information from an optical disc that conforms to the DVD-RAM standard, or records information on the optical disc,
An objective lens for condensing a laser to form a light spot, an actuator for moving the objective lens, a photodetector for detecting reflected light from the optical disc,
Based on the tracking error signal generated from the signal output from the photodetector,
The actuator is driven to control a track jump that is a movement from a land on the optical disk to a land adjacent to the land or a movement from a groove on the optical disk to a groove adjacent to the groove by the light spot. Control means,
The control means starts the track jump after the light spot passes through any one address information recording unit of the plurality of address information recording units, and the light spot is the arbitrary spot during the track jump. The time from when the light spot passes through the one address information recording unit to the start of the track jump is set so as to pass through the two address information recording units next to the one address information recording unit. An optical disc apparatus characterized by setting . The optical disc apparatus according to claim 1,
An optical disc apparatus, wherein the optical disc is an optical disc compatible with recording or reproduction at a speed of 5 times or more . The optical disc apparatus according to claim 1,
The control means accelerates the objective lens and performs the track jump by decelerating the objective lens when the tracking error signal reaches a predetermined threshold value after reaching a maximum value or a minimum value. An optical disc device characterized .   The optical disc apparatus according to claim 1,
  The optical disc is an optical disc having a plurality of zones;
  The optical disk apparatus according to claim 1, wherein the control unit sets a time period from when the light spot passes through the arbitrary one address information recording unit to the start of the track jump for each zone.   The optical disc apparatus according to claim 1,
  The optical disc is an optical disc having a plurality of zones;
  The optical disc apparatus, wherein the control means sets a drive voltage for driving the actuator for each zone.   An optical disc apparatus that has a plurality of address information recording units, reproduces information from an optical disc that conforms to the DVD-RAM standard, or records information on the optical disc,
  An objective lens for condensing a laser to form a light spot, an actuator for moving the objective lens, a photodetector for detecting reflected light from the optical disc,
  The actuator is driven based on a tracking error signal generated from a signal output from the light detector, and the light spot moves from a land on the optical disk to a land adjacent to the land, or the optical disk Control means for controlling a track jump, which is a movement from the upper groove to the groove adjacent to the groove,
  When the track jump period is longer than the interval from when the light spot passes through one address information recording unit to the next address information recording unit, during the track jump, A time from when the light spot passes through the address information recording unit to when the track jump starts is set before the start of the track jump so that the spot passes through two address information recording units. Optical disk device to perform.

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