JPH0573932A - Positioning control system for optical beam for optical disk device - Google Patents

Abstract

PURPOSE:To attain a high speed positioning by providing first and second position detectors, follow-up-controlling a corresponding tracking actuator with one detection signal, and, at the same time, controlling the other with a signal calculated based on this signal. CONSTITUTION:A reproduction beam 42 controlled by a second tracking actuator 60 is positioned at a target track at a high speed and with a high stability by counting moving tracks, and a first tracking actuator 56 which controls an erase beam 40, and a relative displacing actuator 62 (not indicated) which controls a recording beam 41, are displaced for positioning a light beam at the same track as the beam 42, so that the optical beam can be positioned at the target track simultaneously with the beam 42. That is, the present track number of the beam 42 is compared with the target track number, and a seek means is selected by the number of the moving tracks, so that the position operation can be operated, by a positioning command from a positioning controller 80.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is concerned with erasing, recording and reproducing.
The present invention relates to a light beam positioning control method for an optical disk device that has improved access frequency, track pull-in stability, and positioning accuracy in an optical disk device such as a magneto-optical disk device having one light beam.

[0002]

2. Description of the Related Art As a rewritable optical disk device, there is a magneto-optical disk device. When writing data to an ISO standard magneto-optical disk, three steps are required: "erasing" the previous data, "recording" the data, and "playing" to confirm whether the data was written correctly. Since the conventional magneto-optical disk device realizes the above-mentioned three functions with one light beam, it is necessary to rotate the disk three times to write data of one sector, and the writing speed is low.
In order to solve this, a magneto-optical disk device has been developed in which the above-mentioned three functions are shared by three light beams and the steps of "erasing", "recording" and "reproducing" are realized by one rotation of the disk.

FIG. 8 shows a structural example of a magneto-optical disk device having three light beams for erasing, recording and reproducing. In the figure, reference numeral 51 is a magneto-optical disk, in which tracks for recording data are spiral in the radial direction, and a spindle 52
Is driven to rotate. Reference numeral 53 denotes an optical unit, which includes a collimator system that guides a light beam from a semiconductor laser for erasing, recording, and reproducing into a parallel light beam to the objective lenses 54 and 58,
It is composed of a detection system for detecting and discriminating the focus error signal, the track error signal, the track / sector number information and the reproducing magneto-optical signal of the erasing, recording and reproducing beam from the reflected light of the disk.

Reference numeral 54 is a first objective lens for focusing the erasing beam 40 on the disk medium surface, and 55 is the first objective lens 5.
4 is a first lens actuator that moves 4 in the focusing direction and the tracking direction, and the erasing beam shakes the disk surface and follows the track eccentricity by a drive signal based on a focus error signal and a track error signal input to a control device (not shown). To be controlled. In addition, the track / sector number information positions the erase beam at the target track.

Reference numeral 58 is a second objective lens that focuses the recording beam 41 and the reproduction beam 42 on the disk medium surface, and 59 is a second lens actuator that drives the second objective lens 58 in the focusing and tracking directions. ,
By the drive signal based on the focus error signal of one or both of the reproducing beam and the recording beam and the track error signal of the reproducing beam input to the control device (not shown), the reproducing beam and the recording beam follow the disk surface deflection, and the reproducing beam tracks. It is controlled to follow the eccentricity. Further, the reproduction beam is positioned on the target track according to the track / sector number information of the reproduction beam.

Reference numeral 62 is a relative displacement actuator for driving the recording beam in the tracking direction with respect to the reproduction beam, so that the recording beam follows the track eccentricity by a drive signal based on the track error signal of the recording beam input to a control device (not shown). Controlled by. Further, the recording beam is positioned on the target track according to the track / sector number information of the recording beam. Reference numeral 64 denotes a wavelength selection mirror, which combines and separates the reproduction beam and the recording beam by the wavelength difference. Reference numeral 65 is a positioner that moves the light beam in the disk radial direction. Reference numeral 66 is a positioner guide, 67 is a positioner motor, 68 is a base of the magneto-optical disk device, 69 is a magnet for generating an erasing magnetic field, and 70 is a magnet for generating a recording magnetic field.

When recording data on a track, first the positioner 65 is moved in the disk radial direction, and then the lens actuators 55, 59 and the relative displacement actuator 62 erase and record three light beams on the target track. , Position them so that they are in the playback order. After that, when the track / sector number at which each light beam records a signal is detected, the erase beam is made to emit direct current at a high output during one sector passage, the medium temperature is set to the Curie point or higher, and the magnetization direction of the medium is changed. Align with the direction of the erase field. As for the recording beam, the beam is emitted with high output based on the recording data while passing through one sector, the medium temperature is partially raised above the Curie point, and the medium magnetization direction is partially reversed from the erasing magnetic field. .. Regarding the reproduction beam, the signal demodulation circuit and the signal comparison circuit are operated during the passage of one sector to demodulate the magneto-optical signal and then collate with the recorded data. As a result, the "erasing", "recording" and "reproducing" steps are completed almost at the same time, and the writing speed is greatly improved.

In such an operation, the seek performance is degraded unless the three light beams are positioned on the target track at high speed and at the same time. On the other hand, JP-A-02-5225
In the publication, the reproducing beam controlled by the second lens actuator 59 counts the moving track and accurately positions it on the target track. For the erasing beam and the recording beam, the first lens actuator 55 and the relative displacement actuator 62 are displaced in advance by the amount necessary for positioning the beam on the same track as the reproducing beam, and the relative position with respect to the target track. A positioning control method for improving the positioning accuracy and positioning is disclosed.

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The optical beam positioning control method in the conventional optical disk device disclosed in Japanese Patent No. 5225 discloses "technology for moving a reproducing beam at a high speed and then stably pulling it to a target track, which is important in realizing a high-speed seek operation. ",
There is a problem that "technology for drawing the recording beam and erase beam to the target track at the same time as the reproducing beam" and "technology for determining the displacement required to position the recording beam and the erase beam on the same track as the reproducing beam" are lacking. is there.

The present invention has been made in view of the above,
It is an object of the present invention to provide a light beam positioning control system in an optical disc device having improved seek performance in an optical disc device having three light beams for erasing, recording and reproducing.

[0011]

In order to achieve the above object, the optical beam positioning control method in the optical disk device of the present invention is such that a position substantially symmetrical with respect to a radial straight line of the disk medium passing through the center of the spindle as a center line. Arranging the first objective lens and the second objective lens arranged on the disk medium on a positioner which is movable in the radial direction of the disk medium, and the erasing beam is condensed on the surface of the disk medium by the first objective lens. A first tracking actuator for condensing the recording beam and the reproducing beam on the surface of the disk medium by the second objective lens, and controlling the position of the light beam condensed by the first objective lens in the tracking direction; A first position detecting device for detecting a displacement of the tracking actuator of No. 1 and a track of one light beam condensed by the second objective lens. A second tracking actuator for controlling the grayed-direction position, and a second position detecting device for detecting a displacement of the second tracking actuator,
A method of positioning a light beam in an optical disk device, comprising: a relative displacement actuator that controls the position of the other light beam focused by the second objective lens in the tracking direction. A light beam controlled by the other tracking actuator during speed control and tracking control in which the positioner follows the movement of one tracking actuator corresponding to the one position detection device using the detection signal of either one of the devices. (1) At the time of tracking control in which a signal corresponding to the displacement of the other tracking actuator necessary for positioning on the same target track as the light beam controlled by the one tracking actuator is stored at (1) at least two disk radii. The other tracking actuator Position detection signal and drive signal DC component value, (2) the position detection signal and drive signal AC component value of the other tracking actuator during tracking control stored at at least one disk radius, (3) spindle A design distance from a straight line in the radial direction of the disk medium passing through the center to a light beam controlled by the second and first tracking actuators, (4) a disk radius at which the target track is located, (5) the positioner follows. Gain and phase of closed-loop characteristic from track eccentricity of tracking control system of light beam controlled by tracking actuator to positioner displacement, (6) Track eccentricity of speed control system of light beam controlled by tracking actuator which the positioner follows To the positioner displacement Calculated using the gain and phase values of the characteristics, and subject matter to control the other of the tracking actuator based on the calculated signal.

Further, the optical beam positioning control system in the optical disk apparatus of the present invention is arranged such that the first objective lens and the second objective lens are arranged substantially symmetrically with respect to a radial straight line of the disk medium passing through the center of the spindle. The objective lens is arranged on a positioner movable in the radial direction of the disk medium, the erasing beam is focused on the surface of the disk medium by the first objective lens, and the recording beam and the reproducing beam by the second objective lens. And a first tracking actuator for controlling the position of the light beam focused by the first objective lens in the tracking direction, and a first tracking actuator for detecting the displacement of the first tracking actuator. Position detecting device and a second trajector for controlling the position in the tracking direction of one of the light beams condensed by the second objective lens. And King actuator, the second
Of a light beam in an optical disc device having a second position detecting device for detecting the displacement of the tracking actuator of the above and a relative displacement actuator for controlling the position in the tracking direction of the other light beam condensed by the second objective lens. A positioning control method, using one of the detection signals of the first and second position detecting devices,
A light beam controlled by the relative displacement actuator during the velocity control and the tracking control for causing the positioner to follow the movement of one tracking actuator corresponding to the one position detection device, and a light beam controlled by the one tracking actuator. A signal corresponding to the displacement of the relative displacement actuator required for positioning on the same target track is stored in (1) at least two disk radii, and the DC component of the position detection signal and the drive signal of the relative displacement actuator during tracking control. value,
(2) Calculated using the design distance from the radial line of the disk medium passing through the center of the spindle to the light beam controlled by the second tracking actuator, and (3) the value of the disk radius where the target track is located. The gist is to control the relative displacement actuator based on the calculated signal.

Further, in the optical beam positioning control system in the optical disc apparatus of the present invention, the first objective lens and the second objective lens which are arranged substantially symmetrically with respect to a radial straight line of the disc medium passing through the center of the spindle as a center line. The objective lens is arranged on a positioner movable in the radial direction of the disk medium, the erasing beam is focused on the surface of the disk medium by the first objective lens, and the recording beam and the reproducing beam by the second objective lens. And a first tracking actuator for controlling the position of the light beam focused by the first objective lens in the tracking direction, and a first tracking actuator for detecting the displacement of the first tracking actuator. Position detecting device and a second trajector for controlling the position in the tracking direction of one of the light beams condensed by the second objective lens. And King actuator, the second
Of a light beam in an optical disc device having a second position detecting device for detecting the displacement of the tracking actuator of the above and a relative displacement actuator for controlling the position in the tracking direction of the other light beam condensed by the second objective lens. In the positioning control method, the minimum energy positioning control means for positioning the light beam so that the speed of the light beam on the target track becomes substantially zero in a predetermined positioning time, and shifts of the light beam from the target track at the end of control. Means for generating a position reference signal corresponding to, a means for generating a speed reference signal corresponding to the speed of the light beam at the end of control, and a force corresponding to the product of the viscous friction coefficient and the speed of the light beam at the end of control. Means for generating a feedforward input that cancels the position reference signal, means for subtracting the position reference signal from the position signal, and Means for subtracting the degree reference signal and means for adding the feedforward input in front of the current amplifier are added, and are condensed by the second objective lens mounted on the positioner by the means and the second tracking is performed. After controlling the light beam controlled by the actuator or the light beam focused by the first objective lens and controlled by the first tracking actuator so as to have a constant velocity before a certain number of tracks of the target track. , The second or first tracking actuator controls the light beam so as to follow a reference velocity curve defined as a function of the number of residual tracks, and the positioner controls the position detection device of the tracking actuator to detect the light velocity. Based on the number of residual tracks by controlling the tracking actuator to follow After the degree control is finished, and summarized in that for positioning the light beam on the target track by the tracking actuator.

The optical beam positioning control method in the optical disk apparatus of the present invention is a first objective lens and a second objective lens which are arranged substantially symmetrically with respect to a radial line of the disk medium passing through the center of the spindle. A lens is arranged on a positioner movable in the radial direction of the disk medium, an erasing beam is focused on the surface of the disk medium by a first objective lens, and a recording beam and a reproducing beam are recorded by a second objective lens on the disk. Focus on the surface of the medium, first
A first tracking actuator for controlling the position in the tracking direction of the light beam condensed by the objective lens of
A first position detecting device that detects a displacement of the first tracking actuator; a second tracking actuator that controls a position of one light beam focused by the second objective lens in a tracking direction; Optical beam in an optical disk device having a second position detecting device for detecting the displacement of the second tracking actuator and a relative displacement actuator for controlling the position of the other light beam focused by the second objective lens in the tracking direction Positioning control system, the speed control for the reference speed curve of the light beam controlled by the second or first tracking actuator and the follow-up control of the positioner for the tracking actuator operate to operate the first and second positions. The positioner is detected by using the detection signal from one of the detection devices. The light beam controlled by the other tracking actuator is the same as the light beam controlled by the one tracking actuator during the velocity control and the tracking control in which the movement of the one tracking actuator corresponding to the one position detection device is followed. Calculate a signal corresponding to the displacement of the other tracking actuator required to position on the target track,
The other tracking actuator is controlled on the basis of the calculated signal, and the positioner uses one detection signal of one of the first and second position detection devices to detect one of the tracking signals corresponding to the one position detection device. A relative displacement actuator necessary for positioning the light beam controlled by the relative displacement actuator on the same target track as the light beam controlled by the one tracking actuator during the velocity control and the tracking control to follow the movement of the actuator Of the residual beam of the light beam after the transient response of the positioner to the tracking actuator is settled, and the relative displacement actuator is controlled based on the calculated signal. At the end of speed control, other The track pull-in operation of both the light beam controlled by the tracking actuator and the light beam controlled by the relative displacement actuator or the former light beam is performed almost at the same time as the track pull-in operation of the light beam for which the speed control is completed. To do.

Further, in the optical beam positioning control system in the optical disk device of the present invention, the reference velocity curve V _r during the velocity control of the light beam controlled by the second or first tracking actuator is used to control the velocity of the positioner. Of the transition speed V _t, which is the terminal speed of the tracking actuator, and the final speed V _f and the maximum speed V _max of the speed control for the tracking actuator, the time function “V _r = (V _t
−V _f ) exp (−at) + V _f , a> 0, V _r ≦ V
_{The point is} to convert " _max " into a function of the number of residual tracks and use it.

[0016]

In the optical beam positioning control system in the optical disk device of the present invention, the positioner corresponding to one of the position detecting devices is used by using the detection signal of one of the first and second position detecting devices. The other required for positioning the light beam controlled by the other tracking actuator on the same target track as the light beam controlled by the one tracking actuator during speed control and tracking control to follow the movement of the tracking actuator A signal corresponding to the displacement of the tracking actuator is calculated, and the other tracking actuator is controlled based on the calculated signal.

Further, in the optical beam positioning control system in the optical disk apparatus of the present invention, the positioner responds to one of the position detection signals by using the detection signal of one of the first and second position detection devices. Necessary for positioning the light beam controlled by the relative displacement actuator on the same target track as the light beam controlled by the one tracking actuator during speed control and tracking control to follow the movement of one tracking actuator. A signal corresponding to the displacement of the relative displacement actuator is calculated, and the relative displacement actuator is controlled based on the calculated signal.

Further, in the light beam positioning control system in the optical disk apparatus of the present invention, the minimum energy positioning control means for positioning the light beam so that the speed of the light beam on the target track becomes substantially zero within a predetermined positioning time, Means for generating a position reference signal corresponding to the deviation of the light beam from the target track at the end of control, means for generating a speed reference signal corresponding to the speed of the light beam at the end of control, viscous friction coefficient and end of control Means for generating a feedforward input for canceling the force corresponding to the product of the speed of the light beam at time, means for subtracting the position reference signal from the position signal, means for subtracting the speed reference signal from the speed signal, and a current amplifier And a means for adding a feedforward input are added in front of, and the second objective lens mounted on the positioner collects light by the means. And the light beam controlled by the second tracking actuator, or the light beam focused by the first objective lens and controlled by the first tracking actuator, is moved at a constant speed several tracks before the target track. Control is performed so that the light beam follows the reference velocity curve defined as a function of the number of residual tracks by the second or first tracking actuator, and the positioner controls the position of the tracking actuator. The tracking actuator is controlled to follow the detection signal of the detection device, and after the velocity control based on the number of residual tracks is completed, the tracking actuator positions the light beam on the target track.

In the optical beam positioning control system in the optical disk device of the present invention, the speed control for the standard velocity curve of the light beam controlled by the second or first tracking actuator and the tracking control for the tracking actuator of the positioner operate. , The speed control based on the residual track number of the light beam ends after the control for the other tracking actuator operates, the control for the relative displacement actuator operates, and the transient response of the positioner to the tracking actuator settles At the point of time, the track pulling operation of both the light beam controlled by the other tracking actuator and the light beam controlled by the relative displacement actuator, or the former light beam, is completed. Perform the actual operation almost at the same time.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing the arrangement of an apparatus for implementing a light beam positioning control system in an optical disk apparatus according to an embodiment of the present invention. The magneto-optical disk 51 shown in the center of the figure is the same as the magneto-optical disk 51 shown in FIG. 8, and shows the case viewed from the arrow II-II in FIG. Recording tracks are spirally provided in the radial direction and are configured to be rotationally driven by a spindle 52. However, in FIG. 8 described above, the type in which the objective lens is driven in the focusing direction and the tracking direction as an actuator that follows the surface deflection of the disc and the eccentricity of the track is shown, but the embodiment shown in FIG. For the sake of clarity, the form in which the objective lens is driven is shown in the focusing direction, and the form in which the mirror is rotationally driven is shown in the tracking direction. In FIG. 1, the same components as those in FIG. 8 are designated by the same reference numerals.

In FIG. 1, 54 is a first objective lens for focusing the erasing beam 40 on the disk medium surface, 101 is a first focusing actuator for driving the first objective lens 54 in the focusing direction, and 56 is an erasing beam. Reference numeral 57 denotes a first tracking actuator that drives 40 in the tracking direction, and reference numeral 57 denotes a first position detection device that detects a mirror rotation displacement of the first tracking actuator 56.

Reference numeral 58 is a second objective lens that focuses the recording beam 41 and the reproduction beam 42 on the disk medium surface, 102 is a second focusing actuator that drives the second objective lens 58 in the focusing direction, and 60 is a recording beam. 41 is a second tracking actuator for driving the reproduction beam 42 in the tracking direction, and 61 is a second position detecting device for detecting the rotational displacement of the mirror of the second tracking actuator 60.

Reference numeral 62 (not shown) is a relative displacement actuator for driving the recording beam in the tracking direction with respect to the reproduction beam, 65 is a positioner, 66 is a positioner guide,
67 is a positioner motor, 68 is a base of the magneto-optical disk device, 69 is a magnet for generating an erasing magnetic field, and 70 is a magnet for generating a recording magnetic field.

Reference numeral 80 is a positioning control device for controlling the positioning operation, and 83 is the first tracking actuator 56.
Track controller for controlling the second tracking actuator 60, 84 for controlling the second tracking actuator 60, 8
Reference numeral 5 is a track control device for controlling a relative displacement actuator 62 (not shown), and each track control device comprises a compensation circuit section, a track jump pulse generation section, a power amplifier and the like.

Reference numeral 86 is a positioner position control device, 87 is a positioner speed control device, 88 is a storage device, 89 is a prediction control device, and 90 is a second tracking actuator speed control device.

E is a reproduction beam tracking error signal, F is a second tracking actuator drive signal, and G is a second tracking actuator drive signal.
Position detection signal, H is a positioner drive signal, I is an erase beam track error signal, J is a first tracking actuator drive signal, K is a recording beam track error signal, L is a relative displacement actuator drive signal, and M is a first track actuator drive signal. 1 position detection signal.

N, O, and P are predictions for displacing the first tracking actuator 56 and the relative displacement actuator 62 as much as necessary to position the erase beam and the recording beam on the same track as the reproducing beam during seek and tracking. A signal, N is a predicted position signal at the seek time of the erasing beam, and is composed of a DC component due to an adjustment error and an AC component due to a track eccentricity. O is a predictive drive signal at the time of seek / tracking of the recording beam, which is a DC component mainly due to the beam interval in the track circumferential direction between the reproducing beam and the recording beam. P is a prediction drive signal at the time of tracking of the erasing beam, and like N, is composed of a DC component due to an adjustment error and an AC component due to track eccentricity.

1 to 10 are switches (abbreviated as SW).

In the above-described structure, the number of moving tracks is counted, the reproducing beam 42 controlled by the second tracking actuator 60 is positioned on the target track at high speed and high stability, and the erasing beam 40 is controlled. Tracking actuator 56 and recording beam 41
The relative displacement actuator 62 for controlling the reproduction beam 4
The positioning control operation of displacing the light beam on the same track as that of No. 2 by a necessary amount for positioning and positioning the light beam on the target track almost at the same time as the reproducing beam 42 will be described below.

First, when the positioning controller 80 issues a command to position the light beam on a predetermined track,
The track number at which the reproducing beam 42 is currently positioned is compared with the track number of the track (target track) to be positioned, and the seek means described below is selected according to the number of moving tracks to perform the positioning operation.

Seek means 1: When the number of moving tracks is small The predicted signals N, O, P on the target track are calculated by the prediction control unit 89 using the track numbers and the calculated basic data stored in the storage unit 88, and updated. To do.

The number of moving tracks is set in the track residual counter of the reproduction beam. Also, the number of moving tracks is set in the track residual counter of the erase beam.

SW8 is turned off to stop the tracking control of the recording beam. The reproducing beam and the erasing beam are moved at a low speed by a track jump using the track control device, and when the track residual counter reaches zero, they are positioned on the track.

It is determined from the track / sector number information whether the track is a target track.

If it is not the target track, the track is corrected by the track jump using the track controller.

After the positioning of the reproducing beam is completed, the SW8 is turned on to execute the recording beam.

Seek means 2: When the number of moving tracks is relatively small SW8 is turned off and the tracking control of the recording beam is stopped. SW1 and SW4 are turned off, tracking control of the erasing beam and feedforward control by signal P are stopped, SW2 and SW3 are turned on, and position feedback of the first tracking actuator 56 is performed by using signal N for vibration suppression during seek. Start control.

The number of moving tracks is set in the track residual counter of the reproduction beam.

SW7 is turned off, the reproduction beam tracking control is stopped, SW5 is turned on, and the tracking actuator speed control device 90 is used to start the speed control of the reproduction beam with respect to the relatively low standard speed curve.
Here, the reference velocity curve V _r is the transition velocity V _t , which is the terminal velocity of the velocity control in the positioner velocity control device described in the following seek means 3, and the final velocity V _f and the maximum velocity V _max of the velocity control for the tracking actuator. It is used and is attenuated with the passage of time "V _r = (V
_t −V _f ) exp (−at) + V _f , a> 0, V _r ≦ V
_The function defined by " _max " is converted into the function of the residual track number and used.

Predicted signals N, O, P on the target track
Is calculated and updated by the predictive control device 89 using the track number and the calculated basic data stored in the recording device 88.

When the transient response of the positioner to the second tracking actuator 60 at the start of the reproduction beam velocity control for the reference velocity curve using the tracking actuator velocity control device 90 is settled and the track residual counter becomes zero, SW2 is set. And SW3 OFF,
SW1 and SW4 are ON, SW5 is OFF, SW7 is ON
Then, the tracking control of the erase beam and the reproduction beam is started using the track controller.

It is determined from the track / sector number information whether the track is a target track.

If it is not the target track, the track is corrected by the track jump using the track controller.

After positioning the reproduction beam, switch SW8 to O
Then, the recording beam is processed.

Seek means 3: When the number of moving tracks is large SW8 is turned off to stop the tracking control of the recording beam. SW1 and SW4 are turned off, tracking control of the erase beam and feedforward control by the signal P are stopped, SW2 and SW3 are turned on, and the first tracking actuator 5 using the signal N for vibration control during seek.
The position feedback control of 6 is started.

The number of moving tracks is set in the track residual counter of the reproduction beam, and the condition of the positioner speed control device 87 is set.

In order to prevent a track counting error of the reproducing beam at the initial acceleration of the positioner, first SW9 is turned off.
And the second tracking actuator 6 of the positioner
After the follow-up control for 0 is stopped, the SW10 is turned on, and the positioner speed control device 87 is used to start the high speed control of the reproduction beam. Next, SW7 is turned off, tracking control of the reproduction beam is stopped, SW6 is turned on, and a second position detection signal value that is attenuated after a fixed time sampled and held immediately before turning on SW6 to suppress vibration during seek is used. Then, the position feedback control of the second tracking actuator is started.

Predicted signals N, O, P on the target track
Is calculated and updated by the prediction control device 89 using the track number and the calculated basic data stored in the storage device 88.

When the speed control time by the positioner speed control device 87 reaches a certain value, SW10 and SW6 are turned off, SW5 and SW9 are turned on, and a comparatively low speed reference speed curve is obtained by using the tracking actuator speed control device 90. Then, the follow-up control of the positioner for the second tracking actuator is started by using the speed control of the reproduction beam and the positioner position control device 86. Here, standard speed curve, decays with the passage of time _{"V r = (V t -V} f) exp (-at) + V f, a
> 0, V _r ≦ V _max ″ is used by converting it to a function of the residual track number.

When the transient response of the positioner to the second tracking actuator at the start of the velocity control of the reproducing beam with respect to the standard velocity curve is settled by using the tracking actuator velocity control device 90 and the track residual counter becomes zero, SW2 is set. And SW3 OFF, S
W1 and SW4 are ON, SW5 is OFF, SW7 is ON
Then, the tracking control of the erase beam and the reproduction beam is started using the track controller.

It is judged from the track / sector number information whether the track is a target track.

If the track is not the target track, the track is corrected by a track jump using the track controller.

After the positioning of the reproducing beam is completed, the SW8 is turned on to execute the recording beam.

The above is the outline of the positioning operation for positioning the reproducing beam, the erasing beam and the recording beam on the target track at the same time according to the present invention.

After that, the arrangement relationship of the erasing, recording, and reproducing light beams on the target track is judged from the track / sector number information, and the light beams are rearranged so as to be erased, recorded, and reproduced in order by a track jump. .. As a result, it becomes possible to record data in a predetermined sector of the target track.

When the light beam moves from the target track to the outer circumference along the spiral track by the tracking control, the change of the positioning track is detected and predicted from the track / sector number information or the spindle rotation synchronizing signal. The signals N, O and P are calculated and updated by the predictive control device using the track number and the calculated basic data stored in the storage device.

As described above, the positioning control method of the present invention has the following effects.

The seek means 3 performs seek control combining high-speed speed control utilizing the high thrust of the positioner and high-accuracy relative speed control utilizing the good vibration characteristics of the tracking actuator. For this reason, the control system is a high-speed control system for controlling velocity disturbance due to track eccentricity or the like with high accuracy immediately before the track is pulled in. further,
Tracking reference speed curve of the speed control using the actuator velocity control device, "V _r = decays with time _{(V t -V f) exp (} -at) + V f,
Since the function defined by a> 0, V _r ≤V _max "is converted into a function of the number of residual tracks and used, the second tracking actuator of the positioner has no discontinuity in the acceleration change during speed control. The transient response to is settled early, and as a result, it is possible to shorten the positioning time of the reproducing beam controlled by the second tracking actuator and improve the stability of track pull-in.

In the seek means 2 and the seek means 3, the signal N is set after the transient response of the positioner to the second tracking actuator at the time of starting the speed control of the reproducing beam using the tracking actuator speed controller.
The tracking control of the erase beam, which is position feedback controlled by using, is started almost simultaneously with the tracking control of the reproduction beam. Therefore, the position / velocity disturbance to the erase beam caused by the track eccentricity or the like is canceled by the position feedback control using the signal N, and the track of the erase beam is pulled into the target track at the same relative velocity as the reproducing beam. .. As a result, the positioning of the erase beam ends almost simultaneously with the reproducing beam and is stable.

The seek unit 1, the seek unit 2, and the seek unit 3 control the position of the recording beam by feedforward control using the signal O. Therefore, if the recording beam is pulled in after the reproduction beam is positioned on the target track, the recording beam is positioned on the target track. As a result, positioning of the recording beam and the reproducing beam and the erasing beam are completed almost at the same time.

By the above description, the "technology for stably drawing the reproducing beam to the target track" and the "technology for drawing the recording beam and the erasing beam to the target track at the same time as the reproducing beam" have been described in detail.

Next, "technology for obtaining the displacement required to position the recording beam and the erasing beam on the same track as the reproducing beam" and "technology for moving the reproducing beam at high speed"
Will be described.

First, a technique for obtaining a prediction signal for displacing the relative displacement actuator 62 and the first tracking actuator 56 as much as necessary to position the recording beam and the erasing beam on the same track as the reproducing beam will be described. ..

FIG. 2 is a diagram for explaining a technique for obtaining a prediction signal. In FIG. 2, Yr: Distance from X-axis passing through spindle center to reproduction beam Yw: Distance from X-axis passing through spindle center to recording beam Ye: Distance from X-axis passing through spindle center to erase beam D: Spindle center Design distance from the Y-axis passing through to the reproduction beam, design distance from the Y-axis passing through the spindle center to the erase beam d0: Deviation from the design distance from the Y-axis passing through the spindle center to the reproduction beam d1: Y passing through the spindle center Deviation from the design distance from the axis to the erasing beam L: Design distance in the X-axis direction from the reproducing beam to the recording beam R: Disk radius calculated from the track number Rn, Rm: Basic calculation data for calculating the prediction signal Is the disk radius calculated from the stored track number.

By the way, the storage of the calculated basic data is performed by the following procedure when the disc is replaced.

First, the seek means moves the light beam to the n-th track (disk radius Rn). Although the seek means applies the control using the prediction signal to the erase beam and the recording beam, this control is not performed at the stage of the storage operation because the calculated basic data is not stored. Then, the calculated basic data is stored in the storage device 88. The calculated basic data to be stored are the DC component and AC component of the position detection signal M for the erase beam, and the DC component and AC component of the tracking actuator drive signal J,
For the recording beam, it is the DC component of the tracking actuator drive signal L. The AC component is stored in synchronization with the rotation of the disk, and the DC component and the AC component are separated by an analog filter or digital calculation. The above operation is performed for the m-th track (disk radius Rm), and the process ends. Since the track eccentricity has a small disc radius dependence, the AC components of the erase beam position detection signal M and the tracking actuator drive signal J may be stored only in the nth track (disc radius Rn). Further, in order to further increase the accuracy of the prediction signal, there is no problem even if the number of disk radii for storing the calculated basic data is increased. Further, in the case where the relative displacement actuator is equipped with a position detection device in FIG. 1, if the DC component of the position detection signal is also stored, the relative position at the time of seek is controlled by the same control system as the position feedback control of the first tracking actuator. Vibration suppression control of the displacement actuator becomes possible. However, since the relative displacement actuator is not mounted on the positioner, the vibration generated at the time of seek is minute and the necessity of vibration suppression control is small.

Next, referring to FIG. 2, using the above-mentioned symbols, (1) calculation of the DC component of the predicted drive signal of the recording beam, (2) DC component of the predicted position signal of the erase beam and the predicted drive signal And (3) calculation of the predicted position signal of the erase beam and the AC component of the predicted drive signal.

(1) Calculation of the DC component of the predictive drive signal of the recording beam will be described.

From the geometrical relationship shown in FIG. 2, the following equation is obtained.

[0071]

[Equation 1]

[0072]

[Equation 2]

Since D >> d0, L, the distance between the recording beam and the reproducing beam is given by the following equation.

[0074]

[Equation 3]

The relationship between the drive signal L and Yw-Wr is as follows.

Drive signal = (Yw−Yr) / Kvw + ΔVw (2) Here, Kvw: voltage-current conversion coefficient × motor sensitivity × angle / beam displacement conversion coefficient (μm / V) ΔVw: offset voltage (V).

The above equations (1) and (2) and the storage device 88
The function of the drive signal L at the radii Rm and Rn stored in is as follows.

[0078]

[Equation 4]

As a result, L / which has a large individual difference depending on the device.
Kvw is calculated by the following equation.

[0080]

[Equation 5]

Next, using the equation (2), [L / Kvw] and (driving signal) _Rn , ΔVw is obtained as follows.

[0082]

[Equation 6]

From the above results, the predictive drive signal of the direct current component of the recording beam at the time of seeking at an arbitrary radius and tracking can be calculated with high accuracy by using the following equation (3).

[0084]

[Equation 7]

(2) The calculation of the DC component of the predicted position signal of the erase beam and the predicted drive signal will be described.

From the geometrical relationship shown in FIG. 2, the following equation is obtained.

[0087]

[Equation 8]

[0088]

[Equation 9]

Since D >> d0 and d1, the distance of the erasing beam with respect to the reproducing beam is given by the following equation.

[0090]

[Equation 10]

The relationship between the position detection signal M and Ye-Yr is as follows.

Position detection signal = (Ye−Yr) · Ks + ΔVes (5) Here, Ks: detection sensitivity (V / μm) ΔVes: offset voltage (V).

The above equations (4) and (5) and the storage device 88.
The relationship with the position detection signal M at the radii Rm and Rn stored in is as follows.

[0094]

[Equation 11]

As a result, there are large individual differences depending on the device (d
0-d1) · Ks is calculated by the following equation.

[0096]

[Equation 12]

Next, equations (5) and [Ks (d0-d
1)] and (position detection signal) _Rn , ΔVes is calculated as follows.

[0098]

[Equation 13]

From the above results, the predicted position signal of the DC component of the erase beam at the seek at an arbitrary radius can be calculated with high accuracy using the following equation (6).

[0100]

[Equation 14]

The relationship between the drive signal J and Ye-Yr is given by the following equation.

Drive signal = (Ye−Yr) / Kve + ΔVev (7) where Kve: voltage / current conversion coefficient × motor sensitivity × beam displacement conversion coefficient (μm) ΔVes: offset voltage (V) Expression (4) described above , (7) and the drive signal J at the radii Rm, Rn stored in the storage device 88 are as follows.

[0103]

[Equation 15]

As a result, there is a large individual difference depending on the device (d
0-d1) / Kve is calculated by the following equation.

[0105]

[Equation 16]

Next, equation (7), [(d0-d1) / Kv
e] and (drive signal) _Rn , ΔVev is calculated as follows.

[0107]

[Equation 17]

From the above results, the predicted drive signal of the DC component of the erase beam at the time of tracking at an arbitrary radius can be calculated with high accuracy using the following equation (8).

[0109]

[Equation 18]

(3) Calculation of the AC component of the predicted position signal of the erase beam and the predicted drive signal will be described.

(A) Calculation of predicted position signal during seek First, the position detection signal M stored with the radius Rn will be considered. Track eccentricity viewed from the disk coordinate system is X = A.
SIN (W · t).

At this time, the track eccentricity seen from the reproducing beam is Xr = A.SIN (W.t-.delta.), And the track eccentricity seen from the erasing beam is Xe = A.SIN.
(W · t + δ). In FIG. 2, δ is an angle formed by a line segment connecting the spindle center and the reproducing beam and the Y axis, and an angle formed by the line segment connecting the spindle center and the erasing beam and the Y axis, and both are substantially equal.

When the track eccentricity viewed from each light beam is described by the above equation, the AC component (Xp) of the positioner displacement during tracking, the AC component (XLr) of the second tracking actuator displacement, and the first tracking actuator displacement The relationship with the AC component (XLe) of is described by the following equation.

Xr = XLr + Xp = XLr + Gt * A * SIN (W * t- [delta] + Dt) Xe = XLe + Xp = XLe + Gt * A * SIN (W * t- [delta] + Dt) Gt: Frequency W of closed loop characteristic from Xr to Xp in FIG.
Gain Dt: frequency W of the closed loop characteristic from Xr to Xp in FIG.
Therefore, the XLe corresponding to the stored position detection signal is described by the following equation.

XLe = Xe−Xp = A · SIN (W · t + δ) −Gt · A · SIN (W · t−δ + Dt) = Bt · A · SIN (W · t + φt) (9) A position detection signal was used. The position feedback control is used for velocity control of a reproducing beam using a tracking actuator velocity controller. FIG. 4 shows a block diagram of the control system. Assuming that the reproduction beam completely follows the velocity of track eccentricity, the relationship between the AC component of positioner displacement (Xps), the AC component of second tracking actuator displacement (XLrs), and track eccentricity at the time of seek is as follows. Described by a formula.

Xr = XLrs + Xps = XLrs + Gs · A · SIN (W · t−δ + Ds) Gs: Gain at frequency W of closed loop characteristic from Xr to Xps in FIG. 4 Ds: Closed loop characteristic from Xr to Xps in FIG. Phase at frequency W From this, the AC component (XLe) of the displacement of the first tracking actuator that matches the trajectory of Xe and the erase beam
Is described by the following formula.

XLes = Xe−Xps = A · SIN (W · t + δ) −Gs · A · SIN (W · t−δ + Ds) = Bs · A · SIN (W · t + φs) (10) The calculation of the AC component of the predicted position signal is performed as follows.

Using equations (9) and (10), [Bt], [φt], [Bs], and [φs] at the disk radius Rn are calculated, and the characteristic difference between the control system at the time of tracking and the characteristic at the time of seek is calculated. To compensate.

Although various concrete methods are conceivable, a method may be considered in which the amplitude is [Bs] / [Bt] times and the phase is shifted by [φs]-[φt] with respect to the fundamental rotation frequency.

Using equation (10), Bs and φs at an arbitrary disc radius are obtained, and the amplitude is set to Bs / [Bs] by the operation of
The operation of shifting the phase by φs− [φs] is added.

(B) Calculation of predicted drive signal at the time of tracking Since the drive signal J at the time of tracking is stored and used as calculation basic data, it is not necessary to perform the operation of the above (a).

Therefore, using the above equation (9), Bt and φt at an arbitrary disk radius are obtained, and [B
Based on t] and [φt], an operation of shifting the amplitude by Bt / [Bt] and shifting the phase by φt- [φt] is added.

In operation, it is not always necessary to perform all the amplitude and phase operations described in (a) and (b). In particular, the phase operation complicates the apparatus, and therefore only the amplitude operation does not affect accuracy.

By the way, when the track eccentricity is large, it is not always correct to assume that the reproducing beam completely follows the speed of the eccentricity during seek. In this case, increasing the amplitude by the amplitude operation may increase the prediction error. Therefore, the radius Rn for storing the calculated basic data is
It is desirable that the predicted signal is calculated in the inner radius of the disk radius area using the calculated basic data, and the amplitude operation is multiplied by a numerical value smaller than 1. When only one radius is stored, the innermost circumference is preferable.

The method of calculating the prediction signal has been described above.

It is easy to analogize that the calculation of the predicted position signal when the relative displacement actuator is equipped with the position detecting device in the configuration of FIG. 1 may be performed in the same manner as the calculation of the DC component of the predicted drive signal of the recording beam. it can.

Next, a technique for moving the reproducing beam at high speed will be described.

For high-speed seek control of the positioner,
The minimum energy positioning control that minimizes heat generation in the positioner coil and improves access frequency is effective.

As the construction method of the minimum energy control system,
Patent-1409310: Positioning control method (positioning control method using time-varying feedback coefficient. In the state feedback control system, a feedback coefficient is generated as a function of the elapsed time from the positioning start time), and Patent-1423447: Positioning control method (hour A method of generating a variable feedback coefficient curve. A feedback coefficient for the longest positioning time is prepared, and a part of it is cut out and used), but the position / speed condition of the positioner at the end of control is Since the target position and speed are zero, the position / speed condition of the positioner at the end of the control is constant track residual (position Δx) and reference speed (speed Δv) as described in the means 3 above. To do so, it is necessary to devise the configuration of the control system.

The control system construction method for leaving the position Δx and the speed Δv at the end of control will be described below.

The operation of moving the positioner from the initial position to the target position will be considered by using a linear motor whose input is current as a model. This is a model that can be applied to a case where a rotary motor is combined with an appropriate transmission mechanism to make a linear motion, and has generality.

Movable part mass: M, motor force constant: Kf, input current: i, viscous friction coefficient: Cm

[0133]

[Outer 1]

[0134]

[Formula 19]

When this is displayed in the state space, it becomes as follows.

[0136]

[Equation 20]

In the conventionally proposed minimum energy control, the target value at the control end time t _f is as shown in the following equation.

[0138]

[Equation 21]

The object of the present invention is the case of the following formula.

[0140]

[Equation 22]

Here,

[0142]

[Equation 23]

Using

[0144]

[Outside 2]

As a result, control to the desired position Δx and speed Δv is realized.

The specific configuration method of this control will be described below.

FIG. 5 is a block diagram showing a circuit configuration showing an embodiment of the present invention.

In FIG. 5, the position 2 and the speed 1 of the positioner (equivalent to the reproduction beam) with respect to the target track of the optical disk can be obtained by counting the zero cross points of the track error signal. You can use it. Given that the speed detection sensitivity is Gv, a constant voltage Δv / Gv is applied to the voltage 3 corresponding to the speed Δv. The position reference signal 4 which changes with time is recorded in advance in the ROM 12 as data for each sampling time ΔT. The content and recording method will be described later. The signal 5 is the difference between the speed 1 and the speed Δv3 of the positioner, and the signal 6 is the position 2 of the positioner.
And the position reference signal 4. The two multipliers 7 multiply the signal 5 by the velocity feedback coefficient 8 and the signal 6 by the position feedback coefficient 9, adjust the gains by the gain adjustment amplifiers 18, respectively, and then add the feedforward input 19 to add the current. The positioner is driven by the amplifier 20. The feed-forward input 19 is Δw described above, and gives a constant voltage of Δw = Cm · Δv / K _f . However, since Cm is usually minute, this is often omitted. A position feedback coefficient, a velocity feedback coefficient, and a position reference signal are recorded in the ROMs 10, 11, and 12, the contents of which are cut out from an arbitrary position,
The data is output every fixed sampling period ΔT, and its mechanism is as follows. Before the seek, the read start address 16 is set to the initial value of the address counter 14.
Address counter 1 after input of seek start signal 17
4 is counted up by the sample clock 15. As a result, the read address 13 is sequentially updated,
Data that changes with time is output from the ROMs 10, 11, and 12.

End of seek control, that is, control end time t
The detection signal 23 indicating that f has been obtained is obtained by comparing the read address 13 and the read end address 22. The read start address is the seek control time = Δ
T × | Read end address-Read start address + 1 |
Seek from the relationship.

The position reference signal is the above-mentioned Δx + Δv ·
(T−t _f ) is calculated in advance, discretized for each sampling time ΔT, and recorded in the ROM 12. RO
The memory address in M and its contents are shown in FIG. Address N
Xref (Nend) whose value is Δx is recorded in end, and the value obtained by sequentially adding Δv · ΔT in the lower direction of the address is recorded.

Since the position feedback coefficient and the velocity feedback coefficient are clear in Japanese Patent No. 1409310: Positioning control method, their explanations are omitted.

The above is an example in which the present invention is configured by a circuit, but it is of course possible to configure this by software.

FIG. 7 shows an example of a software configuration. The position reference signal, the position feedback coefficient, and the velocity feedback coefficient that change every sampling time ΔT are transferred from the ROM to the RAM in advance. The CPU captures the positioner's position and speed in digital quantities, and internally u = K _x (t) (x (t) -x _ref (t)) + K
_The calculation of _v (t) (v (t) −Δv) + Cm · Δv / K _f is performed. Where K _x (t), K _v (t), x
_{For ref} (t), the values obtained by reading the position feedback coefficient, the velocity feedback coefficient, and the position reference signal that have been transferred to the RAM in advance are used. Also, Δv, Cm · Δv / K _f
Is prepared beforehand as a constant on the program.

According to the present invention, the positioner (equivalent to the reproducing beam) position (Δ
T), velocity (ΔV) and the position and velocity conditions at the start of velocity control of the reproducing beam using the tracking actuator velocity control device of the means 3 can be substantially matched, so that the velocity control from the positioner to the tracking actuator can be performed. Stable transition to speed control. As a result, the speed control time by the tracking actuator can be shortened and the track pull-in stability can be increased. Further, since the energy control is the minimum that minimizes the heat generation of the positioner coil, the access frequency can be improved.

In the above-described embodiment, referring to FIG. 1, the second tracking actuator controls the reproducing beam, the relative displacement actuator controls the recording beam, and the first tracking actuator controls the erasing beam. It was explained that the positioner is controlled by using the second position detection signal. However, the recording beam is controlled by the second tracking actuator, the reproducing beam is controlled by the relative displacement actuator, and the first tracking is performed. Even if the actuator controls the erase beam and the positioner is controlled using the second position detection signal,
It can be easily analogized that it can be applied by rereading the relationship between the beams. Further, in the configuration of FIG. 1 and the configuration described above, it can be easily inferred that the configuration in which the positioner is controlled by using the first position detection signal can be similarly applied if the relationship between the beams is read. Further, it is easy to be effective not only in a device having one light beam for each function of erasing, recording, and reproducing, but also in a device having a plurality of light beams for each function using an arrayed semiconductor laser. Can be analogized to.

Also, it is obvious that each elemental technique of the present invention can be applied as a positioning control method for an optical disk device such as a one-beam or two-beam type.

[0157]

As described above, according to the present invention,
The reproducing beam, the erasing beam, and the recording beam can be positioned on the target track almost simultaneously, at high speed and with high stability. Further, since the heat generation of the positioner coil can be minimized, the access frequency can be improved. As a result, there is an advantage that it is possible to realize a high-performance optical disk device that has excellent random access performance and can record signals at high speed.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an apparatus that implements a light beam positioning control method in an optical disk apparatus according to an embodiment of the present invention.

FIG. 2 is an arrangement diagram of light beams for explaining a technique for obtaining a prediction signal.

FIG. 3 is a block diagram of a reproduction beam tracking control system.

FIG. 4 is a block diagram of an example of control in which the velocity of a reproduction beam is made to follow a reference velocity curve by a tracking actuator.

FIG. 5 is a block diagram showing a circuit configuration of minimum energy control which is an embodiment of the present invention.

FIG. 6 is a diagram illustrating a method of recording a position reference signal in a ROM.

7 is a diagram showing a configuration example of software for the minimum energy control shown in FIG.

FIG. 8 is a diagram showing a configuration of a conventional three-beam magneto-optical disk device.

[Explanation of symbols]

 40 erase beam 41 recording beam 42 reproducing beam 51 magneto-optical disk 52 spindle 54 first objective lens 56 first tracking actuator 57 first position detecting device 58 second objective lens 60 second tracking actuator 61 second Position detecting device 101 First focusing actuator 102 Second focusing actuator

Claims (5)

[Claims] 1. A first objective lens and a second objective lens, which are arranged substantially symmetrically with a radial line of a disk medium passing through the center of a spindle as a center line, are movable in the radial direction of the disk medium. The first objective lens collects the erasing beam on the surface of the disk medium, and the second objective lens collects the recording beam and the reproducing beam on the surface of the disk medium. A first tracking actuator that controls the position of the light beam focused by the objective lens in the tracking direction, a first position detection device that detects a displacement of the first tracking actuator, and a second objective lens that collects the light beam. A second tracking actuator for controlling the position in the tracking direction of one light beam emitted, and the displacement of the second tracking actuator A second position detecting device for detecting
A method of positioning a light beam in an optical disk device, comprising: a relative displacement actuator that controls the position of the other light beam focused by the second objective lens in the tracking direction. A light beam controlled by the other tracking actuator during speed control and tracking control in which the positioner follows the movement of one tracking actuator corresponding to the one position detection device using the detection signal of either one of the devices. (1) At the time of tracking control in which a signal corresponding to the displacement of the other tracking actuator necessary for positioning on the same target track as the light beam controlled by the one tracking actuator is stored at (1) at least two disk radii. The other tracking actuator Position detection signal and drive signal DC component value, (2) the position detection signal and drive signal AC component value of the other tracking actuator during tracking control stored at at least one disk radius, (3) spindle A design distance from a straight line in the radial direction of the disk medium passing through the center to a light beam controlled by the second and first tracking actuators, (4) a disk radius at which the target track is located, (5) the positioner follows. Gain and phase of closed-loop characteristic from track eccentricity of tracking control system of light beam controlled by tracking actuator to positioner displacement, (6) Track eccentricity of speed control system of light beam controlled by tracking actuator which the positioner follows To the positioner displacement Calculated using the gain and phase values of the characteristics, the light beam positioning control method in the optical disc apparatus, characterized by controlling the other of the tracking actuator based on the calculated signal. 2. A first objective lens and a second objective lens, which are arranged substantially symmetrically with a radial line of the disk medium passing through the center of the spindle as a center line, are movable in the radial direction of the disk medium. The first objective lens collects the erasing beam on the surface of the disk medium, and the second objective lens collects the recording beam and the reproducing beam on the surface of the disk medium. A first tracking actuator that controls the position of the light beam focused by the objective lens in the tracking direction, a first position detection device that detects a displacement of the first tracking actuator, and a second objective lens that collects the light beam. A second tracking actuator for controlling the position in the tracking direction of one light beam emitted, and the displacement of the second tracking actuator A second position detecting device for detecting
A method of positioning a light beam in an optical disk device, comprising: a relative displacement actuator that controls the position of the other light beam focused by the second objective lens in the tracking direction. By using the detection signal of either one of the devices, a light beam controlled by the relative displacement actuator is controlled during speed control and tracking control in which the positioner follows the movement of one tracking actuator corresponding to the one position detection device. Relative displacement required for positioning on the same target track as the light beam controlled by the one tracking actuator (1) Relative at the time of tracking control in which at least two disk radii are stored as signals. Position detection signal and drive signal of displacement actuator DC component value of (2) Design distance from radial line of disk medium passing through center of spindle to light beam controlled by second tracking actuator, (3) Value of disk radius where target track is located Is used to control the relative displacement actuator based on the calculated signal. 3. A first objective lens and a second objective lens, which are arranged substantially symmetrically with respect to a radial line of the disk medium passing through the center of the spindle as a center line, are movable in the radial direction of the disk medium. The first objective lens collects the erasing beam on the surface of the disk medium, and the second objective lens collects the recording beam and the reproducing beam on the surface of the disk medium. A first tracking actuator that controls the position of the light beam focused by the objective lens in the tracking direction, a first position detection device that detects a displacement of the first tracking actuator, and a second objective lens that collects the light beam. A second tracking actuator for controlling the position in the tracking direction of one light beam emitted, and the displacement of the second tracking actuator A second position detecting device for detecting
A method of positioning a light beam in an optical disk device, comprising: a relative displacement actuator for controlling the position of the other light beam focused by the second objective lens in the tracking direction, wherein the light beam is positioned at a predetermined positioning time. , A means for generating a position reference signal corresponding to the deviation of the light beam from the target track at the end of control, and a minimum energy positioning control means for positioning so that the speed at the target track becomes almost zero, and A means for generating a velocity reference signal corresponding to the velocity of the light beam, a means for generating a feedforward input for canceling a force corresponding to the product of the viscous friction coefficient and the velocity of the light beam at the end of control, and a position signal for determining the position. A means for subtracting the reference signal, a means for subtracting the speed reference signal from the speed signal, and a feedforward in front of the current amplifier. A means for adding forces, the light beam being condensed by the second objective lens mounted on the positioner by the means and controlled by the second tracking actuator, or condensed by the first objective lens And controlling the light beam controlled by the first tracking actuator so as to have a constant velocity a few tracks before the target track, and then the second or first
Controlling the light beam to follow a reference velocity curve defined as a function of the number of residual tracks, and the positioner to follow the tracking actuator by a detection signal of a position detecting device of the tracking actuator. A light beam positioning control method in an optical disk device, wherein the light beam is positioned on a target track by the tracking actuator after the control is completed to complete the speed control based on the number of residual tracks. 4. A first objective lens and a second objective lens, which are arranged substantially symmetrically with respect to a radial straight line of a disk medium passing through the center of a spindle, are movable in the radial direction of the disk medium. The first objective lens collects the erasing beam on the surface of the disk medium, and the second objective lens collects the recording beam and the reproducing beam on the surface of the disk medium. A first tracking actuator that controls the position of the light beam focused by the objective lens in the tracking direction, a first position detection device that detects a displacement of the first tracking actuator, and a second objective lens that collects the light beam. A second tracking actuator for controlling the position in the tracking direction of one light beam emitted, and the displacement of the second tracking actuator A second position detecting device for detecting
A positioning control method for a light beam in an optical disc device, comprising: a relative displacement actuator that controls a position in the tracking direction of the other light beam focused by the second objective lens, wherein the second or first tracking actuator is used. The speed control for the standard speed curve of the light beam to be controlled and the tracking control for the tracking actuator of the positioner operate, and the positioner is controlled by the detection signal of one of the first and second position detecting devices. The same light beam controlled by the other tracking actuator as the light beam controlled by the other tracking actuator during speed control and tracking control to follow the movement of one tracking actuator corresponding to the position detecting device Position on track A signal corresponding to the displacement of the other tracking actuator necessary for that purpose is calculated, the other tracking actuator is controlled based on this calculated signal, and the detection signal of either one of the first and second position detecting devices is calculated. Is used to control the light beam controlled by the relative displacement actuator during the velocity control and the tracking control for causing the positioner to follow the movement of the one tracking actuator corresponding to the one position detection device by the one tracking actuator. A signal corresponding to the displacement of the relative displacement actuator necessary for positioning on the same target track as the light beam to be moved, and controlling the relative displacement actuator based on this calculated signal to cause a transition of the positioner with respect to the tracking actuator. After the response has settled And at the time when the speed control based on the number of residual tracks of the light beam ends, the track pull-in operation of both the light beam controlled by the other tracking actuator and the light beam controlled by the relative displacement actuator or the former light beam. The optical beam positioning control method in an optical disk device, wherein the speed control is performed almost at the same time as the track pulling operation of the optical beam. 5. A reference velocity curve V _r during velocity control of a light beam controlled by the second or first tracking actuator is defined as a transition velocity V _t , which is a terminal velocity in velocity control of a positioner, and a velocity with respect to a tracking actuator. time is represented by the final velocity V _f and the maximum speed V _max of the control function _{"V r = (V t -V} f) exp
_{(-At) + V f, a} > 0, V r ≦ V max " the light beam positioning control method in the optical disc apparatus according to claim 3, wherein the use is converted to a function of the number of residual tracks ..