JP2000339707A - Traverse driving device for optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit stable track jump by moving an optical pickup in the direction of a radius of an optical disk in accordance with quantity of track jump, after elapse of the prescribed time, switching a tracking actuator to actuator increasing/decreasing speed control by which speed of the tracking actuator is increased or decreased, to suppress displacement of the tracking actuator. SOLUTION: When track jump is performed, track jump control of a control section 16 is started by a track jump quantity setting command of a jump quantity setting command input section 19, and jump quantity is set to a discrimination value setting section 14. The discrimination value setting section 14 outputs a discrimination value based on jump quantity to a comparator 15, simultaneously, a counter 13 starts counting of a time. The control section 16 switches selection of a second selecting section 10 to an access control section 9. The access control section 9 selected by switching of the second selecting section 10 outputs a traverse driving signal 101 in accordance with setting of jump quantity, and starts movement of a traverse 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traverse drive apparatus for an optical disc which moves a light spot for recording or reproducing information on or from an optical disc having concentric or spiral information tracks in a radial direction of the optical disc. In particular, the present invention relates to a traverse drive device for an optical disk having a so-called access function for moving a light spot to a predetermined track.

[0002]

2. Description of the Related Art An optical disk has an advantage in speed of an access operation as compared with a device using a tape medium, and stability of the access operation is also an important issue. Conventionally, an optical disk traverse driving device is disclosed in
No. 55286 is known.

FIG. 7 is a block diagram of a conventional optical disk traverse drive device. In FIG. 7, reference numeral 1 denotes an optical disk having concentric or spiral information tracks, and reference numeral 2 denotes an objective lens (not shown) and reflection from the optical disk 1. It consists of a photodetector that converts light into an electric signal and a tracking actuator 20 that moves the objective lens in the radial direction of the optical disk 1. It focuses a light beam on the information surface of the optical disk 1 to form a light spot and detects the reflected light. An optical pickup 3 generates a tracking error signal from an output of the optical pickup 2 and outputs the tracking error signal. A tracking circuit 4 receives the signal of the tracking error detection circuit 3 as an input so that the light spot follows the information track. Control for moving the actuator 20 A racking control unit 5 is an actuator acceleration / deceleration control unit that controls acceleration or deceleration of the tracking actuator 20 so that the light spot moves across the information track to a target track. 6 is a tracking control unit based on the output of the control unit 16. A selection unit for selecting an output of the actuator 4 and an output of the actuator acceleration / deceleration control unit 5; an actuator driving circuit 7 for driving the tracking actuator 20 by an output of the selection unit 6;
Reference numeral 8 denotes a traverse control unit for filtering out low-frequency components of the output of the selection unit 6, performing dead zone processing, and moving the traverse 12 in a direction in which the displacement of the tracking actuator 20 decreases. Is a signal proportional to the displacement of the tracking actuator 20. The dead zone process operates to set the output to 0 only when the low-frequency component of the output of the selection unit 6 is equal to or less than a predetermined value, and realizes stable traverse driving by eliminating unnecessary traverse movement. Reference numeral 11 denotes a traverse drive circuit that drives the traverse 12 based on the output of the traverse control unit 8, 12 denotes a traverse that moves the optical pickup 2 in the radial direction of the optical disk 1, 16 denotes a control unit that performs control described later, and 19 denotes a control unit 16 This is a jump amount setting command input unit for inputting a command for setting a track jump amount.

The operation of the traverse driving apparatus for an optical disk configured as described above will be described below.

When the track jump is not performed, the output of the control section 16 selects the output of the tracking control section 4 and the actuator drive circuit 7 causes the light spot to follow the information track. Tracking control is performed. At this time, the traverse control unit 8 extracts the low-frequency component of the output of the selection unit 6 and performs a dead zone process.
And the traverse 12 is moved so that the displacement of the tracking actuator 20 becomes small.

[0006] When a track jump is performed, the track jump control of the control unit 16 is started by the track jump amount setting command of the jump amount setting command input unit 19. The control unit 16 that has received the track jump amount setting command switches the selection of the selection unit 6 to the actuator acceleration / deceleration control unit 5. Subsequently, the control unit 16 sets the jump amount in the actuator acceleration / deceleration control unit 5, and the actuator acceleration / deceleration control unit 5 starts controlling the acceleration according to the set jump amount. The output of the actuator acceleration / deceleration control unit 5 is input to the actuator drive circuit 7 and the actuator drive circuit 7
, The tracking actuator 20 starts moving so that the light spot crosses the information track. At this time, the traverse control unit 8 makes the dead band width of the dead band processing performed on the low-frequency component of the output of the selection unit 6 smaller than when the track jump is not performed, inputs this output to the traverse drive circuit 11, and
The traverse 12 is moved so that the displacement of 0 becomes small. As described above, when the track jump is performed, by reducing the dead zone width, the delay in following the traverse mechanism at the start of the track jump is reduced.

When the actuator acceleration / deceleration control unit 5 that has started accelerating according to the setting of the jump amount detects that the destination track is approaching from the set jump amount and the output of the tracking error detection circuit 3, it starts deceleration. When the arrival at the destination track is detected, a detection signal is output to the control unit 16. Upon receiving the detection signal, the control unit 16 switches the selection of the selecting unit 6 to the tracking control unit 4, and returns to the above-described control in which the track jump is not performed, and performs the tracking control.

[0008]

In such a traverse drive apparatus for an optical disk, it is required that the traverse follow the movement of the tracking actuator so that the displacement of the tracking actuator does not increase during a track jump. Since the traverse is moved by detecting the displacement, the traverse movement is delayed, and if the acceleration at the time of starting the traverse is slow, the traverse can be followed during the track jump even if the dead zone width is set to 0. However, the track jump operation becomes unstable.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a traverse driving apparatus for an optical disk which can suppress a displacement of a tracking actuator at the time of a track jump and perform a stable track jump operation even when the traverse has a slow acceleration at the time of startup. It was done as.

[0010]

SUMMARY OF THE INVENTION In order to solve this problem, a traverse drive device for an optical disk according to the present invention is a traverse drive device for an optical disk which irradiates an information track on the optical disk with a light beam to perform recording and reproduction. A tracking actuator for converging the light beam on the optical disc to form a light spot, moving the light spot in a radial direction of the optical disc, detecting reflected light of the light beam, and outputting as an electric signal An optical pickup, a tracking error detecting means for detecting a relative position error between the information track and the light spot from an output of the optical pickup, and a signal from the tracking error detecting means for inputting the light spot to the information track. A track that controls the tracking actuator to follow the Actuator control means for accelerating or decelerating the tracking actuator to move the light spot to a target track position; traverse for moving the optical pickup in a radial direction of the optical disc; Access control means for accelerating or decelerating the traverse according to a jump amount; selecting means for selecting one of an output of the tracking control means and an output of the actuator acceleration / deceleration control means and supplying the output to the tracking actuator; And control means for starting the movement of the traverse and switching the selection means from the output of the tracking control means to the output of the actuator acceleration / deceleration control means after a lapse of a predetermined time.

Thus, at the start of the track jump,
First, only the traverse starts moving ahead, and by starting the track jump by the tracking actuator after the time required for the traverse to move by a predetermined amount, even if the traverse has a slow acceleration at the time of startup,
The displacement of the tracking actuator during a track jump can be suppressed, and a stable track jump operation can be performed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a traverse drive apparatus for an optical disk for irradiating an information track on an optical disk with a light beam to perform recording and reproduction, wherein the optical disk has the optical disk. Forming a light spot by condensing a beam, having a tracking actuator for moving the light spot in a radial direction of the optical disc,
An optical pickup that detects reflected light of the light beam and outputs the signal as an electric signal; a tracking error detection unit that detects a relative position error between the information track and the light spot from an output of the optical pickup; Tracking control means for controlling the tracking actuator so as to make the light spot follow the information track by inputting a signal of means, and for moving the light spot to a target track position,
Actuator acceleration / deceleration control means for accelerating or decelerating the tracking actuator, traverse for moving the optical pickup in a radial direction of the optical disk, access control means for accelerating or decelerating the traverse according to a track jump amount, Selecting means for selecting one of the output of the control means and the output of the actuator acceleration / deceleration control means and supplying the selected output to the tracking actuator; and starting the movement of the traverse at the time of a track jump, and controlling the selection means after a predetermined time has passed. And control means for performing control for switching from the output of the means to the output of the actuator acceleration / deceleration control means. Only when the traverse starts moving ahead, and after the time required for the traverse to move a predetermined amount has elapsed, the track jump is started by the tracking actuator. This has the effect of suppressing the displacement of the tracking actuator and performing a stable track jump operation.

According to a second aspect of the present invention, there is provided an optical disk traverse drive device for irradiating an information track on an optical disk with a light beam to perform recording and reproduction, wherein the light beam is condensed on the optical disk. An optical pickup that forms a spot, has a tracking actuator that moves the light spot in the radial direction of the optical disc, detects reflected light of the light beam, and outputs the reflected light as an electric signal,
A tracking error detection unit that detects a relative position error between the information track and the light spot from an output of the optical pickup, and a signal from the tracking error detection unit that is input so that the light spot follows the information track. Tracking control means for controlling a tracking actuator; actuator acceleration / deceleration control means for accelerating or decelerating the tracking actuator to move the light spot to a target track position; displacement detection for detecting displacement of the tracking actuator Traverse means for moving the optical pickup in a radial direction of the optical disc;
Access control means for accelerating or decelerating the traverse according to a track jump amount; selecting means for selecting one of an output of the tracking control means and an output of the actuator acceleration / deceleration control means and supplying the output to the tracking actuator; Comparing means for comparing the output of the detecting means with a predetermined value; and starting the movement of the traverse at the time of a track jump, and selecting the selecting means from the output of the tracking control means in accordance with the output of the comparing means. And control means for controlling the switching to the output of the optical disk, characterized in that it is a traverse drive device of an optical disc, characterized in that at the time of the start of track jump, first, only the traverse starts moving first,
By starting the track jump by the tracking actuator after the tracking actuator is in the predetermined displacement state, even when the traverse has a slow start-up acceleration, the tracking actuator displacement is suppressed during the track jump, and a stable track jump operation is performed. It has the effect that it can be performed.

According to a third aspect of the present invention, there is provided an optical disk traverse drive device for irradiating an information track on an optical disk with a light beam to perform recording and reproduction, wherein the light beam is condensed on the optical disk. An optical pickup that forms a spot, has a tracking actuator that moves the light spot in the radial direction of the optical disc, detects reflected light of the light beam, and outputs the reflected light as an electric signal,
A traverse for moving the optical pickup in a radial direction of the disk; and control means for starting the movement of the traverse before the light spot crosses the information track by the tracking actuator during a track jump. It is a traverse drive device for an optical disk, and does not make the tracking actuator follow the movement of the traverse at the time of a track jump, but makes the movement of the traverse follow the movement of the tracking actuator in advance.
Even when the traverse is slow in acceleration at the time of starting, the displacement of the tracking actuator that occurs at the time of a track jump is suppressed, so that a stable track jump operation can be performed.

According to a fourth aspect of the present invention, in the traverse driving apparatus for an optical disk according to the third aspect, the control means starts the movement of the traverse at the time of a track jump, and after a lapse of a predetermined time, the light spot has the information. Characterized in that it is configured to start the movement of the tracking actuator so as to cross the track,
By starting the movement of the traverse at the time of the track jump and starting the movement of the tracking actuator after a lapse of a predetermined time, the displacement of the tracking actuator can be suppressed more stably.

According to a fifth aspect of the present invention, in the optical disk traverse driving apparatus according to the third aspect, the control means starts the movement of the traverse at the time of a track jump and the displacement of the tracking actuator becomes a predetermined displacement amount. After detecting that the tracking actuator has reached the position, the movement of the tracking actuator is started so that the light spot crosses the information track. By starting the movement of the tracking actuator after detecting that the displacement of the tracking actuator has reached the predetermined amount of displacement, the displacement of the tracking actuator can be suppressed more stably.

According to a sixth aspect of the present invention, in the optical disk traverse driving apparatus according to the third to fifth aspects, a tracking error for detecting a relative position error between the information track and the light spot from an output of the optical pickup. A tracking control means for controlling the tracking actuator so as to make the light spot follow the information track by inputting a signal of the tracking error detection means; and Actuator acceleration / deceleration control means for controlling the tracking actuator so as to move to a target track, and selecting one of an output of the tracking control means and an output of the actuator acceleration / deceleration control means and supplying the output to the tracking actuator. means And switching the selection of the selection means from the output of the tracking control means to the output of the actuator acceleration / deceleration control means to start the movement of the tracking actuator so that the light spot crosses the information track. The control of the tracking actuator is separated into tracking control means for controlling the light spot to follow the information track and actuator acceleration / deceleration control means for controlling the movement to the target track position. By the selection by the selection means, it is possible to perform more responsive tracking actuator control at the time of a track jump.

According to a seventh aspect of the present invention, in the traverse drive device for an optical disk according to the third to sixth aspects, traverse control means for controlling the movement of the traverse so as to reduce the displacement of the tracking actuator, and a track jump. Access control means for controlling the movement of the traverse so that the light spot crosses the information track in accordance with the amount; and one of an output of the traverse control means and an output of the access control means is selected and supplied to the traverse. Selecting means for switching the selection means from the output of the traverse control means to the output of the access control means at the time of a track jump, thereby starting the movement of the traverse. Traverse control, tracking actuating Traverse control means for compensating for data displacement and access control means for performing track jump are individually provided and selected by the selection means, so that more responsive traverse control can be performed at the time of track jump. Has an action.

An embodiment of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIG. 1 is a block diagram of an optical disk traverse drive device according to a first embodiment of the present invention, FIG. 2 is a waveform diagram of the optical disk traverse drive device of FIG. 1, and FIG. 2 shows a control flowchart of a control unit of the optical disk traverse drive device of FIG. 1.

In FIG. 1, reference numeral 1 denotes an optical disk having concentric or spiral information tracks, 2 denotes an objective lens (not shown), a photodetector for converting light reflected from the optical disk 1 into an electric signal, and the radius of the objective lens An optical pickup that focuses a light beam on the information surface of the optical disk 1 to form a light spot and detects the reflected light, and 3 generates a tracking error signal from the output of the optical pickup 2. Output tracking error detection circuit,
Reference numeral 4 denotes a tracking control unit which receives the signal of the tracking error detection circuit 3 and controls the movement of the tracking actuator 20 so that the light spot follows the information track. An actuator acceleration / deceleration controller 6 for controlling acceleration or deceleration of the tracking actuator 20 so as to move to the track, and 6 is a controller 16
A first selector for selecting the output of the tracking controller 4 and the output of the actuator acceleration / deceleration controller 5 according to the output of
Reference numeral 7 denotes an actuator drive circuit that drives the tracking actuator 20 based on the output of the first selection unit 6. Reference numeral 8 denotes a traverse control unit that performs control to correct the position of the traverse 12 so as to reduce the displacement of the tracking actuator 20. The method filters out the low-frequency component of the output of the first selection unit 6, performs dead zone processing, and controls the traverse 12, and performs the same operation as the conventional example. 9 is a traverse 1 so that the light spot crosses the information track according to a track jump amount.
An access control unit for performing control for accelerating or decelerating 2; a second selection unit for selecting an output of the traverse control unit 8 and an output of the access control unit 9 based on an output of the control unit 16; A traverse drive circuit for driving the traverse 12 by the output of 10, a traverse 12 for moving the optical pickup 2 in the radial direction of the optical disk 1, a counter 13 for counting the movement time of the traverse 12, and a control unit 16 for moving the traverse 12 Cleared at start and starts counting. Reference numeral 14 denotes a determination value setting unit for setting the time from the start of the movement of the traverse 12 to the start of the track movement of the tracking actuator 20 in accordance with the track jump amount input from the control unit 16. Is greater than the output of the determination value setting unit 14,
Reference numeral 16 denotes a control unit for performing control described later, and 19 denotes a jump amount setting command input unit for setting a track jump amount in the control unit 16 and inputting a track jump command.

In FIG. 2, the vertical axis indicates a traverse drive signal 101 as an input of the traverse drive circuit 11, a tracking error signal 102 as an output of the tracking error detection circuit 3, and a reference numeral 103 of the first selector 6. An actuator drive signal, which is an output, 104 is a counter 13
, The reference value 105 is the output of the determination value setting unit 14, the reference value 111 is the position of the traverse 12, which is not shown in FIG. 4, and the reference numeral 112 is the displacement of the tracking actuator 20, and FIG. Indicates a traverse displacement not shown.

The horizontal axis represents time, A is the time when a jump amount setting command is input from the jump amount setting command input unit 19 to the control unit 16, B is the counter value 104 and the judgment value 1
05 indicates a point in time, C indicates a point in time when the actuator acceleration / deceleration control unit 5 detects the end of the track jump, and D indicates a point in time when the traverse 12 ends the movement by the track jump.

The operation of the traverse driving apparatus for an optical disk configured as described above will be described below with reference to the flowchart of FIG.

First, when the track jump is not performed, the output of the control section 16 causes the first selection section 6 to select the output of the tracking control section 4 and the second selection section 10
The output of the traverse control unit 8 is selected, and the tracking control is performed by the actuator drive circuit 7 so that the light spot follows the information track in the same manner as in the conventional example. Further, the traverse control unit 8 extracts a low-frequency component of the output of the first selection unit 6 and performs a dead zone process. The output is input to a traverse drive circuit 11, and the traverse control unit 8 reduces the displacement of the tracking actuator 20. To move.

When a track jump is performed, the track jump control of the control unit 16 is started by the track jump amount setting command of the jump amount setting command input unit 19. This corresponds to A in FIG. 2 and is the start of the processing in FIG.

In step 21, the control unit 16 sets the jump amount in the judgment value setting unit 14. Subsequently, at step 22, the counter 13 is started. The determination value setting unit 14 outputs a determination value 105 based on the jump amount to the comparator 15. The started counter 13 starts counting time.

Next, at step 23, the control unit 16
Switches the selection of the second selector 10 to the access controller 9. Subsequently, in step 24, the control unit 16 sets the jump amount in the access control unit 9. Second selector 1
The access control unit 9 selected by switching 0 outputs a traverse drive signal 101 according to the setting of the jump amount, and starts the movement of the traverse 12. Steps 21 to 24 are performed at the point A in FIG.

The acceleration / deceleration method in the access control unit 9 may be any method, but here, as an example, it is assumed that the acceleration pulse is applied by a DC motor.

In step 25, the control unit 16 waits for the input of the comparator 15. This corresponds to the time from A to B in FIG.

After a lapse of a predetermined time from the start of the movement of the traverse 12, that is, when the counter value 104 output from the counter 13 is equal to the determination value 10
When the value exceeds 5, the comparator 15 outputs a detection signal to the control unit 16. This corresponds to B in FIG. 2, and the processing in FIG. 3 is restarted.

In step 26, the control section 16 switches the selection of the first selection section 6 to the actuator acceleration / deceleration control section 5. Subsequently, in step 27, the control unit 16 sets the jump amount in the actuator acceleration / deceleration control unit 5.
The actuator acceleration / deceleration control unit 5 selected by the switching of the first selection unit 6 starts the control of acceleration according to the set jump amount. Actuator acceleration / deceleration controller 5
Is input to the actuator drive circuit 7, and the tracking actuator 20 starts moving so that the light spot crosses the information track by the output of the actuator drive circuit 7. Steps 26 and 27 are shown in FIG.
At the point B in FIG.

In step 28, the control unit 16 waits for an input from the actuator acceleration / deceleration control unit 5. This corresponds to the time from B to C in FIG. The actuator acceleration / deceleration control unit 5 that has started acceleration according to the setting of the jump amount as described above starts deceleration when detecting that the destination track is approaching from the set jump amount and the tracking error signal 102. When the arrival at the preceding track is detected, a detection signal is output to the control unit 16. This corresponds to C in FIG. 2, and the processing in FIG. 3 is restarted.

In step 29, the control section 16 switches the selection of the first selection section 6 to the tracking control section 4.
Subsequently, in step 30, the control unit 16 switches the selection of the second selection unit 10 to the traverse control unit 8.

When the stepping motor is used for the traverse, the moving distance can be accurately managed. Therefore, the output of the second selector 10 may be switched after the movement corresponding to the track jump amount is completed.

Steps 29 to 30 correspond to C in FIG.
And the control shown in FIG. 3 ends. But,
This does not mean that all the track jumps have been completed, and the displacement of the tracking actuator 20 is continuously corrected by the same control as that of a general track trace in which no track jump is performed thereafter.

At this time, the light spot of the optical pickup 2 has already traced the destination track, but the tracking actuator 20 still has a large displacement since the traverse 12 has been largely moved by the access control unit 9. State. The position of the traverse 12 is corrected by the same control as that of a general track trace without a track jump, that is, by the traverse control unit 8 which receives the actuator drive signal 103 so as to reduce the displacement of the tracking actuator 20. These are C to D in FIG.

The traverse controller 8 controls the traverse 12
When the correction of the position is converged, the movement of the traverse by the track jump ends. This is D in FIG.

The control performed between C and D in FIG. 2 is the same as in the prior art, so that the details are omitted.

The judgment value 105 set by the judgment value setting unit 14
Indicates that the actuator 2
If the displacement of 0 can be ignored, 0 is set.

The judgment value 105 together with the track jump amount
And its value is determined by the following requirements. If the light spot does not cross the information track even after the movement of the traverse 12 is started, the displacement of the tracking actuator 20 increases. If the displacement increases excessively, focus and tracking control cannot be performed stably. For this reason, the determination value 105 is set within a range in which focus and tracking control can be performed stably, and further, a tracking error of the traverse control unit 9 with respect to the optical pickup 2 in a track trace state where no track jump is performed is taken into consideration. Is set.

As described above, according to the present embodiment, at the time of a track jump, only the traverse 12 starts moving first, and after a predetermined time elapses, the first selector 6 controls the actuator acceleration / deceleration from the output of the tracking controller 4. Since the track jump is started by the tracking actuator 20 by switching to the output of the control unit 5, the traverse 12 does not follow the tracking actuator 20 at the time of the track jump.
In this case, the tracking actuator 20 is made to follow the movement of the tracking actuator 2 in advance, and even if the traverse has a slow acceleration at the time of starting, the displacement of the tracking actuator is suppressed at the time of the track jump, and a stable track jump operation can be performed. .

In FIG. 1, the tracking control unit 4, actuator acceleration / deceleration control unit 5, first selection unit 6, traverse control unit 8, access control unit 9, second selection unit 10, counter 13. Judgment value setting unit 1
4. The comparator 15, the control unit 16, and the jump amount command input unit 19 are configured by a microcomputer, an interface circuit, and software control. As long as the same control is performed, any part of the entire configuration shown in FIG. 1 may be configured by hardware and any part may be configured by software.

(Embodiment 2) Next, FIG. 4 is a block diagram of a traverse driving device for an optical disk according to a second embodiment of the present invention, FIG. 5 is a waveform diagram of the traverse driving device for an optical disk of FIG. FIG. 6 is a control flowchart of the control unit of the optical disk traverse drive device of FIG.

In FIG. 4, reference numeral 1 denotes an optical disk having concentric or spiral information tracks, 2 denotes an objective lens (not shown), a photodetector for converting light reflected from the optical disk 1 into an electric signal, and a radius of the optical disk 1 An optical pickup that focuses a light beam on the information surface of the optical disk 1 to form a light spot and detects the reflected light, and 3 generates a tracking error signal from the output of the optical pickup 2. Output tracking error detection circuit,
Reference numeral 4 denotes a tracking control unit which receives the signal of the tracking error detection circuit 3 and controls the movement of the tracking actuator 20 so that the light spot follows the information track. An actuator acceleration / deceleration controller 6 for controlling acceleration or deceleration of the tracking actuator 20 so as to move to the track, and 6 is a controller 16
A first selector for selecting the output of the tracking controller 4 and the output of the actuator acceleration / deceleration controller 5 according to the output of
Reference numeral 7 denotes an actuator drive circuit that drives the tracking actuator 20 based on the output of the first selection unit 6. Reference numeral 8 denotes a traverse control unit that performs control to correct the position of the traverse 12 so as to reduce the displacement of the tracking actuator 20. The method filters out the low-frequency component of the output of the first selection unit 6, performs dead zone processing, and controls the traverse 12, and performs the same operation as the conventional example. 9 is a traverse 1 so that the light spot crosses the information track according to a track jump amount.
An access control unit for performing control for accelerating or decelerating 2; a second selection unit for selecting an output of the traverse control unit 8 and an output of the access control unit 9 based on an output of the control unit 16; A traverse drive circuit for driving the traverse 12 with the output of 10; 12 is a traverse for moving the optical pickup 2 in the radial direction of the optical disk 1; 15 is an output of an actuator displacement detection unit 17 described later and an output of a determination value setting unit 18 described later , A comparator that outputs a detection signal to the control unit 16, 16 is a control unit that performs control described later, 17 is an actuator displacement detection unit that detects the amount of displacement of the tracking actuator 20, and 18 is one of traverses at the time of a track jump.
After the start of the movement of No. 2, a determination value setting unit that sets the displacement amount at which the tracking actuator 20 starts the track movement according to the track jump amount input from the control unit 16, and 19 sets the track jump amount in the control unit 16. A jump amount setting command input unit for inputting a track jump command.

In FIG. 5, the vertical axis indicates a traverse drive signal 101 as an input of the traverse drive circuit 11, a tracking error signal 102 as an output of the tracking error detection circuit, and an output 103 of the first selector 6. Is an actuator drive signal which is an output of the actuator displacement detector 17;
Reference numeral 107 denotes a judgment value which is an output of the judgment value setting unit 18;
Indicates the position of the traverse 12 and indicates a traverse position not shown in FIG.

The horizontal axis represents time, A is the time when a jump amount setting command is input from the jump amount setting command input unit 19 to the control unit 16, and B is the actuator displacement signal 10.
6 and the determination value 107, C indicates the time when the actuator acceleration / deceleration control unit 5 detects the end of the track jump, and D indicates the time when the traverse 12 ends the movement by the track jump.

The operation of the traverse driving apparatus for an optical disk configured as described above will be described below with reference to the flowchart of FIG.

First, when the track jump is not performed, the output of the tracking control unit 4 is selected by the output of the control unit 16 and the output of the tracking control unit 4 is selected by the first selection unit 6.
The output of the traverse control unit 8 is selected, and the tracking control is performed by the actuator drive circuit 7 so that the light spot follows the information track in the same manner as in the conventional example. Further, the traverse control unit 8 extracts a low-frequency component of the output of the first selection unit 6 and performs a dead zone process. The output is input to a traverse drive circuit 11, and the traverse control unit 8 reduces the displacement of the tracking actuator 20. To move.

When a track jump is performed, the track jump control of the control unit 16 is started by the track jump amount setting command of the jump amount setting command input unit 19. This corresponds to A in FIG. 5 and is the start of the processing in FIG.

In step 31, the control section 16 sets the jump amount in the judgment value setting section 18. Judgment value setting unit 18
Outputs a displacement determination value 107 based on the jump amount to the comparator 15.

Subsequently, at step 32, the control unit 16
Switches the selection of the second selector 10 to the access controller 9. Subsequently, in step 33, the control unit 16 sets the jump amount in the access control unit 9. Second selector 1
The access control unit 9 selected by switching 0 outputs a traverse drive signal 101 according to the setting of the jump amount, and starts the movement of the traverse 12. Steps 31 to 33 are performed at the point A in FIG.

The accelerating / decelerating method in the access control unit 9 may be any method, but here, as an example, the accelerating pulse is applied by a DC motor.

In step 34, the control unit 16 waits for the input of the comparator 15. This corresponds to the time from A to B in FIG.

The movement of the traverse 12 is started, and it is detected that the displacement of the tracking actuator 20 has reached a predetermined displacement amount, that is, the actuator displacement signal 106 output from the actuator displacement detecting unit 17 is output by the output of the judgment value setting unit 18. The comparator 15 outputs a detection signal to the control unit 16 when detecting that the value exceeds a certain determination value 107. This corresponds to B in FIG. 5, and the processing in FIG. 6 is restarted.

In step 35, the control section 16 switches the selection of the first selection section 6 to the actuator acceleration / deceleration control section 5. Subsequently, at step 36, the control unit 16 sets the jump amount in the actuator acceleration / deceleration control unit 5.
The actuator acceleration / deceleration control unit 5 selected by the switching of the first selection unit 6 starts the control of acceleration according to the set jump amount. Actuator acceleration / deceleration controller 5
Is input to the actuator drive circuit 7, and the tracking actuator 20 starts moving so that the light spot crosses the information track by the output of the actuator drive circuit 7. These steps 35 to 36 are shown in FIG.
At the point B in FIG.

In step 37, the control section 16 waits for an input from the actuator acceleration / deceleration control section 5. This corresponds to the time from B to C in FIG. The actuator acceleration / deceleration control unit 5 that has started acceleration according to the setting of the jump amount as described above starts deceleration when detecting that the destination track is approaching from the set jump amount and the tracking error signal 102. When the arrival at the preceding track is detected, a detection signal is output to the control unit 16. This corresponds to C in FIG. 5, and the processing in FIG. 6 is restarted.

In step 38, the control section 16 switches the selection of the first selection section 6 to the tracking control section 4.
Subsequently, in step 39, the control unit 16 switches the selection of the second selection unit 10 to the traverse control unit 8.

When the stepping motor is used for the traverse, the moving distance can be accurately managed. Therefore, the output of the second selecting section 10 may be switched after the movement corresponding to the track jump amount is completed.

Steps 38 to 39 correspond to C in FIG.
And the control shown in FIG. 6 ends. But,
This does not mean that all the track jumps have been completed, and the displacement of the tracking actuator 20 is continuously corrected by the same control as that of a general track trace in which no track jump is performed thereafter.

At this point, the light spot of the optical pickup 2 has already traced the destination track, but since the traverse 12 has been largely moved by the access control unit 9, the tracking actuator 20 still has a large displacement. State. The position of the traverse 12 is corrected by the same control as that of a general track trace without a track jump, that is, by the traverse control unit 8 which receives the actuator drive signal 103 so as to reduce the displacement of the tracking actuator 20. These are C to D in FIG.

The traverse controller 8 controls the traverse 12
When the correction of the position is converged, the movement of the traverse by the track jump ends. This is D in FIG.

The control performed between C and D in FIG. 5 is the same as that of the prior art, so that the details are omitted.

The judgment value 107 set by the judgment value setting section 18
Indicates that the actuator 2
If the displacement of 0 can be ignored, 0 is set.

The judgment value 105 together with the track jump amount
And its value is determined by the following requirements. If the light spot does not cross the information track even after the movement of the traverse 12 is started, the displacement of the tracking actuator 20 increases. If the displacement increases excessively, focus and tracking control cannot be performed stably. For this reason, the determination value 105 is set within a range in which focus and tracking control can be performed stably, and further, a tracking error of the traverse control unit 9 with respect to the optical pickup 2 in a track trace state where no track jump is performed is taken into consideration. Is set.

As described above, according to the present embodiment, at the time of a track jump, only the traverse 12 starts to move first, and the first selector 6 is moved from the output of the tracking controller 4 to the actuator according to the output of the comparator 15. By switching to the output of the acceleration / deceleration control unit 5 and starting the track jump by the tracking actuator 20, the traverse 12 does not follow the tracking actuator 20 at the time of the track jump.
The tracking actuator 20 is caused to follow the movement of the traverse 12 in advance, so that even if the traverse has a slow acceleration at the time of starting, the displacement of the tracking actuator is suppressed at the time of the track jump, and a stable track jump operation can be performed. Become.

In FIG. 4, the tracking control unit 4, the actuator acceleration / deceleration control unit 5, the first selection unit 6, the traverse control unit 8, the access control unit 9, the second selection unit 10, the comparator, which are enclosed by a broken line in FIG. 15, control unit 1
6. Actuator displacement detection unit 17, judgment value setting unit 1
8. The jump amount command input unit 19 is configured by a microcomputer, an interface circuit, and software control. If the same control is performed, any part of the entire configuration shown in FIG. 4 may be configured by hardware and any part may be configured by software.

[0068]

As described above, according to the present invention, at the start of a track jump, only the traverse starts to move first, and after a predetermined condition is reached, the track jump by the tracking actuator is started. , Even if the traverse has a slow start-up acceleration,
An advantageous effect is obtained in that the displacement of the tracking actuator during a track jump can be suppressed and a stable track jump operation can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of an optical disc traverse drive device according to a first embodiment of the present invention;

FIG. 2 is a waveform diagram of the traverse driving device for the optical disk of FIG. 1;

FIG. 3 is a control flowchart of a control unit of the traverse driving device for the optical disc of FIG. 1;

FIG. 4 is a block diagram of an optical disc traverse drive device according to a second embodiment of the present invention;

FIG. 5 is a waveform diagram of the traverse driving device for the optical disk of FIG. 4;

6 is a control flowchart of a control unit of the optical disk traverse driving device of FIG. 4;

FIG. 7 is a block diagram of a conventional optical disk traverse drive device.

[Explanation of symbols]

 Reference Signs List 1 optical disk 2 optical pickup 3 tracking error detection circuit 4 tracking control unit 5 actuator acceleration / deceleration control unit 6 first selection unit 8 traverse control unit 9 access control unit 10 second selection unit 12 traverse 15 comparator 16 control unit 17 displacement detection Part 20 Tracking actuator

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Katsumi Sumida 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 5D117 AA02 EE08 EE14 EE18 EE23 FF27 FX02 GG06 5D118 AA13 BA01 BF11 CA14 CD03

Claims (7)

[Claims] An optical disk traverse drive device for irradiating an information track on an optical disk with a light beam to perform recording and reproduction, wherein the light beam is condensed on the optical disk to form a light spot, An optical pickup that has a tracking actuator that moves a spot in a radial direction of the optical disk, detects reflected light of the light beam, and outputs the detected light as an electric signal, and outputs the information track and the light spot from the output of the optical pickup. Tracking error detection means for detecting a relative position error; tracking control means for controlling the tracking actuator so that the light spot follows the information track by inputting a signal from the tracking error detection means; To move to the track position Actuator acceleration / deceleration control means for accelerating or decelerating a locking actuator, traverse for moving the optical pickup in a radial direction of the optical disc, and access control means for accelerating or decelerating the traverse according to a track jump amount;
Selecting means for selecting one of the output of the tracking control means and the output of the actuator acceleration / deceleration control means and supplying the output to the tracking actuator; and starting the movement of the traverse at the time of a track jump, and setting the selecting means after a predetermined time has elapsed. A traverse driving device for an optical disk, comprising: control means for performing control for switching from the output of the tracking control means to the output of the actuator acceleration / deceleration control means. 2. A traverse drive for an optical disk for irradiating an information track on an optical disk with a light beam to perform recording and reproduction, wherein the light beam is condensed on the optical disk to form a light spot. An optical pickup that has a tracking actuator that moves a spot in a radial direction of the optical disk, detects reflected light of the light beam, and outputs the detected light as an electric signal, and outputs the information track and the light spot from the output of the optical pickup. Tracking error detection means for detecting a relative position error; tracking control means for controlling the tracking actuator so that the light spot follows the information track by inputting a signal from the tracking error detection means; To move to the track position Actuator acceleration / deceleration control means for accelerating or decelerating the locking actuator; displacement detection means for detecting the displacement of the tracking actuator; traverse for moving the optical pickup in a radial direction of the optical disc; Access control means for accelerating or decelerating the traverse; selecting means for selecting one of the output of the tracking control means and output of the actuator acceleration / deceleration control means and supplying the output to the tracking actuator; output of the displacement detection means and a predetermined value And control for starting the movement of the traverse at the time of a track jump and switching the selection means from the output of the tracking control means to the output of the actuator acceleration / deceleration control means according to the output of the comparison means. Traverse driving device of an optical disk being characterized in that a control means. 3. A traverse driving device for an optical disk for irradiating an information track on an optical disk with a light beam to perform recording and reproduction, wherein the light beam is condensed on the optical disk to form a light spot, and An optical pickup having a tracking actuator for moving a spot in a radial direction of the optical disk, detecting reflected light of the light beam and outputting the signal as an electric signal, a traverse for moving the optical pickup in a radial direction of the disk, and a track; A traverse driving device for an optical disk, comprising: a control means for starting movement of the traverse before the light spot crosses the information track by the tracking actuator during a jump. 4. The apparatus according to claim 1, wherein the control means starts moving the traverse at the time of a track jump and starts moving the tracking actuator so that the light spot crosses the information track after a predetermined time has elapsed. The optical disk traverse drive device according to claim 3. 5. The tracking means starts the movement of the traverse at the time of a track jump and detects that the displacement of the tracking actuator has reached a predetermined amount of displacement, and thereafter, causes the light spot to cross the information track. 4. The optical disk traverse driving device according to claim 3, wherein the movement of the actuator is started. 6. A tracking error detecting means for detecting a relative position error between the information track and the light spot from an output of the optical pickup, wherein the control means comprises:
Tracking control means for controlling the tracking actuator so that the light spot follows the information track by inputting the signal of the tracking error detection means as input, and the light spot moves across the information track to a target track. An actuator acceleration / deceleration control unit that controls a tracking actuator; and a selection unit that selects one of an output of the tracking control unit and an output of the actuator acceleration / deceleration control unit and supplies the selected output to the tracking actuator. By switching the selection from the output of the tracking control means to the output of the actuator acceleration / deceleration control means, the movement of the tracking actuator is started so that the light spot crosses the information track. Traverse driving device of an optical disk according to claim 3-5, wherein the symptom. 7. The traverse control means for controlling the movement of the traverse so as to reduce the displacement of the tracking actuator, and the traverse means so that the light spot crosses the information track in accordance with a track jump amount. Access control means for controlling the movement of the traverse control means, and a selection means for selecting one of the output of the traverse control means and the output of the access control means and supplying the selected output to the traverse. 7. An optical disk traverse driving apparatus according to claim 3, wherein the traverse movement is started by switching from the output of said traverse control means to the output of said access control means.