JP2755010B2 - Track jumping equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a track jump apparatus for an optical disk.

[0002]

2. Description of the Related Art In recent years, optical disks have been applied in a wide range of fields, and particularly in applications requiring random access such as audio / video, karaoke, data files, and external storage of computers, high-speed access operations are required. ing. Therefore, high speed operation and high accuracy of the track jump device are also important issues.

[0003] A conventional track jump apparatus will be described below. FIG. 8 is a block diagram of the conventional track jump apparatus. In FIG. 8, reference numeral 1 denotes an optical disk on which information signals are recorded in a predetermined track form, 2 denotes a rotating unit for rotating the optical disk 1, and 3 denotes a light spot formed by condensing a light beam on the information surface of the optical disk 1. An optical pickup that outputs a recorded information signal and a relative position error between the track and the optical spot in the disk radial direction by detecting the reflected light,
A tracking error signal generating means for generating a tracking error signal from the output of the optical pickup 3;
Is a tracking control means for inputting a tracking error signal to perform phase compensation, etc., 13 is a track jump command means for generating a track jump command, 14 is a target track number setting means for setting a target track jump number, 1
5 is a second track number counting means for counting the number of track jumps by the output of the optical pickup 3, 16 is a reset signal input terminal for resetting the counting content of the second track number counting means 15, and 17 is a second track. Third comparing means for comparing the output of the number counting means 15 with the output of the target track number setting means 14; relative speed detecting means 18 for detecting the relative speed between the track and the light spot based on the output of the optical pickup 3; Is a track number / target speed conversion table for converting the output of the second track number counting means 15 into a target speed, 19 is a relative speed detecting means 18
Speed control means for performing speed control by comparing the output of the number of tracks / output of the track number / target speed conversion table 20, a selection means 7 for selecting an output of the tracking control means 6 and an output of the speed control means 19, and a tracking means 8 The input terminal of the selection means 7 for inputting the output of the control means 6, 9 is the speed control means 1
9 is an input terminal of the selection means 7 for inputting the output of
The control signal input terminal 11 selects the input terminal 8 in the selection means 7 according to the output of the comparison means 17. The control signal input terminal 11 selects the input terminal 9 in the selection means 7 according to the output of the track jump instruction means 13. , 12 receive the output of the selection means 7 as an input and
Is driving means for driving.

[0004] The operation of the track jump apparatus configured as described above will be described below.

First, when an information signal is read from the optical disk 1, the input terminal 8 is selected by the selection means 7. Here, the relative position error in the radial direction of the disk is detected by the optical pickup 3, and this is used as a tracking error signal by the tracking error generating means 5.
Performs phase compensation for stabilizing the tracking control, and inputs the output to the tracking driving means 12 through the selection means 7 to drive the tracking actuator 4. Thereby, the light spot can follow the recording track, and the information signal on the recording track can be read.

Next, in the case of a track jump, first, the output of the track jump instruction means 13 causes the second
Reset the counting contents of the track number counting means 15 of
The target number of track jumps is set by the target track number setting means 14, and the tracking servo loop is opened by selecting the input terminal 9 by the selection means 7 to start the track jump. Here, relative speed detecting means 1
Numeral 8 detects the relative speed between the track and the light spot (a method of detecting the relative speed may be any method, for example, a method of measuring a zero-crossing time interval of the tracking error signal), and is detected. The speed control unit 19 controls the speed so that the relative speed matches the target speed output from the track / target speed conversion table 20, and the driving unit 12 drives the tracking actuator 4 to perform a track jump. The second track number counting means 15 always counts the number of actual track jumps, and the third comparison means 17 constantly compares this output with the output of the target track number setting means 14. Here, when the target number is reached, the comparison results match, so the output of the third comparing means 17 is applied to the input terminal 10 of the selecting means 7, the input terminal 8 is selected, the tracking servo loop is closed and the track jump is performed. finish.

The method of setting the target speed in this case is described below.
This will be described below with reference to FIG. 9 and (Table 1). FIG. 9 is a waveform chart showing the operation of the conventional track jump device, and Table 1 is a conversion table showing a track / target speed conversion table at the time of the conventional track jump operation.

[0008]

[Table 1]

In FIG. 9, the horizontal axis indicates the number of tracks, and the vertical axis indicates the target speed. In FIG. 9 and (Table 1),
N is the number of target track jumps, N _{1 to} N ₆ are the number of tracks determined by the number of tracks / target speed conversion table 20, and V _{0 to} V ₃ are the number of tracks / target speed conversion table 2
0 is the target speed determined.

[0010] Here, when the track jump operation, (Table 1) using a conversion table as shown, V ₀ ~V ₃ target speed by comparing the actual number of tracks jumped to date with N1～N ₆ The track jump operation is performed while selecting from among. The target speed profile at this time is shown in FIG.
It becomes as shown in. As a result, the target speed is increased during the middle of the track jump operation (V = V ₃ ), and at the same time,
At the end of the track jump, the target speed is reduced to a speed at which the tracking servo can sufficiently pull in (V = V ₀ ).
Therefore, a fast and stable track jump can be performed.

[0011]

However, in the above-mentioned conventional configuration, it is necessary to previously store a conversion table as shown in (Table 1) in order to create a target speed profile as shown in FIG. However, as the setting of the target speed is made finer, the conversion table becomes larger, and a conversion table is required for each number of target track jumps. Therefore, the cost of a memory element for storing the conversion table increases, and an arbitrary number of track jumps is required. It had a problem that it was difficult.

The present invention solves the above-mentioned conventional problems. By creating an arbitrary target speed profile for an arbitrary number of target track jumps without using the conversion table at all, it is simple and inexpensive. It is an object of the present invention to provide a track jump apparatus having a configuration and performing a high-speed and stable track jump of an arbitrary number.

[0013]

In order to achieve this object, a track jump device according to the present invention comprises a relative speed detecting means for detecting the relative speed of a track and a light spot in the radial direction of a disk by using an output of an optical pickup as an input. Track number counting means for counting the number of tracks jumped by using the output of the optical pickup as input; target speed determining means for receiving the output of the track number counting means as input.
Or, target speed determining means for inputting the output of the track number counting means and the target speed, or target speed determining means for receiving the output of the track number counting means and the switching signal as input,
Storage means for storing the number of tracks required for the target speed to increase to the current value; remaining number detection means for detecting the remaining number obtained by subtracting the number of actual track jumps from the target track jump number; The second comparator is configured to output a switching signal by using the output and the output of the remaining number detector as inputs, and the speed controller is configured to receive the output of the relative speed detector and the output of the target speed determiner as inputs. .

[0014]

According to the present invention, the target speed determining means changes the target speed for each predetermined number of tracks, or changes the target speed for each number of tracks corresponding to the current target speed. Changes the target speed from increase to decrease when the remaining number is equal to or less than the number of tracks required for the target speed to increase to the current value, thereby changing the target speed profile at the time of track jump. To create.

[0015]

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

FIG. 1 is a block diagram of a track jump device according to a first embodiment of the present invention. In FIG.
1 to 18 are the same as those in FIG. 21 is a track number counting means for counting the number of tracks actually jumped by the output of the optical pickup 3;
Reference numeral 22 denotes a reset signal input terminal for resetting the count content of the track number counting means 21. Reference numeral 23 denotes the number of tracks output by the track number counting means 21, which outputs a target speed changed for each predetermined number of tracks. Target speed determining means for outputting a reset signal for resetting the counting content of the track number counting means 21, 24, 25, 26
Is a component of the target speed determining means 23, 26 is a comparing means for comparing the number of tracks output from the track number counting means 21 with a predetermined value, and outputting a speed change signal 27 when they match, and 24 is a speed Target speed changing means for changing and outputting the target speed in response to the change signal 27, and resetting means 25 for outputting a reset signal for resetting the contents of the track number counting means 21 in response to the speed changing signal 27. Reference numeral 19 denotes a speed control means for inputting the output of the relative speed detecting means 18 and the output of the target speed changing means 24 to perform speed control.

The operation of the track jump apparatus of the present embodiment configured as described above will be described below.

First, when reading an information signal from the optical disk 1, the input terminal 8 is selected by the selection means 7. Since this is the same as the operation of the conventional example, the details are omitted.

Next, in the case of a track jump, the input terminal 9 is selected by the selection means 7 based on the output of the track jump instruction means 13, and the track jump operation is executed while controlling the speed, thereby reaching the target track jump number. Then, end and close the tracking servo loop. The outline of the operation in this case is the same as the operation of the conventional example, and therefore, the details are omitted.

Here, the present invention differs from the conventional example in the method of creating the target speed. Although the conversion table as shown in (Table 1) is used in the conventional example, it is not used in the present invention at all.
First, the track number counting means 21 always counts the number of tracks actually jumped. The counting result is constantly compared with a predetermined value by the comparing means 26, and when they match, a target speed change signal 27 is output. Target speed changing means 24
Changes the current target speed in response to the output of the target speed change signal 27, and at the same time, the reset means 25 outputs a reset signal in response to the output of the target speed change signal 27 to count the contents of the track number counting means 21. Reset is performed, and counting of the number of tracks is newly started. Thus, the target speed can be changed for each predetermined number of tracks.

Next, the operation at this time will be described with reference to FIG. FIG. 2 is a waveform chart showing the operation of the track jump device in the first embodiment. In FIG. 2, the horizontal axis represents the time axis, (a) the tracking error signal, and (b) the target speed profile. N is target track jump number, N _r is a predetermined number of tracks for changing the target speed, V ₀ is the target speed after the initial value of the target speed during the track jumping operation is started, V ₁ ~V ₃ change, T ₀ ~ T ₂ is,
Each target speed is the time required when the V ₀ ~V _2.

First, at the start of the track jump, the target speed is V ₀ , and thereafter, by changing the target speed in the increasing direction every N _r lines, the target speed is changed in the order of V ₀ → V ₁ → V ₂ → V ₃ . Speed increases. When the number of jumps reaches N / 2, this time N _r
By changing the target speed in the decreasing direction for each train, V
_The speed decreases in the order of ₃ → V ₂ → V ₁ → V ₀ , becomes just equal to the initial value V ₀ at the end of the track jump, and the tracking servo can be stably pulled in with the relative speed being sufficiently low.

As described above, according to this embodiment, the relative speed detecting means (18) for detecting the relative speed of the track and the optical spot in the disk radial direction by using the output of the optical pickup (3) as an input, Track number counting means (21) for counting the number of tracks jumped by using the output of the track number as an input, and a target speed determining means (2) for outputting a target speed by receiving an output of the track number counting means as an input.
3) and speed control means (19) which receives the output of the relative speed detection means and the output of the target speed determination means as inputs, and the target speed determination means changes the target speed for each predetermined number of tracks, Since the target speed profile can be created without using any conversion table, a simple and inexpensive configuration can be achieved as compared with the related art.

Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a block diagram of a track jump device according to a second embodiment of the present invention.
In FIG. 3, reference numerals 1 to 18, 21 and 22 are the same as those of the first embodiment shown in FIG. Reference numeral 23 inputs the number of tracks output from the track number counting means 21 and the current target speed, changes and outputs the target speed for each track number according to the current target speed, and counts the contents of the track number counting means 21. Target speed determining means for outputting a reset signal for resetting the speed, 24, 25 and 28 are constituent elements of the target speed determining means 23, and 28 is the input of the number of tracks output from the track number counting means 21 and the current target speed. Calculating means for outputting a target speed change signal 29 for each track number corresponding to the current target speed;
4 is a target speed changing means for changing and outputting the target speed in response to the speed changing signal 29, and 25 is a resetting means for outputting a reset signal for resetting the contents of the track number counting means 21 in response to the speed changing signal 29. . Reference numeral 19 denotes a speed control means for inputting the output of the relative speed detecting means 18 and the output of the target speed changing means 24 to perform speed control.

The operation of the thus configured track jump apparatus of the second embodiment will be described below.

The operation of reading the information signal from the optical disk 1 and the outline of the track jump operation are the same as those in the first embodiment, and the description is omitted.

The difference from the first embodiment is the operation of the target speed determining means 23. The arithmetic unit 28 also receives the output of the track number counting unit 21 and the current target speed at the same time, and outputs a target speed change signal 29 for each track number according to the current target speed. Here, assuming that the target speed is changed every _Nr lines, for example, when the target speed is a small value, _Nr is set to a small value, and when the target speed is a large value, _Nr is set to a large value. If the target speed change amount per hit is always constant, the target speed change amount per unit time, that is, the acceleration, can always be kept constant.

This operation will be described in more detail below with reference to FIG. FIG. 4 is a waveform chart showing the operation of the track jump device according to the second embodiment of the present invention. In FIG. 4, the horizontal axis represents (a), (b), N, V ₀ to
V ₃ , T _{0 to} T _2, etc. are all the same as in FIG. N _{r0 to} N
_r2 is a predetermined number of tracks for changing the target speed, respectively, a value when the target speed is V ₀ ~V _2.

[0029] In the first embodiment (FIG. 2), the track number N _r of changing the target speed is constant. Since the time required for N _r This jump will vary depending on the target speed, and duration T ₀ when the target speed is smaller as V _0, and a required time T ₂ of the case where the target speed is high as V ₂ By comparison, T ₀ > T ₂ (1). Here, assuming that the target speed change amount per one time is always constant, the time required to change the speed by a constant amount varies depending on the target speed, that is, the acceleration changes depending on the target speed, Speed control by the control means 19 is difficult, and a speed following error is likely to occur.

On the other hand, in the second embodiment (FIG. 4),
Predetermined number of tracks N _r to change the target speed is not constant, but changes in proportion to the target speed. Specifically, for example, by using the following formula to determine the number of tracks N _ri corresponding to the target velocity V _i.

N _ri = N _r0 · (V _i / V ₀ ) (i = 0,1,2,3) (2) Accordingly, the time T _{i at} each target speed is T _i = (N _ri · D) / V _i (i = 0,1,2,3) (3) where D is the track pitch. Substituting (2) into (3), T _i = (N _r0 · D) / V ₀ (i = 0,1,2,3) (4), so T _i is always a constant value .

Here, assuming that the target speed change amount per operation is always constant, the acceleration can always be constant regardless of the target speed, so that the speed control by the speed control means 19 is easy and the speed following error is small. Stable control becomes possible.

As described above, according to the second embodiment, there is provided the target speed determining means (23) for outputting the target speed by using the output of the track number counting means (21) and the target speed as inputs. By changing the target speed for each track according to the current target speed, the acceleration can always be kept constant irrespective of the target speed, so that stable speed control with a small speed following error can be performed. .

Next, a third embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a block diagram of a track jump device according to a third embodiment of the present invention.
In FIG. 5, reference numerals 1 to 18 and 21 are the same as those in FIG. 1 of the first embodiment and FIG. 3 of the second embodiment, and thus description thereof will be omitted. Numeral 30 denotes a counting result output terminal of the track number counting means 21, 31 denotes an internal information output terminal of the track number counting means 21, and 23 changes and changes the target speed according to the number of tracks output by the track number counting means 21. Is the increasing direction immediately after the start of the track jump, and is switched to the decreasing direction in response to the switching signal. Reference numeral 32 denotes a target speed output terminal of the target speed determining means 23. Reference numeral 33 denotes switching of the target speed determining means 23. A signal input terminal; 34, an internal information output terminal of the target speed determination means 23;
35 is a storage means for calculating and storing the number of tracks required for the target speed to increase to the current value based on the internal information of the track number counting means 21 and the target speed determining means 23; Remaining number detecting means 39 for detecting the remaining number obtained by subtracting the actual number of track jumps, 39 is the remaining number output terminal of the third comparing means 17 and the remaining number detecting means 38, and 36 is the storage means 35
Is a switching signal output from the second comparing means 36. The second comparing means 37 outputs the switching signal by comparing the output of the second number with the output of the remaining number detecting means 38.

The operation of the track jump apparatus of the third embodiment configured as described above will be described below.

The case where an information signal is read from the optical disk 1 and the outline of the track jump operation are the same as those in the first and second embodiments of the present invention, so that the description will be omitted.

Here, the difference from the first and second embodiments is the method of determining the timing for switching the direction of changing the target speed from the increasing direction to the decreasing direction.

The storage means 35 stores the track number counting means 2
In accordance with 1 and the internal information of the target speed determining means 23, the number of tracks required for the target speed to increase to the current value is always calculated and stored. This number and the remaining number detected by the remaining number detecting means 38 are compared with the second comparing means 36.
When the number is equal to or less than the remaining number, a switching signal 37 is output, and the target speed is switched from the increasing direction to the decreasing direction by the target speed determining means 23. This operation is described below with reference to FIGS.
This will be described in more detail with reference to FIG.

FIGS. 6 and 7 are waveform diagrams showing the operation of the track jump device in the third embodiment. FIG.
7 and FIG. 7, the horizontal axis represents (a), (b), N, V _0.
ＶV ₂ , N _r0 ＮN _r2 are all the same as in FIG. 4 of the second embodiment. N _x is the remaining number obtained by subtracting the number of actual track jump from target track jump number, V _max in the maximum value of the target speed which is determined in advance and to be limiting process in V _max so as not to increase more .

[0040] First, in FIG. 6, the target speed immediately after the track jump operation is started is V _0, and change the target speed in the increasing direction every time N _ri (i = 0,1,2) the jump, V ₀ → V ₁
→ V ₂ next, it is limiting process in the V _max. During this time always seeking the number of tracks required for the target speed increases to the current value, it is compared to the rest number N _x.
Specifically, for example, a comparison as shown in Expression (5) is performed.

[0041]

(Equation 1)

A is the number of times the target speed has been changed so far.
N _x is depending on switching the change direction of the target speed deceleration direction when satisfying the equation (5), as shown in FIG. 6,
The target speed at the end of the track jump can be made equal to the initial value (= V ₀ ) at the start, and the tracking servo can be drawn in a state where the relative speed is sufficiently small.

Here, when the target jump number is sufficiently large,
In this case, as shown in FIG. _maxAt the time
N_xIs N_x≤ (N_r0+ N_r1+ N_r2(6) The deceleration starts as shown in FIG.
Become trapezoidal.

[0044] In addition, when the target speed target jump number is small does not reach the V _max, the target speed as shown in FIG. 7 =
The remaining number N _x deceleration becomes _{N x ≦ (N r0 + N} r1) (7) begins when the V2, the target velocity profile becomes triangular, as in Fig.

As described above, depending on the number of target track jumps, the target speed profile is automatically switched between a trapezoid when the number is large and a triangle when the number is small. There is no need to prepare tables, and a target speed profile can be easily set for an arbitrary number of track jumps.

As described above, according to the third embodiment, the output of the track number counting means (21) and the switching signal are input, the target speed is changed according to the output of the track number counting means, and Immediately after the start of the track jump, the direction of the change is an increasing direction first, and the target speed determining means (23) switches in a decreasing direction according to a switching signal, and a track required for increasing the target speed to a current value. Storage means (35) for storing the number of tracks, remaining number detection means (38) for detecting the remaining number obtained by subtracting the number of actual track jumps from the target track jump number, and the output of the storage means and the remaining number detection means The second comparing means 36 which outputs the switching signal with the output of
Is provided, the target speed profile can be set with a simple and inexpensive configuration for an arbitrary number of target track jumps.

In the first and second embodiments of the present invention, the counting contents of the track number counting means 21 are reset every predetermined number of tracks. However, it is not always necessary to reset, and the target speed is not necessarily reset. The number of tracks at the time of the change may be stored, and the target speed may be changed when the number of tracks is increased from the value, and the gist of the present invention does not change at all.

In the first and second embodiments of the present invention, the number of target track jumps × (1/2)
Although the change direction of the target speed is switched from the increase direction to the decrease direction, the change direction may be changed in any manner, and the gist of the present invention does not change at all.

Further, in the second embodiment of the present invention, the acceleration is made constant when the target speed is changed. However, the acceleration is not always required to be constant, and the target speed is changed for each track number corresponding to the current target speed. , It is possible to create an arbitrary target speed profile. Therefore, it is clear that the calculation method shown in Expression (2) is merely an example and does not narrow the scope of the technical idea of the present invention. In this regard, the same applies to the expression (5) in the third embodiment of the present invention.

In the third embodiment of the present invention, the accumulation of N _ri is determined in order to determine the number of tracks required to reach the current target speed. However, the N _ri determined separately are necessarily accumulated. Needless to say, it is needless to say that the accumulation of the number of tracks required for increasing the target speed to the current value may be simply obtained.

[0051] In the third embodiment of the present invention, although the target speed and limit process at the maximum value V _max, which is not always necessary.

The means in the first, second and third embodiments of the present invention are hardware, software,
Needless to say, it can be realized by any method of analog processing and digital processing.

[0053]

As described above, according to the present invention, the number of tracks is counted by the track number counting means, and the target speed is changed by comparing the number of tracks with a predetermined value by the target speed changing means. Changing the target speed by comparing the value according to the target speed with the number of tracks in the determining means,
Alternatively, by switching the target speed from increase to decrease when the remaining number detected by the remaining number detection means becomes equal to or less than the number of tracks required for the target speed to increase to the current value, Since the configuration is such that a target speed profile at the time of a track jump is created, an arbitrary target speed profile is created for an arbitrary number of target track jumps without using any conversion table. In addition, a stable arbitrary number of track jumps can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a track jump device according to a first embodiment of the present invention.

FIG. 2 is a waveform chart showing the operation of the track jump device in the first embodiment.

FIG. 3 is a block diagram showing a configuration of a track jump device according to a second embodiment of the present invention.

FIG. 4 is a waveform chart showing the operation of the track jump device in the second embodiment.

FIG. 5 is a block diagram showing a configuration of a track jump device according to a third embodiment of the present invention.

FIG. 6 is a waveform chart showing the operation of the track jump device in the third embodiment.

FIG. 7 is a waveform chart showing the operation of the track jump device in the third embodiment.

FIG. 8 is a block diagram showing a configuration of a conventional track jump device.

FIG. 9 is a waveform chart showing the operation of the conventional track jump device.

[Explanation of symbols]

 Reference Signs List 18 relative speed detecting means 19 speed controlling means 21 track number counting means 23 target speed determining means 24 target speed changing means 25 resetting means 26 comparing means 28 calculating means 35 storage means 36 second comparing means 38 remaining number detecting means

Claims (3)

(57) [Claims] A rotating means for rotating an optical disk on which an information signal is recorded in a predetermined track form; a light beam formed on an information surface of the optical disk to form a light spot; An optical pickup for outputting the information signal and a relative position error between the track and the optical spot in the disk radial direction, a tracking actuator for moving the optical pickup in the disk radial direction, and an output from the optical pickup as an input. A relative speed detecting means for detecting a relative speed of a track and the light spot in a disk radial direction; a track number counting means for counting the number of tracks jumped by using an output of the optical pickup as an input; an output of the track number counting means Target speed to output target speed with input A step, a speed control unit that receives an output of the relative speed detection unit and an output of the target speed determination unit as inputs, and a driving unit that drives the tracking actuator by using an output of the speed control unit as an input. The speed determination means determines the number of tracks input
A track jump device for comparing a target speed with a target speed to change the target speed. 2. A rotating means for rotating an optical disk on which an information signal is recorded in a predetermined track form, and a light spot formed by condensing a light beam on an information surface of the optical disk, and detecting the reflected light. An optical pickup for outputting the information signal and a relative position error between the track and the optical spot in the disk radial direction, a tracking actuator for moving the optical pickup in the disk radial direction, and an output from the optical pickup as an input. A relative speed detecting means for detecting a relative speed of a track and the light spot in a disk radial direction; a track number counting means for counting the number of tracks jumped by using an output of the optical pickup as an input; an output of the track number counting means And output the target speed with the target speed as input. Target speed determination means; speed control means that receives the output of the relative speed detection means and the output of the target speed determination means as inputs; and drive means that drives the tracking actuator with the output of the speed control means as an input. The target speed determination means inputs a value corresponding to the current target speed.
A track jump device for comparing the number of tracks to be applied with each other for each target speed and changing the target speed. 3. A rotating means for rotating an optical disk on which an information signal is recorded in a predetermined track form, and a light beam is focused on an information surface of the optical disk to form a light spot, and the reflected light is detected. An optical pickup for outputting the information signal and a relative position error between the track and the optical spot in the disk radial direction, a tracking actuator for moving the optical pickup in the disk radial direction, and an output from the optical pickup as an input. A relative speed detecting means for detecting a relative speed of a track and the light spot in a disk radial direction; a track number counting means for counting the number of tracks jumped by using an output of the optical pickup as an input; an output of the track number counting means And the switching signal as input, Target speed determining means for changing the target speed in accordance with the output of the counting means, and wherein the direction of the change is an increasing direction immediately after the start of the track jump, and switching to a decreasing direction by a switching signal; Storage means for storing the number of tracks required to increase the current value to the current value; remaining number detection means for detecting the remaining number obtained by subtracting the actual number of track jumps from the target number of track jumps; output of the storage means And second output means for receiving the output of the remaining number detection means and outputting the switching signal; speed control means for receiving the output of the relative speed detection means and the output of the target speed determination means; A drive unit for driving the tracking actuator by using an output of a speed control unit as an input. Location.