JP3271247B2 - Optical disc playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk reproducing apparatus, and more particularly to an optical disk reproducing apparatus for optically reproducing a disk on which a video, a PCM audio signal and the like are recorded.

[0002]

2. Description of the Related Art A conventional optical disk device irradiates a disk with a laser beam or the like, detects reflected light from pits arranged in a spiral shape on the disk, and reads recorded information. By moving the tracking device mounted on the block or the optical system block in the radial direction, a predetermined address track can be accessed in a short time.

Therefore, information recorded on a track of a disc includes pits of information (images, music information, etc.) to be reproduced, and the number, absolute address, and other control information of the information include control bits (information to be reproduced). (Including a P signal indicating the presence / absence of).

When a track is to be reproduced by jumping a track, an optical system block on which a tracking device, a focus servo device and the like are mounted may be moved in a radial direction of the device by a thread feed mechanism. In order to increase the moving speed, a method is used in which a jump signal is supplied only to the tracking device, and the optical system block follows thereafter.

[0005] Then, 100 to 100
The large moving means for jumping 200 tracks and the small moving means for moving one track at a time are used to access the address of the target track (the middle moving means may be combined).

That is, as shown in FIG. 7 as an example, when a tracking device is to be jumped from a point A to a point D on a disk, a jump command is used to move the point A from a point A to a point B by means of a large moving means. When the control bit of the track is read and it is judged that the address has not reached the address of the point D, the jump is made again by the large moving means, and one track is moved by the small moving means at the point where the destination address is exceeded or approached. One approach is to approach the target address track at a time.

In this case, when a tracking device mounted on the optical system block is moved, a jump pulse having an acceleration period t1 and a deceleration period t2 is used as a drive signal as shown by a waveform W. After that, even if the tracking servo operates from the time when the drive pulse ends due to the inertia of the moving means and the deflection of the member supporting the tracking device, the laser beam captures the track.
捉, and the longer the period t3 of to settle, there is a disadvantage that the time to access because eventually address read of the destination of the track will be slower longer.

For this reason, in this period t3, it is conceivable to provide a braking effect to the servo function to speed up the settling. In this case, too, the reflectance of the deposited aluminum or the like forming the pits of the disk and the detected value are determined. If the modulation degree of the RF signal is different, the level of the RF signal changes and there is a problem that an accurate braking action cannot be obtained.

In order to solve this problem, Japanese Patent Publication No. 4-21933 filed by the same applicant has improved a brake circuit provided to speed up the setting of the braking effect, There is disclosed an apparatus in which an accurate braking action can be obtained even when there is a variation in the reflectance or the degree of modulation.

[0010]

However, a braking effect can be obtained by improving the above-described conventional brake circuit. However, this is a method of turning off the tracking device when jumping a track. No change.

That is, since the tracking servo of the tracking device mounted on the optical system block is turned off during the track jump, there is no holding force in the tracking direction.

Therefore, for example, when moving at a high speed by the large moving means, the inertia of the objective lens of the optical system block largely deviates from the center of the moving point of the tracking servo.

When the tracking servo is turned on in this deviated state, the slide system for moving the optical system block is moved.
It becomes unstable in relation to the servo.

Therefore, after moving with the slide servo,
Since the tracking device is turned on after a certain period of time when the tracking is expected to return to the center of the operating point, it takes a long time from the entire search to the end of the search even if the braking effect is obtained. there were.

Therefore, in the case of a track jump, a quick and stable on-track state of the track jump cannot be obtained unless the time delay of on-tracking after turning the tracking device from off to on is solved.

Therefore, a quick operation is performed in combination with a circuit for obtaining an effective braking effect for on-track.
Cormorant it is a problem to be solved in the optical disc reproducing apparatus having a tracking device, such as can.

[0017]

In order to solve the above-mentioned problems, an optical disk reproducing apparatus according to the present invention is configured as follows. (1) Light receiving means for irradiating an optical disk with a laser beam through an objective lens and receiving reflected light from the optical disk, and tracking for generating a tracking error signal based on the reflected light received by the light receiving means Error signal generating means, transferring means for transferring the objective lens in a radial direction of the optical disk, the objective lens and the transferring means
And a damping signal generating means for generating a signal having a damping characteristic, which frequency is about twice the resonance frequency of the movable part comprising: a tracking error signal generated by the tracking error signal generating means during normal reproduction. An optical disc reproducing apparatus comprising: a switching unit that drives the objective lens based on a signal having an attenuation characteristic generated by the attenuation signal generation unit during a seek operation. (2) an on-tracking signal generating means for generating an on-tracking signal based on the reflected light received by the light receiving means; and an on-tracking signal generated by the on-tracking signal generating means and the tracking error signal generating means. (1) The optical disc reproducing apparatus according to (1), further comprising: counting means for counting the number of tracks at the time of seeking based on the tracking error signal generated as described above. (3) The optical disk according to (1), wherein when the number of tracks to be transferred at the time of the seek is equal to or less than a predetermined value, generation of a signal having an attenuation characteristic generated by the attenuation signal generation means is prohibited. Playback device.

[0018]

As described above, at the time of seeking, that is, at the time of a track jump, the objective lens is set on the basis of a signal having an attenuation characteristic which is about twice the resonance frequency of the movable portion having the objective lens and the transfer means. Is driven, the on-track can be detected quickly and stably.

The number of tracks at the time of seeking is based on the on-tracking signal and the tracking error signal, and when the number of tracks is less than a predetermined value, generation of a signal having an attenuation characteristic is prohibited. By
Malfunction due to noise on the counter can be cut off.

[0020]

Next, an embodiment of an optical disk reproducing apparatus according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of an optical disc reproducing apparatus according to the present embodiment. The track jump stabilizing circuit mounted in the optical disc reproducing apparatus 1 is an optical disc. The optical disk medium 2, a spindle motor 3 for rotating the optical disk medium 2 at a predetermined speed, and a laser beam irradiating the optical disk medium 2 via an objective lens 7 (see FIG. 2) of a biaxial device 5. An optical system block 4 serving as a photodetector constituting light receiving means for receiving reflected light from the optical disc medium 2; and a tracking error signal (hereinafter referred to as a TE signal) based on the reflected light received by the light receiving means. A photodetector 16 that constitutes a tracking error signal generating means for performing the operation, a tracking main loop 17 for shaping the TE signal, and the objective lens 7 Driving the tracking coil constituting transfer means for transferring the radial direction of the click medium 2
Comprises a tracking drive 20, a tracking servo controller 21, an objective lens 7, and a transfer unit.
An attenuation signal generator for generating a signal having an attenuation characteristic at a frequency which is about twice the resonance frequency of a movable portion having a tracking coil for performing an attenuation operation, and an AND gate 23; Sometimes, the objective lens 7 of the two-axis device 5 is driven based on the tracking error signal generated by the tracking error signal generation means, and a signal having an attenuation characteristic generated by the attenuation signal generation means which is the attenuation wave oscillator 22 at the time of seeking. On the basis of the
First and second switches 18 constituting switching means for switching the objective lens 7 of the biaxial device 5 so as to be driven;
19, and the function of each component and the connection state of each component are as follows.

The optical disk medium 2 is formed by uniformly coating a light-sensitive substance, for example, a photoresist, on the surface of a disc-shaped transparent plastic, and having a reflective layer formed of an extremely thin metal thereon. And a hard protective layer formed thereon. An address area and a recording area are formed at predetermined positions on the uniformly applied photoresist.

The spindle motor 3 is an optical disk medium 2
Is rotated at a predetermined speed, and the speed is
It is controlled by a spindle servo based on a detection signal of an optical system block 4 described later.

The optical system block 4 detects an optical signal. The optical system block 4 includes a biaxial device 5 having tracking coils 9 and 10, a photodetector 16 for generating a TE signal, and an optical signal (not shown). An analog waveform shaping mechanism for electrically converting a signal on a track of the disk medium 2 from light to generate an RF signal.

As shown in FIG. 2, the biaxial device 5 is, for example, a hinge type biaxial device, and has a tracking direction indicated by an arrow A (a central axis direction of the optical disc medium 2).
The configuration is such that it has two degrees of freedom in the focus direction (the surface direction of the optical disc medium 2) indicated by the arrow B.

That is, the biaxial device 5 is composed of a movable part 6 and a support 11, one end of which is supported by an arm 8, and an objective lens 7 is provided at a position off the center. Tracking coils 9 and 10 and a focus coil are provided at both ends off the center so as to sandwich 7. Although not shown, the focus coil is formed integrally with the tracking coils 9 and 10.

On the other hand, the support 11 comprises iron cores 12, 13 formed so as to be surrounded by the tracking coils 9, 10 and the focus coil, and the iron cores 12, 13 and the tracking coils 9, 10 and the focus coil. Are provided with yoke magnets 14 and 15 at positions sandwiching a part of.

The movement in the tracking direction (arrow A) is rotated by applying a current to the tracking coils 9 and 10 , and the movement in the focus direction (arrow B) is performed by applying a current to the focus coil. Can move up and down.

As shown in FIG. 1, the photodetector 16 outputs an RF signal and a TE signal that pick up the return light beam reflected from the optical disk medium 2.

Here, the relationship between the RF signal and the TE signal will be described based on a so-called three-spot method.

That is, as shown in FIG. 3, the main spot S0
Auxiliary spots S1, S2 (± primary light) are formed before and after the (0th-order light), and when these spots S0, S1, S2 are irradiated on the surface of the optical disc medium 2, the auxiliary spots S1, S2, The main spot S0 is positioned on the tracks T1 and T2 based on the intensity of the return light beam obtained in S2.

That is, as shown in the position P1, when the main spot S0 is on the track T1, the auxiliary spot S1,
The intensity of the return light beam in S2 is equal, and the TE signal (S1-
S2) becomes zero, and the track information (RF signal) detected by the main spot S0 becomes the maximum.

When the main spot S0 jumps over the track and moves to, for example, positions P2, P3, P4, P5, and P6, the TE signal (S1-S2) and the RF signal change as shown in the figure.

Therefore, the main spot S0 is controlled to return to the center of the track T1 with the plus side component of the TE signal (S1-S2), that is, pulled back, and the main spot S0 is moved to the center of the track T2 with the minus side component. If the main spot S0 is controlled to move in the direction, the main spot S0 captures either the track T1 or T2 and is in a servo-operated state, which is stable.

The optical system block 4 has the TE signal output side connected to the input side of the tracking main loop 17, and the tracking coils 9, 10 connected to the output side of the tracking drive 20.

As shown in FIG. 1, the tracking main loop 17 is for shaping the TE signal. The input side is connected to the TE signal output terminal of the optical system block 4, and the output side is the first side. Is connected to the input terminal of the switch 18.

The first switch 18 is a switch which is switched by a tracking loop signal from the tracking servo controller 21. Here, the tracking loop signal is a signal that is turned off at the time of a track jump by a so-called seek command.

The input terminal side of the first switch 18
The output side of the tracking main loop 17 is connected to one input terminal of the second switch 19, and the control terminal is connected to the tracking loop off signal terminal of the tracking servo controller 21. Have been.

The second switch 19 is a switch for switching to a TE signal side or a signal side having an attenuation characteristic based on a tracking loop signal and a seek signal from the tracking servo controller 21, and has one input terminal 19A. Is connected to the output side of the first switch 18, the other input terminal 19B is connected to the output side of the attenuation wave oscillator 22, the common terminal 19C is connected to the input side of the tracking drive 20, and the control terminal is an AND gate. 2
3 is connected to the output terminal.

The tracking drive 20 is a driver that drives the tracking coils 9 and 10 of the optical system block 4 based on a TE signal or a signal having an attenuation characteristic. The output side is connected to the tracking coils 9 and 10 of the optical system block 4.

Tracking servo controller 21
Outputs various signals for controlling the tracking servo, for example, a tracking off time signal, a tracking loop signal, and a seek signal.

Here, the tracking off time signal is
The signal generated based on the time required for the track jump by the seek command, the curve of the signal having the attenuation characteristic generated by the attenuation wave oscillator 22 in the seek command of the track jump at a long distance (large movement) is gentle, The curve of a signal having an attenuation characteristic in a seek command (middle movement) of a track jump at a short distance becomes sharp.

When the track jump distance is a seek command (small movement) of a track jump of a short distance such that the movement of the movable part including the optical system block 4 can be ignored, the tracking off time signal Does not occur. As a result, the signal having the attenuation characteristic from the attenuation wave oscillator 22 is not output.

The output terminal of the tracking off time signal of the tracking servo controller 21 is connected to one input side of the attenuated wave oscillator 22, and the output terminal of the tracking loop signal is connected to one terminal of the AND gate 23 and It is connected to the switching terminal of the first switch 18.

The output terminal of the seek signal is connected to the other input side of the attenuation wave oscillator 22 and the other input side of the AND gate 23.

The attenuation wave oscillator 22 generates a signal having an attenuation characteristic corresponding to the distance of the track jump, and one input side thereof is connected to the output side of the tracking servo controller 21 for outputting the tracking off time signal. The other input side is connected to the seek signal output side of the tracking servo controller 21, and the output side is connected to the terminal 19 B of the second switch 19.

The AND gate 23 controls a TE signal from the tracking main loop 17 and a signal having an attenuation characteristic from the attenuated wave oscillator 22. One input terminal is a tracking servo controller. The other input side terminal is connected to the seek signal terminal of the tracking servo controller 21, and the output terminal is connected to the control terminal of the second switch 19. .

The operation of the track jump stabilizing circuit of the optical disc reproducing apparatus 1 having such a configuration will be described with reference to FIGS.

Generally, a seek command for a track jump includes a case where the track of the optical disk medium 2 is moved relatively many times, that is, a large movement (for example, 256 tracks or more). The focus loop mechanism moves on a track of the optical disc medium 2 in an on state (direction B in FIG. 2), and the tracking loop mechanism turns off (direction A in FIG. 2).

When this predetermined distance is moved, that is, when the tracking loop mechanism is off, a signal having an attenuation characteristic is applied to the tracking coils 9 and 10 of the optical system block 4 to provide the signal on the biaxial device 5. When a certain objective lens 7 is braked and the movement of the optical system block 4 is completed, control can be performed so that the movable portion 6 is located at the center position of the tracking operation point.

With respect to the mode in which the signal having this attenuation characteristic is applied to the tracking coils 9 and 10, when the medium movement is a short distance (T1), the small movement is almost negligible (T1).
2) The case of a long distance (T3) of a large movement will be described with reference to FIG.

[1]. In the case of a track jump at a short distance (T1), the tracking loop signal is turned off (T1).
L1), and the switch of the first switch 18 is in the open state (S1).

At this time, since the seek signal is at a high level (SK1) to cause a track jump,
The input condition of the AND gate 23 is satisfied, and the common terminal 19C of the second switch 19 is connected to one input terminal 19B.

At the same time, the tracking servo controller 21 determines whether the track jump amount generated by the seek command is equal to or larger than a predetermined value (large movement), equal to or smaller than a predetermined value (middle movement), or can be ignored (small movement). do. In this case, since the value is equal to or less than the predetermined value, the value is equal to or less than the predetermined value (middle movement).
Generates a tracking off time signal corresponding to.

By the tracking-off time signal and the seek signal, as shown in FIG. 4, a signal having an attenuation characteristic output from the attenuation wave oscillator 22 has a sharp attenuation curve for a short distance time zone (T1). Thus, a signal (G1) having the attenuation characteristic is formed.

The signal (G 1) having this attenuation characteristic enters the tracking drive 20 via the second switch 19 and is supplied to the tracking coils 9 and 10 of the optical system block 4 as shown in FIG. Optical system block 4
The tracking jump is performed while the objective lens 7 is braked to a predetermined position.

[2]. Next, in the case of almost negligible track jump (T2), first, a seek signal is generated (SK2) and a tracking loop signal is generated (TL2).
8 is in the open state (S2), the input condition of the AND gate 23 is satisfied, and the input terminal 19B of the second switch connected to the output side of the attenuation wave oscillator 22 is connected to the common terminal 19C. .

However, the tracking servo controller 21 does not generate the tracking off time signal when the track jump amount by the seek signal is almost negligible, for example, when the number of tracks is one or several.

Therefore, if the tracking off time signal is not generated, the signal having the attenuation characteristic is not generated from the attenuation wave oscillator 22, and even if the first switch 18 and the second switch 19 are switched, for example. No braking is applied to the tracking coils 9 and 10 of the optical system block 4.

[3]. Next, when the track jump amount is a long distance (T3), the first time is obtained by the tracking loop signal (TL3) in the same manner as in [1].
Switch 18 is opened (S3), and the seek signal (SK3) and the tracking loop signal (TL)
3) satisfies the input condition of the AND gate 23,
The second switch 19 is connected to the input terminal 19B side and the common terminal 1B.
9C is connected.

At the same time, in the tracking servo controller 21, when the track jump amount is long (T
If the determination is 3), a tracking off time signal corresponding to the long distance time zone (T3) is generated. Therefore,
Due to the tracking-off time signal and the seek signal, the time period is longer than the signal (G1) having an attenuation characteristic generated at a short distance (T1) from the attenuation wave oscillator 22,
In addition, a signal (G2) having a gradual attenuation characteristic of an attenuation curve corresponding to a long distance time is output.

The signal (G 2) having this attenuation characteristic is supplied to the tracking coils 9, 10 of the optical system block 4 via the second switch 19 and the tracking drive 20.
And the objective lens 7 of the optical system block 4 can be braked to a predetermined position in response to a track jump movement at a long distance.

Here, the signals (G1) and (G2) having the attenuation characteristics generated in the above [1] and [3] are preferably sinusoidal waves, but may be other AC signal waveforms. For example, the resonance frequency is set to about twice (2fθ) the resonance frequency fθ of the movable portion where the optical system block 4 is movable. In addition, since the braking is performed using a frequency that is about twice the resonance frequency of the movable part in which the optical system block 4 moves,
Since the frequency and phase of the vibration of the objective lens 7 and the signal having this attenuation characteristic do not match, the position fluctuation of the objective lens 7 does not increase. If the frequency is higher than this, the response of the movable portion is poor, and the holding force for braking the objective lens 7 is reduced.

As described above, during the track jump described in the above [1] and [3], the tracking coils 9, 1
By applying a signal having an attenuating characteristic of an AC signal to 0 and braking the position of the objective lens 7 to a position at the center of the operating point, when the tracking slide servo is turned on at the end of the track jump, rapid turning on is performed. It is possible to be in a track state.

Next, when a signal having an attenuation characteristic is supplied to the tracking coils 18 and 19 during a track jump, an on-track state can be obtained quickly and stably. A false clock signal may be generated in a counter that counts the number of track jumps using a signal.

The cause of the generation of the false clock signal is as follows.
The track jump was performed while supplying a TE signal when a track jump was performed without energizing the biaxial device 5 of the optical system block 4 and energizing (a signal having the above-described attenuation characteristic) to the biaxial device 5 of the optical system block 4. In time, T
This is because a false clock signal is generated because the E signal is different.

In order to prevent this adverse effect, the counter for controlling the number of track jumps based on the RF signal using the TE signal is controlled as shown in FIGS.
The circuit shown in FIG.

FIG. 5 is a block diagram in which the clock signal of the counter is controlled by the TE signal. The counter section 24 generates an on-tracking signal based on the reflected light received by the light receiving means. Envelope detection 25 and waveform shaping 26 constituting the generating means
A D flip-flop 27 which constitutes counting means for counting the number of tracks at the time of seeking based on the on-tracking signal generated by the on-tracking signal generating means and the TE signal generated by the tracking error signal generating means;
Counter 28, TE signal waveform shaping 29, edge detection 30
When the number of tracks to be transferred at the time of seeking is equal to or less than a predetermined value, the control is performed so as to prohibit the generation of the signal having the attenuation characteristic generated by the attenuation signal generating means.
Hereinafter, the function and connection state of each component will be described with reference to the waveform diagram shown in FIG.

The first and second switches 18 and 19 for supplying a signal having an attenuation characteristic to the tracking coils 9 and 10 by the TE signal, the attenuation wave oscillator 22 and the tracking drive 20 are described above. The description is omitted because it is the same as FIG. 1 described above.

The envelope detection 25 detects a signal (FIG. 6 (b)) (on-tracking signal) connecting the peaks of the waveform based on the RF signal (FIG. 6 (a)) which is a carrier signal. belongs to. Although not shown, the input side of the envelope detection 25 is connected to the RF signal output terminal of the optical system block 4, and the output side is connected to the input side of the waveform shaping 26.

The waveform shaping 26 is for generating a rectangular wave (FIG. 6C) based on the signal (FIG. 6B) (on-tracking signal) formed by the envelope detection 25.

The input side of the waveform shaping 26 is connected to the output side of the envelope detection 25, and the output side is connected to the D terminal of the D flip-flop 27.

The D flip-flop 27 is a flip-flop that holds the value from the input terminal D based on the clock signal from the CK terminal. This D flip-flop 2
7, the output side of the waveform shaping 26 is connected to the D terminal.
The output side of the edge detection 30 is connected to the terminal, and the Q terminal on the output side is connected to the input side of the counter 28.

The counter 28 is a counter for counting the number of track jumps based on the RF signal, and the input side is connected to the Q terminal of the D flip-flop 27.

The waveform shaping 29 of the TE signal is for generating a rectangular wave ((e) in FIG. 6) indicating the positive / negative of the TE signal ((d) in FIG. 6), and its input side generates the TE signal. Output terminal, the output of which is connected to the edge detection 30
Is connected to the input side.

The edge detection 30 detects an edge pulse signal (see FIG. 6) based on a positive or negative edge of a rectangular wave ((e) in FIG. 6) generated based on the TE signal ((d) in FIG. 6). (F)).

The input side of the edge detection 30 is connected to the output side of the TE signal waveform shaping 29, and the output side is connected to the CK terminal of the D flip-flop 27.

The counter 24 configured as described above
The RF signal (FIG. 6 (a)) which is on-track information is
An edge pulse signal (FIG. 6 (f)) based on the TE signal (FIG. 6 (d)) can be latched as a clock signal and counted. When the count value, that is, the counted number of tracks is equal to or less than a predetermined value, control is performed so as to prohibit generation of a signal having an attenuation characteristic, thereby preventing the count of the number of track jumps due to a false clock signal. .

[0079]

As described above, according to the present invention, the tracking coil for rotating the objective lens of the optical system block in the tracking direction at the time of a track jump is provided for the tracking coil .
Of the resonance frequency of the movable part comprising the object lens and the transfer means .
By supplying a signal having a frequency of about twice and having an attenuation characteristic, by arranging the objective lens at the center position where the objective lens operates during a track jump, so-called off-track, at the time of arrival at the target track In addition, it is possible to maintain the on-track state quickly and stably, thereby significantly shortening the search operation time and obtaining a stable seek operation.

Further, the clock of the counter for the on-track information based on the RF signal is counted based on the TE signal and the on-tracking signal, and when the count is equal to or less than a predetermined value, generation of a signal having an attenuation characteristic is prohibited. In this case, even when a signal having an attenuation characteristic is supplied to the tracking coil, an excellent effect that the count of the number of track jumps due to a false clock signal can be prevented can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a circuit for generating a signal having an attenuation characteristic mounted on an optical disc reproducing apparatus according to the present invention.

FIG. 2 is a perspective view showing a main part of an optical system block.

FIG. 3 is an explanatory diagram showing a three spot method for detecting tracking information.

FIG. 4 is a timing chart based on the circuit of FIG. 1;

FIG. 5 is a block diagram showing a circuit of a counter for on-track information based on an RF signal according to the present invention.

FIG. 6 is a waveform diagram based on the RF signal and the TE signal shown in the block diagram of FIG. 5;

FIG. 7 is an explanatory diagram showing a driving waveform and a movement relationship of a tracking device when performing a track jump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk reproducing apparatus 2 Optical disk medium 3 Spindle motor 4 Optical system block 5 Biaxial device 6 Moving part 7 Objective lens 8 Arm 9 Tracking coil 10 Tracking coil 11 Support 12 Iron core 13 Iron core 14 Yoke magnet 15 Yoke Magnet 16 Detector 17 Tracking main loop 18 First switch 19 Second switch 20 Tracking drive 21 Tracking servo controller 22 Attenuated wave oscillator 23 AND gate 24 Counter unit 25 Envelope detection 26 Waveform shaping 27 D flip-flop 28 Counter 29 TE signal waveform shaping 30 Edge detection

Claims (3)

(57) [Claims] 1. A light receiving means for irradiating a laser beam to an optical disk via an objective lens to receive reflected light from the optical disk, and generating a tracking error signal based on the reflected light received by the light receiving means. A tracking error signal generating means, a transfer means for transferring the objective lens in a radial direction of the optical disk, and a frequency which is about twice a resonance frequency of a movable part including the objective lens and the transfer means , An attenuating signal generating means for generating a signal having an attenuating characteristic; and the objective lens is driven based on the tracking error signal generated by the tracking error signal generating means during normal reproduction, and is generated by the attenuating signal generating means during seek. Switching means for switching such that the objective lens is driven based on a signal having the obtained attenuation characteristic. That the optical disc playback device. 2. An on-tracking signal generating means for generating an on-tracking signal based on reflected light received by the light receiving means, and an on-tracking signal generated by the on-tracking signal generating means. 2. The optical disc reproducing apparatus according to claim 1, further comprising: counting means for counting the number of tracks at the time of seeking based on the tracking error signal generated by said tracking error signal generating means. 3. The method according to claim 1, wherein when the number of tracks to be transported at the time of the seek is equal to or less than a predetermined value, generation of a signal having an attenuation characteristic generated by the attenuation signal generating means is prohibited. Optical disc playback device.