JPH05120818A - Jumping scanner - Google Patents

Abstract

PURPOSE:To perform a comparatively stable jump even in the existence of disturbance by lowering the whole gain while a servo loop is closed during the time of supplying a driving pulse to a pickup. CONSTITUTION:While the driving pulse for acceleration and deceleration is supplied to the pickup 3 from a jumping pulse generating part 9, the whole gain is lowered leaving the servo loop in a jumping control part 10 closed. Since a high band gain is lowered in accordance with the whole gain, the pickup 3 can easily be driven by the driving pulse of acceleration and deceleration having a high frequency component as a main component. Moreover, since a servo gain exists from a low band to a medium band, although it is slightly lowered because of the closed servo loop as it is, even when there is disturbance during a jumping period, its influence can be suppressed in accordance with the gain amt., thus exhibiting an excellent effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jumping scanning device in an optical disc reproducing device such as a CD player or a laser disc player.

[0002]

2. Description of the Related Art Generally, in a pause operation (standby operation) of a CD player or the like, in order to maintain a predetermined track position, one track is made in a direction opposite to the traveling direction of the track for every one revolution (360 degrees) of the spiral track. This is realized by performing a minute (1.6 μm) jumping operation (kickback operation).

Conventionally, in this jumping operation, as disclosed in, for example, Japanese Patent Laid-Open No. 54-128707, an acceleration pulse and a deceleration pulse are sequentially supplied to a drive circuit of a pickup in order to perform a jumping operation, during which a tracking servo is performed. It is realized by the configuration that opens the loop.

[0004]

However, according to the above-mentioned conventional method, the tracking servo loop is opened at least while the acceleration / deceleration pulse is being supplied to the pickup, and if disturbance vibration is applied during this period, the servo There was a big problem that the suppression effect could not be expected, and it became unstable due to the influence of the disturbance.

An object of the present invention is to realize a device capable of performing a jumping operation relatively stably even if there is a disturbance during the jumping operation.

[0006]

To achieve this object, the jumping scanning device of the present invention keeps the servo loop closed during the jumping operation without opening it, but reduces the servo loop gain, In the meantime, an acceleration / deceleration driving pulse is supplied to the pickup.

Further, the jumping scanning device of the present invention is
During the jumping operation, the tracking servo loop,
The open / close operation is repeatedly performed at a frequency sufficiently higher than the gain intersection point of the servo loop, and an acceleration / deceleration drive pulse is supplied to the pickup during the open / close operation.

Further, the jumping scanning device of the present invention is
Keep the servo loop closed during the jumping operation without opening it, however, by removing the high-frequency compensating circuit in the servo loop, the high-frequency servo loop gain is reduced, and in the meantime, the pickup is accelerated / decelerated. The pulse is supplied.

The jumping scanning device of the present invention is
During the jumping operation, keep the servo loop closed without opening it, but insert a low-pass filter in the servo loop to reduce the servo loop gain in the high frequency range, during which the acceleration / deceleration drive pulse is applied to the pickup. It is something that is supplied.

[0010]

According to the present invention, the above-mentioned method reduces the overall gain of the servo loop while the acceleration / deceleration driving pulse is being supplied to the pickup, and accordingly the high-frequency gain is reduced. The pickup can be easily driven by the acceleration / deceleration driving pulse whose main component is the high frequency component.

According to the present invention, the servo loop is opened / closed at a high frequency while the drive pulse for acceleration / deceleration is being supplied to the pickup by the above-mentioned method, so that the overall gain of the servo loop is equivalently obtained. Since the gain is lowered and the high-frequency gain is accordingly lowered, the pickup can be easily driven by the acceleration / deceleration driving pulse whose main component is the high frequency component.

Further, according to the present invention, since the servo loop gain in the high frequency range is reduced while the drive pulse for acceleration / deceleration is being supplied to the pickup by the above method, the acceleration / deceleration whose main component is a high frequency component. The drive pulse can easily drive the pickup.

[0013]

1 is a block diagram showing the configuration of a jumping scanning device according to a first embodiment of the present invention.
In FIG. 1, the disk 1 is a spindle motor controller 2
It is driven by a spindle motor 2a whose rotation speed is controlled by b. The pickup unit 3 detects the data recorded on the disc 1 as an optical signal via a focus lens 3a supported by an actuator (not shown), and converts it into an electric signal. The focus error signal, tracking error signal,
Although an RF signal indicating data content is included, the focus error signal and RF signal not directly related to the operation of the present invention are omitted here. Reference numeral 3b is a tracking error detector that detects a tracking error signal detected from the focus lens 3a, and reference numeral 3c is a tracking direction drive unit that drives the focus lens 3a in the tracking direction. Reference numeral 4 denotes a traverse drive unit for slowly moving the pickup unit 3 in the tracking direction, that is, in the radial direction of the disc 1 as the reproduction of the disc 1 progresses. Reference numeral 5 denotes an amplification unit for amplifying the tracking error signal output from the tracking error detection unit 3b, which has a gain control terminal 5a, and its gain is variably controlled by the jumping control unit 10. When the tracking servo loop is established, the output of the amplifier 5 is phase-compensated by the high frequency compensator 6 to secure the phase margin of the loop. The phase-compensated output is added by the adder 7 to the output pulse of the jumping pulse generator 9. The jumping pulse generator 9 receives a command from the jumping controller 10 at the time of track jump and generates a predetermined jumping pulse. The output of the adder 7 is power-amplified by the drive unit 8 and input to the tracking direction drive unit 3c.

The operation will be described below with reference to the block diagram of FIG. In the normal reproduction state, the tracking error detection unit 3b, the amplification unit 5, the high frequency compensation unit 6, the addition unit 7, the drive unit 8 and the tracking direction drive unit 3c form a tracking servo loop, and the pickup unit 3 is Follow servo on a predetermined track.

Next, in order to maintain a predetermined track position, a pause operation will be described in which the jumping operation is continuously performed in the direction opposite to the reproduction direction for one track per one rotation (360 degrees).

FIG. 2 is a time chart for performing the jumping operation. (A) shows the tracking servo loop gain, and (b) shows the energy for driving the focus lens 3a of the pickup unit 3 for one track. The timing of the acceleration / deceleration jumping pulse for giving is shown. In the figure, t indicates the jumping time required to jump one track.

At time τ0, the jumping controller 10 issues a command to operate the gain control terminal 5a of the amplifier 5 to change the gain of the amplifier 5 from the normal "high" to "low",
At the same time, the jumping pulse generation unit 9 outputs an acceleration pulse having a predetermined width to drive the focus lens 3a, and then outputs a deceleration pulse for decelerating the speed of the focus lens 3a, and at the time of entering the area of the adjacent track, The supply of the deceleration pulse is stopped, and at the same time or immediately after that (τ1), the gain of the amplification unit 5 is returned from “low” to “high”.

FIG. 3 is a diagram showing the state of the open loop gain of the tracking servo loop which changes during the jumping operation. A is the tracking servo loop gain "high" during the normal tracking operation, and B is the jumping operation. Tracking servo loop gain is "Low".

In the normal tracking state A, the gain crossing point f1 crosses 0 at an inclination of 6 dB / oct, so a stable damping state is maintained, and since the loop gain is sufficient, stable tracking characteristics can be maintained.

On the other hand, in the state B during jumping, the jumping pulse generator 9 is included in the tracking servo loop.
Since the jumping pulse is injected by this to drive the focus lens 3a, the gain of the amplifier 5 is lowered and the tracking servo loop gain is lowered in order to facilitate the movement of the focus lens 3a.

In this case, the gain intersection point f2 is 12 dB / o.
Since it crosses the 0 point with the inclination of ct, if this state is maintained for a long time, the oscillation state is reached. However, in a normal laser disc player or CD player, this jumping period is within the range of about 0.3 ms to 1 ms. Since it can be designed, it does not reach the oscillation state. That is, the time t required for jumping can be made sufficiently smaller than about 1 cycle of the oscillation frequency at the 0 cross point (f2).

Moreover, although the overall loop gain is reduced, there is a gain in the low frequency range, and even if there is a vibration component of a low frequency, the suppression effect according to the gain is provided regardless of the jump. Can be done.

Further, in the conventional configuration, the tracking servo loop is once cut to be in the open loop state, so that it is greatly affected by the offset voltage and the like of the circuit system, whereas in the present invention, the loop is closed. Since it remains as it is, the influence of the offset voltage of the circuit system can be made very small.

Although the above description has been made for the jumping operation of one track, it is not particularly limited to one track, and similar effects can be obtained for kickback and kickforward operations by jumping a plurality of tracks. Needless to say.

FIG. 4 is a block diagram showing the configuration of the jumping operating device according to the second embodiment of the present invention. In FIG. 4, the disk 1 is driven by a spindle motor 2a whose spindle motor control unit 2b controls the rotation speed to a predetermined value. The pickup unit 3 detects the data recorded on the disc 1 as an optical signal via a focus lens 3a supported by an actuator (not shown), and converts it into an electric signal. The electric signals include a focus error signal, a tracking error signal, an RF signal indicating data content, and the like, but the focus error signal and the RF signal not directly related to the operation of the present invention are omitted here. 3b is a focus lens 3a
A tracking error detector 3c for detecting a tracking error signal detected from the tracking error detector 3c is a tracking direction driver for driving the focus lens 3a in the tracking direction. 4 shows the pickup unit 3 slowly moving in the tracking direction as the reproduction of the disc 1 progresses, that is,
A traverse drive unit for moving the disk 1 in the radial direction. 5 is a tracking error detector 3b
Is an amplifying unit for amplifying the tracking error signal output by the high frequency compensating unit 6 to secure the phase margin of the loop when the tracking servo loop is established. The phase-compensated output is controlled by the jumping control unit 10 to open / close the loop switch 1
The output pulse of the jumping pulse generator 9 is added by the adder 7 via 1. The jumping pulse generator 9 is a jumping controller 10 during a track jump.
To generate a predetermined jumping pulse. The output of the adder 7 is power-amplified by the drive unit 8 and input to the tracking direction drive unit 3c.

The operation will be described below with reference to the block diagram of FIG. In the normal reproduction state, the tracking error detector 3b, the amplifier 5, the high frequency compensator 6, the loop switch 1
1, the addition unit 7, the drive unit 8 and the tracking direction drive unit 3c form a tracking servo loop, and the pickup unit 3 performs follow-up servo on a predetermined track.

Next, in order to hold a predetermined track position, a pause operation will be described in which the jumping operation is continuously performed in the direction opposite to the reproduction direction for one track per one rotation (360 degrees).

FIG. 5 is a time chart for performing the jumping operation. (A) shows the open / closed (ON / OFF) state of the tracking servo loop, and (b) shows the equivalent gain of the tracking servo loop. , (C) show timings of jumping pulses for acceleration / deceleration for giving energy for driving the focus lens 3a of the pickup unit 3 by one track. In the figure, t indicates the jumping time required to jump one track.

At time τ0, the jumping control unit 10 issues a control command to the loop switch 11, and the loop switch 1
By repeatedly opening and closing 1 at a high frequency, the servo loop gain is reduced equivalently, and the loop gain is changed from the normal "high" to "low" as shown in FIG. The generation unit 9 outputs an acceleration pulse having a predetermined width to drive the focus lens 3a, and then outputs a deceleration pulse for decelerating the speed of the focus lens 3a, and when it enters the area of the adjacent track,
The servo loop gain is changed from "low" by stopping the supply of the deceleration pulse and ending the opening / closing operation of the loop switch 11 at the same time or immediately after that (τ1).
Return to high.

The decrease in the gain of the servo loop is determined by the ratio of the loop opening period and the loop closing period. For example, the ratio of the loop opening period and the loop closing period is 3:
When set to 1, the loop gain is reduced to 1/4 as compared with the case where all the loops are closed.

FIG. 6 is a diagram showing the open loop gain state of the tracking servo loop which changes during the jumping operation. A is the tracking servo loop gain "high" state during the normal tracking operation, and B is the jumping operation. Tracking servo loop gain is "Low".

In the normal tracking state A, the gain crossing point f1 crosses 0 with a slope of 6 dB / oct, so that a stable damping state is maintained, and since the loop gain is sufficient, stable tracking characteristics can be maintained.

On the other hand, in the state B during jumping, the jumping pulse generator 9 is included in the tracking servo loop.
Since the jumping pulse is injected to drive the focus lens 3a, the loop switch 11 is opened / closed at a predetermined ratio to reduce the servo loop gain in order to easily move the focus lens 3a.

In this case, the gain intersection point f2 is 12 dB / o.
Since it crosses the 0 point with the inclination of ct, if this state is maintained for a long time, the oscillation state is reached. However, in a normal laser disc player or CD player, this jumping period is within the range of about 0.3 ms to 1 ms. Since it can be designed, it does not reach the oscillation state. That is, the time t required for jumping can be made sufficiently smaller than about 1 cycle of the oscillation frequency at the 0 cross point (f2).

Moreover, although the overall loop gain is reduced, there is a gain in the low frequency range, and even if there is a vibration component of a low frequency, a suppression effect corresponding to the gain is provided regardless of the jump. Can be done.

The repetition frequency of opening and closing of the loop is sufficiently higher than the gain intersection frequency of the servo loop, for example, about 10 times or more, so that it can be treated in the same way as almost complete linear control operation.

Although the above description has been made for the jumping operation of one track, it is not particularly limited to one track, and similar effects can be obtained for kickback and kickforward operations by jumping a plurality of tracks. Needless to say.

FIG. 7 is a block diagram showing the configuration of a jumping operating device according to the third embodiment of the present invention. In FIG. 7, the disk 1 is driven by a spindle motor 2a whose spindle motor control unit 2b controls the rotation speed to a predetermined value. The pickup unit 3 detects the data recorded on the disc 1 as an optical signal via a focus lens 3a supported by an actuator (not shown), and converts it into an electric signal. The electric signals include a focus error signal, a tracking error signal, and an RF signal indicating data content, but the focus error signal and the RF signal which are not directly related to the operation of the present invention are omitted here. 3b is a focus lens 3a
A tracking error detector 3c for detecting a tracking error signal detected from the tracking error detector 3c is a tracking direction driver for driving the focus lens 3a in the tracking direction. 4 shows the pickup unit 3 slowly moving in the tracking direction as the reproduction of the disc 1 progresses, that is,
A traverse drive unit for moving the disc in the radial direction. Reference numeral 5 is an amplification section for amplifying the tracking error signal output from the tracking error detection section 3b, and its output is phase-compensated by the high-frequency compensating section 6 for securing the phase margin when the tracking servo loop is established. To be done. The high frequency compensator 6 has a high frequency compensation control terminal 6a controlled by the jumping controller 10 and is controlled so that the high frequency compensation operation for enhancing the high frequency component does not work during the jumping operation. The output of the high frequency compensator 6 is added by the adder 7 to the output pulse of the jumping pulse generator 9. The jumping pulse generator 9 receives a command from the jumping controller 10 at the time of track jump and generates a predetermined jumping pulse. The output of the adder 7 is power-amplified by the drive unit 8 and input to the tracking direction drive unit 3c.

The operation will be described below with reference to the block diagram of FIG. In the normal reproduction state, the tracking error detection unit 3b, the amplification unit 5, the high frequency compensation unit 6, the addition unit 7, the drive unit 8 and the tracking direction drive unit 3c form a tracking servo loop, and the pickup unit 3 is Follow servo on a predetermined track.

Next, in order to hold a predetermined track position, a pause operation will be described in which the jumping operation is continuously performed in the direction opposite to the reproduction direction for one track per one rotation (360 degrees).

FIG. 8 is a time chart for performing the jumping operation. (A) shows a state with or without high frequency compensation in the tracking servo loop, and (b) shows a focus lens 3a of the pickup section 3. The timing of a jumping pulse for acceleration / deceleration for giving energy for driving the track by one track is shown. In the figure, t indicates the jumping time required to jump one track.

At time τ0, the jumping control unit 10 issues a command to eliminate the high frequency compensation operation of the high frequency compensation unit 6 to reduce the high frequency gain, and at the same time, the jumping pulse generation unit 9 outputs an acceleration pulse of a predetermined width. To drive the focus lens 3a, and then outputs a deceleration pulse for decelerating the speed of the focus lens 3a, and when the area of the adjacent track is reached, the supply of the deceleration pulse is stopped and at the same time or immediately thereafter. At the time point (τ1), the high frequency compensating operation of the high frequency compensating unit 6 is restored and the high frequency gain of the servo loop is restored.

FIG. 9 is a diagram showing the open loop gain characteristic of the tracking servo loop which changes during the jumping operation, where A is the characteristic of the tracking servo loop when there is high frequency compensation during the normal tracking operation, and B ( The broken line shows the characteristics of the tracking servo loop when the high frequency compensation characteristic during the jumping operation is lost and the high frequency compensation is not performed.

In the normal tracking state A, the gain crossing point f1 crosses 0 at a slope of 6 dB / oct, so that a stable damping state can be maintained, and since the loop gain is sufficient, stable tracking characteristics can be maintained.

On the other hand, in the state B during jumping, the jumping pulse generator 9 is placed in the tracking servo loop.
Since the jumping pulse is injected to drive the focus lens 3a, the high frequency compensator 6 is controlled to reduce the high frequency gain in order to facilitate the movement of the focus lens 3a.

In this case, the gain intersection point f2 is 12 dB / o.
Since it crosses the 0 point with the inclination of ct, if this state is maintained for a long time, the oscillation state is reached. However, in a normal laser disc player or CD player, this jumping period is within the range of about 0.3 ms to 1 ms. Since it can be designed, it does not reach the oscillation state. That is, the time t required for jumping can be made sufficiently smaller than about 1 cycle of the oscillation frequency at the 0 cross point (f2).

Moreover, although the loop gain in the high frequency range is reduced, the gain in the low frequency range remains unchanged, that is, it does not change from the normal tracking servo state, and therefore jumps even if there is a low frequency vibration component. Regardless of the inside, it is possible to give the same suppression effect as in the state where the normal tracking servo loop is established.

Further, in the conventional configuration, the tracking servo loop is temporarily cut to be in the open loop state at the time of track jump, so that the present invention is greatly affected by the offset voltage and the like of the circuit system. , The loop remains closed, and the low-frequency gain including the DC component is constant regardless of the jumping state, so that it is not affected by the offset voltage of the circuit system.

Although the above description has been made with respect to the jumping operation of one track, it is not particularly limited to one track, and the same effect can be obtained for kickback and kickforward operations by jumping a plurality of tracks. Needless to say.

FIG. 10 is a block diagram showing the configuration of a jumping operating device according to the fourth embodiment of the present invention. In FIG. 10, the disk 1 is driven by a spindle motor 2a whose rotation speed is controlled by a spindle motor controller 2b. The pickup unit 3 detects the data recorded on the disc 1 as an optical signal via a focus lens 3a supported by an actuator (not shown), and converts it into an electric signal. The electric signals include a focus error signal, a tracking error signal, and an RF signal indicating data content, but the focus error signal and the RF signal which are not directly related to the operation of the present invention are omitted here. 3b is a focus lens 3a
A tracking error detection unit 3c for detecting a tracking error signal detected from is a tracking direction drive unit for driving the focus lens 3a in the tracking direction. 4 shows the pickup unit 3 slowly moving in the tracking direction as the reproduction of the disc 1 progresses, that is,
A traverse drive unit for moving the disk 1 in the radial direction. 5 is a tracking error detector 3b
Is an amplifying unit for amplifying the tracking error signal output by, and its output is phase compensated by the high frequency compensating unit 6 for securing the phase margin when the tracking servo loop is established. A high-pass component of the output of the high-frequency compensator 6 is removed by a low-pass filter 12 having a low-pass filter control terminal 12a whose filter operation is controlled by a jumping controller 10, and an adder 7
It is added to the output pulse of the jumping pulse generator 9. The jumping pulse generator 9 receives a command from the jumping controller 10 at the time of track jump and generates a predetermined jumping pulse. The low-pass filter 12 shows a low-pass characteristic of 6 dB / oct at the cut-off frequency f0 when the low-pass function is turned on (present) by the jumping control unit 10 and a gain of 1 when turned off (none). It is configured to exhibit flat characteristics. The output of the adder 7 is power-amplified by the drive unit 8 and input to the tracking direction drive unit 3c.

The operation will be described below with reference to the configuration diagram of FIG. In a normal reproduction state, the tracking error detection section 3b, the amplification section 5, the high frequency compensation section 6, the low pass filter 12, the addition section 7, the drive section 8 and the tracking direction drive section 3c constitute a tracking servo loop, The pickup unit 3 follows and servos on a predetermined track.

Next, in order to hold a predetermined track position, a pause operation will be described in which the jumping operation is continuously performed in the direction opposite to the reproduction direction for one track per one rotation (360 degrees).

FIG. 11 is a time chart for performing the jumping operation. (A) shows the states of the low-pass filter 12 in the tracking servo loop, “present” and “none”, and (b) shows the pickup section. The timing of jumping pulses for acceleration / deceleration for giving energy for driving the focus lens 3a of No. 3 by one track is shown. In the figure, t indicates the jumping time required to jump one track.

At time τ0, the jumping control unit 10 controls the low-pass filter control terminal 12a of the low-pass filter 12 to turn on the low-pass filter function to reduce the high-frequency gain, and at the same time, the jumping pulse generation unit 9 sets the predetermined width. To drive the focus lens 3a, and then to output the deceleration pulse for decelerating the speed of the focus lens 3a, and when the next track area is entered, the supply of the deceleration pulse is stopped and at the same time. , Or immediately after that (τ1), the low-pass filter function is turned off to restore the high frequency gain of the servo loop.

FIG. 12 is a diagram showing the open loop gain characteristic of the tracking servo loop which changes during the jumping operation. A shows the characteristic of the tracking servo loop when there is no low pass filter (function) during the normal tracking operation, and B shows the characteristic. (Shown by a broken line) shows the characteristics of the tracking servo loop when the low-pass filter (function) is inserted in the servo loop during the jumping operation.

In the normal tracking state A, the gain crossing point f1 crosses 0 with a slope of 6 dB / oct, so that a stable damping state can be maintained, and since the loop gain is sufficient, stable tracking characteristics can be maintained.

On the other hand, in the state B during jumping, the jumping pulse generator 9 is placed in the tracking servo loop.
Since the jumping pulse is injected to drive the focus lens 3a, the low-pass filter 12 lowers the high-frequency gain to facilitate the movement of the focus lens 3a.

In the case of this embodiment, the gain intersection point f2 is 18
Since it crosses the 0 point with the inclination of dB / oct, if this state is maintained for a long time, the oscillation state is reached. However, in a normal laser disc player or CD player, this jumping period is in the range of about 0.3 ms to 1 ms. Since it can be designed inside, it does not reach the oscillation state. That is,
The time t required for jumping is 0 cross point (f
It can be made sufficiently smaller than about 1 cycle of the oscillation frequency in 2).

Moreover, although the loop gain in the high frequency range is reduced, the gain in the low frequency range remains unchanged, that is, it does not change from the normal tracking servo state, and therefore jumps even if there is a low frequency vibration component. Regardless of the inside, it is possible to give the same suppression effect as in the state where the normal tracking servo loop is established.

Further, in the conventional configuration, the tracking servo loop is temporarily cut to be in the open loop state at the time of track jump, so that the operating point of the servo loop is greatly affected by the offset voltage and the like of the circuit system. On the other hand, in the present invention, since the loop remains closed and the low-frequency gain including the DC component is constant regardless of whether the jumping state is “present” or “none”, the offset voltage of the circuit system, etc. It will not be affected.

Although the above description has been made for the jumping operation for one track, it is not particularly limited to one track, and similar effects can be obtained for kickback and kickforward operations by jumping a plurality of tracks. Needless to say.

[0062]

According to the present invention, while the acceleration / deceleration driving pulse is being supplied to the pickup by the above method,
Since the overall gain of the servo loop is reduced and the high-frequency gain is reduced accordingly, the pickup can be easily driven by the acceleration / deceleration driving pulse whose main component is the high frequency component. Furthermore, since the servo loop remains closed, there is a slight decrease, but since there is servo gain from the low range to the middle range, even if there is disturbance during the jumping period, the effect is suppressed according to the gain amount. It has an excellent effect such as being able to.

According to the present invention, while the drive pulse for acceleration / deceleration is being supplied to the pickup, the overall gain of the servo loop is reduced equivalently by opening / closing the loop switch at a predetermined frequency. Accordingly, the gain in the high frequency band is reduced, so that the pickup can be easily driven by the acceleration / deceleration driving pulse whose main component is the high frequency component. Further, since the servo gain exists from the low band to the mid band, even if there is a disturbance during the jumping period, the effect can be suppressed according to the gain amount, which is an excellent effect.

Further, according to the present invention, while the acceleration / deceleration driving pulse is being supplied to the pickup, the high-frequency gain of the servo loop is reduced. The pickup can be easily driven. Furthermore, since the servo loop remains closed and the servo gain from the low range to the middle range is the same as the state of the normal tracking servo loop, even if there is disturbance during the jumping period, it will be the same as during normal tracking servo. It is possible to have the same effect of suppressing the disturbance.

Further, according to the present invention, while the acceleration / deceleration driving pulse is being supplied to the pickup, the high-frequency gain of the servo loop is reduced. The pickup can be easily driven. Furthermore, since the servo loop remains closed and the servo gain from the low range to the middle range is the same as the state of the normal tracking servo loop, even if there is disturbance during the jumping period, it will be the same as during normal tracking servo. It is possible to have the same effect of suppressing the disturbance.

[Brief description of drawings]

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

FIG. 2 is a time chart for explaining a jumping operation in the first embodiment.

FIG. 3 is a Bode diagram for explaining changes in characteristics during a jumping operation in the first embodiment.

FIG. 4 is a block diagram showing a configuration of a jumping scanning device according to a second embodiment of the present invention.

FIG. 5 is a time chart for explaining a jumping operation in the second embodiment.

FIG. 6 is a Bode diagram for explaining a change in characteristics during a jumping operation in the second embodiment.

FIG. 7 is a block diagram showing a configuration of a jumping scanning device according to a third embodiment of the present invention.

FIG. 8 is a time chart for explaining a jumping operation in the third embodiment.

FIG. 9 is a Bode diagram for explaining changes in characteristics during a jumping operation in the third embodiment.

FIG. 10 is a block diagram showing a configuration of a jumping scanning device according to a fourth embodiment of the present invention.

FIG. 11 is a time chart for explaining a jumping operation in the fourth embodiment.

FIG. 12 is a Bode diagram for explaining changes in characteristics during a jumping operation in the fourth embodiment.

[Explanation of symbols]

 1 disk 2a spindle motor 2b spindle motor control unit 3 pickup unit 3a focus lens 3b tracking error detection unit 3c tracking direction drive unit 4 traverse drive unit 5 amplification unit 5a gain control terminal 6 high frequency compensation unit 6a high frequency compensation control terminal 7 addition Section 8 driving section 9 jumping pulse generating section 10 jumping control section 11 loop switch 12 low pass filter 12a low pass filter control terminal

Claims (12)

[Claims] 1. An apparatus for reading information recorded on a track on an information record carrier, comprising means for irradiating the information track with a radiation beam, and a device for responding to a track shift between the information track and the irradiated radiation beam. A tracking error signal detecting means for detecting a tracking error signal, and a tracking control means for controlling the radiation beam to match the track according to the tracking error signal. When the radiation beam is moved to the information track, the open loop gain of the tracking servo loop forming the tracking control means is reduced, and the predetermined information track is moved toward the other adjacent information track. Jumping pulse to move the radiation beam The supply to the tracking control means, after the movement of said radiation beam, jumping scan apparatus characterized by returning to the original gain of the tracking servo loop. 2. The jumping scanning device according to claim 1, wherein the jumping pulse is arranged so that the deceleration pulse comes after the acceleration pulse in time series. 3. The start and end of the period for reducing the loop gain are made to coincide with the supply start point of the acceleration pulse and the end point of the deceleration pulse, respectively.
Or the jumping scanning device described in 2. 4. An apparatus for reading information recorded on a track on an information record carrier, comprising means for irradiating the information track with a radiation beam, and a device for responding to a track shift between the information track and the irradiated radiation beam. A tracking error signal detecting means for detecting a tracking error signal, and a tracking control means for controlling the radiation beam to match the track according to the tracking error signal. When the radiation beam is moved to the information track, the tracking servo loop that constitutes the tracking control means is repeatedly opened and closed at a frequency higher than the gain intersection frequency of the tracking servo loop, and at the same time from the predetermined information track. For adjacent information tracks of The jumping pulse for moving the radiation beam supplied to said tracking control means Te, after the movement of said radiation beam,
A jumping scanning device characterized by stopping the opening / closing operation of the tracking servo loop. 5. The jumping scanning device according to claim 4, wherein the jumping pulse is arranged so that the deceleration pulse comes after the acceleration pulse in time series. 6. The jumping according to claim 4, wherein the start and end of the opening and closing period of the tracking servo loop are made to coincide with the supply start point of the acceleration pulse and the end point of the deceleration pulse, respectively. Scanning device. 7. An apparatus for reading information recorded on a track on an information record carrier, comprising means for irradiating the information track with a radiation beam, and a device for responding to a track shift between the information track and the irradiated radiation beam. A tracking error signal detecting means for detecting a tracking error signal, and a tracking control means for controlling the radiation beam to match the track according to the tracking error signal. When the radiation beam is moved to the information track, the high frequency compensation of the tracking servo loop which constitutes the tracking control means is taken, and the radiation beam is directed from the predetermined information track to the other adjacent information track. Tracking control of jumping pulse to move It is supplied to the stage, after the movement of said radiation beam, jumping scan apparatus characterized by returning to the original again high frequency compensation of the tracking servo loop. 8. The jumping scanning device according to claim 7, wherein the jumping pulse is arranged so that the deceleration pulse comes after the acceleration pulse in time series. 9. The jumping according to claim 7, wherein the start end and the end of the high frequency compensation period are made to coincide with the supply start point of the acceleration pulse and the end point of the deceleration pulse, respectively. Scanning device. 10. An apparatus for reading information recorded on a track on an information record carrier, comprising means for irradiating the information track with a radiation beam, and a device for responsive to a track shift between the information track and the irradiated radiation beam. A tracking error signal detecting means for detecting a tracking error signal, and a tracking control means for controlling the radiation beam to match the track according to the tracking error signal. When moving the radiation beam to the information track, the low-pass filter is inserted in the tracking servo loop which constitutes the tracking control means, and the radiation is emitted from the predetermined information track to the other adjacent information track. In front of the jumping pulse that moves the beam It is supplied to the tracking control means, after the movement of said radiation beam, jumping scan apparatus characterized by turning off the function of the low-pass filter. 11. The jumping scanning device according to claim 10, wherein the jumping pulse is arranged so that the deceleration pulse comes after the acceleration pulse in time series. 12. The method according to claim 10, wherein the start and end of the period in which the low-pass filter is inserted are made to coincide with the supply start point of the acceleration pulse and the end point of the deceleration pulse, respectively.
1. The jumping scanning device described in 1.