JPH02267740A - Rotary type storage device and optical storage device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a rotary storage device having a plurality of heads for writing and/or reading on a rotating recording medium, the purpose of which is to control the position of the head on the recording medium, a first head moving means for moving a first head leading in the rotation direction of the recording medium; and a second head movement means for moving a second head located behind the first head with respect to the rotation direction of the recording medium. a means for moving the first head and the second head, and a total head moving means for integrally moving the first head and the second head; and a means for moving the first head and the second head together; a first servo means for reading a signal and controlling the position of the first head by the first head moving means based on the position signal; and a first servo means for controlling the position of the first head by the first head moving means based on the position signal; a second servo means for integrally controlling the position; and a second head reading a position signal from the recording medium;
and third servo means for controlling the position of the second head by the second head moving means based on the position signal read by the second head.

[Industrial application field]

The present invention relates to a rotary storage device such as a magnetic disk device or an optical disk device that moves and jumps a beam of an optical head to an arbitrary track of an optical storage medium.

Optical storage devices are widely used in optical disk devices and optical card devices, and are attracting attention as large-capacity storage devices because they can be read/written using a light beam.

[Conventional technology]

Optical disk devices that can be written by erasing include, for example, magneto-optical disk devices, and such optical disk devices include an external magnetic field type and a non-external magnetic field type. In the former case, when writing to a storage area that has been previously written, only a write operation using a light beam is required; however, in the former case,
After the erasing operation using the erase beam, it is necessary to perform the writing operation using the write beam. Therefore, in the latter non-external magnetic field type optical disk device, it is necessary to further irradiate the light beam after irradiating the erase beam from the objective lens. Therefore, when writing to a storage area that has previously been written to, an erase and write process is required, so the optical disc must be rotated twice for each track. Therefore, write operations are slower than read operations. Therefore, as a means to solve such problems, a technique has recently appeared in which an optical disk device is provided with two objective lenses to simultaneously irradiate an erase beam and a light beam.

As shown in FIG. 7, two beams are emitted from a single optical head 2. The two beams are irradiated from respective objective lenses, and the optical head 2 is provided with two actuators.

As shown in FIG. 6, the optical head 2 is moved and positioned in the radial direction of the optical disc 1 by a head drive motor 81 with respect to the optical disc 1 rotating around a rotation axis (not shown), and the optical head 2 is positioned to read the optical disc 1. (play), write (record).

Erasing is performed. The optical head drive motor 81 is composed of a voice coil motor VCM.

Now, in Fig. 6, the beam is emitted from the semiconductor laser 2 which is the light source.
4 (240), the semiconductor laser 24 emits an erase beam for erasing, and 240 emits a light beam for writing. Hereinafter, numbers in parentheses refer to the erase beam lens actuator 28, which controls the track position of the erase beam on the left side of the drawing. The numbers in parentheses constitute the light beam lens actuator 280 that controls the track position of the light beam on the right side as viewed from the drawing.

The emitted beam is transmitted through a polarizing beam splitter 23
(230), via the 1/4λ plate 100 (1000),
The objective lens 20 (200) is guided to the objective lens 20 (200).
(200) to focus on the beam spot and optical disc 1.
and the reflected light from the optical disc 1 is sent to the objective lens 20.
(200) through polarizing beam splitter 23 (23
0), the light beam is configured to enter the four-split light receiver 26 (26) via the lens 25b (25b).

Now, in such an optical disk device, a large number of tracks are formed at intervals of several microns in the radial direction of the optical disk, and even a slight eccentricity causes a large displacement of the track position, and the undulation of the optical disk 1 causes the beam to be distorted. The position of the spot shifts, and it is necessary to make the beam spot of 1 micron or less follow these position shifts.

For this purpose, there is a focus actuator 22 (220) that moves the objective lens 20 (200) of the optical head 2 vertically in the figure to change the focal position, and a lens actuator 21 (210) that changes the objective lens left and right in the figure. is provided.

Correspondingly, a focus error signal FES is generated from the light reception signal of the light receiver 26 (26), and the erase beam focus servo section 4 (light beam focus servo section 40) and the light reception signal of the light receiver 26 (260) are activated. Erase beam track servo unit 3 (light beam track servo unit 3) generates track error signal TBS from the signal and drives lens actuator 21 (210).
32) is provided.

Track servo control utilizes a change in the amount of reflected light due to a diffraction phenomenon of a beam spot due to a spiral guide groove (trunk) provided in advance on the optical disc 1, for example.

That is, a position error signal (track error signal) of the beam spot with respect to the track is obtained by utilizing the fact that the distribution of the amount of reflected light on the light receiver 26 changes due to the diffraction of light by the track depending on the position of the beam spot with respect to the track. be.

A TES signal is created in the erase beam track servo section 3 based on the light reception signal obtained by the light receiver 26,
The erase beam track servo unit 3 moves the erase beam using the lens actuator 21 according to the TES signal, and the erase beam spot 91 is aligned with the optical disk 1.
The servo is applied so that it is located at the center of the trunk 11.

In the light beam, the light receiver 26
The light beam track servo unit 332 generates a TES signal based on the light reception signal obtained at 0, and the light beam track servo unit 333 generates a TES signal using the TES signal.
The lens actuator 210 moves the light beam and applies servo so that the light beam spot 910 is located at the center of the track 11 of the optical disc 1.

[Means to solve problems]

Now, there are two actuators 21 and 210 for one optical head 2. Therefore, the erase beam spot 91. The light beam spot 910 is track-followed by the erase beam track servo section 3 and the light beam track servo section 332, respectively.

As mentioned above, since one optical radar 2 has two beams, it is necessary to make the two beams follow the same track. However, the tracking range of the laser beam in the track direction is narrow, and the tracking range may be exceeded due to eccentricity of the optical disc. Normally, the beam spot can move within a range of 30 to 50 degrees using only the actuator.
track (track width is about 1 micron). If the tracking range is exceeded, the optical head drive unit moves the optical head 2 to place the beam spot on the track. However, if the optical head is only moved when it exceeds the tracking range of the actuator, the accuracy of track tracking will be poor.

Traditionally, when an optical head has only one objective lens, servo control is applied to both the optical head drive unit and the lens actuator as a means of achieving highly accurate track following (double The servo). That is, the TES position signal region of the light beam is separated, the low frequency component of the TBS signal drives the voice coil motor of the optical head drive section, and the high frequency component of the TBS signal drives the lens actuator. It is something.

However, in the above-mentioned means, there is only one objective lens actuator in the optical head. Conventionally, in optical disk devices that emit a plurality of beams using a plurality of objective lenses, there has been no means for stably tracking the plurality of beams.

[Problem to be solved by the invention]

In order to achieve the above object, the present invention provides a rotary storage device having a plurality of heads for writing and/or reading on a rotating recording medium 1. a first head moving means 28 for moving one head; a second head moving means 280 for moving a second head located behind the first head with respect to the rotational direction of the recording medium 1; head and second
A total head moving means 81 includes heads and moving means for the heads and moves the first head and the second head integrally, reads a position signal from the recording medium 1 by the first head, and reads a position signal from the recording medium 1 based on the position signal. The first servo means 3 controls the position of the first head by the first head moving means 28, and the position of the first head and the second head is integrally moved by the entire head moving means 81 based on the position signal from the first head. A second servo means 331 for controlling a position signal is read from the recording medium 1 by a second head, and based on the position signal read by the second head,
The third servo means 332 controls the position of the second head by the second head moving means 280.

[Effect]

The first servo means controls the position of the first head by the first head moving means 28 according to the position signal obtained from the preceding first head, and the third servo means controls the position of the first head according to the position signal obtained from the second head. The head moving means 28 controls the position of the second head.

Further, the second servo means 331 moves the positions of the first head and the second head using the all head moving means 81 based on the position signal from the first head. In other words, all the head moving means 81 are
By driving the servo system, the phase delay generated in the servo system is reduced with respect to the second head, and the tracking accuracy of the second head is increased.

〔Example〕

(a) Explanation of the configuration of the embodiment Fig. 2 is a block diagram of an embodiment of the present invention, Fig. 3 is a block diagram of the objective lens of the optical head, and Fig. 4 is a block diagram of the voice coil motor that moves the optical head. It is.

First, the configuration of the optical head will be explained using FIG. 3. Numbers related to actuators that irradiate erase beams are not shown in parentheses, and numbers related to actuators that irradiate light beams are shown in parentheses. Third
In Figure (A), the semiconductor laser 24 (240) is
The light from the semiconductor laser 24 (240) is made into parallel light by the collimator lens 25a (250a), and the light from the semiconductor laser 24 (240) is converted into parallel light by the polarizing beam splitter 23 (230), 1/
It passes through the 4λ plate 207 (207) and passes through the objective lens 20 (
200) beam spot 9 on optical disk 1
It is narrowed down to 1 (910). The reflected light from the optical disc 1 is transmitted through an objective lens 20 (200) and a 1/4λ tentative 207
(2070), polarizing beam splitter 23 (230
) and enters the four-split light receiver 26 (260) through the condenser lens 25b (250b).

The objective lens 20 (200) has a rotating shaft 28a (280
Lens actuator body 28 rotatable around a)
(280) is provided at one end, and a fixed sling) 28b (280b) is provided at the other end.

A coil portion 28c (280c) of the lens actuator body 28 (280) is provided, and the coil portion 28c
Focus coil 22 (220) is placed around (280c).
However, there is a spiral lens actuator coil 21 on the side.
(210) is provided, and the coil portion 28 c (2
A magnet 28d (280d) is provided around the magnet 80c).

Therefore, when current is applied to the focus coil 22 (220), the lens actuator 2B (280) equipped with the objective lens 20 (200) moves upward or downward in the X-axis direction in the figure, similar to the voice coil motor. This allows the focus position to be changed, and when current is applied to the lens actuator coil 21 (210), the lens actuator 28 (280) rotates in the α direction around the rotation axis 28a (280a), thereby changing the position in the track direction. It can change.

For the fixed slit 28b (280b) provided at the end of the lens actuator 2B (280), the light emitting part 27 (270) and the light receiver 2 constituting the position sensor
9 (290) is provided, as shown in Fig. 3 (A),
As shown in (B), the light emitting section 27 (270) and the four-part light receivers 29a (290a) to 29d (290d) are provided so as to face each other via the fixed slit 28b (280b).

The fixed slit 28b (280b) is provided with a window W, and the light from the issuing unit 27 (270) passes through the window W to the four-split light receivers 29a (290a) to 29d (290
d).

Therefore, as shown in FIG. 3(C), the light reception distribution of the four-part light receivers 29a (290a) to 29d changes depending on the amount of movement of the lens actuator 2B (280) in the α and X directions. Therefore, the light receivers 29a to 29d (290d
), the lens position signal ELPO3 (WLOPS) in the track direction and the position signal EFPS (WFPS) of the focus signal are obtained as follows.

ELPO3 (WLPO3) = (A+C)-(B10) EFPS (WFPS) = (A+B)-(C+D) Conoposite 3 signal ELPO3 (WLPO3).

As shown in Figure 3 (C), EFPS (WFPS) becomes an S-shaped signal that becomes zero at the center position in response to deviation from the center position, and this signal is used to generate electrical current in the direction of the center position. Can provide spring force.

Next, the optical head drive motor for moving the optical head will be explained using FIG. 4. The motor is a voice coil motor.

The voice coil motor is as shown in FIG. 4(a), in which an iron core 81 is provided with two spaces, and a coil 401 is wound around the iron core extending through the spaces. A coil portion 80 fixes the coil 401. 82 is a magnet, and the magnetic poles are as shown. Therefore, by passing a predetermined current through the coil 401, the coil portion moves left and right in the drawing.

As shown in FIG. 4(b), the coil portion 80 of the voice coil motor is equipped with an optical head 2, and the optical head 2 includes a lens actuator for controlling the position of the objective lens 20°200 as explained in FIG. 28.280 is provided. Therefore, by passing a current through the coil 401, the optical head 2 is moved.

Next, the configuration shown in FIG. 2 will be explained.

5.50 is an operation control unit, which is composed of a microprocessor (hereinafter abbreviated as MPU), and includes an erase beam track servo unit 3.50, respectively. It controls the light beam track servo section 332.

Erase beam track servo section 3 using Figure 2.
I will explain about it. Reference numeral 7 denotes a head circuit section, which includes an RF creation circuit 60 that creates an RF doubler RFS from the 4-split photo receiver 26 of the erase beam, and an output A of the 4-split photo receiver 26.
An amplifier 61 that amplifies -D and outputs a servo output of 5VA-3VD, and 4-division light receivers 29a to 29d of the position sensor.
ELPO creates a lens position signal ELPO3 for the objective lens that irradiates the erase beam from the outputs A-D of
3 creating circuit 62. The RF generating circuit 60 generates an RF multiplied signal (RFS) from the quadrant optical receiver 26, and the signal is used to read the track address preformatted on the optical disc.

30 of the erase beam track servo unit 3 is an erase beam TBS (1-rack error signal) generation circuit, which generates a track error signal TBS from the servo outputs 5VA-3VD of the amplifier 61. 31 is a total signal creation circuit which adds the servo outputs SVA to SVD to create a total signal DSC which is a total reflection level; 32a;
, 32b.

32c is AC; C (8UTOMATIC GAIN C0
NTR0L) circuit, which divides the track error signal TBS by the total signal (total reflection level) DSC, performs AGC using the total reflection level as a reference value, and compensates for fluctuations in the irradiation beam intensity and reflectance. be.

301 is a low pass filter, created by TES l1lfl
one that separates the high frequency range of the TBS signal created in step 30;
A bypass filter 302 separates the high frequency range of the TBS signal created by the TBS creation circuit 30. The separated signals are sent to AGC circuits 32a and 32, respectively.
b. 33a.

33b is a phase compensation circuit which differentiates the track error signal TBS to which a gain has been given, and outputs the track error signal T.
In addition to the proportional amount of ES, the phase is advanced.

Reference numeral 35 denotes a servo switch, which is closed by the servo-on signal SvS of the MPU 5 to close the servo loop, and opened by the servo-on signal SvS of the MPU 5 to open the servo loop.

34a is a zero-crossing detection circuit, which detects the zero-crossing point of the track error signal TES, and outputs a track zero-crossing signal TZC3 to the MPU 5; 34b is an off-track detection circuit, in which the track error signal TBS is set to a constant value v0 in the positive direction; A constant value in the negative direction that exceeds 1■. The off-track signal TO3 is detected when the off-track state is detected.
What outputs to PU5, 35 is a servo switch,
The servo loop is closed and opened by the servo-on signal SVS of the MPU5, and 36 is a return signal generation circuit, and the ELPO
The return signal RPS is generated from the 3-creation circuit 62 to generate a return force in the track direction toward the center position of the lens actuator 28 shown in FIG. 3(a).

37 is a lock-on switch, which closes when the lock-on signal LKS of the MPU is turned on and sends a return signal RP to the servo loop.
39 is a power amplifier that amplifies the output of the return signal generation circuit 36 and sends the track drive current TDV to the lens actuator coil 21. It is something to give.

The phase compensation circuit 33b differentiates the output of the AGC 32b, adds it to the proportional part of the track error signal TBS, and advances the phase. A power amplifier 391 amplifies the output of the phase compensation circuit 33b, outputs it to the coil 401 of the voice coil motor VCM, and drives the coil 401 of the voice coil motor VCM.

Next, the light beam track servo section 332 will be explained. An RF creation circuit 600 that creates an RF multiplied signal FS from the light beam 4-split receiver 260, and a servo output 5VA that amplifies the outputs A-D of the 4-split light receiver 260.
An amplifier 610 that outputs -3VD and a lens position signal WL of the objective lens that irradiates the light beam from the outputs A-D of the four-division light receivers 290a to 290d of the position sensor.
It has a WLPO3 creation circuit 620 that creates a POS.

The RF generating circuit 600 generates an RF multiplied signal (RFS) from the quadrant optical receiver 26, and the signal is used to read the track address preformatted on the optical disc.

300 of the light beam track servo section 332 is a light beam TES (track error signal) generation circuit, which generates a track error signal TBS from the servo outputs 5VA-3VD of the amplifier 610. 310 is a total signal creation circuit which adds the servo outputs SVA to SVD to create a total signal DSC which is a total reflection level;
2d is 80 C (IN C0N to AUTOMATTCG
TR0L) circuit, which divides the track error signal TES by the total signal (total reflection level) DSC, performs ACC using the total reflection level as a reference value, and compensates for fluctuations in the irradiation beam intensity and reflectance. be.

330a is a phase compensation circuit that differentiates the track error signal TES to which a gain has been applied, adds it to the proportional part of the track error signal TES, and advances the phase.

340a is a zero-cross detection circuit that detects the zero-cross point of the track error signal TBS and outputs the track zero-cross signal TZC3 to the MPU5; 340b is an off-track detection circuit that detects the track error signal TE;
S is a constant value in the positive direction■. or above and a constant value in the negative direction -■. The off-track signal TO3 is detected by detecting the following conditions, that is, the off-track state.
350 is a servo switch that closes and opens the servo loop with the servo-on signal S■S of the MPU 50, and 360 is a return signal generation circuit, which is connected to the WLPO3 generation circuit 620 as shown in FIG. 3(A). A return signal RPS that generates a return force in the track direction toward the center position of the lens actuator 280 is generated.

370 is a lock-on switch, which closes when the lock-on signal LKS of the MPU 50 is turned on and guides the return signal RPS to the servo loop, and opens when it is turned off to cut the introduction of the return signal RPS to the servo loop; 390 is a power amplifier The output of the return signal generation circuit 360 is amplified and the track drive current TDV is sent to the lens actuator coil 2.
10.

(b) Description of the operation of the embodiment The operation of the erase beam track servo unit 3 will be explained.

The erase beam of the semiconductor laser 24 is reflected on the optical disk l and then enters the four-division light receiver 26 . The amplifier 61 amplifies the signal 5VA-3VD, inputs it to the TES signal generation circuit 30 of the track servo section 3, and outputs the signal 5VA-3V.
A track error signal TBS is created from D. The total signal creation circuit 31 adds the servo outputs 5VA-3VD to create a total signal DSC which is a total reflection level.

The high frequency of the TES signal created by the TES creation circuit 30 is separated by a bypass filter HPS301. Next, the ACC circuit 32a divides the high-frequency separated track error signal TBS by the total signal (total reflection level) DSC, performs AGC using the total reflection level as a reference value, and corrects fluctuations in the irradiation beam intensity and reflectance. do. Phase compensation circuit 33
a differentiates the track error signal TBS given the gain and adds it to the proportional part of the track error signal TES. The servo switch 35 is normally on, and the signal is amplified by the power amplifier 39, and the signal is amplified by the power amplifier 39. The output is input to the lens actuator coil 21 to control the track position of the beam.
3b and the power amplifier 39b constitute an optical head drive motor servo section 331.

Furthermore, the TBS signal created by the TES creation circuit 30 has its low frequency separated by a low pass filter LPF 302. Eccentricity information of the optical disc 1 is extracted by the low frequency signal, and the coil 401 of the CM 81 is driven. That is, the AGC circuit 32c converts the low frequency separated track error signal TBS into a total signal (total reflection level) DS.
Divide by C and perform ACC using the total reflection level as a reference value to correct fluctuations in the irradiation beam intensity and reflectance. The phase compensation circuit 33b receives the track error signal TE given the gain.
S is differentiated and added to the proportional part of the track error signal TES, and the signal is amplified by a power amplifier 391, and the output of the power amplifier is inputted to the coil 401 of the VCM, so that the signal is adjusted to the eccentricity of the optical disc 1. Control the track position of the beam.

In this way, the TES signal of the erase beam is separated into low and high frequencies, and the lens actuator 28 that moves the objective lens 20 and the voice coil motor that moves the optical radar 2 are doubly servoed.

Track servo control using the return signal RPS is used when the optical head 2 is brought close to the target track by the VCM 81. While the optical head 2 is moving, the MPU 5 turns on the lock-on signal LKS while keeping the servo-on signal SvS off. Therefore, a servo loop is not formed based on the track error signal TBS, but the lens actuator coil 21 is locked and controlled by the lens position signal ELPO3 based on the outputs A-D of the position sensors 29 a-d. That is, the lens actuator coil 21 is driven by the power amplifier 39 based on the return signal RPS of the return signal generation circuit 39, and the lens actuator 28 is driven by the power amplifier 39.
It is controlled to return to the center position and is fixed.

The reason why the lens actuator 28, that is, the objective lens 26, is locked in this way is to prevent the lens actuator 28 from moving within the head due to vibration while the optical head 2 is moving, and to prevent damage to the lens. Electrical locking is performed using position signal LPO3.

Furthermore, the servo-on signal Sv after the movement of the optical gear head 2 is completed.
When retracting the servo immediately after S is turned on, the lock-on signal is kept on, and the return signal RPS is used as shown in Figure 3 (
C) Track following is controlled by the track error signal TES while applying the return force to the center position.

Therefore, servo pull-in to the track of the eccentric optical disk 1 is performed at the point with the least amount of movement in the radial direction (direction across the track), and stable pull-in can be started.

Further, after the servo pull-in is completed, the lock-on signal LKS is turned off while the servo signal SVS is kept on, and the control by the return signal RPS is released.

Further, when off-track of the light beam is detected by the off-track detection circuit 34b, a track-off signal T is output.
Send O5 to MPU5. MPU5 is servo switch 35
is turned off, the lock-on switch 37 is turned on, and control is performed to approach the target track.

Next, the operation of the light beam track servo section 332 will be briefly explained.

The light beam from the semiconductor laser 240 is reflected by the optical disk 1 and then enters the four-split photoreceiver 260 . The amplifier 610 amplifies the signal 5VA-3VD and sends it to the TES signal generation circuit 30 of the light beam track servo section 3000.
0 and track error signal T from SVA to SVD.
Create ES. The total signal creation circuit 310 adds the servo outputs SVA to SVD to create a total signal DSC, which is a total reflection level.

Next, the AGC circuit 320 converts the high frequency separated track error signal TES into a total signal (total reflection level) DSC.
AGC is performed using the total reflection level as a reference value to correct fluctuations in the irradiation beam intensity and reflectance. Phase compensation circuit 3
30a is a gain-applied track error signal TE;
The servo switch 350 is normally on, and the signal is amplified by a power amplifier 390, the output of which is applied to the light beam lens actuator coil 210. The track position of the beam is controlled by inputting .

Track servo control using the return signal RPS is used when the optical head 2 is brought close to the target track by the VCM 81. While the optical head 2 is moving, the MPU 50 keeps the servo-on signal SVS off and outputs the lock-on signal LKS.
Turn on. Above 620.360,370,390,2
The loop 10 operates in the same way as the erase beam track servo unit 3.

According to this embodiment, which has been described above, when performing double servo in an optical disk device having a plurality of objective lenses in one movable part, it can be realized with an extremely simple circuit. Furthermore, the servo residual due to the phase delay that always occurs in the feedback system becomes a problem, but the TES signal of the erase beam is used as predictive control for the light beam.
By driving the VCM 81, the phase delay of the light beam is reduced. Furthermore, the sum of the servo residuals of the erase beam and the light beam can be kept small.

(C) Description of other examples FIG. 5 shows the configuration of the second embodiment.

The erase beam track servo section 3 will be explained.

After being reflected by the optical disc 1, the erase beam enters the four-division light receiver 26. The signal obtained by the photoreceiver 26 passes through an amplifier 61 and is input to a TBS signal generation circuit 30 to generate a track error signal TBS. The total signal creation circuit 31 creates a total signal DSC from the output of the amplifier 61.

The TBS signal created by the TBS creation circuit 30 is A
The signal passes through a GC circuit 32 and a phase compensation circuit 33a. The servo switch 35 is normally on, and the phase compensation circuit 3
The track position of the beam is controlled by amplifying the output signal of 3a with a power amplifier 39 and inputting it to the lens actuator coil 21. Further, the phase compensation circuit 33b of the optical head drive motor servo unit 331 differentiates the erase beam lens position signal ELPO3 from the outputs of the lens position sensors 29a to 29d, and differentiates the erase beam lens position signal ELPO3.
In addition to the proportional bone, amplify with power amplifier 391, VC
The M coil 401 is driven.

Therefore, erase beam lens actuator coil 2
1 is applied to the servo by the TBS signal, and at the same time, the VC
The M coil 401 is servoed by the signal ELPO8 obtained by the lens position sensor 29a-d of the erase beam lens actuator.

Next, the light beam track servo section 331 will be explained. After being reflected by the optical disc 1, the light beam enters the four-part light receiver 260.

The signal obtained by the light receiver 260 is inputted to the TBS signal generating circuit 30 and the beam lens actuator coil 210 through the amplifier 6, thereby controlling the track position of the light beam.

The present invention has been described above according to examples. In the embodiment, a case has been described in which the number of objective lens actuators of the optical head is two, but the number is not limited to this, and the number may be three or four. As shown above, the present invention can be modified in various ways according to the gist of the present invention, and the present invention does not exclude them.

[Effect] When performing double servo with an optical disk device that has multiple objective lens actuators in one movable part, the circuit configuration becomes simple, and servo residuals due to phase delays that always occur in the feedback control system become a problem. Since the signal from the first actuator is used for predictive control of the second beam, the sum of the servo residuals of the second beam is reduced, and the accuracy of track following is significantly improved.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a block diagram of an embodiment of the present invention, Fig. 3 is a configuration diagram of the objective lens of the optical head, and Fig. 4 is a diagram of the voice coil motor that moves the optical head. FIG. 5 is a block diagram of the second embodiment, and FIGS. 6 and 7 are explanatory diagrams of the conventional technology. 28 ・ 3 ・ ・ 8 1 ・ Erase beam lens actuator・Light beam lens actuator Erase beam track servo section・Optical head drive motor servo section・Light beam track servo control section Optical head drive motor diagram;・Nodon°4 lecture (L≧Ri゛Tomi3)
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Claims (5)

[Claims] (1) In a rotary storage device having a plurality of heads for writing and/or reading on a rotating recording medium (1), a first head that moves a first head leading in the rotational direction of the recording medium (1) a second head moving means (280) for moving a second head located behind the first head with respect to the rotational direction of the recording medium (1); an all-head moving means (81) on which a head and a second head and means for moving them are mounted and moves the first head and the second head integrally; The signal is read, and the first head moving means (2) is moved according to the position signal.
8) and a first servo means (3) for controlling the position of the first head; and a total head moving means (81) that integrally moves the positions of the first head and the second head based on the position signal from the first head. a second servo means (331) for controlling, a second head reading a position signal from the recording medium (1), and a second head moving means (280) based on the position signal read by the second head; A rotary storage device comprising: third servo means (332) for controlling the position of the head. (2) In a rotary storage device having a plurality of heads for writing and/or reading on a rotating recording medium (1), a first head that moves a first head leading in the rotational direction of the recording medium (1); a second head moving means (280) for moving a second head located behind the first head with respect to the rotational direction of the recording medium (1); a total head moving means (81) on which a head, a second head, and their moving means are mounted and moves the first head and the second head integrally; and a position signal transmitted from the recording medium (1) by the first head. is read, and the first head moving means (2) is read based on the position signal.
8); a first servo means (3') for controlling the position of the first head; and a first head position detection means (62) for detecting the position of the first head on the first head moving means (28); , From the position information of the first head on the first head moving means (28) obtained by the first head position detecting means (62), the positions of the first head and the second head are determined by all the head moving means (81). The second servo section (331'
), a position signal is read from the recording medium (1) by a second head, the position of the second head moving means (280) is controlled based on the position signal read by the second head, and the position signal is read from the recording medium (1). 1. A rotary storage device characterized by comprising a third servo means (332') for following the track of ). (3) In an optical storage device that irradiates a plurality of light beams for writing and/or reading onto a rotating optical recording medium (1), a first light beam preceding the rotating optical recording medium (1) in the direction of rotation of the optical recording medium (1); a first beam moving means (28) for moving one beam; and a second beam moving means for moving a second beam located behind the first beam with respect to the rotational direction of the optical recording medium (1). means (280); and total beam moving means (81) that is equipped with the first beam moving means (28) and the second beam moving means (280) and moves the first beam and the second beam integrally. , a first beam receiving the first beam from the optical recording medium (1);
a light receiving section (26); a first servo means (3) for controlling the position of the first beam by a first beam moving means (28) based on a light receiving signal obtained by the first light receiving section (26); A second servo means (3) integrally controls the positions of the first beam and the second beam by the total head moving means (81) from the light reception signal obtained by the light receiving section (26).
31), a second light receiving section (260) that receives the second beam from the optical recording medium (1), and a second beam moving means (28) based on the light reception signal obtained by the second light receiving section (260). 1. An optical storage device comprising third servo means for controlling one of the second beams. (4) In an optical storage device that irradiates a plurality of light beams for writing and/or reading onto a rotating optical recording medium (1), a first light beam preceding the rotating optical recording medium (1) in the direction of rotation of the optical recording medium (1); a first beam moving means (28) for moving one beam; and a second beam moving means (28) for moving a second beam located behind the first beam with respect to the rotational direction of the optical recording medium (1). 280), total beam moving means (81) equipped with the first beam moving means and second beam moving means and moving the first beam and the second beam integrally, and the optical recording medium (1).
a first light receiving section (26) that receives a first beam from the first light receiving section (26); a servo means (3'); a first beam position detecting means (62) for detecting the position of the first beam on the first beam moving means (28); and a position obtained by the first beam position detecting means (62). The second servo section (331') controls the positions of the first beam and the second beam by the entire beam moving means (81) based on the position information of the first beam on the first beam moving means (28).
), a second light-receiving section (260) that receives the second beam from the optical recording medium (1) and creates a light-receiving signal; An optical storage device comprising second servo means (332) for controlling the position of the second beam by the two-beam moving means (280). (5) The optical storage device according to claim 3 or 4, wherein the first beam is an erase beam and the second beam is a read or write beam.