JPH0388130A - Optical disk device - Google Patents

Abstract

PURPOSE:To stabilize seeking control and to perform fast seeking control by generating a positioner driving signal based on relative speed between a positioner and a track obtained at first and second optical head sides. CONSTITUTION:A signal generating part 70 finds the relative speed between a first optical head 10 and the track of an optical disk 30. The relative speed coincides with the one between the positioner 40 and the track. The generating part 70 generates a first positioner driving signal WPDV for positioner driving signal PSDV generation. Meanwhile, a signal generating part 80 finds the relative speed between a second optical head 20 and the optical disk 30, and generates a second positioner driving signal EPDV similarly. A signal generating part 90 generates a positioner driving signal PSDV by receiving the signal WPDV and EPDV and taking arithmetical mean. The signal PSDV goes to a moderate signal, which stably controls the positioner 40.

Description

[Detailed Description of the Invention] [Summary] Two optical heads mounted on one positioner allow
Regarding an optical disk device that can perform erasing and writing simultaneously, the first optical head and In an optical disk device equipped with a positioner equipped with a second optical head that tracks on at a position different from that of the first optical head, seek control is performed using Similarly, during seek control, a second positioner drive signal is generated based on the relative speed between the positioner and the track, which is determined from the relative speed between the second optical head and the track, and a first positioner drive signal is generated. and the second positioner drive signal to generate a positioner drive signal for driving the positioner.

[Industrial application field]

The present invention relates to an optical disc device that uses two optical heads mounted on one positioner to simultaneously perform erasing/writing on an optical disc in one rotation of the optical disc.

[Conventional technology]

In recent years, optical disk devices that can be erased and rewritten, such as magneto-optical disk devices, have appeared.

Such erasable/writable optical disk devices include an external magnetic field type and a non-external magnetic field type.

The external magnetic field type does not require an erase operation using an erase beam, and can be written immediately by overwriting with a light beam. On the other hand, in the non-external magnetic field type, it is necessary to perform writing using a light beam after performing erasing using an erase beam.

If the erasure/writing required in such a non-external magnetic field type optical disk device is performed with one optical head, 1
Since it is necessary to rotate the optical disk twice to write a track, the write operation is slower than the read operation.

To solve this problem, optical disk devices have been introduced that are equipped with two optical heads, one for erasing and one for writing, so that one trunk can be erased/written just by rotating the optical disk once. It's here.

FIG. 5 is a block diagram showing the basic configuration of an optical disc device provided with two objective lenses, one for erasing and one for writing.

In FIG. 5, 30 is an optical disk, and information is written on a plurality of tracks (one track is shown as 31).

Reference numeral 10 denotes a first optical head, which includes a first optical system 11 and a first lens actuator 12 therein, and is equipped with an optical disc 3
Read/write to 0.

The first optical system 11 includes a first objective lens 111,
The first light beam 112 is projected onto the optical disk 30, and a first track error signal WTES indicating the deviation of the first light beam 112 from the track center in the track direction and a first track error signal WTES indicating the focus error of the first light beam 112 are transmitted.
Each light reception signal for creating a focus error signal WFES is generated.

The first lens actuator 12 drives the first objective lens 11 by a first focus drive signal WFDV from the outside.
1 in the vertical direction of the figure to perform focus control, and also to control the focus by moving the lens drive signal WLDV from the outside.
Control is performed to move the first objective lens 111 in the horizontal direction (track direction) in the figure to follow the track.

It also includes a position sensor (not shown) inside, and generates a light reception signal for creating a first position signal WTPS that indicates the position of the first Luns actuator 12 on the optical disk 30.

A second optical head 20 includes a second optical system 21 and a first lens actuator 22 therein, and erases the optical disk 30.

The second optical system 21 includes a second objective lens 211,
The second optical beam 212 is projected onto the optical disk 30, and a second track error signal ETBS indicating a radial deviation of the second optical beam 212 from the track center is generated.
Each light reception signal is generated to create a second focus error signal EFES indicating a focus error of the light beam 212.

The first lens actuator 12 drives the second objective lens 21 in response to a second focus drive signal EFDV from the outside.
1 in the vertical direction of the figure to perform focus control, and also a second lens drive signal ELD from the outside.
Control is performed using V to move the second objective lens 211 in the horizontal direction (track direction) in the figure to follow the track.

It also includes a position sensor (not shown) inside, which generates a light reception signal for creating a second position signal ETPS that indicates the position of the first lens actuator 22 on the optical disk 30.

40 is a positioner, which is a voice coil motor (VCM).
41 (shown as ), on which a first optical head 10 and a second optical head 20 are mounted, and movement of both optical heads is controlled by an external VCM drive signal vCDV applied to the VCM 41.

The first optical head lO and the second optical head 20 are shown in FIG.
As shown in A), when the first light beam 112 of the first optical head 10 illuminates one track 31 of the optical disk 30, the second light beam 212 of the second optical head 20 illuminates other tracks on the same trunk 31. It is mounted on the positioner 40 in such a positional relationship that it illuminates the position.

50 is a first track servo control section, and the first optical system 1
The first lens drive signal WLDV generates a first track error signal WTES and a first track position signal WTPS from the light reception signals from the first and second lens actuators 12, and controls the movement of the first objective lens 111 based on these signals. is generated and supplied to the Luns actuator 12. Further, a VCM drive signal VCDV for controlling the position of the positioner 40 is generated from the above-mentioned two signals, and the VCM
41.

60 is a second track servo control section, and the second optical system 2
A second track error signal ETES and a second track position signal ETPS are generated from the light reception signals from the first lens actuator 1 and the first lens actuator 22.
The first lens actuator 22 generates a second lens drive signal ELDV that controls the movement of the objective lens 211.
supply to.

A first focus servo control section 110 generates a first focus error signal WFES for controlling the focus of the first objective lens 111 based on the light reception signal from the first optical system 11 and supplies it to the first lens actuator 12 .

Reference numeral 120 denotes a second focus servo control unit, which generates a second focus error signal EFES for controlling the focus of the second objective lens 211 based on the light reception signal from the second optical system 21 and supplies it to the first lens actuator 22. .

With this configuration, track servo control is performed using the first optical head 10 as a reference.

That is, the first track servo control section 50 generates a first track error signal WTES and a first track position signal WTPS from the light reception signals from the first optical system 11 and the first lens actuator 12, and from these two signals. ,
The first lens actuator 12 generates a first lens drive signal WLDV that controls the movement of the first objective lens 111.
supply to. In addition, a VCM drive signal VCDV for controlling the movement of the positioner 4° is generated from both of the above signals.
Supply to CM41 (double servo).

Thereby, the first optical head 10 is controlled so that the first light beam 112 projected from the first objective lens 111 correctly on-tracks and follows the predetermined track 31 of the optical disc 30.

Further, the first focus servo control unit 110 generates a first focus error signal WFES for controlling the focus of the first objective lens 111 based on the light reception signal from the first optical system 11, and supplies it to the first lens actuator 2. do. Thereby, the first light beam 112 projected by the first optical head 10 is controlled to correctly focus on the predetermined track 31 of the optical disc 30.

On the other hand, the first optical head 10 and the second optical head 20 are
As shown in FIG. 6, when the first optical head 10 illuminates one track 31 of the optical disk 30, the positional relationship is such that the second optical head 20 illuminates another position on the same track 31. It is installed in 40. Then, when the first optical head 10 is controlled to correctly track on and follow a predetermined track 31 of the optical disc 30, the second optical head 20 is correctly tracked on the same track 31 by a host device (not shown). controlled as follows.

When tracked onto the predetermined track 31, the second track servo control unit 60 controls the track servo so that the second light beam 212 projected from the first optical head 10 correctly follows the predetermined track 31 of the optical disc 30. controlled.

Further, the second focus servo control unit 120 generates a second focus error signal EFES for controlling the focus of the second objective lens 211 based on the light reception signal from the second optical system 21, and supplies it to the first lens actuator 22. do.

Thereby, focus servo control is performed so that the second light beam 212 projected by the second optical head 20 is correctly focused on the predetermined track 31 of the optical disc 30.

[Problem to be solved by the invention]

The conventional optical disk device described in FIGS. 5 and 6 that performs erasing/writing using two optical heads uses one optical head (first optical head) as a reference for operations such as seek and track jump. It controlled the position of the positioner in position control.

By the way, data is written on optical disks in sector units, and the sector format is basically 7th.
As shown in Figure (A), it is composed of an address section, a flag section, a data section, and a buffer section.

The address portion stores the physical address of each sector on the optical disk. The flag section indicates whether each sector is a written block or a defective block.
Each flag indicating whether the block has already been deleted is stored. The data section stores data used by the user. The buffer section is provided to prevent writing from reaching the address section of the next sector even if there is a change in the data when writing data to the data section.

Among the various parts of these sector formats, the address part is already preformatted when optical discs are manufactured.
As shown in FIG. 7(B), it consists of a 3M field and an ID field. The 3M field stores a mark indicating the beginning of the sector format.

V-E O is the V used when reading the ID field.
E. The address of the sector is stored in the ID field, which is the section in which the clocks are synchronized, but in order to ensure that it can be read without error even if there is a single omission in the address data, it is stored multiple times (in the figure). ID.

~IDs 3 times) The same address is written.

This address section has already been preformatted at the time of manufacturing the optical disc.

When seek control is performed to bring the optical head to a desired track position on the optical disc 30 having such a format portion, the track error signal TBS output from the optical head is as shown in (a) of FIG. 8(a). As shown,
When the optical head traverses the track portion, the signal waveform rapidly changes from positive to negative. However, if the optical head crosses the preformatted portion, both the level and waveform are disturbed, as shown in (0) in Figure 2(a).This disturbance in the level and waveform is caused by the movement of the optical head. It varies in a complicated manner depending on the speed, data content of the preformat part, etc.

As a result, the speed of the optical head detected by the track servo control section becomes discrete in this preformat part,
The VCM drive signal VCDV becomes discontinuous and an abnormal current begins to flow through the VCM.

For this reason, the error between the speed of the positioner 40 and the target speed becomes large, causing a problem that a seek error occurs.
Furthermore, this has led to the problem that stable position control is not possible and speeding up of position control is hindered.

The present invention stabilizes seek control by reducing the influence from the preformat portion formed on the optical disc,
An object of the present invention is to provide an optical disc device improved to enable high-speed seek control.

[Means for solving the problems] The means adopted by the present invention to solve the above-mentioned problems are as follows:
This will be explained with reference to FIG. FIG. 1 is a block diagram showing the basic configuration of the present invention.

In FIG. 1, components common to the optical disc apparatus described in the previous FIG. 1 are designated by the same reference numerals.

That is, 30 is an optical disk, and a plurality of tracks 3
Information is written to 1.

Reference numeral 10 denotes a first optical head, which includes a first optical system 11 and a first lens actuator 12 therein, and reads/writes from/to the optical disc 30 .

The first optical system 11 includes a first objective lens 111,
A first track error signal WTES indicating a radial deviation from the track center of the first light beam 112 and a first track error signal WTES indicating a focus error of the first light beam 112 are projected onto the optical disk 30 . Each light reception signal for creating a focus error signal WFES (not shown) is generated.

The first lens actuator 12 is activated by a first focus drive signal WFDV (not shown) from the outside.
The objective lens 111 is moved in the vertical direction in the figure to perform focus control, and the first objective lens 111 is also moved in the horizontal direction (track direction) in the figure to follow the track using the first lens drive signal WLDV from the outside. Take control.

It also includes a position sensor therein, and generates a light reception signal (none of which is shown) for creating a first position signal WTPS that indicates the position of the first lens actuator 12 on the optical disk 30.

A second optical head 20 includes a second optical system 21 and a first lens actuator 22 therein, and erases the optical disk 30.

The second optical system 21 includes a second objective lens 211,
The second optical beam 212 is projected onto the optical disk 30, and a second track error signal ETES indicating the deviation of the second optical beam 212 from the track center in the radial direction is generated.
Each light reception signal is generated to create a second focus error signal EFES (not shown) indicating a focus error of the light beam 212.

The first lens actuator 12 is activated by a second focus drive signal EFDV (not shown) from the outside.
Focus control is performed by moving the objective lens 211 in the vertical direction in the figure, and the second objective lens 211 is also moved in the horizontal direction (track direction) in the figure to follow the track using the second lens drive signal ELDV from the outside. control.

It also includes a position sensor inside and generates a light reception signal (none of which is shown) for creating a second positive signal ETPS that indicates the position of the first lens actuator 22 on the optical disk 30.

40 is a positioner, which is a voice coil motor (VCM).
41 (indicated by ), a first optical head lO and a second optical head 20 are mounted thereon, and movement of both optical heads is controlled by an external positioner drive signal PSDV applied to the VCM 41.

The first optical head 10 and the second optical head 20 are shown in FIG.
As shown in A), when the first light beam 112 of the first optical head 10 illuminates one track 31 of the optical disk 30, the second light beam 212 of the second optical head 20 illuminates other tracks on the same track 31. It is mounted on the positioner 40 in such a positional relationship that it illuminates the position.

Reference numeral 50 denotes a first track servo control unit, which generates a first track error signal W from the light reception signals from the first optical system 11 and the first Luns actuator 12 during normal read/write.
TES and a first track position signal WTPS are generated, and from these signals, a first lens drive signal WLDV for controlling the movement of the first objective lens 111 is generated and supplied to the first lens actuator 12. Also, during seek control, track servo control is stopped to enable seek control.

60 is a second track servo control section, which is a normal glue-1
At the time of 7941, a second track error signal ETES and a second track position signal ETPS are created from the light reception signals from the second optical system 21 and the first lens actuator 22, and based on these signals, the movement of the second objective lens 211 is determined. A second lens drive signal ELDV for controlling is generated and supplied to the first lens actuator 22. Also, during seek control, track servo control is stopped to enable seek control.

Note that the first focus servo control section 11 shown in FIG.
Since the zero and second focus servo control units 120 have no direct relation to the present invention, their illustrations and descriptions are omitted.

70 is a first positioner drive signal generation unit, which generates a positioner drive signal for driving the positioner 40 based on the relative speed between the positioner 40 and the track 31, which is determined from the relative speed between the first optical head 10 and the track 31, during seek control. A first positioner drive signal WPDV for PSDV creation is created.

Reference numeral 80 denotes a second positioner drive signal generation unit, which generates a second positioner drive signal for generating a positioner drive signal PSDV from the relative speed between the positioner 40 and the track 31, which is determined from the relative speed between the second optical head 20 and the track 31, during seek control. Create a 2-position drive signal EPDV.

Reference numeral 90 denotes a positioner drive signal creation unit, which creates a positioner drive signal PSDV for driving the positioner based on the first positioner drive signal WPDV and the second positioner drive signal EPDV.

Note that the first positioner drive signal generation section Ma0 and the second
When creating the first positioner drive signal WPDV and the second positioner drive signal EPDV, the positioner drive signal control unit 80 controls the first track servo control unit 6
In addition to the signals created by the zero and second track servo controllers 70, the light reception signals from the first optical head 10 and the second optical head 20 can be used to create the signals, as shown by broken lines in the figure.

[For production]

The operation of the present invention will be explained with reference to the seek operation waveform diagram in FIG.

When performing seek control, the first track servo control section 50
The second track servo control unit 60 stops track servo control and enables position control of each optical head.

In this state, the first positioner drive signal generation section 70 determines the relative speed between the first optical head 10 and the track of the optical disk 30. This relative speed is determined by the first track error signal WTE generated by the first track servo control section 50.
S or the light reception signal from the first lens actuator 12 (the specific calculation method will be explained in the example section). Since the first optical head 10 and the positioner 40 move together, the relative speed between the first optical head 10 and the track of the optical disk 30 matches the relative speed between the positioner 40 and the track.

Next, the first positioner drive signal generation section 70 further generates a positioner drive signal PSDV for driving the positioner 40 based on the relative speed between the positioner 40 and the track.
A first positioner drive signal WPDV is created (the specific creation method will be explained in the embodiment).

On the other hand, the second position drive signal regulation section 80
The relative speed between the optical head 20 and the track of the optical disk 30 is determined. This relative velocity is obtained using the second track error signal ETES generated by the second track servo control section 60 or the light reception signal from the second Luns actuator 12 (the specific calculation method will be explained in the example section). do).

Since the second optical head 20 and the positioner 40 move together, the second optical head 20 and the optical disc 30 move together.
The relative speed between the positioner 40 and the truck matches the relative speed between the positioner 40 and the truck.

The second positioner drive signal generation unit 80 further calculates the positioner 40 based on the relative speed between the positioner 40 and the track.
Create the second positioner drive signal EPDV for creating the positioner drive signal PSDV that drives the
The specific preparation method will be explained in Examples).

The positioner drive signal generation unit 90 generates a first positioner drive signal WPDV and a second positioner drive signal E.
A positioner drive signal PSD■ for driving the positioner 40 is created based on the PDV. This positioner drive signal PSDV includes, for example, a first positioner drive signal WPDV and a second positioner drive signal EPD.
It is the arithmetic mean of V.

Now, assuming that the first track error signal WTES on the first optical head IO side has a waveform as shown in (a) of FIG. The second track error signal ETES generated on the side is as shown in FIG. 2(c). Same figure (
In a) and (c), (a) shows the waveform when each optical head is traversing the track, and (0) shows the waveform when each optical head is traversing the preformat part. First track error signal WTES and second track error signal ET
In the ES, a phase shift occurs as shown in the figure, depending on the positional relationship between the first optical head 10 and the second optical head 20, so the waveforms of both of them while crossing the preformat portion do not occur at the same time.

Therefore, corresponding to the first track error signal WTES and the second track error signal ETES, the first positioner drive signal WPDV and the second positioner drive signal EPDV are set as shown in FIGS. 2(b) and (d), respectively.
), and an abnormal current is generated in the portion corresponding to each preformat. Note that each positioner drive signal indicates characteristics at the time of differential speed control.

However, by taking the arithmetic average of the first positioner drive signal WPDV and the second positioner drive signal EPDV, as shown in FIG. The overall characteristics can be made smooth.

Therefore, the positioner drive signal PSDV generated by the positioner drive signal generating section 90 becomes smooth as shown in FIG. 2(e), and the positioner 40 can be stably controlled.

As described above, the positioner drive drives the positioner 40 based on the relative speed between the positioner 40 and the track obtained on the first optical head 10 side and the relative speed between the positioner 40 and the track obtained on the second optical head 20 side. Since the signal PSDV is created, it is possible to reduce the influence of the preformat portion formed on the optical disc 30, stabilize seek control, and enable high-speed seek control.

〔Example〕

Embodiments of the present invention will be described with reference to FIGS. 2 to 4. FIG. 3 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 4 is a flowchart of a seek operation of the embodiment. The seek operation waveform diagram in FIG. 2 has already been described.

(8) Configuration of the embodiment In FIG. 3, the first optical head 10, the first optical system 11
, first objective lens 111, first light beam 112, first lens actuator 2, second optical head 20, second optical system 21, second objective lens 211, second light beam 212,
First lens actuator 22, position goner 40, VC
M41, the first track servo control section 50, the second track servo control section 60, the first positioner drive signal generation section 70, the second positioner drive signal regulation section 80, and the positioner drive signal generation section 90 are as follows. This is as explained in Figure 1.

In the first track servo control unit 50, 51 is a first servo signal generation circuit, which instructs the tracking error of the first light beam with respect to a predetermined track center based on the light reception signal sent from the first optical system 11. Create an error signal WTES.

Reference numeral 52 denotes a first track servo drive circuit, which amplifies the power of a signal obtained by performing high frequency phase compensation (to stabilize the save lube) on the first track error signal WTES to generate a first run drive signal WLDV.

In the second track servo control unit 60, 61 is a second servo signal generation circuit, which instructs the tracking error of the second light beam with respect to a predetermined track center based on the light reception signal sent from the second optical system 21. Create error signal ETES.

A second track servo drive circuit 62 generates a second lens drive signal ELDV by power amplifying a signal obtained by high-frequency phase compensation (for stabilizing the save loop) of the second track error signal ETES.

In the first positioner drive signal control section 70, 71
is a comparator, and 72 is a first track counter (hereinafter referred to as the first TC).
73 is a first microprocessor (hereinafter referred to as 1MPU), and 74 is a D/A converter.

The comparator 71 receives the first signal from the first servo signal control circuit 51.
The track error signal WTES is compared with the zero potential point to generate a first zero cross signal WTZC indicating the zero cross point of the first track error signal WTES, and the first TCN
T72 and the first MPU73.

The first track counter 72 is loaded with a seek difference measurement and receives the first zero cross signal W from the comparator 71.
Every time TZC is input, it is discounted from the seek deflection scale, and the remaining seek deflection amount is output and sent to the first MPU 73.

The first MPU 73 receives the first zero cross signal WTZC and the first TCNT 72 from the comparator 71, calculates the relative speed between the first optical head 10 and the track, that is, the actual speed of the first optical head 10, and calculates the error between the target speed and the actual speed. Processes such as speed calculation and generation of a positive or negative accelerating current signal corresponding to this error speed are performed.

The D/A converter 74 converts the digital acceleration current signal input from the first MPU 73 into an analog acceleration current signal, that is, the first positioner drive signal WPDV.

In the second positioner drive signal generation section 80, 81
is a comparator, and 82 is a first track counter (hereinafter referred to as 27C).
83 is a second microprocessor (hereinafter referred to as second MPU), and 84 is a D/A converter.

The comparator 81 receives the second signal from the second servo signal generation circuit 61.
The track error signal ETES is compared with the zero potential point to generate a second zero-cross signal ETZC indicating the zero-cross point of the second track error signal ETES, and the second TCN
It is supplied to T82 and second MPU83.

The second track counter 82 is loaded with a seek difference measurement and receives the second zero cross signal E from the comparator 81.
Every time TZC is input, it is discounted from the seek deflection scale, and the remaining seek deflection amount is output and sent to the second MPU 83.

The second MPU 83 receives the second zero cross signal ETZC and the second TCNT 82 from the comparator 81, calculates the relative speed between the second optical head 20 and the track, that is, the actual speed of the second optical head 20, and calculates the error between the target speed and the actual speed. Processes such as speed calculation and generation of a positive or negative accelerating current signal corresponding to this error speed are performed.

The D/A converter 84 converts the digital acceleration current signal input from the second MPU 83 into an analog acceleration current signal, that is, the second positioner drive signal EPDV.

The positioner drive signal generation section 90 has an adder 91 inside.
and a power amplifier 92, the first positioner drive signal WP from the first positioner drive signal generation section 70
A positioner drive signal PSDV is generated based on DV and the second positioner drive signal EPDV from the second positioner drive signal generator 80. In this embodiment, the adder 91 generates the first positioner drive signal WP.
The DV and the second positioner drive signal EPDV are arithmetic averaged, and the power is amplified by the power amplifier 92 to generate the positioner drive signal PSDV, which is supplied to the VCM 41 of the positioner 40.

(B) Operation of the Embodiment The operation of the embodiment will be explained according to its operational steps with reference to the seek operation flowchart of FIG.

■ Step SI At the start of seek, the first MPU is
73 and the second MPU 83 to determine the seek difference, that is, the number of tracks to seek.

The first MPU 73 and the second MPU 83 store and hold the instructed seek difference 'WkD in a memory (not shown), and the first TCNT 72 and the second TCN
Load each into T82.

Note that inside the first MPU 73 and the second MPU 83,
A ROM (
A ROM (hereinafter referred to as a ROM) that specifies and stores the correspondence between the optical head error speed (error between the target speed and the actual speed) and the acceleration current signal in a table format (hereinafter referred to as a target speed table)
(neither is shown in the figure).

When seek control is started, each optical head 10 and 20
Each time the track is traversed at high speed, the first servo signal generating circuit 51 and the second servo signal generating circuit 62 generate a first track error signal W'TES and a second track error signal ETES, 1 track error signal WTE
The signal S is supplied to the first track servo drive circuit 52 and the comparator 71, and the second track error signal ETES is supplied to the second track servo drive circuit 62 and the comparator 81.

During a seek, track servo control of both the first track servo drive circuit 52 and the second track servo drive circuit 62 is stopped so that the seek operation is not hindered.

(2) Step St, Step S3 The first MPU 73 and second MPU 83 sample the count values of the first TCNT 73 and second TCNT 82 at a constant period T (step S2), and obtain the count values B1 and Bt (step S3). Here, the sampling frequency of each TCNT is about 10 times the band of the positioner 40, which is about 300 times the band of the positioner 40.
Assuming H2, the sampling frequency is selected to be approximately 3KZ.

(2) Step S4 At the first T, CNT 73, the count value B is equal to the remaining seek deviation amount after l sampling periods. Further, if the difference between D and 81 is VI, then this Vl is the first zero cross signal W input within the sampling time T.
Indicates the number of TZCs, that is, the number of tracks decreased within the sampling time T. Note that the interval W between each track is constant, (D-B,) W/T=VI W/T! :
l: The actual speed of the first optical head 10 is calculated.

Similarly, in the second TCNT 83, the difference between D and 82 is set to V
, then the actual speed of the first optical head 10 is calculated by (D Bz )W/T=VzW/T. As can be seen from these speed calculation formulas, Vl and V2 are proportional to the actual speeds of the optical heads 10 and 20.

■ Step Ss The first MPU 73 and the second MPU 83 each optical head 1
Determine whether the speeds 0 and 20 have become zero. This determination is made when the first zero-cross signal WTZC and second zero-cross signal ETZC generated by each comparator 71 and 81 are not detected within a predetermined period. Before the end of the seek, the first zero-crossing signal WTZC and the second zero-crossing signal ETZC are naturally detected within a predetermined period, so it is determined that the actual speed of each optical head 10 and 20 is not zero.

■ Step S6 The first MPU 73 and the second MPU 83
2 and the sampling count number B of the second TCNT82,
and B2, that is, the target speed corresponding to the remaining seek deviation amount, are determined by referring to each target speed table.

■ The 1st MPU 73 and the 2nd MPU 83 of ST 913 calculate the error between the actual speed of each optical head IO and 20 found in step S4 and the target speed corresponding to the remaining seek deviation amount B+ and B2 found in step S. That is, the error velocity (
VE, and in degrees VEz).

■ Step S8, Step S9 The first MPU 73 and the second MPU 83 calculate the error velocity VE of each optical head 10 and 20 obtained in step S,
The accelerating current signal values corresponding to degrees VE2 and VE2 are obtained by referring to the respective accelerating current tables (step S), and the D/A converters 74 and 8 are used as digital accelerating current signals.
4 (step S9).

■ Step SIO The first MPU 73 and the second MPU 83 are connected to the first TCNT 7
2 and the second TCNT82, and when the above processing is completed, the first TCNT72
And the seek deviation scales loaded in the second TCNT 82 are updated to the sampling count values B and B2, respectively.

Thereafter, the process returns to step S2, and the processes from step 32 to step 5l11 described above are repeated.

(2) On the other hand, the D/A converters 74 and 84 are connected to the first MPU 73 and the second MPU 8 in the process of step S described above.
The adder 9 of the positioner drive signal generation section 90 converts each digital acceleration current signal input from 3 into analog acceleration current signals, that is, the first positioner drive signal WPDV and the second positioner drive signal EPDV.
Send to 1.

Adder 91 arithmetic averages the first positioner drive signal WPDV from D/A converter 74 and the second positioner drive signal EPDV from D/A converter 84 , and sends the average to power amplifier 92 . 1st positioner drive signal WPD
V and the second positioner drive signal EPDV, the first positioner drive signal WPDV and the second positioner drive signal
The abnormal current portion (see FIG. 2) and FIG. 2(d) occurring in the positioner drive signal EPDV is smoothed as shown in FIG. 2(e).

The power amplifier 92 generates a positioner drive signal PSDV by power amplifying the arithmetic mean of each manually inputted positioner drive signal W, and supplies the positioner drive signal PSDV to the VCM 41 of the positioner 40 . As a result, stable seek control is performed in accordance with the predetermined target speed characteristics.

■ Step Ss When it is detected that the aforementioned steps 82 to 310 are repeated and the speeds of both optical heads IO and 20 have become zero, that is, that the track is on the target track, the seek control ends. do. Both optical heads 10
The fact that the speeds of
The determination is made when ZC and the second zero-crossing signal ETZC are not detected within a predetermined period.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications can be made in accordance with the gist of the present invention.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects can be obtained.

(1) Positioner 40 obtained on the first optical head IO side
a positioner drive signal P that drives the positioner 40 based on the relative speed of the track and the positioner 40 obtained on the second optical radar 20 side;
Since the SDV is created, the influence of the preformat portion formed on the optical disc 30 can be reduced and seek control can be stabilized.

(2) This enables high-speed position control.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the basic configuration of the present invention, FIG. 2 is a seek operation waveform diagram of the present invention, FIG. 3 is an explanatory diagram of the configuration of an embodiment of the present invention, and FIG. 4 is a seek operation of the same embodiment. Flowchart, FIG. 5 is an explanatory diagram of a conventional erase/write optical disk device, FIG. 6 is an explanatory diagram of a positioner equipped with an erase/write optical head and its track-on state, FIG. 7 is an explanatory diagram of a sector format, and FIG. FIG. 8 is a seek operation waveform diagram of a conventional erase/write optical disk device. 1 and 3, 10...first optical head, 11...first optical system, 1
DESCRIPTION OF SYMBOLS 11... 1st objective lens, 112... 1st light beam, 12... 1st lens actuator, 20... 2nd optical head, 21... 2nd optical system, 211... 1st 2 objective lens, 212...second light beam, 22...
First lens actuator, 40...positioner, 4
1... VCM, 50... First track servo control section, 60-... Second track servo control section, 70...
1st positioner drive signal generation section, 80... 2nd positioner drive signal regulation section, 90... Positioner drive signal generation section. (a) (a) (b) (b) Fig. Seek operation waveform diagram of the present invention Fig. Seek operation flowchart of the embodiment

Claims (1)

[Scope of Claims] A first optical head (10) including a first lens actuator (12) that controls the movement of a first light beam (112) projected onto a track (31) of an optical disk (30);
a first track servo control section (50) that controls the position of the first lens actuator so that the first light beam (112) is located at the center of a predetermined track;
);
A second lens actuator (22) that controls the position of the second lens actuator (22) so that the light beam (212) is centered on a predetermined track.
Track servo control section (60) and both optical heads (10)
, 20) in a predetermined positional relationship.
(a) During seek control, a positioner (40) determined from the relative speed between the first optical head (10) and the track (31);
) and the truck (31), the positioner (
40) positioner drive signal PSDV that drives
(b) A first positioner drive signal generator (70) that generates a first positioner drive signal WPDV for generation; The desired positioner (40
) and the track (31), a second positioner drive signal generation unit (80) generates a second positioner drive signal EPDV for generating the positioner drive signal PSDV; (c) a first positioner An optical disc device comprising: a positioner drive signal creation section (90) that creates a positioner drive signal PSDV for driving a positioner based on a drive signal WPDV and a second positioner drive signal EPDV.