JPH0373423A - Optical storage device and method for measuring relative position movement driving amount of second beam - Google Patents

Abstract

PURPOSE:To remove the generation of shift between a main beam and a subbeam at the time of accessing a track by executing track access and test seaking by the main beam and finding out the initial value of a servo necessary for the track movement of the sub-beam during the operation of the device. CONSTITUTION:The 1st beam photodetector 21 receives light from an optical disk 1 of the 1st beam to obtain the 1st photodetecting signal and the 2nd beam photodetector 22 receives light from an optical storage medium 1 of the 2nd beam to obtain the 2nd photodetecting signal. Driving information obtained when the 2nd beam moves on a track is found out by the 2nd beam movement driving amount measuring means 500. Since the 2nd beam is moved on the track based upon the driving information, the 1st and 2nd beams can access the same track.

Description

[Detailed description of the invention] [Table of contents] Overview Industrial field of application Conventional technology (Figs. 11 and 12) Means for solving the ffJ problem that the invention aims to solve (Fig. 1) Working examples (a) Explanation of the configuration of one embodiment (Fig. 2, Fig. 3, Fig. 4, Fig. 5) Φ) Description of the operation of one embodiment (Fig. 6, Fig. 7, Fig. 8, Fig. 5) (Figure 9) (C) Other embodiments (Figure 10) Effects [Summary] Regarding an optical storage device equipped with an optical storage medium and an optical head that irradiates a plurality of beams from one objective lens to the optical storage medium. , a second beam receiving device for the purpose of accessing the same track with the plurality of beams at the time of track access, receiving a second beam of the plurality of beams from the optical storage medium L7 to obtain a light reception signal; a second beam moving means for moving the position of the second beam; and a second beam moving means for moving the second beam, and moving the second beam by the second beam moving means.
Determining the position of the second beam on the optical storage medium based on the light reception signal obtained by the beam receiver, determining the track movement amount of the second beam from the position, and determining the driving amount of the second beam moving means with respect to the movement amount. An optical storage device comprising two beam movement drive amount measuring means.

[Industrial application field]

In an optical storage device such as an optical disk device, the present invention allows a plurality of beams to pass through an objective lens of an optical head, and for example, a light beam and a read beam are used to write data to a certain track by the light beam. , relates to an optical storage device characterized in that information written by the light beam is read by a read beam located behind the light beam in the disk rotation direction.

[Conventional technology]

Conventionally, verify reading has been performed in optical disk devices. The verify read is to read the data written on the optical disc after writing and to compare the written data with the read data to ensure the reliability of the optical disc device.

Conventionally, one beam is irradiated onto an optical disk from an objective lens, and the one beam is used for both writing and reading. That is, the beam performs writing in one rotation of the optical disk, reads in the next rotation,
Compare the written data and read data.

However, with the device that performs the verify read described above, when writing data, the optical disk must be rotated twice.
It takes time.

Therefore, in recent years, a plurality of beams are passed through the objective lens of an optical head. A technology has emerged that simultaneously performs data writing and verify reading by reading information written by the light beam using a linear beam, thereby shortening the data writing time of an optical disk device.

FIG. 11 is an explanatory diagram of the prior art.

As shown in FIG. 11, in the optical disk device, an optical head 2 is moved and positioned by a head drive motor 9001 in the radial direction of the optical disk 1 with respect to an optical disk 1 which is rotated around a rotation axis by a motor 1a. Reading (reproduction) and writing (recording) to the optical disk 1 are performed by the following.

A light beam and a read beam are simultaneously incident on the optical disk 1 from one objective lens 10.

Now, in FIG. 11, the light beam is generated by reflecting the light emitted from the semiconductor laser 91 that is the light source by the dichroic mirror 99, guiding it to the objective lens 10 via the polarizing beam splitter 12° 1/4λ plate 1001, and beaming from the objective lens 10. The light is narrowed down to a spot 101 and irradiated onto the optical disc 1, and the reflected light from the optical disc 1 is passed through the objective lens 10 and the 1/4λ plate 10.
The beam is configured such that it enters the polarizing beam splitter 12 via the polarizing beam splitter 01, and enters the 4-split light receiver 96 via the lens 8.

The read beam has a different wavelength from the light beam. The polarized beam emitted from the semiconductor laser 92 passes through the lens 9 and then passes through the polarizing beam splitter 12.1/4.
It is reflected by the dichroic mirror 93 via the λ plate 1002, and is further reflected by the 1/4 λ plate 1002. Polarizing beam splitter 12. 1/4λ plate 1001. The beam is narrowed down to a beam spot 102 through the objective lens 10 and irradiated onto the optical disk 1. After that, 1/4λ plate 1001. The dichroic also passes through the polarizing beam splitter 12 and the optical receiver 99, and enters the light receiver 100. The dichroic mirrors 93 and 99 have the property of reflecting light of a certain wavelength and transmitting light of a certain wavelength. In this case, the dichroic mirror 93 reflects the light beam and transmits the light beam. Further, the dichroic mirror 99 reflects the light beam and transmits the read beam.

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 i causes the beam to be distorted. Misalignment occurs in the spot position, and it is necessary for the beam spot of 1 micron or less to follow these positional misalignments.

For this purpose, there is a focus actuator (focus coil) 94 that moves the objective lens 10 of the optical head 2 downward in the L direction in the figure to change the focal position, and a track actuator (track coil) that changes the objective lens to the left or right in the figure.
95 are provided.

Correspondingly, a focus error signal FES is generated from the light reception signal of the light receiver 96, a track error signal TBS is generated from the light reception signal of the focus servo control section 400 and the light receiver 96, and the track actuator 95 A track servo control section 3 is provided to drive the track servo control section 3.

Track servo system? 213 utilizes a change in the amount of reflected light due to a diffraction phenomenon of a beam spot due to a spiral guide groove (track) provided in advance on the optical disk 1, for example.

That is, the track error signal (TBS signal) of the beam spot relative to the track is obtained by utilizing the fact that the distribution of the amount of reflected light on the light receiver 96 changes due to the diffraction of light by the track depending on the position of the beam spot relative to the track. be.

This TBS signal is obtained by receiving the reflected light amount of the light beam with the light receiver 96, and the actuator 95
control.

Also, similarly to the light beam, a two-split light receiver 100
, the lead beam is received, and the T of the lead beam is
Create an ES signal. The galvano mirror 93 is rotatable around a shaft 931, and the galvano mirror 93
The galvano servo control section 4 controls the track position of the lead beam by controlling the position of the galvano mirror 93 based on the galvano position signal (GPS) obtained from the galvano position signal (GPS).

Now, when accessing a certain track of the optical disk 1, conventionally, an RF multiplied signal is generated from the four-division light receiving 2S96 that receives the light beam, and the track address where the current light beam is located is read from the signal.

The track address is preformatted in advance when the optical disc 1 is manufactured.

The track access control unit 900 detects the difference between the read track address and the track address specified by the host device to be accessed, and while reading the RF multiplied signal from the light beam, the head drive motor 9
001 (voice coil motor) moves the optical head 2 and stops when it reaches the target track address. At this time, since the optical head 2 also moves, at the same time, the read beam should similarly access the same track position as the write beam. However, since the relationship between the track position of the light beam and the track position of the read beam differs between the inner side and the outer side of the optical disc, some kind of correction is required. FIG. 12 is an explanatory diagram of the correction.

711, 712, and 713 are concentric circles centered on the center O of the optical disk 1. It is assumed that the objective lens 10 of the optical head 2 moves on a dotted line 720. The access operation is performed by moving the objective lens 10 located on the optical head 2 on the dotted line 720 using the drive motor 9001.

Now, the light beam and lead beam are connected to the concentric circle 71.
It must be located on the tangent to the circles 711, 712, 713 at the intersection of 1,712, 713 and the dotted line 720.

FIG. 12 (b), (C), and (d) show the intersection 701,
This is an ideal positional relationship between the light beam W and the read beam R at 702 degrees and 703 degrees.

In other words, the distance between the read beam and the light beam is y, and the perpendicular line to the dotted line 720 at the intersections 701, 702, and 703,
The angle of the tangents at the intersections 701, 702, and 703 is defined as θ1. θ, 2 θ, the light beam and read beam are y*tanθI, y*tan in the track direction.
θ wealth, y*tan θ, if it is not shifted, there is no warning.

The objective lens 10 of the optical head 2 is moving on the dotted line 720. The objective lens 10 is on the dotted line 730, that is,
If the optical disk 1 moves on a line passing through the center point of the optical disk 1, the above problem will not occur.

In other words, if the objective lens moves on the dotted line 730, the tangent line will always be perpendicular to the dotted line 730, and the read beam and light beam need only be on the perpendicular line, so the angle at the tangent line will not change. .

However, in recent years, a technique has appeared in which a plurality of objective lenses are provided, and an objective lens for irradiating the optical disk 1 with an erase beam is installed.

Therefore, it is not possible to move all the objective lenses on a line that passes through the center point of the optical disk 1. Therefore, it is necessary to move the objective lenses on a line that deviates from the center point.

Correction of the track position during track access of the lead beam is performed by a lead beam track access control unit (first
Figure 1 1000) is carried out.

The distance between the read beam and the light beam is y, and the intersection point 701.
The angle formed by the perpendicular line to the dotted line 720 at points 702 and 703 and the tangent line at the intersections 701, 702 and 703 is defined as θ3.
Assuming θo, θ, the write beam and read beam are y*tanθ+, 3'*ta in the track direction as mentioned above.
The positions must be shifted by nθ,,y*Lanθ.

In other words, the distance between the read beam and the light beam is y, and the dotted line 720, which is the trajectory of the objective lens, and the optical disk 1
The distance from the center 0 of the circle is X, the distance between the concentric circle and the center O is
, D, , D, the positions 701, 702, 70
3, respectively, y*tanθ+ = X*y/D
Iy*tanθx=X*y/Dz y*tanθx=X*y/I) 1. The read beam will not work if there is no deviation from the light beam.

The operation of the lead beam track access control section 1000 will be described below.

The track access control unit 900 notifies the read beam track access control unit 1000 that the read beam will access the track access control unit 900 . At this time, the lead beam track access control unit 1000 obtains the track address to be accessed.

Next, the lead beam track access control section 1ooo
The galvano servo control unit 51 controls the position of the galvano mirror 93 based on the galvano position signal obtained from the galvano mirror 93 and the TBS signal obtained from the lead signal. Stop the servo by TBS signal.

Next, the distance is calculated from the track address of the access destination. In other words, in 701 of FIG. 8(a), DI,
In 702, the beam is calculated, and in 703, the beam is calculated. Calculate the track deviation caused by access. The deviation is as follows: y*tanθr −X*y/D Hy*tan
θt=X*y/Dly*tanθs−X*y/D2 Said X")'/D+, X*y/Dz, X*y/
Ds is multiplied by a predetermined constant value C to obtain A=C*X*Y/D.

Next, a current corresponding to the above A is applied to the galvano servo control section 4.
Output to.

A current is applied to the galvanomirror actuator according to the position where the lead beam should be positioned, and the lead beam shifts from the position corresponding to the track jump start address to the position shown in FIGS. 12(b), (c), and (d). become a state.

Thereafter, when the light beam accesses the target track, servo is again performed using the TES signal obtained from the two-split photoreceiver 22 that receives the read beam to control the track position.

[Problem to be solved by the invention]

In the prior art, the track position was controlled by the voltage added to the carbanolock loop.

The lead beam track access control unit 1000 had memorized how much the actual track position would move if the voltage was changed at this time. In other words, the constant C was memorized. However, since this constant C changes depending on the sensitivity of the galvanometer sensor and the galvano-lock loop gain, it needs to be adjusted at the time of shipment from the factory.

Moreover, this value may deviate from the adjusted value at the time of shipment because the sensitivity of the galvanophysical sensor and the characteristics of the lens in the optical head change due to temperature changes.

Therefore, an object of the present invention is to provide an apparatus and a method that are capable of controlling the access of the sub-beam during track access even when the temperature and sensor sensitivity change.

[Means to solve the problem]

FIG. 1 is a diagram explaining the principle of the present invention. FIG. 1 shows an optical storage device equipped with an optical storage medium 1 (optical disk) and an optical head 2 that irradiates a plurality of beams onto the optical storage medium 1 from one objective lens.

The first beam receiver 21 receives the first beam of light from the optical disk t and obtains a first light reception signal.

Further, the second beam receiving section 22 receives the second beam of light from the optical storage medium 1 to obtain a second light reception signal.

The optical head track access control section 900 determines the track address of the optical disk drive from the first light reception signal, moves the optical head 2 to the designated track address, and positions the first beam at the track position.

The second beam moving means 4 controls the track position of the second beam based on the second light reception signal.

The second beam movement driving amount measuring means 500 moves the track position of the second beam by the second beam track moving means 4, and determines the track movement based on the light reception signal obtained from the second beam receiver 22. Then, the amount of drive of the second beam track position control unit according to the track moving bone is determined.

[Effect]

In the present invention, drive information when the second beam moves on a track is obtained by the second beam movement drive amount measuring means 500. When moving the second beam during track movement, it is moved based on the drive information, so the first beam is moved based on the drive information.
This makes it possible for the second beam and the second beam to access the same track.

〔Example〕

(a) Explanation of the configuration of one embodiment FIG. 2 is a block diagram of one embodiment of the present invention, and FIG. 3 is a block diagram of one embodiment of the present invention.
FIG. 4 is an explanatory diagram of the position sensor of the actuator in FIG. 3, and FIG. 5 is a diagram of the galvanometer mirror in FIG. 3.

First, the configuration of the optical head will be explained using FIG. 3. In FIG. 3, the semiconductor laser 24 is a light beam and outputs a beam with a wavelength of 830n+w. The light from the semiconductor laser 24 is collimated by a collimator lens 203 and reflected by a dichroic mirror 201. ,
Polarizing beam splitter 28. Passes through 1/4λ plate 27,
The beam is narrowed down to a beam spot 252 on the optical disk 25 by the objective lens 26 . The reflected light from the optical disk 25 enters an objective lens 26, a polarizing beam splitter 28, and a 1/4λ plate 2000. The light passes through a galvanometer mirror 29 and enters a four-part light receiver 21 .

On the other hand, the semiconductor laser 23 outputs a beam with a wavelength of 780 rv. The beam is a lead beam, and the light from the semiconductor laser 23 is made into parallel light by a collimator lens 202, and is incident on a polarizing beam splitter 28, and the beam is 1/4λ.
After passing through the plate 2000 and being reflected by the galvanometer mirror 29, the 1/4λ plate 2000. Polarizing beam splitter 2
It enters the sun, passes through the 1/4λ plate 27, and passes through the optical disk 25.
The beam is narrowed down to a beam spot 251 above. The reflected light from the optical disk 25 passes through the objective lens 26.1/41 plate 27
．． The light enters the polarizing beam splitter 28 , passes through the dichroic mirror 201 , and enters the two-split light receiver 22 .

The above 201.29 is composed of a dichroic circuit. The dichroic ink beam has a property of reflecting a certain wavelength and transmitting a certain wavelength, and the dichroic mirror 201 passes a wavelength of 780 nm and reflects a wavelength of 830 nm. Also, the guichroic mirror 29 is 83
Passes 0 nm wavelength and reflects 780 open wavelength.

The objective lens 26 is provided at one end of the actuator body 204 which is rotatable around the rotation axis 205, and a fixing slit 207 is provided at the other end.

The actuator body 204 is provided with a coil section 211, and a focus coil 208 is provided around the coil section 211.
However, a spiral track coil 210 is provided on the side surface, and a magnet 209 is provided around the coil portion 211.

Therefore, when current is applied to the focus coil 208, the actuator 204 equipped with the objective lens 26 moves up or down in the X-axis direction in the figure, similar to the voice coil motor, thereby changing the focus position, and the track coil When a current is applied to the actuator 210, the actuator 204 rotates in the α direction about the rotating shaft 205, thereby changing the position in the track direction.

A light emitting section 206 that constitutes a position sensor is connected to a fixed slit 207 provided at the end of the actuator 204.
．． A light receiver 212 is provided, as shown in FIG. 4(a), (
As shown in b), the light emitting section 206 and the four-part light receiver 212a
212d are provided so as to face each other with the fixed slit 207 interposed therebetween.

The fixed slit 207 is provided with a window W, and the light from the issuing unit 206 passes through the window W to the four-split light receivers 212a to 2.
The light is received at 12d.

For this reason, as shown in FIG. 4), the actuator 204
4-divided light receiver 212a~ according to the movement amount in the α and X directions.
The light reception distribution of 212d changes.

Therefore, the outputs A and B of the light receivers 212a to 212d.

From C and D, the position signal FPS of the track direction position signal TPS1 and focus signal is obtained for the next birch.

TPS-(A+C)-(B+D) FPS-(A+B)-(C+D) These positive signals TPS and FPS have S which becomes zero at the center position with respect to the deviation from the center position, as shown in Fig. 4 rb>. This becomes a square-shaped signal, and this signal can be used to apply an electrical spring force in the direction of the center position.

Also (see FIG. 3), the galvanometer mirror 29 rotates on the drawing plane around the shaft 220. The galvano mirror 29 is provided with a galvano position sensor 222. As shown in FIG. 5(a), the galvanometer mirror 29 has
A galvano main coil section 51 is provided, and a lead beam track coil 501 is provided. A magnet 52 is provided around the coil portion 51 . By passing a current through the coil 501, the galvano mirror 29
rotates about axis 220.

The galvano position sensor 222 consists of a light emitting part 55, a slit 56, and a two-split light receiver 57, and includes a galvano mirror.
For the fixed slit 56 provided at the end of 29,
A light emitting section 55 and a two-part light receiver 57 are provided, and a fifth
As shown in FIG.
, 57b are provided on the birch facing each other through the fixed slit 56.

The fixed slit 56 is provided with a window W (FIG. 5(C)), and the light from the issuing section 55 is received by the two-split light receivers 57a and 57b through the window W.

Therefore, as shown in FIGS. 5(C), (e), and (d), the light receiving distribution of the two-split light receivers 57a and 57b changes depending on the amount of movement of the galvano mirror 29 about the axis 220. Therefore, the output A of the light receivers 57a and 57b.

From B, the position signal GPS in the track direction is determined to the next birch.

GPS-A-B This position signal GPS becomes an S-shaped signal that becomes zero at the center position with respect to the deviation from the center position as shown in Fig. 4 Q)), and this signal is used to determine the center position. Electrical spring force can be applied in the positional direction.

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

5 is an operation control unit, which is a microprocessor (hereinafter referred to as M
(abbreviated as PU), and controls the toruck servo section 3 and the sub-beam servo section 4. In the MPU 5, a test seek program 5OO is activated.

7 is a head circuit section, which includes an RF generating circuit 30 that generates an RF signal RFS from the light beam 4-split receiver 21, amplifies the outputs A to D of the 4-split receiver 21, and generates a servo output 5VA-3VD. From the output amplifier 317 to output, the output of the 4-split photo receiver 212a to 212d of the position sensor, the TPS signal generation 302 that creates the track position signal TPS, and the output of the 2-split photo receiver 57 of the galvano position sensor 222. , a CP interrogation circuit 310 that creates a GPS signal, amplifies the outputs RA and RB of the lead beam split receiver 22, and outputs servo outputs 5VRA and 5VRB.
an amplifier 317 that outputs an RF signal (RFS) from the output RA and RB signals of the two-split optical receiver 22;
It has an F production path 320, etc.

The RF generating circuit 30 generates an RF signal (RFS) from the 4-split optical receiver 21. Said signal is used to read the pre-formatted track address on the optical disc. Further, the RFS created from the outputs RA and RB of the two-split photoreceiver 22 is used for reading data.

32 of the track servo section 3 is a TES (rack error signal) generation circuit, and the servo output 5 of the amplifier 31
A track error signal TBS is created from VA-3VD. 33 is a total signal generation circuit, which has an output of 5VA-
3VD is added to create the total signal DO3 which is the total reflection level, 32 is A G C (AUTOMATrC
GAIN C0NTR0L) circuit, which divides the track error signal TES by the total signal (total reflection level) DSC,
It performs AGC using the total reflection level as a reference value,
36 is a phase compensation circuit that corrects fluctuations in the irradiation beam intensity and reflectance, and differentiates the gain-applied track error signal TES, adds it to the proportional part of the track error signal TES, and advances the phase. be. 35 is an off-track detection circuit, in which the track error signal TBS is set to a certain value V0 or more in the positive direction and a certain value - in the negative direction.
■. The off-track signal TO3 is output to the MPU 5 upon detecting that the off-track state has occurred.

37 is a servo switch which is closed by the servo-on signal SVS of the MPU 5, closes the servo loop, opens by turning off, and opens the servo loop; 39 is a return signal generation circuit, which connects the TP production path 302 to the servo loop shown in FIG. ) to generate a return signal RPS that generates a return force in the track direction toward the center position of the actuator 210.

301 is a lock-on switch, which closes when the lock-on signal LKS of the MPU is turned on, and sends a return signal R to the servo loop.
38 is a power amplifier that amplifies the output of the return signal generation circuit 39 and provides the track drive current TDV to the track actuator 210. It is something.

318 of the sub-beam track servo unit 4 is a TBS (track error signal) generation circuit, which generates a track error signal TB from the servo outputs 5VRA and 5VRB of the amplifier 317.
Create S. 316 is an integrator that integrates the TBS signal. 315 is an A/D (analog/digital) converter which digitizes and outputs the analog output of the integrator 315 and inputs it to the MPU 5. The integrator 316 is
It is reset by the reset signal of MPU5.

After the MPU 5 performs a predetermined calculation on the digital input,
Output to D/A (digital/analog) converter 3I4.

312 is a phase compensation circuit, which differentiates the GPS signal output from the galvano position signal generation circuit 310,
In addition to the proportional portion of the GPS, the phase is advanced. 313 is a power amplifier, and the phase compensation circuit 31
2 output is amplified and the read beam track coil 501
It is given to 311 is an adder, and the MP
The output of U5 is added to the GPS signal. 330
is an A/D converter which digitally converts the output from the TES signal generation 318 and inputs it to the MPU 5.

57 above. 310. 312. 313. A servo loop 501 electrically locks the galvano mirror 29 and controls the position of the galvano mirror 29.

Figure 6 is a processing flowchart of one embodiment, Figure 7 is a graph for explaining an example of operation, Figure 8 is a flowchart for beam access, and Figure 9 is a flowchart for explaining the operation of one embodiment. FIG. 7 is an explanatory diagram of track servo of the read beam when the read beam is not accessed by light reception.

Now, the light beam from the semiconductor laser 24 is reflected off the optical disk 1 and then enters the four-division light receiver 21 . The amplifier 31 amplifies the signal 5VA-3VD, inputs it to the TES signal generation circuit 32 of the track servo section 3, and outputs the signal 5VA-3VD.
-Create a track error signal TBS from 3VD. The total signal creation circuit 33 adds the servo outputs 5VA-3VD to create a total signal DSC which is a total reflection level.Next, the AGC circuit 32 divides the track error signal TES by the 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. The phase compensation circuit 36 differentiates the gain-applied track error signal TBS and adds it to the proportional component of the track error signal TBS.The servo switch 37 is normally on, and the power amplifier 38 amplifies the signal. The output of the power amplifier is input to a track actuator 210 to control the track position of the light beam.

Also, track servo control using the return signal RPS moves the optical head 2 to the head drive motor (voice coil motor) 9.
001 is used when accessing the target track.

While the optical head 2 is moving, the MPU 5 outputs a servo-on signal SvS.
remains off, and turns on the lock-on signal LKS. Therefore, a servo loop is not formed based on the track error signal TES, but the track actuator 210 is locked by the track position signal TPS based on the outputs A to D of the position sensors 212 a to 212 d. That is, the track coil 21 receives the return signal RP of the return signal generation circuit 39.
Driven by the power amplifier 3 by S, the track actuator 210 is controlled to return to the center position,
Fixed.

The reason why the track actuator 210, that is, the objective lens 26 is locked in this way is to prevent the actuator 210 from moving within the head due to vibration while the optical head 2 is moving, and to prevent damage. Electrical locking is performed by signal TPS.

Furthermore, the servo-on signal SV after the movement of the optical head 2 is completed.
When retracting the servo immediately after turning on S, leave the lock-on signal on and use the return signal RPS as shown in Figure 4 (
Track following is controlled by the track error signal TES while applying the return force to the center position in a).

Therefore, servo pull-in to the track of the eccentric optical disk 1 is performed at the point where the amount of movement is least 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 I beam is detected by the off-track detection circuit 35, a track-off signal T is output.
Send O3 to MPU5. MPU5 is servo switch 37
is turned off, the lock-on switch 301 is turned on, and control is performed to approach the target track.

The light beam track position correction control has been described above. The operations of the track servo unit 3 and MPU 5 are similar to conventional operations, and the track positions of the write beam and read beam are simultaneously moved according to the servo.

The optical head 2 performs correction control of the track positions of the light beam and the read beam, and also controls the track position of the read beam according to the track position of the light beam using a TES signal of the read beam.

Hereinafter, correction control of the track position of the lead beam will be explained.

Galvanometer mirror body sensor 5702 split light receiver 5
From the outputs A and B of the receivers 57a and 57b of 7, the GPS
GPS YoAB is requested by the Precepts 10. A phase compensation circuit 312 differentiates the GPS, adds it to the proportional component of the GPS, advances the phase, amplifies it with a power amplifier 313, and outputs it to the read beam track coil 501. The servo loops 57, 310, 312, 313, and 501 electrically lock the galvano mirror 29,
This is for controlling the position of the galvano mirror 29.

On the other hand, after a track error signal TBS is generated from the servo outputs 5VRA and 5VRB of an amplifier 317 using the output from the two-split photodetector 22 that receives the read signal, the signal is integrated by an integrator 316. The integration is performed to magnify the error and detect subtle deviations.

The flowchart in FIG. 9(a) will be referred to below.

Step 71 The MPU 5 resets the integrator 316 using a reset signal.

Step 72 Then, the timer 5a in the MPU 5 is activated.

Step 73 The timer 5a is counted up, and when the pre-stored time for the optical disk 1 to complete one revolution is reached, step 7
Proceed to step 4.

Step 74 Sample the integration result 0FTES. Integral result○FTE
That is, S is a value obtained by converting the value of the TBS signal integrated by the integrator 316 into a digital signal by the A/D converter 315.

Step 75 Multiply the 0FTES by a predetermined constant and set it as A.

Step 76 The value obtained by subtracting the above A from DAOUT, which is the previous output to the D/A converter 314, is set as DAOUT.

Step 77 The DAOUT is output to the D/A converter 314.

Now, the DAOUT output to the D/A converter 314
is converted into an analog signal and added to the output of the phase compensator 312 in an adder 311.

FIG. 6 shows the output value of the signal.

A TBS signal created from the output of the two-split photodetector 22 that has received the lead beam is output as shown in 701.

The TES signal 701 is integrated by an integrator 316, and the I
TES701). The ITES 702 is an MP
Each time the integrator 316 is reset by U5, O
become.

DAOUT 704 is output by the MPU 5, and outputs a value obtained by subtracting the integral value from the previous 0DAOUT.

The DAOUT is added to GPS in an adder 311,
The signal output to the phase compensation circuit 312 changes depending on the positional deviation of the read beam in the track direction. The phase compensation circuit 312 differentiates the signal, adds it to the proportional part of the signal, advances the phase, and outputs it to the power amplifier 313. The DAOUT generated by the TES signal from the adder 311 is converted into an analog signal by the D/A converter 3]4, and the addition of the analog-converted signals is performed every time the disk goes around.

Therefore, the track position of the light beam is corrected by the track servo unit 3 as in the conventional case, and at the same time, the track position of the read beam is corrected from the position of the galvanometer mirror and the TBS signal of the read beam every time the optical disk goes around. It's being done.

Next, the track access operation of this embodiment will be explained.

In this embodiment, a test seek of the lead beam is performed at intervals of several minutes when the device is started or by a timer, the amount of tracks actually moved by the output voltage of the D/A is stored in memory, and the value of the track to be moved is set in the D/A. /A converter 314.

DAOUT, that is, D/A converter 314, is shown in FIG.
By increasing the power to the lead beam, the lead beam becomes
) to move the track. At that time, the TBS signal obtained by the two-split optical receiver 22 changes as shown in FIG. 7(C). When moving from the center 7a of a track to the center 7b of the track next to said track, the TBS signal 70a
Move from to 70b. In other words, the value goes from zero to a positive value, then to a negative value, and then to zero again. Also, DAOUT moves from 71a to 71b. At this time,
The difference between 71b and 71a is the output value necessary for moving one track.

In other words, I) gradually increase the output of AOUT, and
71a and 71b are detected from the S signal, and the value of 71b - 71a is required for the lead beam to move by one track, resulting in AOtJT.

The above values will differ if the sensor sensitivity of the galvano position sensor 57 and the two-split light receiver 22, the refractive index of the objective lens, etc. change due to temperature changes, etc. This can be solved by doing this at regular intervals.

A higher level device (not shown) is a track access control unit 900.
Indicates the track address to be accessed. The track access control unit 900 operates the drive motor 9001 to access the address. Light beam access is as described in the prior art. The head drive motor 90 is driven by the RF signal obtained from the light beam.
01 moves the optical radar 2 and the light beam accesses any track. Further, as described above, 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 track actuator 210 is locked by the track position signal TPS based on the outputs A to D of the position sensors 212a to 212d. That is, the track coil 21 is driven by the power amplifier 38 in response to the return signal RPS from the return signal generation circuit 39, and the track actuator 210 is controlled to return to the center position and is fixed.

Hereinafter, with reference to FIGS. 6 and 7 (d) and (e),
The operation of the above processing will be explained. FIG. 6 shows a test seek program 500 started by the MPU 5.

FIG. 7(d) shows the output value of DAOUT, and FIG. 7(C) shows the TES signal.

Step 601 The current DAOUT is stored in the memory 51 of the MPU 5.

That is, the output from the MPU 5 to the D/A converter 314 is stored. CB-DAOUT) where the value is B.

Step 602 Add 1 to DAOUT.

Step 603 Output the DAOUT to the D/A converter 314 and read the resulting TES signal. The TBS signal is digitally converted by an A/D converter 330 and input to the MPU 5.

Step 604: Determine whether the TBS signal is greater than or equal to a predetermined value a. If the number is greater than or equal to a, step 603 is executed. If not, execute Step 02 again.

Now, steps 602 to 604 are a process of adding DAOUT and detecting whether the TBS signal (FIG. 7(e)) has reached 75a.

Step 605 Add 1 to DAOUT.

Step 606 Output the DAOUT to the D/A converter 314 and read the resulting TES signal. The TES signal is digitally converted by an A/D converter 330 and input to the MPU 5. Step 607: Determine whether the TBS signal is less than or equal to a predetermined value -a. If it is less than or equal to -a, step 807 is executed. If not, step 604 is executed again.

Now, steps 605 to 607 are a process of adding DAOUT and detecting whether the TBS signal (FIG. 7(e)) has reached 75b.

Step 608 Add 1 to DAOtJT.

Step 609 Output the DAOUT to the D/A converter 314 and read the resulting TBS signal. The TBS signal is digitally converted by an A/D converter B530 and input to the MPU5. Step 610: Determine whether the TBS signal is greater than or equal to a predetermined value -a. If it is greater than or equal to -a, step 611 is executed. If not, step 608 is executed again.

Now, steps 608 to 610 are a process of adding DAOUT and detecting whether the TES signal (FIG. 7(e)) has reached 75c.

Step 611 Add 1 to DAOUT.

Step 612 N=10. Let A=O.

Step 613 Read TBS signal.

Step 614 Determine whether the TES signal is greater than or equal to zero. If it is greater than or equal to zero, step 615 is executed. If it is less than or equal to zero, step 616 is executed.

Step 615 Add 1 to A.

Step 616 Subtract 1 from N.

Step 617 Determine whether N is zero. If it is zero, step 618
Execute. Otherwise, step 613 is executed.

Step 618 If A is 5 or more, step 619 is performed.

Otherwise, step 611 is executed.

Step 619 Let C = D A OU T, -B.

The above steps 611 to 619 will be explained. T
The ES signal is read (step 613), and if the result is greater than or equal to zero (step 614), 1 is added to A (step 615). Steps 613 to 615
Processing is performed 10 times in steps 616 and 617. As a result, if A is 5 or more, that is, if A is 5 or more out of 10 times as a result of reading the TBS signal, then C
=DAOUT-B. In other words, the above C is required for the lead beam to move one track, which is A, OUT.

Read the TES signal 10 times (step 613~
Step 617), if A is less than 5, DAOU
Add 1 to T (step 611, 10DoTES again
Read the signal (step 613 to step 61)
7).

Now, C (the initial value of the servo necessary for moving the read beam angle l track) obtained in the above processing is used at the time of track access. The microprogram shown in FIG. 8 is activated on the MPU 5. The flowchart in FIG. 8 is a flowchart for track access.

Track access of the lead beam will be explained below. Refer to FIG. 12. The distance between the read beam and the light beam is y, and the intersection point 701.
The angle between the perpendicular line to the dotted line 720 at points 702 and 703 and the tangent line at the intersection points 701, 702 and 703 is defined as θ1.
θ2. Assuming θ3, the light beam and lead beam are
In the track direction, y tanθ+, y*tanθz,
)'*tan03 must be shifted.

In other words, the distance between the read beam and the light beam is y, the dotted line 720, which is the trajectory of the objective lens, and the optical disc l.
The distance between the center O and the concentric circle is X, and the distance between the concentric circle and the center O is
, Dt, Dff, then the above! 701,702,7
03 respectively, y*tanθ+ = X*y/
D Hy * tan θt = X * y / Dz y * tan θ word = X ” y / D s The read beam is not present unless it deviates from the write beam. During track access, servoing by the TES signal of the read beam is not performed. shall be taken as a thing.

Step 82 The track access control unit 900 notifies the MPU 5 that the light beam will access.

At this time, the MPU 5 obtains the track address to be accessed.

Step 83: Calculate the distance ID from the track address of the access destination. In other words, 701 in FIG. 12(a), 702
In 703, the beam is calculated.

Step 84: Calculate the track deviation caused by the access, and the deviation is as follows: y*tanθI=X*y/DI y*tanθ,=X*y/D.

y*tanθa=X*)'/Ds Multiply the above X*y/D+, X*y/Dz, X*y/Ds by the amount of movement C required for one track movement determined earlier, A=α* Let C*X*y/D. α is a value determined by the track width.

Step 85 Output the above A to the D/A converter 314. When the output of the D/A converter 314 is 0, the read beam optical disk 1
When the positions of the light beam and the read beam are connected, the spot position for irradiating is perpendicular to the locus of movement of the objective lens 1 (perpendicular to the dotted line 720 in FIG. 12(a)).

Therefore, a current is applied to the galvanometer mirror actuator 501 according to the position where the read beam should be located, and when the positions of the read beam and the read beam are connected, the read beam is perpendicular to the locus of movement of the objective lens 1 (perpendicular to the dotted line 720). ) to the states shown in Figure 12 (b), (C), and (d).

Step 86 After that, when the light beam accesses the target track, servo is started again using the TBS signal obtained from the two-split photoreceiver 22 that receives the read beam, and the track position is controlled.

Step 87 finish.

The present invention has been described above according to examples. Furthermore, in this embodiment, the light beam is used for track access of the optical head, and the access position of the read beam is relatively controlled. However, the read beam is used for access control of the optical head, and the light beam is relatively controlled. It's okay. Also, although two beams were output from one objective lens, even with three beams, four beams were output.
I don't care if it's a book or something.

(C) Other Embodiments FIG. 10 is a flowchart of a test seek program 500 that is started on the MPU 5.

On the side of the device or similar to FIG.

A test seek program 500 started on the MPU 5 is different from the previous embodiment.

This will be explained below.

Step knob 1101 to step 1110 are the same as the flowchart in FIG.

Step 1111 Add 1 to D A, OU T.

Step 1112 A reset signal is output to the integrator 316.

Step 1113 Turn off the reset signal.

Step 1114 Count up the timer and wait for a certain period of time (urns~2m
5) Step 1 of executing step 1115
115 Read the output from the A/D converter 315 of the integrator 316.

Step 1116 If the integration result is greater than or equal to zero, execute step 1117; otherwise, execute steps 1111 to 111.
6 again.

Step 1117 Subtract the value of B stored in step 1101 from the current DAOUT, which is necessary for moving one track, and output to the A converter 314.

The above has been explained according to the embodiments. In the second embodiment, rather than directly reading the TBS signal to determine whether the vehicle has moved one track, the determination is made by integrating over a certain period of time.

Two embodiments have been described above. As described above, the present invention can be modified in various ways in accordance with the gist of the present invention, and the present invention does not exclude them.

[Effects] As explained above, according to the present invention, in an optical head that outputs a plurality of main beams and sub beams from one objective lens, track access is performed using the main beam, and test seek is performed. Since the initial value of the servo necessary for track movement of the sub beam is determined while the optical storage device is operating, there is no deviation between the main beam and the sub beam when accessing the track.

[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 invention, Fig. 3 is a block diagram of the optical head configured in Fig. 2, and Fig. 4 is a diagram of the actuator shown in Fig. 3. An explanatory diagram of the position sensor, Figure 5 is a configuration diagram of the galvano mirror in Figure 2,
FIG. 6 is a flowchart of the test seek program of the embodiment, FIG. 7 is an explanatory diagram of the test seek program, FIG. 8 is a flowchart of halide beam track access, and FIG. 9 is a flowchart of lead beam servo. and signal output graph, FIG. 10 is a flowchart of the test seek program of the second embodiment, and FIG.
12 are explanatory diagrams of the prior art. 1... Optical disc 2... Optical head 4... Second beam track position control section 21... First
Beam light receiving section 22...Second beam receiving section 500...Second beam movement testing section Kantochi J's Flow, / Gourmet Go No. 4 (a) CD) Honmaki Akari Ichigase Gun 1 F "mouth, ri D 5th mouth 4th valley 4 - ¥US layer) flowch Y- Toshose AJs1's flow + Y-To umpire 8 Figure (C) (d) (a) (b 9th AJs 1 flow + Yard umpire I0 A1 Monura + 1 p < 1 % formula % Name of invention ic Relationship with f'l Special - Import/Import (1. Location Kanagawa Prefecture j Saki City Nakaha: L Ward 1. Elementary 1 (1 middle 1 (11 5 address name (!+22) ):・:Kawa:Tsu Co., Ltd. Representative Representative Otosekizawa Yo 4゜Pif person Japanese mail number 11 5゜Supplementary iE 1 The number of claims will increase from this, 6゜Issuance + IE order dated 8Ji28, 1990, dated 11th (Delivery [1) 7° Amendment subject matter 111! Brief explanation of the drawings in the book (Fig. 2)

Claims (6)

[Claims] (1) An optical storage medium (1) and an optical head (2) that irradiates a plurality of beams onto the optical storage medium (1) from the same objective lens.
) and receives the first beam among the plurality of beams, and the optical head (2
) and positions the first beam at an arbitrary track position, the optical storage device receives light from the optical storage medium of a second beam among the plurality of beams, and generates a received light signal. The second beam receiver (2
2), a second beam moving means (4) for moving the position of the second beam, and a second beam moving means (4) for moving the second beam, and for moving the second beam to the second beam receiving section ( 22) Determine the position of the second beam on the optical storage medium based on the received light signal, determine the track movement amount of the second beam from the position, and drive the second beam moving means (4) with respect to the movement amount. An optical storage device characterized by comprising second beam movement drive amount measuring means (500) for determining the amount of movement of the second beam. (2) An optical system that determines the track address of the optical storage medium from the light reception signal of the first beam, moves the optical head (2) to the track of the specified address, and positions the first beam on the track. Head access control means (9
00), and from the track address, calculate the relative movement amount of the second beam with respect to the first beam, which is predetermined for each track address, and calculate the relative movement amount of the second beam with respect to the first beam, which is determined in advance for each track address, and then calculate the relative movement amount of the second beam with respect to the first beam, which is determined in advance for each track address.
The second beam moving means (500) is characterized in that a driving amount corresponding to the relative movement amount is determined from the driving amount determined by the above-mentioned driving amount, and the second beam is moved by the driving amount corresponding to the relative movement amount. 4) The optical storage device according to claim 1, characterized by having the following. (3) An optical storage medium (1) and an optical head (2) that irradiates a plurality of beams onto the optical storage medium (1) from the same objective lens.
) and receives the first beam among the plurality of beams, and the optical head (2
) and positions the first beam at an arbitrary track position, the optical storage device receives light from the optical storage medium of a second beam among the plurality of beams, and generates a received light signal. The second beam receiver (2
2), a second beam moving means (4) that moves the position of the second beam by applying a predetermined voltage to a servo section that controls the position of the second beam, and the second beam moving means (4), the applied voltage is changed to move the second beam, and the position of the second beam on the optical storage medium is determined by the light reception signal obtained by the second beam receiver (22). An optical storage device characterized in that it has second beam movement driving amount measuring means (500) for calculating the ratio of the changed voltage to the track movement of the beam. (4) An optical system that determines the track address of the optical storage medium from the light reception signal of the first beam, moves the optical head (2) to the track of the designated address, and positions the first beam on the track. Head access control means (9
00), and from the track address, calculate the relative movement amount of the second beam with respect to the first beam, which is predetermined for each track address, and calculate the relative movement amount of the second beam with respect to the first beam, which is determined in advance for each track address, and then calculate the relative movement amount of the second beam with respect to the first beam, which is determined in advance for each track address.
500), a voltage corresponding to the relative movement amount is determined from the changed voltage ratio of the second beam moving means (4), and the voltage is used to control the second beam. 4. The optical storage device according to claim 3, further comprising second beam moving means (4) for moving the second beam in addition to the servo section. (5) The optical storage device according to claim 1 or 2 or 3 or 4, wherein the first beam is a writing beam and the second beam is a reading beam. (6) an optical storage medium; an optical head that irradiates the optical storage medium with a plurality of beams from the same objective lens; In an optical storage device that moves a head, the second beam is moved, the position of the second beam on the optical storage medium is determined based on the light reception signal of the second beam, and the track movement amount of the second beam is determined from this position. , the amount of drive of the second beam relative to the amount of movement is determined, the optical head moves, and the first
When the beam and the second beam access an arbitrary track position, the second beam is
A method for measuring the amount of relative position movement of a second beam, the method comprising determining the amount of drive of relative position movement of the beam.