JPH05242616A - Positioning device - Google Patents

Abstract

PURPOSE:To perform accurate positioning even when there are variations of a circuit and a mechanism in the positioning device for detecting an absolute position of a positioner and controlling positioning the positioner into a target position. CONSTITUTION:In the positioning device having the positioner 12 for positioning operation, a position detecting part 18 for detecting the absolute position of the positioner 12 and a control part 46 for driving control on the positioner 12 by a difference between a detecting output of the position detecting part and a driving output of the target position, the driving output is controlled by the control part 46 to perform the positioning in two reference point positions. Then, a relationship between the position and the driving output is measured from the two point positions and the driving output, and is stored in a storage part (nonvolatile memory) 47, and at the time of driving control of the positioner 12, the driving output corresponding to the target position is calculated from the stored measured value.

Description

Detailed Description of the Invention

(Table of Contents) Industrial Application Field of the Prior Art Problems to be Solved by the Invention Means for Solving the Problems (FIG. 1) Action Example (a) Description of the Configuration of One Example (FIGS. 2 to 3) (B) Description of processing of one embodiment (FIGS. 4 to 9) (c) Description of another embodiment Effects of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device for detecting the absolute position of a positioner and controlling the positioning of the positioner at a target position.

In a magnetic disk device, an optical disk device (including a magneto-optical disk device), etc., a positioner is used because the head seeks in the radial direction of the disk. For example, in an optical disk device, by irradiating a rotating disk-shaped record carrier with light from a laser diode, information is recorded and the nature of the reflected light (amount of light,
Information is reproduced by detecting a change in the polarization plane.

In order to record / reproduce information on the entire circumference of the optical disk from the inner circumference to the outer circumference, it is necessary to move the head in the radial direction of the optical disk, and this movable part is called a positioner.

In such a positioner, an absolute position detecting mechanism is used to position at a target position because of its simple structure, and an accurate positioning operation is required.

[0006]

2. Description of the Related Art In an optical disk apparatus, a semiconductor position detecting element is provided in a moving path of an optical head, the absolute position of the optical head is detected by the semiconductor detecting element, and the optical head is driven by a difference from a drive signal of a target position. There has been proposed a device for controlling a part (for example, Japanese Patent Laid-Open No. 63-2812).
No. 31, etc.).

In such a structure, since the driving is performed by the difference between the driving signal of the target position and the detection output of the semiconductor detection element, the driving signal needs to correspond to the target absolute position. The relationship with the drive signal must be known.

This relationship can be obtained by calculation from design values, and conventionally, it was determined by design values.

[0009]

However, the prior art has the following problems. There are variations in the mechanism such as the characteristics of the circuit and the fixed positions of the elements between the devices, and the design values do not allow an accurate relationship to be achieved, and an accurate positioning operation cannot be realized.

In particular, in the case of performing micron-order positioning such as with an optical disc, the positioning cannot be accurately performed even with a slight variation. Therefore, it is an object of the present invention to provide a positioning device that can perform accurate positioning even if there are variations in circuits and mechanisms.

[0011]

FIG. 1 shows the principle of the present invention. According to a first aspect of the present invention, the positioner 12 that performs a positioning operation, the position detection unit 18 that detects an absolute position of the positioner 12, and the positioner based on the difference between the detection output of the position detection unit and the drive output of the target position are used. In a positioning device having a control unit 46 for driving and controlling 12, the control unit 46 controls the drive output to position it at a reference two-point position, and to determine the position of the two points and the drive output. , The relationship between the position and the drive output is measured and stored in the storage unit 47, and when the drive control of the positioner 12 is performed, the drive output corresponding to the target position is calculated from the stored measured value. To do.

According to claim 2 of the present invention, in claim 1,
The control unit 46 positions at two predetermined positions,
After measuring the drive output and the detection output and measuring the relationship between the drive output and the detection output, positioning is performed at the positions of the two reference points, and the relationship between the detection output and the position is measured. It is characterized by doing.

A third aspect of the present invention is based on the second aspect.
The controller 46 drives the drive output to the limit position of the positioner 12 and then positions the positioner 12 at the predetermined two positions.

According to a fourth aspect of the present invention, in the first, second or third aspect, the positioner 12 includes a head 10 for reading at least the contents of the information storage disk 20,
The output of the head 10 is used to position the information storage disk 20 at two reference positions, an inner circumference and an outer circumference.

According to a fifth aspect of the present invention, in the fourth aspect,
The information storage disk 20 is an optical disk, and the two reference positions are a boundary between a groove and a mirror surface of the optical disk and a PEP zone.

A sixth aspect of the present invention is characterized in that, in the third, fourth or fifth aspect, the control section 46 stores the detection output of the limit position in the storage section 47.

[0017]

According to the first aspect of the present invention, the control unit 46 controls the drive output to position it at the reference two-point positions, and based on the position and the drive output of the two points, the position and the drive output. And the characteristic of each device is measured and stored in the storage unit 47, and when the drive control of the positioner 12 is performed, the drive output corresponding to the target position is obtained from the stored measured value. By calculating, even if there are variations in the circuit and mechanism, accurate positioning control suitable for each device becomes possible.

According to a second aspect of the present invention, the control section 46 positions at two predetermined positions, measures the drive output and the detection output, and establishes the relationship between the drive output and the detection output. After the measurement, the two positions of the reference are positioned and the relationship between the detection output and the position is measured. Therefore, the relationship between the position, the detection output, and the drive output can be easily measured. Even if there are variations, accurate positioning suitable for each device is possible.

In the third aspect of the present invention, the control unit 46 drives the drive output to the limit position of the positioner 12 and then positions the positioner at the predetermined two points. Therefore, the relationship between the drive output and the position is controlled. Even if the user does not know it, the characteristic can be measured by positioning it at a predetermined position with reference to the limit position.

In the fourth aspect of the present invention, the positioner 12
Includes a head 10 for reading at least the contents of the information storage disk 20, and uses the output of the head 10 to position the information storage disk 20 at two reference positions on the inner and outer circumferences of the information storage disk 20. Against
The characteristic can be easily measured by positioning it at the reference position.

In the fifth aspect of the present invention, the information storage disk 20 is an optical disk, and the two reference point positions are the boundary between the groove and the mirror surface of the optical disk and the PEP zone. You can position it at and measure the characteristics.

In the sixth aspect of the present invention, since the control unit 46 stores the detection output of the limit position in the storage unit 47, the limit position can also be measured, can be used for error detection of drive output, etc., and runaway can be performed. It can be prevented.

[0023]

【Example】

(a) Description of Configuration of One Embodiment FIG. 2 is a configuration diagram of one embodiment of the present invention, and FIG. 3 is a block diagram of one embodiment of the present invention, showing a magneto-optical disk device.

In FIG. 2A, reference numeral 1 is a magneto-optical disk device, 10 is an optical head for writing and reading on the optical disk 20, and 11 is a VCM (voice coil motor) coil for the optical head. 10 is a device for driving the optical disc 20 in the radial direction, 12 is a positioner (movable part), and the optical head 10 and the VCM coil 1
1 is provided.

Reference numeral 13 is an inner peripheral stopper of the positioner 12, 14 is an outer peripheral stopper of the positioner, and 15
Is a spindle motor that rotates the optical disc 20, and 16 is an external magnet that applies a magnetic field to the optical disc 20 to enable writing.

Reference numeral 2 is an optical disk cartridge, which is equipped with an optical disk 20 and is attached to and detached from the magneto-optical disk device 1. In FIG. 2 (B), 17 is a light emitting part, which is composed of an LED (light emitting diode), is provided in the positioner 12, and emits light to the semiconductor position detecting element 18, and 18 is a semiconductor position detecting element (PSD). It is provided in parallel with the movement path of the positioner 12, detects the light of the light emitting portion 17 by the light receiving surface 18a, and generates a current output corresponding to the position (absolute position) of the positioner 12.

In FIG. 3, reference numerals 30 and 31 respectively denote current / voltage converters for converting the current outputs I ₁ and I ₂ across the semiconductor position detecting element 18 into voltages V ₁ and V ₂ , respectively.
32 is a difference circuit, which subtracts the voltage V ₂ from the voltage V ₁ .
An AD (analog / digital) converter 33 that generates a position signal converts an analog position signal into a digital signal and inputs the digital signal to the control unit 46.

Reference numeral 34 is a differentiating circuit for differentiating the position signal to obtain a speed signal. Reference numeral 35 is an AD (analog / digital) converter for converting the analog speed signal into a digital signal and sending it to the control section 46. To enter, 3
6 is a DA (digital / analog) converter, which converts the digital drive signal of the control unit 46 into an analog drive signal, and 37 is a difference circuit, which subtracts the drive signal from the position signal to generate a position error signal. It is a thing.

Reference numeral 38 denotes a phase compensating circuit for advancing the high frequency component of the position error signal to compensate for the phase. Reference numeral 39 denotes a first switch, which is controlled by the control unit 46 to add the phase compensating circuit 38 to the sum circuit. For connecting to 42, 40 is the second
Is a switch for connecting the differentiating circuit 34 to the summing circuit 42, and 41 is a DA (digital / analog) converter for converting the digital drive signal of the control unit 46 into an analog drive signal.

Reference numeral 42 is a sum circuit, which takes the sum of the position error signal of the first and second switches 39 and 40, the speed signal, and the drive signal of the DA converter 41, and 43 is a VCM drive amplifier, and the sum circuit Positioner 1 by the output of 42
The second VCM coil 11 is current-driven.

Reference numeral 44 is a track servo control unit, which detects the track error signal TES from the reflected light of the optical head 10 to servo-control the track actuator of the optical head 10, and 45 is a focus servo control unit, The focus error signal FES is detected from the reflected light of the head 10, and the focus actuator of the optical head 10 is servo-controlled.

Reference numeral 46 is a control unit, which is composed of a microprocessor (MPU) and performs seek control and the like by executing a program. Reference numeral 47 is a non-volatile memory, EE
PROM (Electrically erasable programmable read
It is composed of only memory) and stores measured characteristic values and the like.

In this embodiment, the VCM coil 11 can be driven by the position error signal, which is the difference between the drive signal of the control unit 46 and the position signal, the speed signal, and the drive signal of the control unit 46.

(B) Description of Processing of One Embodiment FIGS. 4, 5, and 6 are flow charts of measurement processing of one embodiment of the present invention (No. 1), (No. 2), (No. 3), and FIG. FIG. 8 is a diagram for explaining the measurement operation of one embodiment of the present invention, and FIG. 8 is a diagram for explaining the optical disk medium layout of one embodiment of the present invention.

As shown in FIG. 8, the layout of an ISO-compliant 5-inch optical disk medium is such that the inner circumference to the mirror surface portion and the type of medium (the number of sectors in one track, the number of bytes in one sector, magneto-optical or write-once). , PEP (Phase-Enco) recording the reflectance of the recording film, land or groove recording, etc.
ded Part) zone, transition (PEP to SFP) zone, and detailed information (write power, pulse width, etc. for each device)
Inner circumference SFP zone that recorded the value and inner circumference manufacturer zone (guard band, manufacturer test zone, guard band)
, User zone, peripheral manufacturer zone, peripheral SF
It consists of a P zone, a lead-out zone, and a peripheral mirror surface portion.

Using the layout of such an optical disc, characteristic measurement is performed as shown in FIG. The measurement process is performed at the time of adjustment at the factory, and the control unit (hereinafter, referred to as a processor) 46 turns off the first and second switches 39 and 40 by starting the measurement process, and the DA converter 41 receives 80H (center). It is a value and does not move to either the inner or outer) + 8H is output, and the sum circuit 42,
The VCM coil 11 is driven by the VCM drive amplifier 43 to move the positioner 12 to the outer side.

As a result, the position signal is generated from the difference circuit 32 and the speed signal is obtained from the differentiation circuit 34 by the output from the semiconductor position detecting element 18. Since this drive is an open loop, as shown in FIG.
Hits the outer peripheral stopper 14 on the outer side and is mechanically stopped. Therefore, the processor 46 monitors the speed output of the AD converter 35 and determines whether the speed is zero. It is determined that the stopper 14 has been hit and stopped.

Since this position is the movement limit e on the outer peripheral side,
The processor 46 reads the position signal of the AD converter 33, saves it as the outermost position Y0. Next, the processor 46 causes the DA converter 41 to output 8
It outputs 0H (center value, which does not move to either the inner or outer), sum circuit 42, VCM drive amplifier 4
The VCM coil 11 is driven from 3 to lock the movement.

The processor 46 calculates the output value (driving signal) X0 of the DA converter 36 for position locking the positioner 12 from the circuit constant to the outermost position Y0, and outputs it to the DA converter 36 to output the first switch. 39
Is turned on, and the sum circuit 42 and the VCM drive amplifier 43 generate VC
The M coil 11 is driven to lock the position at the outermost position.

Next, in order to seek to point d in FIG. 7, the processor 46 causes the DA converter 36 to send Xd (= X0).
-10H) to output the sum circuit 42 and the VCM drive amplifier 4
The VCM coil 11 is driven from 3 to position at the point d, the position signal of the AD converter 33 is read, and the position Y at the point d
As d, save is performed, the first switch 39 is turned off, and the position lock is released.

Next, the processor 46 outputs 80H (center value) -8H to the DA converter 41, and the sum circuit 4
2. The VCM coil 11 is driven by the VCM drive amplifier 43 to move the positioner 12 to the inner side.

As a result, the position signal is generated from the difference circuit 32 and the speed signal is obtained from the differentiation circuit 34 by the output from the semiconductor position detecting element 18. Since this drive is an open loop, as shown in FIG.
Hits the inner peripheral stopper 13 on the inner side and mechanically stops, so the processor 46 monitors the speed output of the AD converter 35 and determines whether the speed is zero. If the speed is zero, the positioner 12 It is determined that the inner peripheral stopper 13 has been hit and stopped.

Since this position is the movement limit f on the inner circumference side,
The processor 46 reads the position signal of the AD converter 33, and saves it as the innermost position Yi. Turning to FIG. 5, the processor 46 uses the DA converter 41.
80H (center value) is output to drive the VCM coil 11 from the sum circuit 42 and the VCM drive amplifier 43 to lock the movement.

The processor 46 calculates the output value (driving signal) Xi of the DA converter 36 for position-locking the positioner 12 from the circuit constant to the innermost position Yi, outputs it to the DA converter 36, and outputs it to the first switch. 39
Is turned on, and the sum circuit 42 and the VCM drive amplifier 43 generate VC
The M coil 11 is driven to lock the position at the innermost position.

Next, in order to seek to point a in FIG. 7, the processor 46 causes the DA converter 36 to display Xa (= Xi).
-10H) to output the sum circuit 42 and the VCM drive amplifier 4
The VCM coil 11 is driven from 3 to position at the point a, the position signal of the AD converter 33 is read, and the position a at the point Y
Save as a.

As a result, the value (driving signal) of the DA converter 36 and the value (position detection output) of the AD converter 33 at two points a and d that are constant distances from the outer and inner limits can be measured. 46 is a DA converter 36
The coefficient of the following equation (1), which is the relational expression between the drive signal X and the position detection output Y of the AD converter 33, is calculated.

X = A1 · Y + B1 (1) This coefficient is calculated by the following formula. A1 = (Xd-Xa) / (Yd-Ya) B1 = Xa-[(Xd-Xa) / (Yd-Ya)] Ya Then, the processor 46 determines the coefficients A1, B1 and the outer and inner limit values. Y0 and Yi are saved in the non-volatile memory 47.

Next, in order to move to the point b in the PEP zone, the processor 46 increments the output value (driving signal) of the DA converter 36 by 1 and outputs it to the DA converter 36, and the sum circuit 42 and VCM driving amplifier 43 The VCM coil 11 is driven step by step, the amount of light reflected from the medium is monitored, and it is checked whether a signal peculiar to the PEP zone is generated.

As shown in FIG. 8, since the PEP zone is next to the mirror surface portion from the inner circumference, the amount of light reflected from the medium is almost constant and does not change at the mirror surface portion.
Since the signal peculiar to the P zone is generated, when the signal peculiar to the PEP zone is generated, it can be determined that the PEP zone has been moved.

When the processor 46 determines that it has moved to the PEP zone b point, the position signal Y of the AD converter 33 is detected.
Read b and save. At this time, b of this PEP zone
The absolute position rb of the point is, as shown in the radial position of FIG.
The drive signal value Xb of the DA converter 36 is also known.

Similarly, to move to the outer peripheral groove / mirror surface boundary point c, the processor 46 causes the DA converter 3 to move.
The output value (driving signal) of 6 is incremented by 1, and the DA converter 3
6 and outputs from the sum circuit 42 and the VCM drive amplifier 43 to V
The CM coil 11 is driven step by step to check whether or not the track error signal TES from the track servo control unit 44 will be generated.

As shown in FIG. 8, since the mirror surface portion on the outer periphery is next to the lead-out zone, the track error signal TES is generated in the lead-out zone, and when entering the mirror surface portion, the track error signal TES is generated. Because it will not
When the track error signal TES is not generated, it can be determined that the track error signal TES has moved to the groove / mirror surface boundary c point.

When the processor 46 determines that it has moved to the boundary c point, it reads the position signal Yc of the AD converter 33 and saves it. At this time, the absolute position r of the point c on this boundary
c is known, as shown in the radial position in FIG. 8, and D
The drive signal value Xc of the A converter 36 is also known.

In this way, by positioning at two standard points whose absolute positions are known and measuring the absolute position r and the position signal Y of the AD converter 33, the processor 46 determines the absolute position r and the position of the AD converter 33. The coefficient of the following equation (2), which is a relational expression with the detection output Y, is calculated.

Y = A2 · r + B2 (1) This coefficient is calculated by the following equation. A2 = (Yc-Yb) / (rc-rb) B2 = Yb-[(Yc-Yb) / (rc-rb)] rb Then, the processor 46 uses the coefficients A2 and B2 and a standard two-point AD converter. The values Yb and Yc of 33 are saved in the non-volatile memory 47, the switch 39 is turned off, and the process ends.

In this way, the relationship between the drive signal X of the DA converter 36 and the position detection signal Y of the AD converter 33 and the relationship between the absolute position r and the position detection signal of the AD converter 33 can be measured. It is possible to convert the absolute position r that matches the mechanical characteristics into the drive signal X of the DA converter 36.

Next, the seek operation using the relationship based on the measured values will be described. FIG. 9 is an explanatory diagram of a seek process according to an embodiment of the present invention. When the power is turned on, the processor 46 sets the nonvolatile memory 4
Load the coefficients A1, B1, A2, B2 from 7.

Next, prior to the seek, the processor 46
Turns off the first and second switches 39 and 40 and calculates the output value X for the target position r given from the higher order. Therefore, according to the equation (2), the coefficients A2 and B2 and the target position r are calculated.
After calculating the value Y of the AD converter 33 from the above, the drive signal X of the DA converter 36 is calculated from the coefficients A1 and B1 and the calculated value Y of the AD converter 33 by the equation (1).
To calculate.

The processor 46 uses the DA converter 36.
When the drive signal X is output to the first switch 39 and the first switch 39 is turned on, the position error signal between the position signal of the semiconductor position detecting element 18 generated from the difference circuit 37 and the drive signal X of the DA converter 36 becomes the phase compensation circuit 38. , The first switch 39, the sum circuit 42, and the VCM drive amplifier 43, the VCM coil 1
Seek given to 1.

When the position error signal becomes zero, the position has been set to the target position (track) and the speed becomes zero. The processor 46 monitors the speed signal of the AD converter 35. When the speed signal becomes zero, the processor 46 determines that the seek is completed, and ends the seek operation.

The seek operation is performed by the inner peripheral stopper 13
GO HOME seek to, seek to the mirror surface of the medium when adjusting the laser diode emission of the optical head 10, P
Used to seek to the PEP zone when reading data from the EP zone. When seeking to the track of the normal user zone, the position is detected by counting the track error signal TES, and the speed control signal is output from the DA converter 41. And seek.

In this way, the drive characteristic due to the variation of the circuit and the mechanism is measured, the relation coefficient is stored, and it is used for the calculation of the drive signal for the target position at the time of seek, thereby enabling the accurate seek.

Further, since the inner and outer circumferences are mechanically positioned and the reference point is sought from there, the reference point can be found early and the limit position can be measured. (c) Description of Other Embodiments In addition to the above embodiments, the present invention can be modified as follows.

In order to search for the standard point, the outer limit and the inner limit are positioned. However, the standard point may be directly searched to find the relationship between the absolute position and the drive signal of the DA converter. As described in the magneto-optical disk device, the optical disk device,
It can also be applied to a magnetic disk device or the like.

The position error signal may be used for normal seek. Although the embodiments of the present invention have been described above, various modifications are possible within the scope of the gist of the present invention, and these modifications are not excluded from the scope of the present invention.

[0066]

As described above, according to the present invention,
It has the following effects. The control unit controls the drive output, positions it at two reference positions, measures the relationship between the position and the drive output from the positions of the two points and the drive output, and determines the characteristics of each device. The positioner 1 is measured and stored in the storage 47.
By calculating the drive output corresponding to the target position from the stored measurement value during the drive control of No. 2, it is possible to perform accurate positioning control suitable for each device even if there are variations in the circuit and the mechanism.

Since the measurement is performed, the driving characteristics can be accurately obtained, and the accurate positioning operation can be easily performed.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is a block diagram of an embodiment of the present invention.

FIG. 4 is a flowchart of the measurement processing according to the embodiment of the present invention (No. 1).
Is.

FIG. 5 is a flowchart of the measurement processing according to the embodiment of the present invention (part 2).
Is.

FIG. 6 is a flowchart of the measurement processing according to the embodiment of the present invention (part 3).
Is.

FIG. 7 is an explanatory diagram of a measurement operation according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram of an optical disc medium layout according to an embodiment of the present invention.

FIG. 9 is a flow chart of seek processing according to an embodiment of the present invention.

[Explanation of symbols]

 1 Magneto-optical disk device 2 Optical disk cartridge 10 Optical head 11 VCM coil 12 Positioner 13 Inner circumference stopper 14 Outer circumference stopper 17 Light emitting part 18 Semiconductor position detecting element 46 Control part 47 Non-volatile memory

Claims (6)

[Claims] 1. A positioner (12) for positioning operation
And a position detection unit (18) for detecting the absolute position of the positioner (12), and a control unit for driving and controlling the positioner (12) by the difference between the detection output of the position detection unit and the drive output of the target position. In the positioning device having (46), the control unit (46) controls the drive output to set the reference 2
Positioning is performed at the position of the point, and the relationship between the position and the drive output is measured from the position of the two points and the drive output, and the storage unit (4
The positioning device is stored in 7), and the drive output corresponding to the target position is calculated from the stored measured value during drive control of the positioner (12). 2. The control unit (46) measures the drive output and the detection output by positioning them at predetermined two positions, and after measuring the relationship between the drive output and the detection output. The positioning device according to claim 1, wherein the positioning device is positioned at two positions of the reference and the relationship between the detection output and the position is measured. 3. The control section (46) drives the drive output to the limit position of the positioner (12) and then positions it at the predetermined two positions. Positioning device. 4. The positioner (12) includes a head (10) for reading at least the content of the information storage disk (20), and at two reference positions of the inner circumference and the outer circumference of the information storage disk (20), Positioning is performed using the output of the head (10).
Or the positioning device of 3. 5. The information storage disk (20) is an optical disk, and the two reference point positions are a boundary between a groove and a mirror surface of the optical disk, and a PEP zone. Positioning device. 6. The positioning device according to claim 3, wherein the control unit (46) stores the detection output of the limit position in the storage unit (47).