JP2003091847A - Method and device for driving optical head device, and optical information processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a driving means of an expander lens excellent in terms for various conditions. SOLUTION: A light beam emitted from a light emitting element 10 is turned to a parallel light beam by a collimator lens 11, etc., and made incident on a beam splitter 13. The light beam transmitted through the beam splitter 13 is made incident on the expander lens 16 constituted of a concave lens 16a and a convex lens 16b and a recoding medium (not illustrated) is irradiated with the light beam passed through the expander lens 16 via a mirror 17, a wavelength plate 18 and an objective lens 19. For example, a stepping motor 22 is further provided as a rotation motor for driving the expander lens 16, a lead screw mechanism 23 is connected with its rotational axis and a rotational motion is converted into sliding motion. And the sliding motion is transmitted, for example, to a lens holding member 25a of the concave lens 16a of the expander lens 16 via a rack 24 for driving.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to MD, CD and DV.
The present invention relates to a driving method and device of an optical head device and an optical information processing device suitable for use in a recording and / or reproducing device using an optical disc recording medium such as D. For more information,
For example, the present invention relates to driving an expander lens for correcting wavefront aberration due to variations in layers of an optical disc recording medium.

[0002]

2. Description of the Related Art In a recording / reproducing apparatus using an optical disc recording medium such as an MD, a CD or a DVD, an optical head device for recording / reproducing an information signal on / from the recording medium is provided. That is, in FIG. 6, a light emitting element 50 for generating a light beam of an arbitrary wavelength is provided, and the light beam emitted from this light emitting element 50 is collimated by a main lens, a collimator lens 51, and a predetermined optical system 52. Then, the beam is incident on the beam splitter 53.

In the beam splitter 53, for example, when recording an information signal, a part of the recording light beam is extracted by reflection, and a part of the extracted light beam is passed through a lens 54 to a detector 55. The light beam for recording is monitored by irradiating the light. On the other hand, the light beam transmitted through the beam splitter 53 is a concave lens 5
The light enters the expander lens 56 that is composed of 6a and the convex lens 56b.

The expander lens 56 is for correcting wavefront aberration due to, for example, variations in layers of the optical disc recording medium, and a focal point of a light beam is formed on the recording layer regardless of variations in layers of the recording medium. Adjustments are made as described above. Furthermore, this expander lens 5
The light beam that has passed through 6 is reflected by the mirror 57 and is incident on the objective lens 59, which is the main lens, via the wave plate 58. Then, the light beam condensed by the objective lens 59 is applied to a recording medium (not shown).

The light beam reflected by this recording medium (not shown) is an objective lens 59, a wave plate 58, and a mirror 5.
7. The beam travels backward through the expander lens 56 and enters the beam splitter 53. Then, in this beam splitter 53, the light beam is reflected in a direction opposite to that of the lens 54 and the detector 55, and is further reflected to a predetermined optical system 60.
Is incident on the detector 61 through. As a result, the information signal contained in the light beam reflected by the recording medium (not shown) is extracted.

Although not shown, the above-mentioned objective lens 59 is provided with a biaxial actuator for driving in the focus direction and the tracking direction. Further, the expander lens 56 is also provided with a driving means (not shown). As a drive means for such an expander lens 56, a voice coil motor (hereinafter
VCM) was used.

[0007]

However, as a driving means for such an expander lens 56, the above-mentioned VCM is used.
It has been found that the following problems occur when using. The VCM is provided with a coil and a magnet around the concave lens 56a or the convex lens 56b for driving.

Seismic resistance: Since the position is determined by the coil and the magnet, the current position cannot be held against impact. Reliability: Resistance changes due to changes in temperature and drive performance deteriorates. Complexity: The structure of the driving means is simple, but a servo circuit is required for driving, and the circuit structure becomes complicated. Impact resistance: Damage to the drive unit is large due to impact.

Regarding the above-mentioned problems, VC
Since M does not normally have means for fixing the position, it is necessary to always supply a drive current to fix the position. Therefore, as a configuration of the servo circuit used for driving the VCM, for example, the configuration shown in FIG. 7 is used.

In FIG. 7, a position command signal supplied from an external system control circuit or the like to a terminal 70 is supplied to a D / A converter 72 through a digital signal processor (hereinafter abbreviated as DSP) 71, and this D / A converter 72 is supplied. A converter 72
A voltage corresponding to the position command signal from is supplied to the inverting input of the differential amplifier 73. The drive current from the differential amplifier 73 is balanced transformerless (hereinafter,
Coil 75 through a driver 74.
Is supplied to.

Further, the voltage across the resistor 76 provided in series with the coil 75 is detected by the differential amplifier 77, and this detection signal is supplied to the non-inverting input of the differential amplifier 73. That is, in driving the VCM, since the drive current is always supplied to the coil 75, it is necessary to feed back the drive current to perform servo control. Therefore, the servo circuit requires the configuration of the resistor 76, the differential amplifier 77, and the like, and also requires a work procedure such as adjusting these circuits at the time of manufacturing.

By the way, the VCM has an excellent followability with respect to a drive signal, and is suitable for, for example, the biaxial actuator used for driving the above-mentioned objective lens 59. On the other hand, regarding the wavefront aberration due to the dispersion of the layers of the recording medium corrected by the expander lens 56, the dispersion between the disks is large, but the dispersion such as the inside / outside difference on one disk is small. ing. Therefore, if the variation between the disks is corrected, the following follow-up property is not required.

This application has been made in view of such a point, and the problem to be solved is that the conventional VC
It is said that the device using M causes problems in earthquake resistance, reliability, complexity, shock resistance, etc., and these problems cannot be easily solved.

[0014]

Therefore, in the present invention, the drive of the expander lens is performed by using the rotary motor. According to this, the state after adjustment is performed by using the rotary motor. Since it is retained, it has excellent seismic resistance, high reliability in position accuracy / control accuracy against temperature changes, etc., and because a servo circuit is not required, the configuration is simple and it is driven by mechanical fastening. It is possible to form a driving means that is excellent in impact.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION That is, according to the present invention, there is provided a driving method of an optical head device for irradiating a recording medium with a light beam through a main lens to record and / or reproduce an information signal. An expander lens is provided in series, and the expander lens is driven by using a rotary motor.

Further, in the present invention, a recording medium is irradiated with a light beam through a main lens to record and / or record an information signal.
Or a drive device of an optical head device for reproducing,
An expander lens is provided in series with the main lens, a drive mechanism for driving the expander lens is provided, and the drive source of the drive mechanism is a rotary motor.

Further, in the present invention, the recording medium is irradiated with the light beam through the main lens to record and / or record the information signal.
Or an optical information processing apparatus having an optical head device adapted to perform reproduction, wherein an expander lens is provided in series with a main lens, and a drive mechanism for driving the expander lens is provided, and the drive mechanism is driven. The source is a rotary motor.

The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an optical head device to which the method and device for driving an optical head device according to the present invention is applied. Note that in FIG. 1, only the optical system of the optical head device and the drive mechanism of the expander lens are extracted and shown for the sake of clarity, and other signal paths, drive parts, etc. are omitted. .

In FIG. 1, a light emitting element 10 for generating a light beam of an arbitrary wavelength is provided, and the light beam emitted from this light emitting element 10 is arbitrarily arranged by a collimator lens 11 as a main lens and a predetermined optical system 12. After being converted into parallel rays, they are incident on the beam splitter 13. In this beam splitter 13, for example, when recording an information signal,
A part of the recording light beam is extracted by reflection, and a part of the extracted light beam is applied to the detector 15 via the lens 14 to monitor the recording light beam.

On the other hand, the light beam transmitted through the beam splitter 13 is made incident on the expander lens 16 constituted by the concave lens 16a and the convex lens 16b.
The expander lens 16 is for correcting wavefront aberration due to, for example, variations in the layers of the optical disc recording medium, and the focal point of the light beam is formed on the recording layers regardless of the variations in the layers of the recording medium. Adjustments are made.

Further, the light beam that has passed through the expander lens 16 is reflected by the mirror 17, and the wave plate 1
It is incident on the objective lens 19, which is the main lens, via 8. Then, the light beam condensed by the objective lens 19 is applied to a recording medium (not shown). Further, the light beam reflected by this recording medium (not shown) is reflected by the objective lens 1
9, wave plate 18, mirror 17, expander lens 1
The beam is incident on the beam splitter 13 by tracing 6 in the opposite direction.

In the beam splitter 13, the light beam is reflected in the direction opposite to that of the lens 14 and the detector 15, and is further reflected and made incident on the detector 21 through a predetermined optical system 20. As a result, the information signal contained in the light beam reflected by the recording medium (not shown) is extracted. Although not shown, the above-mentioned objective lens 1
9 is provided with a biaxial actuator for driving in the focus direction and the tracking direction.

Further, in this apparatus, for example, a stepping motor 22 is provided as a rotary motor for driving the expander lens 16, and a lead screw mechanism 23 is connected to the rotary shaft of the stepping motor 22. The lead screw mechanism 23 converts the rotary motion of the stepping motor 22 into a sliding motion, and this sliding motion is passed through the drive rack 24.
For example, it is transmitted to the lens holding member 25a of the concave lens 16a of the expander lens 16.

The stepping motor 22 and the lead screw mechanism 23 are integrally formed by an angle 26. Further, the driving rack 24 and the lens holding member 2
5a is integrally fastened, and a guide shaft 27 is inserted into the drive rack 24 to regulate the direction of the sliding movement along the optical axis of the light beam through which the drive of the lens holding member 25a is transmitted. It Further, a photo sensor 28 for detecting the driving position of the lens holding member 25a is provided at a predetermined portion of the driving rack 24.

Thus, in this apparatus, when the stepping motor 22 is rotated, the lead screw mechanism 2
By 3 the rotational movement is converted into a sliding movement. Then, for example, by configuring the lead screw mechanism 23 so as to obtain a sliding motion of 0.125 mm for one step rotation of the stepping motor 22, ± 0.
The concave lens 16a is driven by 125 mm.

Further, FIG. 2 shows a stepping motor 22.
2 shows the configuration of a circuit used to drive the. In FIG. 2, a position command signal supplied from an external system control circuit or the like to the terminal 1 is a digital signal processor (DSP).
It is supplied to the D / A converter 3 via 2. And D / A
The pulse corresponding to the relative position movement from the converter 3 is balanced transformerless (BT) depending on the rotation direction.
L) It is supplied to the drivers 4a and 4b to drive the A-phase coil 5a and the B-phase coil 5b of the stepping motor 22.

That is, in this circuit, the A-phase coil 5a or the B-phase coil 5b of the stepping motor 22 is activated every time a pulse corresponding to the relative position movement from the D / A converter 3 is supplied to the BTL driver 4a or 4b. It is driven to rotate one step at a time in each desired direction. And this 1 of stepping motor 22
Each time the step is rotated, the concave lens 16 is separated by a predetermined distance.
The drive of a is performed.

In this case, the driving of the stepping motor 22 is fixed at the rotated position,
Since the position is not moved after driving, it is not necessary to perform servo control by feedback or the like unlike the conventional VCM. Further, as described above, the driving of the concave lens 16a by ± 0.125 mm for each rotation of the stepping motor 22 is sufficient for the wavelengths of the red to blue lasers currently used as the light beam, for example. Resolution.

Further, in FIG. 3, the stepping motor 2
Specific configurations of the driving mechanism from 2 to the lens holding member 25a of the concave lens 16a and the lens holding member 25b of the convex lens 16b are shown in plan and perspective views from each direction. Note that, in FIG. 3, portions corresponding to those in FIG. 1 are denoted by the same reference numerals. Therefore, with this configuration, the stepping motor 2
When 2 is rotated, the lead screw mechanism 23 converts the rotational movement into a sliding movement, and the lens holding member 25 a is driven via the driving rack 24.

Although the stepping motor 22 is used as the rotary motor for driving the expander lens 16 in the above-described embodiment, a direct current motor that can rotate in the forward and reverse directions may be used. Further, the mechanism for converting the rotational movement into the sliding movement is not limited to the lead screw mechanism 23 described above, and a gear mechanism can be used. Further driven expander lens 16
Is not limited to the lens holding member 25a of the concave lens 16a described above, but may be the lens holding member 25b of the convex lens 16b.

Therefore, in this embodiment, since the expander lens is driven by using the rotary motor, the adjusted state is maintained by using the rotary motor, so that it is excellent in earthquake resistance and is resistant to temperature changes and the like. High reliability in position accuracy / control accuracy is obtained, a servo circuit is not necessary, the structure is simple, and the driving means is driven by mechanical fastening, so that it is possible to form a driving means excellent in impact resistance.

As a result, the conventional apparatus using the VCM has the problems of earthquake resistance, reliability, complexity, shock resistance, etc. According to the present invention, these problems can be easily solved. Is something that can be done.

Thus, according to the above-described optical head device driving method, the optical head device is driven by irradiating the recording medium with the light beam through the main lens to record and / or reproduce the information signal. An expander lens is provided in series with the main lens, and the rotary motor is used to drive the expander lens, whereby good driving can be performed with a simple configuration.

Further, according to the above-mentioned drive device for the optical head device, the drive device for the optical head device for irradiating the recording medium with the light beam through the main lens to record and / or reproduce the information signal. , An expander lens is provided in series with the main lens, and a drive mechanism for driving the expander lens is provided. By using a rotary motor as the drive source of the drive mechanism, a good drive device is formed with a simple configuration. Is something that can be done.

Further, in the present invention, an optical information processing apparatus can be constructed by using the above-described driving method and apparatus for the optical head device. That is, FIG. 4 shows a schematic configuration of an embodiment of the optical information processing apparatus according to the present invention. In FIG. 4, the recording disk 10
0 is irradiated with a light beam from the optical head device 101 including the above-mentioned objective lens driving device, and information signals are recorded and / or reproduced.

On the other hand, the recording disk 100 is rotationally driven by a shaft motor 103 driven according to a control signal from the system control device 102 so that the linear velocity becomes constant, for example. Further, the feed motor 104 driven in accordance with a control signal from the system control device 102 moves so that the light beam from the optical head device 101 is irradiated to a desired position on the recording disk 100.

Then, for example, an information signal from the input terminal 105 is supplied to the light beam drive detection circuit 107 through the recording / reproduction circuit 106, and the output of the light beam in the optical head device 101 is controlled according to the signal from the drive detection circuit 107. As a result, the information signal from the input terminal 105 is recorded on the recording disc 100. Also,
The drive detection circuit 107 detects the information signal recorded on the recording disk 100, and the detected information signal is taken out to the output terminal 108 through the recording / reproducing circuit 106.

At the same time, the drive detection circuit 107 detects error signals of tracking and focusing of the light beam, and these error signals are supplied to the servo circuit 109. Then, the control signal from the servo circuit 109 is supplied to the optical head device 101 to perform tracking and / or
Alternatively, focusing control drive is performed. Further, an operation signal from the operation panel 110 is transmitted to the system control device 102.
And the optical head device 101 is moved to a desired recording position or reproducing position.

In such an optical information processing apparatus as well, by providing the expander lens 16 provided in the optical head device 101 with a drive device using a rotary motor (stepping motor 22), a good optical configuration is achieved with a simple structure. An information processing device can be formed. That is, the stepping motor 22 is driven according to a control signal generated by the system controller 102 based on a detection signal from the drive detection circuit 107, for example.

That is, FIG. 5 shows a flowchart for performing the above control. In FIG. 5, when the operation is started, first in step [1], the mounting of the disk is awaited. When the disc is loaded, the process proceeds to step [2], and the optical head device 101 is moved to a predetermined detection position. Further, the irradiation of the light beam is started in step [3], and the correction value for driving the expander lens 16 is detected in step [4].

Further, in step [5], the expander lens 16 is driven based on the above-mentioned correction value. Then, in step [6], it is determined whether or not the driven position of the expander lens 16 is correct (OK), and if it is not correct (No), the process returns to step [3] and the process is repeated. If the position is correct in step [6] (Yes), the optical head device 101 is moved to the recording / reproducing start position in step [7], and information signals are recorded / reproduced thereafter.

Thus, the above-mentioned optical information processing apparatus is an apparatus having an optical head device which irradiates a recording medium with a light beam through a main lens to record and / or reproduce an information signal. In addition, an expander lens is provided in series with the main lens, and a drive mechanism for driving the expander lens is provided. By using a rotary motor as the drive source of the drive mechanism, good optical information processing with a simple configuration can be performed. A device can be formed.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0044]

Therefore, according to the first aspect of the present invention, since the expander lens is driven by using the rotary motor, the adjusted state is maintained by using the rotary motor, so that the vibration resistance is improved. Excellent, high reliability in position accuracy / control accuracy against temperature changes, etc., no servo circuit is required, the structure is simple, and it is driven by mechanical fastening. It can be formed.

According to the second aspect of the present invention, the rotary motor is a stepping motor, and by driving the expander lens via the lead screw mechanism or the gear mechanism, excellent driving of the optical head device is performed. It is a thing.

Further, according to the invention of claim 3, the rotary motor is a DC motor, and by driving the expander lens via the lead screw mechanism or the gear mechanism, a good optical head can be used even if the DC motor is used. The device is driven.

Further, according to the invention of claim 4, the light beam irradiated to a predetermined portion of the recording medium when the recording medium is first mounted is detected, and the expander lens is driven based on the detection signal. Thus, it is possible to correct the variation for each disk and drive the optical head device satisfactorily.

Further, according to the invention of claim 5, since the expander lens is driven by using the rotary motor, the condition after adjustment is held by using the rotary motor, which is excellent in earthquake resistance, High reliability in position accuracy / control accuracy with respect to temperature change, etc. is obtained, and since a servo circuit is not required, the structure is simple, and since it is driven by mechanical fastening, a driving means excellent in impact resistance is formed. Is something that can be done.

Further, according to the invention of claim 6, the rotary motor is a stepping motor, and the optical head device is favorably driven by driving the expander lens through the lead screw mechanism or the gear mechanism. It is a thing.

Further, according to the invention of claim 7, the rotary motor is a direct current motor, and by using the lead screw mechanism or the gear mechanism to drive the expander lens, good optical performance can be obtained even if the direct current motor is used. The head device is driven.

Further, according to the invention of claim 8, there is provided a detecting means for detecting the light beam applied to a predetermined portion of the recording medium when the recording medium is first mounted, and the expander lens is based on the detection signal. By driving
It is possible to correct the variation for each disk and drive the optical head device satisfactorily.

Further, according to the invention of claim 9, since the expander lens is driven by using the rotary motor, the condition after the adjustment is held by using the rotary motor, which is excellent in earthquake resistance, High reliability in position accuracy / control accuracy with respect to temperature change, etc. is obtained, and since a servo circuit is not required, the structure is simple, and since it is driven by mechanical fastening, a driving means excellent in impact resistance is formed. Is something that can be done.

According to the tenth aspect of the invention, the rotary motor is a stepping motor, and by driving the expander lens via the lead screw mechanism or the gear mechanism, the optical head device can be favorably driven. It is a thing.

Further, according to the invention of claim 11, the rotary motor is a direct current motor, and it is possible to obtain a good optical performance by driving the expander lens through the lead screw mechanism or the gear mechanism or by using the direct current motor. The head device is driven.

According to the twelfth aspect of the invention, there is provided a detecting means for detecting the light beam applied to a predetermined portion of the recording medium when the recording medium is first mounted, and the expander lens is based on the detection signal. It is possible to correct the variation for each disk and drive the optical head device satisfactorily.

As a result, in the conventional apparatus using the VCM, there are problems in earthquake resistance, reliability, complexity, shock resistance, etc., but according to the present invention, these problems can be easily solved. Is something that can be done.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an optical head device to which an optical head device driving method and device according to the present invention are applied.

FIG. 2 is a circuit diagram for explaining the operation.

FIG. 3 is a configuration diagram for the explanation.

FIG. 4 is a configuration diagram of an embodiment of an optical information processing apparatus to which the present invention is applied.

FIG. 5 is a flow chart diagram for explaining the explanation.

FIG. 6 is a configuration diagram of a conventional optical head device.

FIG. 7 is a circuit diagram for the explanation.

[Explanation of reference numerals] 10 ... Light emitting element, 11 ... Collimator lens, 12 ... Optical system, 13 ... Beam splitter, 14 ... Lens, 15 ... Detector, 16 ... Expander lens, 16a ... Concave lens, 16b ... Convex lens, 17 ... Mirror , 18 ... Wave plate,
19 ... Objective lens, 20 ... Optical system, 21 ... Detector, 22
... stepping motor, 23 ... lead screw mechanism, 24 ... drive rack, 25a, 25b ... lens holding member, 26 ... angle, 27 ... guide shaft, 28 ... photo sensor

Claims (12)

[Claims] 1. A driving method of an optical head device for recording and / or reproducing an information signal by irradiating a recording medium with a light beam through a main lens, wherein an expander lens is provided in series with the main lens. A method for driving an optical head device, wherein the expander lens is driven by using a rotary motor. 2. The method of driving an optical head device according to claim 1, wherein the rotary motor is a stepping motor, and the expander lens is driven via a lead screw mechanism or a gear mechanism. 3. The method of driving an optical head device according to claim 1, wherein the rotary motor is a direct current motor, and the expander lens is driven via a lead screw mechanism or a gear mechanism. 4. The light beam applied to a predetermined portion of the recording medium when the recording medium is first mounted is detected, and the expander lens is driven based on the detection signal. 2. The method of driving the optical head device according to 1. 5. A drive device of an optical head device for irradiating a recording medium with a light beam through a main lens to record and / or reproduce an information signal, wherein an expander lens is provided in series with the main lens. A drive mechanism for driving the expander lens is also provided, and the drive source of the drive mechanism is a rotary motor. 6. The driving device of an optical head device according to claim 5, wherein the rotary motor is a stepping motor, and the expander lens is driven via a lead screw mechanism or a gear mechanism. 7. The drive device for an optical head device according to claim 5, wherein the rotary motor is a DC motor, and drives the expander lens via a lead screw mechanism or a gear mechanism. 8. A detector is provided for detecting a light beam applied to a predetermined portion of the recording medium when the recording medium is first mounted, and the expander lens is driven based on the detection signal. The drive device for an optical head device according to claim 5, wherein the drive device is an optical head device. 9. An optical information processing device having an optical head device for irradiating a recording medium with a light beam through a main lens to record and / or reproduce an information signal, An optical information processing apparatus, wherein an expander lens is provided in series, a drive mechanism for driving the expander lens is provided, and a drive source of the drive mechanism is a rotary motor. 10. The optical information processing apparatus according to claim 9, wherein the rotary motor is a stepping motor, and drives the expander lens via a lead screw mechanism or a gear mechanism. 11. The optical information processing apparatus according to claim 9, wherein the rotary motor is a direct current motor, and the expander lens is driven via a lead screw mechanism or a gear mechanism. 12. A detecting device for detecting a light beam applied to a predetermined portion of the recording medium when the recording medium is first attached, and the expander lens is driven based on the detection signal. The optical information processing apparatus according to claim 9, characterized in that.