JP2009181663A - Optical pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup device capable of preventing the collision of an actuator body with a disk recording medium even when no information is read from the disk recording medium. <P>SOLUTION: The optical pickup device 1 includes a pickup base 2 disposed to move in the radial direction of an optical disk, an actuator body 9 having an objective lens 11 facing the optical disk with a space attached thereto, and an actuator driving part 10 having the actuator body 9 attached to the pickup base 2 to move in at least the radial direction and the thickness direction of the optical disk D. The optical pickup device 1 is further provided with a motor 4 and a lens holder 5 disposed in the pickup base 2. The lens holder 5 is disposed to move to a position for regulating the contact of the actuator body 9 with the optical disk D by a driving force of the motor 4 and a permit position for permitting the contact of the actuator body 9 with the optical disk. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical pickup device used for an optical disk reproducing device or the like.

  Various kinds of optical pickups have been conventionally used for reading information recorded on an optical disk as a disk-type recording medium such as a CD (Compact Disk), a DVD (Digital Versatile Disc), or a BD (Blu-ray Disc). An apparatus (for example, see Patent Document 1) is used.

  The optical pickup device disclosed in Patent Document 1 described above is an actuator in which a pickup base that is movable in the radial direction of an optical disk such as a CD described above, and an objective lens that is opposed to the optical disk with a space therebetween. A main body and an actuator driving unit in which the actuator main body is attached to the pickup base so as to be movable in both the radial direction and the thickness direction of the optical disk.

  Magnets that are spaced apart from each other in the circumferential direction of the optical disk and that position the actuator body between them are attached to the pickup base. A printed coil is attached to the actuator body so as to face the magnet with a gap. The actuator driving unit includes a plurality of linear elastic members that are made of a highly conductive material and have an elastic force such as a copper alloy.

  The linear elastic member has one end attached to the actuator body and the other end attached to the pickup base. The longitudinal direction of the linear elastic member is along the circumferential direction of the optical disc. Since the linear elastic member is elastically deformable, the actuator main body is supported so as to be displaceable with respect to the pickup base.

  Further, the linear elastic member has one end portion electrically connected to the printed coil, and the other end portion on the pickup base side is supplied with a current for focus control and tracking control from the outside.

In the optical pickup device having the above-described configuration, a current for focus control and tracking control is supplied to the print coil via the linear elastic member, and the print coil and the magnet cooperate with each other, so that the actuator main body, that is, the objective. The lens is moved at least along both the thickness direction of the optical disk, that is, the focus direction, and the radial direction of the optical disk, that is, the tracking direction, and laser light is irradiated to a desired position on the information recording surface of the optical disk. Thus, the optical pickup device reads information from the optical disc.
JP 2005-122828 A

  When reading the information from the optical disk, the optical pickup device described above supplies current to the print coil via the linear elastic member so that the objective lens is always focused on a desired position on the information recording surface. . For this reason, even if vibration is applied from the outside, the actuator body can be prevented from vibrating with respect to the pickup base, and the objective lens is prevented from coming into contact with the optical disk. In addition, when no information is read from the optical disk, no current is supplied to the printed coil via the linear elastic member. Therefore, when vibration is applied from the outside, the actuator body is moved by the elasticity of the linear elastic member. Free vibration with respect to the pickup base. In such a case, the actuator body is provided with a protrusion made of a material that comes into contact with the optical disk prior to the objective lens and whose contact portion does not easily damage the optical disk so that the objective lens does not contact the optical disk.

  However, even if the above-described protrusion is a material that does not easily damage the optical disk, when the magnitude and number of vibrations increase, contact marks remain on the optical disk, and in the worst case, the optical disk is damaged. Further, when dust or the like adheres to the tip of the protrusion, the dust attached to the protrusion comes into contact with the optical disk due to vibration, thereby damaging the optical disk.

  Accordingly, an object of the present invention is to provide an optical pickup device capable of preventing the actuator body from colliding with a disk-shaped recording medium even when information is not read from the disk-shaped recording medium, for example. It is in.

  In order to solve the above-mentioned problems and achieve the object, the present invention as claimed in claim 1 is characterized in that a pickup base provided movably in a radial direction of the disk-shaped recording medium and a space between the disk-shaped recording medium. An optical pickup device comprising: an actuator main body to which an opposing objective lens is attached; and an actuator driving unit that is attached to the pickup base so that the actuator main body can move at least in the radial direction and the thickness direction of the disk-type recording medium. A drive source for moving an optical component provided on the pickup base and through which a laser beam for reading information from the disk-type recording medium passes, and the actuator body is driven by the driving force of the drive source. A restriction position for restricting contact with the recording medium, and the actuator body It is characterized in that and a restriction member provided movably over the allowable position for allowing the contact with the disc-shaped recording medium.

  Hereinafter, an optical pickup device according to an embodiment of the present invention will be described. An optical pickup device according to an embodiment of the present invention allows an actuator main body to come into contact with a restriction position that restricts the actuator body from coming into contact with a disk-type recording medium by a driving force of a driving source provided in the pickup base. A restricting member that is movable over the position is provided. For this reason, when information is not read from the disk-shaped recording medium, the actuator body can be prevented from colliding with the disk-shaped recording medium by positioning the restricting member at the restricting position.

  Further, the restricting member may include a fixing portion that fixes the actuator body to the pickup base when positioned in the restricting position. In this case, when the information is not read from the disk-type recording medium, the actuator main body is fixed when the restricting member is positioned at the restriction position, so that the actuator main body can be more stably prevented from colliding with the disk-type recording medium. can do.

  Furthermore, the limiting member may be attached with an optical component. In this case, there is no need to provide a restricting member exclusively for restricting the movement of the actuator body, so that the number of parts can be reduced.

  Furthermore, when reading information from a multi-layer disc-shaped recording medium, the restricting member moves to any one of a plurality of allowable positions located within a predetermined range according to the layer of the recording surface to reduce the aberration of the laser beam. If correction is performed and information is not read from the disk-type recording medium, the information may be moved to a restriction position located outside a predetermined range. In this case, since the restricting member is not positioned at the restricting position when reading information from the disk-type recording medium, it is possible to prevent the movement of the actuator body from being restricted during the reading of information.

  An optical pickup device 1 according to a first embodiment of the present invention will be described with reference to FIGS. An optical pickup device 1 is an optical disc reproducing device as an information processing device for reproducing information recorded on an optical disc D (shown in FIGS. 2, 4 and 6) as a disc-type recording medium such as a CD, DVD, or BD. In order to read the information recorded on the optical disc D, the focus control for controlling the distance between the information recording surface of the optical disc D and an objective lens 11 to be described later with respect to the warp or shake of the optical disc D, and the optical disc D When the optical disk D to be reproduced is a multilayer BD, a collimator to be described later according to the layer of the recording surface to be reproduced is performed. The position of the lens 7 is changed.

  As shown in FIG. 1, the optical pickup device 1 includes a pickup base 2, an actuator device 3, a motor 4 as a drive source, a lens holder 5 as a limiting member, and μCOM (not shown) as control means. Yes. The pickup base 2 is provided so as to be movable along the radial direction of the optical disc D on the lead screw 6 by a motor (not shown) or a lead screw 6 that is driven to rotate about an axis by a driving force from the motor. .

  The pickup base 2 is formed in a box shape and accommodates a light source as an optical component, a collimator lens 7, a beam splitter, a light receiver, and the like. The optical components such as the light source, the collimator lens 7, the beam splitter, and the light receiver described above generate laser light having an optimum wavelength for the light source to read information from the optical disk D, and guide the laser light to the disk D. The laser beam reflected from D is guided to the light receiver and received by the light receiver.

  As shown in FIG. 1, the actuator device 3 includes an actuator base 8, an actuator body 9, and an actuator driving unit 10.

  The actuator base 8 is fixed to the pickup base 2. The actuator base 8 and the pickup base 2 are attached with magnets (not shown) arranged at positions where the actuator main body 9 is sandwiched between each other along the circumferential direction of the optical disc D.

  The actuator body 9 is formed in a flat box shape, and an objective lens 11 facing the optical disc D and a print coil (not shown) are attached.

  In the illustrated example, two objective lenses 11 are provided. One objective lens 11 on the near side in FIG. 1 passes laser light for CD and DVD, and the other objective lens 11 on the far side in FIG. 1 passes laser light for BD. These objective lenses 11 irradiate the optical disk D with the laser light emitted from the light source for reading information and passed through the optical components, and pass the laser light through the laser light reflected from the optical disk D. Is a lens for outputting to the optical component.

  In the illustrated example, two print coils are provided. Each of these printed coils is opposed to the magnet with a gap. The printed coil is attached to the actuator body 9 with a known adhesive or the like. The printed coil has a coil wiring pattern formed on a substrate, and a focus control coil and a tracking control coil are formed respectively. The printed coil is electrically connected to a linear elastic member 13 described later by soldering.

  The actuator body 9 is provided with a protruding piece 12 as shown in FIG. The protruding piece 12 is provided at the tip of the actuator body 9 on the side away from the actuator base 8 and at the edge near the pickup base 2. The protruding piece 12 is integrally provided with a vertical portion 12a that protrudes from the edge of the actuator body 9 toward the pickup base 2, and a horizontal portion 12b that protrudes from the tip of the vertical portion 12a along the circumferential direction of the optical disc D. ing.

  The actuator driving unit 10 includes the magnet described above, the printed coil described above, and a plurality of linear elastic members 13. The linear elastic member 13 is made of a material having good elasticity and having an elastic force such as a copper alloy, and is formed in a rod shape (linear shape) extending linearly. In the illustrated example, four linear elastic members 13 are provided and are arranged in parallel with the circumferential direction of the optical disc D, respectively. Of these four linear elastic members 13, the pair of linear elastic members 13 and the other pair of linear elastic members 13 are arranged with a space therebetween in the radial direction of the optical disc D, and each pair of lines. The elastic members 13 are arranged at intervals in the thickness direction of the optical disc D.

  Each linear elastic member 13 has one end attached to the actuator body 9 and the other end attached to the actuator base 8. The actuator body 9, the actuator base 8, and the linear elastic member 13 are integrally formed when the actuator body 9 and the actuator base 8 are formed by insert molding. That is, one end of the linear elastic member 13 is included in the actuator body 9, the other end is included in the actuator base 8, and the other part (that is, the central part) is fixed in an exposed state.

  Furthermore, the linear elastic member 13 has one end on the actuator body 9 side electrically connected to the printed coil, and the other end on the actuator base 8 side receives current for focus control and tracking control from the outside. Supplied. That is, the linear elastic member 13 is elastically deformed to support the actuator body 9 so as to be movable with respect to the actuator base 8, that is, the pickup base 2, and also has a function of wiring for supplying current to the printed coil. Hold.

  The actuator drive unit 10 is capable of moving the actuator body 9 in at least the radial direction and the thickness direction of the optical disc D by a printed coil and a magnet to which the linear elastic member 13 is elastically deformed and supplied with the above-described control current. The actuator base 8 is attached to the pickup base 2.

  The motor 4 is accommodated in the pickup base 2 and fixed to the pickup base 2. The motor 4 has a screw shaft 14 attached to its output shaft. The longitudinal direction of the screw shaft 14 is arranged in parallel with the circumferential direction of the optical disc D. Further, the motor 4 is arranged at a position along with the actuator device 3 along the radial direction of the optical disc D. Further, a guide shaft 15 parallel to the screw shaft 14 is provided in the vicinity of the screw shaft 14 attached to the output shaft of the motor 4.

  The lens holder 5 is integrally provided with a frame-shaped frame portion 16 and a rod-shaped portion 17. The frame-like portion 16 accommodates the above-described collimator lens 7 as an optical component inside, and the collimator lens 7 is attached. The rod-shaped portion 17 extends linearly from the outer peripheral surface of the frame-shaped portion 16 in the outer peripheral direction of the frame-shaped portion 16. A through hole 18 through which the guide shaft 15 passes and a nut portion 19 that is screwed to the screw shaft 14 are provided at the distal end of the rod-like portion 17 on the side away from the frame-like portion 16.

  When the screw shaft 14 is rotated around the axis by the driving force of the motor 4, the lens holder 5 is guided to the guide shaft 15 through the through hole 18 because the nut portion 19 is screwed with the screw shaft 14. , And moves along the longitudinal direction of the screw shaft 14. The lens holder 5 brings the collimator lens 7 into and out of contact with the actuator device 3. When the optical disk D to be reproduced is a multi-layer BD, the motor 4 moves the lens holder 5 and the collimator lens 7 in the circumferential direction of the optical disk D according to the layer of the recording surface to be reproduced, and the objective lens 11 The position of the collimator lens 7 is changed to a position where the spherical aberration on the information recording surface of the optical disc D becomes appropriate.

  Further, the lens holder 5 is integrally provided with a displacement limiting unit 20. The displacement limiting unit 20 is provided on the outer edge of the frame-like portion 16 near the actuator device 3. As shown in FIG. 2, the displacement restricting portion 20 includes a vertical standing portion 20a erected from the aforementioned outer edge portion of the frame-like portion 16 toward the optical disc D, and a frame-like portion 16 of the vertical standing portion 20a. A horizontal extending portion 20b extending from the tip toward the actuator device 3 is integrally provided.

  Further, when the lens holder 5 is moved along the longitudinal direction of the screw shaft 14 by the motor 4, the lens holder 5 moves between the restriction position shown in FIGS. 5 and 6 and the allowable position shown in FIGS. Is done. That is, the lens holder 5 is provided so as to be freely movable between the restriction position and the allowable position.

  In the restricting position, as shown in FIG. 6, the horizontal portion 12 b of the protruding piece 12 and the horizontal extending portion 20 b of the displacement restricting portion 20 overlap with each other along the thickness direction of the optical disc D. At this time, in a state where the linear elastic member 13 is not elastically deformed, the interval T2 between the horizontal portion 12b and the horizontal extending portion 20b is narrower than the interval T1 between the actuator body 9 and the optical disc D. For this reason, in the restricting position, even if the linear elastic member 13 is elastically deformed and the horizontal portion 12b and the horizontal extending portion 20b contact each other, the actuator body 9 does not contact the optical disc D. Thus, at the restriction position, the displacement restriction unit 20 cooperates with the protruding piece 12 to restrict the actuator body 9 from contacting the optical disk D.

  At the allowable position, the horizontal portion 12b of the protruding piece 12 and the horizontal extending portion 20b of the displacement limiting portion 20 do not overlap with each other along the thickness direction of the optical disc D. For this reason, in the permissible position, the actuator main body 9 can come into contact with the optical disc D when the linear elastic member 13 is elastically deformed. Thus, at the allowable position, the displacement limiting unit 20 allows the actuator body 9 to contact the optical disc D. The allowable position is a position other than the restriction position of the lens holder 5. For this reason, the allowable position of the lens holder 5 is formed in a predetermined range in the longitudinal direction of the screw shaft 14 where the horizontal portion 12b and the horizontal extending portion 20b do not overlap each other along the thickness direction of the optical disc D. 1 and 2 show the position of the lens holder 5 farthest from the actuator device 3 in the allowable position, and FIGS. 3 and 4 show the position of the lens holder 5 closest to the actuator device 3 in the allowable position. ing. That is, when reading information from the multilayer optical disk D, the lens holder 5 has a plurality of positions located within a predetermined range (within the range from the position in FIG. 1 to the position in FIG. 3) according to the layer of the recording surface. When the spherical aberration on the information recording surface is corrected by moving to any of the allowable positions and information is not read out, it moves to a regulation position (position in FIG. 6) located outside a predetermined range.

  The μCOM includes a central processing unit (CPU) that performs various processes according to a program, a ROM that is a read-only memory that stores a program for processes performed by the CPU, a work area that is used in various processes performed by the CPU, A RAM, which is a readable / writable memory having a data storage area for storing various data, is built in, and these are connected to each other by a bus line.

  The μCOM is connected to the print coil of the actuator driving unit 10 and controls the above-described current supplied to the print coil, thereby controlling the entire actuator device 3. Further, the μCOM is connected to the motor 4 described above and controls these operations to control the entire optical pickup device 1.

  When μCOM starts reading information from the optical disk D, first, the motor 4 is driven to position the lens holder 5 at an allowable position, and the lens holder 5 is positioned at an appropriate position within the allowable position. The information recording surface of the optical disc D is irradiated with laser light while supplying current for focus control and tracking control to the print coil via the linear elastic member 13, and information is read and reproduced.

  When μCOM stops irradiation of the information recording surface of the optical disk D with the laser beam and stops reading information from the optical disk D, the supply of current for focus control and tracking control to the print coil is stopped. The motor 4 is driven to position the lens holder 5 at the restriction position. As described above, when the information is not read from the optical disk D, the μCOM positions the lens holder 5 at the restriction position and restricts the actuator body 9 from contacting the optical disk D.

  According to this embodiment, the driving force of the motor 4 provided on the pickup base 2 moves between the restriction position for restricting the actuator body 9 from contacting the optical disc D and the allowable position for allowing the actuator body 9 to contact the optical disk D. A flexible lens holder 5 is provided. For this reason, when information is not read from the optical disk D, the actuator body 9 can be prevented from colliding with the optical disk D by positioning the lens holder 5 at the restriction position.

  When reading information from the optical disk D, the actuator body 9 can follow the movement of the optical disk D so that the information can be read from a desired position on the information recording surface by positioning the lens holder 5 at an allowable position. .

  Further, the lens holder 5 is provided with a collimator lens 7 as an optical component. For this reason, it is not necessary to provide a restricting member exclusively for restricting the movement of the actuator main body 9, so that the number of parts can be reduced.

  Next, an optical pickup device 1 according to a second embodiment will be described with reference to FIGS. The same parts as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  In the present embodiment, as shown in FIGS. 7 to 12, the protruding piece 12 extends linearly in a direction away from both the actuator base 8 and the optical disk D as it protrudes from the actuator body 9. Yes.

  In the present embodiment, the displacement restricting portion 20 approaches the actuator base 8 and the optical disc D as it protrudes from the frame-like portion 16 of the lens holder 5 as shown in FIGS. It extends in a straight line. In this embodiment, when the lens holder 5 is positioned at the restricting position, as shown in FIGS. 11 and 12, the protruding piece 12 and the displacement restricting portion 20 are closely overlapped with each other. For this reason, in the present embodiment, at the restriction position, the displacement limiting portion 20 closely overlaps the protruding piece 12 to fix the actuator body 9 to the pickup base 2 and the actuator body 9 contacts the optical disc D. To regulate. Specifically, when the displacement restricting portion 20 presses the protruding piece 12, the elastic force of the linear elastic member 13 works and the actuator body 9 is fixed. That is, the displacement limiting part 20 of the present embodiment is a fixed part described in claim 2. The displacement limiting portion 20 may have a shape that completely fixes the actuator main body 9 so as to sandwich the protruding piece 12.

  According to the present embodiment, the lens holder 5 includes the displacement limiting portion 20 as a fixing portion that fixes the actuator body 9 to the pickup base 2 when positioned at the restricting position. For this reason, when the lens holder 5 is positioned at the restricting position when information is not read from the optical disk D, the actuator main body 9 is fixed, so that the actuator main body 9 can be prevented from colliding with the optical disk D.

  According to the above-described embodiment, the lens holder 5 to which the collimator lens 7 as an optical component is attached is moved by the motor 4 between the restriction position and the allowable position. However, in the present invention, not only the collimator lens 7 but also a limiting member to which various optical components are attached may be moved. Further, in the present invention, it is of course possible to provide a dedicated member that is movably provided between the restricting position and the allowable position without attaching an optical component to the restricting member.

  According to the embodiment described above, the following optical pickup device 1 is obtained.

(Supplementary note) Pickup base 2 provided so as to be movable in the radial direction of the optical disc D;
An actuator body 9 having an objective lens 11 attached to the optical disc D with a gap therebetween;
An actuator drive unit 10 that is mounted on the pickup base 2 so that the actuator body 9 can move in at least the radial direction and the thickness direction of the optical disc D;
In the optical pickup device 1 comprising:
A motor 4 that is provided on the pickup base 2 and moves a collimator lens 7 through which a laser beam for reading information from the optical disk D passes;
The actuator 4 is movable between a restricting position where the actuator main body 9 is prevented from contacting the optical disk D and a permissible position where the actuator main body 9 is allowed to contact the optical disk D by the driving force of the motor 4. A lens holder 5 provided in
An optical pickup device 1 comprising:

  According to the remarks, the driving position of the motor 4 provided in the pickup base 2 covers the restriction position where the actuator body 9 is restricted from contacting the optical disk D and the allowable position where the actuator body 9 is allowed to contact the optical disk D. A movable lens holder 5 is provided. For this reason, when information is not read from the optical disk D, the actuator body 9 can be prevented from colliding with the optical disk D by positioning the lens holder 5 at the restriction position.

  In addition, the Example mentioned above only showed the typical form of this invention, and this invention is not limited to an Example. That is, various modifications can be made without departing from the scope of the present invention.

1 is a perspective view of an optical pickup device according to a first embodiment of the present invention. It is sectional drawing of the principal part of the optical pick-up apparatus shown by FIG. FIG. 2 is a perspective view of a state in which a lens holder positioned at an allowable position of the optical pickup device illustrated in FIG. 1 is positioned closest to an actuator body. It is sectional drawing of the principal part of the optical pick-up apparatus shown by FIG. FIG. 2 is a perspective view showing a state where a lens holder of the optical pickup device shown in FIG. 1 is positioned at a restriction position. It is sectional drawing of the principal part of the optical pick-up apparatus shown by FIG. It is a perspective view of the optical pick-up apparatus concerning the 2nd Example of this invention. It is sectional drawing of the principal part of the optical pick-up apparatus shown by FIG. FIG. 8 is a perspective view of a state in which the lens holder positioned at the allowable position of the optical pickup device illustrated in FIG. 7 is positioned closest to the actuator body. It is sectional drawing of the principal part of the optical pick-up apparatus shown by FIG. FIG. 8 is a perspective view of a state in which a lens holder of the optical pickup device illustrated in FIG. 7 is positioned at a restriction position. It is sectional drawing of the principal part of the optical pick-up apparatus shown by FIG.

Explanation of symbols

1 Optical pickup device 2 Pickup base 4 Motor (drive source)
5 Lens holder (restriction member)
7 Collimator lens (optical component)
9 Actuator body 10 Actuator drive unit 11 Objective lens 20 Displacement limiting unit (fixed unit)
D Optical disc (disc-type recording medium)

Claims (4)

A pickup base provided to be movable in the radial direction of the disk-type recording medium;
An actuator body having an objective lens attached to the disk-shaped recording medium with a gap therebetween;
An actuator drive unit that is attached to the pickup base so that the actuator body is movable in at least the radial direction and the thickness direction of the disc-shaped recording medium;
In an optical pickup device comprising:
A drive source for moving an optical component provided in the pickup base and through which a laser beam for reading information from the disk-shaped recording medium is passed;
A restriction position that restricts the actuator body from coming into contact with the disk-shaped recording medium by a driving force of the drive source, and a permissible position that allows the actuator body to contact the disk-shaped recording medium. A restricting member provided movably,
An optical pickup device comprising:   The optical pickup device according to claim 1, wherein the limiting member includes a fixing portion that fixes the actuator body to the pickup base when positioned in the restriction position.   The optical pickup device according to claim 1, wherein the optical member is attached to the restricting member.   When the information is read from the multi-layer disc-shaped recording medium, the limiting member moves to one of a plurality of allowable positions located within a predetermined range according to the layer of the recording surface, and the aberration of the laser light 4. The optical pickup device according to claim 3, wherein when the information is not read out from the disk-type recording medium, the optical pickup device moves to the restriction position located outside the predetermined range.

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