JP6008579B2 - Optical pickup device - Google Patents

Description

  The present invention relates to an optical pickup device in which a pickup main body having an objective lens is mounted on a moving base that moves along a recording surface of a recording medium, and the inclination posture of the pickup main body can be adjusted on the moving base.

  2. Description of the Related Art An optical pickup device that uses various optical discs such as DVDs, CDs, and Blu-ray discs as a recording medium is provided with a moving base that moves along the recording surface of the optical disc, and an objective lens that faces the recording surface. A pickup body equipped with is mounted.

  The pickup body is supported so that the tilt posture can be adjusted on the moving base, and can be adjusted so that the opposing angle between the optical axis of the objective lens and the recording surface of the recording medium is as vertical as possible.

  In the optical pickup devices described in Patent Literature 1 and Patent Literature 2 below, a side piece extending laterally from the holding portion of the objective lens is provided on the pickup base constituting the pickup body. Is provided with a downward projection, and a hole is formed in the installation surface of the moving base to fit the projection. And the side piece is urged downward by a leaf spring, and the projection is pressed against the hole.

  Two adjusting screws are inserted into the moving base from the lower side, and each adjusting screw is screwed to the pickup base. By rotating the two adjusting screws, the pickup main body can tilt with the contact portion between the projection and the hole as a fulcrum.

JP 2002-279665 A JP 2004-13977 A

  In the conventional optical pickup devices described in Patent Document 1 and Patent Document 2, a side piece that extends to the side at the same height as the holding portion of the objective lens is provided in the pickup body. A protrusion serving as an inclination fulcrum is formed.

  Therefore, in the moving base, it is necessary to form the installation surface in which the hole portion to be fitted to the protrusion is formed at a high position, and the height dimension of the moving base is increased and the weight is likely to be increased.

  Further, a leaf spring that presses the side piece of the pickup base downward is fixed to the upper surface of the moving base, and is disposed at a high position approaching the recording surface of the recording medium. Therefore, the plate thickness of the leaf spring cannot be increased, and the amount of vertical deflection cannot be increased, making it difficult to design the leaf spring. Furthermore, since the leaf spring is exposed on the upper surface of the moving base, an unintentional external force may act on the leaf spring during assembly work or maintenance work, which may cause plastic deformation.

In addition, since the distance between the tilt fulcrum of the contact portion between the protrusion and the hole and the optical axis of the objective lens is long, the light of the objective lens is tilted when the posture of the pickup body is tilted around the fulcrum. There is a drawback that the ratio of the amount of movement of the objective lens in the vertical direction to the tilt angle of the shaft becomes large.

  The present invention solves the above-described conventional problems, and the tilt fulcrum formed at the contact portion between the pickup main body and the moving base can be disposed below the objective lens, and the tilt fulcrum is disposed on the objective lens. It is an object of the present invention to provide an optical pickup device that can be set at a position close to.

The present invention provides a moving base that moves along a recording surface of a recording medium, a pickup main body mounted on the moving base, an objective lens that is provided on the pickup main body and faces the recording surface, and through the objective lens. In an optical pickup device provided with an optical device that gives light to the recording surface,
At least a part of the pickup main body is formed of a metal plate, and the metal plate is bent at a substantially right angle downward from the upper plate portion and the side plate portion extending in the optical axis direction of the objective lens. And a fulcrum piece bent at a substantially right angle so as to face the upper plate part from the lower side of the side plate part, which is the side away from the recording medium, toward the inside of the pickup main body. ,
Between the fulcrum piece and the moving base, a fulcrum abutting portion that is an inclination fulcrum of the pickup body is formed, and at the fulcrum abutting portion, the fulcrum piece is pressed against the moving base by a leaf spring. And
A posture adjusting mechanism is provided between the moving base and the pickup main body to tilt the pickup main body with the fulcrum contact portion as a fulcrum .
The leaf spring has a base fixed to the moving base, a tip entering between the upper plate and the fulcrum piece, and the fulcrum piece being pressed against the moving base by the tip. It is what.

  In the optical pickup device of the present invention, the fulcrum abutting portion serving as the tilt fulcrum of the pickup main body is disposed on the lower side farther from the recording medium than the objective lens. The moving base can be made thin. Further, since the leaf spring can be arranged below the objective lens, the thickness and shape of the leaf spring can be freely set, and the amount of bending in the vertical direction can also be freely set.

  In addition, since the fulcrum contact portion and the objective lens can be brought close to each other, when the tilt adjustment of the optical axis of the objective lens is performed, the ratio of the vertical movement amount of the objective lens to the tilt angle can be reduced. Become.

In the above structure, since the tip of the leaf spring is disposed in the space between the upper plate portion of the pickup body and the fulcrum piece, the leaf spring can be disposed at a position away from the recording medium, During maintenance work, it becomes difficult for fingers to touch the leaf spring.
The objective lens is held by a lens holder supported by a free end of a suspension wire, and a base end portion of the suspension wire is fixed to a wire support member fixed to the metal plate, and the suspension wire It is preferable that the front portion of the leaf spring is located in the space surrounded by the fulcrum piece, the side plate portion, and the upper plate portion on the free end side in the extending direction.

According to the present invention, in the fulcrum contact portion, a fulcrum protrusion is formed on one of the fulcrum piece and the moving base, and a support recess or a support hole is formed on the other, and the fulcrum protrusion is the support recess or the support hole. It can be configured as being pressed against the part.

  Further, according to the present invention, the side plate portion formed on the metal plate can be structured so as not to protrude to the side of the moving base, and the width of the optical pickup device can be shortened.

  In the optical pickup device of the present invention, the fulcrum contact portion serving as the tilt fulcrum of the pickup body can be disposed on the lower side away from the recording medium with respect to the objective lens. Therefore, the degree of freedom in designing the leaf spring is increased, and the moving base can be made thinner. Also, it becomes difficult for fingers to touch the leaf spring. Furthermore, it is possible to shorten the amount of vertical movement of the objective lens with respect to the adjustment angle of the optical axis of the objective lens.

The perspective view of the optical pick-up apparatus of embodiment of this invention, An exploded perspective view showing a pickup body, a leaf spring and an adjusting screw; Sectional drawing which cut | disconnected the optical pick-up apparatus of FIG. 1 by the III-III line | wire, Sectional drawing which cut | disconnected the optical pick-up apparatus of FIG. 1 by the IV-IV line,

  An optical pickup device 1 shown in FIG. 1 is mounted on a disk device that reproduces and records data recorded on various optical disks such as a DVD, a CD, or a Blu-ray disk. The R direction shown in FIG. 1 is a radial direction, which is the radial direction of an optical disc that is a recording medium. The T direction is the tangential direction and is the tangential direction of the optical disc.

  The optical pickup device 1 has a moving base 10. The moving base 10 is made of a light metal material such as an aluminum alloy or a synthetic resin material.

  As shown in FIGS. 1 and 4, a reference bearing hole 11 is opened on the right side of the movable base 10 in the figure, and a bearing recess 12 is formed on the left side in the figure. As shown in FIG. 4, in the disk device, a reference guide shaft 2 and a drive screw shaft 3 are provided in parallel to each other, and each shaft extends in the R direction. The reference bearing hole 11 of the moving base 10 is inserted so that almost no gap is formed in the reference guide shaft 2. A bearing recess 12 is disposed on the outer periphery of the drive screw shaft 3.

  An engagement plate spring 13 is provided on the left side of the moving base 10 in the figure, and an engagement protrusion 13 a provided on the engagement plate spring 13 is slidably fitted in a thread groove formed on the outer periphery of the drive screw shaft 3. ing. When the drive screw shaft 3 rotates, a driving force in the axial direction is applied to the moving base 10 via the engagement leaf spring 13, and the moving base 10 moves in the R direction with the reference guide shaft 2 as a movement reference, and the recording medium It moves along the recording surface of the optical disc.

  As shown in FIGS. 1 and 4, a concave portion 14 is formed in the central portion of the moving base 10, and a pickup main body 20 is disposed in the concave portion 14.

  As shown in FIG. 2, the pickup body 20 has a pickup base 30. The pickup base 30 is formed by bending a metal plate. The pickup base 30 includes a first upper plate portion 31 and a second upper plate portion 32 that are separated from each other in the left-right direction, and the first upper plate portion 31 and the second upper plate portion 32 are arranged in a first direction. The side plate portion 33 and the second side plate portion 34 are connected. The first side plate portion 33 and the second side plate portion 34 are substantially perpendicular to both sides of the first upper plate portion 31 and the second upper plate portion 32, that is, in a direction away from the optical disk as a recording medium. It is bent.

  As shown in FIGS. 1 and 2, a magnet holding piece 35 and a counter yoke piece 36 are bent downward on the first upper plate portion 31 so as to face each other. Similarly, the magnet holding piece 37 and the opposing yoke piece 38 are bent downward on the second upper plate portion 32 so as to face each other. The magnet 21 is fixed to the surface of the magnet holding piece 35 facing the counter yoke piece 36, and the magnet 22 is fixed to the surface of the magnet holding piece 37 facing the counter yoke piece 38.

  The pickup base 30 is integrally formed with a fulcrum piece 41 that is bent at a substantially right angle from the lower left side of the first side plate portion 33 toward the inside of the pickup base 30 (inward of the pickup body 20). ing. The pickup base 30 is integrally formed with an adjustment piece 42 bent from the first side plate portion 33 and an adjustment piece 43 bent from the second side plate portion 34.

  The surfaces of the first upper plate portion 31, the second upper plate portion 32, the fulcrum piece 41, and the two adjustment pieces 42, 43 are substantially parallel to the TR plane. One adjustment piece 42 is located away from the fulcrum piece 41 mainly in the T direction, and the other adjustment piece 43 is located away from the fulcrum piece 41 mainly in the R direction.

  As shown in FIGS. 3 and 4, the fulcrum piece 41 faces the lower side of the first upper plate portion 31. The fulcrum piece 41 is integrally formed with a downward fulcrum protrusion 41a. The fulcrum protrusion 41a is formed by pressing a metal plate constituting the fulcrum piece 41 downward. As a result, a concave portion 41b is formed on the upper surface of the fulcrum piece 41. The fulcrum protrusion 41a is a protruding surface whose downward surface approximates a spherical surface.

  As shown in FIG. 2, a female screw hole 42 a is formed in one adjustment piece 42, and a female screw hole 43 a is formed in the other adjustment piece 43.

  As shown in FIGS. 1 and 2, a lens holder 23 is disposed between the first upper plate portion 31 and the second upper plate portion 32 of the pickup base 30. An objective lens 24 is held by the lens holder 23. The optical axis O of the objective lens 24 is ideally oriented perpendicular to the R direction and the T direction.

  As shown in FIGS. 1 and 2, a wire support member 25 is fixed to the pickup base 30 on the right side in the drawing. The base end portions of the four suspension wires 26 are fixed to the wire support member 25, and the suspension wires 26 extend under the second upper plate portion 32 of the pickup base 30 in parallel with each other. The lens holder 23 is supported on the free end of each suspension wire 26. Therefore, the lens holder 23 can be finely moved in the R direction and the vertical direction along the optical axis O.

  The lens holder 23 is provided with a focusing coil and a tracking coil, and both coils are opposed to the magnets 21 and 22. A driving current is applied to the focusing coil and the tracking coil through the four suspension wires 26.

  As shown in FIGS. 3 and 4, a support surface 15 is formed on the upper surface of the moving base 10, and a support recess 16 is formed on the support surface 15. The support recess 16 is a tapered hole having a circular cross section and gradually decreasing in diameter as it goes downward. Instead of the support recess 16 that is a tapered hole, a support recess or a support hole that has a circular cross section and whose diameter extends uniformly in the vertical direction may be formed.

  As shown in FIGS. 3 and 4, the fulcrum protrusion 41 a formed on the pickup base 30 of the pickup main body 20 is fitted into the support recess 16 to form a fulcrum contact portion. In the fulcrum contact portion, an upward support protrusion may be formed on the support surface 15 of the moving base 10, and a support recess may be formed on the fulcrum piece 41 of the pickup base 30.

As shown in FIGS. 1, 2, and 4, a leaf spring 45 is attached on the moving base 10. The leaf spring 45 is formed of a metal plate, and a mounting hole 45b through which the mounting screw 46 is inserted is formed in the base portion 45a. A positioning portion 45c extends integrally from the base portion 45a to the rear, and a positioning hole 45d is opened in the positioning portion 45c. An urging protrusion 45 f that protrudes downward is integrally formed on the tip 45 e of the leaf spring 45. Between the base portion 45a and the tip portion 45e is an elastic arm portion 45g. As shown in FIG. 4, a bent portion 45h is formed at the center of the elastic arm portion 45g.

  As shown in FIG. 4, an installation surface 17 having a female screw hole is formed on the upper surface on the left side of the moving base 10, a positioning surface 18 is formed at a position higher than the left side, and a positioning projection 19 is integrated with the positioning surface 18. Is formed. The base 45 a of the leaf spring 45 is installed on the installation surface 17, and the positioning unit 45 c is installed on the positioning surface 18. The positioning protrusion 19 is fitted into the positioning hole 45d, the leaf spring 45 is positioned, and the mounting screw 46 inserted into the mounting hole 45b is screwed into the female screw hole of the installation surface 17 so that the base portion 45a of the leaf spring 45 is secured. Is fixed on the moving base 10.

  As shown in FIGS. 3 and 4, the tip 45e of the leaf spring 45 enters the space between the first upper plate 31 and the fulcrum piece 41 of the pickup base 30, and is formed in the tip 45e. The biasing protrusion 45f is fitted into the recess 41b formed in the fulcrum piece 41 from above. In a state where the urging protrusion 45f is fitted in the recess 41b, the elastic arm portion 45g is lifted upward from the installation surface 17 of the moving base 10 and bent, and the moving base 10 is elastically based on this bending. The fulcrum protrusion 41 a of the fulcrum piece 41 is pressed against the support recess 16 of the support surface 15 of the moving base 10.

  As shown in FIG. 2, the optical pickup device 1 is provided with adjustment screws 51 and 52 that constitute a posture adjustment mechanism 50. As shown in FIG. 3, one adjustment screw 51 is inserted upward from below into an insertion hole 10 a penetrating the moving base 10 up and down, and the tip of the adjustment screw 51 is the adjustment piece 42 of the pickup base 30. Is screwed into the female screw hole 42a. Similarly, the other adjustment screw 52 is also inserted upward from below into an insertion hole penetrating the moving base 10 up and down, and its tip is screwed into a female screw hole 43 a formed in the adjustment piece 43 of the pickup base 30. Has been.

  As shown in FIG. 4, the optical device 60 is mounted on the moving base 10. The optical device 60 includes a light transmitting / receiving element 61 disposed on the left side of the moving base 10 in the figure. The light transmitting / receiving element 61 is a light emitting element and a light receiving element mounted on the same substrate. The optical device 60 has a lens 62 and a mirror 63 located on the lower side of the pickup body 20. As shown in FIG. 3, the laser light emitted from the light transmitting / receiving element 61 passes through the optical path 10b formed at the bottom of the moving base 10, passes through the lens 62, is reflected by the mirror 63, and faces upward. It is done. This laser beam is condensed by the objective lens 24 and applied to the recording surface of the optical disc.

  The posture adjustment process of the pickup body 20 in the optical pickup device 1 having the above structure will be described.

  The optical pickup device 1 is made to face the recording surface of the inspection disk and the adjusting screws 51 and 52 are rotated so that the pickup main body is centered on the fulcrum contact portion where the fulcrum protrusion 41a and the support recess 16 are in contact. 20 tilt posture is adjusted.

  When one adjustment screw 51 constituting the attitude adjustment mechanism 50 is rotated, the pickup body 20 rotates in the α direction about the R axis, and the optical axis O of the objective lens 24 in the tangential direction (T direction). The tilt angle is adjusted. When the other adjustment screw 52 is rotated, the pickup main body 20 rotates in the β direction about the T axis, and the tilt angle of the optical axis O of the objective lens 24 in the radial direction (R direction) is adjusted.

  By this adjustment, the optical axis O of the objective lens 24 is adjusted so as to be as perpendicular as possible to the recording surface of the optical disc.

  The pickup base 30 is provided with a fulcrum piece 41 bent at a substantially right angle from the lower portion of the first side plate portion 33 toward the inside of the pickup body 20, and the fulcrum piece 41 is provided with a fulcrum protrusion 41 a. Yes. Therefore, the support surface 15 of the moving base 10 for the fulcrum protrusion 41a to contact can be formed at a position sufficiently lower than the objective lens 24, that is, a position away from the optical disk as a recording medium. Since the support surface 15 having the support recess 16 can be formed at a low position, the height of the moving base 10 can be reduced, and the optical pickup device 1 can be easily reduced in thickness and weight.

  As shown in FIG. 4, since the fulcrum piece 41 of the pickup base 30 is at a lower position than the objective lens 24, the leaf spring 45 that presses the fulcrum piece 41 downward is also sufficiently separated from the objective lens 24 downward. Placed in a different position. Since the leaf spring 45 can be disposed at a position away from the lower surface of the optical disk, the thickness dimension of the leaf spring 45 and the degree of freedom in designing the bending structure are increased. As shown in FIG. 4, the leaf spring 45 of the embodiment has a structure in which a bent portion 45h is formed on an elastic arm portion 45g, and the bent portion 45h is lifted upward. Since the elastic arm portion 45g can be separated upward from the installation surface 17 of the moving base 10, it is possible to exert an elastic force that presses the fulcrum piece 41 downward over the entire length of the elastic arm portion 45g. Therefore, it is possible to always contact the fulcrum protrusion 41a and the support recess 16 with a strong force.

  As shown in FIG. 4, the leaf spring 45 has a bent portion 45 h and a positioning portion 18 at a higher position and has a three-dimensional structure in the vertical direction. Since the entire spring 45 is disposed at a position lower than the objective lens 24, the leaf spring 45 and its supporting structure do not hit the lower surface of the optical disk.

  Since the leaf spring 45 is in a low position, it is easy to avoid an excessive bending force from being applied to the leaf spring 45 by a finger when the optical pickup device 1 is assembled or maintained. In particular, since the tip portion 45e of the leaf spring 45 is disposed inside a space surrounded by the first upper plate portion 31, the first side plate portion 33 and the fulcrum piece 41 of the pickup base 30, a finger or the like Is less likely to hit the tip 45e of the leaf spring 45, and the leaf spring 45 is easily protected.

  As shown in FIG. 2, since a part of the pickup base 30 is bent toward the inside of the pickup body 20 to form the fulcrum piece 41, the fulcrum where the fulcrum protrusion 41a and the support recess 16 abut. The distance L1 between the contact portion and the optical axis O of the objective lens 24 is shortened.

  When the posture adjustment for rotating the pickup main body 20 in the α direction and the β direction is performed, the center of the objective lens 24 performs a circular motion with the distance L1 as a radius around the fulcrum contact portion. As shown in FIG. 2, the amount of vertical movement of the objective lens 24 relative to the tilt angle of the optical axis O of the objective lens 24 can be shortened by shortening the distance L1. Therefore, when the tilt of the optical axis O of the objective lens 24 is adjusted, the amount by which the objective lens 24 moves up and down is shortened.

  When operating the optical pickup device 1, the drive screw shaft 3 is rotated to move the moving base 10 in the R direction.

As shown in FIG. 1, the side surface 10c of the moving base 10 facing the inner circumferential side of the disk is a concave curved surface that is a part of the cylindrical surface, and the moving base 10 moves in the R direction to move the inner circumferential side of the disk. , The concave side surface 10c approaches the outer peripheral surface of the spindle motor that rotates the optical disk.

  As shown in FIG. 3, since the fulcrum piece 41 constituting the fulcrum contact portion is bent toward the inside of the pickup main body 20, the fulcrum piece 41 does not protrude from the side surface 10c toward the center of the disk. Further, since the side surface 10c can be formed close to the objective lens 24, the width dimension in the R direction of the optical pickup device 10 can be configured to be short.

  The laser light emitted from the light transmitting / receiving element 61 passes through the lens 62, is reflected by the mirror 63, and is given to the recording surface of the optical disk. The reflected light from the recording surface is received by the light transmitting / receiving element 61 through the mirror 63 and the lens 62. Information received on the optical disk is read by the received light output, and a focus error signal and a tracking error signal are detected. A current for correcting the error signal is applied to a focusing coil and a tracking coil provided in the lens holder 23, and the lens holder 23 is moved in the vertical direction along the optical axis O and in the R direction to correct the error signal. Is done.

DESCRIPTION OF SYMBOLS 1 Optical pick-up apparatus 2 Reference | standard guide shaft 3 Screw shaft 10 Moving base 15 Support surface 16 Support recessed part 20 Pickup main body 23 Lens holder 24 Objective lens 26 Suspension wire 30 Pickup base 31 1st upper plate part 32 2nd upper plate part 33 First side plate portion 34 Second side plate portion 41 Support point piece 41a Support point protrusions 42, 43 Adjustment pieces 42a, 43a Female screw hole 45 Leaf spring 45a Base portion 45e Tip portion 45f Energizing protrusion portion 45g Elastic arm portion 46 Mounting screw 50 Posture Adjustment mechanisms 51, 52 Adjustment screw 60 Optical device 61 Light transmitting / receiving element 62 Lens 63 Mirror

Claims (4)

A moving base that moves along the recording surface of the recording medium, a pickup body mounted on the moving base, an objective lens that is provided on the pickup body and faces the recording surface, and the recording surface through the objective lens In an optical pickup device provided with an optical device that provides light,
At least a part of the pickup main body is formed of a metal plate, and the metal plate is bent at a substantially right angle downward from the upper plate portion and the side plate portion extending in the optical axis direction of the objective lens. And a fulcrum piece bent at a substantially right angle so as to face the upper plate part from the lower side of the side plate part, which is the side away from the recording medium, toward the inside of the pickup main body. ,
Between the fulcrum piece and the moving base, a fulcrum abutting portion that is an inclination fulcrum of the pickup body is formed, and at the fulcrum abutting portion, the fulcrum piece is pressed against the moving base by a leaf spring. And
A posture adjusting mechanism is provided between the moving base and the pickup main body to tilt the pickup main body with the fulcrum contact portion as a fulcrum .
The leaf spring has a base fixed to the moving base, a tip entering between the upper plate and the fulcrum piece, and the fulcrum piece being pressed against the moving base by the tip. Optical pickup device.   The objective lens is held by a lens holder supported at a free end of a suspension wire, and a base end portion of the suspension wire is fixed to a wire support member fixed to the metal plate;
  The front portion of the leaf spring is located in a space surrounded by the fulcrum piece, the side plate portion, and the upper plate portion on the free end side in the extending direction of the suspension wire. Item 5. The optical pickup device according to Item 1. In the fulcrum contact portion, a fulcrum protrusion is formed on one of the fulcrum piece and the moving base, and a support recess or a support hole is formed on the other, and the fulcrum protrusion is pressed against the support recess or the support hole. The optical pickup device according to claim 1 or 2.   4. The optical pickup device according to claim 1, wherein the side plate portion formed on the metal plate does not protrude to the side of the moving base. 5.

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