JP3943059B2 - Optical head device - Google Patents

Description

  The present invention relates to an optical head device used for reproducing an optical recording disk such as a CD or a DVD.

  An optical head device used for recording and reproduction of an optical recording disk such as a CD or a DVD generally has an objective lens drive for driving an objective lens for converging light emitted from a light source onto the optical recording disk in a tracking direction and a focusing direction. And a device frame in which an optical system that holds the objective lens driving mechanism and transmits and receives laser light to and from the objective lens is disposed.

  Here, in order to accurately record or reproduce information on the optical recording disk, the optical axis of the objective lens mounted on the objective lens driving mechanism is optical when the objective lens driving mechanism is attached to the apparatus frame. It is necessary to set the recording disk so that it is exactly perpendicular to the disk surface. Therefore, an objective lens tilt adjustment mechanism is provided between the objective lens drive mechanism and the apparatus frame to adjust the tilt of the objective lens by adjusting the tilt of the objective lens drive mechanism with respect to the apparatus frame. .

Such an objective lens tilt adjustment mechanism includes a fulcrum portion that serves as a fulcrum when the objective lens drive mechanism is tilted with respect to the apparatus frame, and an adjustment member that tilts the objective lens drive mechanism with the fulcrum portion as a fulcrum. In order to construct the fulcrum part, conventionally, a steel ball, a spherical convex part, a spherical concave part or the like is used. According to such a fulcrum portion, it is possible to adjust the inclination of the objective lens in the tracking direction (radial direction of the optical recording disk) and the jitter direction (tangential direction of the optical recording disk). (For example, see Patent Documents 1, 2, and 3). Further, the fulcrum portion may be formed by receiving the spherical protrusion portion by the concave groove portion (see, for example, Patent Document 4).
Japanese Patent No. 2634852 Japanese Patent No. 2880631 Japanese Patent No. 3085377 JP-A-5-20703

  In order to accurately record or reproduce information on the optical recording disk, it is necessary to adjust the optical axis position of the objective lens, but such adjustment is impossible with the conventional objective lens tilt adjustment mechanism. . Therefore, in the conventional optical head device, in order to be able to adjust the optical axis position, in addition to the tilt adjustment mechanism of the objective lens, the position of the objective lens is adjusted in the in-plane direction substantially orthogonal to the focusing direction. There is a problem that a mechanism must be provided separately.

  In view of the above problems, an object of the present invention is to provide an optical head device capable of adjusting the optical axis position of an objective lens in an in-plane direction substantially orthogonal to the focusing direction without complicating the configuration. is there.

In order to solve the above problems, in the present invention, an objective lens driving mechanism that drives an objective lens that converges light emitted from a light source onto an optical recording disk at least in a tracking direction and a focusing direction, and the objective lens driving mechanism are fixed. And an objective lens for adjusting an inclination in the tracking direction and the jitter direction of the objective lens driving mechanism with respect to the apparatus frame. In the optical head device having the tilt adjusting mechanism, the objective lens tilt adjusting mechanism includes a fulcrum portion serving as a fulcrum when the objective lens driving mechanism is tilted with respect to the device frame, and the objective using the fulcrum as a fulcrum. Adjustment for tilting the lens drive mechanism in the tracking and jitter directions And the fulcrum part includes a convex part protruding from one side of the device frame and the objective lens driving mechanism, and a concave part receiving the convex part on the bottom side on the other side, and the convex part The portion is configured to be slidable in an in-plane direction substantially perpendicular to the focusing direction within the recess.

  In the present invention, it is preferable that the objective lens tilt adjusting mechanism includes a biasing member that exerts a biasing force in a direction in which the convex portion comes into contact with the bottom surface of the concave portion.

In the present invention, it is preferable that the convex portion is a protrusion formed by press working on a yoke constituting the objective lens driving mechanism . Such a convex portion can be configured as, for example, a protrusion formed by bending a yoke that constitutes the objective lens driving mechanism . If comprised in this way, when forming the yoke of a predetermined shape, since a convex part can be formed simultaneously, a manufacturing process can be simplified. Moreover, if it is a bending process, a convex part of a desired dimension can be formed compared with a drawing process etc.

In the present invention, it is preferable that a phase plate is disposed between the objective lens driving mechanism and the apparatus frame. In the present invention, the fulcrum portion of the objective lens tilt adjusting mechanism has a structure in which the convex portion enters the concave portion, so that a gap of a predetermined dimension can be formed between the objective lens driving mechanism and the apparatus frame. Therefore, if the phase plate is arranged using such a gap, useless space can be reduced, so that the dimension of the optical head device in the focusing direction can be compressed. Further, when assembling the optical head device, the phase plate can be attached in advance to the lower surface of the objective lens driving mechanism or the upper surface of the device frame, so that the assembling process can be simplified.

  In the optical head device of the present invention, at the fulcrum portion of the objective lens tilt adjusting mechanism, the convex portion protruding from one side of the device frame and the objective lens driving mechanism is the bottom surface of the concave portion formed on the other side as the focusing direction. It is slidable in an in-plane direction that is substantially orthogonal. Therefore, the objective lens tilt adjustment mechanism can adjust the tilt of the objective lens, and the optical axis position of the objective lens can be adjusted in the in-plane direction substantially orthogonal to the focusing direction without providing a new mechanism. be able to. Further, the fulcrum portion has a structure in which the convex portion enters the concave portion, so that an excessive gap is not generated between the objective lens driving mechanism and the apparatus frame. Therefore, the dimension in the focusing direction of the optical head device can be compressed. Therefore, the structure of the optical head device can be simplified, and as a result, the product cost can be reduced.

  An example of an optical pickup to which the present invention is applied will be described with reference to the drawings.

[overall structure]
1 and 2 are a perspective view of an optical head device to which the present invention is applied as viewed obliquely upward on one guide shaft side, and a perspective view of the optical head device viewed from an obliquely upward side. is there. 3 and 4 are a side view and a plan view, respectively, showing the optical system of the optical head device shown in FIG.

  As shown in FIGS. 1 and 2, an optical head device 1 to which the present invention is applied performs information recording and information reproduction on an optical recording disk (not shown) such as a CD or a DVD. The objective lens drive mechanism 3 that drives the objective lens 2 that condenses the emitted light from the optical recording disk 19 in the tracking direction, the focusing direction, and the tilt direction, and holds the objective lens drive mechanism 3 and an optical system that will be described later And the device frame 4 on which the laser diodes 18 and 19 are mounted.

  The apparatus frame 4 is supported by the guide shafts 50 and 51 so as to be movable in the radial direction of the optical recording disk, and is, for example, a resin molded product formed by injection molding. The two laser diodes 18 and 19 mounted on the apparatus frame 4 include a DVD laser diode that emits a first laser beam having a wavelength of 650 nm or 635 nm (short wavelength), and a wavelength of 760 to 800 nm (long wavelength). It is a laser diode for CD that emits the second laser beam.

  As shown in FIGS. 3 and 4, in the optical head device 1 of the present embodiment, the optical system 5 mounted on the device frame 4 includes the first laser beam emitted from the first laser diode 18 and the second laser beam. The second laser light emitted from the laser diode 19 is guided to a common optical path 21 toward the optical recording disk by a first beam splitter 20 that is an optical element that combines and separates the optical paths of these laser lights. The objective lens 2 is configured to condense on the optical recording disk. Further, the return light of the laser beam reflected by the optical recording disk is configured to be guided to the light receiving element 22.

  On the optical path that guides the first laser beam emitted from the first laser diode 18 to the common optical path 21, the first grating lens 23, the second beam splitter 24, and the first beam splitter 20 are arranged in this order. Has been placed. Accordingly, the first laser light emitted from the first laser diode 18 passes through the first grating lens 23, then partially passes through the second beam splitter 24, and further part thereof passes through the first grating lens 23. One beam splitter 20 is transmitted to the common optical path 21.

  On the optical path that guides the second laser light emitted from the second laser diode 19 to the common optical path 21, the second grating lens 25, the relay lens 26, the half-wave plate 27, and the first The beam splitter 20 is arranged in this order. Accordingly, the second laser light emitted from the second laser diode 19 passes through the second grating lens 25, the relay lens 26, and the half-wave plate 27, and then enters the first beam splitter 20. A part of the light is partially reflected by the first beam splitter 20 and reaches the common optical path 21.

  On the common optical path 21, a collimator lens 28, a rising mirror 29, a quarter wavelength plate 30, and the objective lens 2 are arranged in this order. The laser light guided to the common optical path 21 is converted into parallel light by the collimator lens 28 and then guided to the objective lens 2 through the rising mirror 29 and the quarter wavelength plate 30. The first laser beam is condensed as a light spot on the recording surface of the DVD, which is an optical recording disk, by the objective lens 2, and the second laser beam is collected by the objective lens 2 as a CD or CD−, which is an optical recording disk. Condensed as a light spot on the R recording surface.

  Further, the return light of the laser light reflected by the optical recording disk is configured to pass through the first beam splitter 20 through the common optical path 21. A second beam splitter 24 and a sensor lens 31 are arranged in this order on the optical path that guides the return light transmitted through the first beam splitter 20 to the light receiving element 22. Accordingly, part of the return light transmitted through the first beam splitter 20 is partially reflected by the second beam splitter 24, then enters the sensor lens 31, and reaches the light receiving element 22 through the sensor lens 31. . The sensor lens 31 is a lens for generating astigmatism with respect to the return lights of both laser beams.

  5, 6 and 7 are a plan view, a front view and a bottom view of the objective lens driving mechanism of the optical head device shown in FIG. 1, respectively.

  5, 6, and 7, the objective lens driving mechanism 3 includes a lens holder 12 that holds the objective lens 2, and six wires 13 that are arranged in three stages on the left and right sides of the lens holder 12. A holder support member 14 that supports the lens holder 12 so as to be displaceable in the tracking direction, the focusing direction, and the tilt direction, a yoke 11 that holds the holder support member 14 fixedly, and a focusing drive mounted on the lens holder 12 side. A coil 61, a tracking drive coil 62, a tilt drive coil (not shown), and these three types of drive coils and drive magnets 15 and 16 constituting a magnetic drive circuit for tracking, focusing, and tilt. Have. The objective lens driving mechanism 3 is not limited to the wire suspension type, but is provided with a support shaft on the yoke, and a so-called shaft sliding / supporting mechanism that supports the lens holder so as to be slidable and rotatable with respect to the support shaft. A rotary objective lens driving mechanism 3 may be used.

  The yoke 11 is formed by pressing a thin plated steel plate of 0.8 mm, and the drive magnet 16 is an outer yoke formed upright from the bottom surface portion 11b of the yoke 11 outside the lens holder 12 in the tracking direction. It is fixed to the inner surface of 110. Further, the drive magnet 15 is fixed to the inner surfaces of a pair of outer yokes 111 erected from the bottom surface portion 11 b of the yoke 11 in a direction orthogonal to the drive magnet 16.

  Each of the six wires 13 is used as a feeding wire to the focusing drive coil 61, the tracking drive coil 62, and the tilt drive coil. For this reason, the base end side of the wire 13 is fixed to the wiring pattern of, for example, the printed circuit board 41 attached to the back surface of the holder support member 14 by solder or the like. Further, the distal end side of the wire 13 is fixed to the relay substrate 42 fixed to the left and right sides of the lens holder 12 by solder.

[Fixing structure of the objective lens driving mechanism 3 to the apparatus frame 4]
8 and 9 are a plan view and a bottom view of the device frame of the optical head device shown in FIG. 1, respectively. FIGS. 10 and 11 are a plan view showing a state where the objective lens driving mechanism shown in FIGS. 5 to 7 is mounted on the apparatus frame shown in FIGS. .

  In assembling the optical head device 1 of this embodiment, the objective lens driving mechanism 3 shown in FIGS. 5 to 7 is mounted on the device frame 4 shown in FIGS. At that time, in order to accurately record or reproduce information on the optical recording disk, the tracking direction of the optical recording disk is set so that the optical axis of the objective lens 2 is accurately perpendicular to the disk surface of the optical recording disk. It is necessary to adjust the inclination in the radial direction of the optical recording disk / direction indicated by arrow R and the jitter direction (tangential direction of the optical recording disk / direction indicated by arrow J). For this reason, in this embodiment, as described below, the inclination in the tracking direction and the jitter direction of the objective lens driving mechanism 3 is set between the objective lens driving mechanism 3 and the apparatus frame 4 on the apparatus frame 4. An objective lens tilt adjusting mechanism 10 to be adjusted is configured.

  In this embodiment, the objective lens tilt adjusting mechanism 10 is configured at the four corners of the objective lens driving mechanism 3, and tilts the objective lens driving mechanism 3 in the radial direction R and the jitter direction J with respect to the apparatus frame 4. A fulcrum part 9 serving as a fulcrum, a compression coil spring 8 (biasing member) disposed on the opposite side of the fulcrum part 9 on a substantially diagonal line passing through the fulcrum part 9, and the fulcrum part 9 and the compression coil spring 8 are configured. It has two adjustment screws 6 and 7 (adjustment members) arranged at both corners other than the two.

  The fulcrum portion 9 is formed on the convex portion 11 a bent downward (on the opposite side to the outer yokes 110 and 111) from the bottom surface portion 11 b of the yoke 11 and the upper surface 4 a of the apparatus frame 4 in the objective lens driving mechanism 3. The convex portion 11a is in contact with the bottom surface 4b1 in the concave portion 4b.

  The convex portion 11a is formed integrally with the yoke 11 by, for example, bending with a press, and protrudes from the bottom surface portion 11b to the device frame 4 side by 0.5 mm to 2 mm. Further, the tip portion 11a1 of the convex portion 11a is subjected to so-called R processing with a radius that is 1/2 of the width of the convex portion 11a.

  On the other hand, the recess 4b has a bottom surface 4b1 extending in a plane direction orthogonal to the focusing direction (direction indicated by arrow Fo), and a tapered surface 4b2 that expands the inner diameter from the bottom surface 4b1 toward the outside. Here, the inner diameter of the bottom surface 4b1 of the concave portion 4b is larger than the width dimension of the convex portion 11b. For this reason, the objective lens drive mechanism 3 can be moved in a plane direction substantially orthogonal to the focusing direction Fo while the convex portion 11a is inserted into the concave portion 4b. For example, the inner diameter of the bottom surface 4b1 of the concave portion 4b is set to be 0.1 mm to 0.5 mm larger than the width dimension of the convex portion 11b. Moreover, the depth dimension of the recessed part 4b is shallower than the protrusion dimension (0.5 mm to 2 mm) of the convex part 11b, and is set to 0.1 mm to 1.7 mm. For this reason, when the concave portion 4b is inserted into the convex portion 11b, the leading end portion 11a1 of the convex portion 11b abuts on the bottom surface 4b1 formed on the flat surface of the concave portion 4b, and the leading end portion 11a1 of the convex portion 11b is the bottom surface of the concave portion 4b. 4b1 can be moved in a plane direction substantially orthogonal to the focusing direction Fo while sliding on 4b1. In addition, about the recessed part 4b, you may form as a straight hole, without providing the taper surface 4b2.

In the fulcrum part 9 configured as described above, a gap is always ensured between the apparatus frame 4 and the objective lens driving mechanism 3 in a state where the convex part 11a is in contact with the bottom surface 4b1 of the concave part 4b. For this reason, in this embodiment, the quarter-wave plate 30 is fixed to the gap between the apparatus frame 4 and the objective lens driving mechanism 3, that is, the upper surface 4a of the apparatus frame 4 by a method such as adhesion.

  The compression coil spring 8 is disposed between the yoke 11 of the objective lens driving mechanism 3 and the apparatus frame 4 at a position opposite to the fulcrum part 9 on a diagonal line passing through the fulcrum part 9. Here, receiving portions 11d and 4c of the compression coil spring 8 are formed on the bottom surface portion 11b of the yoke 11 and the upper surface 4a of the device frame 4, and the receiving portion 4c on the device frame 4 side is simply circular. On the other hand, the receiving portion 11d on the yoke 11 side has a structure in which a cylindrical protrusion 11d1 is formed at the center of a circularly recessed portion 11d2. For this reason, the compression coil spring 8 is held in a state in which the end on the yoke 11 side is fitted into the protrusion 11d1.

  In this embodiment, the protrusion 11d1 and the recess 11d2 are formed on the yoke 11 by press working, and the height from the bottom surface 11b of the protrusion 11d1 is about 0.2 mm to 0.3 mm, and from the bottom surface 11b of the recess 11d2. The depth is also about 0.2 mm to 0.3 mm. Here, the inner diameter of the receiving portion 4c is such that the end of the compression coil spring 8 can be held even when the objective lens driving mechanism 3 is moved in the in-plane direction substantially orthogonal to the focusing direction Fo. It is set larger than the diameter dimension.

  The two adjusting screws 6 and 7 are screwed from the back side of the apparatus frame 4 at two corners of the four corners of the objective lens driving mechanism 3 where the fulcrum portion 9 and the compression coil spring 8 are not arranged. The screw attachment portions 4d and 4e formed in the device frame 4 are inserted through the insertion holes 4d1 and 4e1 and screwed into the screw holes 11c1 and 11c2 formed in the bottom surface portion 11b of the yoke 11. In this embodiment, the inner diameter dimensions of the insertion holes 4d1, 4e1 are the outer diameters of the screw portions of the adjusting screws 6, 7 so that the objective lens driving mechanism 3 can be moved in an in-plane direction substantially orthogonal to the focusing direction Fo. It is set to be larger than the dimensions.

[Attaching process of the objective lens driving mechanism 3 to the apparatus frame 4]
In assembling the optical head device 1 configured as described above, first, the objective lens driving mechanism 3 is attached to the device frame 4 in which the optical system 5 is disposed. For this purpose, a compression coil spring 8 is arranged between the apparatus frame 4 and the objective lens driving mechanism 3, and the convex part 11 a formed on the yoke 11 of the objective lens driving mechanism 3 is inserted into the concave part 4 b of the apparatus frame 4. In this state, the objective lens driving mechanism 3 is temporarily fixed on the apparatus frame 4 by the adjusting screws 6 and 7 inserted from the back side of the apparatus frame 4. At this time, the yoke 11 (objective lens driving mechanism 3) is urged in the focusing direction Fo by the urging force of the compression coil spring 8, the tip 11a1 of the convex portion 11a abuts against the bottom surface 4b1 of the concave portion 4b, and the adjusting screw 6 , 7 comes into contact with 4d2 and 4e2 around the insertion holes 4d1 and 4e1 on the back side of the device frame 4.

  Next, alignment with the center position of the objective lens 2 mounted on the objective lens driving mechanism 3 is performed with respect to the optical axis of the optical system 5 arranged in the apparatus frame 4. The objective lens 2 is adjusted in position in the in-plane direction substantially orthogonal to the focusing direction Fo, that is, in both the tracking direction and the jitter direction. At the time of this position adjustment, the tip end portion 11a1 of the convex portion 11a slides along the bottom surface 4b1 of the concave portion 4b.

  After adjusting the position of the objective lens 2 in this way, the inclination of the objective lens 2 is adjusted. The tilt adjustment of the objective lens 2 is performed by tightening or loosening while rotating the adjusting screws 6 and 7. In this embodiment, the adjustment screw 6 adjusts the inclination in the jitter direction J, and the adjustment screw 7 adjusts the inclination in the radial direction R. During the tilt adjustment, the contact point between the tip 11a1 of the convex portion 11a and the bottom surface 4b1 of the concave portion 4b serves as a fulcrum for tilt adjustment.

  After adjusting the tilt of the objective lens 2 in this way, the adjusting screws 6 and 7 are fixed by adhesion or the like, and the tilt of the objective lens 2 is maintained.

  Next, the optical head device 1 is completed by performing the inspection process of the optical head device 1.

[Effect of this embodiment]
As described above, since the objective lens tilt adjusting mechanism 10 is configured in the optical head device 1 of the present embodiment, the objective lens driving mechanism 3 is attached to the device frame 4 when the objective lens driving mechanism 3 is attached. The inclination of the lens driving mechanism 3 in the radial direction R and the jitter direction J can be adjusted. Therefore, the optical axis of the objective lens 2 mounted on the objective lens driving mechanism 3 can be accurately adjusted so as to be perpendicular to the disk surface of the optical recording disk. The objective lens tilt adjusting mechanism 10 is configured such that the objective lens driving mechanism 3 is movable in an in-plane direction perpendicular to the focusing direction Fo with respect to the apparatus frame 4. For this reason, when the objective lens driving mechanism 3 is attached to the apparatus frame 4, the objective lens driving mechanism 3 is moved in an in-plane direction (radial direction R and jitter direction J) substantially orthogonal to the focusing direction Fo with respect to the apparatus frame 4. Therefore, the optical axis position of the objective lens 2 can be adjusted in accordance with the optical axis of the emitted light guided by the optical system 5 mounted on the apparatus frame 4. Therefore, it is possible to accurately record or reproduce information on the optical recording disk.

  In addition, since the optical axis position of the objective lens 2 can be adjusted by using the objective lens tilt adjusting mechanism 10 as it is without providing a separate optical axis position adjusting mechanism, the apparatus can be simplified. As a result, the product cost can be reduced.

  In the present embodiment, the convex portion 11 a is formed on the yoke 11 constituting the objective lens driving mechanism 3 by press working. Therefore, the convex portion 11a can be processed at the same time when the yoke 11 is pressed, and the processing process is simplified.

  Furthermore, since the convex portion 11a is formed by bending, the amount of protrusion from the objective lens driving mechanism 3 can be increased while keeping the width dimension of the convex portion 11a small. Thus, since the width dimension of the convex part 11a can be made small, although it is the small recessed part 4b, the convex part 11a1 can be comprised so that a movement within the recessed part 4b is possible. Therefore, the fulcrum portion 9 can be formed small, and as a result, the optical head device 1 can be miniaturized. In addition, it is easy to secure an adjustment amount in the radial direction and the jitter direction of the optical axis of the objective lens 2. Furthermore, since the protruding amount of the convex portion 11a can be increased, a large gap between the objective lens driving mechanism 3 and the apparatus frame 4 can be secured, so that the amount of inclination adjustment of the objective lens 2 can be increased.

  Further, as described above, since a predetermined gap can be secured between the objective lens driving mechanism 3 and the apparatus frame 4, the quarter wavelength plate 30 can be fixed to the upper surface 4 a of the apparatus frame 4. Therefore, the work for assembling the quarter-wave plate 30 is facilitated. Further, since the quarter wavelength plate 30 can be disposed on the apparatus frame 4, the balance of the entire optical system can be improved. The quarter wavelength plate may be fixed to the objective lens drive mechanism 3 side, that is, the bottom surface 11b1 of the yoke 11.

[Other embodiments]
The optical head device 1 in the above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited to this and can be variously modified without departing from the scope of the present invention. For example, in the above-described embodiment, the convex portion 11a is provided on the objective lens driving mechanism 3 side and the concave portion 4b is provided on the apparatus frame 4 side. However, the concave portion 4b is provided on the objective lens driving mechanism 3 side, and on the apparatus frame 4 side. You may provide the convex part 11a.

  Further, since the depth of the concave portion 4b is shallower than the protruding height of the convex portion 11b, a gap is formed between the objective lens driving mechanism 3 and the apparatus frame 4. Therefore, in order to securely fix the objective lens driving mechanism 3 to the device frame 4, the projection is provided on the bottom surface 11b1 of the objective lens driving mechanism 3 and the top surface 4a of the device frame 4, and the projections are bonded to each other for the objective. The lens driving mechanism 3 may be fixed to the device frame 4.

  In the embodiment described above, the compression coil spring 8 is used as the biasing member, but the biasing member may be a biasing member such as a plate spring or a tension coil spring.

  As described above, in the optical head device of the present invention, the tilt of the objective lens can be adjusted by the objective lens tilt adjusting mechanism, and the in-plane substantially orthogonal to the focusing direction can be provided without providing a new mechanism. The optical axis position of the objective lens can be adjusted by the direction. Further, the fulcrum portion has a structure in which the convex portion enters the concave portion, so that an excessive gap is not generated between the objective lens driving mechanism and the apparatus frame. Therefore, the dimension in the focusing direction of the optical head device can be compressed. Therefore, the structure of the optical head device can be simplified, and as a result, the product cost can be reduced.

It is a perspective view when the optical head device to which the present invention is applied is viewed obliquely upward on one guide shaft side. FIG. 2 is a perspective view when the optical head device shown in FIG. 1 is viewed from a diagonally upper side. It is a side view which extracts and shows the optical system of the optical head apparatus shown in FIG. It is a top view which extracts and shows the optical system of the optical head apparatus shown in FIG. It is a top view of the objective lens drive mechanism of the optical head apparatus shown in FIG. It is a front view of the objective lens drive mechanism of the optical head apparatus shown in FIG. It is a bottom view of the objective lens drive mechanism of the optical head apparatus shown in FIG. It is a top view of the apparatus frame of the optical head apparatus shown in FIG. It is a bottom view of the apparatus frame of the optical head apparatus shown in FIG. FIG. 2 is a plan view showing a state where an objective lens driving mechanism is mounted on an apparatus frame in the optical head apparatus shown in FIG. 1. FIG. 2 is a cross-sectional view taken along the line AA in a state where an objective lens driving mechanism is mounted on the apparatus frame in the optical head apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical head apparatus 2 Objective lens 3 Objective lens drive mechanism 4 Apparatus frame 4b Recessed part (receiving part with respect to a convex part)
4c Compression coil spring receiving portion 4d, 4e Screw mounting portion 5 Optical system 6, 7 Adjustment screw (adjustment member)
8 Compression coil spring (biasing member)
9 fulcrum part 10 objective lens tilt adjustment mechanism 11 yoke 11a convex part 30 1/4 wavelength plate (phase plate)

Claims (5)

An objective lens driving mechanism for driving the objective lens at least in a tracking direction and the focusing direction to focus the light emitted from the light source to the optical recording disc, thereby fixedly holding the objective lens driving mechanism, the light emitted from the light source to said objective lens In an optical head device having an apparatus frame on which an optical system for guiding the optical system is mounted, and an objective lens tilt adjusting mechanism for adjusting the tilt in the tracking direction and jitter direction of the objective lens driving mechanism with respect to the apparatus frame,
The objective lens tilt adjusting mechanism includes a fulcrum portion that serves as a fulcrum when the objective lens drive mechanism is tilted with respect to the apparatus frame, and the objective lens drive mechanism in the tracking direction and the jitter direction with the fulcrum portion as a fulcrum. An adjustment member for tilting,
The fulcrum portion includes a convex portion protruding from one side of the device frame and the objective lens driving mechanism, and a concave portion receiving the convex portion on the other side on the bottom surface, and
The convex portion is configured to be slidable in an in-plane direction substantially orthogonal to the focusing direction within the concave portion.   2. The optical head device according to claim 1, wherein the objective lens tilt adjusting mechanism includes a biasing member that exerts a biasing force in a direction in which the convex portion comes into contact with a bottom surface of the concave portion. 3. The optical head device according to claim 1, wherein the convex portion is a projection formed by press working on a yoke constituting the objective lens driving mechanism . 3. The optical head device according to claim 1, wherein the convex portion is a protrusion formed by bending a yoke that constitutes the objective lens driving mechanism . 5. The optical head device according to claim 1, wherein a phase plate is disposed between the objective lens driving mechanism and the device frame.

Images