JP3552006B2 - Optical head actuator - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical head actuator for recording / reproducing on / from an optical recording medium such as an optical disk.
[0002]
[Prior art]
An example of a conventional optical head actuator will be described with reference to FIGS. In FIG. 6, an optical head actuator includes a lens holder 30 for holding an objective lens 31, a focusing coil 32a and a tracking coil 32b wound around a coil bobbin provided in the lens holder 30, and a damper A suspension wire 34 that supports the base 33 so as to be movable in the focusing direction F and the tracking direction Tr, a pickup base 35 that supports the damper base 33 so as to be able to swing and adjust in the radial direction R, and a pickup base 35 that supports the pickup base 35 And an actuator base 40 that is supported so as to be swingable in the axial direction Ta.
[0003]
In the illustrated case, a total of four suspension wires 34 are provided, two pairs in total, and the mechanical wires and the damper base 33 are connected by connecting the lens holder 30 and the damper base 33 on both sides of the lens holder 30, respectively. It is designed to be electrically connected.
[0004]
The pickup base 35 is integrally formed with two yokes 35a and 35b. A magnet 36 is provided on a surface of the yoke 35a facing the yoke 35b, and the yoke 35a is inserted into the focusing coil 32a together with the magnet 36. On the other hand, the yoke 35b is opposed to the tracking coil 32b on the surface facing the yoke 35a, and is just cooperated with the yoke 35a so as to sandwich the tracking coil 32b at intervals in the horizontal direction X perpendicular to the tracking direction Tr. It is arranged. The pickup base 35 further includes a rising portion 35c for fixing the damper base 33 in the X direction, a screw 35d that passes through the rising portion 35c and is screwed into a screw hole 33a provided in the damper base 33, and a pickup from below. It includes a screw 35e that penetrates through the base 35 and contacts the lower surface of the damper base 33, and a coil spring 35f (see FIG. 7) that urges the lower surface of the damper base 33 upward.
[0005]
The actuator base 40 includes a support 40a for the pickup base 35 so as to adjustably support the pickup base 35 in the tangential direction Ta. The actuator base 40 further includes a laser diode 40b, a beam splitter 40c, a rising mirror 40d, and a photodiode 40e. Further, the actuator base 40 includes a screw 40f that penetrates the actuator base 40 from below and is screwed into a screw hole provided on the lower surface of the pickup base 35, and a coil spring 40g that urges the lower surface of the pickup base 35 upward (see FIG. 8).
[0006]
Note that, at both ends in the longitudinal direction of the damper base 33 to which one ends of the plurality of suspension wires 34 are fixed, accommodation spaces for a gel-like vibration damping material for suppressing vibration of the plurality of suspension wires 34 are formed. The gel cover 37 is attached. The gel cover 37 accommodates a portion near the fixing portion of the suspension wire 34, and a gel-like damping material (not shown) is injected into an accommodation space formed between the gel cover 37 and the damper base 33. You. As described above, in the related art, the damper base 33 and the gel cover 37 are configured separately.
[0007]
According to the optical head actuator 1 configured as described above, the light emitted from the laser diode 40b is reflected by the beam splitter 40c, then by the rising mirror 40d, and is reflected by the objective lens 31 through the objective lens 31. The light is focused on a signal surface of a recording medium (not shown). Then, the light reflected on the signal surface of the optical recording medium is reflected again by the rising mirror 40d via the objective lens 31, passes through the beam splitter 40c, and then enters the photodiode 40e. Thus, information recorded on the signal surface of the optical recording medium can be detected based on the output signal from the photodiode 40e.
[0008]
Incidentally, the optical head actuator 1 is assembled through the following steps. First, the lens holder 30 is assembled as shown in FIG. Next, one ends of the plurality of suspension wires 34 are attached to the lens holder 30. Subsequently, a damper base 33 is attached to the other ends of the plurality of suspension wires 34, and a gel cover 37 is attached to the damper base 33. Then, a gel-like damping material is injected into the gel cover 37. A jig such as a syringe is used for injecting the vibration damping material. Further, the assembly assembled as described above is assembled to the pickup base 35, which is further attached to the actuator base 40.
[0009]
More specifically, the combination of the lens holders 30 is such that reference lines C1 and C2 orthogonal to each other for defining the center position of the objective lens 31 are set in a receiving portion of the objective lens 31, and the intersection of the objective lenses 31 The objective lens 31 is incorporated such that the centers of the two coincide. On the other hand, the damper base 33 is combined with the lens holder 30 such that the center line thereof coincides with the reference line C2. Further, the damper base 33 is fixed to the pickup base 35 such that its center line coincides with a reference position set at the rising portion 35c of the pickup base 35.
[0010]
[Problems to be solved by the invention]
As described above, in the conventional optical head actuator, since the damper base and the gel cover are separate bodies, a mold for forming them is separately required, and furthermore, the gel cover is attached to the damper base. Since a manufacturing process is required, there is a problem that the manufacturing cost is increased accordingly. Further, since the damper base and the gel cover are separate bodies, there is a problem that the damping material leaks from a gap between them.
[0011]
Therefore, an object of the present invention is to provide an optical head actuator that reduces the number of parts, facilitates manufacturing, reduces manufacturing cost, and does not leak out the damping material .
[0012]
[Means for Solving the Problems]
According to the first aspect of the present invention, a lens holder holding a lens for an optical pickup, and the lens holder is supported so as to be vertically and horizontally displaceable via a plurality of suspension wires, and one end of the suspension wire And a damper base for connecting to a wiring board provided on the wall side thereafter, and an optical head actuator including a gel-like damping material for attenuating the vibration of the plurality of suspension wires, wherein the damper base comprises: A fixing portion having a notch on the rear wall side for exposing a fixing surface for fixing one end of the plurality of suspension wires, and a notch for passing one end of the plurality of suspension wires through the notch of the fixing portion. accommodating the damping material causes the insertion hole, and one end of the plurality of suspension wires into the notch of the fixed part Comprising containers space, and a said fixing portion leg-like portion formed integrally with, the hole is closed by synthetic resin while being inserted through the plurality of suspension wires therein, said plurality of suspension The optical head actuator is characterized in that the wire is fixed to the notch of the fixing portion by a synthetic resin and is connected by soldering to the wiring board .
[0014]
According to the second aspect of the present invention, the damper base is made of a transparent synthetic resin, and the damping material is formed into a gel state by the ultraviolet light transmitted through the damper base. The optical head actuator according to 1 is obtained.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing an optical head actuator according to an embodiment of the present invention, FIG. 2 is a bottom view thereof, and FIG. 3 is a sectional view taken along line AA ′ in FIG. Referring to FIG. 1, an optical head actuator 1 includes an actuator base 2, a lens holder 3 including an objective lens 3-1, a tracking coil 3-2, and a focusing coil 3-3 (see FIG. 3), and a lens An actuator frame 5 and the like accommodating the holder 3 and the damper base 4 are provided.
[0016]
With reference to FIG. 3, the optical head actuator 1 includes a laser unit 11 that generates a laser beam. Laser light emitted from the laser unit 11 is irradiated from a beam splitter 12 to an optical disc 13 as an optical recording medium via an objective lens 3-1. The reflected light from the optical disk 13 enters the light receiving device 14 from the objective lens 3-1 via the beam splitter 12. That is, the light receiving device 14 receives the reflected light from the optical disc 13.
[0017]
The laser section 11 and the beam splitter 12 are held by the actuator base 2. Note that the actuator base 2 is further held and fixed to the housing of the optical disk drive. A circuit board 15 is fixed to a side surface of the actuator base 2. The circuit board 15 is electrically connected to other circuit elements of the optical disk drive by a connector 16 mounted thereon.
[0018]
The light receiving device 14 described above is assembled on the lower surface of the actuator base 2. The light receiving device 14 includes a photodiode 14-2 mounted on an element holder 14-1. The actuator frame 5 is provided with a cover 17 that exposes the objective lens 3-1 and covers the remaining surface.
[0019]
Returning to FIG. 1, a plurality of suspension wires 6 are connected between the lens holder 3 and the damper base 4, and these assemblies are housed in the actuator frame 5. A yoke 7 is further mounted on the actuator frame 5, and a magnet 8 is mounted on the yoke 7.
[0020]
Referring to FIG. 4, actuator frame 5 has a receiving portion for damper base 4 on one end side of a substantially box-shaped body formed of a resin material. The receiving portion has a support block 5-1 for fixing the damper base 4 with screws 9. The bottom wall of the actuator frame 5 is provided with an opening 5a through which incident light and reflected light to the objective lens 3-1 can pass. Further, on both side walls of the substantially box-like body, a substantially semicircular protrusion 5-2 supported by a support portion 2-1 (FIG. 1) provided on the actuator base 2 is provided, and a gel is provided. There is provided a hole 5-3 through which an injector for injecting a damping material in a shape of a pen can be inserted. The hole 5-3 is preferably formed in an elliptical shape in order to restrict the vertical movement of the injector. This is to prevent a part of the injector from being in contact with the suspension wire 6 and being deformed when the damping material is injected. The support 2-1 has the same shape as that described with reference to FIG.
[0021]
The damper base 4 has a U-shape, and has a fixing portion 4-1 for fixing one end of the suspension wire 6, and leg portions 4-2 integrally provided on both sides of the fixing portion 4-1. Consisting of The four corners of the fixing portion 4-1 are notched, and the upper and lower end surfaces of the notch portion serve as fixing surfaces 4-3 for fixing one end of the suspension wire 6. The leg 4-2 is a portion corresponding to a gel cover of a conventional optical head actuator. The leg portion 4-2 is formed in a rectangular cylindrical shape, and its internal space is provided with a vibration damper for passing one end of the suspension wire 6 to the fixing portion 4-1 and attenuating the vibration of the suspension wire 6. An accommodation space 4-4 for accommodating materials (not shown) is provided. The leg portion 4-2 is formed with a hole 4-5 for allowing one end of the suspension wire 6 to pass through the fixing surface 4-3. The holes 4-5 are closed by a synthetic resin (not shown) after the suspension wires 6 are passed therethrough. On the rear wall of the damper base 4, a flexible wiring board (not shown) for soldering connection with one end of the suspension wire 6 is provided. In the case of the present embodiment, the damper base 4 is formed of a transparent synthetic resin, and the damping material is a material that gels by ultraviolet light transmitted through the damper base 4 (for example, UV curable silicone is used). Gel).
[0022]
The damper base 4 is fixed with screws 9 in a state where the leg-shaped portions 4-2 on both sides are inserted into the space between both side walls of the actuator base 2 and the support block 5-1. As described below, the suspension wire 6 is attached to the damper base 4 before fixing the damper base 4 to the actuator base 2. That is, the lens holder 3 and the damper base 4 are housed and fixed in the actuator frame 5 in a state of an assembly connected by a plurality of suspension wires 6.
[0023]
A method of assembling the optical head actuator 1 according to the embodiment will be described. First, the lens holder 3 is assembled while being held by the jig. Next, a plurality of suspension wires 6 are attached to the assembled lens holder 3. Subsequently, the lens holder 3 to which the suspension wire 6 is attached is positioned in the actuator frame 5 fixed by another jig. Then, the damper base 4 is attached to the ends of the plurality of suspension wires 6 in the positioned lens holder 3. In this case, the damper base 4 is also held by another jig, and the damper base 4 is fixed to the actuator frame 5 so that the ends of the suspension wires 6 enter the accommodation spaces 4-4 on both sides of the damper base 4. The assembly is performed by horizontally moving the support block 5-1. Further, the assembled damper base 4 is fixed to the support block 5-1 of the actuator frame 5 with screws 9, and the suspension wire 6 is fixed to the fixing portion 4-1 of the damper base 4. Finally, the damping material is injected into the accommodation space 4-4 of the damper base 4 that accommodates the suspension wire 6. For this injection, an injector such as a syringe is used, and the injection is performed through holes 5-3 on both side walls of the actuator frame 5.
[0024]
In particular, with reference to FIG. 5, the positioning of the lens holder 3 is such that the center of the objective lens 3-1 passes through the actuator frame 5 in advance through a line segment S1 connecting the centers of the protrusions 5-2 on both sides thereof. An optical axis L1 to be positioned is set, and a reference laser beam is emitted from a laser diode LD attached to a jig (not shown) through the opening 5a from below the actuator frame 5 in accordance with the optical axis L1. . A monitor camera is provided above the lens holder 3 to monitor the incident point of the reference laser beam on the objective lens 3-1. In FIG. 5, a hatched area indicates a monitor area by a monitor camera. While monitoring with this monitoring camera, the reference laser beam is incident on the center of the objective lens 3-1, that is, the lens holder 3 is held so that the optical axis L2 of the objective lens 3-1 coincides with the optical axis L1. The lens holder 3 is positioned in the actuator frame 5 by adjusting the position of the jig being adjusted.
[0025]
As described above, in the present embodiment, since the lens holder 3 and the damper base 4 are assembled in a state where the lens holder 3 is positioned in the actuator frame 5, the lens holder 3 is accurately positioned in the actuator frame 5. Is done. The actuator frame 5 covers and protects the suspension wire 6 on both sides thereof. After the suspension wire 6 is attached to the lens holder 3, the suspension frame 6 is immediately accommodated in the actuator frame 5. Therefore, the suspension wire 6 is not deformed in the subsequent steps. Needless to say, the suspension wire 6 is not deformed by the injector even in the step of injecting the damping material.
[0026]
【The invention's effect】
As described above, in the case of the optical head actuator of the present invention, since the damper base and the gel cover are integrated, the number of components can be reduced, and the manufacturing cost can be reduced. Further, in the case of the optical head actuator of the present invention, since the damper base and the gel cover are integrated, it is possible to eliminate the disadvantage that the damping material leaks out of the gap between the damper base and the gel cover as in the related art. it can.
[Brief description of the drawings]
FIG. 1 is a plan view of an optical head actuator according to an embodiment of the present invention.
FIG. 2 is a bottom view of the optical head actuator shown in FIG.
FIG. 3 is a sectional view taken along line AA ′ of FIG. 1;
4 is a perspective view of a damper base and an actuator frame used in the optical head actuator shown in FIG.
FIG. 5 is an explanatory diagram for explaining a method for positioning a lens holder with respect to an actuator frame in the optical head actuator shown in FIG. 1;
FIG. 6 is an exploded perspective view of a conventional optical head actuator.
FIG. 7 is a partial cross-sectional side view for explaining a damper base mounting structure shown in FIG. 6;
8 is a partial cross-sectional side view for explaining a mounting structure of the pickup base shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Optical head actuator 2 Actuator base 3 Lens holder 3-1 Objective lens 3-2 Tracking coil 3-3 Focusing coil 4 Damper base 4-1 Fixed part 4-2 Leg-shaped part 4-3 Fixed surface 4-4 Housing space 4 -5 hole 5 actuator frame 6 suspension wire 7 yoke 8 magnet

Claims (2)

A lens holder holding a lens for an optical pickup; and a lens holder supporting the lens holder so as to be vertically and horizontally displaceable via a plurality of suspension wires, and one ends of the plurality of suspension wires are provided on a rear wall side. An optical head actuator including a damper base for connecting to a wiring board, and a gel-like damping material for attenuating vibration of the plurality of suspension wires,
The damper base is
A fixing portion having a notch on the rear wall side for exposing a fixing surface for fixing one end of the plurality of suspension wires,
A hole for passing one end of each of the plurality of suspension wires through the notch of the fixed portion, and a receiving space for inserting one end of each of the plurality of suspension wires into the notch of the fixed portion and containing the vibration damping material And a leg portion integrally formed with the fixed portion,
Has ,
The hole is closed by a synthetic resin with the plurality of suspension wires inserted therethrough ,
The optical head actuator, wherein the plurality of suspension wires are fixed to a notch of the fixing portion with a synthetic resin, and are connected to the wiring board by soldering . 2. The optical head actuator according to claim 1, wherein the damper base is made of a transparent synthetic resin, and the damping material is formed in a gel state by ultraviolet light transmitted through the damper base. 3.

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