JPH10312557A - Optical pickup - Google Patents

Abstract

(57) [Problem] To provide an optical pickup capable of fixing a damper base without screws. SOLUTION: A damper base 4 is attached to a support block 5-1.
Was fixed by a spring plate 9 having a U-shaped cross section so as to sandwich the both.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical pickup for recording and reproducing information on an optical recording medium such as an optical disk.

[0002]

2. Description of the Related Art As an example of a conventional optical pickup,
This will be described with reference to FIGS. In FIG. 5, an optical pickup is a lens holder 3 for holding an objective lens 31.
0, a focusing coil 32a and a tracking coil 32b wound on a coil bobbin provided in the lens holder 30, and the lens holder 30 with respect to a damper base 33 fixedly disposed on the optical base 40.
A suspension wire 34 that movably supports the focusing direction F and the tracking direction Tr, an actuator base 35 that supports the damper base 33 so that the swinging adjustment is possible in the radial direction R, and an actuator base 35
And an optical base 40 that supports the optical base in a tangential direction Ta so as to be swingable.

In the case shown in the figure, two pairs of suspension wires 34 are provided as a whole, and a total of four suspension wires 34 are provided. By connecting the lens holder 30 and the damper base 33 on both sides of the lens holder 30, respectively. The connection is made mechanically and electrically.

[0004] The actuator base 35 is integrally formed with two yokes 35a and 35b. These yokes 35a and 35b are disposed so as to sandwich the lens holder 30 at an interval from a horizontal direction X perpendicular to the tracking direction. A magnet 36 is provided on the inner surface of one yoke 35a facing the lens holder 30. The actuator base 35 further includes a rising portion 35 for fixing the damper base 33 from the X direction.
c, a screw 35d passing through the rising portion 35c and screwing into a screw hole 33a provided in the damper base 33, and a damper base 3 passing through the actuator base 35 from below.
A screw 35e abutting on the lower surface of the damper base 3 and a damper base 33
Spring 35f for urging the lower surface of the upper part upward (see FIG. 6)
And

[0005] The optical base 40 includes a support portion 40 for the actuator base 35 so as to adjustably support the actuator base 35 in the tangential direction Ta.
a. The optical base 40 further includes a laser diode 40b, a beam splitter 40c, a rising mirror 40d, and a photodiode 40e. Further, the optical base 40 includes a screw 40f that penetrates the optical base 40 from below and is screwed into a screw hole provided on the lower surface of the actuator base 35,
Spring 40g for urging the lower surface of the upper part (see FIG. 7)
And

A space for accommodating a gel-like vibration damping material for suppressing vibration of the plurality of suspension wires 34 is provided at both ends in the longitudinal direction of the damper base 33 which fixes one end of the plurality of suspension wires 34. Is attached. The gel cover 37 accommodates a portion near the fixing portion of the suspension wire 34, and a gel-like vibration damping material is injected into the gel cover 37.

[0007] According to the optical pickup constructed as described above, the light emitted from the laser diode 40b is reflected by the beam splitter 40c, and then reflected from the rising mirror 40b.
The light is reflected by d and condensed on the signal surface of an optical recording medium (not shown) via the objective lens 31. Then, the light reflected on the signal surface of the optical recording medium is again transmitted to the objective lens 31.
The light is reflected by the rising mirror 40d through the beam splitter 40c, 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]

The optical pickup 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 actuator base 35, and this is mounted to the optical base 40.

More specifically, the combination of the lens holder 30 and the objective lens 3
Mutually perpendicular reference lines C for defining the center position of
1 and C2 are set, and the objective lens 31 is incorporated so that the center of the objective lens 31 coincides with the intersection. 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. The center line of the damper base 33 is the actuator base 35.
The damper base 33 is rotated in the radial direction R shown in FIG. 5 while the screw 35d is loosened so that the objective lens 31 is horizontal. Then, the screw 35d is tightened and fixed to the actuator base 35. The adjustment for leveling the objective lens 31 is called skew adjustment.

However, in the skew adjustment method as described above, it is necessary to control the tightening force of the screw 35d, and a special measuring instrument is required.

It is an object of the present invention to provide an optical pickup which can fix a damper base without screws.

Another object of the present invention is to provide an optical pickup in which skew adjustment with respect to a damper base is simplified.

[0013]

SUMMARY OF THE INVENTION The present invention provides a lens holder for holding a lens for an optical pickup, and a damper base for supporting the lens holder so as to be vertically and horizontally displaceable via a plurality of suspension wires. And a base member having a support block for fixedly supporting the damper base, wherein the fixing of the damper base to the support block is sandwiched between spring members having a U-shaped cross section. It is characterized by having done.

Preferably, the spring member is a leaf spring, and a projection is provided on one of the contact surfaces between the support block and the damper base and on one of the contact surfaces between the damper base and the spring member. It is preferable that the damper base be rotatable around the projection in order to perform skew adjustment.

It is preferable that receiving portions of the projections are provided on the other of the contact surfaces between the support block and the damper base and on the other of the contact surfaces between the damper base and the spring member.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a damper base 4 and an actuator base (base member) 5 in the optical pickup according to the embodiment of the present invention. FIG. 2 is a view showing a structure after an assembly of the lens holder 3 and the damper base 4 is assembled to the actuator base 5 in order to explain a method of fixing the damper base 4. FIG. 3 is a plan view of an optical pickup incorporating the structure of FIG. 2, and FIG. 4 is a sectional view taken along line AA 'of FIG. Referring to FIG. 3, this optical pickup 1 includes an optical base 2, a lens holder 3 having an objective lens 3-1 and a tracking coil 3-2 and a focusing coil (not shown),
An actuator base 5 and the like accommodating the lens holder 3 and the damper base 4 are provided.

Referring to FIG. 4, the optical pickup 1 has a laser section 11 for generating a laser beam. A laser beam emitted from a laser unit 11 is transmitted from a beam splitter 12 via an objective lens 3-1 to an optical disc 1 as an optical recording medium.
3 is irradiated. 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 is
Receives reflected light from the

The laser section 11 and the beam splitter 12 are held on the optical base 2. The optical base 2 is further held and fixed to a housing of the optical disk drive. A circuit board 15 is fixed to a side surface of the optical base 2. The circuit board 15 is electrically connected to other circuit elements of the optical disk drive by a connector 16 mounted thereon.

On the lower surface of the optical base 2, the light receiving device 1 described above is provided.
4 are assembled. The light receiving device 14 includes a photodiode 14-2 mounted on an element holder 14-1.
The actuator base 5 has an objective lens 3-1.
Is provided, and a cover 17 that covers the remaining surface portion is provided. In FIG. 3, the cover 17 is not shown.

Returning to FIG. 3, the suspension between the lens holder 3 and the damper base 4 is connected by a plurality of suspension wires 6, and an assembly of these is accommodated in the actuator base 5. A yoke 7 is further attached to the actuator base 5, and a magnet 8
Are combined.

Referring to FIG. 1, actuator base 5
Has a receiving portion for the 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. That is, the support block 5-1 is formed integrally with the actuator base 5 using a resin material. Also,
The objective lens 3-1 is provided on the bottom wall of the actuator base 5.
An opening 5a through which incident light and reflected light can pass is provided. Further, on both side walls of the substantially box-like body, a substantially semicircular projection 5-2 supported by a support portion 2-1 (FIG. 3) provided on the optical base 2 is provided, and a gel is provided. There is provided a hole 5-3 through which an injector for injecting a vibration damping material in a shape of a pen is inserted. The hole 5-3 preferably has an elliptical shape in order to regulate the vertical movement of the injector. This is to prevent a part of the injector from contacting and deforming the suspension wire 6 when the damping material is injected.
The support 2-1 has the same shape as that described with reference to FIG.

The damper base 4 is formed of a transparent resin material, has a U-shape, and has leg portions on both sides thereof hollow, and a fixing portion 4-1 for fixing one end of the suspension wire 6 is provided at a rear portion thereof. Is provided. Further, on the rear wall of the damper base 4, a flexible wiring board (not shown) for soldering connection with an end of the further fixed suspension wire 6 is provided. The damper base 4 is fixed by a method described later in a state where the leg-like portions on both sides are inserted into the space between the both side walls of the actuator base 5 and the support block 5-1.

Referring also to FIG. 2, the damper base 4 is attached so that the support block 5-1 and the damper base 4 are sandwiched by a U-shaped spring plate 9. One of the contact surfaces between the support block 5-1 and the damper base 4, here the support block 5-1 is provided with a projection 5-1a, and one of the contact surfaces between the damper base 4 and the spring plate 9, here the damper base 4 Is provided with the projection 4-2, so that the damper base 4 can rotate around the projections 5-1a and 4-2. This is to adjust the skew, and the projections 5-1a and 4-2 are provided so as to be coaxially located. Further, in the case of the illustrated example, the damper base 4 facing the projection 5-1a is provided with a receiving portion 4-3 formed by a concave portion for receiving the projection 5-1a, and the spring plate 9 facing the projection 4-2 is provided with a receiving portion 4-3.
A receiving portion 9-1 for the projection 4-2 is provided. The receiving portion 9-1 may be a hole as shown in FIG. 2B or a concave portion. This is to make the damper base 4 rotatable without causing a positional shift. In addition, the lower end of the spring plate 9
When the support block 5-1 and the damper base 4 are sandwiched, they are bent outward so as not to be caught on them.
Further, the relationship between the protrusion and the receiving portion may be reversed. That is, projections may be provided on both sides of the damper base 4 and these receiving portions may be provided on the support block 5-1 and the spring plate 9, or projections may be provided on the support block 5-1 and the spring plate 9 to provide the damper base 4. These receiving portions may be provided on both sides.

As described below, before fixing the damper base 4 to the actuator base 5, the damper base 4
Is provided with a suspension wire 6. That is, the lens holder 3 and the damper base 4 are housed and fixed in the actuator base 5 in a state of an assembly connected by a plurality of suspension wires 6.

A method for assembling the present optical pickup will be described. First, two sets of yokes 7 and magnets 8 are attached to the actuator base 5. This assembly is
The wider rising portion of the two rising portions of the substantially U-shaped yoke 7 is inserted from below into a slit 5-4 (only one is shown) formed in the bottom wall of the actuator base 5 so that the actuator base 5 Standing up inside
The bottom wall of the yoke 7 is bonded to the lower surface of the actuator base 5. In addition, the rising part of the narrower side of the yoke 7 is
It rises into the actuator base 5 through the opening 5a. Next, the magnet 8 is bonded to the wider rising portion of the yoke 7.

On the other hand, 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 base 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 directed toward the support block 5-1 of the actuator base 5 so that the ends of the suspension wires 6 enter the hollow portions on both sides of the damper base 4. To perform horizontal assembling. Further, the assembled damper base 4 and the support block 5-1 of the actuator base 5 are sandwiched between spring plates 9, and the suspension wire 6 is fixed to the fixing portion 4-1 of the damper base 4. Then, the skew adjustment is performed by rotating the damper base 4 so that the objective lens 3-1 is horizontal. After adjusting the skew,
A UV resin as an adhesive is applied to the damper base 4 and the support block 5-1, particularly, a portion between the damper base 4 and the support block 5-1. As a result, the damper base 4 is fixed to the support block 5-1. Finally, a damping material is injected into the hollow space of the damper base 4 containing 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 base 5.

As described above, in this embodiment, since the damper base 4 is mounted on the support block 5-1 by using the spring plate 9 while the damper base 4 is rotatable, the skew adjustment can be easily performed. be able to. Moreover, since no screws are used, it is not necessary to manage the tightening force of the screws. Further, since it is unnecessary to provide a screw hole for screw insertion in the support block 5-1, the tapping can be omitted.

[0028]

As described above, according to the present invention, since the damper base can be fixed without screws, it is not necessary to control the tightening force of the screws, and the assembly work including the skew adjustment is simplified. become.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an actuator base and a damper base in an optical pickup according to an embodiment of the present invention.

FIGS. 2A and 2B are views showing a structure of an optical pickup according to the present invention after an assembly of a lens holder and a damper base is assembled to an actuator base; FIG. 2A is a plan view, and FIG. (A) is a cross-sectional view taken along line XX ', and (c) is a front view of (a).

FIG. 3 is a plan view of an optical pickup according to the present invention.

FIG. 4 is a longitudinal sectional view taken along line AA ′ of FIG. 3;

FIG. 5 is an exploded perspective view of a conventional optical pickup.

FIG. 6 is a partial cross-sectional side view for explaining a damper base mounting structure in FIG. 5;

FIG. 7 is a partial cross-sectional side view for explaining the mounting structure of the actuator base in FIG. 5;

[Description of Signs] 1 Optical pickup 2 Optical base 3 Lens holder 3-1 Objective lens 3-2 Tracking coil 3-3 Focusing coil 4 Damper base 5 Actuator base 6 Suspension wire 7 Yoke 8 Magnet 9 Spring plate

Claims (3)

[Claims] 1. A lens holder for holding a lens for an optical pickup, a damper base for supporting the lens holder so as to be vertically and horizontally displaceable via a plurality of suspension wires, and a fixed support for the damper base. An optical pickup including a base member having a support block for fixing the damper base to the support block by sandwiching the damper base with a spring member having a U-shaped cross section. Optical pickup. 2. The optical pickup according to claim 1, wherein the spring member is a leaf spring, and one of a contact surface between the support block and the damper base and a contact surface between the damper base and the spring member. An optical pickup characterized in that the projection is provided on one side so that the damper base is rotatable around the projection. 3. The optical pickup according to claim 2, wherein a receiving portion for the projection is provided on the other of the contact surface between the support block and the damper base and the other of the contact surface between the damper base and the spring member. An optical pickup characterized in that: