JPH0291824A - Objective lens supporting device - Google Patents

Abstract

PURPOSE:To prevent the protrusion of an adhesive to a leaf spring and to obtain a fixed spring constant by fixing an assembly interposing a holder plates through adhesive sheets fitted to each surface of the leaf spring into grooves in a relay plate and fixing section. CONSTITUTION:The leaf spring 5 for tracking is adhered to holder plates 8 through adhesive sheets 7. The adhesive sheet 7 where the adhesive is formed in a thin planar sheet is adhered to two surfaces of the spring 5 in the direction perpendicular to the track direction 12 and the respective surfaces of the spring 5 are pinched and adhered by means of holder plates 8 to form the leaf spring assembly 13 for tracking. The assembly 13 is fixed into grooves in a relay plate 4 and fixing section 6 with the adhesive. Since the using quantity of the adhesive is increased in a state where the adhesive does not reach the leaf spring for tracking even when the adhesive protrudes from the groove and is only detoured around the holder plates, a fixed spring constant can be always obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an objective lens support device in an objective lens drive device used for an optical head of an optical disk, etc., and in particular, features a fixing means for a tracking leaf spring. The present invention relates to an objective lens support device.

[Conventional technology]

The configuration of a conventional objective lens support device will be explained using FIGS. 4 and 5.

FIG. 4 is a perspective view of a conventional objective lens support device,
FIG. 5 is a partially enlarged plan view.

In FIG. 4, this objective lens support device 1 includes an objective lens 2a, a lens drive section 2b, a pair of focusing leaf springs 3a and 3b, a relay plate 4, and a tracking leaf spring 5.
, a fixing part 6, and the like. Objective lens 2
a is incorporated in the lens drive section 2b. This lens drive section 2b usually includes a focus coil and a tracking coil.

A pair of focusing leaf springs 3a and 3b are fixed in parallel to the upper and lower ends of the lens drive section 2b, with a predetermined distance maintained therebetween, as shown in FIG. At the other end of these focusing leaf springs, a relay plate 4 is fixed between the two leaf springs 3a and 3b. And the relay board 4 is
It is coupled to a fixed part 6 via a tracking leaf spring 5.

The focusing leaf springs 3a, 3b and the relay plate 4 have grooves 11a for adhesively fixing the tracking leaf spring 5,
llb is formed to penetrate in the focus direction 1o. As shown in an enlarged view in FIG. 5, the cross-sectional shape of the groove 11a is rectangular. The groove 1 is also provided in the fixing part 6.
A groove 11b having the same cross-sectional shape as 1a is formed at a position facing the groove 11a. One end of the tracking plate spring 5 is placed in the groove 11a and fixed with an adhesive, and the other end is placed in the groove 11b and fixed with an adhesive. At this time, the surface of the tracking leaf spring 5 is perpendicular to the side surface 4a of the relay plate 4 and the side surface 6a of the fixed part 6. The widths of the grooves 11a and 11b are made as small as possible to prevent twisting of the tracking leaf spring 5.

[Problem to be solved by the invention]

In the conventional objective lens support device described above, the tracking leaf spring is adhesively fixed to the groove provided in the relay plate and the fixing part, but if the thickness of the adhesive layer is increased and the adhesive force is increased, the adhesive The agent may overflow into the tracking leaf spring, changing the effective length of the tracking leaf spring as a spring material, which may increase the spring constant. In addition, if the adhesive is made thinner in order to reduce the amount of adhesive that protrudes onto the tracking leaf spring, the adhesive strength will become weaker, and as a result, when the objective lens is driven or when the objective lens support device is subjected to impact, etc.
There is a drawback that the tracking leaf spring easily comes off from the groove.

[Means to solve the problem]

In the objective lens driving device of the present invention, a lens driving section incorporating an objective lens is supported by a focusing leaf spring, the other end of the focusing leaf spring is fixed to a relay plate, and a gap between the relay plate and the fixed part is provided. In the objective lens support device in which a tracking leaf spring is arranged, four track holder plates are provided on two surfaces perpendicular to the track direction of the tracking leaf spring, each supporting the tracking leaf spring via an adhesive sheet. Two pieces are placed on each surface, and the sides of the track holder plate opposite to the adhesive side to the relay plate and fixing part are arranged parallel to the focus direction and at a constant interval, and the adhesive is applied. A track leaf spring assembly is laminated to the sheet, one end of the track leaf spring assembly is fixed in a groove of the relay plate with an adhesive, and the other end of the track leaf spring assembly is fixed in a groove of the fixing part. It has to be fixed with adhesive.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view of a first embodiment of the invention.

In this embodiment, the tracking leaf spring 5 is attached to the adhesive sheet 7.
It is the same as the conventional objective lens support device except for the parts related to the structure that is bonded with the track holder plate 8 via the holder plate 8, and the same structural parts as in the prior art are given the same reference numerals as in the section of the conventional example.

As shown in FIG. 2(a), two surfaces 5 perpendicular to the tracking direction 12 (see FIG. 1) of the tracking leaf spring 5
Adhesive sheet 7 made of thin plate-shaped sheets of acrylic adhesive, for example, is adhered to surfaces a and 5b, and the respective surfaces are sandwiched between track holder plates 8 and adhered, as shown in Fig. 2 (
As shown in b), the tracking leaf spring assembly 13
is possible.

FIG. 3 is a diagram showing a method of fixing the above-mentioned tracking leaf spring assembly 13 to the relay plate 4 and the fixing part 6. The relay plate 4 has a groove 1 having a rectangular cross section in order to fix the tracking leaf spring assembly 13.
4 is formed.

The longitudinal direction of this groove 14 is the focus 10 (see Figure 1).
is parallel to. In addition, the fixing part 6 is also connected to the relay plate 4.
A groove 15 having the same shape as the groove 14 is formed at a position facing the groove 14. The dimensions of groove 15 are preferably the same as the dimensions of groove 140.

The tracking leaf spring assembly 13 is fixed to the grooves 14 and 15 with adhesive 9, but in order to obtain sufficient adhesive strength between the tracking leaf spring assembly 13 and the fixing portion 6 of the relay plate 4, a layer of adhesive 9 is applied. If thicker, each groove 14,1
When inserting the tracking plate spring assembly 13 into the track holder plate 5, the adhesive oozes out, but with this invention, even if the adhesive 9 protrudes from each groove 14, 15, the adhesive □ just oozes out onto the track holder plate 8. The adhesive 9 does not wrap around the track leaf spring 5. Furthermore, the adhesive 9 that protrudes also adheres the track holder plate 8 from the surface of each groove 14 , 15 where there is no layer of adhesive 9 , and serves to strengthen the support of the track leaf spring assembly 13 .

〔Effect of the invention〕

As explained above, the present invention involves sandwiching a track holder plate between each surface of the tracking leaf spring perpendicular to the track direction via an adhesive sheet when fixing the track leaf spring in the groove of the relay plate and the fixing part. However, by forming the tracking leaf spring assembly 5, even if the adhesive layer is made thick to obtain sufficient adhesive force when adhering the tracking leaf spring to the groove of the relay plate and the fixing part, the adhesive will not adhere to the track holder. Since it only wraps around the plate and does not wrap around the tracking leaf spring, it has the effect of always providing a constant spring constant. Additionally, the adhesive sheet provided on the surface of the leaf spring also has an anti-vibration effect.

Arrival sheet, 8...Track holder plate, 9
...Adhesive, IO...Focus direction, 11a.

Claims (3)

[Claims] (1) Objective lens support for an optical disc device in which a support part on which the objective lens is supported and a fixed part are coupled via a leaf spring inserted into a groove provided in a groove provided on the opposing surface of the support part and the fixed part. In the device, a spacer member is fixed to a portion of the leaf spring inserted into the groove, and the supporting portion and the fixing portion are coupled to the leaf spring via an adhesive between the spacer member and the groove. An objective lens support device for an optical disc device. (2) an adhesive sheet is formed on both sides of the spring material;
The objective lens support device according to claim 1, wherein the spacer member is fixed onto the adhesive sheet. (3) The lens driving section incorporating the objective lens is supported by a focusing leaf spring, the other end of this focusing leaf spring is fixed to a relay plate, and a tracking leaf spring is installed between this relay plate and the fixed part. In the objective lens support device of the optical disk device arranged, four track holder plates are provided on each surface of the tracking leaf spring, each supporting the tracking leaf spring via an adhesive sheet on two surfaces perpendicular to the track direction. Arrange two pieces at a time, and attach the track holder plate to the adhesive sheet so that the side opposite to the adhesive side to the relay plate and fixing part is parallel to the focus direction and maintained at a constant interval. one end of the track leaf spring assembly is fixed in the groove of the relay plate with an adhesive, and the other end of the track leaf spring assembly is fixed in the groove of the fixing part with an adhesive. The objective lens support device according to claim 2, characterized in that: