JP2007257806A - Objective lens drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an objective lens drive device in which positioning accuracy is good, assembly can be performed without providing a process of temporary fixing, an expensive positioning tool is not required, and the number of assembling processes also can be reduced. <P>SOLUTION: A coil frame 10 for positioning, which is engaged with a focus coil 3 is provided at a lens holder 2 in an almost square shape. The focus coil 3 is fitted to an outer periphery of this coil frame 10, and after that, thermosetting adhesive or the like are filled in a gap between the lens holder 2 and the focus coil 3, for adhesion and fixation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an objective lens driving device mounted on an optical pickup used for recording and reproduction on an optical disk such as a high-density disk or a compact disk.

  As a conventional objective lens driving device, first, the lens holder is positioned on a high-precision assembly jig, and then the focus coil is positioned on the assembly jig, and then the lens holder and the focus coil are temporarily fixed with UV adhesive or the like. Then, there is one that is removed from the assembly jig, filled with a thermosetting adhesive between the lens holder and the focus coil, and cured in a high temperature furnace (for example, see Patent Document 1). FIG. 6 shows a conventional objective lens driving device described in Patent Document 1. In FIG.

  In FIG. 6, a lens holder 2 for holding an objective lens 1 for recording or reproducing on a disk is elastically supported by suspension wires 6a, 6b, 6c, 6d, and both ends thereof are connected to terminal plates 5a, 5b and ACT. A focus drive current and a tracking drive current are applied through the ACT lead wires 11a, 11b, 11c, and 11d soldered to the substrate 7 and soldered to the ACT substrate 7. Air core tracking coils 4a and 4b are bonded and fixed to the outer peripheral surface of the focus coil 3 wound in an air core shape. A focus coil 3 and tracking coils 4a and 4b are bonded and fixed to the lens holder 2, and these coils are arranged in a magnetic gap of a magnetic circuit composed of an ATC base 12 and magnets 13a and 13b, and ACT lead wires 11a and 11b. , 11c, and 11d are driven in a direction substantially parallel to the optical axis of the objective lens 1 and a direction perpendicular thereto by the focus drive current and tracking drive current applied through 11c and 11d.

  7A and 7B show the structure of the lens holder 2. FIG. 7A is a top view, FIG. 7B is an AA sectional view, and FIG. 7C is a BB sectional view. It adhere | attaches so that the focus coil 3 may ride on the rib 2b shown in FIG.

The focus coil 3 and the tracking coils 4a and 4b need to be assembled with high precision so that they do not come into contact with the magnets 13a and 13b even if they can be moved vertically and horizontally in a narrow gap between the magnets 13a and 13b. After positioning the lens holder 2 and the focus coil 3 using a UV adhesive, temporarily fix the lens holder 2 with a UV adhesive or the like and then fill the outer periphery of the focus coil 3 and the lens holder 2 with a thermosetting adhesive or the like and cure in a high temperature furnace The book was fixed. A high-precision jig is required to accurately position the focus coil 3 on the lens holder 2, and the position is shifted while the thermosetting adhesive for fixing the focus coil 3 and the lens holder 2 is baked in a high-temperature furnace. It was temporarily fixed so that there was no.
JP 2000-327552 A

  However, in the conventional configuration, a high-precision jig is required for positioning the focus coil 3 and the lens holder 2, and the position is not changed during the time (for example, about 1 hour) when the thermosetting adhesive is baked and hardened in a high-temperature furnace. It was necessary to temporarily fix so as not to shift, and there was a problem that the equipment investment and work man-hours for that purpose increased.

  The present invention solves the above-described conventional problems, and provides an objective lens driving device in which a positioning frame corresponding to a high-precision assembly jig is provided in a lens holder, and a focus coil is fitted to the lens frame and temporarily fixed. For the purpose.

  In order to solve the above conventional problems, the objective lens driving device of the present invention has a focus coil positioning frame in a lens holder, and performs high-precision positioning and temporary fixing by fitting.

  With this configuration, it is possible to reduce capital investment and assembly man-hours for high-precision assembly jigs and temporary fixing.

  As described above, according to the objective lens driving device of the present invention, the positioning of the focus coil is performed by the positioning frame provided on the lens holder, so that a high-precision positioning jig is not required and the outer periphery of the positioning frame is removed. By adopting a fitting size for press-fitting with the focus coil, the step of temporarily fixing the focus coil with a conventional UV adhesive or the like can be omitted. Furthermore, it is possible to improve the magnetic characteristics and reduce the weight of the lens holder by removing a part of the positioning frame arranged in the magnetic gap and a part of the other positioning frame. An apparatus can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is an exploded perspective view of the objective lens driving device according to Embodiment 1 of the present invention. In FIG. 1, the same components as those in FIG.

  In FIG. 1, the focus coil 3 is positioned and fitted to the outside of a rectangular coil frame 10 provided in the lens holder 2, and is temporarily fixed, and the focus coil 3 and the lens holder 2 positioned outside the focus coil 3 are positioned. The gap is filled with a thermosetting adhesive and cured in a high temperature furnace. The focus coil 3 incorporated in the lens holder 2 is a lens holder assembly, and constitutes an objective lens driving device of an optical pickup in an organic manner in association with a magnetic circuit comprising an ACT base 12 and magnets 13a and 13b. Yes.

  2A and 2B are views for explaining the shape of the lens holder 2 in detail. FIG. 2A is a top view, FIG. 2B is an AA sectional view, and FIG. 2C is a BB sectional view. As shown in FIG. 2, the coil frame 10 is formed in a square shape. The focus coil 3 is fitted in the outer space 10a, 10b of the coil frame 10.

  As described above, according to the configuration of the first embodiment of the present invention, the positioning of the focus coil 3 is performed by the rectangular coil frame 10 provided in the lens holder 2, thereby eliminating the need for a highly accurate positioning jig. Further, by making the outer periphery of the coil frame 10 into a fitting dimension for press-fitting with the focus coil 3, the temporary fixing step of the focus coil can be omitted with a conventional UV adhesive or the like.

  In FIG. 2, the outer periphery of the coil frame 10 rises substantially vertically. However, in order to facilitate the attachment of the focus coil 3, the upper end portion may be rounded or sunk.

(Embodiment 2)
3, 4 and 5 are views showing the structure of the lens holder constituting the objective lens driving device according to Embodiment 2 of the present invention. 3, 4, and 5, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals and description thereof is omitted.

  FIG. 3 shows the structure of the lens holder 2 in the second embodiment. FIG. 2A is a top view, FIG. 2B is a cross-sectional view along AA, and FIG. 3C is a cross-sectional view along BB.

  In FIG. 3, a part of the coil frame 10 disposed in the magnetic gap in the magnetic circuit including the ACT base 12 and the magnets 13a and 13b is removed. The focus coil 3 is positioned by the three sides of the coil frame 10 and a partial coil frame near the corner formed outside the magnetic gap.

  Thereby, since the clearance gap between the magnets 13a and 13b can be made small, a magnetic characteristic can also be improved.

  FIG. 4 shows another structural example of the lens holder 2 in the second embodiment. FIG. 2A is a top view, FIG. 2B is a cross-sectional view along AA, and FIG. 3C is a cross-sectional view along BB.

  The lens holder 2 shown in FIG. 4 is one in which the coil frame 10 and the coil receiving surface in the coil height direction of the portion arranged in the magnetic gap in the magnetic circuit are also removed. The focus coil 3 is positioned by the three sides of the coil frame 10 and a partial coil frame near the corner formed outside the magnetic gap.

  Thereby, the clearance gap between the magnets 13a and 13b can be made small, and the lens holder 2 can be reduced in weight.

  FIG. 5 shows another structure example of the lens holder 2 in the second embodiment. FIG. 2A is a top view, FIG. 2B is a cross-sectional view along AA, and FIG. 3C is a cross-sectional view along BB.

  In the lens holder 2 shown in FIG. 5, the rectangular coil frame 10 is formed only in the vicinity of the four corners. The focus coil 3 is positioned by partial frames (substantially L-shaped columns) formed near the four corners of the coil frame 10.

  Thereby, the gap between the magnets 13a and 13b can be reduced, and the lens holder can be further reduced in weight.

  In addition, you may apply the structure which provides the coil frame 10 only in the four corner vicinity as shown in FIG. 5 with respect to the lens holder 2 shown in FIG.

  As described above, according to the configuration of the second embodiment of the present invention, as in the first embodiment, a high-precision positioning jig and a focus coil temporary fixing step are not necessary, and at the same time, the magnetic gap can be reduced. In addition, since the objective lens can be reduced in weight, a high-performance objective lens driving device can be provided.

  The objective lens driving device of the present invention has an effect that the process of temporarily fixing the focus coil can be omitted and the manufacturing cost can be reduced, and is useful as an optical pickup used for recording and reproduction on an optical disc.

1 is an exploded perspective view showing the structure of an objective lens driving device in Embodiment 1 of the present invention. Plane and sectional view showing the structure of the lens holder which is the main component of the objective lens driving device Plane and sectional view showing the structure of a lens holder which is a main part of the objective lens driving device in the second embodiment Plane and sectional view showing another structural example of the lens holder Plane and sectional view showing another structural example of the lens holder An exploded perspective view showing the structure of a conventional objective lens driving device Plane and sectional view showing the structure of a lens holder which is a main part of a conventional objective lens driving device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Objective lens 2 Lens holder 3 Focus coil 4a, 4b Tracking coil 5a, 5b Terminal board 6a, 6b, 6c, 6d Suspension wire 7 ACT board 8a, 8b Gel 9 Gel holder 10 Coil frame 11a, 11b, 11c, 11d ACT lead wire 12 ACT base 13a, 13b Magnet

Claims (4)

An objective lens for recording or reproducing on a disk, a lens holder for holding the objective lens, an optical base having various optical components, and a support means for elastically supporting the lens holder with respect to the optical base; A focus coil wound around an air core that generates a force that moves the lens holder in a direction substantially parallel to at least the optical axis of the objective lens with respect to the optical base, and a magnet that generates a force in the focus coil An objective lens driving device comprising a circuit,
2. The objective lens driving device according to claim 1, wherein the focus coil is fitted and fixed to an outer periphery of a positioning frame formed on the lens holder. The objective lens driving device according to claim 1, wherein a focus coil positioning frame formed on the lens holder is fitted to the focus coil over an entire circumference. 2. The objective lens driving device according to claim 1, wherein the focus coil positioning frame formed on the lens holder lacks a portion in the magnetic circuit. 2. The objective lens driving device according to claim 1, wherein the focus coil positioning frame formed on the lens holder is provided in the vicinity of at least four corners of the focus coil.

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