JP2006185536A - Objective lens drive apparatus and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an objective lens drive apparatus having a constitution in which a housing part of a resonance suppression member is provided with a simple constitution without increasing the number of parts, and its manufacturing method in an objective lens drive apparatus in which an elastic supporting member is insert-molded into a fixed side member and a lens holder. <P>SOLUTION: The apparatus is provided with a gel pot 50 in which an ultraviolet curing type viscoelastic body 9 as the resonance suppression member is filled so as to surround elastic supporting members 61, 71 and 81 to support a lens holder 2 by a yoke 3 having a yoke part 3a at which a magnet for tilt drive is fixed and a fixed side member 5 supporting elastic supporting parts 61, 71 and 82. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an objective lens driving device for an optical head device for recording and reproducing optical disks such as CDs and DVDs. More particularly, the present invention relates to an objective lens support structure.

  2. Description of the Related Art As an objective lens driving device for an optical head device that records and reproduces an optical disc such as a CD or DVD, a device that supports an objective lens with a wire is well known.

The objective lens is fixed to a holder that holds the objective lens, and a plurality of conductive wires are suspended between the holder and the fixing member, and the objective lens is supported so as to be movable in the focusing and tracking directions. Driving in the focusing and tracking direction. The fixing member is provided with a recessed space and filled with silicon gel to suppress the vibration level during resonance. (For example, see Patent Document 1)
Utility Model Registration No. 2521564

  In recent years, along with the downsizing and thinning of devices such as personal computers, the optical head device is also required to be downsized, thinned, and lightened. In the conventional wire suspension system, since the electrical connection between the wire and the driving coil is usually fixed and fixed via a printed wiring board provided on the side of the holder, the lens holder becomes larger by this wiring board. However, there is a problem that it is not possible to sufficiently meet the demands for reduction in size, thickness and weight. Further, when the holder is further reduced in thickness, the wiring board is inevitably reduced in thickness, so that the distance between the wires becomes extremely narrow, and the electric power by soldering between the terminal portion and the wire on the wiring board is reduced. Connection work becomes extremely difficult, and there is a possibility that the wire may be deformed or loosened by mistake. As a result, there is a problem that a stable skew characteristic of the holder cannot be obtained.

In order to cope with this, a suspension type objective lens support device using a lead frame can be considered instead of the wire suspension type. In this method, a resin-made movable portion on which an objective lens holder is mounted and a fixed portion that supports the movable portion are insert-molded on a plurality of lead frames made of metal. (For example, see Patent Document 2)
With this method, the suspension portion and the coil connection terminal portion to which the drive coil is connected can be formed integrally with the lead frame, so that the connection between the terminal portion and the wire becomes unnecessary, and the wiring board is not used. It has the advantage that it can be done.
JP 2002-150583 A

  When such a device is made smaller, thinner, lighter, etc., the structure of Patent Document 2 above is adopted, and when a plurality of elastic support members are insert-molded into a resin lens holder and a fixing portion, the lens holder Alternatively, due to the presence of the fixing portion, it is necessary to insert a mold for determining the separation distance between the elastic support members stacked in multiple stages from the tracking direction. For this reason, it is difficult to integrally form the holding portions (wall portions) constituting a part of the housing portion filled with the viscous elastic body as the resonance suppressing member at both end portions in the tracking direction of the fixed portion, There is a problem that the holding part must be manufactured as a separate part and retrofitted to the fixed part, which increases the number of parts and reduces workability.

  In view of the above problems, the object of the present invention is to reduce the thickness and weight of the apparatus and to provide an objective lens driving apparatus in which an elastic support member that supports the lens holder is fixed to the fixing portion by insert molding. Another object of the present invention is to provide an objective lens driving device having a configuration in which a storage portion for a resonance suppression member is provided with a simple configuration without increasing the number of parts, and a manufacturing method thereof.

  In order to solve the above-described problems, in the present invention, a holder to which an objective lens is attached, and a resin-made fixed-side member disposed so as to face the holder so that the holder can be moved in a focus direction, a tracking direction, and a tilt direction. A plurality of elastic support members that are supported on the resonance side, a resonance suppression member that is filled in the fixed-side member so that a part of the elastic support member is embedded, and an electromagnetic force that applies electromagnetic force for the movement of the holder An objective lens driving device having one end side of the elastic support member fixed to the fixed side member and the other end side fixed to the holder by insert molding, and a coil for tilt driving is arranged on the holder. In addition, a tilt driving magnet is disposed on the fixed side member so as to face the tilt driving coil via a magnetic plate, and the magnetic plate moves forward. Resonance suppression member is characterized in that forming the accommodating portion to be filled.

  In the present invention, it is preferable that the magnetic plate has a pair of opposing wall portions that form an accommodating portion filled with the resonance suppression member. If comprised in this way, it can prevent that the said resonance suppression member flows out from a fixed-side member both end surface.

  Further, in the present invention, the pair of wall portions are formed such that each wall surface extends from both side end surface portions in the tracking direction of the fixed side member toward the holder side, and the fixed side member and the holder are opposed to each other. It is preferable that a yoke portion holding a tilt driving magnet is disposed between the surfaces. With such a configuration, the tilt driving coil can be disposed opposite to the fixed member on the holder, and can be used as a balance weight for balancing the weight with the objective lens. Further, when the tilt driving yoke is fixed, a pair of wall portions can be used as a chuck portion, and the yoke holding the tilt driving magnet is located between the opposing surfaces of the fixed side member and the holder. Can be installed easily even in difficult places.

  In the present invention, when the magnetic plate is a first magnetic plate, the magnetic plate has a second magnetic plate different from the first magnetic plate to which a focusing drive magnet or a tracking drive magnet is attached. The two magnetic plates are spaced apart from each other in a direction orthogonal to both the tracking direction and the focusing direction, and the second magnetic plate is not exposed from the surface of the holder facing the fixed member. It is arranged. With this configuration, even when the resonance suppression member is filled, even if it flows downward from the direction in which the elastic support member is embedded in the housing portion, there is no contact member, and the extra resonance suppression member adheres to the second magnetic plate. In this way, the resonance suppressing member can be stably filled.

  Furthermore, in the present invention, it is preferable that the resonance suppression member is an ultraviolet curable viscous elastic body. When this configuration is employed, the resonance suppression member can be easily filled into the housing portion and can be prevented from flowing out of the housing portion when cured. Further, compared to the thermosetting type, the fixed side member or the like is not deformed by heat during the curing process.

  In the manufacturing method of the objective lens driving device according to the present invention, the elastic support member is formed by insert molding on the fixed side member by laminating a plurality of thin plates formed in a predetermined pattern at intervals in the optical axis direction of the objective lens. A mold for determining a separation distance between the thin plates is inserted and molded from the tracking direction. If comprised in this way, even if it is a case where a some elastic support member is insert-molded integrally with a stationary-side member, it can shape | mold easily and reliably.

  In the objective lens driving device according to the present invention, the holder to which the objective lens is attached, and the holder are supported by a resin fixed side member arranged so as to face the holder so as to be movable in the focus direction, the tracking direction, and the tilt direction. A plurality of elastic supporting members, a resonance suppressing member filled in the fixed side member so that a part of the elastic supporting member is embedded, and electromagnetic driving means for applying an electromagnetic force for the movement of the holder In the objective lens driving apparatus, one end side of the elastic support member is fixed to the fixed side member and the other end side is fixed to the holder by insert molding, and a coil for tilt driving is disposed on the holder. In addition, a tilt driving magnet is disposed on the fixed side member so as to face the tilt driving coil via a magnetic plate, and the magnetic plate moves the front side. Forming a housing part resonance suppression member is filled. Therefore, even in the suspension type objective lens driving device in which the elastic support member is insert-molded and fixed to the fixed side member and the holder, the magnetic plate to which the tilt driving magnet is attached also serves as the housing portion. Therefore, there is no need to retrofit another part holding part as in the prior art, and the number of parts is not increased.

  An objective lens driving device to which the present invention is applied will be described below with reference to the drawings.

(Schematic configuration of the objective lens driving device)
1A and 1B are a plan view and a right side view of an objective lens driving apparatus to which the present invention is applied, and FIGS. 2A and 2B are objective lens driving to which the present invention is applied. The perspective view which looked at the apparatus from diagonally upward, and the perspective view which looked from diagonally downward are shown. However, the state before filling the ultraviolet curable viscous elastic body as a resonance suppression member which will be described later for convenience of explanation is shown.

  An objective lens driving device 1 shown in FIGS. 1A, 1B, 2A, and 2B is used for reproducing an optical recording disk such as a CD or a DVD. In the apparatus 1, a leaf suspension system in which a resin lens holder 2 holding an objective lens 20 for converging light emitted from a light source on an optical recording medium is supported by elastic support members 61, 71, 81 made of thin metal plates. Is adopted.

  In the objective lens driving device 1 of the present embodiment, the lens holder 2 that holds the objective lens 20 and the fixed side member 5 are arranged to face each other, and the drive coils 6, 7, and 8 mounted on the lens holder 2 side are provided. The magnets 17 and 18 mounted directly or indirectly on the side of the yoke 4 as the second magnetic plate serving as the base, and the yoke portion 3a of the yoke 3 as the first magnetic plate on the stationary member 5 A magnetic drive circuit for driving the lens holder 2 in the focusing direction, the tracking direction, and the tilt direction is configured by the magnet 16 fixed thereto. That is, the lens holder 2 includes a tilt driving coil 6, a tracking driving coil 8, and a focusing driving coil 7 in this order from the fixed side member 5 side toward the distal end side (objective lens 20 side). Has been placed. In the objective lens driving apparatus 1, the driving coils 6, 7, 8 and the magnets 16, 17, 18 corresponding to the coils constitute electromagnetic driving means. A magnetic force adjusting spacer 10 made of a magnetic material is interposed between the yoke 4 and the magnet 17.

  Among the drive coils, the tracking drive coil 8 is disposed at a substantially central position in the direction orthogonal to the optical axis of the objective lens 20 in the opening 21 formed in the lens holder 2, and the focusing drive coil is In addition, it is arranged inside the opening 21 so as to abut on the tracking driving coil 8. The tilt driving coil 6 is disposed at a position facing the fixed member 5 in the lens holder 2.

  As is well known, in order to suppress unnecessary resonance when the objective lens is driven, the driving center in focusing and tracking needs to coincide with the position of the center of gravity of the movable part. For this reason, in this embodiment, the tracking driving coil 8 and the focusing driving coil 7 are arranged at substantially the center position of the lens holder and are made to coincide with the center of gravity of the movable portion. The tracking driving coil 8 and the focusing driving coil 7 may be disposed at the center of gravity of the movable portion, and may not necessarily be at the center position of the lens holder. On the other hand, in the tilt drive, after the tilt angle of the objective lens 20 is determined at the initial drive stage of the objective lens driving device 1, the tilt drive coil 6 is not driven so that the tilt drive coil 6 is positioned at the center of gravity of the movable portion. It is not necessary to dispose in Therefore, in the objective lens driving device 1 of the present embodiment, in order to balance the weight with the objective lens 20, the tilt driving coil is disposed at a position facing the fixed side member 5 of the lens holder and functions as a balance weight. Yes.

Accordingly, the tilt driving magnet 16 is disposed at a position facing the lens holder 2 in the fixed member 5, and the tracking driving magnet 18 is opposed to the tracking driving coil inside the opening 21 of the lens holder 2. The focusing driving magnet 17 is disposed inside the opening 21 of the lens holder 2 so as to face the focusing driving coil. The yoke 4 includes an upper surface portion 41 that covers the lens holder 2 through the opening 21 of the lens holder 2.

By the way, in the objective lens driving device 1 of this embodiment, the yoke 3 to which the tilt driving magnet 16 is attached and the yoke 4 to which the focusing driving magnet 17 and the tracking driving magnet 18 are attached are separated. Further, the yoke 4 is disposed at a position where it is not exposed from the surface facing the fixed member 5 in the lens holder 2, that is, between the objective lens 20 and the facing surface in this embodiment.

  Between the lens holder 2 and the fixed side member 5, a pair of left and right elastic support members 61 for tilt driving that also serve as a coil feeding line for driving the lens holder 2 in the tilt direction, and the lens holder 2 in the focusing direction. A pair of left and right focusing driving elastic support members 71 that also serve as coil feeding lines for driving, and a pair of left and right tracking driving elastic support members 81 that also serve as coil feeding lines for driving the lens holder in the tracking direction. And are arranged.

  The elastic support member 61 for tilt drive, the elastic support member 71 for focusing drive, and the elastic support member 81 for tracking drive are arranged in multiple stages in this order from the upper stage to the lower stage, and overlap in plan view. Placed in position. Further, the elastic support member 61 for tilt drive, the elastic support member 71 for focusing drive, and the elastic support member 81 for tracking drive are all connected to the left and right side surfaces of the lens holder 2 and the base end side is fixed. It is connected to the side member 5. The stationary member 5 is provided with an elastic support member 61 for tilt drive, an elastic support member 71 for focusing drive, and a gel pot 50 as a housing for the elastic support member 81 for tracking drive.

  The lens holder 2 and the stationary member 5 of the objective lens driving device 1 configured as described above are both formed from a resin molded product using the same resin material. In addition, the elastic support member 61 for tilt drive, the elastic support member 71 for focusing drive, and the elastic support member 81 for tracking drive are all formed of a metal plate made of the same material.

(Composition of gel pot)
FIG. 3 is a perspective view showing a configuration in which a gel pot of an objective lens driving device to which the present invention is applied is filled with a resonance suppression member, and FIG. 4 forms a part of the gel pot of the objective lens driving device to which the present invention is applied. It is a perspective view which shows the structure of the magnetic body to do.

Based on FIG.3 and FIG.4, the specific structure of the gel pot 50 in the objective lens drive device 1 is demonstrated below.

  An ultraviolet curable viscous elastic body 9 as a resonance suppression member is held by the gel pot 50 so as to surround and flex the base end sides of the elastic support members 61, 71 and 81.

Here, as shown in FIG. 2 (a), the gel pot 50 has a yoke portion 3a that is disposed on the left and right sides of the fixed-side member 5 and has the yoke portions 3a to which the side wall surfaces 51 and 52 orthogonal to each other and the tilt driving magnet 16 are attached. It is formed by wall portions 31 and 32 having L-shaped cross sections provided integrally on both sides of the yoke 3 as one magnetic plate.

More specifically, the yoke portion 3a and the wall portions 31, 32 are integrally manufactured by being bent vertically from the base 30 of the yoke 3, which is the first magnetic plate. The wall surfaces are formed so that the wall surfaces face each other. The yoke portion 3a is disposed between the two wall surfaces, and the wall surfaces are formed in a direction substantially orthogonal to the respective wall surfaces.

In the yoke 3 formed as described above, the base 30 is fixed to the lower side of the fixed side member 5 as shown in FIG. 2B, and the wall portions 31 and 32 are part of the wall surface. Are fixed to both end portions in the tracking direction of the fixed member 5. Moreover, the yoke part 3a is arrange | positioned so that the surface facing the lens holder 2 of the stationary-side member 5 may be covered. The yoke portion 3a has a width in the tracking direction smaller than the width of the tilt driving magnet 16, and the tilt driving magnet 16 has portions 163 and 164 projecting from the yoke portion 3a.

In this way, when the yoke 3 is attached to the fixed side member 5, the side wall surfaces 51 and 52 arranged on the left and right sides of the fixed side member 5 and orthogonal to each other, the base 30 of the yoke 3, the wall portions 31 and 32, and the yoke portion. 3, and UV curable viscoelastic body 9 as a resonance suppressing member is accommodated at portions 163 and 164 projecting from both side end surface portions 161 and 162 of tilt drive magnet 16 and both side end surfaces of yoke portion 3a. A gel pot 50 is configured.

In the objective lens driving device 1 of the present invention, the elastic support members 61, 71, 81, the lens holder 2, and the fixed side member are insert-molded, and then the yoke 3 that is the first magnetic plate is attached to the fixed side member 5. The gel pot 50 is fixed, and the gel pot 50 is filled with the ultraviolet curable viscous elastic body 9. After that, focusing drive and tracking drive magnets 17 and 18 are connected to the optical head device via the yoke 4. For example, it is fixed to a frame or a base. Further, the first magnetic plate 3 having the yoke portion 3a and the yoke 4 are spaced apart in a direction perpendicular to both the tracking direction and the focusing direction, and when filling the ultraviolet curable viscous elastic body 9, Between the opposing end surface portions of the magnetic plate 3 and the yoke 4, nothing is disposed except for the base end portions of the elastic support members 61, 71, 81. Therefore, even if the ultraviolet curable viscous elastic body 9 flows out during filling, the ultraviolet curable viscous elastic body 9 does not adhere to other constituent members.

  As described above, a part of the gel pot 50 is originally used as the first magnetic plate 3 having the yoke portion 3a that constitutes the magnetic circuit, so that the wall portions constituting the gel pot 50 are formed at both ends of the stationary member 5. Since there is no need to provide the lens holder 2 as a movable part and the fixed side member 5 as a fixed part can be insert-molded into the elastic support members 61, 71, 81.

  When such a gel pot 50 is formed, the resonance suppressing member made of the ultraviolet curable viscoelastic body 9 is formed into an L-shaped cross section integrally formed on both side end surface portions 33 and 34 of the yoke portion 3a and both sides of the yoke portion 3a. It can be sufficiently held by the wall portions 31 and 32 and the side wall surfaces 51 and 52 of the stationary member 5.

(Method for forming elastic support member)
FIGS. 5A, 5B, and 5C are plan views showing the configuration of the metal plate before insert molding the elastic support member of the objective lens driving device to which the present invention is applied.

Hereinafter, a method of forming the elastic support members 61, 71, 81 will be described with reference to FIG.

The elastic support member 61 for tilt drive, the elastic support member 71 for focusing drive, and the elastic support member 81 for tracking drive all punch out the thin metal plates 60, 70, 80 into a predetermined shape by pressing or the like. The tip end sides of the elastic support member 61 for tilt drive, the elastic support member 71 for focusing drive, and the elastic support member 81 for tracking drive are formed in the lens holder 2 by the elastic support members 61 and 71. , 81 are embedded at approximately the center position in the extending direction, and each base end side constitutes a portion embedded in the fixed member 5. After the metal plates 60, 70, 80 punched into a predetermined shape are insert-molded into the lens holder 2 and the fixed member 5, unnecessary portions are cut off. The embedded portions 62, 72, and 82 have a shape that extends substantially parallel to the direction in which the elastic support members 61, 71, and 81 extend from the substantially central position.
In the insert molding, the three metal plates 60, 70, 80 are laminated at intervals in the optical axis direction of the objective lens and are inserted into the fixed side member and the lens holder 2. A mold (not shown) for determining the separation distance between the thin plates is inserted between the elastic support members from the tracking direction and subjected to insert molding. After the molding, the mold is moved in the tracking direction and removed.

  The elastic support members 61, 71, 81 are integrally formed with coil connection terminals 63, 73, 83. As a result, the coil ends are soldered in a state of being wound around the coil connection terminals 63, 73 and 83.

(Main effects of this form)
As described above, in the objective lens driving device 1 of the present embodiment, the holder to which the objective lens 20 is attached can be driven in the focus direction, the tracking direction, and the tilt direction, and the tilt driving magnet 16 is attached. The gel pot 50 includes wall portions 31 and 32 integrally formed with the yoke portion 3a, and both end surface portions 161 and 162 of the tilt driving magnet 16 and portions 163 and 164 protruding from both side surfaces of the yoke portion 3a on the yoke portion 3a side. Part of For this reason, even a suspension type objective lens driving device in which a thin metal plate is insert-molded into a lens holder and a fixed side member, it is possible to easily provide a gel pot filled with a resonance suppression member. No need to retrofit.

  Furthermore, the yoke 3 to which the tilt driving magnet 16 is attached is separated from the yoke 4 to which the focusing driving magnet 17 and the tracking driving magnet 18 are attached. Accordingly, there is no need to provide a connecting portion that connects the yoke and the yoke as in the case of integrally forming three yokes (magnet mounting portions) by punching, and the apparatus can be reduced in size or weight, and The yoke cannot be formed (a state in which the height or width of the yoke cannot be secured) due to the small distance between the yokes due to the downsizing of the apparatus.

(Other embodiments)
In the above embodiment, the portions 163 and 164 projecting from the both side end surfaces 161 and 162 of the tilt driving magnet 16 and the both sides of the yoke 3a constitute part of the gel pot 50, but the projecting portion is provided. It does not have to be. Further, the length and size of the overhanging portion may be appropriately changed so as not to interfere with the elastic support members 61, 71, 81 when the lens holder 2 is driven.

  In the above embodiment, the yoke 3 to which the tilt driving magnet 16 is attached and the yoke 4 to which the focusing driving magnet 17 and the tracking driving magnet 18 are attached are separated from each other. It may be integrated by molding or the like.

  Moreover, in the said form, although the ultraviolet curing type viscous elastic body 9 was used for the resonance suppression member, if there is no influence by thermal deformation etc., you may use a thermosetting type viscous elastic body.

(A), (b) is the top view and right view of the objective-lens drive device to which this invention is applied. (A), (b) is the perspective view which looked at the objective-lens drive device to which this invention was applied from diagonally upward, and the perspective view which looked from diagonally downward. It is a perspective view which shows the structure which filled the gel pot of the objective lens drive device to which this invention is applied with the resonance suppression member. It is a perspective view which shows the structure of the magnetic body which forms a part of gel pot of the objective lens drive device to which this invention is applied. (A), (b), (c) is a top view which shows the structure of the metal plate before insert-molding the elastic support member of the objective lens drive device to which this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Objective lens drive device 2 Lens holder 3 Yoke (1st magnetic board)
3a Yoke part 4 Yoke (second magnetic plate)
5 Fixed side member 9 UV curable viscous elastic body 16 Tilt driving magnet 17 Focusing driving magnet 18 Tracking driving magnet 50 Gel pots 60, 70, 80 Metal plates 61, 71, 82 Elastic support members

Claims (6)

A holder to which an objective lens is attached, a plurality of elastic support members that are supported by a fixed member made of resin disposed opposite to the holder so that the holder can be moved in a focus direction, a tracking direction, and a tilt direction; A resonance suppression member filled in the fixed side member so that a part of the support member is embedded, and an electromagnetic driving means for applying an electromagnetic force for the movement of the holder, and the elastic support member In the objective lens driving device formed by fixing one end side to the fixed side member and the other end side to the holder by insert molding,
A coil for tilt driving is disposed in the holder, and a magnet for tilt driving is disposed on the fixed member so as to face the coil for tilt driving through a magnetic plate,
An objective lens driving device characterized in that an accommodating portion filled with the resonance suppressing member is formed by the magnetic plate.   2. The objective lens driving device according to claim 1, wherein the magnetic plate has a pair of opposing wall portions that form an accommodating portion filled with the resonance suppression member. 3.   3. The pair of wall portions according to claim 2, wherein each of the pair of wall portions is formed such that each wall surface extends from both side end surface portions in the tracking direction of the fixed side member to the holder side, and the opposed surfaces of the fixed side member and the holder An objective lens driving device characterized in that a yoke portion holding a tilt driving magnet is disposed therebetween.   4. The method according to claim 1, wherein when the magnetic plate is a first magnetic plate, a second magnetic plate different from the first magnetic plate to which a focusing drive magnet or a tracking drive magnet is attached is provided. The two magnetic plates are spaced apart from each other in the direction orthogonal to both the tracking direction and the focusing direction, and the second magnetic plate is not exposed from the surface of the holder facing the fixed side member. An objective lens driving device, wherein the objective lens driving device is disposed at a position.   5. The objective lens driving device according to claim 1, wherein the resonance suppressing member is an ultraviolet curable viscous elastic body. 2. The method of manufacturing an objective lens driving device according to claim 1, wherein the elastic support member is insert-molded on the fixed side member by laminating a plurality of thin plates formed in a predetermined pattern at intervals in the optical axis direction of the objective lens. A method for manufacturing an objective lens driving device, comprising: molding a mold for determining a separation distance between the thin plates from a tracking direction.

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