JP2679018B2 - Objective lens support device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical information recording method for optically recording or reproducing information by projecting a light spot on an optical recording medium through an objective lens. And / or an objective lens supporting device used for a reproducing device. [Prior Art] For example, in an optical disk device, it is necessary to control so that an optical spot correctly follows an information track in order to accurately record and reproduce information. For this reason, it is conventionally known that the objective lens is movably supported in the focusing direction parallel to the optical axis thereof and the tracking direction orthogonal thereto, and is displaced in both directions by the electromagnetic driving means. For example, in Japanese Patent Laid-Open No. 59-221839, a movable member holding an objective lens is connected to a fixed member through four linear elastic supporting members parallel to each other, for example, metal wires, and the movable member is electromagnetically driven. Therefore, there is disclosed an objective lens driving device in which the objective lens is displaced in the focusing direction and the tracking direction. In an objective lens supporting device that displaceably supports a movable member that holds an objective lens by using such a metal wire, the metal wire is passed through a rubber tube as a damper to reduce the influence of resonance of the metal wire. I am trying to make it work. In the above-described conventional objective lens supporting device having the linear elastic supporting member, as shown in FIG. 11, the metal elastic wire 1a is covered with the rubber tube 1b acting as a tamper member to form the linear elastic supporting member 1. A hole 2a that is configured and has a rubber tube 1b formed at one end of the lens holder 2 as a movable member.
And the metal wire 1a is soldered and fixed to the land 3a of the printed circuit board 3 to which the focusing coil and the tracking coil of the electromagnetic drive means are connected, and the end face of the rubber tube 1b is fixed by the fixing member at the other end. The printed circuit board 4 is brought into contact with a certain printed circuit board 4 and the metal wire 1a is projected through a hole 4a formed in the printed circuit board 4.
Is fixed to the land by solder 5 to support the lens holder 2 so that the lens holder 2 can be displaced in a predetermined direction with respect to the printed circuit board 4 which is a fixing member, and the metal wire 1a drives the lens holder 2 in a predetermined direction. It is also used as a power feeding line for the focusing coil and the tracking coil of the driving means. [Problems to be Solved by the Invention] However, in the above-described conventional objective lens supporting device, the rubber elastic tube 1b is separately molded, and the metal wire 1a is inserted through the center hole of the rubber elastic tube 1b. Since the above is configured, there are the following problems. A rubber tube 1b component is required, resulting in high cost. Since the number of steps for covering the metal wire 1a with the rubber tube 1b is required, the assembly becomes troublesome and the possibility of deforming the thin metal wire 1a increases. The damping characteristics are likely to vary depending on the contact state between the metal wire 1a and the rubber tube 1b. Since the metal wire 1a is covered with the rubber tube 1b, when the end portion of the metal wire 1a is positioned and fixed to the land 3a of the printed circuit board 3 and the land of the printed circuit board 4, it is difficult to determine the position of the metal wire 1a accurately. As a result, harmful resonance is likely to occur. A technique that solves the drawbacks of the rubber tube is disclosed in
No. 62-202340. In this publication, a fixing portion (corresponding to a hole portion having a diameter substantially equal to the diameter of the wire 40 formed in the block 41) to which the end portion of the wire 40 is fixed is formed in the block 41 which is a fixing means and the vicinity of the fixing portion is formed. It is described that a space portion (described in the accommodating portion 42) is formed so that a gap is formed between the wire and the viscoelastic body is arranged in the space portion. However, the publication does not explain how the block 41 and the wire 40 are connected. On the other hand, FIG. 3 of Japanese Utility Model Publication No. 61-86823 discloses that
It is described that the space portion (explained by the hole 5b) is formed in the frame 5 which is the fixing means, and the viscoelastic member is arranged in this space portion. However, in the vicinity of this space portion, the fixing means is used. The wire 7 is not fixed to a certain hole member 12. The present invention has been made by paying attention to such conventional problems, and can be easily assembled and can be manufactured at a low cost, and an objective properly configured so that harmful resonance can be effectively prevented. An object is to provide a lens support device. [Means and Actions for Solving Problems] An objective lens supporting device of the present invention includes a movable member that holds the objective lens and a fixing unit (which is disposed apart from the movable member,
An objective lens supporting device in which the objective lens is displaceable in a predetermined direction by fixing a metal elastic supporting member between the elastic supporting member and the elastic supporting member). At least one of the movable member and the fixing means, a positioning portion for positioning in which the position of the end portion of the elastic support member is determined, and the vicinity of the positioning portion (a position in contact with the positioning portion or close to the positioning portion). A space having a gap with the elastic support member at the position (“a space having a gap with the elastic support member” means in other words “a space where the elastic support member can be arranged and a space where the viscoelastic body can be filled. And a space portion), which are integrally formed with each other (the term "integrally formed" means a mode in which the positioning portion and the space portion are continuously formed in the same member). Is filled with a viscoelastic body that has fluidity (for example, a sticky state corresponds to “fluidity”), and when the elastic support member is used to supply power to the movable portion side. It is characterized by. [Embodiment] FIGS. 1 to 3 show a first embodiment of the present invention, which is applied to an objective lens driving device in an optical pickup for recording and / or reproducing information on a disc-shaped recording medium. Is. The objective lens 11 is fixed to a lens holder 12A of a movable member 12 made of an integrally molded plastic body. In this example, the objective lens 11 is composed of a plano-convex SELFOC lens. The movable member 12 has a rectangular frame 12B surrounding the lens holder 12A, and linear elastic support members 1 are provided on side walls of the frame 12B facing each other.
Support portions 12D to 12G for supporting 3A to 13D are formed. One supporting portion 12G is not visible in FIGS. The print coil 14 is fixed to the outer peripheral surface of the frame 12B by adhesion. In the developed view of FIG. 3, the print coil 14 is shown in a state of being extended in one plane. Printed coil 14
Is a flexible insulating sheet with four tracking coil parts 14A
14D are provided, and two layers of coils are stacked on each coil portion with an insulating film interposed therebetween. These coils are electrically connected to each other and both terminals are land 14E.
And is connected to 14F. In order to perform positioning when mounting the print coil 14 on the outer peripheral surface of the frame 12B, a protrusion 12H is formed on the lower part of one side surface of the frame 12B, and a recess 14G having the print coil 14 formed therein is engaged therewith. A focusing coil 15 is further wound around the print coil 14. The terminal conductors of the focusing coil 15 are the lands 14H and 1 provided on the printed coil 14.
Connect to 4I. The movable member 12 is configured in this manner, and is connected to the fixed member 16 via the elastic support members 13A to 13D. The fixing member 16 is a base 17 made of an integrally molded body of magnetic material.
It is equipped with The base 17 has a bottom portion 17A, and four yoke portions 17B to 17E rising vertically upward from the bottom portion are integrally formed. Permanent magnets 18A and 18B are fixed to the inner surfaces of the yoke portions 17B and 17C, and the yoke portions 17D and 1
7B enters the openings 12I and 12J of the movable member 12 and faces the permanent magnets 18A and 18B via the print coil 14 and the focusing coil 15, respectively. In this example, grooves 17F and 1 are formed on the inner surfaces of these yoke portions 17B and 17C.
After forming 7G and magnetically attracting the permanent magnets 18A and 18B to the predetermined positions of the yoke portions 17B and 17C,
Adhesive is poured into 17F and 17G to fix the permanent magnet to the yoke. With such a configuration, the permanent magnet can be accurately positioned and fixed with respect to the yoke portion, and the assembling becomes easy, which is particularly suitable for automatic assembling by a machine. A printed circuit board 19 is fixed to the outer surface of the yoke portion 17C of the base 17 of the fixing member 16 with screws 20. Holes 19A to 19D into which the ends of the linear elastic support members 13A to 13D are fitted are formed on both side surfaces of the printed circuit board 19. As shown clearly in FIG. 2, a substantially ring-shaped protrusion 17H is formed on the lower surface of the bottom 17A of the base 17.
Is formed, and the front end surface thereof is formed into a curved surface so that it can be rotatably mounted on a carriage that supports the objective lens driving device and is driven in the radial direction of the disk-shaped recording medium. This protrusion
A part of 17H is cut out together with the bottom 17A of the base to form an optical path. Thus, the fixing member 16 is configured. As described above, in this embodiment, the linear elastic support member 13
The movable member 12 and the fixed member 16 are connected via A to 13D.
Each of the linear elastic support members 13A to 13D is made of a metal wire, and one end thereof is connected and fixed to the lands 14E, 14F, 14H and 14I of the print coil 14 via the support portions 12D to 12G of the movable member 12. In this embodiment, the support portion 12D of the movable member 12 is
12G, a hole 21a having a diameter substantially equal to that of the linear elastic support members 13A to 13D is shown in FIG.
And a hole 21b having a diameter sufficiently larger than that, are formed concentrically by connecting them by a taper portion 21c so that the small hole 21a is located on the land side, and as shown in FIG. One end of the support member 13A is inserted into the hole 21a to be positioned and fixed on the land 14I by soldering.
Insertion of one end of the linear elastic support member 13A into the hole 21a,
Since the mouth of the hole 21a is the tapered portion 21c, it can be easily inserted. After that, the hole 21b is filled with a viscoelastic body 22 having a damping action. As the viscoelastic body 22, for example, a butyl rubber adhesive or a nitrile budadien adhesive is used. Further, the other end of the linear elastic supporting member 13A is positioned by inserting it into a corresponding hole 19A formed in the printed board 19 and having a substantially equal diameter, and is soldered and fixed to the land of the printed board 19. . Other linear elastic support members
Also for 13B, 13C and 13D, both ends thereof are fixed in the same manner as above, thereby supporting the movable member 12 so as to be displaceable in the focusing direction and the tracking direction, and printing the linear elastic support members 13A to 13D. Coil 14
It is also used as a power supply line to the tracking coil units 14A to 14D and the focusing coil 15. As described above, in this embodiment, the linear elastic support member 13
A to 13D is composed of only metal wires and their movable parts
Since the viscoelastic body 22 is provided in the vicinity of the fixed end on the 12 side, the movable member 12 is displaced, and when the linear elastic support members 13A to 13D bend as shown in FIG. Elastic support member 13A
To 13D, the linear elastic support members 13A to 13D are suppressed from flexural vibrations, resulting in less harmful resonance. In the first embodiment described above, the linear elastic support member 13
Although the viscoelastic body 22 is provided near the fixed end of the movable members 12 side of A to 13D, in the second embodiment of the present invention, near the fixed end of the linear elastic support members 13A to 13D on the fixed member 16 side. Also, a viscoelastic body is provided. Therefore, as shown in FIG. 7, a holding member 25 is provided between the printed circuit board 19 and the yoke portion 17C of the base 17 of the fixing member 16, and the holding member 25 supports the movable member 12 at its supporting portion.
Similar to 12D to 12G, as shown in FIG. 8, a large-diameter hole 21b and a small-diameter hole 21a are connected by a taper portion 21 to form a concentric shape, and end portions of the linear elastic support members 13A to 13D are connected. The holding member
After the holes 21b and 21a formed in 25 and the corresponding holes 19A to 19D of the printed circuit board 19 are fixed by soldering,
21b is filled with viscoelastic body 22. Thus, if the viscoelastic body 22 is provided in the vicinity of the fixed ends at both ends of each of the linear elastic body supporting portions 13A to 13D, a higher damping effect can be obtained. FIG. 9 shows the essential parts of a third embodiment of the present invention. In this embodiment, the support portions 12D to 12G of the movable member 12,
A portion 26a for positioning the linear elastic support member and a portion 26b for filling the viscoelastic body are formed in a groove shape. With this configuration, the linear elastic support member can be easily inserted into the portion 26a, and the viscoelastic body can be easily filled into the portion 26b. Incidentally, such a structure of the supporting portion can be effectively applied to the holding member 25 of the second embodiment. FIGS. 10A and 10B show a fourth embodiment of the present invention. In this embodiment, a plate-shaped spring is used as the elastic support member.
27A and 27B are used. The springs 27A and 27B are holders for holding the objective lens 28, which is a movable member, at one end thereof.
The grooves 29a and 29b formed in parallel with 29 are fitted and mounted, and the other ends are fitted and fitted into the grooves 30a and 30b formed in the holding member 30, which is a fixing member, respectively. In this embodiment, the groove 30 of the holding member 30 is
Wide grooves 31a and 31b are formed in the a and 30b portions, respectively, and the other ends of the blades 27A and 27B are fitted and fitted into the grooves 30a and 30b.
The viscoelastic body 22 is filled in a and 31b. With this configuration, the plate-shaped springs 27A and 27B are
Resonance can be reduced by the damping action of the viscoelastic body 22. Although the viscoelastic body is provided in the vicinity of the fixed end on the movable member side of the elastic support member of the above-described embodiment, or in the vicinity of the fixed ends of both the movable member side and the fixed member side, the fixed member side is provided. The viscoelastic body may be provided only in the vicinity of. Further, the present invention is effectively applied not only to an optical pickup that records and / or reproduces information on a disc-shaped recording medium, but also to a support device for an objective lens in a recording and / or reproducing device that uses a card-shaped recording medium. be able to. [Advantages of the Invention] The objective lens supporting device of the present invention includes a movable member that holds the objective lens (for example, the movable member 12 and the holder 2 of the above-described embodiment).
9) and fixing means (for example, the printed circuit board 19 of the above embodiment,
In the objective lens supporting device configured to displace the objective lens in a predetermined direction by fixing the holding members 25, 30, the base 17, and the fixing member 16) with an elastic supporting member made of metal, At least one of the fixing means has a positioning portion for positioning in which the position of the end portion of the elastic support member is determined (for example, the hole 21a of the embodiment, the positioning portion 26a, the groove 30a) and the positioning portion. A space portion having a gap with the elastic support member in the vicinity (for example, the hole 21b, the taper portion 21c of the embodiment, a portion 26b for filling the viscoelastic body,
The groove 31b) is integrally formed, and the space is filled with a fluid viscoelastic body, and the elastic support member is used to supply power to the movable portion side. The present invention has the following effects. Easy to assemble and low cost,
The harmful resonance can be effectively prevented and the size can be reduced.

[Brief description of the drawings] 1 to 6 are views showing a first embodiment of the present invention, 7 and 8 are views showing the second embodiment, FIG. 9 is a view showing a third embodiment of the same, 10A and 10B are views showing a fourth embodiment of the same, FIG. 11 is a diagram showing a conventional technique. 11 …… Objective lens, 12 …… Movable member 12A …… Lens holder, 12B …… Frame 12D-12G …… Supporting part 13A to 13D: Linear elastic support member 14 …… Print coil 14A-14D ... Tracking coil 14E, 14F, 14H, 14I ... Land 15 ... Focusing coil 16 …… Fixing member, 17 …… Base 17B to 17E …… Yoke part, 18A, 18B …… Permanent magnet 19 ... Printed circuit board, 19A-19D ... Hole 20 …… screws, 21a, 21b …… holes 22 …… Viscoelastic body, 25 …… Holding member 27A, 27B ... Spring, 28 ... Objective lens 29 …… Holder 29a, 29b, 30a, 30b, 31a, 31b ... Groove 30 …… Holding member

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Claims (1)

(57) [Claims] In an objective lens supporting device configured to displace the objective lens in a predetermined direction by fixing a movable member that holds the objective lens and a fixing unit with an elastic supporting member made of metal, the movable member and the fixing unit. At least one of which is integrally formed with a positioning portion for positioning in which the position of the end portion of the elastic supporting member is determined, and a space portion having a gap with the elastic supporting member in the vicinity of the positioning portion, An objective lens driving device characterized in that a fluid viscoelastic body is filled and arranged in the space portion, and power is supplied to the movable portion side using the elastic support member.