JP2006134411A - Optical pickup - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup which is excellent in displacement characteristic in a focusing focus direction or a tracking direction by taking measures to fix a suspension wire without causing deformation or the like so as to eliminate variation of effective length of the suspension wire when fixing one end or the other end of the suspension wire. <P>SOLUTION: The other end 62 of the suspension wire 6 whose one end 61 is fixed to a fixing side support member 2 is fixed to a movable side lens holder 3 provided with an objective lens. Each suspension wire 6 is arranged on right and left sides of an actuator 1 to be mutually parallel. The one end 61 and the other end 62 of the suspension wire 6 are fixed by conductive adhesives 81, 82 applied to soldering land of wiring substrates 4 and 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical pickup mounted on an optical disc drive, and more specifically, a movable lens holder including an objective lens is supported so as to be displaceable in a cantilever state by an elastic wire extending from a fixed support member. The present invention relates to an optical pickup provided with an actuator.

  FIG. 3 shows an example of an optical pickup. The optical pickup shown in the figure is used to focus the laser beam on the disk surface as a recording medium for writing and reading data, and the position of the objective lens is adjusted according to surface deflection and eccentricity during disk rotation. A function of adjusting in the focus direction or the tracking direction is provided. That is, the actuator 1 employed in this optical pickup is mounted on an optical bench (not shown) that is driven to run in the radial direction of the disk, and is a fixed-side support member 2 that is fixed to the optical bench. And the movable lens holder 3 including the objective lens 31, the wiring substrate 4 fixed to the fixed support member 2, and the wiring substrate 5 fixed to both side surfaces of the movable lens holder 3 located in the left-right direction. , 5 and conductive wires 6 as elastic suspension wires disposed on both the left and right sides of the actuator 1, and the movable lens holder 3 includes a focus direction F or a tracking direction T. A plurality of coils (not shown) for demonstrating the urging force are provided, and the pattern of the wiring board 5 is provided at the end of these coils. There has been connected. Further, the plurality of wires 6 ... and the wiring board 5 are symmetrically arranged on both the left and right sides of the actuator 1, and the wire 6 has three wires on one side as shown in the figure, or on one side 2 although not shown. There are cases of books. Then, one end 61 of the wire 6 is soldered and fixed to the solder land of the wiring substrate 4, and the other end 62 is soldered and fixed to the solder land of the wiring substrate 5. 3 is supported in a cantilevered manner so as to be displaceable with respect to the stationary support member 2 via a plurality of wires 6. Reference numerals 41 and 51 denote solder. In addition, spaces 7 having the same volume are provided at a plurality of locations on the side surfaces of the fixed-side support member 2 in the left-right direction, and the above-described wire 6 is placed in a layer of a damper material (not shown) loaded in these spaces 7. Is inserted.

  In the actuator 1 of FIG. 3, when a current is passed through the pattern of the wiring board 4, the coil is energized through the wiring board 4, the wire 6 and the wiring board 5, and the coil generates a biasing force in the focus direction or the tracking direction. Accordingly, the movable lens holder 5 is driven to move in the focus direction F or the tracking direction T together with the objective lens 31.

On the other hand, in this type of optical pickup, a method using soldering as means for fixing one end and the other end of a suspension wire as a wire to the wiring board of the fixed side support member and the movable side lens holder is shown in FIG. In addition to the conventional examples described above, they are well known (see Patent Document 1 and Patent Document 2).
JP 2001-52357 A JP 2004-5841 A

  However, when the suspension wire as a wire is fixed to the wiring board by soldering, especially when manual soldering is performed, the tip of the soldering iron comes into contact with the suspension wire and deforms the wire, Since the height of the wire is difficult to stabilize (solder unevenness is likely to occur), there is a variation in the effective length between the suspension wires, and in the case of lead-free solder, the amount of lead is not stable. It was happening.

  Further, in the above-mentioned Patent Document 1, when the soldering iron tip approaches the surface of the suspension wire, a part of the surface is heated to a temperature higher than that of the other part, and the cross section in the radial direction of the suspension wire is increased. As a result, the suspension wire is deformed in the radial direction, and as a result, the above deformation remains as it is while the molten solder cools and hardens. In the same way, there is a problem that the wire suspension expands or contracts in the length direction of the wire suspension due to the effect of heating during soldering, and tensile or compressive stress remains on the suspension wire after the solder cools down. In addition, when those problems occur, their suspension wire bending and length variations Spring rate is not uniform, indicating that it may become cause unwanted movement of the rotary motion or the like of the outer focusing and tracking directions when driving the lens holder, have been described. Further, this Patent Document 1 discloses a support unit in which a suspension wire is provided on a lens holder as means for eliminating the bending and length variation of a plurality of suspension wires, although the suspension wire is fixed by soldering. There is a description that it is beneficial to fix the suspension wire in the vicinity of the soldering portion with an ultraviolet curable resin filled in the fixing hole.

  By the way, when the movable lens holder 5 shown in FIG. 3 is displaced in the focus direction F or the tracking direction T together with the objective lens 31, the quality of the displacement characteristics of the movable lens holder 5 is determined by the effectiveness of a plurality of suspension wires. It is greatly affected by the size of the length variation. This point is as described in the above-mentioned Patent Document 1.

  Therefore, even if the configuration in which one end portion 61 and the other end portion 62 of the wire 5 as a suspension wire are soldered like the actuator 1 as shown in FIG. 3 is described in Patent Document 1. By applying this technology, the suspension wire that passes through the fixing hole of the support part provided in the lens holder is fixed in the vicinity of the soldering position by the ultraviolet curable resin filled in the fixing hole. Thus, the variation in effective length is considered to be improved to some extent.

  However, in the soldering work, the melting time and the cooling time of the solder are spent in units of several seconds, which is not only problematic in terms of workability, but particularly soldering and UV curing as described in Patent Document 1. In the case of both fixing with resin, workability may be further reduced, and the structure of the lens holder is so complicated because it is necessary to form the filling part of the UV curable resin in the lens holder. Become.

  The present invention has been made under the above circumstances, and by taking a contrivance that can fix the wire rod as a suspension wire without soldering, which is likely to be accompanied by variations in the effective length due to deformation and solder unevenness, It is an object of the present invention to provide an optical pickup that stabilizes the effective length of these wires and thus has excellent displacement characteristics in the focus direction or tracking direction.

  In the optical pickup according to the present invention, the other ends of a plurality of elastic wires whose one ends are fixed to a fixed-side support member are fixed to a movable-side lens holder including an objective lens, and one ends of the wires In the optical pickup provided with an actuator in which the other end is fixed by soldering to the solder land of the wiring board, the fixing by soldering of the one end and the other end of the wire is changed to fixing by a conductive adhesive That's it.

  According to this, there is no room for a situation where the soldering iron tip contacts the wire and the wire is deformed, and since the wire is fixed by applying the conductive adhesive, Workability is improved compared to the case. Furthermore, since there is no need to heat the wire, expansion and contraction in the radial direction or length direction of the wire as described in Patent Document 1 does not occur. Accordingly, it is possible to provide an optical pickup in which the effective length of the wire is stable and excellent in displacement characteristics in the focusing focus direction or the tracking direction.

  In the present invention, the same number of wires parallel to each other may be provided symmetrically on the left and right sides of the actuator, and even in such an optical pickup, in the focusing focus direction or the tracking direction. An optical pickup having excellent displacement characteristics can be provided.

  The optical pickup according to the present invention can also be configured as follows. That is, the other end of a plurality of elastic wires whose one end is fixed to the fixed support member is fixed to a movable lens holder having an objective lens, and the one end and the other end of the wire are wired. In an optical pickup provided with an actuator fixed by soldering to a solder land of a substrate, the same number of wires parallel to each other are arranged symmetrically on the left and right sides of the actuator, and one end of the wires and It is also possible to adopt a configuration in which the fixing by soldering of the other end is changed to fixing by a conductive adhesive applied to the solder land.

  As described above, according to the present invention, one end and the other end of a wire rod as a suspension wire are bonded to a wiring board of a fixed member or a movable lens holder with a conductive adhesive. There is no room for the tip to contact the wire and the wire is deformed, and the wire is fixed by the conductive adhesive application work, so the workability is improved compared to soldering, In addition, since there is no need to heat the wire, there is no expansion or contraction in the radial or length direction of the wire, the effective length of the wire is stable, and the optical pickup has excellent displacement characteristics in the focusing focus direction or tracking direction. It becomes possible to provide.

  FIG. 1 is a schematic side view of an optical pickup according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a portion taken along line II-II in FIG.

  In FIG. 1, 1 is an actuator attached to the optical bench 10, 2 is a stationary support member, 3 is a movable lens holder, 4 is a wiring board arranged on the side surface of the stationary support member 2, and 5 is a movable lens. A wiring board 6 provided on the side surface of the holder 3 is a wire rod as a suspension wire, and the wire rods 6 are symmetrically arranged in parallel to each other on the left and right sides of the actuator 1. One end portion 61 of each wire 6 is fixed to the wiring substrate 4 of the fixed side support member 2, and the other end portion 62 is fixed to the wiring substrate 5 of the movable side lens holder 3. The items described above are in accordance with the configuration of the conventional optical pickup described with reference to FIG.

  In this embodiment, the difference from the conventional optical pickup described with reference to FIG. 3 is that, in the optical pickup of FIG. 3, one end 61 and the other end 62 of each wire 6 are connected to the wiring board 4 by soldering. In this embodiment, one end portion 61 and the other end portion 62 of each wire 6 are fixed to the solder lands of the wiring substrates 4 and 5 by the conductive adhesives 81 and 82, respectively. This is a fixed point. That is, as can be seen from FIG. 2 showing the fixing portion between the one end 61 of the wire 6 and the solder land 42 of the wiring board 4, the one end 61 of the wire 6 is connected to the solder land 42 of the wiring board 4 with a conductive adhesive. It is fixed by applying 81. The fixing portion between the other end portion 62 of the wire and the solder land of the wiring board 5 has the same configuration. Therefore, the electric path between the wire 6 and each of the wiring boards 4 and 5 is secured by the conductive adhesives 81 and 82 without any trouble.

  With this configuration, the wire 6 is fixed to the wiring boards 4 and 5 by applying the conductive adhesives 81 and 82, so that the soldering iron tip contacts the wire and the wire 6 is There is no room for deformation, and since the wire 6 is not heated, expansion and contraction in the radial direction or length direction of the wire do not occur, and the mutual effective length L of the plurality of wires 6 is uniform. It becomes possible to provide an optical pickup having excellent displacement characteristics in the focusing focus direction or tracking direction. Furthermore, since the wire 6 can be fixed through the application of the conductive adhesive, and the soldering operation is not necessary, the workability is improved as compared with the case of soldering.

  In FIG. 1, 91 is a terminal to which a control circuit is connected, and 92, 93 and 94 are terminals to which the ends of the focus coil and tracking coil are connected.

1 is a schematic side view of an optical pickup according to an embodiment of the present invention. It is an expanded sectional view of the part which follows the II-II line of FIG. It is a schematic perspective view of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Actuator 2 Fixed side support member 3 Movable side lens holder 4,5 Wiring board 6 Wire material 31 Objective lens 42 Solder land 61 One end part of a wire material 62 Other end part of a wire material 81, 82 Conductive adhesive

Claims (3)

The other ends of a plurality of elastic wires whose one ends are fixed to the fixed-side support member are fixed to a movable-side lens holder having an objective lens, and the one end and the other end of the wires are connected to the wiring board. In an optical pickup having an actuator fixed by soldering to a solder land,
The same number of wire rods parallel to each other are arranged symmetrically on the left and right sides of the actuator, and the one end portion and the other end portion of the wire rods are fixed to the solder lands by the soldering. An optical pickup characterized by changing to fixing with an adhesive. The other ends of a plurality of elastic wires whose one ends are fixed to the fixed-side support member are fixed to a movable-side lens holder having an objective lens, and the one end and the other end of the wires are connected to the wiring board. In an optical pickup having an actuator fixed by soldering to a solder land,
An optical pickup, wherein the fixing of the one end and the other end of the wire by soldering is changed to fixing by a conductive adhesive. The optical pickup according to claim 2, wherein the same number of the wires parallel to each other are symmetrically arranged on the left and right sides of the actuator.

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