JP2005018864A - Optical pickup - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup device to which a cover can be installed without significant changes in its composition and which surely fixes the cover even if it is miniaturized. <P>SOLUTION: The cover 30, which covers an objective lens driving mechanism that drives an objective lens 2 in a tracking direction, in a focusing direction and in a tilting direction, is engaged with the engaging part of a york 17, on whose upper side a tilt driving magnet 16 for driving the objective lens 2 in the tilting direction is arranged, and then fixed. An engaging part 37 formed by bending is provided at a position corresponding to the engaging part 17c of the york 17 in the cover 30, and the engaging part 37 is engaged with the engaging part 17c of the york 17. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical pickup used for recording, reproducing, and the like of an optical recording disk such as a CD or a DVD. More specifically, the present invention relates to a cover mounting structure that covers an objective lens driving mechanism that can drive the objective lens in the tilt direction.
[0002]
[Prior art]
As an optical pickup used for recording and reproduction of optical recording disks such as CD and DVD, an optical pickup capable of driving a lens holder holding an objective lens in the tilt direction in addition to the two axes of the tracking direction and the focusing direction has also appeared. ing. Such an optical pickup includes a lens holder that holds an objective lens, a lens holder support member that supports the lens holder with a wire, and a drive mechanism for driving the lens holder in a tracking direction and a focusing direction. And a drive mechanism for driving in the tilt direction. The objective lens driving mechanism including these driving mechanisms includes a focusing driving coil and a tracking driving coil on the side surface of the lens holder, and includes a tracking and focusing driving magnet provided on the lens holder support member. Further, a tilt driving coil and a tilt focusing driving magnet are provided.
[0003]
Such an optical pickup is normally exposed on the disk mounting side when mounted on a recording / reproducing apparatus for an optical recording disk such as a CD or DVD drive. For this reason, dust and foreign matters are likely to be mixed into the objective lens driving mechanism, so that the objective lens driving mechanism is covered with a cover in order to prevent this.
[0004]
The cover mounting structure described above is proposed in Japanese Patent Laid-Open No. 8-63906 (Patent Document 1). That is, as shown in FIG. 8, the biaxial actuator 100 constituting the biaxial actuator (optical pickup) is an actuator from above with respect to the rising portions 113 and 114 of the yoke 111 formed integrally with the biaxial base. A cover 112 is attached. The rising portions 113 and 114 extend upward from the outer edge of the rear end portion of the yoke 111 and are formed in an inverted L shape in which the rear edge upper portion protrudes rearward, and the rear edge has a stepped portion 113a facing downward. 114a is provided.
[0005]
On the other hand, the actuator cover 112 includes a hook 112a extending downward from the lower edge of the front end, and an engaging claw 112b protruding forward from the lower edge. When the actuator cover 112 is placed, the engaging claw 112 b is engaged with the lower edge of the base 111 a of the yoke 111. The actuator cover 112 includes a pair of protruding dowels 112c and 112d, and engages with step portions 113a and 114a formed at the rear edges of the rising portions 113 and 114, respectively. As a result, the actuator cover 112 is fixed and held in the vertical direction and the front-back direction with respect to the yoke 111.
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 8-63906
[Problems to be solved by the invention]
With the mounting structure disclosed in Patent Document 1 described above, the actuator cover can cover the magnetic drive mechanism of the optical pickup. However, since the hook 112a formed on the actuator cover 112 is engaged with the lower edge of the base 111a of the yoke 111, the engaging claw 112b protruding from the tip of the hook 112a protrudes from the lower edge of the yoke 111. For this reason, when the optical pickup is mounted on the recording / reproducing apparatus, it is necessary to consider to avoid the protruding portion of the engaging claw 112b, which causes a problem in designing the recording / reproducing apparatus.
[0008]
Furthermore, since the engaging claw 112b protrudes, the dimension in the height direction becomes large, and there is a problem that hinders downsizing. Further, in order to project the engaging claw 112b at the tip of the hook 112a, it is necessary to mold the actuator cover 112 itself with resin. However, when the optical pickup is downsized, the actuator cover 112 is also downsized, so the hook 112a and the pair of dowels 112c and 112d are also reduced. Therefore, it is difficult to form them by molding, and the engaging portions of the engaging claws 112b and the dowels 112c and 112d are minimized, so that the lower edge of the base 111a and the step portions 113a and 114a are engaged. In other words, there arises a problem that it cannot be engaged or is easily detached due to vibration or the like.
[0009]
SUMMARY OF THE INVENTION An object of the present invention is to provide an optical pickup that allows a cover to be attached without significantly changing the configuration of the optical pickup, and that can securely fix the cover even if the size is reduced.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the present invention, in the optical pickup according to the first aspect of the present invention, a cover that is covered by an objective lens driving mechanism that drives the objective lens in the tracking direction, the focusing direction, and the tilt direction includes the objective lens. A tilt drive magnet for driving in the tilt direction is engaged with and fixed to an engagement portion of a yoke disposed on the upper side. The cover is provided with a locking portion formed by bending at a corresponding position of the engaging portion of the yoke, and this locking portion is engaged with the engaging portion of the yoke. Since the yoke having the tilt drive magnet disposed on the upper side is used, the cover can be attached without changing the configuration of the optical pickup itself. Further, since the degree of freedom is increased by forming the locking portion of the cover by bending, it is possible to cope with downsizing.
[0011]
According to a second aspect of the present invention, in the optical pickup, the yoke provided with the tilt drive magnet is provided on both sides of the tracking direction of the objective lens drive mechanism, and the engaging portion of the yoke is tangered above the yoke. The cover is engaged by bringing the locking portion of the cover into contact with the lower end of the extending portion extending in the local direction. By using the step portion formed by narrowing the lower width of the yoke provided with the tilting drive magnet having a predetermined width as the engaging portion, the yoke itself can be provided without changing the configuration. It becomes possible. Further, there is no need to provide any other attachment member for attaching the cover, which enables downsizing and cost reduction.
[0012]
Further, in the optical pickup according to claim 3, the engaging portion of the cover is constituted by a tongue piece that is bent inwardly toward the inner end of the opening of the window hole for fitting the yoke. The upper end is brought into contact with the engaging portion of the yoke, and the inner end is made adjacent to the leg portion of the yoke. Since the cover locking portion is formed of a tongue piece formed by bending, manufacturing is facilitated with a simple configuration. Furthermore, by making the inner end of the tongue piece adjacent to the leg portion of the yoke, the window hole is almost closed by the yoke, so it is possible to minimize the entry of dust and foreign matter into the objective lens drive mechanism. It becomes.
[0013]
Furthermore, in the optical pickup according to claim 4, the cover is formed by a plate member having elasticity, and slits are formed on both sides of the locking portion so that the lower end side can be displaced. When the cover is attached or the like, only the periphery of the locking portion divided by the slit is displaced, so that it is possible to prevent other parts of the cover from being deformed.
[0014]
The optical pickup according to claim 5 supports the lens holder holding the objective lens movably in a tracking direction, a focusing direction, and a tilt direction by a plurality of wires, and relates to a holder support member that supports the wires. A coupling means is formed so that the cover engaged with the yoke is engaged with the engaging means. By further engaging the cover engaged with the yoke with the holder support member, the attachment strength of the cover can be increased.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of an optical pickup according to the present invention will be described in detail with reference to the drawings.
[0016]
The optical pickup performs information recording and information reproduction with respect to an optical recording disk such as a CD or a DVD. The optical recording disk reflects the laser light emitted from the laser light source with a half mirror and collects it with an objective lens. The information recording surface is focused on. The light reflected by the optical recording disk passes through the objective lens and the half mirror and enters the photodetector, and information reproduction processing is performed based on the optical signal received by the photodetector. Further, based on the output signal from the photodetector, the objective lens driving mechanism is driven and controlled, and the position and angle of the tracking direction and focusing direction or tilt direction of the objective lens are servo controlled, while the laser light source is driven and controlled. The objective lens is driven and controlled by a wire suspension type objective lens driving mechanism.
[0017]
FIG. 1 is a perspective view showing a state where a cover is put on the objective lens driving mechanism of the optical pickup in this embodiment, and this objective lens driving mechanism also includes a driving mechanism for driving the objective lens in the tilt direction. First, a wire suspension type objective lens driving mechanism will be described with reference to FIG. The objective lens driving mechanism 1 includes a lens holder 3 that holds the objective lens 2, and a support member 26 that supports the lens holder 3 with six wires 4, 5, 6, and 7 (wires 8 and 9 are not shown). And a driving mechanism for driving the lens holder 3 in a tracking direction indicated by an arrow Tr, a focusing direction indicated by an arrow Fo, and a tilt direction indicated by an arrow Ti. The wires 4, 5, and 6 constitute a current path for energizing a focusing drive coil 12, a tracking drive coil 13, and a tilt drive coil (not shown), which will be described later.
[0018]
Further, the objective lens drive mechanism 1 includes an annular focusing drive coil 12 provided around the body of the lens holder 3, a tracking drive coil 13 including four planar coils attached to the outer surface of the focusing drive coil 12, and And a pair of tilt drive coils disposed in a space formed inside the lens holder 3. Further, the base member 10 includes a pair of tracking and focusing drive magnets 15 facing the focusing drive coil 12 and the tracking drive coil 13, a pair of focusing drive coils 12 and a pair of focusing facing the tilt drive coil. A tilt drive magnet 16 is provided.
[0019]
The focusing / tilting drive magnet 16 has an inner surface of an outer yoke 17 provided by standing from the bottom plate 10a of the base member 10 outside the both sides in the tracking direction Tr with respect to the lens holder 3 constituting the objective lens driving mechanism 1. It is fixed to. As shown in FIG. 5, the outer yoke 17 forms an extension portion 17a extending in the tangential direction Ta on the upper side, and forms a leg portion 17b narrower than the extension portion 17a on the lower side. The overall shape is substantially T-shaped. Moreover, the lower end of the extension part 17a located in the both sides of the leg part 17b is used as the engaging part 17c. Further, the base member 10 is provided with an inner yoke 18 at a position facing the inner surface of the outer yoke 17.
[0020]
The pair of tracking and focusing drive magnets 15 are fixed to the inner surfaces of a pair of outer yokes 19 that are erected from the bottom plate 10 a of the base member 10 in a direction perpendicular to the focusing and tilting drive magnet 16. The base member 10 is provided with an inner yoke 20 at a position inside the lens holder 3 and facing the inner surface of the outer yoke 19.
[0021]
In the objective lens drive mechanism 1 configured as described above, the focusing drive coil 12 is opposed to the focusing / tilting drive magnet 16 and the tracking / focusing drive magnet 15, and a wire, which will be described later, is applied to the focusing drive coil 12. By energizing through the lens holder 3, the lens holder 3 can be driven in the focusing direction Fo.
[0022]
The tilt driving coil is attached to the lower inner surface of the space formed on both sides of the tracking direction Tr of the lens holder 3 so as to face the focusing / tilt driving magnet 16. The lens holder 3 can be driven in the tilt direction Ti by applying a predetermined current to the tilt drive coil via a wire described later.
[0023]
The tracking drive coil 13 faces the tracking / focusing drive magnet 15 and drives the lens holder 3 in the tracking direction Tr by energizing the tracking drive coil 13 with a predetermined current through a wire to be described later. can do.
[0024]
The lens holder 3 for holding the objective lens 2 is supported by the six wires 4, 5, 6,... Having a predetermined spring constant so as to be movable in the tracking direction Tr, the focusing direction Fo, and the tilt direction Ti. Yes. The set of three wires is symmetrically arranged on both sides of the tracking direction Tr of the lens holder 3 and has the same configuration.
[0025]
One set of wires 4, 5, 6 is fixed to the wiring pattern of the printed circuit board 21, for example, by solder or the like provided on the vertical rear surface of the support member 26 whose base end is fixed to the base member 10. . Further, the distal ends of the wires 4 and 6 are fixed to fixing portions 23 and 24 provided on the front side of the lens holder 3 by means of, for example, adhesion, and further extended and pasted on the front side of the lens holder 3. The printed circuit board 22 is fixed by being connected to the wiring pattern of the printed circuit board 22 by soldering or the like. The distal end side of the wire 5 positioned closer to the wire 4 is inserted into a through hole formed in the fixing portion 23 and fixed to the wiring pattern of the printed circuit board 22 by soldering or the like. Since the inner diameter of the through hole is sufficiently larger than the outer diameter of the wire 5, the movement of the wire 5 is not hindered. Note that through holes are formed in the support member 26 in the tangential direction Ta on the left and right, and the six wires 4, 5, 6,. And the gel-like damping material is put in the through-hole, and the unnecessary vibration of the wires 4, 5, 6,.
[0026]
Meanwhile, the cover 30 is formed in a substantially dish shape by bending a thin metal plate having elasticity of about 0.1 mm to 0.5 mm. That is, as shown in FIG. 4, the flat upper surface 31 has openings 32 corresponding to the objective lens 2 described above, and the side walls 33 are suspended from both sides of the upper surface 31. Further, side walls 34 having a tapered surface are formed on both sides on one side in the tangential direction Ta, and the tip side is open. The other side of the tangential direction Ta is open.
[0027]
Window holes 35 are formed in the side walls 33 on both sides so as to correspond to the outer yoke 17 provided with the focusing / tilting drive magnet 16 described above. At the opening inner end of the window hole 35, tongue pieces 36 bent inward are formed on the left and right sides, and are formed in a substantially T-shape. The tongue piece 36 is formed so as to be adjacent to both sides of the leg portion 17 b of the outer yoke 17, and the upper end thereof is made to correspond to the engaging portion 17 c formed at the lower end of the extending portion 17 a of the outer yoke 17. The upper end of the tongue piece 36 formed in this way is used as a locking portion 37 of the cover 30.
[0028]
Further, a locking tongue piece 38 is formed on the side wall 33 of the cover 30 so as to correspond to the engaging groove 26 a formed on the lower side of the support member 26 described above. Further, the side wall 33 between the locking tongue piece 38 and the window hole 35 is formed with a slit 39 for separating the both, and the side wall 34 of the tapered surface and the upper surface are separated. For this reason, the side wall 33 and the side wall 34 having the window hole 35 are configured to be independently displaceable. The portion of the side wall 33 on which the locking tongue piece 38 is formed can also be displaced independently.
[0029]
Next, a method for attaching the cover 30 will be described. As shown in FIGS. 4 and 5, the cover 30 described above is attached by descending from above the objective lens driving mechanism 1. When the cover 30 is lowered, as shown by a broken line in FIG. 4, the engaging portion 17 c formed on the outer yoke 17 and the locking portion 36 of the cover 30, and the engaging groove 26 a formed on the support member 26 and the cover 30 locking tongue pieces 38 are made to correspond. By descending, the lower end of the tongue piece 36 of the cover 30 contacts the upper end of the outer yoke 17, and the locking tongue piece 38 of the cover 30 contacts the upper end of the support member 26. For this reason, the side wall 33 on which the tongue piece 36 is formed is expanded outwardly against the elastic force, so that the tongue piece 36 gets over the outer surface of the outer yoke 17, and the tongue piece 36 eventually becomes the outer yoke 17. The leg part 17b is reached. When the cover 30 is restored by the elasticity of the cover 30, the engaging portion 37 of the cover 30 formed at the upper end of the tongue piece 36 is engaged with the engaging portion 17 c formed at the lower end of the extending portion 17 a of the outer yoke 17. To do. In this engaged state, as shown in FIG. 2, since the tongue piece 36 is adjacent to the leg portion 17 b of the outer yoke 17, mixing of dust and foreign matter is suppressed.
[0030]
On the other hand, the locking tongue piece 38 of the cover 30 is lowered together with the locking portion 37. However, as shown in FIG. 3A, the locking tongue piece 38 forms a slope in the downward direction. As the cover 30 descends, the side wall 33 expands against the elasticity of the cover 30 and slidably contacts the side surface of the support member 26. Eventually, as shown in FIG. It is dropped into the groove 26a and engaged. Thus, the engaging portion 37 of the cover 30 is engaged with the engaging portion 17c of the outer yoke 17, and the engaging tongue piece 38 of the cover 30 is engaged with the engaging groove 26a of the support member 26. As shown in FIG. 1, the objective lens driving mechanism 1 is crowned by a cover 30. Although the front end side of the side wall 34 on which the tapered surface of the cover 30 is formed is open, it is closed by the outer yoke 19 to which the tracking focusing drive magnet 15 is fixed, and the cover 30 is opened. The other side is closed by the support member 26.
[0031]
As described above, using the outer yoke 17 in which the focusing / tilting drive magnet 16 is disposed, the mounting structure in which the engaging portion 37 formed on the cover 30 is engaged with the lower end as the engaging portion 17c. Thus, the cover 30 can be easily attached without changing the configuration of the optical pickup itself. Further, by forming the engaging portion 37 of the cover 30 by bending, it can be arbitrarily set to a size corresponding to the engaging portion 17c of the outer yoke 17, so that the degree of freedom can be reduced especially for downsizing of the optical pickup. Can be supported.
[0032]
6 shows a modification of the locking portion formed on the cover 30, and FIG. 7 is a cross-sectional view taken along the line AA in FIG. The locking portion 40 shown in FIG. 6 forms a tongue piece having a tapered surface spaced from the side wall 33 toward the upper side, similarly to the locking tongue piece 38 described above. Further, the engaging portion 40 having the tongue piece as described above is formed in a pair corresponding to the left and right engaging portions 17 c formed at the lower end of the outer yoke 17.
[0033]
Then, when the cover 30 is lowered and attached from above the objective lens driving mechanism 1, the pair of locking portions 40 of the cover 30 abuts on the upper end of the outer yoke 17. As a result of the taper surface of the side wall 33 expanding outwardly against the elasticity, the locking portion 40 slidably contacts the outer surface of the outer yoke 17 and eventually comes into contact with the engaging portion 17c formed at the lower end of the outer yoke 17. Dropped and engaged. As a result, the cover 30 is attached in the same manner as in the above-described embodiment.
[0034]
On the other hand, the engaging groove 26a formed on the side surface of the support member 26 is attached by engaging an engaging rib 41 as shown in FIG. That is, the engagement rib 41 corresponding to the engagement groove 26 a formed on the lower side of the support member 26 is formed on the side wall 33 of the cover 30. When the cover 30 is attached, the curved surface of the engaging rib 41 expands against the side wall 33 of the cover 30 against elasticity, and the engaging rib 41 is dropped into the engaging groove 26a while sliding on the side surface of the support member 26. Combined.
[0035]
As described above, when the engagement tongue piece 38 or the engagement rib 41 of the cover 30 is engaged with the engagement groove 26 a of the support member 26, the engagement portion 40 is set as one and the outer yoke 17 is You may make it engage with one engaging part 17c.
[0036]
Although the embodiments of the invention made by the present inventor have been specifically described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. Not too long. For example, the outer yoke 17 is formed in a substantially T shape to form a pair of left and right engaging portions 17c. However, the outer yoke 17 is formed in a substantially L shape to form one engaging portion 17c. May be. Further, the configuration of the optical pickup may be other than the configuration described above.
[0037]
【The invention's effect】
As described above, the optical pickup according to the present invention uses the yoke covered with the tilt driving magnet for driving the objective lens in the tilt direction on the cover to be covered with the magnetic driving mechanism. Since the cover is engaged and fixed to the engaging portion, it is possible to attach the cover without changing the configuration of the optical pickup itself. Further, since the degree of freedom is increased by forming the locking portion of the cover by bending, it is possible to cope with downsizing.
[0038]
According to the invention of claim 2, the step portion formed by narrowing the lower width of the yoke for disposing the tilt drive magnet having a predetermined width is used as the engaging portion. Since the cover locking portion is engaged with this, the engaging portion can be provided without changing the configuration of the yoke itself. Further, there is no need to provide any other attachment member for attaching the cover, which enables downsizing and cost reduction.
[0039]
Further, according to the invention of claim 3, since the engaging portion of the cover is constituted by a tongue piece formed by bending and the upper end of the tongue piece is brought into contact with the engaging portion of the yoke, Manufacturing is facilitated by the configuration. Furthermore, by making the inner end of the tongue piece adjacent to the leg portion of the yoke, the window hole is almost closed by the yoke, so that it is possible to minimize the entry of dust and foreign matter into the magnetic drive mechanism. Become.
[0040]
Furthermore, according to the invention of claim 4, since the slits are formed on both sides of the engaging portion of the cover formed by the elastic plate member so that the lower end side can be displaced, when attaching the cover For example, it is possible to displace only the periphery of the locking portion divided by the slit, which facilitates attachment and prevents deformation of other portions of the cover.
[0041]
According to the invention of claim 5, the engaging means is formed on the holder supporting member that supports the plurality of wires that support the lens holder, and the cover that engages the yoke is engaged with the engaging means. Therefore, it is possible to increase the attachment strength of the cover by further engaging the cover engaged with the yoke with the holder support member.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an optical pickup according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a main part showing a state where a cover is attached to the yoke of the present invention.
FIGS. 3A and 3B are cross-sectional views of main parts showing a state where a cover is attached to the support member of the present invention.
FIG. 4 is an exploded perspective view showing a state where a cover is put on the objective lens driving mechanism of the present invention.
FIG. 5 is a side view showing a state where a cover is put on the objective lens driving mechanism of the present invention.
FIG. 6 is a side view showing another embodiment of the cover of the present invention.
7 is a cross-sectional view taken along the line AA in FIG.
FIG. 8 is an exploded perspective view showing a conventional cover mounting structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Objective lens drive mechanism 2 Objective lens 3 Lens holder 4-6 Wire 10 Base member 12 Focusing drive coil 13 Tracking drive coil 15 Tracking / focusing drive magnet 16 Focusing / tilt drive magnet 17 Outer yoke 17a Extension part 17b Leg Part 17c Engagement part 18 Inner yoke 19 Outer yoke 20 Inner yoke 26 Support member 26a Engagement groove 30 Cover 32 Opening 33, 34 Side wall 36 Tongue piece 37 Locking part 38 Locking tongue piece (engaging means)
39 Slit Fo Focusing direction Ti Tilt direction Tr Tracking direction Ta Tangential direction

Claims (5)

An objective lens driving mechanism that drives an objective lens for converging the light emitted from the light source to the optical recording medium so as to be movable in the tracking direction, the focusing direction, and the tilt direction, and the objective lens driving mechanism is covered with a cover. A pickup,
An engaging portion is provided on a yoke provided with a tilt driving magnet for driving the objective lens in the tilt direction on the upper side, and the cover is formed by bending at a position corresponding to the engaging portion of the cover. An optical pickup characterized in that a cover is provided and the cover is fixed by engaging the engaging part with the engaging part of the yoke. The yoke is provided on both sides of the objective lens drive mechanism in the tracking direction, and the engaging portion is provided at a lower end of an extending portion extending in the tangential direction on the upper side of the yoke. The optical pickup according to claim 1, wherein the engaging portion of the cover is brought into contact with and engaged with the optical pickup. The locking portion of the cover is formed by a tongue piece bent inward with the inner end of the opening of the window hole to which the yoke is fitted, and the upper end of the tongue piece contacts the lower end of the extension portion of the yoke. 3. The optical pickup according to claim 1, wherein the optical pickup is in contact with the inner end and is adjacent to the leg portion of the yoke. 4. The optical pickup according to claim 1, wherein the cover is formed by an elastic plate member, and slits are formed on both sides of the locking portion so that the lower end side can be displaced. 5. A lens holder for holding the objective lens is supported by a plurality of wires supported by a support member so as to be movable in a tracking direction, a focusing direction, and a tilt direction, and an engaging means is formed on the support member to form a support on the yoke. The optical pickup according to claim 1, wherein an engaged cover is engaged with the engaging means.

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