WO2007043578A1

WO2007043578A1 - Collision prevention mechanism and method of producing the same

Info

Publication number: WO2007043578A1
Application number: PCT/JP2006/320315
Authority: WO
Inventors: Yasuhiro Ohira; Jun Suzuki
Original assignee: Pioneer Corporation
Priority date: 2005-10-14
Filing date: 2006-10-11
Publication date: 2007-04-19
Also published as: JPWO2007043578A1; JP4717074B2

Abstract

A collision prevention mechanism for preventing a collision in an optical disk system, between an objective lens mounted on an optical pickup and the surface of the optical disk. The collision prevention mechanism has a bottom surface section, a base, and a collision prevention layer. The bottom surface section is provided on the optical pickup. The base has at least one projection projecting from the bottom surface section in the direction facing the optical disk and provided such that, in a plan view of the bottom surface section, the projection surrounds at least one portion of the bottom surface section by a predetermined width or the projection is adjacent to the at least one portion, over the predetermined width. The collision prevention layer is formed by applying an elastic material softer than the optical disk to at least the projection and one portion out of the base, and in the collision prevention layer, the surface opposite that surface of a first section which is located on the top of the projection and faces the projection is formed at a position farther away from the bottom surface section than the surface opposite that surface of a second section which is located on the one portion and faces the bottom surface section.

Description

Specification

Collision prevention mechanism and manufacturing method thereof

Technical field

The present invention relates to a technical field of a collision prevention mechanism provided in an optical pickup in an optical disc system and a manufacturing method thereof.

Background art

In recent years, an optical disk system is widely used as a means for recording and reproducing data such as video and audio. There is a demand for higher density and smaller size in optical disc systems. To increase the density and size of optical disc systems, it is necessary to reduce the so-called working distance (WD: Working Distance) from the lens surface of the objective lens provided on the optical pickup that irradiates the optical disc to the surface of the optical disc. With this reduction, there is a greater possibility that the objective lens will collide with the optical disk surface. In particular, if the focus servo is lost, there is a high possibility that the objective lens will collide with the optical disc surface.

[0003] Various proposals have been made regarding the prevention of such a collision between the objective lens and the optical disk surface. For example, Patent Document 1 proposes a technique for forming a film in which an objective lens and an objective lens holding member are mixed with polyurethane particles and fluorine resin powder based on urethane resin. In Patent Document 2, the applicant of the present application proposes a technique for forming a buffer layer made of ultraviolet curable resin on the outer edge or outside of an object lens from the periphery of the lens effective surface of the objective lens. Patent Document 3 proposes a technique for forming a coating layer on the end surface of the lens holder on the disk side, which is softer and more slidable than an optical disk. Patent Document 4 proposes a technique in which a synthetic resin-made stubber section or a stubber section integrated with the lens holder by two-color molding is provided at the corner of the lens holder.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-242703

Patent Document 2: JP 2002-237071

Patent Document 3: Japanese Patent Laid-Open No. 2002-222535 Patent Document 4: Japanese Patent Laid-Open No. 2002-197704

Disclosure of the invention

Problems to be solved by the invention

However, in the techniques according to Patent Documents 1 to 4, the anti-collision coating, the buffer layer, and the like are formed relatively thick on the holding portion of the objective lens so as to be higher than the upper surface of the objective lens. Therefore, there is a technical problem that it is difficult to control the thickness of the coating film, buffer layer, and the like. In particular, in order to realize a very small working distance, there is a technical problem that the thickness of the coating film, buffer layer, etc. must be controlled with high precision during the production.

[0006] The present invention has been made in view of the above-described problems, for example, and can prevent collision between the objective lens and the optical disc while reliably preventing collision between the objective lens and the optical disc, thereby preventing collision. It is an object to provide a mechanism and a manufacturing method thereof.

Means for solving the problem

[0007] (Collision prevention mechanism)

In order to solve the above problems, a collision prevention mechanism of the present invention is a collision prevention mechanism for preventing a collision between an objective lens mounted on an optical pickup in an optical disc system and the surface of the optical disc, and is provided on the optical pickup. A bottom surface portion provided on the bottom surface, and protruding on the bottom surface portion in a direction opposite to the optical disc, and at least one portion of the bottom surface portion is surrounded by a predetermined width when viewed in plan on the bottom surface portion. Or a base having at least one protrusion provided so as to be adjacent to the at least one portion over the predetermined width, and at least the protrusion and the one portion above the base Further, an elastic member softer than the optical disk is applied, and a surface of the first portion located on the leading end of the protruding portion is opposite to the surface facing the protruding portion. Wherein the said faces on the bottom surface of the second portion located on the first portion and a side opposite to the collision prevention layer formed away from the bottom portion than the surface of the.

[0008] The collision prevention mechanism of the present invention is provided in an optical pickup equipped with an objective lens in an optical disc system. Specifically, the bottom portion is provided on the optical pickup and the protruding portion protrudes from the optical disk.

According to the collision prevention mechanism of the present invention, during the operation of the optical disc system, for example, Even when the objective lens approaches the surface of the optical disk due to the removal of the orcus servo, the objective lens collides because the softer anti-collision layer collides with the optical disk before the objective lens collides with the optical disk. This can prevent the optical disk from being damaged.

In more detail, the collision prevention mechanism of the present invention includes a base and a collision prevention layer. The base has a bottom surface portion and a protruding portion protruding on the bottom surface portion in a direction facing the optical disk. The bottom surface portion is provided on the optical pickup or integrally with the optical pickup. The projecting portion, when viewed in plan on the bottom surface portion, surrounds at least one portion of the bottom surface portion with a predetermined width, or is adjacent to the at least one portion over the predetermined width. Is provided. In other words, the protrusion has a shape such as a cylindrical shape, an elliptical cylindrical shape, or a polygonal cylindrical shape. Alternatively, it has a circular shape, a rectangular shape, a polygonal shape or the like when viewed from above the bottom surface. An anti-collision layer made of an elastic member softer than the optical disk is formed so as to cover the protruding portion.

[0011] Particularly in the collision prevention mechanism of the present invention, the collision prevention layer is formed by applying an elastic member softer than the optical disk to the protruding portion. Furthermore, the surface of the anti-collision layer opposite to the surface facing the protrusion of the first portion located on the leading end of the protrusion is a part of the anti-collision layer surrounded by the protrusion. It is further away from the bottom surface than the surface opposite to the surface facing the bottom surface of the second part located above. That is, the anti-collision layer is applied so that it is softer than, for example, polycarbonate resin used as a material for the surface of an optical disk, and a liquid elastic member, such as silicon rubber, covers the protruding portion. Is formed. At this time, the liquid elastic member applied to one part of the bottom surface surrounding or adjacent to the protruding portion is projected from the relationship between the surface tension, viscosity, liquid repellency, etc. and the height of the protruding portion. It is not formed so as to be higher than the height. Typically, the applied liquid elastic member immediately after application has a force that covers the entire protrusion including one portion of the bottom surface, and as the time elapses, the tip of the protrusion It flows out from the part to the bottom part (that is, one part surrounded by the protruding part or the outside of the protruding part). Eventually, the first part of the anti-collision layer, which is thinner than that immediately after application, is formed at the tip of the protrusion having a predetermined width, and the first part of the anti-collision layer is formed on one part. 2 parts It is formed. The thickness of the anti-collision layer can be adjusted, for example, by changing the amount and type of the elastic member to be applied (ie, viscosity, thixo ratio, etc.). Furthermore, the thickness of the collision preventing layer can be adjusted by changing the width of the tip of the protrusion, the material of the protrusion, and the like. For example, if the width of the tip of the protrusion is reduced, the thickness of the collision prevention layer can be reduced. Conversely, if the width of the tip of the protrusion is increased, the thickness of the collision prevention layer is increased. be able to . Therefore, a relatively thin anti-collision layer can be formed easily and with high accuracy by forming a narrow width at the tip of the protrusion and applying a soft elastic member thereon. In other words, the anti-collision layer can be formed without having to manage the amount of the soft elastic member to be applied with high accuracy. Therefore, the surface of the first part of the collision prevention layer that faces the optical disk is positioned closer to the position where the objective lens (more precisely, the part of the objective lens that faces the optical disk that is closest to the optical disk) is closest to the optical disk by focusing. For example, in the optical disc system, it is possible to shorten the working distance between the objective lens and the optical disc by forming the anti-collision layer with high accuracy so that the optical disc is closer to the optical disc.

[0012] It should be noted that by making the protruding height of the protruding portion from the bottom surface portion relatively high, the surface of the first portion of the collision preventing layer opposite to the surface facing the protruding portion can The second portion of the second portion can be further away from the bottom surface than the surface opposite to the surface facing the bottom surface.

In one aspect of the collision preventing mechanism of the present invention, the elastic member includes at least an ultraviolet curable adhesive resin.

[0014] According to this aspect, the anti-collision layer can be formed by irradiating ultraviolet rays after applying the ultraviolet curable adhesive resin that is liquid at the time of application to the protrusions.

In addition, the elastic member may be formed of a resin such as a photocurable resin other than ultraviolet rays or a thermosetting resin other than this.

In another aspect of the collision preventing mechanism of the present invention, the first region surrounding the bottom surface portion of the protruding portion facing the bottom surface portion when viewed in plan on the bottom surface portion is: Larger than a second region surrounding the bottom surface of the tip.

[0017] According to this aspect, it is possible to easily collect the elastic member that has flowed out at the tip portion force in the portion surrounded by the protruding portion when applied. Therefore, the bump on the tip of the protrusion The protrusion prevention layer can be formed with a desired thickness, and a large amount of the elastic member can be prevented from flowing outside the protrusion.

[0018] In another aspect of the collision preventing mechanism of the present invention, the protrusion is formed in a cylindrical shape, an elliptical cylindrical shape, or a polygonal cylindrical shape.

[0019] According to this aspect, the elastic member that has flowed out from the tip portion when applied can be stored inside the cylinder. Therefore, it is possible to form the collision preventing layer on the tip portion of the protruding portion with a desired thickness and to prevent a large amount of the elastic member from flowing out of the protruding portion.

[0020] (Method of manufacturing collision prevention mechanism)

In order to solve the above problems, a method for manufacturing a collision prevention mechanism according to the present invention is a collision prevention mechanism for preventing a collision between an objective lens mounted on an optical pickup in an optical disk system and the surface of the optical disk. A collision prevention mechanism manufacturing method for manufacturing a collision prevention mechanism including an anticollision layer provided on a bottom surface portion provided on the optical pickup, and facing the optical disc on the bottom surface portion And the width of the front end is adjusted corresponding to the thickness to be formed of the anti-collision layer and at least one part of the bottom surface is surrounded by a predetermined width or at least Forming the base having at least one protrusion so as to be adjacent to a portion over the predetermined width; and at least the protrusion on the base. An elastic member softer than the optical disk is provided on the protruding portion and the one portion, and the surface of the first portion located on the tip portion of the protruding portion is opposite to the surface facing the protruding portion. Applying the second portion positioned on the portion so as to be farther from the bottom surface than the surface opposite to the surface facing the bottom surface.

[0021] According to the manufacturing method of the collision prevention mechanism of the present invention, the above-described collision prevention mechanism of the present invention can be manufactured. Here, in particular, a relatively thin collision preventing layer can be formed easily and with high accuracy by forming a narrow width at the tip of the protruding portion and applying a soft elastic member thereon. Therefore, the surface of the first part of the collision prevention layer that faces the optical disk is positioned closer to the position where the objective lens (more precisely, the part of the objective lens that faces the optical disk that is closest to the optical disk) is closest to the optical disk by focusing. Also on optical disc In the optical disc system, for example, the working distance between the objective lens and the optical disc can be shortened by forming the anti-collision layer so as to be close to each other.

[0022] The operation and other advantages of the present invention will be clarified in the embodiment described below.

[0023] As described above in detail, the collision preventing mechanism of the present invention includes a bottom surface portion, a base having a protruding portion on the bottom surface portion, and a collision preventing layer formed by applying an elastic member softer than the base. Therefore, a relatively thin anti-collision layer can be formed easily and with high accuracy. That is, the anti-collision layer can be formed without having to manage the amount of the elastic member to be applied with high accuracy. The manufacturing method of the collision prevention mechanism of the present invention includes a step of forming a bottom surface portion and a base having a protruding portion on the bottom surface portion, and a step of applying an elastic member softer than the base to at least the protruding portion on the base Therefore, the collision prevention mechanism of the present invention can be manufactured.

Brief Description of Drawings

FIG. 1 is a perspective view showing a configuration of an optical pickup.

2 is an enlarged perspective view showing the actuator of FIG. 1. FIG.

3 is an enlarged plan view showing a dotted circle C1 part of FIG.

FIG. 4 is a cross-sectional view taken along the line AA ′ of FIG.

FIG. 5 is a flowchart showing manufacturing steps of the collision preventing mechanism according to the first embodiment.

FIG. 6 is an explanatory view showing a temporal change of the anti-collision layer in the manufacturing process of the anti-collision mechanism according to the first example.

FIG. 7 is a perspective view showing a collision preventing mechanism according to a second embodiment.

8 is a cross-sectional view taken along a line along the X direction of the collision prevention mechanism in FIG.

FIG. 9 is an explanatory view showing a simulated protrusion that simulates the protrusion of the collision preventing mechanism according to the first and second embodiments.

FIG. 10 is a diagram showing the contents of an experiment using a simulated protrusion.

Explanation of symbols

[0025] 21 Anti-collision mechanism

22 Protrusion 23 Bottom

24 base

25 Anti-collision layer

25a 1st part

25b 2nd part

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out the present invention will be described in each embodiment in order with reference to the drawings.

[0027] (First embodiment)

First, an optical pickup provided with a collision prevention mechanism according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a perspective view showing the configuration of the optical pickup.

In FIG. 1, an optical pickup 10 includes a laser diode 1, a collimator lens 2, half mirrors 3 and 4, a mirror 5, a multilens 6, a light receiving element 7, an objective lens 8, an actuator 9, and a casing 11. Yes.

The laser diode 1 emits a light beam bl having a specific wavelength and makes the light beam bl incident on the collimator lens 2. The collimator lens 2 emits a light beam b 2 (first light beam) in which the light beam bl is parallel light. The light beam b 2 passes through the half mirrors 3 and 4, enters the mirror 1, and enters the objective lens 8.

[0030] The objective lens 8 is fixed on an objective lens holding portion 9hl that constitutes a part of the actuator 9, condenses the light beam b2, and the light beam b2c (second light) that is spot light. Beam). A support portion 9h2 constituting a part of the actuator 9 is movably fixed on the casing 11, and the objective lens holding portion 9h2 or the objective lens 8 is attached to the radius of the optical disc D as indicated by arrows 9a and 9b. Direction and focusing direction (ie, perpendicular to the optical disk). This makes it possible to perform so-called tracking servo and focus cinder servo in which the spot of the light beam b2c emitted from the objective lens 8 is arranged on the target track of the optical disc D that is a recording medium. The optical pickup 10 configured in this way is operated by a slider motor (not shown). The casing 11 is configured to be movable in the radial direction of the optical disc D.

[0031] The light beam b2c emitted from the objective lens 8 is irradiated onto the information recording surface of the optical disc D. At this time, the reflected light b3 reflected by the optical disc D enters the objective lens 8. The reflected light b 3 is reflected by the mirror 5, passes through the half mirror 4, and enters the multi lens 6. The reflected light b3 is collected by the multi lens 6 and received by the light receiving element 7. As a result, the information recorded on the optical disc D can be read.

In the present embodiment, in particular, the collision prevention mechanism 21 is provided in the objective lens holding portion 9hl that constitutes a part of the optical pickup 10. Therefore, during operation of the optical disk system, even if the objective lens 8 approaches the surface of the optical disk D due to, for example, the focus servo being removed, the objective lens 8 collides with the optical disk D by the collision prevention mechanism 21. This can prevent the optical disk D from being damaged.

Next, the collision prevention mechanism according to the first embodiment of the present invention will be described in detail with reference to FIGS. FIG. 2 is an enlarged perspective view showing the actuator shown in FIG. FIG. 3 is an enlarged plan view showing a portion indicated by a dotted circle C1 in FIG. Fig. 4 is a cross-sectional view taken along line A- in Fig. 3.

As shown in FIG. 2, the actuator 9 includes an objective lens holding portion 9hl, a suspension 9s, and a support portion 9h2.

[0035] The objective lens holding portion 9hl is made of, for example, a synthetic resin, and has an opening 8a for holding the objective lens 8 (see FIG. 1). The objective lens 8 is held in the opening 8a. Further, in this embodiment, in particular, a collision prevention mechanism 21 described later is provided on the surface of the objective lens holding portion 9hl facing the optical disc D.

[0036] The suspension 9s is made of, for example, an elastic wire rod, and connects the objective lens holding portion 9hl and the support portion 9h2.

[0037] The support portion 9h2 also has, for example, synthetic resin isotropic force, and is fixedly disposed on the casing 11 as described above.

As shown in FIGS. 2 to 4, the collision prevention mechanism 21 is provided on the objective lens holding portion 9hl so as to protrude with respect to the optical disk D (see FIG. 1).

More specifically, as shown in FIG. 4, the collision preventing mechanism 21 includes a base 24 and a collision preventing mechanism. It consists of layer 25.

The base 24 has a bottom surface part 23 and a protruding part 22.

[0041] The bottom surface portion 23 is constituted by a part of the objective lens holding portion 9hl, and is also made of, for example, synthetic resin. The protruding part 22 is formed integrally with the bottom part 23. The protruding portion 22 may be formed by attaching a component having the same or different material force as the bottom surface portion 23.

[0042] As shown in FIGS. 3 and 4, the protrusion 22 is formed so as to surround the portion 23a of the bottom surface 23 with a width W1 or to cover the portion 23a over the width W1 when viewed in plan on the bottom surface 23. Adjacent to each other. In other words, the projecting portion 22 has a polygonal cylindrical shape, that is, has a polygonal shape when viewed from above the bottom surface portion 23 as shown in FIG. Note that the protrusion 22 may have a cylindrical shape, an elliptical cylindrical shape, or the like. The portion 23a is an example of the “one portion” according to the present invention. As will be described later, the width W1 is determined in advance according to the thickness of the collision preventing layer 25 at the tip end portion of the protruding portion 22.

The anti-collision layer 25 is formed so as to cover the protrusion 22 with a silicon rubber force that is softer than that of the optical disc D.

In FIG. 4, in the collision preventing mechanism 21 according to the present embodiment, the collision preventing layer 25 is formed by applying silicon rubber softer than the optical disk D to the protruding portion 22. Further, the surface 25as of the first part 25a located on the tip of the protrusion 22 in the collision prevention layer 25 opposite to the surface facing the protrusion 22 is removed by the protrusion 22 in the collision prevention layer 25. The second portion 25b located on the enclosed portion 23a is further away from the bottom surface 23 than the surface 25bs opposite to the surface facing the bottom surface 23 of the second portion 25b. More specifically, the anti-collision layer 25 is applied so as to cover the protrusion 22 with liquid silicone rubber softer than, for example, polycarbonate resin used as the material of the surface of the optical disk D. Is formed by. At this time, the liquid silicone rubber applied to the portion surrounding the protruding portion 22 or the portion 23a adjacent to the protruding portion 22 has a relationship between the surface tension, viscosity, liquid repellency, and the like and the height H of the protruding portion 22. Finally, it is not formed so as to rise above the protrusion 22. In other words, the applied liquid silicone rubber immediately after application, the tip of the protruding portion 22 increases as the force time that covers the entire protruding portion 22 including the portion 23a of the bottom surface portion 23 elapses. It flows out from the end portion to the bottom surface portion 23 (that is, the portion 23a surrounded by the protrusion 22 or the outside of the protrusion 22). Eventually, the first portion 25a of the thin film-like anti-collision layer 25 is formed on the tip portion having the width W1 of the protruding portion 22, and the first portion 25a of the anti-collision layer 25 is formed on the portion 23a. Two portions 25b are formed. The thickness of the anti-collision layer 25 can be adjusted, for example, by changing the amount and type of liquid silicone rubber to be applied (ie, viscosity, thixo ratio, etc.). Further, the thickness of the collision preventing layer 25 can be adjusted by changing the width W1 of the tip portion of the protruding portion 22, the material of the protruding portion 22, and the like. For example, if the width W1 of the tip of the protrusion 22 is reduced, the thickness of the first portion 25a of the collision prevention layer 25 can be reduced, and conversely the width W1 of the tip of the protrusion 22 is increased. If so, the thickness of the first portion 25a can be increased. Therefore, a relatively thin collision prevention layer 25 can be formed easily and with high accuracy by forming the width W1 of the tip portion of the protrusion 22 narrow and applying a soft liquid silicone rubber thereon. . In other words, the anti-collision layer 25 can be formed without having to control the amount of liquid silicon rubber applied with high accuracy. Therefore, the surface 25as facing the optical disk D of the first portion 25a of the collision prevention layer 25 is made the objective lens 8 (more precisely, of the surfaces facing the optical disk D of the objective lens 8 closest to the optical disk D). By forming the anti-collision layer 25 with high accuracy so that the portion) is closer to the optical disc D than the position 8s closest to the optical disc D by focusing, in the optical disc system, between the objective lens 8 and the optical disc D It is possible to shorten the working distance.

Next, a manufacturing method of the collision prevention mechanism for manufacturing the above-described collision prevention mechanism according to the first embodiment of the present invention will be described with reference to FIG. 2 and FIGS. 4 to 6. FIG. 5 is a flowchart showing the manufacturing process of the collision prevention mechanism, and FIG. 6 is an explanatory diagram showing the temporal change of the collision prevention layer in the manufacturing process of the collision prevention mechanism.

As shown in FIG. 5, according to the manufacturing method of the collision preventing mechanism according to the present embodiment, first, the base 24 is formed by the base forming process (step Sl). At this time, as shown in FIG. 4, the bottom surface portion 23 of the base is formed of, for example, a synthetic resin or the like as a part of the objective lens holding portion 9hl (see FIG. 2) on the side facing the optical disc D. Further, on the bottom surface 23, the protrusion 22 protrudes in the direction of the optical disc D and surrounds the portion 23a of the bottom surface 23 with the width W1 of the tip (or adjacent to the portion 23a over the width W1). Formed) It is. That is, the protrusion 22 is formed to have a polygonal cylindrical shape. Note that the protrusion 22 may have a cylindrical shape, an elliptical cylindrical shape, or the like. Further, the protruding portion 22 may be formed integrally with the bottom surface portion 23 or may be formed as a separate component having the same or different material force as the bottom surface portion 23. The width W1 of the tip end of the protrusion 22 is adjusted in accordance with the thickness to be formed of a collision prevention layer 25 described later. As shown in FIG. 2, two protrusions 22 are provided on the objective lens holding part 9hl. Note that only one protrusion 22 may be provided, or three or more may be provided.

Next, as shown in FIG. 6 (a), liquid silicone rubber 26 is applied to the entire protruding portion 22 including the portion 23a of the bottom surface portion 23 of the base 24 (step S). 2). The silicone rubber 26 is an example of the “elastic member” according to the present invention. The elastic member may be a curable resin such as an ultraviolet curable adhesive resin or a thermosetting resin. You can use it! At this time, the liquid silicone rubber 26 should be applied so as to cover the entire protrusion 22 including the portion 23a of the bottom 23, and the amount of the liquid silicone rubber 26 to be applied is not controlled with high accuracy. A little.

Next, in the leaving step, the base 24 coated with the liquid silicone rubber 26 is left for a predetermined time (step S3). As shown in FIG. 6 (a), the applied liquid silicone rubber 26 covers the entire protruding portion 22 including the portion 23a of the bottom surface portion 23 depending on the application method immediately after the application. Also in this case, as time passes, as shown in FIG. 6 (b), as shown in FIG.6 (b), the bottom portion 23 (that is, the portion 23a surrounded by the protrusion 22 or the portion 23a or It flows out to the outside of the protrusion 22). Finally, as shown in FIG. 4, the first portion 25a of the anti-collision layer 25 having a thin film-like silicon rubber force that is thinner than that immediately after coating is formed at the tip portion having the width W1 of the protruding portion 22, A second portion 25b of the collision preventing layer 25 is formed on the portion 23a. Or, depending on the application method, the applied liquid silicon rubber 26 may be a thin thin film at the tip of the protrusion 22 as shown in FIG. 6 (b) or FIG. A first portion 25a of the collision preventing layer 25 also having a silicon rubber force is formed, and a second portion 25b of the collision preventing layer 25 is formed on the portion 23a. In this case, the structure shown in FIG. 4 is finally obtained.

[0049] Particularly in the present embodiment, the protrusion 22 is formed in a polygonal shape by the base forming process as described above. Since it is formed in a cylindrical shape, even if a large amount of liquid silicon rubber 26 is applied, liquid silicon rubber is also applied to the portion 23a surrounded by the protruding portion 22 that extends only outside the protruding portion 22. 26 can be drained. Therefore, it is possible to prevent adverse effects on other components and the like constituting the optical pickup by flowing out of the entire protrusion 22.

[0050] Further, particularly in the present embodiment, the region surrounding the bottom surface portion 23 of the projecting portion 22 facing the bottom surface portion 23 when viewed in plan on the bottom surface portion 23 is the bottom surface portion 23 of the front end portion. The silicon rubber 26 that flows out from the tip when the liquid silicone rubber 26 is applied tends to accumulate in the portion surrounded by the protrusion 22. .

[0051] The surface 25as opposite to the surface facing the protruding portion 22 of the first portion 25a of the collision preventing layer 25 is the surface facing the bottom surface portion 23 of the second portion 25b of the collision preventing layer 25. In order to move away from the bottom surface portion 23 rather than the opposite surface 25bs, the height H from the bottom surface portion 23 of the protruding portion 22 should be made relatively high by the above-described base forming step. It should be noted that the standing time may be left as long as the shape covering the protruding portion 22 of the applied liquid silicone rubber hardly or preferably does not change completely. Such a time is variable depending on the surface tension, viscosity, liquid repellency, etc. on the protrusion 22 relating to the liquid silicon rubber to be applied. For this reason, it is preferable to experimentally determine in advance an optimal time so that the silicon rubber remains at the tip of the projecting portion 22 with a desired thickness, and in an actual manufacturing process, leave this determined time alone.

Next, the anti-collision layer 25 applied to the base 24 is cured by a curing process (Step S4). That is, the anti-collision layer 25 having a liquid silicone rubber force is cured by a curing agent added before or after application. When the anti-collision layer 25 is made of a curable resin such as an ultraviolet curable adhesive resin or a thermosetting resin, the light irradiation or irradiation is cured by heat treatment or the like.

Therefore, according to the manufacturing method of the collision prevention mechanism according to the present embodiment, the collision prevention mechanism 21 according to the first embodiment described above can be manufactured. In particular, a relatively thin anti-collision layer 25 is formed by forming a narrow width at the tip of the protrusion 22 and applying liquid silicone rubber thereon. Can be formed easily and with high accuracy. Therefore, in the optical disc system, the working distance between the object lens 8 and the optical disc D can be shortened.

[0054] (Second embodiment)

Next, a collision preventing mechanism according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a perspective view showing a collision prevention mechanism according to the second embodiment of the present invention, and FIG. 8 is a cross-sectional view taken along a line along the X direction of the collision prevention mechanism in FIG. 7 and 8, the same components as those in the first embodiment shown in FIGS. 1 to 4 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. In FIG. 8, in order to make each layer / member recognizable on the drawing, the scale is different for each layer / member.

As shown in FIGS. 7 and 8, the collision prevention mechanism 31 according to the second embodiment of the present invention includes a base 34 and a collision prevention layer 35.

[0056] Particularly in the collision prevention mechanism according to the present embodiment, the protrusion 32 of the collision prevention mechanism 31 has a plate-like shape protruding from the bottom surface 33. In this case as well, a relatively thin collision prevention layer 35 can be formed easily and with high accuracy by forming the width W2 of the tip of the protrusion 32 narrow and applying liquid silicon rubber or the like thereon. it can. In particular, the thickness D3 of the anti-collision layer 35 that is finally formed on the tip portion of the projecting portion 32 due to the applied liquid silicone rubber or the like flowing out to the bottom portion 33 also from the tip portion force of the projecting portion 32 is the tip of the projecting portion 32. The width of the part is less than W2. Therefore, the thickness D3 of the collision prevention layer can be formed thin by forming the width W2 of the tip portion of the protrusion 32 with relatively high accuracy. That is, it is possible to reduce the thickness D3 of the anti-collision layer without the need to accurately control the coating amount of liquid silicon rubber or the like. Therefore, in the optical disc system, the working distance between the objective lens 8 and the optical disc D can be shortened.

[0057] (Third embodiment)

Next, the relationship between the protrusion tip width and the film thickness of the anti-collision layer in the anti-collision mechanism according to the first and second embodiments of the present invention described above will be described with reference to FIGS. FIG. 9 is an explanatory view showing a simulated protrusion that simulates the protrusion of the collision prevention mechanism according to the first and second embodiments of the present invention. Fig. 10 is a diagram showing the contents of the experiment using the simulated protrusion. Fig. 10 (a) is a table showing the width of the tip of the simulated projection, Fig. 10 (b) is a table showing the thickness of the collision prevention layer, and Fig. 10 (c) is a diagram of the projection. 6 is a graph showing the relationship between the width of the tip and the anti-collision layer.

In FIG. 9, the simulated protrusions 110, 120, and 130 are formed by being cut out from the experimental substrate 100 that also has an aluminum force. The widths Wl l, W12, and W13 of the tip portions of the simulated projections 110, 120, and 130 are 0.2 mm, 0.4 mm, and 0.6 mm, respectively. The results of measuring the width of the actual simulated protrusions 110, 120 and 130 are shown. As shown in Fig. 10 (a), the width Wl l, W12, and W13 were averaged at 0.2061 mm, 0.4027 mm, and 0.6022 mm, respectively, as a result of measuring the width at three locations for each simulated protrusion. /!

[0059] UV curable adhesive (WORLDROCK No. 8125L manufactured by Kyoritsu Chemical Industry Co., Ltd .; viscosity 4500 ± 1000 [cP] at 25 ° C on each of the simulated protrusions 110, 120 and 130 ) And allowed to stand for 20 seconds, and then cured by UV irradiation. As a result, simulated anti-collision layers are formed at eight positions on the tip portions of the simulated protrusions 110, 120, and 130, respectively. In addition, since the UV curable adhesive is applied for 20 seconds after the UV curable adhesive is applied, the UV curable resin has sufficiently flown out to the bottom surface portion 101 of the simulated projecting portions 110, 120 and 130. The simulated anti-collision layer formed at the tip is sufficiently thin.

[0060] As shown in FIG. 10 (b), the thicknesses of the simulated anti-collision layers formed on the simulated protrusions 110, 120, and 130 (that is, the average thicknesses of the eight anti-collision layers, respectively). Were measured as 0.016 mm, 0.058 mm and 0.100 mm, respectively.

Therefore, as shown in the graph of FIG. 10 (c), there is a correlation (see the approximate line L1 in the figure) between the tip width of the simulated protrusion and the thickness of the simulated collision prevention layer. Therefore, the thickness of the anti-collision layer can be controlled by the width of the tip of the protrusion. In other words, the anti-collision layer can be formed without having to manage the amount of the UV curable adhesive to be applied with high accuracy.

[0062] The present invention is not limited to the above-described embodiments, but can be appropriately modified within the scope of the claims and the entire specification without departing from the gist or the idea of the invention which can be read. The collision prevention mechanism with such a change and the manufacturing method thereof are also included in the technical scope of the present invention.

Industrial applicability

The collision prevention mechanism and the manufacturing method thereof according to the present invention can be used for, for example, a collision prevention mechanism provided in an optical pickup in an optical disc system.

Claims

The scope of the claims

[1] A collision prevention mechanism for preventing a collision between an objective lens mounted on an optical pickup in an optical disk system and the surface of the optical disk,

The bottom surface provided on the optical pickup, and the bottom surface protruding in the direction facing the optical disc and at least one portion of the bottom surface in advance when viewed in plan on the bottom surface. A base having at least one protrusion provided to surround with a predetermined width or to be adjacent to the at least one portion over the predetermined width;

An elastic member softer than the optical disk is applied on at least the protruding portion and the one portion of the base, and faces the protruding portion of the first portion located on the distal end portion of the protruding portion. The surface on the side opposite to the surface to be collided is formed with a collision prevention layer formed farther from the bottom surface than the surface on the opposite side to the surface facing the bottom surface of the second portion located on the one portion. When

A collision prevention mechanism characterized by comprising:

[2] The collision preventing mechanism according to claim 1, wherein the elastic member includes at least an ultraviolet curable adhesive resin.

[3] The first region surrounding the bottom surface portion of the projecting portion facing the bottom surface portion when viewed in plan on the bottom surface portion is the second region surrounding the bottom surface portion of the tip portion. 2. The collision prevention mechanism according to claim 1, wherein the collision prevention mechanism is larger than the collision prevention mechanism.

4. The collision preventing mechanism according to claim 1, wherein the protrusion is formed in a cylindrical shape, an elliptical cylindrical shape, or a polygonal cylindrical shape.

[5] A collision prevention mechanism for preventing a collision between the objective lens mounted on the optical pickup in the optical disk system and the surface of the optical disk, and a collision prevention mechanism including a base and a collision prevention layer provided on the base. A method of manufacturing a collision prevention mechanism for manufacturing, comprising: a bottom surface portion provided on the optical pickup; and a bottom surface portion protruding in a direction facing the optical disc and having a width at a tip portion forming the collision prevention layer. Adjusted in accordance with the thickness to be measured and surrounding at least one part of the bottom part with a predetermined width or adjacent to the at least one part over the predetermined width , Forming the base with at least one protrusion;

An elastic member softer than the optical disk is applied to at least the protruding portion and the one portion on the base, and the first portion located on the tip portion of the protruding portion is opposite to the surface facing the protruding portion. And a surface of the second portion located on the one portion is coated so as to be farther from the bottom surface than a surface opposite to the surface facing the bottom surface. Manufacturing method of prevention mechanism.