JPH11232804A - Optical pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup device with an improved slidability while reducing the friction between a bearing and a guide rail. SOLUTION: An optical base bearing part 11 is formed with a sheet metal is provided at one corner of four corners of an optical base 10 whose flat surface is roughly of a suare shape. In the optical base bearing part 11, two sheets of the sheet metal are lapped whose one side remains a flat surface part 12a as it is while the other side is bent by 90 deg. at respective two bending parts, and it is made to be an L-shaped bent part 12b folding back so as to be opposed to the flat surface part 12a, and the bearing part 11 has a structure to hold a guide rail 13 in between the flat surface part 12a and the bent part 12b. Thus the guide rail 13 is brought into contact with smooth surface sides of the sheet metal and the friction between the bearing and the guide rail is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical pickup device, and more particularly, to an optical pickup device used for an optical disk such as a CD-ROM.
The present invention relates to an optical pickup device in which an optical base is formed of a sheet metal material.

[0002]

2. Description of the Related Art Conventionally, an optical pickup device used for an optical disk such as a CD-ROM or the like, in which an optical base is formed of a sheet metal material, has a structure in which a part of an optical base 71 is formed by a guide rail as shown at 70 in FIG. The guide rail 72 is bent in a direction orthogonal to the axis, and a sheet metal part penetrating the guide rail 72 is punched into a groove to form a bearing 73, and the guide rail 72 is sandwiched in the bearing 73 to support the optical base 71.

A bearing 74 is formed on the optical base 71 on the side opposite to the bearing 73, and a guide rail 75 is slidably inserted through a hole provided at the center thereof to support the optical base 71. I have. The guide rails 72 and 75 are provided in parallel with each other. Thus, the optical base 71 of the optical pickup device 70 can slide in the radial direction of the optical disk parallel to the axial direction of the guide rails 72 and 75 while being supported by the bearing portions 73 and 74.

[0004]

However, in the above-mentioned conventional optical pickup device, since the surface of the guide rail 72 and the fracture surface of the sheet metal portion of the optical base 71 are in contact with each other, the friction coefficient is likely to be high. There is a problem that slidability is poor.

Further, in the above-described conventional optical pickup device, the contact between the surface of the guide rail 72 and the fractured surface of the sheet metal part of the optical base 71 may cause the burr of the sheet metal to contact the guide rail 72. There is a possibility that the guide rail 72 may be damaged to accelerate abrasion, or the surface treatment may be eroded to cause rust, which may cause a decrease in accuracy or malfunction.

Further, in the above-mentioned conventional optical pickup device, since the bearing portion 74 is a separate component from the optical base 71, there is a problem that the number of components is increased and the cost is high.

[0007] The present invention has been made in view of the above points,
An object of the present invention is to provide an optical pickup device capable of improving slidability.

Another object of the present invention is to provide an optical pickup device capable of stabilizing the operation with an inexpensive configuration.

[0009]

According to the present invention, in order to achieve the above object, an optical base on which an optical system including at least a laser light source and an objective lens is mounted is slidable on a guide rail by an optical base bearing. In an optical pickup that moves while being supported by an optical base bearing,
A part of the sheet metal constituting the optical base is bent so that the contact surface with the guide rail becomes a smooth surface of the sheet metal.

In the present invention, since the contact surface with the guide rail is configured to be a smooth surface of the sheet metal material, the friction between the optical base bearing portion and the guide rail can be reduced. Further, the optical base bearing portion can be configured using a sheet metal material forming a part of the optical base.

The above-mentioned optical base bearing portion has a flat portion contacting the lower side of the guide rail and a sheet metal material at two places.
After bending at 0 °, 180
° The cross-section in contact with the upper side of the guide rail, which is formed by folding, has an L-shaped bent portion.
Here, the flat portion and the bent portion have a curved structure on the guide rail side, a structure in which a punching portion is formed on the guide rail side by half punching, or a groove on the opposite side of the groove by squeezing the groove by drawing. By adopting a structure in which the portion contacts the guide rail, the contact area with the guide rail can be reduced.

Further, according to the present invention, an optical base bearing is provided.
The optical base is formed by bending two opposite ends of a sheet metal material constituting the optical base, and performing burring processing on each of the bent ends and squeezing the cylindrical shape into two.
The guide rails are respectively penetrated into the cylinders of the two bent portions.

In the present invention, the optical base bearing can be formed by using a sheet metal material forming a part of the optical base.

[0014]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a perspective view of a first embodiment of the optical pickup device according to the present invention. In this embodiment, an optical base bearing 11 is provided at one of four corners of an optical base 10 formed of a sheet metal material and having a substantially square planar shape. An optical base 10 includes a laser light source that emits a light beam and an objective lens 16 that focuses and irradiates the light beam on an optical disc (not shown) and transmits reflected light from the optical disc. The system is installed.

As shown in a side view of FIG. 2A and a front view of FIG.
2A, one of which is the flat portion 12a, and the other is at the bending positions indicated by 14 and 15 in FIG.
The L-shaped bent portion 12b is formed by being bent by 0 °, and the guide rail 13 is sandwiched between the flat portion 12a and the bent portion 12b.

As a result, the optical base bearing 11 is
The guide rail 13 is provided with a flat portion 12a which is a smooth surface of a sheet metal material.
And the bent portion 12b. 1 and 2, the optical base 10 is supported by the optical base bearing 11 in the axial direction of the guide rail 13 (this direction is also parallel to the radial direction of the optical disk), and is not shown. It is moved by the moving mechanism.

Note that the punching direction when punching the sheet metal material is set so that when the bearing 11 is finally formed, burrs appear on the surface opposite to the surface in contact with the guide rail 13. .

Next, a method of forming the optical base bearing 11 will be described. 3A and 3B are a plan view and a front view of the shape of the optical base bearing unit 11 before processing. In FIG. 2A, a solid line 21 at a lower left portion of the sheet metal member 20 formed in a predetermined shape is cut off, and a dotted line 22 is cut in a direction such that it becomes concave.
The dashed line 23 is bent at 90 ° in a direction in which the dotted line 23 is convex, and finally the dotted line 24 is folded in 180 ° in a direction so as to be convex.

Thus, the optical base bearing portion 11 shown in FIGS. 1 and 2 is formed from one sheet metal member 20, and the sheet metal member portion serving as the flat portion 12a and the sheet metal member portion serving as the bent portion 12b are formed. In any case, the smooth surfaces can be opposed to each other. At this time, the direction of punching of the outer shape of the sheet metal material 20 is set in the direction of arrow 25 in FIG. As a result, burrs appear on the surface opposite to the contact surface side with the guide rail 13 at the stage when the bearing is formed, and the burrs of the sheet metal material 20 can be kept away from the guide rail 13.

Next, another embodiment of the present invention will be described. FIG. 4 shows a second embodiment of the optical pickup device according to the present invention.
1 shows a perspective view of the embodiment. This embodiment is directed to an optical base 1 formed of a sheet metal material and having a substantially square planar shape.
An optical base bearing 30 is provided at the end of the zero. As shown in FIG. 4, the optical base bearing portion 30 is formed by bending each of the opposite ends of the sheet metal inwardly by 90 ° to form an L-shape, and performing a burring process on the sheet metal to form a cylindrical shape. Bent part 31a with squeezed shape
And 31b.

A guide rail 32 is slidably penetrated in each cylinder of the bent portions 31a and 31b. This allows the optical base 10 to move in the axial direction of the guide rail 32 (which is also a direction parallel to the radial direction of the optical disk).
While being supported by the optical base bearing unit 30, the optical base is moved by a moving mechanism (not shown).

FIG. 5 is a perspective view of an optical pickup device according to a third embodiment of the present invention. In this embodiment,
This is an optical pickup device in which the first embodiment of FIG. 1 and the second embodiment of FIG. 4 are combined. The same components as those of FIGS. 1 and 4 are denoted by the same reference numerals, and description thereof is omitted. . According to the embodiment shown in FIG. 5, the optical base 10 can be slidably supported on the guide rails 13 and 32 with only one sheet metal material, and the cost can be reduced.

Next, other examples of the optical base bearing unit 11 will be described. FIG. 6A shows the optical base bearing unit 1.
This is an example in which the upper and lower sheet metal parts 41 are curved toward the guide rail. Thereby, the contact between the bearing portion and the guide rail becomes a point contact, and the slidability is improved. In addition, the positioning accuracy of the entire optical base in the vertical direction is improved.

FIG. 6B shows an example in which the upper and lower sheet metal portions 42 of the optical base bearing 11 are subjected to half punching. Thereby, the contact portion with the guide rail is limited to the punched portion, and the contact area is reduced, so that the slidability and the vertical positioning accuracy can be improved.

FIG. 6C shows a groove formed by drawing the upper and lower sheet metal portions 43 of the optical base bearing portion 11 by drawing.
This is an example in which a protrusion opposite to the groove is formed on the guide rail side. Thereby, the contact between the sheet metal material and the guide rail becomes a point contact, and the slidability and the positioning accuracy in the vertical direction are improved. Further, the rigidity of the sheet metal material is increased, and the reliability is improved.

In the above three examples, one of the upper and lower sheet metal members is changed to an elastic material, for example, a phosphor bronze plate or a stainless steel spring plate, and is sandwiched so as to maintain constant contact with the guide rail. By setting, the positioning accuracy in the vertical direction can be further improved.

[0027]

As described above, according to the present invention,
Since the friction between the bearing and the guide rail can be reduced, the movement of the optical pickup in the radial direction of the optical disk can be stabilized.

Further, according to the present invention, since the wear of the bearing and the guide rail is suppressed, the accuracy can be easily maintained, and the reliability can be improved.

Further, according to the present invention, it is possible to form a bearing with one sheet metal material and to reduce the number of parts.
Cost can be reduced. As described above, a highly reliable optical pickup can be realized at lower cost than in the related art.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment of an optical pickup device according to the present invention.

FIG. 2 is a side view and a front view of a main part of FIG. 1;

3A and 3B are a plan view and a front view of an embodiment of a method for producing an optical base bearing of the optical pickup device according to the present invention.

FIG. 4 is a perspective view of a second embodiment of the optical pickup device according to the present invention.

FIG. 5 is a perspective view of a third embodiment of the optical pickup device according to the present invention.

FIG. 6 is a perspective view of each example of an optical base bearing portion of the optical pickup device according to the present invention.

FIG. 7 is a perspective view of an example of a conventional optical pickup device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Optical base 11, 30 Optical base bearing part 12a Plane part 12b, 31a, 31b Bend part 13, 32 Guide rail 14, 15, 22, 23, 24 Sheet metal bending position 16 Objective lens 20 Sheet metal material 41, 42, 43 Sheet metal part

Claims (6)

[Claims] 1. An optical pickup device in which an optical base on which an optical system including at least a laser light source and an objective lens is mounted is moved while being slidably supported on a guide rail by an optical base bearing. An optical pickup device, wherein the portion is configured such that a part of a sheet metal material constituting the optical base is bent so that a contact surface with the guide rail becomes a smooth surface of the sheet metal material. 2. The optical base bearing part is formed by bending a sheet metal material at two places by 90 ° after bending a 180 ° so as to face and separate from the flat part, and a flat part that contacts the lower side of the guide rail. 2. The optical pickup device according to claim 1, wherein the formed cross-section in contact with the upper side of the guide rail comprises an L-shaped bent portion. 3. The structure according to claim 2, wherein the flat portion and the bent portion are curved toward the guide rail.
An optical pickup device as described in the above. 4. The optical pickup device according to claim 2, wherein the flat portion and the bent portion have a punched portion formed by half punching on the guide rail side. 5. The flat portion and the bent portion are formed such that a groove is squeezed out by drawing, and a convex portion on the opposite side of the groove comes into contact with the guide rail. An optical pickup device as described in the above. 6. An optical pickup device in which an optical base on which an optical system including at least a laser light source and an objective lens is mounted is moved while being slidably supported on a guide rail by an optical base bearing. The part was bent at two opposing ends of the sheet metal material constituting the optical base, and squeezed into a cylindrical shape by subjecting each to burring.
An optical pickup device comprising: a plurality of bent portions, wherein the guide rails are respectively penetrated into the cylinders of the two bent portions.