JPH05334710A - Optical pickup - Google Patents

Abstract

PURPOSE:To surely shield a laser light source and to improve the efficiency of assembling work by mounting the laser light source, a penetration capacitor for supplying a drive signal and a wiring board in an optical base opening only two faces from the same direction integrally and thereafter closing the opening faces by a two faces shield plate. CONSTITUTION:After a laser diode 2 and the penetration capacitor 10 for supplying the drive signal are mounted to the wiring board 36, the diode 2 and the capacitor 10 are written and held respectively on a recessed part 24 and the opening 32 provided on the upright wall surface of the optical base 22 formed integrally in a rectangular shape by four wall surfaces and whose two faces are opened. Then, the shield plate 26 with an L shape wall surface opposing to the opening of the base 22 is engaged with the closing surfaces of the base 22 by engaging pieces 26A, 26B. Thus, the assembling work is simplified and the efficiency of the work is improved and the base 22 is shielded surely and undesired radiation is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup for a magneto-optical disc recording / reproducing apparatus.

[0002]

2. Description of the Related Art Conventionally, in a magneto-optical disk recording / reproducing apparatus of this type, a so-called pulse train method of intermittently irradiating a light beam is applied to thermomagnetically record desired recording information. is there.

In this pulse train system, by intermittently irradiating the light beam, the current of the laser diode fluctuates greatly following the irradiation of the light beam.

Therefore, as shown in FIG. 3, in the optical pickup 1 applied to this type of magneto-optical disc recording / reproducing apparatus, the laser light source 2 is shielded to reduce unnecessary radiation.

That is, in the optical pickup 1, a base 4 is formed by die casting of a metal such as aluminum, and a laser diode 2 is inserted and held in a concave portion formed in the base 4. As a result, the optical pickup 1 holds the laser diode 2 at a predetermined position and guides the light beam of the laser diode 2 to the magneto-optical disk.

The laser diode 2 is mounted on a predetermined wiring board 6, and the wiring board 6 is connected to a feedthrough capacitor 10 via a flexible wiring board 7. The feedthrough capacitor 10 penetrates a shield case 8. Is attached to the shield case 8.

As shown in FIG. 4, the shield case 8 is formed by bending a plate-shaped metal plate into a rectangular shape, so that in the optical pickup 1, the shield case 8 and the base 4 are used to form the laser diode 2. , The wiring board 6 and the flexible wiring board 7 are shielded so as to surround them,
It is designed to reduce unnecessary radiation.

[0008]

However, when the optical pickup is shielded by the shield case 8 as described above,
The processing of the shield case 8 is complicated, and as a result, it takes time to assemble the optical pickup 1 itself.

That is, when the shield case 8 is formed by bending a sheet metal, slits are formed at the joints between the respective faces of the shield case 8, so that unnecessary radiation is radiated from the slits. For this reason, this type of shield case 8 needs to close the slit by using a method such as soldering, and it takes time to close the slit.

As one method for solving this problem, a method of applying a squeezing method to form a shield case to prevent the occurrence of a salt can be considered. However, with this method, the processing process becomes complicated,
There is still an insufficient problem in practical use.

On the other hand, as shown in FIG. 5, after bending the sheet metal 12 into a U-shape so that the slits are not formed, the plate-shaped member 14 to which the feedthrough capacitor 10 is attached is soldered to remove the side surface. A method of forming the shield case 16 to form the shield case 16 is conceivable, but this method also has a drawback in that the soldering work takes time.

Further, in the optical pickup 1 having the structure shown in FIG. 3, there is a problem that the assembling becomes three-dimensional and the assembling work becomes complicated accordingly. Further, a flexible wiring board 7 or the like for connecting the feedthrough capacitor 10 attached to the shield case 8 and the wiring board 6 is required, and the number of parts is increased by that amount, and there is a problem that the entire configuration becomes complicated. In particular, when the number of parts is increased in this way, unnecessary radiation is likely to occur in the end.

The present invention has been made in view of the above problems,
The first purpose thereof is to propose an optical pickup which can shield a laser light source easily and surely.

A second object of the present invention is to propose an optical pickup which has a simple structure and can simplify the assembling work.

[0015]

The second object of the present invention is to provide an optical pickup, which intermittently drives a laser light source to irradiate a light beam, with an opening to be closed. An optical base that holds the laser light source, a feedthrough capacitor that supplies a drive signal output from a drive circuit to the laser light source, a wiring board that mounts the laser light source and the feedthrough capacitor, and an opening of the optical base are closed. And a shield plate, wherein the optical base holds the laser light source, the wiring board, and the feedthrough capacitor at a given position by inserting the laser light source into a recess formed at a given position, and the feedthrough capacitor is An optical pickup configured to supply the drive signal through a through hole formed in the optical base in the same direction as the direction of inserting the laser light source. By the up, it is achieved.

The first object is to provide an opening in which the optical base is closed by two or less shield plates,
This is achieved by closing the opening with the shield plate and shielding the laser light source and the wiring board so as to surround the laser light source and the wiring board.

Further, the shield plate is provided with a locking means for locking the optical base, and the locking means is formed by a locking piece integrally provided on a surface that closes the opening of the optical base. The optical base may be configured to hook the locking piece at a predetermined locking position to lock the shield plate.

Further, the optical base is formed with wall surfaces so as to sandwich both end edges of the shield plate when the shield plate is attached, and the shield plate is provided with the optical plate when attached to the optical base. You may make it form the nail | claw standing up from both edge so that the said wall surface of a base may be pressed outside.

In the optical base, when the shield plate is attached, a wall surface is formed so as to sandwich both end edges of the shield plate, and the wall surface formed so as to sandwich both end edges of the shield plate is , A surface parallel to the shield plate may be formed on the inside, which is in close contact with the shield plate.

Further, the feedthrough capacitor is attached to the shield member so as to pass through the plate-shaped shield member and passes through the through hole, and the shield member has a gap between the through hole and the feedthrough capacitor. Can be configured to shield.

[0021]

According to the above-mentioned structure, the laser light source is inserted into the recess formed at the predetermined position to hold the laser light source, the wiring board and the feedthrough capacitor at the given position of the optical base. By forming the through hole for the through capacitor so as to penetrate the optical base in the same direction as the inserting direction, the laser diode and the through capacitor can be mounted on the wiring board and integrally attached to the optical block.

Further, by forming openings on the optical base which are closed by the shield plate on two or less sides and closing the openings by the shield plate, the structure of the shield plate can be simplified. By locking to the optical base via the locking means, the installation work can be simplified,
Also, when the shield plate is attached, a wall surface is formed so as to sandwich both edges of the shield plate, and the claws of the shield plate press the wall surface to the outside to prevent rattling of the shield plate by simple installation work. In addition, it is possible to prevent the formation of a gap.

Further, when the shield plate is attached, a wall surface is formed so as to sandwich both end edges of the shield plate, and a surface parallel to the shield plate is formed inside the wall surface so as to be in close contact with the shield plate. A wall can be formed at a right angle to the shield plate and the slit between the surfaces, and the shield effect can be easily improved.

On the other hand, the through capacitor is attached to the plate-shaped shield member to penetrate the through hole, and the gap between the through hole and the through capacitor is shielded by this shield member, so that the clearance between the through hole and the through capacitor is easily achieved. It is possible to reduce unnecessary radiation generated from

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The examples described below are
Since it is a preferred specific example of the present invention, various technically preferable limitations are given, but the scope of the present invention is, unless otherwise stated in the following description, limiting the present invention.
These modes are not limited.

FIG. 1 is an exploded perspective view showing an embodiment of the optical pickup according to the present invention. In the figure, an optical block 20 is formed by an irradiation optical system that emits a light beam in a predetermined beam shape and a light receiving optical system that receives reflected light from a magneto-optical disk. Hold together.

Further, the optical block 20 is provided on a base held so as to be movable in the radial direction of the magneto-optical disk.
It is held together with an objective lens and the like, and as a result, an optical pickup is formed as a whole.

The optical base 22 is integrally formed by aluminum die casting, and a circular recess 24 is formed on a wall surface that stands upright with respect to the bottom surface of the optical base 22. As a result, the optical base 22 has the concave portion 24.
Insert the laser diode 2 into the laser diode 2
Is held in place.

Further, while the optical base 22 forms an irradiation optical system by arranging grating, collimator lens, polarizing beam splitter, etc. on the extension of the concave portion 24, a light receiving optical system is arranged in parallel with the irradiation optical system. And a light receiving element or the like of this light receiving optical system is arranged adjacent to the laser diode 2 at a predetermined position.

The optical base 22 has four wall surfaces surrounding the laser diode 2 and has a rectangular substrate housing space 2
5 is formed, and the laser diode 22 is completely shielded by closing the remaining two openings with the shield plate 26.

It should be noted that one of the wall surfaces of the optical block 22 (represented by symbol 28) is formed between the arrangement position 30 of the light receiving element forming the light receiving optical system, so that in the optical block 20, the light receiving optical system is formed. The system and the irradiation optical system can be separated to reliably prevent noise from jumping in.

Further, in the optical block 22, a rectangular opening 32 is formed adjacent to the concave portion 24, and the feedthrough capacitor 10 can be attached from the same direction as the laser diode 2 by penetrating the feedthrough capacitor 10 through the opening 32. It is like this.

That is, the feedthrough capacitor 10 is attached to a plate-shaped shield member 34, which will be described later, and then mounted on the wiring board 36 together with the laser diode 2, and then the laser diode 2 is inserted into the recess 24 to form the opening 32. It penetrates and is held at a predetermined position.

As a result, in the optical block 22,
Feedthrough capacitor 10 from the same direction as the laser diode 2
Since the opening 32 is formed so that the
After mounting the laser diode 2 and the feedthrough capacitor 36 on one wiring board 36, the laser diode 2 is recessed into the recess 24.
The feedthrough capacitor 10, the laser diode 2 and the wiring board 36 can be arranged at predetermined positions by a simple operation of simply inserting the through capacitor 10.

Therefore, in the optical pickup, the wiring work between the feedthrough capacitor 10 and the laser diode 2 can be simplified, and the flexible wiring board can be omitted.
As a result, the number of parts can be reduced, the overall configuration can be simplified, the assembly work can be simplified, and the overall shape can be reduced.

Further, as shown in FIG.
In the first embodiment, after the feedthrough capacitor 10 is attached to the plate-shaped shield member 34, the shield member 34 closes the gap between the opening 32 and the feedthrough capacitor 10 by inserting the feedthrough capacitor 10 through the opening 32. The capacitor 10 can be attached to reduce unnecessary radiation.

In addition, in the optical base 22, the wall surface forming the opening 32 is formed at a position deeper than the wall surface to which the laser diode 2 is attached by a predetermined depth, while the shield member 34 is formed in the inner wall. The size is selected so that it fits snugly on the wall.

The shield member 34 has a side surface cut and raised like a spring to form a claw 36A. When the shield member 34 is pushed into the optical base 22, the claw 36A bends and comes into close contact with the inner wall of the inner eye. The whole is urged by 36 to be held at a predetermined position, and further electrically connected to the optical block 22.

As a result, the optical block 20 has the opening 3 after the feedthrough capacitor 10 is attached to the shield member 34.
With a simple assembling work of just penetrating into 2, it is possible to prevent the occurrence of a gap and to electrically connect to the optical base 22 to hold the shield member 34, thereby simplifying the assembling work. It is like this.

The shield plate 26 is formed by bending a metal plate into an L-shaped cross section so as to close the opening of the optical base 22. The tip portion of the shield plate 26 is further bent at a right angle to form a locking piece 26A. And 26B are formed.

Of these, the locking pieces 26A and 26B are respectively locked so as to be hooked on the outside of the wall surface (that is, the wall surface 37 and the wall surface 37 in which the opening 32 is formed) facing the opening of the optical base 22, Thereby, the shield plate 26 is locked to the optical base 22.

As a result, in the optical pickup, 2
The shield plate 26 can be attached by a simple assembling work by simply hooking the two locking pieces 26A and 26B to the outside of the wall surface, and the vertical assembly work can be simplified accordingly.

With respect to the shield plate 26 thus mounted, the optical base 22 has wall surfaces located on both sides of the shield plate (that is, a wall surface 28 for separating the laser diode 2 and the light receiving optical system, and this wall 28). The shield plate 26 is formed with claws 26C at both edges so as to press the wall surfaces 28 and 38.

Accordingly, in the optical block 20,
The claw 26C presses against the wall surfaces 28 and 38 so that the optical base 2
2 and the shield plate 26 are electrically connected, and the shield plate can be held at a predetermined holding position. As a result, in the optical pickup, the connecting work such as soldering can be omitted, and the assembling work can be simplified accordingly. Also, easily attach the shield plate 26,
It is possible to prevent rattling of the shield plate 26.

Further, in the optical block 20, the wall 2
The inside of 8 and 38 is formed stepwise toward the opening,
The step portion formed in the staircase portion extends substantially parallel to the shield plate, and is in close contact with the shield plate 26.

Thus, in the optical pickup, the wall surfaces 28 and 38 are formed so as to stand upright on the outside of the slit generated between the parallel surface and the shield plate 26, and the shield plate 26 and the optical block 22 are formed. It is designed to prevent unnecessary radiation that is generated from the joint.

Thus, in the optical block 20, after the optical parts are attached to the optical base, the shield member 34 is attached.
The feedthrough capacitor 10 attached to the laser diode 2
Along with the mounting on the wiring board 36, the laser 2 is inserted into the recess 24, and then the shield plate 26 is locked.
The whole can be assembled and the optical block can be fixed to the base to form an optical pickup.

Further, by forming two openings in the optical base 22 and closing the openings with a shield plate, the soldering work as in the case of forming a shield case can be omitted, which is simply and surely unnecessary. Radiation can be reduced.

Therefore, the aperture of this type of optical base is set to 1
Even if one surface is set and the one surface is closed by a shield plate, the entire surface can be shielded without using a shield case.

However, in this case, since the opening is formed in one surface, there is a drawback that the work of mounting the laser diode 2 and the like becomes more difficult than in the case of this embodiment. In the small-sized optical pickup as in this embodiment, It was confirmed that the workability is best when the openings are set on two sides, and that unnecessary radiation can be reduced easily and surely.

As a result, it is possible to obtain an optical pickup which can prevent unnecessary radiation by a simple assembling work.

In the above embodiment, the case where the shield plate is locked by the locking piece has been described, but the present invention is not limited to this, and the shield plate may be fixed to the optical base by using a screw or the like. You can

Further, in the above-described embodiment, the case where the optical base and the base of the entire optical pickup are formed separately has been described, but the present invention is not limited to this, and the optical base is common to the base of the entire optical pickup. May be used for.

[0054]

As described above, according to the optical pickup of the present invention, by inserting the laser light source into the concave portion of the optical block with the laser light source and the feedthrough capacitor mounted on the wiring board, the feedthrough capacitor and the laser light source are provided. It is possible to wire between the parts and attach them at a predetermined position, so that the optical pickup can be assembled by a simple assembling work, and the number of parts can be reduced. Further, even if the shield case is not formed, the unnecessary radiation can be surely reduced, and the assembling work can be simplified accordingly.

[Brief description of drawings]

FIG. 1 is a schematic exploded perspective view showing an embodiment of an optical block of an optical pickup of the present invention.

2 is a schematic cross-sectional view of the optical block of FIG.

FIG. 3 is a schematic sectional view showing an example of a conventional optical pickup.

FIG. 4 is a schematic perspective view showing the shield case of FIG.

FIG. 5 is a schematic perspective view showing a shield case according to another conventional example.

[Explanation of symbols]

 1 Optical pickup 2 Laser diode 6,36 Wiring board 10 Feedthrough capacitor 22 Optical base 26 Shield plate 32 Opening 34 Shield member

Claims (6)

[Claims] 1. An optical pickup for intermittently driving a laser light source to emit a light beam, an optical base having an opening to be closed and holding the laser light source, and a drive signal output from a drive circuit. Is provided to the laser light source, a wiring board on which the laser light source and the through capacitor are mounted, and a shield plate that closes an opening of the optical base, and the optical base is provided at a predetermined position. The laser light source is inserted into the concave portion to hold the laser light source, the wiring board, and the feedthrough capacitor at predetermined positions, and the feedthrough capacitor is formed in the optical base in the same direction as the direction of inserting the laser light source. An optical pickup, characterized in that the drive signal is supplied through the hole. 2. The optical base has an opening that is closed by a shield plate having two or less surfaces, and the laser light source and the laser light source that surround the laser light source and the wiring board by closing the opening with the shield plate. The optical pickup according to claim 1, wherein the wiring board is shielded. 3. The shield plate includes locking means for locking the optical base, and the locking means is formed of a locking piece integrally provided on a surface that closes the opening of the optical base. 3. The optical pickup according to claim 1, wherein the optical base hooks the locking piece at a predetermined locking position to lock the shield plate. 4. A wall surface of the optical base is formed so as to sandwich both end edges of the shield plate when the shield plate is attached, and the shield plate, when attached to the optical base,
The optical pickup according to any one of claims 1 to 3, characterized in that a claw rising from both end edges is formed so as to press the wall surface of the optical base outward. 5. A wall surface of the optical base is formed so as to sandwich both end edges of the shield plate when the shield plate is attached, and the wall surface formed so as to sandwich both end edges of the shield plate, The optical pickup according to any one of claims 1 to 3, characterized in that a surface parallel to the shield plate is formed on the inner side thereof so as to be in close contact with the shield plate. 6. The feedthrough capacitor is attached to the shield member and penetrates the through hole so as to penetrate a plate-shaped shield member, and the shield member forms a gap between the through hole and the feedthrough capacitor. The optical pickup according to any one of claims 1 to 5, which is shielded.