JPS62134613A - Grating holding mechanism - Google Patents

Abstract

PURPOSE:To effectively prevent undesired turning of a holding member by setting a grating to the elastically deformable holding member and press-fitting this member into a fixing member and press-holding the holding member freely turnably in the fixing member by an elastic member. CONSTITUTION:A grating 11 is set to a holding member 12 consisting of elastically deformable plastics like a polycarbonate, and this member 12 is press-fitted to an aperture 13a of a fixing member 13 consisting of Al. The outside diameter of the holding member 12 is made slightly larger than the diameter of the aperture 13a. An aperture 12a which guides light to the grating 11 is formed in the center part of the holding member 12, and a notch 12b for adjustment of turning is formed on the outside peripheral surface. The aperture 13a is connected to the front end part of the fixing member 13 to which the holding member 12 is press-fitted, and an aperture 13b whose diameter is smaller than that of the aperture 13a is formed, and the holding member 12 is arranged with one side peripheral edge part and the outside peripheral surface brought into contact with the fixing member 13 so that the grating surface of the grating 11 is orthogonal to the axis of turning shown by an arrow in this front end part.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an optical system for recording and reproducing information on and from optical recording media such as optical discs such as compact discs and video discs, and optical recording media such as magneto-optical discs. The present invention relates to a holding mechanism for a grating attached to a head.

[Conventional technology]

Some conventional optical heads are designed to separate a light beam from a light source such as a semiconductor laser into a plurality of light beams using a grating, for example, in order to detect tracking errors. In such an optical head, in order to project the separated light beam onto the optical disk in a predetermined positional relationship with respect to its track, a holding member 2 with a grating 1 attached thereto is used as shown in FIG. It is loosely fitted into the fixing member 3 and is pressed and held rotatably within the fixing member 3 about the direction of the arrow on which its elastic force is applied by the coil spring 4. By rotating the holding member 2 using an adjustment jig, the direction of the light beam separated by the grating 1 is adjusted.

[Problem that the invention seeks to solve]

However, in the conventional configuration described above, since the holding member 2 is loosely fitted into the fixing member 3, by turning the holding member 2 2J+ times during adjustment, the opposite direction is stored in the coil spring 4. The rotational stress is suppressed only by the frictional force of the pressure contact portion 5 between one end surface of the holding member 2 and the fixed member 3. Therefore, if the frictional force is small, a rotational force in the opposite direction is applied to the holding member 2 after adjustment, causing the holding member 2 to rotate, resulting in a problem that adjustment is time-consuming and difficult to achieve highly accurate adjustment. .

Furthermore, if the pressing force of the coil spring 4 is increased in order to solve this problem, a problem arises in that it becomes difficult to adjust the rotation of the holding member 2.

The present invention has been made in view of these conventional problems, and it is an object of the present invention to provide a grating holding mechanism that is appropriately configured so that the rotation of the grating can be adjusted easily and accurately.

Means and operation for solving problem C] In order to achieve the above object, in this invention, the grating is attached to an elastically deformable holding member, and this is press-fitted into the fixing member, and the elastic member is used to tighten the fixing member. This increases the pressure contact area between the holding member and the fixed member without increasing the elastic force of the elastic member, thereby increasing the frictional force, thereby preventing undesired movement of the holding member by the elastic member. Prevent rotation.

〔Example〕

1 and 2 are an exploded perspective view and a sectional view showing one embodiment of the present invention. In this embodiment, the grating 11 is attached to a holding member 12 made of elastically deformable plastic, such as polycarbonate, and this is press-fitted into an opening 13a of a fixing member 13 made of, for example, Aff. For this reason, the outer diameter of the holding member 12 is made slightly larger than the diameter of the opening 13a.

This holding member 12 has a grating 1 at its center.
1 is formed with an opening 12a for guiding light, and a notch 12b for rotation adjustment is formed on the outer peripheral surface.

The distal end of the fixing member 13 into which the holding member 12 is press-fitted has an opening 13b that communicates with the opening 13a and has a smaller diameter than the opening 13a.
The holding member 1 is formed such that the grating surface of the grating 11 is perpendicular to the rotation axis indicated by the arrow at the tip.
2 is placed so that the peripheral edge of one side and the outer peripheral surface thereof are in contact with the fixing member 13. Further, the semiconductor laser 14 is fixed to the rear end of the fixing member 13, that is, the entrance side into which the holding member 12 is press-fitted, with a plurality of screws 15 via a holding plate 16, and the semiconductor laser 14 and the holding member 12 are connected to each other. A coil spring 17 is interposed in the opening 13a between the two, thereby pressing the holding member 12 toward the tip. Therefore, the peripheral edge of the side surface of the holding member 12 that contacts the tip of the fixing member 13 is pressed against the tip by the coil spring 17, and the outer circumferential surface presses against the inner surface of the opening 13a by press fitting.

In this embodiment, an opening 1 is provided on the outer peripheral surface of the distal end of the fixing member 13.
An opening 13c communicating with 3a is formed, and this frontage 13c
By inserting the adjustment jig 18 having an eccentric shaft 18a into the holder, and rotating the adjustment jig 18 by engaging the eccentric shaft 18a with the notch 12b of the holding member 12, the holding member 12 is moved relative to the fixed member 13. The direction of the light beam separated by the grating 11 is adjusted by rotating the grating 11 about a rotation axis indicated by an arrow.

According to this configuration, even if stress is accumulated in the coil spring 17 to rotate the holding member 12 in the opposite direction due to the rotation of the holding member 12, the outer peripheral surface of the holding member 12 is press-fitted to the inner surface of the opening 13a. Since the peripheral edge of the negative side is pressed against the tip of the fixing member 13 by the coil spring 17, it will not rotate in the opposite direction due to their frictional force.

Therefore, the rotation of the grating 11 relative to the fixed member 13 can be easily and precisely adjusted.

Figure 3 A, B, Figure 4 A, B and Figure 5 A.

B is a front view and a sectional view showing a modification of the holding member, respectively. The holding member 21 shown in FIG. 3 has a gap 21a formed in a part thereof, and the outer periphery of the gap 21a is made into a protrusion, so that the protrusion 21b is elastically deformed. In addition, the holding member 3 shown in FIG.
No. 1 has a plurality of protrusions 31a formed on its outer peripheral surface, and these protrusions 31a are elastically deformed. Further, the holding member 41 shown in FIG. 5 has a plurality of protrusions 41a formed on its outer peripheral surface, and these protrusions 41a are elastically deformable.

In FIGS. 3 to 5, the same reference numerals as those shown in FIGS. 1 and 2 represent components having the same function.

In the modification shown in FIGS. 3 to 5, the holding member 21
3141 is press-fitted by being partially elastically deformed on the inner circumferential surface of the opening 13a of the fixing member 13 shown in FIGS. This has the advantage of being able to effectively absorb the amount of force and reducing the amount of rotational force in the adjustment jig 18.

Note that in order to facilitate the press-fitting of the holding member into the fixing member, the press-fitting end edge of the holding member and/or the press-fitting side edge of the fixing member may be chamfered. Moreover, a cylindrical rubber member can also be used instead of the coil spring 17.

〔Effect of the invention〕

As described above, according to the present invention, the grating is attached to an elastically deformable holding member, and this is press-fitted into the fixed member, and the elastic member presses and holds the grating in a rotatable manner within the fixed member. , it is possible to increase the frictional force between the holding member and the fixed member, so that even if the rotation of the holding member causes stress to be accumulated in the elastic member that causes the holding member to rotate in the opposite direction, the holding member due to the rotation of the holding member It is possible to effectively prevent undesired rotation. Therefore, the rotation of the grating can be adjusted easily and with high precision.

[Brief explanation of drawings]

1 and 2 are an exploded perspective view and a sectional view showing one embodiment of the present invention; FIGS. 3A and 3B; FIGS. 4A and B; and FIG. 5A. B is a front view and a sectional view showing modified examples of the holding member, respectively, and FIG. 6 is a diagram showing a conventional technique. 11... Grating 12... Holding member 13
...Fixing member 14...Semiconductor laser 15
...screw 16...presser hand 17...
・Coil spring 18...adjustment jig 21.31.
41...Holding member l~j3 Figure 4, Go to B 51.4 AI Family Procedures Amendment January 22, 1986 Director General of the Patent Office Uga Michibe 1,
Display of the case 1985 Frame Application No. 274318 2, Name of the invention Grating Holding Mechanism 3, ) 11f Correction Relationship to the case Patent applicant (037) Olympus Optical Industry Co., Ltd. 4, Agent 6, 7 + ff Correction Contents (as shown in the attached sheet) The drawings Medium Temperature Figure 1 and Figure 2 are corrected as shown in the attached sheet.

Claims (1)

[Claims] 1. Attach the grating to an elastically deformable holding member, press fit this holding member into the fixed member, and press and hold the grating so that it can rotate freely within the fixed member around the direction in which the elastic force is applied by the elastic member. A grating holding mechanism consisting of