JPH0862479A - Holding mechanism for optical element - Google Patents

Abstract

PURPOSE: To provide an optical element holding mechanism which has a simple structure and which does not cause a strain or a positional deviation, by providing holding members each of which has an inclined surface for clamping a flattened optical element, and at least one of which is movable. CONSTITUTION: A base member 12 having an U-like cross-sectional shape is formed therein with a pair of reference surfaces 12a, 12a for regulating a loading position of a mirror 11 as a flattened optical element, and a recess 12b formed between the pair of reference surfaces 12a, 12a. Further, two screw holes 12b are formed in wall parts 12c, 12c, and pointed machine screws 13 as holding members are screwed into the screw holes 12b. The tip of each machine screw 13 is formed into a conical shape having an apex angle of about 90 deg. which defines an inclined surface for clamping the mirror 11. Since the tip of the screw 13 for holding the mirror 11 have an inclined surface, an uneven thickness of the mirror 11 can be absorbed by adjusting the fixing positions of the screws 13, and the screws 13 can be tightened to predetermined torque with the use of a torque wrench or the like, and accordingly, it is possible to always hold the mirror with a suitable force value without deforming the mirror.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a holding mechanism for an optical element such as a mirror, which is required to be mounted with high precision.

[0002]

2. Description of the Related Art As a holding mechanism of this type, there is a method using an adhesive, a method using a pressing plate, etc., as disclosed in Japanese Utility Model Laid-Open No. 57-110519. A conventional holding mechanism will be described with reference to FIG. FIG. 4A is a side sectional view of a holding mechanism using an adhesive. Reference numeral 42 in the drawing is a plate-shaped base member, and a first recess 42a for mounting the flat mirror 11 is provided in the center, and the bottom portion thereof serves as a reference surface for defining the mirror 11 in a correct position. Has become. Further, a second lower recess 42b is provided inside the first recess 42a. In the state where the mirror 11 is fitted in the first recess 42a, the side surface portion protruding from the upper surface of the base member 42 is fixed by being bonded at several places with the adhesive 43.

FIG. 4B is a side sectional view of a holding mechanism using a pressing plate. The base member 42 has substantially the same structure as that of (a), and the mirror 11 is placed in the first recess 42a. The mirror 11 is mounted on the base member 42 with screws 45.
It is fixed by a pressing plate 44 having a Z-shaped cross section fixed to the upper surface.

[0004]

In the former method using an adhesive, the mirror may be distorted due to a change in volume when the adhesive is cured, or the fixed position may be displaced during curing, so that the mirror cannot be held in the correct position. There's a problem.

In the latter method using the holding plate, the height of the holding plate is set to be lower than the protruding height of the mirror for holding the mirror, so that a large holding force is generated due to the deformation of the holding plate when tightening the screws. However, unnecessary stress is applied to the mirror to cause distortion. Further, in order to cope with mirrors having different thicknesses, it is necessary to prepare a pressing plate having a height suitable for each, which causes a problem that assembly and component management become complicated. As a solution to this problem, a method of inserting a cushioning material between the mirror and the pressing plate to relieve the stress is disclosed in Japanese Utility Model Laid-Open No. 57-110519, but in this method, an external force such as vibration is applied. At times, a slight misalignment may occur.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a holding mechanism for an optical element having a simple structure and free from distortion and displacement.

[0007]

The present invention has taken the following means in order to achieve the above object. According to a first aspect of the present invention, a base member having a reference surface that defines a mounting position of a flat optical element, and both side surfaces of the flat optical element facing each other on the base member are provided. A holding member having an inclined surface for sandwiching the flat optical element,
At least one of the holding members is movably provided.

According to a second aspect of the present invention, the holding member located on the opposite side of the at least one movable holding member is integrally provided on the base member.

According to a third aspect of the present invention, the movable holding member is a screw member having a conical tip, and the screw member is provided in the vicinity of the flat optical element so as to be movable back and forth.

[0010]

According to the present invention, the flat optical element placed on the reference surface of the base member is slanted on both sides by a holding member having an inclined surface having a predetermined angle with respect to the side surface of the element. By being sandwiched, the optical element is pressed against the reference surface and fixed properly, and at the same time, both side surfaces of the optical element are also fixed. At this time, the optical element is not distorted by setting the holding member to an appropriate position, that is, a position where an excessive force is not applied to the mirror and there is no gap between the holding member and the optical element.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 1 shows a first embodiment of the present invention.
(A) is a plane sectional view and (b) is a side sectional view. On both sides of the bottom of the base member 12 having a U-shaped cross section, a reference surface 12 that defines the mounting position of the flat mirror 11 as an optical element.
a and 12a are formed, and the pair of reference surfaces 12
A lower recess 12b is formed between a and 12a. Further, two screw holes 12d are formed in each of the wall portions 12c, 12c, and a sword screw 13 as a holding member is screwed therein. The tip of the sword screw 13 is formed in a conical shape with an apex angle of about 90 degrees to form an inclined surface that holds the mirror 11.

In this embodiment having such a structure, when the mirror 11 is placed on the reference surfaces 12a, 12a of the base member 12 and the four sword screws 13 are tightened, The upper ridge portion is sandwiched and fixed by the conical portion 13a at the tip of the sword tip screw 13 from both sides.

As described above, since the tip of the sword screw 13 for holding the mirror 11 is an inclined surface, the variation in the thickness of the mirror 11 can be absorbed by adjusting the fixing position thereof, and the torque wrench or the like can be used. By tightening with a predetermined torque, it is possible to always hold the mirror with an appropriate amount of force without distorting it. Further, the same holding member can be applied to mirrors having different thickness dimensions. Further, since the inclined surface is configured to press the upper ridge portion of the mirror, the pressing force of the blade screw 13 is divided by the inclined surface in the direction perpendicular to the direction along the mirror surface, and the mirror is surely fixed on the reference surface. It can be pressed down and does not cause lateral slippage. Also, because the holding member does not overhang on the mirror,
Do not reduce the effective area of the mirror. Since the sword screw 13 is used as the holding member, it is possible to construct a holding mechanism having an extremely simple structure and easy to assemble.

In order to further secure the fixing, the blade screw 13 may be fixed to the base member 12 together with an adhesive or a paint. Further, it is preferable to chamfer the upper ridge portion of the mirror 11 so that the mirror 11 can be held better and the mirror can be prevented from being chipped. As the optical element, various elements such as a prism, a lens and a filter can be applied in addition to the mirror. The number of sword tip screws 13 can be appropriately increased or decreased depending on the size of the fixed mirror.

Further, as the holding member, various shapes other than the sword screw 13 can be used. For example, as in the holding mechanism shown in FIG. 2, the wedge-shaped member 23 slidable along the hole 21 provided in the wall portion 12c is provided with the inclined surface 23 thereof.
It may be configured such that a is arranged so as to face the side surface of the mirror 11 and the back surface thereof is pushed by the push screw 24. In this example, unlike the point where the corner ridge of the mirror is pressed by the point contact with the conical inclined surface, the range of a predetermined length is pressed by the line contact with the inclined flat surface, so that there is an advantage that the holding stability is improved. .

<Second Embodiment> FIG. 3 is a partially cutaway perspective view showing a second embodiment. The second embodiment will be described with reference to this figure. The same or corresponding parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. A sword screw 13 as a holding member is arranged on one of the two wall portions 12c of the U-shaped base member 12, and the other wall portion 12c
An inclined surface 31 that functions as a holding member is integrally formed with c.

In the holding mechanism having such a structure, first, the mirror 11 is placed on the reference surfaces 12a, 12a and pressed against the inclined surface 31 side. After that, adjust the sword tip screws 13 at two places so that the mirror 11 is firmly fixed without looseness, and tighten. In this embodiment, since the inclined surface on one side has a length that extends over almost the entire length of the mirror, it is possible to hold the mirror with high stability, and the number of adjustments of the sword screw 13 is reduced, resulting in a reduction in the number of assembling steps. Will be reduced.

[0018]

According to the present invention, it is possible to provide a holding mechanism for an optical element having a simple structure and free from distortion and displacement.

[Brief description of drawings]

FIG. 1 shows a first embodiment of the present invention, in which (a) is a plan sectional view and (b) is a side sectional view.

FIG. 2 is a side sectional view showing a modified example of the holding member of the first embodiment shown in FIG.

FIG. 3 is a partially cutaway perspective view showing a second embodiment of the present invention.

FIG. 4 is a side sectional view of a conventional optical element holding mechanism, in which (a) is an adhesive and (b) is a holding mechanism using a pressing plate.

[Explanation of symbols]

 11 Mirror (optical element) 12 Base member 12a Reference surface 13 Blade point screw (holding member) 13a Inclined surface 23 Wedge-shaped member (holding member) 23a Inclined surface 24 Push screw 31 Inclined surface (holding member)

Claims (3)

[Claims] 1. A base member having a reference surface that defines a mounting position of a flat optical element, and flat optical elements arranged on opposite side surfaces of the flat optical element on the base member. A holding member having an inclined surface for holding the element, wherein at least one of the holding members is movably provided. 2. The holding mechanism for an optical element according to claim 1, wherein a holding member located on the opposite side of the at least one movable holding member is provided integrally with the base member. 3. The movable holding member is a screw member having a conical tip, and the screw member is provided in the vicinity of the flat optical element so as to be movable back and forth. Optical element holding mechanism.