JPH02161405A - Optical device - Google Patents

Abstract

PURPOSE:To make fine adjustment of lens barrels while aligning optical axes by providing steel balls and tapered projections between the lens barrels and pressing the balls and projections by an elastic material. CONSTITUTION:The steel balls 6 are moved by the action of a coil spring 8 while the balls are held in contact with the slopes of the tapered projections 7 when the lens barrel 1 is rotated around its central axis by a rotating mechanism. The planes running the points in contact with the three steel balls 6 maintain the perpendicularity with respect to the central axis of the lens barrel 1. The two lens barrels 1, 2 are then inserted between the steel balls 6 and the tapered projections 7 and are brought into contact therewith. Both are kept pressed and mated at all times by the elastic material 8 and the steel balls 9 and the elastic material 10 are provided to circumscribe the lens barrels 1, 2. The fine adjustment of the lens barrels is possible in this way while the optical axes of the two lens barrels 1, 2 are kept aligned.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical device in which the optical axes of a plurality of lens groups are made to coincide with each other and fine movement is possible for position adjustment in the optical axis direction.

2. Description of the Related Art In recent years, optical devices of this type have been used for imaging semiconductor laser beams, connecting optical fibers, etc., and highly accurate optical axis alignment is required.

An example of the above-mentioned conventional optical device will be described below with reference to the drawings.

FIG. 5 is a sectional view of a conventional optical device, and FIG. 6 is a sectional view of a conventional optical device.
FIG. 3 is a schematic diagram of fitting of lens barrels. In FIGS. 5 and 6, 1 and 2 are lens barrels, 3 is a second lens barrel that holds the lens barrels 1 and 2, and 4 is a light source, such as a semiconductor laser or an end face of an optical fiber. . Reference numeral 5 denotes an imaging point, which is, for example, an end face of an optical waveguide or an end face of an optical fiber.

The operation of the optical device configured as described above will be described below.

First, the diverging light emitted from the light source 4 becomes parallel light by a lens in the lens barrel 1 and a fine movement mechanism (not shown) of the lens barrel 1. Next, this parallel light is refracted by the lens of the lens barrel 2 and focused on the imaging point 5. During this series of optical operations, the optical axes of the lens barrels 1 and 2, which pose a problem due to imaging aberrations, can be achieved by using a second mirror whose inner diameter matches the outer diameter of the lens barrels 1 and 2 with high precision. By holding the lens barrels 1 and 2 within the lens barrel 3, the lens barrels 1 and 2 are mechanically aligned.

Problems to be Solved by the Invention However, in the above configuration, the lens barrel 1,
Since there is always a gap between the lens barrel 2 and the second lens barrel 3, the angle θ is expressed by the formula θ = 8, where the length of the lens barrel is calculated and the gap is a, as shown in Figure 2. The optical axis is tilted. Therefore, in the conventional method, when the lens barrels are arranged side by side, there is a problem in that a tilt deviation of the optical axis on the order of θ occurs.

In view of the above-mentioned problems, the present invention provides an optical device that can finely move a plurality of lenses while aligning the optical axes of the lenses with high precision.

Means for Solving the Problems A first aspect of the present invention includes a plurality of lens groups, a first lens barrel group that holds the lens groups, and a second lens barrel group that holds the first lens barrel groups in series. a lens barrel, three steel balls of equal diameter provided on the end face of one of the two adjacent lens barrels of the first lens barrel group, and the steel balls on the other lens barrel. and an elastic body provided on the end face of the lens barrel at both ends or one end of the first lens barrel group. It is.

Moreover, the second aspect of the present invention is characterized in that the steel ball and the tapered protrusion are magnetized magnetic bodies instead of providing the elastic body in the first aspect.

Further, a third aspect of the present invention is that in the first and second aspects of the present invention, between the first lens barrel and the second lens barrel, a It is characterized by the provision of a steel ball.

Function In the first aspect of the present invention, the above-described configuration allows the first lens barrel group to contact each other at three points at the end surfaces, and due to the movement of the contact points between the steel ball and the tapered protrusion,
The lens barrels are moved slightly, and the lens barrels are pressed against each other by elastic bodies provided at the ends.

The lens barrel groups are always in contact with each other at their end surfaces, and their optical axes are aligned with the axis perpendicular to the end surfaces.

In the second aspect of the present invention, the tapered protrusions attract the steel balls to each other by magnetic force, so that they always come into contact with each other at the end surfaces of the lens barrel, and the optical axis is aligned with an axis perpendicular to the end surfaces. It happens.

In the third aspect of the present invention, by aligning the central axis of the lens barrel group with the central axis of the second lens barrel, the optical axes of the lenses coincide without angular deviation or eccentricity.

Embodiment An optical device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an optical device according to a first embodiment of the present invention. The same numbers as in FIG. 5 indicate the same items. 6
is a steel ball, and 7 is a tapered protrusion. 8 is a coil spring, which is a type of elastic body. 9 is another steel ball, and 10 is an elastic body such as a spring that presses the steel ball 9 against the lens barrel center axis.

The operation of the optical device configured as described above will be described below with reference to FIGS. 1 and 2.

First, FIG. 2 is a perspective view showing the relationship between the tapered protrusion 7 and the steel ball 6. As can be seen from the figure, the lens barrel 1 is rotated around its central axis by a rotation mechanism (not shown). Then, the steel ball 6 moves while being in contact with the slope of the tapered projection 7 due to the action of a coil spring 8 (not shown). During this operation, the plane passing through the points in contact with the three steel balls 6 remains perpendicular to the central axis of the lens barrel 1. Therefore,
In FIG. 1, the center axes of lens barrels 1 and 2 are parallel to each other, and the optical axes, which were originally made parallel to the center axes, are also parallel to each other.

Furthermore, FIG. 3 is a sectional view showing the relationship between the steel balls 9 and the lens barrel 1. As can be seen from the figure, three steel balls 9 having the same diameter and bullets 11 and 10 having the same elasticity are shown in FIG. The center axis of the lens barrel 1, which receives equal forces from the directions consisting of , becomes stable when it coincides with the center axis of the lens barrel 3. The same applies to the lens barrel 2. So two lenses! if
:Jl,2 has no eccentricity or tilt deviation and the optical axes coincide.

As described above, according to this embodiment, two lens barrels 1,
2 are brought into contact with a steel ball 6 and a tapered protrusion 7 between them, and the two are constantly pressed together by an elastic body 8, and a steel ball 9 and an elastic body 10 are placed in circumscribed contact with the lens barrels 1 and 2.
By providing this, it is possible to make the optical axes of the two lens barrels 1 and 2 coincide with each other and to move the lens barrels slightly.

A second embodiment of the present invention will be described below with reference to FIG. FIG. 4 is a sectional view of an optical device showing a second embodiment of the present invention. In this figure, the same numbers as in FIG. 1 indicate the same parts. The configuration differs from the configuration shown in FIG. 1 in that the steel ball 6 and the tapered protrusion 7 are magnetized magnetic bodies, and that the coil spring 8 is not provided. In the optical device constructed as described above, the steel ball 6 and the tapered protrusion 7 are brought into contact with each other by magnetic force, so the coil spring 8 in the first embodiment is not required. As described above, by making the steel ball 6 and the tapered protrusion 7 from a magnetic material, the same effects as in the first embodiment can be obtained without using an elastic material.

Effects of the Invention As described above, according to the first aspect of the present invention, a steel ball and a tapered protrusion are provided between the lens barrels, and by pressing these with an elastic body, the lens can be adjusted while aligning the optical axis. It is also possible to make slight movements of the lens barrel, which has great effects.

Further, according to the second aspect of the present invention, by making the steel ball and the tapered protrusion from a magnetic material, the same effect can be obtained without using an elastic material.

Further, according to the third aspect of the present invention, by providing three steel balls and an elastic body circumscribing the lens barrel, it is possible to eliminate eccentricity between the center axes of the lens barrel.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an optical device according to a first embodiment of the present invention, FIG. 2 is a perspective view showing the relationship between the tapered protrusion of FIG. 1 and a steel ball, and FIG. FIG. 4 is a sectional view of an optical device according to a second embodiment of the present invention, FIG. 5 is a sectional view of a conventional optical device,
FIG. 6 is a schematic diagram of fitting of the lens barrel. 1.2... Lens barrel (first barrel), 3...
...Second lens barrel, 6...Steel ball, 7...
... Tapered protrusion, 8 ... Coil spring (elastic body), 9 ... Steel ball, 10 ... Elastic body. Name of agent: Patent attorney Shigetaka Awano, 1 person, 6th UA, Toku q, Tobe

Claims (2)

[Claims] (1) A plurality of lens groups and a first lens group that holds the lens groups.
a second lens barrel that holds the first lens barrel group in series; 3 steel balls of equal diameter, and 3 steel balls provided in the other lens barrel so as to be in contact with the steel balls.
An optical device comprising: a tapered protrusion; and an elastic body provided on an end face of the lens barrel at both ends or one end of the first lens barrel group. (2) Instead of the elastic body, the steel balls and the tapered projections provided between the first lens barrel group are made of magnetized magnetic bodies. Optical device as described in section. (3) Three steel balls circumscribing the first lens barrel are provided between the first lens barrel and the second lens barrel. The optical device according to item 2.