JPS5913721B2 - ball lens optics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in a ball lens optical system.

A conventional combination lens used as a ball lens optical system is constructed by gluing a convex lens 1, a concave lens 2, and a convex lens 3 as shown in FIG. In addition, it takes a lot of time and effort to actually align the optical axis through the light beam, and each lens requires polishing to achieve surface precision, making it expensive, especially for optical fiber optic semiconductor devices. A small combination lens used in combination with J lenses has the disadvantage that the radius of curvature of each J lens becomes extremely small, making polishing impossible.

As shown in FIG. 2, another example of use in optical fibers, etc. is a rod lens 4 which has a large refractive index at the center and decreases in a parabolic manner toward the periphery. However, in this case as well, it is not only difficult to control the manufacturing accuracy of the refractive index distribution of the rod lens, but also to actually pass the light beam through the rod lens and its length L.
It is necessary to cut with high precision, which also requires a great deal of time and effort, and increases production costs.

″0 The present invention is intended to solve these problems, and aims to provide a ball lens optical system that can be mass-produced, has high precision, and is easy to align the optical axis. .

Hereinafter, five embodiments of the present invention will be described with reference to FIGS. 3 to 11.

In FIG. 3, 10 is a sphere made of an optical material such as glass, rutile, ruby, etc., and 11 and 12 are cylindrical outer enclosures made of an optical material such as glass or acrylic that surround the sphere 10. The sphere 10 is inserted into a two-split mold (not shown) that forms a cylindrical groove with the same diameter as , and an optical material such as glass or acrylic is press-fitted from both sides of the groove to form the outer parts 11 and 12. A sphere 10 forming a convex lens
, a ball lens 5 optical system consisting of the outer parts 11 and 12 forming a concave lens can be obtained.

Furthermore, when combined with an optical fiber, etc., the ball lens optical system configured as described above can be polished with a centerless grinder to form a ball lens optical system with a desired small diameter as shown in FIG. Fukiru.

The ball lens optical system configured as described above can be configured such that, for example, by changing the diameter of the sphere 10 or the relative refractive index of the sphere 10 and the surrounding parts 11 and 12, as shown in FIG.
As shown in Figure 6, we can obtain the output light of parallel luminous flux, and as shown in Figure T, we can obtain the output light of θ<θ'
output light can be obtained.

FIG. 8 shows another embodiment of the present invention using three spheres, and the spheres 13, 14, 15 are wrapped in cylindrical outer enclosures 16, 17, 18, 19 in the same manner as in the previous embodiment. A lens optical system is formed, and FIG. 9 shows this by centerless polishing to form a small-diameter spherical lens optical system. FIG. 10 shows still another embodiment of the present invention, which includes a spherical lens optical system in which a spherical body 20 is surrounded by outer enclosures 21 and 22, and a spherical lens having a different diameter from the spherical body 20, as in the previous embodiment. A ball lens optical system in which a sphere 23 is wrapped in outer parts 24 and 25 are placed in V grooves at different angles and glued together with their optical axes aligned. The ball lens optical system is polished separately to the same diameter by centerless polishing, placed in a V-groove to align the optical axis, and then glued together.If the outer diameters are unified in this way, the optical axis can be aligned mechanically using the V-groove. Since it is easy to perform and can be arranged in-line, it is easy to combine it with optical fibers, optical semiconductor devices, etc.

Since the present invention is configured as described above, it is possible to accurately make a sphere even if the sphere has a very small diameter of several microns to about 500 microns, and it is possible to form a sphere into a cylindrical shape. A concave lens can be easily made by wrapping it in an outer envelope, and by changing the spacing between the spheres and the refractive index of the material, an effect equivalent to a combination of convex and concave lenses can be obtained, and the optical axis of the lens can be changed. Positioning is simplified, the required diameter can be achieved by centerless polishing, mass production is possible, and a ball lens optical system with a high degree of i can be obtained.

[Brief explanation of the drawing]

Figure 1 is a front view of a conventional combination lens, Figure 2 is an explanatory diagram of a conventional rod lens, Figure 3 is a front view of an embodiment of this invention, and Figure 4 is a smaller diameter version of the lens shown in Figure 3. 5, 6, and 7 are illustrations of light flux in the ball lens optical system of the present invention, and FIGS. FIG. 3 is a front view of the embodiment.

Claims (1)

[Claims] 1. A spherical lens optical system comprising a sphere made of an optical material surrounded by a cylindrical envelope made of an optical material.