JPH0442742Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a light emitting/receiving section of an optical sensor that can accurately input and output light to and from a long distance with a narrow beam diameter. .

[Prior Art] Various types of light emitting/receiving parts of optical sensors have been used in the past, but there are very few that are small and have high performance without expanding the beam diameter. Further, in the case of using an optical fiber, if the relationship between the optical fiber and the lens is not accurately positioned, light loss occurs and errors are likely to intervene. Therefore, positioning requires skill and adjustment takes time.

[Purpose of the invention] The purpose of the invention is to provide a projection optical sensor that can obtain a highly accurate parallel beam of light using an elliptical lens that is said to have little optical aberration, and that also allows easy adjustment of the optical fiber and lens. The object of the present invention is to provide a light receiving section.

[Summary of the invention] The gist of the invention to achieve the above objectives is as follows:
a housing having a light-shielding property; a lens body housed within the housing and having an ellipsoidal front surface and a fiber insertion hole having an innermost portion at the focal point of the ellipsoid; This is a light emitting/receiving part of an optical sensor, characterized in that it has an optical fiber inserted through the housing, and a fixing member for fixing the optical fiber to the housing.

[Embodiments of the invention] The invention will be described in detail based on illustrated embodiments.

In FIG. 1, numeral 1 is an elliptical lens made of, for example, synthetic resin. The outer diameter of this elliptical lens 1 is, for example, about 10 mm, and its front surface is an ellipsoid 1.
A, a cylindrical portion 1b is formed at the rear end, and a fiber insertion hole 1c is provided at the center of the cylindrical portion 1b. Further, the innermost part of the insertion hole 1c is the focal point of the ellipsoidal surface 1a, and its focal length is about 15 mm. An elliptical lens 1 is housed in a substantially cylindrical housing 2 made of a light-shielding synthetic resin material and open at the front, and an optical fiber 3 is inserted from the rear end 2a. The optical fiber 3 is covered with a light-shielding coating 3a,
A core wire 3b having a diameter of approximately 0.5 or 1.0 mm is exposed at the tip thereof, and is inserted into a fiber insertion hole 1c of approximately the same diameter of the elliptical lens 1, and fixed by, for example, adhesive. A cylindrical fixing member 4 made of synthetic resin inserted into the optical fiber 3 is fitted into the rear end 2a of the housing 2. The optical fiber 3 is fixed to the housing 2 by a forced fit around the circumference. Housing 2 and fixing member 4
are locked by respective locking portions 2b and 4a, so that the fixing member 4 is not easily separated from the housing 2.

For example, when this light emitting/receiving section is used as a light emitting section, a light beam emitted from a light emitter (not shown) is transmitted to the elliptical lens 1 via the optical fiber 3. Since the leading edge of the core line 3b of the optical fiber 3 is located at the focal point of the elliptical lens 1, the light beam is projected far away from the elliptical lens 1 as a parallel beam of light.
In addition, since the elliptical lens 1 has less optical aberration than a spherical lens, it becomes an accurate parallel light beam and can project light to a far distance.

On the other hand, when used as a light receiving section, only the light from the object corresponding to the arrival position of the previous parallel beam is focused on the focal position of the elliptical lens 1, and the optical fiber 3
The light is transmitted to a photoelectric converter for light reception (not shown) via the .

Furthermore, if the other end of the optical fiber 3 is branched into two branches and connected to a light emitting body and a photoelectric converter, respectively, it is possible to have the optical fiber 3 serve both as a light emitting part and a light receiving part.

[Effect of the invention] As explained above, the light emitting and receiving part of the optical sensor according to the invention has an elliptical lens fixed in the housing,
Since the optical fiber is inserted into the fiber insertion hole of the elliptical lens, it is easy to assemble and has good performance with little optical aberration peculiar to elliptical lenses.

[Brief explanation of the drawing]

The drawings show an embodiment of the light emitting/receiving section of the optical sensor according to the present invention, and FIG. 1 is a sectional view. Reference numeral 1 is an elliptical lens, 2 is a housing, 3 is an optical fiber, and 4 is a fixing member.

Claims (1)

[Claims for Utility Model Registration] 1. A housing having a light-shielding property, and a lens body housed within the housing, the front surface of which is an ellipsoid, and a fiber insertion hole having the innermost part located at the focal point of the ellipsoid. A light emitting/receiving section of an optical sensor, comprising: an optical fiber whose tip end is inserted into the fiber insertion hole; and a fixing member for fixing the optical fiber to the housing. 2. The light emitting/receiving part of the optical sensor according to claim 1, wherein the inner diameter of the fiber insertion hole is approximately the same size as the outer diameter of the core wire of the optical fiber. 3. The light emitting/receiving part of the light emitting/receiving part of the optical sensor according to claim 1, wherein the lens body is made of synthetic resin.