JPH0418186Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is an attachment for a photoelectric switch using an optical fiber, in particular, an attachment for a photoelectric switch that reflects a light beam emitted and received through the optical fiber and bends the optical path. This invention relates to a functional photoelectric switch attachment.

[Prior Art] Conventionally, an attachment shown in FIG. 4 has been provided as an example of this type of attachment for a photoelectric switch. That is, in FIG. 4, 1 is a substantially triangular prism-shaped prism, 2 is an optical fiber, and 3 is a case that houses the prism 1 and allows one end of the optical fiber 2 to be inserted therethrough. When such an attachment is used on the light projecting side, as shown by the arrow in FIG. The reflected light is projected from the window 3a of the case 3, so that the optical path of the light beam from the optical fiber 2 is bent by 90 degrees. In addition, when the above attachment is used on the light receiving side, contrary to the above, the light beam entering from the window 3a is reflected by the reflecting surface 1a, and the reflected light is transmitted to the light receiving element via the optical fiber 2. This bends the optical path of the light beam by 90°.

However, in the above configuration, since the light beam is simply bent by the prism 1, the proportion of the reflected light, which is the bent light, is increased, resulting in poor efficiency and shortening of the detection distance of the photoelectric switch. There were flaws.

[Purpose of the invention] The present invention was made in view of the above points, and its purpose is to provide an attachment for a photoelectric switch that can efficiently bend the optical path of a light beam with a simple structure with a small number of parts. There is something to do.

[Summary of the invention] The invention consists of a reflecting prism formed by cutting a part of the curved surface of a plano-convex lens at an angle of 45° with respect to the flat surface thereof, and a cut plane of the reflecting prism. an optical fiber whose tip is in contact with the optical fiber, an insertion hole through which the optical fiber is inserted, a positioning storage recess for storing and positioning the reflecting prism, and a remaining part of the curved surface of the reflecting prism are exposed. The device is characterized in that it is equipped with a case having a window portion that allows the light to be reflected, thereby suppressing the dispersion of reflected light.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

Reference numeral 11 denotes a reflecting prism, which is formed by cutting a part of the curved surface portion 11a (indicated by the two-dot chain line in FIG. 3) of a plano-convex lens so as to form an angle of 45° with respect to the flat portion 11b. Case 12
It is stored and positioned in the storage recess 12a for positioning. Reference numeral 13 denotes an optical fiber covered with a protective member 14, which is inserted into the storage recess 12a.
The insertion hole 12b of the case 12 is formed in communication with the
The reflective prism 11 is inserted through the reflective prism 11 and fixed by adhesive or the like, and is provided so that its tip is brought into contact with the cut plane 11c of the reflective prism 11. 12c is a substantially circular window formed at the upper front of the case 12;
This exposes the remaining portion of the curved surface portion 11a of the reflecting prism 11. Then, with the reflective prism 11 stored in the storage recess 12a of the case 12, the reflective prism 1
The reflecting prism 11, the case 12, and the cover 15 are integrated by fixing a substantially triangular prism-shaped cover 15 with adhesive or the like so as to cover the reflecting prism 11, the case 12, and the cover 15.

When the photoelectric switch attachment having the above configuration is used on the light emitting side, the light beam A from the optical fiber 13 enters from the cut plane 11c of the reflecting prism 11, as shown in FIG. The light is emitted and reflected by the flat portion 11b. At this time, the incident light beam A and its reflected light B are, for example, 90°
This reflected light B passes through the remaining portion of the curved surface portion 11a of the reflective prism 11 and is then projected from the window portion 12c of the case 12. Here, the curved surface portion 11 of the reflective prism 11
Since a has the effect of a convex lens, that is, a light focusing effect, the reflected light B is no longer dispersed but is focused, and unlike the conventional case, the optical fiber 13
It is possible to prevent the efficiency from deteriorating when the optical path of the incident light A is bent. Moreover, in this case,
The reflection and focusing effect of the light beam as described above can be obtained by the reflecting prism 11, and the number of parts does not increase.

Furthermore, when the reflecting prism 11 is assembled into the case 12, the storage recess 12 for positioning the case 12 is
Since the reflective prism 11 is housed and positioned within the interior a, the reflective prism 11 can be easily positioned, and the light beam from the optical fiber 13 can be accurately guided to the window 12c. Furthermore, since the reflecting prism 11 is only a part of the plano-convex lens cut out, it is made of the same material as the plano-convex lens alone. For this reason, the reflecting prism 11
Since the material is uniform, when the light beam passes through the reflecting prism 11, the light beam is not attenuated.

In the above embodiment, the cover 15 is attached to the case 12.
Although it is attached by adhesion, it may be attached by welding or integral molding instead.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, but may be applied to, for example, an attachment on the light receiving side, and may be implemented with appropriate modifications within the scope of the gist. Of course.

[Effects of the Invention] As is clear from the above description, the present invention includes a reflecting prism formed by cutting a part of the curved surface of a plano-convex lens at an angle of 45° with respect to the flat part; An optical fiber whose tip is brought into contact with the cut plane of the reflecting prism, an insertion hole through which the optical fiber is inserted, a positioning storage recess for storing and positioning the reflecting prism, and a curved surface portion of the reflecting prism. The optical path of the light beam from the optical fiber can be efficiently bent with a simple structure with a small number of parts.
In addition, the reflecting prism can be easily positioned and the light beam can be prevented from being attenuated when passing through the reflecting prism.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the present invention, with Figure 1 being a longitudinal side view, Figure 2 being an exploded perspective view of the main parts, and Figure 3 being a longitudinal side view of a reflecting prism. 4 is a diagram corresponding to FIG. 1 showing the conventional configuration. In the drawing, 11 is a reflecting prism, 11a is a curved surface part, 11b is a flat part, 11c is a cut plane, 12
is the case, 12a is the storage recess, 12b is the insertion hole,
12c is a window, and 13 is an optical fiber.

Claims (1)

[Scope of utility model registration request] A reflective prism formed by cutting a part of the curved surface of a plano-convex lens at an angle of 45° to the flat surface, and an optical fiber whose tip is in contact with the cut plane of the reflective prism. and a case having an insertion hole through which the optical fiber is inserted, a positioning storage recess for storing and positioning the reflecting prism, and a window portion exposing a remaining part of the curved surface of the reflecting prism. Attachment for photoelectric switch.