JPH048351Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an optical foreign object detection device suitable for use in detecting foreign objects on and around work tables in industrial machines such as NC equipment. .

[Conventional technology]

Conventionally, some automated devices such as NC equipment have used optical foreign object detection devices to detect foreign objects on their work tables. In recent years, as this type of foreign object detection device, foreign object detection light is created by changing the reflection direction of the light transmitted through a half mirror and irradiated by rotating a rotating mirror, and is also reflected adjacent to the surface of the foreign object detection plate. Place the surface,
A foreign object detection device has been proposed in which the foreign object detection light is reflected by the reflecting surface and guided to a detector via the mirror surfaces of the rotating mirror and the half mirror, thereby detecting foreign objects on the surface of the foreign object detection plate. There is.

[Problem that the invention attempts to solve]

However, with such foreign object detectors, when light is transmitted through the half mirror and irradiated onto the rotating mirror, the light that is refracted and reflected at the half mirror section and the light that is diffusely reflected at the rotating mirror section enters the detector as internal noise. Even though the foreign object detection light is not irradiated on the reflective surface,
In the detector, it appears as if the foreign object detection light has already been introduced via the reflective surface, and it takes time and effort to align the reflective surface.

[Means for solving problems]

The present invention was developed to solve these problems, and by disposing a light beam adjustment means between the rotating mirror and the reflecting surface, the foreign object detection light is toned into visible light. This is what I did.

[Effect]

Therefore, according to this invention, it is possible to align the reflecting surface at the time when the visible foreign object detection light is introduced into the detector.

[Example] Hereinafter, the optical foreign object detection device according to the present invention will be described in detail. FIG. 2 is a configuration diagram showing an example of the optical foreign object detection device after positioning the reflecting surface using a light beam color adjusting means (described later). In the same figure. 1 is a work table for industrial machinery such as NC equipment, 2a and 2b are light sources, 3a and 3b
5a and 5b are convex lenses that converge the light emitted from the light projection sources 2a and 2b, 4a and 4b are half mirrors that transmit the light converged by lenses 3a and 3b (hereinafter referred to as spot beams), and 5a and 5b are half mirrors 4a and 4b. rotating mirrors 6a and 6 which reflect the incident spot beam passing through 4b and convert the reflected light into a foreign object detection spot beam;
Reference numeral b indicates a pulse motor that rotates the rotary mirrors 5a and 5b to vary the irradiation direction of the foreign object detection spot beam, and reference numerals 7a and 7b indicate reflective surfaces facing each other with the work table 1 in between. The reflective surfaces 7a and 7b are composed of prisms or glass beads, and the foreign object detection spot beams reflected while rotating by the rotating mirrors 5a and 5b cross the upper surface of the work table 1 and reach the reflective surfaces 7a and 7b. It is becoming irradiated. The foreign object detection spot beams irradiated onto the reflective surfaces 7a and 7b are reflected on the reflective surfaces, guided to the mirror surfaces of the half mirrors 4a and 4b via the mirror surfaces of the rotating mirrors 5a and 5b, and reflected. The light is received by light receiving elements 9a and 9b via convex lenses 8a and 8b. That is, light projection sources 2a and 2b, convex lenses 3a and 3b, half mirrors 4a and 4b, rotating mirrors 5a and 5b, and pulse motors 6a and 6.
b. A first optical foreign object detection means and a second optical foreign object detection means are formed by a first optical system and a second optical system consisting of convex lenses 8a and 8b, light receiving elements 9a and 9b, and reflective surfaces 7a and 7b. is configured.

FIG. 3a is an external perspective view showing a first foreign object detector in which a first optical system and a reflecting surface 7b are integrated;
FIG. 3b is an external perspective view showing the second foreign object detector in which the second optical system and the reflective surface 7a are integrated. In the figure, reference numerals 10a and 11a are light projection windows for the foreign object detection spot beams emitted via rotating mirrors 5a and 5b, and a reflective surface 7b is located in the lower region of the light projection window 10a, and a reflection surface 7b is located in the upper region of the light projection window 11a. The reflective surface 7a is formed in sections. The first foreign object detector 10 and the second foreign object detector 11
and are placed opposite to each other with the work table 1 in between.

In the foreign object detection device configured in this manner, the rotational positions of the rotating mirrors 5a and 5b are set at 45 degrees (as shown) with respect to the incident spot beam, and foreign objects are detected based on this rotational position. ing. That is, when the rotational positions of the rotating mirrors 5a and 5b are in the illustrated state, the reflecting surfaces 7a and 7b are arranged so that the foreign object detection spot beams reflected by the rotating mirrors 5a and 5b are irradiated onto the end surfaces of the reflecting surfaces 7a and 7b. The positioning is done. And rotating mirror 5a
and 5b in a clockwise direction based on this rotational position, the irradiation position of the foreign object detection spot beam on the reflecting surfaces 7a and 7b moves, and when the foreign object detection spot beam is blocked,
At the light receiving elements 9a and 9b, the work table 1
The presence of foreign objects on the surface can be detected. However,
When the irradiation direction of the foreign object detection spot beam moving on the reflective surfaces 7a and 7b matches the diameter a connecting the center of the rotating mirror 5a and the center of the rotating mirror 5b, all foreign objects on the work table 1 are searched. can finish.

Incidentally, in the foreign object detection device configured as described above, the positioning of the reflective surfaces 7a and 7b is performed using a red film 12 as shown in FIG. That is, a red film 12 is disposed on the front side of the reflective surface 7a, and the foreign object detection spot beam passing through the film 12 is colored red to determine the position of the reflective surface 7a. That is, the foreign object detection spot beam introduced into the light receiving element 9a via the mirror surfaces of the rotating mirror 5a and the half mirror 4a is colored red, and the red light is introduced into the light receiving element 9a while moving the terminal surface _7a1 of the reflecting surface 7a up and down. At this point, the reflective surface 7a is accurately positioned. Incidentally, the reflective surface 7b in FIG. 2 can be accurately positioned in the same manner, but in this embodiment, the first foreign object detector 10 and the second foreign object detector 11 are made symmetrically. Therefore, if one of the reflecting surfaces is positioned, the position of the reflecting surface on the other side will be automatically determined even if the reflecting surface on the other side is not positioned. Further, whether or not red light has been introduced into the light receiving elements 9a and 9b is visually confirmed, and this visual inspection is performed by the first and second foreign object detectors 10 and 11.
This can easily be done by providing a viewing window. Furthermore, in this embodiment, the film 12 is red, but the color is not limited to red, and may be any other color as long as the passing foreign object detection spot beam can be converted into visible light. In other words, as long as it is possible to make the foreign object detection spot beam introduced into the light receiving element stand out from other colored lights acting on the surroundings of the table 1, it may be toned to other colors; It goes without saying that the means can be obtained by methods other than film.

After completing the positioning of the reflective surfaces 7a and 7b in this manner, the red film 12 serving as the light toning means is removed and the above-described search for foreign matter is performed.

Incidentally, the red film 12 is directly attached to the reflective surface 7a.
Needless to say, it is also possible to place the red filter (not shown) in front of the optical path of the light receiving elements 9a and 9b in such a state, so that only the red light is transmitted. By transmitting the light and allowing the light to be received by the light receiving elements 9a and 9b, internal noise acting on the light receiving elements 9a and 9b is removed, making it possible to accurately detect foreign objects. Moreover, by doing this, when positioning the reflecting surfaces 7a and 7b, the light receiving elements 9a and 9b can be moved without visually checking the introduction timing of the red light introduced into the light receiving elements 9a and 9b.
It becomes possible to know based on the electrical signal sent from b. In addition, in this embodiment, foreign objects are detected in the shaded area of the work table 1 (FIG. 2), but the foreign object detection range also includes the periphery of the work table 1. It goes without saying that this foreign matter detection range becomes the surface of the foreign matter detection plate.

[Effect of idea]

As explained above, according to the optical foreign object detection device according to the present invention, the foreign object detection light is colored into visible light by arranging the light beam adjustment means between the rotating mirror and the reflecting surface. , it is possible to determine the position of the reflecting surface at the time when the visible foreign object detection light is introduced into the detector, and the light that is refracted and reflected at the half mirror section and the light that is diffusely reflected at the rotating mirror section can be detected as internal noise in the detector. Even if this occurs, the reflecting surface can be positioned accurately and quickly regardless of this internal noise.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram when positioning the reflective surface in an embodiment of the optical foreign object detection device according to the present invention, and Fig. 2 shows the foreign object detection device after removing the red film after positioning the reflective surface. Configuration diagram shown, 3rd
The figure is an external perspective view showing a foreign object detector used in this foreign object detection device. 1...Work table, 2a, 2b...Light source,
4a, 4b...half mirror, 5a, 5b...rotating mirror, 6a, 6b...pulse motor, 7a,
7b... Reflective surface, 9a, 9b... Light receiving element, 1
0, 11... Foreign object detector, 12... Red film.

Claims (1)

[Scope of Claim for Utility Model Registration] A rotating mirror that reflects light transmitted through a half mirror as foreign object detection light and that changes the direction of reflection of this foreign object detection light while rotating, and adjacent to the surface of a foreign object detection plate. and a reflecting surface that reflects the foreign object detection light irradiated across the plate surface and guides it to a detector via the mirror surface of the rotating mirror and the half mirror. What is claimed is: 1. An optical foreign object detection device, comprising: a light beam toning unit disposed between the rotating mirror and the reflective surface, and adjusting the color of the foreign object detection light to make it visible light.