JPS6029057B2 - Reflection inspection device for three-sided mirror reflector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reflection inspection device for a three-sided mirror reflector.

For example, as a tail reflector for a bicycle, etc., a type in which a large number of three-sided mirror-type reflective elements are arranged is often used, which is composed of three reflective surfaces, two of which intersect with each other at the same angle.

In this type of reflector, if two of the three reflective surfaces of each reflective element are orthogonal to each other, the reflected light east is directed in the same direction as the projected light east, and the two reflective surfaces intersect. If the angle is different from a right angle, the direction of the reflected light east makes an angle with the direction of the incident beam. For such reflectors, when inspecting the reflection angle of the product itself or the mold used for manufacturing it, the reflection characteristics such as surface sag, reduction, dust, dirt, etc., conventionally, a position sufficiently far away from the object to be inspected was used. For example, the object to be examined is illuminated and observed from a position about 30 degrees away. Such conventional testing methods require space and are inconvenient in that quantitative and qualitative measurements cannot be made. An object of the present invention is to eliminate the above-mentioned drawbacks of conventional inspection methods, and to provide a reflection inspection device that does not require a large space, is capable of quantitative and qualitative measurements, and is easy to operate. .

That is, the reflection inspection apparatus of the present invention applies parallel light to the reflector to be inspected, focuses the reflected light by a projection lens, and arranges a spatial filter such as a pinhole at the focal point of the projection lens. , which is basically based on observing the light that has passed through the spatial filter.

In the case of a reflector in which two of the two reflecting surfaces in the reflecting element are arranged so that they are perpendicular to each other, the reflected light east perfectly matches the direction of the incident light flux, so the spatial filter is It may be configured by a pinhole placed on the optical axis, and by appropriately selecting the size of the pinhole, the allowable range of error in the reflection angle can be set. In addition, if two of the three reflecting surfaces of the reflector are not orthogonal to each other, the reflected light east forms images at six point symmetrical positions centering on the optical axis at the focal position of the projection lens. So,
The spatial filter may have a structure having pinholes at six positions. The three reflective surfaces in each reflective element can be thought of as being placed on each side of a virtual triangular pyramid, and as a reflector, the axis of this virtual triangular pyramid is placed at right angles to the plane of the reflector. There are two types: the normal type and the so-called wide type, in which all or part of the reflector's koji core is arranged at an angle.When inspecting the latter wide type, the reflector is tilted so that the axis center is the incident optical axis. You can check it so that it matches. The apparatus of the present invention can be used not only to inspect the product itself, that is, the reflector, but also to inspect the mold for manufacturing the reflector. Hereinafter, one embodiment of the present invention will be explained with reference to the drawings. Reference numeral 1 denotes a reflector to be tested, and a reflecting element la is formed on one side by three reflecting surfaces, two of which are orthogonal or almost orthogonal to each other. Many are formed.

A projection lens 2 is arranged facing the reflector 1 to be tested, and a spatial filter 3 is arranged at the total point position of this projection lens 2. In this example, the spatial filter 3 has a pinhole 3a located on the optical axis of the projection lens 2.
A half mirror 4 is arranged between the reflector 1 to be tested and the projection lens 2 at an angle of 45° to the optical axis, and a lens 5 and a laser generator 6 are placed on the reflection optical axis of the half mirror 4.
is located.

Further, a second projection lens 7 is placed behind the spatial filter 3 so that the spatial filter is at the front focal position, and a television camera 8 is placed so as to receive the light passing through this lens 7. Reference numeral 9 denotes a monitor TV that displays the received light based on the signal from the TV camera 8.

When a coherent laser beam is projected from the laser generator 6, the laser beam is turned into parallel light by the lens 5, and is directed toward the reflector 1 to be tested by the half mirror 4.

The light reflected by the test reflector 1 passes through the half mirror 4 and is focused by the lens 2 onto the spatial filter 3 . The difference in the angle of reflection of the incident light with respect to the angle of incidence appears as a lateral deviation of the imaging point from the optical axis. It is possible to block light that has a shift. The light that has passed through the pinhole 3a becomes parallel light again by the lens 7, and projects a reflected image of the reflector 1 on the image receiving surface of the television camera 8. Of course, it is also possible to project the light transmitted through the lens 7 onto a screen and observe it. When the reflection element la of the test reflector 1 is composed of three reflection surfaces that are not orthogonal to each other, the direction of incidence and the direction of reflection do not match, but in this case, a predetermined amount of deviation from the optical axis is applied. A spatial filter having six pinholes arranged point-symmetrically may be used. In addition, in the case of a wide type in which all or part of the reflecting element is arranged with its axis inclined with respect to the plane of the reflector, the axis of the reflecting element is aligned with the direction of the incident light. If the TV camera's image-receiving surface or screen is similarly installed at an angle to the optical axis and measurements are taken, the incident area and effective reflection area will match. Can be done. The device of the present invention can inspect the entire surface of the reflector for defects such as differences in reflection angles, sagging surfaces, curls, dust, dirt, etc. at once, and by selecting the dimensions of the spatial filter, it is possible to The allowable range can be arbitrarily determined.

Furthermore, it has many advantages over conventional measuring methods, such as not requiring much space and being easy to handle.

[Brief explanation of the drawing]

The drawing is a schematic diagram showing an example of the optical system of the reflection inspection apparatus of the present invention. 1...Test reflector, 2, 7...Projection lens, 3...Spatial filter, 4...Half mirror, 6...Laser generator , 8...TV camera, 9...Monitor TV.

Claims (1)

[Scope of Claims] 1. A means for projecting a parallel light beam onto a test reflector; and a first means for projecting a parallel light beam onto a test reflector; a projection lens means, a spatial filter provided at a rear focal position of the first projection lens means, and an image of the reflector to be tested is formed by a light flux transmitted through the spatial filter, the spatial filter being arranged at a front focal position. A reflection inspection device for a three-sided mirror reflector comprising a second projection lens for 2. In the above item 1, the parallel light beam projection means is arranged on an oblique half mirror provided between the test reflector and the first projection lens means, and on a reflection optical axis of the oblique half mirror. A reflection inspection device comprising a light source. 3. The reflection inspection device according to item 2, wherein the light source is a laser light source.