JPS5933208B2 - Double image inspection method for curved plate glass - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is designed to prevent the headlights of an oncoming vehicle from appearing double through the windshield while driving a car at night, obstructing the field of vision. This relates to a method for quantitatively testing.

This kind of double image inspection is used for windshield design and safety testing. Conventionally, double image testing is performed by placing a plate glass specimen in front of a light source, as shown in the Automotive Glass Testing Method JAS07001, and having an observer visually observe the light source through the plate glass to determine the state of the double image of the light source. was observed and inspected. However, such conventional testing methods rely on visual observation, making it difficult to accurately inspect the state of multiple images. The present invention is intended to solve these drawbacks. Before explaining the method according to the present invention, the principle by which a double image appears in a curved plate glass will be explained with reference to FIG.

An internal luminous flux 2 of the light emitted from the light source 1 is refracted and transmitted by the curved plate glass 3 and enters the observer's eye 4, and the image of the light source 1 is observed as a primary image in the direction 5. In addition, the internal luminous flux 6 of the light emitted from the light source is reflected twice (back and forth) inside the curved plate glass 3, and then passes through and enters the observer's eye 4.
The next image is observed in the T direction. In this way, when an observer looks at a light source through the curved plate glass, the light source will be observed as a relatively bright primary image and a relatively dark secondary image. An example of the implementation of the inspection method according to the present invention, which uses a laser beam to accurately detect the position of a double image without relying on visual inspection, will be described with reference to FIG.

As shown in FIG. 2, the irradiation plate 8, the curved glass plate 3 to be inspected, and the laser beam generator 9 are arranged in sequence on a straight line. The laser beam generator 9 is configured to freely change the emission angle of the laser beam, and is positioned with respect to the curved glass plate 3 so that the emission position of the laser beam is at the driver's eye position with respect to the windshield. . The irradiation plate 8 is also arranged at a predetermined position with respect to the curved glass plate 3 so as to correspond to the light source position of the opposing vehicle. To inspect, first, a desired portion of the curved plate glass 3 is irradiated with a beam 10 from a laser beam generator 9.

The light beam 10 is refracted by the curved plate glass 3 and becomes a transmitted light beam 11, creating a relatively bright light spot at a point 12 on the irradiation plate 9. At the same time, it is internally reflected twice inside the curved plate glass, and then becomes a transmitted light beam 13, which forms a point 14. Create a relatively dark light spot. Next, by changing the emission angle of the laser beam, the plate glass 3 is heated without internal reflection.
Find a beam 15 oriented at an angle such that the beam transmitted through the rays reaches position 14.

Note that it is also possible to find a light beam oriented at an angle such that the light beam that has been internally reflected and transmitted through the plate glass 3 reaches the position 12 of the brighter light spot that was transmitted without being internally reflected. In this way, the angular positions of the two laser beams 10 and 15 are determined, so by knowing the difference in angle α between them,
When the light source hits the position 14, it is possible to accurately know the direction in which double images appear and the degree to which they approach each other.

Note that instead of directly detecting the emission angle position of the laser beam,
By removing the curved plate glass, the luminous flux at each emission angle position is 10,
It is also possible to determine the points 16 and 17 where the light beam 15 directly reaches the irradiation plate 8 and determine the degree of proximity of the double images from the distance between the points 16 and 17. Note that when the angle α between the two light beams is small, the distance between points 12 and 16 and the distance between points 14 and 17 are approximately equal.

Therefore, in such a case, the luminous flux 10 from the laser light source 9
passes through the plate glass 3 without internal reflection and reaches the irradiation plate 8.
By finding the distance between the point 12 where the light beam 10 reaches the point 12 and the point 14 where a part of the light beam 10 is internally reflected twice and transmitted and reaches the irradiation plate 8, the separation distance of the double image can be approximately determined. You can ask for it. Furthermore, by changing the laser emission direction, it is possible to similarly inspect other desired portions of the curved glass plate 3 for the state of double images.

As described above, according to the present invention, double images can be measured more accurately and quantitatively than the conventional automotive glass testing method using visual observation. It has the excellent effect of making it possible to easily compare the state and the state of double images of multiple curved glass sheets.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the principle in which double images appear, and FIG. 2 is a diagram showing an example of a configuration for implementing the method of the present invention. Explanation of symbols, 3... Curved plate glass, 8...
...Irradiation plate, 9...Laser beam generator.

Claims (1)

[Scope of Claims] 1. A sample plate glass is placed between a laser light source and an irradiation plate, and a point where the light beam from the laser light source passes through the plate glass without internal reflection and reaches the irradiation plate, and Find two beams of light such that a part of the separate beam of light from the light source is internally reflected twice on the plate glass and transmitted, and the point at which it reaches the irradiation plate coincides. A method of inspecting a double image of a curved glass plate by determining the distance between the points where the light beam passes through the glass plate and directly reaches the illumination plate. 2 A sample plate glass is placed between a laser light source and an irradiation plate, and the point where the light beam from the laser light source passes through the plate glass without internal reflection and reaches the irradiation plate, and the point where a part of the light beam reaches the irradiation plate. A method of inspecting a double image on a curved plate glass by determining the distance between a point that is internally reflected twice by the plate glass, transmitted, and reaches the irradiation plate.