JPH0734000B2 - Lighting equipment for visual inspection of glass products - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device for inspecting a glass product such as a glass bottle used for inspecting the appearance of a glass product.

[0002]

2. Description of the Related Art When performing a visual inspection of a glass bottle or the like, it is necessary to irradiate a light beam of uniform brightness from behind. Therefore, a visual inspection illumination device as shown in FIG. 2 has been conventionally used. In this device, a plurality of light sources 22 such as fluorescent lamps are attached inside a box 21 having a light diffusion plate 20 stretched on the front surface.

However, a plurality of fluorescent lamps has a drawback that the brightness changes with time due to variations in life, and that the brightness is not uniform between the upper part and the lower part of the light diffusion plate 20, for example. . Further, in this conventional device, since a considerable distance L1 is required between the light source 22 and the light diffusing plate 20, the thickness L2 of the entire device becomes large, and there is a drawback that a thin device cannot be obtained.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the prior art, and there is no change in brightness due to variations in the life of the light source, and the appearance of glass products can be made thin as a whole. This is done to provide a lighting device for a vehicle.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In the present invention, two transparent plates which totally reflect a light ray incident at a predetermined incident angle or more are erected in parallel and the inside thereof is arranged. A light source is arranged parallel to the transparent plate above, and a matte plate is arranged on the inner surface of the transparent plate on the back side, the area of which becomes larger as the distance from the light source increases, and a light diffusion plate is arranged on the outside of the transparent plate on the front side. It is characterized by that.

[0006]

The present invention will be described below in more detail with reference to the illustrated embodiments. In FIG. 1, reference numeral 1 is a vertically long box in which two transparent plates 2 are arranged in parallel at a small interval. In the embodiment, these transparent plates 2 are made of a transparent polycarbonate resin, and the back surface (outer surface) thereof is formed with fine vertical grooves 2a having a serrated shape formed of surfaces orthogonal to each other. These transparent plates 2 have a property of totally reflecting a light ray incident at a predetermined incident angle or more. In the embodiment, a light ray having an incident angle of 60 ° or more is totally reflected and a light ray having an incident angle of less than 60 ° is totally reflected. All are transparent.

A light source 3 is arranged in parallel with these transparent plates 2 above the inside of these two transparent plates 2. In the embodiment, the light source 3 is a bent single fluorescent lamp, but any light source other than the fluorescent lamp may be used as long as uniform brightness is obtained in the length direction (width direction of the transparent plate 2). can do.

Reference numeral 4 denotes a matte plate arranged on the inner surface of the transparent plate 2 on the back side. The matte plate 4 is a white plate in the shape of a chevron that spreads downward so that the area increases as the distance from the light source 3 increases. The operation will be described later. Reference numeral 5 denotes a known light diffusing plate arranged outside the transparent plate 2 on the front side, which is similar to the conventional light diffusing plate 20.

[0009]

Next, the operation of the visual inspection illumination device of the present invention will be described. First of all, among the light rays emitted from the light source 3 between the two transparent plates 2 and 2, a part of the light rays enters the transparent plate 2 at an incident angle of 60 ° or less and thus is transmitted to the back surface thereof, but most of them are transmitted. Light rays are incident on the transparent plate 2 at an incident angle of 60 ° or more, and are totally reflected on the surface of the transparent plate 2 and have fine serrated vertical grooves 2a.
Go down along the direction. However, since the matte plate 4 is arranged on the inner surface of the transparent plate 2 on the back side so that the area becomes larger as the distance from the light source 3 increases, the two transparent plates 2,
The portion of the light rays traveling downward while totally reflecting between the two portions is diffusely reflected by the matte plate 4 and enters the transparent plate 2 at an incident angle of 60 ° or more, and is transmitted to the back surface (front side). Therefore, if the upper and lower area ratios of the matte plate 4 are appropriately set in consideration of the degree of light attenuation, the amount of light transmitted to the back surface (front side) of the transparent plate 2 becomes substantially constant both up and down, and the light diffusing plate. The glass product diffused by 5 and passing in front of it is uniformly irradiated.

Therefore, according to the illuminating device for inspecting the appearance of glass products of the present invention, the light emitted from the upper light source 3 can be dispersed uniformly over the entire surface of the light diffusing plate 5, which is similar to the conventional device. In addition, there is no variation due to the difference in brightness of a plurality of light sources. Further, since the light source 3 can be a single unit, energy saving can be achieved, and the gap between the two transparent plates 2 can be narrowed, so that the entire device can be made thin.

[0011]

As described above, since the illuminating device for visual inspection of glass products according to the present invention can uniformly irradiate the whole with a single light source, there is a change in brightness due to variations in life of a plurality of light sources. In addition, there is an advantage that the entire apparatus can be made thin. Therefore, the present invention has a great contribution to the industry as solving the conventional problems.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a conventional example.

[Explanation of symbols]

 2 transparent plate 3 light source 4 matte plate 5 light diffuser plate

Claims (1)

[Claims] 1. A transparent plate on the back side, in which two transparent plates that totally reflect light rays incident at a predetermined incident angle or more are erected parallel to each other, a light source is arranged parallel to the transparent plate above and inside the transparent plate. An illuminating device for a visual inspection of a glass product, comprising a matte plate, the area of which increases as the distance from the light source increases, and a light diffusing plate is arranged outside the front transparent plate.