JPH085566A - Method for inspecting foreign matter or defect in optical component - Google Patents

Abstract

PURPOSE:To detect the surface, on which a foreign matter or a defect is present, among a plurality of light transmitting optical components in a short time. CONSTITUTION:A plurality of light transmitting optical components 1 to be inspected are arranged at a desired interval. The optical component 1 is illuminated from two directions by means of an illuminator 3 and two pin holes 4 or two optical fibers. The positional difference in the shadow of a foreign matter on the optical component 1 is determined on the light receiving face of an image pickup device. The surface of an optical component 1 on which the foreign matter is present is then determined based on the positional difference thus determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting foreign matters and defects existing on a plurality of optical components which transmit light.

[0002]

2. Description of the Related Art FIG. 3 is an explanatory view showing a method of inspecting foreign matters and defects of an optical component in a conventional example.

In FIG. 3, 1 is a plurality of optical components to be inspected that transmit light, 6 is a camera, and 7 is a table that can be vertically moved and positioned.

A plurality of optical components 1 to be inspected arranged at desired intervals are vertically moved by a table 7, and foreign substances 8 and defects on each surface of the optical component 1 to be inspected are sequentially detected by the camera 6.

As described above, in the above-described conventional inspection method, the foreign matter or defect on the surface of each inspected optical component 1 is sequentially detected by the camera 6, so that the foreign matter or defect exists on the surface of any inspected optical component. Can be detected.

[0006]

However, in the above-described conventional inspection method, a plurality of optical components 1 to be inspected are moved in the vertical direction by the table 7, and each optical component 1 to be inspected is moved.
Since the surfaces of (1) and (2) are sequentially detected by the camera 6, there is a problem that it takes time to detect on which surface of the optical component to be inspected the foreign matter or defect exists.

The present invention solves such a conventional problem, and it is possible to quickly determine which surface of an optical component to be inspected has a foreign matter or a defect, regardless of the number of optical components to be inspected. It is an object of the present invention to provide a method for inspecting foreign matters and defects in an optical component that can be detected by the method.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a plurality of optical components to be inspected that transmit light by illuminating them in two directions to allow foreign matter on the optical components to be inspected. The difference between the positions of the shadows of the defect and the defect is determined, and the value of the difference is used to determine which optical component to be inspected contains the foreign matter or the defect.

[0009]

Therefore, according to the present invention, a plurality of optical components to be inspected are illuminated from two directions, and the shadows of foreign matters and defects existing in the optical components to be inspected are collectively projected, so that the same foreign matter and defects are detected. By determining the difference between the positions of the two corresponding shadows and comparing the values, it is possible to determine at one time which optical component to be inspected that contains the foreign matter or defect.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

First, a first embodiment of the present invention will be described. FIG. 1 is an explanatory diagram showing a method for inspecting foreign matters and defects in an optical component according to the first embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a plurality of optical components to be inspected that transmit light, and are arranged at desired intervals. Three
Is an illuminating device that is arranged above the optical component 1 to be inspected and illuminates the optical component 1 to be inspected. 4 is 2 holes 4
Pinholes provided with a and 4b are arranged between the illumination device 3 and the optical component 1 to be inspected, and the light output from the illumination device 3 is divided into two directions to illuminate the optical component 1 to be inspected.
Reference numeral 2 denotes an image pickup device arranged on the opposite side of the illumination device 3 with respect to the optical component 1 to be inspected.

The light output from the illuminating device 3 is divided into two directions by the pinhole 4, and the plurality of optical components 1 to be inspected arranged at desired intervals in the optical axis direction are illuminated in two directions. Then, if there is a foreign substance (or defect) 8 on the surface of each optical component 1 to be inspected, the shadow thereof is collectively projected on two spaced apart positions on the light receiving surface of the imaging device 2.
At this time, since the differences a, b, and c in the positions of the two shadows of the same foreign matter 8 projected by illumination from two directions are values corresponding to the surfaces of the optical components 1 to be inspected, respectively. It is possible to determine which surface of the optical component 1 to be inspected (adhesion) the foreign matter 8 on the basis of the value.

As described above, according to the first embodiment, 2
Direction is applied to a plurality of optical components 1 to be inspected which are arranged at desired intervals in the optical axis direction, and when a foreign substance or defect is present on the surface of the optical component 1 to be inspected, the shadow thereof is projected collectively. However, by detecting at the same time, it is possible to detect in which surface of the inspected optical component 1 the foreign matter or the like exists in a short time.

Next, a second embodiment of the present invention will be described. FIG. 2 is an explanatory diagram showing a method for inspecting foreign matters and defects in an optical component according to the second embodiment of the present invention.

The feature of this embodiment is that, as shown in FIG. 2, the light output from the illuminating device 3 is guided to two optical fibers 5, and the optical component 1 to be inspected is illuminated from two directions. The other configurations and effects are similar to those of the first embodiment.

[0017]

As described above, according to the present invention, a plurality of optical components to be inspected are illuminated from two directions, and the shadows of foreign matters and defects existing in the optical components to be inspected are collectively projected.
It is possible to detect in which optical component the foreign matter or the defect exists in a short time by obtaining the difference between the positions of two corresponding shadows as the shadow of the same foreign matter or defect and comparing the values. .

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a method for inspecting foreign matters and defects in an optical component according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a method for inspecting foreign matters and defects of an optical component according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a conventional method for inspecting foreign matters and defects in optical components.

[Explanation of symbols]

 1 optical component to be inspected 2 imaging device 3 lighting device 4 pinhole 5 optical fiber 8 foreign matter

Claims (1)

[Claims] 1. A plurality of optical components to be inspected that transmit light are illuminated from two directions, the difference in the positions of the shadows of foreign matters and defects on the optical components to be inspected is determined, and the difference is used to determine the foreign matter. Method for inspecting a foreign matter and a defect of an optical component to determine which optical component to be inspected or a defect exists.