JPH06222016A - Pinhole detector - Google Patents

Abstract

PURPOSE:To provide a pinhole detector which allows detection of a micro pinhole having directivity produced in a sheet for shutter blade, for example, by single measurement without relying upon visual confirmation. CONSTITUTION:A camera 5 for imaging a pinhole is disposed in the advancing direction of light from a light source through a sheet 4 to be inspected and a rectangular prism mirror 6 having inside mirror is interposed between the sheet 4 and the camera 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pinhole detecting device for detecting minute pinholes formed on a sheet such as a shutter blade sheet.

[0002]

2. Description of the Related Art Conventionally, when detecting a pinhole in a shutter blade sheet, a pinhole detecting device as shown in FIG. 5 has been used. This pinhole detection device is provided with a light source 2 in a shielding box 1 and a glass window 3 on the surface of the shielding box 1 to which the light from the light source 2 is irradiated.

When a pinhole is detected by using this pinhole detection device, it is performed in a dark room or the like in order to make it easy to see the minute pinhole, and the sheet 4 to be inspected is brought into close contact with the glass window 3 of the shielding box 1 from the outside. , The operator visually detects pinholes from multiple directions on the outside (the side opposite to the light source).

[0004]

However, in the case of using the pinhole detecting device as described above, when the pinhole has directionality, the operator must detect from one direction in order to detect one pinhole. Since it is necessary to observe many times, the work is complicated, and because it relies on visual inspection, it is unreliable, and sometimes it was overlooked even if it was observed from multiple directions.

The present invention has been made in order to solve the above problems, and provides a pinhole detecting device capable of detecting a directional pinhole by a single measurement without relying on visual observation. It is an object.

[0006]

As shown in FIG. 1, the pinhole detecting device of the present invention has a pinhole image capturing camera 5 installed with a sheet 4 to be inspected in the direction of light from a light source. A quadrangular prism mirror 6 having a mirror inside is installed between the inspection sheet 4 and the pinhole image capturing camera 5.

[0007]

When a pinhole detecting device of the present invention is used to detect a pinhole, as shown in FIG. 1, some of the light transmitted through the pinhole goes directly to the pinhole image capturing camera 5. Some of them are reflected by the four mirrors of the quadrangular prism-shaped mirror 6 and head for the pinhole image capturing camera 5, so that images of pinholes captured from five directions in total are captured by the pinhole image capturing camera 5 at the same time. Therefore, the same observation result as when observing from five directions simultaneously is obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the pinhole detecting device of the present invention will be described below with reference to FIG.

The pinhole detecting device of this embodiment is shown in FIG.
As shown in FIG. 2, two line-shaped fiber illuminators 2a and 2a (light sources) that respectively irradiate light from two directions, and a glass window 3 provided on the surface of the line-shaped fiber illuminators 2a and 2a to which light is irradiated are provided. The dark box 7 and the glass window 3
A diffusing plate 8 provided on the side of the line-shaped fiber illuminators 2a, 2a of the sheet 4 to be inspected, which is in close contact with the outside of the inspection sheet 4, and a high-sensitivity CCD camera 5a (a camera for capturing a pinhole image) housed in the dark box 7. , High sensitivity CC in the dark box 7
It is composed of a quadrangular prism mirror 6 installed between the D camera 5a and the glass window 3 and an image measuring device 9 connected to the high sensitivity CCD camera 5a. The diffusion plate 8 also serves as a sheet retainer that retains the inspection sheet 4.

Next, the operation of the pinhole detecting device of this embodiment will be described with reference to FIGS.

Two line-shaped fiber illuminators 2a, 2
The light emitted from a is diffused by the diffusing plate 8 and passes through the pinhole of the sheet 4 to be measured, and some of them are directly reflected, and some of them are reflected by the four mirrors of the quadrangular prism-shaped mirror 6 to provide a high sensitivity CCD. It is incident on the camera 5a. The image signal from the high-sensitivity CCD camera 5a is input to the image measuring device 9 to automatically detect the pinhole.

In the image captured by the high-sensitivity CCD camera 5a, in a normal pinhole, five pinhole images are shown for one pinhole as shown in FIG. On the other hand, a part of the image is missing, and, for example, only three pinhole images are shown as shown in FIG.

[0013]

According to the pinhole detecting device of the present invention,
A pinhole image capturing camera is installed with the sheet to be inspected in the direction of the light from the light source, and a square prism mirror with a mirror inside the sheet to be inspected and the pinhole image capturing camera. Since it is a configuration that has been installed, it is possible to detect pinholes without relying on visual observation,
And since it is possible to detect a directional pinhole with one measurement, it is possible to distinguish similar noise generated by the pinhole image capturing camera from the pinhole image by capturing one frame. Pinholes can be detected easily and accurately.

[Brief description of drawings]

FIG. 1 is a principle view of a pinhole detection device of the present invention.

FIG. 2 is a schematic configuration diagram showing an embodiment of a pinhole detection device of the present invention.

FIG. 3 is a camera image of a non-directional pinhole.

FIG. 4 is a camera image of a directional pinhole.

FIG. 5 is a schematic configuration diagram of a conventional pinhole detection device.

[Explanation of symbols]

 4 Inspection sheet 5, 5a Pinhole image capturing camera 6 Square prism mirror

Claims (1)

[Claims] 1. A pinhole image capturing camera is installed with a sheet to be inspected in a direction in which light from a light source is directed, and a mirror is provided inside the sheet to be inspected and the pinhole image capturing camera. Pinhole detection device with a square prism mirror installed.