JPH01305343A - Nondestructive inspection apparatus for translucent substance - Google Patents

Abstract

PURPOSE:To enable prevention of the effect of a direct light from a light source and a reflected light on detection of an extraneous substance by disposing the light source, an inspection object and a one-dimensional CCD camera so that only light scattered inside and radiated outside the inspection object can be sensed and read. CONSTITUTION:A light emitted from a light emission element 2a of a line-shaped light source 2 is parted into three regions: a transmitted light region (a) wherein the light is transmitted through an inspection object 1 within an emission angle thereof; a scattered light region (b) wherein a scattered light reflected diffusedly in the inspection object 1, out of the emission light projected into the inspection object 1, is radiated outside the region (a) and a reflected light region (c) wherein only a reflected light reflected on the surface of the inspection object 1 is radiated. A one-dimensional CCD camera 4 is disposed obliquely to a line connecting the optical axis of the light source 2 and the axis of the inspection object 1 so that the light in the region (a) of the light source 2 may not be sensed. By checking the lights of high luminance of the light source 2 radiated in the regions (a) and (c) and the reflected light of relatively high luminance from the surface of the inspection object 1 in this way, undetectable matters of an internal structure of the inspection object 1 are removed and accurate detection thereof is enabled.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a non-destructive inspection device for semi-transparent bodies with low light transmittance. This filter alloy is related to a non-destructive measuring device for determining the internal structure of translucent resin plates, etc.

L. Prior Art] Conventionally, this has been carried out using a device that inspects semi-transparent bodies with very low light transmittance.

This device includes, for example, a line light source 2, as shown in FIG.
A transparent inspected object, 1a, and a one-dimensional COD camera 4 are arranged on the same optical axis, and the one-dimensional COD camera 4 reads the amount of light transmitted from the linear light source 2 through the inspected object, and a COD output signal is obtained. The image processing circuit 5 performs A/D conversion to obtain a binary digital signal, and inputs this digital signal to a computer 6 for data processing of the density, size, and number of foreign particles.

[Problem to be solved by the invention]

However, when using a semi-transparent body as an object to be inspected using the above-mentioned conventional internal inspection apparatus for a transparent object and attempting to detect, for example, foreign matter mixed into the object, there are the following difficulties.

In other words, when inspecting the internal structure of a semi-transparent body with very low light transparency using this transparent body inspection device, a linear light source with sufficient brightness to transmit the light through the semi-transparent object to be inspected is required. When the field of view of the one-dimensional CCD camera that receives transmitted light extends to an area without the edge of the inspection object, the high-intensity light that exceeds the sensitivity of the COD sensor in the one-dimensional CCD camera and saturates the one-dimensional Enter the CCD camera,
There was a problem in that it was impossible to detect the end of the object to be inspected and the internal structure of the object at the end. In addition, as a means to avoid this problem, there are other problems such as difficulty in accurately maintaining the positional accuracy between the one-dimensional CCD camera and the object to be inspected, and poor inspection accuracy and efficiency.

[Means to solve the problem]

Therefore, the present inventor has developed a non-destructive inspection device for semi-transparent objects that does not have the above-mentioned difficulties (as a result of intensive study, the present invention has been completed, and its gist is that it uses a linear light source and , the object to be inspected is held at a position K such that the light emission angle from the light emitting end of the linear light source falls within the cross section of the object to be inspected, and the axis of the object to be inspected approximately coincides with the axis of the two-in-line light source. and non-destructive inspection equipment for semi-transparent objects that reflect diffusely within the object to be inspected without receiving light within the angle of incidence of the incident light from a line-shaped light source projected into the object to be inspected. be.

〔Example〕

FIG. 1 shows an example of the configuration of the semitransparent body inspection apparatus of the present invention.

In the figure, the object 1 to be inspected is positioned in such a way that the emission angle of the linear light emitted from the light emitting part 26 of a linear light source 2, such as a fluorescent lamp or a fiber optic line light, passes through the cross section of the object to be inspected. Arrange. Reference numeral 3 denotes a table for placing an object to be inspected, which is made of a transparent body when the apparatus is arranged in the positional relationship shown in FIG. In the apparatus of the present invention for inspecting the internal structure of an object to be inspected with low light transmittance, it is preferable that the linear light source 2 has a sufficiently high illuminance at the light emitting section 26. The light emitted from the light emitting part 26 of the linear light source 2 is divided into a transmitted light area a that is transmitted within the inspection object 1 within the emission angle of the light of the linear light source, and an output area that is projected into the inspection object 1. Among the emitted light, scattered light that is diffusely reflected within the inspection object 1 is emitted to the outside of the transmitted light area a, and the light emitted from the linear light source is reflected on the inspection object surface, and only the reflected light is generated. It is divided into three regions: a reflected light region C where the light is emitted.

4 is a one-dimensional CCD camera that inspects the internal structure of the inspection object 1, and the field of view of the one-dimensional CCD camera 4 is the scattered light area where only scattered light is emitted in the aforementioned areas a, b, and e. Arrange. That is, as shown in the figure, a linear light source 2
One-dimensional C
Place the CD camera 4. By arranging the one-dimensional CCD camera as described above, the high-intensity light from the linear light source emitted within the transmitted light area a will not directly enter the COD camera, and the COD output will be saturated and the inside of the object to be inspected will be saturated. This eliminates the inconvenience of not being able to detect the structure at all, and also prevents the relatively high-intensity reflection light emitted within the reflected light area C from entering the COD camera from entering the COD camera. It is possible to accurately detect the internal structure of The CCD output signal read inside the inspection object 1 by the one-dimensional CCD camera 4 is input to the image processing circuit 5, A/D converted, and then binarized to obtain a digital signal that detects the internal structure. The signal is input to the computer 6 and the concentration of foreign matter contained in the test object 1 is determined.
Perform data processing to find the size, number, etc.

Line light sources are, for example, high-output fluorescent lamps or light sources in which one end of multiple optical fibers is lined up in a line to form a light output end, and the other end is converged to form a high-brightness light source. Although there are fiber line lights and the like, it is preferable to use an optical fiber line light as the linear light source because the light emitted from the linear light source serves as a cold light source. Figure 2 shows the light output end face 21 of the optical fibers arranged in an in-shape used in the present invention, the length of which is 160tz, and the optical fibers of 0.5nφ are
Arranged in columns. The light is shining. 22 is the line part base of the optical fiber line light, 24 is the point part base, 25
is the end face of the point optical fiber. The light source is disposed to face the point base 24 of the line light, and the light source emits light from the end face 21 of the optical fibers arranged in the line direction in a range of 60° around the optical fiber axis. In addition,
As mentioned above, the illuminance at the line end face 21 of the optical fiber line light 2 is such that the light transmission efficiency is 0.0 as the object to be inspected.
When inspecting the internal structure of a 1% translucent body, such as a cigarette filter, using the apparatus of the present invention, it is preferable that the illuminance be 300,000 lx or more. The brightness can be ensured by using a halogen lamp.

As an example of an inspection using the non-destructive inspection device of the present invention, a two-piece cigarette filter is constructed by combining a filter part made of acetate fiber bundles mixed with activated carbon powder, which is the internal structure of a cigarette filter, and acetate fibers containing no activated carbon powder. An example of inspecting the array structure of is explained below.

When attaching a cigarette cylinder to a cigarette cylinder, cut the central part 14 of the acetate filter part containing activated carbon powder for two cigarettes of the cigarette filter shown in FIG. This is a cigarette filter in which an acetate filter part 12 mixed with activated carbon powder for one cigarette is joined. After joining a tobacco cylinder to the filter parts made of acetate fiber bundles mixed with activated carbon powder, which are both ends of the thus obtained cigarette filter, a filter part 1 made of only acetate fiber bundles is attached.
Two filtered cigarettes are obtained by cutting from the center of 3. Therefore, a filter part 12 made of an acetate fiber bundle mixed with activated carbon powder having an exact length equivalent to one cigarette was joined to both ends of the cigarette filter for making six filter-equipped cigarettes, which was used for inspection. Inside there are 2 each
Activated carbon powder-free filter section 13 corresponding to the length of the main part
An examination was conducted to determine whether or not three filters and two activated carbon-containing filter sections 14 were arranged alternately.

Among the cigarette filters shown in Fig. 3, the light transmittance of the filter part made only of acetate fiber bundles is about 0.01%, and the light transmission of Togyomosaki in the filter part made of acetate fiber bundles mixed with activated carbon powder. The rate is extremely low (because it is close to an opaque body, the emission of scattered light from the light projected onto the filter section is also extremely low).

Fig. 4 shows a line-shaped light source using the above-mentioned cigarette filter as shown in Fig. 1.
If the fiber optic line light is 1x, the one-dimensional CO
As a D camera, the number of COD elements is 4096 elements, the scanning period is set to 50th Bcc, and the lens is set to 50th Bcc.
A 3D macro lens was used, the aperture was set to F = 5.6, and an 8-bit A/D converter was used for the image processing circuit.

In FIG. 4, (A) is a pattern when only the scattered light emitted from the cigarette filter is observed with a COD camera. (B) shows C obtained by reading one line in the direction of the arrow in the pattern of (A) with a one-dimensional COD camera.
It is OD multivalued data, and the horizontal axis is addressed to the CCD element, from 1 to
The range of 4096 elements is shown, and the vertical axis shows the COD output, which ranges from 0 to 255 since an 8-bit A/D converter is used. From (B),
Acetate fiber bundle parts 12 and 1 mixed with activated carbon powder
It can be seen that Fiber East No. 4 and Fiber East No. 13 in which activated carbon is not mixed can be clearly distinguished.

(C) shows the CCD binary data, and the CO at the changing point
The detection start part of the filter part 12 made of acetate fiber bundles mixed with activated carbon from the D element, the boundaries between the activated carbon mixed filter parts 12 and 14 and the filter part 13 made of fiber bundles without activated carbon mixed in are clearly defined. Since this can be determined, it becomes possible to measure the internal structure of the cigarette filter in a non-destructive state.

〔Effect of the invention〕

The semitransparent inspection device of the present invention can be used to accurately inspect the internal structure of a semitransparent inspection object, such as a cigarette filter, in a non-destructive state for defects, presence of foreign objects, etc. .

The apparatus of the present invention is equipped with a linear light source, an object to be inspected, and a one-dimensional CCD camera so that the one-dimensional CCD camera can receive and read only the scattered light scattered inside the object and emitted outside the object. It has the effect that the direct light from the object and the light reflected on the surface of the object to be inspected enter the one-dimensional CCD camera and do not affect the detection of foreign objects inside the object to be inspected, making it extremely useful for inspecting semi-transparent objects. It is valid.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the configuration of an inspection apparatus according to the present invention, a diagram for explaining the image processing contents of the conventional inspection apparatus, and FIG. 5 is a configuration diagram of a conventional inspection apparatus. 1...Test object 12.14...Fiber bundle 13 mixed with activated carbon...
- Fiber bundle 2 in which activated carbon is not mixed...Optical fiber line light 21...Line part optical fiber end face 22...Line part base 23...Optical fiber 24...Point part base 25... Point optical fiber end face 3...Table 5...Image processing content 6...Computer patent applicant Mitsubishi Rayon Co., Ltd. f Figure 2 Figure 3 (A) ・ ・・・ Building structure → CCD Nadeshiko No. . Graduation 4 Illustration rate 5 Illustration

Claims (1)

[Claims] A linear light source and the object to be inspected are placed in a position where the light emission angle from the light emitting end of the linear light source is within the cross section of the object to be inspected, and the axis of the object to be inspected almost coincides with the axis of the linear light source. Only the scattered light that is diffusely reflected within the inspected object and emitted outside the inspected object, without receiving the light within the incident angle of the incident light from the linear light source projected into the inspected object. A one-dimensional CCD camera is installed at a position where it can receive the CCD
A non-destructive inspection device for semi-transparent objects, characterized in that it is equipped with means for analyzing signals from a camera.