JPH0656298B2 - Reflective pattern recognition detector - Google Patents

Description

TECHNICAL FIELD The present invention relates to a reflection pattern recognition detector using a light beam such as a laser beam. More specifically, it is composed of an upper plane portion having a light beam intake hole and facing the specimen, and two sets of plane groups in which the planes orthogonal to and facing the upper plane portion are parallel to each other and have the same size, and are adjacent to each other. The four ridge lengths that are orthogonal to each other and have the same ridge length
A photodetector layer is formed on the inner surface of each constituent surface, and a scattered light generated by applying a light beam to the sample (1) is included in the upper flat surface portion by using a reflection pattern recognition detector having an output detection means for each surface. It is characterized in that it is captured by at least three photodetectors (2).

[Conventional technology]

Conventionally, when detecting the surface of a specimen with a light beam such as a laser beam With scratches Since the unevenness of the scattered light generates scattered light different from the original smooth portion, its presence can be detected, but the pattern cannot be judged. In recent years, it has become possible to discriminate patterns to some extent by memorizing the reflected light characteristics peculiar to that pattern in advance, but this is also the case where there are other irregularities or scratches near the measurement part. He could hardly distinguish the pattern.

[Problems to be Solved by the Present Invention]

The present invention, as a result of studies to improve the drawbacks of the conventional method, scatter light generated when a light beam such as a laser beam is applied to the specimen, and the upper flat surface portion arranged at different positions with respect to the specimen. By capturing with a photodetector with at least three sides including Scratches, We have developed a device that can clearly distinguish and recognize irregularities and other fine surface roughness, color changes, steps and edges as well as smooth normal areas.

Next, the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

1 to 5 illustrate an example in which the detector according to the present invention is formed in a box-shaped body.

In this case, the detector according to the present invention is, as shown in FIG. 1, a hexahedron without a bottom surface, and a pinhole or slit (4) for passing a light beam such as a laser beam or a white light beam is provided on the upper surface (3). I can make it.

Everything except the slit (4) part of this upper surface (3) and the left and right side surfaces
The entire inner surface of each of (5), (6), the front surface (7), and the back surface (8) forms a photodetector (2) layer, and the output of the photodetector (2) on each surface is an independent amplifier. , Amplified to a desired strength, and taken out.

The photodetector (2) layer formed on each inner surface can be arbitrarily divided according to the type of specimen, and in this case as well, a unique amplifier is connected to each divided photodetector. To be done.

FIG. 2 shows the box-shaped detector shown in FIG.
1 shows an outline of a method for testing a sample (1).

First, the detector according to the present invention is placed on the specimen (1),
From the slit (4), use a light beam such as a laser beam as a sample
Scan from left to right while touching (1).

In this case, the upper surface (3) excluding the slit part, the left side surface (5),
The inner surfaces of the right side surface (6), the front surface (7) and the back surface (8) all form a single photodetector (2) layer, to which a unique amplifier (9) is connected.

As shown in Figure 2, on the surface of the specimen (1) When there is a scratch The beam striking the left side of the is reflected on the right side and is captured by the photodetector (2) layer on the right side (6) of the detector. Again just like The beam striking the right side of the mirror is reflected to the left and captured by the photodetector (2) layer on the left side (5) of the detector.

In this case, the time series distribution of the output captured by the photodetector (2) layer of the upper surface (3), the left side surface (5) and the right side surface (6) and detected by the amplifier is as shown in FIG. become.

As well The time series distribution of the output in the case of surface color change is as shown in FIGS. 4 and 5.

In this way, by analyzing the output captured in the photodetector (2) layer on each surface, it is possible to accurately recognize not only the presence or absence of an abnormality on the surface of the specimen (1) but also the pattern of the abnormality. . Further, by using an appropriate positioning device and the detector according to the present invention together, it is possible to clearly detect the abnormal pattern and its position on the specimen (1).

As illustrated in FIG. 2, the five detectors (2) constituting the detector according to the present invention are all above, front and back, left and right when viewed from the part of the specimen (1) hit by the beam. They are in different positions. Also, for example, on the right side
Even when the photodetector (2) layer of (6) consists of four photodetectors, each photodetector is on the right side when viewed from the part where the beam of the specimen (1) is hit. However, when viewed from the part where the beam of the sample (1) hits, they are located at different addresses.

Thus, the detector according to the present invention on each surface is
It is characterized in that scattered light generated by applying a light beam to (1) is captured by at least three or more photodetectors (2) including an upper flat surface portion installed at different positions with respect to the specimen (1). .

As described above, the reflection pattern recognition detector according to the present invention recognizes the presence or absence of abnormality on the surface of the sample and its pattern by capturing the scattered light generated by the sample with the photodetector layer and analyzing the output. However, it is possible to respond to the recognition of a more complicated abnormal pattern of a sample and the demand for more accurate analysis by dividing or subdividing the photodetector layer according to the demand.

The light beam used in the detector according to the present invention may be a white light beam in addition to the laser beam, and a laser diode, a helium-neon laser, an argon laser or the like is suitable as the laser. Further, as a photo detector, a photo diode or a glass fiber array is preferable.

[Brief description of drawings]

FIG. 1 is a schematic view of a case in which the detector according to the present invention is formed as a box-shaped body, and FIG. 2 is a partial cross-sectional schematic view showing the usage state of the detector shown in FIG. 1, FIG. 3, and FIG. FIG. 5 and FIG. 5 show the time series distribution of the output of each photo detector in each abnormal pattern. In the figure, (1) shows a specimen, (2) shows a photodetector, and (9) shows an amplifier.

Claims (1)

[Claims] 1. An upper plane portion having a light beam intake hole and facing a specimen, and two sets of plane groups in which planes orthogonal to the upper plane portion and facing each other are parallel to each other and have the same size, Adjacent planes are orthogonal to each other and are composed of four side surfaces having equal ridge lengths, and a photodetector layer for capturing scattered light from the specimen surface is formed on the inner surface of each constituent surface and an output detection means for each surface. A reflection pattern recognition detector characterized by having.