JP2560539B2 - Quartz thin plate twin crystal inspection system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a quartz thin plate twin crystal inspecting apparatus, and more particularly to a quartz plate appearance inspecting apparatus by image processing.

[Conventional technology]

Conventionally, in order to inspect the crystallinity, fine particles are previously sprayed on the crystal surface by compressed air to roughen the surface, and if a crystal defect is generated at this time, unevenness is generated on the surface of the crystal. Inspection method (JP-A-60-129640)
And rotate the crystal sample while irradiating the crystal with X-rays,
There is a method (Japanese Unexamined Patent Publication (Kokai) No. 58-165045) for determining the crystal orientation and the presence or absence of twins by detecting the point where line diffraction occurs.

[Problems to be Solved by the Invention]

In this conventional method, the former has a problem of giving disturbance to the crystal sample, and the latter includes things that are difficult to handle, such as an X-ray tube and an X-ray detector, and has a structure for rotating the crystal sample. There is a problem in terms of the cost of the device because the device is large.

An object of the present invention is to provide an inspection device that inputs an image of a quartz thin plate and detects the presence or absence of twins on the quartz thin plate.

[Means for solving the problem]

In order to achieve the above object, a crystal thin plate twin crystal inspecting device according to the present invention is an inspection device for inputting an image of a crystal thin plate and detecting the presence or absence of twin crystals on the crystal thin plate. The crystal thin plate is illuminated from different directions. A plurality of illuminators, a lighting switcher that switches lighting of the illuminator, an image input unit that inputs an image of an illuminated crystal thin plate in synchronization with the lighting switcher, and an image obtained from the image input unit Storage unit for storing a plurality of images, an arithmetic unit that compares the images stored in the storage unit, and outputs a difference value between the images, and a difference value output by the arithmetic unit is evaluated to determine whether a twin exists. And a determination unit that outputs

[Action]

Illuminate the crystal thin plate from different directions, input the image of the illuminated crystal thin plate, store a plurality of images, compare the stored images with each other, output the difference value, and evaluate the difference value. , Outputs the presence or absence of twins.

〔Example〕

 Next, the present invention will be described with reference to FIG.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In the figure, in the crystal thin plate twin crystal inspection apparatus of the present invention, the image of the crystal thin plate 1 is stored in the frame memories 6a, 6b, 6c, 6d. That is, the crystal thin plate 1 is a spot illuminator.
2a, 2b, 2c, 2d is transmitted illumination, spot illuminator 2a,
2b, 2c, and 2d are controlled by the lighting switching device 3 so as to sequentially light one at a time. The image of the crystal thin plate 1 is passed through the two-dimensional camera 4 and the A / D converter 5 to the frame memories 6a, 6b, 6
It is stored in c and 6d. At this time, the image illuminated by the spot illuminator 2a is the frame memory 6a, the image by the spot illuminator 2b is the frame memory 6b, the image by the spot illuminator 2c is the frame memory 6c, and the image by the spot illuminator 2d is the frame. Stored in memory 6d respectively, total 4
Image input is performed twice. Next, the presence or absence of twins is determined. That is, the maximum value detector 7 is the frame memory 6a.
Raster scans up to 6d at the same time, compares the data, and outputs the maximum value. In other words,
By means of comparing the value of a certain pixel in the frame memory 6a with the value of the corresponding pixel in the other frame memories 6b, 6c, 6d, and outputting the maximum value of the four values. is there. Similarly, the minimum value detector 8 outputs the minimum value. The differencer 9 takes the difference between the outputs of the maximum value detector 7 and the minimum value detector 8. The outputs are added and accumulated in the accumulation adder 10. Comparator 12
When the above raster scan for the frame memories 6a, 6b, 6c, 6d is completed, the comparator 12 compares the output result of the accumulation adder 10 with the reference value obtained from the reference value input terminal 11.
If the output result exceeds the reference value,
A signal indicating twin presence is output to the twin presence / absence output terminal 13. Next, the principle of twin crystal detection of a quartz thin plate will be described with reference to FIGS.

When the crystal thin plate 1 after the etching process has twin crystals, when transmitted illumination is performed obliquely from below, the lightness of the crystal thin plate 1 and the portion forming the twin crystal in the crystal thin plate 1 are different due to the difference in crystal orientation. Furthermore, this difference in brightness varies depending on the direction of illumination. FIG. 2 shows how the brightness changes in the twinned portion with respect to this illumination direction. Assuming that the illumination direction when the twin crystal part of the quartz plate 1 has the brightest brightness to the other part is 0 °, if the 45 ° direction is changed, the twin crystal part and the other part have the same intermediate brightness. , 90 °, the twinned part becomes the dark part. That is, light and dark alternate every 90 ° depending on the lighting direction. A quartz thin plate having a large difference in brightness is determined to have twin crystals.

FIG. 3 is an arrangement of the illuminator 2 around the quartz thin plate 1 viewed from above in the configuration of FIG. The direction of the illuminator 2
When four crystals are arranged at 45 ° intervals and twins are present, the phases of the bright and dark parts are covered.

FIG. 4 shows images on the frame memories 6a, 6b, 6c, 6d after the illuminators 2a, 2b are turned on one by one and are sequentially input to the four frame memories 6a to 6d.

FIG. 5 shows the maximum value detector 7 for the images 6a to 6d in FIG.
6 is an image image 15 through the minimum value detector 8 and FIG. 6 is a difference image image 16 between these two images. Focusing on this difference image, the difference value becomes large in the twinned portion, so the presence or absence of twinning is determined by evaluating this difference value. In the example of FIG. 1, the evaluation mechanism determines the presence or absence by comparing the output of the accumulator-adder 10 which is the accumulative addition result of the difference value with the reference value input from the reference value input terminal 11. .

〔The invention's effect〕

As described above, according to the present invention, the non-contact measurement is performed, the crystal sample is not disturbed, the normal visible light illumination is provided, and the special moving part is not provided. Has the advantage that the device can be handled easily.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a change in brightness depending on an illumination direction of a twin crystal portion on a quartz thin plate, and FIG. 3 is an arrangement of the quartz thin plate and an illuminator. FIG. 4 is a diagram showing a state of being viewed from above, FIG. 4 is a diagram showing an image image of a frame memory in which an image of a crystal thin plate is captured, and FIG.
FIG. 6 is a diagram showing the state after the maximum value detection process, FIG. 6 is a diagram showing the state after the minimum value detection process, and FIG. 7 is a diagram showing an image image after the difference between the images in FIGS. 5 and 6. 1 …… Crystal thin plate 2a, 2b, 2c, 2d …… Spot illuminator 3 …… Lighting switcher 4 …… Two-dimensional camera 5 …… A / D converter 6a, 6b, 6c, 6d …… Frame memory 7 ...... Maximum value detector, 8 ...... Minimum value detector 9 …… Differentiator, 10 …… Storage adder 11 …… Reference value input terminal, 12 …… Comparator 13 …… Twin crystal existence output terminal 14 …… Image image after maximum value detector 15 …… Image image after minimum value detector 16 …… Image image after difference device

Claims (1)

(57) [Claims] 1. An inspection apparatus for inputting an image of a crystal thin plate and detecting the presence or absence of twin crystals on the crystal thin plate, wherein a plurality of illuminators for illuminating the crystal thin plate from different directions and lighting of the illuminator are switched. Lighting switch, image input means for inputting an image of an illuminated quartz thin plate in synchronization with the lighting switch, storage means for storing a plurality of images obtained from the image input means, and storage in the storage means A quartz crystal comprising: an arithmetic unit that mutually compares the formed images and outputs a difference value between the images; and a determination unit that evaluates the difference value output by the arithmetic unit and outputs the presence / absence of twins. Thin plate twin crystal inspection system.