JPH04184243A - Apparatus for inspecting twin crystals of thin quartz plate - Google Patents

Abstract

PURPOSE:To easily handle a crystal sample under usual illumination without imparting disturbance to the sample by inputting the images of a thin quartz plate irradiated from different directions to store several images and mutually comparing the images to evaluate the difference value thereof to output the presence of a twin crystal. CONSTITUTION:A thin quartze plate 1 is subjected to transmitted illumination by spot illuminators 2a-2d successively lighting one at a time by a lighting change-over device 3 and the images thereof are resepectively stored in frame memories 6a-6d. A max. value detector 7 subjects the memories 6a-6d to raster scanning at the same time and compares data to output the max. value. In the same way, a min. value detector 8 outputs the min. valule and a difference device 9 takes the difference between both values to accumulate the same on an accumulation adder 10. A comparator 12 compares this difference value with the reference value from a reference value input terminal 11 and, when the difference value exceeds the reference value, a signal showing a twin crystal is outputted to a twin crystal presence output terminal 13. By this constitution, the thin quartz plate can be easily handled under usual illumination.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a quartz crystal thin plate twinning inspection apparatus, and more particularly to a quartz crystal plate appearance inspection apparatus using image processing.

[Conventional technology 1 Conventionally, in order to test crystallinity, compressed air is used to spray fine particles on the surface of a crystal to roughen the surface, and if crystal defects occur at this time, the surface of the crystal becomes uneven. A method of conducting an inspection using
0) and a method of determining crystal orientation and the presence or absence of twins by rotating a crystal sample while irradiating the crystal with X-rays and detecting the point where X-ray diffraction occurs (Japanese Patent Laid-Open No. 58-16
No. 5045).

[Problems to be Solved by the Invention] In this conventional method, the former has the problem of causing disturbance to the crystal sample, and the latter has the problem that it is difficult to handle objects such as X-ray tubes and X-ray detectors. There was a problem in terms of the cost of the apparatus, which included large-scale components such as a rotating machine tank for crystal samples.

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

[Means for Solving the Problems] In order to achieve the above object, a crystal thin plate twin inspection apparatus according to the present invention is an inspection apparatus that inputs an image of a crystal thin plate and detects the presence or absence of twins on the crystal thin plate. , a plurality of illuminators that illuminate the crystal thin plate from different directions; a lighting switch that switches the lighting of the illuminators; and an image input means that inputs an image of the illuminated crystal thin plate in synchronization with the lighting switch. a storage means for storing a plurality of images obtained from the image input means; a calculation section that compares the images stored in the storage means with each other and outputs a difference value; and a difference value outputted by the calculation section. and a determination unit that evaluates the and outputs the presence or absence of twin crystals.

[Operation] Illuminates the thin crystal plate from different directions, inputs images of the illuminated thin crystal plate, stores multiple images, compares the stored images with each other, outputs the difference value, and calculates the difference value. Evaluate and output the presence or absence of twins.

[Example 1 Next, the present invention will be explained with reference to FIG.

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

In the figure, in the crystal thin plate twinning inspection apparatus of the present invention, images of the crystal thin plate l are stored in frame memories 6a, 6b, 6c.
, 6d. That is, the crystal thin plate 1 serves as spot illuminators 2a, 2b, and 2c.

2d and spot illuminator 2a.

2b, 2c, and 2d are controlled by a lighting switch 3 to turn on one at a time in order. The image of the crystal thin plate 1 is captured by a two-dimensional camera 4. The data are stored through the A/D converter 5 in frame memories 6a, 6b, 6C, and 6d. At this time, the image illuminated by the spot illuminator 2a is stored in the frame memory 6a, the image illuminated by the spot illuminator 2b is stored in the frame memory 6b, the image illuminated by the spot illuminator 2c is stored in the frame memory 6c, and the image illuminated by the spot illuminator 2d is stored in the frame memory 6a. Each image is stored in the memory 6d, and a total of four image inputs are performed. Next, the presence or absence of twins is determined. That is, the maximum value detector 7 scans the frame memories 6a to 6d at the same time, compares the data, and outputs the maximum value.

In other words, the frame memory 6a,
The value of any pixel in the other frame memories 6b, 6c
, 6d, and outputs the maximum value among the four values. Similarly, the minimum value detector 8 outputs the minimum value. Differentiator 9 is maximum value detector 7
and the output of the minimum value detector 8. The outputs are added and accumulated in an accumulation adder 10. After completing the above-described rask scan for the frame memories 6a, 6b, 6c, and 6d, the comparator 12 inputs the output result of the accumulation adder 10 and the reference value obtained from the reference value input terminal 11. If the result of the comparison exceeds the reference value, a signal indicating the presence of twins is output to the twins presence/absence output terminal 13. Next, we will discuss the principle of twin crystal detection in thin crystal plates.
This will be explained with reference to FIGS.

If twin crystals exist in the etched thin crystal plate 1, when transmitted illumination is performed obliquely from below, the brightness of the thin crystal plate 1 and the twinned portion of the thin crystal plate 1 will differ due to the difference in crystal orientation. Furthermore, this brightness difference varies depending on the direction of illumination. FIG. 2 shows how the brightness of the twin portion changes with respect to this illumination direction. If the illumination direction when the twinned part of the thin crystal plate 1 has the brightest brightness compared to other parts is Oo, then if the direction is changed by 45 degrees, the twinned part and other parts will have the same intermediate brightness, In the case of 90°, the twin part becomes a dark part. That is, brightness and darkness alternate every 90' depending on the illumination direction. A crystal thin plate with a large difference in brightness is determined to have twin crystals.

FIG. 3 shows the arrangement of the illuminators 2 around the crystal thin plate 1 in the configuration shown in FIG. 1 when viewed from above. The direction of illuminator 2 is 4
Four are arranged at 5° intervals to cover the bright and dark phases of twins, if any.

FIG. 4 shows that the lighting devices 2a and 2b are turned on one by one,
The images on the frame memories 6a, 6b, 6c, and 6d after being sequentially input to the frame memories 6a to 6d are shown.

5 is an image 14 obtained by passing the maximum value detector 7 on the images 6a to 6d in FIG. 4, FIG. 6 is an image 15 obtained by passing the minimum value detector 8, and FIG. teeth,
This is a difference image 16 between these two images. If we pay attention to this difference image, the difference value becomes large in the twin part, so by evaluating this difference value, the presence or absence of twins is determined. In the example shown in FIG. 1, the presence or absence of the evaluation mechanism is determined by comparing the output of the accumulation adder 10, which is the result of accumulation and addition of the difference values, with the reference value input from the reference value input terminal 11. . .

[Effects of the Invention] As explained above, according to the present invention, the measurement is non-contact, does not cause any disturbance to the crystal sample, uses normal visible light illumination, and has a configuration that does not have any special moving parts. This has the effect that the user can easily handle the device.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing changes in brightness depending on the illumination direction of the twin crystal portion on the thin crystal plate, and Fig. 3 is the arrangement of the thin crystal plate and the illuminator. 4 is a diagram showing an image of the frame memory that has captured the image of the crystal thin plate, 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 the image image after the difference between the images in FIGS. 5 and 6. l... Crystal thin plates 2a, 2b, 2c, 2d - Spot illuminator 3... Lighting switch 4... Two-dimensional camera 5... A/D
Converters 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 presence/absence output terminal 14... ... Image after maximum value detector Image 15 ... Image after minimum value detector 16 ... Image after subtractor Patent applicant NEC Corporation Figure 1 Figure 4

Claims (1)

[Claims] (1) An inspection device that inputs an image of a crystal thin plate and detects the presence or absence of twin crystals on the crystal thin plate, which includes a plurality of illuminators that illuminate the crystal thin plate from different directions, and a lighting switch that switches the lighting of the illuminators. an image input means for inputting an image of the illuminated crystal thin plate in synchronization with the lighting switch; a storage means for storing a plurality of images obtained from the image input means; and a plurality of images stored in the storage means. A crystal thin plate twin characterized by having a calculation unit that compares images with each other and outputs a difference value, and a determination unit that evaluates the difference value outputted by the calculation unit and outputs the presence or absence of twins. Crystal inspection equipment.