JPS60108733A - Striae detecting method of raw rock crystal - Google Patents

Abstract

PURPOSE:To improve the accuracy of striae check, by immersing a raw rock crystal having a specified surface roughness into a matching liquid, which is obtained by mixing two kinds of phenyl silicon oils having different refractive indexes and has the specified refractive indexes. CONSTITUTION:Two kinds of phenyl silicone oils having different refractive indexes are mixed, and a matching liquid 23, whose refractive index is 1.5443- 1.5534, is prepared. In a glass container 22, the liquid 23 and a raw rock crystal 24, whose maximum height of surface roughness is less than 30mum, are contianed. A lens 25 is provided at the upper part of the container 22. A point light source 26 is provided at the focal point of the lens 25 at the upper part of the lens 25. The light emitted from the light source 26 is transformed into parallel light rays by the lens 25. The light rays are projected on the raw rock crystal 24 through the liquid 23. The image of the transmitted light is displayed on an image receiving device 30 through a light receiving part 29 of an image sensor tube 28. The image sensor tube and the image receiving device having high resolution are used. Thus the accuracy in checking can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for inspecting striae of raw quartz used as an optical material.

Conventional Structure and its Problems In recent years, as the performance of optical equipment has improved, standards for optical defects inside optical materials have become stricter.

BACKGROUND ART Conventionally, as a method for detecting optical defects in optical materials, there has been a method using an inspection device for a glass piece for an image pickup tube face plate, as shown in FIG.

In FIG. 1, a test glass piece 4 and a test glass piece 4 are placed in a translucent glass container 2 placed on a table 1.
A point light source 6 is placed above the translucent glass container 2 at a distance of 8 m to 1.5 m.
is provided.

The table 1 is provided with a through hole 6, and a light receiving section 8 of an image pickup tube 7 is attached below the translucent glass container 2, and is connected to a television receiver 9. . 10.11 is a dark box 0 In the configuration above, the light emitted from the point light source 5 becomes a substantially parallel beam with a certain distance apart and is irradiated onto the test glass 4 via the liquid 3.

A transmitted light image 1 of the test glass was captured by a light receiving section 8 of an image pickup tube 7 and displayed on a television receiver 9, and striae in the test glass were detected.

However, conventional testing using this device has only been done on glass materials, and in order to apply it to quartz materials, it was necessary to develop a matching liquid suitable for the refractive index of quartz. In addition, since parallel light is obtained from a point light source, the distance from the test material to the point light source requires a long distance of 0.8772 to 1.5 m, which also poses a problem in terms of miniaturization.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned conventional drawbacks, and aims to provide a complete inspection method suitable for striae inspection of raw quartz.

Structure of the Invention In order to achieve the above-mentioned object, the method for inspecting striae of raw quartz of the present invention involves treating raw quartz having a maximum surface roughness of 30 μm or less with two types of phenyl-based silicone oils having different refractive indexes. The refractive index of the mixture is 1.5443-1.
A description of an embodiment of a method for inspecting striae in raw crystal, which is characterized in that the raw crystal is immersed in a glass container containing a matching solution of No. 5534 to detect striae inside the raw crystal. An example will be explained along with the drawings.

In FIG. 2, a glass container 22 placed on a table 21 is placed in a glass container 22 with a refractive index of 1. A matching liquid 23 of 6443 to 1.6534 is stored, a lens 26 is provided above the glass container 22, and a point light source 26 is provided above the lens 25 at the focal point of the lens 26. It is being

A through hole 27 is provided in the table 21, and a light receiving section 29 of an image pickup tube 28 is attached below the gas container 22, and is connected to a television receiver 30. 31.32 is a dark box.

With the above configuration, the light emitted from the point light source 26 is converted into parallel light by the lens 26, and is irradiated onto the crystal raw stone 24 through the matching liquid 23, and the transmitted light image of the crystal raw stone is transmitted through the image pickup tube 28. The image is captured by the light receiving unit 29 and displayed on the television receiver 30.

When detecting striae in raw crystal, the maximum roughness of the crystal surface is 30 μm or less, and the refractive index of the matching liquid is 1.5443 for the ordinary ray of the crystal and 1.5443 for the extraordinary ray. A value between 1.5534 and 1.5534 is desirable for the refractive index in order to perform accurate detection.

It is also desirable that the resolution of the image pickup tube and television receiver be 700 TV lines or more.

In the embodiments described above, a lens is inserted between the point light source and the test object, thereby making it possible to obtain a compact inspection device.

A more specific embodiment of the present invention will be described below.

The glass container was made using a pressed glass material without striae.

As a matching liquid, use phenyl silicone oil with a refractive index of 1.5160 at a volume ratio of 18.6% and a refractive index of 1.
．． A liquid with a refractive index of 1.550 was prepared by mixing 5577 phenyl silicone oil in a volume ratio of 81.6 cm. The lens used had a focal point of 28 MvI. A tungsten miniature light bulb was used as a light source. A 2/3-inch image pickup tube with a high resolution of 1,000 TV lines or more is used as an image pickup tube, and a 7.0
A resolution of 00 TV lines or higher was used.

Using an inspection device composed of the above-mentioned parts and equipment, we inspected the striae of a Y-rod crystal rough stone with a shape of 5 width 6 o WIM x length 1 x IW x 20 mW and polished the amphibious plane with +1,000 abrasive grains. An inspection was conducted.

As a result, by using the above-mentioned lens, the tungsten miniature light bulb can be made as low as 6°tMl, which is one-third the height of the conventional one, and by using the above-mentioned matching liquid, high-resolution image pickup tube, and television receiver. Conventionally, it was not possible to detect striae in rough quartz. It was possible to detect extremely thin linear striae of about 1 to 1 mm.

Effects of the Invention As described above, according to the present invention, by appropriately determining the refractive index of the matching liquid, it is possible to detect optical defects in the raw crystal with very high accuracy.

[Brief explanation of the drawing]

FIG. 1 is a hemostasis diagram showing a conventional example, and FIG. 2 is a front view for explaining a method for inspecting striae of raw crystal according to an embodiment of the present invention. 21...Table, 22...Glass container, 23...Matching liquid, 24...
Crystal raw stone, 25...Lens, 26...
Point light source, 27... Through hole, 28... Image pickup tube, 29... Light receiving section, 3o... Television receiver, 31, 32... ...Dark box.

Claims (1)

[Claims] A glass container containing a matching liquid with a refractive index of 1.5443 to 1.6634, which is prepared by blending two types of phenyl-based silicone oils with different refractive indexes from raw crystal with a maximum height of surface roughness of 30 μm or less. 1. A method for inspecting striae in raw quartz, comprising detecting striae inside the raw quartz by immersing the raw quartz in water.