Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Production apparatus and method of fluoride crystal, and crucible

Inactive Publication Date: 2004-07-01
CANON KK
View PDF10 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The impurities deteriorate the optical characteristics of the final crystal, and generate the irregularity among the optical parts.
Furthermore, due to the necessity of the pulverizing process, the productivity becomes poor.
Moreover, a problem is involved in that a minute amount of impurities included at the time of the pulverization deteriorates the transmissivity of the crystal.
If the temperature is close to the melting point, it takes a long time to completely melt the material so that the productivity cannot be improved.
On the other hand, with a temperature higher than 1450.degree. C., the fluoride material can be evaporated drastically so that the decline of the productivity by the material loss cannot be avoided.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Production apparatus and method of fluoride crystal, and crucible
  • Production apparatus and method of fluoride crystal, and crucible
  • Production apparatus and method of fluoride crystal, and crucible

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0101] In this example, a calcium fluoride crystal was produced according to a procedure shown in FIG. 6. Hereinafter each process will be explained.

[0102] (Prescription, Mixing Process)

[0103] A powdery calcium fluoride material was placed in a container. 0.08 mol % of a scavenger (ZnF.sub.2) was measured based on the material, and added to the container with the material. The container used has a capacity about double as much as the volume of the material. The material and the scavenger were mixed by rotating the container for about 1 hour.

[0104] (Refining Process)

[0105] The material was refined with a refining furnace shown in FIG. 2.

[0106] A multi-stage crucible shown in FIG. 1A with three stages was used.

[0107] After filling the prepared material in each stage of the crucible, the crucible was set in the refining furnace. By vacuum-exhausting the inside of the chamber 201, the moisture in the material 205 was eliminated.

[0108] While maintaining the vacuum degree at 5.times.10.su...

example 2

[0123] In this embodiment, a fluoride crystal was produced in the process the same as Example 1 except that the crucible shown in FIG. 1B was used instead of the crucible of the refining furnace of Example 1. The degassing holes with a 3 mm diameter were provided at 8 positions symmetrically.

example 3

[0124] In this embodiment, a fluoride crystal was produced in the process the same as Example 1 except that the multi-stage crucible with the configuration of FIG. 4B was used as the growth furnace crucible.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

An object of the present invention is to provide a production apparatus and method of a fluoride crystal, and a crucible for the growth capable of efficiently eliminating impurities and a scavenger remained in the crystal so as to produce a fluoride crystal with a high transmissivity. A crucible divided into a plurality to have multi-stages is used for refining a material in the material refining process by adding a scavenger in the material. Further, a degassing hole was provided to the side wall portion of the crucible. A crucible of the present invention has at least two degassing holes at the side wall portion. Further, a crucible of the present invention has a connecting hole at the center part of the bottom face with at least two degassing holes in the side wall portion.

Description

[0001] 1. Field of the Invention[0002] The present invention relates to a production apparatus of a fluoride crystal preferable for various kinds of optical elements, lens, window materials, prisms, and the like to be used in a wide wavelength range from a vacuum ultraviolet region to a far infrared region, in particular, to a production apparatus of a fluoride crystal to be used for an optical material such as a large aperture lens (aperture of 250 mm or more) for an excimer laser.[0003] 2.Description of the Related Art[0004] An excimer laser attracts attention as the only one high output laser to oscillate outside an ultraviolet region so that the application thereof is expected in the electronic industry, chemical industry, and energy industry.[0005] Specifically, the excimer laser is used in processing metal, resin, glass, ceramics and semiconductors, and a chemical reaction.[0006] An apparatus for generating an excimer laser beam is known as an excimer laser oscillating apparat...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C30B11/00C30B29/12G02B1/02
CPCC30B11/00C30B11/002Y10T117/1092Y10T117/10Y10T117/1016C30B29/12
Inventor ICHIZAKI, TOSHIO
Owner CANON KK
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com