Vitreous silica crucible and distortion-measuring apparatus for the same

Patent metadata

Field	Value
Publication number	US-9816917-B2
Application number	US-201415103609-A
Country	US
Kind code	B2
Filing date	Dec 25, 2014
Priority date	Dec 28, 2013
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

In an embodiment, a distortion-measuring apparatus for measuring a distortion distribution of an entire vitreous silica crucible in a non-destructive way includes: a light source 11 ; a first polarizer 12 and a first quarter-wave plate 13 disposed between the light source 11 and an outer surface of a vitreous silica crucible wall; a camera 14 disposed inside of a vitreous silica crucible 1 ; a camera control mechanism 15 configured to control a photographing direction of the camera 14 ; a second polarizer 16 and a second quarter-wave plate 17 disposed between the camera 14 and an inner surface of the vitreous silica crucible wall. An optical axis of the second quarter-wave plate 17 inclines 90 degrees with respect to the first quarter-wave plate 13.

First claim

What is claimed is:

1. A distortion-measuring apparatus of a vitreous silica crucible, in which the crucible includes an opaque outer layer containing a plurality of bubbles and a transparent inner layer with bubbles removed, the distortion-measuring apparatus comprising:
a light source disposed outside of the vitreous silica crucible;
a first polarizer disposed between the light source and an outer surface of the vitreous silica crucible's wall;
a first quarter-wave plate disposed between the first polarizer and the outer surface of the vitreous silica crucible wall;
a camera disposed inside of the vitreous silica crucible;
a camera control mechanism configured to control a photographing direction of the camera;
a second polarizer disposed between the camera and an inner surface of the vitreous silica crucible wall; and
a second quarter-wave plate disposed between the camera and the inner surface of the vitreous silica crucible wall with an optical axis inclined 90 degrees with respect to the first quarter-wave plate;
wherein the camera conducts color photographing of light which is emitted from the light source and passes through the first polarizer, the first quarter-wave plate, the wall of the vitreous silica crucible, the second quarter-wave plate, and the second polarizer.

2. The distortion-measuring apparatus according to claim 1 , wherein the second quarter-wave plate is disposed between the second polarizer and an inner surface of the vitreous silica crucible wall.

3. The distortion-measuring apparatus according to claim 2 , wherein the first polarizer comprises: a third polarizer covering the entire vitreous silica crucible in a height direction, and a fourth polarizer covering the entire bottom of the vitreous silica crucible;
the first quarter-wave plate comprises: a third quarter-wave plate covering the entire vitreous silica crucible in a height direction, and a fourth quarter-wave plate covering the entire bottom of the vitreous silica crucible.

4. The distortion-measuring apparatus according to claim 3 , wherein the light source comprises: a plurality of first LED lights which are arranged at certain intervals along the height direction of the vitreous silica crucible and illuminate the side portion of the vitreous silica crucible; and
a plurality of second LED lights which are arranged at certain intervals along the radical direction of the vitreous silica crucible and illuminate the bottom portion of the vitreous silica crucible.

5. The distortion-measuring apparatus according to claim 2 , wherein the camera control mechanism makes the camera perform continuous photographing while making the photographing direction of the camera move in one direction along the height direction of the vitreous silica crucible.

6. The distortion-measuring apparatus according to claim 5 , wherein the camera control mechanism makes the photographing direction of the camera move along the circumferential direction of the vitreous silica crucible so as to perform photographing the entire inner circumferential surface of the vitreous silica crucible.

7. The distortion-measuring apparatus according to claim 5 , wherein the camera's position is fixed and the vitreous silica crucible is rotated so as to photograph the entire inner circumferential surface of the vitreous silica crucible.

8. The distortion-measuring apparatus according to claim 1 , wherein the second quarter-wave plate is disposed between the camera and the second polarizer.

9. The distortion-measuring apparatus according to claim 8 , wherein the first polarizer comprises: a third polarizer covering the entire vitreous silica crucible in a height direction, and a fourth polarizer covering the entire bottom of the vitreous silica crucible;
the first quarter-wave plate comprises: a third quarter-wave plate covering the entire vitreous silica crucible in a height direction, and a fourth quarter-wave plate covering the entire bottom of the vitreous silica crucible.

10. The distortion-measuring apparatus according to claim 9 , wherein the light source comprises: a plurality of first LED lights which are arranged at certain intervals along the height direction of the vitreous silica crucible and illuminate the side portion of the vitreous silica crucible; and
a plurality of second LED lights which are arranged at certain intervals along the radical direction of the vitreous silica crucible and illuminate the bottom portion of the vitreous silica crucible.

11. The distortion-measuring apparatus according to claim 8 , wherein the camera control mechanism makes the camera perform continuous photographing while making the photographing direction of the camera move in one direction along the height direction of the vitreous silica crucible.

12. The distortion-measuring apparatus according to claim 11 , wherein the camera control mechanism makes the photographing direction of the camera move along the circumferential direction of the vitreous silica crucible so as to perform photographing the entire inner circumferential surface of the vitreous silica crucible.

13. The distortion-measuring apparatus according to claim 11 , wherein the camera's position is fixed and the vitreous silica crucible is rotated so as to photograph the entire inner circumferential surface of the vitreous silica crucible.

14. The distortion-measuring apparatus according to claim 1 , wherein the first polarizer comprises: a third polarizer covering the entire vitreous silica crucible in a height direction, and a fourth polarizer covering the entire bottom of the vitreous silica crucible;
the first quarter-wave plate comprises: a third quarter-wave plate covering the entire vitreous silica crucible in a height direction, and a fourth quarter-wave plate covering the entire bottom of the vitreous silica crucible.

15. The distortion-measuring apparatus according to claim 14 , wherein the light source comprises: a plurality of first LED lights which are arranged at certain intervals along the height direction of the vitreous silica crucible and illuminate the side portion of the vitreous silica crucible; and
a plurality of second LED lights which are arranged at certain intervals along the radical direction of the vitreous silica crucible and illuminate the bottom portion of the vitreous silica crucible.

16. The distortion-measuring apparatus according to claim 1 , wherein the camera control mechanism makes the camera perform continuous photographing while making the photographing direction of the camera move in one direction along the height direction of the vitreous silica crucible.

17. The distortion-measuring apparatus according to claim 16 , wherein the camera control mechanism makes the photographing direction of the camera move along the circumferential direction of the vitreous silica crucible so as to perform photographing the entire inner circumferential surface of the vitreous silica crucible.

18. The distortion-measuring apparatus according to claim 16 , wherein the camera's position is fixed and the vitreous silica crucible is rotated so as to photograph the entire inner circumferential surface of the vitreous silica crucible.

Assignees

• Sumco Corp

Inventors

• Sudo Toshiaki
• Sato Tadahiro
• Kitahara Ken
• Kitahara Eriko

Classifications

• H04N23/60

  Control of cameras or camera modules · CPC title

• G01N21/23 Primary

  Bi-refringence · CPC title

• C30B15/10

  Crucibles or containers for supporting the melt · CPC title

• H04N5/232

  Electricity · mapped topic

• C03C3/04

  containing silica · CPC title