The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 05, 1999
Filed:
Dec. 15, 1997
Barton V White, Vancouver, WA (US);
David J Vickrey, Vancouver, WA (US);
SEH America, Inc., Vancouver, WA (US);
Abstract
A CCD camera is used to measure the diameter of a growing crystal through optical recognition of the luminous ring at a crystal-melt interface. The result is an optical diameter control method and apparatus that eliminates the negative effects of orbit, melt-level and incorrect camera angle. The CCD camera is positioned such that it focuses on a full half of the circumference of the crystal as it is being grown. An automatic control system uses two points diametrically opposed on the crystal to measure the diameter, and a third point on the crystal closest to the camera to compute the melt level error. The automatic control system controls a crucible height and a crystal pull rate to optimize crystal diameter.