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:
Aug. 31, 1993
Filed:
Jul. 29, 1991
Masahiko Baba, Annaka, JP;
Hiroyuki Ibe, Hukui, JP;
Shin-Etsu Handotai Company, Limited, Tokyo, JP;
Abstract
A device for measuring the diameter of the growing portions of the single crystals grown by the Czochralski technique is provided. This device is capable of measuring the crystal diameter with a high degree of accuracy over a wide range from the small-diameter portion thereof to the large diameter portion. A one-dimensional camera 28 and a two-dimensional camera 48 are fixed to a shoulder chamber 34 in such a manner that the optical axes thereof are parallel to each other. An optical path switch-over device, consisting of a cylinder 56, a movable plane mirror 52 mounted on a cylinder rod, and a fixed plane mirror 54, is provided. When the diameter of a neck portion of the single crystal 20 having a diameter of 10 mm or less is measured, the light reflected by the plane mirrors 52 and 54 is made incident on the two-dimensional camera 48, and the diameter of a bright ring 27 is measured on the basis of the image obtained by the two-dimensional camera. To measure the diameter of the conical and cylindrical portions 24 and 26 having a diameter of 10 mm or more, an image of a line lying across the bright ring 27 is obtained by the one-dimensional camera 28 by retracting the plane mirror 52, and the diameter of the bright ring 27 is measured.