Crystal diameter measuring device
US5240684A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1991 |
| Grant date | Aug 31, 1993 |
| Priority date | — |
| Expiry date | Jul 29, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
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…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.