Crystal diameter measuring device
US5378900A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1993 |
| Grant date | Jan 3, 1995 |
| Priority date | — |
| Expiry date | Nov 29, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T117/1004
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The growing portion of a single crystal 1 grown by the pull method is recorded and the image signal is output to a digitizing circuit 3 that converts the image signal into binary data. A memory device 4 stores the digitized images and the point P at the boundary between dark and light is detected by scanning the stored digitized images starting from the scanning-start pixel and proceeding in the direction parallel to the direction of single crystal pulling. The diameter D of the growing portion of the single crystal is determined based upon the boundary P, and the scanning-start pixel for the current operation is set at the pixel that is separated from the boundary Pb in the preceding operation by a preset number of pixels d in the opposite direction of the scan.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.