Substrate detector with light emitting and receiving elements arranged in staggered fashion and a polarization filter
US5319216A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 12, 1993 |
| Grant date | Jun 7, 1994 |
| Priority date | — |
| Expiry date | Aug 12, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S414/138
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A substrate detector device comprises a boat or chuck for holding substrates, a light emitting section having a plurality of light emitting elements, arranged side by side, for respectively applying light beams to the substrates, a light receiving section, facing the light emitting section and having a plurality of light receiving elements, for receiving light beams passed through the substrates, the light receiving elements arranged side by side so as not face the light emitting elements, a polarization filter provided on optical axes of the respective optical beams incident on the light receiving elements, a memory for storing, as reference data, an amount of light received by a receiving element which has been measured in advance when a light beam is applied to a substrate in a state where no other substrate is present on either side of the substrate, and controller for discriminating the presence, the number, and the state of arrangement of the substrates on the holding means based on the reference data and measured data based on the amount of light received by the light receiving elements after a light beam scattered by the substrate to be detected and a light beam wraparound …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.