Optical sensor device
US5844682A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 1995 |
| Grant date | Dec 1, 1998 |
| Priority date | — |
| Expiry date | Mar 20, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60S1/0833
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Whether or not an object is present, the surface state of the object, the material constituting the object and the presence of scattering bodies are discriminated through a simple arrangement which includes a light-emitting element for projecting light upon an object to be sensed, and a polarization beam splitter upon which light reflected from the object (or light transmitted through or scattered from the object) impinges. Reflected light from the polarization beam splitter is received by a first light-receiving element, and transmitted light from the polarization beam splitter is received by a second light-receiving element. The aforesaid discrimination is performed on the basis of the value of S/P, S-P, S-kP or (S-P)/(S+P), where S and P represent light-reception signals from the first and second light-receiving elements, and k is a constant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.