Sensor for articles such as wafers on end effector
US5539323A · kind A · utility
128Cited by
16References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 7, 1993 |
| Grant date | Jul 23, 1996 |
| Priority date | — |
| Expiry date | May 7, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V9/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The presence of an article at a specified location is detected by measuring a change in capacitance which is caused by the placement of the article at the specified location. The device used for this measurement includes an oscillator the frequency whereof is rendered highly sensitive to the capacitance being measured by structure which includes a triaxial cable and by electrical circuitry which includes a voltage follower circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.