Optical device for detecting a falling object
US6640994B2 · kind B2 · utility
Inventor
Key dates
| Filing date | Feb 19, 2002 |
| Grant date | Nov 4, 2003 |
| Priority date | — |
| Expiry date | Apr 6, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07F11/16
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A falling object, such as a product falling from a magazine to a discharge chute of a vending machine, is detected using a rectangular light curtain having parallel sides. A plurality of light emitters are positioned along one side and a plurality of receptors are positioned along another side opposite the emitters. A timing circuit momentarily illuminates the emitters one at a time at a time while an electronic controller examines the outputs signal from all the receptors. Where one of the receptors fails to receive a signal from one of the emitters an object is presumed to have interrupted the signal. To work properly the electronic controller must complete a cycle of illuminating all the emitters within the time frame that a falling object interrupts the light curtain.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.