Traffic control systems
US5892226A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 1997 |
| Grant date | Apr 6, 1999 |
| Priority date | — |
| Expiry date | Jun 10, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S250/01
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A traffic light control system comprises a passive infra-red presence detection system for detecting the presence of a target emitting infra-red radiation, which comprises a pyro-electric detector including an array of pyro-electric sensor elements. The pyro-electric detector is arranged to generate a signal representative of movement of the target within a detection zone of the detector. By priding a signal processing unit which operates to analyse pulses present in the signal, the said presence detection system is provided with a means whereby it can not only detect movement of the target within the detection zone but also whether that target has moved into and stopped within the detection zone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.