Patent ID: 6079521
Filing Date: 2000-06-27
Classification: B66B

Abstract:
An elevator system, comprising:an elevator hoistway;an elevator car moveable vertically within said hoistway;a laser disposed on said elevator car, said laser providing a laser beam in at least one direction along said hoistway, said laser beam being scanned so as to proceed from being directed toward one side of the hoistway to being directed toward the other side of the hoistway, periodically;one or more pairs of sensors, each pair having one sensor mounted on one side of said hoistway and the other sensor mounted on the other side of said hoistway;and a signal processor responsive to said sensors, said signal processor measuring the time for said laser to scan from one sensor of a pair to another sensor of said pair and calculating, from that time, the vertical distance of said elevator car from said sensor pair, and thereby the position of said elevator car in said hoistway.