Monitoring device e.g. for closure of motor vehicle window

摘要

The reflector (4) is fitted to the inside of the door so as to reflect infra-red (IR) emission from a transmitter at the top of the vertical part of the window frame to a receiver at the front of the windowsill. Closure of the window is arrested if the optical path is interrupted by any obstacle to upward movement of the glass. The reflecting surface (12) is a film or moulding of metal or plastic on the door lining with an approximately sinusoidal shape (6) or an alternation of convex and concave semicircles.