GB390611A - Improvements in devices or means for preventing dazzling effects due to motor-car head-lamps and the like - Google Patents

Abstract

390,611. Vehicle antidazzle screens ; lighting systems ; spectacles. UNDERWOOD, E. N., 121, St. Peter's Street, Derby. July 29, 1932, No. 4797. [Class 103 (ii).] For protecting vehicle drivers from dazzle by the headlights of approaching vehicles, the lamp lenses and windscreens are constructed of a number of layers of transparent material, the surfaces of which are inclined at the angle of polarization to the surface of the lens or screen as a whole, the lamp lens serving as a polarizer and the windscreen as an analyser. In constructing the lens or screen a number of layers f of glass, celluloid or other selected transparent material united by cement g are cut at the polarizing angle y into layers h of suitable thickness and, if desired, mounted between two plane sheets of glass. When the lens is mounted in the lamp the reflected rays serve to illuminate the side of the road, while the refracted rays are projected forward, to be rejected by the windscreen of an approaching vehicle. Rear windows and driving mirrors may be similarly constructed to prevent dazzle by lights at the rear of a vehicle. The plane of polarization is preferably arranged at 45‹ to the vertical. Spectacles for pedestrians or other road users may be provided with lenses built up in a similar manner.