Lens for welder's goggles or mask or sunglasses - for automatic inertia-free control of fluctuations in light intensity

摘要

Lens for automatic control of light transmission comprises two glass panes (1, 2) and an intermediate liquid crystal layer (4) of which the light-transmitting properties depend on applied voltage, light transmission being pref. controlled by varying voltage. Behind the lens may be a photosensors (10) of which the signal is used as a reference value for a control circuit (9) which varies the voltage at the crystal layer so that the quantity of light transmitted remains constant. Photosensors (12) may be mounted at the edge of the lens for supply of current to the lens and control circuit.