AUTOMATICALLY DARKENING LIGHT FILTER AND METHOD OF CONTROLLING SWITCHED LIGHT SHUTTER OF LIGHT FILTER Russian patent published in 2011 - IPC G02F1/1335 

FIELD: physics.

SUBSTANCE: automatically switched light filter has a light shutter control system capable of determining high and low level of intensity of incident light and switching the shutter from dark state to an intermediate state in response to change in said level from high to low. The light shutter control system also enables to hold the shutter in intermediate state for a period of time when the low intensity level of incident light is determined. The light shutter control system switches the shutter to a dark state when the level of intensity of incident light changes from low to high and keeps the shutter in dark state if said level of intensity remains high. In the absence of a high intensity light flux, the shutter switches to a clear state.

EFFECT: minimisation of the level of discomfort when working with high-intensity light sources.

19 cl, 5 dwg, 1 ex