| 摘要 |
An optical filter for welding protective lens assemblies has two parallel electro-optical cells, at least one of the cells being of the nematic type with admixture of dye molecules with anisotropic light absorption. The filter comprises a filter sheet disposed in the ray path of the cells and allowing transmission within a wave range which is offset with respect to the wave range within which said one cell is transmitting residual light in its absorbing state. |
