| 摘要 |
A light control device includes a light shutter having a pair of polarizers and a liquid crystal device operative in response to a prescribed input to control transmission of light therethrough, and a variable polarizer optically aligned with respect to said light shutter and operative to control light transmitted therethrough in response to a prescribed input; the light shutter is operative relatively fast in response to application of electric field to reduce light transmission and the variable polarizer is operative in the event of a power loss, which would cause the light shutter to stop light blocking, to provide a safety light blocking function. The light control device may be employed in a welding helmet or other device intended to provide protection to the eyes of an individual or other animate or inanimate object from selected electromagnetic energy, such as that produced by welding or other source.
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