AUTOMATIC WELDING FILTER WITH TUNABLE SPECTRAL TRANSMISSION

摘要

The present invention relates to an automatic welding filter that changes from a light transmission state to a dark transmission state in response to incident welding light and includes a color-tunable filter whose spectral transmittance can be varied to optimize the visual appearance of a welding task. The color-tunable filter comprises at least one low twist liquid crystal cell disposed between polarization filters having substantially parallel polarization directions. The user is able to adjust the color of the automatic welding filter in the dark transmission state, independently of the shade, in response to a user selected color signal which alters the birefringence properties of the low twist liquid crystal cell.