The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 09, 2016
Filed:
Jan. 15, 2013
3m Innovative Properties Company, St. Paul, MN (US);
Kristina M. Magnusson, Djurmo, SE;
Kenneth Jarefors, Borlange, SE;
3M Innovative Properties Company, St. Paul, MN (US);
Abstract
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.