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:
Dec. 29, 1998
Filed:
Apr. 04, 1997
Emil Ackermann, Wattwil, CH;
Oprel AG, Wattwil, CH;
Abstract
In the invention, an active electrooptical filter cartridge comprises a flat housing (10, 12, 16) forming a closed cavity, which is completely filled with an optical transmissive resin (44, 52, 56, 60, 62) and an active device (14). The active device (14) is completely surrounded and fixed by the resin and comprises as components an LC panel (30, 32) positioned between light-transmissive portions (24, 28) of opposite main walls (10, 16) of the housing, a sensor means (34, 36) for detecting incident light on the filter cartridge, a circuit means (38) for controlling the LC panel (30, 32) in response to an output from the sensor means (34, 36), and a power supply means (40, 42) for operating the active device (14). The filter cartridge can be manufactured with the same dimensions as a passive, darkened filter glass, e.g. for use in welding helmets.