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:
Apr. 24, 2001
Filed:
Jun. 04, 1999
David Davis, Little Rock, AR (US);
Litton Systems, Inc., Woodland Hills, CA (US);
Abstract
A black-out curtain system (S) reduces undesired viewing by an external observer (O) through an opening (,) in a barrier (,) into an interior space (,). A filter sheet (,) that transmits Electro-Magnetic (EM) radiation (,) is adapted to intercept EM radiation originating in the interior space (,) from exiting the interior space (,) through the opening (,). The filter sheet (,) suppresses EM radiation below a selected cut-off frequency (C), and passes EM radiation above the selected cut-off frequency. An internal night viewer (,) detects only EM radiation having a frequency above the selected cut-off frequency (C). An interior illumination source (,) supplies the interior space (,) EM radiation having a frequency below the selected cut-off frequency (C).