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:
Jan. 13, 2004
Filed:
Jul. 30, 1999
Randall D. Blanchard, San Diego, CA (US);
L-3 Communications, Phoenix, AZ (US);
Abstract
Ambient light can saturate the light detectors of a touch screen and cause unreliable operation. To address this concern, one or more filters may be placed proximate the detectors. A first filter may be a spatial filter, such as a microlouvre filter. A microlouvre filter is arranged so that it passes light transmitted by the light detectors and rejects off-axis light. Another filter may be a narrow band optical filter, such as a dichroic notch filter. Such an optical filter passes light having wavelengths within a narrow band selected to correspond to the spectral characteristics of the light emitters, while it rejects light of other wavelengths. The spatial filter and the narrow band optical filter may be used separately or in combination.