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:
Jul. 30, 1996
Filed:
Mar. 21, 1994
Kevork G Arackellian, Everett, WA (US);
Intermec Corporation, Redmond, WA (US);
Abstract
A symbology reader which reduces the effects of specular reflection. A plurality of illumination sources emit light toward a target object. A first polarization filter receives the unpolarized light from the illumination sources and transmits only light polarized in a first direction. Light reflected from the target object travels back to the reader where it is received by a second polarizer which is oriented to block light polarized in the first direction and transmit only light polarized in a second direction orthogonal to the first polarization direction. Non-specularly reflected light reflected from the target object is largely transmitted by the second polarizer to a detector assembly within the symbology reader. In one embodiment the polarization filters are part of a window which covers an output aperture of the reader. The polarization filters are implemented as discrete pieces of laminar polarizing film attached to a transparent window base. In an alternative embodiment, a wavelength filter is employed to block ambient light at wavelengths other than the wavelength of the illumination sources to improve the sensitivity of the detector assembly to reflected illumination light.