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. 16, 1997
Filed:
May. 13, 1996
James P Chew, Jeannette, PA (US);
Union Switch & Signal Inc., Pittsburgh, PA (US);
Abstract
A railroad searchlight signal for producing light signals of selected colors. The searchlight uses a reflector that has an inner surface of reflective material and a focal point. One or more light emitting diodes are provided at the reflector focal point. When a current is supplied to the light emitting diode from a variable current power source, a light having a color that varies dependent upon the current is produced. The colored light produced at the light emitting diode is then directed outward of the reflector as a beam. At least one color filter that allows light of a respective color to pass therethrough is preferably provided proximate the reflector. Light that passes through the color filter is detected by a light detector such as a photovoltaic cell, a phototransistor or a photodiode.