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:
May. 01, 2001
Filed:
May. 07, 1999
John D. Rogers, Coatesville, PA (US);
Steven H. Mersch, Germantown, OH (US);
Automatic Timing & Controls, Inc., Lancaster, PA (US);
Abstract
A laser diode (,) emits laser light which is collimated into parallel rays with collimating lens (,). The collimated beams travels as much as 50 meters or more before being reflected back to a photoreceiver (,). A ball lens (,) focuses the reflected light onto the photoreceiver. The photoreceiver, preferably, is a synchronous detector which issues control pulses to a laser drive circuit (,) for causing the laser diode to emit intermittent bursts of laser light. The synchronous detector then compares the timing of received light with the timing of the control pulses to the laser diode to distinguish between true reflected light and stray light. An intensity adjustment (,) adjusts the intensity of the laser light in accordance with a distance between the laser diode/photoreceiver and a reflector. In this manner, distances of 1-70 meters can be accommodated with no lens modification. A reference voltage (,) proportional to the intensity of the laser light is used in a gated feedback (,) for faster response times.