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. 10, 1989
Filed:
Apr. 11, 1986
Pasco Corporation, Tokyo, JP;
Abstract
A road surface illuminated by sunlight is scanned with a laser beam at right angles to the direction of travel, the intensity of the laser beam being intensity modulated with a predetermined frequency; laser beams reflected from the road surface are received and optically filtered to filter out light having frequencies outside that of the laser beam. The optically filtered laser beam strikes a plurality of beam position sensing elements from which respective electrical signals are derived. The resulting electrical signals are then multiplexed and electrically band-pass filtered wherein the center frequency of the band-pass filtering coincides with the frequency at which the laser beam is intensity modulated.