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:
Aug. 20, 1991
Filed:
Apr. 27, 1990
Bengt Bjorkman, Jarfalla, SE;
Bofors Electronics AB, Jarfalla, SE;
Abstract
Laser-warning method and a laser-warning arrangement, which laser-warning arrangement is intended to warn of laser light from a laser beam source which is used for guiding projectiles, missiles and the like, for example laser light from a pulsed laser beam which is directed towards a target area. The time for the laser beam to reach the laser-warning arrangement, the so-called impact time, is calculated from a first amplitude value, measured at a first point in time, of the scattered light from the laser beam and a second amplitude value, measured at a second point in time, of the scattered light from the laser beam, and the measured time difference between the said first and second points in time on the basis that the amplitude raised to a constant is proportional to the distance to the laser beam according to the equation D=K.multidot.A.sup.n, where K and n are constants, D is the perpendicular distance to the laser beam and A is a measured amplitude value. The laser-warning arrangement comprises a rotatable optics system with two light inputs, a fixed detector system which detects the magnitude of the light coming in via the light inputs of the rotatable optics system and transmitted through the optics system to the fixed detector system, and an evaluation unit which determines the impact time in accordance with the above equation. The optics system comprises, counting from each light input, a first cylindrical lens, prism, reflector, filter, second cylindrical lens, diaphragm and glass block.