Patent ID: 8248619
Filing Date: 2012-08-21
Classification: G01V

Abstract:
1. A light barrier for the detection of an object which interrupts a beam of light of the light barrier, comprising: a sensor with at least one light transmitter for the transmission of a light beam in the direction of a reflector; at least one light receiver for the reception of a reflected portion of the light beam; and an evaluation unit for the evaluation of the reflected light beam detected by the light receiver, wherein the reflector is made as a cylindrical reflector column which has a plurality of retroreflecting elements aligned toward the outer surface, with the diameter of the reflector column being considerably smaller than the extent of the light beam perpendicular to the cylinder axis so that an optically effective detection beam of light is formed between the sensor and the reflector column whose cross-section at the sensor is determined by the light transmitter and by an optical transmission device and, in direct proximity to the reflector column, by the areal overlap of the light beam with the reflector column, and wherein the reflector column has a regular or irregular polygonal cross-sectional surface matched to the structure of the retroreflecting elements.