US 12,111,424 B2
Safety laser scanner and method for front screen monitoring
Joachim Krämer, Waldkirch (DE); Markus Hammes, Waldkirch (DE); and Ino Geisemeyer, Waldkirch (DE)
Assigned to SICK AG, Waldkirch (DE)
Filed by SICK AG, Waldkirch (DE)
Filed on Feb. 5, 2021, as Appl. No. 17/169,019.
Claims priority of application No. 20156075 (EP), filed on Feb. 7, 2020.
Prior Publication US 2021/0247503 A1, Aug. 12, 2021
Int. Cl. G01S 7/497 (2006.01); G01S 7/481 (2006.01); G01S 17/04 (2020.01); G01S 17/08 (2006.01)
CPC G01S 7/497 (2013.01) [G01S 7/4814 (2013.01); G01S 7/4817 (2013.01); G01S 17/04 (2020.01); G01S 17/08 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A safety laser scanner (10) for detecting objects in a monitored zone (20) that has a light transmitter (12) for transmitting a scan beam (16), a movable deflection unit (18) for a periodic scanning of the monitored zone (20) by the scan beam (16), a light receiver (26) for generating a received signal from the scan beam (22) re-emitted by the objects, a front screen (38), and a control and evaluation unit (32) that is configured to acquire information on the objects in the monitored zone (20) from the received signal and to recognize an impaired light permeability of the front screen (38) in a front screen monitoring by evaluating a front screen reflection beam (54) that is generated from the scan beam (16) by reflection at the front screen (38),
characterized by
at least one light deflection element (56, 58) in the optical path of the front screen reflection beam (54) that guides the front screen reflection beam (54) to the front screen (38) again in a region (60) to be tested so that a twice-reflected front screen reflection beam (62) is produced by reflection at the region (60) to be tested.