US 12,436,247 B2
Laser sensor module with soiling detection
Alexander Marc Van Der Lee, Venlo (NL); Johannes Hendrikus Maria Spruit, Waalre (NL); Okke Ouweltjes, Eindhoven (NL); and Robert Weiss, Waldbronn (DE)
Assigned to TRUMPF PHOTONIC COMPONENTS GMBH, Ulm (DE); and ROBERT BOSCH GMBH, Stuttgart (DE)
Filed by TRUMPF Photonic Components GmbH, Ulm (DE); and Robert Bosch GmbH, Stuttgart (DE)
Filed on Nov. 19, 2021, as Appl. No. 17/530,579.
Application 17/530,579 is a continuation of application No. PCT/EP2020/061152, filed on Apr. 22, 2020.
Claims priority of application No. 19175997 (EP), filed on May 22, 2019.
Prior Publication US 2022/0075042 A1, Mar. 10, 2022
Int. Cl. G01S 7/48 (2006.01); G01S 7/481 (2006.01); G01S 7/497 (2006.01)
CPC G01S 7/497 (2013.01) [G01S 7/4813 (2013.01); G01S 7/4815 (2013.01); G01S 7/4816 (2013.01); G01S 2007/4975 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A laser sensor module, comprising:
a laser diode configured to emit a laser beam,
an electrical driver configured to supply the laser diode with a driving current to stimulate emission of the laser beam,
a detector configured to determine an interference signal, and
an optical arrangement configured to focus the laser beam to a focus region, the optical arrangement comprising an emission window, and
a soiling detection unit configured to vary a wavelength of the laser beam with a variation amplitude over a predetermined time period to provide a soiling detection signal indicative of a soiling of the emission window based on the interference signal detected during the varying the wavelength of the laser beam,
wherein the variation amplitude and the predetermined time period are set to generate the soiling detection signal with a soiling detection signal frequency in a range from 1 kHz to 100 MHz and a soiling detection signal duration in a range from 1 μs to 5 ms.