US 11,982,765 B2
Scanning laser devices and methods with detectors for sensing low energy reflections
James Dean, Redmond, WA (US); Christopher Cannon, Redmond, WA (US); Alga Lloyd Nothern, III, Seattle, WA (US); and Joel Sandgathe, Portland, OR (US)
Assigned to Microvision, Inc., Redmond, WA (US)
Filed by Microvision, Inc., Redmond, WA (US)
Filed on Feb. 2, 2021, as Appl. No. 17/165,017.
Prior Publication US 2022/0244358 A1, Aug. 4, 2022
Int. Cl. G01S 7/48 (2006.01); G01S 7/481 (2006.01); G01S 7/484 (2006.01); G01S 7/487 (2006.01); G01S 7/497 (2006.01); G01S 17/10 (2020.01); G01S 17/89 (2020.01)
CPC G01S 7/4817 (2013.01) [G01S 7/484 (2013.01); G01S 7/487 (2013.01); G01S 7/497 (2013.01); G01S 17/10 (2013.01); G01S 17/89 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a laser light source configured to produce laser light pulses;
an optical assembly, the optical assembly including optical elements to scan the laser light pulses into a scan field;
a first detector, the first detector including:
a first sensor configured to receive reflections of the laser light pulses from objects within the scan field through the optical assembly and to further receive back reflections of the laser light pulses from the optical elements within the optical assembly;
a second sensor configured to receive back reflections of the laser light pulses from within the optical assembly while not receiving significant reflections from objects within the scan field; and
a sensing circuit coupled to the first sensor and the second sensor, the sensing circuit configured to at least partially cancel effects of the back reflections to generate an output signal indicative of a reflection from an object in the scan field.