US 11,936,973 B2
Pulse chain-driven infrared imaging assembly
Arjen Gerben Van der Sijde, Eindhoven (NL); Erno Fancsali, Heusden-Zolder (BE); Nicola Bettina Pfeffer, Eindhoven (NL); and Pieter Johannes Quintus van Voorst Vader, Son (NL)
Assigned to Lumileds LLC, San Jose, CA (US)
Filed by Lumileds LLC, San Jose, CA (US)
Filed on Apr. 28, 2022, as Appl. No. 17/732,219.
Application 17/732,219 is a continuation of application No. 16/999,401, filed on Aug. 21, 2020, granted, now 11,350,022.
Claims priority of application No. 19192749 (EP), filed on Aug. 21, 2019.
Prior Publication US 2022/0256061 A1, Aug. 11, 2022
Int. Cl. H04N 5/225 (2006.01); G01B 11/22 (2006.01); G06T 7/50 (2017.01); H04N 5/235 (2006.01); H04N 23/56 (2023.01); H04N 23/71 (2023.01); H05B 45/32 (2020.01)
CPC H04N 23/56 (2023.01) [G01B 11/22 (2013.01); G06T 7/50 (2017.01); H04N 23/71 (2023.01); H05B 45/32 (2020.01); G06T 2207/10048 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An infrared imaging assembly to capture an infrared image of a scene, the infrared imaging assembly comprising:
an infrared-sensitive image sensor;
an irradiator comprising an array of individually addressable infrared-emitting LEDs, each infrared-emitting LED arranged to illuminate at least one image region of a plurality of image regions of the scene;
a driver configured to actuate the irradiator by applying a switching pulse train to each infrared-emitting LED;
an image analyzer configured to analyze a preliminary image of the scene irradiated by the irradiator to determine exposure levels for each of the plurality of image regions, the driver configured to use pulses of a preliminary switching pulse train to drive each infrared-emitting LED during a scan sequence in which the preliminary image is captured; and
an adjusting unit configured to adjust driving of each infrared-emitting LED based on the exposure levels to obtain a final image, the preliminary switching pulse train having a shorter duration than a final switching pulse train used to drive the infrared-emitting LED to obtain the final image, the pulses of the preliminary switching pulse train having a shorter pulse width than pulses of the final switching pulse train.