US 12,240,233 B2
Droplet measurement using strobed LED source
Jerry Chang, Cupertino, CA (US)
Assigned to Kateeva, Inc., Newark, CA (US)
Filed by Kateeva, Inc., Newark, CA (US)
Filed on Dec. 8, 2023, as Appl. No. 18/533,983.
Application 18/533,983 is a continuation of application No. 17/302,618, filed on May 7, 2021, granted, now 11,878,520.
Claims priority of provisional application 63/024,168, filed on May 13, 2020.
Prior Publication US 2024/0100824 A1, Mar. 28, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. B41J 2/045 (2006.01); G01N 15/0227 (2024.01); G01N 15/1433 (2024.01); G01N 15/02 (2006.01); G01N 15/14 (2006.01)
CPC B41J 2/0456 (2013.01) [G01N 15/0227 (2013.01); G01N 15/1433 (2024.01); B41J 2202/21 (2013.01); G01N 2015/0294 (2013.01); G01N 2015/1493 (2013.01); G01N 2015/1497 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An inkjet printer, comprising:
a printhead assembly comprising a printhead and an imaging system, the imaging system comprising a camera and a strobed LED source;
a deposition unit for positioning a substrate to receive droplets dispensed from the printhead and for imaging the droplets on the substrate using the imaging system and the strobed LED source; and
a controller configured to control the printhead assembly and the deposition unit to:
dispense droplets from the printhead onto a substrate disposed on the deposition unit;
relatively scan the printhead assembly and the substrate disposed on the deposition unit;
while relatively scanning the printhead assembly and the substrate, strobe the LED source by:
activating the strobed LED source for a duration selected to ensure any distortion from relative scanning of the camera and substrate is much less than a typical dimension of the droplets being imaged;
deactivating the strobed LED source after the duration; and
reactivating the strobed LED source after a time selected to ensure a previously un-imaged area of the substrate occupies at least a portion of the field of view of the camera; and
while relatively scanning the printhead assembly and the substrate, capture images of the droplets using the camera.
 
9. A method, comprising:
dispensing droplets of a liquid from a printhead of a printhead assembly of an inkjet printer onto a substrate;
relatively scanning the substrate and an imaging system coupled to the printhead assembly, the imaging system comprising a camera and an LED light source; and
imaging the droplets on the substrate by strobing the LED light source and activating the camera when the strobed LED light source illuminates the substrate, wherein strobing the LED light source comprises illuminating an area of the substrate for a duration selected to ensure any distortion from relative scanning of the camera and substrate is much less than a typical dimension of the droplets being imaged.
 
15. An inkjet printer, comprising:
a printhead assembly comprising a printhead and an imaging system, the imaging system comprising a camera and a strobed LED source;
a deposition unit for positioning a substrate to receive droplets dispensed from the printhead and for imaging the droplets on the substrate using the imaging system and the strobed LED source; and
a controller configured to relatively scan the printhead assembly and the substrate, and while relatively scanning the printhead assembly and the substrate, to strobe the LED source and control the camera to capture images to ensure any distortion of images captured by the camera due to relative movement of the camera and substrate is much less than a typical dimension of the droplets being imaged.