US 12,086,966 B2
Method, controller and apparatus for correcting thermal images
Gianluca Dorini, London (GB)
Assigned to Stratasys Powder Production Ltd., London (GB)
Filed by Stratasys Powder Production Ltd., London (GB)
Filed on May 11, 2022, as Appl. No. 17/741,984.
Claims priority of application No. 2107789 (GB), filed on Jun. 1, 2021.
Prior Publication US 2022/0383460 A1, Dec. 1, 2022
Int. Cl. G06T 5/80 (2024.01); G01J 5/00 (2022.01); G01J 5/80 (2022.01)
CPC G06T 5/80 (2024.01) [G01J 5/0066 (2013.01); G01J 5/80 (2022.01); G01J 2005/0077 (2013.01); G06T 2207/10048 (2013.01)] 20 Claims
OG exemplary drawing
 
10. A controller for correcting thermal image distortion of a thermal camera in an apparatus for the layer-by-layer manufacture of three-dimensional objects, the thermal camera comprising a plurality of sensor pixels arranged along a first direction, wherein the controller is configured to:
(a) cause a temperature reference to be at a first steady state temperature;
(b) control movement of the temperature reference at the first steady state temperature to move the temperature reference through a plurality of positions along the first direction through the field of view of the thermal camera;
(c) control the thermal camera during step (b) to record a plurality of thermal images, each thermal image corresponding to one of the plurality of positions and comprising the detected temperature of the temperature reference as detected by at least one pixel of the plurality of pixels;
(d) identify the at least one pixel that detected the temperature of the temperature reference within the respective thermal image at the corresponding one of the plurality of positions within the image;
(e) construct a thermal map from the identified pixels representing the detected temperature of the temperature reference at the plurality of positions;
(f) generate a correction matrix for the identified pixels based on a comparison between the thermal map and the first steady state temperature; and
(g) apply the correction matrix to subsequent measurements of the thermal camera.