US 12,137,203 B2
Method and system for optical calibration of 3D printer
Xin Wan, Guangzhou (CN); Weitao Li, Guangzhou (CN); Peihui Wu, Guangzhou (CN); Songlin She, Guangzhou (CN); Peiyan Gui, Guangzhou (CN); and Heyuan Huang, Guangzhou (CN)
Assigned to GUANGZHOU HEYGEARS IMC. INC, Guangdong (CN)
Appl. No. 17/603,913
Filed by GUANGZHOU HEYGEARS IMC.INC, Guangdong (CN)
PCT Filed Dec. 8, 2020, PCT No. PCT/CN2020/134574
§ 371(c)(1), (2) Date Oct. 14, 2021,
PCT Pub. No. WO2022/027891, PCT Pub. Date Feb. 10, 2022.
Claims priority of application No. 202010787710.9 (CN), filed on Aug. 7, 2020.
Prior Publication US 2022/0311995 A1, Sep. 29, 2022
Int. Cl. H04N 17/00 (2006.01); B29C 64/386 (2017.01); B33Y 50/00 (2015.01); G06T 7/73 (2017.01); G06T 7/80 (2017.01)
CPC H04N 17/002 (2013.01) [B29C 64/386 (2017.08); B33Y 50/00 (2014.12); G06T 7/73 (2017.01); G06T 7/80 (2017.01)] 15 Claims
OG exemplary drawing
 
1. A method for optical calibration of a 3D printer, comprising:
at step 100, projecting, by an optical apparatus of the 3D printer, a projection image to a projection platform, placing a calibration plate on the projection platform, and capturing, by a camera apparatus, the projection platform;
at step 200, identifying, by a calibration apparatus, coordinates of calibration points of the calibration plate and coordinates of actual projection points of the projection image projected by the optical apparatus, according to the captured image, to obtain a matrix of calibration points P1 of the calibration plate and a matrix of actual projection points P2 of the projection image projected by the optical apparatus;
at step 300, rotating and translating, by the calibration apparatus, the matrix of the calibration points of the calibration plate and/or the matrix of the actual projection points of the projection image to convert the calibration points and the actual projection points into a same coordinate system, and then calculating a distance value matrix T0 based on the matrix of the calibration points of the calibration plate and the matrix of the actual projection points of the projection image projected by the optical apparatus in an image coordinate system;
at step 400, converting, by the calibration apparatus, the distance value matrix T0 in the image coordinate system into an offset matrix C1 in a pixel coordinate system, and inversely distorting an initial ideal projection image according to the offset matrix C1 to obtain a new actual projection image, wherein when an error between the new actual projection image and the initial ideal projection image meets a requirement, the optical apparatus of the 3D printer is calibrated;
wherein, both T0 and C1 are matrices composed of vectors;
wherein at step 300, the rotated matrix of calibration points and the rotated matrix of actual projection points are as follows: P1′=R1 P1, P2′=R2 P2;
where P1′ is the rotated matrix of calibration points, P2′ is the rotated matrix of actual projection points, and R1 and R2 are rotation matrix parameters.