System for detecting malfunctioning ejectors in three-dimensional object printing using specular reflectance

• Main Authors: CLARK RAYMOND J, GOMEZ FRANK B. TAMAREZ, FOLEY TIMOTHY P, BONINO PAUL S
• Format: Patent
• Language: English
• Published: 05.04.2016
• Subjects: ADDITIVE MANUFACTURING TECHNOLOGY; ADDITIVE MANUFACTURING, i.e. MANUFACTURING OFTHREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVEAGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING,STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CORRECTION OF TYPOGRAPHICAL ERRORS; i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; LINING MACHINES; PERFORMING OPERATIONS; PRINTING; SELECTIVE PRINTING MECHANISMS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; STAMPS; TRANSPORTING; TYPEWRITERS; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

A printer detects malfunctioning ejectors during printing of three-dimensional objects or two-dimensional printed matter. The printer operates the printhead or printheads in the printer to form convex drops of material on a substrate. A camera is positioned to minimize light reflections from the substrate into the camera. The camera is configured to generate image data of the light reflected from the substrate and specularly from the convex drops on the substrate. A controller analyzes the image data to identify malfunctioning inkjets.