US 9,808,994 B2
Methods for monitoring electro-magnetic radiation power in solid freeform fabrication systems
Eliahu M. Kritchman, Tel Aviv (IL); Alexander Libinson, Holon (IL); Moshe Levi, Tel-Aviv (IL); and Guy Menchik, Ra'anana (IL)
Assigned to STRATASYS LTD., Rehovot (IL)
Filed by STRATASYS LTD., Rehovot (IL)
Filed on Jan. 7, 2016, as Appl. No. 14/989,799.
Application 14/989,799 is a continuation of application No. 12/349,512, filed on Jan. 6, 2009, granted, now 9,242,411.
Prior Publication US 2016/0114535 A1, Apr. 28, 2016
Int. Cl. B29C 67/00 (2017.01); B33Y 30/00 (2015.01); B33Y 50/02 (2015.01)
CPC B29C 67/0088 (2013.01) [B29C 67/0055 (2013.01); B29C 67/0059 (2013.01); B29C 67/0096 (2013.01); B33Y 30/00 (2014.12); B33Y 50/02 (2014.12)] 7 Claims
OG exemplary drawing
 
1. A dispensing system for forming three-dimensional objects, layer by layer, on a fabrication platform, the system comprising:
a printing assembly movable between a printing area and a service area, wherein the printing assembly includes an irradiation unit comprising a housing and a radiation source and a printing head;
a first light sensor positioned at the service area to measure output radiation power of the irradiation unit, wherein a vertical distance between the light sensor and the irradiation unit at a time of measuring the output radiation power is the same as a vertical distance between the irradiation unit and a top deposited layer of the three-dimensional object being formed at a time of printing;
a second light sensor positioned with the housing and configured to directly measure output radiation power of the radiation source; and
a controller to receive measurements from the first light sensor and from the second light sensor, to compare between the measurements from the first light sensors and the second light sensor and to automatically adjust electrical power supplied to the irradiation unit based on the measurements.