Joseph F Schoelen

US Patent:

61531421, Nov 28, 2000

Filed:

Feb 8, 1999

Appl. No.:

9/247113

Inventors:

Arvind Chari - West Hills CA
Joseph F. Schoelen - Hillsboro OR
Raymond J. Bishop - Santa Clarita CA

Assignee:

3D Systems, Inc. - Valencia CA

International Classification:

B29C 3508
B29C 4102

US Classification:

264401

Abstract:

A rapid prototyping and manufacturing (e. g. stereolithography) method and apparatus for making three-dimensional objects with enhanced control of the temperature of the build environment. A modulated control signal is supplied to a heating element based on a difference between a desired build temperature and a detected temperature. The modulated signal result in the heater supplying, on average, more energy to the build chamber when the temperature difference is large and supplying, on average, less energy to the build chamber when the difference is small. The detection of the build chamber temperature may occur at one or more locations. If multiple locations are used, the detected temperatures may be averaged, or otherwise combined, to derive a single difference value that will be used to control the heater. Alternatively, the multiple detected temperatures may be used to produce multiple difference values that can in turn be used to control the quantity of heat applied directly to different locations in the build environment by either using multiple heaters or multiple controllable ducts.