Formlabs, Inc.

Henry Whitney

Andrew M Goldman

Justin Keenan

Maxim Lobovsky

Benjamin FrantzDale

Shane Wighton

Michael Fogleman

Dmitri Megretski

Hayley Whelan

Mehmet Dogan

A curing system for an additive fabrication system includes a light source, a liquid crystal cell, and a first polarizer. The light source is configured to emit light at a wavelength suitable for curing a material. The liquid crystal cell is configured to receive the light from the light source. The first polarizer comprises a polyvinyl alcohol (PVA) matrix and organic dyes impregnated into the PVA matrix.

Use of dye-type polarizers in a photopolymer curing device

According to some aspects, techniques are provided for identifying contamination in additive fabrication devices by measuring light interacting with the contamination using one or more light sensors. Contamination located between a light source and a target of a light source can affect the uniformity and intensity of the light source when incident upon the target. For instance, in an inverse stereolithography device, contamination located between a light source and a liquid photopolymer resin that is to be cured can affect the quality of the fabricated object when the light is scattered or blocked by the contamination. Identifying the presence of contamination between the light source and the liquid photopolymer resin and alerting the user prior to initiating a fabrication process may increase the quality of the resulting fabricated object and improve the user experience by saving time and photocurable liquid.

Techniques for contamination detection in additive fabrication and related systems and methods

According to some aspects, calibration techniques are provided that allow an optics module of an additive fabrication device to be installed and operated in a stereolithography device by a user. In particular, the calibration techniques enable the optics module to be calibrated in a way that only depends on the characteristics of the optics module, and not upon any other components of the stereolithography device. As a result, the techniques enable a user of a stereolithography device to remove one optics module and replace it with another, without it being necessary to repair or replace the whole device. In some cases, the calibration techniques may include directing light onto one or more fiducial targets within the stereolithography device and measuring light scattered from said targets.

Swappable optics module for additive fabrication devices

According to some aspects, techniques are provided to more accurately produce fine features in additive fabrication. According to some embodiments, the techniques comprise a process that amplifies exposure to edges and thin positive features whilst not substantially affecting negative features. In particular, an area to be cured may be adapted using signal processing techniques to produce an energy density map. The area may subsequently be cured according to the generated energy density map by, for example, adjusting the scan speed, light power and/or number of passes of the light beam according to the map. As a result, the net exposure to edges and thin positive features may be amplified.

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Weymoth, MA, United States of America

Henry Whitney