Formlabs, Inc.

Gsi Group Corporation

Candledragon Inc.

Novanta Corporation

Andrew M Goldman

Henry Whitney

Benjamin FrantzDale

William G Thorburn

Justin Keenan

Arkady Pittel

Maxim Lobovsky

Shane Wighton

Dmitri Megretski

Donald K Mitchell

Paul A Remillard

Keith M Hinrichs

Sergey Liberman

Michael Fogleman

Ilya Schiller

Garry Shleppi

Vladimir V Subach

Simon Selitsky

Mario A Stein

Joel Mikael Petersen

Christopher Chapman Rich

Donald L Grimes

Stuart A Dodson, Ii

Stanislav Elektrov

Mark Lang

Marc A Bernard

Ethan A Funk

Leonid Reznik

Hayley Whelan

Mehmet Dogan

Scott Norton

Robert Morgan

A curing system includes a basin configured to receive a photopolymer resin, an ultraviolet light source, and a translating device. The ultraviolet light source is configured to selectively emit ultraviolet light. The ultraviolet light defines a pixelated array that illuminates at least a portion of the photopolymer resin. The pixelated array includes a first array axis and a second array axis oriented perpendicular to the first array axis. The translating device is configured to translate the pixelated array along a translation axis at an oblique angle relative to the first array axis.

Scanned DLP with pixel drift

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, techniques that address one or more drawbacks of laser-based optical systems in additive fabrication devices are described. In some aspects, an additive fabrication device may include one or more variable focus lenses that may be operated (e.g., actuated) during fabrication to adjust the focus, and thereby the spot size, of a laser beam. In some aspects, an additive fabrication device may comprise a laser array, such as a plurality of vertical-cavity surface-emitting lasers (VCSELs), that may be operated to direct light into a build region, rather than using a single laser beam, such as a single diode laser. In some aspects, an additive fabrication device may comprise a container that includes a flexible display film, such as a flexible LCD screen, which may be operated to direct light into the container to thereby cure a liquid photopolymer therein.

Techniques for generation and direction of light in additive fabrication and related systems and methods

Techniques for illuminating a photocurable material within a build area of an additive fabrication device are described. According to some aspects, a light source is provided that can be moved alongside a build area, allowing light to be directed to any desired position within the build area by moving the light source. This configuration may also allow the distance from the light source to the build area to be substantially the same for each position across the build area by moving the light source whilst maintaining a fixed distance from the light source to the build volume. The described approach may allow for fabrication of larger parts in an additive fabrication device by expanding or eliminating the practical upper limit on the area of the build volume that can be imposed by use of a laser light source in such a device.

Techniques for application of light 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

Techniques for directing light from a movable stage in an additive fabrication device are provided. According to some aspects, the movable stage may include a parabolic mirror onto which light may be directed at various different incident angles to produce light along different positions along an axis. In some cases, this axis may be perpendicular to a direction of motion of the movable stage.

Techniques for directing light from a movable stage in additive fabrication and related systems and methods

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.

Techniques for optimizing photopolymer cure energy in additive fabrication

A communication system that involves superimposing data over DC power. The data takes the form of high bitrate digital signals, where the bitrate is much higher than 0 Hz (DC); this separation allows the AC signal to be easily separated from the DC power. The physical system consists of a two conductor cable, and integration is modular, in that multiple slaves can be connected and disconnected to a master through a routing bus also comprising two conductors. The master can communicate bi-directionally with the slave(s), and the data is encoded using DC-balanced encoding in an FPGA. The data is sent to and from a differential signaling transmitter/receiver pairs at each end of the cable. The system is may be used with position sensors, and provides the benefit of reducing cable costs and sensor size due to the decrease in number of conductors and elimination of power components in the sensor.

System and method of bi-directional communication for position sensors involving superposition of data over low voltage DC power using two conductors

An optical position encoder includes a scale having multiple tracks separated in a direction perpendicular to travel, the tracks including an incremental track and an absolute track, the scale interacting with an incident first light beam to generate a second light beam having components carrying respective optical patterns produced by the incremental track and absolute track respectively. The encoder further includes a set of optical detectors including at least first and second detector arrays of differing properties to detect the respective optical patterns produced by the incremental track and absolute track respectively, each of the first and second detector arrays spanning multiple tracks of the scale and configured to respond to a respective detector-specific component of the second light beam more strongly than to another component of the second beam specific to another of the detector arrays.

Multi-track absolute encoder

A position encoder provides one or more trigger outputs based on position signals developed within the encoder, in addition to traditional position output signals used by other system components such as a motion controller. The trigger outputs may be used directly by a triggered device, bypassing the motion controller and obviating any separate trigger generation electronics. The trigger output(s) can be fully synchronous with the encoder's position output signal(s) with essentially no latency or jitter, increasing accuracy and providing improved system performance. The trigger functionality can be incorporated in a variety of encoder types (e.g., absolute and incremental) and technologies (optical, magnetic, inductive etc.), and used in conjunction with different position output signal formats (e.g., quadrature, serial).

Position encoder with programmable trigger output signal

Motion of a writing instrument is tracked from sensors located in the vicinity. The signals generated from the sensors are processed and used in a wide variety of ways.

Electronic pen holding

An array of sensitive pixel elements is configured to generate signals representative of sensed light that is associated with writing being done by a user, and an optical system concentrates light from a light source across a section of the array of sensitive pixel elements, the signals being useful to compute a subpixel measurement of a position of the light source.

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Stow, MA, United States of America

Andrew M Goldman