Most DLP-based SLA printers utilize traditional projectors that you might find within a home theater. The engineers at SprintRay stepped outside of the box and instead created a custom projector made specifically for their new machine. Called the Ray1, this projector is not only 70% smaller and 90% more energy efficient than a typical commercial projector, but it produces 100% UV light, and has a lifespan of 50,000 hours. This is compared to 5% UV light and a 2000 hour life found with a typical commercial projector. What this equates to is much more uniform output with a distortion of under 1%, while overheating and noise is no longer a concern. (Source)

Device for ultraviolet and color light emission; (US 20160151521 A1)
ZUSAMMENFASSUNG  Devices and uses of said devices for transmitting UV light over a broad area and for a long distance to inactivate microbes and non-microbial sources. The device is activated by a variable or dynamic logic process that controls activation of the device, such that activation is automatic and only when there is either a predetermined target or an absence of an action or activity within an effective range of the device. The device comprises at least one ultraviolet light emitting source emitting ultraviolet light in a range from about 10 to 400 nanometers and a lens formed of an ultraviolet light transmissive material. The at least one ultraviolet light emitting source is embedded within the lens. The lens may be formed into a functional or ornamental shape and does not filter or refract significantly the ultraviolet light emitted from the at least one ultraviolet light emitting source. (Source)