Innovations in Optics has introduced the 3300P-100 TIR prism assembly that enables on-axis illumination and compact optical system designs.
The 3300P mounts to the LumiBright 3300B series of UV-LED Illuminators for high power UV DLP applications such as 3D printing, computer-to-screen, computer-to-plate printing, direct image writing and digital maskless lithography.
DLP chips are digital micromirror devices (DMD) made by Texas Instruments (TI). They are reflective; the illumination and projection paths to the device share the same space in front of the device. Illumination light enters the 3300P-100 TIR prism assembly and reflects within the prism through total internal reflection (TIR) to illuminate the DLP chip. The reflected image passes through the prism without reflection for projection to the image plane. The paths separated in glass rather than air space leads to compressed overall path length, improved image quality and reduced back working distance of the projection lens.
The 3300P-100 TIR prism assembly supports a telecentric optical system for the illumination path to provide uniform angles of incidence across the entire DLP chip creating uniform black levels for the dark field. The projection axis is perpendicular to the DLP chip so that the telecentric condition also prevents spatial non-uniformities in projected brightness. Ultimate optical efficiency and performance in the 3300P-100 TIR prism assembly is achieved by employing high-quality antireflection (AR) coated prism surfaces, high-quality blackening on metal housing surfaces, and a tightly controlled air gap between the prism sections.