Luminit’s Unique Patented TIR 180° Optic

Submitted on Thu, 04/01/2021 - 08:09

Luminit has been granted a patent for an optic that takes a collimated light source and converts it to a wide 180 degree fan of illumination. Flat optics like our Lighting Shaping Diffusers use refraction to increase the beam angle of a collimated light source; this typically is limited to about 100 degrees. The 180 degree Illuminator, however, takes a different approach with a combination of cylindrical and conical sections. Here’s how it works. 

After a collimated light source (i.e., VCSEL, laser, LED) enters the cylinder along its axis (flat surface), the beam strikes the inside of a concave cone. It then experiences Total Internal Reflection (TIR), which spreads the light out in 360 degrees. Half (180 degrees) of the light exits through the side of the cylinder. The other half gets reflected from another set of cone surfaces. The second half of the light now faces the same direction as the first half as it exits the cylinder. As the light exits the cylinder, a diffuser can be applied in the axial direction, resulting in most (>90%) of the light spreading uniformly 180 degrees in the radial direction and being controlled by the Light Shaping Diffuser in the axial direction. The shape in the axial direction can be either a Gaussian or rectangular (uniform) shape.

illuminator diffuser

Figure 1: Example of how a light beam travels through the Illuminator 180.

This cylindrical molded optic provides a perfectly uniform light field with 180 degrees of coverage. Applications that can benefit from this patented optic include LiDAR for autonomous vehicles, automotive lighting, and beacon lighting.

diffusers for LiDar

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