Sometimes it’s fun to see what’s up-and-coming by looking at patents filed and granted. Here’s an interesting one that was just granted: US Patent 20160175609 A1, Multicolour light emitting diode treatment system with uniform illumination, issued to Catherine L. Dye and Markus P. Hehlen.

Per the patent summary, simply by illuminating the skin with LED monochromatic light, success has been achieved in the treatment of a variety of skin conditions. The challenge, however, is that uniform and efficient lighting of the target area is difficult because of point-like emission and narrow divergence of lensed LEDs.

The solution involves an illumination apparatus and method that produces the uniform and efficient illumination by combining a well-distributed computed arrangement of each of the LED colours on an array that enhance the spatial overlap of individual LED outputs across the target area. This is achieved by using a diffuse secondary reflector between the LEDs that has high reflectivity, which allows light to bounce between LED array panels and the skin.

The invention overcomes previous shortcomings by providing a multi-colour LED panel that produces a substantially uniform illumination for each of the LED colours individually, on a subject in close proximity (6 inches away) without secondary optics or moving the LED panel. There are four emission colours that produce high illumination uniformity and high illumination efficiency of a large treatment area, blue (˜452nm), yellow (˜592nm), red (˜642nm) and near-infrared (˜838nm) LED.

Phototherapy patent 01 (cr) Figure 1: The invention provides a multi-colour LED panel that produces a substantially uniform illumination for each of the LED colours individually, on a subject in close proximity without secondary optics or moving the LED panel.

Features include a hinged three-panel design that allows the face and neck treatment area to be intimately enveloped by the LED light source. LEDs on each panel are arranged to achieve optimal emission from each colour across the entire panel with effective spatial overlap of the LED outputs, and the space between the LEDs on the panel is covered with a diffuse reflector having high reflectance (white), allowing light to bounce back and forth between panels and the skin for uniform lighting.

The use of surface-mount LEDs allows for a thinner, lighter system that is convenient to use and cheap to manufacture. The space between the surface-mount LEDs is used to place the circuitry for the LED drivers, so that the drivers and associated heat load is spread out across the panel. Existing devices use traditional through-hole LEDs rather than miniature surface-mount LEDs (compact and cost-effective assembly).

The invention, also called phototherapy, is being used to successfully treat such skin conditions as acne, vitiligo, psoriasis, neonatal jaundice, and various seasonal affective disorders and wounds. Specific colours of light are particularly effective for treating certain conditions.

This article first appeared on EDN.