RPC Photonics receives grant to improve LED signage

Jan. 31, 2005
RPC Photonics, working with the LRC, plans to apply its Engineered Diffuser technology to improve the performance of lighted signs that use LEDs
RPC Photonics, Inc. has recently been awarded a $200,000 research and development contract by the New York State Energy Research and Development Authority (NYSERDA) to develop new technology to improve the efficiency, visibility and performance of LED signage.

Under the contract, RPC Photonics plans to extend its patented Engineered Diffuser™ technology into a film designed to shape and control light. The Rochester, NY-based company will conduct this work in collaboration with the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute.

"Using LEDs and RPC's light control film, we can improve the brightness, reduce energy consumption by up to 80%, and lessen the environmental impact of outdoor channel letter signs," says Stephen Chakmakjian, RPC's Chief Technology Officer.

Lighted signs used by retail and commercial companies to identify their name and logo generally remain lit throughout the night-time hours, consuming a significant amount of energy depending on their size, brightness, and other factors. In addition, much of the light generated by signs using current technology is wasted, since they have no effective method of controlling the light distribution.

RPC will integrate its Engineered Diffuser light control film into lighted signage to control light direction to where it is needed, thus reducing wasted light and light pollution, and resulting in significant power savings. Channel letter signs, consisting of a neon tube enclosed in box-like container which is shaped like a large alphabetic character or logo, will be studied as part of this contract.

Nadarajah Narendran, the LRC's director of research, said, "LEDs are an ideal light source for this application because they have the potential to save energy and reduce maintenance. This study will look more closely at ways to optimize their performance inside signs, as well as explore people's preferences and perceptions of lighted signs."

Engineered Diffuser technology

This new proprietary light-shaping technology offers significant performance enhancements and enables the efficient use of energy by controlling light propagation and directing light specifically where it is needed.

Unlike conventional light control diffusers, RPC's Engineered Diffusers control each scatter center, generally with refractive microlens cells. At the heart of RPC's Engineered Diffuser technology is the capability to design and manufacture close-packed arrays of accurately- and independently-produced microlenses, each microlens being specified by a unique profile prescription and spatially distributed in a specified manner.

In addition to light control, RPC's Engineered Diffusers can be used for RGB mixing to produce white light with a specified color temperature, which depends of the RGB content of the source. A single Engineered Diffuser component can be used for efficient color mixing and illumination control. This technology has potential applications in many types of illumination but has particular benefits in shaping LED light for general lighting and signage.