Case History #2: Light Valves For Remote Lighting Systems

Remote lighting systems (RLS) are based on the concept of a light source enclosed in a chamber from which light guides carry light to the point of use. For automotive applications, they produce more precise light beams, improve styling and aerodynamics and reduce electrical problems. In many applications, particularly for vehicle lighting systems, it is necessary to have light valves in the RLS to control the light.

Surveying the available technology and its trends

TIG carried out an extensive survey of light valve technologies to identify the most promising candidates. After reviewing essentially all known approaches to light valves, several approaches were selected for further testing. Testing covered optical performance, mechanical performance, thermal response and temperature resistance, among other factors.

Carrying out design, prototype fabrication and testing

The most promising candidate found in the survey was based on a metalized polymer foil moving under the influence of electrostatic forces. TIG worked with a small company familiar with the technology by subcontracting certain phases of construction of shutters to our designs. The concepts, tested by TIG, proved capable of meeting all optical, mechanical and, with certain innovative heat transfer concepts, thermal requirements. The devices are silent and extremely long lived. Testing showed them capable of operating over a hundred million cycles before failure. The inherent cost is low. We also carried out a limited run of prototype units for the client to be used in a variety of applications, including road operating vehicles.

Transferring technology and establishing relationships

Although our original partner was able to support our development work, it was not in a position to enter production. Consequently, we entered into a relationship with a second company that was interested in producing the entire light valve assembly.

In order to expedite technology transfer from the first company to the new company, several steps were carried out. First we designed and built a fully automated, computer controlled test rack at the new company's site. As soon as this was complete we began life testing early sample shutters. Secondly we documented the critical fabrication steps of the shutter concept and produced a detailed illustrated manual. Thirdly we developed a detailed plan for a computer controlled pilot production facility.

Developing intellectual property positions for the client

Several aspects of the valve design have been patented by the client with TIG personnel as coinventors.