Solid Light Guide Optics for Thin Lamp Applications

Today's requests from automotive manufacturers for innovative designs for signal and interior lamps are driven by three typical tasks:

• Saving space and depth in the lamp for easier and cost saving integration in the body construction. Lamp thickness should be reduced to a technically achievable minimum.
• A homogeneous illumination needs to be realized with a minimum number of emitters (particular with LED).
• Line design should be supported by reliable technologies, enabling stylists to develop contour-driven designs.

All these demands can be supported by “Solid Light Guide Optics”. In this optical concept a solid light guide with the basic geometry of a tube receives the light from a light source (bulb or LED) directly, or via an additional flexible light guide. The rays are transmitted in the circular solid light guide by total internal reflection and will be also coupled out partly with the aid of prisms or structures on the rear side of the longitudinal axis of the guide. Precise optical calculation allows a homogenous illuminated line design to be developed, which can successfully achieve the requested light distribution for various signal functions and other illumination tasks.

This paper will attempt to demonstrate the possibilities for several applications with realized concepts and additional demonstrations for future systems.