Abstract:
Various techniques are described herein for combining two or more LEDs in a single reflective cavity for a rear lamp in an automobile. The LEDs may be two or more different colors for performing different functions, such as a stop light, a turn signal, and a tail light. In one embodiment, the LEDs have side emitting lenses and are coaxially aligned in a parabolic reflector. The LEDs may be mounted facing each other or mounted in the same direction, or a combination of both. The LEDs may share a common heat sink. A second reflector may be positioned inside a larger reflector, where a first LED is mounted near the focal point of the larger reflector, and a second LED is mounted near the focal point of the inner reflector. Additional LEDs may also be mounted in either reflector and separately controlled.
Abstract:
An optical system includes a cylindrical side emitter lens, a reflector and a cylindrical Fresnel lens to produce a substantially uniformly illuminated exit plane with well collimated light in the forward direction. The cylindrical side emitter lens redirects light from a light source, such as a number of light emitting diodes placed in a straight line, into side emitted light along an optical axis that is parallel with the exit plane. The reflector may be a stepped multi-focal length reflector that includes multiple reflector surfaces with different focal lengths based on the surfaces distance to the light source and height to redirect light from the cylindrical side emitter lens to illuminate the exit plane and collimate the light along one axis in the forward direction. The cylindrical Fresnel lens is used to collimate the light along an orthogonal axis in the forward direction.
Abstract:
A method for creating a magnetically permeable film on a substrate surface by deposition of successive layers of a magnetic material, during deposition of each layer a magnetic field being provided near said surface having a field direction substantially parallel to the surface. In order to tune the permeability of the magnetic material the method builds up the magnetically permeable film by forming each layer by depositing a ferromagnetic material to a thickness maximally corresponding to substantially ##EQU1## where L.sub.ex is equal to ##EQU2## with A being the exchange constant of the ferromagnetic material and K.sub.u being the uniaxial anisotropy constant, and changing the magnetic field direction during formation of said layer by an angle other than substantially 180.degree..