Side-emitting collimator

DETAILED DESCRIPTION Briefly stated, a side-emitting collimator according to the present invention comprises a pair of collimator halves configured to meet over an LED to form a cavity defined by refracting surfaces.
The upper boundary of each collimator half is defined by a surface configured to internally reflect light refracted into the collimator lens by one of the refracting surfaces.
Each half of the side-emitting collimator redirects light from the light source in a direction substantially perpendicular to the optical axis of the light source.
The side-emitting collimator redirects the light from an LED into diametrically opposed collimated beams perpendicular to the optical axis of the light source.
Each half of the side-emitting collimator includes an aspheric upper internal reflecting surface whose shape is calculated from the path of light refracted by the corresponding internal refracting surface.
As used in this application, the term "aspheric" means "not spherical".
The illustrated aspheric surfaces are created by rotating a non-circular curve about an axis of symmetry.
These surfaces can be described as "rotationally symmetric" about the axis of symmetry.
Each half of the side-emitting collimator defines one half of a cavity that receives the light source.
The upper surface of the cavity includes two adjoining substantially cylindrical surfaces that meet over the optical axis of the LED light source.
Each end of the cavity is defined by one half of an aspheric surface.
The partial-cylindrical surfaces are positioned to refract light from the light source onto the upper internal reflecting surface.
The partial aspheric refracting surface redirects light from the light source into a direction of light emission parallel to light reflecting from the partial aspheric upper internal reflecting surface.
These surface shapes and relationships are an example of surfaces that efficiently gather light from an LED and re-direct that light into a pair of opposed collimated beams perpendicular to the optical axis of the LED