Patent ID: 6367941
Filing Date: 2002-04-09
Classification: G02B,Y10S

Abstract:
An illumination device, comprising:a light guide including a light guide core having an optically smooth surface for propagating light therethrough and a light emitting region extending along a portion of the core, the light emitting region including: a plurality of light extraction structures distributed along the optically smooth surface of the light guide core, each light extraction structure including an optically reflective surface extending into the light guide core and oriented to reflect light at an angle less than a critical angle so that light is emitted from the light guide through the optically smooth surface, each such optically reflective surface forming a notch angle with respect to an axis that extends from the respective light extraction structure to a side of the optically smooth surface opposite such light extraction structure; wherein at least one of the light extraction structures has a notch angle that is different from a notch angle of at least one other light extraction structure; and wherein the plurality of light extraction structures include a series of light extraction structures defined by a particular sequence of notch angles, said series of light extraction structures being repeated a prescribed number of times along the optically smooth surface of the light guide core.