Lighting apparatus

Abstract

A three dimensional light control lens (2, 2A, 2B) of special configuration is fitted on the outer surface of a cylindrical or spherical light source (1, 1A, 1B) so as to cover at least a part thereof directly. A light coming out of the light source is transmitted through the light control lens and emitted. The light control lens (2, 2A, 2B) is of such three-dimensional shape as to control the luminous flux from the light source (1, 1A, 1B) to have a predetermined distribution and range of incidence. Typically, the sectional shape of the light control lens taken along a plane including the luminous flux which has passed therethrough is such as to have a pair of swelled portions (2a) protruding in the direction away from the light source, and a recessed portion (2c) recessed on the side counter to the light source between the swelled portions, the swelled portions (2a and 2a) and the recessed portion (2c) having a shape bounded and defined by a smoothly continuous curve. The light control lens also has various other possible sectional shapes.

Dependencies are inferred from the claim text.