Linear fresnel optic for reducing angular spread of light from LED array

摘要

A light source may comprise a cylindrical lens, for example a cylindrical Fresnel lens, a linear array of light-emitting elements, the linear array aligned with and emitting light through the cylindrical Fresnel lens, wherein the cylindrical Fresnel lens reduces the angular spread of light in a widthwise axis of the linear array, the linear array spanning a lens length.

主权项

1. A method of irradiating light, comprising:
irradiating light from a linear array of light-emitting elements, the linear array of light-emitting elements aligned with and emitting light through a cylindrical Fresnel lens, wherein the cylindrical Fresnel lens reduces an angular spread of light in a widthwise axis of the linear array, the linear array of light-emitting elements comprising a middle portion in between two end portions, the linear array having only a single row of elements, wherein:
the middle portion comprises a plurality of light-emitting elements distributed over the middle portion with a first spacing throughout the middle portion;each of the end portions comprises a plurality of light-emitting elements distributed over the end portion with a second spacing throughout each end portion,the first spacing is greater than the second spacing;a third spacing between the middle portion and each of the end portions is greater than the second spacing and less than the first spacing;the plurality of light-emitting elements in the middle portion have a first irradiance; andthe plurality of light-emitting elements in each end portion have a second irradiance.