Control of luminous intensity distribution from an array of point light sources

Abstract

In various embodiments, a lens array comprises a plurality of aspheric lens elements each optically coupled to a light-emitting element and producing an out-of-focus image thereof. The images combine to generate a target luminous intensity distribution, e.g., providing constant illuminance on a plane.

What is claimed is: 
     
         1 - 27 . (canceled) 
     
     
         28 . A luminaire comprising:
 a substantially planar array of light-emitting elements; and   a lens array comprising a continuous layer of transparent material having a first surface for receiving light from the light-emitting elements and, formed on a second surface thereof opposed to the first surface, a two-dimensional array of aspheric lens elements, at least some of which are optically coupled to a closest one of the light-emitting elements,   wherein (i) the light-emitting elements each have an optical axis shifted relative to an optical axis of the closest lens element, (ii) the light-emitting elements are spaced apart from the first surface by a first distance, and (iii) a light distribution pattern of the luminaire is radially asymmetric with respect to a direction perpendicular to a plane defined by the array of light-emitting elements.   
     
     
         29 . The luminaire of  claim 28 , wherein the aspheric lens elements in the two-dimensional array are substantially co-linear in a first direction, and the light distribution pattern of the luminaire is (i) tilted along the first direction and (ii) substantially spatially constant with respect to a plane not parallel to the plane defined by the array of light-emitting elements. 
     
     
         30 . The luminaire of  claim 29 , wherein the aspheric lens elements in the two-dimensional array are substantially co-linear in a second direction substantially perpendicular to the first direction. 
     
     
         31 . The luminaire of  claim 28 , wherein the lens elements each have a lens profile described by the lowest-order mathematical equation that generates a predetermined luminous intensity distribution when light emitted by the light-emitting elements and passing through the lens elements is combined, the profile specifying a lens shape and a lens thickness. 
     
     
         32 . The luminaire of  claim 31 , wherein the equation comprises parameters including a refractive index of the lens and dimensions of the light-emitting element, the thickness corresponding to a distance from a front surface of the lens element to the light-emitting element. 
     
     
         33 . The luminaire of  claim 31 , wherein the equation is a quadratic equation. 
     
     
         34 . The luminaire of  claim 31 , wherein the equation is a cubic equation. 
     
     
         35 . The luminaire of  claim 28 , wherein each lens element has an aspheric cubic lens profile. 
     
     
         36 . The luminaire of  claim 28 , wherein each lens element has an aspheric cubic linear lens profile. 
     
     
         37 . The luminaire of  claim 28 , wherein the light-emitting elements have rectangular emission surfaces. 
     
     
         38 . The luminaire of  claim 28 , wherein each lens element is shaped to produce a batwing luminous distribution profile when the optical axis of the lens element is not shifted relative to the optical axis of the closest light-emitting element. 
     
     
         39 . The luminaire of  claim 28 , wherein each lens element is shaped to produce a substantially collimated light distribution profile when the optical axis of the lens element is not shifted relative to the optical axis of the closest light-emitting element. 
     
     
         40 . The luminaire of  claim 39 , wherein the substantially collimated light distribution profile has a beam angle less than 15°. 
     
     
         41 . The luminaire of  claim 28 , wherein the asymmetric light distribution pattern is an asymmetric collimated light distribution pattern. 
     
     
         42 . The luminaire of  claim 41 , wherein the asymmetric collimated light distribution pattern has a beam angle less than 40°. 
     
     
         43 . The luminaire of  claim 28 , wherein the asymmetric light distribution pattern is an asymmetric batwing light distribution pattern. 
     
     
         44 . The luminaire of  claim 28 , wherein the first distance is essentially zero. 
     
     
         45 . The luminaire of  claim 44 , wherein each light-emitting element is directly bonded to the first surface. 
     
     
         46 . The luminaire of  claim 28 , wherein the light distribution pattern of the luminaire has a cutoff angle varying with changes in the first distance. 
     
     
         47 . The luminaire of  claim 28 , wherein the first distance is less than about 4.3 mm. 
     
     
         48 . The luminaire of  claim 28 , wherein the optical axis of each light-emitting element is shifted by about 1.5 mm. 
     
     
         49 . The luminaire of  claim 28 , wherein the light distribution pattern has a beam angle less than 40°. 
     
     
         50 . The luminaire of  claim 28 , wherein the two-dimensional array of aspheric lens elements forms a linear lens array. 
     
     
         51 . The luminaire of  claim 28 , wherein a thickness of the luminaire is less than about 9 mm. 
     
     
         52 . The luminaire of  claim 28 , wherein the aspheric lens elements in the two-dimensional array are substantially co-linear in a first direction, and the light distribution pattern of the luminaire is (i) tilted along the first direction and (ii) substantially radially symmetric with respect to a direction not perpendicular to the plane defined by the array of light-emitting elements.