Illumination apparatus

Abstract

An illumination apparatus comprises a plurality of LEDs aligned to an array of directional optical elements wherein the LEDs are substantially at the input aperture of respective optical elements. An electrode array is formed on the array of optical elements to provide at least a first electrical connection to the array of LED elements. Advantageously such an arrangement provides low cost and high efficiency from the directional LED array.

1 - 15 . (canceled) 
     
     
         16 . A method for manufacturing an illumination apparatus, the method comprising:
 forming a first array of light-emitting elements on a substrate;   determining a first plurality of the light-emitting elements which pass a functional criterion;   determining a second plurality of the light-emitting elements which fail the functional criterion;   selectively removing a plurality of the passed light-emitting elements whose relative positions in the first array correspond to desired relative positions in a desired array of light-emitting elements, the selectively removing being performed in a manner that preserves the relative spatial position of the selectively removed passed light-emitting elements; and   forming a second array of light-emitting elements with the selectively removed passed light-emitting elements in a manner that preserves the relative spatial position of the selectively removed passed light-emitting elements, by virtue of which in the formed second array of light-emitting elements desired relative positions of the desired array that correspond to passed light-emitting elements in the first array are occupied by passed light-emitting elements.   
     
     
         17 . The method according to  claim 16 , wherein further light-emitting elements are added to the formed second array of light-emitting elements in unoccupied desired relative positions of the desired array. 
     
     
         18 . The method according to  claim 17 , wherein the further light-emitting elements have been determined as passing the functional criterion. 
     
     
         19 . The method according to  claim 17 , wherein the further light-emitting elements are from the first array of light-emitting elements. 
     
     
         20 . The method according to  claim 17 , wherein the further light-emitting elements are from a third array of light-emitting elements that is different to the first and second arrays of light-emitting elements. 
     
     
         21 . The method according to  claim 16 , wherein the functional criterion includes at least one of intensity, colour, forward voltage, or defect density. 
     
     
         22 . The method according to  claim 16 , wherein the first array of light-emitting elements is made of a plurality of layers on the substrate, and wherein selectively removing the plurality of light-emitting elements comprises selectively illuminating the plurality of the light-emitting elements with an illumination that separates, at least to an extent, the selected light-emitting elements from the substrate. 
     
     
         23 . The method of  claim 22 , wherein the illumination further breaks the connection in the layers between each selectively illuminated light-emitting element and the other light-emitting elements. 
     
     
         24 . The method of  claim 22 , wherein the connection in the layers between each selectively illuminated light-emitting element and the other light-emitting elements is broken, at least to an extent, by at least one of a scribing step, an ablation step or an etch step. 
     
     
         25 . The method according to  claim 22 , wherein the selective illumination comprises a plurality of shaped laser beams. 
     
     
         26 . The method according to  claim 22 , where the selective illumination comprises electromagnetic radiation in the ultraviolet wavelength band. 
     
     
         27 . The method according to  claim 22 , wherein the substrate permits transmission of electromagnetic radiation therethrough. 
     
     
         28 . The method according to  claim 22 , further comprising providing a patterned support layer formed on the plurality of light-emitting elements. 
     
     
         29 . The method according to  claim 22 , wherein the light-emitting elements which fail the functional criterion are not illuminated or are illuminated below a threshold illumination level. 
     
     
         30 . The method according to  claim 22 , wherein a light intensity reduction region is formed on a surface of the substrate, the light intensity reduction region being aligned with at least one of the second plurality of light-emitting elements. 
     
     
         31 . The method according to  claim 30 , wherein the light intensity reduction region is arranged to absorb, diffuse, or reflect the selective illumination such that the power density at the surface of the substrate falls below a threshold. 
     
     
         32 . The method according to  claim 16 , further comprising aligning the second array of light-emitting elements with an array of optical elements. 
     
     
         33 . The method according to  claim 16 , wherein the light-emitting elements each have a maximum dimension of 0.1 mm or less. 
     
     
         34 . The method according to  claim 16 , wherein:
 a first sub-plurality of the light-emitting elements of the second array provides a first average color in a first region of the second array; and   a second sub-plurality of the light-emitting elements of the second array provides a second average color in a second region of the second array; and   the first average color and second average color are substantially the same.   
     
     
         35 . An illumination apparatus formed by a method comprising the steps of:
 forming a first array of light-emitting elements on a substrate;   determining a first plurality of the light-emitting elements which pass a functional criterion;   determining a second plurality of the light-emitting elements which fail the functional criterion;   selectively removing a plurality of the passed light-emitting elements whose relative positions in the first array correspond to desired relative positions in a desired array of light-emitting elements, the selectively removing being performed in a manner that preserves the relative spatial position of the selectively removed passed light-emitting elements; and   forming a second array of light-emitting elements with the selectively removed passed light-emitting elements in a manner that preserves the relative spatial position of the selectively removed passed light-emitting elements, by virtue of which in the formed second array of light-emitting elements desired relative positions of the desired array that correspond to passed light-emitting elements in the first array are occupied by passed light-emitting elements.