Illumination Devices Including Multiple Light Emitting Elements

Abstract

A variety of illumination devices are disclosed that are configured to manipulate light provided by one or more light-emitting elements (LEEs). In general, embodiments of the illumination devices feature one or more optical couplers that redirect illumination from the LEEs to a reflector which then directs the light into a range of angles. In some embodiments, the illumination device includes a second reflector that reflects at least some of the light from the first reflector. In certain embodiments, the illumination device includes a light guide that guides light from the collector to the first reflector. The components of the illumination device can be configured to provide illumination devices that can provide a variety of intensity distributions. Such illumination devices can be configured to provide light for particular lighting applications, including office lighting, task lighting, cabinet lighting, garage lighting, wall wash, stack lighting, and downlighting.

What is claimed is: 
     
         1 . A light emitting device, comprising:
 a plurality of light emitting elements arranged along a path in a plane and oriented to emit light having a first spectral power distribution in a common direction away from the plane;   an optical coupler arranged to receive light from the plurality of light emitting elements, direct the received light to an exit aperture of the optical coupler and collimate the received light;   a solid optical element arranged to receive light exiting the optical coupler through the exit aperture in a first angular range, the solid optical element being configured to emit the light in a second angular range different from the first angular range; and   a wavelength-conversion material positioned remote from the light emitting elements downstream from the optical coupler and configured to convert light with the first spectral power distribution to light having a second spectral power distribution,   wherein the light emitting device emits light with a third spectral power distribution corresponding to a combination of light having the first spectral power distribution emitted by the light emitting elements and light having the second spectral power distribution emitted by the wavelength-conversion material.   
     
     
         2 . The light emitting device of  claim 1 , wherein the optical coupler is a solid optical coupler comprising a material transparent to the received light. 
     
     
         3 . The light emitting device of  claim 2 , wherein the optical coupler comprises a plurality of dielectric compound parabolic concentrators. 
     
     
         4 . The light emitting device of  claim 1 , wherein the optical coupler directs light to the exit aperture by total internal reflection of the light at side walls of the optical coupler. 
     
     
         5 . The light emitting element of  claim 1 , wherein the optical coupler is a linear optical coupler having a uniform cross-section along the path. 
     
     
         6 . The light emitting device of  claim 1 , wherein the optical coupler is a hollow optical coupler. 
     
     
         7 . The light emitting device of  claim 1 , wherein the optical coupler comprises a plurality of coupler elements each configured to receive light from a corresponding one of the light emitting elements. 
     
     
         8 . The light emitting device of  claim 7 , wherein each coupler element has a width of about 2 mm to about 6 mm and a height of about 3 mm to about 8 mm. 
     
     
         9 . The light emitting device of  claim 1 , wherein the plurality of light emitting elements are arranged in a linear array. 
     
     
         10 . The light emitting device of  claim 1 , wherein the solid optical element comprises a light guide. 
     
     
         11 . The light emitting element of  claim 10 , wherein the solid optical element further comprises an extraction optic arranged to received light from the light guide and direct the light out of the light emitting device. 
     
     
         12 . The light emitting device of  claim 1 , wherein the solid optical element is arranged between the optical coupler and the wavelength-conversion material. 
     
     
         13 . The light emitting device of  claim 1 , wherein the wavelength-conversion material is a phosphor disposed in a phosphor layer. 
     
     
         14 . The light emitting device of  claim 13 , wherein the phosphor layer is a flat phosphor layer. 
     
     
         15 . The light emitting device of  claim 13 , wherein the phosphor layer is a curved phosphor layer. 
     
     
         16 . The light emitting device of  claim 1 , wherein the light having the third spectral power distribution exiting the light emitting device is white light. 
     
     
         17 . The light emitting device of  claim 1 , wherein white light has a color temperature in a range from 2800K-5000K. 
     
     
         18 . The light emitting device of  claim 1 , wherein the light emitting elements are light emitting diode (LED) dies.