US 10,539,730 B2
Light source with diffractive outcoupling
Dirk Kornelis Gerhardus De Boer, Eindhoven (NL); Marcus Antonius Verschuuren, Eindhoven (NL); Anne Souren, Eindhoven (NL); and Hendrik Johannes Boudewijn Jagt, Eindhoven (NL)
Assigned to SIGNIFY HOLDING B.V., Eindhoven (NL)
Appl. No. 15/759,954
Filed by SIGNIFY HOLDING B.V., Eindhoven (NL)
PCT Filed Apr. 26, 2016, PCT No. PCT/EP2016/059220
§ 371(c)(1), (2) Date Mar. 14, 2018,
PCT Pub. No. WO2017/054937, PCT Pub. Date Apr. 6, 2017.
Claims priority of application No. 15187285 (EP), filed on Sep. 29, 2015.
Prior Publication US 2018/0252855 A1, Sep. 6, 2018
Int. Cl. H01L 33/50 (2010.01); F21V 8/00 (2006.01); H01L 25/075 (2006.01); G02B 19/00 (2006.01); F21Y 115/10 (2016.01); G03B 21/20 (2006.01)
CPC G02B 6/0003 (2013.01) [G02B 19/0009 (2013.01); G02B 19/0066 (2013.01); H01L 25/0753 (2013.01); H01L 33/505 (2013.01); F21Y 2115/10 (2016.08); G02B 6/0053 (2013.01); G02B 6/0068 (2013.01); G03B 21/204 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An illumination device comprising:
a plurality of solid state light sources and
a concentrating wavelength converter arranged to inject light from said light sources through at least one entrance surface and to extract wavelength converted light from at least one exit surface,
wherein said wavelength converter is configured to provide total internal reflection of converted light when an incidence angle at a side surface is between an angle A and 90 degrees, where the angle A is determined by the refractive index of the converter and the surrounding media, respectively, and wherein the geometry of said wavelength converter is such that an incidence angle of converted light at said exit surface, after total internal reflection in said side surface, is in a range including angles greater than the angle A, wherein the angle A is defined as A=a sin(nsurr/nconv) where nsurr is the index of refraction of the surrounding media of the wavelength converter and where nconv is the index of refraction of the material forming the wavelength converter,
a structured layer provided on said exit surface, wherein said structured layer has a structure period less than 5 micrometers, so as to enable out-coupling by a combination of refraction and diffraction, and the index of refraction of the material forming said structured layer is equal to or greater than nconv−0.3.