F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
F21V9/00—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters
F21V9/30—Elements containing photoluminescent material distinct from or spaced from the light source
F21V9/32—Elements containing photoluminescent material distinct from or spaced from the light source characterised by the arrangement of the photoluminescent material
F21V9/35—Elements containing photoluminescent material distinct from or spaced from the light source characterised by the arrangement of the photoluminescent material at focal points, e.g. of refractors, lenses, reflectors or arrays of light sources