| CPC A01M 21/04 (2013.01) [F21V 5/007 (2013.01); F21V 5/008 (2013.01); F21Y 2115/10 (2016.08); F21Y 2115/30 (2016.08)] | 18 Claims |
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1. A weeding apparatus comprising a concentrator assembly (1) having:
a two-dimensional array of discrete semiconductor light emitters (2);
a primary optical stage (3) comprising a plurality of collimating lenses (4) each corresponding to one of said semiconductor light emitters (2) to collimate light therefrom whereby the primary optical stage is operable to produce a compound collimated beam (10);
a secondary optical stage (5) which incorporates a lens system arranged to convert the compound collimated beam (10) into a convergent beam (11) to concentrate the emitted light at a focal position;
wherein the semiconductor light emitters (2) are light emitting diodes;
wherein the compound collimated beam (10) produced by the primary optical stage (3) passes directly to the secondary optical stage (5) without any intervening lens system;
the weeding apparatus being arranged such that the concentrator assembly (1) can be moved to direct the focal position onto a selected plant to be damaged by light which is thereby concentrated thereon.
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