EFFICIENT COLLIMATING OPTICS BY COLLECTING THE FULL HEMISPHERE IN TIR-FRESNEL LENS DESIGNS

摘要

The invention provides a lighting device (1) comprising a light source unit (10), the light source unit (10) comprising a light source (100), a lens comprising optical element (200), and a light redirection element (300), wherein: - the lens comprising optical element (200) comprises (i) a first lens part (210) with Fresnel functionality, and (ii) a second lens part (220) having total internal reflection 5 functionality; - the light source (100) is configured to generate light source light (101) having a light exit angle (σ) larger than 45° relative to the optical axis, wherein a first part (101a) of the light source light (101) can reach the lens comprising optical element (200) without a redirection, and a second part (101b) of the light source light (101) cannot reach the lens 10 comprising optical element (200) without a redirection; and - the light redirection element (300) is configured to redirect at least part of the second part (101b) of the light source light (101) to the second lens part (220) having total internal reflection functionality.