Patent ID: 6873446
Filing Date: 2005-03-29
Classification: G02B

Abstract:
1. An optical deflector comprising a deflecting lens ( 1 , 13 ) having a first aspheric lens surface of positive optical power and having a first focal length giving rise to a first focal point ( 3 ) and a second aspheric lens surface of positive optical power and having a second focal length giving rise to a second focal point ( 5 ), the first focal length being shorter than the second focal length, whereby a divergent beam ( 7 ) of light substantially at one of the first and second focal points is focussed by the lens at the other of the first and second focal points, means ( 19 ) adapted to rotate the lens about an axis substantially perpendicular to an optical axis of the lens and substantially coincident with one of the first and second focal points, and a focussing lens ( 9 ) provided in a light path extending on that side of the first focal point ( 3 ) remote from the lens ( 1 , 13 ) and adjustable so as to alter the depth of the second focal point.