Patent ID: 6809869
Filing Date: 2004-10-26
Classification: F21V,G02B

Abstract:
An apparatus for controlling divergence of a beam of light, comprising:a first multiple-lens array comprising a plurality of positive-power lenses arranged in a pattern and supported on a transparent substrate, said plurality of positive-power lenses having a positive optical power and a focal length; a second multiple-lens array comprising a plurality of negative-power lenses arranged in a pattern and supported on a transparent substrate, said plurality of negative-power lenses having a negative optical power different from said optical power of said positive-power lenses of said first multiple-lens array; the first and second multiple-lens arrays being formed so that each positive-power lens surface of the first array corresponds to and is aligned with a negative-power lens surface of the second array; the first and second multiple-lens arrays being disposed serially and coaxially in a light beam path such that positive-power lens surfaces of the first array are generally adjacent negative-power surfaces of the second array; one of the multiple-lens arrays being movable coaxially with respect to the other of the multiple-lens arrays; wherein the divergence of the beam of light is controlled by a variable spacing between the first and second multiple-lens arrays and wherein a combined optical power of said first and second lenses is substantially zero when said first and second multiple-lens arrays are separated at a distance greater than zero but less than the focal length of said positive-power lenses of said first multiple-lens array.