Patent ID: 7729578
Filing Date: 2010-06-01
Classification: F21V,F21Y,G02B

Abstract:
1. An apparatus comprising: at least one ray guide substantially cylindrically symmetrical about an axis; said at least one ray guide being arranged to substantially image at least a portion of the rays, which emanate from a non-point object towards an entrance pupil of the said at least one ray guide, to an image; and in each individual cross-sectional plane which includes the said axis and a portion of the entrance pupil, said at least one ray guide being arranged to image an individual subset of the rays which emanate from the non-point object along the individual cross-sectional plane towards a portion of the entrance pupil which is on the individual cross-sectional plane and on one side of the axis to an intermediate image on the individual cross-sectional plane, and to further substantially image the at least a portion of the rays from the intermediate image to an cross-sectional image on the cross-sectional plane, which cross-sectional image substantially coincides with a cross-section of the image at the said individual cross-sectional plane, such that no two said intermediate images of two different individual cross-sectional planes cross each other.