Patent ID: 7473000

Claim:
An apparatus comprising: a substantially planar surface; a curved primary mirror having a first perimeter, at least a portion of the first perimeter being in contact with the substantially planar surface; a secondary mirror disposed between the substantially planar surface and the curved primary mirror, the secondary mirror associated with a desired focal area located between the curved primary mirror and the secondary mirror; and a substantially non-reflecting shield element disposed at least partially between the substantially planar surface and a portion of the desired focal area, wherein a portion of the shield element is disposed between the substantially planar surface and a plane which is substantially parallel to the substantially planar surface and which includes a portion of the desired focal area, and wherein the portion of shield element is disposed between the secondary mirror and an area of the primary mirror toward which the secondary mirror directs light which is not substantially normal to the substantially planar surface when entering the substantially planar surface.