Patent ID: 8011793

Claim:
A telescope comprising: an entrance pupil region; a first concave mirror (M 1 ) belonging to a first imaginary axially symmetric aspheric surface and reflecting light passing through said entrance pupil region; a second convex mirror (M 2 ) belonging to a second imaginary axially symmetric aspheric surface and reflecting light reflected by said first mirror; a third convex mirror (M 3 ) belonging to a third imaginary aspheric surface axially symmetric about a symmetry axis z and reflecting light reflected by said second mirror; a fourth concave mirror (M 4 ) belonging to a fourth imaginary axially symmetric aspheric surface and reflecting light reflected by said third mirror and passing through an exit pupil; wherein said third mirror is axially symmetric about the symmetry axis z, and said first, second, third and fourth axially symmetric aspheric surfaces being centered on the symmetry axis z of the third mirror, said first, second and fourth mirrors being centered about a first plane formed by said symmetric axis z and a first direction perpendicular to said symmetry axis z and off-centered in a second plane perpendicular to said first plane along said symmetry axis z.