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US 4,342,503 AGranted
Catadioptric telescopes
AssigneeThe Perkin-Elmer Corporation
InventorDavid R. Shafer
Life of this patent
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AssigneeThe Perkin-Elmer Corporation
InventorDavid R. Shafer
Estimating the term…
The first element comprises a relatively thin transmissive shell concave toward the front. The second element comprises a mirror concave toward the front. The front surface of the shell may be spherical, and the rear surface aspheric, or vice versa. The central portion of the first element on either the front or back surface is mirrored to form the secondary of the system. Preferably the secondary mirror is on the front of the first element. In one embodiment the second element is also a transmissive shell. In one form of this embodiment the second transmissive shell is aspheric on the front and spherical on the back. In another form it is spherical on the front and aspheric on the back. In both of these forms the primary mirror is located on the back of the second element. In another embodiment the second transmissive element is aspheric on the front and flat on the back; the front surface being mirrored except for the central portion thereof, through which light from the secondary is focused. In most embodiments all radii of curvature (the base curve in case of aspherics) are substantially equal. Higher dispersion in the second shell than in the first can correct for spherochromatism.
A two-element catadioptric telescope consisting of:
A two-element catadioptric telescope consisting of:
A two-element catadioptric telescope consisting of:
A two-element catadioptric telescope consisting of:
Dependencies are inferred from the claim text.