Optical: systems and elements – Lens – Afocal
Reexamination Certificate
2009-06-24
2010-11-30
Spector, David N (Department: 2873)
Optical: systems and elements
Lens
Afocal
C359S712000
Reexamination Certificate
active
07843650
ABSTRACT:
An afocal monolithic optical element formed of a shallow cylinder of optical material (glass, polymer, etc.) with fast aspheric surfaces, nominally confocal paraboloids, configured on the front and back surfaces. The front surface is substantially planar, and this lends itself to deposition of multi-layer stacks of thin dielectric and metal films to create a filter for rejecting out-of-band light. However, an aspheric section (for example, a paraboloid) can either be ground into a small area of this surface (for a Cassegrain-type telescope) or attached to the planar surface (for a Gregorian-type telescope). This aspheric section of the surface is then silvered to create the telescope's secondary mirror. The rear surface of the cylinder is figured into a steep, convex asphere (again, a paraboloid in the examples), and also made reflective to form the telescope's primary mirror. A small section of the rear surface (approximately the size of the secondary obscuration, depending on the required field of the telescope) is ground flat to provide an unpowered surface through which the collimated light beam can exit the optical element. This portion of the rear surface is made to transmit the light concentrated by the reflective surfaces, and can support the deposition of a spectral filter.
REFERENCES:
patent: 3811749 (1974-05-01), Abel
patent: 5654831 (1997-08-01), Byren et al.
patent: 5973858 (1999-10-01), Sekita
patent: 2010/0091396 (2010-04-01), Hutson et al.
Devany, Optical design for two telescopes, Applied Optics, Feb. 1963, vol. 2, Issue 2, p. 201.
Smith, Warren J., Modern Lens Design: a resource manual, McGraw-Hill Professional I 1992, pp. 295-296.
Homer Mark
Spector David N
The United States of America as represented by the Administrator
LandOfFree
Monolithic afocal telescope does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Monolithic afocal telescope, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Monolithic afocal telescope will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-4204308