US3752559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ritchey-chretien telescope
Assignee: Individual
•
Filing: 1971-10-29
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Granted: 1973-08-14
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Expires: 1991-10-29
Abstract
Abstract A Ritchey-Chretien telescope responsive to images located off the telescope optical axis includes transparent flat plate means positioned in the ray path of the image. The flat plate means has a tilt angle relative to the ray path to compensate substantially for astigmatism introduced by the Ritchey-Chretien telescope. The tilt angle of the plate means is directly proportional to the off axis angle of the image. The plate means preferably comprises two flat plates having opposite inclination angles relative to the ray path. A detector responsive to the optical image as transmitted through the flat plate means is positioned approximately on the sagittal focus of the telescope.
Inventors
- 👤 J Fletcher
- 👤 S Rosin
- 👤 M Amon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:14
CPC Classifications
G; G02; G02B; G02B23/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
100 words
In a Ritchey-Chretien telescope having an optical axis and a primary optical system for detecting on-axis images, a separate secondary optical system located on a projection of said optical axis and having a field of view intercepting ray energy for offaxis images simultaneously with on-axis images, said secondary optical system including a detector for off-axis energy rays, and compensating means positioned in the off-axis energy ray path, said compensating means comprising flat transparent plate means positioned with its major surface tilted at an angle relative to said energy ray path to compensate substantially for astigmatism introduced in the off-axis images.
Claim 2
Dependent Claim
100 words
In a Ritchey-Chretien telescope having an optical axis and a primary optical system for detecting on-axis images, a separate secondary optical system located on a projection of said optical axis and having a field of view intercepting ray energy for offaxis images simultaneously with on-axis images, said secondary optical system including a detector for off-axis energy rays, and compensating means positioned in the off-axis energy ray path, said compensating means comprising flat transparent plate means positioned with its major surface tilted at an angle relative to said energy ray path to compensate substantially for astigmatism introduced in the off-axis images.
Claim 3
Dependent Claim
33 words
The telescope of claim 1 wherein the tilt angle of said plate means from the normal of the energy ray path is approximately directly proportional to the off axis angle of the image.
Claim 4
Dependent Claim
23 words
The telescope of claim 1 wherein the detector for off-axis energy rays is positioned approximately at the sagittal foci of the Ritchey-Chretien telescope.
Claim 5
Dependent Claim
25 words
The telescope of claim 3 wherein the detector lies in a plane having an inclination angle realtive to the axis that approximates the sagittal foci.
Claim 6
Dependent Claim
23 words
The telescope Of claim 1 wherein the plate means comprises two flat, transparent plates having opposite inclination angles relative to the ray path.
Claim 7
Dependent Claim
28 words
The telescope of claim 5 wherein the plates have substantially the same index of refraction and thickness and equal but opposite inclination angles relative to the ray path.
Claim 8
Dependent Claim
30 words
The telescope of claim 6 wherein the tilt angle of each plate from the normal of the axis is approximately directly proportional to the off axis angle of the image.
Claim 9
Dependent Claim
32 words
The telescope of claim 1 further including means for positioning the detector and plate means at a position displaced from the optical axis commensurate with the off axis angle of the image.
Claim 10
Dependent Claim
33 words
The telescope of claim 1 further including means for positioning the detector and plate means at an angle about the optical axis commensurate with the angular position of the image about the axis.
Claim 11
Dependent Claim
32 words
The telescope of claim 9 further including means for positioning the detector and plate means at a postion displaced from the optical axis commensurate with the off axis angle of the image.
References Cited (Backward Citations)
US2672072A
Cited
US3598468A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |