US4354742A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical system having a dual field of view
Assignee: Honeywell Inc
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Filing: 1980-11-10
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Granted: 1982-10-19
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Expires: 2000-11-10
Abstract
Abstract An optical system having a dual field of view. The system includes a wide-angle objective comprising a lens, a concave primary mirror, and a movable convex secondary mirror having a first position and a second position. When in the first position, the secondary mirror permits the wide-angle objective to focus radiation. When in the second position, the secondary mirror prevents radiation from being focused by the wide-angle objective. The combination of the secondary mirror when in the second position and the primary mirror comprise a narrow-angle objective with the primary mirror converging radiation to the secondary mirror and the secondary mirror focusing radiation. Thus, the optical system has a wide-angle field of view whenever the secondary mirror is in the first position and a narrow-angle field of view whenever the secondary mirror is in the second position.
Inventors
- 👤 Irving R. Abel
- 👤 Marcus R. Hatch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:27
CPC Classifications
G; G02; G02B; G02B17/00; G02B17/08; G02B17/0856; G02B17/0804; G02B17/0808; G02B17/0852; G02B17/0884; G02B17/0896
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
134 words
An optical system having a duel field of view comprising: a wide-angle objective comprising a lens; a concave primary mirror; a movable convex secondary mirror having a first position and a second position; the secondary mirror when in the first position permitting the wide-angle objective to focus radiation; the secondary mirror when in the second position preventing radiation from being focused by the wide-angle objective; the combination of the secondary mirror when in the second position and the primary mirror comprising a narrow-angle objective with the primary mirror converging radiation to the secondary mirror and the secondary mirror focusing radiation; whereby the optical system has a wide-angle field of view whenever the secondary mirror is in the first position, and a narrow-angle field of view whenever the secondary mirror is in the second position.
Claim 2
Dependent Claim
134 words
An optical system having a duel field of view comprising: a wide-angle objective comprising a lens; a concave primary mirror; a movable convex secondary mirror having a first position and a second position; the secondary mirror when in the first position permitting the wide-angle objective to focus radiation; the secondary mirror when in the second position preventing radiation from being focused by the wide-angle objective; the combination of the secondary mirror when in the second position and the primary mirror comprising a narrow-angle objective with the primary mirror converging radiation to the secondary mirror and the secondary mirror focusing radiation; whereby the optical system has a wide-angle field of view whenever the secondary mirror is in the first position, and a narrow-angle field of view whenever the secondary mirror is in the second position.
Claim 3
Dependent Claim
23 words
The apparatus of claim 1 wherein the radiation is focused at the same location by both the wide-angle objective and the narrow-angle objective.
Claim 4
Dependent Claim
19 words
The apparatus of claim 2 wherein at least one of the primary mirror and the secondary mirror is aspheric.
Claim 5
Dependent Claim
16 words
The apparatus of claim 3 wheein both the primary mirror and the secondary mirror are aspheric.
Claim 6
Dependent Claim
21 words
The apparatus of claim 3 wherein the primary mirror has an aperture for transmission of radiation reflected from the secondary mirror.
Claim 7
Dependent Claim
24 words
The apparatus of claim 5 wherein compactness of the narrow-angle objective is measured by the ratio: ##EQU2## and wherein the ratio is approximately 0.3.
Claim 8
Dependent Claim
19 words
The apparatus of claim 1 wherein at least one of the primary mirror and the secondary mirror is aspheric.
Claim 9
Dependent Claim
16 words
The apparatus of claim 7 wherein both the primary mirror and the secondary mirror are aspheric.
Claim 10
Dependent Claim
21 words
The apparatus of claim 7 wherein the primary mirror has an aperture for transmission of radiation reflected from the secondary mirror.
Claim 11
Dependent Claim
24 words
The apparatus of claim 9 wherein compactness of the narrow-angle objective is measured by the ratio: ##EQU3## and wherein the ratio is approximately 0.3.
Claim 12
Dependent Claim
21 words
The apparatus of claim 1 wherein the primary mirror has an aperture for transmission of radiation reflected from the secondary mirror.
Claim 13
Dependent Claim
24 words
The apparatus of claim 11 wherein compactness of the narrow-angle objective is measured by the ratio: ##EQU4## and wherein the ratio is approximately 0.3.
Claim 14
Dependent Claim
24 words
The apparatus of claim 1 wherein compactness of the narrow-angle objective is measured by the ratio: ##EQU5## and wherein the ratio is approximately 0.3.
Claim 15
Dependent Claim
68 words
The apparatus of claim 1 wherein the convex secondary mirror comprises a lens having a first and second surface, the second surface being coated with reflective material, the radiation received from the primary mirror being refracted at the first surface, reflected back from the second surface, and then refracted once again by the first surface, the configuration of the first and second surfaces providing control of field curvature.
Claim 16
Dependent Claim
112 words
The apparatus of claim 1 wherein the convex secondary mirror comprises a lens having a first and a second surface, the second surface being coated with reflective material, the radiation received from the primary mirror being refracted at the first surface, reflected back from the second surface, and then refracted once again by the first surface, the first and second surfaces each having radii which determine the field curvature by the equation 1/R=2[n-1)/r.sub.1+ 1/r.sub.2 ]/n where R is the radius of the field curvature, n is the index of refraction of the lens, r 1 is the radius of the first surface, and r 2 is the radius of the second surface.
Claim 17
Dependent Claim
83 words
The apparatus of claim 15 wherein the power of the secondary mirror is 1/f and is defined by the equation 1/f=2[n/r.sub.2 -(n-1)r.sub.1 ] wherein f is the focal length of the secondary mirror, n is the index of refraction of the lens, r 1 is the radius of the first surface, and r 2 is the radius of the second surface, whereby the radii of the first and second surfaces can be selected by provide any combination of focusing power and field curvature.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-18 | 1986-04-19 | 1986-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-18 | 1990-04-19 | 1990-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-18 | 1994-04-19 | 1994-10-19 | $7700.00 | Window Closed / Lapsed |