Patent US3942877A successfully refreshed from Google Patents.
US3942877A
Expired / Lapsed
US
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Short focal length Petzval-type optical system
Assignee: Bell and Howell Co
•
Filing: 1974-11-11
•
Granted: 1976-03-09
•
Expires: 1994-11-11
Abstract
Abstract This invention relates to a short focal length, large aperture Petzval-type optical system primarily designed to efficiently transmit light rays to an image plane with an extraordinarily high degree of correction over a prescribed field.
Inventors
- 👤 Andor A. Fleischman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:44
CPC Classifications
G; G02; G02B; G02B13/00; G02B9/00; G02B9/34; G02B13/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
176 words
An optical system of relatively short focal length and large aperture having substantially the following specification: EFL = 7.38mm
1/2 Angle of Field = 2.58°
LENS RADII (IN.) THICKNESS (IN.)
SPACING (IN.)
______________________________________
L.sub.1
R.sub.1 =
.8013
D.sub.1 = .0890
R.sub.2 =
1.7049
S.sub.1 = .0163
L.sub.2
R.sub.3 =
- .4552
D.sub.2 = .0400
R.sub.4 =
.8970
S.sub.2 = .3381
L.sub.3
R.sub.5 =
.5318
D.sub.3 = .0852
R.sub.6 =
1.4273
S.sub.3 = .0050
L.sub.4
R.sub.7 =
.1864
D.sub.4 = .0861
R.sub.8 =
- .2589
S.sub.4 = .1320 BFL
ALL ELEMENTS: V = 25.8, N.sub.D = 1.785
______________________________________ wherein the first column lists the lens elements numerically starting at the ray entrance side of the system which elements each have the same dispersive index and refractive index; the second column lists the respective base radii R 1 to R 8 ; the third column lists the thickness D 1 to D 4 of the respective elements; and the fourth column lists the axial spacings S 1 to S 4 between the respective elements, and the image plane.
Claim 2
Dependent Claim
176 words
An optical system of relatively short focal length and large aperture having substantially the following specification: EFL = 7.38mm
1/2 Angle of Field = 2.58°
LENS RADII (IN.) THICKNESS (IN.)
SPACING (IN.)
______________________________________
L.sub.1
R.sub.1 =
.8013
D.sub.1 = .0890
R.sub.2 =
1.7049
S.sub.1 = .0163
L.sub.2
R.sub.3 =
- .4552
D.sub.2 = .0400
R.sub.4 =
.8970
S.sub.2 = .3381
L.sub.3
R.sub.5 =
.5318
D.sub.3 = .0852
R.sub.6 =
1.4273
S.sub.3 = .0050
L.sub.4
R.sub.7 =
.1864
D.sub.4 = .0861
R.sub.8 =
- .2589
S.sub.4 = .1320 BFL
ALL ELEMENTS: V = 25.8, N.sub.D = 1.785
______________________________________ wherein the first column lists the lens elements numerically starting at the ray entrance side of the system which elements each have the same dispersive index and refractive index; the second column lists the respective base radii R 1 to R 8 ; the third column lists the thickness D 1 to D 4 of the respective elements; and the fourth column lists the axial spacings S 1 to S 4 between the respective elements, and the image plane.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-09 | 1979-09-08 | 1980-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-09 | 1983-09-08 | 1984-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-09 | 1987-09-08 | 1988-03-09 | $7700.00 | Window Closed / Lapsed |