US3622786A
Expired / Lapsed
US
⏱️ 0.0 years remaining
X-ray image converter using a high performance folded objective lens
Assignee: General Electric Co
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Filing: 1969-11-19
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Granted: 1971-11-23
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Expires: 1989-11-19
Abstract
Abstract A high performance folded objective lens and a compact fluoroscopic apparatus incorporating the lens are disclosed. The objective lens has a relative aperture of f/1.0 and its performance has been optimized for use with an X-ray image intensifier tube. The lens consists of two spaced groups with a fold of 90* introduced between the two groups. The first group, which consists of four elements, is of relatively low power. The second group which consists of six elements is of relatively high power, designed particularly to have a short physical length. Provision has been made for makeup glass in the back focal region. The fluoroscopic apparatus, of which the lens is a part, achieves compactness measured along the axis of the X-ray beam by folding the optical axis. In a preferred application, this feature permits location of the fluoroscopic apparatus in the limited vertical dimensions available beneath an examination table without reduction in the efficiency of optical coupling to the conventional multiple output devices.
Inventors
- 👤 Bruce H Walker
- 👤 Robert Godbarsen Jr
- 👤 John A Bickford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:49
CPC Classifications
G; G02; G02B; G02B13/00; G03; G03B; G03B42/00; G03B42/02; G03B42/021; G03B42/023; H; H04; H04N; H04N5/00; H04N5/30; H04N5/32
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
132 words
In a fluoroscopic apparatus adapted for use with an X-ray beam, the combination comprising: a. an image converter and intensifier coaxially oriented along said beam; b. a folded objective lens having two groups with a mirror interposed between; one of said groups being a back group of relatively high power coaxially arranged with said image intensifier and optically coupled thereto, and a second, front group of relatively low power, whose axis is folded to a position orthogonal to that of said rear group, said mirror providing said fold in said axis, the exit pupil of said folded lens being a substantial distance in front of said front group; and c. output optical means including at least one lens having the entrance pupil thereof coupled to said folded lens at said exit pupil.
Claim 2
Dependent Claim
132 words
In a fluoroscopic apparatus adapted for use with an X-ray beam, the combination comprising: a. an image converter and intensifier coaxially oriented along said beam; b. a folded objective lens having two groups with a mirror interposed between; one of said groups being a back group of relatively high power coaxially arranged with said image intensifier and optically coupled thereto, and a second, front group of relatively low power, whose axis is folded to a position orthogonal to that of said rear group, said mirror providing said fold in said axis, the exit pupil of said folded lens being a substantial distance in front of said front group; and c. output optical means including at least one lens having the entrance pupil thereof coupled to said folded lens at said exit pupil.
Claim 3
Dependent Claim
32 words
The combination set forth in claim 1 wherein said back group consists of all positive doublet and singlet elements to achieve minimum physical length, said physical length approximating the focal length thereof.
Claim 4
Dependent Claim
31 words
The combination set forth in claim 1 wherein means are provided for reflecting the output of said objective lens orthogonal to the horizontal axis thereof, to one of said output means.
Claim 5
Dependent Claim
24 words
The combination set forth in claim 3 wherein at least one of the orthogonal positions is displaced from said axis in a horizontal plane.
Claim 6
Dependent Claim
19 words
THe combination set forth in claim 3 wherein one of the orthogonal positions is vertically displaced above said axis.
Claim 7
Dependent Claim
44 words
The combination set forth in claim 3 wherein said reflective means is a beam splitter partially reflecting the light coupled thereto to at least one output means and partially transmitting the light coupled thereto to a second output means coaxial with said horizontal axis.
Claim 8
Dependent Claim
45 words
The combination set forth in claim 6 wherein the minimum transmissive path length through said beam splitter from said front group to said output means approximates said substantial distance to permit said output means to be arranged substantially at said exit pupil to minimize vignetting.
Claim 9
Dependent Claim
45 words
The combination set forth in claim 3 wherein the minimum reflective path length via said reflecting means from said front group to said output means approximates said substantial distance to permit said output means to be arranged substantially at said exit pupil to minimize vignetting.
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) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |