US3697154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical viewing system
Assignee: United States Department of the Navy
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Filing: 1971-05-12
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Granted: 1972-10-10
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Expires: 1991-05-12
Abstract
Abstract Images formed on the screen of a cathode ray tube (CRT) are reflected from a curved mirror having a general aspheric surface of revolution to a partially reflective combiner having two nonparallel hyperboloid surfaces. The combiner is positioned in the normal line of sight of an observer, for instance, in the windshield area of an aircraft cockpit. A collimated CRT image is reflected from the near surface of the combiner to the observer''s eyes. The combiner is adapted to transmit light incident from the outside so that the CRT display is superimposed without parallax on the real world to provide a head-up display.
Inventors
- 👤 Frithiof V Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:34
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/01; G02B27/0101
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
159 words
A viewing system comprising a beam combiner element positioned in the normal line of sight of an observer, said combiner having a transparent body provided with a convex aspheric outer surface and a concave partially reflective aspheric inner surface, said inner and outer surfaces being sections of surfaces of revolution about a first axis below and substantially parallel to the line of sight; said inner surface being a section of a hyperboloid and being shaped to collimate rays of light coming from a mirror element, said mirror element having a convex aspheric reflecting surface of revolution about said first axis facing said combiner inner surface and spaced therefrom along said first axis; and a display screen positioned on said first axis opposite said mirror at the focal plane of said combiner and mirror surfaces, whereby light from the display screen is reflected by the convex mirror toward the combiner, and collimated by the combiner and reflected toward the observer.
Claim 2
Dependent Claim
159 words
A viewing system comprising a beam combiner element positioned in the normal line of sight of an observer, said combiner having a transparent body provided with a convex aspheric outer surface and a concave partially reflective aspheric inner surface, said inner and outer surfaces being sections of surfaces of revolution about a first axis below and substantially parallel to the line of sight; said inner surface being a section of a hyperboloid and being shaped to collimate rays of light coming from a mirror element, said mirror element having a convex aspheric reflecting surface of revolution about said first axis facing said combiner inner surface and spaced therefrom along said first axis; and a display screen positioned on said first axis opposite said mirror at the focal plane of said combiner and mirror surfaces, whereby light from the display screen is reflected by the convex mirror toward the combiner, and collimated by the combiner and reflected toward the observer.
Claim 3
Dependent Claim
25 words
An optical system according to claim 1 further comprising: said combiner outer surface being a section of a second hyperboloid different from said first hyperboloid.
Claim 4
Dependent Claim
41 words
An optical system according to claim 2 further comprising: said mirror surface being a sectioned aspheric surface above a first plane, including the first axis, perpendicular to a second plane substantially defined by the first axis and the line of sight.
Claim 5
Dependent Claim
92 words
An optical system according to claim 3 further comprising: said screen being disposed on the intersection of the first axis and a second axis orthogonal thereto and lying in the second plane, said screen extending perpendicularly to the second plane and tilted by an angle Alpha with respect to said second axis, a geometrical extension of said combiner inner surface crossing said first axis at a distance d1 behind said screen, and a geometrical extension of said mirror surface crossing said first axis at a distance d2 in front of said screen.
Claim 6
Dependent Claim
68 words
An optical system according to claim 4 further comprising: said combiner inner surface having a cross-sectional profile in the second plane defined in relation to the first and second axes, designated x and y axes respectively as x (1.5106448y2 + 26.570992) 1/2 - 26.57099, the dimensions being in inches; and said mirror surface having a cross-sectional profile similarly defined as x 0.00342035y + 0.0418094y2 - 0.00761052y3 + 0.000468966y4.
Claim 7
Dependent Claim
39 words
An optical system according to claim 5 further comprising; said combiner outer surface having a cross-sectional profile similarly defined as x (1.5065y2 + 26.60822) 1/2 - 26.6082, said combiner element having an average thickness of about a quarter inch.
Claim 8
Dependent Claim
26 words
An optical system according to claim 6 further comprising: said screen having a sperhical surface similArly defined as (x - 6.70)2 + (y - 0.835)2 6.752.
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) | 1975-10-10 | 1976-04-10 | 1976-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-10 | 1980-04-10 | 1980-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-10 | 1984-04-10 | 1984-10-10 | $7700.00 | Window Closed / Lapsed |