Patent US4743092A successfully refreshed from Google Patents.
US4743092A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polarizing grids for far-infrared and method for making same
Assignee: United States Department of the Army
•
Filing: 1986-11-26
•
Granted: 1988-05-10
•
Expires: 2006-11-26
Abstract
Abstract A polarizing wire grid filter for use at far infrared frequencies is provided through simple photographic method which employs a newly marketed silver diffusion transfer-developer combination package film and a portable instant developing machine, all supplied by the manufacturer of the film.
Inventors
- 👤 Helmut H. Pistor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:31
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/04; G03C7/06; G03C7/10; G03C7/12; G02; G02B; G02B5/00; G02B5/30; G02B5/3025; G02B5/3058; G03C8/00; G03C8/02; G03C8/04; G03C8/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
68 words
In a far-infrared system having a polarized wire grid filter, the improvement wherein said filter comprises: only a sheet of silver diffusion transfer film, exposed to a light image of said grid and developed, so that said grid is formed as a specularly reflecting silver image covered only by a transparent protective layer with a thickness measuring only a small fraction of a wavelength in the far-infrared spectrum.
Claim 2
Dependent Claim
68 words
In a far-infrared system having a polarized wire grid filter, the improvement wherein said filter comprises: only a sheet of silver diffusion transfer film, exposed to a light image of said grid and developed, so that said grid is formed as a specularly reflecting silver image covered only by a transparent protective layer with a thickness measuring only a small fraction of a wavelength in the far-infrared spectrum.
Claim 3
Dependent Claim
18 words
A system according to claim 1 wherein: said grid consists of a series of straight, parallel silver strips.
Claim 4
Dependent Claim
18 words
A system according to claim 1 wherein: said grid consists of a series of curved, parallel silver strips.
Claim 5
Dependent Claim
18 words
A system according to claim 1 wherein: said grid consists of a series of circular, parallel silver strips.
Claim 6
Independent Claim
91 words
The method for making a far-infrared wire grid filter, comprising the steps of: focussing a light image of said grid on the emulsion layer of a first sheet of unexposed silver diffusion transfer film; and instantly developing said film, such that the emulsion and antihalation layers are removed and said filter consists only of a thin specularly reflecting silver image of said grid in a thin receiving layer on a film support layer, said receiving layer being covered only by a protective layer less than a wavelength thick at far-infrared frequencies.
Claim 7
Independent Claim
91 words
The method for making a far-infrared wire grid filter, comprising the steps of: focussing a light image of said grid on the emulsion layer of a first sheet of unexposed silver diffusion transfer film; and instantly developing said film, such that the emulsion and antihalation layers are removed and said filter consists only of a thin specularly reflecting silver image of said grid in a thin receiving layer on a film support layer, said receiving layer being covered only by a protective layer less than a wavelength thick at far-infrared frequencies.
Claim 8
Dependent Claim
59 words
The method according to claim 5 wherein said first sheet is color film containing a filter screen of repeating parallel color stripes and the step of focussing a light image further includes the steps of: exposing said first sheet to colored light sources corresponding to one and not more than two adjacent stripes, and instantly developing said color film.
Claim 9
Dependent Claim
34 words
Claim 6 further including the step of: contact printing the resultant color image on a second sheet of black and white silver diffusion transfer type film; and instantly developing said black and white film.
Claim 10
Dependent Claim
41 words
The method according to claim 5 wherein said light image prior to focussing is orders of magnitude greater than said silver image and said step of focussing involves: focussing said light image by means of the lens system of a camera.
Claim 11
Dependent Claim
61 words
The method according to claim 5 wherein said step of focussing comprises: placing said first sheet of developed silver diffusion transfer film, so that its image protecting layer is directly in contact with the corresponding layer of said second unexposed sheet, said first sheet being between said unexposed sheet and at least one source of light passed by said first sheet.
Claim 12
Dependent Claim
15 words
The method according to claim 9 wherein: said source of light is a point source.
References Cited (Backward Citations)
US648748A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-10 | 1991-11-09 | 1992-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-10 | 1995-11-09 | 1996-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-10 | 1999-11-09 | 2000-05-10 | $7700.00 | Window Closed / Lapsed |