US3734592A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High intensity light limiting device
Assignee: United States Department of the Army
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Filing: 1971-06-21
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Granted: 1973-05-22
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Expires: 1991-06-21
Abstract
Abstract An optical device for limiting the transmission of high intensity light radiation through an optical system is disclosed. The device includes a limiting mirror consisting of a thin evaporative partially absorbing, partially reflective coating deposited on a radiation absorbing substrate. An objective lens is provided to focus incident light on a portion of the limiting mirror to maximize the energy density of the incident light beam. If the energy density of the focused beam exceeds a predetermined level, a small portion of the reflective coating is vaporized, markedly reducing the reflectivity of that portion of the limiting mirror. A portion of the substrate material may also be vaporized if the focused beam is of a particularly high energy density.
Inventors
- 👤 Z Sztankay
- 👤 R Holland
- 👤 J Swirczynski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:04
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/22; G02B5/23
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
114 words
An optical device for limiting the transmission of high energy density radiation comprising: limiting mirror means for normally reflecting radiation incident thereon, said limiting mirror including a black-dyed plastic radiation absorbing substrate material, a reflective coating deposited on the front surface of said substrate material facing the incident radiation, said reflective coating designed to vaporize when subjected to radiation of a predetermined energy density; and an objective lens positioned in the path of radiation incident upon said limiting mirror means for increasing the energy density of said incident radiation, said objective lens having an axis parallel to the axis of said limiting mirror for insuring that off-axis beams will focus on said limiting mirror.
Claim 2
Dependent Claim
114 words
An optical device for limiting the transmission of high energy density radiation comprising: limiting mirror means for normally reflecting radiation incident thereon, said limiting mirror including a black-dyed plastic radiation absorbing substrate material, a reflective coating deposited on the front surface of said substrate material facing the incident radiation, said reflective coating designed to vaporize when subjected to radiation of a predetermined energy density; and an objective lens positioned in the path of radiation incident upon said limiting mirror means for increasing the energy density of said incident radiation, said objective lens having an axis parallel to the axis of said limiting mirror for insuring that off-axis beams will focus on said limiting mirror.
Claim 3
Dependent Claim
21 words
An optical device as in claim 1, wherein: said reflective coating comprises a layer of aluminum approximately 150 angstrom units thick.
Claim 4
Dependent Claim
29 words
An optical device as in claim 1, wherein: said radiation absorbing substrate material is designed to vaporize when subjected to radiation energy densities greater than said predetermined energy density.
Claim 5
Dependent Claim
32 words
An optical device as in claim 1, further comprising: defocusing means positioned in the path of radiation reflected from said limiting mirror means for reducing the energy density of said reflected radiation.
Claim 6
Dependent Claim
19 words
An optical device as in claim 4, wherein: said objective lens and said defocusing means comprise a single lens.
Claim 7
Dependent Claim
14 words
An optical device as in claim 4, wherein: said defocusing means comprises a mirror.
Claim 8
Dependent Claim
31 words
An optical device as in claim 4, further comprising: conventional mirror means positioned to intercept radiation reflected from said limiting mirror means for directing said reflected radiation toward said defocusing means.
Claim 9
Dependent Claim
32 words
An optical device as in claim 7, wherein: said radiation absorbing substrate material comprises a sheet of black dyed plastic in the range of from 10 5 to 10 3 centimeters thick.
References Cited (Backward Citations)
US3213752A
Cited
US3301624A
Cited
GB1008952A
Cited
US3289099A
Cited
US3455627A
Cited
US3561842A
Cited
US3602576A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |