US3734624A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus using reflected polarized light to inspect a moving web
Assignee: Eastman Kodak Co
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Filing: 1971-05-06
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Granted: 1973-05-22
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Expires: 1991-05-06
Abstract
Abstract In an inspection system for detecting defects in the photosensitive surface of photographic material, laser means grazes visible light off the photosensitive surfaces of photographic material. The light is swept rapidly across the surface of the photosensitive material; and such light is polarized so that its plane of polarization is perpendicular to its plane of incidence. The special polarization, together with the rapid sweeping of the light across the photosensitive surface, prevents the photosensitive surface from producing latent images.
Inventors
- 👤 E Cornelius
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:22
CPC Classifications
G; G03; G03B; G03B35/00; G03B35/18; G03B35/24
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
115 words
In a system for inspecting the specular surface of photosensitive material by means of radiation reflected off said surface, comprising: a. means for providing and beaming electromagnetic radiation at a grazing angle with respect to the surface of said photosensitive material, and b. signal producing photopickup means for receiving radiation that grazes off the surface of said photosensitive material, the improvement wherein said means for providing and beaming electromagnetic radiation is adapted to produce polarized electromagnetic radiation, and is so disposed to beam said polarized electromagnetic radiation that the plane of polarization for said electromagnetic radiation is perpendicular to the plane of incidence for said radiation as it grazes the surface of said photosensitive material.
Claim 2
Dependent Claim
115 words
In a system for inspecting the specular surface of photosensitive material by means of radiation reflected off said surface, comprising: a. means for providing and beaming electromagnetic radiation at a grazing angle with respect to the surface of said photosensitive material, and b. signal producing photopickup means for receiving radiation that grazes off the surface of said photosensitive material, the improvement wherein said means for providing and beaming electromagnetic radiation is adapted to produce polarized electromagnetic radiation, and is so disposed to beam said polarized electromagnetic radiation that the plane of polarization for said electromagnetic radiation is perpendicular to the plane of incidence for said radiation as it grazes the surface of said photosensitive material.
Claim 3
Dependent Claim
17 words
The invention of claim 1 wherein said means for providing and beaming electromagnetic radiation is laser means.
Claim 4
Dependent Claim
63 words
The invention of claim 2 wherein said laser means comprises: a. a laser of the type that produces polarized light, and b. a polarity rotator for receiving the laser light output and rotating the plane of polarity of said light output so that it is perpendicular to the plane of incidence for said radiation as it grazes the surface of said photosensitive material.
Claim 5
Dependent Claim
65 words
The invention of claim 1 a. wherein said means for providing electromagnetic radiation is adapted to provide visible light, b. wherein the photopickup is responsive principally to visible light, and c. wherein said system includes means for sweeping said visible light across the surface of said photosensitive material at a rate which is sufficient to prevent latent images from being formed in said photosensitive material.
Claim 6
Dependent Claim
17 words
The invention of claim 4 Wherein said means for providing and beaming visible light is laser means.
Claim 7
Dependent Claim
68 words
The invention of claim 5 wherein said laser means comprises: a. a laser of the type that produces polarized visible light, and b. a polarity rotator for receiving the visible light output of said laser and rotating the plane of polarity of said visible light output so that it is perpendicular to the plane of incidence for said light as it grazes the surface of said photosensitive material.
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) | 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 |