US4239383A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Illumination means for electrographic reproduction
Assignee: 3M Co
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Filing: 1979-09-17
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Granted: 1980-12-16
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Expires: 1999-09-17
Abstract
Abstract An illumination means for an electrographic reproduction machine in which a single light source is used in combination with a primary and a secondary elliptical reflector to furnish direct and reflected light as a narrow band of illumination and in which a third flat reflector is used to reflect a portion of the light from the light source which would not otherwise be directed in such a narrow band back into the primary and secondary reflectors to be reflected into the narrow band and to balance the direct and reflected light.
Inventors
- 👤 John A. Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:01
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/024; H04N1/028; H04N1/02815; H04N1/02845; H04N1/0285; G; G03; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/54; G03B27/542; H04N1/0287; H04N1/02895
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
203 words
An illumination means for concentrating and directing light within an electrographic reproduction machine comprising a frame; a light source mounted to said frame; a primary elliptical reflector attached to said frame and positioned to partially envelop said light source, said primary reflector having opposing first and second sides with an opening therebetween such that said opening is generally perpendicular to the elliptical axis of said primary reflector, and being disposed to reflect a portion of the light emerging from said light source through said opening and onto a predetermined area; a secondary elliptical reflector attached on said frame adjacent the second side of said primary reflector disposed to reflect toward the predetermined area the light emerging from said light source toward said secondary reflector and a portion of the light reflected from said primary which would not otherwise be incident at said predetermined area from said primary reflector; a generally flat reflector fixed across a portion of the opening of said primary reflector adjacent its first side to reflect a portion of the light emerging from said light source that would not otherwise be incident on said predtermined area, back toward said primary reflector so as to be reflected toward said secondary reflector.
Claim 2
Dependent Claim
203 words
An illumination means for concentrating and directing light within an electrographic reproduction machine comprising a frame; a light source mounted to said frame; a primary elliptical reflector attached to said frame and positioned to partially envelop said light source, said primary reflector having opposing first and second sides with an opening therebetween such that said opening is generally perpendicular to the elliptical axis of said primary reflector, and being disposed to reflect a portion of the light emerging from said light source through said opening and onto a predetermined area; a secondary elliptical reflector attached on said frame adjacent the second side of said primary reflector disposed to reflect toward the predetermined area the light emerging from said light source toward said secondary reflector and a portion of the light reflected from said primary which would not otherwise be incident at said predetermined area from said primary reflector; a generally flat reflector fixed across a portion of the opening of said primary reflector adjacent its first side to reflect a portion of the light emerging from said light source that would not otherwise be incident on said predtermined area, back toward said primary reflector so as to be reflected toward said secondary reflector.
Claim 3
Dependent Claim
41 words
An illumination means as claimed in claim 1 which includes heat-reflecting means mounted between said first side and said second side of said primary reflector for affording the minimization of the heat transfer from the light source toward said predetermined area.
Claim 4
Dependent Claim
41 words
An illumination means as claimed in claim 1 which includes a plurality of opaque tabs slidably positioned along said generally flat reflector and disposed so as to project over said flat reflector toward said second side of said primary elliptical reflector.
Claim 5
Dependent Claim
17 words
An illumination means as claimed in claim 3 wherein said tabs are spring-biased against said flat reflector.
Claim 6
Dependent Claim
30 words
An illumination means as claimed in claim 1 wherein said flat reflector covers slightly less than half of the opening between the first and second sides of said primary reflector.
References Cited (Backward Citations)
US3302519A
Cited
US3532424A
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US3947115A
Cited
US3977784A
Cited
US3982116A
Cited
US4092066A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-16 | 1984-06-16 | 1984-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-16 | 1988-06-16 | 1988-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-16 | 1992-06-16 | 1992-12-16 | $7700.00 | Window Closed / Lapsed |