US5170211A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air filtration for xerographic corona devices
Assignee: Xerox Corp
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Filing: 1990-12-14
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Granted: 1992-12-08
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Expires: 2010-12-14
Abstract
Abstract A copying apparatus which includes a filtering system defining an inlet and an outlet to the corotron cavity. Both the inlet and the outlet include filter material for filtering the air before it is delivered to the corotron cavity and filtering effluents generated during actuation of scorotron wires. The pathways to the inlet and the scorotron cavity are sealed to ensure little or no leakage of contaminated air which could be exposed to the scorotron wires. For this purpose two activated charcoal filters are doped with silver on a foam substrate, utilized both for the inlet and the outlet filters.
Inventors
- 👤 George J. Haupt
- 👤 Bruce E. Thorp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:09
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/02; G03G15/0258; G03G15/0291; G03G21/00; G03G21/20; G03G21/206
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
142 words
An apparatus for filtering air in an image forming machine comprising; (a) an imaging element; (b) a charger for imparting an electrostatic charge on said imaging element; (c) a housing for said charger having an opening for exposing said charger to said imaging element; (d) said housing having an inlet for permitting gas flow into said housing and an outlet for permitting gas flow out of said housing, with said charger being exposed to gas flow between said inlet and said outlet; (e) a first filter located in said inlet for filtering contaminating gases contaminating said charger; and (f) a second filter located in said outlet for filtering effluents generated by said charger during operation, at least one of said filter and said second filter being a conductive electrostatic element capable of being charged to a voltage approaching that of the charger.
Claim 2
Independent Claim
142 words
An apparatus for filtering air in an image forming machine comprising; (a) an imaging element; (b) a charger for imparting an electrostatic charge on said imaging element; (c) a housing for said charger having an opening for exposing said charger to said imaging element; (d) said housing having an inlet for permitting gas flow into said housing and an outlet for permitting gas flow out of said housing, with said charger being exposed to gas flow between said inlet and said outlet; (e) a first filter located in said inlet for filtering contaminating gases contaminating said charger; and (f) a second filter located in said outlet for filtering effluents generated by said charger during operation, at least one of said filter and said second filter being a conductive electrostatic element capable of being charged to a voltage approaching that of the charger.
Claim 3
Dependent Claim
14 words
The apparatus according to claim 1 wherein said imaging element is a photoconductive surface.
Claim 4
Dependent Claim
24 words
The apparatus according to claim 2 wherein said first filter and said second filter include activated charcoal doped with silver on a foam substrate.
Claim 5
Dependent Claim
18 words
The apparatus according to claim 2 wherein said first filter and said second filter include coated corrugated cardboard.
Claim 6
Dependent Claim
29 words
The apparatus according to claim 2 wherein said first filter and said second filter include carbon coated with polyester fiber or conventional HEPA (High Efficiency Particulate Arresting) filter material.
Claim 7
Independent Claim
215 words
An apparatus for filtering air in an image forming machine comprising: (a) an imaging element, said imaging element being a photoconductive surface; (b) a charger for imparting an electrostatic charge on said imaging element; (c) a housing for said charger having an opening for exposing said charger to said imaging element; (d) said housing including a first end and a second end, said second end being displaced from said first end, said housing having an upper portion between said first end and said second end, said housing defining inlets in said upper portion and said first end and outlets in said upper portion and said second end, said inlets and said outlets and said upper portion being separated by a center support, said inlets permitting gas flow into said housing and said outlets permitting gas flow out of said housing, with said charger being exposed to gas flow between said inlets and said outlets; (e) a first filter located in said inlets for filtering contaminating gases contaminating said charger; and (f) a second filter located in said outlets for filtering effluents generated by said charger during operation, at least one of said first filter and said second filter being a conductive electrostatic element capable of being charged to a voltage approaching that of the charger.
Claim 8
Independent Claim
215 words
An apparatus for filtering air in an image forming machine comprising: (a) an imaging element, said imaging element being a photoconductive surface; (b) a charger for imparting an electrostatic charge on said imaging element; (c) a housing for said charger having an opening for exposing said charger to said imaging element; (d) said housing including a first end and a second end, said second end being displaced from said first end, said housing having an upper portion between said first end and said second end, said housing defining inlets in said upper portion and said first end and outlets in said upper portion and said second end, said inlets and said outlets and said upper portion being separated by a center support, said inlets permitting gas flow into said housing and said outlets permitting gas flow out of said housing, with said charger being exposed to gas flow between said inlets and said outlets; (e) a first filter located in said inlets for filtering contaminating gases contaminating said charger; and (f) a second filter located in said outlets for filtering effluents generated by said charger during operation, at least one of said first filter and said second filter being a conductive electrostatic element capable of being charged to a voltage approaching that of the charger.
Claim 9
Dependent Claim
25 words
The apparatus according to claim 6 wherein said housing includes a cavity and said charger being located within that cavity and including a corotron wire.
Claim 10
Dependent Claim
25 words
The apparatus according to claim 7 wherein said housing further includes a grid extending across the opening for exposing said charger to said photoconductive surface.
Claim 11
Dependent Claim
18 words
The apparatus according to claim 8 further comprising sealing means for sealing said opening against said photoconductive surface.
Claim 12
Dependent Claim
50 words
The apparatus according to claim 9 wherein said cavity is defined in part by a baffle, said baffle cooperating with said upper portion and said second end wall to define a path for effluents from said cavity to said outlets in said upper portion and in said second end wall.
Claim 13
Dependent Claim
61 words
The apparatus according to claim 10 further comprising an imaging path for allowing passage of images to said photoconductive surface, said imaging path defined by said first wall and an image baffle, said inlets in said housing and said imaging wall being fluidly sealed with surrounding structure to form a sealed path for air flow to the inlets of said housing.
Claim 14
Dependent Claim
56 words
The apparatus according to claim 11 further comprising a precharger wall spaced from said second end wall to define an area for discharging to a background level, the photoconductive surface prior to its exposure to said charger, said outlet of said housing being exposed to the area between said second end wall and said charger wall.
Claim 15
Independent Claim
185 words
An apparatus for filtering air in an image forming machine comprising: (a) a photoconductive surface; (b) a charger for imparting an electrostatic charge on said photoconductive surface; (c) a housing for said charger having an opening for exposing said charger to said photoconductive surface, said housing including a first end and a second end, said second end being displaced from said first end, said housing having an upper portion between said first end and said second end, said housing defining inlets in said upper portion and said first end and outlets in said upper portion and said second end, said inlets and said outlets and said upper portion being separated by a center support; (d) said housing having an inlet for permitting gas flow into said housing and an outlet for permitting gas flow out of said housing, with said charger being exposed to gas flow between said inlet and said outlet; (e) a first filter located in said inlet for filtering contaminating gases contaminating said charger; and (f) a second filter located in said outlet for filtering effluents generated by said charger during operation.
Claim 16
Independent Claim
185 words
An apparatus for filtering air in an image forming machine comprising: (a) a photoconductive surface; (b) a charger for imparting an electrostatic charge on said photoconductive surface; (c) a housing for said charger having an opening for exposing said charger to said photoconductive surface, said housing including a first end and a second end, said second end being displaced from said first end, said housing having an upper portion between said first end and said second end, said housing defining inlets in said upper portion and said first end and outlets in said upper portion and said second end, said inlets and said outlets and said upper portion being separated by a center support; (d) said housing having an inlet for permitting gas flow into said housing and an outlet for permitting gas flow out of said housing, with said charger being exposed to gas flow between said inlet and said outlet; (e) a first filter located in said inlet for filtering contaminating gases contaminating said charger; and (f) a second filter located in said outlet for filtering effluents generated by said charger during operation.
Claim 17
Dependent Claim
25 words
The apparatus according to claim 13 wherein said housing includes a cavity and said charger being located within that cavity and including a corotron wire.
Claim 18
Dependent Claim
25 words
The apparatus according to claim 14 wherein said housing further includes a grid extending across the opening for exposing said charger to said photoconductive surface.
Claim 19
Dependent Claim
18 words
The apparatus according to claim 15 further comprising sealing means for sealing said opening against said photoconductive surface.
Claim 20
Dependent Claim
50 words
The apparatus according to claim 16 wherein said cavity is defined in part by a baffle, said baffle cooperating with said upper portion and said second end wall to define a path for effluents from said cavity to said outlets in said upper portion and in said second end wall.
Claim 21
Dependent Claim
61 words
The apparatus according to claim 17 further comprising an imaging path for allowing passage of images to said photoconductive surface, said imaging path defined by said first wall and an image baffle, said inlets in said housing and said imaging wall being fluidly sealed with surrounding structure to form a sealed path for air flow to the inlets of said housing.
Claim 22
Dependent Claim
56 words
The apparatus according to claim 18 further comprising a precharger wall spaced from said second end wall to define an area for discharging to a background level, the photoconductive surface prior to its exposure to said charger, said outlet of said housing being exposed to the area between said second end wall and said charger wall.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-12-08 | 1996-06-08 | 1996-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-12-08 | 2000-06-08 | 2000-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-12-08 | 2004-06-08 | 2004-12-08 | $7700.00 | Window Closed / Lapsed |