Patent US4796475A successfully refreshed from Google Patents.
Patent US4347298A successfully refreshed from Google Patents.
US4347298A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrographic development apparatus and method for use with partially-conductive developer
Assignee: Eastman Kodak Co
•
Filing: 1981-04-27
•
Granted: 1982-08-31
•
Expires: 2001-04-27
Abstract
Abstract Improved electrographic development apparatus and procedure for use with partially-conductive developer employs transport of the developer through a first development zone in a direction generally countercurrent to a moving image member and through a second development zone in a direction generally co-current to the moving image member. The extent of image development within each such zone is controlled by the rate of developer transport and/or the magnitude of developer bias, so that overall development of the different portions of large solid image areas (particularly leading and trailing portions of such areas) is equalized.
Inventors
- 👤 Arthur S. Kroll
- 👤 Frank A. Shuster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:21
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0806; G03G13/00; G03G13/06; G03G15/09; G03G2215/00; G03G2215/06; G03G2215/0602; G03G2215/0604; G03G2215/0607; G03G2215/0609
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
72 words
A method of developing an electrostatic image on the surface of an image member, said method comprising: (a) moving said member past a development zone in a downstream direction; (b) at a first location in said zone transporting partially-conductive electrographic developer across said surface in a direction generally opposite said downstream direction; and (c) at a second location in said zone transporting partially-conductive developer across said surface in generally said downstream direction.
Claim 2
Independent Claim
72 words
A method of developing an electrostatic image on the surface of an image member, said method comprising: (a) moving said member past a development zone in a downstream direction; (b) at a first location in said zone transporting partially-conductive electrographic developer across said surface in a direction generally opposite said downstream direction; and (c) at a second location in said zone transporting partially-conductive developer across said surface in generally said downstream direction.
Claim 3
Dependent Claim
44 words
The method defined in claim 1 wherein the velocities of developer transport at said first and second locations are of different magnitudes which are predeterminedly selected to balance the density of development of leading and trailing edge portions of solid-area images on said member.
Claim 4
Dependent Claim
16 words
The method defined in claim 2 wherein said second location is downstream of said first location.
Claim 5
Dependent Claim
48 words
The method defined in claim 1 wherein developer transport at said first and second locations is respectively in the presence of first and second reference potentials which are predeterminedly selected to balance the density of development of leading and trailing edge portions of solid-area images on said member.
Claim 6
Dependent Claim
33 words
The method defined in claim 4 wherein said first location is upstream of said second location and wherein the reference potential at said first location is substantially less than at said second location.
Claim 7
Dependent Claim
18 words
The method defined in claim 1 wherein said developer is transported at both locations by a magnetic brush.
Claim 8
Dependent Claim
28 words
The method defined in claim 1 wherein said developer comprises a triboelectric mixture of carrier particles and toner particles having a resistance of less than 10 9 ohms.
Claim 9
Independent Claim
119 words
A method of developing an electrostatic image on the surface of an image member, said method comprising: (a) moving said member past a development zone in a downstream direction; (b) at a first location in said zone and in the presence of a first reference potential, transporting electrographic developer comprising a triboelectric mixture of carrier particles and toner particles having a resistance of less than 10 9 ohms across said surface in a direction generally opposite said downstream direction; and (c) at a second location in said zone downstream from said first location and in the presence of a second reference potential higher than said first reference potential, transporting such developer across said surface in generally said downstream direction.
Claim 10
Independent Claim
119 words
A method of developing an electrostatic image on the surface of an image member, said method comprising: (a) moving said member past a development zone in a downstream direction; (b) at a first location in said zone and in the presence of a first reference potential, transporting electrographic developer comprising a triboelectric mixture of carrier particles and toner particles having a resistance of less than 10 9 ohms across said surface in a direction generally opposite said downstream direction; and (c) at a second location in said zone downstream from said first location and in the presence of a second reference potential higher than said first reference potential, transporting such developer across said surface in generally said downstream direction.
Claim 11
Dependent Claim
45 words
The method defined in claim 8 wherein the velocities of developer transport and the reference potentials at said first and second locations are predeterminedly selected to balance the density of development of leading and trailing edge portions of solid-area images passing through said development zone.
Claim 12
Independent Claim
63 words
A method of developing an electrostatic image on the surface of an image member, said method comprising: (a) moving said member past a development zone; (b) transporting partially-conductive electrographic developer across said surface in a direction generally countercurrent to the movement of said member; and (c) transporting partially-conductive developer across said surface in a direction generally co-current with the movement of said member.
Claim 13
Independent Claim
63 words
A method of developing an electrostatic image on the surface of an image member, said method comprising: (a) moving said member past a development zone; (b) transporting partially-conductive electrographic developer across said surface in a direction generally countercurrent to the movement of said member; and (c) transporting partially-conductive developer across said surface in a direction generally co-current with the movement of said member.
Claim 14
Dependent Claim
67 words
The invention defined in claim 10 wherein the sequential developer transports occur at separate locations in said development zone and in the presence of electric reference potential, said countercurrent transport precedes said co-current transport and at least one of (a) the relative velocity of developer transport and (b) the reference potential at said separate locations is predeterminedly controlled to balance development of portions of said electrostatic image.
References Cited (Backward Citations)
US4193376A
Cited
US4177757A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-08-30 | 1986-03-01 | 1986-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-30 | 1990-03-01 | 1990-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-30 | 1994-03-01 | 1994-08-31 | $7700.00 | Window Closed / Lapsed |