Patent US3839840A successfully refreshed from Google Patents.
Patent US4656964A successfully refreshed from Google Patents.
US4656964A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developing device
Assignee: Ricoh Co Ltd
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Filing: 1983-12-27
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Granted: 1987-04-14
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Expires: 2003-12-27
Abstract
Abstract A device for developing an electrostatic latent image formed on a photosensitive member includes a composite sleeve which is comprised of a cylindrical support, a dielectric layer formed on the support and a plurality of fine magnets serving as floating electrodes embedded in the dielectric layer and which is driven to rotate to carry magnetic toner as magnetically attracted to its outer peripheral surface.
Inventors
- 👤 Fuchio Kanno
- 👤 Kazuo Kobayashi
- 👤 Koji Sakamoto
- 👤 Toshio Kaneko
- 👤 Wataru Yasuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:07
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0806; G03G15/0818; G03G15/09; G03G15/0921; G03G2215/00; G03G2215/06; G03G2215/0602; G03G2215/0604; G03G2215/0614; G03G2215/0617; G03G2215/0634; G03G2215/0636
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
221 words
A device for developing an electrostatic latent image by applying magnetically attractable toner hereto, comprising: transporting means for transporting said toner along a predetermined path including a developing region where said latent image is developed, said transporting means including a rotatable supported sleeve whose outer peripheral surface defines a transporting surface on which said toner is carried as magnetically attracted thereto to travel along a circular path defined by the circumference of said sleeve, said sleeve including an electrically conductive, cylindrical support, a dielectric layer formed on the outer peripheral surface of said support, and a plurality of fine magnets comprised of an electrically conductive material and provided as embedded in said dielectric layer as separate from one another and from said support, thereby causing said toner to be magnetically attracted to said transporting surface; supply means disposed upstream of said developing means with respect to the direction of transportation of said toner for supplying said toner to said transporting means; and toner film forming means disposed between said supply means and said developing region with respect to the direction of transportation of said toner, said toner film forming means including a blade in pressure contact with said transporting means thereby pressing said toner into a thin film of predetermined thickness while having said toner charged triboelectrically to a predetermined polarity.
Claim 2
Independent Claim
221 words
A device for developing an electrostatic latent image by applying magnetically attractable toner hereto, comprising: transporting means for transporting said toner along a predetermined path including a developing region where said latent image is developed, said transporting means including a rotatable supported sleeve whose outer peripheral surface defines a transporting surface on which said toner is carried as magnetically attracted thereto to travel along a circular path defined by the circumference of said sleeve, said sleeve including an electrically conductive, cylindrical support, a dielectric layer formed on the outer peripheral surface of said support, and a plurality of fine magnets comprised of an electrically conductive material and provided as embedded in said dielectric layer as separate from one another and from said support, thereby causing said toner to be magnetically attracted to said transporting surface; supply means disposed upstream of said developing means with respect to the direction of transportation of said toner for supplying said toner to said transporting means; and toner film forming means disposed between said supply means and said developing region with respect to the direction of transportation of said toner, said toner film forming means including a blade in pressure contact with said transporting means thereby pressing said toner into a thin film of predetermined thickness while having said toner charged triboelectrically to a predetermined polarity.
Claim 3
Dependent Claim
40 words
A device of claim 1 wherein said plurality of fine magnets are arranged closer to the outer peripheral surface of said dielectric layer, at least some of them being partly exposed at said outer peripheral surface of said dielectric layer.
Claim 4
Dependent Claim
23 words
device of claim 2 wherein the magnetic dipoles of said magnets are directed substantially in parallel with the rotational axis of said sleeve.
Claim 5
Dependent Claim
20 words
A device of claim 2 wherein the magnetic dipoles of said magnets are directed along the circumference of said sleeve.
Claim 6
Dependent Claim
20 words
A device of claim 2 wherein the magnetic dipoles of said magnets are directed along the radius of said sleeve.
Claim 7
Dependent Claim
36 words
A device of claim 1 wherein said plurality of fine magnets are arranged so that at least some are partly exposed at the outer peripheral surface of said dielectric layer and as separated from one another.
Claim 8
Dependent Claim
47 words
A device of claim 1 wherein said blade is comprised of a magnetic material and said blade is pivotally supported at its base end with its free end kept in pressure contact with said transporting surface of said sleeve while being magnetically attracted thereto by said magnets.
Claim 9
Dependent Claim
51 words
A device of claim 7 further comprising discharging means disposed between said developing region and said supply means with respect to the transporting direction of said toner for removing charge at least from the electrically conductive fine magnets provided in said dielectric layer and exposed at the outer peripheral surface thereof.
Claim 10
Dependent Claim
38 words
A device of claim 8 wherein said discharging means includes an electrically conductive brush which is disposed with its tip end lightly in contact with or at a position spaced apart over a predetermined distance from said sleeve.
Claim 11
Dependent Claim
36 words
A device of claim 7 wherein said blade is disposed in a forward arrangement in which the free end of said blade is pointed toward the direction of movement of said sleeve at the contact therebetween.
Claim 12
Dependent Claim
36 words
A device of claim 7 wherein said blade is disposed in a counter-arrangement in which the free end of said blade is pointed opposite to the direction of movement of said sleeve at the contact therebetween.
Claim 13
Dependent Claim
24 words
A device of claim 7 further, comprising means for applying a predetermined electrical potential to said blade and said cylindrical support of said sleeve.
Claim 14
Independent Claim
201 words
A device for developing an electrostatic latent image by applying magnetically attractable toner thereto, comprising: transporting means for transporting said toner along a predetermined path including a developing region where said latent image is developed, said transporting means including a rotatably supported sleeve whose outer peripheral surface defines a transporting surface on which said toner is carried as magnetically attracted thereto to travel along a circular path defined by the circumference of said sleeve, said sleeve including an electrically conductive, cylindrical support and a dielectric layer formed on the outer peripheral surface of said support, said dielectric layer being comprised of a magnetic material and magnetized alternately in magnetic polarity along its outer peripheral surface; supply means disposed upstream of said developing means with respect to the direction of transportation of said toner for supplying said toner to said transporting means; and toner film forming means disposed between said supply means and said developing region with respect to the direction of transportation of said toner, said toner film forming means including a blade in pressure contact with said transporting means thereby pressing said toner into a thin film of predetermined thickness whill having said toner charged triboelectrically to a predetermined polarity.
Claim 15
Independent Claim
201 words
A device for developing an electrostatic latent image by applying magnetically attractable toner thereto, comprising: transporting means for transporting said toner along a predetermined path including a developing region where said latent image is developed, said transporting means including a rotatably supported sleeve whose outer peripheral surface defines a transporting surface on which said toner is carried as magnetically attracted thereto to travel along a circular path defined by the circumference of said sleeve, said sleeve including an electrically conductive, cylindrical support and a dielectric layer formed on the outer peripheral surface of said support, said dielectric layer being comprised of a magnetic material and magnetized alternately in magnetic polarity along its outer peripheral surface; supply means disposed upstream of said developing means with respect to the direction of transportation of said toner for supplying said toner to said transporting means; and toner film forming means disposed between said supply means and said developing region with respect to the direction of transportation of said toner, said toner film forming means including a blade in pressure contact with said transporting means thereby pressing said toner into a thin film of predetermined thickness whill having said toner charged triboelectrically to a predetermined polarity.
Claim 16
Dependent Claim
33 words
A device of claim 13 wherein said sleeve is provided with a plurality of non-magnetic electrically conductive islands formed on the outer peripheral surface of said dielectric layer as isolated form one another.
Claim 17
Dependent Claim
31 words
A device of claim 14 wherein said sleeve is further provided with dielectric isolations provided between said electrically conductive islands as formed on the outer peripheral surface of said dielectric layer.
References Cited (Backward Citations)
US3003462A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |