US3865080A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Toner pickoff apparatus
Assignee: Xerox Corp
•
Filing: 1973-01-17
•
Granted: 1975-02-11
•
Expires: 1993-01-17
Abstract
Abstract Weakly charged toner particles are removed from a developer mix prior to developing an electrostatic latent image by bringing the developer in contact with a segmented biased roller. Also, toner that is charged to the wrong polarity may be removed from the developer mix by the same biased roller prior to developing the electrostatic latent image. The removal of the toner particles from the developer prior to presenting the developer to an electrostatic latent image substantially reduces background when developing the latent image.
Inventors
- 👤 Frederick W Hudson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:05
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0801; G03G15/0822; G03G15/0887; G03G15/0891
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
133 words
In an electrostatic copier having a photosensitive surface for carrying an electrostatic latent image, a development system for developing said latent image through the use of a developer having toner particles triboelectrically attracted to carrier particles; said development system comprising the combination of means for transporting said developer along a path leading to said photosensitive surface and means along said path and upstream of said photosensitive surface for electrostatically withdrawing from said developer improperly charged toner particles which would otherwise tend to be attracted to background areas of said image; said withdrawing means including segmented member having at least one pair of conductive segments electrically insulated from each other, and means for providing an electrical potential between said segments, thereby establishing a field for selectively attracting improperly charged toner particles from said developer.
Claim 2
Dependent Claim
133 words
In an electrostatic copier having a photosensitive surface for carrying an electrostatic latent image, a development system for developing said latent image through the use of a developer having toner particles triboelectrically attracted to carrier particles; said development system comprising the combination of means for transporting said developer along a path leading to said photosensitive surface and means along said path and upstream of said photosensitive surface for electrostatically withdrawing from said developer improperly charged toner particles which would otherwise tend to be attracted to background areas of said image; said withdrawing means including segmented member having at least one pair of conductive segments electrically insulated from each other, and means for providing an electrical potential between said segments, thereby establishing a field for selectively attracting improperly charged toner particles from said developer.
Claim 3
Dependent Claim
58 words
The structure as recited in claim 1 wherein said means for transporting said developer to said photosensitive surface comprises a chute located above the photosensitive surface and means for cascading said developer onto said chute, and said means for withdrawing toner particles from said developer is located above said photosensitive surface within the path of the cascading developer.
Claim 4
Dependent Claim
38 words
The structure as recited in claim 1 wherein said means for transporting said developer to said photosensitive surface comprises a magnetic brush, and said means for withdrawing toner particles from said developer is located contiguous said magnetic brush.
Claim 5
Dependent Claim
22 words
The structure as recited in claim 1 further comprising means for returning to said developer those toner particles which are withdrawn therefrom.
Claim 6
Dependent Claim
15 words
The structure as recited in claim 1 wherein said segmented member is a rotatable roller.
Claim 7
Dependent Claim
28 words
The structure as recited in claim 5 wherein said meanS for providing said electrical potential between said pair of conductive segments includes means for selectively varying said potential.
Claim 8
Dependent Claim
28 words
The structure as recited in claim 1 wherein said means for providing said electrical potential between said pair of conductive segments includes means for selectively varying said potential.
Claim 9
Dependent Claim
50 words
The structure as recited in claim 1 wherein said electrical potential between said pair of conductive segments is selected to create a field for attracting from said developer toner particles charged to the same polarity as the electrostatic latent image and toner particles relatively weakly charged to the opposite polarity.
Claim 10
Dependent Claim
15 words
The structure as recited in claim 8 wherein said segmented member is a rotatable roller.
Claim 11
Dependent Claim
27 words
The structure as recited in claim 8 wherein said means for providing said electrical potential between said pair of segments includes means for selectively varying said potential.
Claim 12
Dependent Claim
21 words
The structure as recited in claim 8 further comprising means for returning to said developer those toner particles previously withdrawn therefrom.
Claim 13
Dependent Claim
54 words
The structure as recited in claim 8 wherein said means for transporting said developer comprises a chute located above the photosensitive surface and means for cascading said developer onto said chute and said photosensitive surface, and said means for withdrawing toner particles from said developer is located within the path of the cascading developer.
References Cited (Backward Citations)
US3412710A
Cited
US3411482A
Cited
US3536042A
Cited
US3592675A
Cited
US3550556A
Cited
US3634077A
Cited
US3649262A
Cited
US3574301A
Cited
US3662711A
Cited
US3637306A
Cited
US3754962A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |