US4619518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-color image forming apparatus
Assignee: Casio Computer Co Ltd
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Filing: 1985-07-26
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Granted: 1986-10-28
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Expires: 2005-07-26
Abstract
Abstract When, in a two-color image forming apparatus, a first visible image is formed on a photosensitive drum, and sequentially a second visible image is formed on the drum on which the first visible image remains, said second visible image being different in color from said second visible image, a cylindrical non-magnetic sleeve rotates in a direction opposite to a rotation of a permanent magnet equipped with the sleeve, thereby enabling a developer to be conveyed in a direction opposite to a rotation of the permanent magnet.
Inventors
- 👤 Kazuhiro Kameyama
- 👤 Nobuo Akiba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:36
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/01; G03G15/0105; G03G15/0126
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
104 words
A two-color image forming apparatus comprising means for forming a first visible image on an image bearing member, means for forming a second visible image on said image bearing member still carrying the first visible image, with said second visible image being different in color from said first visible image, and means for rotating a cylindrical non-magnetic sleeve and a permanent magnetic roll equipped within said non-magnetic sleeve in opposite directions with regard to each other, thereby allowing a developer for the second visible image to be conveyed onto said non-magnetic sleeve in a direction opposite to the rotation of said permanent magnetic roll.
Claim 2
Dependent Claim
104 words
A two-color image forming apparatus comprising means for forming a first visible image on an image bearing member, means for forming a second visible image on said image bearing member still carrying the first visible image, with said second visible image being different in color from said first visible image, and means for rotating a cylindrical non-magnetic sleeve and a permanent magnetic roll equipped within said non-magnetic sleeve in opposite directions with regard to each other, thereby allowing a developer for the second visible image to be conveyed onto said non-magnetic sleeve in a direction opposite to the rotation of said permanent magnetic roll.
Claim 3
Dependent Claim
49 words
The two-color image forming apparatus according to claim 1, wherein the development gap l is more than 0.8.d and less than 1.2.d, where l is the distance between the image bearing member and non-magnetic sleeve and d is the defined thickness of the developer for the second visible image.
Claim 4
Dependent Claim
36 words
The two-color image forming apparatus according to claim 1, wherein said developer for the second visible image has at least a toner and carrier, with said carrier comprising fine magnetic particles dropped into an insulative resin.
Claim 5
Dependent Claim
23 words
The two-color image forming apparatus according to claim 3, wherein said fine magnetic particles are barely exposed from the surface of said carrier.
Claim 6
Dependent Claim
29 words
The two-color image forming apparatus according to claim 3, wherein the rate of said fine magnetic particles contained in said carrier ranges from 30 to 90 percent by weight.
Claim 7
Dependent Claim
30 words
The two-color image forming apparatus according to claim 1, wherein the rotation speed of said permanent magnetic roll is more than ten times greater than that of said non-magnetic sleeve.
Claim 8
Dependent Claim
36 words
The two-color image forming apparatus according to claim 2, wherein said developer for the second visible image has at least a toner and carrier, with said carrier comprising fine magnetic particles dropped into an insulative resin.
Claim 9
Dependent Claim
30 words
The two-color image forming apparatus according to claim 2, wherein the rotation speed of said permanent magnetic roll is more than ten times greater than that of said non-magnetic sleeve.
References Cited (Backward Citations)
US4086006A
Cited
US4308821A
Cited
US4416533A
Cited
US4413899A
Cited
US4395112A
Cited
US4486089A
Cited
US4538898A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-27 | 1990-04-28 | 1990-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-27 | 1994-04-28 | 1994-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-27 | 1998-04-28 | 1998-10-28 | $7700.00 | Window Closed / Lapsed |