US4385829A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image developing method and device therefor
Assignee: Canon Inc
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Filing: 1981-02-26
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Granted: 1983-05-31
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Expires: 2001-02-26
Abstract
Abstract An electrostatic latent image developing method and a device therefor, featured in supplying one-component magnetic developer onto a developer-feeding non-magnetic bearing member to form thereon a magnetic brush of developer under the effect of a magnetic field, then bringing said magnetic brush into contact with the surface of an image-developing developer bearing member to form thereon a thin uniform layer of the developer, and bringing said thin layer to a developing position to develop an electrostatic latent image formed on a latent image bearing member. At the development the thin layer of the developer is so spaced in the developing position from the latent image bearing surface as to form a clearance therebetween, across which an AC bias electric field is applied.
Inventors
- 👤 Kimio Nakahata
- 👤 Koichi Tanigawa
- 👤 Hiroyuki Adachi
- 👤 Tsuyoshi Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:52
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0914; B; B82; B82Y; B82Y15/00
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
137 words
A method for developing a latent image on the surface of a latent image bearing member, comprising the steps of: forming a magnetic brush of one-component magnetic developer on a developer-feeding member under the influence of a magnetic field; bringing said magnetic brush into contact with the surface of an image-developing member positioned in the proximity of the surface to be developed thereby forming a thin developer layer on said image-developing member; transporting said thin developer layer to a developing position for performing image development on said surface; and regulating the magnetic brush present in the mutually opposed portions of said developer-feeding member and said image-developing member to reduce the density of developer present in said mutually opposed portions after the completion of a developing process but prior to the termination of displacement of said image-developing member.
Claim 2
Independent Claim
137 words
A method for developing a latent image on the surface of a latent image bearing member, comprising the steps of: forming a magnetic brush of one-component magnetic developer on a developer-feeding member under the influence of a magnetic field; bringing said magnetic brush into contact with the surface of an image-developing member positioned in the proximity of the surface to be developed thereby forming a thin developer layer on said image-developing member; transporting said thin developer layer to a developing position for performing image development on said surface; and regulating the magnetic brush present in the mutually opposed portions of said developer-feeding member and said image-developing member to reduce the density of developer present in said mutually opposed portions after the completion of a developing process but prior to the termination of displacement of said image-developing member.
Claim 3
Dependent Claim
33 words
A developing method according to claim 1, wherein the image development is conducted by said thin developer layer spaced in the developing position from the latent image bearing surface by a clearance therebetween.
Claim 4
Dependent Claim
18 words
A developing method according to claim 2, wherein an AC bias electric field is applied across said clearance.
Claim 5
Dependent Claim
117 words
A developing device for developing a latent image on a latent image bearing member, comprising: an image-developing member for supporting one-component magnetic developer on the periphery thereof; means for displacing said image-developing member for transporting a layer of said developer to a developing portion; a developer-feeding member positioned in the proximity of said image-developing member; and magnetic-field generating means positioned opposite to said image-developing member with said developer-feeding member extending therebetween, said magnetic-field generating means having a magnetic pole in facing relationship to said image-developing member for forming a magnetic brush on said developer-feeding member in such a manner that said magnetic brush comes into contact with said image-developing member to form a thin developer layer thereon.
Claim 6
Dependent Claim
117 words
A developing device for developing a latent image on a latent image bearing member, comprising: an image-developing member for supporting one-component magnetic developer on the periphery thereof; means for displacing said image-developing member for transporting a layer of said developer to a developing portion; a developer-feeding member positioned in the proximity of said image-developing member; and magnetic-field generating means positioned opposite to said image-developing member with said developer-feeding member extending therebetween, said magnetic-field generating means having a magnetic pole in facing relationship to said image-developing member for forming a magnetic brush on said developer-feeding member in such a manner that said magnetic brush comes into contact with said image-developing member to form a thin developer layer thereon.
Claim 7
Dependent Claim
33 words
A developing device according to claim 4, further comprising a magnetic member positioned inside said image-developing member so as to be in facing relationship to said magnetic pole for forming the magnetic brush.
Claim 8
Dependent Claim
127 words
A developing device for developing a latent image on a latent image bearing member, comprising: a image-developing member for supporting one-component magnetic developer on the periphery thereof; means for displacing said image-developing member for transporting a layer of said developer to a developing position; a developer-feeding member positioned in the proximity of said image-developing member; magnetic-field generating means positioned opposite to said image-developing member across said developer-feeding member, said magnetic-field generating means having a magnetic pole in facing relationship to said image-developing member for forming a magnetic brush on said developer-feeding member in such a manner that said magnetic brush comes into contact with said image-developing member to form a thin developer layer thereon; and a magnet positioned inside said magnetic pole for forming the magnetic brush.
Claim 9
Dependent Claim
127 words
A developing device for developing a latent image on a latent image bearing member, comprising: a image-developing member for supporting one-component magnetic developer on the periphery thereof; means for displacing said image-developing member for transporting a layer of said developer to a developing position; a developer-feeding member positioned in the proximity of said image-developing member; magnetic-field generating means positioned opposite to said image-developing member across said developer-feeding member, said magnetic-field generating means having a magnetic pole in facing relationship to said image-developing member for forming a magnetic brush on said developer-feeding member in such a manner that said magnetic brush comes into contact with said image-developing member to form a thin developer layer thereon; and a magnet positioned inside said magnetic pole for forming the magnetic brush.
Claim 10
Dependent Claim
19 words
A developing device according to claim 4, wherein said image-developing member and said developer-feeding member are formed as belts.
Claim 11
Dependent Claim
26 words
A developing device according to claim 5, wherein said image-developing member is formed as a belt, while said developer-feeding member is formed as a cylindrical sleeve.
Claim 12
Dependent Claim
165 words
A developing device for developing a latent image on a latent image bearing member, comprising: an image-developing member for supporting one-component magnetic developer on the periphery thereof; means for displacing said image-developing member for transporting a layer of said developer to a developing position; a developer-feeding member positioned in the proximity of said image-developing bearing member; magnetic-field generating means positioned opposite to said image-developing member with said developer-feeding member extending therebetween, said magnetic-field generating means having a magnetic pole in facing relationship to said image-developing member for forming a magnetic brush on said developer-feeding member in such a manner that said magnetic brush comes into contact with said image-developing member to form a thin developer layer thereon; and regulating means for regulating the magnetic brush in the mutually facing portions of said developer-feeding member and said image-developing member to control the developer density in the developing position after the completion of a developing process but prior to the termination of displacement of the image-developing member.
Claim 13
Dependent Claim
165 words
A developing device for developing a latent image on a latent image bearing member, comprising: an image-developing member for supporting one-component magnetic developer on the periphery thereof; means for displacing said image-developing member for transporting a layer of said developer to a developing position; a developer-feeding member positioned in the proximity of said image-developing bearing member; magnetic-field generating means positioned opposite to said image-developing member with said developer-feeding member extending therebetween, said magnetic-field generating means having a magnetic pole in facing relationship to said image-developing member for forming a magnetic brush on said developer-feeding member in such a manner that said magnetic brush comes into contact with said image-developing member to form a thin developer layer thereon; and regulating means for regulating the magnetic brush in the mutually facing portions of said developer-feeding member and said image-developing member to control the developer density in the developing position after the completion of a developing process but prior to the termination of displacement of the image-developing member.
Claim 14
Dependent Claim
34 words
A developing device according to any one of claims 4 to 9, further comprising a member for defining the thickness of developer positioned in facing relation to said developer-feeding member with a clearance therebetween.
Claim 15
Dependent Claim
45 words
A developing device according to any one of the claims 4 to 9, wherein the surface of said image-developing member is composed of a material capable, in the triboelectric series, of charging said developer to a polarity opposite to that of the latent image potential.
Claim 16
Dependent Claim
20 words
A developing device according to any one of claims 4 to 9, wherein said one-component magnetic developer is electrically insulating.
Claim 17
Dependent Claim
44 words
A developing device according to any one of claims 4 to 9, wherein said image-developing member and said developer-feeding member are so mutually spaced that the thin developer layer on said image-developing member is spaced by a clearance from the latent image bearing surface.
Claim 18
Dependent Claim
18 words
A developing device according to claim 13, wherein an AC bias electric field is applied across said clearance.
Claim 19
Dependent Claim
43 words
A developing device according to claim 9, wherein said regulating means for magnetic brush comprises a doctoring blade which is displaced from a position during the developing process to another position closer to the developer-feeding member after the completion of the developing process.
Claim 20
Dependent Claim
62 words
A developing device according to claim 9, wherein said regulating means for the magnetic brush comprises a magnetic pole positioned inside said developer-feeding means in facing relation to a magnetic doctoring blade, said magnetic pole being displaced from a position during the developing process to another position for reducing the height of said magnetic brush after the completion of the developing process.
Claim 21
Dependent Claim
70 words
A developing device according to claim 9, wherein said regulating means for magnetic brush comprises a magnetic pole or a magnetic member positioned inside said image-developing member in facing relation to the magnetic pole for forming the magnetic brush, said magnetic pole or magnetic member being displaced from a position during the developing process to another position more distant from said developer-feeding member after the completion of the developing process.
Claim 22
Dependent Claim
68 words
A developing device according to claim 9, wherein said regulating means for magnetic brush comprises a magnetic pole positioned inside said image-developing member in facing relation to said magnetic pole for forming said magnetic brush and another magnetic pole of opposite polarity also positioned inside said image-developing member, said magnetic poles being so shifted after the completion of the developing process as to generate a repulsive magnetic field.
Claim 23
Dependent Claim
74 words
A developing device according to claim 9, wherein said regulating means for magnetic brush comprises a magnetic pole for forming a magnetic brush positioned inside said developer-feeding member and in facing relation to said image-developing member and another magnetic pole of the opposite polarity also positioned in said developer-feeding member, said magnetic poles in said developer-feeding member being so shifted after the completion of the developing process as to form a repulsive magnetic field.
Claim 24
Dependent Claim
81 words
A developing device according to claim 9, wherein said regulating means for the magnetic brush comprises a magnetic pole for forming a magnetic brush positioned inside said developer-feeding member and in facing relation to said image-developing member, said magnetic pole being displaced from a position during the developing process to another position more distance from said image-developing member after the completion of the developing process thereby removing the magnetic pole from the portion of said developer-feeding member facing said image-developing member.
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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) | 1986-05-30 | 1986-11-29 | 1987-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-30 | 1990-11-29 | 1991-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-30 | 1994-11-29 | 1995-05-31 | $7700.00 | Window Closed / Lapsed |