US4498755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Developing device for use in electrophotography
Assignee: Canon Inc
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Filing: 1981-10-07
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Granted: 1985-02-12
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Expires: 2001-10-07
Abstract
Abstract A developing device for developing an electrostatic latent image formed by the electrophotographic process, etc., in which, when a developer on a non-magnetic sleeve used for developing an image is separated from the surface of this sleeve, the developer is divided into two streams, one of which is directly fed to a developer conveying device to convey the developer to a developing section for the image development, and the other of which is led to an agitating device to agitate the developer in the axial direction of the sleeve, and, after sufficient agitation, the developer stream is applied to the developer conveying device. By the abovementioned construction, the developer from at least one of the abovementioned streams is supplied to the developer conveying device without failure, whereby a required quantity of the developer can always be supplied even when the developing device is driven at a high operating speed.
Inventors
- 👤 Masaharu Ohkubo
- 👤 Nobuhiro Hayashi
- 👤 Tomohiro Aoki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:13
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09; G03G15/0822
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
147 words
A developing device for developing a latent image on an image holding member, comprising: (a) magnetic field generating means having magnetic poles; (b) non-magnetic sleeve means disposed around said magnetic field generating means for conveying developer on the surface thereof upto a developing position; and (c) means for dividing developer which has left the surface of said sleeve means, after development, into two streams, said dividing means being positioned at the downstream side of a developing position in the moving direction of said developer on said sleeve means, and leading the first developer stream directly to said sleeve means, and leading the developer in the second stream to the side of agitating means for the developer, said sleeve means carrying the developer of said first developer stream and the developer at the position of the agitating means, thereby developing the latent image on said image holding member.
Claim 2
Dependent Claim
147 words
A developing device for developing a latent image on an image holding member, comprising: (a) magnetic field generating means having magnetic poles; (b) non-magnetic sleeve means disposed around said magnetic field generating means for conveying developer on the surface thereof upto a developing position; and (c) means for dividing developer which has left the surface of said sleeve means, after development, into two streams, said dividing means being positioned at the downstream side of a developing position in the moving direction of said developer on said sleeve means, and leading the first developer stream directly to said sleeve means, and leading the developer in the second stream to the side of agitating means for the developer, said sleeve means carrying the developer of said first developer stream and the developer at the position of the agitating means, thereby developing the latent image on said image holding member.
Claim 3
Dependent Claim
28 words
The developing device as set forth in claim 1, wherein said magnetic field generating means is fixed, and said sleeve means rotates around said magnetic field generating means.
Claim 4
Dependent Claim
124 words
A developing device for developing a latent image on an image holding member, comprising: (a) magnetic field generating means having magnetic poles; (b) non-magnetic sleeve means disposed around said magnetic field generating means for conveying developer on the surface thereof upto a developing position; (c) means for applying the developer to said sleeve means; (d) screw means for conveying the developer in the axial direction of said sleeve means; and (e) means for dividing the developer removed from the surface of said sleeve means, after development, into two developer flows of substantially the same flow rate, said developer dividing means being positioned so as to lead one developer flow directly onto said developer applying means and the other developer flow onto said screw means.
Claim 5
Dependent Claim
124 words
A developing device for developing a latent image on an image holding member, comprising: (a) magnetic field generating means having magnetic poles; (b) non-magnetic sleeve means disposed around said magnetic field generating means for conveying developer on the surface thereof upto a developing position; (c) means for applying the developer to said sleeve means; (d) screw means for conveying the developer in the axial direction of said sleeve means; and (e) means for dividing the developer removed from the surface of said sleeve means, after development, into two developer flows of substantially the same flow rate, said developer dividing means being positioned so as to lead one developer flow directly onto said developer applying means and the other developer flow onto said screw means.
Claim 6
Dependent Claim
28 words
The developing device as set forth in claim 3, wherein said magnetic field generating means is fixed, and said sleeve means rotates around said magnetic field generating means.
Claim 7
Dependent Claim
52 words
A developing device according to claim 3, wherein said developer dividing means (17) is placed near said sleeve (2B) in such a manner that the leading edge (17a) of said developer dividing means scrapes the developer disposed on said sleeve (2B) to form two developer flows of substantially the same flow rate.
References Cited (Backward Citations)
US4177757A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |