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US3977361A Expired / Lapsed US ⏱️ 0.0 years remaining

Magnetic brush developing device

Assignee: Fujifilm Business Innovation Corp
•
Filing: 1975-05-13
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Granted: 1976-08-31
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Expires: 1995-05-13
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Abstract

Abstract A magnetic brush developing device including a plurality of developing rollers each consisting of a cylindrical stationary magnet and a cylindrical sleeve rotating around said magnet, said plurality of developing rollers being disposed among the surface of a latent image forming member, wherein said cylindrical stationary magnets each have (a) a developing magnetic pole positioned in a portion facing the surface of latent image forming member, (b) a transporting magnetic pole positioned rearwardly of said developing magnetic pole in the travelling direction of a developing agent and having an opposite polarity to that of the developing magnetic pole, and (c) an auxility transporting magnetic pole positioned in a portion facing the preceding developing roller in the travelling direction of developing agent and having a polarity identical with the polarity of said transporting magnetic pole, said developing magnetic poles having the identical polarity and thus delivery and receipt of the developing agent between the adjacent developing rollers is effected between the transporting magnetic pole of the preceding developing roller and the developing magnetic pole of the succeeding developing roller.

Inventors

  • 👤 Toshio Nagashima
  • 👤 Mitsuharu Nakaguchi
  • 👤 Takuzo Tsukamoto
  • 👤 Ryuzo Okada
  • 👤 Hidetoshi Kito
  • 👤 Kenichi Handa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 09:13
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/09

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 178 words
A magnetic brush developing device including a plurality of developing rollers each consisting of a cylindrical stationary magnet and a cylindrical sleeve rotating around said magnet, said plurality of developing rollers being disposed along the surface of a latent image forming member, wherein; said cylindrical stationary magnets each have (a) a developing magnetic pole positioned in a portion facing the surface of latent image forming member, (b) a transporting magnetic pole positioned rearwardly of said developing magnetic pole in the travelling direction of a developing agent and having an opposite polarity to that of the developing magnetic pole, and (c) an auxiliary transporting magnetic pole positioned in a portion facing the preceding developing roller in the travelling direction of developing agent and having a polarity identical with the polarity of said transporting magnetic pole, said developing magnetic poles having the identical polarity and thus delivery and receipt of the developing agent between the adjacent developing rollers is effected between the transporting magnetic pole of the preceding developing roller and the developing magnetic pole of the succeeding developing roller.
Claim 2
Dependent Claim 178 words
A magnetic brush developing device including a plurality of developing rollers each consisting of a cylindrical stationary magnet and a cylindrical sleeve rotating around said magnet, said plurality of developing rollers being disposed along the surface of a latent image forming member, wherein; said cylindrical stationary magnets each have (a) a developing magnetic pole positioned in a portion facing the surface of latent image forming member, (b) a transporting magnetic pole positioned rearwardly of said developing magnetic pole in the travelling direction of a developing agent and having an opposite polarity to that of the developing magnetic pole, and (c) an auxiliary transporting magnetic pole positioned in a portion facing the preceding developing roller in the travelling direction of developing agent and having a polarity identical with the polarity of said transporting magnetic pole, said developing magnetic poles having the identical polarity and thus delivery and receipt of the developing agent between the adjacent developing rollers is effected between the transporting magnetic pole of the preceding developing roller and the developing magnetic pole of the succeeding developing roller.

References Cited (Backward Citations)

US3392432A Cited
US3457900A Cited
US3543720A Cited
US3641980A Cited
US3654902A Cited
US3724422A Cited
US3881446A Cited
US3908595A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-08-31 1980-03-01 1980-08-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-08-31 1984-03-01 1984-08-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-08-31 1988-03-01 1988-08-31 $7700.00 Window Closed / Lapsed

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