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US4664502A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid developing apparatus for use in electrophotographic copying machine

Assignee: Dainippon Screen Manufacturing Co Ltd
•
Filing: 1985-05-22
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Granted: 1987-05-12
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Expires: 2005-05-22
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Abstract

Abstract Apparatus for an electrostatic copying machine using a liquid developer or toner includes a pair of electrodes for developing the latent image on the electrostatically charged photosensitive sheet, of which the auxiliary or back electrode has a specially grooved surface such that the contact area with the sheet is smaller at the front and rear ends of the auxiliary electrode than at the central portion. In one embodiment, the grooves comprise two series of uniformly spaced identical circular arcs, the two series having opposite curvatures for intersection and defining the contact areas.

Inventors

  • 👤 Masao Fukushima
  • 👤 Iwao Hirose
  • 👤 Yoshio Miyauchi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 09:56
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/10; G03G15/108

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 86 words
An apparatus for developing a latent electrostatic image on a photosensitive sheet by contact with a liquid developer, comprising a main electrode and an auxiliary electrode disposed face to face for forming a common passageway for the developer of which at least the auxiliary electrode includes on its face a plurality of grooves for defining projecting portions for contact with the sheet characterized in that the projecting portions form smaller contact areas at the upstream and downstream portions of the passageway than at the intermediate portion.
Claim 2
Independent Claim 86 words
An apparatus for developing a latent electrostatic image on a photosensitive sheet by contact with a liquid developer, comprising a main electrode and an auxiliary electrode disposed face to face for forming a common passageway for the developer of which at least the auxiliary electrode includes on its face a plurality of grooves for defining projecting portions for contact with the sheet characterized in that the projecting portions form smaller contact areas at the upstream and downstream portions of the passageway than at the intermediate portion.
Claim 3
Dependent Claim 40 words
The apparatus of claim 1 further characterized in that the grooves form two series of uniformly spaced identical circular arcs, each arc extending between the upstream and downstream ends of the passageway, the arcs of each series having opposite curvatures.

References Cited (Backward Citations)

US3547076A Cited
US3753393A Cited
US3791345A Cited
JPS4962148A Cited
US3929099A Cited
US4114999A Cited
US4133292A Cited
JPS5614525A Cited
JPS58116709A Cited
US4576467A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-05-11 1990-11-10 1991-05-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-05-11 1994-11-10 1995-05-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-05-11 1998-11-10 1999-05-12 $7700.00 Window Closed / Lapsed

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