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US4828951A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for the formation of multicolor images

Assignee: Konica Minolta Inc
•
Filing: 1988-03-15
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Granted: 1989-05-09
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Expires: 2008-03-15
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Abstract

Abstract An image forming method by the electrophotographic process is disclosed. The image forming method comprises the steps of forming a plurality of toner images different in color on an image carrying member by repeating the developing of the electrostatic latent image on the image carrying member with developers containing both toner and carrier, and transferring said plurality of the toner images at a time onto a receiving material, in which the toner to be provided for at least the initial toner image formation is mixed with 0.2 to 2% by weight of metal oxide particles having a BET specific surface area determined by nitrogen adsorption of from 30 m 2 /g to 60 m 2 /g. The method provides clear multicolor images free from any deterioration in the resolution due to transfer doubling trouble as well as in the image quality due to transfer-off spots.

Inventors

  • 👤 Tadashi Kaneko
  • 👤 Yoshiaki Kobayashi
  • 👤 Mitsutaka Arai

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 09:06
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/097; G03G9/09708; G03G9/09725; G03G13/00; G03G13/01; G03G13/013; G03G13/0133

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 108 words
A method for forming an image comprising the steps of forming a plurality of toner images different in color on an image carrying member by repeating the developing of the electrostatic latent image on the image carrying member with developers containing both toner and carrier, and transferring said plurality of the toner images at a time onto a receiving material, in which the toner to be provided for at least the initial toner image formation is mixed with 0.2 to 2% by weight of metal oxide particles having a BET specific surface area determined by nitrogen adsorption of from 30 m 2 /g to 60 m 2 /g.
Claim 2
Independent Claim 108 words
A method for forming an image comprising the steps of forming a plurality of toner images different in color on an image carrying member by repeating the developing of the electrostatic latent image on the image carrying member with developers containing both toner and carrier, and transferring said plurality of the toner images at a time onto a receiving material, in which the toner to be provided for at least the initial toner image formation is mixed with 0.2 to 2% by weight of metal oxide particles having a BET specific surface area determined by nitrogen adsorption of from 30 m 2 /g to 60 m 2 /g.
Claim 3
Dependent Claim 44 words
The method of claim 1, wherein said metal oxide is one selected from the group consisting of silicon oxide, titanium oxide, aluminum oxide, zinc oxide, tin oxide, calcium oxide, barium oxide, strontium oxide, cerium oxide, chromium oxide, nickel oxide, iron oxide and zirconium oxide.
Claim 4
Dependent Claim 20 words
The method of claim 1, wherein said metal oxide particle is covered with a layer having a high electric resistivity.
Claim 5
Dependent Claim 20 words
The method of claim 1, wherein said metal oxide particle has a volume resistivity of at least 10 6 Ωcm.
Claim 6
Dependent Claim 26 words
The method of claim 1, wherein said step of developing the electrostatic latent image is performed in an oscillating electric field under a non-contact developing condition.
Claim 7
Dependent Claim 14 words
The method of claim 1, wherein said image carrying member comprises an organic photoreceptor.
Claim 8
Dependent Claim 22 words
The method of claim 6, wherein said photoreceptor is a function-separated-type photoreceptor comprising a carrier generating layer and a carrier transferring layer.
Claim 9
Dependent Claim 30 words
The method of claim 1, wherein said toner has a particle size of from 5 μm to 30 μm and a volume resistivity of not less than 10 13 Ωcm.
Claim 10
Dependent Claim 32 words
The method of claim 1, wherein said carrier has a particle size of from 5 μm to 50 μm and a volume resistivity of from 10 11 Ωcm to 10 15 Ωcm.

References Cited (Backward Citations)

US3998634A Cited
JPS5730847A Cited
US4640882A Cited
US4629669A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-05-08 1992-11-07 1993-05-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-05-08 1996-11-07 1997-05-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-05-08 2000-11-07 2001-05-09 $7700.00 Window Closed / Lapsed

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