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US5142337A Expired / Lapsed US ⏱️ 0.0 years remaining

Printing grey scale images

Assignee: International Business Machines Corp
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Filing: 1990-10-09
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Granted: 1992-08-25
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Expires: 2010-10-09
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Abstract

Abstract An electrophotographic printing process enables a two-color printer having only binary printing capability to produce high-quality monochrome grey-scale output having, for example, up to 100 grey levels in a 3×3 super-pixel through the use of a second toner comprising a mixture of opaque black, opaque white, and clear toner. A layer of the second toner is applied so as to overlie the first toner layer on the substrate, the first toner comprising black toner. The composition of the second toner may be, for example, 9 percent opaque black toner, 9 percent opaque white toner, and 82 percent clear toner. Another embodiment extends this concept to the high-quality, enhanced grey-scale printing of a color other than black. In another embodiment, the layer of the second toner is comprised of a mixture of equal amounts of opaque black toner and opaque white toner and is applied so as to overlie the first toner layer on the substrate, the first toner layer comprised of black toner having a charge-to-mass ratio in the range of 2 to 10 times less than the second toner. This embodiment is also extended to high-quality, enhanced grey-scale printing of a color other than black. The use of these concepts is also extended to a full-color printer, in which each color is printed using enhanced grey-scale.

Inventors

  • 👤 John P. Karidis
  • 👤 Timothy C. Reiley
  • 👤 Lawrence B. Schein

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 11:09
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/40; H04N1/40087; G; G03; G03G; G03G13/00; G03G13/06; G03G13/08; G03G13/22

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 80 words
An electrophotographic printing process comprising the steps of: (a) applying a first layer of first toner material composed of either opaque black toner or opaque white toner onto a defined region of a receiving surface; and (b) thereafter applying a second layer of second toner material composed of a mixture of at least one of opaque black toner, opaque white toner, and clear toner onto the defined region so as to overlie said first layer of the first toner material.
Claim 2
Dependent Claim 80 words
An electrophotographic printing process comprising the steps of: (a) applying a first layer of first toner material composed of either opaque black toner or opaque white toner onto a defined region of a receiving surface; and (b) thereafter applying a second layer of second toner material composed of a mixture of at least one of opaque black toner, opaque white toner, and clear toner onto the defined region so as to overlie said first layer of the first toner material.
Claim 3
Dependent Claim 35 words
An electrophotographic printing process as set forth in claim 1 wherein the composition of the second toner material is approximately 9 percent opaque black toner, 9 percent opaque white toner, and 82 percent clear toner.
Claim 4
Dependent Claim 69 words
An electrophotographic printing process as set forth in claim 1 wherein the receiving surface is an intermediate surface; and wherein the sequence of steps (a) and (b) is reversed; and including the step of: (c) transferring the combined layers of first and second toner material to a final surface; whereby, on the final surface, the layer of the second toner material overlies the layer of the first toner material.
Claim 5
Dependent Claim 39 words
An electrophotographic printing process as set forth in claim 3 wherein black toner may be replaced by toner of a color other than black; and wherein white toner may be replaced by toner of a color other than white.
Claim 6
Dependent Claim 49 words
An electrophotographic printing process as in claim 1 wherein steps (a) and (b) are repeated at least one more time; and wherein the black toner in repeated steps (a) and (b) is of a color other than black and other than that of any of the preceding repeated steps.
Claim 7
Dependent Claim 116 words
An electrophotographic printing process comprising the steps of: (a) applying a layer of first toner material composed of either opaque black toner or opaque white toner onto a defined region of a receiving surface; (b) imparting an electrical charge to the first toner material having a first predetermined charge to mass ratio; and (c) thereafter applying a layer of second toner material composed of a mixture of approximately equal amounts of opaque black toner and opaque white toner onto the defined region so as to overlie the layer of the first toner material by imparting an electrical charge thereto having a second predetermined charge to mass ratio which is substantially higher than the first predetermined charge.
Claim 8
Dependent Claim 116 words
An electrophotographic printing process comprising the steps of: (a) applying a layer of first toner material composed of either opaque black toner or opaque white toner onto a defined region of a receiving surface; (b) imparting an electrical charge to the first toner material having a first predetermined charge to mass ratio; and (c) thereafter applying a layer of second toner material composed of a mixture of approximately equal amounts of opaque black toner and opaque white toner onto the defined region so as to overlie the layer of the first toner material by imparting an electrical charge thereto having a second predetermined charge to mass ratio which is substantially higher than the first predetermined charge.
Claim 9
Dependent Claim 33 words
An electrophotographic printing process as set forth in claim 6 wherein the second predetermined charge to mass ratio is in the range of 2 to 10 times higher than the first predetermined charge.

References Cited (Backward Citations)

US3236776A Cited
US4385823A Cited
JPS5923350A Cited
JPS5924857A Cited
US4855204A Cited
US4845524A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-08-25 1996-02-24 1996-08-25 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-08-25 2000-02-24 2000-08-25 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-08-25 2004-02-24 2004-08-25 $7700.00 Window Closed / Lapsed

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