US5633110A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry toner for direct electrostatic printing (DEP)
Assignee: Agfa Gevaert NV
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Filing: 1995-11-07
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Granted: 1997-05-27
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Expires: 2015-11-07
Abstract
Abstract A method for direct electrostatic printing (DEP) on an intermediate substrate or on a final substrate is provided, using a device that comprises a back electrode (105), a printhead structure (106) comprising a control electrode in combination with apertures (107), and a toner delivery means (101) presenting a cloud (104) of dry toner particles in the vicinity of said apertures (107), characterised in that (i) the toner particles have as topological criterium that the ratio of the length of the long axis of the projected microscopic image of said particles to the length of the short axis, is between 1.00 and 1.40 and (ii) the toner particles after addition of 0.5% by weight of fumed hydrophobic silica having a specific surface area of 260 m 2 /g show a ratio of apparent density (ρ app ) over real density (ρ real ) ##EQU1##
Inventors
- 👤 Guido Desie
- 👤 Serge Tavernier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:06
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/22; G03G15/34; G03G15/344; G03G15/346; G03G9/00; G03G9/08; G03G9/0819; G03G9/0821; G03G9/0827
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
168 words
A method for direct electrostatographic printing (DEP) on an intermediate substrate or on a final substrate, using a device that comprises a back electrode, a printhead structure comprising a control electrode in combination with apertures, and a toner delivery means for presenting a cloud of dry toner particles in the vicinity of said apertures, wherein (i) said toner particles are such that the ratio of the length of the long axis of the projected microscopic image of said particles to the length of the short axis is between 1.00 and 1.40, said ratio being the average of the ratios measured on at least 20 different toner particles (ii) said toner particles after addition of 0.5% by weight of fumed hydrophobic silica having a specific surface area of 260 m 2 /g show a ratio of apparent density (ρ app ) over real density (ρ real ) ##EQU7## (iii) said toner particles having a ratio between measured BET (BET meas ) and calculated BET (BET calc ) of ##EQU8##
Claim 2
Independent Claim
168 words
A method for direct electrostatographic printing (DEP) on an intermediate substrate or on a final substrate, using a device that comprises a back electrode, a printhead structure comprising a control electrode in combination with apertures, and a toner delivery means for presenting a cloud of dry toner particles in the vicinity of said apertures, wherein (i) said toner particles are such that the ratio of the length of the long axis of the projected microscopic image of said particles to the length of the short axis is between 1.00 and 1.40, said ratio being the average of the ratios measured on at least 20 different toner particles (ii) said toner particles after addition of 0.5% by weight of fumed hydrophobic silica having a specific surface area of 260 m 2 /g show a ratio of apparent density (ρ app ) over real density (ρ real ) ##EQU7## (iii) said toner particles having a ratio between measured BET (BET meas ) and calculated BET (BET calc ) of ##EQU8##
Claim 3
Dependent Claim
36 words
A method according to claim 1, wherein said ratio of the length of the long axis of the projected microscopic image of said particles to the length of the short axis is between 1.00 and 1.30.
Claim 4
Independent Claim
25 words
A method according to claims 1, wherein said ratio of apparent density (ρ app ) over real density (ρ real ), is greater than 0.55.
Claim 5
Dependent Claim
13 words
A method according to claim 1, wherein said ratio fulfils the equation ##EQU9##
Claim 6
Dependent Claim
24 words
A method according to claim 1, wherein said toner particles have an average charge per volume diameter (q/d) wherein 1 fC/10 μm≦|q/d|≦20 fC/10 μm.
Claim 7
Dependent Claim
23 words
A method according to claim 1, wherein said toner particles have a charge distribution with a coefficient of variability, v, lower than 0.50.
Claim 8
Dependent Claim
43 words
A method according to claim 1, wherein the volume average diameter of the toner particles is between 3 and 20 μm and the volume particles size distribution of said toner particles is basically gaussian with a coefficient of variability, v, lower than 0.50.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-05-26 | 2000-11-25 | 2001-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-05-26 | 2004-11-25 | 2005-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-05-26 | 2008-11-25 | 2009-05-27 | $7700.00 | Window Closed / Lapsed |