US5708464A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for direct electrostatic printing (DEP) with "previous correction"
Assignee: Agfa Gevaert NV
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Filing: 1996-11-04
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Granted: 1998-01-13
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Expires: 2016-11-04
Abstract
Abstract A DEP device adapted for grey-scale printing comprising a back electrode (105), a printhead structure (106), an array of printing apertures (107) in the printhead structure (106) through which a particle flow can be electrically modulated by a control electrode (106a), a toner delivery means (101), at least one control means (111) for applying an electric field to the control electrodes, wherein: (i) the control means controls each single control electrode to enable the printing through each single printing aperture (107) of pixel dots (PD), each of the pixel dots intended to have a density D, and (ii) the control means controls the printing of the pixel dots through the each single printing aperture as a function of both the intended density (D intend ) and the density (D prev ) previously produced through the single printing aperture, i.e. the control means use "previous correction".
Inventors
- 👤 Guido Desie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:44
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/385; B41J2/41; B41J2/415; B41J2/4155; G; G03; G03G; G03G15/00; G03G15/22; G03G15/34; G03G15/344; G03G15/346; G03G2217/00; G03G2217/0008; G03G2217/0025
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
107 words
A DEP device adapted for grey-scale printing comprising: a back electrode(105), a printhead structure(106), an array of printing apertures(107) in said printhead structure(106) through which a particle flow can be electrically modulated by a control electrode(106a), a toner delivery means(101), at least one control means(111) for applying an electric field to said control electrodes, wherein: (i) said control means controls each single control electrode to enable the printing of pixel dots through each single printing aperture(107) each of said pixel dots intended to have a predetermined density, and, (ii) said control means controls said printing of said pixel dots using previous electrode parameter characteristics as correction data.
Claim 2
Dependent Claim
107 words
A DEP device adapted for grey-scale printing comprising: a back electrode(105), a printhead structure(106), an array of printing apertures(107) in said printhead structure(106) through which a particle flow can be electrically modulated by a control electrode(106a), a toner delivery means(101), at least one control means(111) for applying an electric field to said control electrodes, wherein: (i) said control means controls each single control electrode to enable the printing of pixel dots through each single printing aperture(107) each of said pixel dots intended to have a predetermined density, and, (ii) said control means controls said printing of said pixel dots using previous electrode parameter characteristics as correction data.
Claim 3
Dependent Claim
113 words
A DEP device according to claim 1, wherein said grey-printing is controlled by said control means by voltage modulation of electrical fields applied to said control electrodes according to the following formula: V3real=V3intend+(V3prev×Kv) wherein, V3real is the value of the real blocking voltage V3 at time LTn; V3intend is the value of the blocking voltage V3 to be used at time LTn when previous correction data is not applied; V3prev is the value of V3 at time LTn-1; Kv is a correction constant that is smaller than 1; LTn is a line time interval used to print an nth line; and, LTn-1 is a line time interval used to print the n-1th line.
Claim 4
Dependent Claim
11 words
A DEP device according to claim 2, wherein K v ≦0.20.
Claim 5
Dependent Claim
127 words
A DEP device according to claim 1, wherein said grey-scale printing is controlled by said control means by time modulation of electrical fields applied to said control electrodes according to the following formula: WRTreal=WRTintend-((LT-WRTprev)×Kt) wherein, WRTreal is the real value of the write time interval used at time LTn; WRTintend is the value of the write time interval to be used at time LTn when previous correction data is not applied; WRTprev is the value of the write time interval at LTn-1; Kt is a correction constant that is smaller than 1; LTn is the line time interval used to print an nth line; LTn-1 is the line time interval used to print the n-1th line; and, LT is the line time interval for printing a line.
Claim 6
Dependent Claim
29 words
A DEP device according to claim 1, wherein said correction data takes into account the electrical field used to print the density of more than one previous image dot.
Claim 7
Dependent Claim
20 words
A DEP device according to claim 1, wherein said correction data is combined with correction data of neighboring image dots.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-01-12 | 2001-07-14 | 2002-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-01-12 | 2005-07-14 | 2006-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-01-12 | 2009-07-14 | 2010-01-13 | $7700.00 | Window Closed / Lapsed |