US3971465A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-scanning electrostatic print head for a dot matrix printer
Assignee: Unisys Corp
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Filing: 1974-11-27
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Granted: 1976-07-27
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Expires: 1994-11-27
Abstract
Abstract An electrostatic dot matrix printer includes a print head utilizing a self-scanning ion charge transfer system to reduce the number of dot drivers and the operating potential required for electrostatic printing. In the print head, ionization is transferred from a set of scanning anodes to a set of apertured cathodes in a cyclical aperture-by-aperture fashion. In synchronism with the cylical transfer a selected pattern of ionization is transferred from the apertured cathodes, to a set of printing anodes. The selected pattern of ionization is further transferred to a portion of electrostatic paper by a planar electrode, thereby depositing a selectively determined charge pattern on the electrostatic paper.
Inventors
- 👤 Robert E. Benn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:04
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/385; B41J2/41; B41J2/415; B41J2/435; B41J2/447; B41J2/45; B41J2002/453; Y; Y10; Y10S; Y10S101/00; Y10S101/37
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
287 words
In an electrostatic printer, a dot matrix electrostatic print head system for cyclically generating a continuous self-scanning ionization pattern, generating therefrom a selective ionization pattern in synchronization with the self-scanning pattern, and depositing the selective ionization pattern onto electrostatic paper, the print head system comprising: a planar electrode for supporting the back of electrostatic paper; a set of parallel printing anodes in a plane juxtaposed in parallel to the front surface of the electrostatic paper a set of apertured parallel cathodes in a plane juxtaposed in parallel to the front surface of the electrostatic paper, the cathode plane being further removed from the paper than the printing anode plane, said set of cathodes being orthogonal to said set of printing anodes, and the cathode apertures being aligned with the apparent intersections of said set of cathodes and said set of printing anodes; a set of parallel scanning anodes in a plane juxtaposed in parallel to the front surface of the electrostatic paper, the scanning anode plane being further removed from the paper than the cathode plane, said set of scanning anodes being parallel to said set of printing anodes and aligned with the apertures in said set of apertured cathodes; scanning means for cyclically transferring aperture-by-aperture ionization between said set of scanning anodes and set of apertured cathodes; selective pattern generating means synchronized with said scanning means for selectively transferring a pattern of ionization through the apertures in said set of cathodes to said set of printing anodes; and potential referencing means cooperating with said planar electrode for attracting the selective ionization pattern from said printing anodes through the electrostatic paper to said planar electrode thereby causing the selective pattern to be deposited on the electrostatic paper.
Claim 2
Dependent Claim
287 words
In an electrostatic printer, a dot matrix electrostatic print head system for cyclically generating a continuous self-scanning ionization pattern, generating therefrom a selective ionization pattern in synchronization with the self-scanning pattern, and depositing the selective ionization pattern onto electrostatic paper, the print head system comprising: a planar electrode for supporting the back of electrostatic paper; a set of parallel printing anodes in a plane juxtaposed in parallel to the front surface of the electrostatic paper a set of apertured parallel cathodes in a plane juxtaposed in parallel to the front surface of the electrostatic paper, the cathode plane being further removed from the paper than the printing anode plane, said set of cathodes being orthogonal to said set of printing anodes, and the cathode apertures being aligned with the apparent intersections of said set of cathodes and said set of printing anodes; a set of parallel scanning anodes in a plane juxtaposed in parallel to the front surface of the electrostatic paper, the scanning anode plane being further removed from the paper than the cathode plane, said set of scanning anodes being parallel to said set of printing anodes and aligned with the apertures in said set of apertured cathodes; scanning means for cyclically transferring aperture-by-aperture ionization between said set of scanning anodes and set of apertured cathodes; selective pattern generating means synchronized with said scanning means for selectively transferring a pattern of ionization through the apertures in said set of cathodes to said set of printing anodes; and potential referencing means cooperating with said planar electrode for attracting the selective ionization pattern from said printing anodes through the electrostatic paper to said planar electrode thereby causing the selective pattern to be deposited on the electrostatic paper.
Claim 3
Dependent Claim
57 words
The dot matrix electrostatic print head system according to claim 1 wherein said means for selectively transferring includes: a printing anode driver individually associated with each anode in said set of printing anodes; and an information signal source connected to all said printing anode drivers for selectively energizing the printing anodes in said set of printing anodes.
Claim 4
Dependent Claim
33 words
The dot matrix electrostatic print head system according to claim 1 wherein: said set of parallel printing anodes and said set of parallel scanning anodes each comprise a set of thin wire electrodes.
Claim 5
Dependent Claim
24 words
The dot matrix electrostatic print head system according to claim 1 wherein said potential referencing means includes means for electrically grounding said planar electrode.
Claim 6
Dependent Claim
66 words
The dot matrix electrostatic print head system according to claim 1 wherein said scanning means includes: a scanning anode power source providing potential in common to all scanning anodes in said set of scanning anodes; a coupling circuit for electrically interconnecting said cathodes into groups; a cathode driver individually associated with each group of cathodes; and energizing means for cyclically powering said individually associated cathode drivers.
Claim 7
Dependent Claim
20 words
The dot matrix electrostatic print head system according to claim 5 wherein said coupling circuit forms three groups of cathodes.
Claim 8
Dependent Claim
119 words
The dot matrix electrostatic print head system according to claim 1 further including a closed environmental system for housing said planar electrode, said set of printing anodes, said set of cathodes and said set of scanning anodes in an atmosphere of a preselected gas at low pressure, said closed environmental system comprising: an environmental control enclosure encasing said planar electrode, said set of printing anodes, said set of cathodes, and said set of scanning anodes; a pair of wipers secured to said enclosure for permitting the electrostatic paper to enter and exit said enclosure with minimum environmental contamination or leakage; and an environmental control system for supplying an atmosphere of low pressure neon gas to said environmental control enclosure.
Claim 9
Dependent Claim
201 words
In an electrostatic printer, a dot matrix electrostatic print head for cyclically generating a continuous self-scanning ionization pattern and generating therefrom a selective ionization pattern in synchronization with the self-scanning pattern, the selective pattern then being deposited onto electrostatic paper, said print head comprising: an apertured front non-conducting panel; an apertured intermediate non-conducting panel; and an aft slotted non-conducting panel, all panels being sealed together along their peripheries; a set of parallel scanning anodes disposed between said aft panel and said intermediate panel; a set of parallel printing anodes disposed between said front panel and said intermediate panel, each printing anode being parallel to and individually aligned with a scanning anode in said set of scanning anodes; a set of cathodes embedded in said center panel and orthogonally positioned to said scanning and printing anodes, said set of cathodes including apertures for providing an ionization communication path from each scanning anode to its individually aligned printing anode; scanning means for cyclically transferring aperture-by-aperture ionization between said set of scanning anodes and said set of apertured cathodes; and selective pattern generating means synchronized with said scanning means for selectively transferring a pattern of ionization through the apertures in said set of cathodes.
Claim 10
Dependent Claim
201 words
In an electrostatic printer, a dot matrix electrostatic print head for cyclically generating a continuous self-scanning ionization pattern and generating therefrom a selective ionization pattern in synchronization with the self-scanning pattern, the selective pattern then being deposited onto electrostatic paper, said print head comprising: an apertured front non-conducting panel; an apertured intermediate non-conducting panel; and an aft slotted non-conducting panel, all panels being sealed together along their peripheries; a set of parallel scanning anodes disposed between said aft panel and said intermediate panel; a set of parallel printing anodes disposed between said front panel and said intermediate panel, each printing anode being parallel to and individually aligned with a scanning anode in said set of scanning anodes; a set of cathodes embedded in said center panel and orthogonally positioned to said scanning and printing anodes, said set of cathodes including apertures for providing an ionization communication path from each scanning anode to its individually aligned printing anode; scanning means for cyclically transferring aperture-by-aperture ionization between said set of scanning anodes and said set of apertured cathodes; and selective pattern generating means synchronized with said scanning means for selectively transferring a pattern of ionization through the apertures in said set of cathodes.
Claim 11
Dependent Claim
101 words
In an electrostatic printer, a dot matrix electrostatic print head system for cyclically generating a continuous self-scanning ionization pattern, generating a selective ionization pattern in synchronization with the self-scanning pattern, and depositing the selective pattern onto electrostatic paper, said print head system comprising: a set of apertured parallel cathodes; means for cyclically transferring ionization aperture-by-aperture to said cathodes; scanning means for driving said cyclically transferring means; means synchronized with said scanning means for selectively transferring ionization from said cathodes; and means for attracting said selectively transferred ionization to the electrostatic paper, thereby depositing a selectively determined charge on the electrostatic paper.
Claim 12
Dependent Claim
101 words
In an electrostatic printer, a dot matrix electrostatic print head system for cyclically generating a continuous self-scanning ionization pattern, generating a selective ionization pattern in synchronization with the self-scanning pattern, and depositing the selective pattern onto electrostatic paper, said print head system comprising: a set of apertured parallel cathodes; means for cyclically transferring ionization aperture-by-aperture to said cathodes; scanning means for driving said cyclically transferring means; means synchronized with said scanning means for selectively transferring ionization from said cathodes; and means for attracting said selectively transferred ionization to the electrostatic paper, thereby depositing a selectively determined charge on the electrostatic paper.
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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) | 1979-07-27 | 1980-01-26 | 1980-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-27 | 1984-01-26 | 1984-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-27 | 1988-01-26 | 1988-07-27 | $7700.00 | Window Closed / Lapsed |