US5144340A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inkjet printer with an electric curtain force
Assignee: Minolta Co Ltd
•
Filing: 1991-08-14
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Granted: 1992-09-01
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Expires: 2011-08-14
Abstract
Abstract An inkjet printer which comprises a nozzle having an exit opening; an electric field curtain forming unit for causing an electric field curtain force or a travelling-wave electric field curtain to act on inking material located in the vicinity of the exit opening of the nozzle; a charge injecting unit disposed in the vicinity of the exit opening of the nozzle for injecting an electric charge into the inking material; and an image control unit operable in response to image information to control the charge injecting unit to vary the amount of electric charge to be injected into the inking material. The inking material located in the vicinity of the nozzle can be expelled outwardly from the nozzle by the action of the electric field curtain force in a quantity dependent on the amount of the electric charge injected by the charge injecting unit.
Inventors
- 👤 Hideo Hotomi
- 👤 Hisashi Myochin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:24
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/015; B41J2/04; B41J2/06; B41J2002/061
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
104 words
An inkjet printer which comprises: a nozzle for containing ink and having an exit opening through which the ink may be spattered; means for forming an unequal alternating electric field oriented towards the exit opening at a constant level; means controlled separately from the electric field forming means for injecting an electric charge into ink situated within the unequal alternating electric field; and means for controlling the charge injecting means to vary an amount of electric charge to be injected into the ink in accordance with an image forming signal while said electric field forming means maintains said electric field at a constant level.
Claim 2
Dependent Claim
104 words
An inkjet printer which comprises: a nozzle for containing ink and having an exit opening through which the ink may be spattered; means for forming an unequal alternating electric field oriented towards the exit opening at a constant level; means controlled separately from the electric field forming means for injecting an electric charge into ink situated within the unequal alternating electric field; and means for controlling the charge injecting means to vary an amount of electric charge to be injected into the ink in accordance with an image forming signal while said electric field forming means maintains said electric field at a constant level.
Claim 3
Dependent Claim
42 words
The inkjet printer as claimed in claim 1, wherein said electric field forming means comprises at least one pair of electrodes disposed in a vicinity of the exit opening, and an electric power source for applying an alternating voltage between the electrodes.
Claim 4
Dependent Claim
37 words
The inkjet printer as claimed in claim 1, wherein said electric field forming means comprises a generally coil-shaped electrode disposed circumferentially around the nozzle and an electric power source for applying an alternating voltage to the electrode.
Claim 5
Dependent Claim
37 words
The inkjet printer as claimed in claim 1, wherein said charge injecting means comprises an electrode held in contact with the ink within the nozzle and an electric power source for applying a voltage to the electrode.
Claim 6
Dependent Claim
103 words
The inkjet printer as claimed in claim 1, wherein said charge injecting means comprises a charge injecting electrode disposed so as to contact the ink within the nozzle, a counter electrode disposed interiorly in the nozzle in face-to-face relationship with said charge injecting electrode, and an electric power source for applying a voltage between the charge injecting electrode and the counter electrode whereby, when the voltage from the power source is applied between the charge injecting electrode and the counter electrode, an electric field is produced between the charge injecting electrode and the counter electrode for injecting an electric charge into the ink.
Claim 7
Dependent Claim
43 words
The inkjet printer as claimed in claim 1, wherein said charge injecting means comprises a pair of electrodes juxtaposed with respect to each other and held in contact with the ink within the nozzle, and means for applying a voltage between the electrodes.
Claim 8
Dependent Claim
38 words
The inkjet printer as claimed in claim 1, wherein said nozzle comprises an ink supply unit made of material having an affinity with the ink and the exit opening made of material having no affinity with the ink.
Claim 9
Dependent Claim
21 words
The inkjet printer as claimed in claim 1, wherein said nozzle has a plurality of nozzle openings juxtaposed in a line.
Claim 10
Dependent Claim
22 words
The inkjet printer as claimed in claim 1, further comprising a roller supported for rotation within the nozzle for mixing the ink.
Claim 11
Dependent Claim
24 words
The inkjet printer as claimed in claim 9, wherein said roller is applied a direct current bias voltage for preliminarily electrically charging the ink.
Claim 12
Dependent Claim
37 words
The inkjet printer as claimed in claim 1, further comprising ink which is an organic liquid carrier having a resistance within a range of 10 7 to 10 8 Ω.cm and pigment particles which are electrically charged.
Claim 13
Dependent Claim
24 words
The inkjet printer as claimed in claim 1, further comprising ink which is an aqueous inking solution having pigment dissolved in an aqueous solvent.
Claim 14
Dependent Claim
114 words
An inkjet printer which comprises: a nozzle for containing ink and having an exit opening through which the ink may be spattered in a spattering direction; means for forming a travelling-wave unequal alternating electric field travelling towards the exit opening and which runs substantially parallel to said spattering direction of the ink; means, controlled separately from said electric field forming means, for injecting an electric charge into a portion of the ink situated within the travelling-wave unequal alternating electric field; and means operable in response to image information for controlling the charge injecting means to vary an amount of electric charge to be injected into the ink in accordance with an image forming signal.
Claim 15
Dependent Claim
114 words
An inkjet printer which comprises: a nozzle for containing ink and having an exit opening through which the ink may be spattered in a spattering direction; means for forming a travelling-wave unequal alternating electric field travelling towards the exit opening and which runs substantially parallel to said spattering direction of the ink; means, controlled separately from said electric field forming means, for injecting an electric charge into a portion of the ink situated within the travelling-wave unequal alternating electric field; and means operable in response to image information for controlling the charge injecting means to vary an amount of electric charge to be injected into the ink in accordance with an image forming signal.
Claim 16
Dependent Claim
47 words
The inkjet printer as claimed in claim 13, wherein said travelling-wave electric field forming means comprises a plurality of electrodes disposed within the nozzle, and an electric power source for applying a plurality of single-phase alternating voltages, different in phase from each other, to each neighboring electrode.
Claim 17
Dependent Claim
25 words
The inkjet printer as claimed in claim 14, wherein said electric power source is operable to apply a three-phase alternating voltage to each neighboring electrode.
Claim 18
Dependent Claim
46 words
The inkjet printer as claimed in claim 13, wherein said travelling-wave electric field forming means comprises a plurality of generally coil-shaped electrodes, and an electric power source for applying a plurality of single-phase alternating voltages, different in phase from each other, to each neighboring coil-shaped electrode.
Claim 19
Dependent Claim
68 words
The inkjet printer as claimed in claim 13, wherein said charge injecting means comprises a first electrode and a second electrode, and a first electric power source and a second electric power source for applying direct current voltages to the first electrode and second electrode, respectively, said first electrode being positioned downstream of the second electrode with respect to a direction of travel of the travelling-wave electric field.
Claim 20
Dependent Claim
62 words
The inkjet printer as claimed in claim 17, wherein said image control means responds to an image signal such that, after a direct current voltage has been applied from the first electric power source to the first electrode, the direct current voltage is applied from the second electric power source to the second electrode to inject the electric charge into the ink.
Claim 21
Dependent Claim
33 words
The inkjet printer as claimed in claim 14, wherein said charge injecting means comprises at least one electrode located opposite an electrode of said travelling-wave electric field forming means closest to said nozzle.
Claim 22
Dependent Claim
61 words
An inkjet printer as claimed in claim 19 wherein each time said charge injecting means injects a charge into the ink, an electric field is generated between said at least one electrode of the charge injecting means and the electrode of the travelling-wave electric field forming means closest to the nozzle, whereby a droplet of ink is expelled from said nozzle.
Claim 23
Dependent Claim
55 words
An inkjet printer as claimed in claim 13 wherein said nozzle comprises an upper panel member and a lower panel member, said lower panel member having a plurality of grooves formed therein, and wherein said charge injecting means comprises a plurality of electrodes, each of said electrodes disposed in a respective one of said grooves.
Claim 24
Dependent Claim
78 words
An inkjet printer as claimed in claim 13 wherein said travelling-wave electric field forming means applies a predetermined force to the ink in a direction of the nozzle opening and wherein said predetermined force is such that a magnitude of all forces acting on the ink in the nozzle direction is equal to a magnitude of a surface tension force acting on the ink opposite the nozzle direction prior to the injection of any charge into the ink.
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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) | 1995-09-01 | 1996-03-02 | 1996-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-01 | 2000-03-02 | 2000-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-01 | 2004-03-02 | 2004-09-01 | $7700.00 | Window Closed / Lapsed |