US4403234A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ink jet printing head utilizing pressure and potential gradients
Assignee: Panasonic Holdings Corp
•
Filing: 1982-01-20
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Granted: 1983-09-06
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Expires: 2002-01-20
Abstract
Abstract An ink jet printing head comprises laminar airflow chamber having a front channel through which a combined stream of air and ink droplets is discharged toward a writing surface, and a rear channel axially aligned with the front channel connected to a source of liquid. The chamber is further provided with an air intake connected to a pressurized air supply source for directing an airstream to a point between the front and rear channels so that the airstream makes a sharp turn at the entry into the front channel with the result that a sharp pressure gradient is produced in the liquid discharge path. An electrode is provided for establishing a field between the front channel and the liquid's meniscus at the exit end of the rear channel to cause the latter to extend toward the front channel by combined effects of the potential and pressure gradients and to be torn apart into a droplet which is carried by the airstream discharged through the front channel.
Inventors
- 👤 Masayoshi Miura
- 👤 Hiroshi Naito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:17
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/015; B41J2/04; B41J2/06; B41J2002/061; B41J2/135; B41J2/14; B41J2002/14475; B41J2202/00; B41J2202/01; B41J2202/02
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
135 words
An ink jet printing head comprising a laminar airflow chamber having a front channel, a rear channel axially aligned with said front channel connected to a source of liquid and an air intake channel connected to a source of pressurized air for directing an airstream to a point between said front and rear channels so that the airstream makes a sharp turn at the entry into said front channel creating a sharp pressure gradient along a path between the exit ends of said rear and front channels, and means for establishing an electric field between said front channel and the meniscus of the liquid at the exit end of said rear channel to cause said meniscus to extend toward said front channel and to be torn apart into a droplet expelled through said front channel.
Claim 2
Dependent Claim
135 words
An ink jet printing head comprising a laminar airflow chamber having a front channel, a rear channel axially aligned with said front channel connected to a source of liquid and an air intake channel connected to a source of pressurized air for directing an airstream to a point between said front and rear channels so that the airstream makes a sharp turn at the entry into said front channel creating a sharp pressure gradient along a path between the exit ends of said rear and front channels, and means for establishing an electric field between said front channel and the meniscus of the liquid at the exit end of said rear channel to cause said meniscus to extend toward said front channel and to be torn apart into a droplet expelled through said front channel.
Claim 3
Dependent Claim
31 words
An ink jet printing head as claimed in claim 1, further comprising a liquid chamber rearwardly of said laminar airflow chamber connected to said rear channel and to said liquid source.
Claim 4
Dependent Claim
29 words
An ink jet printing head as claimed in claim 2, further comprising a second rear channel parallel with the first mentioned rear channel substantially aligned with said front channel.
Claim 5
Dependent Claim
50 words
An ink jet printing head as claimed in claim 1 or 2, further comprising a member in which said rear channel is formed, said member having a surface which defines the exit end of said rear channel and is formed with a rearwardly recessed portion to partially deform said meniscus.
Claim 6
Dependent Claim
29 words
An ink jet printing head as claimed in claim 4, wherein said surface is formed with irregularities in an immediate area around the exit edge of said rear channel.
Claim 7
Dependent Claim
31 words
An ink jet printing head as claimed in claim 1, wherein said front channel extends at an acute angle to said airstream flowing from said intake channel to said front channel.
Claim 8
Dependent Claim
19 words
An ink jet printing head as claimed in claim 1, wherein said field establishing means comprises a ring electrode.
Claim 9
Dependent Claim
22 words
An ink jet printing head as claimed in claim 1, wherein said field establishing means comprises a cylindrical electrode having a throughbore.
Claim 10
Dependent Claim
35 words
An ink jet printing head as claimed in claim 1, wherein the ratio of the axial dimension of said chamber to the diameter of said front channel is in a range from 1:1 to 2.5:1.
Claim 11
Dependent Claim
24 words
An ink jet printing head as claimed in claim 1 or 9, wherein the diameter of said front channel is less than 250 micrometers.
Claim 12
Dependent Claim
22 words
An ink jet printing head as claimed in claim 1, wherein the diameter of said rear channel is less than 100 micrometers.
Claim 13
Dependent Claim
52 words
An ink jet printing head as claimed in claim 1, wherein said field establishing means comprises a front panel of an insulative material in which said front channel is formed and a ring electrode provided on the surface of said front panel remote from said rear channel to encircle said front channel.
Claim 14
Dependent Claim
44 words
An ink jet printing head as claimed in claim 1, wherein said field establishing means comprises a front panel of an insulative material in which said front channel is formed and a ring electrode embedded in said front panel to encircle said front nozzle.
Claim 15
Dependent Claim
84 words
An ink jet printing head as claimed in claim 1, wherein said field establishing means comprises a front panel in which said front channel is formed, said front panel comprising an insulative layer sandwiched between a pair of rear and front conductive layers, said rear conductive layer being adapted to be biased to a given polarity with respect to said liquid, and said front conductive layer being adapted to be biased with respect to said liquid to a polarity opposite to said given polarity.
Claim 16
Dependent Claim
103 words
An ink jet printing head as claimed in claim 1, wherein said field establishing means comprises a front panel in which said front channel is formed, said front panel comprising an inner and outer concentrically arranged conductive rings, an inner insulative ring between said inner and outer conductive rings and an outer insulative ring in which said outer conductive ring is disposed, said inner conductive ring being adapted to be biased to a given polarity with respect to said liquid, and said outer conductive ring being adapted to be biased with respect to said liquid to a polarity opposite to said given polarity.
Claim 17
Dependent Claim
17 words
An ink jet printing head as claimed in claim 1, wherein said chamber comprises a disk-like chamber.
Claim 18
Dependent Claim
36 words
An ink jet printing head as claimed in claim 1, wherein said chamber further comprises an annular chamber surrounding said disk-like chamber and having an axial dimension greater than the axial dimension of said disk-like chamber.
Claim 19
Dependent Claim
197 words
An ink jet printer comprising: a source of pressurized air; a liquid container; and an ink jet printing head comprising a laminar airflow chamber having a front channel, a rear channel axially aligned with said front channel connected to said liquid container and an air intake channel connected to said pressurized air supply source for directing an airstream to a point between said front and rear channels so that the airstream makes a sharp turn at the entry into said front channel creating a sharp pressure gradient along a path between the exit ends of said rear and front channels, and means for establishing an electric field between said front channel and the meniscus of the liquid at the exit end of said rear channel to cause said meniscus to extend toward said front channel and to be torn apart into a droplet expelled through said front channel, said liquid container being connected to receive air from said pressurized air source so that in the absence of said electric field the liquid pressure in said rear channel is balanced against the combined forces of air pressure acting on said meniscus and the surface tension of the meniscus.
Claim 20
Dependent Claim
197 words
An ink jet printer comprising: a source of pressurized air; a liquid container; and an ink jet printing head comprising a laminar airflow chamber having a front channel, a rear channel axially aligned with said front channel connected to said liquid container and an air intake channel connected to said pressurized air supply source for directing an airstream to a point between said front and rear channels so that the airstream makes a sharp turn at the entry into said front channel creating a sharp pressure gradient along a path between the exit ends of said rear and front channels, and means for establishing an electric field between said front channel and the meniscus of the liquid at the exit end of said rear channel to cause said meniscus to extend toward said front channel and to be torn apart into a droplet expelled through said front channel, said liquid container being connected to receive air from said pressurized air source so that in the absence of said electric field the liquid pressure in said rear channel is balanced against the combined forces of air pressure acting on said meniscus and the surface tension of the meniscus.
Claim 21
Dependent Claim
22 words
An ink jet printer as claimed in claim 18, further comprising means for regulating the air pressure received in said liquid container.
Claim 22
Dependent Claim
30 words
An ink jet printer as claimed in claim 18, further comprising a liquid chamber rearwardly of said laminar airflow chamber connected to said rear channel and to said liquid source.
Claim 23
Dependent Claim
28 words
An ink jet printer as claimed in claim 20, further comprising a second rear channel parallel with the first mentioned rear channel substantially aligned with said front channel.
Claim 24
Dependent Claim
49 words
An ink jet printer as claimed in claim 18 or 20, further comprising a member in which said rear channel is formed, said member having a surface which defines the exit end of said rear channel and is formed with a rearwardly recessed portion to partially deform said meniscus.
Claim 25
Dependent Claim
28 words
An ink jet printer as claimed in claim 22, wherein said surface is formed with irregularities in an immediate area around the exit edge of said rear channel.
Claim 26
Dependent Claim
30 words
An ink jet printer as claimed in claim 18, wherein said front channel extends at an acute angle to said airstream flowing from said intake channel to said front channel.
Claim 27
Dependent Claim
18 words
An ink jet printer as claimed in claim 18, wherein said field establishing means comprises a ring electrode.
Claim 28
Dependent Claim
21 words
An ink jet printer as claimed in claim 18, wherein said field establishing means comprises a cylindrical electrode having a throughbore.
Claim 29
Dependent Claim
34 words
An ink jet printer as claimed in claim 18, wherein the ratio of the axial dimension of said chamber to the diameter of said front channel is in a range from 1:1 to 2.5:1.
Claim 30
Dependent Claim
21 words
An ink jet printer as claimed in claim 18, wherein the diameter of said rear channel is less than 100 micrometers.
Claim 31
Dependent Claim
51 words
An ink jet printer as claimed in claim 18, wherein said field establishing means comprises a front panel of an insulative material in which said front channel is formed and a ring electrode provided on the surface of said front panel remote from said rear channel to encircle said front channel.
Claim 32
Dependent Claim
43 words
An ink jet printer as claimed in claim 18, wherein said field establishing means comprises a front panel of an insulative material in which said front channel is formed and a ring electrode embedded in said front panel to encircle said front nozzle.
Claim 33
Dependent Claim
83 words
An ink jet printer as claimed in claim 18, wherein said field establishing means comprises a front panel in which said front channel is formed, said front panel comprising an insulative layer sandwiched between a pair of rear and front conductive layers, said rear conductive layer being adapted to be biased to a given polarity with respect to said liquid, and said front conductive layer being adapted to be biased with respect to said liquid to a polarity opposite to said given polarity.
Claim 34
Dependent Claim
103 words
An ink jet printing head as claimed in claim 18, wherein said field establishing means comprises a front panel in which said front channel is formed, said front panel comprising an inner and outer concentrically arranged conductive rings, an inner insulative ring between said inner and outer conductive rings and an outer insulative ring in which said outer conductive ring is disposed, said inner conductive ring being adapted to be biased to a given polarity with respect to said liquid, and said outer conductive ring being adapted to be biased with respect to said liquid to a polarity opposite to said given polarity.
Claim 35
Dependent Claim
17 words
An ink jet printing head as claimed in claim 18, wherein said chamber comprises a disk-like chamber.
Claim 36
Dependent Claim
36 words
An ink jet printing head as claimed in claim 18, wherein said chamber further comprises an annular chamber surrounding said disk-like chamber and having an axial dimension greater than the axial dimension of said disk-like chamber.
References Cited (Backward Citations)
US4031563A
Cited
US4293865A
Cited
US4167742A
Cited
JPS54160242A
Cited
US4312009A
Cited
US4272773A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-05 | 1987-03-07 | 1987-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-05 | 1991-03-07 | 1991-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-05 | 1995-03-07 | 1995-09-06 | $7700.00 | Window Closed / Lapsed |