US5812162A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power supply connection for monolithic print heads
Assignee: Eastman Kodak Co
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Filing: 1996-04-10
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Granted: 1998-09-22
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Expires: 2016-04-10
Abstract
Abstract Large print heads with many thousands of nozzles may have current consumption in excess of 20 Amperes. This would cause significant problems if standard interconnection techniques were used. The present invention effects very high current delivery to print heads by utilizing the entire long edges of the print head as power terminals. The V+ and V- connections are fabricated as 200 μm wide strips of 1 μm aluminum along the edges of the chip which are perpendicular to the print direction. Lines of aluminum extend from the V + connection until the row of nozzles closest to the V - connection. These lines pass between every second nozzle, and are as wide as the device layout and process technology will allow. Lines of aluminum extend from the V - connection until the row of nozzles closest to the V + connection. These lines are interdigitated with the V + lines. This power supply configuration allows tens of amperes to be supplied to print heads with very low electrical resistance and without significant temperature rise in the on-chip connections. Also, electromigration is sufficiently low that it is not a significant factor in device reliability.
Inventors
- 👤 Kia Silverbrook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:16
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/135; B41J2/14; B41J2/14451
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
61 words
A drop on demand print head comprising a plurality of electrothermal heater elements formed on a silicon chip and electrical power connections for supplying power to said electrothermal elements, the improvement wherein said connections are formed on the chip surface substantially at opposite edges of the print head and extend a distance substantially equal to the length of the corresponding edge.
Claim 2
Dependent Claim
61 words
A drop on demand print head comprising a plurality of electrothermal heater elements formed on a silicon chip and electrical power connections for supplying power to said electrothermal elements, the improvement wherein said connections are formed on the chip surface substantially at opposite edges of the print head and extend a distance substantially equal to the length of the corresponding edge.
Claim 3
Dependent Claim
19 words
The invention defined in claim 1 wherein said connections are adapted to conduct current in excess of 20 Amperes.
Claim 4
Dependent Claim
20 words
The invention defined in claim 1 wherein said connections have a width equal to or greater than approximately 200 μm.
Claim 5
Dependent Claim
16 words
The invention defined in claim 1 wherein said connections have a thickness of approximately 1 μm.
Claim 6
Dependent Claim
21 words
The invention defined in claim 1 wherein said connections are generally perpendicular to the print feed direction of said print head.
Claim 7
Dependent Claim
52 words
The invention defined in claim 1 further comprising a main connection from the electrical power circuits on said chip surface to an external circuit, said main connection being characterized by the region of contact to said chip electrical power circuits being situated in a recess formed in the substrate of said chip.
Claim 8
Dependent Claim
30 words
The invention defined in claim 6 wherein said recess is formed to a depth which is in excess of 10 μm, and is less than the thickness of said substrate.
Claim 9
Dependent Claim
35 words
The invention defined in claim 6 wherein said recess is formed to a depth so that the tops of said main electrical connection do not protrude beyond the surface of said chip electrical power circuits.
Claim 10
Dependent Claim
119 words
The invention defined in claim 1 wherein said print head comprises: (a) a plurality of drop-emitter nozzles; (b) a body of ink associated with said nozzles, said body of ink forming a meniscus with an air/ink interface at each nozzle; (c) drop selection apparatus operable upon the air/ink interface to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (d) drop separation apparatus adapted to cause ink from selected nozzles to separate as drops from the body of ink, while allowing ink to be retained in non-selected nozzles, said drop selection apparatus being capable of producing said difference in meniscus position in the absence of said drop separation apparatus.
Claim 11
Dependent Claim
117 words
The invention defined in claim 1 wherein said print head comprises: (a) a plurality of drop-emitter nozzles; (b) a body of ink associated with said nozzles, said body of ink forming a meniscus with an air/ink interface at each nozzle and said ink exhibiting a surface tension decrease of at least 10 mN/m over a 30° C. temperature range; (c) drop selection apparatus operable upon the air/ink interface to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (d) drop separation apparatus adapted to cause ink from selected nozzles to separate as drops from the body of ink, while allowing ink to be retained in non-selected nozzles.
Claim 12
Dependent Claim
122 words
The invention defined in claim 1 wherein said print head comprises: (a) a plurality of drop-emitter nozzles; (b) a body of ink associated with said nozzles; (c) a pressurizing device adapted to subject ink in said body of ink to a pressure of at least 2% above ambient pressure, at least during drop selection and separation to form a meniscus with an air/ink interface; (d) drop selection apparatus operable upon the air/ink interface to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (e) drop separation apparatus adapted to cause ink from selected nozzles to separate as drops from the body of ink, while allowing ink to be retained in non-selected nozzles.
Claim 13
Dependent Claim
58 words
In a drop on demand print head comprising a plurality of integrated circuits formed on a silicon substrate, an arrangement of an electrical connection from said integrated circuits to an external circuit, said arrangement being characterized by the region of contact to said integrated circuits being situated in a bevel formed in the substrate of said integrated circuits.
Claim 14
Dependent Claim
58 words
In a drop on demand print head comprising a plurality of integrated circuits formed on a silicon substrate, an arrangement of an electrical connection from said integrated circuits to an external circuit, said arrangement being characterized by the region of contact to said integrated circuits being situated in a bevel formed in the substrate of said integrated circuits.
Claim 15
Dependent Claim
43 words
The invention defined in claim 12 wherein said bevel is formed to a depth so that the tops of said electrical connections do not protrude beyond the surface of said integrated circuit, said surface being the surface in which said bevel is formed.
Claim 16
Dependent Claim
122 words
The invention defined in claim 12 wherein said print head comprises: (a) a plurality of drop-emitter nozzles; (b) a body of ink associated with said nozzles; (c) a pressurizing device adapted to subject ink in said body of ink to a pressure of at least 2% above ambient pressure, at least during drop selection and separation to form a meniscus with an air/ink interface; (d) drop selection apparatus operable upon the air/ink interface to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (e) drop separation apparatus adapted to cause ink from selected nozzles to separate as drops from the body of ink, while allowing ink to be retained in non-selected nozzles.
Claim 17
Dependent Claim
118 words
The invention defined in claim 12 wherein said print head comprises: (a) a plurality of drop-emitter nozzles; (b) a body of ink associated with said nozzles said body of ink forming a meniscus with an air/ink-interface at each nozzle; (c) drop selection apparatus operable upon the air/ink interface to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (d) drop separation apparatus adapted to cause ink from selected nozzles to separate as drops from the body of ink, while allowing ink to be retained in non-selected nozzles, said drop selection apparatus being capable of producing said difference in meniscus position in the absence of said drop separation apparatus.
Claim 18
Dependent Claim
117 words
The invention defined in claim 12 wherein said print head comprises: (a) a plurality of drop-emitter nozzles; (b) a body of ink associated with said nozzles, said body of ink forming a meniscus with an air/ink interface at each nozzle and said ink exhibiting a surface tension decrease of at least 10 mN/m over a 30° C. temperature range; (c) drop selection apparatus operable upon the air/ink interface to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (d) drop separation apparatus adapted to cause ink from selected nozzles to separate as drops from the body of ink, while allowing ink to be retained in non-selected nozzles.
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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) | 2001-09-21 | 2002-03-23 | 2002-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-21 | 2006-03-23 | 2006-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-21 | 2010-03-23 | 2010-09-22 | $7700.00 | Window Closed / Lapsed |