Patent US5808639A successfully refreshed from Google Patents.
US5808639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nozzle clearing procedure for liquid ink printing
Assignee: Eastman Kodak Co
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Filing: 1996-04-09
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Granted: 1998-09-15
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Expires: 2016-04-09
Abstract
Abstract A method of clearing nozzles of thermally activated drop on demand printing head which have been blocked by dried ink by applying a consecutive sequence of heater energizing pulses. The method is particularly applicable to coincident forces drop on demand printing systems. A series of consecutive pulses is applied to the heater. These pulses accumulate heat at the nozzle tip, and the ink in contact with the tip, above the boiling point of the ink. The formation of vapor bubbles at the tip can dislodge a crust of dried ink, which is then expelled with the ink drop. A single power pulse of longer than normal duration, or greater than normal energy, can be used. However, this may require substantial additional electronic circuitry to generate. The need for this circuitry is eliminated by applying an integral number (greater than one) of consecutive power pulses of the energy, duration, and time varying power profile that is used to expel drops on demand under normal operating conditions. A nozzle clearing sequence can be automatically applied to all nozzles before printing each page.
Inventors
- 👤 Kia Silverbrook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:26
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/135; B41J2/165; B41J2/16517
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
159 words
A method for clearing blocked nozzles of a thermal drop on demand printing mechanism, said method including the step of applying energy to a heater of such printing mechanism to cause ink in blocked nozzles to be raised above the boiling point of said ink mechanism where said drop on demand printing mechanism comprises: (a) a body of ink associated with said nozzles; (b) 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; (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 2
Independent Claim
159 words
A method for clearing blocked nozzles of a thermal drop on demand printing mechanism, said method including the step of applying energy to a heater of such printing mechanism to cause ink in blocked nozzles to be raised above the boiling point of said ink mechanism where said drop on demand printing mechanism comprises: (a) a body of ink associated with said nozzles; (b) 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; (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 3
Dependent Claim
32 words
A method for clearing blocked nozzles of drop on demand printing mechanisms as claimed in claim 1 where said drop on demand printing mechanism uses a thermal drop selection or ejection step.
Claim 4
Dependent Claim
40 words
A method for clearing blocked nozzles of drop on demand printing mechanisms as claimed in claim 1 where said energy applied to said heater is generated by applying electric power for a predetermined duration, and said heater is electrically resistive.
Claim 5
Dependent Claim
44 words
A method for clearing blocked nozzles of drop on demand printing mechanisms as claimed in claim 3 where said electric power is substantially similar to the electric power which is applied when a drop is selected or ejected on demand during normal printing operation.
Claim 6
Dependent Claim
50 words
A method for clearing blocked nozzles of drop on demand printing mechanisms as claimed in claim 4 where said duration is an integral multiple, greater than one, of the duration of the electric power which is applied when a drop is selected or ejected on demand during normal printing operation.
Claim 7
Independent Claim
157 words
A method for clearing blocked nozzles of a thermal drop on demand printing mechanism, said method including the step of applying sufficient energy to a heater of such printing mechanism to cause ink in blocked nozzles to be raised above the boiling point of said ink mechanism where said drop on demand printing mechanism comprises: (a) a body of ink associated with said nozzles, said ink exhibiting a surface tension decrease of at least 10 mN/m over a 30° C. temperature range; (b) drop selection apparatus adapted to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (c) 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 separation apparatus being capable of producing said difference in meniscus position in the absence of said drop separation apparatus.
Claim 8
Independent Claim
157 words
A method for clearing blocked nozzles of a thermal drop on demand printing mechanism, said method including the step of applying sufficient energy to a heater of such printing mechanism to cause ink in blocked nozzles to be raised above the boiling point of said ink mechanism where said drop on demand printing mechanism comprises: (a) a body of ink associated with said nozzles, said ink exhibiting a surface tension decrease of at least 10 mN/m over a 30° C. temperature range; (b) drop selection apparatus adapted to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (c) 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 separation apparatus being capable of producing said difference in meniscus position in the absence of said drop separation apparatus.
Claim 9
Dependent Claim
40 words
A method for clearing blocked nozzles of drop on demand printing mechanisms as claimed in claim 6 where said energy applied to said heater is generated by applying electric power for a predetermined duration, and said heater is electrically resistive.
Claim 10
Dependent Claim
44 words
A method for clearing blocked nozzles of drop on demand printing mechanisms as claimed in claim 7 where said electric power is substantially similar to the electric power which is applied when a drop is selected or ejected on demand during normal printing operation.
Claim 11
Dependent Claim
50 words
A method for clearing blocked nozzles of drop on demand printing mechanisms as claimed in claim 8 where said duration is an integral multiple, greater than one, of the duration of the electric power which is applied when a drop is selected or ejected on demand during normal printing operation.
Claim 12
Dependent Claim
32 words
A method for clearing blocked nozzles of drop on demand printing mechanisms as claimed in claim 6 where said drop on demand printing mechanism uses a thermal drop selection or ejection step.
Claim 13
Independent Claim
136 words
A method for clearing blocked nozzles of a thermal drop on demand printing mechanism, said method including the step of applying sufficient energy to a heater of such printing mechanism to cause ink in blocked nozzles to be raised above the boiling point of said ink mechanism where said drop on demand printing mechanism comprises: (a) a body of ink associated with said nozzles, said ink exhibiting a surface tension decrease of at least 10 mN/m over a 30° C. temperature range; (b) drop selection apparatus adapted to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (c) 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 14
Independent Claim
136 words
A method for clearing blocked nozzles of a thermal drop on demand printing mechanism, said method including the step of applying sufficient energy to a heater of such printing mechanism to cause ink in blocked nozzles to be raised above the boiling point of said ink mechanism where said drop on demand printing mechanism comprises: (a) a body of ink associated with said nozzles, said ink exhibiting a surface tension decrease of at least 10 mN/m over a 30° C. temperature range; (b) drop selection apparatus adapted to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (c) 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 15
Dependent Claim
32 words
A method for clearing blocked nozzles of drop on demand printing mechanisms as claimed in claim 4 where said drop on demand printing mechanism uses a thermal drop selection or ejection step.
Claim 16
Dependent Claim
40 words
A method for clearing blocked nozzles of drop on demand printing mechanisms as claimed in claim 11 where said energy applied to said heater is generated by applying electric power for a predetermined duration, and said heater is electrically resistive.
Claim 17
Dependent Claim
44 words
A method for clearing blocked nozzles of drop on demand printing mechanisms as claimed in claim 13 where said electric power is substantially similar to the electric power which is applied when a drop is selected or ejected on demand during normal printing operation.
Claim 18
Dependent Claim
50 words
A method for clearing blocked nozzles of drop on demand printing mechanisms as claimed in claim 14 where said duration is an integral multiple, greater than one, of the duration of the electric power which is applied when a drop is selected or ejected on demand during normal printing operation.
Claim 19
Dependent Claim
131 words
In a drop on demand printing apparatus comprising a print head having a plurality of drop ejection nozzles, an ink supply, and means for energizing said print head to effect drop ejections, a system for clearing ink from blocked nozzles comprising: (1) means for heating ink in said nozzles: (2) means for energizing said heating means to cause ink in the nozzles to be raised above its boiling point, said energizing means is an electric power source and said heating means is a resistive heater element; and (3) control means for operating said electric power source to energize said heater in a series of predetermined duration pulses, wherein said pulse's duration is an integral multiple greater than one of the normal drop ejection or selection operation period of said heater means.
Claim 20
Dependent Claim
131 words
In a drop on demand printing apparatus comprising a print head having a plurality of drop ejection nozzles, an ink supply, and means for energizing said print head to effect drop ejections, a system for clearing ink from blocked nozzles comprising: (1) means for heating ink in said nozzles: (2) means for energizing said heating means to cause ink in the nozzles to be raised above its boiling point, said energizing means is an electric power source and said heating means is a resistive heater element; and (3) control means for operating said electric power source to energize said heater in a series of predetermined duration pulses, wherein said pulse's duration is an integral multiple greater than one of the normal drop ejection or selection operation period of said heater means.
Claim 21
Dependent Claim
170 words
In a drop on demand printing apparatus comprising a print head having a plurality of drop ejection nozzles, an ink supply, and means for energizing said print head to effect drop ejections, a system for clearing ink from blocked nozzles comprising: (1) means for heating ink in said nozzles; and (2) means for energizing said heating means to cause ink in the nozzles to be raised above its boiling point, where said apparatus comprises: (a) 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; (b) 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 (c) 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 22
Dependent Claim
170 words
In a drop on demand printing apparatus comprising a print head having a plurality of drop ejection nozzles, an ink supply, and means for energizing said print head to effect drop ejections, a system for clearing ink from blocked nozzles comprising: (1) means for heating ink in said nozzles; and (2) means for energizing said heating means to cause ink in the nozzles to be raised above its boiling point, where said apparatus comprises: (a) 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; (b) 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 (c) 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 23
Dependent Claim
162 words
In a drop on demand printing apparatus comprising a print head having a plurality of drop nozzles, an ink supply, and means for energizing said print head to effect ejection nozzles, an ink supply, and means for energizing said print head to effect drop ejections, a system for clearing ink from blocked nozzles comprising: (1) means for heating ink in said nozzles; and (2) means for energizing said heating means to cause ink in the nozzles to be raised above its boiling point, where said apparatus comprises: (a) drop selection apparatus adapted to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (b) 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 separation apparatus being capable of producing said difference in meniscus position in the absence of said drop separation apparatus.
Claim 24
Dependent Claim
162 words
In a drop on demand printing apparatus comprising a print head having a plurality of drop nozzles, an ink supply, and means for energizing said print head to effect ejection nozzles, an ink supply, and means for energizing said print head to effect drop ejections, a system for clearing ink from blocked nozzles comprising: (1) means for heating ink in said nozzles; and (2) means for energizing said heating means to cause ink in the nozzles to be raised above its boiling point, where said apparatus comprises: (a) drop selection apparatus adapted to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (b) 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 separation apparatus being capable of producing said difference in meniscus position in the absence of said drop separation apparatus.
Claim 25
Dependent Claim
155 words
In a drop on demand printing apparatus comprising a print head having a plurality of drop ejection nozzles, an ink supply, and means for energizing said print head to effect drop ejections, a system for clearing ink from blocked nozzles comprising: (1) means for heating ink in said nozzles; and (2) means for energizing said heating means to cause ink in the nozzles to be raised above its boiling point, where said apparatus comprises: (a) a body of ink associated with said nozzles, said ink exhibiting a surface tension decrease of at least 10 mN/m over a 30° C. temperature range; (b) drop selection apparatus adapted to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (c) 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 26
Dependent Claim
155 words
In a drop on demand printing apparatus comprising a print head having a plurality of drop ejection nozzles, an ink supply, and means for energizing said print head to effect drop ejections, a system for clearing ink from blocked nozzles comprising: (1) means for heating ink in said nozzles; and (2) means for energizing said heating means to cause ink in the nozzles to be raised above its boiling point, where said apparatus comprises: (a) a body of ink associated with said nozzles, said ink exhibiting a surface tension decrease of at least 10 mN/m over a 30° C. temperature range; (b) drop selection apparatus adapted to select predetermined nozzles and to generate a difference in meniscus position between ink in selected and non-selected nozzles; and (c) 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.
References Cited (Backward Citations)
US1941001A
Cited
US3373437A
Cited
US3416153A
Cited
US3946398A
Cited
GB2007162A
Cited
US4166277A
Cited
US4293865A
Cited
US4164745A
Cited
US4275290A
Cited
US4312009A
Cited
US4490728A
Cited
US4580158A
Cited
US4710780A
Cited
US4751533A
Cited
US4752783A
Cited
US4751532A
Cited
US4748458A
Cited
US4737803A
Cited
WO1990014233A1
Cited
US5107276A
Cited
EP0471374A2
Cited
US5371527A
Cited
EP0600712A2
Cited
US5644343A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-09-14 | 2002-03-16 | 2002-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-14 | 2006-03-16 | 2006-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-14 | 2010-03-16 | 2010-09-15 | $7700.00 | Window Closed / Lapsed |