US3750191A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Synchronization of multiple ink jets
Assignee: International Business Machines Corp
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Filing: 1972-09-25
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Granted: 1973-07-31
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Expires: 1992-09-25
Abstract
Abstract A method is described for sequentially determining if drop formation for each jet in an array of ink jets is occurring at the proper time.
Inventors
- 👤 H Naylor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:26
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/07; B41J2/115
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
214 words
An ink jet synchronization system particularly suitable for apparatus utilizing a plurality of ink jets, comprising: a plurality of nozzle assemblies for forming and propelling ink drops in respectively associated ink jet streams, each of said nozzle assemblies incorporating driving crystals, charge electrodes, and deflection electrodes, means for driving said respective crystals at a predetermined frequency in order to form streams of drops for propulsion from said respective nozzle assemblies; individual charge driving circuits interconnected with said charge electrodes, respectively, for producing a charge potential on drops passing therethrough, when required; gutter-sensor means respectively associated with each of said nozzle assemblies, said gutter-sensor means being positioned for reception of drops propelled from said assemblies when said drops carry a particular predetermined charge level and said gutter-sensor means developing signals representative of charge levels on drops passing therethrough; a detector circuit responsive to signal levels developed in said gutter-sensor means to provide a corrective signal in said system for insuring proper relationship of said crystal driving circuits and said charge driving circuits; and switch circuit means interconnected for reception of signals from each of said gutter-sensor means and operable to supply signals from one and one only of said gutter-sensor means to said detector circuit during each of a number of succeeding synchronization testing intervals.
Claim 2
Dependent Claim
214 words
An ink jet synchronization system particularly suitable for apparatus utilizing a plurality of ink jets, comprising: a plurality of nozzle assemblies for forming and propelling ink drops in respectively associated ink jet streams, each of said nozzle assemblies incorporating driving crystals, charge electrodes, and deflection electrodes, means for driving said respective crystals at a predetermined frequency in order to form streams of drops for propulsion from said respective nozzle assemblies; individual charge driving circuits interconnected with said charge electrodes, respectively, for producing a charge potential on drops passing therethrough, when required; gutter-sensor means respectively associated with each of said nozzle assemblies, said gutter-sensor means being positioned for reception of drops propelled from said assemblies when said drops carry a particular predetermined charge level and said gutter-sensor means developing signals representative of charge levels on drops passing therethrough; a detector circuit responsive to signal levels developed in said gutter-sensor means to provide a corrective signal in said system for insuring proper relationship of said crystal driving circuits and said charge driving circuits; and switch circuit means interconnected for reception of signals from each of said gutter-sensor means and operable to supply signals from one and one only of said gutter-sensor means to said detector circuit during each of a number of succeeding synchronization testing intervals.
Claim 3
Dependent Claim
123 words
The apparatus of claim 1, further comprising: control logic in said system for sequentially gating each of said charge driving circuits in order to develop a sequence of charged drops from each of said nozzle assemblies, each of the sequences of drops from the respective nozzle assemblies being separated by an inactive charge time interval; means in said system for synchronously activating said switch circuit to receive developed signals from said gutter-sensor means during any time interval when charged drops are being received by said respective gutter-sensor means; and means responsive to output signals from said detector circuit means for correcting the crystal drive or charge drive, as appropriate, to insure proper synchronization of drop formation and charging in the respective nozzle assemblies.
Claim 4
Dependent Claim
47 words
The apparatus of claim 2, wherein said switching means comprises individual Field Effect Transistor pairs and associated switch circuits operable in timed sequence: a common operational amplifier; and means interconnecting the respective switch circuits to the input of said operational amplifier in timed sequence during synchronization activities.
Claim 5
Dependent Claim
71 words
The appaRatus of claim 1, further comprising: control logic in said system for activating the crystal drive and charge electrode drive circuits associated with each of said respective nozzle assemblies and for applying corrective potentials as required for each of said nozzle assemblies, in turn, in order to complete the synchronization process for each respective nozzle assembly in turn prior to any synchronization activities with respect to the other nozzle assemblies.
Claim 6
Dependent Claim
60 words
The apparatus of claim 1, wherein individual drops are formed in successive drop intervals comprising a finite time interval, and further comprising: control logic in said system for activating said charge driving circuits during an early portion of said drop time interval and for activating said crystal driving circuits during a later portion of said drop interval thereby achieving synchronization.
References Cited (Backward Citations)
US3298030A
Cited
US3681778A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |