US3928855A
Expired / Lapsed
US
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Method and apparatus for controlling satellites in an ink jet printing system
Assignee: International Business Machines Corp
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Filing: 1974-12-18
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Granted: 1975-12-23
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Expires: 1994-12-18
Abstract
Abstract A continuous jet stream of a ferrofluid ink is broken into individual drops by an asymmetrical perturbation force applied to the stream. The ink, as it exits from an orifice under pressure, is excited by an electromagnetic transducer energized with an asymmetrical excitation signal having a fundamental and higher harmonics. An asymmetrical excitation signal, such as a sawtooth, having a substantial second and/or third harmonics content which produce an excitation signal with different rise and fall times can form a stream of drops free of satellites. Asymmetry of magnetic field forces can be produced with single stage or multistage transducers located at spaced positions along the stream. Asymmetry can also be produced using an electromagnetic transducer having a non-uniform gap.
Inventors
- 👤 Edward F Helinski
- 👤 Ho C Lee
- 👤 Jack L Zable
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:34
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/07; B41J2/12
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
79 words
In an ink drop forming system of the type having means for supplying ink under pressure to a nozzle or the like to cause a continuous jet stream of ink to flow From said nozzle, and a transducer for causing periodic perturbations in said stream at a predetermined frequency whereby drops are formed in said jet stream, the improvement comprising, a method of controlling the formation of satellites by energizing said transducer with a signal having an asymmetrical waveform.
Claim 2
Dependent Claim
79 words
In an ink drop forming system of the type having means for supplying ink under pressure to a nozzle or the like to cause a continuous jet stream of ink to flow From said nozzle, and a transducer for causing periodic perturbations in said stream at a predetermined frequency whereby drops are formed in said jet stream, the improvement comprising, a method of controlling the formation of satellites by energizing said transducer with a signal having an asymmetrical waveform.
Claim 3
Dependent Claim
32 words
In an ink drop forming system of the type in accordance with claim 1, the improvement further comprising energizing said transducer with an asymmetrical waveform having a fundamental frequency and higher harmonics.
Claim 4
Dependent Claim
36 words
In an ink drop forming system of the type in accordance with claim 2, the improvement further comprising energizing said transducer with an asymmetrical waveform in which the higher harmonics includes at least the second harmonic.
Claim 5
Dependent Claim
35 words
In an ink drop forming system of the type in accordance with claim 3 in which the ratio of the amplitude of the second harmonic to the fundamental frequency is at least equal to 0.5.
Claim 6
Dependent Claim
86 words
In an ink drop forming system of the type having means for supplying magnetic ink under pressure to a nozzle or the like to cause a continuous jet stream of magnetic ink to flow from said nozzle and magnetic transducer means for forming periodic perturbations in said stream, the improvement comprising: said transducer having means for generating an asymmetrical force field at a predetermined frequency in the vicinity of a segment of said jet stream for controlling the formation of satellites produced by said periodic perturbations.
Claim 7
Dependent Claim
86 words
In an ink drop forming system of the type having means for supplying magnetic ink under pressure to a nozzle or the like to cause a continuous jet stream of magnetic ink to flow from said nozzle and magnetic transducer means for forming periodic perturbations in said stream, the improvement comprising: said transducer having means for generating an asymmetrical force field at a predetermined frequency in the vicinity of a segment of said jet stream for controlling the formation of satellites produced by said periodic perturbations.
Claim 8
Dependent Claim
78 words
In an ink drop forming system of the type in accordance with claim 1 in which said transducer means comprises a magnetic core device disposed proximate at least one segment of said stream, said core device being structured to produce an asymmetrical force field on said segment of said stream, and means for periodically energizing said magnetic core device at said predetermined frequency in timed relation with the flow of said stream relative to said magnetic core device.
Claim 9
Dependent Claim
44 words
In an ink drop forming system of the type in accordance with claim 6 in which said magnetic core device includes pole portions disposed proximate said segment of said stream, and said pole portions forming a non-uniform gap along said segment of said stream.
Claim 10
Dependent Claim
33 words
In an ink drop forming system of the type in accordance with claim 7 in which said pole portions are tapered in the direction of said stream flow to form said non-uniform gaps.
Claim 11
Dependent Claim
61 words
An ink drop system of the type in accordance with claim 5 in which said magnetic transducer means comprises a magnetic core device disposed to produce a magnetic field proximate at least one segment of said stream, and means for periodically applying an energizing signal at said predetermined frequency to said magnetic core device, said energizing signal having an asymmetrical waveform.
Claim 12
Dependent Claim
29 words
In an ink drop forming system of the type in accordance with claim 9 in which said energizing signal contains harmonics higher than one for producing said asymmetrical waveform.
Claim 13
Dependent Claim
22 words
In an ink drop system of the type in accordance with claim 9 in which said higher harmonics includes a second harmonic.
Claim 14
Dependent Claim
26 words
In an ink drop system in accordance with claim 10 in which said higher harmonics are out of phase with the fundamental frequency of said signal.
Claim 15
Dependent Claim
24 words
In an ink drop system in accordance with claim 9 in which said signal has a long rise time relative to its fall time.
Claim 16
Dependent Claim
27 words
In an ink drop system of the type in accordance with claim 9 in which said signal has a short rise time relative to its fall time.
Claim 17
Dependent Claim
86 words
In an ink drop forming system of the type having means for supplying field controllable ink under pressure to a nozzle or the like to cause a continuous jet stream of ink to flow from said nozzle, and transducer means for forming periodic perturbations in said stream, the improvement comprising: said transducer means having means for generating an asymmetrical force field at a predetermined frequeNcy in the vicinity of a segment of said jet stream for controlling the formation of satellites produced by said periodic perturbations.
Claim 18
Dependent Claim
86 words
In an ink drop forming system of the type having means for supplying field controllable ink under pressure to a nozzle or the like to cause a continuous jet stream of ink to flow from said nozzle, and transducer means for forming periodic perturbations in said stream, the improvement comprising: said transducer means having means for generating an asymmetrical force field at a predetermined frequeNcy in the vicinity of a segment of said jet stream for controlling the formation of satellites produced by said periodic perturbations.
Claim 19
Dependent Claim
77 words
In an ink drop forming system of the type having means for supplying ink under pressure to a nozzle or the like to cause a continuous jet stream of ink to flow from said nozzle, and transducer means for forming periodic perturbations in said stream, the improvement comprising: said transducer means having means for applying an asymmetrical force at a predetermined frequency to said jet stream for controlling the formation of satellites produced by said periodic perturbations.
Claim 20
Dependent Claim
77 words
In an ink drop forming system of the type having means for supplying ink under pressure to a nozzle or the like to cause a continuous jet stream of ink to flow from said nozzle, and transducer means for forming periodic perturbations in said stream, the improvement comprising: said transducer means having means for applying an asymmetrical force at a predetermined frequency to said jet stream for controlling the formation of satellites produced by said periodic perturbations.
Claim 21
Dependent Claim
71 words
In an ink drop forming system of the type having means for supplying ink under pressure to a nozzle or the like to cause a continuous jet stream of ink to flow from said nozzle means for forming drops in said stream comprising in combination, a transducer for causing periodic perturbations in said stream at a predetermined frequency, and means for energizing said transducer with a signal having an asymmetrical waveform.
Claim 22
Dependent Claim
71 words
In an ink drop forming system of the type having means for supplying ink under pressure to a nozzle or the like to cause a continuous jet stream of ink to flow from said nozzle means for forming drops in said stream comprising in combination, a transducer for causing periodic perturbations in said stream at a predetermined frequency, and means for energizing said transducer with a signal having an asymmetrical waveform.
Claim 23
Dependent Claim
19 words
In an ink drop forming apparatus in accordance with claim 17 in which said signal has a sawtooth waveform.
Claim 24
Dependent Claim
26 words
In an ink drop forming apparatus in accordance with claim 18 in which said sawtooth waveform has a slow rise time and a fast drop time.
Claim 25
Dependent Claim
26 words
In an ink drop forming apparatus in accordance with claim 18 in which said sawtooth waveform has a fast rise time and a slow drop time.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |