EP0194852A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Operating an ink jet apparatus
Assignee: Ricoh Printing Systems America Inc
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Filing: 1986-03-11
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Granted: —
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Expires: 2006-03-11
Abstract
Abstract For both reducing the ligament length and satellite droplet problems associated with producing high velocity ink droplets from an ink jet head printing at relatively high ink jet head-transport speeds, the ink jet head is driven by composite waveform including independent and successive first, second, and third electrical pulses (332,334,336), each having an exponential leading edge and a step-like trailing edge, the pulses having amplitudes, pulse widths (T 1 ,T 3 ,T 5 ), and dead times (T 2 ,T 4 ) between pulses, for causing the ink jet head to eject three successive ink droplets, each of increased velocity (V,, V 2 , V 3 ) relative to the preceding droplet, for causing the droplets to merge in flight to form a single or ultimate droplet (344) having a predetermined velocity (V4).
Inventors
- 👤 Stuart David Howkins
- 👤 Lisa Mae Schmidle
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 10:41
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/015; B41J2/04; B41J2/045; B41J2/04501; B41J2/04516; B41J2/04528; B41J2/04531; B41J2/04581; B41J2/04588; B41J2/07; B41J2/12; B41J2/21; B41J2/2121; B41J2/2128; B41J2/135; B41J2/14; B41J2002/14387; B41J2202/00; B41J2202/01; B41J2202/06
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
202 words
1 . A method for driving an ink jet head with a composite waveform, characterized in that said waveform comprises independent and successive first, second, and third electrical pulses (332, 334, 336) for ejecting successively higher velocity first, second and third ink droplets (338, 340, 342), respectively, whereby said droplets merge in flight for producing an ultimate ink droplet (344) having a predetermined velocity V, thereby permitting printing at droplet velocities in excess of 4.0 meters per second, with ink jet head transport speeds up to and exceeding 50 inches per second (1.27 meters per second) relative to a print medium being printed upon by said ultimate droplet, said method being further characterized by the steps of: (1) producing said first, second and third electrical pulses such that they have relative to one another appropriate waveshapes, pulse widths (T" T 3' T s ), amplitudes and dead times (T., T 4 ) therebetween for causing ejection from said ink jet head of said first, second and third ink droplets, respectively; and (2) producing said first pulse (332) such as to have both a ' pulse width (T,) and amplitude each less than the pulse width (T and amplitude of said second pulse.
Claim 2
Dependent Claim
202 words
1 . A method for driving an ink jet head with a composite waveform, characterized in that said waveform comprises independent and successive first, second, and third electrical pulses (332, 334, 336) for ejecting successively higher velocity first, second and third ink droplets (338, 340, 342), respectively, whereby said droplets merge in flight for producing an ultimate ink droplet (344) having a predetermined velocity V, thereby permitting printing at droplet velocities in excess of 4.0 meters per second, with ink jet head transport speeds up to and exceeding 50 inches per second (1.27 meters per second) relative to a print medium being printed upon by said ultimate droplet, said method being further characterized by the steps of: (1) producing said first, second and third electrical pulses such that they have relative to one another appropriate waveshapes, pulse widths (T" T 3' T s ), amplitudes and dead times (T., T 4 ) therebetween for causing ejection from said ink jet head of said first, second and third ink droplets, respectively; and (2) producing said first pulse (332) such as to have both a ' pulse width (T,) and amplitude each less than the pulse width (T and amplitude of said second pulse.
Claim 3
Dependent Claim
12 words
A method as claimed in claim 1, further comprising the following step:
Claim 4
Dependent Claim
83 words
(3) adjusting the relative amplitudes and pulse widths - (T 1 ,T 3 ,T 5 ) between said first to third electrical pulses - (332,334,336), and the dead time (T 2 ,T 4 ) between said first and second (332,33 4 ), and second and third (33 4 ,336), electrical pulses, for reducing to a minimum the length of the ligament (346) of said ultimate ink drokplet (3 4 4), thereby substantially reducing the deleterious effect upon printing quality caused by said ligament.
Claim 5
Dependent Claim
83 words
(3) adjusting the relative amplitudes and pulse widths - (T 1 ,T 3 ,T 5 ) between said first to third electrical pulses - (332,334,336), and the dead time (T 2 ,T 4 ) between said first and second (332,33 4 ), and second and third (33 4 ,336), electrical pulses, for reducing to a minimum the length of the ligament (346) of said ultimate ink drokplet (3 4 4), thereby substantially reducing the deleterious effect upon printing quality caused by said ligament.
Claim 6
Dependent Claim
12 words
A method as claimed in claim 1, further comprising the step of:
Claim 7
Dependent Claim
73 words
(3) adjusting the relative amplitudes and pulse widths - (T 1 ,T 3 ,T 5 ) between said first to third electrical pulses (332,334,336), and the dead times (T 2 ,T 4 ) between said first and second (332,33 4 ), and second and third (334,336) electrical pulses, for breaking up a ligament (346) of said ultimate ink droplet (344) into an incoherent stream of small satellites, thereby improving the quality of printing.
Claim 8
Dependent Claim
73 words
(3) adjusting the relative amplitudes and pulse widths - (T 1 ,T 3 ,T 5 ) between said first to third electrical pulses (332,334,336), and the dead times (T 2 ,T 4 ) between said first and second (332,33 4 ), and second and third (334,336) electrical pulses, for breaking up a ligament (346) of said ultimate ink droplet (344) into an incoherent stream of small satellites, thereby improving the quality of printing.
Claim 9
Dependent Claim
12 words
A method as claimed in claim 1, further comprising the step of:
Claim 10
Dependent Claim
64 words
(3) adjusting the relative amplitudes, pulse widths (T 2 ,T3,T s ) and dead times (T 2 ,T 4 ) between said first to third electrical pulses (332,334,336), for both shortening the length of a ligament (346) of said ultimate ink droplet (344), and for breaking up the shortened ligament (346) into an incoherent stream of small satellites, thereby improving the quality of printing.
Claim 11
Dependent Claim
64 words
(3) adjusting the relative amplitudes, pulse widths (T 2 ,T3,T s ) and dead times (T 2 ,T 4 ) between said first to third electrical pulses (332,334,336), for both shortening the length of a ligament (346) of said ultimate ink droplet (344), and for breaking up the shortened ligament (346) into an incoherent stream of small satellites, thereby improving the quality of printing.
Claim 12
Independent Claim
37 words
A method as claimed in any one of the preceding claims, further comprising the step of shaping said first, second, and third electrical pulses (332,334,336) to each have an exponential leading edge, and a step-like trailing edge.
Claim 13
Independent Claim
28 words
A method as claimed in any preceding claim, further comprising, for dynamically providing grey scale printing over successive cycles driving said ink jet head, the further steps of:
Claim 14
Dependent Claim
40 words
(4) using selectively over a given cycle a waveform consisting of either one of, two of, or all three of said first, second, and third electrical pulses, for obtaining an ultimate ink droplet having a desired volume of ink; and
Claim 15
Dependent Claim
40 words
(4) using selectively over a given cycle a waveform consisting of either one of, two of, or all three of said first, second, and third electrical pulses, for obtaining an ultimate ink droplet having a desired volume of ink; and
Claim 16
Dependent Claim
36 words
(5) causing the selected one(s) of said first, second and third electrical pulses to have relative and respective amplitudes, pulse widths, and dead times therebetween, for obtaining an ultimate ink droplet having said predetermined velocity V.
Claim 17
Dependent Claim
36 words
(5) causing the selected one(s) of said first, second and third electrical pulses to have relative and respective amplitudes, pulse widths, and dead times therebetween, for obtaining an ultimate ink droplet having said predetermined velocity V.
References Cited (Backward Citations)
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