US4368474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ink droplet formation control in an ink jet system printer
Assignee: Sharp Corp
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Filing: 1980-10-10
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Granted: 1983-01-11
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Expires: 2000-10-10
Abstract
Abstract An ink jet system printer includes a nozzle for emitting an ink liquid under a predetermined pressure, an electro-mechanical transducer secured to the nozzle for vibrating the nozzle in accordance with an excitation signal of a given frequency, thereby forming ink droplets at the given frequency, and a charging tunnel for charging the ink droplets in accordance with print information. A charge condition detection unit is provided for monitoring the charge condition of the ink droplets, the output signal of the charge condition detection unit being indicative of a droplet formation condition. When the output signal of the charge condition detection unit indicates the occurrence of satellite ink droplets in addition to the normal ink droplets, the voltage level of the excitation signal, which is applied to the electrode-mechanical transducer, is varied to eliminate the occurrence of the satellite ink droplets.
Inventors
- 👤 Fumio Togawa
- 👤 Yoichi Shimazawa
- 👤 Hitoshi Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:20
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/07; B41J2/115
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
156 words
An automatic ink droplet formation control system in an ink jet system printer which includes a nozzle for emitting an ink jet, an electro-mechanical transducer secured to the nozzle for vibrating the nozzle in response to an excitation signal of a given frequency, thereby forming ink droplets at the given frequency, and charging means for charging the ink droplets in accordance with print information, said automatic ink droplet formation control system comprising: variation means for automatically varying a voltage level of said excitation signal to be applied to said electro-mechanical transducer; and control means for developing a control signal to said variation means for automatically maintaining said voltage level of said excitation signal within a range where no satellite ink droplet is formed; said control means including a charge detection unit for detecting a charge condition of said ink droplets effected by said charging means in order to monitor the occurrence of said satellite ink droplets.
Claim 2
Dependent Claim
156 words
An automatic ink droplet formation control system in an ink jet system printer which includes a nozzle for emitting an ink jet, an electro-mechanical transducer secured to the nozzle for vibrating the nozzle in response to an excitation signal of a given frequency, thereby forming ink droplets at the given frequency, and charging means for charging the ink droplets in accordance with print information, said automatic ink droplet formation control system comprising: variation means for automatically varying a voltage level of said excitation signal to be applied to said electro-mechanical transducer; and control means for developing a control signal to said variation means for automatically maintaining said voltage level of said excitation signal within a range where no satellite ink droplet is formed; said control means including a charge detection unit for detecting a charge condition of said ink droplets effected by said charging means in order to monitor the occurrence of said satellite ink droplets.
Claim 3
Dependent Claim
64 words
An automatic ink droplet formation control system of claim 1, said charge condition detection unit comprising: a metal member electrically making contact with said ink jet emitted from said nozzle; a capacitor electrically connected to said metal member; a search pulse generation circuit for applying a search pulse to said charging means; and detection means for detecting a charge level stored on said capacitor.
Claim 4
Dependent Claim
149 words
An automatic ink droplet formation control system in an ink jet system printer which includes a nozzle for emitting an ink jet, an electro-mechanical transducer secured to the nozzle for vibrating the nozzle in response to an excitation signal of a given frequency, thereby forming ink droplets at the given frequency, and charging means for charging the ink droplets in accordance with print information, said automatic ink droplet formation control system comprising: variation means for automatically varying a voltage level of said excitation signal to be applied to said electro-mechanical transducer; and control means for developing a control signal to said variation means for automatically maintaining said voltage level of said excitation signal within a range where no satellite ink droplet is formed; said control means including an ambient temperature detection means for developing said control signal to said variation means in response to variations of the ambient temperature.
Claim 5
Dependent Claim
149 words
An automatic ink droplet formation control system in an ink jet system printer which includes a nozzle for emitting an ink jet, an electro-mechanical transducer secured to the nozzle for vibrating the nozzle in response to an excitation signal of a given frequency, thereby forming ink droplets at the given frequency, and charging means for charging the ink droplets in accordance with print information, said automatic ink droplet formation control system comprising: variation means for automatically varying a voltage level of said excitation signal to be applied to said electro-mechanical transducer; and control means for developing a control signal to said variation means for automatically maintaining said voltage level of said excitation signal within a range where no satellite ink droplet is formed; said control means including an ambient temperature detection means for developing said control signal to said variation means in response to variations of the ambient temperature.
Claim 6
Dependent Claim
25 words
An automatic ink droplet formation control system of claim 3, wherein said voltage level of said excitation signal is reduced when the ambient temperature increases.
Claim 7
Dependent Claim
21 words
An automatic ink droplet formation control system of claim 1, 2, 4 or 3 wherein said given frequency is 100 KHz.
Claim 8
Dependent Claim
22 words
An automatic ink droplet formation control system of claim 5, wherein said ink droplets have a travelling velocity of about 18 m/sec.
Claim 9
Dependent Claim
33 words
An automatic ink droplet formation control system according to claim 2, wherein said charge condition detection unit further includes a switch means operatively connected in parallel with said capacitor for resetting the capacitor.
Claim 10
Dependent Claim
52 words
An automatic ink droplet formation control system according to claim 2, wherein said charge condition detection unit further includes a resistor operatively connected in parallel with said capacitor for discharging the charge stored on the capacitor in accordance with a time constant which is a function of the capacitor and the resistor.
Claim 11
Dependent Claim
35 words
An automatic ink droplet formation control system according to claim 8, wherein said charge condition detection unit further includes an amplifier operatively connected to said capacitor for amplifying the charge voltage level of the capacitor.
Claim 12
Dependent Claim
42 words
An automatic ink droplet formation control system according to claim 3, said ambient temperature detection means comprising: a thermistor operatively connected in parallel to an operation amplifier; said operation amplifier being operatively connected through a resistor to receive a base frequency signal.
Claim 13
Dependent Claim
153 words
An ink droplet formation control system in an ink jet system printer which includes a nozzle for emitting an ink jet, an electro-mechanical transducer secured to the nozzle for vibrating the nozzle in response to an excitation signal of a given frequency, thereby forming ink droplets at the given frequency, and charging means for charging the ink droplets in accordance with print information, said ink droplet formation control system comprising: variation means for varying a voltage level of said excitation signal to be applied to said electro-mechanical transducer; and control means for developing a control signal to said variation means for maintaining said voltage level of said excitation signal within a range where no satellite ink droplet is formed; said control means including a charge condition detection unit for detecting a charge condition of said ink droplets effected by said charging means in order to monitor the occurrence of said satellite ink droplets.
Claim 14
Dependent Claim
153 words
An ink droplet formation control system in an ink jet system printer which includes a nozzle for emitting an ink jet, an electro-mechanical transducer secured to the nozzle for vibrating the nozzle in response to an excitation signal of a given frequency, thereby forming ink droplets at the given frequency, and charging means for charging the ink droplets in accordance with print information, said ink droplet formation control system comprising: variation means for varying a voltage level of said excitation signal to be applied to said electro-mechanical transducer; and control means for developing a control signal to said variation means for maintaining said voltage level of said excitation signal within a range where no satellite ink droplet is formed; said control means including a charge condition detection unit for detecting a charge condition of said ink droplets effected by said charging means in order to monitor the occurrence of said satellite ink droplets.
Claim 15
Dependent Claim
64 words
An ink droplet formation control system according to claim 11, said charge condition detection unit comprising: a metal member electrically making contact with said ink jet emitted from said nozzle; a capacitor electrically connected to said metal member; a search pulse generation circuit for applying a search pulse to said charging means; and detection means for detecting a charge level stored on said capacitor.
Claim 16
Dependent Claim
145 words
An ink droplet formation control system in an ink jet system printer which includes a nozzle for emitting an ink jet, an electro-mechanical transducer secured to the nozzle for vibrating the nozzle in response to an excitation signal of a given frequency, thereby forming ink droplets at the given frequency, and charging means for charging the ink droplets in accordance with print information, said ink droplet formation control system comprising: variation means for varying a voltage level of said excitation signal to be applied to said electro-mechanical transducer; and control means for developing a control signal to said variation means for maintaining said voltage level of said excitation signal within a range where no satellite ink droplet is formed; said control means including an ambient temperature detection means for developing said control signal to said variation means in response to variations of the ambient temperature.
Claim 17
Dependent Claim
145 words
An ink droplet formation control system in an ink jet system printer which includes a nozzle for emitting an ink jet, an electro-mechanical transducer secured to the nozzle for vibrating the nozzle in response to an excitation signal of a given frequency, thereby forming ink droplets at the given frequency, and charging means for charging the ink droplets in accordance with print information, said ink droplet formation control system comprising: variation means for varying a voltage level of said excitation signal to be applied to said electro-mechanical transducer; and control means for developing a control signal to said variation means for maintaining said voltage level of said excitation signal within a range where no satellite ink droplet is formed; said control means including an ambient temperature detection means for developing said control signal to said variation means in response to variations of the ambient temperature.
Claim 18
Dependent Claim
25 words
An ink droplet formation control system according to claim 13, wherein said voltage level of said excitation signal is reduced when the ambient temperature increases.
Claim 19
Dependent Claim
21 words
An ink droplet formation control system according to claim 11, 12, 13 or 14, wherein said given frequency is 100 KHz.
Claim 20
Dependent Claim
22 words
An ink droplet formation control system according to claim 15, wherein said ink droplets have a travelling velocity of about 18 m/sec.
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) | 1986-01-10 | 1986-07-12 | 1987-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-10 | 1990-07-12 | 1991-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-10 | 1994-07-12 | 1995-01-11 | $7700.00 | Window Closed / Lapsed |