US3868698A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stimulation control apparatus for an ink jet recorder
Assignee: Eastman Kodak Co
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Filing: 1973-10-24
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Granted: 1975-02-25
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Expires: 1993-10-24
Abstract
Abstract A drive circuit for a stimulation transducer suppresses generation of satellite drops in an ink jet recorder. The drive circuit is an oscillator which tracks the resonant frequency of the stimulation transducer. As the resonant frequency of the transducer changes during normal operation, the frequency of the driving signal also changes, so that the power output of the transducer remains essentially unchanged. This provides accurate regulation of the filament length for the jets being stimulated and unexpectedly also suppresses generation of satellite drops. The drive circuit comprises an amplifier, a load resistor and positive and negative feedback paths to the input terminals of the amplifier. The load resistor is incorporated within the negative feedback path as well as within the supply path for the stimulation transducer. In general the impedance of the stimulation transducer is minimum at the resonant frequency thereof, so that for any shifting of the resonant frequency there is an increase in the input impedence to the transducer. This produces a voltage variation across the load resister which in turn alters the negative feedback to the amplifier. Means are provided for adjusting the negative feedback signal so as to maintain the amplifier in a state of continuous oscillation. The frequency at which this oscillation occurs is the frequency at which the impedance of the transducer is minimum, and therefore the drive circuit tracks the resonant frequency of the stimulation transducer.
Inventors
- 👤 John L Dressler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:03
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/005; B41J2/01; B41J2/07; B41J2/115
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
94 words
Apparatus for stimulating a filament of recording fluid to break up into uniformly sized and regularly spaced drops comprising electically driven vibrating means having a naturally resonant frequency near the natural frequency of said filament, an amplifier for supplying an electrical driving signal for said vibrating means, and positive and negative feedback means for causing oscillation of said amplifier; said negative feedback means comprising means for generating a negative feedback signal corresponding to the impedance of said vibrating means and causing oscillation of said amplifier to occur at a frequency which minimizes said impedance.
Claim 2
Dependent Claim
94 words
Apparatus for stimulating a filament of recording fluid to break up into uniformly sized and regularly spaced drops comprising electically driven vibrating means having a naturally resonant frequency near the natural frequency of said filament, an amplifier for supplying an electrical driving signal for said vibrating means, and positive and negative feedback means for causing oscillation of said amplifier; said negative feedback means comprising means for generating a negative feedback signal corresponding to the impedance of said vibrating means and causing oscillation of said amplifier to occur at a frequency which minimizes said impedance.
Claim 3
Dependent Claim
24 words
a power amplifier having an input terminal and an output terminal, said input terminal being connected to the output terminal of said differential amplifier,
Claim 4
Dependent Claim
24 words
a power amplifier having an input terminal and an output terminal, said input terminal being connected to the output terminal of said differential amplifier,
Claim 5
Dependent Claim
22 words
Apparatus for stimulating a filament of recording liquid to break up into a stream of uniformly sized and regularly spaced drops comprising:
Claim 6
Dependent Claim
22 words
Apparatus for stimulating a filament of recording liquid to break up into a stream of uniformly sized and regularly spaced drops comprising:
Claim 7
Dependent Claim
10 words
means mounting said transducer for vibrational stimulation of said filament,
Claim 8
Dependent Claim
10 words
means mounting said transducer for vibrational stimulation of said filament,
Claim 9
Dependent Claim
10 words
means mounting said transducer for vibrational stimulation of said filament,
Claim 10
Dependent Claim
10 words
means mounting said transducer for vibrational stimulation of said filament,
Claim 11
Dependent Claim
22 words
Apparatus for stimulating a filament of recording liquid to break up into a stream Of uniformly sized and regularly spaced drops comprising:
Claim 12
Dependent Claim
22 words
Apparatus for stimulating a filament of recording liquid to break up into a stream Of uniformly sized and regularly spaced drops comprising:
Claim 13
Dependent Claim
19 words
a load resister connected between the output terminal of said power amplifier and an imput terminal of said transducer,
Claim 14
Dependent Claim
19 words
a load resister connected between the output terminal of said power amplifier and an imput terminal of said transducer,
Claim 15
Dependent Claim
20 words
means for producing said electrical operating current and adjusting the frequency thereof for correspondence with said naturally resonant frequency, and
Claim 16
Dependent Claim
20 words
means for producing said electrical operating current and adjusting the frequency thereof for correspondence with said naturally resonant frequency, and
Claim 17
Dependent Claim
17 words
an amplifier for producing a driving signal which drives said operating current at a common frequency therewith,
Claim 18
Dependent Claim
17 words
an amplifier for producing a driving signal which drives said operating current at a common frequency therewith,
Claim 19
Dependent Claim
12 words
amplitude adjustment means for regulating the peak amplitude of said operating current.
Claim 20
Dependent Claim
12 words
amplitude adjustment means for regulating the peak amplitude of said operating current.
Claim 21
Dependent Claim
39 words
a load resister connected to the input side of said transducer so that at least a portion of said operating current passes therethrough whereby the voltage drop across said resister varies inversely with the electrical impedance of said transducer,
Claim 22
Dependent Claim
39 words
a load resister connected to the input side of said transducer so that at least a portion of said operating current passes therethrough whereby the voltage drop across said resister varies inversely with the electrical impedance of said transducer,
Claim 23
Dependent Claim
27 words
a first negative feedback branch comprising a feedback resister and connected between said input terminal of said transducer and the negative input terminal of said differential amplifier,
Claim 24
Dependent Claim
27 words
a first negative feedback branch comprising a feedback resister and connected between said input terminal of said transducer and the negative input terminal of said differential amplifier,
Claim 25
Dependent Claim
20 words
Apparatus according to claim 3 said amplifier having both positive and negative feedback terminals for connection to said feedback means.
Claim 26
Dependent Claim
32 words
Apparatus according to claim 4 the portion of said feedback means connected to said negative feedback terminal comprising a path joining said negative input terminal to the input side of said transducer.
Claim 27
Dependent Claim
34 words
feedback means connected to the input side of said amplifier for causing said driving signal and said operating current to oscillate at a frequency which maximizes the voltage drop across said load resister, and
Claim 28
Dependent Claim
34 words
feedback means connected to the input side of said amplifier for causing said driving signal and said operating current to oscillate at a frequency which maximizes the voltage drop across said load resister, and
Claim 29
Dependent Claim
28 words
a second negative feedback branch comprising gain adjusting means and connected between said input terminal of said transducer and said negative input terminal of said differential amplifier, and
Claim 30
Dependent Claim
28 words
a second negative feedback branch comprising gain adjusting means and connected between said input terminal of said transducer and said negative input terminal of said differential amplifier, and
Claim 31
Dependent Claim
27 words
positive feedback comprising a frequency selective resistance capacitance network connected between the output terminal of said differential amplifier and the positive input terminal of said differential amplifier.
Claim 32
Dependent Claim
27 words
positive feedback comprising a frequency selective resistance capacitance network connected between the output terminal of said differential amplifier and the positive input terminal of said differential amplifier.
Claim 33
Dependent Claim
24 words
feedback adjustment means for applying to the input side of said amplifier an adjustment signal which regulates the peak amplitude of said operating current.
Claim 34
Dependent Claim
24 words
feedback adjustment means for applying to the input side of said amplifier an adjustment signal which regulates the peak amplitude of said operating current.
Claim 35
Dependent Claim
58 words
Apparatus according to claim 5 further comprising a second amplifier having its input side connected for receiving said driving signal from the first aforesaid amplifier and its output side connected to the side of said load resister which is remote from said transducer, whereby said second amplifier generates said operating current and delivers it to said load resister.
Claim 36
Dependent Claim
33 words
Apparatus according to claim 6 the portion of said feedback means connected to said positive feedback terminal comprising a path joining said positive feedback terminal to the input side of said second amplifier.
Claim 37
Dependent Claim
33 words
Apparatus according to claim 7 said path joining said positive feedback terminal comprising means for producing initial oscillation of said driving signal at a frequency near the naturally resonant frequency of said transducer.
Claim 38
Dependent Claim
12 words
Apparatus according to claim 7 said resistance-capacitance network comprising wien bridge circuit.
Claim 39
Dependent Claim
14 words
Apparatus according to claim 6 said initial oscillation producing means comprising a resistance-capacitance network.
Claim 40
Dependent Claim
30 words
Apparatus according to claim 3 said load resister having a resistance between about 10 and 100 percent of the impedance of said transducer when driven at said naturally resonant frequency.
Claim 41
Dependent Claim
29 words
Apparatus according to claim 3 said load resister having a resistance equal to about 25 percent of the impedance of said transducer when driven at said naturally resonant frequency.
Claim 42
Dependent Claim
40 words
Apparatus according to claim 3 said feedback adjustment means comprising a voltage peak detector for detecting peak values of said operating current as seen at the input to said transducer and a voltage dependent resistance responsive to said peak detector.
Claim 43
Dependent Claim
14 words
Apparatus according to claim 13 said voltage dependent resistance comprising a field effect transistor.
Claim 44
Dependent Claim
63 words
In a jet drop recording system comprising an orifice plate for generating a row of filaments of recording liquid, an electrically driven and frequency resonant transducer for launching drop stimulating bending waves along said orifice plate and means for charging and deflecting the drops which are generated by said liquid filaments; driving means for driving said transducer at a resonant frequency thereof comprising:
Claim 45
Dependent Claim
63 words
In a jet drop recording system comprising an orifice plate for generating a row of filaments of recording liquid, an electrically driven and frequency resonant transducer for launching drop stimulating bending waves along said orifice plate and means for charging and deflecting the drops which are generated by said liquid filaments; driving means for driving said transducer at a resonant frequency thereof comprising:
Claim 46
Dependent Claim
40 words
Apparatus according to claim 15 said resistance-capacitance network being tuned for passage of frequencies near the resonant frequency of said transducer and comprising adjustment means for facilitating initial locking of said driving means to the resonant frequency of said transducer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |