US3828110A
Expired / Lapsed
US
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Control circuitry for electronic musical instrument
Assignee: Arp Instruments Inc
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Filing: 1973-07-11
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Granted: 1974-08-06
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Expires: 1993-07-11
Abstract
Abstract In an electronic musical instrument of the type including a keyboard and a resistor voltage divider having points there along respectively coupled by way of actuable keys associated with the keyboard to a single output bus, there is provided improved control electronics having output signals that control, for example, an envelope generator and a voltage controlled oscillator. The control electronics includes an oscillator and gate circuit coupled to the bus for providing a gate output signal which is present as long as at least one key is actuated, a sample/hold circuit coupled to the bus for providing a control voltage signal the amplitude of which is a function of the position of the actuated key, and a trigger signal means coupled to the keyboard and responsive to the gate circuit and the actuation of two or more keys for providing a trigger signal of shorter duration than the gate signal and occurring near the commencement of the gate signal.
Inventors
- 👤 D Colin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:30
CPC Classifications
G; G10; G10H; G10H1/00; G10H1/02; G10H1/04; G10H1/053; G10H1/057; G10H5/00; G10H5/002; Y; Y10; Y10S; Y10S84/00; Y10S84/20
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
193 words
In an electronic musical instrument of the type having keyboard means including a keyboard, means for providing a first signal coupled from the keyboard the amplitude of which corresponds to the actuated key, and means for providing a second signal coupled from the keyboard indicative of the actuation of at least two keys or the release of a key, control circuitry coupled from the means for providing the first and second, signals and comprising, in combination: first circuit means coupled from said first signal providing means for providing a gating signal which is present as long as at least one key is actuated; second circuit means including delay means and coupled from said second signal providing means for providing a triggering signal which is generally of shorter duration than the gating signal and is present at about the commencement of the gating signal; sample and hold means coupled from said first signal providing means and enabled by the gating signal derived from said first circuit means for establishing a control signal proportional to the first signal, and means coupled from said second circuit means for controlling operation of said sample and hold means.
Claim 2
Dependent Claim
193 words
In an electronic musical instrument of the type having keyboard means including a keyboard, means for providing a first signal coupled from the keyboard the amplitude of which corresponds to the actuated key, and means for providing a second signal coupled from the keyboard indicative of the actuation of at least two keys or the release of a key, control circuitry coupled from the means for providing the first and second, signals and comprising, in combination: first circuit means coupled from said first signal providing means for providing a gating signal which is present as long as at least one key is actuated; second circuit means including delay means and coupled from said second signal providing means for providing a triggering signal which is generally of shorter duration than the gating signal and is present at about the commencement of the gating signal; sample and hold means coupled from said first signal providing means and enabled by the gating signal derived from said first circuit means for establishing a control signal proportional to the first signal, and means coupled from said second circuit means for controlling operation of said sample and hold means.
Claim 3
Dependent Claim
59 words
The circuitry of claim 1 wherein said keyboard circuitry includes a voltage divider having a plurality of resistors coupled in series and a current source feeding the voltage divider, said first signal being coupled from said voltage divider at a point corresponding to the actuated key, and said second signal being coupled from an end of said voltage divider.
Claim 4
Dependent Claim
64 words
The circuitry of claim 2 wherein said keyboard has a number of key actuated switches and said keyboard and voltage divider are arranged with each key actuated switch coupled to a corresponding resistor of the voltage divider so that actuation of two keys bypasses the associated resistors therebetween causing said second signal to decrease, and releasing a key causes said second signal to increase.
Claim 5
Dependent Claim
63 words
The circuitry of claim 1 wherein said first circuit means comprises an oscillator and a gate circuit for generating a gate pulse upon the actuation of at least one key which is coupled to the second circuit means for providing the triggering signal when one key is actuated, and wherein said oscillator couples from said first signal providing means to said gate circuit.
Claim 6
Dependent Claim
40 words
The circuitry of claim 4 whereIn said oscillator includes an amplifier section and a phase shift section, said oscillator including means defining a low impedance path for inhibiting said amplifier section to stop oscillator operation upon actuation of a key.
Claim 7
Dependent Claim
41 words
The circuitry of claim 4 wherein said sample and hold means includes a capacitor charge network and means copuling said gating signal to said capacitor charge network to provide a charging current thereto for the approximate duration of the gating signal.
Claim 8
Dependent Claim
13 words
The circuitry of claim 6 wherein said charging current is a holding current.
Claim 9
Dependent Claim
52 words
The circuitry of claim 1 wherein said second circuit means comprises an AC coupled amplifier coupled from the second signal providing means, and a trigger circuit coupled from the AC coupled amplifier and responsive to actuation of at least two keys or the release of a key to provide the triggering signal.
Claim 10
Dependent Claim
47 words
The circuitry of claim 8 wherein said first circuit means comprises a gate circuit for generating a gate pulse upon the actuation of a key, said trigger circuit comprises an input circuit for receiving said gate pulse for providing the triggering signal when one key is actuated.
Claim 11
Dependent Claim
38 words
The circuitry of claim 9 wherein said trigger circuit comprises a phase splitter network and an output transistor which is conductive when the output of the AC coupled amplifier goes positive or negative from a predetermined reference level.
Claim 12
Dependent Claim
56 words
The circuitry of claim 1 wherein said second circuit means includes a trigger circuit coupled from the second signal providing means for providing the triggering signal and said first circuit means comprises a gate circuit for generating a gate impulse, said trigger circuit also including means responsive to the gate impulse for providing the triggering signal.
Claim 13
Dependent Claim
41 words
The circuitry of claim 11 wherein said sample and hold means includes a capacitor charge network and means coupling said triggering signal to said capacitor charge network to provide an initial charging current thereto for the duration of the triggering signal.
Claim 14
Dependent Claim
31 words
The circuitry of claim 12 comprising means coupling said gating signal to said capacitor charge network to provide a sustaining charging current thereto for the approximate duration of the gating signal.
Claim 15
Dependent Claim
31 words
The circuitry of claim 13 wherein said capacitor charge network includes a pair of transistors, one being controlled by the gating signal and the other being controlled by the triggering signal.
Claim 16
Dependent Claim
24 words
The circuitry of claim 14 wherein said transistors are field effect transistors and comprising a capacitor having one side coupled to both said transistors.
Claim 17
Dependent Claim
47 words
The circuitry of claim 1 wherein said second circuit means comprises a trigger circuit coupled from the second signal providing means and a threshold circuit coupled from the trigger circuit and responsive to a triggering signal of a predetermined amplitude or greater for activating the threshold circuit.
Claim 18
Dependent Claim
19 words
The circuitry of claim 16 comprising a delay circuit coupled from said threshold circuit for delaying the triggering signal.
Claim 19
Dependent Claim
38 words
The circuitry of claim 17 comprising an AND circuit coupled from the delay circuit and the first circuit means for generating a trigger output signal when said delayed triggering signal is present and said gating signal is present.
Claim 20
Dependent Claim
13 words
The circuitry of claim 18 wherein said delay circuit includes a monostable multivibrator.
Claim 21
Dependent Claim
28 words
The circuitry of claim 16 wherein said threshold circuit includes a transistor and resistor means for biasing the control electrode of the transistor at a fixed threshold level.
Claim 22
Dependent Claim
58 words
The circuitry of claim 1 wherein said sample and hold means includes an input voltage follower coupled from the first signal providing means, a capacitor charging network coupled from the voltage follower and responsive to both the gating and triggering signals, and an output follower coupled from the capacitor charging network and having a control voltage output terminal.
Claim 23
Dependent Claim
34 words
The circuitry of claim 21 wherein saId output follower includes a pair of field effect transistors coupled from the capacitor charging network and a different circuit coupled from the transistors to the output terminal.
Claim 24
Dependent Claim
111 words
The circuitry of claim 1 wherein said sample and hold means includes a charging network coupled from the first signal providing means and including a capacitor means, and first and second field effect transistors coupling from an input of the network to the capacitor means, said first transistor having a control electrode responsive to said gating signal for controlling the conduction of said first transistor to sustain the charge on said capacitor means while a key is being actuated, said second transistor having a control electrode responsive to said triggering signal for controlling the conduction of said second transistor to initially quick charge said capacitor means upon actuation of a key.
Claim 25
Dependent Claim
179 words
In an electronic musical instrument of the type having keyboard circuitry including a keyboard means for providing a first signal the amplitude of which corresponds to the actuated key, and means for providing a second signal indicative of the actuation of at least two keys or the release of a key, control circuitry coupled from the means for providing the first and second signals and comprising, in combination; a first circuit means coupled from said first signal providing means for providing a gating signal; a second circuit means coupled from said second signal providing means for providing a triggering signal which is generally shorter in duration than the gating signal and is present at about the commencement of the gating signal; third circuit means coupled from said first signal providing means for establishing a control signal proportional to the first signal, means coupled from said second circuit means for controlling operation of said third circuit means, and means coupled from said first circuit means to said second circuit means for providing the triggering signal when one key is actuated.
Claim 26
Dependent Claim
179 words
In an electronic musical instrument of the type having keyboard circuitry including a keyboard means for providing a first signal the amplitude of which corresponds to the actuated key, and means for providing a second signal indicative of the actuation of at least two keys or the release of a key, control circuitry coupled from the means for providing the first and second signals and comprising, in combination; a first circuit means coupled from said first signal providing means for providing a gating signal; a second circuit means coupled from said second signal providing means for providing a triggering signal which is generally shorter in duration than the gating signal and is present at about the commencement of the gating signal; third circuit means coupled from said first signal providing means for establishing a control signal proportional to the first signal, means coupled from said second circuit means for controlling operation of said third circuit means, and means coupled from said first circuit means to said second circuit means for providing the triggering signal when one key is actuated.
Claim 27
Dependent Claim
21 words
The circuitry of claim 24 comprising means responsive to said gating signal for enabling the output of said second circuit means.
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) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |