US4134321A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Demultiplexing audio waveshape generator
Assignee: MUSICCO LLC
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Filing: 1977-04-14
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Granted: 1979-01-16
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Expires: 1997-04-14
Abstract
Abstract In an electronic musical instrument a demultiplexing audio waveshape generator, which accepts multiplexed frequency signals and generates a complex audio waveshape. This is accomplished by having a multiplexed frequency source with one or more outputs with each output being individually connected to a weighted resistor. The outputs of the resistors are connected in common to create a current source for presentation to an analog switch. The analog switch selects the multiplexed channels to be combined to produce the audio output signal, and through the use of gating signals can be made to create pulsed waveshapes. In the preferred embodiment of the present invention the signal from the analog switch is presented to a capacitance-resistance combination. The switched current presented to the capacitor causes an incremental charging and discharging of the capacitor which corresponds to the desired contribution of that particular channel to the audio output signal. The capacitance-resistance combination also functions as a low-pass filter to smooth the waveshape and provide some formant filtering.
Inventors
- 👤 Robert P. Woron
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:47
CPC Classifications
G; G10; G10H; G10H7/00; G10H1/00; G10H1/18; G10H1/183; G10H1/187; G10H2250/00; G10H2250/471; G10H2250/481; Y; Y10; Y10S; Y10S84/00; Y10S84/02; Y10S84/09
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
80 words
In a method of generating an audio waveshape wherein octavely related multiplexed frequency signals are generated by a multiplexed accumulator in respect to a preselected number of waveshape generator channels and wherein a sample gating signal is generated to select at least one of said channels, the steps of: weighting each of said plural multiplexed octavely related frequency signals, selectively combining the plural weighted frequency signals in response to said sample gating signal, and smoothing the combined weighted frequency signals.
Claim 2
Dependent Claim
80 words
In a method of generating an audio waveshape wherein octavely related multiplexed frequency signals are generated by a multiplexed accumulator in respect to a preselected number of waveshape generator channels and wherein a sample gating signal is generated to select at least one of said channels, the steps of: weighting each of said plural multiplexed octavely related frequency signals, selectively combining the plural weighted frequency signals in response to said sample gating signal, and smoothing the combined weighted frequency signals.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein said step of weighting said frequency signals includes weighting said plural multiplexed octavely related frequency signals according to a binary code.
Claim 4
Dependent Claim
17 words
The method of claim 1 including the step of modulating said plural multiplexed octavely related frequency signals.
Claim 5
Dependent Claim
24 words
The method of claim 3 including modifying said sample gating signal in accordance with preselected ones of said plural multiplexed octavely related frequency signals.
Claim 6
Dependent Claim
134 words
In an electronic musical instrument having means for producing plural multiplexed octavely related frequency signals in respect to a preselected number of waveshape generator channels, and means for producing a sample gating signal for selecting at least one of said channels, a demultiplexing audio waveshape generator, comprising: a plurality of interconnected weighting resistors connected to said means for producing said plural multiplexed octavely related frequency signals for weighting each of said plural multiplexed frequency signals, an analog switch connected to each of said weighting resistors and said means for producing a sample gating signal for selectively combining said plural frequency signals weighted by said resistors in response to said sample gating signal, and a capacitor and a resistor connected to said analog switch for smoothing said weighted frequency signals combined by said analog switch.
Claim 7
Dependent Claim
134 words
In an electronic musical instrument having means for producing plural multiplexed octavely related frequency signals in respect to a preselected number of waveshape generator channels, and means for producing a sample gating signal for selecting at least one of said channels, a demultiplexing audio waveshape generator, comprising: a plurality of interconnected weighting resistors connected to said means for producing said plural multiplexed octavely related frequency signals for weighting each of said plural multiplexed frequency signals, an analog switch connected to each of said weighting resistors and said means for producing a sample gating signal for selectively combining said plural frequency signals weighted by said resistors in response to said sample gating signal, and a capacitor and a resistor connected to said analog switch for smoothing said weighted frequency signals combined by said analog switch.
Claim 8
Dependent Claim
40 words
The demultiplexing audio waveshaped generator in accordance with claim 5 including digital logic circuitry connected between said means for producing said plural multiplexed octavely related frequency signals and said weighting resistors for modulating said plural multiplexed octavely related frequency signals.
Claim 9
Dependent Claim
42 words
The demultiplexing audio waveshape generator in accordance with claim 6 including means connected to said analog switch and preselected ones of said plural multiplexed octavely related frequency signals for modifying said sample gating signal in accordance with said preselected multiplexed frequency signals.
Claim 10
Dependent Claim
127 words
An electronic musical instrument, comprising: means for selecting the notes of a musical scale, multiplexed generating means having plural channels for generating plural octavely related frequency signals associated with each of said channels, assignment means responsive to said note selection means for generating a sample gating signal to assign a channel of said multiplexed generating means to a selected note, a plurality of interconnected weighting resistors for producing plural weighted frequency signals in response to said plural octavely related frequency signals, an analog switch connected to each of said resistors for selectively combining said plural weighted frequency signals in response to said sample gating signal, and a capacitor and a resistor connected to said analog switch for smoothing said weighted frequency signal combined by said analog switch.
Claim 11
Dependent Claim
127 words
An electronic musical instrument, comprising: means for selecting the notes of a musical scale, multiplexed generating means having plural channels for generating plural octavely related frequency signals associated with each of said channels, assignment means responsive to said note selection means for generating a sample gating signal to assign a channel of said multiplexed generating means to a selected note, a plurality of interconnected weighting resistors for producing plural weighted frequency signals in response to said plural octavely related frequency signals, an analog switch connected to each of said resistors for selectively combining said plural weighted frequency signals in response to said sample gating signal, and a capacitor and a resistor connected to said analog switch for smoothing said weighted frequency signal combined by said analog switch.
Claim 12
Dependent Claim
17 words
The demultiplexing audio waveshape generator in accordance with claim 8 wherein said weighting resistors are binary weighted.
Claim 13
Dependent Claim
32 words
The demultiplexing audio waveshape generator in accordance with claim 8 including digital logic circuitry connected between said multiplexed generating means and said weighting resistors for modulating said plural octavely related frequency signals.
Claim 14
Dependent Claim
42 words
The demultiplexing audio waveshape generator in accordance with claim 10 including means connected to said analog switch and preselected ones of said plural multiplexed octavely related frequency signals for modifying said sample gating signal in accordance with said preselected multiplexed frequency signals.
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) | 1982-01-15 | 1982-07-17 | 1983-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-15 | 1986-07-17 | 1987-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-15 | 1990-07-17 | 1991-01-16 | $7700.00 | Window Closed / Lapsed |