US4840099A
Expired / Lapsed
US
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Electronic musical instrument
Assignee: Kawai Musical Instruments Manufacturing Co Ltd
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Filing: 1987-09-29
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Granted: 1989-06-20
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Expires: 2007-09-29
Abstract
Abstract Calculations by an envelope circuit and a waveform calculation circuit, which are principal functions of an electronic musical instrument, can be performed by the same calculation routine through use of the same general formula A=B±C×D. Accordingly, their circuit structures are substantially simplified and the circuits can be fabricated as a one-chip large scale integrated circuit.
Inventors
- 👤 Hiroshi Kitagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 02:46
CPC Classifications
G; G10; G10H; G10H1/00; G10H1/02; G10H1/04; G10H1/053; G10H1/057; G10H1/0575; G10H7/00; G10H7/08; G10H7/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
239 words
An electronic musical instrument comprising: multiplying means for multipling input data C and input data D to obtain output data E; adding means for adding the output data E and input data B, or substracting them one from the other, to obtain output data A; memory means for temporarily storing the output data A to be read out later; selector means which receives the output data A, waveform data and envelope coefficient data and selectively outputs the input data B, C and D; calculation control means whereby, for a calculation A =B+(C×D), an envelope calculation represented by (1) X=Env-Env×Step, (2) Env=X+Step×Speed, wherein X represents a buffer for calculation, Step represents envelope level coefficient data, Speed represents envelope speed coefficient data and Env represent envelope data, and an envelope-appended musical waveform calculation represented by (3) S=S+Wave×Env, wherein S represents a composite waveform in each channel and wave represents waveform data, are switched between the envelope calculation and the envelope appended musical waveform calculation them on a time-shared basis for each step of each calculation cycle; and D/A converting means whereby digital musical waveform data obtained by the calculations is converted to analog form for acoustic output; wherein the calculation A=B±C×D, is performed on a time-shared basis and the input data is controlled, by which calculations of different functions such as calculations of an envelope waveform and a musical waveform, are performed by the same calculation means, obtaining a musical waveform.
Claim 2
Dependent Claim
239 words
An electronic musical instrument comprising: multiplying means for multipling input data C and input data D to obtain output data E; adding means for adding the output data E and input data B, or substracting them one from the other, to obtain output data A; memory means for temporarily storing the output data A to be read out later; selector means which receives the output data A, waveform data and envelope coefficient data and selectively outputs the input data B, C and D; calculation control means whereby, for a calculation A =B+(C×D), an envelope calculation represented by (1) X=Env-Env×Step, (2) Env=X+Step×Speed, wherein X represents a buffer for calculation, Step represents envelope level coefficient data, Speed represents envelope speed coefficient data and Env represent envelope data, and an envelope-appended musical waveform calculation represented by (3) S=S+Wave×Env, wherein S represents a composite waveform in each channel and wave represents waveform data, are switched between the envelope calculation and the envelope appended musical waveform calculation them on a time-shared basis for each step of each calculation cycle; and D/A converting means whereby digital musical waveform data obtained by the calculations is converted to analog form for acoustic output; wherein the calculation A=B±C×D, is performed on a time-shared basis and the input data is controlled, by which calculations of different functions such as calculations of an envelope waveform and a musical waveform, are performed by the same calculation means, obtaining a musical waveform.
Claim 3
Dependent Claim
84 words
The electronic musical instrument of claim 1 which has a plurality of channels and in which the input data is controlled by the following two steps on a time-shared basis: (1) Y=Env 1+Wave 2×Env 2, (2) A=O+Wave 1×Y, wherein Y represents a buffer for calculation, Wave 1 and Wave 2 represent different waveform data, 0 represents a zero value, and Env 1 and Env 2 represent different envelope data; whereby a musical waveform AM-modulated by a waveform of a different channel is further calculated.
Claim 4
Dependent Claim
73 words
The electronic musical instrument of claim 1, wherein the multiplying means comprises a floating point multiplier for multiplying the input data C and D which are floating points 2 -P × M represented by an exponent part P and mantissa part M, and which further includes a fixed point converter for converting the output of the floating point multiplier for converting the output data A from the memory means into a floating point.
Claim 5
Dependent Claim
190 words
An electronic musical instrument comprising: multiplying means for multiplying input data C and input data D to obtain output data E; adding/subtracting means for adding/subtracting the output data E and input data B to obtain output data A; memory means for temporarily storing the output data A to be read out later; selector means for receiving output data A, waveform data and envelope coefficient data and for selectively outputting received data as input data B, C, and D; calculation control means for controlling said selector means, memory means and adding/subtracting means for switching between an envelope calculation and an envelope-appended musical waveform calculation on a time-shared basis for each step of each calculation cycle for an envelope calculation represented by (1) X=Env-(Env+Step) (2) Env=X+(Step×Speed) wherein X represents a buffer for calculation, Step represents envelope level coefficient data, Speed represents envelope speed coefficient data and Env represents envelope data, and for an envelope - appended musical waveform calculation represented by (3) S=S+(Wave×Env) wherein S represents a composite waveform in each channel and wave represents waveform data, musical waveform data obtained by the calculations is converted to analog form for acoustic output.
Claim 6
Dependent Claim
190 words
An electronic musical instrument comprising: multiplying means for multiplying input data C and input data D to obtain output data E; adding/subtracting means for adding/subtracting the output data E and input data B to obtain output data A; memory means for temporarily storing the output data A to be read out later; selector means for receiving output data A, waveform data and envelope coefficient data and for selectively outputting received data as input data B, C, and D; calculation control means for controlling said selector means, memory means and adding/subtracting means for switching between an envelope calculation and an envelope-appended musical waveform calculation on a time-shared basis for each step of each calculation cycle for an envelope calculation represented by (1) X=Env-(Env+Step) (2) Env=X+(Step×Speed) wherein X represents a buffer for calculation, Step represents envelope level coefficient data, Speed represents envelope speed coefficient data and Env represents envelope data, and for an envelope - appended musical waveform calculation represented by (3) S=S+(Wave×Env) wherein S represents a composite waveform in each channel and wave represents waveform data, musical waveform data obtained by the calculations is converted to analog form for acoustic output.
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) | 1992-06-19 | 1992-12-19 | 1993-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-19 | 1996-12-19 | 1997-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-19 | 2000-12-19 | 2001-06-20 | $7700.00 | Window Closed / Lapsed |