US4119005A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for generating tone source waveshapes
Assignee: Nippon Gakki Co Ltd
•
Filing: 1977-04-04
•
Granted: 1978-10-10
•
Expires: 1997-04-04
Abstract
Abstract The system comprises a frequency number memory device for storing information regarding the frequencies of respective tones, a keyboard switch for reading out frequency number information corresponding thereto from the memory device, an address generator including an adder for adding a predetermined number of the frequency number information thereby producing an address signal consisting of plural bits, address composers for processing the bits of the address signal and thereby composing digital tone signals constituting a saw-tooth, square and triangular waveshape, and digital-analog converters for converting the digital tone signals into analog tone signals, which are thereafter used to synthesize waveshapes of any tone.
Inventors
- 👤 Michio Kondo
- 👤 Akira Nakada
- 👤 Masanobu Chibana
- 👤 Tsuyoshi Futamase
- 👤 Akiyoshi Ohya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:06
CPC Classifications
G; G10; G10H; G10H1/00; G10H1/02; G10H1/04; G10H1/053; G10H1/057; G10H1/0575; G10H7/00; G10H7/02; G10H7/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
208 words
A system for generating tone source waveshapes comprising a pre-loaded frequency number memory device which stores in digital representation a plurality of frequency numbers corresponding respectively to the fundamental frequencies of the notes of said waveshapes; a keyboard switch circuit having a key-actuated switch for each of said notes for reading out a frequency number respectively corresponding thereto from said frequency memory device; an address generator responsive to the frequency number read out from said frequency memory device for producing a given number of successive address signals periodically, each address signal consisting of a plurality of bits; at least one address composer connected to receive said successive address signals from said address generator directly and responsive to a predetermined number of said plurality of bits of each address signal in the range from one bit to n bits, where n is more than one and less than the bit plurality, for digitally composing a tone waveshape having a fundamental frequency corresponding to said read out frequency number with an amplitude versus time characteristic determined by the digital word value of each predetermined number of address signal bits to which said one address composer responds; and means for converting the digitally composed tone waveshape into an analog equivalent thereof.
Claim 2
Independent Claim
208 words
A system for generating tone source waveshapes comprising a pre-loaded frequency number memory device which stores in digital representation a plurality of frequency numbers corresponding respectively to the fundamental frequencies of the notes of said waveshapes; a keyboard switch circuit having a key-actuated switch for each of said notes for reading out a frequency number respectively corresponding thereto from said frequency memory device; an address generator responsive to the frequency number read out from said frequency memory device for producing a given number of successive address signals periodically, each address signal consisting of a plurality of bits; at least one address composer connected to receive said successive address signals from said address generator directly and responsive to a predetermined number of said plurality of bits of each address signal in the range from one bit to n bits, where n is more than one and less than the bit plurality, for digitally composing a tone waveshape having a fundamental frequency corresponding to said read out frequency number with an amplitude versus time characteristic determined by the digital word value of each predetermined number of address signal bits to which said one address composer responds; and means for converting the digitally composed tone waveshape into an analog equivalent thereof.
Claim 3
Dependent Claim
41 words
The system according to claim 1 wherein said address generator includes an adder for successively adding the read-out frequency number to itself and a buffer memory for storing the accumulated frequency number resulting from the successive addition performed by said adder.
Claim 4
Dependent Claim
53 words
The system according to claim 2 wherein said buffer memory stores said accumulated frequency number in the form of a plurality of bits, and said address composer comprises a buffer memory for storing a predetermined number of bits counting from the most significant bit in said address signal, thereby producing a saw-tooth wave.
Claim 5
Dependent Claim
18 words
The system according to claim 1 wherein said address composer is a duty variable square wave address generator.
Claim 6
Dependent Claim
48 words
The system according to claim 2 wherein said buffer memory stores said accumulated frequency number in the form of a plurality of bits and said address composer includes inverter means connected to receive only the most significant bit of said address signal, thereby producing a symmetrical square wave.
Claim 7
Dependent Claim
75 words
The system according to claim 2 wherein said buffer memory stores said accumulated frequency number in the form of a plurality of bits and said address composer comprises an AND gate circuit connected to receive the most significant bit of said address signal and a bit which is one bit less significant than said most significant bit, and inverter means responsive to the output of said AND gate circuit, thereby producing an asymmetrical square wave.
Claim 8
Dependent Claim
146 words
The system according to claim 2 wherein said buffer memory stores said accumulated frequency number in the form of a plurality of bits and wherein said address composer comprises a second buffer memory connected to receive a predetermined number of bits counting from the most significant bit in the address signal, inverter means, a selector for applying said predetermined number of the bits except the most significant bit and the bit which is one bit less significant than said most significant bit directly to and through said inverter means to said selector, means for controlling said selector in accordance with said bit which is one bit less significant than said most significant bit, complementing means responsive to the output from said selector for forming a two's complement, and means for controlling said complementing means in accordance with said most significant bit, thereby forming a triangular wave.
Claim 9
Dependent Claim
91 words
The system according to claim 1 which further comprises an attack-decay oscillator, an attack-decay logic circuit responsive to a signal indicating the operation of said key-actuated switch and the output from said attack-decay oscillator for producing an address signal, an attack-decay memory device storing information regarding attack and decay envelopes and connected to receive said address signals for producing said attack and decay envelope information, and a multiplier connected between said address composer and said digital-analog converting means for multiplying said digital tone signal by said attack and decay envelope information.
References Cited (Backward Citations)
US3610799A
Cited
US3610805A
Cited
US3610806A
Cited
US3683096A
Cited
US3697661A
Cited
US3755608A
Cited
US3809786A
Cited
US3789719A
Cited
US3809788A
Cited
US3809789A
Cited
US3809790A
Cited
US3878750A
Cited
US3910150A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-09 | 1982-04-10 | 1982-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-09 | 1986-04-10 | 1986-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-09 | 1990-04-10 | 1990-10-10 | $7700.00 | Window Closed / Lapsed |