US4876935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic musical instrument
Assignee: Kawai Musical Instruments Manufacturing Co Ltd
•
Filing: 1987-09-29
•
Granted: 1989-10-31
•
Expires: 2007-09-29
Abstract
Abstract This eliminates the possibility of the generation of quantizing noise in a small amplitude portion of the waveform when it is compressed to an 8-bit quantized form. The present invention is effective when a percussive or like musical tone, provided in the form of a 16-bit quantized digital form is compressed to the 8-bit quantized form.
Inventors
- 👤 Hiroshi Kitagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:14
CPC Classifications
G; G10; G10H; G10H7/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
112 words
An electronic musical instrument in which a natural musical tone is converted into a digital signal and at least a section of the waveform of the digital signal is compressed to a quantized waveform, stored in a memory and read out therefrom for producing a musical tone, including; means for storing data of the compressed waveform section in the memory, wherein said compressed waveform section has had its amplitude expanded in accordance with a predetermined envelope waveform; and, means for reading the stored amplitude-expanded digital waveform section data out of the memory and for digitally multiplying the digital waveform data read out by a digital envelope waveform, thereby reproducing the original waveform.
Claim 2
Dependent Claim
112 words
An electronic musical instrument in which a natural musical tone is converted into a digital signal and at least a section of the waveform of the digital signal is compressed to a quantized waveform, stored in a memory and read out therefrom for producing a musical tone, including; means for storing data of the compressed waveform section in the memory, wherein said compressed waveform section has had its amplitude expanded in accordance with a predetermined envelope waveform; and, means for reading the stored amplitude-expanded digital waveform section data out of the memory and for digitally multiplying the digital waveform data read out by a digital envelope waveform, thereby reproducing the original waveform.
Claim 3
Dependent Claim
26 words
An electronic musical instrument according to claim 1, in which the multiplying means multiplies said section of the waveform by the reciprocal of the envelope value.
Claim 4
Dependent Claim
15 words
An electronic musical instrument according to claim 1, in which the whole waveform is compressed.
Claim 5
Dependent Claim
133 words
An electronic musical instrument in which a natural musical tone is converted into a digital signal for storage comprising: a waveform envelope generator; means for multiplying a quantized waveform of the tone by a reciprocal of the value of an envelope produced by the generator thereby expanding the amplitude of a portion of small amplitude of the original waveform; means for compressing the multiplied quantized waveform thereby reducing the number of quantizing bits; waveform memory means for storing the compressed amplitude expanded waveform; waveform read out means for reading out the compressed waveform from the waveform memory means; and, means for multiplying the waveform that has been read out by the said envelope value to reproduce the original uncompressed waveform; and, a digital to analog converter for converting the waveform into analog form.
Claim 6
Dependent Claim
133 words
An electronic musical instrument in which a natural musical tone is converted into a digital signal for storage comprising: a waveform envelope generator; means for multiplying a quantized waveform of the tone by a reciprocal of the value of an envelope produced by the generator thereby expanding the amplitude of a portion of small amplitude of the original waveform; means for compressing the multiplied quantized waveform thereby reducing the number of quantizing bits; waveform memory means for storing the compressed amplitude expanded waveform; waveform read out means for reading out the compressed waveform from the waveform memory means; and, means for multiplying the waveform that has been read out by the said envelope value to reproduce the original uncompressed waveform; and, a digital to analog converter for converting the waveform into analog form.
References Cited (Backward Citations)
US4162462A
Cited
US4123711A
Cited
US4353035A
Cited
US4414878A
Cited
US4437377A
Cited
US4433434A
Cited
US4507791A
Cited
US4627094A
Cited
US4642583A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-30 | 1993-05-01 | 1993-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-30 | 1997-05-01 | 1997-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-30 | 2001-05-01 | 2001-10-31 | $7700.00 | Window Closed / Lapsed |