US5195140A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic signal processing apparatus
Assignee: Yamaha Corp
•
Filing: 1990-12-28
•
Granted: 1993-03-16
•
Expires: 2010-12-28
Abstract
Abstract An acoustic signal processing apparatus comprising infinite impulse response type digital filters and phase control device. The filters receive an acoustic signal. Outputs from the filters are synthesized to generate an output signal. The phase control device controls the phase of the output signals so as to cause limit cycle noise components generated by the filters to cancel each other on synthesizing.
Inventors
- 👤 Masaki Kudo
- 👤 Hideaki Shimaya
- 👤 Tokio Ogi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:35
CPC Classifications
H; H03; H03H; H03H17/00; H03H17/02; H03H17/04; H03H17/0461; A; A61; A61F; A61F11/00; A61F11/06; A61F11/14; A61F11/145; G; G10; G10H; G10H1/00; G10H1/0091; G10H1/02; G10H1/06; G10H1/12; G10H1/125; G10H2250/00; G10H2250/055; G10H2250/111; G10H2250/121
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
110 words
An acoustic signal processing apparatus comprising: a plurality of infinite impulse response type digital filters for filtering an acoustic signal, each of said plurality of infinite impulse response type digital filters having an input for receiving said acoustic signal and an output for generating a filtered output signal in response to said acoustic signal; phase control means for controlling relative phases of said filtered output signals to provide phase controlled output signals from said infinite impulse response type digital filters; and mixing means for respectively mixing said phase controlled output signals to substantially cancel a limit cycle noise component generated by said plurality of infinite impulse response type digital filters.
Claim 2
Dependent Claim
110 words
An acoustic signal processing apparatus comprising: a plurality of infinite impulse response type digital filters for filtering an acoustic signal, each of said plurality of infinite impulse response type digital filters having an input for receiving said acoustic signal and an output for generating a filtered output signal in response to said acoustic signal; phase control means for controlling relative phases of said filtered output signals to provide phase controlled output signals from said infinite impulse response type digital filters; and mixing means for respectively mixing said phase controlled output signals to substantially cancel a limit cycle noise component generated by said plurality of infinite impulse response type digital filters.
Claim 3
Dependent Claim
41 words
An apparatus according to claim 1, wherein said phase control means appropriately selects at least one of absolute values and signs of coefficients to be multiplied with said filtered output signals from said plurality of infinite impulse response type digital filters.
Claim 4
Dependent Claim
30 words
An apparatus according to claim 1, wherein said phase control means delays said filtered output signal from at least one of said plurality of infinite impulse response type digital filters.
Claim 5
Dependent Claim
17 words
An apparatus according to claim 2, wherein said limit cycle noise component is of a DC value.
Claim 6
Dependent Claim
18 words
An apparatus according to claim 3, wherein said limit cycle noise component is an oscillating limit cycle noise.
Claim 7
Dependent Claim
20 words
An apparatus according to claim 1, wherein the acoustic signal processing apparatus is applied to a reverberation tone adding apparatus.
Claim 8
Dependent Claim
30 words
An apparatus according to claim 2, wherein said phase control means delays said filtered output signal from at least one of said plurality of infinite impulse response type digital filters.
Claim 9
Dependent Claim
33 words
An apparatus according to claim 1, wherein said phase control means inverts a sign of said filtered output signal from at least one of said plurality of infinite impulse response type digital filters.
Claim 10
Dependent Claim
28 words
An apparatus according to claim 1, wherein said phase control means multiplies coefficients with said filtered output signals from said plurality of infinite impulse response type digital filters.
Claim 11
Dependent Claim
33 words
An apparatus according to claim 1, wherein said phase control means appropriately selects signs of coefficients to be multiplied with said filtered output signals from said plurality of infinite impulse response-type digital filters.
References Cited (Backward Citations)
US3906199A
Cited
US4034197A
Cited
US4338581A
Cited
US4475229A
Cited
JPS5814898A
Cited
US4586417A
Cited
US4868878A
Cited
US4731835A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-03-15 | 1996-09-14 | 1997-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-03-15 | 2000-09-14 | 2001-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-03-15 | 2004-09-14 | 2005-03-16 | $7700.00 | Window Closed / Lapsed |