Electrical audio signal processing systems and devices – Acoustical noise or sound cancellation – Within cabin or compartment of vehicle
Reexamination Certificate
2005-05-31
2005-05-31
Isen, Forester W. (Department: 2644)
Electrical audio signal processing systems and devices
Acoustical noise or sound cancellation
Within cabin or compartment of vehicle
C381S071500
Reexamination Certificate
active
06901147
ABSTRACT:
A three-dimension active silencer includes a measuring unit for detecting a signal relating to a sound radiated from a target sound source which is located in a closed box. A plurality of additional sound sources are arranged around the target sound source. A microphone is arranged at a predetermined position for detecting a sound power at the position. A controller is adapted to control respective amplitudes of the additional sound sources which can be different from an amplitude of the target sound source and respective phases of the additional sound sources, based on the signal detected by the measuring unit, in such a manner that the microphone detects the lowest sound power. The additional sound sources are arranged in such a manner that a position xpof the target sound source, respective relative positions di(i=1, 2, . . . , N) of the N additional sound sources from the target sound source and a wave number k of the sound radiated from the target sound source can substantially satisfy the following expression.1N ∑i=1N cos k (xp-di)-cos k·xp≅0According to the feature, it can be achieved to reduce the total sound power in the closed box including the target sound source.
REFERENCES:
patent: 5478199 (1995-12-01), Gliebe
patent: 5535283 (1996-07-01), Saruta et al.
patent: 6192133 (2001-02-01), Enamito et al.
patent: 05-231706 (1993-09-01), None
patent: 07134590 (1995-05-01), None
K. Kido, et al., Transactions of the ASME, vol. 111, pps. 480-485, “Active Reduction of Noise by Additional Noise Source and its Limit,” Oct. 1989.
P.A. Nelson, et al., Journal of Sound and Vibration, vol. 116, No. 3, pps. 397-413, “The Minimum Power Output of Free Field Point Sources and the Active Control of Sound,” 1987.
P.A. Nelson, et al., Journal of Sound and Vibration, vol. 117, No. 1, pps. 1-13, “The Active Minimization of Harmonic Enclosed Sound Fields, Part I: Theory,” 1987.
Aoyagi Satoshi
Enamito Akihiko
Hayashi Takuro
Matsukura Kunio
Shioyama Tsutomu
Faulk Devona E.
Isen Forester W.
Kabushiki Kaisha Toshiba
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
LandOfFree
Three-dimension active silencer does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Three-dimension active silencer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Three-dimension active silencer will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3416464