04435751 is referenced by 31 patents and cites 4 patents.

A vibration/noise reducing device for applying contrary vibrations/sound waves whose phases are substantially opposite to vibrations/noises generated from an electrical apparatus is disclosed, in which the vibrations/noises from the electrical apparatus are sensed by a sensor, the sensed analog time-domain signal is A/D converted, the resulting digital time-domain signal is then Fourier-transformed, the resulting Fourier-transformed digital frequency-domain signal is modified in its amplitude/phase to produce a second digital frequency-domain signal for generating a vibration/noise reducing control signal, the second digital-frequency-domain signal is inverse-Fourier-transformed, the resulting inverse-Fourier transformed second digital time-domain signal is D/A converted, and the resulting analog time-domain signal is used as the control signal to generate the contrary vibration/sound waves to be applied to the vibrations/noises.

Title
Vibration/noise reduction device for electrical apparatus
Application Number
6/279814
Publication Number
4435751
Application Date
July 2, 1981
Publication Date
March 6, 1984
Inventor
Syuya Hagiwara
Hitachi
JP
Kazuyuki Seino
Hitachi
JP
Minoru Kanoi
Ibaraki
JP
Yasuro Hori
Katsuta
JP
Agent
Antonelli Terry & Wands
Assignee
Hitachi
JP
IPC
H04B 15/00
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