Title:
EXPIRED AIR FLOW SENSOR
Document Type and Number:
Japanese Patent JP3041743
Kind Code:
B2
Abstract:
PURPOSE: To form an expired air flow sensor with a high detection rate and stable quality by providing plural sensor units to a sound receiving face of a case, selecting a difference from amplification factors of amplifiers so as to give a weight to each output of sensor elements and summing the outputs so as to eliminate an unstable state due to a pressure change in the expired air flow.
CONSTITUTION: A sensor element 1 is fixed to a gas chamber 4 formed by a unit case 3 whose one end is open and has a sound reception hole 2 so that a detection face is exposed to an inner side face to obtain a sensor device 5. Furthermore, plural sensor devices 5 are provided so that the sound reception hole 2 faces a sound reception face 6a of a case 6 and sensor elements 1a, 1b,..., 1d are arranged. An expired air flow produced from a mouth reaches the sound reception face 6a of the case 6 and flows into the gas chamber 4 through the hole 2. Then the pressure rise in the gas chamber 4 is detected by the sensor elements 1a, 1b,..., 1d and the output is weighted by head amplifiers 7a, 7b,..., 7d and the outputs are added by a mixer 8, the summed output is amplified (9), a voice component is eliminated by an LPF 10 and peak holding is implemented.
Inventors:
Kazuhiko Kajiwara
Yuasa Etsuko
Yuasa Etsuko
Application Number:
JP24840192A
Publication Date:
May 15, 2000
Filing Date:
September 18, 1992
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
G09B21/00; G10L15/00; G10L15/02; G10L17/00; G10L25/00; H04R1/42; (IPC1-7): H04R1/42; G09B21/00; G10L15/02
Attorney, Agent or Firm:
Shigetaka Awano