Title:
SPEAKER
Document Type and Number:
Japanese Patent JP2023030533
Kind Code:
A
Abstract:
To provide a speaker for measuring a movement state of a vibration part including a diaphragm so as to perform feedback control.SOLUTION: A speaker 1 includes a detection part for detecting the vibration of a vibration part. The detection part includes: a fixed magnet 11 constituting a magnetic circuit 10; and a mobile magnet 22 and magnetic sensor 21 arranged under a cap 8. A fixed magnetic field component H1 directed in a Z2 direction acts on the magnetic sensor 21 by a leak magnetic flux from the magnetic circuit 10, and a mobile magnetic component H2 acts on the magnetic sensor 21 from the mobile magnet 22 in a Y2 direction. The magnetic sensor 21 detects the change of an angle θ of a detection magnetic field component Hd being the synthetic vector of the magnetic field components H1, H2 from the two directions, and an active position of the mobile magnet 22 is measured in response to the detection output.SELECTED DRAWING: Figure 1
Inventors:
TOITA DAIKI
Application Number:
JP2021135710A
Publication Date:
March 08, 2023
Filing Date:
August 23, 2021
Export Citation:
Assignee:
ALPSALPINE CO LTD
International Classes:
H04R9/02
Attorney, Agent or Firm:
Field Saki Teruo
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