Title:
HANDS-FREE INTERCOM SYSTEM
Document Type and Number:
Japanese Patent JP2017163418
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a hands-free intercom system which prevents howling in simple configuration using a bandpass filter.SOLUTION: A hands-free intercom system comprises a first DSP 25 constituting a first multi-bandpass filter in the middle of a reception voice transmission line L1a from voice reception by a slave unit microphone 11 to emission from a master unit speaker 21 and a second DSP 26 constituting a second multi-bandpass filter in the middle of a transmission voice transmission line L1b from voice collection by a master unit microphone 23 to emission from a slave unit speaker 13. Each of the first and second DSPs 25 and 26 includes bandpass filters configured to pass voice signals in different frequency bands in a combline state at ten positions on a frequency axis, and the bandpass filters of the first and second DSPs 25 and 26 are disposed alternately without overlapping frequency bands on the frequency axis.SELECTED DRAWING: Figure 1
Inventors:
KAWADA TOSHIO
Application Number:
JP2016047394A
Publication Date:
September 14, 2017
Filing Date:
March 10, 2016
Export Citation:
Assignee:
AIPHONE CO LTD
International Classes:
H04M9/00; H04B3/21; H04R3/02
Attorney, Agent or Firm:
Kyoichi Ueda