Title:
INTERCOM SYSTEM
Document Type and Number:
Japanese Patent JP2015091016
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide an intercom system which reduces the number of components and has a simple and inexpensive configuration.SOLUTION: An intercom master apparatus 2 comprises: a master apparatus acoustic/electric conversion transducer 20 in which either of a call transmission function of receiving voice of a person in a room as input and generating a master apparatus voice signal and a call reception function of outputting voice of a visitor on the basis of a slave apparatus voice signal transmitted from an intercom slave apparatus 1 is active; a master apparatus voice switch 21 which compares a sound pressure level of the master apparatus voice signal generated by the call transmission function of the master apparatus acoustic/electric conversion transducer with a sound pressure level of the slave apparatus voice signal transmitted from the intercom slave apparatus 1, and detects a call transmission state or call reception state on the basis of difference between the levels; and a master apparatus changeover unit 22 which is controlled by a master apparatus voice switch 21 and is changed over in order to activate either of the call transmission function and call reception function of the master apparatus acoustic/electric conversion transducer 20.
Inventors:
NAGAYAMA MUNEHITO
Application Number:
JP2013230008A
Publication Date:
May 11, 2015
Filing Date:
November 06, 2013
Export Citation:
Assignee:
AIPHONE CO LTD
International Classes:
H04M9/08; H04M1/60; H04M9/00
Attorney, Agent or Firm:
Kazuo Moriya
Hiromichi Watanabe
Hiromichi Watanabe