Title:
VIDEO INTERPHONE SYSTEM FOR MULTIPLE DWELLING HOUSE
Document Type and Number:
Japanese Patent JP3532732
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To allow a situation in an entire central entrance to be surely grasped by allowing a central entrance set to have a plurality of cameras whose operations are switched.
SOLUTION: With a camera changeover switch SW1 operated, a camera selection control signal is fed to a control signal modulation circuit 26 and a modulated camera selection control signal is fed to a multiplexer circuit 21. The multiplexer circuit 21 gives the camera selection control signal to a demultiplexer circuit 38 of a video control device PQ1, and the demultiplexer circuit 38 extracts only the camera selection control signal from multiplexed signals and gives the camera selection control signal to a multiplexer circuit 32. The multiplexer circuit 32 gives the multiplexed camera selection control signal to a central entrance set EQ1. A demultiplexer circuit 12 of the central entrance set EQ1 extracts only the camera selection control signal from the multiplexed signals and gives the camera selection control signal to a control signal demodulation circuit 13. The control signal demodulation circuit 13 demodulates the camera selection control signal and gives the demodulated camera selection control signal to a control side of a changeover device 14 to activate the changeover device 14. Then an externally provided television camera CQ2 is connected to a video transmission line L1.
Inventors:
Sugiyama, Yoshiji
Katou, Tomoka
Katou, Tomoka
Application Number:
JP14027197A
Publication Date:
May 31, 2004
Filing Date:
May 29, 1997
Export Citation:
Assignee:
AIPHONE CO LTD
International Classes:
H04N7/18; G08B21/00; G08B21/22; G08B25/04; H04M9/00; (IPC1-7): H04N7/18; G08B21/00; G08B25/04; H04M9/00
Attorney, Agent or Firm:
守谷 一雄