Fujitsu Corporation

Yasuo Miyazaki

Kenichi Ogawa

Kenji Takato

Mitsutoshi Ayano

Kiyoshi Shibuya

Atsuo Serikawa

Shoji Nojiri

Yoshimi Iijima

Kiyoshi Kasahara

In a calling signal transmitting apparatus, a ring trip equipment, including a ring trip detecting circuit for detecting a ring trip signal in response to an off-hook operation of the telephone set during a signal state of an intermittent ringing signal and a loop detecting circuit for detecting a loop signal in response to an off-hook operation of the telephone set during a nonsignal state of the intermittent ringing signal. Also included are a logical OR gate circuit, for providing, as a status signal, a logical sum of the ring trip signal and the loop signal, and a supervising circuit for supervising the status signal. When an incoming call is being received by the telephone set, when the supervising circuit detects an off-hook state in the status signal, the supervising circuit stops the transmission of a ringing signal to the telephone set, and carries out a second supervising operation for supervising the status signal, and, if an on-hook state is detected during the second supervising operation, said supervising circuit again transfers the ringing signal to the telephone set.

Calling signal transmission apparatus

Growing community of inventors

Fukuoka, Japan

Yasuo Miyazaki