Iwasaki Tsushinki Kabushiki Kaisha

Tsunetaka Sakata

Yoshihiro Kawata

Teruo Matsufuji

Makoto Ueno

Tetsuro Inomata

Hiroyuki Miyashita

Masaru Shinohara

A click tone removing system for a time division switching system which performs switching of speech channels by a highway switch inserted in a highway. When a hook information detector and a dial information detector detect hook information and a dial information, respectively, delivery of a PCM speech sending signal to the highway is prevented by a blocking function for a fixed period of time, so that the highway is controlled to switch the speech channel, thereby removing a click tone generated by dialing. A subscriber's circuit of an exchange, which changes over a speech sending highway and a speech receiving highway by means of a highway switch, is characterized by the provision of an A/D converter for digitizing a speech sending signal to a digitized speech sending signal sent out to the speech sending highway, a D/A converter for converting a digitized speech receiving signal applied from the speech receiving highway into an analog signal, a gate for gating the input signal to the D/A converter, and a control circuit for controlling the gate, so that during real time processing the speech receiving signal highway is interrupted by opening and closing the gate without controling the higway switch.

Subscriber's circuit for time division switching system

A facsimile connection system, which is provided with a plurality of facsimile terminal equipments having no CO line interface circuit, at least one facsimile signal processor having a CO line interface circuit, and an exchange for interconnecting the plurality of facsimile terminal equipments and the facsimile signal processor, so that the facsimile terminal equipments can use the facsimile signal processor in common to them. An additional information generator may be further provided in common to the facsimile terminal equipments so as to be connected to the exchange.

Facsimile connection system

Growing community of inventors

Hachioji, Japan

Tsunetaka Sakata