Hitachi Denshi Kabushiki Kaisha

Hiroyuki Nisikawa

Yoshizumi Eto

Nobuo Murata

Kazuhiro Tanabe

In a video signal transmission method and system wherein a signal containing a video signal is bidirectionally transmitted and received in a substantially real time in video appliances coupled via a transmission path to each other, a digital signal containing a digital video signal is time-compressed, and a transmission operation is controlled in such a manner that a transmission period and a no transmission period are alternately produced in a preselected period. Then, the time-compressed digital signal is transmitted to the transmission path during the transmission period, whereas another digital signal transmitted via the transmission path from the video appliance on the counter side is received during the no transmission period. Then, the received digital signal is time-expanded to reproduce the original signal.

Method for bidirectionally transmitting digital video signal and digital

In a transmission system for bi-directionally transmitting and receiving a plurality of signals between two units, interconnected through a predetermined transmission path, if one of the plurality of signals falls into any of a transmission disabled state, a transmission not required state, a reception disabled state, and a reception not required state, at least one of a transmission operation and a reception operation for the signal in the one state is stopped or set into a stand-by state, thereby reducing electric power consumed by the transmission system. In addition, a transmission bandwidth of the transmission path is reduced by a portion associated with the signal in the one state, or an entire bandwidth for all signals except for the signal in the one state is expanded without changing the transmission bandwidth of the transmission path.

Growing community of inventors

Kamifukuoka, Japan

Hiroyuki Nisikawa