| 摘要 |
PROBLEM TO BE SOLVED: To increase a transmittable distance by compensating a loss in a transmission line and providing a switch preventing a bi-directional signal from forming a loop at a repeater part provided in the middle of a cable. SOLUTION: A video and speech signal transmitted and received mutually between a camera head part 1 and a camera control part 2 is digitized, time- base-compressed and then bi-directionally and alternately transmitted by a time division multiplexing system through a single coaxial cable 2. The repeater part 7 provided in the middle of the cable 2 sends a signal, which is inputted to a terminal 8, to a camera control part 2 from a terminal 9 through amplifiers 5a and 4a and a signal inputted to the terminal 9, from the camera control part 2 is sent to the camera head part 1 through amplifiers 5b and 4b. Then a switch 10a is connected only when a signal from the camera head part 1 to a camera control part 2 exists, a switch 10b is connected only when a signal from the camera control part 2 to the camera head part 1 exists. |
