| 摘要 |
PURPOSE: An image distribution device through loop voltage detection of an image signal line of a video phone is provided to simplify a circuit configuration in distributing of an image signal using a common wire between common entrance camera terminal and household terminal and to improve image quality. CONSTITUTION: Each of loop voltage detection units (300a,300b) output a detection signal by detecting current or voltage with respect to an image signal line flowing through each impedance matching resistor of household terminals (200a,200b). Each of master relay control units (400a,400b) receives the detection signal outputted from each of the loop voltage detection units. The each of the master relay control units controls each of relays to connect the image signal line to the each of the household terminals. [Reference numerals] (AA) Household terminal 1; (BB) Common entrance camera; (CC) Household terminal 2 |
