To synchronously perform the lighting control or flickering control of arrow slickers and outlet flickers in a plurality of units of an automated machinery, to improve the appearance of a number of arrow flickers and outlet flickers, and to provide easy-to-follow guide for inserting and discharging a media, with respect to a display synchronizing method and a display synchronizing device for displaying a number of arrow flickers and/or outlet flickers.

The arrow flickers as insertion guide or take-out guide are mounted near media inlet and outlet ports of each of the plurality of units, a clock signal and a start signal generated from a main control unit are supplied to each unit, and the arrow flickers are successively lit in accordance with the clock signal in synchronization with the start signal with respect to the arrow flickers to be lit, when the arrow flickers are lit in each of the units.