| 摘要 |
PURPOSE:To simplify the constitution of a signal transmission and reception device, by controlling the correspondence of information signals with circuits, which are operated in accordance with information signals, through a switching signal to transmit and receive a time series signal between a camera and a flash device without interference. CONSTITUTION:When an electronic flash device where the power source is not interlocked with a camera is set to the TTL dimming mode and the camera is set to the shutter electric control mode or the like, a mode switch SW10 and a power switch S12 are connected to contacts (c) and (h) respectively, and a changeover swigch SW1 of the camera is closed, and switches SW6 and SW7 are opened. Consequently, power is supplied to a TTL dimming circuit 7; and if TTL dimming is impossible, a warning oscillating resistances R25-R28, a capacitor C15, etc., are operated through a transistor Q5, terminals T1 and T'1, etc. A dimming signal passing through a photodetector is switched after the shutter is opened to its full width, and dimming is stopped when this switching is transmitted through terminals T2 and T'2; and thus, signals are transmitted and received without interference in time series to realize a signal transmitting and receiving device with a small number of terminals. |
