| 摘要 |
<p>PURPOSE:To allow an electronic flash device to be mounted on both cameras whose automatic dimming means differ in operation start point by providing a detecting means which detects which camera the device is mounted on and a control means which outputs a lighting start signal for operating the automatic dimming means. CONSTITUTION:When a shutter is released, current mirror circuit Q5 and Q6 of the camera turn off and a release signal from an external terminal T3 is outputted as an L-level signal to operate the circuit at the side of the flash device, which sends out a control signal to the camera side through terminals T3' and T3 after a specific time determined by monostable multivibrators 5 and 6, so that a voltage is applied to the terminal T3. This control signal turns on a transistor (TR) Q7 of the camera side to hold the output of an AND gate G1 at L and also turn off a dimming circuit, and this state is maintained until the lighting start signal of the flash device is outputted. A camera side SW2 is switched to a terminal (b), a flashbulb Xe is lighted a lighting start signal (L) is impressed to a terminal T3' synchronizing with the lighting, Tr Q7 is turned off, an output of a gate G goes to 'H', and a dimming circuit is a started.</p> |
