| 摘要 |
<p>PURPOSE:To decrease the number of connection terminals for signal transmission and reception between a camera and a flash device and decrease the occurrence of accidents owing to connection failure by deciding the control signal on camera side according to the opening and closing of a synchronizing switch, and controlling preliminary light emission. CONSTITUTION:A monostable multivibrator 22 is triggered in cooperation with the shutter, by which the control pulse of more than the time width when the stopping down of a diaphragm 4 completes is generated. The pulse goes through the AND gate 28 on the flash device side and is decided as a flash emission control signal, by which the preliminary emission circuit 50 of a preliminary flash emission circuit and the discharge trigger circuit 47 of a flash tube 47 are controlled. Thereby, preliminary light emission is accomplished and the required setting of the diaphragm 4 is automatically accomplished. When the shutter 1st curtain opens fully, and synchronizing contacts 42 close, a transistor 75 is conducted via an inverter 72, and gates 78, 79 close and open respectively, so that the control pulse through the gate 79 is decided as an emission stop signal, which is applied to an emission stop circuit 65. The number of signal transmission and reception terminals between the camera and the flash device decreases and the occurrence of accidents by connection failure decreases.</p> |
