| 摘要 |
PURPOSE:To always keep a color temperature constant irrespective of the emitting light quantity by emitting multi-flash having a fixed constant color temperature only the number of times capable of obtaining optimum exposure. CONSTITUTION:A trigger circuit 23 supplies a trigger signal to a flash discharge tube 21 by operating a switch which is closed by depressing a shutter release button, and also an action starting signal is supplied to a control circuit 4. In this case, the on/off operation of the switching circuit 3 is repeated synchronously with a rectangular wave input signal from the control circuit 4, so that the flash discharge tube 21 is repeatedly turned on/off synchronously with it. Then, when the input from a photodetector reaches a value equivalent to the optimum exposure quantity, a stop signal is inputted in a control circuit 4 so as to turn off the switch circuit 3, and then, the flash is turned off. A light emitting cycle in this case is fixed by the light emitting characteristic of the flash discharge tube 21 and the cycle of the rectangular wave inputted in the switching circuit 3. |
