| 摘要 |
<p>PURPOSE:To obtain proper exposure by reversing a stepping motor when the time corresponding to the quantity of interpolation accumulates after a final step driving pulse is outputted during shutter release operation. CONSTITUTION:When a shutter release button is depressed, a switch 24 turns on to put a subject brightness detecting circuit 23 in operation, and an exposure data storage circuit 27 outputs the number of steps of the motor and the quantity of interpolation to a rotation mode changeover counter circuit 29 and presets them. If the shutter release button is pressed in to the 2nd position after the exposure is set, a switch 32 turns on to put a driving pulse generating circuit 28 in operation, and the stepping motor 12 begins to open a sector. When the 1st counter 29a counts down to zero, a clock for interpolation is inputted from a gate G3 to the 2nd down counter 29b. When clocks as many as the preset number of the 2nd counter 29b are inputted, a forward/backward switching circuit 30 is inverted to set a motor driving circuit 31 to the reverse driving side, and the stepping motor reverses to close the sector.</p> |
