| 摘要 |
PURPOSE:To drive a diaphragm by a stepping motor at a high speed by detecting the power source voltage under a real load conducting state before driving, detecting an accurate power source voltage, and determining a pulse period or the variation in the pulse period of the motor in response to it. CONSTITUTION:The output voltage of a battery 145 is divided by resistors 146-148. Voltage comparators 149, 150 compare the divided power source voltages with a reference voltage Vc, and output signals to the input ports Pi0-Pi2 of a microcomputer 101. The microcomputer 101 outputs stepping motor driving information such as a pulse period from output ports Po1-Po3, and supplies a current to the coils 12, 13 of a motor in response thereto. A controller 201 is connected with a communication line with the microcomputer 101 through a mounting contact 28 to instruct a diaphragm drive and driving amount to the lens side. |
