Portable video camera having power saving control of stepping motors

摘要

A signal for controlling a stepping motor (4) for moving a focusing lens is supplied from a circuit (13) to an adder (14). An externally entered zooming command is supplied to a circuit (12). A signal for controlling a stepping motor (3) for moving a zoom lens is supplied from the circuit to the adder. The adder superposes these signals and supplies them to pre-drivers by serial transmission. The pre-drivers (16,17) read out sine-wave data having appropriate amplitudes, and deliver them to motor drivers to drive the motors, respectively. The motor control signals are depending on the estimated load of each stepping motor in order to decrease the consumption of the battery power.