SPEED CONTROLLING METHOD FOR STEPPING MOTOR

PURPOSE:To suppress oscillation and enable operation to be performed up to the range of high speed rotation by controlling a speed so that an acceleration at the time of the acceleration or deceleration of a stepping motoh may be changed with a gentle curve oontinuously. CONSTITUTION:A time change for an acceleration at the time of the acceleration or a deceleration is set with a pattern shown by a sine function. In this case, the acceleration at the time of the acceleration or deceleration is slowly regulated according to the continuous curve of the sine function from the time of the start of a stepping motor till the time of shifting to a constant speed or from the time of shifting to the deceleration till stopping, and is slowly changed since there ia no change bending linearly on the way at the time of the acceleration or deceleration. As a result, the oscillation of the stepping motor is not excited, and rotation at the time of the acceleration or deceleration is smoothly performed, and the oscillation to be generated on the way at the time of the acceleration or deceleration can also be suppressed.