Image reading apparatus, image forming device, and method for controlling reading so frequency of pulse signal to stepper motor reduces vibration during quiet scanning mode

摘要

A light source section of the image reading apparatus illuminates a document with light. An image sensor outputs image signals. An operating section accepts input of an enlargement factor and selection of a document scanning mode. An image processing section generates image data, from pixels (lines) in a quantity according to an enlargement factor. A stepper motor moves the document or the light source section. During a quiet mode, a signal generating section inputs to the stepper motor a pulse signal of a fixed frequency within a quiet mode frequency band. The quiet mode frequency band is a frequency band in which vibration of the stepper motor is at or below a predetermined normal vibration level.