IMAGE FORMING APPARATUS, METHOD OF CONTROLLING IMAGE FORMING APPARATUS, AND STORAGE MEDIUM

摘要

An image forming apparatus includes: a light source; a polygon mirror; a brushless motor rotating a rotary polygon mirror; a light receiver configured to receive the light beam reflected by the polygon mirror; and a controller configured to perform driving control; detect a value related to an induced voltage; and perform a phase switching process. In a start-up period, the controller performs a control switching process of performing switching from rotation speed control based on the induced voltage to rotation speed control based on the light receiving timing of the light beam in a specific range in which a length from a start timing of an interruption period of the power to a timing when the detected value reaches the reference value does not become shorter than a length of a reference-disabled period.

主权项

1. An image forming apparatus comprising:
a light source configured to emit a light beam; a polygon mirror configured to reflect the light beam emitted from the light source; a brushless motor including a plurality of coils, the brushless motor being configured to rotate the polygon mirror; a light receiver configured to receive the light beam reflected by the polygon mirror; and a controller configured to: perform driving control on the brushless motor by switching between supply and interruption of power to each of the plurality of coils; detect a value related to an induced voltage which is generated in at least one of the plurality of coils in a period of the interruption of the power during the brushless motor is rotated; perform a phase switching process of referring to the detected value and performing phase switching based on a timing when the detected value reaches a reference value; and in a start-up period when the brushless motor is started up from a stop state to a target rotation speed, perform a control switching process of performing switching from rotation speed control based on the induced voltage according to the phase switching process to rotation speed control based on the light receiving timing of the light beam by the light receiver in a specific range in which a length from a start timing of an interruption period of the power to a timing when the detected value reaches the reference value does not become shorter than a length of a reference-disabled period in which the induced voltage cannot be detected due to a regeneration current attributable to the phase switching in the phase switching process.