Scanning optical device and image forming apparatus

A scanning optical device comprising:

• a light source device;
• a rotational polygon mirror which rotates to deflect laser light emitted from the light source device;
• a rotor which holds the rotational polygon mirror and rotates together with the rotational polygon mirror;
• and
• a stator which rotates the rotor,
• wherein a substrate for holding the stator includes a first regulation portion arranged so as to overlap with a portion of the rotor in a rotational axis direction of the rotor, and in a case where the rotor is caused to move in the rotational axis direction, the first regulation portion comes into contact with the rotor, and
• wherein a second regulation portion is arranged in a position in relation with the first regulation portion so as to maintain the first regulation portion in a position where the first regulation portion overlaps with the portion of the rotor in the rotational axis direction, so as to regulate deformation of the first regulation portion.