Light beam scanning apparatus and image forming apparatus provided with the same

A light beam scanning apparatus comprising:

• a light source;
• a first light deflecting unit adapted to scan a light flux emitted from said light source in a main scanning direction;
• a photosensitive member adapted to form an electrostatic latent image in an irradiation position irradiated by the scanned light flux;
• a second light deflecting unit that is disposed in a light path between said light source and said first light deflecting unit and is adapted to deflect a course of the light flux emitted from said light source to the main scanning direction by applying a voltage;
• and
• a control unit which is electrically connected to said first light deflecting unit and said second light deflecting unit and is adapted to control a voltage to be applied to said second light deflecting unit based on scanning information of said first light deflecting unit,
• wherein said control unit maintains the irradiation position on said photosensitive member irradiated by the light flux, by applying a voltage according to the scanning information to said second light deflecting unit during the time period in which an electrostatic latent image corresponding to one dot is formed on said photosensitive member.