Patent ID: 7858923

Claim:
A light beam scanning apparatus comprising: a light source; a first light deflecting unit configured to deflect a light flux from said light source so that the light flux scans on a photosensitive member to form an electrostatic latent image in an irradiation position of the light flux on the photosensitive member; a second light deflecting unit configured to deflect the light flux to adjust the irradiation position of the light flux on the photosensitive member with respect to a scanning direction in which the light flux is to be scanned by said first light deflecting unit, said second light deflecting unit deflecting the light flux when a voltage is applied thereto; a voltage applying unit configured to apply the voltage to said second light deflecting unit; and a control unit configured to control the voltage to be applied to said second light deflecting unit by said voltage applying unit, wherein said control unit is configured to control the voltage so that a dot diameter of the electrostatic latent image for one dot to be formed on the photosensitive member is substantially same in size as a spot diameter of the light flux to be irradiated on the photosensitive member for producing the electrostatic latent image for one dot, wherein said first light deflecting unit has a rotating member which is provided with a reflecting surface for reflecting the light flux emitted from said light source, and said control unit is configured to control a voltage to be applied to said second light deflecting unit, based on a rotation number of said rotational member, and wherein in forming an electrostatic latent image corresponding to dots in series on said photosensitive member, said control unit is configured to apply a first applying voltage according to the rotation number of said rotational member to said second light deflecting unit during the time after the formation of the first one dot starts until a predetermined time passes, and is configured to apply a second applying voltage according to the rotation number of said rotational member to said second light deflecting unit during the time after the formation of the last one dot out of the dots in series starts until a predetermined time passes.