Patent ID: 7196717

Claim:
An image forming apparatus comprising: a photosensitive member; a beam emitting device that irradiates a beam modulated based on an image signal onto said photosensitive member to form an electrostatic latent image on said photosensitive member; a variable current control device that variably controls a driving current for driving said beam emitting device; a modulating device that modulates a pulse width of the beam based on the image signal; a measuring device that measures a potential of said photosensitive member after said photosensitive member is irradiated by a beam having a predetermined luminous intensity; and a control device that causes said variable current device to correct the driving current based on low frequency components of irregularities of the potential measured by said measuring device and changes a modulation coefficient used for modulating the pulse width by said modulating device based on high frequency components of the irregularities of the potential measured by said measuring device, to thereby form an image based on the image signal.