Patent ID: 7453484

Claim:
An image forming apparatus comprising: a photoconductive drum on which a photoconductor is applied; a charging unit for uniformly charging a surface of the photoconductive drum; an exposing unit for irradiating and scanning a laser beam on the surface of the photoconductor to form a latent image; a developing unit for applying toner to a portion of the photoconductor on which the latent image is formed to form a toner image; a transfer unit disposed to face the surface of the photoconductive drum at a predetermined transfer position downstream of the developing unit in a rotation direction of the photoconductive drum for transferring the toner image formed on the surface of the photoconductive drum to a recording paper sheet; a fixing unit for applying predetermined heat and pressure to the recording paper sheet on which the toner image is transferred to fix the toner image on the recording paper sheet; a control unit that performs an automatic power control of the light-emitting device, and counts and stores a number of continuously-printed sheets when printing is continuously performed within a predetermined time; and a temperature detecting unit for detecting ambient temperature of the photoconductive drum, wherein the control unit estimates a temperature of a laser chip based on the number of continuously-printed sheets within the predetermined time and the ambient temperature of the photoconductive drum, and sets a frequency of the automatic power control according to the estimated temperature of the laser chip and wherein the control unit performs the automatic power control at every scanning of one line when the ambient temperature of the photoconductor drum is lower than a predetermined value, and performs the automatic power control at each time after performing scanning of a plurality of lines when the ambient temperature of the photoconductor drum is equal to or higher than the predetermined value.