Patent ID: 6829443
Filing Date: 2004-12-07
Classification: G03G

Abstract:
A method of detecting toner depletion in an image forming apparatus which comprises a photosensitive medium, a laser scanning unit to scan light on the photosensitive medium and to form an electrostatic latent image thereon, a developing unit to supply toner to the electrostatic latent image and thereby form a toner image, and an image controller to control the forming of the toner image, the method comprising:calculating a reference pixel number Qr from an amount of toner initially received by the developing unit; comparing an accumulation pixel number Qt obtained by accumulating and counting a number of pixels of the formed image, with the reference pixel number Qr, and recognizing that the image forming apparatus is in a toner low state if the accumulation pixel number Qt is larger than the reference pixel number Qr; comparing a concentration of the formed image Di with a reference concentration Dr and detecting a toner depletion state upon recognizing that the image forming apparatus is in the toner low state; determining whether the developing unit is reinstalled; and determining whether the developing unit is a new developing unit, upon determining that the developing unit is reinstalled.