| 摘要 |
PURPOSE:To prevent fixing failure and offset by measuring a value corresponding to the concentration of a document image, and varying according to the value the temperature to which a heating element is heated when power is transmitted thereto. CONSTITUTION:In a printer 2, after a photoreceptor drum 3 is drivingly rotated by a drive portion and uniformly charged by a charger 4, an image is written by a writing device 5 so that an electrostatic latent image is formed. The writing device 5 receives the input of an image signal from a scanner 1 after the signal is processed by an image processing portion, and the device 5 also receives the input of an image signal from a host computer and writes the image by projecting an optical image on the photoreceptor drum 3 according to the input image signal. Also, a value corresponding to the concentration of the document image is measured by an image concentration sensor 52 provided on the image reading plate 51 of the scanner 1, and is provided to a write controlling portion as an image concentration signal, so as to control the temperature to which a heating element is heated. |
