ELECTROPHOTOGRAPHY APPARATUS

PROBLEM TO BE SOLVED: To provide an electrophotography apparatus having a mechanism for automatically correcting a focal length of an LED printer head in the electrophotography apparatus using the LED head as an exposing device. SOLUTION: This electrophotography apparatus is equipped with automatic positioning devices 2 for adjusting a focus which are respectively provided to both ends of the LED printer head 1 and are capable of adjusting distances with a photosensitive body 5 independently at right and left sides. The electrophotography apparatus comprises a focus adjusting controller 3 that performs printing a predetermined test pattern by continuously varying the distance between the photosensitive body and the LED printer head by using the automatic positioning devices 2 when adjusting the focal length. The electrophotography apparatus further comprises a density sensor 4 for detecting a printed density of a printed image of the test pattern provided on the photosensitive body, an intermediate transfer body, or a printing medium. The focus adjusting controller 3 performs the controlling to adjust the focal length of the LED printer head such that the density is detected by means of the density sensor 4 and the focal length at a position where the density is the lowest is determined to be the optimum focal length. COPYRIGHT: (C)2005,JPO&NCIPI