| 摘要 |
<p>PURPOSE:To obtain stable image quality without sticking toner to the light emitting surface of a lens array, even in long-term use by adopting a constitution so that, at least, the light emitting surface of an exposing head can be electrostatically charged to the same polarity as that of a potential by electrification, at the time of forming an image. CONSTITUTION:An electrostatic charging unit 4 is composed of a corotron wire 41, and a metallic shielding case 43 on which an electrostatic charging grid 42 is formed. The exposing head 3 is provided with a SELFOC(R) lens array 31 and an LED chip array. The side of the light emitting surface 31a of the lens array 31 is arranged so as to face the electrostatic charging grid 42 in the adjacent relation. When a high electrostatic charging voltage is applied to the corotron wire 41, the grid voltage of the same polarity, lower than an electrostatic charging voltage is applied to the electrostatic charging grid 42 via the shielding case 43, to uniformly/electrostatically charge the side of a photosensitive drum. At this time, the side of the lens array 31 is exposed by a discharge current from the electrostatic charging grid 42, and the light emitting surface 31a of the lens array 31 is electrostatically charged to the same polarity as that of the potential by the electrification.</p> |
