| 摘要 |
<p>PURPOSE:To speed up picture formation and prevent the quality of a picture from being deteriorated by contracting a light flux group projected from light emitting diodes (LEDs) on a LED array by a condensing lens to condense the light flux group on a photosensitive drum. CONSTITUTION:A contracting lens system 10 to be used as a condensing optical system is mounted between a LED array 11 and a photosensitive drum 12 so as to move in one united body with the array 11. On the array 11, LEDs 13 each of which has a larger surface area than that of each light spot to be formed on the photosensitive element are arrayed and a projected light flux group from the LEDs 13 forms spots 14 whose surface areas are contracted than that of the LEDs 13 on the drum 12 by the lens system 10 at a pitch contracted than that of the LEDs 13. The array 11 is fitted to a guide rail 3 so that the array direction of the LEDs meets with the main scanning direction at an angle alpha other than 90 deg.</p> |
