| 摘要 |
PURPOSE:To enhance humidity resistance and ensure that light required for erasing or the like can be made to be incident on a photosensitive surface, by a construction wherein an LED row provided on a substrate is covered hermetically by a columnar seal body, and the seal body is provided with a radius of curvature at a part opposite to a photosensitive surface. CONSTITUTION:The LEDs 4 placed on and fixed to the surface of the substrate 1 and wired comprise a plurality of chips arranged in a row in the same direction as the direction of the axis of rotation of a charging drum 2. The seal body 5 consisting of a semicylindrical quartz glass or the like is fixed on the substrate 1 so as to entirely cover the LEDs 4, and the inside of the seal body 5 is maintained to be airtight, at a pressure lower than the atmospheric pressure. Accordingly, an LED head can be provided which has excellent humidity resistance, can transmit a sufficient quantity of light to the photosensitive surface without using special optical means, and is particularly suitable for erasing. |
