| 摘要 |
PURPOSE:To effectively prevent moisture or the like in the atmosphere from adhering to LEDs, to ensure normal and stable emission of light from the LEDs and print high-quality images, by covering the outside surfaces of the LEDs with an electrically insulating transparent coated layer. CONSTITUTION:In an optical printer head comprising a multiplicity of LEDs arranged in a straight line on a major surface of an electrically insulating substrate, a coated layer 7 of an electrically insulating transparent material such as a silicone resin and an epoxy resin is provided on the outside surfaces of the LEDs 3 by a thick film printing method, thereby perfectly shielding the LEDs 3 from the atmosphere. Therefore, moisture or the like in the atmosphere will not adhere to the LEDs 3, and there is no possibility that a lowering in the withstand voltage of the LEDs 3 or short-circuiting between individual electrodes 3b for the LEDs 3 is caused by the adhesion of moisture or the like to the LEDs 3. Since the coated layer 7 is transparent, it does not interrupt the light emitted from the LEDs 3 but transmits the light to the exterior, and since the layer 7 is electrically insulating, it does not cause a short circuit between the individual electrodes 3b of the LEDs 3. |
