| 摘要 |
PURPOSE:To improve reaction rate of resin when an optical part such as a Fresnel lens is manufactured by using photosetting resin. CONSTITUTION:Matrixes 1a and 1b provided with quartz glass sheets 1a and a mold 1b with a brass Fresnel pattern disposed in parallel are formed. At that time, a heater 8 is disposed on the lower face of the mold 1b and the temperature of the mold is kept constant. Photosetting resin 4 is injected from an injection hole 3 into a space 2 in the matrixes 1a and 1b. Resin 4 injected from the side of the quartz sheet is initially cured by a metal halide lamp, and the matrixes 1a and 1b composed of the quartz glass sheet 1a and the mold 1b are removed to manufacture a sheet with Fresnel pattern composed of photosetting resin 4. Said sheet is placed on a heated stainless sheet 8 with the Fresnel face of the sheet facing up, and further ultraviolet rays are emitted from a light source under nitrogen gas atmosphere and post-cured to manufacture a Fresnel lens as an optical part 6c. As a result, deformation generated by heat and humidity, the generation of odor, lowering of light transmittance generated by coloring and the like can be prevented, and the optical part of high performance and high reliability can be manufactured. |
