| 摘要 |
PURPOSE:To remarkably improve precision in the direction of Z-axis and improve molding precision of an overhung shape by increasing numerical aperture of a lighting lens. CONSTITUTION:A pinhole is lighted by using a thermal light source 1 such as extra-high pressure mercury lamp and metal halide lamp without using laser as a light source. The pinhole image is projected on a photo-cure resin 9 by a lighting lens 5 of high NA (of high numerical aperture). As the pinhole image is to be formed, a size dc of the pinhole image can be kept in a necessary size with the high NA. When an energy density at a part separated from a focus by DELTA is 1/4, NA=dc/2DELTA is established. When dc = about 100mum and DELTA= about 100mum, NA=0.5 is established, so that NA satisfies a condition larger than 0.167. Here, NA represents numerical aperture and dc represents diameter of beam. |
