| 摘要 |
PURPOSE:To prevent damage due to an increase in size and a laser light beam and to transfer a necessary video pattern securely even if there is dust, etc., interposed by arranging a cylindrical lens on the optical axis of the laser light beam and generating astigmatism at the focus of a condenser lens through the unidirectional convergence of the lens. CONSTITUTION:The laser light beam L which is given a necessary video pattern by being transmitted through a mask 2 is transmitted through the cylindrical lens 3 and then converted by the condenser lens 4. The cylindrical lens 3 has unidirectional converging operation, so the laser light beam L which is transmitted through the lens and further converged by the condenser lens 4 has a focus f1 nearby the condenser lens 4 in a Y direction and a focus f2 more at distance than the focus f1 in an X direction. Therefore, astigmatism is generated at the focus f1 on the whole and the beam diameter at the part increases. Consequently, even if there is dust present at the focus (f), the loss of the energy of the laser light beam L is reduced and the video pattern is printed on a body 5 to be irradiated securely. |
