| 摘要 |
PURPOSE:To easily produce a lens having an arbitrary shape at a low cost by pressing the end of a hollow cylindrical molding cylinder to the stock in a softened state and reducing the pressure in the hollow hole or pressurizing the inside of the hole at the time of producing the flat plate optical element having the convex or concave lens. CONSTITUTION:The optical element stock 5 is formed to a flat plate and is fitted into the recess 2 of a holding mold 1 where the flat plat is heated and softened by a heater 6. The end part of the molding cylinder 4 having the hollow hole 3 is then pressed to the optical element stock 5 and the pressure in the hole 3 is reduced down to the pressure lower than the pressure on the outside of the molding cylinder 4. The optical element stock 5 is sucked into the hollow hole 3 of the molding cylinder 4 in this way and the convex lens of a spherical shape formed without contact at the point of the time when the pressure balances with the surface tension. On the other hand, the concave lens having a spherical shape is formed when the pressure in the hollow hole 3 of the molding cylinder 4 is regulated higher than the external pressure. |
