| 摘要 |
PURPOSE:To form a glass lens uniformly by a method wherein a glass ball with a diameter greater than that of the lens sealing hole is placed on a lens sealing hole, and then the glass ball is fused by heat. CONSTITUTION:The glass ball 17 is placed on the lens sealing hole 9 in a metal shell 8. This glass ball 17 has volume enough to form a desired glass lens and its diameter is greater than that of the lens sealing hole 9. Accordingly, the glass ball 17 is locked by an upper edge 9' of the lens sealing hole 9 and brought into such a stabilized state that a part of the glass ball 17 is slightly projected into the lens sealing hole 9. In other words, the glass ball 17 is positioned on the lens sealing hole 9. After setting the glass ball 17 on the lens sealing hole 9, the glass ball 17 is fused by heat in a furnace to form a glass lens. |
