| 摘要 |
PURPOSE:To reduce the cost of the sealing operation and improve the yield by arranging the prism which has a columnar part coaxially in the cylindrical hold fittings and fusing a glass ring fitted in the annular gap between the both and performing the sealing operation. CONSTITUTION:The glass ring 20 and prism 30 made of optical glass are fitted coaxially in the edge opening 12 of the hold fittings 1 which is improved in wettability by a preheating-oxidizing treatment and they are mounted on the amount base 4 consisting of a mount base main body 31 and a carbon plate 42. Then a high-frequency heating device 5 which radiates a microwave for heating is used to perform the sealing operation in an atmosphere by raising and reducing the temperature. In this case, the high-frequency heating device 5 is only brought under heating control so that the heating ends in 5-10 minutes, so the sealing operation is easily carried out. In the sealing operation, the glass ring 20 is fused without being pressed to fill the gap between the hold fittings 1 and prism 3, so strict dimension control over the holt fittings 1, glass ring 20, and prism 3 is not necessary. |
