| 摘要 |
PURPOSE:To decrease the cathode part in a neck zone and also to narrow down said cathode part very effciently and to enable it to be fused and sealed, by making the fusing-sealing process to be carried out through heating said zone by means of the laser beam with a predetermined diameter from the laser oscillator with a predetermined output. CONSTITUTION:A fusing part 131 somewhat below a stem 12 is irradiated by a laser beam 20 from a laser oscillator 19 through an optical system such as a condensing lens as not shown in the figure, etc.; in this case this irradiation is carried out from a through hole 18 of the mounting jig 17, meanwhile the pressure P2 between a mounting jig 17 and the fusing part 13 is gradually forced to become suitably larger than the outside atmosphere's pressure P1; When this laser beam 20 and the fusing part 131 are made to rotate relatively, the resisting force F3 of the laser beam 20 to the fusing part 131 becomes zero; hence, F1 is a force which expands the melted neck glass and F2 is a force which contracts the melted neck glass, and even if F1 is forced to be a necessary minimum of F1>=F2, the fusing can be carried out due to the surface tension in the state of P2>P1. |
