| 摘要 |
A region (R) to be welded is consecutively irradiated with laser light (L) having a cross-sectional shape perpendicular to the optical axis (OA), the cross-sectional shape being annular at the laser light incidence-side end (R1) of the region (R) to be welded. Due to this, at the laser light incidence-side end (R1) of the region (R) to be welded and in the vicinity of the end (R1), the center of a region irradiated with the laser light (L) can be prevented from suffering damage caused by overheating (bubbles, turbidity, burning, etc.). Furthermore, since the laser light (L) is convergent in the region (R) to be welded, the optical density of the laser light, which attenuates due to light absorption, is compensated for and the resinous members (5, 6) can hence be melted throughout the region (R) to be welded, which extends from the laser light incidence-side end (R1) to the laser light emission-side end (R2). |
