PURPOSE: To give a sufficient heating to the surface to be heated by giving a lens system a lens portion for providing a high illuminance to the central area of beam spot and another lens portion for lowering and overhanging the illuminance distribution in the vicinities.
CONSTITUTION: In the illuminance distribution of beam spot, a circular central area 'a' has a high illuminance, and a circular ring-shaped nearby area 'b' surrounding the central area 'a' falls from the central area with a level difference and overhangs in a hill shape, so that the whole has an illuminance distribution similar to a hemmed hat. The beam spot with illuminance distribution of this type is able to build a double focus lens 11 in a lens system focusing laser light radiated from a laser element 10. And the beam spot formed on a surface to be heated 12 has an illumination distribution as described above, so that the periphery can be heated by the ring-shaped nearby area 'b' of a low illuminance while a solder layer is melted at the central area of a high illuminance and the soldering treatment can be carried out smoothly and reliably.
| WO/2021/021581 | MITIGATION OF LENS CONDENSATION USING HEAT |
| JPS559574 | OPTICAL INFORMATION READER |
KABESHITA AKIRA
KANAYAMA SHINJI
NISHIDA KAZUTO
