Process for laser welding resinous members, apparatus for the same and laser-welded resinous product

A process for laser welding, resinous members, the process comprising the steps of:

• overlapping a transparent resinous member on an absorptive resinous material,
• the transparent resinous member having a first predetermined shape, and comprising a part including a strip-shaped first weld surface, at least the part formed of a transparent resin allowing a laser beam to transmit therein,
• the absorptive resinous member having a second predetermined shape, and comprising a part including a strip-shaped second weld surface to be welded to the first weld surface, at least the part formed of an absorptive resin which absorbs the laser beam;
• and
• irradiating the transparent resinous member with the laser beam, thereby welding an interface between the first weld surface of the transparent resinous member and the second weld surface of the absorptive resinous member as a strip shape, the interface having a weld line welded as a strip shape and comprising linear parts neighboring with each other, a major-curvature-radius curved part intervening between the linear parts and a minor-curvature-radius curved part intervening between the linear parts, wherein energy averaging means averages the energy of the laser beam acting on a side of the major-curvature-radius curved part and the energy of the laser beam acting on a side of the minor-curvature-radius curved part in the second weld surface of the absorptive resinous member,
• wherein the energy averaging means lets the laser beam traverse along a scanning line shifted on a side of the major-curvature-radius curved part with respect to the center line of a strip-shaped width of the weld line.

A process for laser welding, resinous members, the process comprising the steps of:

• overlapping a transparent resinous member on an absorptive resinous material,
• the transparent resinous member having a first predetermined shape, and comprising a part including a strip-shaped first weld surface, at least the part formed of a transparent resin allowing a laser beam to transmit therein.
• the absorptive resinous member having a second predetermined shape, and comprising a part including a strip-shaped second weld surface to be welded to the first weld surface, at least the part formed of an absorptive resin which absorbs the laser beam;
• and
• irradiating the transparent resinous member with the laser beam, thereby welding an interface between the first weld surface of the transparent resinous member and the second weld surface of the absorptive resinous member as a strip shape, the interface having a weld line welded as a strip shape and comprising linear parts neighboring with each other, a major-curvature-radius curved part intervening between the linear parts and a minor-curvature-radius curved part intervening between the linear parts, wherein energy averaging means averages the energy of the laser beam acting on a side of the major-curvature-radius curved part and the energy of the laser beam acting on a side of the minor-curvature-radius curved part in the second weld surface of the absorptive resinous member,
• wherein the energy averaging means functions as an energy-density controlling means for controlling an energy density of the laser beam acting on the major-curvature-radius curved part so as to be relatively greater than an energy density of the laser beam acting on the linear parts or the minor-curvature-radius curved part.