Structure for connecting a lens to a lens holder without using an adhesive

摘要

In a structure for connecting a lens (17) to a lens holder (25) having a mounting surface (31), the lens has a flange (26) placed on the mounting surface. The flange has a particular surface faced to the mounting surface and at least three protrusions (27) on the particular surface. The mounting surface has a plurality of recesses (32) formed at positions corresponding to the protrusions. Each of the recesses has a depth smaller than a height of a corresponding one of the protrusions and a volume greater than that of the corresponding one. The protrusions are placed in the recesses, respectively, and ultrasonic welded to the lens holder.