A hot crimping structure for fixing at least one lens element to a lens frame
made
of synthetic resin, the lens element being accommodated in a lens holder opening
of the lens frame, a portion of the lens frame being crimped by heat to serve as
a crimped edge which lies on a surface of the lens element adjacent to a rim of
the lens element. The lens frame includes an outward expansion surface which extends
outwards from a close vicinity of the rim of the lens element. A hot crimping tool
is brought into contact with the outward expansion surface to form a recess on
the outward expansion surface by heat, to thereby produce the crimped edge by movement
of melting synthetic resin which is melted due to the formation of the recess.
