A projection lens (46) comprises: a cylindrical exterior case (621) having
a lens-shifting through-hole (625) on a side thereof and an inner
circumferential step or inner flange (623); a lens (610) of which outer
periphery (611) on a first side is abutted to the inner circumferential
step or inner flange (623); a flexible or elastic spacer (660) abutted to
an outer periphery (612) of a second side of the lens (610); and a
retainer (670) holding the spacer (660), where the lens (610) is fixed on
the exterior case (621).