Patent ID: 7046344

Claim:
A range finder comprising: a package having a lead, a semiconductor chip attached to the package and having a first light detecting section and a second light detecting section, connecting means for electrically connecting the semiconductor chip to the lead, an optical casing attached to the package, a first lens and a second lens, and a lens holder attached to the optical casing and having a first lens hole and a second lens hole for holding the first lens and the second lens, said lens holder being formed of a material having a thermal expansion coefficient substantially equal to a thermal expansion coefficient of the semiconductor chip, wherein each of said first and second lenses is formed of a transparent resin and has a reference boss and an absorbing boss, and said lens holder has circular reference holes and long absorbing holes on a line connecting centers of the first and second lens holes, each of said reference bosses being inserted into one circular reference hole and fixed by an elastic adhesive layer while one absorbing boss is moveably inserted into one long absorbing hole to attach each of the first and second lens to each of the first and second lens holes.