US Patent 7193731 Optical displacement sensor

Optical displacement sensor may possess light-emitting element(s) for projecting light onto distance measurement target(s), and light-receiving element(s) capable of receiving light reflected from distance measurement target(s) and disposed such that light-receiving surface(s) thereof is or are substantially perpendicular to optical axis or axes R1 of projected light. Furthermore, such optical displacement sensor(s) may be equipped with slit(s) capable of narrowing light beam(s) projected toward distance measurement target(s), and slit(s) capable of narrowing light reflected from distance measurement target(s).