Patent ID: 7122782

Claim:
A multi-optical axis photoelectric sensor comprising: an elongate casing including an opening along a longitudinal direction; a front cover covering the opening of said elongate casing; a main element holder disposed within said elongate casing including a plurality of light guide housings disposed along a longitudinal axis of said main element holder, each having an optical element therein, said main element holder having a first engagement portion; an additional element holder disposed within said elongate casing including a plurality of light guide housings disposed along a longitudinal axis of said additional element holder, each having an optical element therein, said additional element holder having a second engagement portion capable of mechanically engaging and disengaging said first engagement portion of said main element holder; wherein said main element holder and said additional element holder are disposed so that said plurality of light guide housings of said additional element holder disposed along the longitudinal axis of said main element holder, and said plurality of light guide housings of said main element holder disposed along the longitudinal axis of said additional element holder, are disposed in a line adjacent to the opening of said elongate casing when said additional element holder is engaged with said main element holder by said first and second engagement portions within said elongate casing; wherein said second engagement portion of said additional element holder and said first engagement portion of said main element holder are engaged by relative movement of at least one of said main element holder and said additional element holder; and wherein said first engagement portion of said main element holder is located between at least two of said plurality of light guide housings disposed on said main element holder.