Patent 7122782 was granted and assigned to Keyence on October, 2006 by the United States Patent and Trademark Office.
A multi-optical axis photoelectric sensor where a main element holder and an additional element holder are relatively moved in a direction perpendicular to an arrangement direction of optical axes. An engagement projection of the additional element holder is fit into a receiving hole of the main element holder and the hook of the additional element holder engages with the end edge of the main element holder, whereby the main element holder and the additional element holder are mechanically coupled to each other.