Abstract: A push button switch includes a push button, a movable contact that moves together with the push button, and a fixed contact with respect to which the movable contact comes into contact or separates in accordance with the operation of the movable contact. The push button switch includes a light emitting element, and a light receiving element. A light emitting position where light emitted from the light emitting element is radiated to the outside, and a light receiving position where light detected by the light receiving element is received from the outside are disposed outward of an edge of the push button when viewed in a pushing direction. The light receiving element is disposed to detect light emitted from the light emitting element and reflected by an object in a detection region set in a space on the push button side in the opposite direction to the pushing direction.

Abstract: A push button switch 1 comprises: a push button 10 that can be pushed in; a movable contact 120 that is linked to the push button 10; and a fixed contact 121 that comes into contact with or separates from the movable contact 120 by operation of the movable contact 120. The push button switch 1 further comprises a light-emitting element 130 for emitting light, and a light-receiving element 131 for detecting light. The light-receiving element 131 is disposed so as to detect the light emitted from the light-emitting element 130 and reflected by an object within a prescribed region. The push button switch 1 outputs an ON signal if the push button 10 has been pushed in, thereby causing the movable contact 120 to come into contact with the fixed contact 121, or if it is determined that the light-receiving element 131 has detected light reflected by an object.

Abstract: A limited reflection type sensor which irradiates exit light from a light emitting unit toward an object sensing region through an exit light lens and receives, at a light receiving unit, reflected light from an object existing in the object sensing region through a reflected light lens, may include a casing including a latching portion formed on a side surface and a first opening facing the object sensing region, the casing accommodating the light emitting unit and the light receiving unit; and a lens part including a light incident/exit part formed integrally with the exit light lens and the reflected light lens, and a side surface covering part in which an end of the light incident/exit part is extended along the side surface, in which the lens part covers the first opening with the light incident/exit part and the side surface covering part is latched by the latching portion.