METHOD FOR ARRANGING PHOTORECEIVING LENS, AND OPTICAL DISPLACEMENT SENSOR

An optical displacement sensor (10) comprises a projection module (9); a light-receiving element (13) configured to receive light projected by the projection module (9) and reflected by an object to be measured (16); and a light-receiving lens (14) for imaging the reflected light onto the light-receiving element (13), the light-receiving lens being positioned between the object to be measured (16) and the light-receiving element (13). A position where the light is reflected by the object to be measured (16) is set so as to lie within a predetermined range (W 1 ) on an optical axis (L 1 ) of the projection module (9), between a first position (P N1 ) closer to a light source (11) and a second position (P F1 ) further away from the light source (11). The light-receiving lens (14) is arranged so that the angle of incidence (¸1) of reflected light incident on the light-receiving lens (14) from the first position (P N1 ) and the angle of incidence (¸2) of reflected light incident on the light-receiving lens (14) from the second position (P F1 ) are identical.