Optical sensing device

An optical sensing device, which scans a projected beam toward an outside detection area and detests a reflected beam from the detection area with respect to the projected beam, the optical sensing device comprising:

• an optical unit including a light projecting portion that projects the projected beam, and a light receiving portion that receives the reflected beam of which a footprint of an optical path overlaps with that of the projected beam;
• and
• an accommodation unit which forms an accommodation chamber accommodating the optical unit therein, wherein
• the accommodation unit includes:
• an optical window portion which transmits the projected beam from the accommodation chamber to the detection area and transmits the reflected beam from the detection area to the accommodation chamber;
• a holding portion which holds the optical window portion from a side of an outer periphery;
• and
• an optical partition member, in which a reflectance rate to the projected beam is lower than that of the holding portion on a side of the optical window portion and an absorptance rate to the projected beam is higher than that of the holding portion on a side of the optical window portion, is arranged to partition between the optical unit and the optical window portion, wherein
• the light receiving portion includes a light-receiving lens system guiding the reflected beam which is formed with a large diameter protruding toward a side of the optical window portion more than a light-projecting lens system guiding the projected beam in the light projecting portion, and wherein
• the optical partition member includes a deflection structure which is deflected to a side of the optical window portion 16 at a location next to the light-receiving lens system more than a location next to the light-projecting lens system.