Optical sensing device

An optical sensing device, which scans a projected beam toward an outside detection area and detects 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,
• the optical partition member includes a deflection structure which is deflected to a side of the optical window portion at a location next to the light-receiving lens system more than a location next to the light-projecting lens system,
• the optical partition member is arranged to surround footprints of the projected beam and the reflected beam from a side of an outer periphery and has a separation structure spaced apart from the optical window portion toward a side of the optical unit,
• the deflection structure placed between the light receiving portion and the optical window portion is deflected toward a side of the optical window portion more than the separation structure placed between the light projecting portion and the optical window portion,
• the optical partition member is formed in a shape of a stepped plate frame to provide the separation structure and the deflection structure,
• the optical partition member has an outer peripheral side edge supported by the holding portion,
• the optical sensing device further comprises a scanning unit which is accommodated in the accommodation chamber, scans the projected beam from the light projecting portion toward the detection area, and reflects the reflected beam from the detection area toward the light receiving portion, and includes a mirror portion which is driven in a rotational manner, and
• the optical window portion includes an inclined surface structure which is inclined with respect to a rotational axis direction of the mirror portion, on a side of the accommodation chamber.