US 11,746,970 B2
Ceiling-mounted type lighting device
Michiru Sasaki, Tokyo (JP); and Takahito Yoshizawa, Tokyo (JP)
Assigned to ELCO CO., LTD, Kanagawa (JP); EVERS CO., LTD, Kanagawa (JP); and DAI-ICHI SHOMEI CO., LTD, Tokyo (JP)
Appl. No. 17/630,996
Filed by ELCO CO., LTD, Sagamihara (JP); EVERS CO., LTD, Sagamihara (JP); and DAI-ICHI SHOMEI CO., LTD, Tokyo (JP)
PCT Filed Jun. 22, 2020, PCT No. PCT/JP2020/024400
§ 371(c)(1), (2) Date Jan. 28, 2022,
PCT Pub. No. WO2021/019957, PCT Pub. Date Feb. 4, 2021.
Claims priority of application No. 2019-138849 (JP), filed on Jul. 29, 2019.
Prior Publication US 2022/0178507 A1, Jun. 9, 2022
Int. Cl. F21S 8/02 (2006.01); F21V 21/26 (2006.01); F21V 23/04 (2006.01); F21Y 115/10 (2016.01)
CPC F21S 8/026 (2013.01) [F21V 21/26 (2013.01); F21V 23/0457 (2013.01); F21Y 2115/10 (2016.08)] 8 Claims
OG exemplary drawing
 
1. A ceiling-mounted type lighting device, comprising:
a light-receiving unit containing four optical sensors arranged crosswise and a light-shielding body through which four through-holes are cut as positions that are respectively opposite to light-receiving surfaces of the optical sensors; and
a tilt adjustment mechanism containing a first movable body and a second movable body which are mounted on first and second rotation shafts arranged on a same plane to cross at right angles,
wherein the light-shielding body is arranged so as to be opposite to the optical sensors with a clearance between the light-shielding body and the optical sensors,
wherein a single tilt adjustment light emitted from a light emitter passes through the through-holes to form four spotted tilt adjustment lights which are respectively concentrated on the sensors,
wherein the tilt adjustment mechanism is mounted in a housing constituting the ceiling-mounted type lighting device, and
wherein the light-receiving unit and a lighting lamp illuminating a side of the light emitter are mounted on a rotational center axis of the second movable body, and a tilt of the light-receiving unit is adjusted according to amounts of the four spotted tilt adjustment lights formed on the optical sensors.