An optical sensor 25 that detects intensity of light is disposed, inside an optical case 30, at a position that allows the optical sensor 25 to receive light other than light received by a lens system 22, out of light emitted by an LED 21. The optical sensor 25 is housed in a dedicated photometric case 40. The photometric case 40 is provided with a light guide portion 42 that includes a transmission part 43 and a shielding part 44. The transmission part 43 is disposed in an optical path of light that directly travels from the LED 21 to the optical sensor 25 and allows transmission of the light. The shielding part 44 blocks indirect light that is reflected or scattered inside the optical case 30, from entering the optical sensor 25. Accordingly, it is possible to accurately detect only the light in the direct optical path from the LED 21.
