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