at the rear side of the solenoid attachment portion 16 the projection lens 9 is formed in a substantially hemisphere shape and attached to the lens attachment portion 13 of the lens holder 8 the inner surface of the reflector 10 is formed as a reflecting surface 10 a the reflector 10 is attached to the top surface of the light source unit 11 the light source unit 11 includes a circuit board 18 and a light source 19 mounted on the top surface of the circuit board 18 as the light source 19 for example a light emitting diode led is used the light source unit 11 is provided with a heat sink 20 disposed below the circuit board 18 a cooling fan 12 is disposed inside of the heat sink 20 the light source unit 11 is attached to the attachment surface portion 17 of the lens holder 8 a light quantity control mechanism 21 is attached to the lens holder 8 the light quantity control mechanism 21 includes a movable shade 22 a support plate 23 a rotation shaft 24 a solenoid 25 and an orthogonal transformation mechanism 26 see e g fig2 and 3 the movable shade 22 includes a light quantity control portion 27 which is formed in a substantially circular arc surface shape protrusions 28 28 protruding from the left and right ends of the light quantity control portion 27 to the outer sides lateral sides respectively and a stopper portion 29 protruding rearward from the light quantity control portion 27 at the front surface side of the lower end portion of the light quantity control portion 27 a spring tray.