A highly stable broadband light source includes a semiconductor light source having a specific emission spectrum, an optical filter having a specific bandpass filtering function and a predetermined bandwidth and a coupling element, to which the light emissions of the semiconductor light source and of the optical filter are fed. Solving Means Laser light from a semiconductor laser 12 is split and formed into sheet lights Ls using a cylindrical lens 22, and the sheet lights Ls are crossed with each other at a predetermined position. An inside connector section 28 which is connected to the substrate connector 27 is provided integrally on an inner surface side of the camera housing 25, and an outside connector section 29 which is connected to an external connector 22 provided at the end of an external harness 21 is provided integrally on an outer surface side of the camera housing 25. The selected evaluation order of test points, faults, and fault resistance values reduces computational and storage costs. The back gate of the further MOS field-effect transistor is connected to a fixed voltage, which is greater than the voltage supplied by the reference voltage source.