Method of measuring and adjusting optical axis of headlight

摘要

An optical axis of a headlight is measured by disposing a lattice member in front of the headlight. The lattice member has a plurality of longitudinally elongated lattice holes which are arranged in a form of a matrix. An illuminated area and an illuminance of light beams to be transmitted through the lattice member are measured at each of illuminating regions which are divided into a form of a matrix by the lattice holes. The position of a light source of the headlight is located from an illuminating region of maximum illuminated area and a position of an optical axis of the headlight is located from an illuminating region of maximum illuminance. The optical axis is adjusted depending on the located position of the light source and the position of the optical axis such that the inclination angle of the optical axis coincides with a set inclination angle. An illuminance distribution pattern is used to judge the type of headlight during adjustment of the optical axis of the headlight.