A method of examining the state of alignment of headlamp beam axis has the following steps: taking up by a TV camera the image of the light distribution pattern of a headlamp beam on a screen; specifying a closed curved area of illumination intensities higher than a predetermined level in the taken-up...http://www.google.de/patents/US4634275?utm_source=gb-gplus-sharePatent US4634275 - Method of and apparatus for examining automotive headlamp
