Cut-off Line of Passing Beam - Theory and Practice

Tomasz Targosinski Motor Transport Institute ITS

Warsaw, Poland

tomasz.targosinski@its.waw.pl

Abstract—Important part of headlightspassing beam image isthe“cut-offline”.Itserveforadjustmentofpassingbeamduringtype approval and during exploitationaiming. Correctaiming should leadto appropriate road illumination and protectagainst excessive glare. Cut-off line from it nature is a partseparating bright and dark area in thepassing beam. Practical functionis thevisual aiming of headlights in laboratories, invehicles factories, in services and during technical periodicalinspection. Cut-offlinewasfirstlydefinedover50yearsago.Toguarantee good road visibility and glareprotection aiming shouldhavehigher precision than present realcut-off shapetollerances. Definitionof cut-off line, their performance, changes duringyears and connection with progress of headlamps designare analyzed. Examples of real cut-offlines, relations withsignificantbeam pattern characteristics and possibleaiming results are shown.Perspectivesforfuturecut-offlineuse,orothermeansaredescribed.

Keywords- Headlamps aming,illumination, passingbeam