REFLECTION SURFACE DESIGN METHOD OF REFLECTION MIRROR OF VEHICLE LIGHTING FIXTURE

摘要

PROBLEM TO BE SOLVED: To provide a reflection surface design method of a reflection mirror of a vehicle lighting in which controllability of a light distribution pattern and efficiency in designing are enhanced. SOLUTION: The design method of the reflection surface RS related to the present invention is provided with a step for producing an XY curve Q on an XY plane including an X axis (optical axis) and a Y axis; a step for producing an XZ curve R on a plane (UZ plane) including a base point P and being parallel to a reflection direction of the light at the base point and perpendicular to the XY plane with respect to a plurality of base points existing on the XY curve Q; and a step for producing a surface shape of the reflection surface RS based on the XY curve Q and a plurality of XZ curve R.