The method of designing a reflective surface of a reflector in a vehicle
lamp according to the present invention comprise (1) a segment creating
step of sectioning a free curved surface and creating a plurality of
segments having a plurality of vertexes, and (2) a curved surface
generating step of deciding the light reflecting direction at each one of
the plurality of vertexes, and generating curved surfaces to be assigned
to the segments based on the reflecting direction for each one of the
plurality of segments. The present invention provides a method of
designing a reflective surface of a reflector in a vehicle lamp whereby
the controllability of the luminous intensity distribution pattern is
improved.