DEFINITION PROCESS FOR AN ASPHERICAL LENS AND LIGHTING MODULE FOR A MOTOR VEHICLE COMPRISING SUCH A LENS

摘要

A method for defining an aspherical lens (120) having a predetermined optical axis, comprising an incident surface (121) capable of receiving a luminous flux from a light source (110) disposed at the focal point (F) of the lens (120) on the optical axis (x) and an exit surface (122) from which the rays of the luminous flux emerge having passed through the lens (120). The incident surface (121) is obtained by rotating a straight line about a vertical axis (z) perpendicular to the optical axis (x) of the lens (120) and the exit surface (122) is obtained after rotating the generating curve (124) about the optical axis (x), said generating curve (124) being calculated to direct the rays emerging from the exit surface (122) in a direction parallel to the optical axis (x). The method is characterised in that it consists of constructing the incident surface (121) from a substantially planar area (126) centred around the median plane (PM) of the lens (120), then adjusting this outcome for each radial section of the lens (120), from the median plane of the lens (120), until a cylindrical profile is obtained on the edge (123) of the lens (120).