Patent DE-102008023551-A1 (DE)
Title: Optical lens useful in headlight of automobile vehicle to form image of light beam emitted by light source for production of lighting distribution, comprises optical diffusion effect areas subdivided into periodic frame of individual cells
Inventor: KIESEL MARKUS
IPC: G02B3/04
Filed: 2008-05-14
Abstract: The optical lens comprises optical diffusion effect areas subdivided into a periodic frame of individual cells, which have respectively a structure element that causes a targeted diffusion of the light. The form of structure elements in a first plane passing through the optical axis of the lens is parallel, and formed by an iterative mathematical function. The form of structure elements in the first plane is such that the structure elements diffuse a quantity of light decreasing in the large angle of deviation, and is formed by power of trigonometric functions. The optical lens comprises optical diffusion effect areas subdivided into a periodic frame of individual cells, which have respectively a structure element that causes a targeted diffusion of the light. The form of structure elements in a first plane passing through the optical axis of the lens is parallel, and formed by an iterative mathematical function. The form of structure elements in the first plane is such that the structure elements diffuse a quantity of light decreasing in the large angle of deviation, and is formed by power of trigonometric functions, polynomial functions or spline functions. The parameters of the function used in the first plane for forming the form of the structure element are prescribed according to a position of individual cell corresponding to the lens surface, and are prescribed by maintaining a tangential continuity of the lens surface. A segment of function is determined in a first part and respectively four segments of function are assembled continuously in a differentiable global function for the structure element. The segment of function in a second part corresponding to segments of function in a second part determined by symmetry with respect to a point 180[deg] and the segments of function in a third part corresponding to segments of function in the first and second part on a second plane passing by the optical axis of the lens or it is parallel and perpendicular to the first plane. The line of the surface of the lens is obtained in the part of an individual cell by multiplying two orthogonal functions or making an angle between them. The line of the surface of the lens in the part of an individual cell is obtained by rotating a function around an axis of rotation, at the center of the individual cell extending parallel to the optical axis of the lens or normal to the surface of the lens. The trace of the lens surface is obtained in the part of an individual cell by moving the function along a modulation function. The modulation function is a straight, a trigonometric function or a circle. The line of the lens surface in the part of an individual cell is obtained by addition or subtraction of two functions. The form of structure elements in the direction of an optical axis of the lens is circular, triangular, square, rectangular, trapezoidal or hexagonal considered by height or in the direction normal to the surface of the lens. The structural elements are formed, without rotation, around a rotation axis extending parallel to the optical axis of the lens or normal to the surface of the lens at the center of the individual cell and in that the line of the lens surface, in the part of the individual cell is obtained by a rotation of the structure element, which is not rotating around the axis of rotation angle of 45[deg] . The structure elements arranged on the surface of the lens are neighbors of each other continuously or with intervals as prescribed. The structure elements are arranged on the surface of the lens along the straight line, spirals or circles of the trigonometric functions. The surface of the lens has an elevation or a cavity in the part of an individual cell in which the specific function for the structure element is superimposed by addition, subtraction or multiplication. The lens surface has, on a large part of cells, an elevation or a cavity, where the function determined for the structure element is superimposed by addition, subtraction or multiplication at a value of the elevation or the cavity, which depends on the location. The form of the elevation or cavity in the direction of an optical axis of the lens considered from height or within the direction normal to the surface of the lens, is circular, triangular, square, rectangular, trapezoidal or hexagonal. The structure elements are deformed, and formed from an iterative mathematical function. The structure elements are anamorphically deformed, stretched or suppressed, and formed from iterative mathematical function.