提出一种渐进环焦自由曲面镜片设计, 从周边离焦防控及光焦度渐变的角度出发构建一个多焦点镜片。在镜片的中心部位形成有一个圆形的中心定焦区, 在外周形成多个环形的周边定焦区, 镜片的光焦度沿着镜片子午线及镜片水平轴按设定的光焦度高阶多项式从内至外渐变;依据相邻定焦区边缘点切平面重合的原则, 由内至外依序计算各个定焦区后表面上所有点的矢高, 再根据所有定焦区后表面的所有点的矢高数据生成镜片后表面。与传统非球面镜片仿真结果对比, 表明渐进环焦自由曲面镜片光焦度和散光符合理论设计要求, 符合正常人眼在看物体时眼球的调节功能, 镜片边缘也较薄, 镜片的棱镜度也较小。设计为渐进多焦点自由曲面镜片提供了一种新的途径。

Considering controlling the surrounding defocus and the power of the lens changes from the central area to the edge area, a new design method for freeform progressive ring-focus lenses is proposed. A circular fixed focus area is formed at the center of the lens and a plurality of annular peripheral fixed focus areas are formed on the outer periphery. The power of the lens is progressively changed along the meridian and horizontal axis. According to the principle of coincidence of the tangent plane of the adjacent fixed focus area, the vector heights of all points on the back surface of each fixed focus area is calculated from the inside to the outside. The back surface of the lens is generated based on the vector data of all dots of the back surface of all the focal zones. Compared with the simulation results of the traditional aspherical lenses, it shows that the power and astigmatism of freeform progressive ring-focus lenses are in accordance with the design value. It is in accordance with the regulation function of the normal human eye when looking at the object. The lens edge is thinner and the prism is also smaller. A new type design method of freeform progressive ring-focus lenses is provided.