DEVELOPMENT ON HIGH-ACCURACY FABRICATION TECHNOLOGY OF ASPHERIC OPTICAL COMPONENTS USING THE PARALLEL GRINDING METHOD

高精度凸面非球面玻璃透镜制造技术的发展：本子项目的目标是制造直径为20 ~ 150mm，形状精度为100nm，表面粗糙度为lOnm的玻璃凸面非球面透镜。这种透镜用于数据投影仪等光学系统。主要研究结果如下：(1)对丰田机械有限公司生产的AHN60-3D超精密非球面磨床进行了改造，采用了平行磨削方法。(2)开发了按并行法由非球面方程生成NC代码的软件。(3)在传统的CG （Curve Generating）方法的基础上，开发了球面砂轮的高精度修形技术，使直径75mm、目数SD600 ~ SD5000的球面金刚石砂轮轮廓达到1微米的形状精度成为可能。(4)通过适当改变树脂结合剂、填料类型、发泡剂等材料，研制了用于沥青超精密磨削的金刚石砂轮。在Use终磨实验中，实现了30nm的表面粗糙度和100nm的形状精度。这提供了在不抛光的情况下在玻璃上获得超精密非球面的可能性。(5)对直径150mm的非球面玻璃透镜进行了磨削实验。实验证明，采用平行磨削方法磨削大半径透镜，由于一次磨削过程中砂轮的磨损小到可以忽略不计，因此可以实现超精密磨削。硬质合金凹非球面模具和微非球面模具制造技术的开发：本子项目的目标是生产CCD相机和内窥镜用非球面透镜的模具。主要研究结果如下：(1)根据微非球面的最小曲率半径，设计制造了直径为1mm、目数为600 ~ 3000的树脂结合剂球形金刚石砂轮。(2)提出了一种以不锈钢管为搭接工具的微型球面轮的机上整形方法。采用上述方法成功地将直径为1mm的砂轮修整成球形。(3)采用该方法对内窥镜用非球面镜硬质合金模具进行磨削。在半径为2mm的非球面透镜模具上获得了50mmRy的表面粗糙度和100nm的形状精度。(4)设计并研制了一种带有空气微探头的机上测量系统。该系统可在10nm分辨率和10mm动态范围下进行测量。(5)考虑X方向、Y方向偏移误差和砂轮磨损，对整弧装置误差形成机理进行了理论分析和仿真。提出了一种误差补偿方法。最终获得了100nm的形状精度。少

Development of the manufacturing technology for high-accuracy convex aspheric glass lenses: The objective of this sub-project was to fabricate the convex aspheric lens made of glass, 20〜150mm in diameter, having a form accuracy of 100 nm and a surface roughness of lOnm. This kind of lens is used in the optical systems such as data projector. The main results are listed as follows: (1) The ultraprecision aspheric grinder AHN60-3D, produced by the Toyada Machine Co., Ltd. was renovated for the use of the parallel grinding method. (2) The software, which is able to generate the NC codes from the aspheric equations according to the parallel method, was developed. (3) Based on the traditional CG (Curve Generating) method, high-accuracy truing technology far spherical wheels was developed, and it has become possible to contour the spherical diamond wheel, 75mm in diameter, SD600〜SD5000 in mesh number to an form accuracy of 1 micrometer. (4) The diamond wheel for ultraprecision grindinof asph … More eric glass lenses were developed by changing the material properly of the resin bind, filler type and blowing agent etc.. As a result, 30nmRy surface roughness and 100 nm form accuracy were realized in Use final grinding experiments. This provides the possibility of obtaining ultraprecision aspheric surface on glass without polishing. (5) The grinding experiment of the 150mm-diameter aspheric glass lens was performed. It was proved that, using the parallel grinding method, the ultra-precision grinding is possible even for large radius lenses, since the grinding wheel wear during one grinding pass is as small as can be neglected.Development of the manufacturing technology for concave aspheric mold and micro aspheric mold made of cemented carbide: The objective of this sub-project was to produce the molds of aspheric lenses for CCD cameras and endoscopes. The main results are listed as fellows: (1) According to the minimum curvature radius of the micro aspheric surface to be ground, spherical resin-bond diamond wheels, 1mm in diameter, 600-3000 in mesh number, were designed and manufactured. (2) An on-machine truing method for micro spherical wheel was developed by utilizing a stainless steel pipe as the lap tool. A 1mm-ditmeter grinding wheel was successfully dressed to a spherical shape by using the above method. (3) Cemented carbide mold of aspheric lens for endoscopes applications were ground using the proposed method. 50mmRy surface roughness and 100 nm form accuracy were obtained on a 2mm-radius aspheric lens mold. (4) An on-machine measurement system having an air-micro-probe was designed and developed. The system can perform measurement at l0nm resolution and l0mm dynamic range. (5) Theoretical analysis and simulation of the error formation mechanism of the arc-truing device was carried out with considering the offset errors in X direction, Y direction and the wear of the grinding wheel. An error compensation method was developed. As a result, 100nm form accuracy was obtained. Less