使用高精度三坐标测量仪实现透镜定中心

传统的光学测量定中心法受限于光源、转台大小和装调误差传递性而不适用于大口径、多透镜光学系统的装调,为此本文提出了使用三坐标测量仪接触式测定透镜中心的精密机械测量法。介绍了使用三坐标测量仪测量大口径透镜中心偏的原理,即在测量透镜上表面与基准轴等距离各点坐标的基础上拟合得到透镜光轴与基准轴的夹角,从而解算出透镜的中心偏。通过大口径长焦距镜头的装调对该方法进行了检验。检验结果表明:该透镜的装调偏差为6.47″,重复性误差为(1.16×10-4)″。该方法将光学测量变为机械测量,利于装调,可在保证装调精度的同时简化装调难度,提升装调效率,满足大口径多透镜光学系统对高精度装调的要求。

Lens centering using high-precision three coordinate measuring machine

Due to the limits of light sources,the sizes of rotating platforms and the propagation of assembling errors, traditional methods of lens centering are not suitable for the assembly of large-aperture and multi-lens optical systems. Thus a new high-precision mechanical measurement method for lens centering was proposed based on a three Coordinate Measuring Machine (CMM). Principles and algorithms for measuring off-centering of the large aperture lens using the high-accuracy CMM were introduced. In the measurements, the angle between the optic axis of lens and the reference axis was calculated after the figure fitting of the measuring points, and then the centering of deviation was calculated. The method was verified by the assembling of a long focal length and large aperture imaging system. The assembling result shows that the lens off-centering is 6.47" and the repeatability error is (1.16×10^-4)". As changing the optical measurement into a mechanical measurement, this proposed method ensures the accuracy, reduces the difficulty and improves the efficiency of lens assembly. It is able to be applied to the high-precision assembly of large aperture transmitting optical systems.