基于机器视觉的小景深高分辨率双远心光学系统的设计

Designon Bilateral Telecentric Optical System with Small Depth of Field and High Resolution for Machine Vision

针对机器视觉检测Pin针位置度的应用需求,确定光学系统技术指标,选择合适的初始结构和玻璃组合,通过像差优化设计一款小景深、高分辨率、低远心度的双远心光学系统。系统包括8片球面透镜,物方线视场2y=32 mm,工作距离120 mm,景深0.5 mm,像面CCD尺寸1英寸,最大畸变小于0.1%,远心度最大值控制在0.007°以内,在空间频率208 lp/mm处调制传递函数(MTF)值大于0.3,各种像差均得到很好的矫正,像质优良,并对光学系统进行公差分析。该结构在连接器Pin针位置度检测领域内具有广泛的通用性,在一定程度上提高检测效率、降低劳动成本,有很好的市场前景。

In order to meet the application requirements of the machine vision to detect the position of the Pin needle,this paper designed a bilateral telecentric optical system with small depth of field,high resolution and low telecentricity by determining the optical system technical indicators and selecting the appropriate initial structure and glass combination.The system consists of 8 spherical lenses.It has a field of view of 32 mm,a working distance of 120 mm and a depth of field of 0.5 mm.The CCD camera is 1 inch in size.The maximum distortion of the system is less than 0.1%and the maximum telecentricity is controlled within 0.007°.The modulation transfer function value of this system is greater than 0.3 at space frequency 208 lp/mm.All kinds of aberrations were well corrected and the image quality is excellent.The tolerances of the designed optical system were also analyzed.This optical structure is widely versatile in the field of connector pin position detection.It has a good market prospect because it can improve the detection efficiency and reduce the labor cost to some extent.