The Design of a Double Telecentric Endoscopic Optical System

High-precision non-destructive testing (NDT) of blind hole in deep cavity has been one of the difficult problems in the field of precise measurement and testing. The practical conditions that traditional contact or non-contact testing methods cannot carry out high precision testing of blind hole in deep cavity are discussed, a novel dual-telecentric imaging method for high-precision non-destructive measurement of deep-cavity blind hole is proposed, and a dual-telecentric imaging device for high-precision measurement of deep-cavity blind hole is constructed in detail, the light source of the important part of double telecentric endoscopic imaging device for high precision measurement of deep cavity blind hole is compared and analyzed, and the light source is optimized based on the practice and effect, the application effect of imaging is tested on the inner surface of the main cylinder of automobile parts, and the correctness of selecting the light source is proved, the structure of double telecentric endoscopic optical system for high precision measurement of deep cavity blind hole is analyzed and designed, and the analytic design of double telecentric optical path is completed with practical examples. Finally, the validity of the research is verified by the on-line deep cavity blind hole measurement experiment on two different specifications of the brake master cylinder components