**4. Conclusions**

This study combined CODE V optical analysis software, the Taguchi experimental design method, and Moldex3D flow analysis simulations to optimize the injection molding processing parameters for a bilateral telecentric lens (BTL) barrel in such a way as to maximize the coaxiality of the tube and improve the imaging performance as a result. The Taguchi analysis results show that a larger maximum packing pressure, a lower melt temperature, and a longer cooling time are all beneficial in improving the coaxiality of the BTL barrel. Moreover, the CODE V and grayscale analysis results show that the BTL barrel molded using the optimal processing conditions yields a better MTF response and focusing performance than a BTL tube molded using the general processing parameters for the chosen polymer material (PA66).

**Author Contributions:** Conceptualization, C.-M.L., Y.-J.C.; formal analysis, C.-M.L., Y.-J.C.; writing— original draft preparation, C.-M.L., Y.-J.C.; data curation, Y.-J.C.; writing—review and editing, C.-M.L.; supervision, C.-M.L.; funding acquisition, C.-M.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the Ministry of Science and Technology of Taiwan, ROC, under Grant Numbers MOST 109-2221-E-415-001-MY3 and MOST 109-2221-E-415-002-MY3.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Acknowledgments:** The authors gratefully acknowledge the financial support provided to this study by the Ministry of Science and Technology of Taiwan, ROC.

**Conflicts of Interest:** The authors declare no conflict of interest.
