Rose-Hulman Institute of Technology Rose-Hulman Scholar Graduate Theses - Physics and Optical Engineering Physics and Optical Engineering Fall 11-23-2020 Design of a Miniaturized Imaging System for As-built Performance Jake Joo Follow this and additional works at: https://scholar.rose-hulman.edu/dept_optics Design of a Miniaturized Imaging System for As-built Performance A Thesis Submitted to the Faculty of Rose-Hulman Institute of Technology by Jake Joo In Partial Fulfillment of the Requirements for the Degree of Master of Science in Optical Engineering November 2020 © 2020 Jake Joo ROSE-HULMAN INSTITUTE OF TECHNOLOGY Final Examination Report Joonha Joo Optical Engineering Name Graduate Major Thesis Title ____________________________________________________Design of a Miniaturized Imaging System for As-Built Performance ______________________________________________________________ DATE OF EXAM: November 23, 2020 EXAMINATION COMMITTEE: Thesis Advisory Committee Thesis Advisor: Hossein Alisafaee PHOE Azad Siahmakoun PHOE Jay McCormack ME X PASSED ___________ FAILED ___________ ABSTRACT Jake Joo M.S.O.E. Rose-Hulman Institute of Technology November 2020 Design of a Miniaturized Imaging System for As-Built Performance Thesis Advisor: Dr. Hossein Alisafaee During the past two decades, many advancements in the field of optical design have occurred. Some of the more recent topics and concepts regarding optical system design are complex and require a comprehensive understanding of aberration theory, in-depth knowledge and experience with optical design software, and extensive lens design experience. This thesis focuses on the development and application of simpler methods for successful lens design for standard and miniaturized imaging systems. The impact of manufacturing tolerances of an optical system is considered, analyzed, and tested. A study of various design approaches using optical design software is presented. The design approaches introduced focus on the as-built performance of the lens, and their results are compared to determine the most effective design approach. The results of the different design approaches considered were then applied to the design of a mobile phone camera. The topics of tolerancing and miniaturized lens design are considered together during the design process for a cellphone camera. The performance, manufacturability, and design process of the cellphone camera are also presented, along with suggestions on possible improvement for future work. The as-built performance of the final design compared to the initial design resulted in a 2.5 times improvement in performance for the same percent-yield. This thesis is dedicated to my parents, Wonjong Joo and Anna Shin, and my brothers, Inha and Alex Joo. ACKNOWLEDGEMENTS I would like to profoundly acknowledge my thanks to my advisor, Dr. Hossein Alisafaee. His advice, recommendations, and insight on relevant topics was paramount to the success of the research presented, and his role as an advisor extended beyond the classroom by inspiring his students with his enthusiasm for teaching and for optics in general. The availability, openness, and willingness to help his students is something that I believe educators at any level should strive to achieve, and it is something that I appreciated deeply. I would also like to thank my professors that I have had the pleasure of learning from during my graduate studies, particularly Dr. Azad Siahmakoun. From my first day at Rose, he was patient, welcoming, and provided us with a wide berth of knowledge of the optics world, and his experience in research and academia made me appreciate him being on my thesis defense committee. I would also like to extend my thanks to my other defense committee member, Dr. Jay McCormack, for agreeing to be on the committee and providing crucial comments during the defense. I am also grateful to my classmates James Dilts and Changkee Hong for their helpful presence inside and outside of the classroom. Their insight and work ethic were truly valuable. Most importantly, I would like to thank my parents and my brothers, especially, for their willing support. I could not have done this without them. i TABLE OF CONTENTS LIST OF FIGURES ....................................................................................................................... iv LIST OF TABLES ........................................................................................................................ vii 1. INTRODUCTION ................................................................................................................... 1 1.1 Background ...................................................................................................................... 1 1.2 Brief History of Mobile Phone Cameras .......................................................................... 1 1.3 Recent Trends in Smartphone Camera Designs ............................................................... 5 2. THEORY ................................................................................................................................. 9 2.1 Effective Focal Length and Field-of-view ....................................................................... 9 2.2 Airy Disk ........................................................................................................................ 10 2.3 Rayleigh and Marechal Criterion for Diffraction Limited Performance........................ 11 2.4 High-Yield Optimization................................................................................................ 12 3 STUDY OF OPTIMIZATION APPROACHES FOR AS-BUILT PERFORMANCE......... 15 3.1. Background .................................................................................................................... 15 3.2 Optimization Approaches ............................................................................................... 17 3.2.1 Best Nominal .......................................................................................................... 17 3.2.2 High-Yield (HYLD)................................................................................................ 18 3.2.3 Nominal + HYLD ................................................................................................... 18 3.2.4 Nominal + TOLR .................................................................................................... 18 3.2.5 HYLD + TOLR ....................................................................................................... 19 3.2.6 Nominal + HYLD + TOLR .................................................................................... 19 3.2.7 Nominal + TOLR + HYLD (with and without TOLR) .......................................... 19 3.2.8 Nominal + HYLD + Nominal + TOLR .................................................................. 19 3.3 Design Parameters and Initial Configuration ................................................................. 19 3.4 Results ............................................................................................................................ 22 3.5 Discussion ...................................................................................................................... 31 3.6 Takeaways ...................................................................................................................... 33 4. MOBILE PHONE CAMERA DESIGN ................................................................................ 34 4.1 Background .................................................................................................................... 34 4.2 Design Points.................................................................................................................. 34 ii 4.2.1 Review of Three Recent Designs ............................................................................ 35 4.2.2 Scaling Effects ........................................................................................................ 36 4.2.3 Design Parameters .................................................................................................. 36 4.3 Design Approach ............................................................................................................ 40 4.4 Results ............................................................................................................................ 42 4.4.1 Nominal Performance ............................................................................................. 42 4.4.2 As-built Performance .............................................................................................. 56 4.5 Analysis of Results ......................................................................................................... 58 5. CONCLUSION ..................................................................................................................... 65 5.1. Future Work ................................................................................................................... 66 LIST OF REFERENCES .............................................................................................................. 68 APPENDIX ................................................................................................................................... 70 iii LIST OF FIGURES CHAPTER 1 FIGURE 1.1: (LEFT) J-SH04 CELLPHONE (2000); (RIGHT) IMAGE TAKEN BY J-SH04 [2]. ................. 2 FIGURE 1.2: NOKIA 7650 (2002) [3]. ..............................................................................................