Recently, inkjet-printed microoptics, such as microlens arrays, have become popular in scientific research as well as industrial applications due to the fast prototyping and production. Naturally, the process parameters have a strong influence on the printed end results. However, optimization of these parameters requires expert knowledge and manual quality control which is subjective and error-prone. To overcome these limitations, we propose an automated evaluation pipeline utilizing both light and confocal microscope images as well as multiple quality measures to quantitatively evaluate the quality of the printed microlens arrays, including the individual microlens radii, sag heights, and focal lengths, as well as the array’s grid parameters.
In jüngster Zeit sind Inkjet-gedruckte Mikrooptiken, wie beispielsweise Mikrolinsenarrays, sowohl in der wissenschaftlichen Forschung als auch in der industriellen Anwendung aufgrund des schnellen Prototypings und der schnellen Produktion beliebt geworden. Natürlich haben die Prozessparameter einen starken Einfluss auf das gedruckte Endergebnis. Die Optimierung dieser Parameter erfordert jedoch in der Regel Expertenwissen und eine manuelle Qualitätskontrolle, welche subjektiv und fehleranfällig ist. Um diese Einschränkungen zu überwinden, schlagen wir eine automatisierte Bewertung vor, die sowohl Hellfeld- als auch konfokale Mikroskopbilder sowie mehrere Qualitätsmaße verwendet, um die Qualität gedruckter Mikrolinsenarrays quantitativ zu bewerten. Dies beinhaltet die Schätzung der einzelnen Mikrolinsenradien, -höhen und -brennweiten sowie der Gitterparameter des Arrays.
Funding statement: This work was financed by the Baden-Württemberg Stiftung gGmbH.
About the authors
Maximilian Schambach received the B. Sc. degree in physics from Friedrich-Schiller University Jena in 2013, and the M. Sc. degree in physics from Leipzig University in 2016. He is currently working as a Research Associate with the Institute of Industrial Information Technology at the Karlsruhe Institute of Technology where he is persuing a Ph. D. degree. His current research interests include signal and image processing, computational imaging, and compressed sensing.
Qiaoshuang Zhang received the B. Sc. degree in optical science and engineering from Zhejiang University and the M. Sc. degree in optics and photonics from Karlsruhe Institute of Technology. She is currently a Ph. D. student at Karlsruhe Institute of Technology under the supervision of Prof. Uli Lemmer. Her research concentrates on printed microopitcs for solar cells and advanced imaging.
Uli Lemmer received the diploma degree in physics from RWTH Aachen University in 1990 and a Ph. D. from the University of Marburg in 1995. From 1995 to 1996, he held a postdoctoral position with the University of California at Santa Barbara. He was with the University of Munich from 1996 to 2002. In 2002, he was appointed a full Professor and director of the Light Technology Institute, Karlsruhe Institute of Technology. Since 2006 he is also the coordinator of the Karlsruhe School of Optics & Photonics (KSOP) and he is also heading the device physics competence center within the InnovationLab in Heidelberg. His research interests are in the technology and the applications of printable organic and inorganic semiconductors.
Michael Heizmann received the M. Sc. degree in mechanical engineering and the Ph. D. degree in automated visual inspection from the University of Karlsruhe, Germany, in 1998 and 2004, respectively. From 2004 to 2009, he was a Postdoctoral Research Assistant with the Fraunhofer Institute of Optronics, System Technologies and Image Exploitation (IOSB), Karlsruhe, Germany, where he was the Head of the Department Systems for Measurement, Control and Diagnosis, from 2009 to 2016. From 2014 to 2016, he was a Professor of mechatronic systems with the Karlsruhe University of Applied Sciences. Since 2016, he has been a Full Professor of mechatronic measurement systems and has been the Director of the Institute of Industrial Information Technology, Karlsruhe Institute of Technology. His research interests include measurement and automation technology, machine vision and image processing, and image and information fusion.
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