In this research, a unique freeform microlens array was designed and fabricated for a compact compound-eye camera to achieve a large field of view. This microlens array has a field of view of , with a thickness of only 1.6 mm. The freeform microlens array resides on a flat substrate, and thus can be directly mounted to a commercial 2D image sensor. Freeform surfaces were used to design the microlens profiles, thus allowing the microlenses to steer and focus incident rays simultaneously. The profiles of the freeform microlenses were represented using extended polynomials, the coefficients of which were optimized using ZEMAX. To reduce crosstalk among neighboring channels, a micro aperture array was machined using high-speed micromilling. The molded microlens array was assembled with the micro aperture array, an adjustable fixture, and a board-level image sensor to form a compact compound-eye camera system. The imaging tests using the compound-eye camera showed that the unique freeform microlens array was capable of forming proper images, as suggested by design. The measured field of view of also matches the initial design and is considerably larger compared with most similar camera designs using conventional microlens arrays. To achieve low manufacturing cost without sacrificing image quality, the freeform microlens array was fabricated using a combination of ultraprecision diamond broaching and a microinjection molding process.
© 2012 Optical Society of AmericaFull Article | PDF Article
Jacques Duparré, Peter Dannberg, Peter Schreiber, Andreas Bräuer, and Andreas Tünnermann
Appl. Opt. 44(15) 2949-2956 (2005)
A. Y. Yi and L. Li
Opt. Lett. 30(13) 1707-1709 (2005)
Klemens Stollberg, Andreas Brückner, Jacques Duparré, Peter Dannberg, Andreas Bräuer, and Andreas Tünnermann
Opt. Express 17(18) 15747-15759 (2009)