Single freeform surface imaging design with unconstrained object to image mapping

An imaging design approach which is free of third-order astigmatism for one freeform optical surface and the image is presented in this paper. A set of differential equations is derived from generalized ray tracing. The solution of the above derived equations provides the anastigmatic freeform optical surface, the image surface and the object to image mapping. The obtained design can be used as a good starting point for optimization. As an example, a reflective freeform surface is designed for a single reflective Head Mounted Display (HMD). This example has a 3 mm pupil, 15mm eye clearance, 24-degree diagonal full field of view, and the final design yields an average MTF of 62.6% across 17 field points

Systematic investigation of methods for multiple freeform optimization in multi-lens imaging systems

With the development in freeform technology, it has now become more and more feasible to use freeform surfaces in real system designs. While the freeform surfaces helping optical designers achieve more and more challenging system features, the methods for multiple freeform implementations are still underdeveloped. We therefore investigate strategies to use freeform surfaces properly in imaging optical systems with one Scheimpflug system and one lithographic system. Based on the studies of the influences of the freeform normalization radius, freeform order and system eccentricity, the methods of determining the optimal location for implementing one freeform surface are discussed. Different optimization strategies to optimize two freeform surfaces are discussed to compare their resulting influences on the system performance. On top of that, ways to implement more than one freeform surface in the optical system is also investigated. In the end, a workflow is presented as guidance for implementing multiple freeform surfaces with respect to system aberration constitutions

Solid Freeform Fabrication Research In Engineering Education

Because Solid Freeform Fabrication (SFF) has an extremely wide range of potential applications, crossing traditional engineering and science boundaries, it is a technology that lends itself to multi-disciplinary activities and projects. SFF is an ideal mechanism to present scientific concepts including materials science and mechanics, as well as larger-scope engineering topics such as agile manufacturing. At Milwaukee School of Engineering (MSOE), we are using SFF technologies as a means to teach engineering concepts to undergraduate students through multidisciplinary research. MSOE was awarded a five-year grant under the NSF Research Experiences for Undergraduates Program (EEC-9619715) to facilitate student exploration in the field of Solid Freeform Fabrication. Sixty undergraduates will participate in summer and academic year programs by the year 2001. Eighteen students from around the country have participated in the program to date, bringing with them a diverse background of university experience, skill level, and interests. Working closely with a faculty advisor possessing expertise in a particular research area, they have performed research on Solid Freeform Fabrication applications in the biomedical, aerospace, architectural, manufacturing, and electronics industries. Some ofthe keys to the success of this program include: • Hands-on access to Solid Freeform Fabrication equipment through the facilities ofthe MSOE Rapid Prototyping Center (SLA 250, LOM 2030, and FDM 1650). • Close partnerships of the students with faculty and industry mentors in specialized areas of expertise. • Teaming with other educational institutions. • Significant cross-pollination between projects; faculty from diverse departments. • Encouraging students to publish and present results at national conferences and symposia.Mechanical Engineerin