Zoom systems with tunable lenses and linear lens movements. - In: Journal of the European Optical Society, ISSN 1990-2573, Bd. 15 (2019), 1, 9, S. 1-10
Background: Classical zoom lenses are based on movements of sub-modules along the optical axis. Generally, a constant image plane position requires at least one nonlinear sub-module movement. This nonlinearity poses a challenge for the mechanical implementation. Tuneable lenses can change their focal length without moving along the optical axis. This offers the possibility of small system lengths. Since the focal range of tuneable lenses with significant aperture diameters is still limited, the use of tuneable optics in zoom lenses is usually restricted to miniaturized applications. Methods: To solve the challenge of the nonlinear movement in classical zoom lenses and the limitations of tuneable lenses for macroscopic applications we propose a combination of both concepts. The resulting 'Hybrid Zoom Lens' involves linear movements of sub modules as well as changing the focal length of a tuneable lens. The movements of the sub-modules and the focal length tuning of the lens are already determined by the collinear layout of the zoom lens. Therefore, we focus on collinear considerations and develop a method that allows a targeted choice of specific collinear layouts for our 'Hybrid zoom lenses'. Results: Based on examples and an experimental setup we demonstrate the feasibility of our approach. We apply the proposed method to examples of classical zoom lenses and zoom lenses based exclusively on tuneable lenses. Thereby we are able to show possible advantages of our 'Hybrid zoom lenses' over these widespread system types. Conclusions: We demonstrate important collinear considerations for the integration of tuneable lenses into a zoom lens. We show that the combination of classical zoom lens concepts with tuneable lenses offers the possibility to reach smaller system lengths for macroscopic zoom lenses while requiring only a small focal tuning range of the tuneable lens.
https://doi.org/10.1186/s41476-019-0106-3
In situ production of titanium aluminides during wire arc additive manufacturing with hot-wire assisted GMAW process. - In: Metals, ISSN 2075-4701, Bd. 9 (2019), 5, 578, insges. 13 S.
https://doi.org/10.3390/met9050578
Temperature dependence of dynamic parameters of contact thermometers. - In: Sensors, ISSN 1424-8220, Bd. 19 (2019), 10, 2299, insges. 9 S.
https://doi.org/10.3390/s19102299
Electrochemical deposition of silicon from a sulfolane-based electrolyte: effect of applied potential. - In: Electrochemistry communications, ISSN 1873-1902, Bd. 103 (2019), S. 7-11
https://doi.org/10.1016/j.elecom.2019.04.008
Ultra-wideband temperature dependent dielectric spectroscopy of porcine tissue and blood in the microwave frequency range. - In: Sensors, ISSN 1424-8220, Bd. 19 (2019), 7, 1707, insges. 21 S.
https://doi.org/10.3390/s19071707
Objective measurement of forward-scattered light in the human eye: an electrophysiological approach. - In: PLOS ONE, ISSN 1932-6203, Bd. 14 (2019), 4, e0214850, insges. 14 S.
https://doi.org/10.1371/journal.pone.0214850
Modeling and design of flexure hinge-based compliant mechanisms. - In: Kinematics, (2019), S. 1-24
A compliant mechanism gains its mobility fully or partially from the compliance of its elastically deformable parts rather than from conventional joints. Due to many advantages, in particular the smooth and repeatable motion, monolithic mechanisms with notch flexure hinges are state of the art in numerous precision engineering applications with required positioning accuracies in the low micrometer range. However, the deformation and especially motion behavior are complex and depend on the notch geometry. This complicates both the accurate modeling and purposeful design. Therefore, the chapter provides a survey of different methods for the general and simplified modeling of the elasto-kinematic properties of flexure hinges and compliant mechanisms for four hinge contours. Based on non-linear analytical calculations and FEM simulations, several guidelines like design graphs, design equations, design tools or a geometric scaling approach are presented. The obtained results are analytically and simulatively verified and show a good correlation. Using the example of a path-generating mechanism, it will be demonstrated that the suggested angle-based method for synthesizing a compliant mechanism with individually shaped hinges can be used to design high-precise and large-stroke compliant mechanisms. The approaches can be used for the accelerated synthesis of planar and spatial flexure hinge-based compliant mechanisms.
https://doi.org/10.5772/intechopen.85224
They need more than technology-equipped schools: teachers' practice of fostering students' digital protective skills. - In: Media and communication, ISSN 2183-2439, Bd. 7 (2019), 2, S. 137-147
https://doi.org/10.17645/mac.v7i2.1902
Over-the-air testing of automotive antennas and wireless links in the installed state on the basis of LTE downlink communication parameters. - In: Advances in science, technology and engineering systems journal, ISSN 2415-6698, Bd. 4 (2019), 1, S. 282-291
https://doi.org/10.25046/aj040127
Vehicle-to-Pedestrian communication for vulnerable road users: survey, design considerations, and challenges. - In: Sensors, ISSN 1424-8220, Bd. 19 (2019), 2, 358, insges. 18 S.
https://doi.org/10.3390/s19020358