Scanning laser projection using resonant actuated MEMS scanning mirrors is expected to overcome the current limitation of small display size of mobile devices like cell phones, digital cameras and PDAs. Recent progress in the development of compact modulated RGB laser sources enables to set up very small laser projection systems that become attractive not only for consumer products but also for automotive applications like head-up and dash-board displays. Within the last years continuous progress was made in increasing MEMS scanner performance. However, only little is reported on how mass-produceability of these devices and stable functionality even under harsh environmental conditions can be guaranteed. Automotive application requires stable MEMS scanner operation over a wide temperature range from -40° to +85°Celsius. Therefore, hermetic packaging of electrostatically actuated MEMS scanning mirrors becomes essential to protect the sensitive device against particle contamination and condensing moisture. This paper reports on design, fabrication and test of a resonant actuated two-dimensional micro scanning mirror that is hermetically sealed on wafer level. With resonant frequencies of 30kHz and 1kHz, an achievable Theta-D-product of 13mm.deg and low dynamic deformation <20nm RMS it targets Lissajous projection with SVGA-resolution. Inevitable reflexes at the vacuum package surface can be seperated from the projection field by permanent inclination of the micromirror

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A refinement of cascade control tuning to reduce oscillations in the inner loop without deteriorating performance of the controlled (outer) variable is proposed. It is illustrated that the problem can rise for very common process dynamics and tuning techniques. The basic idea is to perform a balanced retuning of master and slave controllers, by acting on proportional and integral components of the two (PI) controllers. A distinctive feature of the method is that, once the problem shows up, appropriate actions can be performed on the two controllers without any additional knowledge about process dynamics. The effectiveness of the technique is validated in simulation on a significant class of process dynamics and in application on industrial loops

Testing and characterization of Micro-Electro-Mechanical Systems (MEMS) and Micro-Opto-Electro-Mechanical Systems (MOEMS) can be very challenging due to the multi-domain nature of these devices. Nowadays high volume, high-cost, and accurate measuring systems are necessary to characterize and test MEMS and MOEMS especially to examine motions, deflections and resonance frequencies. This paper presents a fast-developing and low-cost environment for MEMS and MOEMS testing and characterization. The environment is based on a flexible mixed-signal platform, named ISIF (Intelligent Sensor InterFace). As a case study we consider the characterization of a double axis scanning micromirror. The testing environment has been validated by comparing measurement results with results obtained by Finite Element Method simulation performed with Comsol MultiphysicsTM. Finally, these results have been used to create an electrical equivalent model of the micromirror

This paper presents the Simulink model of a new 2D torsional scanning micromirror. This micro-opto-electro-mechanical-system (MOEMS) is very important towards the integration into a system on a package of a complete laser projection system. Modeling and simulation of the MOEMS is a key point for the development of the proper micromirror electronic conditioning interface thus reducing time to market and production costs. In literature, there are not exhaustive examples of complete characterizations of 2D torsional scanning micromirrors. The aim of this work is to develop a Simulink model which incorporates the main mechanical and electrostatic parameters of the sensor such as the resonance frequency, the torsional constant and capacitance versus rotation angle characteristic. This model has been successfully verified via experimental measurements and it proved his effectiveness in the development of the relevant electronic conditioning circuitry