Piezostack deformable mirror with high technological effectiveness

Deformable mirror (DM) is an active element that can change the shape of the surface to compensate for wavefront aberrations. Historically, the development of DMs started from piezostack deformable mirrors (PDM) due to their large stroke, flexibility in actuators geometry, high resonant frequency. However, the cost of PDMs is comparatively high because of their labor-intensive process of manufacturing. In the article innovative design of PDM is presented. The assembling of unconventional PDMs was carried out using piezoceramic combs. This step should allow to decrease number of technological steps, increase spatial resolution of the mirror and thereby reduce the cost of final product.

Design of a 6-DOF VCM-Driven Micro Stage

This paper presents design of micro stage performing 6 degree-of-freedom (DOF) motions, which actuated by voice coil motor (VCM). The VCMs generate forces to perform in-plane motions and out-of-plane motions. The stage is supported by springs for compensating mass of the moving part of the stage and the stiffness of the springs has been chosen to meet the moving range requirement and to have high resonant frequency at the same time. Moving magnet type has been selected against moving coil type due to few merits of the type. The size of the stage is 380 X 380 X 60 mm3 and the motions are measured by laser interferometer and gap sensors.

The Application of Fault Diagnosis Based on EMD and Real Modulation Zoom Method

It is first to make Empirical Mode Decomposition (EMD) and achieve Hilbert-Hung transform (HHT) of envelope spectrum after Hilbert transformation, which can resolve the cross fault existing in Hilbert transformation is utilized merely. However, it can’t improve the resolution of envelope spectrum, which doesn’t adapt the characteristic of high resonant frequency of rolling bearing and low fault frequency. The paper utilizing the principle of real modulation shift frequency moves the EMD decomposition components of high frequency section to low frequency section and makes analysis of envelope spectrum after Hilbert transformation, which resolves the problem of low frequency resolution of pure HHT.

Low voltage operation electrostatic comb drive micro-mirror for laser scanning display

Electrostatic comb drive micro-mirror has limitation of high operation voltage, which has limited its practice use. Recent developments in decreasing operation voltage are promising for mobile micro-mirror. Especially, the operation voltage is decreased substantially by removing the air friction of comb-drive micro-mirror at a high resonant frequency when the mirror is operated at low pressure. Removing simultaneously the air friction and anchor loss, electrostatic comb-drive micro-mirror operating at a few voltages at a high resonant frequency becomes possible. This paper presents our recent developments as well as emerging techniques introduced in literature for decreasing the operation voltage of electrostatic comb drive micro-mirror. Methods for decreasing the operation voltage at large rotation angle and high scan frequency for application in the laser scanning display are focused to discuss in this paper.