Showing papers on "Tilt (optics) published in 2011"

Game system and game information storage medium used for same

Abstract: A game system includes a housing to be held by a player. The housing incorporates an XY-axis acceleration sensor to detect an acceleration in an X-axis and Y-axis direction and a Z-axis contact switch to detect an acceleration in an Z-axis direction. These sensor and switch detect at least one of an amount (e.g., tilt amount, movement amount, impact amount or the like) and a direction (e.g., tilt direction, movement direction, impact direction or the like) of a change applied to the housing. A simulation program provides simulation such that a state of a game space is changed related to at least one of the amount and direction of the change applied to the housing.

Molecular Orientation Affects Localization Accuracy in Superresolution Far-Field Fluorescence Microscopy

Abstract: We investigate the cooperative effect of molecular tilt and defocus on fluorophore localization by centroid calculation in far-field superresolution microscopy based on stochastic single molecule switching. If tilt angle and defocus are unknown, the localization contains systematic errors up to about (125 nm. When imaging rotation-impaired fluorophores of unknown random orientation, the average localization accuracy in three-dimensional samples is typically limited to about (32 nm, restricting the attainable resolution accordingly.

Experimental demonstration of coherent beam combining over a 7 km propagation path

Abstract: We demonstrate coherent combining (phase locking) of seven laser beams emerging from an adaptive fiber-collimator array over a 7 km atmospheric propagation path using a target-in-the-loop (TIL) setting. Adaptive control of the piston and the tip and tilt wavefront phase at each fiber-collimator subaperture resulted in automatic focusing of the combined beam onto an unresolved retroreflector target (corner cube) with precompensation of quasi-static and atmospheric turbulence-induced phase aberrations. Both phase locking (piston) and tip–tilt control were performed by maximizing the target-return optical power using iterative stochastic parallel gradient descent (SPGD) techniques. The performance of TIL coherent beam combining and atmospheric mitigation was significantly increased by using an SPGD control variation that accounts for the round-trip propagation delay (delayed SPGD).

Multiple high-pressure phase transitions in BiFeO 3

Abstract: We investigate the high-pressure phase transitions in BiFeO${}_{3}$ by single-crystal and powder x-ray diffraction, as well as single-crystal Raman spectroscopy. Six phase transitions are reported in the 0--60-GPa range. At low pressures, four transitions are evidenced at 4, 5, 7, and 11 GPa. In this range, the crystals display large unit cells and complex domain structures, which suggests a competition between complex tilt systems and possibly off-center cation displacements. The nonpolar $Pnma$ phase remains stable over a large pressure range between 11 and 38 GPa, where the distortion (tilt angle) changes only little with pressure. The two high-pressure phase transitions at 38 and 48 GPa are marked by the occurrence of larger unit cells and an increase of the distortion away from the cubic parent perovskite cell. We find no evidence for a cubic phase at high pressure, nor indications that the structure tends to become cubic. The previously reported insulator-to-metal transition at 50 GPa appears to be symmetry breaking.

A piezoelectric unimorph actuator based tip-tilt-piston micromirror with high fill factor and small tilt and lateral shift

Abstract: This paper presents the design, fabrication and characterization of a piezoelectrically actuated high-fill-factor tip-tilt-piston (TTP) micromirror with small tilt and lateral shift during scanning. The piezoelectric material is a sol–gel lead zirconate titanate (PZT) thin film with a Zr/Ti ratio of 53/47. The small initial tilt and lateral-shift-free (LSF) of the mirror plate is achieved by a folded, three-segment piezoelectric unimorph actuator design. The piezoelectric unimorph actuation beams consist of Pt/Ti/PZT/Pt/Ti/SiO 2 multilayers, which are released via undercutting the substrate silicon. The fabricated piezoelectric micromirror can be actuated about two rotational axes in the mirror plane and for translational vertical scan (piston actuation). The resonant frequencies of the piston and rotation modes are 316 Hz and 582 Hz, respectively. At their respective resonant frequencies, the maximum piston magnitude at resonant driving is 32 μm, and the two-dimensional rotating scan ranges are about 5°, both measured at a 2V pp sinusoidal driving voltage.

Regulation of navigation speed among displayed items and tilt angle thereof responsive to user applied pressure

Abstract: An electronic device can include a touch sensitive display screen and a controller circuit. The touch sensitive display screen identifies a location where a user is pressing and generates a force signal that indicates how hard the user is pressing. The controller circuit controls a speed at which information items are scrolled across the screen and controls a tilt angle of the displayed information items responsive to the force signal. The controller circuit graphically renders the tilt angle on the screen by tapering width of the displayed information items in a defined direction and regulates the tapered width responsive to the force signal. No tilt angle is rendered when the force signal indicates that the user is not pressing the screen. The scrolling speed and the tilt angle of the displayed information items are increased, to provide a visual indication to the user of the increased scrolling speed, responsive to the force signal indicating that the user is pressing harder against the screen.

Photosensitivity control of an isotropic medium through polarization of light pulses with tilted intensity front

Abstract: We present the first experimental evidence of anisotropic photosensitivity of an isotropic homogeneous medium under uniform illumination. Our experiments reveal fundamentally new type of light induced anisotropy originated from the hidden asymmetry of pulsed light beam with a finite tilt of intensity front. We anticipate that the observed phenomenon, which enables employing mutual orientation of a light polarization plane and pulse front tilt to control interaction of matter with ultrashort light pulses, will open new opportunities in material processing.

Tilt-wing aircraft

Abstract: The invention relates to a tilt wing aircraft having a rear drive/control unit which is designed to generate propulsion and to generate an upward or downward directed propulsion component and/or a laterally directed propulsion component even in the hovering and in the climb mode of the aircraft.

Accurate Tilt Sensing With Linear Model

Abstract: We propose a tilt sensing scheme using a physical model with three sensitive axes of microelectromechanical systems (MEMS) accelerometers. Based on the physical model in which the gravitational acceleration is resolved into three components, we propose three numerical models to sense the tilt angle. First, two exact numerical models are presented to measure the gravitational acceleration and its one component along the tilt direction, respectively. The parameters of these two models are specific angles of the physical model, which can be used to assess the configuration of the physical model. Next, the measurement bias model is introduced to reduce the error resulting from the nonlinear relation between the gravitational acceleration and the tilt angle. Third, all the three numerical models are unified into a linear model whose parameters can be efficiently estimated using the least squares method. In the experiments, we evaluate the performance of the proposed scheme by examining the mean, the standard deviation, and the maximum of the errors. The experiment results show that our scheme is able to perform accurate tilt sensing with the average error below 0.1° in the measurement range (0°, 120°).

Holographic display with tilted spatial light modulator.

Abstract: In this paper, we analyze a holographic display system utilizing a phase-only spatial light modulator (SLM) based on liquid crystal on silicon (LCoS). An LCoS SLM works in reflection, and, in some applications, it is convenient to use with an inclined illumination. Even with a highly inclined illumination, the holographic display is capable of good-quality image generation. We show that the key to obtain high-quality reconstructions is the tilt-dependent calibration and algorithms. Typically, an LCoS SLM is illuminated with a plane wave with normal wave vector. We use inclined illumination, which requires development of new algorithms and display characterization. In this paper we introduce two algorithms. The first one is designed to process a digital hologram captured in CCD normal configuration, so it can be displayed in SLM tilted geometry, while the second one is capable of synthetic hologram generation for tilted SLM configuration. The inclined geometry asymmetrically changes the field of view of a holographic display. The presented theoretical analysis of the aliasing effect provides a formula for the field of view as a function of SLM tilt. The incidence angle affects SLM performance. Both elements of SLM calibration, i.e., pixel phase response and wavefront aberrations, strongly depend on SLM tilt angle. The effect is discussed in this paper. All of the discussions are accompanied with experimental results.

New developments of the magnetic tilt-depth method to improve structural mapping of sedimentary basins

Abstract: This paper interprets aeromagnetic data for a deep basin section of the Karroo rift in south-east Tanzania.We use a novel integrated approach involving the application of advanced derivatives to define structure and the tilt-depth method to determine and map the depth to basement. In the latter case we use the result of both reduced to pole and reduced to equator data to help constrain the shape and depth of the basin. We show that for a reduced to pole aeromagnetic data set, the generalized form of the local phase, called the tilt derivative, is an effective means of providing an initial (first pass) mapping of a sedimentary basin in terms of its fault structure, dip direction of faults and depth to basement. Since the amplitude of the tilt derivative does not contain information on the strength of the geomagnetic field nor magnetization (other than inclination) of the causative body, the susceptibility contrast across faults/contacts is derived from the analytic signal derivative. We also investigate how effective the tilt derivative and tilt-depth method are for structural and depth to basement mapping in regions close to the magnetic equator, where the reduction to pole transform is often unstable; this is done using the same Tanzania data set transformed to the pole and the equator. We find that the tilt derivative applied to the reduction to equator data cannot be used to map the structure because of the effects of magnetic anisotropy, which results in the magnetic response of structures varying with strike azimuth. To overcome this anisotropy problem the analytic signal and/or local wavenumber derivatives, which are for all practical purposes independent of inclination, provide the best means of defining the major structural trends.We also find that the tilt-depth method provides coherent depth to basement estimates for both reduced to pole and reduced to equator data. For the deep basin sections of the Karroo rift, there is a sparsity of tilt-depth results from both the reduced to pole and reduced to equator data sets. However, each set of results has a different spatial coverage, so when combined they provide a better spatial sampling of the long wavelength magnetic character of the basin and thus improve the constraints on the minimum curvature gridding method to map the shape and depth of the basin.

Control system for construction machine

Abstract: A construction machine control system capable of detecting a plurality of targets with a single measuring device. A construction machine control system including a measuring device, wherein the construction machine includes two targets 73a and 73b installed at a required position, an inclination detection unit that detects an inclination in the front-rear direction, and a drive. , A machine control unit 66 that controls the drive unit, and a mechanical communication unit that can communicate with the measurement device. The measurement device includes a distance measurement unit that performs distance measurement using distance measurement light, and a distance measurement Measure and measure the three-dimensional position of the measurement point based on the optical axis deflection unit that deflects the optical axis of the light and reflected distance measuring light, and the emission direction detection unit that detects the deflection angle and deflection direction of the optical axis deflection unit A measurement control unit that communicates the result to the machine control unit, the measurement control unit controls the optical axis deflection unit, and alternately measures the target in a time-division manner, and the detection result of the three-dimensional position of the target and the tilt detection unit Based on Controlling the driving unit based on the operation result of the constant controller. [Selection] Figure 5

Acquiring and pointing: an empirical study of pen-tilt-based interaction

Abstract: Research literature has shown that pen tilt is a promising input modality in pen-based interaction. However, the human capability to control pen tilt has not been fully evaluated. This paper systematically investigates the human ability to perform discrete target selection tasks by varying the stylus' tilt angle through two controlled experiments: pen tilt target acquiring (Experiment 1) and tilt pointing (Experiment 2). Results revealed a decreasing power relationship between angular width and selection time in Experiment 1. The results of Experiment 2 confirmed that pen tilt pointing can be modeled by Fitts' law. Based on our quantitative analysis, we discuss the human ability to control pen tilt and the implications of pen tilt use. We also propose a taxonomy of pen tilt based interaction techniques and showcase a series of possible pen tilt technique designs.

Scaling limit for a class of gradient fields with nonconvex potentials.

Abstract: We consider gradient fields (φ x : x ∈ ℤ d ) whose law takes the Gibbs-Boltzmann form Z -1 exp{- Σ(x,y) V(φ v - φ x )}, where the sum runs over nearest neighbors. We assume that the potential V admits the representation V(η) :=-log ∫ ϱ(dκ) exp[-1/2κη 2 ], where ϱ is a positive measure with compact support in (0, ∞). Hence, the potential V is symmetric, but nonconvex in general. While for strictly convex V's, the translation-invariant, ergodic gradient Gibbs measures are completely characterized by their tilt, a nonconvex potential as above may lead to several ergodic gradient Gibbs measures with zero tilt. Still, every ergodic, zero-tilt gradient Gibbs measure for the potential V above scales to a Gaussian free field.

Uncertainty evaluation for three-dimensional scanning electron microscope reconstructions based on the stereo-pair technique

Abstract: 3D-SEM is a method, based on the stereophotogrammetry technique, which obtains three-dimensional topographic reconstructions starting typically from two SEM images, called the stereo-pair. In this work, a theoretical uncertainty evaluation of the stereo-pair technique, according to GUM (Guide to the Expression of Uncertainty in Measurement), was carried out, considering 3D-SEM reconstructions of a wire gauge with a reference diameter of 250 µm. Starting from the more commonly used tilting strategy, one based on the item rotation inside the SEM chamber was also adopted. The latter enables multiple-view reconstructions of the cylindrical item under consideration. Uncertainty evaluation was performed starting from a modified version of the Piazzesi equation, enabling the calculation of the z-coordinate from a given stereo-pair. The metrological characteristics of each input variable have been taken into account and a SEM stage calibration has been performed. Uncertainty tables for the cases of tilt and rotation were then produced, leading to the calculation of expanded uncertainty. For the case of rotation, the largest uncertainty contribution resulted to be the rotational angle; however, for the case of tilt it resulted to be the pixel size. A relative expanded uncertainty equal to 5% and 4% was obtained for the case of rotation and tilt, respectively.

Relation between Monomer Structure and Image Sticking Phenomenon of Polymer-Sustained-Alignment Liquid Crystal Displays

Abstract: We investigated the image-sticking phenomenon of polymer-sustained-alignment liquid crystal displays (PSA-LCDs) by the evaluation of residual DC and the difference in tilt angle. Experimental results indicate that the difference in tilt angle affects the image sticking of PSA-LCDs more than the residual DC. We also found that the difference in tilt angle is strongly dependent on the chemical structure of the monomer that forms the polymer layer between the alignment layer and the liquid crystal layer by photopolymerization.

High precision tilt observation at Mt. Etna Volcano, Italy

Abstract: In 2007–2008, we installed on Mt. Etna two deep tilt stations using high resolution, self-leveling instruments. These installations are a result of accurate instrument tests, site selection, drilling and sensor positioning that has allowed detecting variations related to the principal diurnal and semidiurnal tides for first time on Mt. Etna using tilt data. We analyzed the tidal effects recorded on tilt signals and we removed tidal effects from signals, thereby allowing to detect changes of about 20 nrad with a considerable improvement in respect to the previous installation. Tilt changes have accompanied the Mt. Etna main eruptive phases and are generally related to the rapid rise of magma and formation of dikes and eruptive fissures. However, tilt changes may characterize lava fountains, earthquakes, and inflation-deflation phases. The 2008–2009 eruption represents an example of the potential of the tiltmeters we used, which provides new perspectives for highly precise monitoring of ground deformation on volcanoes.