Search results for "Contrast ratio"
showing 8 items of 8 documents
Performance data of optically stimulable irradiated materials (doped alkali halides) oriented for imaging and dosimetry purposes
1997
Performance characteristics of a doped alkali halide (KBr:In)-based imaging plate (IP) and dosemeter (D) both the devices utilizing optically stimulated luminescence (OSL) and suitable for UV-light and x-ray energy recording are described. By exploiting (silicon) photodiode array as a photodetector, the detective quantum efficiency of 0.1 for IP (KBr:In) can be achieved. A very wide dynamic range, 1010:1 for UV (6.35 eV) and 1011:1 for x-ray (44 kV tube voltage) OSL recording at the spatial resolution of 1 mm2, is favorable for digital imaging and considerably improves image quality. These possibilities are illustrated by presenting available information capacities, energy consumption per b…
SPECTRAL AND TEMPORAL CHARACTERISTICS OF LIQUID CRYSTAL GOGGLES FOR VISION RESEARCH
2008
ABSTRACT Spectral and switching characteristics of two manufacturer liquid crystal goggles are tested. Experimentally the human stereovision acuity and threshold were studied for the case, when one eye random dot stereo stimulus simulated on the display is continuously blurred or the stimulus contrast is decreased. In order to determine the artefacts of two eye channel crosstalk on the stereostimuli separation the contrast ratio limits for the computer display phosphors wavelengths are determined.
<title>Long-term testing results of WO<formula><inf><roman>3</roman></inf></formula>-based electrochromic c…
1997
Two batches of the samples of electrochromic cell with WO3 and IrOx electrodes and Sb2O5 (DOT) water based solid electrolyte were tested at constant contrast ratio up to 107 cycles or stored during five years and the changes of current-voltage characteristics were studied. Two kinds of the changes were observed. The shift of curves along the voltage axis is supposed to be associated with the changes in the oxidation degree of tungsten oxide, while the changes in their shapes are associated with changes of water content in pores. The processes in the samples during cycling and storing are discussed.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the…
Acousto-optical multiple interference switches
2007
The authors introduce an alternative approach for acousto-optical light control based on the interference of light propagating through several waveguides, each subjected to a periodic refractive index modulation induced by a surface acoustic wave. The feasibility of the concept is demonstrated by the realization of an optical switch for arbitrary time intervals with an on/off contrast ratio of 20.
Poincaré sphere analysis of a ferroelectric liquid crystal optical modulator: application to optimize the contrast ratio
2008
The Poincare sphere representation is used to analyze the polarization transformation achieved with a ferroelectric liquid crystal (FLC) optical modulator. This device acts as a switchable wave-plate, in which the orientation of the principal axes rotates under the action of an applied bipolar voltage. In the standard operational mode for intensity switching, the rotation angle of the principal axes is �θ = π/4 and the phase shift is φ = π (half-wave-plate). However, for wavelengths different from the design one, the FLC deviates from the half-wave-plate performance and the optical contrast is diminished. We use the Poincare sphere representation to perform a theoretical analysis of the int…
Synergistic effects of childhood adversity and polygenic risk in first-episode psychosis
2023
The European Network of National Schizophrenia Networks Studying Gene-Environment Interactions (EU-GEI) Project is funded by grant agreement HEALTH-F2-2010-241909 (Project EU-GEI) from the European Community’s Seventh Framework Programme.
Plantxel: Towards a plant-based controllable display
2018
The use of plants as a mean for both visualization and interaction has been already explored in smart environments. In this work, we explore the possibility of constructing a controllable dynamic plant-based display using thigmonastic plants, i.e. plants that change the shape and position of their leaves as a response to external stimuli. As an initial step towards this vision, we first introduce our approach of building a plant-based pixel (plant-pixel, or plantxel), and the principles of composing a plantxel-based public display. We then present the results of a feasibility study conducted with Mimosa spegazzinii plants, showing that our approach can achieve an acceptable contrast ratio, …
Liquid crystal goggles for vision science applications
2003
Spectral and switching characteristics of two manufacturer liquid crystal goggles are tested, and a contrast ratio for the computer display phosphors wavelengths is determined. Goggles are used in vision science experiments for random dot stereo stimuli phase separation. The human stereovision acuity and threshold was studied for case, when one eye random dot stereo stimulus simulated on the display is cotinuously blurred or the stimulus contrast is decreased.