Yu H.-L.,Industrial Technology Research Institute of Taiwan |
Young R.,Instrument Systems GmbH |
Hsiao C.-C.,Industrial Technology Research Institute of Taiwan
Measurement Science and Technology | Year: 2015
Due to the advantages of fast measurement speed, imaging luminance measurement devices (ILMDs) have become more and more popular in the recent years. However, even though an ILMD is corrected by flat field calibration, the measured results deviate from the real values when measuring curved surface sources. The deviation is larger in particular when the curvature of the source is smaller or when the source is unlike a Lambertian source. This paper shows how to obtain correction factors to increase the measurement accuracy of the ILMD when measuring different types of curved surface sources. The issue of how the measurement conditions affect the level of image blur is also discussed in this paper. © 2015 IOP Publishing Ltd.
Mauch F.,University of Stuttgart |
Fleischle D.,University of Stuttgart |
Lyda W.,University of Stuttgart |
Osten W.,University of Stuttgart |
And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011
Simulation of grating spectrometers constitutes the problem of propagating a spectrally broad light field through a macroscopic optical system that contains a nanostructured grating surface. The interest of the simulation is to quantify and optimize the stray light behaviour, which is the limiting factor in modern high end spectrometers. In order to accomplish this we present a simulation scheme that combines a RCWA (rigorous coupled wave analysis) simulation of the grating surface with a selfmade GPU (graphics processor unit) accelerated nonsequential raytracer. Using this, we are able to represent the broad spectrum of the light field as a superposition of many monochromatic raysets and handle the huge raynumber in reasonable time. © 2011 SPIE.
Young R.,Instrument Systems GmbH |
Senft M.,Instrument Systems GmbH |
Tribes D.,Instrument Systems GmbH |
Peters F.,Instrument Systems GmbH
Lighting Research and Technology | Year: 2016
Performance indices f'1 through to f12 are used in selecting and comparing photometers. These indices are expressed in percent with the ideal being 0%. Uncertainties may be expressed in the same way and performance indices are often mistaken for uncertainties. There is no functional relationship between performance indices and uncertainties but a limiting relationship has been previously established for f'1. Here, an analogous limiting relationship is shown for the cosine response index, f2, by simulating a range of realistic photometer responses and measurements of a sample of fourteen lighting scenarios. For most lighting scenarios the limiting error is the f2 value plus 1%. However, some (mainly outdoor) scenarios give much larger errors so care is required in estimating errors in such lighting measurements. © SAGE Publications.
Konjhodzic D.,Instrument Systems GmbH |
Distl R.,Instrument Systems GmbH
Light and Engineering | Year: 2011
An integrating sphere with a spectrometer is the recommended instrument for the measurements of LED lamps and modules. A new coating solution for the integrating spheres with an optimum coefficient of reflectance will be presented as a compromise between the sensitivity of the sphere to contamination and aging and the directional dependence during the measurement. It will be shown, that prior stabilisation of the lamp and the correction of its self-absorption are crucial for the measurements of SSL light sources in the middle of integrating sphere (4 π). Large lamps with forward directed light should be measured on the side port of the sphere in the 2 π geometry due to large self-absorption when placed at the sphere centre.
Becker M.E.,Instrument Systems GmbH |
Neumeier J.,Instrument Systems GmbH
Digest of Technical Papers - SID International Symposium | Year: 2014
This contribution introduces a first implementation of the measurement setup according to IEC 62341-6-2 for evaluation of the effect of ambient illumination on OLED display contrast and chromaticity. A sampling sphere is providing hemispherical diffuse illumination, with and without specular components, in the d/8-geometry, and a point-light source is providing directional illumination. From the spectral reflectance factors thus obtained contrast and chromaticity for arbitrary illuminants (i.e. spectra) and illuminance levels can easily be calculated. © 2014 Society for Information Display.
Becker M.E.,Instrument Systems GmbH
Digest of Technical Papers - SID International Symposium | Year: 2015
This paper provides art introduction to recent activities and achievements of three standardization organizations, CIE (Commission Internationale de VEclairage), IEC (International Electrotechnical Commission) and ISO (International Organization for Standardization), insofar as they are relevant to display metrology and, more generally, to measurement of light. The status quo is summarized in this contribution and plans and schedules are presented. © 2015 SID.