Person: Álvarez Fernández-Balbuena, Antonio
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First Name
Antonio
Last Name
Álvarez Fernández-Balbuena
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Óptica
Area
Optica
Identifiers
18 results
Search Results
Now showing 1 - 10 of 18
Item Horizontal daylighting system for office buildings(Energy and Buildings, 2013) Vázquez Molini, Daniel; González Montes, Mario; Álvarez Fernández-Balbuena, AntonioThis work is focused on a sunlight collection device for solar lighting systems aimed at non-residential buildings. The design takes advantage of solar energy that reaches the facade of the building for lighting purposes, thereby reducing building energy consumption by supplementing it with clean, renewable energy. This daylighting system's structure comprises a light collector located outside the vertical facade of the building, a modular light guide that runs along the horizontal false ceiling and light extractor luminaires strategically positioned along the guide. The system is configured specifically to the particular characteristics of each building (façade orientation, latitude and longitude) to optimize the global performance. The present paper describes in detail the anidolic collecting system as a part of the comprehensive daylighting system. However the entire daylighting system has been completely developed and experimentally tested, and its prototype is currently integrated into Lledó S.A company's facilities.Item Iluminar obras de arte mejorando la conservación. El proyecto Zeus(2015) Benítez, Anton J.; Vázquez Moliní, Daniel; Álvarez Fernández-Balbuena, AntonioLa iluminación de obras de arte se enfrenta al reto de resultar adecuada para la exhibición y de minimizar en lo posible los daños a la superficie y los materiales que las componen. En esta encrucijada, en la que la investigación es imprescindible tanto en tecnología como acerca de la recepción por parte del público, el proyecto Zeus trata de obtener una precisa información sobre el color de la obra, y trasladarla a un modelo de iluminación individualizado punto a punto, que permite simular condiciones precisas y compensar efectos indeseables del deterioro, minimizando la luz absorbida por la obra.Item Smooth light extraction in lighting optical fibre(Illumination Optics II, 2011) Álvarez Fernández-Balbuena, Antonio; Vázquez Molini, Daniel; García Botella, Ángel; Martínez Antón, Juan Carlos; Bernabeu Martínez, Eusebio; Kidger, Tina E.; David, StuartRecent advances in LED technology have relegated the use of optical fibre for general lighting, but there are several applications where it can be used as scanners lighting systems, daylight, cultural heritage lighting, sensors, explosion risky spaces, etc. Nowadays the use of high intensity LED to inject light in optical fibre increases the possibility of conjugate fibre + LED for lighting applications. New optical fibres of plastic materials, high core diameter up to 12.6 mm transmit light with little attenuation in the visible spectrum but there is no an efficient and controlled way to extract the light during the fibre path. Side extracting fibres extracts all the light on 2π angle so is not well suited for controlled lighting. In this paper we present an extraction system for mono-filament optical fibre which provides efficient and controlled light distribution. These lighting parameters can be controlled with an algorithm that set the position, depth and shape of the optical extraction system. The extraction system works by total internal reflection in the core of the fibre with high efficiency and low cost. A 10 m length prototype is made with 45° sectional cuts in the fibre core as extraction system. The system is tested with a 1W white LED illuminator in one side.Item Application of dynamic merit function to nonimaging systems optimization(Optical Engineering, 2015) Álvarez Fernández-Balbuena, Antonio; González Montes, Mario; García Botella, Ángel; Vázquez Moliní, DanielAutomatic optimization algorithms have been recently introduced as nonimaging optics design techniques. Unlike optimization of imaging systems, nonsequential ray tracing simulations and complex noncentered systems design must be considered, adding complexity to the problem. The merit function is a key element in the automatic optimization algorithm; nevertheless, the selection of each objective’s weight, {wi}{wi}, inside the merit function needs a prior trial and error process for each optimization. The problem then is to determine appropriate weights’ values for each objective. We propose a new dynamic merit function with variable weight factors {wi(n)}{wi(n)}. The proposed algorithm automatically adapts weight factors during the evolution of the optimization process. This dynamic merit function avoids the previous trial and error procedure by selecting the right merit function and provides better results than conventional merit functions.Item Optics detailed analysis of an improved collimation system for LED light sources(Illumination Optics II, 2011) González Montes, Mario; Vázquez Molini, Daniel; Álvarez Fernández-Balbuena, Antonio; García Botella, Ángel; Bernabeu Martínez, Eusebio; Kidger, Tina E.; David, StuartThroughout present study will be discusses the influence of the manufacturing margins, adjustment precision and ray model accuracy of a collimating LED unit in the overall system performance. It will be also analyzed the angular performance and the collimated in relation to the relative position of the LED and the collimator's dimensions. Finally the results will be compared with existing publications in this field.Item Spectral damage model for lighted museum paintings: Oil, acrylic and gouache(Journal of Cultural Heritage, 2016) Mayorga Pinilla, Santiago; Vázquez Moliní, Daniel; Álvarez Fernández-Balbuena, Antonio; Muro, Carmen; Muñóz, JavierA spectral aging test was developed to estimate the photochemical damage of oil, acrylic and gouache paints exposed to permanent lighting. The paints were irradiated at seven different wavelengths in the optical range to control and evaluate their spectral behaviour. To reach this objective, boxes with isolated aging cells were made. In each of box, one LED of a different wavelength and one photodiode were installed. Inside the boxes, the temperature of an exhibit area was recreated through a thermocouple sensor that controlled the temperature using a fan. The heat produced by the LED was dissipated by a thermal radiator. Moreover, to evaluate the exposure time dependence of the irradiation level, the test was performed using two different irradiation levels in ten exposure series. After each series, the spectral reflectance was measured, and the data collected for each paint and wavelength were used to develop a model of damage produced by the interaction between the spectral radiant exposure and the paint.Item Hyperparabolic concentrators(Applied Optics, 2009) García Botella, Ángel; Álvarez Fernández-Balbuena, Antonio; Vázquez Molini, Daniel; Bernabeu Martínez, Eusebio; González Cano, AgustínWe present a family of three-dimensional concentrators constructed from the photic field generated by a Lambertian emitter. The profile of these concentrators is obtained from the field lines for a two-dimensional truncated wedge and is based on the union between a hyperbola and a tilted parabola. By revolution of this profile, we obtain hyperparabolic concentrators (HPCs). In the limiting case when the focal length of the hyperbola becomes the radius of the exit aperture, the HPC becomes the well-known compound parabolic concentrator. On the other hand, when the focal length of the hyperbola becomes infinite, the HPC achieves the thermodynamic limit of concentration.Item Improved and customized secondary optics for photo-voltaic concentrators(Proceedings of SPIE, Nonimaging Optics: Efficient Design for Illumination and Solar Concentration XII, 2015) Vázquez Molini, Daniel; Álvarez Fernández-Balbuena, Antonio; García Botella, Ángel; Alda, JavierIn this contribution the line flow method is applied to an optimized secondary optics in a photovoltaic concentration system where the primary optics is already defined and characterized. This method is a particular application of photic field theory. This method uses the parameterization of a given primary optics, including actual tolerances of the manufacturing process. The design of the secondary optics is constrained by the selection of primary optics and maximizes the concentration at a previously specified collection area. The geometry of the secondary element is calculated by using a virtual source, which sends light in a first concentration step. This allows us to calculate the line flow for this specific case. This concept allows designing more compact and efficient secondary optics of photovoltaic systems.Item Ideal 3D asymmetric concentrator(Solar Energy, 2009) García Botella, Ángel; Álvarez Fernández-Balbuena, Antonio; Vázquez Moliní, Daniel; Bernabeu Martínez, EusebioNonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used for producing reflective and refractive optical devices, including reverse engineering techniques. In this paper we apply photometric field theory and elliptic ray bundles method to study 3D asymmetric – without rotational or translational symmetry – concentrators, which can be useful components for nontracking solar applications. We study the one-sheet hyperbolic concentrator and we demonstrate its behaviour as ideal 3D asymmetric concentrator.Item Louvers design for LED displays for sunny days(Displays, 2007) Vázquez Moliní, Daniel; Álvarez Fernández-Balbuena, Antonio; Alda Serrano, Javier; Bernabeu Martínez, EusebioThe use of louvers attached to variable information display needs to be optimized taking into account different intrinsic and extrinsic parameters. The analysis of the performance of the display–louvers system takes into account the location, orientation, and daily and seasonal variations. The observation of the system is divided depending on the distance of observation. The far distance vision performance use the background luminance. The medium distance performance needs the use of the Contrast Sensitivity Function of the eye.