Journal of Light & Visual Environment
Online ISSN : 1349-8398
Print ISSN : 0387-8805
ISSN-L : 0387-8805
Search
Advanced search
OR
Browse
Search
Volume 37, Issue 2_3
Displaying 1-14 of 14 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Foreword
Special Reviews
  • New Benefit Metrics for More Valuable Lighting
    Mark S. Rea
    Article type: Special Review
    2013 Volume 37 Issue 2_3 Pages 41-45
    Published: December 01, 2013
    Released on J-STAGE: January 28, 2014
    Advance online publication: November 07, 2013
    DOIhttps://doi.org/10.2150/jlve.IEIJ130000498
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Lighting is installed for the benefits of seeing. Lighting manufacturers and regulators primarily focus on two formal metrics for providing these benefits, the lumen and color rendering index (CRI). These two metrics represent only a small fraction of the benefits that actually can be provided by lighting. Because many of the benefits provided by lighting remain unmeasured, current lighting practice wastes capital and operational expenses as well as our natural resources. By accepting and promulgating new benefit metrics, lighting will become less wasteful and thereby more valuable.
    View full abstract
    Download PDF (329K)
  • Class A Color Designation for Light Sources Used in General Illumination
    Jean Paul Freyssinier, Mark S. Rea
    Article type: Special Review
    2013 Volume 37 Issue 2_3 Pages 46-50
    Published: December 01, 2013
    Released on J-STAGE: January 28, 2014
    Advance online publication: November 07, 2013
    DOIhttps://doi.org/10.2150/jlve.IEIJ130000501
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Solid state lighting has reignited interest among lighting specialists and manufacturers in the color qualities of illumination used in architectural applications. This renewed interest has highlighted the known problems with the two currently accepted metrics used by the lighting industry to communicate the color qualities of sources of illumination, correlated color temperature (CCT) and color rendering index (CRI). These two metrics are poor predictors of viewer responses to the color characteristics of illumination and both metrics are poorly understood among consumers. The proposed “Class A color” designation serves two important purposes for helping to move the consumer market toward a broader acceptance of solid state lighting. First, the “Class A color” designation reflects bundled metrics shown to be predictive of user acceptance of color attributes from sources of illumination and, second, the designation can be readily understood by consumers as denoting light sources of high color quality.
    View full abstract
    Download PDF (478K)
  • An Overview of the Effects of Light on Human Circadian Rhythms: Implications for New Light Sources and Lighting Systems Design
    Mariana G. Figueiro
    Article type: Review
    2013 Volume 37 Issue 2_3 Pages 51-61
    Published: December 01, 2013
    Released on J-STAGE: January 28, 2014
    Advance online publication: November 07, 2013
    DOIhttps://doi.org/10.2150/jlve.IEIJ130000503
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Circadian rhythms are seen at every level of biology, from single cells to complex behaviors. The timing of every biological function in mammals is governed by the master clock in the suprachiasmatic nuclei (SCN), which has an intrinsic period of slightly longer than 24 hours. The light/dark pattern incident on the retina synchronizes the SCN to the 24-hour local time, coordinating and enabling diverse biological functions to occur at the correct time of day and night for optimum species survival. Without exposure to a regular, daily pattern of light and dark, circadian rhythms become disrupted. A wide range of modern maladies, from sleep disorders to cancer, has been linked to light-induced circadian disruption. Light has, however, been defined only in terms of the human visual system, not the circadian system. Light source and systems development should consider the needs of both the visual and non-visual systems. Discussed are the lighting characteristics impacting these two systems and the implications for designing light for various healthcare and medical applications.
    View full abstract
    Download PDF (2411K)
Papers
Technical Trend
  • Technological Strategy of Solid State Lighting
    Katsumi Sato, Shin Ukegawa, Katsumasa Nakai
    Article type: Technical Trend
    2013 Volume 37 Issue 2_3 Pages 89-91
    Published: December 01, 2013
    Released on J-STAGE: January 28, 2014
    Advance online publication: October 07, 2013
    DOIhttps://doi.org/10.2150/jlve.IEIJ130000500
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Recent advances in solid-state lighting technologies are causing major changes in the lighting industry worldwide. In other words, Lighting is in the midst of one of its most revolutionary and complex change not seen since Thomas Edison's light bulb. Speedy and dynamic decisions are required in the Lighting R&D. Panasonic R & D direction is the integration of comfort and ecology with customer satisfaction. The Quality of Light and the Energy Saving technologies are the two important keywords to realize comfort and ecology. The technological strategy and the products to achieve such objectives are discussed in this paper.
    View full abstract
    Download PDF (1923K)
Research Note
  • Modulation Scheme for Dimming High-Brightness LED Lamps
    Christian Brañas, Francisco J. Azcondo, Rosario Casanueva
    Article type: Research Note
    2013 Volume 37 Issue 2_3 Pages 92-94
    Published: December 01, 2013
    Released on J-STAGE: January 28, 2014
    DOIhttps://doi.org/10.2150/jlve.IEIJ130000506
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    This paper presents a phase-controlled two-phase resonant converter as a highly flexible platform for evaluating different modulation patterns of the operating current for high-brightness light emitting diode (LED) lamps. This control flexibility arises from the wide bandwidth of the resonant converter ensuring an operation free of instabilities and flicker effects. The control parameter is the phase-shift, Ψ, between the drive signals of each inverter leg. The proposed driver is designed as a current source able to set different patterns of amplitude modulated (AM) output current to implement light dimming controls. A 120 W prototype has been built to validate the design proposal.
    View full abstract
    Download PDF (505K)
Paper
  • Incoherentized High-brightness White Light Generated Using Blue Laser Diodes and Phosphors—Effect of Multiple Scattering—
    Yoshihisa Ikeda, Yuji Takeda, Misaki Ueno, Yoshiaki Matsuba, Atsushi H ...
    Article type: Paper
    2013 Volume 37 Issue 2_3 Pages 95-100
    Published: December 01, 2013
    Released on J-STAGE: January 28, 2014
    DOIhttps://doi.org/10.2150/jlve.IEIJ130000499
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    A new type of 4000–5000 lm-class white lamp system using high-power blue laser diodes and phosphors has been developed for high-luminance lighting applications. Using fibre-optics, the lamps can be arranged separately from a light engine containing the blue laser diodes. One of the new lamp systems achieved much higher luminance of 140 Mcd/m2 than the conventional white LEDs. Their lighting quality and safety categorization have been discussed based on speckle contrast as an index of coherence. Speckle contrast values less than 2% as low as the LEDs have been obtained, implying that these lamps are considered to be incoherent as well as the conventional white LEDs. Multiple scattering processes in the lamp structure including the phosphor layer are found to be indispensable for reducing speckle contrast completely, adding to multi-longitudinal mode operation of the blue laser diodes.
    View full abstract
    Download PDF (1730K)
Research Note
  • The Experiments Giving Illuminations to the Street by Residents Participation
    Shigeo Kobayashi, Kazutaka Murakawa
    Article type: Research Note
    2013 Volume 37 Issue 2_3 Pages 101-105
    Published: December 01, 2013
    Released on J-STAGE: January 28, 2014
    Advance online publication: August 13, 2013
    DOIhttps://doi.org/10.2150/jlve.IEIJ120000491
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    This research attempted to create a lighting environment of a street by residents and carried out two experiments. The first experiment was to run a workshop in which children from the neighborhood added illuminations to a 1/25 model of the street. As a result, lights were installed taking account of the types and characteristics of the buildings and the street, and an original lighting environment that the existing concept did not have was created. The next experiment involved holding an event in which handmade lights were placed on the actual street. Using LED lamps with switches, children and adults from the neighborhood made lighting products, attached magnets to them, and stuck them on shutters, guardrails, signboards, vending machines, etc. The individual landscape was produced by residents. The psychological effect and social value to the area were confirmed through the interviews.
    View full abstract
    Download PDF (9801K)
Papers
  • Lighting Control Systems and End-users—Establishing an Interactive Relationship
    Amardeep M Dugar
    Article type: Paper
    2013 Volume 37 Issue 2_3 Pages 106-113
    Published: December 01, 2013
    Released on J-STAGE: January 28, 2014
    Advance online publication: August 13, 2013
    DOIhttps://doi.org/10.2150/jlve.IEIJ120000474
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    This paper aims to identify end-user requirements that help improve the effectiveness of lighting control systems. The crucial question posed is, what is the nature of interface designs sought by end-users for maximising interaction with lighting control systems? Literatures from the most influential studies on interactive systems are reviewed to list end-user requirements in the order of three stages of human interface with technology: Recognition, Exploration and Reliance. Results of two interactive studies with end-users are then reviewed to validate this list of requirements. The objective is to provide perspectives and themes for analysis, as well as conceptual guidance for designing lighting control interfaces that are easier to understand and use for end-users.
    View full abstract
    Download PDF (3766K)
  • Color Image Correction of Art Paintings Based on Artists' Color Features and Illuminant Conversion
    Yoshie Imai, Ryoichi Saito, Takahiko Horiuchi, Shoji Tominaga
    Article type: Paper
    2013 Volume 37 Issue 2_3 Pages 114-125
    Published: December 01, 2013
    Released on J-STAGE: January 28, 2014
    Advance online publication: September 27, 2013
    DOIhttps://doi.org/10.2150/jlve.IEIJ120000489
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    This paper proposes a method to correct the color-mismatch images of paintings based on artists' color features, and reproduce the exact color images under a specific illumination condition. First, we describe a standard image database consisting of oil paintings and an algorithm for extracting artists' color features. The color distribution is analyzed by PCA and described with an ellipsoid to represent the standard color features. Next, the color correction is based on the coordinate transformation of pixel values in a color-mismatch image so that the color features are fitted to the artist's color features. We present the correction algorithms using two color spaces of the sRGB and the CIELAB. Moreover, we describe a procedure for rendering the exact color images under a favorite illuminant. The correlated color temperature of scene illuminant is estimated and the color image under D65 is further transformed to a target image. The feasibility of the proposed method to recover the exact color images is examined with color-mismatch image samples of famous oil paintings.
    View full abstract
    Download PDF (11334K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top