JOURNAL OF THE ILLUMINATING ENGINEERING INSTITUTE OF JAPAN
Online ISSN : 1349-838X
Print ISSN : 0019-2341
ISSN-L : 0019-2341
Volume 81, Issue 11
Displaying 1-10 of 10 articles from this issue
  • Equation for “Fukami” Prediction in Low Value Chromatic Color
    Shigeo Ohagi, Yoshihiko Hazama, Takeshi Nishimura
    1997 Volume 81 Issue 11 Pages 947-957
    Published: November 01, 1997
    Released on J-STAGE: July 19, 2011
    JOURNAL FREE ACCESS
    One of the important characteristic appearances of colored materials is “Fukami” sensation (Similar but identical to depth sensation). Usually its sensation is recognized as a very important property for colored materials. But there is no scale for evaluating it.
    In this paper, we examine the relationship between “Fukami” and the color attributes of colored materials.
    First, we carried out a subjective evaluation by paired comparison with colored chips to examine the contribution of three attributes to “Fukami”, and to make the “Fukami” scale (Fukami). The test colors, in the experiment, were limited to low values and chromatic color areas where we presume that many people strongly sense “Fukami” in general.
    We found that “Fukami” is related to the decrease in value and chroma, and also depends on the difference of hue.
    Next, we formulated an equation for “Fukami” prediction of the object color based on this direction.
    Fukami (1) cal=F0+Asin {3.6 (ΔH10RP-10H0)}
    This equation consists of two terms. F0 gives the “Fukami” based on the position of the certain hue circle V/C Group, which has equal value and equal chroma. Asin {3.6 (ΔH10RP-10H0)} gives the amount of “Fukami” variation depending on hue in the V/C Group. F0, A, Ho are the parameters calculated from the three attributes. Except for hue Y, this equation is accurate enough in the experiment color area.
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  • part 1: Various Artificial Skies in the World
    Masaaki Okado, Hiroshi Nakamura, Yasuko Koga, Koichi Goto, Shun'ichi F ...
    1997 Volume 81 Issue 11 Pages 958-966
    Published: November 01, 1997
    Released on J-STAGE: July 19, 2011
    JOURNAL FREE ACCESS
    Daylighting is fundamental and essential in constructing a comfortable interior environment in architectural space.
    Research work on daylight and daylighting designs are often carried out applying scale models which is an important technique for the prediction of daylit interior spaces.
    Artificial skies can be used to reproduce sky luminance distribution through artificial light sources. They are the most effective and useful in the evaluation of daylit environments with scale models. As a result, a number of artificial skies have been constructed at various research organizations throughout the world in the last half a century.
    A new artificial sky was intended to be developed and constructed by the authors. The artificial skies already constructed throughout the world are being surveyed, for the planning of the new facility. These artificial skies can be roughly classified into four categories as follows: 1. Mirror type, 2. Reflection type, 3. Translucent type, and 4. Direct type.
    After a survey and comparison of the performance of these types of artificial skies, the concept of a new artificial sky will be established.
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  • Shigeaki Wada, Makoto Toho
    1997 Volume 81 Issue 11 Pages 968-973
    Published: November 01, 1997
    Released on J-STAGE: July 19, 2011
    JOURNAL FREE ACCESS
    The speckle phenomenon, which is discoloration on the inner surface of a lamp tube, sometimes appears in rapid-start fluorescent lamps with internal starting aids. There is a great deal of patent literature on methods of preventing this phenomenon but most of it is experimental or fragmentary. We analyzed this phenomenon by numerical analysis with a computer and were able to gain a comprehensive understanding of the mechanism of its occurrence and were able to obtain ideas on how to prevent it.
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  • Toshihiko Ishigami
    1997 Volume 81 Issue 11 Pages 975-982
    Published: November 01, 1997
    Released on J-STAGE: July 19, 2011
    JOURNAL FREE ACCESS
    This paper presents considerations on thermodynamic calculations for four lamp phenomena of HID lamps.
    The first phenomenon is the reactions of Sc or Sc iodide with silica. The standard free energy changes of the reactions associated with Sc2O3 and Sc2Si2O, formations were calculated. Using these calculation results, the Sc analysis result of the experimental lamp was considered.
    The second phenomenon is Na reactions with alumina in a high-pressure sodium lamp. The standard free energy changes of the reactions associated with NaAlO2 and β-alumina formations were calculated. The reacting areas for gaseous Na reactions with alumina were defined.
    The third phenomenon is tungsten transport from the electrodes to the lamp wall in an Fe iodide lamp. By comparing the calculated gaseous Fe pressure with Fe vapor pressure at the electrode temperature region, the formation of the W-Fe alloy which has a low melting point can be explained.
    The last phenomenon is the chemical reactivity of metal elements with silica. Using the standard free energy formation data for fifty metal oxides, the standard free energy changes of the reactions of fifty metal elements with silica were calculated. From these results fifty metal elements were classified according to the probability of their reaction with silica.
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  • Measurement and Reconstitution of Spectral Distribution
    Kazuhisa Kobayashi, Takao Ikemori, Genro Kawakami
    1997 Volume 81 Issue 11 Pages 983-989
    Published: November 01, 1997
    Released on J-STAGE: July 19, 2011
    JOURNAL FREE ACCESS
    The spectral distribution of daylight can be reconstituted by using the characteristic vector analysis, as described by Judd et al in 1964. In the ultraviolet range, however, the spectral distribution reconstituted with this method is more or less different from that of actual daylight, since it is difficult to conjecture the spectral distribution in the ultraviolet range using the scalar multipliers as a function of chromaticity coordinates (x, y). To obtain a reconstituted spectral distribution closer to the actual one, the scalar multipliers were used as a function of the correlated color temperature and chromaticity deviation from the typical chromaticity locus. As a result, the spectral distribution thus reconstituted was closer to that of actual daylight than through Judd et al's method.
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  • Ryoji Yoshitake
    1997 Volume 81 Issue 11 Pages 991-1003
    Published: November 01, 1997
    Released on J-STAGE: July 19, 2011
    JOURNAL FREE ACCESS
    To improve the image quality of thin film transistor liquid crystal displays (TFT/LCDs), we performed photometric measurements and subjective evaluations on nine kinds of TFT/LCDs with different physical characteristics. The photometric measurements evaluated reflection characteristics, luminance contrast, gamma curve, primary color points, white points, luminance/color uniformity and effects of viewing angle. The subjective evaluations consisted of two sessions.
    In the first session, basic patterns such as all-pixels-on were presented and basic feelings such as sharpness of reflected images and color saturation were collected by the Scheffe's paired comparison method. At the other session, seven kinds of general patterns such as an MS-windows desktop and natural images were displayed, and distinctive features of the image quality of each display were summarized.
    It was found that the feelings when the basic patterns were displayed corresponded with the results of photometric measurements. Although it was difficult to estimate image qualities of general patterns from the measured photometric characteristics, white point was found to be one of the most important factors affecting image quality of TFT/LCDs among the above-mentioned characteristics.
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  • Mitsuo Ikeda, Hiroyuki Shinoda, Tomohiro Uchida
    1997 Volume 81 Issue 11 Pages 1004-1009
    Published: November 01, 1997
    Released on J-STAGE: July 19, 2011
    JOURNAL FREE ACCESS
    When a test patch is locally illuminated by, for example, a slide projector, so that its luminance is much higher than those of other objects in a scene illuminated with a main lighting source, the appearance of the patch is perceived as unnaturally bright and the situation is expressed as the appearance being out of the Recognized Visual Space of Illumination (RVSI) of the scene. If the illuminance of the scene is gradually increased, the appearance of the patch shifts into the RVSI and becomes natural. The shifting limit was obtained for two different patches, N4.0 and 5YR4/8 placed among objects in a room simulating a study, when the illuminance of the room was increased. Determining the limit was quite easy even for naive subjects. It was suggested that the limit was reached when the subjective lightness of the test patch became nearly 100, when the subjective lightness was calculated by the CIE L* in which Y0 is replaced by the illuminance of the brightest object in the scene.
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  • Toshihiko Ishigami
    1997 Volume 81 Issue 11 Pages 1010-1017
    Published: November 01, 1997
    Released on J-STAGE: July 19, 2011
    JOURNAL FREE ACCESS
    A simulation model for a ScI3-NaI metal halide lamp based upon an energy balance equation has been investigated.
    The radiations of this lamp are composed of three radiations from Na, Sc and Hg.
    Starting from the calculation of partial pressure distributions of the existing gases in the arc tube, several material functions of the plasma were calculated.
    Arc temperature distributions of lamps were calculated by solving the energy balance equation making use of the above material functions. In these calculations Na and Hg radiations were treated asoptical thick and Sc radiation was treated as optical thin.
    Calculated spectral characteristics (general color rendering index and correlated color temperature) for two lamps whose NaI to ScI3 filling weight ratios were 2 and 7 over the lamp coldest spot temperature range of 500-800°C agreed with experimental results. The calculated tendency of the spectral characteristics dependence on the lamp coldest spot temperature was in comparatively good agreement with the experimental one.
    More extensive plasma data refinements are necessary to obtain better agreement with experimental results.
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  • Solid Perception by Shading
    Naoyoshi NAMEDA
    1997 Volume 81 Issue 11 Pages 1018-1021
    Published: November 01, 1997
    Released on J-STAGE: July 19, 2011
    JOURNAL FREE ACCESS
    Recently, aged persons who are laid up with illness have increased in our country. They have to observe TV while lying on a bed.
    This report concerns image recognition by a people lying on a bed. It describes in details how an impression of solidity induced by shading can be given to observers in a horizontal posture, and those in a vertical posture. The pattern used in this experiment was a pattern whose induced solid shape was reversed when the pattern was rotated by 180 degrees. This phenomenon is already well known. It is said that human beings are imprinted psychologically with a bias to assume that illumination is from above. When people observe a bright and dark pattern whose illuminating direction is unknown, they recognize a convex or concave shape, analyzing the pattern as lighted from above. Human beings also detect the vertical by mean of a mechanism in the ear sensitive to gravity. These two cues were investigated in this experiment which measured the depth induced from the pattern by observation in vertical and horizontal postures.In the discussion, it is confirmed that the perceived solid shape is almost the same as the shape calculated by applying the illuminating engineering technique to the center line of the pattern in a vertical direction. From this experiment, it is suggested that a person lying on a bed observes a picture (for example a TV picture) vividly, when the picture is inclined slightly.
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  • Masayoshi Kawai, Keiji Uchikawa, Genro Kawakami
    1997 Volume 81 Issue 11 Pages 1022-1026
    Published: November 01, 1997
    Released on J-STAGE: July 19, 2011
    JOURNAL FREE ACCESS
    Reaction time to search for a colored target among some colored distracters was measured. The number of distracters was varied in six steps. Two methods of presenting stimuli fixed area and fixed density were compared. There was no significant difference between these two methods. There was also no difference when the target color was exchanged with the distracter color. When the color difference between target and distracter colors was small, the reaction time increased with increasing number of distracters. This searching function could be approximated using a monotonically increasing function. On the other hand when the color difference was large, there was no influence from the number of distracters. The reaction time remained short. This searching function was approximated using a linear function with zero slopes. The present study on the effect of color difference suggests that a mechanism other than the color discrimination mechanism would contribute to a visual search for a colored target.
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