JOURNAL OF THE ILLUMINATING ENGINEERING INSTITUTE OF JAPAN
Online ISSN : 1349-838X
Print ISSN : 0019-2341
ISSN-L : 0019-2341
Volume 88, Issue 2
Displaying 1-6 of 6 articles from this issue
Papers
  • Yoshio Watanabe, Taku Karita
    Article type: Others
    Subject area: Others
    2004 Volume 88 Issue 2 Pages 71-76
    Published: 2004
    Released on J-STAGE: December 07, 2004
    JOURNAL FREE ACCESS
    A composite rectifier circuit for a partially smoothing circuit and a voltage doubler rectifier circuit is proposed. The proposed rectifier circuit has the same smoothing output voltage characteristics as the partially smoothing circuit, but its input characteristics are greatly improved: The total capacity of the three capacitors in the composite circuit is reduced by 37%, even though one more dc-capacitor is needed. The crest factor of the input current is reduced from 2.25 to 1.36. The input power factor is increased from 0.948 to 0.969. The relative harmonics content rate is reduced from 32.2% to 12.7%. The rush current produced at power switch ON is effectively suppressed since the small capacitance is available to the input capacitor.
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  • —Brightness Prediction Based on Luminance Contrast Part 1—
    Yoshiki Nakamura, Kotoku Egawa
    Article type: Others
    Subject area: Others
    2004 Volume 88 Issue 2 Pages 77-84
    Published: 2004
    Released on J-STAGE: December 07, 2004
    JOURNAL FREE ACCESS
    An experiment was conducted with three experimental variables of target luminance, target size, and background luminance to predict brightness perception of a circular target with a uniform background. Brightness estimates obtained in the experiment were examined with those of previous studies, and were shown to be highly correlated with the results of those studies. A further analysis of the results showed brightness estimates can be predicted by adding the estimates of target luminance to those of simultaneous contrast. A brightness prediction formula composed of target luminance, target size, and background luminance was described.
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Research Note
  • Masafumi Suzuki, Kohzou Akazawa, Noboru Yoshimura
    Article type: Others
    Subject area: Others
    2004 Volume 88 Issue 2 Pages 85-90
    Published: 2004
    Released on J-STAGE: December 07, 2004
    JOURNAL FREE ACCESS
    Luminous intensity distribution of luminaires with specular reflectors was studied. Specular reflectors have high reflectance compared with diffuse reflectors, therefore it is possible to conserve energy by raising instrument efficiency. It is also possible to obtain the specific light distribution characteristics by optimizing the shape of the reflector. Therefore, it is necessary to understand the relationship between the shape of the reflector and the light distribution characteristics. In this study, the luminous intensity distribution of the luminaires with specular reflectors was calculated by a Monte Carlo method.
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