JOURNAL OF THE ILLUMINATING ENGINEERING INSTITUTE OF JAPAN
Online ISSN : 1349-838X
Print ISSN : 0019-2341
ISSN-L : 0019-2341
Volume 74 , Issue 2
Showing 1-7 articles out of 7 articles from the selected issue
  • Tomohiko Hattori
    1990 Volume 74 Issue 2 Pages 67-71
    Published: February 01, 1990
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    A new US imaging system of “Real time 3-D echograph” for the medical application is described in this paper. It is theoretically explained that characteristics of transformation from an acoustic distribution to a light intensity one.
    The approximate analytic formula of this characteristics is compared with the experimental data that a light intensity was directly proportional to an amplitude of vibration concerning transformation from an acoustic distribution to a light intensity one.
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  • Tamaki Yaji, Yasuo Nakagawa, Fumio Ohtani, Yoshitaka Kodama, Kazuaki O ...
    1990 Volume 74 Issue 2 Pages 72-79
    Published: February 01, 1990
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    An infrared irradiance meter with a pyroelectric detector, which is an instrument to estimate a heater, an luminaire utilizing infrared radiation and a lighting system, has been developed. Its characteristics are as follows:(1) it is compact and portable, (2) it is hardly influenced by a change of temperature and a vibration, (3) it has an approximate flat spectral responsivity in wide infrared region, (4) the detectivity is better than 1mW/cm2, (5) the response time is 0.7 sec. Actually infrared radiation of several radiation sources are measured by the fabricated instrument, it is recognized that the instrument is very useful for the measurement of infrared radiation. Finally, it is discussed that the absorptions of air and the detector window influence the response of the instrument, and then the correcting expression for the absorptions is derived.
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  • Sadao Sawada, Yosuke Sakai, Hiroaki Tagashira, Kastuya Ohtani
    1990 Volume 74 Issue 2 Pages 80-87
    Published: February 01, 1990
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    The electron swarm parameters in Hg/Ar and Hg/Ar: 0.1%H2 mixtures are analyzed using a Boltzmann equation in which the generation of secondary electrons through Penning and cumulative ionization, and collisions between two metastable Hg (Hg*) atoms are taken properly into consideration. The present values of the Townsend first ionization coefficient and the concentration of Hg* agree well with the experimental values of Burgumann et al and Bigio respectively. It is shown that mixing 0.1%H2 in Hg/Ar lowers the ionization coefficient significantly. This lowering effect is discussed how it influences the characteristics of discharge lamps.
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  • Minoru Isomura, Motomi Yamauchi
    1990 Volume 74 Issue 2 Pages 88-95
    Published: February 01, 1990
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    One of the important aspects of an interior lighting environment is the determination of the illuminance distribution on the working plane.
    The calculation of luminous flux transfer in a space bounded by uniform diffused surfaces are based on an assumption that the space between the plane of the luminaires and the working plane is empty.
    In reality most interiors contain objects such as screens, bookcases or partitions which project above the working plane.
    This paper describes the effect of room fixtures on the total illuminance distribution on working plane in a room by using the conventional calculation.
    Furthermore, the paper calculated the direct illuminance and the interreflected illuminance incident on working plane in a room, and discribe the effect of room fixtures on the those results.
    This paper presents on approximate calculation of the total illuminance on working plane in a room containing fixtures.
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  • Kenjiro Hashimoto, Yoshinobu Nayatani
    1990 Volume 74 Issue 2 Pages 96-101
    Published: February 01, 1990
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    We had already found that the change in “brightness sensation” of object colors by changing the color-rendering properties of light sources was closely related to that in affection of contrast of object colors.
    In order to establish the estimation method for “brightnessensation” based on “affection of contrast”, in the present study, we analyzed the following two points. One is to clarify two-color combinations that can be most effectively estimated for the affection of contrast under various illuminants. The other is to clarify the predicting method of the illuminance value for the equal affection of contrast under various illuminants. The subjective estimation and computed analysis on affection of contrast under some illuminants were done.
    The results are as follows.(1) The change of the affection of contrast under the illumination can be most effectively estimated by using the two-color combinations, one of which has high saturated red.(2) The affection of contrast of two-color combinations under the illumination can be estimated appropriately based on the brightness and colorfulness of each component color of two-color combinations.(3) The illuminance value for the equal affection of contrast can be predicted by using the predicting equations for evaluating the affection of contrast of two-color combinations and chromatic adaptation transformation derived by Nayatani et. al.
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  • Yoshihiko Tabuchi, Koji Mastushima, Hajimu Nakamura
    1990 Volume 74 Issue 2 Pages 102-108
    Published: February 01, 1990
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    A subjective appraisal of the effects of reflected images of dispersed small sources on the readability of characters on the display screen with a specular surface was previously reported in 1987.
    It was suggested that the luminous pattern of the external light source reflected on the screen also has a major effect on display readability. If a reflected image is separated into many pieces with a non-luminous grid and every piece is small compared with a displayed letter, they might overlap on the letters randomly, then the letters would be recognized to be different ones, and readability of them would be disturbed.
    On the other hand, if reflected image is relatively large and continuous compared with a letter, interference of the image to readability of letters might be reduced.
    Therefore, influence of luminous pattern of the reflected source such as size and arrangement on a permissible luminance of them was studied. One large continuous source and many dispersed small ones are compared.
    The results are as follows:
    Permissible luminance for reflected images of relatively large-area source is slightly higher than that for many dispersed small sources.
    However, in actual lighting designs, this is not so significant as to cause a change of the permissible luminance for light sources of various size and arrangement.
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  • Tatsuya Saito
    1990 Volume 74 Issue 2 Pages 109-112
    Published: February 01, 1990
    Released: July 19, 2011
    JOURNALS FREE ACCESS
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