JOURNAL OF THE ILLUMINATING ENGINEERING INSTITUTE OF JAPAN
Online ISSN : 1349-838X
Print ISSN : 0019-2341
ISSN-L : 0019-2341
Volume 78 , Issue 6
Showing 1-12 articles out of 12 articles from the selected issue
  • Yoshiro Aoki, Tetsuo Taniguchi, Takashi Irikura
    1994 Volume 78 Issue 6 Pages 243-247
    Published: June 01, 1994
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    A computer program was developed to simulate surface movement of aircraft in an airport. This program can automatically select the shortest route, taking account of the delay caused by the approach between aircraft. The following results were clarified by the use of the program:
    (1) Surface movement times calculated for the simulated automatic surface guidance system are not very different from those measured in a real system. The automatic surface guidance system operates as efficiently as a real system operating in the daytime and in good visibility, if block section composition and route selection method are good.
    (2) When traffic density is light, the majority of the average aircraft deceleration events in the automatic surface guidance system occur at the taxi holding positions. However, aircraft deceleration occurs frequently even at the stop bar positions other than the taxi holding positions and the total number of aircraft decelerations increases, as traffic density increases. Therefore, availability of stop bar will extend to all areas of airport surface, as traffic density increases.
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  • Masatoshi Ryoko, Tatsushi Fujino, Makoto Kubo, Ryohei Itatani
    1994 Volume 78 Issue 6 Pages 248-254
    Published: June 01, 1994
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    We tried to control the 253.7nmHgl ultraviolet radiation for an application of our multicolored discharge. We have developed a new method to change the color of a low pressure Ne-Hg discharge lamp radiating three primary colors.
    This paper describes the principles of our new method and results of tests. We used various discharge tubes made of quartz for the tests. Some of them had a few probes for measurement of electron temperature.
    We applied triangular pulses with short rise time to a tube to get red spectra from neon and ones with long rise time to get blue spectra from mercury. The optimum pulse width was about 300, μs for any condition, but the optimum repetition frequency depended on a diameter of the tube
    When the pulse frequency was about 20kHz and pulse width was a few, us, the relative intensity of 253.7nmHgI radiation to visible radiation was very strong.
    We were able to get the green luminescence, if green fluorescent material was painted on the inner wall of the tube. Although the color difference between blue and green was not necessarily enough, we were able to get the three primary colors by adjusting the density of fluorescent material.
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  • Kazuaki Ohkubo, Yasuo Nakagawa, Fumio Ohtani, Hachihiro Nakamura
    1994 Volume 78 Issue 6 Pages 255-261
    Published: June 01, 1994
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    An experiment has been done to validate the correlation of spectral responsivity of thermal detectors and spectral absorption index of their receiving areas in a visible wavelength region. The detectors were polivinylidene fluoride (PVDF) pyroelectric detectors coated with paints of colors. The paint colors were blue, green, yellow and red.
    Each paint color was applied in three different thickness. In all the color detectors, there was good correlation between the relative spectral responsivity and the relative spectral absorptance of the detectors. The correlation factors were more than 0.99. The ratio of the relative spectral responsivity and the relative spectral absorptance of the detector was constant in the wavelength region.
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  • Kazuaki Ohkubo, Yasuo Nakagawa, Fumio Ohtani
    1994 Volume 78 Issue 6 Pages 263-267
    Published: June 01, 1994
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    An experiment has been done to clarify that the relation between the spectral responsivity of a thermal radiation detectors with fluorescenct absorption layers and the spectral absorptance of the absorption layers. The thermal radiation detectors consist of polyvinylidene fluoride (PVDF) pyroelectric film and radiation absorbing paint which contains fluorescent dyes. There is no correlation between the spectral responsivity and the spectral absorptance in the fluorescent exciting and emitting wavelength regions. For the fluorescence emission of the absorption layer, it is difficult to establish the dependency between the spectral responsivity and the spectral absorptance on the thermal radiation detectors.
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  • Ryohji Yoshitake, Tohru Tamura
    1994 Volume 78 Issue 6 Pages 268-275
    Published: June 01, 1994
    Released: July 19, 2011
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    The purpose of this study is to investigate the required luminance for a thin film transistor liquid crystal display (TFT/LCD). This study consists of two experiments.
    In Experiment 1, preferable luminance was estimated. Thirty participants were asked to adjust the brightness of both a TFT, /LCD and a CRT display as they most preferred, under four kinds of ambient illuminance conditions: 125, 250, 500 and 1000 lx at the surface of each display. The average preferable luminance adjusted for the TFT/LCD at the 250 lx was 42.1±13.0 cd/m2, and it was 114.2±59.2 cd/m2 for the CRT when an English text pattern was displayed.
    In Experiment 2, allowable luminance, that is the lower limits of the preferable luminance, was asked. About 90 percent of the participants accepted the luminance of the TFT/LCD as low as 25 cd/m2 at 250 lx.
    All of participants adjusted the luminance of TFT/LCD lower than CRT as their preferable luminances in the Experiment 1. Many participants, however, felt that the luminance of the TFT/LCD was brighter than that of the CRT. This result seems to suggest that images displayed on the TFT/LCD was perceived brighter than those on the CRT, although they were displayed at the same luminance. Regarding the effects of ambient illuminance, the TFT/LCD showed the same tendency as CRT display, that is, higher luminance and lower contrast were required as the ambient illuminance was increased.
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  • Takashi Higo, Yukitaka Shinoda
    1994 Volume 78 Issue 6 Pages 276-283
    Published: June 01, 1994
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    In this paper the methods of illuminance calculation are discussed by means of Stokes' theorem.
    The authors present the general expressions of illuminance calculation by the use of an integral of the inverse of the square of the distance around the contour of a surface source.
    A new vector function T is introduced in order to obtain these expressions. The function is defined by T={-rr} (nP·r) / r3.
    Variable r is the distance between irradiated surface and contour of the surface source.
    Variable t is the unit vector of r, while np, is the unit normal vector of the irradiated surface.
    It is shown that Kamisaka's expressions are directly proved by the use of Stokes' theorem and the vector function T.
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  • Toshio Yamanaka, Akio Nishimoto, Yoshimi Kakui, Motoi Nanjo
    1994 Volume 78 Issue 6 Pages 284-292
    Published: June 01, 1994
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    An apparatus has been designed to measure the spectral coefficient of retroreflection of materials used for traffic signs under nighttime geometric conditions.
    This paper describes the configuration of the apparatus and its performance, and also gives an estimate of accuracy in the measurement of the spectral coefficient of retroreflection by means of the apparatus.
    A small integrating sphere is used to overcome the geometric conditionof small observation angle and to eliminate the error due to polarization effect in the optical system. Retroreflected light from thesample is effectively collected by the sphere, and transferred to a double monochromator through an optical fiber bundle.
    It is estimated that the accuracy in the spectral coefficient of retroreflection is better than ±1%.
    The measurement results obtained by the use of the apparatus are presented, where the typical retroreflective materials have been prepared for the international inter comparison measurement conducted by CIE TC-2.19.
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  • Kazunori Yoshii, Hidetoshi Kaji, Atsushi Nishino
    1994 Volume 78 Issue 6 Pages 293-298
    Published: June 01, 1994
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    A porous ceramic compounded of alumina silica, and oxides of several rare-earth coating on the quartz tube of this lamp heater radiates 20% more far infraredthan quartz does, and contains platinum that catalyzes the oxidation of fatty acids, ammonia and other smelly compounds at typical operation temperatures.
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  • Chiaki Tonami, Naoyoshi Nameda, Tenji Wake
    1994 Volume 78 Issue 6 Pages 299-301
    Published: June 01, 1994
    Released: July 19, 2011
    JOURNALS FREE ACCESS
    This paper reports the seeing properties for traffic signs by blurred vision, When a deteriorated eye of anaged person, a non corrected near-sighted eye, or peripheral vision is used to observe traffic signs, this investigation is to discover what spatial frequency components of the sign pattern is effective to recognition. There are many traffic signs, such as limit of car speed, warnings, and so on. For this study, 18 signs were chosen from 46 signs. Chosen sign patterns were representative of the typically recognized patterns. Every patterns were previously blurred by Macintosh computer to simulate blurred vision. The patterns were then displayed for a sufficient time to 10 subjects. 9 students were all 20 years of age and 1 aged person was 50 years of age. None of these subjects had any special defect to their eyes. Students were all corrected by glasses, if they were near sighted. An aged subject had no glasses.
    For speculation of the sign patterns features, each blurred pattern was dissolved by Fourier Transformation by the computer.
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  • Yoshito Kato, Mitsuo Yamada
    1994 Volume 78 Issue 6 Pages 302-304
    Published: June 01, 1994
    Released: July 19, 2011
    JOURNALS FREE ACCESS
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  • Yoshiko Moriyama, Kunio Takeda
    1994 Volume 78 Issue 6 Pages 305-307
    Published: June 01, 1994
    Released: July 19, 2011
    JOURNALS FREE ACCESS
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  • 1994 Volume 78 Issue 6 Pages 312
    Published: 1994
    Released: July 19, 2011
    JOURNALS FREE ACCESS
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