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Volume 68, Issue 2
Displaying 1-8 of 8 articles from this issue
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Suteo Tsutsumi, Yasumasa Itakura, Masaru Tsudagawa, Kohji Takemura, To ...1984 Volume 68 Issue 2 Pages 55-60
Published: February 01, 1984
Released on J-STAGE: July 19, 2011
JOURNAL FREE ACCESSAn improved vehicular ground-speed sensor with a parallel-spoke reticle limited byduplex parallelogram.form aperture, has been designed and built for and-skid control, and tested on the several traffic roads. On the basis of the knowledge of the Wiener spectra for the spatial radiance distribution on the highway road surfaces (illuminated by the lamp), detector noise, and something unfavorable to occur, how to design the sensor is described, assuming that the measurement accuracy of about ±5 percent is to be allowable. Some typical experimental results are shown. The measurement accuracy of ±5 percent at the worst is obtained in the speed range from 10 to 100 km/h on any highway, except for a bad one so wet as to splash through water in a puddle.View full abstractDownload PDF (9179K) -
Tomoyuki Nishita, Eihachiro Nakamae1984 Volume 68 Issue 2 Pages 61-66
Published: February 01, 1984
Released on J-STAGE: July 19, 2011
JOURNAL FREE ACCESSIn lighting design, shadows are one of the important elements to be considered. This paper proposes a method of illuminance calculation in consideration of shadows caused by several objects (approximated by convex polyhedra) and flat surface sources having arbitrary shapes (approximated by convex polygons). This paper also discusses the depiction method of the calculated illuminance by using the perspective viewed from an arbitrary position.
The advanced points of this paper are as follows:
(1) Obtaining volumes of penumbrae and umbrae, and calculating the shadow boundaries on each illuminated face prior to illuminance calculation, shorten the computation time.(2) Applying to contour integration method for the visible segments of the source's boundary when viewed from the calculating point and for the visible segments of the contour line of polyhedra simplify the calculation of the illuminance in the penumbrae caused by several polyhedra.(3) Even though the shape of the light source is basically treated as a convex polygon, using the hypothetical sources or the cover face beneath the source makes it possible to deal with a concave polygon source (including holes).(4) The illuminance values are displayed on the perspective image viewed from an arbitrary position, then even laymen can discuss the psychological effects and can easily grasp the distribution of illuminance.View full abstractDownload PDF (4620K) -
Yoshinobu Nayatani, Kenjiro Hashimoto, Kotaro Takahama, Hiroaki Sobaga ...1984 Volume 68 Issue 2 Pages 67-71
Published: February 01, 1984
Released on J-STAGE: July 19, 2011
JOURNAL FREE ACCESSThe purpose of the present study consists of the following two items: (1) to clarify the cause of the significant difference found between the total variation and the estimated change due to age differenceof color matches on metameric-sample pairs for color-normal observers from age 20 to 60 studied by P. K. Kaiser et al (Color Res. and Appl. 5 (1980) 65), and (2) to confirm whether the metameric-sample pairs of the Davidson and Hemmendinger (abbreviated by D · H) color. rule are representative for assessing the relation between observer and illuminant metamerism index. The former is analyzed by using the D · H color-rule samples and the Stiles's 20 color-matching functions. The latter is studied by using the Wyszecki's 12 gray metameric-sample pairs.
Results are summarized as follows: (1) The significant difference between the total variation and the age effect found in the study by P. K. Kaiser et al. is supposed to be caused mainly by the matching errors of their observers in this kind of experiments.(2) The D · H color-rule samples can not be representative for determining the relation between observer and illuminant metamerism index.(3) The Stiles's 20 color-matching functions are suitable for assessing observer metamerism on color-normal observers.View full abstractDownload PDF (999K) -
Kotaro Shimogaki, Ikuo Iwai, Hisao Yoshiike1984 Volume 68 Issue 2 Pages 72-76
Published: February 01, 1984
Released on J-STAGE: July 19, 2011
JOURNAL FREE ACCESSAn energy conserving incandescent lamp which the infrared reflective film has been studied.
This lamp can be called the heat mirror lamp, because it has an envelope internally coated with a multilayer heat refl ective mirror such as consisting of Ti02-Ag-Ti02.
A theoretical formula which led the luminous efficacy and the energy conserving ratio of the lamp could be found.
Those are depend on the spectral transmittance and reflectance of the heat mirror, the spectral emissivity of the radiator and the geometrical factor of the lamp components.
In case of the spherical envelope lamp with tungsten coiled coil filament at the center, a geometrical factor of 0.63 has been experimentally obtained, and the luminous efficacy of 27 lm/W can be expected by using the Ti02-Ag-Ti02 film coated lamp.
An experimental luminous efficacy of the lamp with a bulb internally coated with a thin gold film almost coincides with the results of theoretical calculations.View full abstractDownload PDF (704K) -
Taisuke Hirota1984 Volume 68 Issue 2 Pages 77-82
Published: February 01, 1984
Released on J-STAGE: July 19, 2011
JOURNAL FREE ACCESSAs a rule, fluorescent lamps are filled with mercury and argon. As regards mercury dosiny into the bulb, the method which drops a few drops of liquid mercury through the exhaust tube has been employed. Such conventional method in production is of advantage to exhaust the gaseous impurities from the bulb but causes various defects of quality and characteristic. To eliminate such disadvantages, a manufacturing method which uses a mercury dispenser such as a strip mounted around the etctrode and releases mercury within the tube by means os R. F heating after sealing is introduced. Advantages using mercury dispenser are as follows:
(1) The quantity of mercury enclosed in the lamp is very precise.
(2) The pressure fluctuation of argon fill can be reduced, therefore it is possible to reduce the fluctuation of lamp life and to increse its average life.
(3) In addition, if the new production process is applied for conventional mercury dosing method it is possible to decrease the mercury contents of lamp.View full abstractDownload PDF (1025K) -
Mitsuhiro Habu, Mamoru Suzuki1984 Volume 68 Issue 2 Pages 83-89
Published: February 01, 1984
Released on J-STAGE: July 19, 2011
JOURNAL FREE ACCESSFor the utilization of the Solar Radiation, it is necessary to have knowledge about the spectral radiant power of the solar radiation on the earth's surface. From such a view point two kinds of measurements on the solar radiation were carried out by comparison with the irradiance of a spectral irradiance standard lamp during the whole period between July 1976 and February 1980 at Tanashi, Tokyo (35°43'N. L., 73m above the sea level). One is the measurement of the direct solar radiation onto a plane perpendicular to it in the wavelength range from 297.6 to 1083.7 nm for the period July 1976 to November 1978. The data of 628 Sets are obtained. Another is the measurement of the global solar radiation onto a horizontal plane in the wavelength range from 295. 1 to 1083.7 nm for the period December 1978 to February 1980. The data of 318 Sets are collected. Above two kinds of data are analyzed for many purposes.
This study has been reported in a series of publications of“Researches of the Electrotechnical Laboratory” (1981, 1981, 1983). This report is summary of above publications.View full abstractDownload PDF (1140K) -
1984 Volume 68 Issue 2 Pages 94a
Published: 1984
Released on J-STAGE: July 19, 2011
JOURNAL FREE ACCESSDownload PDF (129K) -
1984 Volume 68 Issue 2 Pages 94b
Published: 1984
Released on J-STAGE: July 19, 2011
JOURNAL FREE ACCESSDownload PDF (129K)
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