J. of IEIJ Vol.88, No.2

The Abstracts of the Papers
J.Illum. Engng. Inst. Jpn. Vol. 88, 2004

No. 2 February
No. 5 May
No. 8A August
No. 11 November

Development of a Composite Rectifier Circuit for a Partially Smoothing Circuit and a Voltage Doubler Rectifier Circuit
Yoshio WATANABE and Taku KARITA

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.

KEYWORDS : partially smoothing rectifier circuit, voltage doubler rectifier circuit, higher harmonics, relative harmonics content rate

Brightness of a Circular Object with a Uniform Luminance Background
—Brightness Prediction Based on Luminance Contrast Part 1—
Yoshiki NAKAMURA and Kotoku EGAWA

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.

KEYWORDS : brightness, apparent brightness, luminance contrast, luminance-brightness relation, simultaneous contrast

Luminous Intensity Distribution of Luminaires with Specular Reflectors
Masafumi SUZUKI, Kohzou AKAZAWA and Noboru YOSHIMURA

Luminous intensity distribution of Luminaire with specular reflectors was studied. Specular reflectors have a high reflectance compared with diffuse reflectors, therefore it is possible to conserve energy saving by raising instrument efficiency. It is also possible to obtain the specific light distribution characteristic by optimizing the shape of the reflector. Therefore, it is necessary to understand the relationship between the shape of the reflector and light distribution characteristics. In this study, luminous intensity distribution of luminaire which has specular reflector was calculated by a Monte Carlo method.

KEYWORDS : luminous intensity distribution, specular reflector, Monte Carlo method

The Band of Blue-Light Emission Independent of Bandgap Energy in Si:SiO₂ Sputtered Films
Osamu HANAIZUMI, Takehiro KOGA, Osamu TAKEI, Kazutaka ONO, Yuichi OGAWA, Toshiaki MATSUMOTO and Yuji HIRATANI

KEYWORDS : Si nanocrystal, blue-light emission, rf sputtering, photoluminescence, without annealing

Effect of Driver's Fatigue on Visual Search Time of Blinking Light
Tatsuya NAGURA and Takashi IRIKURA

KEYWORDS : driver’s fatigue, visual search time, blinking light, conspicuity, vigilance task