TOP / Publications / Abstracts of papers in J. of IEIJ / J. of IEIJ Vol.89, No.8A

The Abstracts of the Papers J.Illum. Engng. Inst. Jpn.Vol. 89, 2005

No.8A  August

CONTENTS

Papers

Study on Brightness for Relaxation —Influence of Initial Adaptation Level and Elapsed Time—

K. ISHIDA and Y. INOUE

445

On Estimation of the Luminance Distribution by the Diffuse Reflection Component of the Object Surface and Shape Measurement —Experimental Analysis—

N. IKEMOTO and M. ISOMURA

453

Effects of Visual and Conversation Loads on Functional Visual Field on a Dynamic Background

M. AYAMA, Y. MEKADA, D. KODAMA and M. KASUGA

463

A Study on the End Shape of the Sealed Parts of the Bulb Side in the Super High Pressure Discharge Lamps to Im-prove the Lamp Strength under Internal Pressure

M. KASE and T. SAWA

472

 

ABSTRACTS

Study on Brightness for Relaxation —Influence of Initial Adaptation Level and Elapsed Time—
Kyoko ISHIDA, and Youko INOUE

The purpose of this paper was to investigate how the initial adaptation level and the elapsed time affected proper illuminance for relaxation. The experiment car-ried out three lighting patterns which changed the placement and the shape of the lamp. Ten females aged 21 to 25 were the subjects.

In the experiment the initial adaptation levels were set to 20 lx and 150 lx as defined by the horizontal illumi-nance in the center of the floor. The subject adjusted the illuminance to get the best relaxation situation and evaluated the degree of satisfaction after two minutes when the subject entered the evaluation room, and re-peated the same adjustment and evaluation after five minutes, nine minutes, 17 minutes, and 32 minutes.

In the first nine minutes, there were the remarkable changes in the illuminance for relaxation and the satis-faction but after nine minutes there werenít many changes. The proper illuminance made by the subject after 32 minutes was different depending on whether the initial adaptation level was 20 lx or it was 150 lx. The effect of the initial adaptation level was compatible with the elapsed time. Furthermore the illuminance level for relaxation obtained in this research was lower than the results of other researches.

In conclusion, the initial adaptation level and the elapsed time affect the illuminance and evaluations of satisfaction and therefore it is necessary to take them into consideration when studying lighting conditions and using the investigation results for lighting design.

KEYWORDS : relaxation, illuminance, satisfaction, ini-tial adaptation level, elapsed time

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On Estimation of the Luminance Distribution by the Diffuse Reflection Component of the Object Surface and Shape Measurement —Experimental Analysis—
Naotaka IKEMOTO and Minoru ISOMURA

Photometric stereo method can be used to find the orien-tation of the surface of an object to be measured. This method cannot avoid the influence of highlights in an image that are caused by the specular reflection compo-nents of mixed diffuse-specular objects. In a previous paper, we presented that estimate luminance distribu-tion in highlight regions can eliminate influence of high-lights in an image. However, the previous method is un-stable when some highlight regions overlap.

We have proposed a new method of measuring the shapes of mixed diffuse-specular objects. First, highlight is detected using the bi-directional reflectance distribu-tion function. Next, highlight regions that overlap in a gray-level image are divided using the watershed algo-rithm. Then, the luminance distribution caused by the diffuse reflection components in the highlight regions is estimated based on the luminance distribution in a gray-level image without highlights.

Shape measurement experiments using mixed diffuse-specular objects with different characteristic reflectances and shapes showed that our method can accurately measure the 3-D shape of mixed diffuse-specular objects.

KEYWORDS : bi-directional reflectance distribution function, watershed algorithm, reflection characteristics, photometric stereo, highlights, shape measurement, mixed diffuse-specular objects

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Effects of Visual and Conversation Loads on Functional Visual Field on a Dynamic Background
Miyoshi AYAMA, Yoshito MEKADA, Daisuke KODAMA and Masao KASUGA

The effects of performing a visual task and/or conversa-tion task on a functional visual field ( FVF ) on a dy-namic background simulating a driving situation were experimentally studied. A red or pink circular target was briefly presented somewhere on a movie scene depicting driver's view, and the observer's task was to indicate the targetís position. The visual task loaded on the observer was to read out two alphabet letters presented at the center of the visual field. The conversation task was to answer to an easy question orally. The FVF narrowed with the visual task as well as with the conversation task, while it markedly shrunk when both visual and conversation tasks were imposed simultaneously.

KEYWORDS : functional visual field, driver’s cognitive load, visual load, conversation load, target detection

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A Study on the End Shape of the Sealed Parts of the Bulb Side in the Super High Pressure Discharge Lamps to Im-prove the Lamp Strength under Internal Pressure
Masahiko KASE and Toshiyuki SAWA

Super high pressure mercury discharge lamps have been used as a UV and visible light sources for photolithogra-phy exposure process, such as patterning LCDs, PCBs and semiconductors. This study examines their rupture characteristics and discuss a guideline for designing a part of lamp between the end of bulb and the end of the sealed part under internal pressure. Finite-Element method ( FEM ) was employed to investigate the maximum principal stress σ1 distribution near the end of the sealed part. Furthermore, static water pressure tests were conducted to examine the strength character-istic of the bulbs. As the results, the rupture characteris-tics near the end of the sealed parts can be elucidated and the guideline for designing the end of the sealed parts were drawn up. Moreover, the relationships among the rupture pressure and the outer diameter D2of the glass parts in the sealed parts and the length L1 near the end of the sealed parts were obtained for in-creasing the bulb strength. It was found that the strength near the end of the bulb was increased as the diameter D2 was decreased and the length L1 was in-creased. The rupture characteristics obtained by the numerical results were in fairly good agreements with those by the experiments.

KEYWORDS : super high pressure, lamp, bulb, sealed parts, rupture, internal pressure

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