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J. of IEIJ Vol.84, No.2

The Abstracts of the Papers J.Illum. Engng. Inst. Jpn. Vol. 84, 2000

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

CONTENTS of No.2 February
Color Appearance in Peripheral Vision:Effects of Test Stimulus and Surround Luminance
Effects of Wall Color and Awakening Fragrance on Workers Using VDTs
Differences in Visual Acuity and Color Discrimination between Darker and Fairer Eyes at Lower Illuminance
Effect of Change in Spectral Transmittance of Crystalline Lens with Aging on Color Vision
Effects of Using a Mobile Phone on the Visual-Information Management of Driving Activities
Letters Observation of Luminous Color of Phosphor in a Pulse-Modulated Radio Frequency Discharge
Apparent Magnitude of a Visible Star under the Hazard of a Glare Light
Color Appearance in Peripheral Vision: Effects of Test Stimulus and Surround Luminance

Masato SAKURAI, Takayuki KOSEKI, Hirofumi HAYASHI and Miyoshi AYAMA

To determine the appropriate experimental conditions for measuring the color zone map covering the visual field, the color appearances of red, yellow, green and blue lights of a CRT display presented across the horizontal meridian of the visual field were measured. The test stimulus settings were equal luminance and equal brightness at the fovea, with dark, gray, or white surround conditions. The perceived strength of the red, yellow, green and blue hue components in the test stimuli decreased from the fovea to the periphery under all conditions. The luminance level of the test stimuli and the surround conditions did not significantly affect the results. All four of the unique-hue component curves as a function of the eccentricity normalized at the fovea were within the range of the data obtained in previous studies in which monochromatic lights were used as the test stimuli. These curves may thus not depend on whether the test stimulus is monochromatic or complex light. The recommended experimental conditions for measuring the color zone map are equal-luminance test stimuli (no need for brightness-matching testing) with a gray surround (more applicable to actual visual environments than a dark or white surround).

KEYWORDS: peripheral vision, color zone map, unique hue, achromatic surround, equal luminance, equal brightness

Effects of Wall Color and Awakening Fragrance on Workers Using VDTs
Mitsuyuki KAWAKAMI, Shuichi MATSUMOTO and Shigeo OHTSUKI

The effect of color and fragrance on workers using Visual Display Terminals (VDTs) has been investigated. In particular, the effect of the wall color and of an "awakening". fragrance on worker contraction and mental stability were measured experimentally. The evaluation indices were obtained by measuring the productivity (working efficiency and working quality) of ten subjects performing tasks on VDTs, by determining the subjects' mental activities (stability) recorded using an electroencephalograph (EEG), by observing the survey of subjective symptoms and by measuring their eye fatigue.
””Three significant results were obtained. (1)Of the four colors tested, "green" produced the highest levels of concentration on work and mental stability. (2)When an awakening fragrance with 20% density was sprayed in the test area productivity increased 20% and workload decreased. (3)When the walls were green and fragrance was sprayed productivity increased 30%

KEYWORDS: VDT work, fragrance, color, worker productivity, workload

Differences in Visual Acuity and Color Discrimination between Darker and Fairer Eyes at Lower Illuminance
Kazumi NAKAYAMA, Masao INUI, Masato SATO and Miki KUNITOMO

This study was conducted to clarify the difference in visual acuity and color recognition between the darker color eyes of Japanese and the fairer color eyes of Westerners at lower illuminance. A series of experiments were carried out in an experimental room in which the illuminance level could be changed. The parameters were the illuminance on a desk and the color of the subject's eyes. Ten illuminance levels, which increased geometrically from 0.001 to 30 lx, were used. The subjects comprised two groups having different eye colors. One group was made up of Japanese, who have dark eyes, and the other Europeans and North Americans with fair eyes. At each illuminance level, after 7 minutes for adaptation, each subject's visual acuity was tested using 4 types of color Landolt rings and color discrimination was tested using 12 different-color cards. The following results were obtained.
(1) For a black Landolt ring on a white background, there was very little difference between the two groups' visual acuity.
(2) For a green Landolt ring on a blue background, the visual acuity of the dark-eyes group was remarkably lower than that of the fair-eyes group.
(3) In the color discrimination test, at an illumination of 1lx or lower, the dark-eyes group confused colors more than the fair-eyes group.
Accordingly, the differences in visual acuity and color discrimination between the two eye-color groups were only in color discrimination at lower illuminance.

KEYWORDS: lower illuminance, visual acuity, color recognition, eye color

Effect of Change in Spectral Transmittance of Crystalline Lens with Aging on Color Vision
Ichiro KURIKI, Wataru ISHII and Keiji UCHIKAWA

We conducted four kinds of psychophysical measurements on color vision to investigate whether the change in lens spectral transmittance that comes with aging is the primary factor in the change in color vision. We asked two observers (22 and 24 years old) to adapt to the scene while wearing goggles equipped with filters that simulate spectral transmittance at the retinal level of a person of 80 years old. when worn by 20 years old observer. During the test, which lasted as long as 12 hours, the observers performed (1)unique-white setting ,(2)heterochromatic flicker photometry (HFP), (3)hetero-chromatic brightness matching (HBM), and (4)100”¾hue test. The change in the results with and without the goggle showed that only difference in HFP sensitivity coincided exactly with the filter transmittance. A similar tendency was found in the difference between 20- and 80-year-old observers in a previous study. The other tests matched with neither the difference in spectral transmittance nor the difference between 20- and 80-year-old experimental results. Our results suggest that neural circuits, which may differ from those for illuminant change, play a significant role in correcting the relative spectrum change on the retina.

KEYWORDS: aging, color vision, lens spectral transmittance, simulation of aging, flicker photometry, brightness matching

Effects of Using a Mobile Phone on the Visual- Information Management of Driving Activities
Mitsuyuki KAWAKAMI, Hidetoshi FUKUI, Shuichi MATSUMOTO and Takao OHKUBO

Today we live in a highly technological and car oriented society. Car access has achieved noticeable developments and grown on a worldwide level. Along with the social benefits of the automobile, it is a widely known fact that major accidents and loss of life are occurring at increasing rates in almost every society today.
This paper describes the effect of using a mobile phone on a driver's reaction time was evaluated experimentally by measuring the movement of the driver's eye-fixation point and his reaction time when a stimulus light was shines on his face from inside or outside the car.
The results showed that using a mobile phone while driving (1) reduces the movement of the eye-fixation point to both the right and to the left, thus narrowing the range of the fixation point, and (2) delayed the reaction time by about 0.2 seconds. It also proposed the desirable position of setting up a visual display.

KEYWORDS: mobile phone, stimulus light, reaction time, eye-fixation point