FACTORS IN PHSIOLOGICAL OPTICS ON VISUAL FATIGUE IN DISPLAY WORK

Research Project

Project/Area Number	60460068
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	物理計測・光学
Research Institution	TOKYO INSTITUTE OF TECHNOLOGY
Principal Investigator	IKEDA MITUO TOKYO INSTITUTE OF TECHNOLOGY, PROFESSOR, 国立大学(その他), 教授 (30016604)
Co-Investigator(Kenkyū-buntansha)	NAKATSUE MIYOSHI TOKYO INSTITUTE OF TECHNOLOGY,RESEARCH ASSOCIATE, 大学院総合理工学研究科, 助手 (50183512) UCHIKAWA KEIJI TOKYO INSTITUTE OF TECHNOLOGY,RESEARCH ASSOCIATE, 大学院総合理工学研究科, 助手 (00158776)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥6,300,000 (Direct Cost: ¥6,300,000) Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1985: ¥5,800,000 (Direct Cost: ¥5,800,000)
Keywords	flicker / CFF / increment threshold / temporal characteristics of visual process chromaticity / luminance / 輝度 / 文字パターン認識
Research Abstract	In Experiment I, increment threshold was measured on flickering background stimulus of which waveform was one of step, sinusoidal, on-ramp, or off-ramp function. At low flicker frequencies, increments vary sinusoidally independent from the waveform of background stimulus suggesting that the first Fourier component is the most important factor. At high frequencies, increments fluctuate randomly. Above CFF, where subject does not see perceptual flicker, increment threshold differs from that on steady background of equal luminance. It suggests that some kind of transient responses occur in visual pathway, even though the stimulus looks steady. In Experiment ll, a target letter pattern was superimposed on a noise letter parrern of different chromaticity and luminance, and the percent correct in recognition of the target letter was measured for two stimulus sizes and two durations. One letter was white and the other was one of red, green, yellow, or blue. For all subjects, decrease of percent correct was found where the target is in equal luminance and/or equal brightness with the noise. At equal luminance condition, recognition of colored stimulus is easier than white one except yellow which is almost same as white. These color effects increase with stimulus size and duration. The results of Experiment ll showed that condition where target and noise (or background) are equal luminance and/or brightness is undesirable condition for recognizing a target letter in display work.