title: Comparison of viewing angle and observer performances in different types of liquid-crystal display monitors.
abstract: It is known that the performance of liquid-crystal display (LCD) monitors, such as the luminance and contrast ratio, is dependent on the viewing angle. Our purpose in this study was to compare the angular performance and the effect on observer performance of different types of LCD monitors. The luminance performance and contrast ratio as a function of viewing angle (-60 degrees to 60 degrees) in each direction for two types of LCD monitors, namely, a general-purpose LCD monitor and one especially designed for medical use, were measured in this study. Furthermore, the observer performance at various viewing angles in the horizontal direction for a medical-grade LCD monitor was investigated by eight observers based on a contrast-detail diagram. The two types of LCD monitors showed notable variations in luminance and contrast ratio as a function of the viewing angle. Acceptable viewing angles in terms of the contrast ratio were much smaller in each direction than those for nominal viewing angles in the specifications provided by the manufacturers, and those for the medical-grade LCD monitor in the horizontal and vertical directions were broader than those of the general-purpose LCD monitor. There was no significant difference in observer performance between 0 degrees and 40 degrees. On the other hand, our results showed a statistically significant difference in observer performance between 0 degrees and 60 degrees.
authors.affiliation: Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Higashiku, Fukuoka, Japan. shiro.hatanaka@gmail.com
authors.forename: Shiro
authors.initials: S
authors.lastname: Hatanaka
authors.forename: Junji
authors.initials: J
authors.lastname: Morishita
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hiwasa
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Dogomori
authors.forename: Fukai
authors.initials: F
authors.lastname: Toyofuku
authors.forename: Masafumi
authors.initials: M
authors.lastname: Ohki
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Higashida
mesh_terms: D003626:Data Display; D008027:Light; D050866:Liquid Crystals; D015588:Observer Variation
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