• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1092-1094
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• 2009

The purpose of the research was to figure out the optimal binocular parallax inducing the least 3D visual fatigue. Subjective 3D visual fatigue was measured while the revolution depth and the average depth of an object were manipulated. The optimal binocular parallax was figured out by using data fitting method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.1117-1123
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• 2009

Head fixed type multi-focus display system using Galvano-scanner and DMD(Digital Micro-mirror Device), which is able to perfectly accommodate, can solve eye fatigue due to conflict between convergence eye movement and accommodation action in stereoscopic display. This system is able to accommodate through making convergence point about each view point and offering it in front of observer's pupil by using laser scanning method. In this paper, we analyzed laser scanning method of this multi-focus display system. And multi-focus display system based on this analysis was made, which showed that focus adjustment was possible through video camera. As a result, formation principle of view point of multi-focus system by laser scanning method was verified.

• Journal of the Ergonomics Society of Korea
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• v.33 no.3
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• pp.191-202
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• 2014

Objective: This study is conducted on the differences between flat and curved displays with respect to location of focused points, posture and satisfaction as well as preferred tilt angles. Background: In order to avoid physical and eye fatigue caused by misplayed sitting posture, many studies have asserted that the display requires appropriate location, size and tilt angle as well as curvature. However, most studies have focused on the work environment and the results are varied in the extent. Method: Eye height data in sitting posture were collected from 30 participants. Participants selected the most comfortable viewing angle within the range from $0^{\circ}$ to $12^{\circ}$ while watching videos for both curved and flat display. Then, physical and eye fatigue and overall satisfaction were subjectively evaluated. Lateral diagram describing viewing display condition was set and used to develop linear models for expecting the preferred tilt angle. Results: Due to sitting in the natural viewing posture rather than upright, the eye height is lowered to about 4.6 centimeters, on average, for both displays showing no significant differences. In contrast, preferred angles for the two displays are significantly different and this can be interpreted that curvature vary the points focused. Two linear models as functions of sitting eye height are developed to expect preferred tilt angle for each display. Based on the result of overall satisfaction evaluation, curved display is statistically better than flat display. Conclusion: The results show that flat and curved displays are significantly different expect for the viewing posture. However, reasons for preferring curved display are not accurately factorized and the linear models are limited in the experiment condition such as size of display, distance between display and viewer and other physical environmental factors. Further studies on curved displays under more various conditions are required. Application: This study can contribute to use of the curved display in various way.

• Journal of Broadcast Engineering
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• v.17 no.6
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• pp.1004-1013
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• 2012

3D images and videos are required viewers to wear 3D glasses. According to the data, about half of Korean people wear glasses or contact lens and this implies 3D video viewers may have a trouble due to putting a pair of 3D glasses atop their glasses. The purpose of this study is to examine gamers' perceived characteristics, presence, and fatigue according to video gaming display (2D vs. 3D) and glasses whether wearing or not. The results show that the interaction effect of the display and wearing glasses was statistically significant in the perceived presence, and the main effect of the display was statistically significant in the perceived characteristics and fatigue.

• Journal of the Korea Safety Management & Science
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• v.10 no.2
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• pp.15-24
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• 2008

This study was to investigate the relationship of VDT(visual display terminal) work condition and fatigue severity in the financial office workers. Questionnaires were completed by 662 persons in VDT workers of Post Office from January to May 2006. Multidimensional Fatigue Scale(MFS) that was developed in Korea Occupational Safety &Health Agency to estimate the degree of fatigue was used for study. In results, 149 persons(22.5%) in VDT workers were felt low fatigue severity, 351 workers(53.0%) were middle, and 162 workers (24.5%) were high. So it was appeared that one in four VDT workers felt the high fatigue severity. And woman VDT workers felt more fatigue severity than man. Also, fatigue severity was increased with increasing work time. Our findings suggest that VDT workers in financial office need proper health program to prevent occupational fatigue and disease.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.8 no.1
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• pp.5-14
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• 2002

Objectives : In order to investigate industrial fatigue due to visual display terminal (VDT) work of post office. Methods : The questionnaire survey for subjective symptoms of fatigue was carried out on 39 post office clerks who had been engaged in VDT work for various length of work hours. The questionnaire comprised three groups of 10 items each, representing dullness and sleepiness, difficulty in concentration and bodily projection of fatigue. Results : The scores of dullness and sleepiness was 16.62, scores of concentration difficulty was 16.35, those of bodily fatigue was 16.23, and total scores was 49.21. Fatigue scores was significantly associated with age and work duration, VDT of work hours, ventilation, illumination, nosie. Conclusions : Data from this study support a statistically significant association between age and scores of dullness, scores of concentration difficulty, between work duration and scores of dullness, scores of bodily fatigue, between VDT of work hours and scores of bodily fatigue.

• Journal of the Ergonomics Society of Korea
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• v.21 no.1
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• pp.95-112
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• 2002

Two experiments were carried out to compare the suitability in visual tasks between cathode-ray tube (CRT) and thin film transistor-liquid crystal display (TFT-LCD). In the first experiment, the subjects were requested to detect pre-assigned target words or icons among distracters presented under time-invariant (static) image mode. The subjects' visual performance and fatigue were assessed while carrying out search tasks with dim and bright ambient light conditions. Significant interaction effects were found among displays, task types, and ambient light conditions. Due to visual fatigue, the subjects' accommodative power decreased in the end of task and the degradation was more significant for the CRT users and under bright ambient light. IN the second experiment, the subjects performed information processing task with time-varying road signs at a driving simulator to assess interaction effects between display types and changing speed of dynamic image. The perception time using TFT-TCD was shorter under slow image change while that of CRT was shorter rapid image change. Findings from this study suggest that, to improve visual task performance, users should carefully select their visual display type depending on the task to be performed.

• Journal of Information Display
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• v.13 no.4
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• pp.159-166
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• 2012

In this paper, a display's emotional image quality can be primarily determined by designing the proper luminance level. Though displays with high luminance are preferred, too much light emission from a display may cause glare or visual fatigue to viewers. To find out the proper luminance level based on various video contents, this study was conducted with an OLED display with a real-black level and a wide color gamut, and with an LCD display with a high luminance level, to set the glare threshold under various conditions. The optimum luminance levels according to the display's loading ratio were found, and the maximum luminance that did not cause a glare in the test is proposed.

• Journal of Broadcast Engineering
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• v.7 no.4
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• pp.362-367
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• 2002

The 3-dimensional image display system using only binocular disparity can induce the eye fatigue because of the mismatch between the accommodation of eye and the convergence of two eyes. A new 3-dimensional display system for one observer that can solve eye fatigue caused by mismatch between accommodation and convergence was introduced in this paper. A proof about the possibility of satisfaction of accommodation of one eye was given as the experimental result in this 3-dimensional display system.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1033-1036
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• 2008

In this paper, we describe the development of the polarized-light stereoscopic monitoring system based on full HDTV. The system consists of the stereoscopic camera part, image processing device for the stereoscopic image recording and stereoscopic display. The developed stereoscopic imaging display system reduces eyestrain and viewer fatigue.