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F4-1 Are curved displays ergonomically advantageous over flat displays? Some positive results from three display curvature studies on monitors and TVs

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  • S cube design lab

Abstract and Figures

Background: Though curved display products such as curved monitors, TVs, and smartphones are available, it seems still inconclusive whether or not curved display is ergonomically advantageous over flat display, and if so in terms of what ergonomic aspects. To examine a visual display comprehensively, three aspects, productivity, safety, and well-being, should be considered. Objective: We aimed to determine whether or not display curvature is ergonomically recommendable, especially for monitors and TVs. Methods: Overall, we examined the effect of display curvature on visual task performance, visual fatigue, and/or watching experience by conducting three different studies. In Study 1, we examined the effect of display curvature (400R, 600R, 1200R, and flat) on visual task performance and visual fatigue. A visual search task was performed on 50" multi-monitors. In Study 2, we examined the effect of display curvature (600R, 1140R, 2000R, 4000R, and flat) on visual task performance, visual fatigue, and display satisfaction. A proofreading task was performed on 27" monitors. In Study 3, we examined the effect of display curvature (2300R, 4000R, 6000R, and flat) on presence and display satisfaction. A TV watching task was done on 55" TVs. Results: First, curved displays increased productivity. The mean visual search accuracy and speed were both higher at the 50" 600R and 1200R multi-monitor settings, and the mean proofreading speed was the fastest at the 27" 600R curved monitor setting. Second, curved displays increased safety. The mean visual fatigue was lower at the 50" 600R and 1200R multi-monitor settings. However, the effect of display curvature on visual fatigue was not significant in the case of the 27" monitors. Third, curved displays improved well-being. Compared to the 55" flat TV, the mean spatial presence and engagement did not significantly decrease up to a more lateral viewing position especially when the display curvature was similar to the viewing distance. The effect of display curvature on display satisfaction was, however, not significant in Studies 2 and 3. Applications: The findings of three studies suggest that display curvature, if its level is carefully selected, can improve monitors and TVs in terms of productivity, safety, and/or well-being.
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Pretest 2Posttest
Rt. 3.28±0.3 3.25± 0.1 0.317
Lt. 3.25±0.3 3.25±0.1 1.000
Rt. 0.32±0.1 0.24± 0.10 0.040
*
Lt. 0.30±0.2 0.26±0.18 0.007
**
138.19±9.6 142.07±9.2 0.009
**
138.36±11.1 142.02±10.2 0.007
**
149.94±10.6 155.65±11.3 0.006
**
149.42±11.3 155.53±10.6 0.010
*
136.39±9.8 140.06±10.7 0.007
**
137.31±9.7 140.95±10 0.006
**
148.24±13.1 151.76±14.1 0.007
**
148.24±12.5 151.78±14.1 > 0.001
***
Rt. 25.95±4.81 27.23± 5.1 0.009
**
Lt. 25.37±4.7 26.45±5.8 0.030
*
M ean±SD
P-values
Rt.
Lt.
Power grip
strength (kg)
Sensory
response
(level)
Sides
Chronaxy (ms)
Paramet ers
Median neural
tension
response
(degrees)
Table 1. Comparison of parameters between Pretest2
and Posttest.
4. Discussion
This study investigated the immediate effects of
Thai dancing for 10 min on median neural tension
responses, chronaxy, power grip strength and sensory
response in people with WMSDs. The result showed
that the degree of elbow extension of all neural tension
responses immediately after Thai dancing for 10 min
were increased. This was confirmed by decreasing of
chronaxy values and increasing of power grip strength,
which was found immediately after Thai dancing. Thus,
from the results of the median neurodynamic test,
strength duration test and grip strength test indicated
that Thai dancing for 10 min could immediately
decrease median neural tension effectively. Thai
dancing is composed of gentle oscillation of maneuver,
repetitive movement and slow rhythm. Due to this
characteristics of the Thai dance, it allows gliding and
sliding of nerve which may increase pumping blood
circulation into the nerves, and bring in more nutrient
and oxygen for the function of nerve (6). So, Thai
dancing-10 min can improve the physiological response
of median nerve as a consequence of decreased neural
tension.
There are some limitations in this study. There was
no control group. However, this study measured pretest
twice. Age of participants was between 21 to 28 years,
indicating early adulthood. Further study should
determine the effect of age on the change of
neurodynamic by Thai dancing. Elderly age may decline
some body systems such as stiffness of joint can inhibit
the gliding of the nerve (10). This study can’t suggest
appropriate duration time and frequency of Thai
dancing program. Further studies should investigate
proper duration and frequency of Thai dancing program
for the best improvement for nerve.
5. Conclusion
People using computers for a long period may
develop median neural tension. This study found Thai
dancing could reduce the neural tension and improve
nerve functions such as sensation, muscle power and
chronaxy value. Therefore, this study suggested that
Thai dancing for 10 min could help people who have
suffered from the early stage WMSDs and it can be
recommended as an exercise for computer users.
References
Staal J.B., DeBie R.A., Hendriks EJM. Aetiology and management of
work-related upper extremity disorders., Best Pract Res Clin
Rheumatol, 21(1), 33-123, 2007.
Ming Z., Zaproudina N. Computer use related upper limb musculoskeletal
(ComRULM) disorders., Pathophysiology, 9, 60-155, 2003.
Ong CN, Chian SE, Jeyaratnam J, Tan KC., Musculosketal disorders
among operators of visual display terminals, Scand J Work Environ
Health, (21), 60-64, 1995.
Butler DS., Mobilization of the nervous system, Longman Cheshire Pty
Limited, Australia.1991.
C. B. Wynn Parry, “Strength-duration curves,” in Electrodiagnosis and
Electromyography, Baltimore. 241-271, 1971.
Mlyamoto MD. Probability of quantal transmitter release from nerve
terminals: theoretical considerations in the determination of spatial
variation, J Theor Biol, 289-304, 1986.
North coast page, https://www.ncmedical.com/item_1278.html (retrieved
April 19, 2017).
Upiriyasakul R., Mekhora J., Jalayondeja W., Alteration of Median Neural
Tension From 4 Hours of Computer Use., The Journal of Ergonomic,
S44-S50, 2016.
Gill, D., Reddon, J., Renney, C., Stefanyk, W., “Hand Dynamometer:
Effects of Trials and Session,” Perceptual and Motor Skills
61:195-198, 1985.
Merck Manual page, http://www.merckmanuals.com/home (retrieved
April 18, 2017).
Values are mean±SD. *p<.05, **p<.01, ***p<.001; Values were
statistically significantly different.
(P1, R1, P2, R2)
Are curved displays ergonomically advantageous over flat
displays? Some positive results from three display curvature
studies on monitors and TVs
Sungryul Park (psr926@unist.ac.kr), Jihhyeon Yi (yjh90@unist.ac.kr), Donghee Choi
(choidh@unist.ac.kr), Songil Lee (songil@unist.ac.kr), Gyouhyung Kyung (ghkyung@unist.ac.kr)
Interaction and Experience Lab, UNIST, Ulsan, Korea, 44919
ABSTRACT
Background: Though curved display products such as curved monitors, TVs, and smartphones are available, it seems
still inconclusive whether or not curved display is ergonomically advantageous over flat display, and if so in terms of
what ergonomic aspects. To examine a visual display comprehensively, three aspects, productivity, safety, and
well-being, should be considered. Objective: We aimed to determine whether or not display curvature is
ergonomically recommendable, especially for monitors and TVs. Methods: Overall, we examined the effect of
display curvature on visual task performance, visual fatigue, and/or watching experience by conducting three different
studies. In Study 1, we examined the effect of display curvature (400R, 600R, 1200R, and flat) on visual task
performance and visual fatigue. A visual search task was performed on 50" multi-monitors. In Study 2, we examined
the effect of display curvature (600R, 1140R, 2000R, 4000R, and flat) on visual task performance, visual fatigue, and
display satisfaction. A proofreading task was performed on 27" monitors. In Study 3, we examined the effect of
display curvature (2300R, 4000R, 6000R, and flat) on presence and display satisfaction. A TV watching task was
done on 55" TVs. Results: First, curved displays increased productivity. The mean visual search accuracy and speed
were both higher at the 50" 600R and 1200R multi-monitor settings, and the mean proofreading speed was the fastest
at the 27" 600R curved monitor setting. Second, curved displays increased safety. The mean visual fatigue was lower
at the 50" 600R and 1200R multi-monitor settings. However, the effect of display curvature on visual fatigue was not
significant in the case of the 27" monitors. Third, curved displays improved well-being. Compared to the 55" flat TV,
the mean spatial presence and engagement did not significantly decrease up to a more lateral viewing position
especially when the display curvature was similar to the viewing distance. The effect of display curvature on display
satisfaction was, however, not significant in Studies 2 and 3. Applications: The findings of three studies suggest that
display curvature, if its level is carefully selected, can improve monitors and TVs in terms of productivity, safety,
and/or well-being.
Keywords: Curved display, visual ergonomics, visual task
1. Introduction
Since the introduction of curved display products (e.g.
monitors, TVs, smartphones, and smart watches) in the
market, there have been a variety of comparative studies
between curved and flat displays.
Recently, it has been shown that curved displays are
advantageous over flat displays in terms of visual task
performance, visual fatigue, preference, and satisfaction
(Czerwinski et al. 2003; kkinen et al. 2008). In
contrast, some negative effects of display curvature
were reported in terms of legibility (Lin et al. 2009;
Wang et al. 2012) and visual processing speed
(Mustonen et al. 2015).
In order to evaluate new display products from the
perspective of visual ergonomics (IEA 2012), three
aspects of productivity, safety, and well-being should be
considered. However, few studies on curved display
have considered all these factors.
The purpose of the current study was to
comprehensively evaluate the effects of display
curvature on visual task performance, visual fatigue,
and viewing experience.
502 
F4-1
Pretest 2Posttest
Rt. 3.28±0.3 3.25± 0.1 0.317
Lt. 3.25±0.3 3.25±0.1 1.000
Rt. 0.32±0.1 0.24± 0.10 0.040
*
Lt. 0.30±0.2 0.26±0.18 0.007
**
138.19±9.6 142.07±9.2 0.009
**
138.36±11.1 142.02±10.2 0.007
**
149.94±10.6 155.65±11.3 0.006
**
149.42±11.3 155.53±10.6 0.010
*
136.39±9.8 140.06±10.7 0.007
**
137.31±9.7 140.95±10 0.006
**
148.24±13.1 151.76±14.1 0.007
**
148.24±12.5 151.78±14.1 > 0.001
***
Rt. 25.95±4.81 27.23± 5.1 0.009
**
Lt. 25.37±4.7 26.45±5.8 0.030
*
M ean±SD
P-values
Rt.
Lt.
Power grip
strength (kg)
Sensory
response
(level)
Sides
Chronaxy (ms)
Paramet ers
Median neural
tension
response
(degrees)
Table 1. Comparison of parameters between Pretest2
and Posttest.
4. Discussion
This study investigated the immediate effects of
Thai dancing for 10 min on median neural tension
responses, chronaxy, power grip strength and sensory
response in people with WMSDs. The result showed
that the degree of elbow extension of all neural tension
responses immediately after Thai dancing for 10 min
were increased. This was confirmed by decreasing of
chronaxy values and increasing of power grip strength,
which was found immediately after Thai dancing. Thus,
from the results of the median neurodynamic test,
strength duration test and grip strength test indicated
that Thai dancing for 10 min could immediately
decrease median neural tension effectively. Thai
dancing is composed of gentle oscillation of maneuver,
repetitive movement and slow rhythm. Due to this
characteristics of the Thai dance, it allows gliding and
sliding of nerve which may increase pumping blood
circulation into the nerves, and bring in more nutrient
and oxygen for the function of nerve (6). So, Thai
dancing-10 min can improve the physiological response
of median nerve as a consequence of decreased neural
tension.
There are some limitations in this study. There was
no control group. However, this study measured pretest
twice. Age of participants was between 21 to 28 years,
indicating early adulthood. Further study should
determine the effect of age on the change of
neurodynamic by Thai dancing. Elderly age may decline
some body systems such as stiffness of joint can inhibit
the gliding of the nerve (10). This study can’t suggest
appropriate duration time and frequency of Thai
dancing program. Further studies should investigate
proper duration and frequency of Thai dancing program
for the best improvement for nerve.
5. Conclusion
People using computers for a long period may
develop median neural tension. This study found Thai
dancing could reduce the neural tension and improve
nerve functions such as sensation, muscle power and
chronaxy value. Therefore, this study suggested that
Thai dancing for 10 min could help people who have
suffered from the early stage WMSDs and it can be
recommended as an exercise for computer users.
References
Staal J.B., DeBie R.A., Hendriks EJM. Aetiology and management of
work-related upper extremity disorders., Best Pract Res Clin
Rheumatol, 21(1), 33-123, 2007.
Ming Z., Zaproudina N. Computer use related upper limb musculoskeletal
(ComRULM) disorders., Pathophysiology, 9, 60-155, 2003.
Ong CN, Chian SE, Jeyaratnam J, Tan KC., Musculosketal disorders
among operators of visual display terminals, Scand J Work Environ
Health, (21), 60-64, 1995.
Butler DS., Mobilization of the nervous system, Longman Cheshire Pty
Limited, Australia.1991.
C. B. Wynn Parry, “Strength-duration curves,” in Electrodiagnosis and
Electromyography, Baltimore. 241-271, 1971.
Mlyamoto MD. Probability of quantal transmitter release from nerve
terminals: theoretical considerations in the determination of spatial
variation, J Theor Biol, 289-304, 1986.
North coast page, https://www.ncmedical.com/item_1278.html (retrieved
April 19, 2017).
Upiriyasakul R., Mekhora J., Jalayondeja W., Alteration of Median Neural
Tension From 4 Hours of Computer Use., The Journal of Ergonomic,
S44-S50, 2016.
Gill, D., Reddon, J., Renney, C., Stefanyk, W., “Hand Dynamometer:
Effects of Trials and Session,” Perceptual and Motor Skills
61:195-198, 1985.
Merck Manual page, http://www.merckmanuals.com/home (retrieved
April 18, 2017).
Values are mean±SD. *p<.05, **p<.01, ***p<.001; Values were
statistically significantly different.
(P1, R1, P2, R2)
Are curved displays ergonomically advantageous over flat
displays? Some positive results from three display curvature
studies on monitors and TVs
Sungryul Park (psr926@unist.ac.kr), Jihhyeon Yi (yjh90@unist.ac.kr), Donghee Choi
(choidh@unist.ac.kr), Songil Lee (songil@unist.ac.kr), Gyouhyung Kyung (ghkyung@unist.ac.kr)
Interaction and Experience Lab, UNIST, Ulsan, Korea, 44919
ABSTRACT
Background: Though curved display products such as curved monitors, TVs, and smartphones are available, it seems
still inconclusive whether or not curved display is ergonomically advantageous over flat display, and if so in terms of
what ergonomic aspects. To examine a visual display comprehensively, three aspects, productivity, safety, and
well-being, should be considered. Objective: We aimed to determine whether or not display curvature is
ergonomically recommendable, especially for monitors and TVs. Methods: Overall, we examined the effect of
display curvature on visual task performance, visual fatigue, and/or watching experience by conducting three different
studies. In Study 1, we examined the effect of display curvature (400R, 600R, 1200R, and flat) on visual task
performance and visual fatigue. A visual search task was performed on 50" multi-monitors. In Study 2, we examined
the effect of display curvature (600R, 1140R, 2000R, 4000R, and flat) on visual task performance, visual fatigue, and
display satisfaction. A proofreading task was performed on 27" monitors. In Study 3, we examined the effect of
display curvature (2300R, 4000R, 6000R, and flat) on presence and display satisfaction. A TV watching task was
done on 55" TVs. Results: First, curved displays increased productivity. The mean visual search accuracy and speed
were both higher at the 50" 600R and 1200R multi-monitor settings, and the mean proofreading speed was the fastest
at the 27" 600R curved monitor setting. Second, curved displays increased safety. The mean visual fatigue was lower
at the 50" 600R and 1200R multi-monitor settings. However, the effect of display curvature on visual fatigue was not
significant in the case of the 27" monitors. Third, curved displays improved well-being. Compared to the 55" flat TV,
the mean spatial presence and engagement did not significantly decrease up to a more lateral viewing position
especially when the display curvature was similar to the viewing distance. The effect of display curvature on display
satisfaction was, however, not significant in Studies 2 and 3. Applications: The findings of three studies suggest that
display curvature, if its level is carefully selected, can improve monitors and TVs in terms of productivity, safety,
and/or well-being.
Keywords: Curved display, visual ergonomics, visual task
1. Introduction
Since the introduction of curved display products (e.g.
monitors, TVs, smartphones, and smart watches) in the
market, there have been a variety of comparative studies
between curved and flat displays.
Recently, it has been shown that curved displays are
advantageous over flat displays in terms of visual task
performance, visual fatigue, preference, and satisfaction
(Czerwinski et al. 2003; kkinen et al. 2008). In
contrast, some negative effects of display curvature
were reported in terms of legibility (Lin et al. 2009;
Wang et al. 2012) and visual processing speed
(Mustonen et al. 2015).
In order to evaluate new display products from the
perspective of visual ergonomics (IEA 2012), three
aspects of productivity, safety, and well-being should be
considered. However, few studies on curved display
have considered all these factors.
The purpose of the current study was to
comprehensively evaluate the effects of display
curvature on visual task performance, visual fatigue,
and viewing experience.
2
2. Method
Three studies on display curvature were done. In the
first study, visual task performance and visual fatigue
were evaluated using a visual search task on a 50"
multi-monitor. In the second study, visual task
performance, visual fatigue, and satisfaction were
evaluated using a proofreading task on five 27"
mock-up monitors. In the third study, the viewer's
presence and satisfaction associated with a TV watching
task were evaluated using four 55" mock-up TVs.
2.1 Study 1
Twe n ty-seven students (male: 14, female: 13) participated
in Study 1. Their mean (SD) age was 20.9 (1.2) yrs.
Exclusion criteria were as follows: having visual acuity < 0.8
(Wu 2011), wearing a pair of glasses, being color blind
based on the Ishihara test (Ishihara and Force 1943), or
suffering from any ocular disease in the past six months.
The multi-monitor used in this experiment consisted of
five display panels [5 display zones; LP171EE3, LG, Korea]
of 244mm (width) Í 382mm (height), and the overall size
was 50" (1220 mm Í 382 mm). The horizontal viewing
distance to the central display (Z3; Figure 1) was 500 mm.
Figure 1. Experimental setting for Study 1
A pseudo text was randomly presented on a display
zone for 3 min, and a visual search task (ISO, 2008) was
repeated twice on each display zone.
Two independent variables were used in Study 1.
Four levels of display curvature (400R, 600R, 1200R,
and flat; within-subjects) were considered. Display
zones (within-subjects) had five levels – Z1 (leftmost),
Z2, Z3 (Center), Z4, and Z5 (rightmost). The order of
presenting the display curvature was determined by
using a 4Í4 Latin Square.
Five dependent variables were used in Study 1. Error
rate and searching speed were used to measure the
visual search task performance. To measure visual
fatigue, a 100mm visual analogue scale (VAS),
eye-complaint questionnaire [(ECQ; Steenstra et al.
(2009)], and critical fusion frequency (CFF) were used.
2.2 Study 2
Fifty students (male: 17, female: 33) participated in Study
2. Their mean (SD) age was 22.3 (1.5) yrs. Exclusion criteria
were the same as in Study 1.
The mock-up monitor used a projected image
(EB-4950WU, EPSON) on a 27" polycarbonate rear screen
(603mm × 346mm; Exzen, Korea; Figure 2). Image
distortion on the screen was corrected using Desktop
Warpalizer® (UniVisual Technologies, Sweden). The
viewing distance used in Study 2 was 600 mm.
Figure 2. Experimental setting for Study 2
Each participant performed a proofreading task on a
screen with a specific curvature. Korean texts from the
Naver Cast (http://navercast.naver.com/) were used for
proofreading. A reference article without grammatical
errors was displayed on the left side of the screen, and
an article with grammatical errors on the right side.
Referring to the left article, each participant needed to
503
Proceedings of The 2nd Asian Conference on Ergonomics and Design 2017
find and mark errors in the article on the right side using
editing symbols.
Two independent variables were used in Study 2.
Five levels of display curvature (600R, 1140R, 2000R,
4000R, and flat; between-subjects) were considered.
Task durations (five levels; within-subjects) were 0, 15,
30, 45, and 60 min. Nine dependent variables were used in
Study 2. Proofreading speed and accuracy, visual
discomfort, subjective visual fatigue,
psychophysiological visual fatigue, blink duration, blink
frequency, mental workload, and display satisfaction
were measured.
2.3 Study 3
Fifty-six students (male: 20, female: 36) participated in
Study 3. Their mean (SD) age was 20.9 (1.5) yrs. Exclusion
criteria for participation were the same as in Study 1. Each
mock-up TV screen used in the experiment was made by
attaching a projection film (Sunnano, Korea) on the front of
a 55" (1218mm × 685mm) styrofoam panel having a
specific curvature. Images were projected on the screen
(Figure 3).
Figure 3. Experimental setting for Study 3
The visual stimuli used in Study 3 consisted of ten 5-min
videos, which was a combination of 1-min sample from five
types of video. One of ten videos was randomly used for
each viewing distance Í viewing location condition. Image
distortions on the screen were corrected using Desktop
Warpalizer ™ (UniVisual Technologies, Sweden).
Three independent variables were used in Study 3. Four
levels of display curvature (2300R, 4000R, 6000R, and flat;
between-subjects) were considered. Viewing distance had
two levels (2.3m and 4m; within-subjects). Lateral viewing
position (within-subjects) had five levels – P1 (Center), P2
(35cm rightward from P1), P3 (70cm), P4 (105cm), and P5
(140cm). Seven dependent variables related to watching
experience were used in Study 3presence, visual comfort,
image quality, and display satisfaction. Presence was further
divided into four categories – spatial presence, engagement,
ecological validity, and negative effects.
3. Results and discussion
3.1 Study 1
In the 50" multi-monitor study, curved display settings
showed a better visual search task performance than the flat
display setting. Compared to the flat setting, the mean error
rate was 20% lower at the 1200R setting, and the mean
speed was 8% faster at the 400R and 600R settings. Task
performance was degraded as the display became planar,
and the display zone was more lateral. The mean error rate
was not significantly different across the display zones of the
curved display settings, while it increased by 37% at Z1
(leftmost) compared to Z3 (center) of the flat display setting.
The mean speed was not significantly different across the
display zones in the case of the 400R and 600R settings,
while it decreased by 10%18% at Z1 and Z5 (the left and
rightmost) compared to Z3 in the case of the 1200R and flat
settings. The mean error rate increased by 8% and the mean
search speed decreased by 2% during the second session,
compared to the first session.
Less visual fatigue was reported at the curved display
settings than at the flat display setting. The mean perceived
visual fatigue was 13% lower at the 600R setting than at the
flat setting. In addition, in the case of the curved display
setting, visual fatigue was similar across the display zones,
while it increased up to 45% at Z1 compared to Z3 in the case
of the flat setting.
3.2 Study 2
The effect of display curvature on proofreading speed on
the 27" monitors was significant. The mean proofreading
speed was 14% faster at the 600R than at the flat. The effect
of task duration on proofreading speed and accuracy was
504 
find and mark errors in the article on the right side using
editing symbols.
Two independent variables were used in Study 2.
Five levels of display curvature (600R, 1140R, 2000R,
4000R, and flat; between-subjects) were considered.
Task durations (five levels; within-subjects) were 0, 15,
30, 45, and 60 min. Nine dependent variables were used in
Study 2. Proofreading speed and accuracy, visual
discomfort, subjective visual fatigue,
psychophysiological visual fatigue, blink duration, blink
frequency, mental workload, and display satisfaction
were measured.
2.3 Study 3
Fifty-six students (male: 20, female: 36) participated in
Study 3. Their mean (SD) age was 20.9 (1.5) yrs. Exclusion
criteria for participation were the same as in Study 1. Each
mock-up TV screen used in the experiment was made by
attaching a projection film (Sunnano, Korea) on the front of
a 55" (1218mm × 685mm) styrofoam panel having a
specific curvature. Images were projected on the screen
(Figure 3).
Figure 3. Experimental setting for Study 3
The visual stimuli used in Study 3 consisted of ten 5-min
videos, which was a combination of 1-min sample from five
types of video. One of ten videos was randomly used for
each viewing distance Í viewing location condition. Image
distortions on the screen were corrected using Desktop
Warpalizer ™ (UniVisual Technologies, Sweden).
Three independent variables were used in Study 3. Four
levels of display curvature (2300R, 4000R, 6000R, and flat;
between-subjects) were considered. Viewing distance had
two levels (2.3m and 4m; within-subjects). Lateral viewing
position (within-subjects) had five levels – P1 (Center), P2
(35cm rightward from P1), P3 (70cm), P4 (105cm), and P5
(140cm). Seven dependent variables related to watching
experience were used in Study 3presence, visual comfort,
image quality, and display satisfaction. Presence was further
divided into four categories – spatial presence, engagement,
ecological validity, and negative effects.
3. Results and discussion
3.1 Study 1
In the 50" multi-monitor study, curved display settings
showed a better visual search task performance than the flat
display setting. Compared to the flat setting, the mean error
rate was 20% lower at the 1200R setting, and the mean
speed was 8% faster at the 400R and 600R settings. Task
performance was degraded as the display became planar,
and the display zone was more lateral. The mean error rate
was not significantly different across the display zones of the
curved display settings, while it increased by 37% at Z1
(leftmost) compared to Z3 (center) of the flat display setting.
The mean speed was not significantly different across the
display zones in the case of the 400R and 600R settings,
while it decreased by 10%18% at Z1 and Z5 (the left and
rightmost) compared to Z3 in the case of the 1200R and flat
settings. The mean error rate increased by 8% and the mean
search speed decreased by 2% during the second session,
compared to the first session.
Less visual fatigue was reported at the curved display
settings than at the flat display setting. The mean perceived
visual fatigue was 13% lower at the 600R setting than at the
flat setting. In addition, in the case of the curved display
setting, visual fatigue was similar across the display zones,
while it increased up to 45% at Z1 compared to Z3 in the case
of the flat setting.
3.2 Study 2
The effect of display curvature on proofreading speed on
the 27" monitors was significant. The mean proofreading
speed was 14% faster at the 600R than at the flat. The effect
of task duration on proofreading speed and accuracy was
4
significant. During the 60-minute task, the mean
proofreading speed increased by 16%, while the
proofreading accuracy decreased by 22%.
The effects of display curvature on visual discomfort,
visual fatigue, mental workload, and display satisfaction
were not significant, while the effect of task duration was
significant. During the 60-min proofreading task, the mean
visual discomfort increased by 207%, the mean perceived
visual fatigue increased by 166%, the mean CFF decreased
by 0.6 Hz (indicating an increase in visual fatigue), and the
mean mental workload increased by 153%.
3.3 Study 3
For the 55" TVs, the mean spatial presence and
engagement were high when the display curvature was equal
to the viewing distance, and began to decrease at a more
lateral viewing position. Compared to the 4000R4m–P1,
which provided the highest mean spatial presence, the mean
spatial presence at the 2300R, 4000R, and 6000R settings at
the viewing distance of 2.3m reduced by 30%39% at P5,
but the mean spatial presence at the flat setting at the same
distance began to reduce by 32%37% at P3. In addition, the
mean spatial presence at the 4000R setting at the viewing
distance of 4m reduced by 32% at P5, while those of the
2300R and flat settings reduced by 32% (at P4) and
31%44% (at P1, P3, P4, and P5), respectively. Compared to
the 4000R4m–P1, which provided the highest mean
engagement, the mean engagement at the curved settings
(2300R, 4000R, and 6000R) at the viewing distance of 2.3m
decreased by 22%27% at P5, but that at the flat setting
decreased by 30% at P3–P5. In addition, the mean
engagement at the 4000R and 6000R settings at the viewing
distance of 4m decreased by 29% and 24% at P5, while those
at the 2300R and flat settings decreased up to 30% at P3–P5.
For ecological validity, negative effects, visual comfort,
image quality, and display satisfaction, no effect was
significant.
4. Conclusions
Three studies examined the effects of display
curvature on user productivity (visual task performance),
safety (visual fatigue and visual discomfort), and
well-being (presence and satisfaction). The results of
these three studies can contribute to determining
appropriate display curvatures for monitors or TVs.
Acknowledgements
This research was supported by the Basic Science
Research Program through the National Research
Foundation of Korea funded by the Ministry of Education
(NRF-2016R1A2B4010158).
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http://www.iea.cc/index.php
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Proceedings of The 2nd Asian Conference on Ergonomics and Design 2017
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Ergonomics of Human-System Interaction -Part 304: User Performance Test Methods for Electronic Visual Displays
ISO, 2008. Ergonomics of Human-System Interaction -Part 304: User Performance Test Methods for Electronic Visual Displays.