Display Curvature Research Articles

Effects of Display Layout on Spatial Memory for Immersive Environments

In immersive environments, positioning data visualisations around the user in a wraparound layout has been advocated as advantageous over flat arrangements more typical of traditional screens. However, other than limiting the distance users must walk, there is no clear design rationale behind this common practice, and little research on the impact of wraparound layouts on visualisation tasks. The ability to remember the spatial location of elements of visualisations within the display space is crucial to support visual analytical tasks, especially those that require users to shift their focus or perform comparisons. This ability is influenced by the user's spatial memory but how spatial memory is affected by different display layouts remains unclear. In this paper, we perform two user studies to evaluate the effects of three layouts with varying degrees of curvature around the user (flat-wall, semicircular-wraparound, and circular-wraparound) on a visuo-spatial memory task in a virtual environment. The results show that participants are able to recall spatial patterns with greater accuracy and report more positive subjective ratings using flat than circular-wraparound layouts. While we didn't find any significant performance differences between the flat and semicircular-wraparound layouts, participants overwhelmingly preferred the semicircular-wraparound layout suggesting it is a good compromise between the two extremes of display curvature.

64‐3: Simulation of Beam Shaping by Micro‐textures for Curved Displays

We simulate the guiding and out‐coupling of light in strongly curved backlight units with edge illumination using a 3D ray‐tracing tool with custom light emission and scattering features. The impact of the display curvature is assessed regarding the uniformity and angular characteristics of light outcoupling in a complex backlight with position‐dependent bottom roughness, a diffuser element and a textured brightness enhancement film.

Curved Versus Flat Monitors: Interactive Effects of Display Curvature Radius and Display Size on Visual Search Performance and Visual Fatigue.

The aim of this study is to examine the interactive effects of display curvature radius and display size on visual search accuracy, visual search speed, and visual fatigue. Although the advantages of curved displays have been reported, little is known about the interactive effects of display curvature radius and size. Twenty-seven individuals performed visual search tasks at a viewing distance of 50 cm using eight configurations involving four display curvature radii (400R, 600R, 1200R, and flat) and two display sizes (33″ and 50″). To simulate curved screens, five flat display panels were horizontally arranged with their centers concentrically repositioned following each display curvature radius. For accuracy, speed, and fatigue, 33″-600R and 50″-600R provided the best or comparable-to-best results, whereas 50″-flat provided the worst results. For accuracy and fatigue, 33″-flat was the second worst. The changes in the horizontal field of view and viewing angle due to display curvature as well as the association between effective display curvature radii and empirical horopter (loci of perceived equidistance) can explain these results. The interactive effects of display curvature radius and size were evident for visual search performance and fatigue. Beneficial effects of curved displays were maintained across 33″ and 50″, whereas increasing flat display size from 33″ to 50″ was detrimental. For visual search tasks at a viewing distance of 50 cm, 33″-600R and 50″ 600R displays are recommended, as opposed to 33″ and 50″ flat displays. Wide flat displays must be carefully considered for visual display terminal tasks.

Curved TVs improved watching experience when display curvature radii approached viewing distances: Effects of display curvature radius, viewing distance, and lateral viewing position on TV watching experience.

Although watching TV often involves multiple viewing distances and viewers, less attention has been paid to the effects of display curvature radius, viewing distance, and lateral viewing position on TV watching experience. This study examined the effects of four display curvature radii (2300R, 4000R, 6000R, and flat), two viewing distances (2.3 m and 4 m), and five lateral viewing positions (P1-P5; 0, 35, 70, 105, and 140 cm off-center) on seven TV watching experience elements (spatial presence, engagement, ecological validity, negative effects, visual comfort, image quality, and user satisfaction). Fifty-six individuals (14 per display curvature radius) were seated in pairs to watch videos, each time at a different viewing position (2 viewing distances × 5 paired lateral viewing positions). The spatial presence and engagement increased when display curvature radius approached a viewing distance and lateral viewing position approached P1, with 4000R-4m-P1 (display curvature radius-viewing distance-lateral viewing position) providing the best results. Lateral viewing position alone significantly affected five TV watching experience elements; the spatial presence and engagement decreased at P3-P5, and ecological validity, image quality, and user satisfaction decreased at P4-P5. However, display curvature radius alone did not appreciably affect TV watching experience, and viewing distance alone significantly affected visual comfort only, with a 4-m viewing distance increasing visual comfort. This study demonstrated that effective display curvature radii for watching TV are viewing distance-dependent, and less off-center lateral viewing positions (P1-P2) are recommended for TV watching experience. Finally, among the TV watching experience elements, engagement explained user satisfaction to the greatest degree.

Effects of display curvature and task duration on proofreading performance, visual discomfort, visual fatigue, mental workload, and user satisfaction

This study examined the effects of display curvature and task duration on proofreading performance, visual discomfort, visual fatigue, mental workload, and user satisfaction. Five 27″ rear-screen mock-ups with distinct curvature radii (600R, 1140R, 2000R, 4000R, and flat) were used. Ten individuals per display curvature completed a series of four 15 min comparison-proofreading trials at a 600 mm viewing distance. Only proofreading speed benefited from display curvature, with 600R providing the highest mean proofreading speed. Proofreading speed increased and accuracy decreased for all display curvatures over the 1 h proofreading period. Visual discomfort, visual fatigue, and mental workload increased during the first 15 min of proofreading. A decrease in critical fusion frequency during that period indicated increases in visual fatigue and mental workload. A short break between 15 min proofreading tasks could be considered to prevent further degradation of task performance and ocular health.

Ambivalent effects of display curvature on smartphone usability

The current study examined the effects of display curvature and hand length on various smartphone usability measures. In total, 20 young participants completed reading, image viewing, video watching, calling, and texting using four smartphone devices with distinct display curvatures. Diverse usability measures related to these tasks were obtained. The four curvatures (flat, horizontally convex, vertically concave, and horizontally concave) each demonstrated both beneficial and detrimental effects; however, hand size effects were non-significant across all usability measures. No single fixed display curvature was found to be beneficial across all considered smartphone usability measures, indicating multiple curvatures (e.g. combinations of flat and vertically concave curvatures) are required from a single smartphone model rather than a single fixed curvature to improve an overall smartphone usability. Such varying curvatures are feasible with bendable displays. Comprehensive usability evaluations, especially focusing on grip comfort and image distortion, are needed when applying display curvatures on small devices.

Effects of Display Curvature, Presbyopia, and Task Duration on Visual Fatigue, Task Performance, and User Satisfaction.

This study examined the effects of display curvature, presbyopia, and task duration on visual fatigue, task performance, and user satisfaction. Although curved displays have been applied to diverse display products, and some studies reported their benefits, it is still unknown whether the effects of display curvature are presbyopia-specific. Each of 64 individuals (eight nonpresbyopes and eight presbyopes per display curvature) performed four 15-min proofreading tasks at one display curvature radius setting (600R, 1140R, 4000R, and flat; mm). Diverse measurements were obtained to assess visual fatigue, task performance, and user satisfaction. The mean pupil diameter was the largest with 1140R, indicating this curvature radius was associated with the least development of visual fatigue; 600R was comparable with 1140R in terms of pupil diameter. The presbyopic group showed a 28.5% slower proofreading speed compared with the nonpresbyopic group, whereas their proofreading accuracy was comparable. For both groups, the mean visual fatigue increased significantly during the first 15 min of proofreading, as indicated by a decrease of 0.11 mm in the mean pupil diameter, an increase of 3.8 in the mean bulbar conjunctival redness, and an increase of 9.13 in the mean eye complaint questionnaire score. The effect of display curvature was not presbyopia-specific. Low visual fatigue was observed with 1140R and 600R. Display curvature radii near or in the range of 600R and 1140R and frequent breaks are recommended for both presbyopic and nonpresbyopic groups to reduce their visual fatigue due to visual display terminal tasks.

P‐93: Optimization of Multi‐Projector Light‐Field Display Based on Convex Display Properties

An optimized convex multi‐projector light‐field display system is proposed. The effect of display curvature on the image are analyzed. The projector positions and viewing distances are discussed. A convex light‐field display is constructed based on the optimized parameters, and is compared with a planar counterpart to verify the enhancements.

Effects of display curvature and hand length on smartphone usability

The purpose of this study was to examine the effects of display curvature and hand length on smartphone usability, which was assessed in terms of grip comfort, immersive feeling, typing performance, and overall satisfaction. A total of 20 younger individuals with the mean (SD) age of 20.8 (2.4) yrs were divided into three hand-size groups (small: 8, medium: 6, large: 6). Two smartphones of the same size were used – one with a flat display and the other with a side-edge curved display. Three tasks (watching video, calling, and texting) were used to evaluate smartphone usability. The smartphones were used in a landscape mode for the first task, and in a portrait mode for the other two. The flat display smartphone provided higher grip comfort during calling (p = 0.008) and texting (p = 0.006) and higher overall satisfaction (p = 0.0002) than the curved display smartphone. The principal component regression (adjusted R2 = 0.49) of overall satisfaction on three principal components comprised of the remaining measures showed that the first principal component on grip comfort was more important than the other two on watching experience and texting performance. It is thus necessary to carefully consider the effect of display curvature on grip comfort when applying curved displays to hand-held devices such as smartphones.

F5-1 Effects of display curvature and hand length on smart watch touch interaction

The objective of the current study was to examine the effects of display curvature on smart watch touch interaction. A total of 36 younger individuals with the mean (SD) age of 22.2 (3.3) yrs were divided into three groups according to the length of their dominant hand. Each hand-size group was comprised of 12 individuals. Two smart watches were used, one with a flat display and the other with a curved display. To evaluate touch interaction, two types of touch gesture (short and long touches) and four types of swiping gesture (upward, downward, leftward, and rightward swiping) were considered. The flat display smart watch provided better touch and swiping feels during upward and downward swiping, higher swiping satisfaction with respect to touch, swiping, and gap feels, and higher overall touch interaction satisfaction with respect to touch and swiping gestures. The curved display smart watch provided more errors during leftward and downward swiping. Touch and swiping feels during upward and downward swiping were more influenced by display curvature. In the case of the smart watch display that is curved along the wrist, the index finger appeared to lose contact with the touch screen earlier than intended during upward and downward swiping.

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

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

Effects of display curvature, display zone, and task duration on legibility and visual fatigue during visual search task

This study examined the effects of display curvature (400, 600, 1200 mm, and flat), display zone (5 zones), and task duration (15 and 30 min) on legibility and visual fatigue. Each participant completed two 15-min visual search task sets at each curvature setting. The 600-mm and 1200-mm settings yielded better results than the flat setting in terms of legibility and perceived visual fatigue. Relative to the corresponding centre zone, the outermost zones of the 1200-mm and flat settings showed a decrease of 8%–37% in legibility, whereas those of the flat setting showed an increase of 26%–45% in perceived visual fatigue. Across curvatures, legibility decreased by 2%–8%, whereas perceived visual fatigue increased by 22% during the second task set. The two task sets induced an increase of 102% in the eye complaint score and a decrease of 0.3 Hz in the critical fusion frequency, both of which indicated an increase in visual fatigue. In summary, a curvature of around 600 mm, central display zones, and frequent breaks are recommended to improve legibility and reduce visual fatigue.

Effects of Display Curvature and Task Duration on Proofreading Task Performance, Visual Fatigue, Visual Discomfort, and Display Satisfaction

With more curved display products in the market and more exposure to such products, it is necessary to examine the effects of display curvature and task duration from the ergonomics perspective. The current study examined the effects of these two factors on visual performance, visual fatigue, visual discomfort, and display satisfaction during proofreading tasks. We incorporated five display curvatures (600R, 1140R, 2000R, 4000R, and flat) and five task durations (0, 15, 30, 45, and 60 min). Each of 50 individuals completed a 1-hr proofreading task at one of five display curvature conditions. The horizontal viewing distance was fixed at 600mm. Proofreading performance (speed and error rate), subjective visual fatigue [on ECQ (Eye Complaint Questionnaire)], physiological visual fatigue [CFF (Critical Fusion Frequency), blink duration, and blink frequency], visual discomfort (on VAS), and display satisfaction (on VAS) were measured. The highest mean proofreading speed was at 600R. The mean proofreading speed and error rate increased by 15.5% and 22.3%, respectively, over the 1-h task. The mean ECQ score and visual discomfort increased by 188.6% and 107.2% during 45 and 60 min of the task, respectively. The mean CFF and display satisfaction decreased by 0.49Hz and 11.2% during 15 and 15-45 min of the task. A polynomial regression model for subjective visual fatigue was developed (adjusted R2 = 0.6). These findings can be used when determining ergonomic display curvatures and predicting visual fatigue.

66-4: Effects of Display Curvature and Lateral Viewing Position on Spatial Presence and Image Quality for 55″ TVs

66-4: Effects of Display Curvature and Lateral Viewing Position on Spatial Presence and Image Quality for 55″ TVs

Effects of Large Display Curvature on Postural Control During Car Racing Computer Game Play

Effects of Large Display Curvature on Postural Control During Car Racing Computer Game Play

A study on the optimum curvature for the curved monitor

Curved displays have been actively developed beyond the limits of the conventional flat displays. The curved displays are known to be advantageous for immersion, preferences, and viewing convenience. As such, it is necessary to conduct ergonomic studies on the curvature of the curved display. In this study, experiments were conducted to determine the optimal curvature of the curved display for six kinds of contents. The results of the experiments showed that the optimal curvature is 560.9 mm at the standard viewing distance of 600 mm, which can be considered an evidence that there is an intriguing correlation between the viewing distance and the display curvature. It is expected that the results of this study would improve the existing display products and would provide ergonomic guidelines for the users.

P‐30: A Study on Viewing Zone of Curved Barrier‐type Auto‐stereoscopic Display

Based on previous studies on the viewing zone and design results of planar barrier‐type autostereoscopic displays, this study introduces a display curvature to rederive the designed eye position and viewing zone for flexible displays. To maintain the same viewing quality, we suggest to design ZDEP = 2L for maximized viewing zone, and R ≥ ⅔ ZDEP to avoid forward shifts of the designed eye position.

Visual Performance With Small Concave and Convex Displays.

In this study, we aim to investigate how users' visual performance with a small flexible display changes based on the direction (i.e., convex, concave) and the magnitude (i.e., low, high) of the display curvature. Despite the wide interest in flexible display materials and deformable displays, the potential effects of nonplanar display surfaces on human perception and performance have received little attention. This study is the first to demonstrate how curving affects visual performance with an actual flexible display (4.5-in. active-matrix organic light-emitting diode). In a series of three experiments, we compared the performance with a planar display to the performance with concave and convex display surfaces with low and high curvature magnitudes. Two visual search tasks were employed that required the subject to detect target letters based on their contrast (Experiments 1 and 2) and identity (Experiment 3). Performance was measured as the sensitivity of target detection (d') and threshold time of the search, respectively. There were similar sensitivities for targets across the curvature variants, but the high-magnitude curvatures resulted in prolonged search times, especially for the convex form. In both of the tasks, performance was dependent on the display location, which was defined as the target's distance from the display center. High curvature magnitudes should be avoided, even in small displays, because large local changes in visual stimuli decrease processing speed outside the central display. The findings have implications for the development of technologies, applications, and user interfaces for flexible displays and the design of visual display devices.

11.3: A Curvature Sensing Circuit for Flexible Display

AbstractA sensory system able to measure the geometric profile of a flexible display is proposed. The sensory system is embedded within the flexible display and manufactured by the thin‐film transistor process. The sensory system provides an alternative user‐display interaction for flexible display applications. A numerical interpolation technique is proposed for the display curvature computation. The sensor performances of three different materials are respectively investigated for the accuracy consideration. Preliminary results seem promising through an embodiment of the design.

The Forbidden Transition ofYttrium91andCesium137

${\mathrm{Y}}^{91}$ decays by the emission of a single beta-particle with a maximum energy of 1.54 Mev, while ${\mathrm{Cs}}^{137}$ decays in two ways, (1) beta-decay (maximum energy=0.518 Mev) to ${\mathrm{Ba}}^{137*}$ followed by a gamma-transition to the ground state, and (2) beta-decay (maximum energy=1.2 Mev) directly to the ground state. Probably not more than 5 percent of the ${\mathrm{Cs}}^{137}$ nuclei decay directly to the ground state. Conventional (allowed transition) Kurie plots of ${\mathrm{Y}}^{91}$ and the low energy group of beta-particles of ${\mathrm{Cs}}^{137}$ display curvature which is concave toward the energy axis at high energies and concave upward at low energies. If it is assumed that Gamow-Teller selection rules govern the beta-process, the Fermi function $F(Z,W)$ for allowed spectra must be multiplied by a factor $G=({W}^{2}\ensuremath{-}1)+{({W}_{0}\ensuremath{-}W)}^{2}$ in a beta-transition for which there is a change of parity and for which the spin change is two units. If these conventional Kurie plots of ${\mathrm{Y}}^{91}$ and ${\mathrm{Cs}}^{137}$ are modified by the factor $G$, the resulting plots are approximately straight lines. This indicates that the beta-decay of ${\mathrm{Y}}^{91}$ and the low energy beta-decay of ${\mathrm{Cs}}^{137}$ involve a spin change of two units and a parity change. These results contribute evidence for the validity of the Fermi theory of beta-decay and the Gamow-Teller selection rules.The $K$ internal conversion coefficient for the 0.663-Mev gamma from the decay of ${\mathrm{Cs}}^{137}$ was found to be 0.081, while the ratio of the $K$ conversion electrons to the $L$ conversion electrons was 5.0. The gamma-radiation seems to be either magnetic ${2}^{4}$-pole or electric ${2}^{5}$-pole.