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en: Analysis and fabrication for the dimensional expansion of arc 3D display to cone-shaped display

en: This paper successfully describes the analysis between 3D image location in air and arc-shaped scratches on cone-shaped arc 3D display. The arc 3D display is typically flat and its analysis has already appeared. However, when we would like to extend it to cone shape, the dimensional extension of analysis should be necessary, since the lack of adequate analysis increases the approximation error of the 3D image location. In this paper, we discuss the three-dimensional analysis for cone-shaped arc 3D display. In addition, we describe the actual fabrication of a cone-shaped arc 3D display and show that the 3D image can be displayed similarly with the analysis.

en: Optical Review

ja: Optical Review


en: Accommodation and vergence responses to electronic holographic displays and super multiview holographic stereograms

en: Electronic holography is an ideal 3-D display technique to ameliorate the vergence-accommodation conflict, which is a possible cause of visual fatigue and discomfort from viewing conventional stereoscopic 3-D displays. Previous studies have measured accommodative and vergence responses to holographic images and to real objects, and the results showed that these responses are in good agreement. To demonstrate the effectiveness of electronic holography as a possible solution to the vergence-accommodation conflict caused by viewing conventional stereoscopic 3-D displays, we measured both accommodative and vergence responses to reconstructed images of holograms and super multiview holographic stereograms. We also measured responses to real objects located at various distances and conventional two-view stereo images for comparison. The results indicate that the accommodative responses to the electro-holographic display and super multiview holographic stereogram change with the vergence response in a similar manner, as is the case with real objects as compared to conventional two-view stereo display. This suggests that the electronic holographic display and super multiview holographic stereograms are promising candidates for resolving the vergence-accommodation conflict.

en: IEEE Transactions on Industry Applications


en: Unstable depth perception of aerial images in crossed mirror array can be controlled by changing fixation distance

en: The unstable depth perception of aerial images in a crossed-mirror array (CMA) can be improved by changing the distance of fixation points. The perceived depths of aerial images in CMA suffer from large instability even when an aerial image is a geometrical optical real image. The perceived depth instability of aerial images is mainly influenced by their geometrical position from CMA. The perceived depths of aerial images shift toward the fixation points, and the stable depth perception of aerial images can be obtained if the fixation points are located near the aerial image distance. To stabilize the depth perception of aerial images, it is sufficient to appropriately control the observer's vergence even if the fixation point is not a real object. In addition, the luminance of aerial images affects the stability of their depth perception.

ja: IEEE Transactions on Industry Applications


en: Theoretical and Experimental Perceived Depths in Arc 3D Display and Its On/Off Switching Using Liquid-Crystal Active Devices

en: IEEE Industry Applications Magazine

ja: IEEE Industry Applications Magazine


en: Edge-Based DFD (Depth-Fused 3D) Display with Enlarged Viewing Angle & Maximum Perceived Depth


en: Importance of visual information at change in motion direction on depth perception from monocular motion parallax

en: This article demonstrates the importance of visual information on depth perception from monocular motion parallax presented at the time of change in the motion direction of head and stimulus movements. In head-tracking systems, a longer delay time between the head and stimulus movements degrades the depth perception from the monocular motion parallax. Because this delay is noticeable at this time, we hypothesized that the visual information given at the time of the direction change plays a critical role in the depth perception from motion parallax. We evaluated depth perception from monocular motion parallax with and without a visual stimulus at the time of the motion direction change to confirm our hypothesis and clarified that stable and unambiguous depth can be perceived by presenting the change of the stimulus motion direction. We also demonstrated that it is the change in motion direction itself that is important rather than the temporal stop between deceleration and acceleration of the stimulus motion.


en: Super multi-view 3D displays reduce conflict between accommodative and vergence responses

en: Journal of the Society for Information Display


en: Difference between Perceived Sizes of a Real 3D Object and the 2D Image

ja: 三次元実物体とその二次元画像に対する大きさ知覚の違い

en: 実物体の知覚的大きさと,写真やビデオ映像などにおけるその物体の二次元像の知覚的大きさが異なることが経験的に知られている.しかしこの現象が,刺激のどのような要素と関連があるのか,またなぜ生じるのかについては明らかであるとは言えない.そもそもこの現象は,実物体とその二次元画像を観察する際の観察条件などの違いによるアーティファクトの可能性も考えられる.そこで本研究では,頭部の三次元模型及び単純な凹凸形状をもつ三次元実物体とそれらの写真画像の知覚的大きさの比較実験により,この現象を定量的に記述し,その原因を明らかにすることを目的とした.実験の結果,頭部模型の二次元画像は実物体より数パーセント程度横に広がって知覚されることが示された.また,単純な物体についても,実物体に対する二次元画像の知覚的大きさの拡大が見られ,その拡大の方向は,対象物体の奥行きに変化がある方向に沿っていることが明らかになった.この現象における,実物体を観察する際に左右眼像に生じる単眼領域の影響,及び実物体とその二次元画像を観察する際の知覚的奥行きの違いによる影響を考察した.

en: The Transactions of the Institute of Electronics, Information and Communication Engineers A

ja: 電子情報通信学会論文誌(A)


en: Accommodative and Vergence Responses to Super Multi-View 3D Images

ja: 超多眼立体表示に対する調節・輻輳応答

en: A super multi-view (SMV) 3D display has been proposed for reducing conflict between accommodation and vergence, which is a possible cause of visual fatigue. Previous studies reported that measured accommodative responses to SMV images were similar to those of real objects. We need to measure vergence response along with accommodative response to investigate the conflict between them. In this study, we measured accommodative and vergence responses while observers were viewing a static visual target presented on an SMV display. We also examined the responses to two-view displays and real objects for comparison. The results show that the SMV display induced a natural accommodative response relative to the two-view 3D display while no difference was found among the viewing conditions of the vergence response. This suggests that the SMV 3D display is effective for reducing conflict between accommodative and vergence responses.

en: The Journal of the Institute of Image Information and Television Engineers

ja: 映像情報メディア学会誌


en: Static and Dynamic Characteristics of Accommodation and Vergence Responses while Viewing Stereoscopic Displays and Real Objects

ja: 立体映像および実物体観視時の調節・輻輳応答の静特性と動特性

en: The conflict between accommodation and vergence stimuli has been identified as a possible cause of visual fatigue from viewing stereoscopic images. We examined static and dynamic characteristics of accommodation and vergence responses while viewing stereoscopic displays and real objects to clarify the effect of stereoscopic images on the visual function. We used an instrument based on the Shack-Hartmann wavefront sensor to measure accommodation and vergence responses simultaneously. Accommodation responses to the static stereoscopic target with large binocular disparity were deviated from those to the real target, i.e., static characteristics. The step responses of the accommodation response showed considerable individual differences, i.e., dynamic characteristics. In addition, the asymmetries of step responses of accommodation were observed between the near-to-far and the far-to-near step directions. These results suggest that we need to examine both static and dynamic characteristics of accommodation and vergence responses to clarify the biological effect of stereoscopic images.


en: The Relationship between Psychological Stress Induced by Task Workload and Dynamic Characteristics of Saccadic Eye Movements

ja: 課題遂行時の作業負荷により誘発された心理的ストレスとサッカード眼球運動の動特性との関係

en: 機器使用時のユーザの心理的ストレスを客観的に評価するために,心拍や皮膚導電率等の生体信号を用いる手法が提案されている.しかしそれらの手法には電極の装着等の煩わしさが伴うため,それ自体がストレスの原因となる可能性もある.その点において,眼球運動は非接触で計測可能であるため,ストレスの優れた指標になり得ると考えられる.本論文はそのための基礎的な知見を得ることを目的とし,多様な課題の遂行時における眼球運動を計測した.また,そのときの心理状態の主観評価も併せて行い,眼球運動の特性との対応を検討した.その結果,課題によって時間的な切迫感を与えた場合に,振幅の小さいサッカード眼球運動の分布における振幅の平均値と主観的な「焦り感」との間に正の相関が見られた.このことから,サッカード眼球運動の動特性が心理的ストレスの指標として利用できる可能性が示された.一方,課題の遂行に関連すると考えられる振幅の大きなサッカードの分布においては,眼球運動の動特性と心理状態との間に相関は見られなかった.このことから,心理状態は課題の遂行に関連しない振幅の小さい眼球運動により強く反映されると考えられる.

en: The IEICE transactions on information and systems (Japanese edetion)

ja: 電子情報通信学会論文誌. D, 情報・システム


en: Effect of Texture Continuity on the Depth Discrimination Threshold of Binocular Disparity

ja: テクスチャーの連続性が両眼視差による奥行き弁別閾値に与える影響

en: JAPANESE JOURNAL OF OPTICS

ja: 光学


en: The Relationship between Pupil Diameter and Psychological Stress Induced by Task Workload for Young and Elderly People

ja: 若年者及び高齢者における課題遂行時の作業負荷による瞳孔径変動と心理的ストレスの対応

en: 機器使用時におけるユーザの心理的ストレスを客観的に評価することは,人間に優しいヒューマンマシンインタフェースを設計する上で重要である.しかし,従来提案されている心拍・脳波・皮膚電位等の生体信号をストレスの指標とする場合,電極の装着等の煩わしさが生じる.その点において,非接触で計測可能な瞳孔径は優れた指標になり得ると考えられる.また指標の汎用性を考慮すると,幅広い年齢層のユーザに適用可能なことが重要である.本論文ではその基礎的な知見を得るために,若年者と高齢者を対象に,多様な課題の遂行時における瞳孔径を計測し,そのときの心理状態の主観評価との対応を検討した.その結果,本研究で用いた3種類の作業負荷条件下においては,いずれの場合も負荷量の増大とともに瞳孔径変動量が増大した.また,タイムプレッシャーを与えた場合と聴覚刺激の識別難易度を操作した場合においては,心理的ストレスの要因となり得る「不安感」の主観評価と瞳孔径変動量との間に相関が見られた.瞳孔径変動に関しては,定性的には若年者と高齢者でほぼ同様の挙動が観察されたため,心理的ストレス指標として幅広い年齢層に適用できる可能性が示された.

ja: 電子情報通信学会論文誌(A)


en: Effects of Tilt of the Visual Stimuli on the Perception of Gravitational Vertical under Normal- and Hyper-Gravity Conditions

en: Optical Review


en: Effects of Visual Tilt, Kind of Images and Body Orientation on the Perception of Gravitational Orientation

ja: 重力方向知覚における視覚刺激の傾きと種類および身体の傾きの影響


en: The cyclopean illusion unleashed.

ja: The cyclopean illusion unleashed.

en: The cyclopean illusion is the apparent lateral shift of stationary stimuli on a visual axis that occurs when vergence changes. This illusion is predictable from the rules of visual direction. There are three stimulus situations reported in the literature, however, in which the illusion does not occur. In the three experiments reported here we examine those stimulus situations. Experiment 1 showed that an afterimage seen on a stimulus moving on the visual axis does not produce the illusion as reported in the literature but an afterimage seen on a screen does. Experiment 2 showed that the illusion occurs for an intermittently presented stimulus in contrast to what has been reported previously. Experiment 3 showed that a monocular stimulus presented against a random-dot background produced the illusion, also in contrast to what has been reported. The results were consistent with the rules of visual direction.

en: Vision Research

ja: Vision Research


en: Effects of Stimulus Size on Detection of Stimulus Displacement Across Saccade

ja: サッカード時の刺激変位知覚における刺激サイズの影響

en: VISION

ja: VISION


en: Displacement detection across saccade in a whole visual field

ja: 全視野刺激によるサッカード時の変位検出


en: 新入生への「スタディスキルズ教育」システム

ja: 新入生への「スタディスキルズ教育」システム

en: 高知工科大学紀要

ja: 高知工科大学紀要