Journal of the Society for Information Display最新文献

Though micro-LED (light-emitting diode) displays are considered the emerging display technology, the micron-scale LED chip size encounters severe efficiency degradation that may impact the power budget of the displays. This work proposes an ion implantation method to deliberately create a high-resistivity sidewall in the InGaN/GaN green LED. Our study demonstrates that ion implantation suppresses reverse leakage current due to the mitigation of sidewall defects. For an LED mesa size of 10 × 10 μm², optical output power density is improved by 36.2% compared to the device without implantation. Compared to a larger 100 × 100 μm² device without implantation, we achieve only 21.3% degradation of output power density under 10 A/cm² injection for a 10 × 10 μm² LED with implantation. In addition, the ion implantation method can lower the wavelength shift by reducing light emission from the region near the sidewall (where the amount of Indium [In] clustering differs from the mesa region). The results show promise in addressing the efficiency challenges of micro-LED displays by selective ion implantation.

Many low-power technologies have been developed for high-performance displays. One method is to vary the refresh rate according to the input image, where frequencies are reduced over still images and slow-moving videos. To support the variable refresh rate scheme, the programmable gate driver circuit should be integrated. This paper proposes a thin-film transistor (TFT) shift register of which output pulse is simply controlled by an enable signal. Because the output pulse generation is directly adjusted without the previous programming period, various output pulse sequences are possible with the high flexibility. The shift register is composed by adding six TFTs and one capacitor to a conventional circuit that provides a carry pulse to a next stage. The simulation program with integrated circuit emphasis (SPICE) simulation ensures that gate pulses for any numbers of lines in any regions can be generated within one frame only by applying the enable signal at the corresponding timing, resulting in multiple refresh frequencies in a screen. In addition, it is verified that additional TFTs and capacitor contribute to only the negligible increase in power consumption by 2.1%, compared to a conventional shift register.

We propose a rendering method that enables the perception of 3D images at precise positions independent of the interocular distance of the observer by combining stacked stereo display and depth-fused 3D (DFD) display and confirm its effectiveness through evaluation experiments. The depth range that can be expressed in stereo displays causes discomfort in observers because of the discrepancy between vergence and accommodation. However, the depth perceived differs depending on the interocular distance of the observer, resulting in discontinuity of the 3D image. Therefore, we propose a rendering method for stacked stereo displays that is independent of the observer's interocular distance using DFD display.

Cybersickness is a major problem hindering the use of fully immersive virtual reality (VR) systems. A mismatch between the interpupillary distance (IPD) and the inter-optical system distance (IOSD) can cause discomfort when using VR devices. To solve this, the IOSD must be aligned according to the user's IPD. Herein, we investigated the effects of the optimum alignment of IPD and IOSD on eye fatigue when using VR systems. A method was used such that the IPD and IOSD for each participant were initially aligned under the condition that binocular fusion did not occur by displaying different left and right images. Fifteen university students aged 20–26 years were included. In the alignment and misalignment states, a symptom questionnaire was used to evaluate changes in the symptoms of participants after viewing a short movie using the VR device. We found that the obtained results in the eye strain category were statistically improved in the aligned state compared with those in the misaligned state. However, there were no significant differences in the general discomfort, nausea, focusing difficulty, or headache categories. Consequently, we confirmed that the alignment of the VR device using the proposed method can reduce eye fatigue when viewing VR content.

Increases in display resolution, frame rate, and bit depth, particularly with advances in stereoscopic 3D (S3D) displays, have increased demand for efficient compression throughout the imaging pipeline. To meet such requirements, typically the aim is to reduce bandwidth while presenting content that is visually indistinguishable from the original uncompressed versions. Subjective image quality assessment is essential and multiple methods have been proposed. Of these, the ISO/IEC 29170-2 flicker paradigm is a rigorous method used to define visually lossless performance. However, it is possible that the enhanced sensitivity to artifacts in the presence of flicker does not predict visibility under natural viewing conditions. Here, we test this prediction using high-dynamic range S3D images and video under flicker and non-flicker protocols. As hypothesized, sensitivity to artifacts was greater when using the flicker paradigm, but no differences were observed between the non-flicker paradigms. Results were modeled using the Pyramid of Visibility, which predicted artifact detection driven by moderately low spatial frequencies. Overall, our results confirm the flicker paradigm is a conservative estimate of visually lossless behavior; it is highly unlikely to miss artifacts that would be visible under normal viewing. Conversely, artifacts identified by the flicker protocol may not be problematic in practice.

A new gate driver with metal oxide thin-film transistors (MO-TFTs) has been presented for micro-light-emitting diode (Micro-LED) display. The proposed gate driver employing linearly decreasing sweep signal generated module could realize the line-by-line pulse width modulation (PWM) driving method, which is valuable for application in high-resolution Micro-LED display compared with the conventional driving method employing global sweep signal. A simple Micro-LED pixel circuit including an inverter module driven by the analog PWM method is employed to demonstrate the feasibility of the proposed gate driver. A 10 × 10 green Micro-LED display array has been fabricated with MO-TFTs backplane technology. It is shown that a 10-μs width pulse and linearly scanning sweep signal can be successfully output. Consequently, the pixel circuit array can be driven properly under analog line-by-line PWM driving method.

A head-up display (HUD) is conveniently used to provide information on the display without changing the user's gaze. 3D HUDs, capable of projecting three-dimensional information beyond the 2D HUDs, enable the projection of augmented reality (AR) objects into the real world. Research on the perception of 3D AR HUDs is crucial for their efficient utilization and secure commercialization. In this study, we examined whether a 3D HUD is more comfortable than a 2D HUD in the context of viewing real-world environments and augmented reality objects together. Additionally, we analyzed participants' perception of distance and fatigue for AR objects at varying distances from the 3D HUD. The study found that using a 3D HUD in an AR environment resulted in less fatigue than using a 2D HUD, as determined by a Mann–Whitney statistical analysis. Participants were able to match the depth of AR objects in a 3D HUD within a range of 3 to 50 m, with similar diopter and parallax angular distance errors, regardless of the distance of the AR object. Visual fatigue increases with increasing distance from the virtual-image plane and can be modeled as a quadratic function in the domain of diopter and parallax angles.

Building on several decades of research and development, the recent progress in virtual reality (VR) and augmented reality (AR) devices with spatial computing technologies marks a significant leap in human–computer interaction, with applications ranging from entertainment and education to e-commerce and healthcare. Advances in these technologies promise immersive experiences by simulating and augmenting the real world with computer-generated digital content. The core objective of the VR and AR systems is to create convincing human sensory perceptions, thereby creating immersive and interactive experiences that bridge the gap between virtual and physical realities. However, achieving true immersion remains a goal, and it necessitates a comprehensive understanding of the neuroscience of human multisensory perception and accurate technical implementations to create a consistency between natural and synthetic sensory cues. This paper reviews the human sensory-perceptual requirements vital for achieving such immersion, examines the current status and challenges, and discusses potential future advancements.

Fatigued driving is one of the main causes of traffic accidents. In order to improve the detection speed of fatigue driving recognition, this paper proposes a driver fatigue detection method based on multi-parameter fusion of facial features. It uses a cascaded Adaboost object classifier to detect faces in video streams. The DliB library is employed for facial key point detection, which locates the driver's eyes and mouth to determine their states. The eye aspect ratio (EAR) is calculated to detect eye closure, and the mouth aspect ratio (MAR) is calculated to detect yawning frequency and count. The detected percentage of eye closure (PERCLOS) value is combined with yawning frequency and count, and a multi-feature fusion approach is used for fatigue detection. Experimental results show that the accuracy of blink detection is 91% and the accuracy of yawn detection is 96.43%. Furthermore, compared to the models mentioned in the comparative experiments, this model achieves two to four times faster detection times while maintaining accuracy.

Mixed reality technology can be applied to simulation training, improve surgical performance, enhance 3D game experience, and so on, attracting extensive attention of researchers. The perception of the user about head-mounted display MR using HoloLens is critical, especially for precision applications such as virtual hoisting. Designing and adding appropriate depth cues in MR scenes is an effective way to improve users' depth perception. In this study, taking virtual hoisting training system as an example, the depth perception strategy of multi-cue fusion is proposed to improve the perception effect. Based on the mechanism of human depth perception, five kinds of depth cues are designed. The depth perception effect of adding single cue is studied by perceptual matching experiment. Based on the principle of fuzzy clustering, a multiple-cue comprehensive depth optimization strategy on viewing distance scale is proposed. Finally, the perceptual matching results demonstrate the effectiveness of the multi-cue fusion strategy, and the average error is reduced by 20.68% compared with the single-cue strategy, which can significantly improve the spatial depth perception. This research can provide a reference for improving users' depth perception in interactive MR simulation systems.