Journal of the Society for Information Display最新文献

Micro-LED displays are widely acknowledged as upcoming display innovations. However, the reduced size of micro-LED devices may compromise their light extraction efficiency. Additionally, the encapsulation structure required for the finished product of micro-LED displays leads to about a 40% loss in light intensity compared to only LED chips without encapsulation. This paper extends the EQE equation and implements a LEE secondary optics factor (the secondary optics of light extraction efficiency). We consider four different optical effects on micro-LED displays, including refraction, reflection, black matrix, and focusing. The main purpose of this paper is to study how to enhance the display-level light extraction and LEE secondary optics parameters under different conditions. We conduct optical simulations for three different LED sizes and various structures, including glue, black matrix, white glue, and microlens array. Comparing the simulation results with real experiment results, our findings show that a combination of black and white glue structures resulted in a 20% enhancement in efficiency compared to using black glue alone. Furthermore, the microlens structure led to a significant 45% enhancement in normal angle intensity compared to the protective glue structure.

Eyebox expansion of retinal projection-based augmented reality display may lead to image deviation from the fovea of the human eye. Hence, this paper proposes an eyebox-extended retinal projection display (RPD) with gaze-matching for augmented reality. The system's exit pupil is a composite image combiner composed of three holographic optical elements (HOEs). Each HOE is positioned at a specific location on the waveguide, allowing the diffracted beams to be imaged on the fovea of the human eye. Gaze-matching is achieved. In the experiment, the RPD systems of the traditional structure and proposed structure were both established in Zemax software for simulation. A detector was added at the retinal position for the comparison of the light distribution when viewing from different viewpoints. Optical experiments were also conducted to record the distribution of light on the receiving screen and observe the display performance of the proposed system. Both simulation and optical experiments show that the proposed system has the ability to project virtual images onto the fovea of the human eye to achieve gaze-matching.

With the widespread use of E-paper technology, numerous documents are being digitized and displayed on E-paper screens. However, the display quality of degraded document images on E-paper often suffers from a lack of detail. To address this challenge, we introduce a mapping model that converts color images into E-paper display images. This model leverages U-Net++ as its backbone, integrating residual connectivity and dual attention modules. Given the presence of varying stroke thicknesses in document images, a fixed-size convolutional kernel is insufficient. Therefore, we propose multi-branch channels and spatial attention modules (MCSAM), which combines the selective kernel network (SKNet) with a spatial attention mechanism to adaptively select the appropriate convolutional kernel size based on font size. To demonstrate its effectiveness, we tested the mapped images on a custom E-paper display platform. Experimental results highlight the superior performance of our proposed method.

Displays are the ubiquitous medium to convey information in the modern world. The perceived quality of images seen on displays can be affected by lighting, contrast, and spatial characteristics of the content. While past studies investigated the impact of display luminance and ambient illuminance on preference and discomfort, granular perceptual qualities, such as visual clarity, interest, and complexity, have been rarely investigated. This study investigates the potential use of lighting and image quality metrics to develop a computational model of viewers' response to images of indoor environments shown on a display. In a psychophysical experiment, 42 participants evaluated images of indoor environments under different display luminance (50 cd/m² and 250 cd/m²) and ambient illuminance (50 lx, 150 lx, 450 lx, and 900 lx) conditions. Ambient illuminance and display luminance had minimal impact on perceived qualities, implying optimal visual experiences can be achieved without resorting to high illuminance or luminance levels, thus offering potential energy-saving opportunities. The results also highlighted the interconnectedness of visual attributes, such as increased visual interest with visual clarity and colorfulness. Linear regression analysis leads to a computational model with a low predictive power, which highlights the challenges of developing an accurate model of visual perception.

Near-to-eye displays (NED) require a large field of view (FOV), high resolution, and a small form factor that requires a small display size. These design parameters are often mutually coupled, making it difficult to create a system that satisfies all three at once. Moreover, the FOV in the NED combiner is typically restricted by the refractive index (RI), limiting the use of low-cost glass and polymer materials for image guides. In this paper, the problem: an image transfer that exceeds RI-limited FOV and reduces display size without sacrificing the resolution is demonstrated by multi-domain multiplexed image transfer. In the proposed techniques, we leverage time-wavelength and diffractive multiplexing to reduce a display size by factors of five while achieving 60 degrees FOV transferred over a commercially available 30 degrees FOV geometric waveguide, and maintaining the 32.26 pixels/degree resolution.

LTPO (LTPS&Oxide) AMOLED display can work in a wide refresh rate range such as 1–120 Hz in the advantage of the low off current for oxide TFTs. Threshold voltage one-time detection (OTD) architecture is a potential low-power technology including the connotations of nonvolatile memory and in-memory computing, which can be applied in the LTPO AMOLED to greatly decrease the dynamic power consumption, especially at the high refresh rate. An LTPO pixel circuit driven by the OTD method is presented, in which there exists a data refresh frame without threshold voltage compensation compared with the traditional LTPO pixel circuit. However, for the OTD LTPO pixel circuit, the pixel area is a little larger, and feed through effect induced by capacitor coupling could be more serious due to the two series-connected storage capacitors. The flicker induced by the hysteresis of the driving TFT may be more severe since the threshold voltage of driving TFT is only compensated once per Nc frame.

Amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) would exhibit significant drain current drop (DCD) degradation at high drain voltage, which has been ascribed to the impact of hot carriers on the lattice of a-IGZO films. This study unveils that interstitial oxygen (O_i) defects also contribute to DCD degradation. It is inferred that the weak interstitial oxygen bonds near the drain region would be easily broken by the impact of hot carriers. Thus, the acceptor-like interstitial oxygen trap states are generated, leading to the aggravated deterioration of DCD. In addition, it is observed that the introduction of hydrogens effectively alleviates the DCD degradation, which is attributed to hydrogen-induced transitions from the weak interstitial oxygen bonds to the strong oxygen−hydrogen bonds.

A laser beam-scanning display using a new red–green–blue (RGB) laser beam collimation system was demonstrated. The collimation system used here has only one single lens, but can simultaneously collimate three RGB laser beams. The characteristic features of the system are 1) a simple and compact configuration, 2) simultaneous shaping of all RGB beams from elliptical to circular, 3) Gaussian-like RGB beams, 4) reduction of dead space in the projected image caused by non-coaxial beams, and 5) high laser power transmission (>100 mW).

The laser beam-scanning display constructed with this collimation system provides clear full-color 720p movie images, which verifies its performance. Thus, the laser beam-scanning display shown here is a compact display system that can be embedded not only in head-mounted displays or augmented reality glasses but also in high-power head-up displays for automobile applications.

It has been proved that waveguide near-eye displays with a pin-mirror array can extend the depth of field (DOF) for part of field of view (FOV), which can alleviate the vergence-accommodation conflict (VAC) to a certain extent. During the usage, stray light has been treated as a pivotal factor affecting the image display quality of this waveguide structure, leading to image ghosting or flipping problems. In this paper, we propose a stray-light-free waveguide near-eye display using a pin-mirror array and multiple thin plates. A two-step optimization method has been used to eliminate stray light. Firstly, the effects of the parameters of near-eye displays have been investigated, such as eye relief, pin-mirror size, and spacing size; further, the position and range of total reflection on the front and rear surfaces of the waveguide for the residual stray light are quantitatively analyzed. According to the position and range of the total reflection, multiple thin plates can be introduced to optimize the stray-light paths. To minimize the proportion of stray light in the eye box, the thickness and height of the plates can be optimized. Finally, a compact waveguide near-eye display with stray-light ratio below 0.1% across the eye box is obtained, which can effectively improve the display quality of virtual image. To verify the effectiveness of the method, image simulation was performed, and the results are consistent with the analysis. This method can also improve the vertical FOV while eliminating the stray light, which is very helpful to improve the performance of this kind of waveguide structure.

The visual experience of viewing three-dimensional (3D) content is dependent on parallax and screen size. A 5x4x2 completely within-subject design was conducted in this study through a subjective assessment experiment. A total of 50 subjects viewed four scenes of 3D video sequences varying at five parallax levels on the autostereoscopic 3D displays of two screen sizes. Each of the overall viewing experiences of perceived depth, perceived image quality, naturalness, and viewing comfort was assessed. As indicated by the results of the experiment, parallax and screen size levels affected all viewing experience factors, whereas scenes only exerted a certain effect on perceived depth, naturalness, and visual comfort. The sensitivity of perceived image quality to parallax variation was lower than other parameters. To be specific, an excessive increase in the depth led to the reduced perceived image quality and visual comfort due to the occurrence of 3D artifacts, which becomes a problem to be solved. Although the large screen outperformed the small screen in perceived depth and naturalness, the small screen led to an improvement in perceived image quality and visual comfort. Moreover, the result confirmed that scene nature can serve as a critical factor for the 3D visual experience.