Journal of the Society for Information Display最新文献

Recent breakthroughs in generative AI have markedly elevated the realism and controllability of synthetic media. In the visual modality, long-context attention mechanisms and diffusion-style refinements now deliver videos with superior temporal consistency, spatial coherence, and high-resolution detail. These techniques underpin an expanding set of applications ranging from text-guided storyboarding and animation to engineering visualization and virtual prototyping. In the audio modality, token-based representations combined with hierarchical decoding enable the direct production of faithful speech, music, and ambient sound from textual prompts, powering rapid voice-over creation, personalized music, and immersive soundscapes. The frontier is shifting toward unified audio–visual pipelines that synchronize imagery with dialog, sound effects, and ambience, promising end-to-end tooling for a wide variety of applications such as education, simulation, entertainment, and accessible content production. This review surveys these advances across modalities and outlines future research directions focused on improving generation efficiency, coherence, and controllability across modalities.

In this paper, we present an amorphous indium-gallium-zinc-oxide (a-IGZO) based pulse width modulation (PWM) pixel circuit for micro light-emitting diode (micro-LED) displays, designed to enhance low gray-level expression. Conventional PWM circuits suffer from a long falling time, causing inaccurate gray-level representation. To address this, the proposed circuit employs a continuous piecewise linear sweep signal with two distinct slopes: a steeper slope for low gray levels and a shallower slope for mid-to-high gray levels. This approach reduces the falling time from 209 to 62 μs, enabling accurate gray-level expression down to 41 G without distortion. To prevent falling time distortion from sweep signal slope transitions, a newly proposed separation part divides the emission period into low and high gray phases. By maintaining a constant sweep signal slope within each phase, the circuit ensures stable emission and eliminates distortion. HSPICE simulation verifies the circuit operation and confirms that it maintains stable performance under threshold voltage variations.

The adoption of variable refresh rate (VRR) technology in displays—aimed at reducing input lag, minimizing video stuttering, and improving power efficiency—has introduced an unforeseen challenge: flicker caused by minor changes in luminance due to the varying duration of each frame. Existing industry flicker measuring metrics are inadequate, often overly restrictive or reliant on impractical subjective evaluations. This highlights the need for an accurate, objective flicker metric specifically designed for VRR displays. Developing such a metric requires a comprehensive dataset that captures a wide range of flicker intensities across different display technologies and luminance conditions. To facilitate this, we compiled a unique VRR dataset consisting of 160 signals, ranging from 2 to 40 cd/m², along with perceived flicker levels obtained through extensive subjective testing, following a standard protocol defined in ITU-R BT.500-15. This dataset serves as a critical resource for flicker assessment, providing valuable insights for display manufacturers, and it is instrumental in advancing VRR technology. Our analysis revealed that JEITA, the most widely used flicker metric for VRR displays, correlates with subjective flicker perception at only 71.43%. This finding underscores the limitations of current metrics and the pressing need for a more reliable standard tailored to VRR technology.

This study investigates the angular dependence of far-field electroluminescence (EL) emission in InGaN/GaN LEDs and micro-LEDs to enhance their performance for micro-display and visible optical communication applications. We developed a measurement setup to analyze far-field EL emission across various wavelengths and compared the results with 1D optical simulations. This approach allowed us to observe the well-known dependence of emission directivity and light extraction efficiency (LEE) on the structural parameters of flip-chip LEDs, particularly the thicknesses of p-GaN and n-GaN layers, and to quantify the impact of total thickness variation resulting from wafer thinning processes. Using larger LEDs, the test vehicle offers a valuable tool for designing micro-LEDs with the desired directivity and for process monitoring. We also observed that the angular dependence of far-field emission varies with the applied bias and demonstrated how this could affect wafer-level micro-LED characterizations. Finally, we showed that the far-field EL emission of micro-LEDs progressively deviates from the description by a 1D optical cavity alone, suggesting an increasing influence of the limited size and necessitating 3D-FDTD simulations to accurately model both vertical cavity and sidewall effects. However, for sizes down to 5 μm, the directivity predicted by a 1D model seems roughly preserved.

In this work, a system for the real-time spatially resolved detection of visible light on a large area is realized on glass. Schottky photodiodes, consisting of hydrogenated amorphous silicon (a-Si:H) and molybdenum–tantalum (MoTa), are employed as detectors. The detectors exhibit an internal quantum efficiency of up to 70.96% and a response time smaller than 20 μs. The noise equivalent power was measured at 2.424e-10 W/√Hz. Process compatibility with commonly employed amorphous indium gallium zinc oxide (a-IGZO) and a-Si:H thin-film transistors (TFT) is shown. The driving and real-time readout of a photosensor array is demonstrated using a microcontroller and a current-input ADC.

High-resolution printing technology is crucial for electroluminescent (EL) quantum dot light-emitting diodes (QD-LEDs) to be used in high-end display applications such as AR/VR displays. This study successfully demonstrates the patterning of PEDOT:PSS, ZnO nanoparticles (NPs), and InP-based QD/organic nanohybrids using electrohydrodynamic (EHD)-jet printing, fabricating top-emitting green conventional or inverted QD-LEDs on a PEN flexible substrate. The integration of a hydrophobic pixel defining layer and continuous-jet modes in the EHD-jet printing system enhances the patterning processability, showcasing the EL of patterned conventional and inverted QD-LEDs. Especially, the EL spectrum of an inverted QD-LED exhibits a sharp green emission at a peak wavelength of 542 nm, with a full width at half maximum (FWHM) of 46 nm. This indicates that the uniform layers were achieved through EHD-jet printing and balanced charge carriers in the device, despite the active layer consisting of not only InP-based QDs but also n-type and/or p-type organic transport materials. This research opens up new possibilities for the utilization of EHD-jet printing in various QD-LED structures for commercially viable printed display applications.

State-of-the-art displays are emerging with a technology called variable refresh rate (VRR) that supports a wider range of refresh rates, both above and below 60 Hz. While VRR can reduce power consumption, it can cause flicker issues for users when the refresh rate is lowered below 60 Hz or when the refresh rate is changed even above 60 Hz. Since users can perceive both types of flicker as similar image artifacts, we developed the integrated flicker index to predict them. We introduced time-domain analysis using impulse response functions (IRFs) to capture the onset of aperiodic luminance fluctuations in the VRR waveform and interpret human response to these fluctuations. In addition, based on the previous studies that display characteristics (e.g., luminance and size) affect flicker experience, we need to incorporate both effects of brightness and size into IRF. For this purpose, we utilized the converted IRFs from the TCSF model, which can explain these two effects. To validate the integrated flicker index, we conducted three experiments: flicker when the refresh rate is reduced below 60 Hz flicker (Exp1 and 2) and VRR flicker when the refresh rate is changed (Exp3). The results demonstrate that IRF converted from the appropriate TCSF could offer a more accurate prediction of flicker experience of VRR displays.

This paper presents a newly developed process for interconnecting microICs with microLEDs through ultra-precise dispensing of conductive silver-based paste. Special cleaning and surface energy modification processes have been introduced to achieve interconnects with a width of 5 μm and a minimum pitch of 20 μm. The developed technology is part of the EU funded project “Building Active matrix MicroLED displays By Additive Manufacturing” (BAMBAM), which develops unique manufacturing technologies for realizing microLED displays without TFT backplanes.