ABSTRACT White‐Boosting is a display technique for White Organic Light‐Emitting Diode (WOLED) panels with an RGBW subpixel layout, designed to increase peak brightness. This study explored how White‐Boosting influences the perception of image vividness through psychophysical testing using a paired‐comparison method. Participants viewed pairs of images with identical content but simulated under different display conditions and indicated which appeared more vivid. Across three experiments involving 15–20 participants and 10 image stimuli, peak luminance, chromaticity gamut area, and White‐Boosting ratio were systematically varied. The findings revealed a clear trend: Higher White‐Boosting levels consistently enhanced perceived vividness. In addition, the color gamut volume (CGV) derived in the CIELAB color space using a single reference white condition—referred to as perceptual color gamut volume (pCGV)—demonstrated strong predictive power for the average vividness ratings across display settings. These results highlight the potential of White‐Boosting to enhance the visual impact of WOLED displays and suggest that pCGV can serve as a practical objective indicator for predicting subjective vividness.
ABSTRACT This paper presents a voltage‐programmed 6T‐2C pixel circuit using amorphous indium gallium zinc oxide thin‐film transistors (a‐IGZO TFTs) for active‐matrix organic light‐emitting diode (AM‐OLED) displays. The circuit adopts a source‐follower programming path to compensate threshold‐voltage (V TH ) variations even when the driving TFT exhibits depletion‐mode (negative‐V TH ) behavior. To reduce programming errors caused by fabrication‐induced storage‐capacitance mismatch, the data voltage (V DATA ) is applied to the common plate of two series‐connected storage capacitors, which suppresses capacitive‐coupling sensitivity to capacitor deviation. Circuit operation is evaluated in HSPICE using measured a‐IGZO TFT transfer characteristics and measured capacitor‐mismatch statistics, and the line‐time settling behavior is verified with an analytical model. A compact 30 μm × 50 μm layout is also demonstrated for feasibility in a 10‐inch UHD (440‐PPI) panel. The proposed circuit compensates for V TH shifts up to ±2 V and capacitor deviation of ±10%, with maximum OLED current error rates of −10.0% (ΔV TH = −2 V) and 7.9% (ΔC = −10%).
ABSTRACT A ‐ (480 m)‐pixel cardiac ultrasound patch LTPS TFT system on flexible substrate is presented in this paper. The design is capable of selecting emission windows on both horizontal and vertical direction enabling 2D beamsteering at 5 kfps. The system is verified for 10V pp 500 kHz transducer signal with an SNR of 39.82 dB. Power dissipation is measured 7.72 mW. Non‐uniformity of the signal inside the emission is measured below 0.3%. High‐voltage gate drivers enable 60 V pp output from 3.3‐V input. A short transistor suppresses cross‐talk by more than 3 .
ABSTRACT E‐paper, as an emerging eco‐friendly display technology, has gained significant attention due to its paper‐like visual effect and low power consumption characteristics. The concept was first proposed in the 1970s, and after years of development, it has evolved from the initial black‐and‐white image display technology to full‐color video display. Electrophoretic display shows images by controlling charged particles within microcapsules using an electric field, offering high reflectivity and contrast, and is widely used in various fields such as e‐readers, mobile phones, automobiles, wearable devices, and more. The e‐paper display system mainly consists of the e‐paper screen, control circuits, image processing algorithms, and electronic ink driving waveforms. The review introduces the research history and applications of electrophoretic display, e‐paper image processing algorithms, and driving waveforms. It also summarizes the current challenges and development trends in the field of e‐paper.
A polycrystalline In-Ga-O (poly-IGO) thin-film transistor (TFT) with field-effect mobility (mu FE) over 40 cm2/Vs has been developed and analyzed by mobility modeling and self-heating simulation. The mu FE is the highest among metal-oxide semiconductor (OS) TFTs using common semiconductor materials and mature production processes. Moreover, the subthreshold swing (S) is 0.13 V/dec, and the threshold voltage (Vth) is 0.0 V, which are also superior. These excellent characteristics are accomplished by inherent features of the polycrystalline phase and IGO material. The mobility modeling is executed by the modeling procedure once we developed and clarifies that due to a behavior of potential barriers at grain boundaries, the intrinsic mobility (mu) positively depends on the carrier density (n), which enhances the mu FE. The mu-n dependence can be a universal curve and is indispensable to design devices and circuits in the future. Moreover, the self-heating simulation is executed by implementing the T-dependent mu-n dependence and clarifies that the mu slightly but also positively depends on the temperature (T), which also enhances mu FE. We expect that poly-IGO TFTs can replace amorphous In-Ga-Zn-O (alpha-IGZO) TFTs in the near future.
A - (480 m)-pixel cardiac ultrasound patch LTPS TFT system on flexible substrate is presented in this paper. The design is capable of selecting emission windows on both horizontal and vertical direction enabling 2D beamsteering at 5 kfps. The system is verified for 10Vpp 500 kHz transducer signal with an SNR of 39.82 dB. Power dissipation is measured 7.72 mW. Non-uniformity of the signal inside the emission is measured below 0.3%. High-voltage gate drivers enable 60 Vpp output from 3.3-V input. A short transistor suppresses cross-talk by more than 3.
Wide color gamut (WCG) displays mark a significant and timely evolution in display technology, enabling high-fidelity color reproduction that extends well beyond the limitations of legacy color spaces. This study explores the color range of real-world scenes and examines the extent to which real-world colors fall outside the sRGB and even the more modern DCI-P3 color gamut. It further evaluates the capability of OLED displays with ultra-Wide Color Gamut (ultra-WCG-referring to a gamut larger than DCI-P3) to accurately reproduce these colors and identifies which color areas remain unproducible on such displays. The results show that a significant number of real-world images fall within the boundaries of the sRGB and mostly DCI-P3 color spaces. However, certain colors, such as cyan, pure green, or highly saturated reds and yellows, fall outside these gamuts, which suggests that some ultra-WCG displays, such as our test vehicle (a QD-OLED television) enable more accurate reproduction of a larger, more impactful portion of the colors we encounter in real life, without needing the full gamut of BT.2020.
When measuring display-specific parameters such as luminance, contrast, or color, which depend on the viewing angle, precise and reproducible positioning of the measuring system is essential for achieving reliable results. This study examines how photometric robots, which integrate imaging luminance measurement devices (ILMDs) with industrial robotic systems, can be used as goniophotometers for display and illuminated object measurement technology. Physical limitations are discussed, and the position accuracy and repeatability are analyzed. Recent advancements in this field are explored, including enhanced goniophotometric functions, spectroradiometer integration, absolute robot calibration methods, and specialized software innovations.
This study developed an excimer-light-assisted solution process using aqueous metal-nitrate precursors and 172 nm deep-ultraviolet irradiation to fabricate In2O3 and Ga-doped In2O3 (IGO) thin-film transistors (TFTs). Photochemical activation enabled precise control of precursor decomposition and film crystallization. Excimer irradiation promoted dehydration-condensation reactions, forming polycrystalline In2O3 at a low processing temperature of 200 degrees C. TFTs annealed at 300 degrees C exhibited an on/off ratio of 4.2 & times; 106 and a field-effect mobility of 28 cm2/Vs. Increasing the annealing temperature to 500 degrees C enhanced the mobility to 106 cm2/Vs, indicating improved carrier transport due to enhanced crystallization. With Ga incorporation, high mobility was maintained at 90.8 cm2/Vs for 10 mol% Ga and 70.9 cm2/Vs for 25 mol% Ga. Hysteresis width and subthreshold swing were significantly reduced, with an improved on/off ratio of 2.0 & times; 107, demonstrating enhanced operational stability. These improvements are attributed to suppression of oxygen-vacancy-related trap states by stronger Ga-O bonds. Gate-length-dependent analysis indicates that mobility degradation under high electric fields arises from self-heating rather than short-channel effects. These results demonstrate that photochemical control combined with compositional engineering mitigates the mobility-stability trade-off in In2O3-based TFTs.
Screen reflections represent an important factor in the visibility and readability of displays under ambient light conditions. Initial efforts to quantify these reflection characteristics were attempted in early display standards. ISO 9241-305 reflection measurements were primarily designed for cathode ray tube displays exhibiting predominantly mirror and Lambertian reflection components. Modern displays exhibit haze scatter and diffraction, which are not sufficiently addressed by this standard. Recent work using the point spread function method now enables high-resolution reflection characterization and, together with ISO TR 9241-313 and IEC 62977-2-8 methods, provides a framework for revising standards like ISO 9241-305 for current display technologies.
Here, we present our recent advances and prospects in enhancing the efficiencies of Visionox intelligent Pixelization (ViP) organic light-emitting diodes (OLEDs) through a combination of experiments, simulations, and in-depth mechanism analysis. Our results demonstrate the bright future of ViP technology for further improving OLED efficiencies over traditional fine metal mask (FMM) technology.
Liquid crystal displays (LCDs) suffer from inherent efficiency losses due to the absorption of unpolarized backlight by the front polarizer, with approximately 50%-60% of light wasted. To address this polarization bottleneck, we present a scalable and non-contact strategy to fabricate macroscopically aligned perovskite nanorod enhancement films (NREFs) that emit intrinsically polarized light, enabling direct integration as color conversion layers in LCDs. The core challenge of incompatibility between CsPbBr3 perovskite nanorods (PNRs) and liquid crystal monomers (LCMs) was resolved via a ligand design and exchange. Utilizing an SD1 sulfonic bisazodye photoalignment layer, we achieved high-fidelity, lithographically defined alignment of the PNR/LCM composite, permanently locked by in situ photopolymerization. The resulting freestanding films exhibit a degree of polarization (DOP) of 0.5, representing one of the highest values reported for solution-processed PNR composites without mechanical or field-based treatment. Furthermore, we demonstrate spatially patterned polarized emission with a domain boundary resolution of similar to 20 mu m via sequential masked exposures, meeting the pixel pitch requirements for modern high-resolution displays. This work establishes a practical route toward pixelated, polarization-resolved quantum-dot color converters, directly addressing the dual challenges of efficiency and color gamut in next-generation LCD architectures.
We integrate (sic)LIP into an MMSE-based subpixel-rendering framework to improve display visual performance. Using mean (sic)LIP errors as loss in a Nelder-Mead optimizer, we refine the kernel to reduce perceptual distortion. The proposed method begins with an MMSE-derived kernel based on a virtual-image reconstruction model, which provides a physically meaningful baseline filter for subpixel rendering. The perceptual optimization stage then iteratively adjusts the kernel coefficients to minimize (sic)LIP errors rather than purely numerical RGB differences, enabling improved chromatic accuracy and edge fidelity. Verified with ISO 12233, DIV2K, TID2013, and ImageNet, the method achieves a 27.67% reduction in mean (sic)LIP errors over the diagonal direct subpixel-based down-sampling approach, based on a mini-LED panel with GRBG subpixel layout. These results demonstrate that perceptually guided subpixel rendering provides an effective strategy for improving perceptual image quality in modern display systems.
We proposed an ultracompact, on-axis liquid-crystal-on-silicon (LCoS) illumination scheme with local dimming, by taking advantage of the polarization selectivity of polarization volume grating (PVG), which serves as both an analyzer for the LCoS and an input-coupler for the waveguide. The fabrication process of the diffractive waveguide and a monochromatic monocular demonstration of the proposed LCoS illumination design in a waveguide-based AR system are described. This design improves the coupled optical efficiency to about 30%, enhances the contrast ratio by local dimming, and achieves a total volume less than 0.3 cc, including projection optics, for a 720 x 720 LCoS panel with pixel pitch at 4.25 mu m. If the pixel pitch is reduced from 4.25 to 3 mu m while keeping the same resolution (720 x 720), the volume is expected to reduce by similar to 2x.
This paper presents an electrically controlled liquid crystal (LC) prism for dynamic beam steering and divergence control. By engineering the electrode voltage distribution, the device generates two distinct types of equivalent prism configurations within the LC layer. One is a uniform phase gradient, mimicking a constant-pitch prism, enables precise and continuous beam deflection to specific angles, such as 20 degrees and 30 degrees. Another equivalent nonuniform phase gradient, corresponding to a combination of prisms with varying pitches, achieves significant beam divergence enhancement, expanding the field of view (FOV) from 15 degrees to approximately 70 degrees while maintaining uniform light distribution. The device operates entirely without mechanical moving parts, offering key advantages in programmability, compact integration, and low power consumption. With its flexible and electronically adjustable beam control, this technology has potential applications in intelligent lighting, automotive head-up displays, AR/VR systems, privacy-enabled displays, and laser processing.
This study designs, fabricates, and evaluates both conventional AC-dispersive inorganic electroluminescent (EL) devices and novel planar electrode-type EL devices. The devices utilize a copper- and chlorine-doped zinc sulfide (ZnS:Cu,Cl) luminescent layer and comb-shaped electrode structures made of ITO, Au, and Pt. The influences of the electrode material conductivity and transparency on the luminescence characteristics and brightness were systematically investigated through comprehensive electrical characterization including impedance analysis, I-V characteristics, and voltage retention measurements. Optical pathway differences between device architectures were analyzed, considering light extraction efficiency and surface plasmon effects. Basic electromagnetic field simulations were performed to visualize field patterns. We discovered that the luminescence characteristics and brightness of the devices were primarily affected by the transparency of the comb electrodes rather than by the conductivity of the electrode materials. The absence of a dielectric layer in comb-electrode devices resulted in reduced brightness due to limited charge accumulation and optical losses. This research provides valuable insights into inorganic EL device design and evaluation methodologies.
Dynamic navigation is a technology for computer-assisted dental surgery that utilizes real-time imaging, patient-specific anatomical data, and preoperative planning to dynamically guide surgical instruments in order to optimize clinical outcomes. It improves the precision of dental implant placement, but shifting attention between the surgical site and the monitor causes ergonomic and workflow issues. This model-based proof-of-concept study introduces augmented reality (AR) integration that projects X-Guide navigation data directly onto the surgical field. The AR overlay eliminates repeated head movements, offering a high ergonomics and cognitively efficient paradigm for computer-assisted implant surgery. Results demonstrated precise implant positioning (coronal deviation: 1.6 +/- 1.4 mm; apical deviation: 1.6 +/- 1.2 mm; angular deviation: 2.5 +/- 1.9 degrees) with efficient surgical times (5.9 +/- 2.6 min per implant). Attention shifts caused by looking at the X-Guide monitor were reduced to zero. Results of the author-developed questionnaire showed a high score on the domains of System Usability Scale (SUS; 5.0 out of 5.0) and a low score on the domains of NASA Task Load Index (NASA-TLX; 1.7 out of 5.0), confirming a high acceptability and low workload. Our findings support AR-integrated dynamic navigation as an accurate and ergonomic solution for guided implantology, warranting further clinical validation.
Narrowband green multi-resonant thermally activated delayed fluorescence (MR-TADF) emitters are essential for next-generation BT.2020 OLED displays; however, achieving high efficiency and long operational lifetime remains a significant challenge. Herein, we demonstrate two complementary molecular design strategies that independently target device stability and efficiency through rational structural modulation. The stability-oriented emitters, tBuICzBN-Q and tBuICzBN-DPPM, incorporate electron-deficient heteroaromatic units to enhance molecular rigidity and suppress nonradiative decay, resulting in maximum external quantum efficiencies (EQEs) of up to 28.9% and operational lifetimes (LT97) exceeding 2500 h at 1000 cd m-2. Efficiency-driven Ph-NapBF emitter is designed to maximize oscillator strength and promote efficient energy transfer, delivering a record-high EQE of 37.7%. Furthermore, top-emission OLEDs exhibit BT.2020-compliant green emission with CIE coordinates of (0.17, 0.79) and a current efficiency exceeding 277.2 cd A-1. These results highlight the molecular design strategies can address the efficiency and lifetime limitations of narrowband green MR-TADF.
Achieving uniform low-gray luminance in high-resolution active-matrix organic light-emitting diode (AMOLED) displays remains a critical challenge. As pixel density increases, driving transistors are forced to operate in the deep subthreshold regime, where the steep subthreshold swing (SS) of conventional oxide thin-film transistors (TFTs) makes the drain current highly sensitive to threshold voltage variations and noise. To address this, we propose a novel indium-gallium-zinc-oxide (IGZO) floating-gate TFT architecture capable of precise and wide-range SS modulation. By engineering the layout-defined gate coupling ratio (GCR), specifically through the adjustment of floating gate width and the introduction of a source-overlapped floating gate (SO-FG) structure, the SS can be linearly tuned with minimal additional fabrication process. Experimental characterization and 3D TCAD simulations confirm that the SS is strictly governed by capacitive coupling ratios, demonstrating a controllable range from 80.5 mV/dec (for switching) to over 499 mV/dec (for driving). Notably, the SO-FG design enables area-efficient SS expansion, significantly extending the driving voltage range from 0.5 to 2.4 V. This design facilitates the monolithic integration of high-speed switches and robust driving transistors, providing a practical solution for enhancing low-gray uniformity in high-density pixel circuits.
