ABSTRACT In this paper, we presented a hybrid pulse modulation (HPP) pixel circuit for micro light emitting diode (micro‐LED) display, which was designed for low‐cost and large‐sized splicing display modules. Conventional HPP pixel circuits required two data signals per frame to control the amplitude and width of the output current pulse, respectively, which limited the size of the display modules and increased the costs. To address this problem, the pulse amplitude modulation (PAM) part of the proposed pixel circuit was specially designed to work in tandem with the pulse width modulation (PWM) part. Both of them were controlled by the same data signal. Therefore, the pixel circuit only required one data signal per frame to implement the HPP driving method, making it suitable for large‐sized display modules. Additionally, the compensation function for the threshold voltage shift and supply voltage drop was also supported by the circuit, ensuring improved image uniformity. Using theoretical analysis and circuit simulation, we demonstrated that, compared with the conventional PWM circuit, the proposed HPP pixel circuit could improve the image quality at low grayscale. Furthermore, a micro‐LED sample was tested to verify the conclusion.
Recently, the meta-universe is one of the hottest keywords. The micro-display is the door to the meta-universe. This paper presents an integrated fractal scan method for digital driving silicon-based micro light-emitting diode (micro-LED) micro-display. High bit adopts fractal scan to achieve 100% transmission efficiency, and low bit of two frames are fused to improve the lighting efficiency and refresh rate. Compared with traditional digital scan methods, this scan method has high transmission efficiency, high gray levels, high linearity, and high refresh rate. A 1280 & times; 720 monochromatic silicon-based micro-LED micro-display manufactured by SMIC 180-nm process and a timing controller (TCON) chip manufactured by SMIC 110-nm process jointly verify the effectiveness of the scan method. The pixel pitch is 5 mu m, and the pixel density is 5064 pixels per inch (PPI). Under the 50-MHz pixel clock frequency, the theoretical maximum refresh rate reaches 289.35 Hz. This high-performance, high-resolution micro-LED display demonstration provides a promising solution towards the design of micro-displays for VR/AR applications.
This study addresses the critical challenges in developing microcrystalline silicon (mu c-Si) processes for display applications, where limited industrial expertise in crystallization characterization and the absence of standardized experimental protocols hinder optimal process optimization. We present a machine-learning-driven framework employing Random Forest regression to quantitatively model the relationships between key deposition parameters-chamber pressure, plasma power (P), substrate temperature (T), and gas flow ratio (R)-and crystallinity metrics. Through systematic feature engineering and hyperparameter optimization, the proposed model achieved state-of-the-art predictive performance, yielding a mean squared error (MSE) of 20.1172 and a coefficient of determination (R 2) of 0.94 on validation datasets. Feature selection was conducted in two sequential phases: (1) preliminary screening via the Pearson correlation coefficient to remove numerical noise and weakly correlated variables, and (2) identification of second-order interaction terms, followed by feature ranking based on Random Forest importance scores.
Night vision goggles (NVGs) are head-worn display systems that support visual performance under low-illumination conditions, yet the perceptual effects of phosphor screen type remain incompletely understood. In particular, direct empirical comparisons of white-phosphor (P45) and green-phosphor (P43) NVG displays under degraded visual conditions are still limited. This study evaluated object recognition performance with white- and green-phosphor NVGs in a field-based night experiment involving 40 military helicopter pilots. Participants identified aviation-relevant objects across nine progressively blurred image conditions, and recognition performance was scored on a 0-20 scale. Stratified Cochran-Mantel-Haenszel analysis showed that white-phosphor NVGs were associated with substantially higher recognition odds than green-phosphor NVGs (common OR = 4.12, chi(2)(1) = 140.11, p < 0.001). Recognition advantages for white phosphor were especially noticeable at intermediate blur levels, where higher recognition scores were observed. Although object-level onset differences were not statistically significant in all comparisons, the overall results indicate that phosphor type may influence visual recognition efficiency under degraded viewing conditions. These findings suggest that white-phosphor NVG displays may offer perceptual advantages for object recognition tasks and may be relevant to the design and evaluation of near-eye display systems for low-light operational environments.
The preparation method for uniaxial-homogeneously and vertically aligned liquid crystal (LC) molecules were proposed without using conventional alignment layer materials such as polyimides. The method produces the homogeneously and vertically self-aligned layers (HSAL and VSAL) by polymerization of monomer agents solubilized in the LC layer. The LC alignment modes, fringe-field-switching (FFS) and vertically aligned (VA) modes, with the SALs (self-FFS and self-VA cells) formed from the monomers exhibited equivalent level of alignment state, electrical property, and electro-optical property compared with the cells formed from conventional alignment layers such as the polyimides. The self-FFS and the self-VA cells would be useful for next-generation displays because the method does not need any solvents and heating process over 200 degrees C, indicating that the fabrication process would be environmentally friendly. In addition, as the process does not need high temperature process, this would also be suitable for next-generation LCD technologies such as flexible and narrow-frame displays.
