Journal of the Society for Information Display最新文献

A new highly recoverable and robust AMOLED display with a novel double-stacked structure consisting of two smart elastomer layers with high modulus and low modulus was suggested and significantly improved pen drop height from 2 cm to 9.5 cm with additional special treatment for elastomer layer removing electro-static damage on panel image, coming from the increase of gate voltage of 1.2 V due to repeated friction between top layer and bottom layer during cyclic rolling. The top protective layer of elastomer enormously reduced the strain of the panel and PSA and therefore, lessened the deformation height of the rollable display at the edge up to 4 mm after a rolling radius of 15 mm and rolling cycles of 200,000, which looks almost flat. The top protective layer of elastomer with tensile hardening property was able to remarkably increase the energy damping effect for the pen drop test and led to the rise of pen drop height. The unique rolling strain distribution was systematically studied using a strain gauge sensor and simulation tool and validated by experimental results. This novel double-stacked structure also showed outstanding environmental reliability results as well.

Understanding the degradation mechanisms of the charge generation layer (CGL) is crucial for developing stable tandem organic light-emitting diodes (OLEDs). Using capacitance-voltage (C-V) measurements and modulus spectroscopy, we visualized the charge distribution within the CGL and analyzed its changes before and after aging. Results indicate that the degradation of the CGL is primarily driven by dopant diffusion, which induces impurity compensation at the interface and increases the driving voltage. Equivalent circuit fitting further quantified the changes in resistance and capacitance across layers, confirming the impact of dopant diffusion on CGL performance. Additionally, the role of spontaneous orientation polarization (SOP) in CGL stability was explored, suggesting its potential influence on the interface barrier height. These findings provide insights for optimizing the CGL design to enhance the long-term stability of tandem OLEDs.

Accurate estimation and brightness-calibration of individual LEDs in large display walls is crucial to the delivery of high-quality content. Viewpoint angle and sampling artifacts due to pixelization are key challenges in achieving precise brightness estimation. In this work, we propose a novel metric for assessing brightness accuracy, based on the consistency of brightness estimation between two closely spaced camera viewpoints, which maintain the same angular perspective while altering the camera pixel alignment with the LED grid. Experimental results demonstrate that EBA effectively quantifies the accuracy of any method used to mitigate sampling artifacts.

We reduced image noise in broadband full-color holographic image capture in a compact self-interference incoherent digital holography (SIDH) system by combining a cholesteric liquid crystal (CLC) circular polarizer with a quarter-waveplate-based geometric phase lens (QW-GPL). To address chromatic wavefront noise issues commonly found in conventional half-waveplate-based SIDH systems, we explore a SIDH system incorporating a quarter-waveplate-based GPL (QW-GPL). In particular, we resolve angular polarization-dependent noise in QW-GPL wavefront modulation by utilizing circularly polarized Bragg reflection of CLC as a circular polarization filter. This approach ensures an ideal circularly polarized beam state across a wide range of incident angles and wavelengths. By effectively mitigating circular polarization distortion in QW-GPL, our method significantly improves the quality of reconstructed holographic images in full-color SIDH with a compact form factor, as demonstrated by reduced entropy values.

Inkjet printing (IJP) technology enables high-precision color patterning for quantum dot light-emitting diode (QD-LED) displays, but there are many technological challenges to achieving high pixel densities. Especially, the compatibility between ink properties and inkjet printing processes is crucial for high-resolution display. Here, we developed advanced inkjet printing processes for fabricating high-resolution 264-ppi QD-LED displays. The analysis and optimization of rheological properties of inks for printing charge transporting layers and QD emissive layers have been studied using a piezo axial vibrator (PAV) which provides useful rheological information for inkjet printing. In addition, post-inkjet processes, such as drying and thermal baking, are optimized to produce high-performance devices. This work demonstrates that the IJP is a promising technology for cost-effective large-scale production of high-quality QD-LED displays suitable for high-quality TVs, monitors, and IT products including tablets and laptops.

The display manufacturing industry is exploring operational optimization strategies using digital twins to address the challenges of complex production lines and rapidly changing market demands. In this study, we explored an optimal solution to release equipment constraints in manufacturing lines using digital twin technology and deep reinforcement learning. As a result, the number of released equipment constraints was reduced by 5% compared to the conventional approach, and production volume increased by 5.6%. To facilitate the interaction between digital twins containing on-site reference information and deep reinforcement learning, the study adhered to the international ISO23247 standard. This research marks the world's first attempt at a digital transformation study focused on manufacturing line operations using this approach.

We report flexible and stretchable, ferroelectric thin-film transistors (FE-TFTs) based on a metal–insulator–semiconductor-ferroelectric (MISF) structure. The devices are fabricated on polyimide (PI)/polydimethylsiloxane (PDMS) substrate. During the MISF fabrication process, we could obtain conventional oxide TFTs (SW-TFTs) by etching out the bottom ferroelectric (FE) layer. This leads to the advantage of fabricating both FE-TFT and conventional oxide TFT simultaneously. The fabricated FE-TFTs exhibited a memory window of 9.1 V and showed stable operation under bending on a cylinder of 1 mm radius. The FE-TFTs were first fabricated on the PI substrate and cut and transferred onto a PDMS substrate to achieve a stretchable device. The devices maintained stable operation under biaxial stretching up to 30% and demonstrated reliable performance for 100 hrs. For display application, we proposed a 3T0C circuit with FE-TFTs without a capacitor for pulse-width modulation (PWM) mode in micro-LED displays. The proposed FE-TFTs could be used for next-generation flexible and stretchable displays.

The revolution in display form factors is anticipated to enhance the delivery of diverse information and provide immediate feedback. The fundamental transformation is based on flexible display technology, and to achieve higher form factor innovation and variations, the development of stretchable displays is currently necessary. In this paper, we have demonstrated the first result of 200PPI stretchable display by applying serpentine-shaped bridge design with a micro-light emitting diode (micro-LED) based on the conventional display process, overcoming fundamental limitations of two existing development directions, pixel density and the stretchability. Methods like Kirigami remove portions of the substrate to implement structural stretchability, offering a high pixel resolution and maintaining image quality by using existing processes. Our new structure, which demonstrates high pixel resolution without any degradation of stretchability, is expected to play a key role in the realization of stretchable displays for the television, IT, and automotive markets, and to accelerate the innovation of display form factors in the near future.

We present a high-resolution aerial 3D display that was developed by combining lens-enhanced aerial imaging by retro-reflection (LeAIRR) with a light-field display. The display forms a high-resolution 3D image that is floating in mid-air. LeAIRR reduces image degradation caused by the micro-corner-cube prisms in the retro-reflector. The prisms cause ray shift and diffraction, which decrease the resolution. The edges of prisms also cause scattering, which decreases the contrast. LeAIRR reduces diffraction and scattering effects by employing a lens to make the aerial image and the retro-reflector optically conjugate, after which the retro-reflected light is focused by a convex lens. Furthermore, the convex lens performs optically reduced imaging of the corner-cube prisms on the aerial image position. Thus, the ray shifts caused by the prisms are reduced. Our prototype of the aerial 3D display provides the contrast transfer function (CTF) to be 2.5 times better than the conventional aerial 3D display based on the AIRR optical system.

The Electrically Suppressed Helix Ferroelectric Liquid Crystal (ESHFLC) is a promising candidate for contemporary display applications because of its fast response at lower voltages and exceptional optical contrast. Despite its advantages, the limited alignment techniques have impeded the widespread adoption of ESHFLC displays. To address this challenge, we have adopted a Polyimide (PI) that has been commercialized in the display industry; achieving an impressive contrast ratio of up to 9,000:1 for 1.23 wt% PI concentration by exploring varied PI concentrations and rubbing torques. Furthermore, the investigation into ESHFLC diffraction patterns enables us to comprehend the balance between anchoring energy and elastic energy, as well as the influence of varying PI concentrations. These findings not only enhance our understanding of the alignment capabilities of this PI but also offer more possibilities for the large-scale production of ESHFLC utilizing this PI.