Transparent Display Research Articles

Dual-sided transparent display enabled by polymer stabilized liquid crystals for augmented reality.

In the past decade, display technology has been reimagined to meet the needs of the virtual world. By mapping information onto a scene through a transparent display, users can simultaneously visualize both the real world and layers of virtual elements. However, advances in augmented reality technology have primarily focused on wearable gear or personal devices. Here we present a single display capable of delivering visual information to observers positioned on either side of the transparent device. This dual-sided display system employs a polymer stabilized liquid crystal waveguide technology to achieve a transparency window of 65% while offering active-matrix control. An early-stage prototype exhibits full-color information via time-sequential processing of a red-green-blue light-emitting diode strip. The dual-sided display provides a perspective on transparent mediums as display devices for human-centric and service-related experiences that can support both enhanced bi-directional user interactions and new media platforms.

Flexible and Transparent Electrovibration-Based Haptic Display with Low Driving Voltage.

Electrovibration haptic technology, which provides tactile feedback to users by swiping the surface with a finger via electroadhesion, shows promise as a haptic feedback platform for displays owing to its simple structure, ease of integration with existing displays, and simple driving mechanism. However, without electrical grounding on a user's body, the frequent requirement of a high driving voltage near 50 V limits the use of electrovibration haptic technology in practical display applications. This study introduces materials and fabrication strategies that considerably reduce the driving voltage. We used a transparent poly(vinylidene fluoride) (PVDF) thin film deposited on transparent conductive polymers through a simple spin-coating process, thereby enabling easy integration with existing display technologies. The high dielectric constant characteristics of PVDF enabled the production of tactile cues at low voltages (approximately 15 V), which are within the safety limits of common electronics. We verified the feasibility of our electrovibration haptic feedback system on the basis of the absolute threshold voltage through two-alternative forced choice psychological tests. The results revealed that the PVDF dielectric layer exhibited a relatively lower absolute threshold than commonly used polymer films, which possess a relatively lower dielectric constant. To validate the tactile attributes, a Likert five-point scale survey was conducted, considering flat, concave, and convex curvatures. The results indicated that our haptic device can render diverse surface textures, such as "hairy" and "groovy", on the fingertips through the control of applied pulse width modulated voltage signals.

Exploring the Human-Centric Interaction Paradigm: Augmented Reality-Assisted Head-Up Display Design for Collaborative Human-Machine Interface in Cockpit

Human-cybernetic interfaces (HCI) focuses on the integration and synergy of human-centric design, human factors (HFs) and economics, and human–machine interaction (HMI). The scrutiny of single pilot operations (SPO) approval from civil aviation authorities (CAAs) is subject to the aviation safety and pilot capability during exceptional handling and flight emergency. Airliners advocate the possibility from dual pilot operations (DPO) to SPO because of the financial considerations and captain shortage in the post-pandemic era. One could expect that SPO can only realise when reduced crew operations initiative is proven to be safe and airworthy. Public concerns pilot mental workload and potentially low situational awareness (SA) when handling overwhelmed multi-source information from the HMI in a cockpit, leading to degraded skills and flying performance. Advanced head up display (HUD) design, an integrated transparent display, can assist pilots in maintaining their optimal performance when SPO exercised. In this study, we are interested to design a SPO-favoured cockpit design with HUD and investigate the potential of integrating augmented reality (AR) and HUD in SPO in flight operations. An experiment involving 21 pilots was conducted to assess the effectiveness of AR-HUD on SA and workload in DPO, SPO, and SPO with AR-HUD scenarios. The Situation Awareness Present Assessment Method (SPAM) and a self-rated workload scale were used to evaluate SA and workload levels. Eye-tracking data was also collected to analyse behavioural performance. Results indicated that the AR-HUD scenario achieved optimal workload and SA levels and demonstrated superior performance in handling emergencies. Eye-tracking data revealed that AR-HUD facilitated a more equitable distribution of gaze between instruments and external view. In conclusion, the integration of AR in cockpit design introduces a human-centric interaction paradigm, contributing to aviation safety, SPO implementation and adaptive HMI design.

Sense of embodiment with synchronized avatar during walking in mixed reality.

Gait guidance systems that synchronize the gait rhythm with an avatar in a mixed reality (MR) environment are attracting attention owing to their rehabilitation applications. More effective gait guidance can be achieved by changing body sensations for the sense of embodiment (SoE), which refers to the feeling of owning, controlling, and being inside a body in MR. This study investigated full-body synchronous motion between a human and a virtual avatar to enhance the SoE in walking with actual position changes in the real world. The full-body motion and gait rhythm were measured using body-worn inertial measurement units and a visual avatar was provided through a transparent head-mounted display. The results showed that the SoE of the participants was enhanced under higher synchronization conditions. In addition, questionnaire results showed that the SoE in the synchronous condition was significantly higher than that in the asynchronous condition, and the SoE in the self-avatar condition was significantly higher than that in the other-avatar condition. This indicates that a higher synchronization level with the appearance of an avatar leads to a stronger SoE in the human perception mechanism, which is important for potential application in medical or other fields.

Perception-Driven Soft-Edge Occlusion for Optical See-Through Head-Mounted Displays.

Systems with occlusion capabilities, such as those used in vision augmentation, image processing, and optical see-through head-mounted display (OST-HMD), have gained popularity. Achieving precise (hard-edge) occlusion in these systems is challenging, often requiring complex optical designs and bulky volumes. On the other hand, utilizing a single transparent liquid crystal display (LCD) is a simple approach to create occlusion masks. However, the generated mask will appear defocused (soft-edge) resulting in insufficient blocking or occlusion leakage. In our work, we delve into the perception of soft-edge occlusion by the human visual system and present a preference-based optimal expansion method that minimizes perceived occlusion leakage. In a user study involving 20 participants, we made a noteworthy observation that the human eye perceives a sharper edge blur of the occlusion mask when individuals see through it and gaze at a far distance, in contrast to the camera system's observation. Moreover, our study revealed significant individual differences in the perception of soft-edge masks in human vision when focusing. These differences may lead to varying degrees of demand for mask size among individuals. Our evaluation demonstrates that our method successfully accounts for individual differences and achieves optimal masking effects at arbitrary distances and pupil sizes.

Surface engineering of Al2O3 dielectric layer for all-sputtered-oxide transparent and flexible a-IGZO thin film transistor

Transparent flexible display devices have attracted massive attention in recent years owing to their practical applications that can be compatibly adapted to human demand and technological development. Worldwide researchers have studied flexible transparent thin film transistors (TFTs) to qualify them for the backplane component of future transparent and flexible displays. Simplifying the fabrication process of a TFT can be considered a critical need for reducing consumed cost, time, toxic chemicals. In this study, sputtering was utilized as a major fabrication method for manufacturing a transparent oxide TFT device, which demonstrated good mechanical flexibility. A simple surface treatment process was applied to enhance the susceptibility of the sputtered Al2O3 dielectric through multiple coatings of solution processed Al2O3. It is noteworthy that the transparent oxide TFT device exhibits a high optical transparency of 81.12% and good electrical switchability at low operating voltage (3 V) with a decent mobility of 4.37 cm2 V−1 s−1 and proven mechanical durability.

Transfer of Micro‐LEDs with Roll‐Based Direct Overlay Alignment for Manufacturing Transparent Displays

AbstractTransparent displays are crucial for various applications, particularly for their potential use as windows in future self‐driving cars. These displays require high transparency, low power consumption, and high mechanical reliability. Micro‐LEDs have emerged as ideal devices for the transparent displays. Efficient mass‐production processes are essential for the commercialization of transparent micro‐LED displays. This study presents roll‐based mass transfer to enhance the productivity of transparent micro‐LED displays. Roll transfer processes traditionally face resolution challenges in alignment repeatability and positional errors in both the transverse direction (TD) and machine direction (MD). This study proposes a roll‐to‐plate (R2P) transfer process with overlay alignment to improve the repeatability precision of the alignment. Detailed experimental analyses address positional errors in the TD and MD, attributed to initial contact errors and linear velocity asynchrony, respectively. The results demonstrate successful micro‐LED transfer onto a transparent circuit board (TCB) with a maximum positional error of 3.2 µm and a 99.75% yield. The resulting micro‐LED display achieves a transparency of 72.5% with 68 pixels per inch. This study overcomes the alignment challenges in the R2P process and contributes to the commercialization of transparent micro‐LED displays. It is expected to positively impact the manufacturing of transparent applications that involve rolling processes.

P‐218: Research on Improving the Performance and Immersion of Flexible Transparent AMOLED

In recent years, transparent display has attracted lot of attention for wide application such as smart window and showcase. The see‐through capability, which is closely related to transmittance, reflectivity, haze and yellowness index, is a key indicator to measure the performance of transparent display. In this paper, we tried many methods to further improve the quality of flexible transparent AMOLED. In addition, one bezel‐less transparent display has been developed to improve immersion with surroundings.

89‐3: Invited Paper: An Investigation of Quantitative Measure of See‐Through Image Quality for Transparent Displays

To provide clear see‐through image quality is one of the most important performances of a transparent display, because of its see‐through capability. Purity is one of the quantitative measure can evaluate the see‐through image quality in terms of perceived blurriness. In this paper, the characteristics of purity are investigated. Experimental results indicate that the purity values have highly correlated with perceptual blurriness of see‐through images. Furthermore, the perceptual limit of purity value is also derived.

P‐211: Double Capping Layers Technology For Transparent OLED Display

With its enhanced display and innovative digital experience, transparent display has gradually penetrated in the fields of culture and education, transportation, and business, and has become one of the important development directions of the next generation display product form. However, in order to improve the transmittance of transparent OLED displays, the scheme of reducing the opening rate is usually used, resulting in decrease in the brightness of the screen; Due to the removal of the polarizer, the reflectivity of the screen further increases. In addition, due to the color properties of the screen material, the display cannot be integrated with the environment very well. In this paper, a double Capping layer (CPL) structure is mentioned. which can increase the brightness of transparent OLED by 10% and reduce the reflectivity by 10% at the same time. The transmission subpixel scheme is proposed. The combination of CPL thickness and transmission sub‐pixel area can realize the integration of screen and environment very well.

72‐3: The Transparent 55 inch OLED Display Products with Improved Imaging Quality

In this work, a transparent OLED Display Products with improves imaging quality. Display Products provided the better imaging uniformity and high imaging. The transparent 55‐inch OLED Display Products is fabricated by using RIB structure auxiliary electrode process and dark pixel reduction process.

P‐119: Evaluating Seamlessness: A Quantitative Index for Transparent Tiled MicroLED Displays

The objective of this study was to develop a method for accurately evaluating the quality of splicing seams in tiled transparent MicroLED displays, replacing subjective human observation with a quantitative indicator. The study utilized the validated Structural Similarity (SSIM) index method, which enabled precise guidance in the production process and established common measurement standards for defining splicing seam quality. This study would significantly contribute to the advancement of panel technology development by providing a standardized and objective evaluation approach for assessing splicing seam quality.

Cation-Modified Poly(vinyl alcohol) Film to Optimize the Bistability of Transparent Electrophoretic Display Based on Charge Adsorption Behavior in Nonpolar Solvent.

Electrophoretic displays (EPDs) utilize the electrophoretic particles in electronic ink (e-ink) to display different color states with bistability. Bistability of EPDs is achieved by placing colloidal particles in a highly viscous solvent to keep the distribution of colloidal particles stable without sustaining the external field, so it only consumes power when updating the image. The feature of low power consumption makes it suitable for applications such as advertising boards, price tags, etc. Apart from these applications, recent research on lateral-driving EPDs extends its applications to smart windows, privacy control, and so on. However, achieving bistability by simply increasing the viscosity of solvent is inefficient in the case of lateral driving operation. Therefore, it is deserving to have intensive study on the mechanism of bistability from other aspects. Herein, we propose a mechanism to investigate the charge adsorption behavior on the electrode to affect the bistability of particles, which is based on the "Stern layer adsorption/desorption" model. Based on the above mechanism, we further fabricated a hexadecyl trimethylammonium bromide (CTAB)/poly(vinyl alcohol) (PVA) composite film on the electrode to improve the bistability of lateral-driving EPD by reducing the diffusion current caused by unabsorbed charges. This developed lateral-driving EPD can significantly improve the bistability, which is enhanced from 40 s to 7 min, an increase by a factor of approximately 10. This work gives a way to consider the bistability of colloidal particles in nonpolar solvent.

Hydrothermal synthesis and photoluminescent properties of (Ca/Sr)2P2O7: Eu2+ pyrophosphate-based blue-emission phosphors

In this work, the luminescent properties of blue-emission (Ca/Sr)2P2O7: Eu2+ phosphors prepared by hydrothermal synthesis method are extensively investigated. The Rietveld refinement verified that Eu2+ was successfully doped into the phosphors. The SEM results showed that the samples of Ca2P2O7 and Sr2P2O7 were composed of tetragonal particles and short nanorods particles, respectively. Under ultraviolet excitation, the blue emission peak of the sample had a small full width half maximum (FWHM), with Ca2P2O7 (λem = 417 nm, FWHM = 24 nm), Sr2P2O7 (λem = 420 nm, FWHM = 28 nm). The quantum efficiencies of Ca2P2O7: Eu2+ and Sr2P2O7: Eu2+ were 70.13 % and 69.26 %, respectively. Under the temperature of 480 K, the luminescence intensity of Ca2P2O7: 0.03Eu2+ and Sr2P2O7: 0.03Eu2+ phosphors decreased to 30.02 % and 82.47 % of the initial intensity. Therefore, (Ca/Sr)2P2O7: Eu2+ phosphors with narrow-band blue emission have potential applications in Light emitting diodes and transparent display.

Sustainable, low-cost, high-contrast electrochromic displays via host–guest interactions

Electrochromic (EC) displays with electronically regulating the transmittance of solar radiation offer the opportunity to increase the energy efficiency of the building and electronic products and improve the comfort and lifestyle of people. Despite the unique merit and vast application potential of EC technologies, long-awaited EC windows and related visual content displays have not been fully commercialized due to unsatisfactory production cost, durability, color, and complex fabrication processes. Here we develop a unique EC strategy and system based on the natural host and guest interactions to address the above issues. A completely reusable and sustainable EC device has been fabricated with potential advantages of extremely low cost, ideal user-/environment friendly property, and excellent optical modulation, which is benefited from the extracted biomass EC materials and reusable transparent electrodes involved in the system. The as-prepared EC window and nonemissive transparent display also show comprehensively excellent properties: high transmittance change (>85%), broad spectra modulation covering Ultraviolet (UV), Visible (Vis) to Infrared (IR) ranges, high durability (no attenuation under UV radiation for more than 1.5 mo), low open voltage (0.9 V), excellent reusability (>1,200 cycles) of the device's key components and reversibility (>4,000 cycles) with a large transmittance change, and pleasant multicolor. It is anticipated that unconventional exploration and design principles of dynamic host-guest interactions can provide unique insight into different energy-saving and sustainable optoelectronic applications.

2‐2: Charging and Transport Behaviors of Species in Nonpolar Media for Lateral Driven Transparent Electrophoretic Display

2‐2: Charging and Transport Behaviors of Species in Nonpolar Media for Lateral Driven Transparent Electrophoretic Display

Enhancing Early Childhood Cultural Education through the Ponorogo Reyog Theater Suitcase: A Development and Evaluation Study

This research explores the Reyog Theater Suitcase (Koper Teater Reyog) as an innovative educational tool for introducing the cultural heritage of Ponorogo to early childhood education. Utilizing a Research and Development (R&D) approach and the ADDIE model, which includes the Analyze, Design, Development, Implement, and Evaluation stages, the study employed a Posttest-only experimental design with nonequivalent groups. An initial needs analysis revealed a scarcity of practical storytelling media that incorporate local narratives, such as Reyog Ponorogo, despite its prevalence in local education. Consequently, the Reyog Theater Suitcase was developed, featuring a transparent display panel, barcode-activated musical features, and manageable cultural figurines. Data collection involved expert validation through questionnaires, teacher surveys, and authentic assessments using qualitative and quantitative analyses. The findings indicated that classes using the Reyog Theater Suitcase achieved significantly better outcomes in cultural education than traditional picture books. After two rounds of feedback and revisions from experts, the quality and educational appropriateness of the product were enhanced. Hypothesis testing in both small and large-scale settings resulted in p-values of 0.000 and 0.002, respectively, leading to the rejection of the null hypothesis and acceptance of the alternative hypothesis; this confirmed that the experimental group exposed to the Reyog culture through the suitcase differed significantly from the control group using conventional media. Integrating physical and digital storytelling elements advances the discourse on delivering educational content in the digital era. However, focusing on a specific cultural narrative might limit its application to similar educational settings. Further research is recommended to evaluate its broader applicability in diverse educational environments. This study underscores the importance of innovative storytelling media that integrate local cultures, offering potential pathways to enrich global early childhood education.

Fusion information refresh rate improvement based on adaptive visual tracking in vehicle augmented reality sightseeing interactive system

AbstractThis paper proposes a dynamic information fusion interactive system with a transparent display applied in the vehicle. The dynamic information fusion interactive system integrates three leading technologies: relative position acquisition, fusion information mapping, and visual field tracking adaptive information generation. For visual field tracking adaptive information generation, the position of fusion information changes as the observer's field of view varies to help observers use this system more comfortably and intuitively. The frame rate of the dynamic virtual information display can be increased from 10 to 20 Hz without increasing the AI computing power and providing observers with a better observer experience. Integrating those technologies could achieve an AR‐based interactive system on a direct‐view transparent display. Such a system can provide passengers with location‐based interactive virtual and real integration information in the mobile field.

Preparation and Application of Polymer-Dispersed Liquid Crystal Film with Step-Driven Display Capability.

The realization of multifunctional advanced displays with better electro-optical properties is especially crucial at present. However, conventional integral full drive-based transparent display is increasingly failing to meet the demands of the day. Herein, partitioned polymerization as a novel preparation method was introduced innovatively into polymer-dispersed liquid crystals (PDLC) for realizing a step-driven display in agreement with fluorescent dye to solve the above drawback. At first, the utilization of fluorescent dye to endow the PDLC film with fluorescent properties resulted in a reduction in the saturation voltage of the PDLC from 39.7 V to 25.5 V and an increase in the contrast ratio from 58.4 to 96.6. Meanwhile, the experimental observations and theoretical considerations have elucidated that variation in microscopic pore size can significantly influence the electro-optical behavior of PDLC. Then, the step-driven PDLC film was fabricated through the exposure of different regions of the LC cell to different UV-light intensities, resulting in stepwise voltage-transmittance (V-T) responses of the PDLC film for the corresponding regions. Consequently, under appropriate driving voltages, the PDLC can realize three different states of total scattering, semi-transparent and total transparent, respectively. In addition, the PDLC film also embodied an outstanding anti-aging property and UV-shielding performance, which makes it fascinating for multifunctional advanced display applications.

Digital self-aligned focusing schlieren.

In this Letter, a digital self-aligned focusing schlieren (D-SAFS) system is introduced. This system uses a digital transparent micro liquid crystal display (μLCD), in combination with a linear polarizer, to act on the linear polarization state of light transmitted in both the forward and reverse directions, essentially acting as both the source and cutoff grids. The use of the μLCD display allows for on-the-fly changes to the cutoff pattern type, spatial frequency, and orientation. This eliminates the need to physically access the source/cutoff grid in order to optimize the instrument's sensitivity, which is necessary with a conventional self-aligned focusing schlieren (SAFS) system.