We have developed novel coating materials capable of absorbing fingerprint oils over time. When touch screens are operated with fingers, these oils adhere to the surface, rendering them visibly dirty. When finger oils adhere to anti-reflective coatings and structures, such as moth-eye films, their anti-reflective efficacy is substantially compromised. Specifically, in moth-eye films, the oils penetrate the grooves of the bell-shaped array and are difficult to remove. In this paper, we discuss our investigation into a technique for developing anti-fingerprint properties using these novel coating materials.

We introduce a new aquatic display optical system based on aerial imaging by retro-reflection (AIRR). This system places passive optical components (a beam splitter and retro-reflector) in water to eliminate disturbances due to water motion. To demonstrate the effectiveness of the proposed optical system, we develop a prototype optical system and compensate for the motion of the water surface. We analyze the motion compensation and quantify its effectiveness using peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) metrics. From these results, we see that the optical system maintains a static image in water even when the water surface is undulating.

In this study, we introduce a lateral electric-field driving system based on continuous potential-difference driving using lateral transparent electrodes to achieve a wide viewing zone angle in electronic holographic displays. We evaluate light modulation to validate the independent driving capability of each pixel at a high resolution (pixel pitch: 1 μm). Additionally, we demonstrate the feasibility of two-dimensional driving by integrating the driving and ground electrodes.

To improve throughput in security inspection procedures, a millimeter-wave (mmW) imaging system with a high-throughput operation with reasonable resolution compared to conventional mmW imaging systems is developed. Investigates the distinctive attributes of mmW, including its safe penetration through clothing, the study demonstrates the generation of detailed two-dimensional reconstructions of objects. Through the strategic use of a lens, signal amplitudes and phases are effectively captured, yielding reconstruction images from the signal reflected from the target. Experimental validations further affirm the effectiveness of mmW imaging with a dielectric lens, showcasing successful reconstructions of targets positioned at the lens’s front focal plane. Notably, the approach exhibits proficiency in discerning objects obscured behind non-metallic materials such as paper and cloth. These findings highlight the potential of utilizing Fourier transform analysis and a dielectric lens in mmW imaging, presenting a promising approach for security applications, particularly in the detection of concealed objects.

The slit coater method is an excellent liquid crystal (LC) alignment control technique that can order the LC alignment even on plastic substrates without pre-forming optional LC alignment films. However, controlling an arbitrary pretilt angle is still one of the issues. To elucidate the essence of the mechanism of the alignment transition from the planer to vertical alignment by UV polymerization, an in-liquid atomic force microscope was introduced. As a result, it was deduced that the LC alignment transition is induced by the realignment of mesogenic groups rather than surface topological change.

Holography is a three-dimensional (3D) technology that enables natural stereoscopic viewing with deep depth and expected for practical use in the future. Based on the recording process of holography, the electronic data generated through numerical simulation in a computer are called computer-generated holograms (CGHs). Displaying the generated CGH on a spatial light modulator and reconstructing a 3D object by illuminating it with light is called electro-holography. One of the issues in the development of 3DTV using electro-holography is the compression and transmission of a CGH. Because of the data loss caused by compression in a CGH, the quality of the reconstructed image may be affected, unlike normal 2D images. In wireless transmission of a CGH, not only data loss due to compression but also retransmissions and drops of data due to unstable network environments occur. These may degrade the quality of the reconstructed image, cause frame drops, and decrease the frame rate. In this paper, we developed a system for streaming CGH videos for reconstructing 3D objects using electro-holography. CGH videos were generated by merging multiple CGHs into a timeline, and the uncompressed or lossless compressed CGH videos were streamed via a network such as wired and wireless local area networks, a local 5G network, and mobile network. The performance of the network and quality of the CGH videos and reconstructed images were evaluated. Optically reconstructed images were obtained from the uncompressed CGH videos streamed via the networks. It was also confirmed that the required bit rate could be reduced without degrading the quality of the reconstructed image by using lossless compression. In some cases of wireless transmission, even when packet loss or retransmission occurs, there was no degradation in the reconstructed image quality.

We describe a tunable liquid crystal lens based on Fresnel optics that enables variable focus of virtual images displayed by a head-worn VR or AR device. This lens has been fabricated using ultra-thin, light bioplastic film instead of glass, uniquely enhancing visual comfort whilst reducing weight and thickness compared to glass-based approaches.

The Origin of the low turn-on voltage in the blue organic light-emitting diode using upconversion is discussed. We have discovered the properties of the intermediate state at the donor/acceptor interface such as the energy levels and the molecular interactions determines the efficiency of the upconversion process.

Integrated circuits used in automotive or aerospace applications must have high soft error tolerance. Redundant Flip Flops (FFs) are effective to improve the soft error tolerance. However, these countermeasures have large performance overheads and can be excessive for terrestrial applications. This paper proposes two types of radiation-hardened FFs named Primary Latch Transmission gate FF (PLTGFF) and Feed-Back Gate Tri-state Inverter FF (FBTIFF) for terrestrial use. By increasing the critical charge (Q_crit) at weak nodes, soft error tolerance of them were improved with low performance overheads. PLTGFF has the 5% area, 4% delay, and 10% power overheads, while FBTIFF has the 42% area, 10% delay, and 22% power overheads. They were fabricated in a 65 nm bulk process. By α-particle and spallation neutron irradiation tests, the soft error rates are reduced by 25% for PLTGFF and 50% for FBTIFF compared to a standard FF. In the terrestrial environment, the proposed FFs have better trade-offs between reliability and performance than those of multiplexed FFs such as the dual-interlocked storage cell (DICE) with larger overheads than the proposed FFs.