Flexible microelectronics: New application for thin‐film transistors in fingerprint sensors

Abstract— Thin‐film transistors (TFTs) are field‐effect transistors that can be used to create large‐scale‐integrated (LSI) circuits. The combination of high‐performance TFTs and transfer technology of the TFTs has the potential to foster the rise of a new flexible microelectronics industry. This paper discusses the current status of flexible microelectronics, using a TFT fingerprint sensor (FPS) as an example. Technology used in active‐matrix displays can easily be applied to the TFT FPS. TFT technology should not be confined to the display industry; its use should be expanded into the semiconductor industry. With the result presented in this paper, we declare a new era of flexible microelectronics open.     

Low‐temperature poly‐Si TFT transferred onto plastic substrates by using surface free technology by laser ablation/annealing (SUFTLA®)

A novel technology that makes it possible to transfer electronic devices from an original substrate to another substrate is introduced. Because laser irradiation is utilized during the transfer process, this technology was named SUFTLA® (surface free technology by laser ablation/annealing). Low‐temperature poly‐Si TFTs first manufactured on a quartz substrate were transferred onto a PES substrate without any damage or characteristic degradation. A trial TFT‐LCD device with peripheral integrated driver circuits was also transferred onto the PES substrate and their operation was observed under typical conditions. These results indicate that the SUFTLA technology is one of the leading candidates for fine‐patterned high‐performance electronic‐device manufacturing on flexible substrate.     

Flexible AMOLEDs with low‐temperature‐processed TFT backplane technologies

Developments of backplane technologies, which are one of the challenging topics, toward the realization of flexible active matrix organic light‐emitting diodes (AMOLEDs) are discussed in this paper. Plastic substrates including polyimide are considered as a good candidate for substrates of flexible AMOLEDs. The fabrication process flows based on plastic substrates are explained. Limited by the temperature that plastic substrates can sustain, TFT technologies with maximum processing temperature below 400 °C must be developed. Considering the stringent requirements of AMOLEDs, both oxide thin‐film transistors (TFTs) and ultra‐low‐temperature poly‐silicon TFTs (U‐LTPS TFTs) are investigated. First, oxide TFTs with representative indium gallium zinc oxide channel layer are fabricated on polyimide substrates. The threshold voltage shifts under bias stress and under bending test are small. Thus, a 4.0‐in. flexible AMOLED is demonstrated with indium gallium zinc oxide TFTs, showing good panel performance and flexibility. Further, the oxide TFTs based on indium tin zinc oxide channel layer with high mobility and good stability are discussed. The mobility can be higher than 20 cm²/Vs, and threshold voltage shifts under both voltage stress and current stress are almost negligible, proving the potential of oxide TFT technology. On the other hand, the U‐LTPS TFTs are also developed. It is confirmed that dehydrogenation and dopant activation can be effectively performed at a temperature within 400 °C. The performance of U‐LTPS TFTs on polyimide is compatible to those of TFTs on glass. Also, the performance of devices on polyimide can be kept intact after devices de‐bonded from glass carrier. Finally, a 4.3‐in. flexible AMOLED is also demonstrated with U‐LTPS TFTs.     

An affordable surround‐screen virtual reality display

Abstract— Building a projection‐based virtual reality display is a time‐, cost‐, and resource‐intensive enterprise, and many details contribute to the final display quality. This is especially true for surround‐ screen displays where most of them are one‐of‐a‐kind systems or custom‐made installations with specialized projectors, framing, and projection screens. In general, the costs of acquiring these types of systems have been in the hundreds and even millions of dollars, specifically for those supporting synchronized stereoscopic projection across multiple screens. Furthermore, the maintenance of such systems adds an additional recurrent cost, which makes them hard to afford for general introduction in a wider range of industry, academic, and research communities. A low‐cost easy‐to‐maintain surround‐screen design based on off‐the‐shelf affordable components for the projection screens, framing, and display systems is presented. The resulting system quality is comparableto significantly more expensive commercially available solutions. Additionally, users with average knowledge can implement this design, and it has the added advantage that single components can be individually upgraded based on necessity as well as available funds.     

Flexible OLED display development: Strategy and status

Abstract— In this paper, the current status of flexible OLED (FOLED®) display development will be reviewed, including previous results for passive‐matrix displays on plastic and current progress on active‐matrix displays on steel foil. The displays incorporate high‐efficiency small‐molecule phosphorescence OLED (PHOLE?) technology. The ultimate goal is to develop high‐information‐content high‐performance long‐lived, and large‐area FOLED displays that can be pulled or rolled out from a smaller pen‐like housing. The strategy for achieving this goal will be presented.     

A Flexible electronic‐paper display with an ultra‐thin and flexible LSI driver using quick‐response liquid‐powder technology

Abstract— A thin and flexible LSI driver with a thickness of less than 35 μm for a passive‐matrix‐driven Quick‐Response Liquid‐Powder Display (QR‐LPD?) was successfully mounted onto the flexible printed circuit (FPC) and the back substrates of a flexible QR‐LPD?. Amounted LSI driver on a plastic substrate shows no significant degradation in the driving performances and maintains physical flexibility without any connection failures. This technology can realize a fully flexible electronic paper in combination with a plastic‐substrate QR‐LPD? fabricated by a roll‐to‐roll process.     

Development of a 10.4‐in. UXGA display using low‐temperature poly‐Si technology

A new 10.4‐in.‐diagonal display with UXGA resolution (1600 H × 1200 V pixels) using low‐temperature polysilicon (poly‐Si) TFTs has been developed for notebook‐PC applications. The source drive technique uses integrated selector switches, which decreases the number of tape carrier packages (TCPs) for a poly‐Si TFT‐LCD and increases the connection pitch of the TCPs to the glass substrate. In this paper, we present a new display configuration and fabrication process.     

虚拟现实技术搭建高职教育工学结合的新桥梁

虚拟现实技术被越来越多的行业所应用,也引起了教育界专家的广泛关注。虚拟现实技术的发展必将给教学领域中情境化的教学带来革命性的进步。本文重点论述,在高等职业教育中虚拟现实技术所发挥的重要作用,它能够搭建一个崭新的平台,把学校与行业与企业与国际大环境与市场紧密的连接在一起。为学生真正搭建起一个大行业,大环境,全球化,多企业参与共享的真实的虚拟平台。     

Dynamics and Noncollocated Model‐Free Position Control for a Space Robot with Multi‐Link Flexible Manipulators

In this paper, both the dynamics and noncollocated model‐free position control (NMPC) for a space robot with multi‐link flexible manipulators are developed. Using assumed modes approach to describe the flexible deformation, the dynamic model of the flexible space robotic system is derived with Lagrangian method to represent the system dynamic behaviors. Based on Lyapunov's direct method, the robust model‐free position control with noncollocated feedback is designed for position regulation of the space robot and vibration suppression of the flexible manipulators. The closed‐loop stability of the space robotic system can be guaranteed and the guideline of choosing noncollocated feedback is analyzed. The proposed control is easily implementable for flexible space robot with both uncertain complicated dynamic model and unknown system parameters, and all the control signals can be measured by sensors directly or obtained by a backward difference algorithm. Numerical simulations on a two‐link flexible space robot are provided to demonstrate the effectiveness of the proposed control.     

Low‐temperature amorphous‐silicon backplane technology development for flexible displays in a manufacturing pilot‐line environment

Abstract— A low‐temperature amorphous‐silicon (a‐Si:H) thin‐film‐transistor (TFT) backplane technology for high‐information‐content flexible displays has been developed. Backplanes were integrated with frontplane technologies to produce high‐performance active‐matrix reflective electrophoretic ink, reflective cholesteric liquid crystal and emissive OLED flexible‐display technology demonstrators (TDs). Backplanes up to 4 in. on the diagonal have been fabricated on a 6‐in. wafer‐scale pilot line. The critical steps in the evolution of backplane technology, from qualification of baseline low‐temperature (180°C) a‐Si:H process on the 6‐in. line with rigid substrates, to transferring the process to flexible plastic and flexible stainless‐steel substrates, to form factor scale‐up of the TFT arrays, and finally manufacturing scale‐up to a Gen 2 (370 × 470 mm) display‐scale pilot line, will be reviewed.     

A 23‐in. full‐panel‐resolution autostereoscopic LCD with a novel directional backlight system

Abstract— An autostereoscopic display that shows stereoscopic images with full‐panel resolution has been developed,¹ but it has a problem in terms of unit size. To resolve this problem, a new directional backlight system was developed, and it was applied to a prototype autostereoscopic LCD. The backlight system has two light sources — one for the right eye and the another for the left eye — and an elliptically shaped mirror that controls the direction of light from the light sources. The LCD uses a field‐sequential method which re‐writes an image for one eye and one for the other eye at a frame rate of 120 Hz, and the light sources alternately blink in synchronization with each frame so that the LCD shows full‐panel‐resolution stereoscopic images without flicker. In this paper, the new backlight system is described. The backlight system is effective for large screen such as 23 in. on the diagonal. By using this backlight system, the prototype LCD achieved practible unit size, brightness over the entire screen, and cross‐talk.     

Clocked control scheme of separating TFTs for a node‐sharing LTPS TFT shift register with large number of outputs

This paper proposes the node‐sharing low‐temperature poly‐silicon (LTPS) thin‐film transistor (TFT) shift register with the clocked control scheme that completely turns separating TFTs off during the bootstrapping period to compensate for internal resistive and capacitive loads. The fluctuation is also addressed by adding pull‐down TFTs or raising the low level of the control signal.     

柔性臂漂浮基空间机器人建模与轨迹跟踪控制

利用拉格朗日法和假设模态方法建立了末端柔性的两臂漂浮基空间机器人的非线性动力学方程．通过坐标变换,推导出一种新的以可测关节角为变量的全局动态模型,并在此基础上运用基于模型的非线性解耦反馈控制方法得到关节相对转角与柔性臂的弹性变形部分解耦形式控制方程．最后,讨论了柔性臂漂浮基空间机器人的轨迹跟踪问题,并通过仿真实例计算,表明该模型转换及控制方法对于柔性臂漂浮基空间机器人末端轨迹跟踪控制的有效性．     

Beyond ‘mobility’: A new understanding of moving with technology

We report a surprising experience with mobile technology: the lead author found herself seeing and acting differently while running over part of her usual running track with the exercise‐tracking application ‘Strava’ on her phone, even without focal attention to the app. We apply the method of problematization to a detailed empirical account of this experience, in conjunction with a literature analysis of taken‐for‐granted assumptions underpinning research on ‘mobile technology use’. This reveals that, while the relationship of attention, perception, movement and technology was a key element of the surprise, these themes are not well accounted for in current IS literature. In response, we employ William Gibson's ecological theory of visual perception to reinterpret the empirical account and thereby build a new understanding of the human plus mobile technology that we term moving‐with‐technology. We introduce to IS: moving‐with‐technology as a new analytical perspective; the new phenomena of digital sub‐species, digital‐niches and asynchronous co‐location; and stimulus for new ecologically oriented ‘mobile methods’. Moving‐with‐technology also has practical implications for urban planners who are using data from digital trace‐making tools such as Strava in their decision‐making, thereby generating what we call ecological feedback loops.     

Achieving a foldable and durable OLED display with BT.2020 color space using innovative color filter structure

A foldable active‐matrix organic light‐emitting diode display capable of enduring very severe folding and environmental impact was obtained using symmetric panel stacking with an innovative design of color filter structure. The display was subjected to in situ folding cycle under an ambient test condition of 60°C/90% relative humidity, and no performance degradation was found for the display and the touch function during and after the test. In addition, 95% coverage of BT.2020 color space was obtained without additional power consumption compared with that of the panel with National Television System Committee (NTSC) color space.     

High‐performance 55‐in. diagonal WXGA PDP with extended ALIS technology

Abstract— We have developed a high‐performance 55‐in. diagonal WXGA PDP module with a novel structure by using Extended ALIS (Alternate Lighting of Surfaces) technology. The new cell structure that uses the common bus electrode concept was invented with a new driving scheme aimed toward progressive lighting. A new method of reducing dynamic false contour (DFC), motion adaptive subfield coding, was also developed. The newly developed 55‐in. WXGA panel has a 1000‐cd/m² peak luminance and a 160‐cd/m² full‐screen white luminance with a 9000 K color temperature at a 350‐W display power consumption.     

Development and behavioral pattern analysis of a mobile guide system with augmented reality for painting appreciation instruction in an art museum

A mobile guide system that integrates art appreciation instruction with augmented reality (AR) was designed as an auxiliary tool for painting appreciation, and the learning performance of three groups of visiting participants was explored: AR-guided, audio-guided, and nonguided (i.e., without carrying auxiliary devices). The participants were 135 college students, and a quasi-experimental research design was employed. Several learning performance factors of the museum visitors aided with different guided modes were evaluated, including their learning effectiveness, flow experience, the amount of time spent focusing on the paintings, behavioral patterns, and attitude of using the guide systems. The results showed that compared to the audio- and nonguided participants, the AR guide effectively enhanced visitors' learning effectiveness, promoted their flow experience, and extended the amount of time the visitors spent focusing on the paintings. In addition, the visitors' behavioral patterns were dependent upon the guided mode that they used; the visitors who were the most engaged in the gallery experience were those who were using the AR guide. Most of the visitors using the mobile AR-guide system elicited positive responses and acceptance attitudes.     

An 81‐in. 8 K OLED Kawara‐type multidisplay with flexible displays that provides a seamless image

We fabricated a Kawara‐type multidisplay, providing a seamless image by precisely arranging 13.5‐in. organic light‐emitting diode flexible panels with transparent edges on two adjacent sides. To make overlapping portions less visible, the transparent regions were adjusted optically and corrected in luminance and chromaticity. We used 36 panels to fabricate an 81‐in. 8 K organic light‐emitting diode Kawara‐type multidisplay.