Portable Display Devices Research Articles

Development and Prospect of Viewing Angle Switchable Liquid Crystal Devices

As we move from the industrial age to the information age, nowadays, the opportunity to access personal information in public increases as personal computers (PCs), cell phones, automated teller machines (ATM) and other portable display devices have come into wider use, so it is well suited for these liquid crystal displays (LCDs) to switch between wide viewing angle (WVA) (share mode) and narrow viewing angle (NVA) (privacy mode). In this review, we have summarized structures, principles and characteristics of several devices that show great potential application in controllable anti-peeping displays in the eyesight of materials consist of pure liquid crystals (LCs), polymer dispersed LCs (PDLCs), polymer stabilized LCs (PSLCs) or polymer network LCs (PNLCs) and non-LCs, which provides systematic information for next-generation viewing angle-controllable LCDs with lower operating voltage, higher transmittance and good viewing angle controllable characteristics. Because LCs/polymer composite films have the advantages of long life, low power consumption and energy saving, they are regarded as the mainstream technology of next-generation viewing angle controllable displays.

Hierarchical Self-Assembly of Organic Core/Multi-Shell Microwires for Trichromatic White-Light Sources.

White-light-emissive organic micro/nanostructures hold exotic potential applications in full-color displays, on-chip wavelength-division multiplexing, and backlights of portable display devices, but are rarely realized in organic core/shell heterostructures. Herein, through regulating the noncovalent interactions between organic semiconductor molecules, a hierarchical self-assembly approach of horizontal epitaxial-growth is demonstrated for the fine synthesis of organic core/mono-shell microwires with multicolor emission (red-green, red-blue, and green-blue) and especially organic core/double-shell microwires with radial red-green-blue (RGB) emission, whose components are dibenzo[g,p]chrysene (DgpC)-based charge-transfer (CT) complexes. In fact, the desired lattice mismatching (≈2%) and the excellent structure compatibility of these CT complexes facilitate the epitaxial-growth process for the facile synthesis of organic core/shell microwires. With the RGB-emissive substructures, these core/double-shell organic microwires are microscale white-light sources (CIE [0.34, 0.36]). Besides, the white-emissive core/double-shell microwires demonstrate the fascinating full-spectrum light transportation from 400 to 700nm. This work indeed opens up a novel avenue for the accurate construction of organic core/shell heterostructures, which provides an attractive platform for the organic integrated optoelectronics.

Interaction concept and system architecture for the sterile information system OR-Pad in the perioperative area

Abstract Access to clinical information during interventions is an important aspect to support the surgeon and his team in the OR. The OR-Pad research project aims at displaying clinically relevant information close to the patient during surgery. With the OR-Pad system, the surgeon shall be able to access case-specific information, displayed on a sterilepackaged, portable display device. Therefore, information shall be prepared before surgery and also be available afterwards. The project follows an user-centered design process. Within the third iteration, the interaction concept was finalized, resulting in an application that can be used in two modes, mobile and intraoperative, to support the surgeon before/after and during surgery, respectively. By supporting the surgeon perioperatively, it is expected to improve the information situation in the OR and thereby the quality of surgical results. Based on this concept, the system architecture was designed in detail, using a client-server architecture. Components, communication interfaces, exchanged data, and intended standards for data exchange of the OR-Pad system including connecting systems were conceived. Expert interviews by using a clickable prototype were conducted to evaluate the concepts.

Development of a Three-Dimensional Multimode Visual Immersive System With Applications in Telepresence

Three dimensional (3-D) visual immersive system provides a better experience of virtual or remote environments compared with 2-D vision and is thus becoming one of the most active research fields of virtual reality. This paper describes how a 3-D multimode visual immersive system (3DMVIS) is developed, including system architecture, triplet lens module, head orientation tracking circuit, display module, and sensor signal processing. It supports two operation modes for different applications, corresponding to different combinations of lens. As a portable head-mounted display (HMD) device, it can be used in extensive virtual reality and telepresence applications. In addition, this HMD provides visual accommodation with the aid of manual focus and compatibility with various types of 3-D videos. Hence, users with various levels of myopia can experience this facility without wearing glasses. Meanwhile, a typical application in telepresence is investigated along with a compact panoramic camera system. The 3DMVIS is tested and evaluated with various virtual reality scenes, standard-format 3-D movies, and real-world 360° panoramic videos. In addition, comparisons with other commercial counterparts are presented. Technical specification indicates that the 3DMVIS with its telepresence system satisfies the requirements of practical applications.

Interoperable conditional access with video selective encryption for portable devices

The pay-TV industry seeks to extend its reach to portable display devices. At the same time, it seeks to ensure a horizontal market by making interoperable the Conditional Access Systems (CASs) employed to protect content. To achieve interoperability for such devices, this paper proposes a form of selective encryption for video that allows simultaneous distribution of a small percentage of video data on a per-CAS basis, allowing sharing of the unencrypted video between the CASs. The bitrate overhead for each additional CAS enabled is found to be on average 7.41 %, whereas the computational overhead amounts to no more than 40 ms for the benchmark sequences tested. Adaptation of CAS to transparent encryption of scalable video is also demonstrated in this paper.

Forming Spacers in Situ by Photolithography to Mechanically Stabilize Electrofluidic-Based Switchable Optical Elements.

Electro-Fluidic Displays (EFD) have been demonstrated to be an attractive technology for incorporation into portable display devices. EFDs have excellent optical efficiency and fast switching enabling video content. Ensuring mechanical stability of EFD display cells is a key challenge and essential for developing large area as well as flexible displays. Although the electro-optic performance of an EFD, unlike a liquid crystal display (LCD), is insensitive to cell-gap, extreme changes in cell-gap can result in irreversible collapse of the cell. Here we use photolithography to develop spacers to prevent cell-gap collapse and provide the required mechanical stability for EFD devices. The spacer is formed directly on the cover plates (ITO/glass) after cell assembly with UV light induced phase separation polymerization in the illuminated area. Phase separation behavior between polar aqueous solution and polymer is closely related to the solubility of acrylate monomers. In this work, polyethylene glycol diacrylate (PEGDA) as cross-linker, 2-hydroxyethyl acrylate (HEA) and acrylic acid or acrylamide as co-monomers are investigated for fabricating the spacers. PEGDA was added to the mixtures in order to increase the mechanical strength of the spacer. The spacers showed excellent performance for cell-gap control in EFD devices.

Super multi-view three-dimensional display technique for portable devices.

Portable display devices, such as intelligent telephones and panel PCs, have become parts of modern people's daily life. Their mainstream display interfaces are based on two-dimensional (2D) images. Although some three-dimensional (3D) technologies have been proposed for portable devices, comfortable visual effects are untouched until now. A super multi-view (SMV) system with comfortable 3D effects, constructed by a group of OLED microdisplay/projecting lens pairs, is proposed in this paper. Through gating different segments of each projecting lens sequentially and refreshing the virtual image of the corresponding microdisplay synchronously, the proposed SMV system greatly decreases the demand on the number of employed microdisplays and at the same time takes a thin optical structure, endowing great potential for portable devices.

Ergonomics and work-related musculoskeletal disorders in ophthalmic practice

Purpose: To increase the awareness of eye health care providers about Work related musculoskeletal disorders and proper ergonomics. Method: Literatures review of all aspect of work related musculoskeletal disorders and ergonomics pertaining to heath care in general and particularly to eye care providers. Results: Work related Musculoskeletal disorders (WRMSD's) among health care workers including Physicians, nurses, dental hygienist, and Custodial worker are well known. In the last two decades WRMSD's and related problems have being substantiated by different studies on the above mention groups, and in particular Ophthalmologists along with dentists and some surgical subspecialties (Laparoscope surgeons and Ear, Nose, and Throat surgeons). It was attributed to the specific nature of the job which requires prolonged awkward position and repetition. In these series of four articles will try to highlight the most important areas where health care providers especially the ophthalmologist should take care and aware of to prevent or at least reduce the WRMSD's. These areas involve: in the work and outside of work activities and include: (A) Clinic: The proper way of conducting slit lamp examination with or without the use of different lenses. How to perform direct and indirect ophthalmoscopes with the least stressful way to cervical and lumbar spine (will be covered in part 2 of this review). (B) Work station and office: How to set in proper way and how to select ergonomic and comfortable chair, tables, mouse, keyboard, screen and foot rest (will be covered in part 2 of this review). Also computer vision syndrome (will be discussed in part 4 of this review). (C) Operating room: Tips in how to adjust surgeon chair, microscope, and operating table to achieve the best ergonomic position. Also hints in the proper way of selecting and using surgical loupes (will be covered in part 2 of this review). (D) Outside the Hospital: Advises in the proper way of using portable visual display devices (smart phones and tablets etc…) along with hints on how to sit while driving and how to sleep with the least stress to the back and neck(will be covered in part 3 of this review). Conclusion: Adopting a healthy neutral posture and along with the comply of basic ergonomics principles in different areas of ophthalmic works early in the medical career (i.e. Residency) along with maintaining regular muscles stretches and exercise will reduce those unwanted Musculoskeletal squeals and hopefully leading to prolonged and productive healthy career life.

레이저 빔 스캔 시스템의 Blur현상 개선

Recently, as the wide spread of smart phone, pico projector which is used at the smart phone is appeared as a portable display device. In this paper, among several pico projectors, laser beam scanner module is dealt with in which laser is used as light source, and mems-mirror is used as optical panel. In this device, screen image quality is a special issue, and blur effect is a typical adverse effect to the quality of this device. So the enhancement of this blur effect has an important factor of the quality of the device. The definition of the blur and the main source of the blur are studied and the simulation results and way of improvement are also suggested.

Highly transparent and flexible field electron emitters based on hybrid carbon nanostructure

AbstractWe demonstrate a unique strategy to fabricate highly transparent and flexible field electron emitters (FEEs) based on combined carbon nanostructures, i.e., conical nanocarbon structures (CNCSs) and single‐walled carbon nanotubes (SWNTs). The combined structure was prepared by spray coating of 1,2‐dichloroethane (DCE) dispersed SWNTs onto neon ion (Ne+) irradiation induced CNCSs on nafion substrate. The field emission (FE) property of SWCNTs on both flat nafion and CNCSs surfaces increased with increasing the SWCNTs amount. The best FE result was attained for the highest amount of SWCNTs on the CNCSs substrate. This kind of collective structures is found to be effective emitters on transparent and flexible ion‐irradiated nafion substrate. Moreover, the combined carbon nanostructures showed improved transparency and emission performance compared to the individual nanostructures. The FE properties of 0.5 ml SWCNTs solution on CNCSs surfaces were equal to those of 1.5 ml SWCNTs solution on flat nafion surface. The hybrid structure based emitters (CNCSs and SWCNTs) produced by this method are lower‐cost cathode materials than hybrid structures of SWCNTs and flat nafion. Thus the combined nanostructures of SWCNTs/CNCSs might have huge prospects for the fabrication of efficient transparent and flexible FEEs and their broad application in next‐generation portable display devices. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Digital comics – new tools and tropes

Abstract The medium of comics is undergoing a transition, as digital display becomes an increasingly popular mode of consumption. Portable display devices such as smart phones and tablet computers have provided a single platform of consumption on which comics, film, animation, games and other interactive visual media are equally at home. As comics gradually leave behind the trappings of print and embrace those of the screen, so too do they invite new crossovers and appropriations of tropes from other screen-based media. This article considers the relationship between space and time in comics and how this relationship has changed during the medium’s transition from print to screen. Using the theories of S. McCloud, T. Groensteen and N. Cohn as its starting point, it examines the passage of time’s representation within the spatially based medium of traditional comics. It then looks at how this representation of time has been distorted by the range of new tropes and devices that comics have appropriated from other screen-based media. Key topics covered in the article include: Replacements for the page turn and their impact on the pacing of comic sequences; The infinite canvas and its implications for panel spacing and layout; Multicursal structures and a reconsideration of comic as temporal map; The impact of animation, both within the panel and in the movement of panels; The limits of animation in comics and the foregrounding of reader control as a key element of the medium.

45.4: Advanced Grinding Development for Laminated TFT‐LCDs

AbstractReducing the overall thickness and weight of LCD panels for mobile display could enhance the aesthetic and eases use of portable display devices. However, laminated cells have unstable control on scribing and the edge strength would get decreased after grinding process. In this study, we illustrated an “advanced” grinding process which could remove the defect of scribed edge and get 40% enhancing by process optimized. Meanwhile, it also has 20%∼50% strength improving for laminated cells with thickness from 0.3mm to 0.8mm.

57.1: Invited Paper: Novel Thin Glass for 3D Shaped Electronics Display Covers

AbstractAs the market for consumer electronic portable display devices continues to grow, designers and manufacturers of such devices are increasingly demanding display cover glasses that are extremely lightweight, with higher impact strength, better scratch resistance and impressive durability to stand up to the wear and tear of everyday life. Furthermore, the rapid emergence of innovative touch display technologies means that such glass characteristics are becoming even more important to the industry. Demand for impressive technical functionality for handheld devices is high, as is the need for strong aesthetical design to meet the needs of next generation consumer electronic devices. For example, most handheld devices today have only flat screens, but many designers are now actively looking to integrate curved glass surfaces into innovative, new designs. Lithium Aluminosilicate (LAS) glasses such as SCHOTT® LAS80 are emerging to fulfill these demanding requirements. Manufactured using hi‐tech glass production technologies such as the standard float process, LAS glasses can be easily chemically toughened to meet stringent mechanical strength and hardness specifications. Furthermore, the low transformation temperature (Tg) of LAS glasses facilitates hot forming processes to produce 3‐D shaped cover glasses, opening up a multitude of options for consumer electronic portable display device designers.

A line inversion-based stepwise data driving for low-power mobile TFT-LCDs

This paper proposes a line inversion-based stepwise data driving scheme for use in low-power mobile TFT-LCDs. The proposed stepwise data driving scheme adopts a stepwise pull-up and pull-down transition operations of source and common lines in an LCD penal, resulting in greatly reduced power consumption as compared to the conventional line inversion-based data driving schemes. Moreover, the proposed scheme shows relatively uniform power consumption for different image patterns, making background image design easy for use in commercial portable display devices. Three test chips for mobile devices having QCIF+, QVGA, and HVGA resolutions were fabricated in a 6-V/0.7-μm quadruple-metal CMOS process. The experimental results showed that overall power reductions of 25%-37% for QCIF+, 31%-47% for QVGA, and 42%-53% for HVGA TFT-LCDs were achieved, depending on image pattern, with a die size overhead of less than 1%. They also indicated that the proposed driving scheme allowed around 55% to 32% reduction on image pattern-dependent power variation as compared to conventional driving schemes.

P‐243L: Late‐News Poster: A 480‐Output TFT‐LCD Source Driver IC for COG Applications

AbstractA 480‐output TFT‐LCD source driver IC for a COG (Chip On Glass) application is presented. To reduce the cost of the TFT‐LCD module, COG technology is being adopted for the portable display devices. To achieve the high data rate transfer on the COG‐type TFT‐LCD module, an ACDS (Advanced Current‐mode Differential Signaling) interface is proposed. The offset compensating algorithm is adopted to alleviate the block dim phenomenon due to the offset of internal gamma buffers. The driver IC was fabricated in 0.35um high voltage CMOS technology process and evaluated with 13.3‐inch diagonal wide XGA (1280RGB×800) TFT‐LCD module of which cost was reduced significantly.

Model for Simulation and Optimization of Liquid Crystal Displays Cell Thinning Process

An abrasive single-sided lapping approach is applied to the thinning of assembled cells of liquid crystal displays (LCDs). The approach reduces the thickness and weight of the panels, thereby enhancing the aesthetics and ease of use of portable display devices. In this study, a new mathematical model has been developed to describe the mechanism applied to this advanced technology and verified by experiments. The model can help find the optimum parameters for the thinning process and the suitable dimensions of a single-sided lapping machine for the LCD cell thinning process.

Environmental Cell Thinning of Advanced Liquid Crystal Displays

A structured abrasive is applied to a thinly assembled liquid crystal display (LCD) cell in single-sided lapping. This effectively reduces the overall thickness and weight of the panels, thereby enhancing the aesthetics and ease of use of portable display devices. The technology enables an environmentally friendly means of mechanical thinning. Moreover, compared with conventional slurry lapping, it achieves a better surface roughness (0.24 µm), a higher cut rate (11.6–13.4 µm/min) and a lower operating pressure (45 g/cm2) for different specimens. Furthermore, it can be used to process 3.5G (610×720 mm2) glass substrates on a 1200-mm-diameter tool.

Ultralow-power organic complementary circuits

The prospect of using low-temperature processable organic semiconductors to implement transistors, circuits, displays and sensors on arbitrary substrates, such as glass or plastics, offers enormous potential for a wide range of electronic products. Of particular interest are portable devices that can be powered by small batteries or by near-field radio-frequency coupling. The main problem with existing approaches is the large power consumption of conventional organic circuits, which makes battery-powered applications problematic, if not impossible. Here we demonstrate an organic circuit with very low power consumption that uses a self-assembled monolayer gate dielectric and two different air-stable molecular semiconductors (pentacene and hexadecafluorocopperphthalocyanine, F16CuPc). The monolayer dielectric is grown on patterned metal gates at room temperature and is optimized to provide a large gate capacitance and low gate leakage currents. By combining low-voltage p-channel and n-channel organic thin-film transistors in a complementary circuit design, the static currents are reduced to below 100 pA per logic gate. We have fabricated complementary inverters, NAND gates, and ring oscillators that operate with supply voltages between 1.5 and 3 V and have a static power consumption of less than 1 nW per logic gate. These organic circuits are thus well suited for battery-powered systems such as portable display devices and large-surface sensor networks as well as for radio-frequency identification tags with extended operating range.

A novel portable LCD using a new AFFS technology for outdoor readability

— The advanced fringe-field switching (AFFS) mode is suitable for portable display devices. It has high transmittance, wide viewing angle, low power consumption, high contrast ratio, and a ripple-free property resistant to pressure. Recently, a 10.4-in. XGA prototype which demonstrates excellent transmittance and very good outdoor readability has been developed. To obtain these properties, a new pixel structure has been designed which has a large aperture and a metal embossing pattern for inner reflectance without the use of a black matrix on the embossing metal pattern. Precise control of the liquid-crystal electrodynamics and surface reflectance using an AR polarizer was achieved. This new panel shows distinguished characteristics for outdoor readability with the backlight on under a bright outside light source.

5521443 Battery residual capacity display and operating device for an electric vehicle

A portable display device is capable of monitoring the residual capacity of a traveling battery from the outside of an electric vehicle, and conducting operations such as locking and unlocking of a door from outside of the vehicle and controlling the operation of the air conditioner through wireless means. This portable display device is inserted into an insertion section provided in an instrument panel of the vehicle for operating the vehicle. If an ID code in the portable display device agrees with an ID code in the vehicle, a traveling switch is unlocked. Then, if the traveling switch is operated, a steering lock device is released and the traveling motor is connected to the traveling battery in a state in which the electric vehicle is operable.