Optical Touch Research Articles

Differential Signal-Amplitude-Modulated Multi-Beam Remote Optical Touch Based on Grating Antenna.

As screen sizes are becoming larger and larger, exceeding human physical limitations for direct interaction via touching, remote control is inevitable. However, among the current solutions, inertial gyroscopes are susceptible to positional inaccuracies, and gesture recognition is limited by cameras' focus depths and viewing angles. Provided that the issue of ghost points can be effectively addressed, grating antenna light-trapping technology is an ideal candidate for multipoint inputs. Therefore, we propose a differential amplitude modulation scheme for grating antenna-based multi-beam optical touch, which can recognize different incidence points. The amplitude of the incident beams was first coded with different pulse widths. Then, following the capture of incident beams by the grating antenna and their conversion into electrical currents by the aligned detector arrays, the incident points of the individual beams were recognized and differentiated. The scheme was successfully verified on an 18-inch screen, where two-point optical touch with a position accuracy error of under 3 mm and a response time of less than 7 ms under a modulation frequency of 10 kHz on both incident beams was achieved. This work demonstrates a practical method to achieve remote multi-point touch, which can make digital mice more accurately represent the users' pointing directions by obeying the natural three-point one-line aiming rule instantaneously.

76‐3: Invited Paper: Integration of Sensing Technologies into MicroLED Displays

MicroIC enables display attributes unattainable from polycrystalline thin‐film transistors, and the complimentary metal‐oxide semiconductor (CMOS) microICs support a wide range of applications beyond driving pixels. Integrating sensors within displays can add value to products, reduce costs and improve performance versus conventional solutions. As evidenced by touch and display integration in mobile displays via TDDI ICs, in‐cell sensing can reduce cost and improve performance to levels that are not available with all display types. Capacitive touch, optical touch, 3D scanning, and proximity sensing can also benefit from the inherent coordination between sensors and display. We present multiple sensing architectures and demonstrations of integration within microLED displays and describe CMOS microIC circuits for touch sensing applications. With diverse heterogenous semiconductor technology tightly woven into displays, the potential for intuitive gesture controls, adaptive interfaces, and enhanced sensory feedback paves the way for more natural and effortless interactions between humans and machines.

Selected methods for material identification on the border of geological layers for the automation of industrial processes of obtaining raw materials

Production plants wishing to become competitive on the local and global market should offer their products at the lowest possible price and, at the same time, in the highest possible quality. One of the key tasks for the engineering and technical staff working on them is improving the organization of work and the degree of use of means of production, allowing to increase work efficiency. The latest technological achievements focused on the concept of the Industry 4.0 create new opportunities for further improvement of production processes, their optimization, reduction of costs, or reduction of the nuisance of physical work and mental effort of employees. Many industries use both renewable and nonrenewable natural resources available on earth. Acquiring some of them requires considerable resources and is very burdensome for people. Especially regarding resources deep underground. In the near future, we will also use material resources obtained from outside the Earth, which is an additional challenge. Therefore, the integration of the latest technologies, especially in the field of automation and autonomous robots, IoT and Big data is becoming an essential research area.The paper presents an overview of technological methods and solutions of material identification that can be used in the processes of automated sourcing of materials on an industrial scale. Particular attention was paid to techniques that can be used by specialized, autonomous robots working in conditions that are hard and unsafe for humans. Discussed recognition systems can use advanced methods and the latest technologies. They are most often implemented using special sensors installed on or close to the executive element of a machine. The differences in rocks hardness and compressive strength allowed for the development of methods using acoustic waves and also methods using the measurement of vibration of the cutting tools and machine parts on which they are installed. Another method uses the natural features of rocks adjacent to the seam being extracted - it measures differences in the level of radioactivity. On this basis, a method was developed based on the recognition of low gamma radiation activity. Methods based on the use of radars or thermal imaging cameras testing the temperature of cutting knives installed on the cutting body were also proposed. Another interesting solution is the optical touch sensor that recognizes different types of rock layers. Difficult working conditions, also for machines, in which there is a high concentration of stone dust limiting visibility, the presence of water, and high noise generated by working devices, reveals a number of advantages and disadvantages in the above methods to use them in autonomous, robotic solutions.

Fracturing Patriarchal Objectivity through Electro-Pop: Purity Ring and the vicissitudes of sight

This article examines the deviated modes of seeing in the work of Canadian electro-pop band Purity Ring. Bringing their recent music into conversation with the theory of Tim Ingold and Eugenie Brinkema, I suggest that Megan James and Corin Roddick perform seeing as a granular, augmented act that continually shapes the boundaries between our bodies and the world around us. Particular attention is paid to James and Roddick’s creative engagement with optical touch and the formal capability of music to engage affectively with the act of seeing. By integrating musical examples, Tallulah Fontaine’s artwork for the band and the poetry of Kiran Millwood Hargrave, this article offers an expanded reading experience that spans the textual, the aural and the visual. I argue that the political crux of Purity Ring’s performance of perception lies in them moving beyond a reactionary response to patriarchal objectivity and towards a creative refiguration of perception as a form of subjectivation. The eyes that Purity Ring instantiate do not passively observe the world; they change it, both consoled and engulfed by the vicissitudes of perception.

Making Soft Optical Sensors More Wearable

This paper discusses new components and approaches to make stretchable optical fiber sensors better meet the power and washability requirements of wearables. First, an allpolymer quick connector allows the light source and photosensor to be quickly detached for washing. Second, the paper investigates the possibility of driving the sensors using ambient light instead of an onboard light source. While optical strain sensors and touch sensors have advantages over electronic ones in wet environments, and the intrinsic stretchability of the fibers is useful for soft robotics and highly conformal wearables, the typical light-emitting diode (LED) light source consumes more power than an electronic resistive or capacitive strain sensor. In this work, ambient light of uniform but unknown intensity is demonstrated to drive an elastomeric optical touch sensor in a differential configuration.

44‐1: Photo Sensors Embedded within TFT‐LCD with Three Primary Colors Optical Touch Function

In this paper, a 15‐inch XGA TFT‐LCD with embedded 113×256 three primary colors photo sensors is successfully developed by a‐Si:H TFT. Each photo sensor consists of one TFT switch, one storage capacitor and diode‐connected TFTs covered with color filters of three primary colors (red, green, and blue). The diode‐connected TFTs include a recently proposed white‐light photocurrent gating (WPCG) sub‐circuit to suppress the effects of ambient light illumination.

Leakage current model of InGaZnO thin film transistor

<sec>In recent years, amorphous InGaZnO thin-film transistor (InGaZnO TFT) has attracted intensive attention. Due to its high mobility, low off-state current, and excellent uniformity over large fabrication area, the InGaZnO TFTs promise to replace silicon-based TFTs in flat panel displays, optical image sensors, touch sensing and fingerprint sensing area. The on-state performances of InGaZnO TFT are used in thin film transistor liquid crystal display, active-matrix organic light emitting display, etc. Consequently, numerous on-current models have been proposed previously. However, for lots of the emerging sensing applications such as optical image sensors, the leakage current of InGaZnO TFTs is critical.</sec><sec>Previous literature has shown that the leakage current generation mechanisms in TFTs include trap-assisted thermal emission, trap-assisted field emission, inter-band tunneling, and auxiliary thermal electron field emission containing Poole-Frenkel effect. However, up to now, there has been few reports on the leakage current model of InGaZnO TFT, which hinders further the development of emerging applications in InGaZnO TFTs for sensor and imagers integrated in display panels.</sec><sec>In this paper, the leakage current model of InGaZnO TFT is established on the basis of carrier generation recombination rate. The feasibility of the proposed model is proved by comparing the TCAD simulations with the measured results. In addition, the influences of geometrical parameters on the leakage current of InGaZnO TFT, i.e. the channel width, the active layer thickness, and the gate dielectric thickness, are analyzed in detail. This research gives insightful results for designing the sensors and circuits by using the InGaZnO TFTs.</sec>

17.1: Invited Paper: Optical interaction enabled by sub‐wavelength metamaterials: fabrication process and system demos

Human‐machine interaction is the inevitable medium for people to obtain information from display devices. The evaluation of interaction technologies consist one of the most important parts of the rapid development of display industry. Fifty years ago, mouse and keyboard had brought about great convenience for people to operate machines, while the transparent capacitive touching technology led by Apple's ‘Iphone’ 10 years ago, revolutionarily enable people to use fingers‐the native and ultimate locating ‘device’ to touch and operate the displays.Until now, most of the ‘touching’ technologies only work on the plane dimensional of screens. While, in this talk, we will show a novel optical touching technology based on sub‐wavelength meta‐materials which cover the incident rays into wave guided light for position detection and interaction. By using roll‐to‐roll nano‐imprinting, larger scale fabrication of the sub‐wavelength optical films have been fulfilled and a prototype of optical touch screen has been made, paving the way to mass commercialization.

56‐2: Optical Touch Screen Integrated With Fingerprint Recognition

An optical touch panel integrated with fingerprint recognition function has been proposed and confirmed. Through tactical design with slanted grating and appropriate pitch, efficient coupling of waveguide mode for touch sensing and sufficient non‐overlapping area for fingerprint detecting were obtained simultaneously, meaning great potential for intelligent touch devices.

A High Optical Transmittance and Low Cost Touch Screen without Patterning

Transparent Conducting Oxide (TCO) materials such as Fluorine Tin Oxide (FTO) and Indium Tin Oxide (ITO) due to their optical and electrical properties are used in touch screens as ele ...

Development of the Ordering System by CMOS

To change for the better of the menu board which is not applied ICT technology, we present automatic ordering system using by CMOS touch technology. Optical touch can be an ambiguous term because there are several different methods of using light to detect touch. The progress that has been made in CMOS technology over the past decade has made it the preferred technology for high speed inspection. CMOS infrared (IR) cameras are placed on top of a display, looking across the surface of the display in order to detect the presence of a touching object. In this paper, we present the process of choosing the menu by the CMOS infrared technology, and the communication with the sever(POS in this case) using WIFI. The propsed system included 5 parts: hardware part, touch technology part, presentation of menu part, Received (February 22, 2016), Review Result (March 8, 2016) Accepted (March 15, 2016), Published (April 30, 2016) Dept. Information and Communications Engineering, Daejeon University, 62 Daehak-ro, Dong-gu, Daejeon, Korea email: sskang@dju.kr (Corresponding Author) Dept.. Fire & Disaster Prevention Engineering, Daejeon University, 62, DaeHackRoo, Dongu, Daejeon, Korea, email: chojo@dju.kr AVONNE lnc., 307, 3 floor, UDIP, Daejeon Univ. Industry-Academic Cooperation Foundation, Daejeon Korea email: ceo@avonne.kr Development of the Ordering System by CMOS Copyright c 2016 HSST 64 controlling the device part, and ordering commnunication part. The advantage of the proposed system is that lower cost by using LED instead of electronic display and energy efficient.

Quantification of gait parameters in freely walking rodents.

BackgroundQualitative and quantitative measurements of motor performance are essential for characterizing perturbations of motor systems. Although several methods exist for analyzing specific motor tasks, few behavioral assays are readily available to researchers that provide a complete set of kinematic parameters in rodents.ResultsHere we present MouseWalker, an integrated hardware and software system that provides a comprehensive and quantitative description of kinematic features in freely walking rodents. Footprints are visualized with high spatial and temporal resolution by a non-invasive optical touch sensor coupled to high-speed imaging. A freely available and open-source software package tracks footprints and body features to generate a comprehensive description of many locomotion features, including static parameters such as footprint position and stance patterns and dynamic parameters, such as step and swing cycle duration, and inter-leg coordination. Using this method, we describe walking by wild-type mice including several previously undescribed parameters. For example, we demonstrate that footprint touchdown occurs instantaneously by the entire paw with no obvious rostral–caudal or lateral–medial bias.ConclusionsThe readily available MouseWalker system and the large set of readouts it generates greatly increases the currently available toolkit for the analysis of wild type and aberrant locomotion in rodents.Electronic supplementary materialThe online version of this article (doi:10.1186/s12915-015-0154-0) contains supplementary material, which is available to authorized users.

External Light Evasion Method for Large Multi-touch Screens

This paper presents an external light evasion method that rectifies the problem of misrecognition due to external lighting. The fundamental concept underlying the proposed method involves recognition of the differences between two images and elimination of the desynchronized external light by synchronizing the image sensor and inner light source of the optical touch screen. A range of artificial indoor light sources and natural sunlight are assessed. The proposed system synchronizes with a Vertical Synchronization (VSYNC) signal and the light source drive signal of the image sensor. Therefore, it can display synchronized light of the acquired image through the image sensor and remove external light that is not from the light source. A subtraction operation is used to find the differences and the absolute value of the result is utilized; hence, the order is irrelevant. The resulting image, which displays only a touched blob on the touchscreen, was created after image processing for coordination recognition and was then supplied to a coordination extraction algorithm.

Design of an fMRI-compatible optical touch stripe based on frustrated total internal reflection.

Previously we developed a low-cost, multi-configurable handheld response system, using a reflective-type intensity modulated fiber-optic sensor (FOS) to accurately gather participants' behavioral responses during functional magnetic resonance imaging (fMRI). Inspired by the popularity and omnipresence of the fingertip-based touch sensing user interface devices, in this paper we present the design of a prototype fMRI-compatible optical touch stripe (OTS) as an alternative configuration. The prototype device takes advantage of a proven frustrated total internal reflection (FTIR) technique. By using a custom-built wedge-shaped optically transparent acrylic prism as an optical waveguide, and a plano-concave lens to provide the required light beam profile, the position of a fingertip touching the surface of the wedge prism can be determined from the deflected light beams that become trapped within the prism by total internal reflection. To achieve maximum sensitivity, the optical design of the wedge prism and lens were optimized through a series of light beam simulations using WinLens 3D Basic software suite. Furthermore, OTS performance and MRI-compatibility were assessed on a 3.0 Tesla MRI scanner running echo planar imaging (EPI) sequences. The results show that the OTS can detect a touch signal at high spatial resolution (about 0.5 cm), and is well suited for use within the MRI environment with average time-variant signal-to-noise ratio (tSNR) loss < 3%.

P‐170: Optical Touch Screen based on Grating and Waveguide

AbstractAn optical touch screen based on gratings and waveguides is proposed. Light from the backlight source with the wavelength of 440nm is coupled into the waveguide matrix by gratings for sensing. Small detector arrays are included. The design significantly reduces the cost and complexity as compared to conventional optical touch technologies, which can also improve the color purity of the display.

Low Dark Current Amorphous Silicon Metal-Semiconductor-Metal Photodetector for Digital Imaging Applications

A novel lateral amorphous silicon (a-Si) metal-semiconductor-metal photodetector architecture is proposed using an organic blocking layer. Fabricated devices exhibit low dark-current, high dynamic range, and a measured external quantum efficiency of 65%, which represents a considerable improvement over previously reported designs. The higher performance is enabled by the introduction of a thin organic blocking layer and subsequently operating at high electric-fields. Unlike industry standard p-i-n photodiodes, our high performance lateral photosensor does not require doped p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> /n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> layers. Thus, the reported device is compatible with current and previous generation a-Si thin film transistor display fabrication process making it promising for low-cost optical touch panel or diagnostic medical imaging applications.

Touch Screen Adjusting Light Design by Neuron Chip

Traditional lighting control gradually replaced by the intelligent lighting control. Based on Neuron chip tuning optical touch screen is based on the experimental platform to design and develop. This paper introduces how to apply Lon-works technology to develop the project's main technical process and the design method of software and hardware,including the necessary interface circuit and control program. It has been run and debug experiment, be good for lighting control and realized remote control.

Optimization of a Multi-Touch Sensing Device for Biomedical Applications

Multi-touch systems are redefining the natural user interface paradigm and their applications can be found ranging from mobile phones, tablets and screens to the control of industrial facilities. While the concepts of multiple touch sensing are not new, there are still large unexplored areas regarding optimization of the user experience for various industrial or medical applications. Along with the ability to detect and process simultaneous touches and gestures, large scale multi-touch devices offer collaborative work along with user-selective content management systems features rarely used in dedicated medical visualization or sensing multi-touch software applications. Based on previous research concerning multi-touch systems and their potential usefulness in the medical field, this paper describes the optimization process of a multi-touch sensing device for biomedical applications. Three important layers of a multi-touch device were chosen as candidates for optimization: sensing, data manipulation and visualization. The results were applied to a prototype optical touch system developed for multi-user/multi-touch environments and several hardware and software modifications were designed and implemented. Since the goal of this research was to explore ways to enhance the user experience in multi-touch applications the conclusions derived from this paper can be extended to other domains where concurrent visualization and processing of information are vital components.

Plastic optical touch panels for large-scale flexible display

A plastic optical touch panel applicable for large-scale flexible display is demonstrated based on a vertical directional coupling between arrayed channel waveguides and a flexible planar waveguide. When a contact force is applied to the surface, the flexible planar waveguide is bent toward the channel waveguide, and then, the guided mode in the channel waveguide is coupled into the flexible planar waveguide, causing an output power drop. An index-matching liquid is used to fill the gap between the channel and the flexible planar waveguide in order to enhance the transparency of the waveguide touch panel. By applying a force of 1.0 N, the output intensity is decreased by 17 dB, which is sufficiently large for producing a contact signal.

Hybrid In-Mould Integration

Next generation of electronic modules and systems in different application areas such as automotive, medical and home appliances will utilize various electronic, optical and mechanical functions integrated in freeform intelligent products with benefits such as decreased volume and weight, lower costs and higher freedom of design when compared to currently available electronics manufacturing and packaging methods. The hybrid in-mould integration technology concept is based on combination of roll-to-roll (R2R) printed electronics, discrete component assembly, film forming and injection overmoulding/in-mould labelling (IML) processes. In this study, compatibility and feasibility of the technology for low-cost disposable healthcare sensor applications, especially pulse oximeters, was investigated. Flexible printed circuit (FPC) substrates for pulse oximeter applications were manufactured in high-volume and low cost fashion by R2R printing and etching processes. Surface mount technology (SMT) and leadframe components were assembled on FPCs by using adhesive bonding technology. The assembly process was also demonstrated using automated, high-volume capable machine. It was proven that SMD components and their interconnections on flex withstand the injection overmoulding process and can thus be embedded seamlessly inside plastic parts. By the use of the same injection moulding process it was also demonstrated that rigid mechanical locking features manufactured by film overmoulding can be combined with the flexibility of FPC. In order to speed up the iteration cycles of the hybrid integration design flow, a new method was developed for rapid prototyping of in-mould integrated products. In the method, 3D printing was used to create a master for a silicone mould, and assembled FPC was overmolded in vacuum casting process with polyurethane material. This paper presents also other research activities at VTT Technical Research Centre of Finland in the field of hybrid system integration carried out in various collaborative projects with companies and research institutes in Europe. The demonstrators realised in these projects include autonomous, intelligent lighting and signaling systems for automotive and traffic signs, in-molded optical touch panel and flexible printed organic light-emitting diode (OLED) embedded into 3D plastic structure using IML-like process in which active OLED foils are used instead of graphic foils. The demonstrators prove that hybrid in-mould integration could be a feasible technology enabling seamless integration of optical, electrical and mechanical features into 3D plastic products.