An in‐cell capacitive touch sensor integrated in an LTPS WSVGA TFT‐LCD

This paper discusses an In‐cell capacitive touch sensor and its integration in an LTPS TFT‐LCD with 7‐inch screen size and WSVGA resolution. The operation of the newly developed sensor is based on capacitive coupling between user's finger and the detection electrode on the TFT substrate, and is purely capacitive. The sensors and the sensor driver circuits have been integrated in the TFT substrate of the prototype TFT‐LCD using LTPS technology. The prototype having 256x150 sensors shows advantages such as smooth operation with no touch force, high position accuracy, multi‐touch (10 or more), a thin and light LCD module, high display quality, and thus is suitable for various applications such as cell‐phones, smart‐phones, mobile‐PCs, and automotive‐use displays.     

Active in‐cell touch circuit using floating common electrode as sensing pad for the large size in‐plane‐switching liquid crystal displays

In this paper, we propose an in‐cell active touch circuit using the concept of floating common electrode for large size in‐plane‐switching liquid crystal displays. Compared with the conventional passive in‐cell touch circuit, the proposed method can greatly reduce the readout channel numbers by sharing the sensing bus for one column. Because the touch signal is amplified in the pixel, the touch panel can be easily scaled up in size. Simulation results show that the difference between touch and no‐touch signals can be as large as 10 μA even with threshold voltage shift of ±1 V. The possible issues of the proposed method are experimentally verified.     

A foldable OLED display with an in‐cell touch sensor having embedded metal‐mesh electrodes

A foldable organic light‐emitting diode display integrating a touch sensor is fabricated. The touch sensor has an in‐cell structure where metal‐mesh sensor electrodes are formed in a counter substrate. It is demonstrated that touch on the entire panel surface, including a bent portion, is detected and that the touch panel operates correctly after 100,000 folding operations with a radius of curvature of 5 mm.     

Robust low power DC-type shift register circuit capable of compensating threshold voltage shift of oxide TFTs

This paper proposes an oxide TFT DC-type shift register that consists of eleven TFTs and one bootstrapping capacitor. The proposed circuit connects drain nodes of large size pull-up TFTs of output drivers to positive supply voltage instead of alternating clock signals for low power consumption. In addition, a robust internal inverter capable of maintaining the high voltage level of the output over the large positive threshold voltage shift by bootstrapping is implemented. For a 120 Hz Full-HD display, the SPICE simulation estimates the clock power consumption of the proposed DC-type circuit as 0.56 mW at 32 shift registers and ensures the robust operation over the wide range of threshold voltage shift from −4 V to 10 V.     

Development of middle size full in‐cell LCD module for PC with IGZO

We developed the world's first middle size full in‐cell LCD for PC with IGZO technology. We evaluated a new Gate driver In Panel structure with latch circuit and confirmed that there were no problems with display and touch panel performance. Furthermore, we did a feasibility study of higher display resolutions and larger size panels, which showed future possibilities.     

Shoot‐through current reduction scheme for low power LTPS TFT programmable shift register

This paper proposes a programmable pulse width shift register where an output pulse width is adjusted only by changing a start pulse width without any additional signals and reconfiguration for the pre‐charging scheme of high resolution and high frame rate active‐matrix flat‐panel displays. In addition, the overall power consumption of a proposed circuitry is dramatically reduced by alleviating the shoot‐through current of an interval inverter, compared with the previous shift registers with the programmable or fixed output pulse width. The proposed shift register is verified by the simulation program with integrated circuit emphasis (SPICE) simulation at low temperature poly‐Si thin film transistor process for 50 stages. The proposed shift register lessens the power consumption by 34% and 54% for the output pulse widths of two and 10 line times, respectively, compared with those of the previous shift register structures.     

Guidelines for supporting real‐time multi‐touch applications

Multi‐touch driven user interfaces are becoming increasingly prevalent because of their intuitiveness and because of the reduction in the associated hardware costs. In recognition of this trend, multi‐touch software frameworks (MSFs) have begun to emerge. These frameworks abstract the low level issues of multi‐touch software development and deployment. MSFs therefore enable software developers who are unfamiliar with the complexities of multi‐touch software development to implement and deploy multi‐touch applications more easily. However, some multi‐touch applications have real‐time system requirements, and at present, no MSFs provide support for the development and deployment of such real‐time multi‐touch applications. The implication of this is that software developers are unable to take advantage of MSFs and, therefore, are forced to handle the complexities of multi‐touch and real‐time systems development and deployment for themselves in an ad hoc manner. The primary consequence of this is that the multi‐touch and/or real‐time aspects of the application may not function correctly. In this paper, guidelines are presented for applying real‐time system concepts to support the development and deployment of real‐time multi‐touch applications using MSFs. This serves to increase the probability that the application will meet its timing requirements while also reducing the complexity of the development and deployment process associated with multi‐touch applications. Copyright © 2013 John Wiley & Sons, Ltd.     

Letter: Dual‐mode oxide thin film transistor shift register for external compensation in active‐matrix organic light emitting diode displays

This letter describes a dual‐mode oxide thin film transistor shift register for active‐matrix organic light emitting diode displays, which provides two separate scanning and sensing pulses on one line. At a 240 Hz full‐high definition (HD) timing, estimated power consumptions are 2.44 and 2.81 mW for scanning and sensing shift registers of 16 stages at V_TH = ?1.56 V, respectively.     

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.     

In‐cell capacitive‐type touch sensor using LTPS TFT‐LCD technology

Abstract— An LTPS TFT‐LCD with an in‐cell capacitive‐type touch sensor has been proposed and prototyped. The embedded sensor in the pixel was designed to amplify the voltage change caused by capacitive coupling between the detection electrode and conductive object (user's finger). No touch force is needed for sensor actuation and no extra electrical connection for the counter‐substrate is needed. The validity of the observed voltage difference of the sensor output on the TFT substrate was examined. The proposed architecture is considered to be applicable to larger LCDs for various applications such as smartphones, automotive navigation systems, and mobile internet devices.     

Integrated a‐Si TFT row driver circuits for high‐resolution applications

Abstract— A 12.1‐in. tablet liquid‐crystal‐display (LCD) panel with integrated amorphous‐silicon row driver circuits has been developed using a standard TFT process and Advanced Fringe‐Field Switching (AFFS) technology. An XGA‐resolution 768‐stage shift‐register circuit with two‐phase clocks has been designed and fabricated. The circuit parameters were optimized in order to obtain a highly reliable a‐Si row‐driver‐circuit structure. Thermal Humidity Operation (THO) test results at 50°C and 80% humidity during 500 hours of operation shows that the fabricated panel is reliable during long‐term operation and any abnormal display phenomenon was not observed at 0°C.     

Peripheral circuit designs using low‐temperature p‐type poly‐Si thin‐film transistors

Abstract— P‐type low‐temperature (450°C) polycrystalline‐silicon thin‐film‐transistor circuits for peripheral driver integration in active‐matrix displays are proposed and verified. A low‐voltage (5 V) driven poly‐Si scan driver is designed by employing a level shifter and shift register. A source driver for six‐bit digital interface is proposed, and the building blocks such as latch, DAC, and analog buffer are described. The latch samples and holds the digital bits (D and D') without an output voltage loss. A new source‐follower type analog buffer is developed and exhibits a small offset deviation regardless of the V_TH variation of the buffer TFT. The simulation and measurement results ensure that the proposed circuits were successfully designed for p‐type panel integration.     

Robust and Optimized Algorithms for the Point‐in‐Polygon Inclusion Test without Pre‐processing

In this work we present new point inclusion algorithms for non‐convex polygons. These algorithms do not perform any pre‐processing or any type of decomposition nor features classification, which makes them especially suitable for deformable or moving polygons. The algorithms are more accurate and robust than others in the sense that they consider the inclusion of the point in the vertices and edges of the polygon, and deal with the special cases correctly. In order to perform this inclusion test efficiently, they use the sign of the barycentric coordinates of the test point with regard to the triangles formed by the edges and an origin that depends on the test point. This set of triangles, which is a special simplicial covering of the polygon, is constructed after a transformation of the polygon that simplifies the calculations involved in the inclusion test. Then, an appropriate ordering of the rejection tests allows us to optimize this method. Our algorithms have been tested for robustness and compared with ray‐crossing methods, showing a significant improvement.     

A compact realization of composite low‐pass filter for monolithic microwave integrated circuit applications

A compact realization of composite low‐pass filter is presented in this article. The filter is realized using on‐chip spiral inductors and metal–insulator–metal capacitors and features an attenuation pole near the cutoff frequency leading to a sharper attenuation response. As well, it offers good matching properties in the passband. Space‐mapping‐based algorithm is used in the design/optimization of spiral inductors toward achieving high quality factors at the filter cutoff frequency. The realization of the proposed filter is compact in size, suitable for monolithic microwave integrated circuit applications, and exhibit broad upper stopband frequency characteristics. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

Next‐generation mobile LCDs with in‐cell retarders

Abstract— In‐cell retarders can be a major breakthrough for mobile LCDs. When a patterned in‐cell retarder replaces the external retarders on transflective LCDs, brighter and thinner transflective LCDs with lower power consumption and wider viewing angle can be obtained. Additionally, when in‐cell retarders are applied in reflective LCDs, the thickness of the LCD is considerably reduced without affecting the optical performance of the reflective LCD. This paper presents the technology needed to make in‐cell retarders and the performance of reflective and transflective LCDs with in‐cell retarders.     

Design and implementation of readout circuit on glass substrate with digital correction for touch‐panel applications

Abstract— A readout circuit on glass substrate with digital correction, which contains a transconductance amplifier, counter, and digital correction circuit, has been designed for touch‐panel applications for 3‐μm low‐temperature polysilicon (LTPS) technology. The voltage difference as a result of a change in capacitance due to a touch event is converted to current by a transconductance amplifier. By charging and discharging the capacitor in the counter, the counter displays different digital‐output codes according to touch or non‐touch events. Furthermore, not only can the touch or non‐touch event be distinguished, but also the influence of LTPS process variation can be compensated by a digital correction circuit in the proposed readout circuit.     

Mean‐field games for multiagent systems with multiplicative noises

This paper studies mean‐field games for multiagent systems with control‐dependent multiplicative noises. For the general systems with nonuniform agents, we obtain a set of decentralized strategies by solving an auxiliary limiting optimal control problem subject to consistent mean‐field approximations. The set of decentralized strategies is further shown to be an ε‐Nash equilibrium. For the integrator multiagent systems, we design a set of ε‐Nash strategies by exploiting the convexity property of the limiting problem. It is shown that under the mild conditions, all the agents achieve mean‐square consensus.     

Initial results on computational performance of Intel many integrated core,sandy bridge,and graphical processing unit architectures: implementation of a 1D c++/OpenMP electrostatic particle‐in‐cell code

We present initial comparison performance results for Intel many integrated core (MIC), Sandy Bridge (SB), and graphical processing unit (GPU). A 1D explicit electrostatic particle‐in‐cell code is used to simulate a two‐stream instability in plasma. We compare the computation times for various number of cores/threads and compiler options. The parallelization is implemented via OpenMP with a maximum thread number of 128. Parallelization and vectorization on the GPU is achieved with modifying the code syntax for compatibility with CUDA. We assess the speedup due to various auto‐vectorization and optimization level compiler options. Our results show that the MIC is several times slower than SB for a single thread, and it becomes faster than SB when the number of cores increases with vectorization switched on. The compute times for the GPU are consistently about six to seven times faster than the ones for MIC. Compared with SB, the GPU is about two times faster for a single thread and about an order of magnitude faster for 128 threads. The net speedup, however, for MIC and GPU are almost the same. An initial attempt to offload parts of the code to the MIC coprocessor shows that there is an optimal number of threads where the speedup reaches a maximum. Copyright © 2014 John Wiley & Sons, Ltd.     

Robust weighted fusion Kalman estimators for multisensor systems with multiplicative noises and uncertain‐covariances linearly correlated white noises

This paper addresses the design of robust weighted fusion Kalman estimators for a class of uncertain multisensor systems with linearly correlated white noises. The uncertainties of the systems include the same multiplicative noises perturbations both on the systems state and measurement output and the uncertain noise variances. The measurement noises and process noise are linearly correlated. By introducing two fictitious noises, the system under consideration is converted into one with only uncertain noise variances. According to the minimax robust estimation principle, based on the worst‐case systems with the conservative upper bounds of the noise variances, the four robust weighted fusion time‐varying Kalman estimators are presented in a unified framework, which include three robust weighted state fusion estimators with matrix weights, diagonal matrix weights, scalar weights, and a modified robust covariance intersection fusion estimator. The robustness of the designed fusion estimators is proved by using the Lyapunov equation approach such that their actual estimation error variances are guaranteed to have the corresponding minimal upper bounds for all admissible uncertainties. The accuracy relations among the robust local and fused time‐varying Kalman estimators are proved. The corresponding robust local and fused steady‐state Kalman estimators are also presented, a simulation example with application to signal processing to show the effectiveness and correctness of the proposed results. Copyright © 2016 John Wiley & Sons, Ltd.     

Short‐distance visible light communication with simple clock data recovery for audio applications

As light emitting diodes (LEDs) of fast response time are wide‐spreading in a variety of applications such as displays, lighting, traffic signals, and automobiles, many researches on transferring the data with the visible lights of LEDs have been conducted. This paper describes such a visible light communication system that supports the audio applications at the short distance up to 80 cm and the data bandwidth of 32 kHz. Especially, a simple clock data recovery (CDR) is used to achieve the optimum sampling and compensate for the frequency offset between transmitter and receiver. The proposed CDR obtains three samples per symbol and then adjusts the sampling point properly with the pattern of three samples over the frequency offset range of ±1.5% without changing the operating frequency of a receiver side. In the prototype system, a transmitter is composed of audio encoder, field programmable gate array, LED driver, and LEDs and a receiver consists of photodiode, comparator, field programmable gate array, and audio decoder. At the distance of 50 cm and the data rate of 32 kbps, the measured bit error rates are 0.101 and less than 10^?8 without and with CDR, respectively.