Recent advances in the hardware architecture of flat display devices

Thesis (Master)--Izmir Institute of Technology, Electronics and Communication Engineering, Izmir, 2007Includes bibliographical References (leaves: 115-117)Text in English; Abstract: Turkish and Englishxiii, 133 leavesThesis will describe processing board hardware design for flat panel displays with integrated digital reception, the design challenges in flat panel displays with integrated digital reception explained with details. Thesis also includes brief explanation of flat panel technology and processing blocks. Explanations of building blocks of TV and flat panel displays are given before design stage for better understanding of design stage. Hardware design stage of processing board is investigated in two major steps, schematic design and layout design. First step of the schematic design is system level block diagram design. Schematic diagram is the detailed application level hardware design and layout is the implementation level of the design. System level, application level and implementation level hardware design of the TV processing board is described with details in thesis. Design challenges, considerations and solutions are defined in advance for flat panel displays

전류 센싱 피드백 시스템을 이용한 고안정성 산화물 TFT 쉬프트 레지스터의 설계 및 제작

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2017. 2. 정덕균.Integration of shift registers on the glass panel allows the display to be thinner, lighter, and cheaper to produce, thanks to the reduction of the number of ICs for scanning horizontal lines. Circuits of the shift register employing n-type thin film transistors (TFTs), such as hydrogenated amorphous silicon (a-Si:H) and oxide TFTs, have been reported. Recently, oxide TFTs attract much attention due to their high mobility (5~10 cm2/V∙s) compared with that of a-Si:H TFT (0.8cm2/V∙s). However, oxide TFTs often suffer from severe degradation of the threshold voltage (VTH) against the temperature and electrical stress. In this paper, in order to compensate the instability of oxide TFTs in the shift register, an oxide TFT with double gates, which can control VTH by varying the top gate bias (VTG) is adopted. The top gate of the double-gate TFT can be fabricated in the same process for the pixel IZO (Indium Zinc Oxide) so that an additional process only for the top gate is not required. Adequate VTG is provided timely, adaptively to the gate of the oxide TFTs to stabilize the threshold voltage. The fabrication result shows that the proposed shift register using VTG set at an adapted value become stable at 100℃ whereas the conventional one is mal-functioning. The optimum VTG varies from product to product and changes continuously over the lifetime of the display. Therefore, the feedback driving system suitable for the proposed shift register is required to search the optimum VTG. The system has two main functionsthe first is to sense the current of shift register and the second is the searching algorithm for finding the optimum VTG. When the transistors are degraded by an external stress, the current of the whole shift registers is changed. The information about the VTH degradation in the shift register can be gathered via current sensing circuit. The sensed current is integrated to generate the output and is forwarded to an ADC. The binary-converted current of shift register is processed by the proposed algorithm in the digital domain for obtaining an optimum VTG and then the result is converted back to analog to generate VTG. The IC implementing such functions is fabricated in a 0.18 μm BCDMOS process. When the shift register current is measured on the conventional system with increasing temperature up to 80℃, it is increased to more than 10 times than that at the room temperature. However, the proposed feedback system keeps a highly stable (<13%) current level of shift register up to 80℃ with an optimized VTG.Abstracts i Table of Contents iii List of Tables v List of Figures vi Chapter 1 Introduction 1 1.1 Background 2 1.2 Outline 7 Chapter 2 Review of oxide-based TFT device and N-type TFT circuit design 8 2.1 Overview 9 2.1.1 Characteristics of Oxide TFT 9 2.2 Oxide-based TFT 14 2.2.1 Electrical characteristics of oxide-based TFT 14 2.2.2 Stability of oxide-based TFT 18 2.3 NMOS driving circuit 24 2.3.1 Bootstrapping driving circuit 24 2.3.2 Shift register with n-type TFT 28 Chapter 3 Proposed Oxide TFT Shift Register 37 3.1 Overview 38 3.2 Characteristic of Double Gate TFT 39 3.3 Design of New shift register 46 3.3.1 Simulation Result of Conventional shift register 46 3.3.2 New shift register using Double Gate TFT 51 3.3.3 Simulation Modeling of Double Gate TFT 58 3.3.4 Simulation and Experimental Result 61 Chapter 4 Real Time Current-Sensing Feedback Compensation System 71 4.1 Overview 72 4.2 System Architecture 74 4.3 Circuit Design 77 4.3.1 Current Sensing Block 77 4.3.2 ADC/DAC Block 85 4.4 Optimum Point Searching Algorithm 100 4.5 System Verification 106 Chapter 5 Summary 116 Appendix A SPICE models 118 Bibliography 120Docto

Railway foreign body vibration signal detection based on wavelet analysis

Based on the wavelet packet analysis method with time-frequency analysis characteristics, the measurement signal of the vibration system is processed for noise reduction, the soft-hard threshold compromise wavelet denoising method used has the advantages of soft threshold and hard threshold denoising, and through the introduction of compromise factors, signal processing can be performed more flexibly in signal analysis. For the denoised signal, the fundamental wavelet time-energy spectrum analysis, the main components of the signal can be clearly displayed, and according to the distribution of its energy in each frequency band, the signal characteristics can be displayed intuitively. Experimental results show: It can be determined that there is a foreign body intrusion incident at a position 520 m away from the monitoring point, rather than a normal train travel incident. In fact, we are walking back and forth at a distance of about 520 m from the monitoring point, simulating the intrusion of illegal foreign objects such as pedestrians and livestock beside the railroad tracks prove that analysis and judgment can be known, the wavelet analysis proposed by the author can realize the monitoring and judgment of some illegal foreign body intrusion incidents such as pedestrians and livestock

Functional Biomarkers to Assess Visual System Integrity: An eye tracking based approach:Functional Biomarkers to Assess Visual System Integrity

Functional Biomarkers to Assess Visual System Integrity: An eye tracking based approac

Functional Biomarkers to Assess Visual System Integrity: An eye tracking based approach:Functional Biomarkers to Assess Visual System Integrity

Functional Biomarkers to Assess Visual System Integrity: An eye tracking based approac

APPARATUSES, SYSTEMS, AND METHODS FOR CALIBRATING DISPLAYS

A display calibration system may include (i) a spectrometry device positioned to capture light emitted by a group of sub-pixels in a sub-region of a display that is both (a) located within a light-emitting region of the display and (b) is smaller than the light-emitting region, (ii) at least one camera device positioned to capture light emitted by a plurality of sub-pixels, in the light-emitting region of the display, that includes the group of sub-pixels, and (iii) a calibration computing device that is (a) communicatively coupled to both the spectrometry device and the at least one camera device and that (b) generates calibration data for driving the plurality of sub-pixels in the light-emitting region of the display based on information received from the spectrometry device and the at least one camera device. Corresponding calibration apparatuses and methods are also disclosed

Modeling of OLED degradation for prediction and compensation of AMOLED aging artifacts

Degradation is still the most challenging issue for OLED, which causes the image-sticking artifact on AMOLED displays and limits their lifetime. To overcome the demerit, OLED degradation is modeled in this thesis, and compensation based on the models is applied for AMOLEDs. A data-counting model is firstly developed to quantitatively evaluate the degradation on OLEDs, with consideration of the accumulation stress during operation. An electro-optical model is further built, based on an equivalent circuit. It can simulate the electro-optical characteristic (I-V, Eff-V) and the degradation behaviors in aging process. Besides, the correlation model is aimed to derive the current efficiency decay with measurable electrical values, delivering more dependable results at strongly aged state. The prediction and compensation are implemented based on developed models. The results show that the models exactly predict the efficiency decay during operation. The image-sticking aging artifact on AMOLED can be suppressed by applying compensation, so that the display lifetime is extended.Durch das Einbrennen von Bildern in AMOLED Displays wird deren Lebensdauer verringert; dieser Qualitätsverlust stellt nach wie vor die größte Herausforderung für die OLED Technologie dar. In dieser Thesis wird die Degradation der OLEDs modelliert und eine Kompensierung anhand der Modelle erreicht. Zunächst wurde ein Data-counting Modell entwickelt, um die Degradation von OLEDs unter Berücksichtigung der akkumulierten Belastung während des Betriebs quantitativ zu bewerten. Des Weiteren wurde ein elektro-optisches Modell entwickelt, das auf einem äquivalenten Schaltungsmodell basiert. Es kann die elektro-optischen Eigenschaft (I-V, Eff-V) und das Degradationsverhalten im Alterungsprozess simulieren. Außer den beiden Modellen wird noch ein Korrelationsmodell entwickelt, das darauf abzielt, die Abnahme der Stromeffizienz aus den messbaren elektrischen Werten abzuleiten. Dieses Modell liefert im stark gealterten Zustand zuverlässigere Ergebnisse. Aufbauend auf die entwickelten Modelle wurden die Vorhersage und die Kompensierung implementiert. Die Ergebnisse zeigen, dass die Modelle den Effizienzverlust während des Betriebes genau vorhersagen. Das Einbrennen des Bildes in das AMOLED-Display kann durch das Anwenden der Kompensierung unterdrückt werden, so dass die Lebensdauer des Displays verlängert wird

Herausforderungen und Qualitätssicherung beim lokalen Dimmen von LC-Displays mit seitlich angeordneten LEDs

Das lokale Dimmen von LC-Displays bietet großes Potential zur Leistungseinsparung und zur Verbesserung der visuellen Qualität. Aufgrund der Besonderheiten von LC-Displays mit seitlich angeordneten LEDs entfalten Local-Dimming-Algorithmen bei diesen Displays zurzeit nicht ihre vollen Möglichkeiten. Beim Dimmen solcher Displays können viele ungewollte visuelle Artefakte auftreten. Daher wird das lokale Dimmen für solche Displays nur moderat eingesetzt. Eine Vermeidung dieser Artefakte kann es ermöglichen, das Potential des Local-Dimmings voll auszuschöpfen. Da nur ausreichend bekannte visuelle Artefakte verhindert werden können, werden diese ausführlich analysiert und Lösungsvorschläge zur Vermeidung gegeben. Hierzu werden acht Displays mit Edge-Lit Hintergrundbeleuchtung betrachtet. Die Displays werden dabei auf statische und dynamische Artefakte untersucht und es werden Möglichkeiten genannt, wie die visuelle Qualität gesichert und gesteigert werden kann. Um insbesondere keine Artefakte in der Darstellung künstlicher Bilder zu erzeugen, wird eine Menü-Detektion eingeführt und alle Parameter des Dimming-Algorithmus angepasst. Durch die abschließende Optimierung der Hintergrundbeleuchtung in Bezug auf das Local-Dimming, welche Anzahl und Position der LEDs sowie die Form der LSF betrifft, kann somit ein Algorithmus vorgestellt werden, welcher die Herausforderung des lokalen Dimmens für Edge-Lit-Displays meistert und gleichzeitig die visuelle Qualität sicherstellt.Local dimming of LC-Displays offers a high potential for power saving and the improvement of the visual quality. Because of the particularities of Edge-Lit LC-Displays, local dimming algorithms do not yet reach best possible results. The dimming of such displays may produce unintentional visual artefacts. Therefore, the impact of local dimming for such displays is rare. Avoiding these artefacts can help local dimming to reach its full potential. Since only sufficiently understood visual artefacts can be prevented, they are analysed and solutions are suggested. There are eight displays with Edge-Lit backlight considered. The static and dynamic visual artefacts of these displays are analysed and a description to ensure und increase the visual quality is given. Especially to avoid artefacts with artificial images, a menu detection is introduced and all parameters of a dimming algorithm are adjusted. The final optimization of the backlight, related to the number and the position of the LEDs and the shape of the LSF, allows a local dimming algorithm, which can reach the dimming challenges of Edge-Lit displays and ensure the visual quality at the same time

Methodology of optical topography measurements for functional brain imaging and the development and implementation of functional optical signal analysis software.

Near-infrared spectroscopy (N1RS) has been used extensively in recent years as a non invasive tool for investigating cerebral hemodynamics and oxygenation. The technique exploits the different optical absorption of oxy-haemoglobin and deoxy-haemoglobin in the near infrared region to measure changes in their concentrations in tissue. By making multiple NIRS measurement simultaneously, optical topography (OT) provides spatial maps of the changes in haemoglobin concentration levels from specific regions of the cerebral cortex. The thesis describes several key developments in optical topography studies of functional brain activation. These include the development of a novel data analysis software to process the experimental data and a new statistical methodology for examining the spatial and temporal variance of OT data. The experimental work involved the design of a cognitive task to measure the haemodynamic response using a 24-channeI Hitachi ETG-100 OT system. Following a series of pilot studies, a study on twins with opposite handedness was conducted to study the functional changes in the parietal region of the brain. Changes in systemic variables were also investigated. A dynamic phantom with optical properties similar to those of biological tissues was developed with the use of liquid crystals to simulate spatially varying changes in haemodynamics. A new software tool was developed to provide a flexible processing approach with real time analysis of the optical signals and advanced statistical analysis. Unlike conventional statistical measures which compare a pre-defined activation and task periods, the thesis describes the incorporation of a Statistical Parametric Mapping toolbox which enables statistical inference about the spatially-resolved topographic data to be made. The use of the general linear model computes the temporal correlations between the defined model and optical signals but also corrects for the spatial correlations between neighbouring measurement points. The issues related to collecting functional activation data using optical topography are fully discussed with a view that the work presented in this thesis will extend the applicability of this technology

SPATIAL TRANSFORMATION PATTERN DUE TO COMMERCIAL ACTIVITY IN KAMPONG HOUSE

ABSTRACT Kampung houses are houses in kampung area of the city. Kampung House oftenly transformed into others use as urban dynamics. One of the transfomation is related to the commercial activities addition by the house owner. It make house with full private space become into mixused house with more public spaces or completely changed into full public commercial building. This study investigate the spatial transformation pattern of the kampung houses due to their commercial activities addition. Site observations, interviews and questionnaires were performed to study the spatial transformation. This study found that in kampung houses, the spatial transformation pattern was depend on type of commercial activities and owner perceptions, and there are several steps of the spatial transformation related the commercial activity addition. Keywords: spatial transformation pattern; commercial activity; owner perception, kampung house; adaptabilit