Display Panel Research Articles

An oxide-based flexible electrochromic transistor under mechanical stress

Today mechanical flexibility has become an important feature for electronic devices, especially in flat display panels. Here we demonstrate the device operation of a tungsten oxide-based flexible electrochromic transistor (ECT), which was fabricated on 0.1 mm thick polyethylene terephthalate film. The ECT can be operated by applying voltage of ±3 V for 1 s when the radius of curvature was larger than 16 mm, indicating that the flexible ECT exhibited a strong resistance to static strains. However, the resistance of the channel increased by fatigues from applying cyclic flexural strains. Present flexible ECT would highly be useful for the economically viable curved display panels. However, its vulnerability to fatigue needs improvements for other applications.

CMOS-Like Logic Circuits With Unipolar Thin-Film Transistors on Flexible Substrate

In this article, the feasibility of CMOS-like logic circuits has been demonstrated on a flexible substrate with only n-type TFTs. Here, a 1-to-2 decoder was realized by bootstrapped inverters and NAND gates. Theoretical analysis and simulation results show low static leakage current and full output-swing features. The effect of applied mechanical strain that causes circuit performance variations is also presented. The decoder is capable of driving the rows of a Quarter-VGA display panel with 60-Hz refresh rate. Experimental results show that the decoder can perform a continuous 48-h crosstalk-free operation under tensile or compressive bending situations, thus proving the effectiveness of bootstrapped logic gates in forming complex multistage digital circuits.

Схема тестування OLED-матриці білого кольору випромінювання

The scheme of testing the organic LED-matrix is proposed, the size of which is 16´16 tricolour pixels, the voltage control range is 5…30 mA, the supply voltage has 16 discrete values that vary in the range from 2 to 6 V in steps of 0,25 V. The purpose of the device for which the scheme is developed is to study the reliability of the failure time in different modes of operation, dynamic and electrical characteristics in the range of the device, which is determined by the condition that the loss of luminosity is from 100 to 70 %. The proposed testing scheme is designed on two boards (two modules) for flexible upgrades if necessary. The main module is the controller of the LED panel. It is built on an eight-bit ATMega8515 microcontroller. Since the size of the test field of the panel is small, the speed of such a microcontroller is quite sufficient. The microcontroller dynamically controls the display driver, display voltage, and communicates with the computer via the USART interface using a USB-USART bus converter. The microcontroller's internal random access memory (RAM) is insufficient, so the data for display on the display panel is stored in the external memory type SRAM, which is connected to the microcontroller. The slave module is the driver board of the LED matrix. The LEDs are powered by a separate adjustable voltage source, which additionally allows you to adjust the overall brightness of the display, explore its operation in different ranges of supply voltages, extend the service life during operation. Switching of supply voltage on lines is carried out through electronic keys on the TD62783 chip. The matrix row is selected by a 4-on-16 decoder 74HC4514. To control the brightness of the LEDs on the columns used specialized chips WS2801. They provide bit control of 8 bits per color, a total of 24 bits, which is more than 16 million shades. The two-wire data recording circuit and the possibility of cascading reduces the number of wires in the circuit. The ability to connect reverse resistors (RFB, GFB, BFB) to the current stabilizer of the LED, allows you to compensate for the variance of the parameters of the LED matrix by selecting the values of these resistors. A special power supply module provides stabilization of supply voltages of digital chips and LED matrix

A Machine Vision Based Monitoring System for the LCD Panel Cutting Wheel Degradation

In Liquid Crystal Display (LCD) panel cutting, in-line monitoring of tool wear is important to maintain the dimension precision of finished products and to avoid possible damages to the workpiece. However, limited by the space for camera installation and the miniature structure of the tool itself, monitoring the wear of LCD panel cutting wheel is not a simple task. In this research, we proposed a machine-vision based instrumentation system and a systematic methodology for cutting wheel degradation monitoring. The proposed method describes the degradation of cutting wheel by estimating the tooth height of the cutting wheel blade based on the partially observed random samples. A series of methods are proposed to improve the reliability of the results. The effectiveness of the proposed method is validated based on the field data that is collected from three maintenance cycles. The validation results demonstrate consistent degradation trend of the cutting wheel over production cycles.

Visualizing Imitation of Typical Intense X-ray Radiation Processes

A visualizing imitation system of typical intense X-ray radiation process which uses the Light Emitting Diode (LED) light source, the Liquid Crystal Display (LCD) panel, and the Charge ...

Deep Learning-Based Intelligent Defect Detection of Cutting Wheels with Industrial Images in Manufacturing

The cutting wheel is an important tool in the television liquid crystal display (LCD) panel manufacturing process. The degradation of the cutting wheel significantly affects the LCD panel quality. Currently, there is few effective approaches that can detect the degradation of the cutting wheel at the working station for health monitoring purpose, due to the small size of the component and the complex manufacturing operation. That leads to high economic costs in the production lines in the real industries. In order to address this issue, this paper presents a deep convolutional neural network-based method for defect detection of the cutting wheels using the industrial images. An end-to-end health monitoring system is built based on machine vision, which directly takes the raw images as inputs, and outputs the detection results. That facilitates the industrial applications since little prior knowledge on image processing and fault detection is required. The experiments on a real-world cutting wheel degradation dataset are carried out for validation. High fault diagnosis testing accuracies are obtained, that indicates the proposed method offers an effective and promising approach for the cutting wheel health monitoring problem.

Nutrition Labeling for Foods: Which Approaches Are Useful?

Nutrition labeling encompasses nutrient declaration, supplemental nutrient information such as interpretative nutrition information on the principal display panel or front-of-pack labeling, and nutrition-related claims used to promote the nutritional properties of packaged foods. These types of labeling are inter-related. In many countries, nutrient declaration is mandatory for most packaged foods and used to inform consumers at the point of purchase to help them make more informed food choices. Supplemental nutrition information on the principal display panel is designed to assist consumers in the interpretation of nutrition information. The use of nutrition-related claims should be regulated to have consistency in what is allowed and avoid claims from being false or misleading. Nutrition labeling should be based on public health priorities and be designed to enable consumers to compare products and judge if a product is high or low in a declared nutrient in the context of the daily diet. Supplemental nutrition labeling can have various purposes and research is needed to validate that it is effective for the intended purpose with the target audience. The presence of standardized nutrition labeling on packaged foods enables the development of education strategies for consumer use of the information. Education is a key component for labeling strategies to be effective.

Product Interface Design for Complexity Management in Assembly Systems

Manufacturing firms are facing the challenge of minimizing variety-induced complexity in assembly systems. One of the effective approaches to complexity management is to reconfigure the assembly system by rearranging its assembly sequence. In order to rearrange an assembly sequence, a design-oriented approach is necessary because assembly is an activity of connecting parts through an interface between them. It means that the assembly sequence in production is restricted by the structure of interface connections in design. In this vein, this paper introduces a new design-oriented approach called interface design approach to complexity management in assembly systems. First, the mechanism of how the structure of interface connections affects assembly system complexity is identified. Then, an interface design framework is proposed for effectively finding an optimal interface structure and its assembly sequence to minimize assembly system complexity. For evaluating the complexity, the operator choice complexity index is adopted and modified for the interface design problem. In the case study, the framework is applied to the interface design problem by using industrial data of a plasma display panel (PDP) family from LG Electronics. The result of the study demonstrates that the assembly system complexity is significantly reduced by the proposed interface design framework.

Advanced cover glass defect detection and classification based on multi-DNN model

Demands for display panels and relevant technologies are rapidly increasing with the recent advances in smart mobile devices. Many manufacturers have begun slowly investing in fully automated inspection systems that enable consistent and objective inspections. Carrying out such undertaking aims to satisfy high user requirements concerning quality while coping with high volumes. Cover glass is one of the important items for inspection because users directly interact with it. Despite the extensive use of typical machine vision-based solutions in this field, many manufacturers continue relying on human-based judgment because of a deficient understanding of defects or poor confidence in algorithms. To overcome these problems, this study proposes a deep-learning neural network (DLNN)-based defect inspection system. The DLNN has advantages over traditional computer vision- or human-based inspection in terms of flexibility and performance. We introduce a weighted multi-DLNN inspection system capable of efficiently utilizing multi-channel measurement data, with a detection rate of up to 99% and a false pass rate below 1%.

An experimental stand for induction cookers investigations

Experimental investigations are the main direction of scientific research in the field of improving design solutions and operating modes of household induction cookers, since experiments provide the most reliable results, which will also serve as a comparative basis for verification of the developed mathematical models and numerical algorithms for computer modelling of the corresponding processes and phenomena in induction cookers and heated dishes. The paper describes a developed experimental stand for studying thermal and energy processes in induction cookers and heated dishes. To create an experimental stand and conduct research, equipment purchased by the Department of Electrical Apparatus of NTU “KhPI” thanks to a grant of 20,000 Euros provided by the Alexander von Humboldt Foundation (Alexander von Humboldt Stiftung, Germany) in 2016 is used. The experiments start using a VES electric V-HP6 induction cooker. Currently, the stand allows to perform the following experimental studies: ˗ measurement of the heating rate of food (water) using various powers of the induction cooker; ˗ temperature measurement of the working surface, digital display and control panel of the induction cooker; ˗ measurement of indicators of electric energy consumed to heat food (water). The following modern measuring equipment is used: a two-channel digital thermometer with thermocouples DT 1320, a pyrometer Flus IR-865U, a digital multimeter (current clamps) DT 3352 and specialized software for it. Preliminary results of experimental studies are obtained and analyzed, features of the functioning of induction cookers depending on power when heating food are determined.

Simulation of slanted color moiré in IP-type 3D displays

A method of simulating slanted color moirés in integral photography (IP)-type 3D displays is described for the slanting angle range of 1° to 45°. The color moirés in the displays are induced by the periodic blocking of a part of each sub-pixel on the panel by the boundary lines or the barrier lines which consist of the viewing zone forming optics. The method first calculates the chirped pixel pattern of the display panel and then the blocked area of each sub-pixel in the chirped pattern by the lines, and then defines the color intensity of the sub-pixel as the unblocked sub-pixel area. The color moirés simulated in this way match well with those from gratings. The simulation reveals that the contrast of the color moirés can be minimized by increasing the slanting angle. In fact, the moiré contrast in the 30° range of the slanting angle is lower than that in other angles for the gratings used. The algorithm can also be used to simulate the moirés in IP displays that have viewing zone forming optics with a 2D line grating pattern.

FPGA-accelerated textured surface defect segmentation based on complete period Fourier reconstruction

Real-time detection of surface defects in high-generation, large-size Liquid Crystal Display (LCD) panels is a serious challenge for both image algorithms and processing speed. For the defect detection of Thin Film Transistor-Liquid Crystal Display (TFT-LCD) images, effectively processing the periodic texture composed of gate lines and data lines is a prerequisite for the success of the algorithm. The traditional one-dimensional Fourier reconstruction algorithm uses a filter-based method to remove most of the texture, but due to the spectral leakage problem, the image boundary cannot be effectively processed. The compensation based on the period extension introduces a more complex ringing effect at the image connection. Starting from the implicit periodic principle of Fourier transform, we propose a strategy of complete period truncation based on subpixel period, which completely eliminates the boundary texture. Furthermore, we fully exploit the potential of parallel execution of the algorithm, resampling the liquid crystal segments truncated in the complete period to an integer power length of 2. The FPGA structure of one-dimensional Fourier reconstruction defect segmentation algorithm with dual-task parallelism and two-pixel parallelism is designed and the calculation bandwidth of 500 MB/s can be realized at 125-MHz clock frequency. We demonstrate the superiority of the proposed method qualitatively and quantitatively. The one-dimensional Fourier reconstruction algorithm based on the complete period truncation can effectively detect various defects such as spots, scratches, fibers and dirt, and the false-positive rate of defects has been reduced by half. The resampling-based Fourier transform speeds up the computational process and the FPGA parallel acceleration architecture is three times faster than comparable server CPUs, reducing the scan detection time of the entire 8.5-generation LCD panel to 8.5 s.

Inhibiting the Kink Effect and Hot-Carrier Stress Degradation Using Dual-Gate Low-Temperature Poly-Si TFTs

This study examines the appearance of a kink effect phenomenon in the I $_{\mathbf {D}}$ -V $_{\mathbf {D}}$ electrical characteristics of low-temperature polycrystalline Si thin-film transistors (LTPS TFTs) after high-current-induced hot-carrier stress (HCS). During HCS, electron–hole pairs were generated in the channel near the drain terminal owing to impact ionization. Next, the electrons were repelled towar the source by the drain electric field, thereby inducing the floating body effect, which lowered the source barrier. In addition, a dual-gate-structured LTPS was found to inhibit the electrical degradation caused by HCS. The COMSOL simulation indicated that in the dual-gate structure, holes at the upper and lower margins of the channel were inverted and inhibited the degradation caused by the floating body effect. Therefore, the use of dual-gate LTPS TFTs could facilitate high-current gate-on-array circuit applications in display panels.

Demonstration of a low-crosstalk super multi-view light field display with natural depth cues and smooth motion parallax.

Due to lack of the accommodation stimulus, an inherent drawback for the conventional glasses-free stereoscopic display is that precise depth cues for the human monocular vision is rent, which results in the well-known convergence-accommodation conflict for the human visual system. Here, a super multi-view light field display with the vertically-collimated programmable directional backlight (VC-PDB) and the light control module (LCM) is demonstrated. The VC-PDB and the LCM are used to form the super multi-view light field display with low crosstalk, which can provide precisely detectable accommodation depth for human monocular vision. Meanwhile, the VC-PDB cooperates with the refreshable liquid-crystal display panel to provide the convergence depth matching the accommodation depth. In addition, the proposed method of light field pick-up and reconstruction is implemented to ensure the perceived three dimensional (3D) images with accurate depth cues and correct geometric occlusion, and the eye tracker is used to enlarge the viewing angle of 3D images with smooth motion parallax. In the experiments, the reconstructed high quality fatigue-free 3D images can be perceived with the clear focus depth of 13 cm in the viewing angle of ± 20°, where 352 viewpoints with the viewpoint density of 1 mm-1 and the crosstalk of less than 6% are presented.

Resolution enhancement of near-eye displays by overlapping images

It has always been a hot topic to break the angular resolution/field-of-view (FOV) invariant and achieve a near-eye display with a large FOV and high-resolution. We present a super-resolution method for near-eye displays by overlapping images from two display panels using a half mirror. Key aspects including theoretical analysis, optimized method, system set-up, and calibration process are discussed detailly. A proof-of-concept prototype was developed to provide a super-resolution image capable of significantly higher sampling rate.

Defect Inspection in Display Panel Using Concentrated Auto Encoder

In this paper, concentrated auto encoder (CAE) is proposed for aligning photo spacer (PS) and for local inspection of PS. The CAE method has two characteristics. First, unaligned images can be moved to the same alignment position, which makes it possible to move the measured PS images to the same position in order to directly compare the images. Second, the characteristics of the abnormal PS are maintained even if the PS is aligned by the CAE method. The abnormal PS obtained through CAE has the same alignment as the reference PS and has its abnormal characteristics. The presence or absence of defects and the location of defects were identified without precisely measuring the height of the PS and critical dimension (CD). Also, alignment and defect inspection were performed simultaneously, which shortened the inspection time. Finally, inspection performance parameters and inspection time were analyzed to confirm the validity of the CAE method and were compared with the image similarity comparison methods used for defect inspection.

A study on the effect of the vertical sound field control of the flat panel display speaker on audience

Technological improvement in the display industry, the organic light-emitting diode(OLED) panel manufacturer changed the quality of picture and sound improvement. In previous research, we introduced the technology that uses the display panel as a speaker and also to improve the sound quality by improving the vibration characteristics and horizontal acoustic characteristics of an OLED panel. In this study, we analyzed the characteristics of the vertical direction sound of the TV and to consider auditory sense at various distances. When watching TV, unlike normal viewers, the infant and child viewers are too close to the screen. Acoustic transmission using conventional TV allows the reflected sound to propagate from downward. So, near the TV and in a low position, a loud sound is formed. This causes hearing damage at close range and low clarity at long range. The exciter speakers can basically eliminate these disadvantages of the sound field. And, by adaptive control of the sound, it is possible to transmit a clear sound in a wide space by reducing loss due to the distance. This paper introduces the results of the study on the improvement of sound quality through control algorithm and the protection of hearing audiences through sound field analysis.Technological improvement in the display industry, the organic light-emitting diode(OLED) panel manufacturer changed the quality of picture and sound improvement. In previous research, we introduced the technology that uses the display panel as a speaker and also to improve the sound quality by improving the vibration characteristics and horizontal acoustic characteristics of an OLED panel. In this study, we analyzed the characteristics of the vertical direction sound of the TV and to consider auditory sense at various distances. When watching TV, unlike normal viewers, the infant and child viewers are too close to the screen. Acoustic transmission using conventional TV allows the reflected sound to propagate from downward. So, near the TV and in a low position, a loud sound is formed. This causes hearing damage at close range and low clarity at long range. The exciter speakers can basically eliminate these disadvantages of the sound field. And, by adaptive control of the sound, it is possible to transmit...

Using Amorphous Silicon Gap-Type Thin Film Transistor as Ambient Light Sensors and Proximity Sensors for Smartphones

In the smartphone industry, there is a clear trend of developing high screen-to-body ratio display. In order to achieve this demand, we proposed the idea of integrating photo sensing devices into display panels. The photosensitive characteristic of amorphous silicon (a-Si) gap-type thin-film transistors is reviewed and the applicability is examined from the viewpoints of ambient light sensor and proximity sensor. The advantages and feasibility of this idea are fully investigated.

MODUL PERCOBAAN INTERFACING PORT PARALLEL DENGAN LIQUID CRYSTALL DISPLAY 2 LINE X 16 CHARACTER YANG DIDUKUNG BAHASA PEMROGRAMAN BORLAND DELPHI 7.0

n principle computer can be used with various need, one of them can display aninformation to Liquid Crystall Display.In this research, displayed information amount to 2 line x 16 character which inputthrough computer by exploiting with paralell port, and also prosessed by computer program.Result of the process will be presented to Liquid Crystall Display panel, good for knowinginformation which input trough the keyboard.

3D Display System Based on Spherical Wave Field Synthesis

We present a novel concept and first experimental results of a new type of 3D display, which is based on the synthesis of spherical waves. The setup comprises a lens array (LA) with apertures in the millimeter range and a liquid crystal display (LCD) panel. Each pixel of the LCD creates a spherical wave cutout that propagates towards the observer. During the displaying process, the curvature of the spherical waves is dynamically changed by either changing the distance between LA and LCD or by adapting the focal lengths of the lenses. Since the system, similar to holography, seeks to approximate the wavefront of a natural scene, it provides true depth information to the observer and therefore avoids any vergence–accommodation conflict (VAC).