Display Quality Research Articles

P‐7.8: Characteristic analysis on special‐shaped pupil of holographic stereogram

In this paper, the light field regulation characteristics of the size and transmittance function of hogel in holographic stereogram are analyzed, which shows that the display quality of holographic stereogram can be effectively improved by using special-shaped pupil. The limitation of hogel size in optimizing the light field regulation characteristics of holographic stereogram is analyzed from the perspective of resolution and view-flipping effect. By establishing the diffraction limited imaging model with aberration in holographic stereogram, the point spread function (PSF) characterizing the image point propagation characteristics is obtained, and the important variable affecting image point propagation, that is, the type of pupil function, is further found. The quantitative comparison of various functions shows that the special-shaped pupil will have better performance. Simulation experiments further verify the theoretical analysis.

16.4: Bandwidth effect correction used for wide color gamut display measurement

With the development of display technology, several new displays have attracted much attention such as OLED display, QLED display, Laser display and Mini/MicroLED display. Displays with high brightness, wide color gamut, high efficiency and long lifetime are our ultimate goal. Defect inspections and color measurements are important for us to evaluate display quality. To obtain wide color gamut, we usually use narrow spectral bandwidth light source. However, it's not easy for traditional color camera or filter camera to measure narrow bandwidth light source because the accuracy is limited. In this paper, we simulate color measurement accuracy by color camera and filter camera. We analyze the influence of bandwidth effect on the color measurement and carry out bandwidth effect correction method. With the correction, the measurement accuracy improves obviously. In addition, different displays with different spectral bandwidth have been measured to validate the corrections. The results show significant improvement in color measurement accuracy. Our bandwidth effect correction can be used for wide color gamut display measurement.

P‐11.2: Super‐thin Mini‐LED Direct Back Light for Liquid Crystal Displays

This work discusses a super thin Mini-LED direct back light for upscale liquid crystal displays. In this manuscript, it is that Mini-LED light is reflected between a gradient reflected pattern combined with Mini-LED driving lines and back reflector of back light unit. The optical length is therefore enlarged in limited distance, which means that the diffusor plate and optical distance can be removed. Meanwhile, light from a red, a green and a blue Mini-LED is mixing to generate white for display, replacing a 0.3–0.5mm thick color changing film, such as quantum dot enhancement film. The total thickness of this designed Mini-LED back light is about 1.595mm when Mini-LED pitch is 4.75mm. The measured uniformity and optical efficiency are verified as designs above 90% and 45%. Additionally, this direct back light can realize high-dynamic range to improving display quality with lower power consumption. This work not only improves display quanlity in limited thickness, but also extends lifetime of liquid crystal display in coming future.

P‐7.11: A Study on Local Dimming Algorithm Design for MINI LED Backlight Display Quality Improvement

Today HDR (High Dynamic Range) Displays are increasingly developed. The HDR Display with mini‐led backlight and liquid‐crystal panel plays an important role, it has a lot of advantages like high light (more than 1000nits), high contrast ratio (more than 100000:1), bright color and good permeability and so on. But it also has some display defects like halo[3] phenomenon in a dark scene. In this paper, first, we discuss some common picture quality issues caused by the normal local dimming algorithm[2] and then present a novel algorithm base on BOE COG (chip on glass) mini‐led backlight HDR display. The BOE COG technology is a global unique glass substrate backlight solution, and has some features to help the algorithm improve its performance. And for the local dimming display issues, the algorithm itself has room for optimizing visual effects. Finally, around the key point of local dimming algorithm, we show several advantages of BOE glass substrate backlight solution, its distinctive features can help the algorithm improve picture quality.

ANALISIS TINGKAT KEPUASAN PENGGUNA APLIKASI MARKETPLACE TOKOPEDIA MENGGUNAKAN ALGORITMA C4.5

The role of information systems in the business world in Indonesia has grown and reached a fairly rapid stage of progress, due to information systems in the business world, which can provide fast, accurate, and available information studies wherever needed, for example with the development of a marketplace business in Indonesia. Marketplace competition to attract potential consumers is getting tougher, therefore every marketplace company needs to maintain their user satisfaction so that they continue to use the marketplace services. The factors used to measure the level of application user satisfaction include system quality, information quality, design display quality, security, system user satisfaction. The object of this study is Tokopedia with the level of user satisfaction of the application as the variable of this study. The method used in this study is descriptive analysis with the C4.5 Decision Tree algorithm technique. Data collection is done by distributing questionnaires to Tokopedia application users and has been filled out by 114 respondents. The quality of information has the most significant influence on the level of satisfaction of the Tokopedia application users, besides the quality of the design display also has a significant influence on the level of satisfaction of the Tokopedia application users. This study shows that the level of user satisfaction with the Tokopedia application is good. The conclusion of this study is that the level of user satisfaction of the Tokopedia application isstrongly influenced by the value ofsystem quality, information quality, design display quality,security,system and service user satisfaction of the Tokopedia application. Keywords: Statisfication Level, Application User, C4.5 Algorithm, Decision Tree

Color Point Defect Detection Method Based on Color Salient Features

Display color point defect detection is an important link in the display quality inspection process. To improve the detection accuracy of color point defects, a color point defect detection method based on color salient features is proposed. Color point defects that conform to the perception of the human vision are used as the key point for detection. First, the human visual perception constraint coefficient is used to correct the RGB three-channel image to obtain the color-channel-transformed image. Then, the local contrast method is used to extract the point features of the color channel, which achieves point defect enhancement, noise and background suppression. Finally, the mean and standard deviation of the defect feature maps of R, G, and B channels are calculated. The maximum mean and standard deviation are selected as thresholds using the maximum fusion criterion to perform binarization segmentation of the defect feature maps of R, G, and B channels. An OR operation was performed on the segmented images and the point defect segmentation results were combined. The experimental results show that the average detection accuracy and recall of the algorithm is higher than 94%, which is a significant improvement compared with mainstream detection methods and meets the needs of industrial production.

Impact of XBRL adoption on financial reporting quality: a global evidence

Purpose This paper aims to examine the effect of eXtensible Business Reporting Language (XBRL) adoption on financial reporting quality at the country-level (developing and developed countries). Design/methodology/approach This study uses data from 98 developed and developing countries between 2005 and 2018. This study collected data from various sources such as the World Economic Forum, World Development Indicators, World Governance Indicators and XBRL website. Findings The results show that XBRL is associated with an increased financial reporting quality. However, the relationship is stronger in developing countries than in developed countries. This study also finds that the results remain the same after accounting for years of XBRL experience and the effect of accounting globalisation. The results are consistent with the assumption that XBRL-formatted financial statements improve information efficiency through increased searching efficiency, quality of display and comparability. The results are robust to alternative econometric modifications such as controlling for country, year effects and endogeneity. Practical implications The results can potentially assist the XBRL promoters and regulators in expeditiously assessing the benefits of XBRL and advocating its adoption by many countries. The findings offer more motivations for regulators around the world to mandate this new filing standard format. Originality/value This study contributes to the literature by providing empirical evidence on the consequences of XBRL at the country level. This study provides evidence on an important question of whether the XBRL, new information technology in the accounting field, can play a useful role in improving financial reporting.

Development of E-Worksheet To Improve Students’ Mathematical Problem Solving Ability

The purpose of this research is to produce learning media in the form of practical and effective student worksheets. In addition, this research is also to improve the mathematical problem solving ability of high school students in class X on the material of a three-variable system of linear equations. The method used is the R&D (Research and Development) method with a 4D model (Define, Design, Development and Disseminate). The validity test was carried out by mathematics teachers, mathematics lecturers, and media expert lecturers. The results showed that the media that had been developed based on the results of the validity test in the aspect of display quality was 94.79% in the very good category, the written text was 93.75% in the very good category, and device engineering 94.79% in the very good category. The developed media was tested practically by 10 respondents. The practicality test showed that the display quality was 99.16% in the very good category, the text results were 99.37% in the very good category, and the results of the device engineering were 100% in the very good category. The results of the students’ mathematical problem solving ability scores ranged from 75 to 100 from the results of answering e-worksheets, so that the average obtained from each student on mathematical problem-solving abilities was in the “high” category and the average percentage obtained was 94.10% in the “very good” category. Based on the results of data acquisition, it shows that the e-worksheet media on the material of a three-variable linear equation system is feasible to be used as a learning resource and can also improve students’ mathematical problem-solving abilities.

Directional modulated light-emitting technology based on airborne display

ABSTRACT High-quality airborne display benefits pilots of making correct interpretation and operation in time, and avoids from moving body due to the unclear transmission of flight data which may lead to flying risk. A directional modulated light-emitting technology based on airborne display is proposed in this paper which can be used on Diamond DA42 New Generation aircraft. Using the proposed technology, a composite optical film with micro-structure is designed which can realise the redistribution of light intensity according to the viewing demand. A collimated display is introduced to reduce the colour shift. When the optical film is attached on a collimated display, the incident light of small viewing angles can be directionally modulated and concentrated to the large viewing angles which are just effective pilot and co-pilot viewing angles. The calculation results show that the brightness of airborne display on two pilots’ viewing angles can be increased by 38.9% and 58.7% respectively after using the proposed technology. Meanwhile, the emergent angles from the collimated display are smaller than both two pilots’ viewing angles, so the proposed optical film is beneficial to reduce the colour shift and resulting in a better display quality.

Solar-powered Mosquito Trap with Air Quality Monitoring

Mosquito pest control is a recurring matter that requires constant monitoring and attainment. This is due to the creature being able to spread various deadly diseases and mosquitoes are responsible for the death of one million people every year. The conventional prevention methods of using insecticides and bug zappers are somewhat less effective and affect the environment in various ways such as the extinction of beneficial insects, the biological evolution of mosquitoes, and climate changes. In this study, a solar-powered mosquito trap is created to trap mosquitoes by sucking them in using a fan while being attracted to a built-in LED to lure them into the trap. An air quality monitor is equipped to observe the change of temperature and carbon dioxide (CO2) of the surroundings and as a method to centralize the installation of the trap. The monitor display and air quality data retrieval are processed by an Arduino microcontroller. In the prototype observation, it was shown that the temperature increased proportional to CO2 concentration. The power efficiency of this device increased by 30% when using a solar panel. At optimal sunlight exposure and adequate battery capacity, the device would run for more than 24 hours and would get charged instantly on the next day when sunlight is present.

How inspection solutions ensure quality and profitability

AbstractTechnologies for ever thinner displays and vibrant display quality, outlandish shapes, and new applications open up additional market potential in consumer electronics and industrial markets. At the same time, however, they demand increasingly higher functionality and optical quality.

Crosstalk Defect Detection Method Based on Salient Color Channel Frequency Domain Filtering.

Display crosstalk defect detection is an important link in the display quality inspection process. We propose a crosstalk defect detection method based on salient color channel frequency domain filtering. Firstly, the salient color channel in RGBY is selected by the maximum relative entropy criterion, and the color quaternion matrix of the displayed image is formed with the Lab color space. Secondly, the image color quaternion matrix is converted into the logarithmic spectrum in the frequency domain through the hyper-complex Fourier transform. Finally, Gaussian threshold band-pass filtering and hyper-complex inverse Fourier transform are used to separate the low-contrast defects and background of the display image. The experimental results show that the accuracy of the proposed algorithm reaches 96% for a variety of crosstalk defect detection. Compared with the current advanced defect detection algorithms, the effectiveness of the proposed method for low-contrast crosstalk defect detection is confirmed.

Production of Head-Up Display windshield and its relation with the image quality

Previously, car windshields served as a barrier against the wind or to prevent the driver from flying outside the vehicle in a collision. The windshield is therefore laminated and consists of two glasses and an intermediate layer consisting of the so-called polyvinyl butyral foil. The latest trend in car windshields is to consider the windshield as a display and project key information onto the windshield. Such glasses are called head-up displays. Various information such as car speed or route can be projected. The driver thus constantly maintains contact with the road, which increases driving safety. Head-Up Display quality is key to display information correctly without negative effects. Such a negative effect is if the displayed information is duplicated, which is called ghosting or double-image. This effect is undesirable and ranks first among the defects we detect in Head-Up Displays. The aim of this article is to compare different production technologies with a focus on the quality of HUD projection and on the double-image occurrence. The production technology enabling optimal HUD image quality is discussed as well. The article deals with a summary of HUD production technologies, focusing on the most common defect that occurs in HUD windshields and which reduce the overall quality of the product. The article evaluates and summarizes the key findings from the perspective of the end customer, but also in terms of the production process. For the driver, as an end customer, it is a source of information according to which he can orient himself in the offer of car equipment. It can be useful for production or development people in terms of processability and process costs. At the same time, the benefits and negatives of using windshields with a Head-Up Display are discussed.

18‐3: 3D Image‐Quality Evaluation Method Based on Image Comparison Metrics

We propose a method for evaluating the 3D image quality with a peak signal to noise ratio (PSNR) and structural similarity index (SSIM), which are image comparison metrics. Compare light field display (LFD) quality level with existing 3D X‐Talk evaluation and depth range evaluation method. And we proceed verification of image comparison metrics through 2D image. After creating a pattern dedicated to 3D evaluation for 3D application of image comparison metrics, 3D image quality evaluation is carried out. In summary, the present paper proposes a method for performing 3D image quality evaluation through image comparison metrics using only 3D images.

75‐4: Low Luminance JND and JNCD

As demands for display uniformity at very low luminance are increasing, the importance of accurate JND and JNCD as display quality standard is growing. Perceptional experiments to find out JND and JNCD at a very low luminance level were carried out and the color and luminance difference values at which 50% of people noticed were obtained, which were not accessible in the past.

76‐2: Development of Custom Shaped OLED Display

We presented custom shaped OLED display prototype. It can meet the customer's personalized requirement to develop the nonregula shaped display with very low cost and high speed. The custom shaped OLED display is based on the LTPS backplane and inkjet printing process. We create a design methodology with specific pixel, driver circuit and fanout design rule. Also, the optical compensation method is upgraded to fit with non‐regular shape display. It can improve the display quality effectively.

64‐2: Ultra‐Thin RGB Mini‐LED Backlight for High‐end Professional Liquid Crystal Displays

This report discusses a glass based ultra‐thin Red, Green and Blue Mini‐LED direct back light for high‐end professional liquid crystal displays. In this work, a gradient reflected pattern combined Mini‐LED driving lines reflect light scattering between the patterns and back reflector of back light unit, and therefore enlarge Mini‐LED optical length. A group of a red, green and red Mini‐LED is using to generate white for display, replacing a 0.3–0.5mm thick color changing film. The total thickness of Mini‐LED direct back light is reduced to 1.595mm when the Mini‐LED pitch is about 4.75mm. This direct back light can realize high‐dynamic range to improving display quality without cost consumption and then extend lifetime liquid crystal display lifetime in coming decent years.

Polarization‐Selective Ultra‐Broadband Reflective Diffuser as a Smart Projection Screen

Herein, active smart screens are increasingly investigated to enhance projection‐type transparent displays owing to the high contrast ratio generated by their switchability between projection and transparent states. Despite the development of various active smart screens, most screens employ the scattering state as the projection state, which suffers from low reflectance of the projection state and optical interference with background light. Herein, an active smart screen composed of a passive polymer‐stabilized cholesteric liquid crystal (PSCLC) diffuser and an active polarization modulator (PM) is proposed. The PSCLCs enabled by the chiral monomer have a pitch‐gradient helical structure, wherein liquid crystal molecules form a multi‐domain planar texture and exhibit a broadband reflection band over the entire visible spectrum; their natural circular polarization selectivity facilitates the operation between projection and transparent states when the PSCLC is observed using opposite‐handed circular polarized light. Unlike traditional active smart screens, both transparent and projection states of the PSCLC diffuser can be switched by driving the PM, thereby eliminating the issue of background interference. The proposed active projection screen based on the polarization‐selective PSCLC can potentially improve the display quality of existing projection‐type transparent displays and form the basis for see‐through windows and near‐eye display applications.

Speckle suppression using F-D2NN in holographic display

We propose a speckle suppression method using Fourier-domain diffraction deep neural networks (F-D2NN) in the holographic display. To the best of our knowledge, it is the first time that F-D2NN is applied for the holographic display quality enhancement. Unlike existing speckle suppression algorithms in the hologram generation, our proposed method works after the hologram reconstruction and improves the reconstructed quality independently of the hologram generation algorithm. The proposed method not only can alone suppress speckle noise generated by different holographic generation algorithms but also is effective to improve reconstruction quality further by jointing with other traditional speckle suppression algorithms. The proposed method provides a new approach for the quality enhancement of the holographic display.

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