{"title":"Large field-of-view microlens array with low crosstalk and uniform angular resolution for tabletop integral imaging display","authors":"Daerak Heo, Beomjun Kim, Sungjin Lim, Woonchan Moon, Dongkil Lee, Joonku Hahn","doi":"10.1080/15980316.2022.2136275","DOIUrl":"https://doi.org/10.1080/15980316.2022.2136275","url":null,"abstract":"Tabletop autostereoscopic displays have the advantage of displaying realistic three-dimensional (3D) content. In particular, the Integral imaging (InIm) method is superior in tabletop displays, as it is possible to make the system small using microlens arrays (MLA). Off-the-shelf MLAs have a small field of view (FOV) and are unsuitable for tabletop displays where the half viewing angle is typically around 45 degrees. The MLA for tabletop display also needs to have uniform angular resolution and low crosstalk to display 3D content. In this paper, we designed a new MLA with a multilayer structure and a reversed lens shape. This lens array has a wide viewing angle of −58 degrees to +58 degrees, with uniform angular resolution and low crosstalk of less than 0.2. We implemented a tabletop display using our MLA and verified its properties experimentally. The misallocation error of the elemental image is experimentally measured and compensated for as well.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44508545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Baeksang Sung, C. Joo, Jun Chang Yang, Akpeko Gasonoo, Seungmin Woo, Jae-Hyun Lee, Steve Park, Jonghee Lee
{"title":"Application of optical property-enhancement film to improve efficiency and suppress angle dependence of top-emitting organic light-emitting diodes","authors":"Baeksang Sung, C. Joo, Jun Chang Yang, Akpeko Gasonoo, Seungmin Woo, Jae-Hyun Lee, Steve Park, Jonghee Lee","doi":"10.1080/15980316.2022.2127950","DOIUrl":"https://doi.org/10.1080/15980316.2022.2127950","url":null,"abstract":"In this paper, we propose the application of an optical property-enhancement film that complements the angular dependence and total reflection of top-emitting organic light-emitting diodes (TEOLEDs). The optical property-enhancement film is composed of a porous pyramid arrangement applied on a thin-film encapsulation layer of TEOLEDs and is applied to distribute the transmitted light evenly. The results confirm that the change in the electroluminescence spectrum for each angle was effectively reduced because the TEOLEDs demonstrated uniform light distribution. In addition, reducing the total internal reflection in the film structure made it possible to improve the external quantum efficiency by approximately 35% and current efficiency by 38%.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44574910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yong-Hoo Hong, Eun Kyo Jung, Hwarim Im, Yong-Sang Kim
{"title":"Improvement of the low gray-level expression using hybrid pulse width modulation and pulse amplitude modulation driving method for a micro light-emitting diode pixel circuit","authors":"Yong-Hoo Hong, Eun Kyo Jung, Hwarim Im, Yong-Sang Kim","doi":"10.1080/15980316.2022.2084464","DOIUrl":"https://doi.org/10.1080/15980316.2022.2084464","url":null,"abstract":"A novel hybrid pulse width modulation (PWM) and pulse amplitude modulation (PAM) (HPP) driving method is proposed for improving the low gray-level expression of a micro light-emitting diode (µLED) display. At the high and middle gray-levels, PWM is adopted in order to suppress the wavelength shift of µLEDs. At the low gray-level, PAM is applied when the emission time and current of µLEDs simultaneously decrease. The HPP driving method is simulated by using a simplified p-type low-temperature polycrystalline silicon (LTPS) thin-film transistor (TFT)-based µLED pixel circuit. HPP driving exhibits stable PWM and PAM operations. Furthermore, HPP driving guarantees a data voltage range approximately 14 times larger than PWM driving, thus resulting in a robust operation with a maximum error rate of 3.83% under data signal distortion. Consequently, the µLED pixel circuit adopting HPP driving improves the low gray-level expression and demonstrates a robust circuit operation.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48002593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Lifetime modeling for organic light-emitting diodes: a review and analysis","authors":"Jaesang Lee","doi":"10.1080/15980316.2022.2126018","DOIUrl":"https://doi.org/10.1080/15980316.2022.2126018","url":null,"abstract":"ABSTRACT Organic light-emitting diodes (OLEDs) of all kinds inevitably undergo permanent performance degradation over time, leading to burn-in in the displays made with the OLEDs. To compensate for display burn-in and extend product lifetimes, having a model that can precisely predict OLED degradation is most essential. In this work, we review a few select studies that focused on the physics-based analysis and modeling of OLED degradation. The framework and features of the lifetime models based on the physical mechanisms behind OLED degradation are discussed. In particular, the post-degradation performance of OLEDs is understood in terms of the detrimental effect of degradation-induced defects on the behavior of charges and excitons. Experimental attempts to identify the type and relevant characteristics of the defects are particularly important and thus, are dealt with in this review. Lastly, we discuss the relevant theories and methodologies for measuring the exciton distribution in OLEDs, which is one of the most crucial pieces of information in understanding the device characteristics. We emphasize the limitation of the current lifetime models and what needs to be improved for practical use to achieve a longer lifetime for OLED displays.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43813605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gunel Huseynova, A. Boampong, K. M. Yu, Ye-Seul Lee, Jang-Sik Lee, Min‐Hoi Kim, Jae-Hyun Lee
{"title":"Highly conductive and low-work-function polymer electrodes for solution-processed n-type oxide thin-film transistors","authors":"Gunel Huseynova, A. Boampong, K. M. Yu, Ye-Seul Lee, Jang-Sik Lee, Min‐Hoi Kim, Jae-Hyun Lee","doi":"10.1080/15980316.2022.2126017","DOIUrl":"https://doi.org/10.1080/15980316.2022.2126017","url":null,"abstract":"We present an n-doped poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) polymer and its application in n-type oxide thin-film transistors (OxTFTs) as a source and drain electrode material. A reduced molecule of a cationic dye, methyl red (MR), was used as an effective solution-processed n-type dopant. The sequential de-doping and doping of the initially p-doped PEDOT:PSS polymer with the reduced MR (r-MR) effectively removed positive charges via cancellation by the added electrons. As a result, the electron conductivity of PEDOT:PSS increased from 3.4 S/cm to ∼51 S/cm, while its work function decreased from 4.8 eV to 3.5 eV. This is one of the lowest values of the work function reported for PEDOT:PSS. The n-doped PEDOT:PSS films were eventually applied as a suitable material to fabricate the contact electrodes of solution-processed bottom-gate top-contact amorphous indium-gallium-zinc oxide-based OxTFTs. The resultant devices exhibited electron mobility over ten times better compared to those with undoped PEDOT:PSS electrodes. Therefore, we suggest this method as a highly suitable and low-cost technique for improving electron transport in PEDOT:PSS and all solution-processed conductors. Further investigations with this method are expected to expand the application of PEDOT:PSS to other sectors of optoelectronics.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46923258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Low-resistance copper conductive balls that prevented migration","authors":"Jong-Keun Choi, Young-Gyun Kim, Kwan-Young Han","doi":"10.1080/15980316.2022.2113830","DOIUrl":"https://doi.org/10.1080/15980316.2022.2113830","url":null,"abstract":"The demand for flexible displays (e.g. foldable and rollable displays) has recently increased, thus necessitating the development of various component technologies. An anisotropic conductive film, which is a conventional surface mount technology, is deemed more necessary than soldering for the implementation of a flexible display. However, it is still difficult to secure the electrical conductivity and reliability of the conductive ball used in the anisotropic conductive film. In this paper, a copper conductive ball having a lower resistance than the conventional conductive ball was fabricated. It has a lower contact resistance than nickel and gold, and the reliability issue, which is a disadvantage of copper, is secured by blocking the reaction with oxygen and coating a thin corrosive solution.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44729748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fabrication technology for light field reconstruction in glasses-free 3D display","authors":"Fengbin Zhou, Wen Qiao, Linsen Chen","doi":"10.1080/15980316.2022.2118182","DOIUrl":"https://doi.org/10.1080/15980316.2022.2118182","url":null,"abstract":"ABSTRACT Light field 3D display has attracted great attention as the hardware interface for a virtual 3D application. The design and fabrication of light-modulating structures directly affect the authenticity of the reconstructed 3D image. The critical challenges in 3D display, such as visual fatigue, limited motion parallax, and insufficient light efficiency, are closely related to the inaccurate phase or angular reconstruction of the virtual light field. While the designs of light field modulators are widely introduced in all kinds of studies, the importance of fabrication for 3D display is usually under-estimated. Large format, small feature size, and high precision in shape are the three critical requirements of fabrication for 3D display. In this paper, we focus on the fabrication technologies for light-modulating structures. Fabrication tools for both microstructures and nanostructures are introduced. The fabrication capability, critical challenges and its applications in light field 3D display are discussed. Finally, the future development of 3D display related fabrication technologies are highlighted.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48178820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Woonchan Moon, Hosung Jeon, Sungjae Park, Soobin Kim, Hwi Kim, Joonku Hahn
{"title":"Seamless holographic image generation for a multi-vision system","authors":"Woonchan Moon, Hosung Jeon, Sungjae Park, Soobin Kim, Hwi Kim, Joonku Hahn","doi":"10.1080/15980316.2022.2112313","DOIUrl":"https://doi.org/10.1080/15980316.2022.2112313","url":null,"abstract":"This paper investigates the optical seamlessness of a holographic multi-vision display. The purpose of the multi-vision approach is to scale up the resolution of a holographic display without requiring a single extremely high-resolution spatial light modulator. Optical experiments reveal that a holographic multi-vision system with 16M pixel resolution successfully generates a seamless virtual reference plane with the essential optical characteristics of a holographic display, such as the accommodation effect and binocular parallax. It is realized from a matrix of eight (4 2) high-resolution transmission-type liquid crystal displays. Theoretical analysis and numerical simulations are presented for the proposed seamless holographic multi-vision system.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49014680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dong-Hwan Jeon, Won-Been Jeong, Jeong-Soo Park, Hoon-Ju Chung, Seung-woo Lee
{"title":"A high-gain two-stage amplifier using low-temperature poly-si oxide thin-film transistors with a Corbino structure","authors":"Dong-Hwan Jeon, Won-Been Jeong, Jeong-Soo Park, Hoon-Ju Chung, Seung-woo Lee","doi":"10.1080/15980316.2022.2102681","DOIUrl":"https://doi.org/10.1080/15980316.2022.2102681","url":null,"abstract":"This paper proposes a complementary metal–oxide–semiconductor (CMOS) amplifier using low-temperature poly-Si oxide (LTPO) thin-film transistors (TFTs). The Corbino structure used in the proposed amplifier has a higher output resistance than conventional amplifiers. The proposed circuit is composed of two CMOS inverters, one CMOS switch, and one input capacitor. It was possible to determine the operating point where the voltage gain could be kept high, regardless of the device variation, by shorting the gate input and output of the first amplifier. The alternating current component of the input signal was increased because the input signal was transferred to the first amplifier via the capacitor. The function of the second amplifier was to increase the total voltage gain. When a peak-to-peak voltage sine wave of 2 mV was applied at a frequency lower than 500 Hz, the proposed circuit showed an average voltage gain of 60.6 dB, which is the highest among the previously published TFT amplifiers.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41628810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Ryu, Seong Hyeon Noh, Selim Yun, Chang Wan Park, Seung-Ji Lee, Y. Do, Jae Soo Yoo
{"title":"Wave energy-assisted fluidic self-assembly of LED chips for display applications","authors":"J. Ryu, Seong Hyeon Noh, Selim Yun, Chang Wan Park, Seung-Ji Lee, Y. Do, Jae Soo Yoo","doi":"10.1080/15980316.2022.2097485","DOIUrl":"https://doi.org/10.1080/15980316.2022.2097485","url":null,"abstract":"Micro-light-emitting diode (micro-LED) displays have excellent image characteristics, particularly in terms of contrast ratio, response to electric field, and color expressions. However, these are expensive due to the price of the LED chips. This can be overcome by reducing the size of the LED chip, but the efficiency will decrease as a result. Moreover, the rapid and accurate arrangement of a few million chips with a size of ∼50 µm to form pixels on the substrate is a challenging task. In this study, fluidic self-assembly process was introduced. The self-assembly design and implementation were limited to building a micro-scale system. With geometric constraints, external forces may influence the outcome of a self-assembled product. In this case, wave energy was used as the external force to manipulate the LED chips on the substrate. Target-generated waveforms in the fluid were used to control the movement of the LED chips. The arrays of the LED chips were arranged on a fine metal mask, i.e. transfer cartridge. The chips were then transferred to a circuit-printed glass plate by face-to-face pressing under high temperature and high pressure. It was found that the wave energy-assisted self-assembly is applicable and beneficial to LED module fabrication.","PeriodicalId":16257,"journal":{"name":"Journal of Information Display","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41859259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}