National Television System Committee Color Research Articles

High efficiency fluorescent perovskite quantum dots encapsulated in superhydrophobic silica aerogel for wide color gamut backlight displays

• A super-hydrophobic Silica Aerogels film for backlight display was prepared. • A wide gamut of 128% of color gamut of NTSC standard was achieved. • Excellent environmental stability was achieved through a composite strategy. Recently, all-inorganic cesium lead halide (CsPbX 3 ) perovskite quantum dots (PQDs) have been widely used in the photoelectric field. However, a major limitation of solution-processed PQDs for applications is inherent instability. Herein, we adopt strategy of passivation, CsPbX 3 (X = Cl, Br, I) PQDs are encapsulated into super-hydrophobic silica aerogels (SiO 2 AGs) to form a protective layer for resisting destruction by external forces. Importantly, the photoluminescence quantum yield (PLQY) of CsPbBr 3 @AGs composites achieves 71%, CsPbCl 2 Br 1 @AGs, CsPbBr 3 @AGs and CsPbBr 1 I 2 @AGs composites with narrow emissions can replace traditional phosphors as color converters. In addition, a high-performance liquid crystal display (LCD) with a wide color gamut (128% of National Television System Committee color space) is demonstrated using the prepared CsPbX 3 @AGs@PS composite film and blue light emitting diode (LED) chip as backlight. The combination of improved stability and wide color gamut of the perovskite material provides a viable approach for LCD backlight.

Quantum-dot and organic hybrid tandem light-emitting diodes with multi-functionality of full-color-tunability and white-light-emission

Realizing of full-color quantum-dot LED display remains a challenge because of the poor stability of the blue quantum-dot and the immature inkjet-printing color patterning technology. Here, we develop a multifunctional tandem LED by stacking a yellow quantum-dot LED with a blue organic LED using an indium–zinc oxide intermediate connecting electrode. Under parallel connection and alternate-current driving, the tandem LED is full-color-tunable, which can emit red, green and blue primary colors as well as arbitrary colors that cover a 63% National Television System Committee color triangle. Under series connection and direct current driving, the tandem LED can emit efficient white light with a high brightness of 107000 cd m−2 and a maximum external quantum efficiency up to 26.02%. The demonstrated hybrid tandem LED, with multi-functionality of full-color-tunability and white light-emission, could find potential applications in both full-color-display and solid-state-lighting.

Bright Signals: A History of Color Television by Susan Murray

Reviewed by: Bright Signals: A History of Color Television by Susan Murray Joshua Yumibe (bio) Bright Signals: A History of Color Television by Susan Murray. Duke University Press. Sign, Storage, Transmission series. 2018. $99.95 hardcover. $26.95 paper; also available in e-book. 320 pages. Color has been a lively topic of research in various disciplines recently, as evidenced, for instance, by the recent work of Regina Blaszczyk on color in fashion and industrial design, of Nicholas Gaskill on color and modernist literature, and of numerous cinema scholars such as Barbara Flueckiger, Scott Higgins, Carolyn Kane, and Sarah Street.1 In various ways, these historically oriented researchers have been attentive to various technical transitions in color practice from the late nineteenth century to the contemporary moment. Much of this scholarship also displays careful, interdisciplinary, and frequently, intermedial methodologies that situate specific technical changes in relation to broader aesthetic transformations in color culture. Historical developments in color's apparatus have been comparatively framed in much of this work, implicitly and often explicitly, by recent transitions in digital technology that have affected cultural production profoundly, especially in terms of the richly chromatic nature of our contemporary media environment. [End Page 170] Susan Murray's Bright Signals: A History of Color Television adds dynamically to this growing body of scholarship, expanding it into the area of television history, which has until now been largely overlooked in the history of color, as color has likewise been underresearched in television studies. Cogently written and richly illustrated, Bright Signals tracks the invention and normalization of color television from 1928 to 1970 with interdisciplinary precision and historical depth. The book's focus is primarily on developments in the United States, although the author is also attentive to international currents. More than just a technical chronicle of the development of color television, Bright Signals examines the rich scientific, industrial, and aesthetic history of the medium while also paying close attention to the cultural and intermedial changes that occurred in tandem with its emergence. Drawing explicitly from media archeology, Murray notes that "television scholars have not yet read industrial discourses around, and studies of, electronic color in relation to broader philosophical and cultural conversations about the nature of color," which her study takes up in rigorous detail.2 In doing so, she delineates how color was both an assumed fulfillment of the medium's ability to replicate and expand human vision while also a profound departure from the coalescing norms of black-and-white television. As such, innovations in technology further realigned the medium with the rapid expansion at midcentury of chromatic culture in, for instance, the domains of cinema, design, architecture, and fashion. As with cinema, the origins of color television are rooted in philosophical and theoretical inquiries into physiology and perception, which structured the technical development of color in both mediums. The opening chapters of Bright Signals trace these intersections, exploring the initial experiments with color television, primarily from the late 1920s through the early 1940s, and the difficulties for standardization and colorimetry that color television raised during the same period. As Murray shows, even as black and white became the standard for television, color was central to the medium's self-conception as a device developed to convey liveness, immediacy, and distant views, for color was imagined to be "essential for the realistic experience of virtual presence."3 Yet the immense demands on both bandwidth and color fidelity hindered the adoption of color until after the war. In her far-reaching account, Murray traces how the science and practice of colorimetry-from the physiological theories of Johann Wolfgang von Goethe, Arthur Schopenhauer, and Hermann von Helmholtz to the research of Albert Munsell and Wilhelm Ostwald, along with standardizing boards like the Optical Society of America-were central to the development of midcentury color media and design. These ideas and practices formed crucial, structuring principles for color broadcasting. They enabled the innovations that led the Federal Communications Commission (FCC) to eventually adopt the National Television System Committee color standard in 1953. In this move, the FCC approved the color system proposed by RCA (which owned NBC) over others, such as CBS's previously favored system. RCA...

High Efficiency Blue and Green Light-Emitting Diodes Using Ruddlesden–Popper Inorganic Mixed Halide Perovskites with Butylammonium Interlayers

Ruddlesden–Popper phase inorganic metal halide perovskites are promising candidates for efficient light-emitting diodes (LEDs) with high brightness and color purity. Here, we demonstrate LEDs made from in situ grown CsPbX3 quasi 2D/3D thin films that are color tunable across the entire visible spectrum. CsPbX3 nanosheets are used to produce RP phase perovskites using butylammonium as a separating ligand to create BA2Csn–1Pbn(Br/Y)3n+1 2D/3D mixed halide thin films, where Y = Cl or I. The number of CsPbBr3 monolayers in these crystals was optimized by changing the butylammonium concentration. We demonstrate a stable perovskite phase with thin emission line widths providing points covering the edge of the CIE triangle and a maximum red/green/blue coverage of ∼130% of the National Television System Committee color standard. Additionally, we are able to report record efficiencies for blue emitting perovskite nanocrystal LEDs with a maximum external quantum efficiency (EQE) of 2.4% and 6.2% at 465 and 487 nm a...

Wide Color Gamut Deep-Blue OLED Architecture for Display Application

Over the last 75 years, there have been four display technologies that have been scientifically advanced and frequently used in the production of direct-view televisions (TVs). They are, namely, cathode ray tube (CRT), liquid crystal display (LCD), Plasma, and organic light emitting diode (OLED), in historical order [1]. Amongst, OLED has made a melodramatic entrance for smartphone and TVs displays. For customers, the new OLED TVs are the natural beneficiaries to substitute their earlier or aging Plasma and CRT TVs because they offer even better Black Levels and Infinite Contrast Ratios for truthfully replicating dark picture content [1]. Additionally, with the goal of enhancing the realism, a wider color gamut is of vital importance to all the display devices. OLEDs with a high color-saturation emerge as full-color displays, having the advantage of a high yield in mass production for large-size displays. International Telecommunication Union (ITU) proposed several standards such as the Adobe RGB [2], National Television System Committee (NTSC) [3], SMPTE RP 431-2 for digital cameras [4], High Definition Television (HDTV) ITU-R BT.709-5 [5], and Rec. 2020 for ultra-high definition (UHD) TVs [6]. An essential requirement for display devices is an accurate representation of color. For an emissive OLED display, it can be achieved by optimizing the device architecture with an engineered molecules to generate more saturated red, green and blue (RGB) primary colors, hence a wider color gamut display. Here, we demonstrate a wide color gamut, deep-blue OLED for the next generation high quality full-panel displays based on the lateral introduction of the cyano group on a local excited (LE) chromophoric axis, which significantly affects the nature of the excited state and leads to the optimal hybridization local and charge transfer states (HCLT) [7]. Most notably, OLED based on the HLCT molecule (C4) showed more than two-fold increment in the external quantum efficiency (EQE) and uncompromised color purity as compared to molecule (C1), which lacks cyano group and possesses LE state. The engineered molecular design features cross-conjugated localized and charge-transfer chromophores which result in a hybridized local charge transfer (HLCT) excited state. An OLED using this material presented high an external quantum efficiency (6.5%) with excellent color saturation (CIEy ~ 0.058) and small full-width at half maximum (48 nm). Moreover, the resultant deep blue emission achieved 99, 101, 101, 100, and 96 % color saturation, respectively, compared with the sRGB, NTSC, Adobe RGB, HDTV ITU-R BT.709-5, and Rec. 2020 standards. To the best of our knowledge, this is the first example of phenathroimidazole free HLCT-based deep-blue emitter exhibiting efficient performance comparable to the deep-blue emitting dopants known in the literature [8-9]. Furthermore, we anticipate that the proposed deep-blue emitter and OLED based on it could serve as a promising candidate in high-quality, wide color gamut, energy-saving, display and solid-state lighting panel fabrication, coupled with the cost-effective solution process. Reference [1] http://www.lg.com/sa_en/lgoled/sub/brandstory/brandstory.html [2] National Television system committee, Proceedings of the IRE, https://doi.org/10.1109/JRPROC.1954.274601 [3] Adobe Systems Inc., “Adobe RGB (1998) color image encoding,” 2005. [4] SMPTE RP 431–2, “D-cinema quality — reference projector and environment,” 2011. [5] ITU-R Recommendation BT.709–5, “Parameter values for the HDTV standards for production and internationalprogramme exchange,” 2002. [6] ITU-R Recommendation BT.2020, “Parameter values for ultra-high definition television systems for productionand international programme exchange,” 2012. [7] K. Konidena, K. R. J. Thomas, D. K. Dubey, S. Sahoo, and J. H. Jou, Chem. Commun., 2017, 53, 11802--11805 [8] C. Chen, X. Yuan, S. F. Ni, Q. X. Tong, F. L. Wong and C.S. Lee, Chem. Sci., 2017, 8, 3599. [9] Liu, Z. Yu, D. He, Z. Zhu, Zheng, Y. Yu, W. Xie, Q. X. Tong and C. S. Lee, J. Mater. Chem. C, 2017, 5, 5402. Figure 1. NTSC color saturation of the fabricated deep-blue OLEDs having device structure of ITO/PEDOT:PSS/CBP:Blue dye/TPBi/LiF/Al. (a) Neat film, (b) 1 wt. %, (c) 3 wt.%, (d) 5 wt.% blue dye having a cyano group on an its local excited chromophoric axis doped in CBP host. Figure 1

Facile synthesis of thermally stable CsPbBr3 perovskite quantum dot-inorganic SiO2 composites and their application to white light-emitting diodes with wide color gamut

In this study, highly efficient green-to-red-emitting CsPbBr3-zIz perovskite quantum dots (PQDs) with high color purity are synthesized and a facile route for the formation of PQD-inorganic SiO2 composites is proposed. To improve thermal and water stability of the PQDs, perhydropolysilazane (PHPS)-derived SiO2 composites are prepared. The CsPbBr3-SiO2 composites exhibit highly enhanced thermal stability and water stability. The green-emitting CsPbBr3-SiO2 composites and red-emitting CsPbBr1·2I1.8 PQDs are coated on blue light-emitting diodes (LEDs) and the fabricated green and red LEDs show high color purities of 95.1 and 99.5%, respectively. Finally, the white LED is fabricated by combining a blue LED with CsPbBr3-SiO2 composites and CsPbBr1·2I1.8 PQDs. The fabricated white LED shows bright natural white light (luminous efficacy = 35.4 lmW−1, correlated color temperature = 5623 K) with excellent color reproducibility due to wide color gamut (127% National Television System Committee color space).

Scenes from an Imaginary Country

American analog color television—so-called NTSC color—is likely the most pervasive image standard of the twentieth century, yet it is infamous for its technical shortcomings. Through a history and analysis of the National Television System Committee (NTSC) standard, this article argues that the political presuppositions of engineers shaped the representational capacities of television for nearly sixty years. In particular, the test images used to develop a perceptually satisfying image evince assumptions of a leisurely and white United States as the “normal” subject matter of television. In this way, test materials coalesce abstract assumptions about the normal and the exceptional at the level of both form and content. This article concludes that NTSC color served as a model for how normed cultural sensibilities about image quality, perceptual ability, and the representational imaginary have been built into subsequent technical standards. A Scalar version of this paper, with more pictures, is available at http://colortvstandards.net

Achieving standard wide color gamut by tuning LED backlight and color filter spectrum in LCD

AbstractIn order to achieve the standard red, green, and blue (sRGB) standard color gamut in color liquid crystal display and improve the image quality, the impact of the backlight and color filter spectrum on module's chroma was simulated and analyzed. The color gamut was enhanced by adjusting and optimizing the two parts of spectrums of LED backlight and color filter and by using red and green phosphor LED backlight to match the new color filter with an appropriate thickness. Experimental results show that: When the thickness of color filter is 2.2 µm, National Television System Committee color gamut increases from 65.3% to 74.9%, and sRGB matching rate enhances from 83.2% to 100%, achieving a full coverage of the sRGB standard color gamut, the transmittance of white light reaches 28.1%. Also, it is verified that shifting the peak position of the backlight and color filter spectrum to purification direction, as well as narrowing its half‐width can upgrade the color gamut. Meanwhile, the thicker the thickness of color filter is, the wider color gamut it has, based on the same pigment material.

A new single chip LSI for an NTSC CTV signal processing

A novel single-chip LSI circuit for National Television System Committee color TV (NTSC CTV) signal processing is described. The circuit covers the entire range of TV chassis. The number of external components and PCB (printed circuit board) area can be reduced to approximately 60% of those for a conventional set. The circuit will contribute to the upgrading of standard TV chassis by saving PCB area and increasing the reliability of sets. The circuit integrates 3980 linear elements, a 1200-pF capacitor, and 590 gates on a 5.1*4.5 mm/sup 2/ chip with a shrink 54-pin dual-in-line package (DIP). >

Color Television - A Primer on the NTSC System

Although the technical aspects of color television are more complex than the monochrome version, this article will show, by a simplified step-by-step approach, that the fundamental make-up of the NTSC (National Television System Committee) color television signal is easily understood, as well as efficient and ingenious. The electronic engineer to whom color television is a new area of thought should find this elementary treatment an ideal introduction to the more detailed articles which have appeared in print. (See Bibliography.)

Transmitting terminal apparatus for NTSC color television

DURING the last few years several laboratories in the United States have been carrying on investigations directed toward supplementing the present monochrome television service with transmissions in color. In most cases these investigations of color television systems have been confined to proposals which were expected to receive the wide public acceptance which has characterized monochrome television. The probable commercial success of a color television system may be estimated by noting the degree to which it satisfies certain important criteria. One of these resides in the fact that the system should be “compatible.” That is, it is desirable, that television broadcasts in color should be reproduced in monochrome by the 20,000,000 odd black-and-white receivers now in the hands of the public without the necessity of modifying these receivers in any way. Second, in addition to providing full color to a color receiver, the system should provide as high a degree of pictorial definition to both monochrome and color receivers as is now realized in the monochrome service. Third, as a purely technical matter, the radio-frequency spectrum space allocated to the television service should be utilized as efficiently as possible. The color television system which is now being field-tested by the National Television System Committee (NTSC)1, 2 represents the results of these investigations. This system satisfies these criteria in large measure.