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1.
Multiprimary display are now widely researched and used. There is little research concerning color temperature design, namely the relationship of the primaries. It is easy to design the relationship in three‐ primary display, because that is a simple 3 × 3 matrix inversion. But it is difficult when the number of primaries gets to be more than three, because the coefficient matrix is not in a square form, which always yields an infinite solution set. This article presents a method to design the relative primary luminances of multiprimary color display. It will be useful in the multiprimary color laser projection or multiprimary color LED‐based backlighting LCD display. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 201–204, 2009 相似文献
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Michael J. Murdoch Dragan Sekulovski Ingrid Heynderickx 《Color research and application》2014,39(2):169-178
Preferred chroma enhancement and its dependence on hue are studied in a two‐part experiment using a wide‐gamut multiprimary display. Earlier research showed a clear dependence on hue but was limited by the gamut of the display it employed; the present work builds on this while easing the gamut constraints. In the first part of the present experiment, a tuning task was used to refine the preference for chroma boost starting with standard‐gamut (Rec. 709) images. The overall median preferred boost is roughly 20%, but it is not uniform over hues: the preferred boost for orange, yellow, green, and cyan colors is greater than that for blue, magenta, and red colors. Dependence on image content and observer is noted, though a content‐independent chroma boost created by aggregating preference over many images performs well. An adjustment parameter for overall chroma, which incorporates the hue dependence averaged over image content, should be sufficient to handle the vast majority of interobserver variance in preference. In the second part of the experiment, various chroma boost algorithms were evaluated through a paired comparison task. The prescribed hue‐dependent chroma boost is preferred over all other variations, and all hue‐preserving chroma boost variations are preferred over both colorimetrically accurate and na??ve same‐drive‐signal renderings. The results may be applied in display design to select gamut boundaries that maximize satisfaction over the observer population. © 2012 Wiley Periodicals, Inc. Col Res Appl, 39, 169–178, 2014 相似文献
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《Journal of the European Ceramic Society》2020,40(6):2439-2444
Currently, phosphor composite films draw much attention in white laser lighting. In this work, we developed a novel phosphor-SiO2 film via a mild method, which avoiding the phosphor degradation. Commercial colloidal silica was elected as the source of SiO2 and acted as an inorganic binder, gap filler and a protective coating layer. Composite films comprised of mixed Lu3Al5O12:Ce3+ and CaAlSiN3:Eu2+ phosphors exhibit a uniform dense strucure and strong adhesion to the substrate. When excited by blue diodes laser, the optimal film exhibits excellent thermal stability (it maintains 89.1 % of the room-temperature intensity at 200 °C), super resistance against laser irradiation (12.9 W/mm2), a broad emission spectra with a full width at half maximum of 180 nm and a high luminous efficiency (183 lm/W). The color rendering index of the film was improved to 85. These outstanding properties indicate that the derived films are a promising candidate for white laser lighting. 相似文献
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Chang Bae Moon HyunSoo Kim Dong Won Lee Byeong Man Kim 《Color research and application》2015,40(2):201-212
The emotional impact of music or color can be maximized if they are used together. This article presents a mood‐lighting system that automatically detects the mood of a piece of music and expresses the mood via synchronized lighting. To do this, the relationship between mood words and colors was analyzed via a web questionnaire (n = 202) on moods associated with music and colors. Data analysis generated lighting scenarios reflecting changes in the mood of music. Each piece of music was divided into several segments using structural analysis, with the mood of each segment detected by the mood classification module using the neural network. A matching color was then assigned. The best performance of our mood classification module was <70%, which is not sufficient for commercial use; however, this figure is high enough to show the potential of this approach. © 2013 Wiley Periodicals, Inc. Col Res Appl, 40, 201–212, 2015 相似文献
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Yujie Zhang Yueyuan Liang Yaqian Zhang Xiaodong Liu Yanxia Yu Yajuan Zhao Xiaojuan Liang Weidong Xiang 《Journal of the European Ceramic Society》2021,41(9):4915-4923
The aim of this study is to investigate a thermally robust white color converter for high-power solid-state lighting, especially laser lighting. Lu3Al5O12:Ce3+/CaAlSiN3:Eu2+ phosphor-in-glass samples (LuAG&CASN-PiGs) were synthesized via a low temperature co-sintering technique. The prepared LuAG&CASN-PiGs exhibited remarkably high internal quantum efficiency of 87 %. Tunable warm white light-emitting diodes (wLED) were acquired by tailoring the sample thicknesses and phosphor contents. The optimized sample showed a high luminous flux of 183.68 lm under a blue laser diodes (LDs). In addition, the chromaticity of white LDs based on the LuAG&CASN-PiGs shifted from cool to warm white by changing the sample thicknesses. High quality white light in wLDs was achieved (Ra=95). More importantly, the constructed LuAG&CASN-PiG converted LDs with a heat sink exhibited the luminous efficiency of 216.79 lm W?1. The results revealed that the prepared LuAG&CASN-PiG had great potential for application in solid-state laser light sources. 相似文献
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Jian Xu Yang Yang Zhi Jiang Baofu Hu Xinliang Wang Haipeng Ji Jian Wang Ziquan Guo Baoli Du Carsten Dam-Hansen Ole B. Jensen 《Ceramics International》2021,47(11):15307-15312
To achieve high color rendering and proper color temperature, a red color converter is essential for phosphor-converted white lighting devices. CaAlSiN3:Eu2+ (CASN) is a highly suitable red phosphor for white light-emitting diodes. However, it can be hardly used in high-power laser lighting due to poor thermal/chemical performance of the phosphor/silicone resin mixture. A series of all-inorganic CASN-based phosphors (e.g., composite ceramic and phosphor-in-glass) were developed to avoid the use of resin. However, new challenges emerged: none of them showed sufficient luminous efficacy (i.e., >50 lm/W) and adequate saturation-threshold (i.e., >30 W or 10 W/mm2). Here, we report a facile fabrication of CASN/glass composite films using a simple and efficient blade-coating method. Upon 450 nm excitation, the resultant composite film presents a high internal quantum efficiency of ~83%, comparable to that of pristine CASN powder (~90%). When irradiated with a blue laser, the composite film shows a record high luminous efficacy of 82 lm/W. Furthermore, its saturation threshold was investigated in high power and high power density mode, respectively. When measured in high power mode, it shows a high saturation threshold over 29.7 W (1.75 W/mm2), thus achieving a high luminous flux of 1576 lm; when measured in high power density mode, it shows a saturation threshold of ~10.2 W/mm2 (1.13 W). With abovementioned excellent properties, the CASN/glass composite film has great potential for use in high-power and high color rendering laser lighting. 相似文献
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An optimization model for luminous efficacy of a spectrally tunable light-emitting diode (LED) daylight simulator under constraint of metamerism index was developed. It was first reported that the optimal spectrally tunable LED daylight simulator of AA grade for D50, D55, D65, and D75 standard illuminants could consist of two quantum dot-integrated LEDs (QDLEDs) with the ultraviolet chip and two other QDLEDs with the blue chip. The optimized spectral parameters of each QDLED, as well as photometric and colorimetric performances of D50, D55, D65, and D75 daylight simulators, were obtained by maximizing luminous efficacy under the metamerism index for both a visible and ultraviolet range less than 0.25. The limit luminous efficacies of four daylight simulators using four QDLEDs under the ideal case will reach 181 lm/W to 205 lm/luminous efficacies with a radiant efficiency of both the ultraviolet and blue chips of 60%, as well as a quantum efficiency of a quantum dots layer of 90%, will reach 100 lm/W to 112 lm/W. 相似文献
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Roy S. Berns 《Color research and application》2011,36(5):324-334
When displaying art, several criteria must be balanced when designing illumination including the artist's intention, damage, energy efficiency, viewing experience and understanding, and for commercial galleries and sales. The most common lighting for art includes natural daylight and incandescent spotlights. Neither source is optimal for all criteria; thus there is considerable interest in the use of white‐light light‐emitting diode (LED) lighting. A feasibility study was conducted to address two questions. First, was it possible to design a three‐primary LED source that yielded the same color rendering as common museum lighting? Second, could one design the lighting to achieve specific color appearance attributes? Three‐primary lights using a Gaussian function were optimized matching the chromaticity of D65 and minimizing color differences for a set of acrylic dispersion paints. The optimal wavelengths depended on bandwidth. Lights were also optimized that either maximized or minimized average chroma. A set of real LEDs was selected that produced similar results when evaluated computationally. A source that increases chroma may be useful when used to illuminate works of art with high light sensitivity: very low illuminances are necessary and such a source will compensate for the reduction of colorfulness and visual clarity. A source that decreases chroma may be used to render art in similar fashion to low‐light conditions such as churches and caves. In general, white LED lighting is advantageous for art conservation because they do not emit UV and IR radiation and their visible radiation is reduced when compared with their continuous spectrum equivalent. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2011 相似文献
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Mengting He Jiannan Jia Junjie Zhao Xvsheng Qiao Jincheng Du Xianping Fan 《Ceramics International》2021,47(3):2963-2980
Solid state lighting, including phosphor converted light-emitting diodes (LEDs) and laser diodes (LDs), have released high demand to develop thermally stable phosphors. For this purpose, inorganic glass-ceramics (GCs) embedded with phosphor particles can act as competitive candidates. They are superior to traditional phosphors or resin/silica composites through successfully overcoming thermal aging and color temperature drifting problems and simultaneously maintaining high luminescent efficiencies. Inorganic GC phosphors can be classified into devitrified glass-ceramics, PiG (Phosphor-in-Glass) and sintered glass-ceramics. This review summarized the recent progress on LED/LD GC phosphors from the aspects of design principles, synthesis methods, microstructure-property relationships and their application studies. In addition, some challenging issues (e.g., crystallization behavior of luminous phase in glass, corrosion behavior of phosphor by glass matrix) are also discussed in detail. Significant issues of glass-ceramics packed LED/LD, such as luminescence efficiency, chromaticity, correlated color temperature and color gamut, are sorted out as well. Potential research directions are further suggested for not only developing new glass-ceramic phosphors but feeding upon various practical application. 相似文献
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Maurizio Rossi 《Color research and application》2023,48(1):32-39
In the last decade, the extensive introduction of LED lighting sources has brought elements of innovation to interior lighting design in terms of color. Besides the new tunable white LED source, lighting is no longer exclusively white; indeed, colored lighting has entered the design practice thanks to the positive effects on people's health and mood. Unfortunately, this element of lighting innovation, color, cannot be computed correctly in commercial lighting design software. These computations are based on the assumption that light is only white or defined in terms of RGB triplets in the relative digital color space of computer graphics, which does not have a physically correct relationship with the actual spectral power distribution (SPD) of luminaires. In this paper, attention is focused on a practical design-oriented approach for describing luminaires in lighting design software that also considers the real SPD and the luminous intensity distribution. The focus is on information available to lighting designers who do not have a laboratory to measure light sources and luminaires. This information could be available in online datasheets or as a Cartesian graph from luminaires and light sources manufacturers. Following this approach, a set of functions is proposed that can be easily implemented in lighting design software to improve light sources' color management and allow lighting designers to add SPD data to luminaires. 相似文献
11.
Ce/Mn/Cr: Y3Al5O12 phosphor ceramics for white LED and LD lighting with a high color rendering index
《Ceramics International》2023,49(15):24703-24711
Ce/Mn/Cr: Y3Al5O12 transparent ceramics with a pure garnet structure and a high color rendering index were prepared by a solid-state reaction method. Mn2+ and Cr3+ enhance the emission between 500 and 700 nm and expand the conventional Ce: YAG phosphors spectrum. The Ce3+ can work both, as activators and sensitizers, and the intense energy transfer from Ce3+ to Mn2+/Cr3+ is realized through the non-radiative and radiative processes. In the sample with the optimized doping concentration the high color rendering index (CRI) value of 75.3 can be achieved under a 450 nm laser diode excitation. The chromaticity coordinates can be tuned from (0.3125, 0.3232) to (0.2917,0.2851) by varying the doping concentration. With the increasing Mn2+/Cr3+ doping concentration, the lifetime of Ce3+, quantum efficiency and luminous efficiency are all gradually decreased. This work effectively offers a scheme for realizing the high color rendering performance of phosphor-converted transparent ceramics in white LEDs/LDs. 相似文献
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Recently, a line of minimum tint in chromaticity space for sources of illumination of different correlated color temperatures (CCTs) from 2700 K to 6500 K has been reported. This line of minimum tint did not correspond to the line of blackbody radiation implicitly associated with sources of white illumination used in architectural applications. It was noted that chromaticities along the line of minimum tint were not metamers but, rather, should represent, for a given CCT, chromaticities where the neural signals from the two spectral opponent channels were minimized. Earlier work provided a theoretical framework for representing the four unique hues where the neural signals from one spectral opponent channel are minimized. This framework was used here to quantitatively represent the line of minimum tint and then to empirically test whether this representation could predict the amount of tint perceived in six different sources of “white” Illumination.” Based on these results, a provisional model is proposed for describing the tint and the amount of tint perceived in “white” Illumination used in architectural applications. © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 466–479, 2014 相似文献
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Nayatani‐theoretical (NT) color order system is a Hue–Tone color order systems. It can be used for determining surface colors with the same Tone (equiperceived lightness and equiperceived chroma) irrespective of hues under reference illuminant. The fundamental structure of NT system uses Munsell attributes HV/C for the easiness of its use. Some deviations caused by the approximation on chroma scale are naturally expected in NT system, although the formula used for deriving equivalent lightness Veq has the same structure as that for deriving L*eq using the corresponding CIELUV formula. The present article discusses the degree of approximation, and confirms the goodness of approximation. NT system can be used as it is for the field of artistic color design (complete accuracy is not required). The corrections, however, should be introduced in NT system, when higher accuracy is required. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 230–233, 2007 相似文献
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Shoji Tominaga Daisuke Nishioka Takahiko Horiuchi 《Color research and application》2015,40(4):329-340
An integrated spectral imaging system constructed by synchronizing a programmable light source, a high‐speed monochrome camera, and a display device is proposed to produce tristimulus images of static and moving objects effectively in real time onto the display. This system is called the CIE‐XYZ display. Active spectral illuminants, containing both the device characteristics of camera and display, are projected onto object surfaces as time sequence. The images are captured synchronously by the camera and quickly transmitted to the display device in the RGB signal form so that the accurate tristimulus images are displayed. First, we describe the principle of the CIE‐XYZ tristimulus display. The theoretically optimal illuminants contain negative parts in the spectral curves. Second, we design practical illuminants with all positive spectral curves. The color images in our system are composed of the time sequence of RGB component images. Then, the synthesized color images on the display contain color artifacts when objects move fast. An image processing algorithm for correcting the motion color artifact is proposed based on optical flow estimation using a graphics processing unit. The comprehensive performance of the proposed system and algorithms is examined using both static and moving objects. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 329–340, 2015 相似文献
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为保证注塑机注塑质量和加工精度,应对注塑机料筒温度进行精确控制,因此设计了基于可编程控制器(PLC)为核心控制器的注塑机温度控制系统。首先介绍了注塑机结构和注塑工艺流程,以PLC、触摸屏为控制器核心设计了注塑机硬件系统。采用热电偶传感器采集各段温度并传送到PLC中,通过比例积分微分(PID)智能控制算法完成温度的闭环精确控制。结果表明:基于PLC的注塑机PID多段温度控制系统能够实现温度的精确控制,温度误差能控制在±0.3℃以内;该控制系统完全满足注塑工艺要求,能够显著提高注塑机的自动化程度。 相似文献
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《Ceramics International》2023,49(20):32843-32849
Gradient index (GRIN) lens could promote the lightweight and miniaturization of optical imaging system, but the development of IR GRIN lens is still in its infancy. A new series of As–S–Se chalcogenide glasses (ChGs) possessing similar glass transition temperature, excellent thermal stability, and large refractive index variation was developed, and these properties enabled them to become a good glass material catalog for co-molding multilayered GRIN IR lens. By employing precision molding, layer-stacked GRIN ChG was co-molded with a maximum refractive index variation of 0.47 at 4 μm, which was correlated to the variation of Raman intensity and elemental content. A mid-IR optical imaging system was designed and fabricated using the GRIN ChGs, and IR images were obtained. This multilayered GRIN ChG could lead to 18% smaller and 35% lighter SWaP IR optical system. 相似文献