Color Display Research Articles

Male nuptial display colour and vocalisation appear to signal independent information in the whirring tree frog

When different modes of communication are used in combination and for example convey visual and acoustic information, they form a multimodal signal. Frogs are best known for using acoustic communication, but many species also use visual or colour signals, some of which are dynamic, and may be combined with acoustic signals. In this context, the question of whether these two modes of communication reinforce the same message or offer different information is poorly understood. Male whirring tree frogs, Litoria revelata, use a multimodal signal during courtship, which combines a vocalisation and dynamic sexual dichromatism, with nuptial display colours shifting from brown or grey to bright yellow. Here, we examined the properties of the advertisement call and nuptial colour of vocalising male whirring tree frogs and tested whether the two signals were likely to reinforce each other or convey independent information. We found only weak associations between elements of male colouration and vocalisations, suggesting that advertisement calls and nuptial colour do not reinforce each other and that the signals may instead convey different information.Significance statementDynamic nuptial colour and vocalisation in combination is a relatively common multimodal signal in frogs but is unstudied. We looked for relationships between properties of colour and vocalisation in an Australian tree frog to explore whether the two sensory modes formed backup signals or multiple messages. We did not find predictive relationships between nuptial colour and vocalisation, supporting the multiple messages hypothesis and suggesting that nuptial colour is not necessarily directed at females for the purposes of mate attraction, potentially differing from the assumed function of the vocalisation. Our study is also the first to formally characterise aspects of dynamic sexual dichromatism in the whirring tree frog (Litoria revelata) and the first to describe the advertisement call of this species in its southern distribution. Whilst we do not specifically address the function of dynamic sexual dichromatism in this species, our findings do not contradict the existing literature in respect to it being a male-male directed signal.

18‐3: Computing Display Color Gamut Volume using Tetrahedra

We describes an approach to computation of display color gamut volume (sometimes called color volume). We describe two methods of partitioning color space into tetrahedra, and methods of aggregating the volume of tetrahedra. There some mathematical subtleties that need to be addressed to efficiently obtain the correct result. We discuss the constraints that guide a suitable choice of color space in which to perform the calculation. Our goal is to characterize the range of physical stimuli produced by a display. We want a perceptual measure of this volume, but we want the metric to cover the entire range of physical display stimuli, not just the range attained at a particular state of the viewer's adaptation. We comment on using CIE LAB or BT.2124 ITP5 as the underlying colorspace, and suggest that ITP is most useful.

Application of Artificial Light in the Interior Design of Green Lake City Cluster East Asia Residential House in Tangerang

The current residence is a primary need for humans, lighting is one of the requirements for humans to carry 
 out an activity, therefore lighting is also needed that supports human needs in living activity. In human 
 activities that require lighting, lighting itself is divided into two types, namely natural lighting and artificial 
 lighting. Natural lighting is lighting that comes from the sun as a source of light, while artificial lighting is 
 lighting that is produced by light sources other than natural light. Along with the times, artificial lighting has 
 various types of lamps, lighting procedures, lighting color display and color temperature. So that artificial 
 lighting is needed in order to achieve the ideal visual view for activities in every room.

Flowering phenology of species with similar flower colours in species-rich communities

Within a community, co-occurring plant species are expected to diverge in floral display or flowering phenology to decrease interspecific competition and thus increase intraspecific pollination. However, co-occurring species can also benefit from floral signal standardisation (similar colour signals among flowers of different species) because it facilitates pollinator attraction. Considering the interaction of flower colour display and flowering phenology, we investigated the visual similarity of rewarding flowers among species from highly diverse tropical and temperate vegetation types. For six groups of co-occurring, closely related bee-pollinated species with similar floral displays from Brazilian campo rupestre (51 species) and Spanish Mediterranean vegetation (30 species), we first investigated whether flower colours can be discriminated by bees based on colour locus distance in the bee vision hexagon. We then tested whether flowering phenology overlapped or was segregated. We found that within both vegetation regions, flower colour was generally not distinguishable within groups by bees. The small perceptual distance of colour loci in the bee visual space did not enable discrimination. The flowering periods of the Mediterranean species overlapped, while the Brazilian campo rupestre species tended to have segregated phenologies. Mediterranean species may benefit from the increased standardisation of signals displayed during the short flowering season, while the sequential flowering phenology of campo rupestre species may decrease interspecific competition and help maintain a recognizable signal for bees over time, favouring flower constancy. We concluded that the standardisation of the floral colour signal within these two species-rich plant communities is advantageous for most of the species studied, despite having different flowering phenologies.

Realization of efficient visual display and radiative cooling thermal emitter with cross-shaped metamaterials

Radiative cooling involves radiating heat into outer space through the atmospheric transparency window without energy consumption. However, the maximum cooling power will inevitably lead to the white color, which does not comply with the visual requirements and greatly hinders its application in color display. In this work, we have designed a novel colored radiative cooling emitter by depositing cross-shaped metamaterials on metal-insulator-metal (MIM). The top structure achieves an average emissivity of 95.6% in the atmospheric window and the bottom layer emits visible light to display a specific color. The adjustable visual display can be obtained with different thickness of the insulator layer. Controllable high emissivity can further be achieved with different incident angle in both TE and TM mode. Based on its unique cooling capacity and color display behavior, the logo of Zhengzhou University is well displayed with our colored radiative cooler. Compared with the traditional radiative cooler, this design has both esthetic and cooling advantages, and it has a broad prospect in various fields such as energy saving, cooling and color display.

Polyphenol‐Mediated Synthesis of Superparamagnetic Magnetite Nanoclusters for Highly Stable Magnetically Responsive Photonic Crystals

AbstractAchieving high stability and excellent optical performance in complex environments is crucial for practical applications of magnetically responsive photonic crystals (MRPCs). It, however, remains a great challenge. This study demonstrates a polyphenol‐mediated strategy for synthesizing size‐controllable superparamagnetic magnetite (Fe3O4) colloid nanocrystal clusters (CNCs) that can be stably dispersed in various polar solvents to form MRPCs with brilliant structural colors for a long term. As tannic acid (TA) functions as a linker to robustly bind polyvinylpyrrolidone (PVP) chains to Fe3O4 surfaces, the MRPCs can maintain nearly constant diffraction wavelength and high reflectance for up to 4 years. The strong coordination between TA and Fe3+ inhibits crystal growth, ensuring the small primary crystal size and superparamagnetism of Fe3O4@TA‐PVP CNCs. Partial oxidation of TA accelerates the crystal nucleation and growth, reducing the overall CNC particle size, which can be utilized for controlling the particle size. Additionally, enhancing the dissolution of PVP before the solvothermal reaction improves the size monodispersity of the products, making the as‐constructed MRPCs ideal for practical applications in color display, sensors, anti‐counterfeiting, and camouflage. The Fe3O4@TA‐PVP CNCs with high stability and versatility for surface‐functionalization are also promising for magnetic resonance imaging, targeting drug delivery, recyclable catalysis, and magnetic nanomotors.

Color‐Tunable Organic Light‐Emitting Displays for Interactive Multi‐Signal Visualization

AbstractOptoelectronic devices integrated with multiple functions for interactive signal visualization have become increasingly important in the intelligent era. Here, a color‐tunable organic light‐emitting diode (CTOLED) is developed to achieve a user‐interaction intelligent device that enables multicolor visualization of infrared light and temperature distribution via the modulation with a multi‐stimuli responsive silicon (Si) sensor for the first time. The key to the color‐tunable functionality of the CTOLED is an ultrathin exciton‐blocking layer between different emitting layers, which leads to the quantitative correlation of driving current and emitted visible color. As a result, the user can manipulate the silicon/color‐tunable organic light‐emitting diode (Si/CTOLED) device through the infrared pen, and the “writing” spatial information and the infrared intensity can influence the display patterns and colors. Besides, the temperature is sensed by the flexible Si/CTOLED device and is displayed in corresponding different colors, which is promising as a wearable temperature visualization monitor and directly interact with a user. The temperature monitor exhibits ultrasensitivity with a low minimum distinguishable temperature difference of only 65 mK. The Si/CTOLED devices open new possibilities for the development of intelligent devices and have promising multi‐disciplinary applications.

Electrochemical Control over the Optical Properties of II–VI Colloidal Nanoplatelets by Tailoring the Station of Extra Charge Carriers

An electrochemical (EC) method has been successfully applied to regulate the optical properties of nanocrystals, such as reducing their gain threshold by EC doping and enhancing their photoluminescence intensity by EC filling of trap states. However, the processes of EC doping and filling are rarely reported simultaneously in a single study, hindering the understanding of their underlying interactions. Here, we report the spectroelectrochemical (SEC) studies of quasi-two-dimensional nanoplatelets (NPLs), intending to clarify the above issues. EC doping is successfully achieved in CdSe/CdZnS core/shell NPLs, with red-shifted photoluminescence and a reversal of the emission intensity trend. The injection of extra electrons (holes) into the conduction (valence) band edges needs high bias voltages, while the passivation/activation process of trap states with the shift of Fermi level starts at lower EC potentials. Then, we explore the role of excitation light conditions in these processes, different from existing SEC research studies. Interestingly, increasing the laser power density can hinder EC electron injection, whereas decreasing the excitation energy evades the passivation process of trap states. Moreover, we demonstrate that EC control strategies can be used to realize color display and anti-counterfeiting applications via simultaneously tailoring the photoluminescence intensity of red- and green-emitting NPLs.

15.1: Invited Paper: Novel method for preparing blue perovskite light emitting pixel diodes

Traditional inkjet printing color quantum dot technology is to print red, green and blue quantum dot inks respectively, while perovskite material is ionic compound, and changing the halogen component can change the light color, which provides a new method for inkjet printing to realize color display. Here, we report a method for implementing blue devices by ion exchange between halogen‐containing inks and underlying perovskite quantum dot films by inkjet‐printing. This method can also be used for full‐color devices.

P‐10.1: Transfer Process of Micro‐LED Using Laser

Micro-LED display technology has the potential to become the next generation of display technology due to its advantages such as high brightness and self-illumination. Currently, micro-LED display technology still faces several important issues, including full color display and integration. In order to realize the display function, the micro-LED needs to be integrated into the drive circuit, which can be achieved through monolithic integration and massive transfer. Laser plays an important role in micro-LED transfer technology. In this work, laser is used to peel off the sapphire substrate, allowing an array of individual micro-LED devices to be transferred onto the blue film.

Application of InP Quantum Dot film by Photolithography Technology on a Micro-LED Display

The technical of realizing full-color display by monochromatic integrated 100 × 100 blue Micro-LED array exciting InP quantum dot color conversion layer is researched in this study. Using photolithography technology to prepare color film on a separate glass cover glass has the advantages of better accuracy and display resolution. The optimum thickness 12 μm of the quantum dot photoresist (QDPR) was verified and 10 μm black matrix (BM) was proposed to reduce the light crosstalk between different sub-pixels. The thickness of color filter 1 ± 0.4 μm was made successfully between the QDPR and the cover glass, which can greatly can significantly increase the display color gamut from 78.7% to 100.8% NTSC. The red and green brightness conversion efficiency reach up to 78.1% and 296.5% respectively. Representative RGB monochromatic pictures with 100% high yield were displayed successfully.

Data Analysis of Ceramic Material Color Matching Collection Points in Furniture Design Based on the Image Difference Prediction Model

The manufacturing process of ceramic materials and exquisite patterns is not simply artistic acts. At the same time, it condensed the excellent traditional culture of ancient China. The application of ceramic materials in modern furniture can not only enhance the taste of living room culture but also show the charm of China’s ceramic culture. Objective. To optimize the scientific data model required by traditional ceramic materials. On the basis of image difference prediction calculation, the data of ceramic material color matching collection points were analyzed and processed, and the image difference prediction model was established. This paper introduces the application and development of ceramic materials in furniture industry. On the basis of the traditional image difference prediction algorithm, the consideration of image difference and difference prediction expansion is added, and the image difference prediction calculation model of ceramic material color matching is established. The survey results show that 83% of customers are very satisfied with the color matching of new ceramic materials calculated by image difference prediction. This experiment uses image difference prediction model to remove the redundant pixels of ceramic material color and make multiple judgments on color display. According to the initial color data of the collection points, this experiment finally obtained a new combination color matching of ceramic wardrobe, which is more suitable for the “minimalist” and “quiet” styles.

Colorimetric and fluorometric ammonia sensor based on protonated bipyridyl-containing polydiacetylene

Chemical sensors based on stimulus-responsive chromogenic materials have found great importance due to their strong capability of manipulating optical properties and vivid color display. In this work, chromogenic polydiacetylene (PDA) is generated by the polymerization of protonated supramolecular assemblies of bipyridyl-containing diacetylene precursor (bpy-PCDA-H+). A blue-colored polymeric PDA of bpy-PCDA-H+ was obtained by UV irradiation of monomeric assembles. Since supramolecular architecture is preorganized through protonation-induced interactions of molecular blocks, bpy-PCPDA-H+ generated intriguing assembly-related sensory response via deprotonation mechanism, producing distinctive blue to red chromatic transition and fluorescence turn-on response against ammonia. The self-assembly behavior, topochemical polymerization, and ammonia sensing properties of bpy-PCPDA-H+ were investigated using spectroscopic methods.

Synthesis of SiO2-coated perovskite quantum dots for micro-LED display applications

Cadmium quantum dots (QDs) have good luminous properties, but cadmium is toxic. So, cadmium-free perovskite QDs were synthesized by chemical solution methods, realizing the new structure of the green CsPbBr3/Cs4PbBr6 perovskite QDs. The SiO2 layer passivated the perovskite QDs by the sol-gel method and hydrolysis of tetramethoxysilane (TMOS) and then dispersed in a polar solvent to facilitate mixing with negative photoresist (SU8-3010) to ensure their luminous properties are not affected by moisture and oxygen. Afterward, perovskite QDs were exposed and developed on the glass substrate by a photolithography process. The pixels were spaced apart through the black matrix to reduce the crosstalk between each other. Applying the pixelated perovskite QDs to the blue light micro-light-emitting diodes (LED) display as the color conversion layer showed that excessive blue light could penetrate through the green pixels, decreasing color purity. Therefore, we used a 23-layer distributed Bragg reflector (DBR) to reflect excess blue light on pixels back to perovskite QDs. DBR did not filter the green light, and the actual luminous intensity of green light increased by 118%, and the transmittance of blue light was only 0.5%. Finally, the alignment attaching of the graph pixelated perovskite QDs on a glass substrate to the blue light display realized monochrome/area color and full-color micro-LED display.

Time-course analysis of change in display color-appearance based on ambient light change

This study investigates the time course of changes in display color appearance according to changes in ambient lighting. Psychophysical experiments were conducted to observe brightness under lighting transitions in illuminance and the perceived white point under lighting transitions in correlated color temperatures. The result shows that significant change in the color appearance occurs immediately after ambient lighting changes. In addition, the initial change in color appearance depends on the lighting transition characteristics. The continuous change in color appearance was observed when ambient lighting was changed to brighter or lower CCT. On the other hand, a significant abrupt change at the initial stage of adaptation was observed when ambient lighting was changed to darker or higher CCT.

Melanopic irradiance defines the impact of evening display light on sleep latency, melatonin and alertness

Evening light-emitting visual displays may disrupt sleep, suppress melatonin and increase alertness. Here, we control melanopic irradiance independent of display luminance and colour, in 72 healthy males 4 h before habitual bedtime and expose each of them to one of four luminance levels (i.e., dim light, smartphone, tablet or computer screen illuminance) at a low and a high melanopic irradiance setting. Low melanopic light shortens the time to fall asleep, attenuates evening melatonin suppression, reduces morning melatonin, advances evening melatonin onset and decreases alertness compared to high melanopic light. In addition, we observe dose-dependent increases in sleep latency, reductions in melatonin concentration and delays in melatonin onset as a function of melanopic irradiance—not so for subjective alertness. We identify melanopic irradiance as an appropriate parameter to mitigate the unwanted effects of screen use at night. Our results may help the many people who sit in front of screens in the evening or at night to fall asleep faster, feel sleepier, and have a more stable melatonin phase by spectrally tuning the visual display light without compromising the visual appearance.

Measurement of individual color space using a luminous vector field.

This study is intended to measure the geometry of the observer's color space when viewing a computer screen and to define individual variations from these data. A CIE photometric standard observer assumes that the eye's spectral efficiency function is constant, and photometry measurements correspond to vectors with fixed directions. By definition, the standard observer decomposes color space into planar surfaces of constant luminance. Using heterochromatic photometry with a minimum motion stimulus, we systematically measure the direction of luminous vectors for many observers and many color points. During the measurement process, the background and stimulus modulation averages are fixed to the given points to ensure that the observer is in a fixed adaptation mode. Our measurements result in a vector field or set of vectors (x,v), where x is the point's color space position, and v is the observer's luminosity vector. To estimate surfaces from vector fields, two mathematical hypotheses were used: (1)that surfaces are quadratic or, equivalently, that the vector field model is affine, and (2)that the metric of surfaces is proportional to a visual origin. Across 24 observers, we found that vector fields are convergent and the corresponding surfaces are hyperbolic. The equation of the surface in the display's color space coordinate system, and in particular the axis of symmetry, varied systematically from individual to individual. A hyperbolic geometry is compatible with studies that emphasize a modification of the photometric vector with changing adaptations.

Strain visualization enabled in dual-wavelength InGaN/GaN multiple quantum wells Micro-LEDs by piezo-phototronic effect

Optical strain sensor for stress visualization is a significant topic in biomechanical imaging or electronic skin. In this study, the dual-wavelength InGaN/GaN multiple-quantum-wells (MQWs) micro light emitting diode (Micro-LED) is demonstrated with color response under mechanical stimulation by piezo-phototronic effect. The peak intensity of green light increases by about 37%, while the blue decreases by 10% at the external strain of 0.20%. Simultaneously, the intensity integral ratio of green and blue light changes from 43:57–53:47, leading to the display color shift from light blue to turquoise significantly. It is noted that electrical injection shows a greater color response than photoluminescence, indicating that the piezo-phototronic effect changes both the recombination in MQWs and the carrier injection. The different piezoelectric modulation between green QW and blue QW lies on the different strain-induced piezoelectric polarized charges in the interface of InGaN QWs, revealed by experiments and APSYS simulation in details. This study is of high significance for the development of optical-based stress sensor with strain visualization and high spatial resolution for smart sensing and micro-opto-electromechanical systems.

Resonance dependence of electrically reconfigurable VO2-based THz metadevice for memory information processing

A terahertz hybrid metamaterial incorporated with active media VO2 holds great promise for the realization of a new generation of reconfigurable and multifunctional devices. However, for the electrical control, many efforts on reducing high working threshold are usually based on the utilization of patterned VO2 patches or additional insulation layers, which will increase the complexity of the fabrication procedure. Here, we have proposed an effective strategy only by combining the surface microstructure and the unpatterned VO2 film to realize the tunability of working current and uncover its highly dependent correlation with the structural resonance responses. It is shown the fully modulated current in our hybrid metastructures can be reduced with the prominently separated hysteresis loops. Further developed binary encoders can perform not only the information transformation of the fixed code symbols but also the arbitrary encoding with the programmable current pulse. Additionally, the dynamic color display can be accomplished to illustrate the intriguing function of the information encryption and multi-image reappearance with the current as the decryption key. Our work provides an approach to reduce the operating current and paves a pathway for the development of photonic memory information processors.

Customized Structural Color Filters by Pixel‐Level Electrothermal Regulation

AbstractReflective structural colors have backlight‐free supremacy and can provide energy‐efficient and environmental‐friendly color production for many applications. However, they are hindered by the complex process and incorrect colors after fabrication. Here, a pixelated electrothermal oxidation technique is proposed that can precisely tailor and produce reflective structural colors covering the entire visible range, providing the possibility for customized structural color filter arrays from a titanium canvas. Furthermore, as a demonstration, a photonic‐firework‐like color filter array is achieved in a single step via thermal engineering. Based on this one‐step‐forming color array, a computational spectrometer is also realized featuring a resolvability of 10 nm and operating bandwidth covering the whole visible range. Considering its compactness and mass production capability, this method has numerous potential applications in, e.g., imaging, anti‐counterfeiting, printing, color display, and spectroscopy.