Emissive Displays Research Articles

Enhanced Packaging for Reliability Improvement of P1.2 Mini-LED Emissive Displays in High Temperature and Humidity

Enhanced Packaging for Reliability Improvement of P1.2 Mini-LED Emissive Displays in High Temperature and Humidity

Flash Blindness Recovery for Pilots in the Modern Cockpit

Intense light can cause flash blindness, a temporary visual impairment. We investigated how various factors influenced time to recover from flash blindness for a task resembling reading a cockpit heading display. Prior studies used only reflective displays while modern cockpits now include emissive displays, so recovery differences between display types were of interest as was the influence of ambient luminance level. Flash blindness recovery times ranged from five seconds to two minutes. Greater flash intensity and smaller (higher acuity) letters led to longer recoveries. For the reflective display, as ambient luminance increased, flash intensity had weaker influence on recovery times and recovery shortened overall. For the emissive display (white at 16 cd/m2) however, ambient luminance did not appreciably modulate recovery times. The reflective display was more advantageous for flash blindness recovery in high (100 cd/m2) ambient luminance and the emissive display was more advantageous in low (1 cd/m2) ambient luminance.

52‐1: Blue‐Light Eye Safety Predictions under Ambient Light: ePaper Displays with Front Light vs. Emissive Displays

Blue light from displays may be hazardous to the viewer's eye. Although reflective ePaper displays can emit blue light if a LED front light is used, the reflection of ambient light effectively reduces its relative proportion in the display's total radiance spectrum. This is predicted by standard optical measurements of ePaper's emissive and reflective characteristics, combined with ambient illumination models. The beneficial effect of ambient light reflection is absent for emissive displays.

Advancing Touch Technology for Flexible Emissive Displays

AbstractAlthough on‐cell architecture improves optical and mechanical performance for flexible OLED displays used in mobile devices, it still poses major technical hurdles. Here, the human‐interface developer Synaptics explains its approach on these issues.

The persistent influence of viewing environment illumination color on displayed image appearance

Chromatic adaptation considering competing influences from emissive displays and ambient illumination is a little studied topic in the context of color management in proportion to its influence on displayed image appearance. An experiment was conducted to identify the degree to which observers adapt to the white point of natural images on an emissive display versus the color of ambient illumination in the room. The responses of observers had no significant difference from those of a previous experiment which was conducted with roughly the same procedure and conditions on a mobile display with a significantly smaller viewing angle. A model is proposed to predict the degree of adaptation values reported by observers. This model has a form such that it can be re-optimized to fit additional data sets for different viewing scenarios and can be used in conjunction with a number of chromatic adaptation transforms.

P‐211: Late‐News‐Poster: Quantum Dot Patterns in Molecularly Ordered Matrix for Emissive Displays with Wide Color Gamut

We demonstrate the quantum dot (QD) hybrid patterns produced from uniformly dispersed QDs in the host matrix with the molecular order. The molecular ordering of the liquid crystalline polymer (LCP) as a host medium plays a critical role on the uniform dispersion of the QDs. The uniformity of the QD patterns and the emission intensity are found to be greatly enhanced by the molecular order compared to the conventional cases. Our emissive color display composed of the QD hybrid patterns shows the emission spectra with the color gamut extended to 87 % of the BT.2020 standard. Our approach will provide a simple and viable method of constructing the QD‐based emissive display with wide color gamut in a cost‐effective manner.

Novel Fully Transparent Emissive Displays on Vehicle Glass

AbstractSun Innovations’ founder describes how his company developed a fully transparent projection display on a novel RGB emissive screen that is applied onto vehicle glazing and presents high‐quality emissive images both inside and outside the vehicle.

III‐Nitride Micro‐LEDs for Efficient Emissive Displays

AbstractEmissive displays based on light‐emitting diodes (LEDs), with high pixel density, luminance, efficiency, and large color gamut, are of great interest for applications such as watches, phones, and virtual displays. The high pixel density requirements of some emissive displays require a particular class of LEDs that are sub‐20‐micrometers in length, called micro‐LEDs. While state‐of‐the‐art emissive displays incorporate organic LEDs, an alternative is inorganic III‐nitride LEDs with potential reliability and efficiency benefits. Here we explore the performance, challenges, and prospective outcomes for III‐nitride micro‐LEDs to produce efficient emissive displays and provide insight to advance this technology. Calculations are performed to determine the operating points for the micro‐LEDs and the efficiency of the overall emissive display. It is shown that III‐nitride micro‐LEDs suffer from some of the same problems as their larger‐sized solid‐state lighting LED cousins; however, the operating conditions of micro‐LEDs can result in different challenges and research efforts. These challenges include improving efficiency at low current densities; improving the efficiency of longer wavelength (green and red) LEDs; and creating device designs that can overcome low coupling efficiency, high surface recombination, and display assembly difficulties.

56‐3: A novel Emissive Projection display (EPD) on Fully‐Transparent Phosphor Screen

A new paradigm of digital projection is on the horizon, based on innovative emissive screen that are fully transparent. It can be readily applied and convert any surface to a high image quality emissive display, without affecting the surface appearance. For example, it can convert any glass window or windshield to completely see‐through displays, with unlimited field of view and viewing angles. It also enables a scalable and economic projection display on a pitch‐black emissive screen with black level and image contrast that rivals other emissive displays such as plasma display or OLED.

19‐4: Invited Paper: Emissive Displays with Transfer‐Printed Microscale Inorganic LEDs

Major advances in flat panel displays can come from the pixel‐level integration of high performance microscale components fabricated on semiconductor wafers and transferred by advanced assembly methods onto large‐area substrates. Displays that use direct light emission from tiny inorganic light emitting diodes (µILEDs) have the potential to be very bright and power efficient. Transfer‐printing with elastomer stamps is a candidate assembly technology for making µILED displays, serving as the metaphorical bridge between the LED wafer and the display panel. This paper presents simple demonstrations of displays made from red, green, and blue µILEDs fabricated on gallium arsenide, silicon, and sapphire wafers, transferred to glass and plastic display substrates by transfer‐printing. The demonstrator displays exhibit interesting characteristics, including transparency, flexibility, repair‐ability, wide color gamut, and pulse‐width modulated active matrix driving schemes facilitated by transfer‐printed micro‐scale driver circuits.

Emissive Displays Rise and Fall – and Rise Again

Information DisplayVolume 32, Issue 6 p. 4-35 Guest EditorialFree Access Emissive Displays Rise and Fall – and Rise Again Qun (Frank) Yan, Qun (Frank) YanSearch for more papers by this author Qun (Frank) Yan, Qun (Frank) YanSearch for more papers by this author First published: 01 November 2016 https://doi.org/10.1002/j.2637-496X.2016.tb00947.xAboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume32, Issue6November-December 2016Pages 4-35 RelatedInformation

Power-Constrained RGB-to-RGBW Conversion for Emissive Displays: Optimization-Based Approaches

We propose an optimization-based power-constrained red-green–blue (RGB)-to-red-green–blue-white (RGBW) conversion algorithm for emissive RGBW displays. We measure the perceived color distortion using a color difference model in a perceptually uniform color space, and compute the power consumption for displaying an RGBW pixel on an emissive display. The central contribution of this paper is to formulate the optimization problem to minimize the color distortion subject to a constraint on the power consumption. Subsequently, we solve the optimization problem efficiently to convert an image in real time. Furthermore, based on the properties of the human visual system, we extend the proposed algorithm to image-dependent conversion that can preserve spatial detail in an input image. The simulation results show that the proposed algorithm provides a significantly less color distortion than the conventional methods, while providing a graceful tradeoff with the amount of power consumed. Specifically, it is shown that the power consumption can be reduced by up to 20%, while providing about 50% less color distortion than the conventional algorithms. In addition, a subjective evaluation on a real RGBW display is performed, which reveals the merits of the proposed image-dependent conversion for improving the perceptual quality over state-of-the-art techniques.

Character‐contrast measurements on emissive displays using replica masks under uniform ambient illumination

AbstractA replica‐mask method is presented to measure the contrast of character strokes on emissive displays under carefully controlled illumination. The method accounts for veiling glare introduced into the detector by the bright areas surrounding the dark characters. A sampling sphere is used to provide a uniform diffuse surround. Measurements of the diffuse reflectances are provided with specular included and with specular excluded. For emissive displays, the contrast depends both upon the darkroom characteristics of the emissive display and its reflective characteristics. Details are provided to replicate the measurement procedure.

Power-Constrained Contrast Enhancement for Emissive Displays Based on Histogram Equalization

A power-constrained contrast-enhancement algorithm for emissive displays based on histogram equalization (HE) is proposed in this paper. We first propose a log-based histogram modification scheme to reduce overstretching artifacts of the conventional HE technique. Then, we develop a power-consumption model for emissive displays and formulate an objective function that consists of the histogram-equalizing term and the power term. By minimizing the objective function based on the convex optimization theory, the proposed algorithm achieves contrast enhancement and power saving simultaneously. Moreover, we extend the proposed algorithm to enhance video sequences, as well as still images. Simulation results demonstrate that the proposed algorithm can reduce power consumption significantly while improving image contrast and perceptual quality.

Properties of Up Conversion Phosphors Necessary for Small Size Emissive Displays

Up converters combined with GaAs based semiconductor light sources are described as having potential for emissive displays with very large color gamut and very high resolution. To enable such displays the efficiency and temporal response of the up converting materials were studied and are reported. High efficiency is shown to be possible by proper preparation and utilization of the up converters. Up conversion displays can operate with refresh rates as high as 240 Hz. Operation as either a visible or near infrared display is possible.

Visualization and Computer Graphics on Isotropically Emissive Volumetric Displays

The availability of commodity volumetric displays provides ordinary users with a new means of visualizing 3D data. Many of these displays are in the class of isotropically emissive light devices, which are designed to directly illuminate voxels in a 3D frame buffer, producing X-ray-like visualizations. While this technology can offer intuitive insight into a 3D object, the visualizations are perceptually different from what a computer graphics or visualization system would render on a 2D screen. This paper formalizes rendering on isotropically emissive displays and introduces a novel technique that emulates traditional rendering effects on isotropically emissive volumetric displays, delivering results that are much closer to what is traditionally rendered on regular 2D screens. Such a technique can significantly broaden the capability and usage of isotropically emissive volumetric displays. Our method takes a 3D dataset or object as the input, creates an intermediate light field, and outputs a special 3D volume dataset called a lumi-volume. This lumi-volume encodes approximated rendering effects in a form suitable for display with accumulative integrals along unobtrusive rays. When a lumi-volume is fed directly into an isotropically emissive volumetric display, it creates a 3D visualization with surface shading effects that are familiar to the users. The key to this technique is an algorithm for creating a 3D lumi-volume from a 4D light field. In this paper, we discuss a number of technical issues, including transparency effects due to the dimension reduction and sampling rates for light fields and lumi-volumes. We show the effectiveness and usability of this technique with a selection of experimental results captured from an isotropically emissive volumetric display, and we demonstrate its potential capability and scalability with computer-simulated high-resolution results.

Review of the Properties of Up-Conversion Phosphors for New Emissive Displays

In this paper, we review the properties of up-conversion (UC) materials and assess their potential for a new display technology. UC materials absorb near infrared light and re-emit in the visible. Some of their most appealing characteristics for displays are: a wide color gamut with very saturated colors, very high brightness operation without damage to the emitters, long lifetimes and efficiencies comparable to those of existing technologies. Other advantages include simplicity of fabrication, versatility of operation modes, and the potential for greatly reduced display weight and depth.

P-73: Determining Power Consumption for Emissive Displays

Power consumption of an emissive display is directly influenced by image content. Therefore, when measuring display power consumption, it is important to select test targets that appropriately represent content that will be displayed within the application for which the display is intended. A model of display power consumption is used to understand the accuracy of various test targets for estimating average display power consumption for a defined application and to propose a technology-independent, but application-specific, method for measuring the average power consumption of a display.

A Dry Phosphor Screening Method for Emissive Displays Using a Tacky Photopolymer

A dry phosphor deposition method for emissive display screens using DuPont’s Tacky Dot photopolymer was developed. This tacky photopolymer, Cromalin, may be adhered to various substrates and patterned through the polymerization of the adhesive when exposed to UV light. It was found that Cromalin is activated at a wavelength of and has a patterning resolution of at least onto which phosphor particles were adhered. The phosphor loading characteristics and the decomposition properties of this adhesive material were evaluated to be suitable for emissive display screens. The degradation of the polymer in argon at was .

P-55: A Tacky Photopolymer for Dry Phosphor Screening of Emissive Displays

A dry phosphor screening process for emissive displays using DuPont's Tacky Dot® technology was developed and investigated. The photopolymer may be adhered to various substrates and patterned by polymerization through UV exposure. Then phosphor particles are loaded onto these patterns. The photopolymer's deposition, adhesion, and decomposition properties have been evaluated.