Improved Light Efficiency Research Articles

Vespa Motorcycle Lighting Modification Using AHP System With Fullwave Ignition

This study focuses on the modification of Vespa motorbike lighting by implementing the Aho system with Fullwave charging. The process involves replacing the regulator cable line with a Honda Tiger regulator to convert the AC lighting system to full wave. Additionally, the upgrade includes replacing the halfwave regulator with a fullwave kiprok type using 4 diode bridges to convert AC to DC current efficiently. LED lamps are also substituted for their energy efficiency and optimal performance with DC current. The research emphasizes the importance of enhancing lighting systems for motorcycle safety and compliance with traffic regulations. The findings highlight the benefits of these modifications in improving lighting efficiency and overall safety for Vespa motorbike users.

Double Path Pancake Optics for HMD to Improve Light Efficiency

Double Path Pancake Optics for HMD to Improve Light Efficiency

60‐4: Distinguished Paper: Novel Pancake‐Based HMD Optics to Improve Light Efficiency

Recently, compactness of Head Mounted Display (HMD) product has been strongly required to improve comfortableness of user. The folded optics, so‐called ‘Pancake optics', is suitable for realizing compact HMD, but there is a big drawback of lowering light efficiency. To overcome this problem, we propose novel pancakebased HMD optics named ‘Double path pancake optics' using two light paths. The optical simulation is performed and we fixed the appropriate design. From our simple evaluation of transmittance, we conclude that light efficiency of ‘Double path pancake optics' becomes 1.8 times higher than conventional pancake optics. We made the prototype using 1,200ppi high resolution Liquid Crystal Display (LCD) and confirmed that the high image quality can be displayed.

Non-integral model-based scatterometry for CD metrology of single high-aspect-ratio microstructures

This article presents an innovative model-based scatterometry method for CD metrology of single high-aspect-ratio (HAR) microstructures, which are increasingly utilized in advanced packaging, especially as vertical interconnects in three-dimensional integrated circuits. The rapidly growing aspect ratio of these HAR structures makes it challenging to monitor their critical dimensions (CD). Furthermore, conventional spectral reflectometry or scatterometry measurements on periodic metrology targets on the scribe lines of the wafer are inadequate in providing a reliable correlation with the in-die structures due to the integral nature of these measurements, which can result in additional measurement errors compared to measuring individual in-die structures. To address these challenges, we propose a novel scatterometry system that can achieve high-precision single-structure measurement of fine-pitch HAR structures with significantly improved light efficiency over conventional optical methods. Our system takes advantage of the high spatial coherence of the supercontinuum laser source and an optical NA-controlled design concept for precise light beam shaping, enabling high spatial resolution and superior light efficiency in measurements. Furthermore, we demonstrate a model-based measurement scheme that uses a virtual optical system for complete characterization of the sample profile. The experimental results show that the proposed system can accurately measure RDL structures with fine nominal spacing as small as 1 μm and an aspect ratio of 3:1 with high fidelity.

Novel pancake‐based HMD optics to improve light efficiency

AbstractRecently, compactness of head‐mounted display (HMD) products have been strongly required to improve comfortableness of user. The folded optics, so‐called “Pancake optics”, is suitable for realizing compact HMD, but there is a big drawback of lowering light efficiency. To overcome this problem, we propose a novel pancake‐based HMD optics named “Double path pancake optics” using two light paths. The optical simulation is performed to find highly optimized optical properties such as thickness, and field of view (FOV). As a result of the simulation, we fixed the appropriate design. From our simple evaluation of both brightness and transmittance, we conclude that light efficiency of “Double path pancake optics” becomes 1.8 times higher than conventional pancake optics. We made the prototype using 1200 ppi high resolution liquid crystal display (LCD) and confirmed that the high image quality can be displayed.

STUDY OF THE ILLUMINATION AND DEVELOPMENT OF RECOMMENDATIONS FOR ITS IMPROVEMENT

Goal. Investigate the existing methods of lighting rooms of various search purposes, make effective decisions on increasing the energy efficiency of electrical engineering systems of internal education through the implementation of automated education management systems and energy-efficient management algorithms, explain the principles of lighting construction using natural lighting and the application of modern technologies of familiar and modern lighting devices.
 Task. Analysis of existing technical solutions to increase the energy efficiency of the internal lighting system and substantiation of their energy efficiency indicators.Synthesis of the internal lighting control system of the administrative building. Development of algorithms for energy-efficient control of the internal lighting system taking into account external factors.
 The result of the study. The work is devoted to the analysis of lighting methods and devices used today, as well as the search for effective solutions to increase the energy efficiency of the electrical system of internal lighting due to the implementation of an automated lighting control system and energy-efficient control algorithms, an explanation of the principles of lighting construction using natural lighting and modern application technologies conventional and modern lighting devices, as well as methods of improving lighting efficiency using the latest technologies from existing lighting devices. The main attention is paid to the problems of the currently existing methods of artificial lighting of rooms in houses of various purposes, and to the solution of these problems with the most effective and real methods in practical use. This article may be useful for those interested in upgrading existing lighting or building a new lighting system with efficient use of electricity.
 Conclusions and practical significance. In this work, an analysis of existing energy-efficient technical solutions in interior lighting systems was carried out, based on the results of which it can be concluded that it is appropriate to use LED lamps in the lighting system due to their excellent indicators of luminous flux, light output, long service life and affordable price. It was also a source of various energy-saving methods in lighting systems, which can be attributed to: the introduction of half-light, LED lights and fluorescent lamps, the installation of electronic start-up control devices, more efficient use of light output, the introduction of a system of automatic lighting regulation depending on external factors and maintaining efficiency. education system.

Improving Lighting Efficiency for Traffic Road Networks: A Reputation Mechanism Based Approach

An urban smart lighting architecture allowing municipalities to manage and control public street lighting lamps is here considered. The system is capable to autonomously modulate the street lamps’ brightness in specific areas or segments of the urban roads of interest to reduce the energy consumption at the minimum allowed by regulations. To this end, a hybrid traffic model is proposed in this article to estimate in each segment of the roads the number of vehicles on which basis the lamps’ brightness minimization is accomplished. The traffic model represents a digital twin of the smart architecture that acts by orchestrating local dimmers, traffic lights, video cameras, and acoustic sensors. A bank of robust switching observers is used to estimate and classify the traffic in all segments. One agent at a time is selected from the bank and put in order. The agent selection is based on a distributed reputation mechanism recently developed for a class of networked systems. As one of its main merits, this methodology is capable to reveal those sensors that have the highest informative contents (Quality of Service) on the basis of their reputation (trust) shared among the agents. Finally, the proposed approach has been evaluated by considering a highly structured road network and, as one of its main results, the simulations show energy savings up to 70% with respect to the traditional street lamps management.

UV LED의 광효율 및 방열성능 향상을 위한 new packaging 특성 연구

Ultra Violet(UV) is gradually being replaced with LED instead of general UV lamps. However, the light efficiency of UV LED is still lower than that of the general lamp, and the light efficiency is also low. Due to the current environment and technical problems of UV lamps, the LED replacements are gradually being made. In this study, a new package design and analysis were performed to increase the lifetime and performance of UV LEDs. A new packaging for UV LED were designed and implemented. The new packaging for UV LED was constructed to improve light efficiency. And the electrical and optical characteristics were analyzed respectively. To improve the optical efficiency in UV LED package, the Al has been used based on high reflectivity and applying the optimal lens focusing. Compared to the existing silver Ag, the light efficiency was improved by about 30% or more, and it was confirmed that the light output degradation characteristic was improved by about 10% in the newly applied optical device chip.

52‐4: Novel Polarizer‐Free OLED Structure with High Optical Gain

With the recent increase in OLED usage, the size and shape of devices are diversifying. In addition, portability is becoming more important along with product performance and improvement. In order to enhance portability, it is necessary to improve battery performance and increase the time available without charging. To this end, it is required to reduce display power consumption, and various methods and structures for reducing power consumption by improving the efficiency of many OLED products have been proposed.Most OLED displays have a polarizer film applied to secure black viewing in the off‐state. However, this reflectance‐reducing film has a transmittance 50% or less, thus the light extraction efficiency is very bad.This paper introduces a simulation‐based design methodology of a new display that is devoid of polarizer film. It required the task of obtaining high outdoor contrast by reducing reflectance of external light with improved light efficiency. By separating the panel structure and optimizing optical filters and OLED devices, reflection reduction, efficiency improvement, and viewing angle characteristics were secured at the same time.The simulation‐based optical design methodology is an important technology that can simultaneously optimize the optical characteristics of new type of display, and is expected to be applied to various product developments in the future.

The effect of building retrofit measures on CO2 emission reduction – A case study with U.S. medium office buildings

Building retrofits have great potential to reduce CO2 emissions since buildings are responsible for 36% of emissions in the United States. Several existing studies have examined the effect of building retrofit measures on CO2 emission reduction. However, these studies oversimplified emission factors of electricity by adopting constant annual emission factors. This study uses hourly emission factors of electricity to analyze the effect of building retrofit measures on emission reduction using U.S. medium office buildings as an example. We analyzed the CO2 emission reduction effects of eight building retrofit measures that related to envelope and mechanical systems in five locations: Tampa, San Diego, Denver, Great Falls, and International Falls. The main findings are: (1) estimating CO2 emission reduction with constant emission factors overestimates the emission reduction for most measures in San Diego, while it underestimates the emission reduction for most measures in Denver and International Falls; (2) The same retrofit measure may have different effects on CO2 emission reduction depending on the climate. For instance, improving lighting efficiency and improving equipment efficiency have less impact in emission reduction in cold climates than hot climates; and (3) The most energy efficient measure may not be the most efficient emission measure. For example, in Great Falls, the most energy efficient measure is improving equipment efficiency, but the most efficient emission measure is improving heating efficiency.

Monolithic Light Reflector‐Nanowire Light Emitting Diodes

AbstractThe development of small size, ultracompact photonic devices is required for a wide range of applications, such as next‐generation automobile displays, micro‐light‐emitting diode (µ‐LED) TVs, smart phones and watches, virtual reality, and augmented reality. Here, for the first time, a new approach is reported to dramatically reduce the size of photonic device chips by using a monolithic light reflector‐nanowire LED system. Moreover, the vertical cavity nanowire structure for the surface‐lighting emission is developed by selective area epitaxy that can precisely control the gaps and diameters of the GaN nanowires. The light reflection is provided by high quality Al metal reflector which is directly deposited by molecular beam epitaxy (MBE) technique. The selective area growth shows uniform GaN heterostructure arrays with excellent crystal quality and desired aspect ratio. Furthermore, an advanced selective area etching process is introduced to fabricate Al mirrors between nanowire arrays. Significantly improved light efficiency is observed at ≈550 nm spectral wavelength from the monolithic Al light reflector‐vertical surface emitting nanowire LED system. To break the “green gap” bottleneck in III‐nitride photonics, the approach will open a new route toward monolithic, ultrasmall, electrically pumped nanoscale light emitters for next‐generation photonic and electronic devices.

Retracted: Research on measurement and energy efficiency improvement of flat panel display based on industrial control

In view of the fact that on flat panel display industrial production line, the power consumption is very important and determined by their different driving modes and light-emitting principles. Based on the industrial control systems, this paper analyses the power consumption of flat panel display, studies the main factors affecting its power consumption and analyses the main methods to improve light efficiency and reduce power consumption. This paper also discusses the focus issues in the current standard of flat panel display power measurement at home and abroad. According to the characteristics of different flat panel displays, this paper discusses the dual indexes of power consumption and efficiency in power measurement, and how to consider the influence of screen brightness and angle of view in the measurement.

Improving lighting efficiency in existing art museums: a case study

PurposeThe inappropriate lighting methods can have irreversible effects on artworks available in museums and exhibitions. Several factors affect the choice of the lighting system in the museums. By surveying all possible elements, this paper aims to propose a sustainability-based solution, as it relates to the development of artwork conservation, visual perception and energy efficiency during operation and maintenance (O&M).Design/methodology/approachThe paper elicits optimal solutions out of the method presented based on functions and expert opinion to improve lighting quality in existing museums. To study the optimization, the energy consumption and life cycle cost (LCC) in both the proposed lighting and the existing lighting system are compared using HoneyBee and LadyBug plugins in GrassHopper, as well as BLCC5 energy cost estimation software.FindingsThe results indicated a practical method to select the most suitable solution for museum lighting. By applying the proposed solutions obtained from the case study, a significant reduction in energy consumption and LCC were achieved. Besides, greenhouse gases were remarkably decreased.Practical implicationsProviding the proper lighting systems for each museum is the issue that is given special attention during the facilities management. The quality of the lighting, energy consumption and costs are analyzed by the simulation software. It is recommended that the validity considerations of the practice are examined.Originality/valueThe present study tried to present an optimal method to choose the best lighting system by the simultaneous utilization of theoretical and practical aspects. The functional model is also introduced for performing the most effective method to enhance the lighting techniques in the art museums.

Use of a rough GaP layer to improve light efficiency of 860-nm GaAs-based vertical-cavity surface-emitting laser

Abstract The effects of using a rough GaP layer to improve the light efficiency of 860-nm GaAs vertical-cavity surface-emitting laser were investigated. The light efficiency was significant increased by enlargement of current flow path caused from use of GaP layer grown on the top distributed Bragg reflector (DBR) of VCSEL. Furthermore, it was found that improved light efficiency significantly could be further increased by optimizing the surface morphology of the p-GaP layer fabricated in limited surface lighting area of VCSEL. Various surface morphologies could be obtained easily by controlling the RF power of an ICP dry etching. The highest output power of 34 mW was obtained from the VCSEL with a rough GaP layer fabricated at a RF power of 40 W introduced with BCl3 gas, showing a noticeable increase of ∼113% than a conventional one (16 mW). This result clearly insists that light efficiency of 860-nm GaAs based VCSEL could be increased effectively by using the rough GaP layer.

Improved Light Efficiency in Si Solar Cells by Coating Mesoporous TiO2 and Cu‐Modified Mesoporous TiO2

In the present work, an improvement in light‐conversion efficiency by coating spherical particles of mesoporous TiO2 (MT) and copper‐modified mesoporous TiO2 (CMT) on single‐crystalline Si solar PV cell is observed. The studies are carried out by spin coating with different concentrations of MT (0.25 to 1.5%) and CMT (0.25 to 1.0%) particles on bare cells independently and compared with a bare solar cell throughout the work. It is observed that in the case of MT coatings, the conversion efficiency increases initially and reaches a maximum of 9.77% at a coating concentration of 1.0%; thereafter, it decreases with an increase in coating concentration. This decrease in efficiency may be attributed to coagulation of MT particles, whereas in the case of CMT particles the conversion efficiency reached a maximum of 8.85% at 0.5% concentration and decreases thereafter. This study indicates that a higher efficiency can be achieved at lower concentrations of CMT coating compared to MT coatings on a bare solar cell. The increase in efficiency may be attributed to better surface passivation and/or trapping of electrons at the metal sites by Cu in CMT. Recombination lifetime measurements results corroborated that CMT particles show better surface passivation as a result of which there is an increase in efficiency. Diffused reflectance and short‐circuit current ratio versus wavelength studies on MT and CMT also revealed that CMT particles perform better than MT particles.

Flicker-Free Electrolytic Capacitor-Less Universal Input Offline LED Driver With PFC

Recent developments in improving lighting efficiency and cost reduction of LEDs have made them suitable alternatives to the current lighting systems. In this paper, a novel offline structure is proposed to drive LEDs. The proposed circuit has a high-input power factor, high efficiency, a long lifetime, and it produces no flicker. To increase the lifetime of the converter, the proposed circuit does not include any electrolytic capacitors in the power stage. The proposed circuit consists of a transition mode flyback converter in order to improve power factor. Additionally, a buck converter is added to the third winding of the flyback transformer in order to create two parallel paths for the electrical power to feed the output load. DC power reaches the load through one stage (flyback) and ac power reaches the load through two stages of conversion (flyback + buck). Therefore, in the proposed one-and-a-half stage circuit, the efficiency is improved compared to a regular two-stage circuit. Although the proposed structure has some output current ripple, it is low enough (less than 8%) that the structure can be rendered flicker free, as shall be discussed. Principles of operation and design equations are presented as well as experimental results for a 700 mA/20 W universal input prototype.

Investigation of a Scanning Laser Projector as an Energy-Efficient Light Source in Plant Production

The energy costs for artificial lighting in plant factories are very high, but may be decreased by introducing more efficient light sources. Light absorption in plants takes place in the order of a femtosecond, while the chemical reactions for carbon fixation of 5 milliseconds are limiting the processing of photons by the photosystems. In this article, the Showwx ™ scanning laser projector (0.1 W) was tested as an energy-efficient lighting source for cultivating lettuce (Lactuca sativa L. cv. Frillice). This projector uses a mirror where three laser beams are combined and scanned in diverging bi-directional pattern. The average pixel scan time is 20 nanoseconds, while the scanning of the complete projection takes 17 milliseconds. The laser projector was used for artificial lighting of lettuce seedlings (1 week after sowing) and bigger crops (4 weeks after sowing). The light levels were very low (10-20 μmol m -2 s -1 ) in order to adapt the illumination area of the laser projector to the plant area. A fluorescent lamp (8 W) was used as a reference light source and was mounted on a height, where an equal PPFD was measured at plant height. No differences in relative growth rate were observed in both experiments between the two light sources. A higher final fresh weight was observed for the seedlings illuminated using the scanning laser projector. This particular projector was considered to be not suitable as an artificial light source, but an improved scanning laser projector (with higher laser powers) provides opportunities to improve light efficiency and decrease production costs greatly.

Generation of Optical Vortices by an Ideal Liquid Crystal Spiral Phase Plate

An ideal spiral phase plate based on liquid crystals and two high resistivity layers is proposed and theoretically analyzed. The proposed structure generates a spiral-like voltage with simple voltage control. The liquid crystal layer produces an optical phase shift that depends on the voltage distribution. These two effects cause light passing through the device to be twisted like a corkscrew around its travel axis. Because of the continuous phase shift, the proposed device is expected to exhibit a conversion efficiency of ~100%. In addition, this device is more efficient and simpler than previously reported optical vortex generators. Moreover, the device is completely reconfigurable, i.e., the operating wavelengths and topological charges are tunable. The device can be used to reduce the fabrication costs of current devices and generate different orbital angular momentum modes with improved light efficiency, simplicity, and possibility of reconfiguration.

Intensifying the density of a horizontal electric field to improve light efficiency in a fringe-field switching liquid crystal display

The transmittance in fringe-field switching liquid crystal (LC) displays, which show a wide viewing angle, is dependent on the position along the electrode position. The reason for this is that the dielectric torque (and hence the twist angle) varies with position. This effect depends on the type of LC: a display using an LC with positive dielectric anisotropy has less transmittance than one with negative dielectric anisotropy. Furthermore, the transmittance decreases with decreasing cell gap. The difference between the LC types can be reduced and the transmittance can be improved greatly even for a low cell gap by optimizing the electrode structure to enhance the region of in-plane twist.

A novel configuration of LCD projectors for efficient orthogonal polarization of two projected views

In this paper, a novel configuration of LCD projectors for efficiently polarized stereoscopic projection with improved light efficiency is presented. In the proposed scheme, polarization orientations of the analyzers in the LCD engine of one projector are rotated by 90° with respect to those of the other one, so it causes to rotate orientations of polarized outputs by 90° as well as to change operational modes of LCD panels from the normally black mode to the normally white mode or vice versa. Then, by exchanging the green color components between the modified and original LCD projectors, two orthogonally polarized views for stereoscopic projection could be obtained without use of external polarizers. Analysis on the operational mode conversions of the LCD engines with rotation of the analyzers is discussed and its experimental results are provided.