Image Fluctuations in LED Electromechanical 3D–Display

2018 ◽  
Vol 17 (02) ◽  
pp. 1850022
Author(s):  
Alexey V. Klyuev ◽  
Arkady V. Yakimov
Keyword(s):  
Steady State ◽  
Rotation Angle ◽  
Light Emitting Diode ◽  
3D Display ◽  
Constant Amplitude ◽  
Harmonic Oscillations ◽  
Light Emitting ◽  
Small Increment ◽  
The Stability ◽  
Periodic Changes

Fluctuations in parameters of light-emitting diode (LED) electromechanical 3D–display are investigated. It is shown, that there are two types of fluctuations in the rotating 3D–display. The first one is caused by a small increment in the rotation angle, which has a tendency to the increase. That occurs in the form of the “drift” without periodic changes of the angle. The second one is the change in small linear increments of the angle, which occurs as undamped harmonic oscillations with constant amplitude. This shows the stability of the investigated steady state because there is no tendency to increase the amplitude of the considered parameter regime. In conclusion we give some recommendations how to improve synchronization of the system.

scholarly journals Can Low-Level Laser and Light-Emitting Diode Enhance the Stability of Dental Implants?

2019 ◽  
Vol 19 (2) ◽  
pp. 302-306
Author(s):  
Hassan Mohajerani ◽  
Abolfazl Mohammad Salehi ◽  
Faraj Tabeie ◽  
Shervin Shafiei ◽  
Reza Tabrizi
Keyword(s):  
Dental Implants ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Low Level ◽  
Low Level Laser ◽  
Level Laser ◽  
The Stability

Battery Charge Affects the Stability of Light Intensity from Light-emitting Diode Light-curing Units

2017 ◽  
Vol 42 (5) ◽  
pp. 497-504 ◽  
Author(s):  
A Tongtaksin ◽  
C Leevailoj
Keyword(s):  
Light Intensity ◽  
Light Emitting Diode ◽  
Resin Composite ◽  
Bottom Surface ◽  
Light Emitting ◽  
Led Light ◽  
Battery Charge ◽  
Light Intensities ◽  
Light Curing ◽  
The Stability

SUMMARY This study investigated the influence of battery charge levels on the stability of light-emitting diode (LED) curing-light intensity by measuring the intensity from fully charged through fully discharged batteries. The microhardness of resin composites polymerized by the light-curing units at various battery charge levels was measured. The light intensities of seven fully charged battery LED light-curing units—1) LY-A180, 2) Bluephase, 3) Woodpecker, 4) Demi Plus, 5) Saab II, 6) Elipar S10, and 7) MiniLED—were measured with a radiometer (Kerr) after every 10 uses (20 seconds per use) until the battery was discharged. Ten 2-mm-thick cylindrical specimens of A3 shade nanofilled resin composite (PREMISE, Kerr) were prepared per LED light-curing unit group. Each specimen was irradiated by the fully charged light-curing unit for 20 seconds. The LED light-curing units were then used until the battery charge fell to 50%. Specimens were prepared again as described above. This was repeated again when the light-curing units' battery charge fell to 25% and when the light intensity had decreased to 400 mW/cm2. The top/bottom surface Knoop hardness ratios of the specimens were determined. The microhardness data were analyzed by one-way analysis of variance with Tukey test at a significance level of 0.05. The Pearson correlation coefficient was used to determine significant correlations between surface hardness and light intensity. We found that the light intensities of the Bluephase, Demi Plus, and Elipar S10 units were stable. The intensity of the MiniLED unit decreased slightly; however, it remained above 400 mW/cm2. In contrast, the intensities of the LY-A180, Woodpecker, and Saab II units decreased below 400 mW/cm2. There was also a significant decrease in the surface microhardnesses of the resin composite specimens treated with MiniLED, LY-A180, Woodpecker, and Saab II. In conclusion, the light intensity of several LED light-curing units decreased as the battery was discharged, with a coincident reduction in the units' ability to polymerize resin composite. Therefore, the intensity of an LED light-curing unit should be evaluated during the life of its battery charge to ensure that sufficient light intensity is being generated.

Electrically-Induced Light Emission in Polymer-Stabilized Proton Gradient Systems

2019 ◽  
Author(s):  
Jerzy J. Langer ◽  
Ewelina Frąckowiak
Keyword(s):  
Light Emission ◽  
Light Emitting Diode ◽  
Proton Gradient ◽  
Light Emitting ◽  
New Device ◽  
Polymeric Scaffold ◽  
Proton Current ◽  
The Stability ◽  
Polymer Stabilized

<div>Experiments with the chemically generated proton gradient, have lead to fabricate the system which emits the light, when electrically powered, owing to proton current flow. A polymeric scaffold preserves the stability of the system and, at the same time is playing a role of dopants of water, due to chemical character (acidic or basic) of side groups, which are responsible for gradient formation. The</div><div>results of experiments with the chemical model of the proton gradient, the protonic p-n junction, as a light emitting diode, make a “proof of concept”, which opens the way into new light generating process and new device (protonic LED), but also, to general understanding the proton gradient role in</div><div>the light emission processes.</div>

Stable CsPbX3@SiO2 Perovskite Quantum Dots for White-Light Emitting Diodes

2020 ◽  
Vol 15 (5) ◽  
pp. 599-606
Author(s):  
Jian Xu ◽  
Hongxiang Zhang ◽  
Chunxia Wu ◽  
Jun Dai
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Light Emission ◽  
Light Emitting Diode ◽  
Synthesis Method ◽  
Water Contact ◽  
Light Emitting ◽  
Perovskite Quantum Dots ◽  
The Stability ◽  
White Light Emitting Diodes

In this article, we reported the synthesis method of stable CsPbX3@SiO2 quantum dots using cesium acetate instead of cesium carbonate. The results showed that CsPbX3@SiO2 presents good crystallinity and excellent luminescence properties. The coating layer of SiO2 on the CsPbX3 quantum dots surface blocks the air and water contact and suppresses anion exchange between the quantum dots, which dramatically enhances the stability. White light-emitting diode devices are manufactured by integrating the green CsPbBr3@SiO2 quantum dots and red CsPbBr1 I2@SiO2 quantum dots on the blue GaN chips. The devices show stable white light emission with Commission Internationale de L'Eclairage color coordinates (0.3511, 0.3437), and the white light intensity keeps unchanged after continuously working for 16 hours. The results indicate that CsPbX3@SiO2 quantum dots can be an ideal down-conversion fluorescent material for white light-emitting diode devices.

Incorporating CsPbBr3 Nanocrystals into Porous AlO(OH) Matrices to Improve their Stability in Backlit Displays

NANO ◽  
2019 ◽  
Vol 14 (12) ◽  
pp. 1950156 ◽  
Author(s):  
Jiangcong Zhou ◽  
Yiqing Lai ◽  
Na Lin ◽  
Xiaotian Huang ◽  
Yu Chen ◽  
...  
Keyword(s):  
Surface Area ◽  
Light Emitting Diode ◽  
Ethanol Solution ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
Transmission Electron ◽  
Bet Specific Surface Area ◽  
Urgent Task ◽  
The Stability

Currently, the poor stability of inorganic perovskite CsPbX3 ([Formula: see text], Br, I) nanocrystals restricts their practical application in optoelectronic devices. Therefore, improving the stability of this material remains an urgent task for most researchers. In this study, incorporation of CsPbBr3 nanocrystals into porous AlO(OH) matrices through simple in situ synthesis was demonstrated to be an efficient approach for improving the nanocrystal stability. X-ray diffraction (XRD) revealed that the as-obtained product was composed of cubic CsPbBr3 nanocrystals and orthorhombic AlO(OH) compounds. In addition, transmission electron microscopy (TEM) revealed that the CsPbBr3 nanocrystals were successfully encapsulated by AlO(OH) matrices. The Brunauer–Emmett–Teller (BET) specific surface area was 234.96[Formula: see text]m2 g[Formula: see text] for AlO(OH) and 60.08[Formula: see text]m2 g[Formula: see text] for the CsPbBr3@AlO(OH) composites. The decrease in surface area could be attributed to the filling of the AlO(OH) pores by the CsPbBr3 nanocrystals. Further, the as-prepared composites showed red-shifted emission at 522[Formula: see text]nm and a larger full width at half-maximum (FWHM) as 26[Formula: see text]nm, compared with those of the CsPbBr3 nanocrystals with the emission at 517[Formula: see text]nm and FWHM as 17[Formula: see text]nm. More importantly, the emission intensity preserved 67% of the original value after a storage time of 120[Formula: see text]h, but bare CsPbBr3 nanocrystals rapidly degraded within only 1[Formula: see text]h in the polar ethanol solution. Finally, a light-emitting diode (LED) device was fabricated by coating the CsPbBr3@AlO(OH) composites and red commercial K2SiF6:Mn[Formula: see text] phosphors on the surface of a blue InGaN chip, covering 96% of National Television Standards Committee. The results indicate that the obtained composites could be promising luminescent materials for backlit displays.

scholarly journals Charge injection and transport properties of an organic light-emitting diode

2016 ◽  
Vol 7 ◽  
pp. 47-52 ◽  
Author(s):  
Peter Juhasz ◽  
Juraj Nevrela ◽  
Michal Micjan ◽  
Miroslav Novota ◽  
Jan Uhrik ◽  
...  
Keyword(s):  
Steady State ◽  
Light Emitting Diode ◽  
Charge Injection ◽  
Activation Energies ◽  
Transport Processes ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Steady State Current ◽  
Voltage Region

The charge behavior of organic light emitting diode (OLED) is investigated by steady-state current–voltage technique and impedance spectroscopy at various temperatures to obtain activation energies of charge injection and transport processes. Good agreement of activation energies obtained by steady-state and frequency-domain was used to analyze their contributions to the charge injection and transport. We concluded that charge is injected into the OLED device mostly through the interfacial states at low voltage region, whereas the thermionic injection dominates in the high voltage region. This comparison of experimental techniques demonstrates their capabilities of identification of major bottleneck of charge injection and transport.

Electrically-Induced Light Emission in Polymer-Stabilized Proton Gradient Systems

2019 ◽  
Author(s):  
Jerzy J. Langer ◽  
Ewelina Frąckowiak
Keyword(s):  
Light Emission ◽  
Light Emitting Diode ◽  
Proton Gradient ◽  
Light Emitting ◽  
New Device ◽  
Polymeric Scaffold ◽  
Proton Current ◽  
The Stability ◽  
Polymer Stabilized

<div>Experiments with the chemically generated proton gradient, have lead to fabricate the system which emits the light, when electrically powered, owing to proton current flow. A polymeric scaffold preserves the stability of the system and, at the same time is playing a role of dopants of water, due to chemical character (acidic or basic) of side groups, which are responsible for gradient formation. The</div><div>results of experiments with the chemical model of the proton gradient, the protonic p-n junction, as a light emitting diode, make a “proof of concept”, which opens the way into new light generating process and new device (protonic LED), but also, to general understanding the proton gradient role in</div><div>the light emission processes.</div>

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