Fabrication of a Beam Shaping Lens for Chip Scale Packaged LEDs

2010 ◽  
Vol 447-448 ◽  
pp. 101-105 ◽  
Author(s):  
Jae Young Joo ◽  
Chang Suk Kang ◽  
Soon Sub Park ◽  
Sun Kyu Lee
Keyword(s):  
Optical System ◽  
Fresnel Lens ◽  
Beam Shaping ◽  
Machining Process ◽  
Viewing Angle ◽  
Form Error ◽  
Aspheric Lens ◽  
Light Emitting ◽  
Blue Chip

In this paper, we demonstrated the machining process of a novel Light Emitting Diodes (LED) beam shaping lens, called TIR Fresnel lens, for GaN-based blue Chip Scale Packaged (CSP) LEDs. Upon achieving a precise alignment of the tool and identifying the best manufacturing condition, we have successfully fabricated a prototype of this lens on poly methyl methacrylate (PMMA) plate. The form error of the central aspheric lens was less than 1 μm deviation, and surface quality of the Fresnel facets were sufficient for Total Internal refraction without any burr or adhesion of the machined chip. Fabricated TIR Fresnel lens reduced the viewing angle of the testing CSP LED from 140° to 17.4° in FWHM. The proposed lens produced extreme compactness as well as high collimation efficiency, thereby applicable to an ultra-thin optical system.

Efficient All-inorganic Perovskite Light-emitting Diodes Enabled by Manipulating Crystal Orientation

2021 ◽  
Author(s):  
Wenjing Feng ◽  
Kebin Lin ◽  
Wenqiang Li ◽  
Xiangtian Xiao ◽  
Jianxun Lu ◽  
...  
Keyword(s):  
Active Layer ◽  
Crystal Orientation ◽  
Light Emitting Diodes ◽  
Metal Halide ◽  
Device Performance ◽  
Light Emitting ◽  
Inorganic Perovskite ◽  
Metal Halide Perovskite ◽  
Halide Perovskite

Metal halide perovskite light-emitting diodes (PeLEDs) are promising in lighting and display application, and the corresponding device performance is highly dependent on the film quality of the active layer. However,...

scholarly journals Holographic Display System to Suppress Speckle Noise Based on Beam Shaping

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 204
Author(s):  
Di Wang ◽  
Yi-Wei Zheng ◽  
Nan-Nan Li ◽  
Qiong-Hua Wang
Keyword(s):  
Optical Element ◽  
Speckle Noise ◽  
Beam Shaping ◽  
Diffractive Optical Element ◽  
The Other ◽  
Spatial Light Modulators ◽  
Viewing Angle ◽  
Display System ◽  
Holographic Display ◽  
Light Modulators

In this paper, a holographic system to suppress the speckle noise is proposed. Two spatial light modulators (SLMs) are used in the system, one of which is used for beam shaping, and the other is used for reproducing the image. By calculating the effective viewing angle of the reconstructed image, the effective hologram and the effective region of the SLM are calculated accordingly. Then, the size of the diffractive optical element (DOE) is calculated accordingly. The dynamic DOEs and effective hologram are loaded on the effective regions of the two SLMs, respectively, while the wasted areas of the two SLMs are performed with zero-padded operations. When the laser passes through the first SLM, the light can be modulated by the effective DOEs. When the modulated beam illuminates the second SLM which is loaded with the effective hologram, the image is reconstructed with better quality and lower speckle noise. Moreover, the calculation time of the hologram is reduced. Experiments indicate the validity of the proposed system.

scholarly journals Increased Plant Quality, Greenhouse Productivity and Energy Efficiency with Broad-Spectrum LED Systems: A Case Study for Thyme (Thymus vulgaris L.)

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 960
Author(s):  
Jenny Manuela Tabbert ◽  
Hartwig Schulz ◽  
Andrea Krähmer
Keyword(s):  
Broad Spectrum ◽  
Energy Savings ◽  
Light Emitting Diode ◽  
Thymus Vulgaris ◽  
Light Spectrum ◽  
Light Emitting ◽  
Biomass Yields ◽  
Lighting Systems

A light-emitting diode (LED) system covering plant-receptive wavebands from ultraviolet to far-red radiation (360 to 760 nm, “white” light spectrum) was investigated for greenhouse productions of Thymus vulgaris L. Biomass yields and amounts of terpenoids were examined, and the lights’ productivity and electrical efficiency were determined. All results were compared to two conventionally used light fixture types (high-pressure sodium lamps (HPS) and fluorescent lights (FL)) under naturally low irradiation conditions during fall and winter in Berlin, Germany. Under LED, development of Thymus vulgaris L. was highly accelerated resulting in distinct fresh yield increases per square meter by 43% and 82.4% compared to HPS and FL, respectively. Dry yields per square meter also increased by 43.1% and 88.6% under LED compared to the HPS and FL lighting systems. While composition of terpenoids remained unaffected, their quantity per gram of leaf dry matter significantly increased under LED and HPS as compared to FL. Further, the power consumption calculations revealed energy savings of 31.3% and 20.1% for LED and FL, respectively, compared to HPS. In conclusion, the implementation of a broad-spectrum LED system has tremendous potential for increasing quantity and quality of Thymus vulgaris L. during naturally insufficient light conditions while significantly reducing energy consumption.

FEA-Methodology for the Prediction of Aluminium Thin Walled Part Deformation in Dry Milling Operations

2011 ◽  
Vol 223 ◽  
pp. 662-670 ◽  
Author(s):  
Hendrik Puls ◽  
Fritz Klocke ◽  
Dieter Lung ◽  
Ralf Schlosser ◽  
Peter Frank ◽  
...  
Keyword(s):  
Mechanical Load ◽  
Machining Process ◽  
Dry Milling ◽  
Collaborative Project ◽  
Power Train ◽  
Automotive Engine ◽  
Milling Operations ◽  
Thin Walled ◽  
The Eu

The presented work is a part of the EU integrated and collaborative project “Aligning, Holding and Fixing Flexible and Difficult to Handle Components” (AFFIX). The deformation of thin-walled components, caused by a thermo-mechanical load in the machining process, is a common challenge in manufacturing automotive engine heads and gearboxes. Geometrical tolerances like flatness are strongly affected by the thermo-mechanical process loads, and therefore cause production scraps and serious engine faults in case of undetected defects. To avoid long process setup times, a methodology has been developed to calculate the resulting part flatness. Based on the developed methodology a clamping strategy has been identified which minimises the resulting part deformation in milling operations and thus ensures the accuracy and quality of thin-walled aluminum power train parts.

Image quality of a novel light-emitting diode (LED)-illuminated colonoscope

Endoscopy ◽  
2016 ◽  
Vol 48 (10) ◽  
pp. 934-938 ◽  
Author(s):  
Sho Sasaki ◽  
Jun Nishikawa ◽  
Hideo Yanai ◽  
Munetaka Nakamura ◽  
Junichi Nishimura ◽  
...  
Keyword(s):  
Image Quality ◽  
Light Emitting Diode ◽  
Light Emitting

scholarly journals Analysis of Forces in Vibro-Impact and Hot Vibro-Impact Turning of Advanced Alloys

2011 ◽  
Vol 70 ◽  
pp. 315-320 ◽  
Author(s):  
Riaz Muhammad ◽  
Agostino Maurotto ◽  
Anish Roy ◽  
Vadim V. Silberschmidt
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
Three Dimensional ◽  
Element Model ◽  
Machining Process ◽  
Strain Rates ◽  
Machining Processes ◽  
Machined Surface ◽  
Cutting Zone

Analysis of the cutting process in machining of advanced alloys, which are typically difficult-to-machine materials, is a challenge that needs to be addressed. In a machining operation, cutting forces causes severe deformations in the proximity of the cutting edge, producing high stresses, strain, strain-rates and temperatures in the workpiece that ultimately affect the quality of the machined surface. In the present work, cutting forces generated in a vibro-impact and hot vibro-impact machining process of Ti-based alloy, using an in-house Ultrasonically Assisted Turning (UAT) setup, are studied. A three-dimensional, thermo-mechanically coupled, finite element model was developed to study the thermal and mechanical processes in the cutting zone for the various machining processes. Several advantages of ultrasonically assisted turning and hot ultrasonically assisted turning are demonstrated when compared to conventional turning.

Syntheses of a Green Organic Phosphorescence Materials and Studies on their Photoluminescent Properties

2012 ◽  
Vol 455-456 ◽  
pp. 880-883
Author(s):  
Lian Ying An ◽  
Zheng Guo Zhang ◽  
Xian Yin Zhao
Keyword(s):  
Raw Materials ◽  
Green Light ◽  
Fluorescence Spectrometry ◽  
High Brightness ◽  
Light Emitting ◽  
Spectrometry Analysis ◽  
New Synthesis ◽  
Optical Luminescence ◽  
Designed Synthesis

Using the second o-nitro aniline and benzoyl chloride as the initial raw materials, a green light-emitting materials (pbi)2Ir (acac)2 was produced utilizing a new designed synthesis plan. The complex’s structures were characterized by IR, MS, and the differential thermal analysis. The optical Luminescence Properties of the complex was studied by the fluorescence spectrometry analysis. The melt point of the product is 343°C which showed that it had thermal stability.. The fluorescence spectrometry analysis experimental results show that the Excitation and emission peaks of the organic Iridium (Ⅲ) complexes got were respectively 470.6nm and 526.21nm which showed that it belong to green high-brightness light-emitting materials. The oxidation of the intermediate products exposed in air which could cause the quality of product instability was avoided in the new synthesis plan improved.

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