MINISTRY OF EDUCATION AND TRAINING
VIETNAM ACADEMY OF SCIENCE AND TECHNOLOGY ----------------------------- GRADUATED UNIVERSITY SCIENCE AND TECHNOLOGY
DUONG THI GIANG RESEARCH AND DEVELOPMENT OF MICRO-NANO
OPTICAL MATERIALS AND FREE-FORM OPTICS
USING IN SOLID STATE LIGHTING
Major: Optical, optoelectronic and photonic materials
Code: 9440127
SUMMARY OF DOCTORAL THESIS IN MATERIAL SCIENCE
Ha Noi – 2020
The thesis has been completed at:
Graduated University of Science and Technology –
Vietnam Academy of Science and Technology
Science supervisors:
1. Ass. Prof. Tran Quoc Tien
2: Ass. Prof. Pham Hong Duong
Reviewer 1: …
Reviewer 2: …
Reviewer 3: ….
This thesis was defended at Evaluation Council held at
Graduated University of Science and Technology – Vietnam
Academy of Science and Technology on , 2020
The thesis can be further referred at:
- The library of Graduated University of Science and
Techonology
- National library of Viet Nam
1
INTRODUCTION
1. The necessity of the thesis
The process of urbanization is fast, people live and work mainly
indoors under artificial lighting. The artificial lighting environment is
different from natural light in terms of length, spectral structure, day
and night cycle, and the circadian rhythm of residents will be
reversed and cause a lot of physical health consequences, physiology
and psychology such as insomnia, obesity, poor physiology,
infertility, fatigue, even cancer. Therefore, creating a lighting
environment for humans to protect eyevision and health is essential.
In this thesis, I will systematically present problems to be
solved in the field of interior lighting, derived from the knowledge
about the role of light for people. Next is the design, manufacture
and application of solid lighting products on the basis of LED
combined with free-form optical components in interior lighting.
2. The research objectives of the thesis
Improve the usability and quality of LED-based lighting
products.
Develop a new generation of high-efficiency LED lights, evenly
distributed, eliminating light pollution, and replacing existing LEDs.
3. The main research content
Design and fabricate white LEDs with Remote-phosphor
configuration.
Calculate, design, simulate and fabricate free-form optical
components (FO) for used in solid lighting.
Design and fabricate SkyLED luminaires with integrated FO
lenses and build some realistic lighting models.
2
CHAPTER I. INTRODUCTION
1.1. Solid state lighting and LED light sources
Solid state lighting with a focus on LED light sources has
opened up a revolution in lighting where key contributors were
awarded the 2014 Nobel Prize in Physics, and in 2015 declared by
the International Union is the light year. With outstanding
advantages such as energy saving, high efficiency, ability to change
the structure of the emission spectrum, safety for the environment
and users, LED light source has become the main alternative light
sources replacing all other traditional light sources.
1.1.1. Working principle of LED
LED - Light-Emitting Diode. To create luminescent devices,
straight band gap semiconductors are used with two impurity types
donor (n type) and acceptor (p type), creating a zone called p-n
junction, while the device is called the diode.
In order to increase the quantum efficiency of components,
instead of using homogeneous semiconductors, people use
semiconductor materials with different band gap Eg to create a p-n
junction called a heterogeneous junction. When the p-n junction uses
a semiconductor material with a lower Eg sandwiched between two
materials with a higher Eg, the free carriers will be locked inside a
region with low Eg, called a quantum well. The quantum well
structure increases the recombination probability of the carrier,
which increases the luminescent efficiency of the component [3].
1.1.2. Phosphor materials
Phosphor-converted materials are very important components
that directly affect the quality and efficiency of the LED light source.
3
Commercial luminescent materials currently used for white LEDs
include: Garnet, Alluminat, Silicate and Nitride. The challenge for
material scientists and manufacturers is to reduce the emission
spectral width of these phosphors or to find new materials to replace.
1.1.3. White LED packages (WLED)
There are 3 way to fabricate WLED: 1) Using 4 types of LED
chips Blue - Amber - Green - Red combined together to form a
White LED Module ( RGBA-WLED); 2) UV LED chip combined
with Blue Green Red 3-color phosphor; 3) BLED chip combined
with 560nm yellow phosphor.
The phosphor-converted White LED (Pc-WLED) is the
configuration that plays a key role in today's LED packaging market
with the advantages: simplicity, high temperature resistance and
stable color quality.
1.1.4. LED luminaire
An LED luminaire (LED luminaire) used in general lighting is
composed of four components, which are the LED module, the
driver source, the heat sink, and the optics.
1.1.5. The characteristics of LED light suorces
Characteristics that evaluate the quality and effectiveness of
light sources are described by the following parameters: optical
parameters (luminous flux, power, optical efficiency), color
parameters (emission spectrum, color temperature correlation, color
rendering coefficient, color cleanliness), luminous intensity and
luminous intensity distribution.
1.2. Free-form optical Devices
1.2.1. Free-form optical devices
4
FO optics is the next generation of modern optics, offering
outstanding differentiation features and high system integration. FO
is defined as the optics of asymmetrical surfaces or of any shape,
designed with non-traditional technologies, including: rotating
symmetrical spherical or aspherical components (off-axis section),
non-standard rotating symmetrical profiles such as cones, arcs or any
other shape, and the FO component conforms to the geometry of the
system.
FO creates new opportunities for optical designers, while also
presenting challenges to fabrication technology and measurement
methods. FO is widely used in the fields of green technology, solid
lighting, aerospace, agriculture and biomedical. FO components have
the potential to revolutionize the optical industry, so now this is an
active research field in terms of both fundamental and applied
research as well as the development of processing tools,
measurement, shown through the number of more than 230
important publications, hundreds of patents and industrial products in
recent times.
1.2.2. FO applications in solid state lighting
The application of FO components in LED-based solid state
lighting technology is one of the most important in recent years due
to the benefits of solid state lighting technology in combination with
FO. However, the design of a non-imaging optical system requires a
new approach, especially because of the variety of optical
characteristics of different types of LEDs.
In the field of interior lighting, there are many studies focusing
on the design and application of smart lighting systems using LEDs
5
[49-51, 78-92], however the non-uniformity of luminance
distribution is still the weakness of solid lighting systems. Integrating
FO lenses with LED light sources for the purpose of evenly
illuminating the ceiling is a trend that attracts a lot of attention from
designers.
1.3. Lighting
1.3.1. Human vision
Recent research results show that the human eye is not only for
seeing, but also a means of connecting the human internal biological
clock with the Earth's rotation and the solar system.
In urban life, when artificial lighting environment is different
from natural light in length, spectral structure, there is no signal at
the beginning and the end of day, circadian rhythm will be reversed
and has many consequences for physical, physiological and mental
health.
1.3.2. Lighting pollution
In modern times and in big cities, people spend more and more
time in artificial lighting environments. The difference between
artificial light environment and natural light environment can be
considered as light pollution. As a result of these differences is one
of the causes of nearsightedness (myopia) and other human
physiological ailments such as poor performance, depression,
insomnia, heart disease, weight gain and even cancer [45]. Light
pollution factors derive from the limited functionality of the light
source types, as well as due to weaknesses in lighting design.
1.3.3. Human centric lighting
6
HCL-Human Centric Lighting- is the most important topic and
most actively discussed today, as the industrial revolution 4.0 comes
to life. Recent studies also show that the huge difference between the
natural light environment and the artificial light environment is one
of the causes of various types of distortion such as myopia,
amblyopia, and sleep, amnesia, depression, infertility ... [46, 59-64].
Scientists, R&D centers of lighting companies have many
researches, looking for new human centric lighting solutions, that is,
creating artificial lighting environments that are close to the natural
light environment that consistent with human circadian rhythms
[106-109].
In this thesis, I will focus on the research, design and fabrication
of new light sources based on LED light sources integrated with FO
components to solve pressing problems in lighting such as glare,
inconvenience, loss of rhythm, protect eyesight and health for users.
CHAPTER II. METHOD, TECHNIQUES AND
TECHNOLOGY
2.1. Calculate, design and simulate using assistant software
We used specialized software such as Excel, Origin to calculate
and analyze data, especially in the process of processing
measurement data of fluorescence spectra, reflection spectrum,
transmission spectrum...
To design optical or mechanical components, we have chosen
Solidworks software to design lens profiles, light trays and auxiliary
details such as headlamps, suspension bars...
After designing the lens profile, we conducted optical
simulation to evaluate the light redistribution efficiency of the optical
7
lens system using optical simulation software such as Optgeo,
Tracepro, Zeemax...
2.2. Techniques and technology
2.2.1. Fabricating FO prototypes
After designing the structure for FO components, we fabricate
FO prototypes using one of two technologies: CNC cutting from
PMMA materials and 3D printing using transparent optical
material.
The prototype after creating has many defects, which needs to
be completed by 3 methods: grinding and polishing; processing
temperature; optical coating. Experimental results for the optical
coating method gave the best results.
2.2.2. FO manufacture using plastic injection molding
technology
We use only thermoplastic injection technology in the
manufacture of FO lenses and other optical components in our LED
luminaire production chain.
The chosen materials for use depend on the needs and specific
use of the product. Specifically, the asymmetrical and narrow lens
sample is manufactured from PS material, while the lens for fish
lamps uses PC material.
2.2.3. Aluminum extrusion technology
For large-scale production, aluminum casting technology and
aluminum extrusion technology are used instead of CNC machine
tool cutting technology. We choose to design linear lamps with the
aim of saving costs, creating a competitive advantage when wanting
to commercialize the product.
8
2.3. Measurement and evaluated method
2.3.1. Methods and equipment for measuring characteristics
of materials
We have used some methods and equipment of the Key
Laboratory of the Institute of Materials Science to measure the
characteristics of materials and components. Fluorescence
measurement system investigates the emission spectrum of phosphor
materials for LEDs.
To determine the gloss of FO components after thermoplastic
injection molding, the FSEM scanning electron microscope is a
suitable device. Usually the gloss of optical components is about λ/5
to λ/10 equivalent to 100nm to 50nm.
2.3.2. Equipment for measuring characteristics of LED light
suorces
Intergrating sphere measuring system is a combination of
measuring devices including: intergrating sphere, spectrometer,
luminous flux probe, computer with display software support, used
to measure optical - electrical parameters of the light source.
Goniophotometer: is a device for measuring the distribution of
light intensity with angle. Measurements are standardized and stored
in IES format, where the luminance (unit of measure cd) is a function
of the projection angle.
2.4. Lighting model installation
Simulating the lighting environment using Dialux Evo
software
We used Dialux Evo simulation software to calculate the
lighting options for buildings to make the best choice. The actual
9
construction model gives the same results as the simulation when
choosing the simulation values close to the actual state of the model.
CHAPTER III. DESIGN AND FABRICATION OF WHITE
LED LIGHT SUORCE USING REMOTE-PHOSPHOR
CONFIGURATION
3.1. Introduction
Today's white LEDs are mainly produced by coating phosphor
directly onto blue LED chips. With this configuration, most of the
light comes out from the LED chip, fluorescent light is reflected
back and causes loss. The configuration to take the phopshor away
from the LED chip has been proposed by many authors, effectively
increasing lighting efficiency and lamp life [95, 96, 105]. In this
thesis, we have proposed and fabricated white LEDs with RP
(remote-phosphor) configuration that have superior features than
previously used configurations.
3.2. Design and fabrication of white LED light suorce with
RP configuration
3.2.1. Design white LED light suorce with RP
configuration
White LED remote - phosphor configuration uses a flat LED
plate designed by us includes the blue LED array as the source, the
radiator tube for the LED, a light guide plate covered with phosphor
+ scattering film, diffuser plate, reflector plate.
3.2.2. Design and fabrication of light guide plate
The novelty of the solution proposed by us in this solution is the
light redistribution and conversion structure that allows the creation
of a new, high-performance, non-glare light source. The selected
10
light guide plate is made by PMMA material with a rectangular
shape. Light beam will propagate along the plate due to the total
reflection effect at the interface between air (n=1) and optical medium (n=1.5) with the critical angle 42o. On the upper interface of guide plate, a matrix of extraction dots was printed using silk
screening technique. The shape, composition and size of the
extraction dots will determine the proportion of the composition of
the light coming out from surface of the light guide sheet.
The matrix of extractions dots is made by silk screen printing method of a mixture YAG:Ce3+ and EPI glue (a solvent used in screen printing technology).
3.2.3. Fabrication of white LED light suorce with RP
configuration
A light guide plate made of PMMA material with size 160x270x5 mm3 above is printed with extraction dots inserted into the slot of the heatsink, below is stuck with LED printed circuit. The
LED we choose to fabricate is Osram's OSLON with efficiency
about 56%. Different color RP-configured white LEDs have been
successfully fabricated (Figure 3.5).
Fig. 3.5. White LED lamps with RP configuration
11
3.2. Measuring and investigating optical parameters of RP-
configured white LEDs
The fluorescence imaging of the extraction dots showed that the
phosphor particles were unevenly arranged and clustered together,
forming a multilayer structure in some locations.
The measurement of the optical parameters of the luminaire
show that, when the phosphor ratio in the glue/phopshor mixture
increases, the CCT of the luminaire decreases, but the color
rendering coefficient (CRI) of the luminaire is almost unchanged. .
The CRI enhancement solution for luminaires is to add the red
phopshor component to the fabricated glue / phosphor mixture.
CHAPTER IV. COMPUTERING, DESIGN,
SIMULATION AND FABRICATION OF FREE-FORM
OPTICS
4.1. Design and simalution of free-form optics
By the ray drawing method, we simulated and selected
asymmetric lens (AL) profile and the optimal installation conditions
of the ceiling beacon to produce a secondary light source (ceiling
house) has the most uniform intensity of light in a fixed size room.
4.1.1. Design free-form optics profile
We started with 04 cylindrical AL lens profiles with cross
section as shown in Figure 4.1. The inner surface of the AL lens has
an asymmetric profile, with the refractive power increasing gradually
from the left side to the right side.
4.1.2. Simulating illuminance on the ceiling and on the floor
We simulated the intensity distribution on the ceiling and the
illumination distribution on the floor with the following conditions:
12
room size: 4x4m2, height 3m; distance from LED to ceiling: 0,4m; initial selected projection angle from the horizontal: 60o; optical detector placement: on the ceiling or on the floor.
Fig. 4.1. Designed lenses by modifying inner and outer curvatures
and thickness
The results of simulating the light intensity distribution on the
ceiling and the illuminance distribution on the floor show that for the
selected asymmetrical profile of 4 AL lens samples, the lens sample
with B4 profile gives the best result. This lens model has been
selected for further calculations of the distance and angle of the lamp
suspension.
4.1.3. Multiparameters optimization
After selecting the B4 profile, we continued to simulate the
dependence of the uniformity on the distance and projection angle to
optimize the lighting solution.
Distance factor optimization: We evaluated the lighting results for a 4x4x3m3 room by varying the distance from the lamp to the
13
ceiling. Simulation results show that uniformity increases with
increasing distance from lamp to ceiling.
Optimized projection angle: We evaluated the lighting results for a room with the size of 4x4x3m3, the distance from the lamp to the ceiling was 0,4m and the projection angle changed. The results show that the angle of 60o is optimal.
Conclusion: In [CT 1], we have proposed a ray drawing
simulation method to optimize the AL lens profile suitable for a
typical lighting model. The limitation of simulation method in the
project [CT 1] is that the criteria for selecting AL lenses with profiles
B1 to B4 are just comparing the illumination uniformity with each
other, not giving the total criteria.
4.2. Theoretical calculation to creat a criterion for lens
design
[CT 2] project proposes a different approach to indirect lighting
solution using LEDs to create a high uniform intensity distribution.
This is a theoretical analysis method to create a criterion for the
design of LED luminaires incorporating FO lenses with an ideal light
intensity distribution curve.
4.2.1. Modeling and theoretical analysis
Our model to be illuminated is a room with length many times
larger than width, whereby the ceiling is lighting by two LED light
sources with the length equal to the length of the room. The
illuminance on the ceiling will be calculated by the formula:
14
The width of the room is L and dividing into n parts of nx∆L.
The angles of θi and αi form between Li and the light source and between the right-edge Li and the side-wall, respectively.
We have investigated the effect of LED installation location and
room size on the illuminance distribution by varying parameters h
and L. The results show that when the h/L ratio increases, the
uniformity increases.
4.2.2. Alternative approach to uniform lighting system
We found it impossible to achieve an evenly distributed indirect
lighting system using two long conventional LED arrays. A
completely new design approach and theoretical approach is required
to create a room with a uniformly illuminated ceiling, becoming a
user-friendly secondary light source.
In order to obtain a perfectly uniform luminance distribution on
the ceiling when illuminated by two linear light sources from
opposite sides, all light sources that produce illuminance
distributions on the ceiling with a Logistic function satisfy this
condition. The Logistic function is represented as:
where L is the curve’s maximum value; k is the Logistic growth rate;
x is the distance; xo is the value of x at the midpoint of ceiling.
Figure 4.14 (a) illustrates the luminance distribution line in the
form of a function f (x) with speed k = 3 on a ceiling projected from
two opposite light sources. When both light sources work together,
the illuminance on the ceiling will be completely uniform due to the
15
superposition of the symmetrical beam across the center of the
ceiling. Figures 4.14 (c) and (d) illustrate the schematic of the
angular illuminance distribution ω between the light ray and the
horizontal direction, plotted in the perpendicular and polar
coordinates of an LED light source integrated with the FO lens
system with k values ranging from 1 to k = 5. It is found that the opening angle of the beam at half height is quite narrow (~ 12o) and is asymmetrical, extending to the right with a large angle ω.
Fig. 4.14. (a) The light distribution for both left and right LEDs
with k = 3; (b) the light distribution of the left LED source following
Logistic function for several k; and (c) and (d) luminous intensities
as the function of beam angle of the left LED source for several k
Conclusion: By the mathematical analysis method, we have
given the general formula for LED luminaires to achieve absolute
uniformity, based on Logistic function form with different k growth
rate. Calculation results in some cases from k = 1 to k = 5 show that
the larger k, the faster the variable speed, so to facilitate the design of
FO lenses, the small k value should be chosen.
16
Another result of the mathematical analysis method in [CT 2] is
the angular luminous intensity distribution diagrams of the lens-
integrated LED light source with different k growth rates. These
obtained theoretical luminance distribution plots allow direct
comparison with the measured luminance distribution plots of actual
luminaires.
4.3. Fabrication of free-form optical components 4.3.1. AL-Asymmetric lens Asymmetric profile lenses are empirically designed based on an idea that has been protected in Utility solution [GPHI- 11]. The AL lens profile is divided into three parts: the converging part is a half-convex cylindrical lens, the non- refractive transmission part is 1/4 cylindrical, and the flat base is used to attach into heatsink, drawn on Figure 4.19a. AL lens version V1 is made by thermoplastic injection molding method, with starting material is GP-PS (Figure 4.19 b).
Figure 4.19 a / (left) AL lens profile V1 version; b / (right) Lens photo V1 version made of GP-PS
4.3.2. NAL - narrow angle lens The V1 first version of the NAL narrow angle lens is designed based on the concept protected by the Utility Solution [GPHI 6], following the technological process employed to
17
make asymmetric lenses AL. The purpose of this Solution is to propose an LED structure with a limited illumination angle of less than 80o, while at the same time creating a uniform luminance distribution on the table top, in order to save energy and prevent glare for the student when they are looking at the board, it contributes to reducing the rate of refractive errors.
Fig 4.27. Light intensity distribution diagram simulated for LEDs with integrated NAL lenses (left) and the photo of NAL lenses made of GP-PS (right)
Figure 4.27 shows some NAL lenses fabricated by thermoplastic injection molding, along with a 3D image of the IES intensity distribution chart of lens integrated LED luminaires.
4.3.3. FO lens for fishing lamps FO lenses are the core difference of the fishing lamp that we designed and manufactured, in order to redistribute light on the sea surface. The cylindrical lens surface is divided into three parts including the converging part, the non-refractive transmission part and the base part used to attach the heatsink. Asymmetrical cylindrical lenses made by thermal injection have the dimensions 165mm long, 120mm wide and the cross- section as shown in Figure 4.29.
18
Fig. 4.29. Sample FO lens for fishing lamps
CHAPTER V. DESIGN, FABRICATION OF SKYLED LUMUNAIRES INTERGRATED FO LENSES AND INSTALLATION LIGHTING MODEL
5.1. LED luminaire incorporates asymmetric profile
lenses
5.1.1. Wall mounted SkyLED luminaires Wall mounted SkyLED luminaire designed by us (Figure 5.1) and manufactured (Figure 5.3) [SC7] uses an LED light source integrated with AL asymmetric lens to redistribute the light, etch to deal with the glare and inconvenience of existing lamps.
The optical - electrical parameters of the luminaire were measured on an intergrating sphere measuring system at the Institute of Materials Science. The results showed that the parameters of the luminaire met the specified standards: color temperature CCT 5054K, CRI ~ 85, optical efficiency E = 97lm/W, total power of the luminaire is 18W.
AL Lens
Driver
Heatsink
19
Module LED
Fig. 5.1. Structure of wall fixed SkyLED luminaire Fig. 5.3. The photo of wall fixed SkyLED luminaire
Luminaire’s luminance distribution was measured on the Goniophotometer measuring system at Quatest 1 Standard Measurement Center
5.1.2. SkyLED luminaire incorporated with NAL lens An Utility solution [GPHI 6] proposes an LED structure with a limited illumination angle of less than 80o, while at the same time creating an even illumination distribution on the table top, in order to save energy and prevent glare for students. When looking at the board, it contributes to reducing the rate of refractive errors.
5.1.3. Fishing Asymmetric Lens LED (FAL LED) The FAL LED - Fishing Asymmetric Lens LED - is designed by us including: an array of parallel LED arrays welded on the printed circuit board; a heatsink; a multi-lens array with an asymmetric structure (AL-Asymmetric Lens) parallel to each other; a transparent light housing to protect against dust and water ingress; a power supply unit with other accessories.
5.2. Human Centric Lighting Parameters of the lighting environment
20
including
intensity,
light
light
As the criteria for artificial lighting environments, we have conducted research on the characteristics of natural lighting environments spectrum structure, light distribution.
- Light quantity: from 500lux to 1000lux. - Light spectrum structure: using 3-color changeable SkyLED lights or smart SkyLEDs that continuously change color and intensity in the room.
- Light distribution: a wide angle of illumination (~ π sr) erases the shadow of everything and low luminance ensures a high amount of light.
- Circadian Rhythm: To create a day-and-night rhythm as suggested by HCL trend, we also utilize intelligent connected and controlled platforms for dynamic lighting with multiple packages different products.
5.3. Installation of realistic lighting models 5.3.1. Meeting rooms, classrooms The lighting model of the meeting room was simulated by us using Dialux software, whereby a 43-square-meter meeting room using 26 wall-mounted SkyLEDs, a total capacity of 468W, lighting power density of 11W/m2, achieves an average illuminance of 590lux. We installed a real model at Institute of Materials Science.
5.3.2. Apartments, houses The HCL Solution in the apartment creates a superior lighting efficiency compared to other traditional lighting solutions, while saving the cost of installation and long-term
21
use. The average illuminance reaches 500lux depending on the space used, with the energy density below 10W/m2, in accordance with the regulations of the Ministry of Construction issued (<13W/m2).
5.3.5. Anti-Myopia light box Concerning the factors causing the prevalence of myopia, to our knowledge, the excessive long time doing near works and bad lighting environment are the most important. Bearing on mind from the evolutional perspective, that light from natural sky is the best for human vision, we have designed and made prototypes of so called light box (Fig. 5.32) that mimics the day sky light.
Fig. 5.32. Structure of anti-myopia light box Fig. 5.33. Photo of the anti-myopic light box using 10 W SkyLED® with illuminance E=1000 lux
The main parameters of our light box are high and uniform illuminance E~1000lux; high and uniform background luminance (>200cd/m2); glare-free and shadow-free lighting environment. Furthermore, a mirror installed in the right corner will help to relax our eyes since the distant objects can be seen through it. The desk lamps of all kinds claimed “anti-
22
myopic” are not suitable to the expected functionality, since they don’t have the attributes of natural daylight environment.
CONCLUSIONS AND RECOMMENDATIONS CONCLUSIONS - We have successfully designed and fabricated Remote- phosphor-configured white LEDs using a flat guide light plate with matrix printing of light-emitting dots.
- We have calculated, designed, simulated and fabricated 3
types of free-form optical lenses:
+ gave a general theoretical model as a criterion to set up the simulation of SkyLED luminaires with uniform distribution and the results were published in international journals ISI [CT 1] and [ CT 2].
to create superior
lamps
+ has designed and fabricated FO lens prototypes: AL asymmetric lens, NAL narrow angle projection lens, lens for fishing luminance distribution features.
- We have designed and manufactured SkyLED luminaires
and installed some realistic lighting models.
+ have designed, manufactured SkyLEDs luminaire, LED fishing lamps, and black board washing lamp with various optical-electrical features, protected by intellectual property rights through Patents and Utility Solutions.
+ developed a Solution for HCL Lighting 5S, installed, measured and evaluated in about 100 projects with a total of 3.000 units. These solutions are ready for technology transfer.
23
RECOMMENDATIONS: The results obtained in the thesis are just the beginning of
a new human centric lighting trend - HCL Lighting.
This thesis was completed with the support of many aspects of the topics, projects, institutes and teachers as in the thank you section. For more widespread use in practice, we would like to continue the support of the Institute and the teachers, as well as support in all aspects of a research and development project.
NEW CONTRIBUTIONS OF THE THESIS Research method: We have given a general theoretical model as a criterion to simulate the design of SkyLED luminaires with uniform distribution.
The results of fabricating components: we have designed, simulated and fabricated three types of FO lenses: asymmetric AL lenses, NAL narrow-angle projection lenses, lenses for LED fishing lamps to creates superior luminance distribution features. These types of FO lenses redistribute light intensity, creating distinctive and superior features for LED light sources.
The results of manufacturing solid lighting sources: we have designed, simulated, manufactured, measured and evaluated 6 types of SkyLEDs, LED fishing lamps, and black board washing lamps with different optical-electrical features. SkyLED luminaires are used to uniformly illuminate ceilings and walls, eliminate glare, and improve lighting efficiency and comfort.
24
Lighting solutions: We installed HCL lighting solution and conducted installation and evaluation for about 100 projects of all kinds such as classrooms, meeting rooms, clinics, apartments, temples...
LIST OF PUBLICATIONS
[CT 1] D. T. Giang, T. Linh T., et al, A simple designed lens for Human Centric Lighting using LEDs, Appl.Sci., 2020, 10(1):343 (IF 2.49) [CT 2] D. T. Giang, T. Son P., et al, An alternative approach for high uniformity distribution of indoor lighting LED, IEEE Photonics J., Vol. 12, No 2, Apr. 2020 (IF 2.83)
[CT 3] P. H. Duong, D. T. Giang, P. H. Minh, 5S Human Centric Lighting
System, Advances in Applied and Engineering Physics (2019)
[CT 4] D. T. Giang, T. Q. Tien and P. H. Duong, Design and fabrication of LED blackboard washing luminaire combined with linear freeform lens, Advances in Applied and Engineering Physics (2019)
[CT 5] D. T. Giang, et al, Design and fabrication of high power LED fishing lamp combined with asymmetric lens, Advances in Applied and Engineering Physics (2019)
[GPHI 6] D.T. Giang, P.H. Dương, Bộ đèn LED tích hợp thấu kính thu hẹp góc chiếu sáng, Đơn đăng ký GPHI số 2-2017-00182, Đã được công bố đơn (2019)
[SC 7] D. T. Giang, P. H. Dương, Thiết bị chiếu sáng trần nhà tích hợp điôt phát quang và thấu kính bất đối xứng, Đơn đăng ký sáng chế số 1- 2018-03215, Đã được chấp nhận đơn (2018)
[SC 8] D. T. Giang, P. H. Dương, Đèn LED thả trần tích hợp thấu kính bất đối xứng, Đơn đăng ký sáng chế số 1-2019-03527, Đã được chấp nhận đơn (2019)
[SC 9] D.T. Giang, P.H. Dương, at el, Bộ đèn LED thả trần chiếu ba phía, Đơn đăng ký sáng chế số 1-2019-03403, Đã được chấp nhận đơn (2019)
[SC 10] D.T. Giang, P.H. Dương, L.A. Tú, P.H. Minh, Đèn LED dẫn dụ cá tích hợp thấu kính bất đối xứng, Đơn đăng ký sáng chế 1-2019-03021, Đã được chấp nhận đơn (2019)
[GPHI 11] D.T. Giang, P. H. Dương, Đèn LED chiếu sáng bảng tích hợp thấu kính bất đối xứng, Đơn đăng ký GPHI số 2-2016-00307, Đã được công bố đơn (2018)
[CT 12] D. T. Giang, L. A. Tú, at el, Thiết kế chế tạo đèn LED trắng cấu hình Remote-phosphor, Advances in Applied and Engineering Physics (2014), pp. 382-388
25
