Use of lighting performance characteristics of the object itself, it can be natural objects or scenic spots, it can be ancient buildings or modern buildings.
LED lights how to show characteristics of the building
Monumental architecture: monumental architecture are some of the artistic, aesthetic features of the building, such as Buckingham Palace in London, France Arc de Triomphe and the Eiffel Tower, the Statue of Liberty in New York and Beijing bronze statue of Chairman Mao Memorial Hall, People’s Heroes Monument, Great Hall, etc., night lighting so that they, too majestic.
Neighborhood: main plaza surrounding the pavement lighting, showcase lighting, advertisement sign lighting and street lighting integrated static and dynamic combination of shapes, three-dimensional staggered, colorful, have shown a bustling scene, thereby increasing vitality .
Art View: Landscape Art based on a variety of raw materials or materials created objects, there are purely decorative role, such as statues, reliefs, gatehouse and some of the landscape, such as listening to music, to these landscapes to decorate or embellishment space, night lighting more students Hui.
Water View: eg fountain, fountains, wells and artificial lakes, etc., they and lighting combine to create a more attractive scenery. Square has marked sexual landscape, trees, drain fill plants, lawns, flower stalls, etc., so that it formed a certain scale, a create a magnificent night.
Building is the city’s landscape, lighting and build a second city skyline. Modern city due to the unique geographical landscape and cultural environment, and their respective aesthetic ideas and shapes, different styles of architecture in the light next to do now decorate its grand and imposing, and strengthen the city’s unique image, and thus play the iconic landscape value.
Beautiful urban landscape lighting not only for the people to create a good nocturnal lighting environment, enrich people’s nightlife, but also for economic prosperity, the development of the tourism industry, especially for propaganda achievements of China’s reform and opening up and thriving excellent situation, establish and the performance of a region or city at night image so has important significance and impact.
Has great potential for development as a light source, LED’s long life, rugged construction, low power consumption and flexible dimensions, etc. by the people more and more attention in recent years, LED especially monochrome LED is widely used in large-screen, lights and landscape lighting. As LED technology continues to evolve, the white LED luminous efficiency, color rendering, color temperature and a single LED power and luminous flux LED module parameters such indicators continue to achieve new breakthroughs, people are looking forward to LED for lighting.
White LED lights for indoor lighting application
However, the white LED used in ordinary indoor lighting is also facing a number of challenges, such as single LED luminous flux is also difficult to meet the demand for general lighting, the unit cost is too high, the low light efficiency than energy-saving lamps, great color, stability is inadequate. Although research is gratifying, but to truly meet the lighting requirements to produce market-oriented products will take some time, which is LED R & D personnel, manufacturers and users inescapable fact. In this paper, lighting ergonomics, analyzes the current situation and development of white LED light environment and health indicators required for the normal difference between the promotion of LED interior lighting application process made some suggestions.
1, lighting ergonomics
Ergonomics Ergonomics is also called ergonomics or to “man – machine – environment” system as the research object, using measurement, statistics, analysis and other methods to study the “man – machine – environment” between the three elements of the system relationships to solve the system of human performance, health problems. In other words, ergonomics research dedicated to the design and * price of human needs, human capacity, human limits, and how various tasks, jobs, products, environments and systems coordination. Lighting ergonomics, is the study of how the design of light environment to meet human needs, to make people better and faster completion of the visual task or try to meet the needs of a comfortable and healthy.
Illumination environment should take full account of the needs of visual function to meet people, so that people can fit in a visual environment to work properly, which can be clearly seen; psychological needs but also to meet people that want to see comfortable. A recent study showed that light can affect the human body through the secretion of melatonin affect the body’s circadian rhythms and health. Therefore, considering the ergonomics of the environment should be good light from human vision, psychological and physiological needs, a number of factors into account, otherwise it will on people’s working efficiency, psychological or physiological cause adverse health effects.
2, white LED current development
2.1 light efficiency
LED since its inception in the 1960s, in order to improve the brightness of every 10 years, 30 times, 10 times lower prices “Hydes Law”-like pace. According to reports, the current white LED luminous efficiency of laboratory data has more than 100lm / W, and into the commercial area of ??high-power white LED has reached 40lm / W. With breakthroughs in key technologies, the future high-power LED light effect still has much room for growth, the highest may reach 150 ~ 200lm / W.
2.2 Flux
With the advent of high-power LED and packaging, cooling and other key technology breakthroughs, 5WLED commercialization process has taken shape, which makes the flux LED module has been greatly improved. From Nichia’s latest research data shows that power was 5.5W and 11W, respectively 250lm and 400lm luminous flux of high-power LED integrated module has been developed. This makes LED for general illumination process forward in a major step forward.
2.3 color temperature and color rendering
White LED color temperature and color rendering with white LED is closely related to the preparation of solutions. 1996 first used Nichia InGaN blue chip plus YAG (yttrium aluminum garnet) $ phosphor method for producing white LED. Since then, people using R, G, B three color chips mixed excitation light and near ultraviolet chip R, G, B three-color phosphor powder mixed light into the white LED.
Blue LED using YAG phosphor way plus its process is simple, low cost technique, preparation of white LED is the most common way, but its color rendering index is relatively low. Add some red and green phosphor phosphor can improve the color rendering index, though, but because of the red phosphor relatively low conversion rate, usually caused by the overall flux attenuation, namely light efficiency decline. Near-ultraviolet LED plus RGB trichromatic phosphor can theoretically get any color temperature and high color rendering index white LED, but for UV LED phosphor technology is not yet mature. Single-chip phosphor coating method of the phosphor coating techniques, it is generally 80 ~ 800K with a color temperature difference. Multi-chip LED is theoretically possible to get any color temperature and high color rendering white LED, but due to multi-chip LED forward voltage and light output are different, in addition they maintain the temperature characteristics and properties of light is not the same, and thus the circuit design requirements is higher, the current technology is not mature, large differences between modules color temperature.
3, considering the ergonomics requirements for white LED lighting
As previously described, considering illumination ergonomics people consider the lighting environment. Indoor environment for people living and working environment stays most of the time, so people on the indoor lighting needs of the environment is getting high. Can meet these requirements, the LED light source instead of traditional interior lighting of the key.
3.1 visual function needs
In order to meet people’s visual needs, namely to make people able to see clearly, which requires illumination environment with a certain level of illumination, illumination uniformity and color rendering.
To meet certain level of illumination, the LED requires a sufficient flux. Reading room with a small example, assume reading area 6m × 8m, then about 20000 ~ 30000lm flux in order to meet people’s normal reading. Without considering other factors, the application of high-power currently on the market 200lm particles 100 to 150 particles also need to be able to reach such an LED illumination requirements. Due to the current market products better light efficiency at 30 ~ 40lm / W or so, whether energy or cost, LED and energy-saving lamps can not compete or fluorescent. In addition, LED lighting optical design technology immaturity make the current LED lamps light distribution is not stable enough to reach a certain uniformity of illumination also requires a very high cost. However, a small area of focus for the lighting of the LED with a small power consumption to meet the visual needs, uniformity also relatively easy to meet. In terms of color, white LED current can basically meet the general needs of indoor activities.
3.2 psychological needs
In normal indoor work or activity, it requires not only get the satisfaction of visual function, but also requires a certain visual comfort, this is the people’s psychological needs illumination light environment, it requires the field of view can not have direct glare light environment or indirect glare, color temperature to the right, lighting layout should be comfortable. In the field of view requirements glare of white LED are both advantages and challenges. As the LED light point and a small beam angle, the light emission direction is easy to control, but on the other hand, the LED light intensity generally more concentrated at the maximum light intensity distribution is easily if mishandled to cause glare to the observer. Studies have shown that not only cause discomfort glare efficiency decline, but also cause visual fatigue and headaches and other adverse reactions. In addition, if the choice of RGB three-chip LED, although able to form any color temperature of white light, but the larger the field of view of the color difference will affect the overall comfort and aesthetics. If the selection of YAG powder blue LED plus the way, the basic color temperature is high. In order to have a good effect of the illumination, the color temperature of the light source must be selected and adapted to the requirements of illumination, Figure 1 shows the illuminance and color temperature corresponding to the comfort zone. Therefore, the higher the color temperature can also affect white LED interior lighting applications, because it requires a high illuminance appropriate to make people feel comfortable. On the other hand, LED flexible dimensions that LED lighting has been designed with a lot of space, we can fully meet the decorative requirements.
3.3 physiological needs
Indoor lighting people on physiological needs mainly for health needs. In addition to long-term UV radiation can cause skin adverse effects other than light affect the health of the other two ways are often overlooked by people, is a light through the visual impact on health, and the other is light through the circadian system affect health. With white LED for indoor lighting has two effects is closely associated retinal blue light through the hazardous effects and suppress the body’s secretion of melatonin circadian rhythms affect the body systems and health. UV damage usually occurs before the eye portion of the human eye, which can cause damage to the cornea. The Blu-ray because of its longer wavelength than UV light can reach the retina through a fundus; while the unit of energy in the visible range of the strongest, easy to burn the retina and the early formation of cataracts. On the other hand, the body’s secretion of melatonin by light effects, when melatonin secretion disorders is likely to cause confusion in the human circadian rhythm, cause cancer or other serious diseases.
In the region of 400 ~ 500nm, the energy distribution of this white LED has a distinct peak. Added after a certain amount of red phosphor can be reduced to some extent this peak, but the current widespread use of white LED and blue peaks of the blue region of the spectral sensitivity curves of retinal damage and affect the circadian rhythm system ganglion cells sensitivity to light curves have more overlap area, which can not but arouse our attention. And if using a UV LED and RGB trichromatic phosphor plus multi-chip white LED, these two effects can be ignored.
4, to promote white LED interior lighting applications
High-power white LED light effect though, the color and the single power has made great breakthroughs in the LED manufacturers are also constantly updated rapid momentum has been achieved. However, taking into account the ergonomic aspects, for the need to create a line with the Habitat lighting environment, LED is clearly still a long way to go. In order to promote LED more and more reasonably applied to indoor lighting, the following aspects are LED designers, producers and the users should be of common concern.
4.1 the importance of appropriate lighting design
Needs in terms of visual function, LED luminous flux and luminous efficiency is also difficult to meet the needs of a large area of ??general lighting. Thus, reasonable lighting design is applied to the LED interior lighting of the key. For example, the partial use of LED accent lighting, or the use of easy to control the characteristics of LED auxiliary lighting and dimming design. Design should be combined with visual function, psychological and physiological needs, weaknesses, creating a healthy and comfortable light environment.
4.2 emphasis on the LED, midstream and downstream of the close contact
Undoubtedly, LED on the upper and middle reaches of the development and application of LED technology has played a key role, but the downstream applications and demand for the LED also play a leading role on the middle reaches. Scientists, engineers, and designers should strengthen ties, the LED industry development more rational and humane.
4.3 Strengthening LED secondary optics design technology
LED lighting applications, a key technology is the LED secondary optics design technology, through the secondary optical design, to optimize the LED light distribution, while avoiding glare emitted from the LED light is more reasonable to achieve the lighting requirements.
With the city’s economic construction and the rapid development of transportation, urban construction as the increasing number of large scale and lighting, urban lighting electricity consumption is also rising rapidly. How to meet the city residents and visitors from all live and work requirements, to meet the traffic safety, traffic smoothly under the premise of promoting low-carbon economy, promote green lighting. In urban road lighting, scientific and rational energy saving has become an important topic. This article on this subject to talk about their experiences.
City lights energy-saving technology
First, the appropriate illumination
In our city road lighting energy-saving work, proper illumination is the first to attention. We want to follow, “city road lighting design standards” CJJ45-2006 standards, according to the nature and scale of urban roads, for urban road lighting design. Meet the requirements of a variety of lighting standards proposed design, undertake a comprehensive technical and economic analysis and comparison, to choose the technology advanced, economical and optimum road illumination energy conservation values ??and lighting power density values. Not be divorced from “urban road lighting design standards”, one-sided pursuit of brightness, the pursuit of beauty, the pursuit of luxury.
Second, the capacitance compensation
The main city road lighting source is a gas discharge lamp, the starting current, the power factor is low, generally 0.45 or less, this will result in large current loops on the line to generate more losses. “Urban road lighting design standards” requirement should be added to the gas discharge lamp capacitor compensation, power factor compensation shall not be less than 0.8. However, the standard does not explicitly single lamp is concentrated dispersion compensation or compensation. Currently two kinds of compensation capacitors are in use. I think, as street lighting facilities are evenly distributed on both sides of the road, by the power to low voltage wiring long street lamps, road lighting system produces losses mainly occurred in this period, the use of lights at centralized power compensation, does not reduce the pressure power wiring. The use of a single light dispersion compensation, will undoubtedly reduce the lamp power to the lamps which generate a loss on the line, will play a good energy-saving effect.
Third, the implementation of control at midnight
Turn off the light source at night half way direct and significant energy-saving effect, saving operation time saving up to 50%, overall about 30% or so. Currently, the city control method commonly used in the night, to take “every one bright one” or “bright one every two” measures, the closure of some light, energy-saving effect is very obvious. However, the use of “bright one every one” or “one every two bright” mode, it will cause bad road illumination uniformity. Unilateral cloth lamps, light sources should not promote close half way. If you choose this approach, the disparity between light and dark lanes late at night, illumination uniformity is far below the design standards. In practice, I believe that the program can be double light fixtures, two light sources such as power or unequal power available. With this cloth lamp options, ShangBanYe two full bright light, late at night close one source. In this way, the control uniformity had no effect, unilateral arrangement, staggered, symmetrical arrangement, can use this program.
Fourth, intelligent light buck – Regulators – dimming technology,
Intelligent Light buck – Regulators – dimming technology, the device is installed in the power distribution circuit Qiduan street in before midnight for the whole loop pressure control the lights, close to midnight, the car came from a lower voltage thin people. Its saving principle there are two, one is to maintain high pressure sodium lights voltage below 198V, the light will not be extinguished; second is due midnight grid users less load is low, the grid voltage higher than 220V, and overvoltage an additional portion of energy consumption, the use of this device is to avoid this part of the waste. According to engineering practice, and its energy-saving effect in about 15%. With this device, not only saves energy, does not affect the uniformity of illumination, but also to avoid light overpressure run, extending the life of electrical light source. It should be noted that this method is a step-down power distribution circuit, within the circuit all fixtures in the low-voltage operation. As street distribution circuit supply radius up to 800 meters, with the lamp and power supply terminal distance increases, the voltage gradually decreased, if the lines are poorly designed, there may be a remote voltage source can not meet the normal maintenance of the required voltage.
Five, using variable power ballast
Variable power ballast, use gas discharge lamp in proper operating current is reduced, the principle still running through the rest of the night to increase ballast reactance, thereby reducing the source current to achieve the purpose of energy saving street lighting system as a whole. In this way because it is installed at the lamp, can be applied to a variety of lamps and lamp combination arrangement. The original road lighting engineering, may also have additional type variable power ballast transformation, supporting the original lamp ballasts shall not replace, convenient transformation of the construction, and reduce system cost.
All LED street lights currently in the design of the processor heat sink can be roughly summarized as aluminum extrusion heat processors, fin-type heat pipe cooling the processor and the processor of combined heat, cooling aluminum extrusion which processors are mostly Processor exterior parts exposed to light, the advantage of this approach is the cost of the processor in the heat can be more inexpensive, especially in mold development costs are more competitive, but during the high-wattage product development, the weight is a need to pay attention factor, because the public regulation of poles to withstand the stress, there will be certain restrictions, and therefore at high wattage products, are generally treated using fin-type radiators, or using heat pipe approach to application design heat treatment plant.
LED street lights have a high level of design standards
In addition to the development of the processor heat outside, LED street lights structure is another important role in the power supply, because the prevailing LED products for the DC-driven approach lights, and therefore the power supply must be customized on the vendor LED street lights for each style of product development dedicated power supply, but also have national product safety standards based on the differences in circuit adjustments to meet product sales around the world again when safety regulations. In recent years, we have three places LED streetlight project case experience, LED street light phenomenon accounted for most of the dead were the proportion of the power supply caused by the instability, so the stability of power supply products, will also affect LED street lights for outdoor use, is it within three years to maintain good control of the light fades.
Second, LED street lights in product development is an important technical threshold optical design capabilities, because good light distribution characteristics, allowing efficient LED street light evenly illuminated the road surface in the current Taiwan NS15233 standards, only For lights in a vertical 80 degree angle and 90 degree angle must be less than 30 and 10 glare quality requirements. In addition, the level of 65 to 95 degree angle, but also need to have more than a certain luminance limit requirements, the rest of the lighting technology, to see each product’s optical design capabilities, because the case will require some engineering road surface illuminance level limit , then a good optical design, the light extraction efficiency can make a little difference of LED street lights, the actual level of illumination of the road surface was good.
So no problem in quality and reliability of the situation, LED street lights of the competition to see the rest of the soft lighting performance show that the existing LED lamp products, most of all by the German giant OSRAM products used in street batwing wide two isotropic optical design, but in the light distribution design, each manufacturer has its own know-how or do not necessarily accept all of the lights can continue to strive to make the product more to improve the efficiency of road lighting.
Europe, the United States and other places of the LED standard, the same angle of light is required, the quality and the light fades and other requirements, with the LED street lights products, technical progress, we believe that the advent of more and better LED street lights to attract more public sector mining Share tenders to improve the visibility of the overall market LED street lights.
LED High Bay Light, generally large power, widely used in premises, warehouses, storerooms, garages and other environments and some industrial applications due to long life, low energy consumption, no radiation and no mercury, received consumers.
How to chose LED High Bay Light
There are several notes to choose LED High Bay Light.
1, The color should be coordinated to avoid back glare LED high bay light, soft light, brightness uniformity are much better to avoid prolonged exposure to the construction workers of eye fatigue.
2, Some special occasions, such as the coal industry and other flammable region, it’s better to use highest level of proof.
3, It’s better to use high-strength alloy casing as the lamp body, such lamps can fight strong collision or impact, to ensure the safety of life.
LED high bay light construction should be noted the followings:
1,It’s better to have a reasonable distribution of the lamp position to achieve a reasonable distribution of the light source, which are not high brightness, but can make people feel larger space, on the contrary it is easy to feel depressed piranha.
2, In order to enrich the atmosphere of the illumination area, we should reduce the lighting level called waste of energy, where the construction area should be carried out on the LED mining lamp power distribution and rational choice.
3, The construction is completed investigations on the premises, there is no lighting dead to ensure the normal operation of the construction.
4, During the installation for the LED High Bay light with the battery, we should be shortly and carefully, don’t cause any circuit and chaos phenomena
5, Do not touch the battery positive and negative at the same time, to prevent the risk of electric shock.
