月份：2012年12月

Bridgelux promoted a new generation of Vero LED array

Bridgelux is the lead manufacturer of LED lighting technologies and solutions. On 5th of December this year, they promoted a new generation of Vero LED array. This innovation not only simplified the design and manufacturing process of LED chips, but also provided a more flexible lighting solution for designers.

 

Bridgelux is the lead manufacturer of LED lighting technologies and solutions.

 

Vero new generation array package technology is more advanced in terms of design flexibility, ease of use and energy efficiency, and meanwhile provides integrated smart sensors and wireless communication technologies for the future constructions of intelligent control systems and all sorts of application innovations.

 

The Vero LED array has three major innovations: a. as the new generation of LED array, Vero array have higher luminous flux density (20% more than current LED arrays); b. the birth of Vero array can further simplify the packaging process of LED chips, improving production efficiency and reliability of the entire system. Overall, Vero LED array can significantly reduce the inventory of electronic and optical components of G24 LED manufacturers, expand the scope of the input current, and enable designers to take optimizations on production efficiency, cost and output luminance.

 

Vero array provides complete application supports for four LED specifications, and provides suitable output luminance and color temperature to multiple areas, such like retails, catering and tourism, commercial, industrial, residential, outdoor and indoor lighting. The new array products will initially provide approximately 800lm warm white (3000K) light, the maximum output luminance of which were expected to reach up to 20,000lm. These new chips also offer multiple options in CCT and CRI, including Décor array products with CRI up to 97.

 

Vero array products are compatible to many standard divers, providing diverse and flexible choice for LED manufacturers, and meanwhile further reducing the research and developing time of new products, reducing inventories and saving costs. They have significant improvement in general lighting designs, more flexible, surpassing all previous array products of Bridgelux in luminous flux density and current stability. The new Vero array brings about interfaces with higher qualities and also multiple connection options to LED makers. They could use general welding boards or plates without welding links (provided by Molex) to establish links. Vero series combined advanced light sources and innovated linker design options to establish simple and easy-to-integrated solutions for LED manufacturers.

Analysis of LED commercial indoor lighting applications

Compared with traditional light sources, LED lighting technology has many incomparable advantages: more easily integrated, can be intelligent controlled, dimmable, color changeable, flexible in designs. Almost every type of LED lights are dimmable, the corresponding approaches are much simple than that of traditional lamps. Basically, via power amplifiers, LED dimmers can simply realize constant 0-100% dimming function without any flickers. Even more intelligently, by using DMX512 controllers, LED lighting fixtures can dynamically controlled according to the specific requirements of clients, since these DMX512 devices are programmable. This new control technology is rather popular among LED commercial indoor lighting applications. On the other hand, it is very difficult for traditional lamps to realize dynamic changes both in brightness and colors.

 

Compared with traditional light sources, LED lighting technology has many incomparable advantages:

 

Currently, the design of commercial lighting applications takes more considerations on user-friendly contents, like different color options for different environments, different color temperatures to meet the specific of customer’s requirements or simply convey the design concept of designers. Take jewelry counter for example, platinum counter areas usually used 7000-8000K white-ray LED lights, which can fully present the elegant and elitist of them. 3500-3800K warm white G24 LED rays are more suitable for gold products, which can present their magnificence and gorgeous. The small size, narrow beam angle and high luminous efficiency let LED lights become a good replacement of fluorescent tubes in jewelry counter lighting applications. Different business environments, different shopping experiences make practical applications have more and more restrict requirements on lighting designs. LED commercial indoor lighting applications can easily achieve all kinds of effect that merchants wanted, which cannot be realized by traditional lamps.

 

The luminous efficiency of LED commercial indoor lighting applications grows increasingly, they started their seizing in the indoor lighting market. At present, traditional light sources still dominate the commercial indoor lighting area. Energy-saving lamps are cumbersome in size. The entire lamp body occupies a large space, lacking of aesthetic feelings. If worked under unstable AC input voltage, there will be flickers. Light sources and shell of LED down lights followed the integration design, applying creamy white shells, nebulizer covers and embedded lamp bodies. Graceful appearance, even light distribution, even light distribution, not subject to the restrictions of the external voltage variations, consistent luminance, all above advantages make LED commercial indoor lighting applications more competitive in the lighting market.

Advantages and prospects of the development of LED commercial indoor lighting industry

Since the birth of LED lighting devices, they has received high attentions from both engineers/designers and consumers, due to their features of high reliability, easy to control, small size and energy-saving. Electronic indicators are the earliest product of LED lighting technology, followed by signal indicators, like traffic lights. However, at the early stage, the output luminance (brightness) and luminous efficiency of LED lights are relatively low, but their selling prices are ridiculously high, thus for a very long time, LED lighting fixtures were hardly cognized and accepted by ordinary buyers. In the commercial applications, LED lights were only sued as outline decorations of buildings and other non-mainstream lighting applications.

 

Advantages and prospects of the development of LED commercial indoor lighting industry

 

In recent years, with the increase of LED thermal energy conversion efficiency (also known as power efficiency) and brightness, and meanwhile the decline of production costs/selling prices, the market had some new recognition on this new generation light source. In fact, LED has multiple incomparable advantages, like long service life, low power consumption, high output luminance. According to related analysis of the lifetime and power consumption of LED lighting fixtures, LED commercial indoor lighting industry has more potentials and prospects in the commercial indoor lighting market. After 20 years development, the production cost of LED bulbs, LED ceiling lamps, G24 LED down lights and LED bars is obviously lower than the cost of traditional light sources. It is estimated that, in 2012, with the further drop of LED chip product cost and further increase of LED chip technology, the performance advantages of LED lights will be more obvious.

 

Compared with traditional light sources, LEDs have more plastically, which means LED chips provide more creative space to fixture designers. The small size enables them to be used in diverse applications in diverse environments. Take LED down lights for instance, they can be made in a variety of shapes, such like round, square, other irregular shapes, also can be made in panels with thickness of only 9mm. All these designs cannot be used on traditional light sources. Incandescent lights are usually made as bulbs and fluorescent lights are usually made as tubes, all depending on their corresponding technological features.

 

However, the development of each industry must follow some certain laws, including LED commercial indoor lighting industry, from start to development to mature then finally to recession. LED commercial indoor lighting industry is still in the stage of development. How to successfully move forward into mature stage, it is a crucial problem.

 

Importance of the design of LED lamp drivers

LED lamp drivers are also power supplies of LED lamps. Efficiency is the most important parameter for them. LED drivers with relatively low efficiency will greatly impact the energy-saving feature of we LED lighting products. Meanwhile, among all LED lighting applications, the unmatched service life and reliability of LED lamp drivers will affect the reliability of LED lamps, which is also seen as the “short blank” of LED lighting devices. Giving full play to their potential is the key supporting factor.

 

LED lamp drivers are also power supplies of LED lamps.

 

In order to meet requirements of different LED lighting devices (with different input voltage/current and different LED chips), LED semiconductor device companies have developed a variety of new white-ray LED drivers. These drivers can also be used on blue-ray, red-ray and other color LEDs as well as white-ray LEDs. In addition, this kind of driver has features of stable output and programmable output. Thus they could be used as a regulated power supply or a programmable constant current source.

 

LED lamp drivers must ensure that the corresponding G24 LED lamp can maintain a normal working condition. For example, as the load of LED power supplies, dozens or even hundreds LED components need to combined together to form a light-emitting module. How to choose a suitable power supply? What type of connection should be used between drivers and LED components? All these factors directly determine the reliability and service life of LED lighting fixtures.

 

Power supplies provide forward input voltage to LEDs to trigger current flow. The output luminance (brightness) of LED chips is usually determined by the forward current flow. However, the internal current flow should below the rated current of LED lighting devices, otherwise, permanent damages may come out. Therefore, the constant current circuit of LED drivers is the best solution to realize current control currently. In other words, LED lamp drivers are a type of conversion circuit that provided constant current rather than constant voltage.

 

LED technology is relatively mature compared with other LED technologies. In normal conditions, the average lifetime of them can reach up to 100,000 hours. Among all sections of LED lighting fixtures, it is LED divers that have the shortest working life. The average service life of general high-powered LED divers is only 30,000 hours, far less than the lifetime of LED chips. Thus how to improve the lifetime of LED power supplies is a crucial point of LED lighting technology.

Advantages of LED urban landscape lighting applications

High efficiency: In fact the luminous efficiency of LEDs is not high. But if study the light spectrum of LED components we will find out that more than 95% light emitted by LED chips is concentrated in the visible light range, 60% luminous efficiency, good monochromaticity, can directly send out pure visible light without filtering. The luminous efficiency of incandescent lamps is only 10%-20%.

 

High efficiency: In fact the luminous efficiency of LEDs is not high.

 

Less energy consumption: the rated power of LED chips is only 0.03-1W. They can realize all kinds of lighting applications by the way of combinations. Since there is no UV ray in LED lighting spectrum, usually LED lamps have much less heat generation and radiation than other traditional lights used in the same area. The pure light spectrum also enables them to generate colorful light without the energy-wasted filtering process. Thus LED urban landscape lighting applications started to attract the attention of people and the government.

 

Safe and reliable: the normal working temperature of single LED chip is around 1.5V-5V, and the normal working current is around 20mA-70mA, no contact hazard. Lamp body is epoxy encapsulated, which is resistant to mechanical shocks/vibrations, free from mercury, sodium and other harmful objects, and also recyclable.

 

Easy to manage: due to the above advantages, LED light sources can realize multiple control methods: centralized control, decentralized control and regulatory control for multiple points. These lamps are dimmable (by controlling the current) and color changeable (via various color combinations). The more than 100,000 hours working life reduced the maintenance cost of LED urban landscape lighting applications.

 

Social and economic benefits: compared with traditional light sources, LEDs, especially white-ray LEDs are smaller, lighter, better direction and resistance to various harsh environments, and also have incomparable advantages in power consumption, service life and environmental protection. LED is sophisticated enough to cause a huge impact on the traditional light source market. With the technological breakthrough of the third generation semiconductor material-gallium nitride and the emergence of blue-ray, green-ray white-ray LEDs, difficulties and risks of LED lighting industry is significantly lower than the microelectronics industry, and enable domestic LED companies to bring their superiority into full play. Take the downstream LED industry (packaging and lighting application industry) for instance, which is a technology-intensive industry as well as a labor-intensive industry, making best use of human resources of our country and developing related industries.

How to create COB packaging LED chips with high luminous efficiency

With the continuous innovations in LED packaging technology and the implementation of the energy saving policies in western countries, LED light source was increasing the market share in the lighting field. Performances LEDs in the aspect of heat dissipation, light efficiency, reliability and cost-effective are still noticeable points. If LED chips cannot have breakthroughs in these aspects, or otherwise, other new lighting technologies except for LED have breakthroughs in advance, then the life of LED will come to an end. Under such pressure, COB (Chip on Board) was promoted as a new packaging technology. Compared with traditional LED packaging technologies,  COB packaging LED chips have better cooling capabilities, high-density output luminous flux.

 

How to create COB packaging LED chips with high luminous efficiency

 

COB packaging LED chips have the shortest thermal path, can rapidly transmit heat from chips to metal substrates, and consequently to heat sinks. The current COB metal substrates are copper, aluminum, alumina, aluminum nitride. Take comprehensive considerations of production cost, cooling capacity and anti-corrosion capacity, aluminum is the most suitable material to make COB LED chips.

 

Normally, when taking the simulation of LED luminance, scientists hope to create sized packaging substructures that provide sufficient output luminance within limited chip size. This is unachievable among discrete-LED packaging solutions. Even using 3535 LED chips (with small size but relatively high luminous flux) cannot reach the high luminance density that COB or MCOB provided.

 

Although that COB packaging LED chips have many advantages, they are still not mainstream product in the market. On one hand, we should utilize these advantages to produce more advanced products. On the other hand, we also need to notice their disadvantages and find out corresponding solutions. Firstly, the luminous efficiency of COB LEDs is still relatively low. Due to the plane luminous mode, there are no assistant light-emitting devices and compartments to reflect sidelight, like PPA to discrete-G24 LED packaging solutions. That means, although each LED chip in the COB packaging solutions can send out more light (high output luminance), there is still a certain part of light (sidelight) will be wasted. Secondly, COB has no shape standards. Currently, most of domestic manufacturers produce lighting fixtures and drivers in accordance with existing COB LEDs. Different manufacturers may have different shape and other parameters for their COB packaging LED chips.

Advantages of high-powered LED lamps

High-powered LED lamps are rather important solutions to achieve high output luminance, which has various advantages and merits. However, how to use them reasonably and how to optimize their working conditions two key points to the high-powered LED lighting industry. In the mean time, this article will also take some comparisons between high-powered LED lamps and traditional light sources and also discuss about corresponding LED lighting applications with high luminous flux.

 

High-powered LED lamps are rather important solutions to achieve high output luminance, which has various advantages and merits.

 

Within the past 20 years, the development of LED technology followed the laws of “Haitz”. The output luminance (brightness) increased by 30 times but the price dropped by 10 times in every 10 years. The output luminance of general white-ray LEDs has reached up to 100lm/W (lab data), and high-powered white-ray LEDs (50lm/W) finished the commercialization. In the aspect of monochromatic light, the luminous efficiency record of red/yellow/blue/green rays were continuously refreshed. As new light source, G24 LED has been widely used in multiple areas, and gradually attracted more attention and expectations from consumers.

 

The current distribution of LED applications was diversified in various industries, including indicators, display, backlight, general lighting and so on. Among them, general lighting is the most promising market. With the constant increase of LED luminous efficiency and decline of the production cost, LED will continue its occupation in the market. China set up a National a semiconductor lighting project group in 2003, aiming to consolidate resources and rapidly advance the LED lighting market. According to the forecast of Lianghui Chen, academician of Chinese Academy of Engineering, from 2005-2015, the semiconductor lighting save approximately 400 billion kWh (totally 260 billion yuan in electricity charges) for users, creating a production value of 150 billion yuan.

 

In the lighting industry, compared high-powered LED lamps with traditional light sources, certain features of the former have incomparable advantages: a. high energy efficiency: LED with luminous efficiency of 75lm/W can save around 80% electricity compared with incandescent lights with the same brightness; b. long service life: the average lifetime of LED products is 50,000 hours, which enable them to be continuously used for 7 years; c. flexible in brightness control and color adjustment: can realize the constant adjustment in brightness and color, high purity, no distortion and digital control; d. flexible dimensions: can realize the organic integration with buildings. e. environmental friendly: no harmful metal mercury, infrared and ultraviolet radiation.

LED light source in Nanchang landscape lighting applications

According to relevant officials of the Ministry of Science and Technology, the government intended to take the opportunity of 2008 Beijing Olympics and 2010 Shanghai World Expo to promote semiconductor landscape lighting applications from 2012. The semiconductor lighting industry has significant social benefits. Nanchang is a midland city of China which has been widely developed in recent years. “As lighting management department, in the process of city transformation, we need to be in line with the base construction of national semiconductor industry, actively promote and develop LED light source in city landscape lighting projects and applications. ” Said Mr. Xiaowen Ma, vice chairman of Nanchang lighting association.

 

According to relevant officials of the Ministry of Science and Technology, the government intended to take the opportunity of 2008 Beijing Olympics and 2010 Shanghai World Expo to promote semiconductor landscape lighting applications from 2012.

 

After 20 years development, Nanchang made huge progress in researches and industrialization of semiconductor light-emitting materials. Nanchang LED lighting industry has certain advantages in researches, patents and applications, basically realizing industrialization in upstream (materials), midstream (chip manufacturing) and downstream (packaging and application). Take midstream chip manufacturing industry for example, products include multi-color LED light source, like infrared, red, orange, yellow, green, blue, white, having fundamentals of further development of large-scale production. Besides, the Nanchang University is also in the leading position in the domestic semiconductor light-emitting material researches. In accordance with a recent survey taken by the Ministry of Science and Technology, Jiangxi Province is one of the four largest industrial areas for semiconductor light-emitting materials and devices.

 

The current price of LED chips is generally higher than incandescent lamps and fluorescent lamps. The biggest problem for high-powered LED devices is their luminous efficiency. Obtaining high lumen output per watt mainly depends on the design of G24 LED packaging structure. This problem can be solved through cost reduction via volume production and technological innovations. Currently, all bottlenecks of semiconductor lighting technology all focused on LED chip manufacturing and chip packaging. In the long term, the development of new materials has significant meanings for the entire LED lighting industry. The popularization of LED light source is not a long long story. Our recent development goal should be special lighting area, like landscape lighting, decorative lighting and other fields. Hope LED light source can take place of high-powered HPS, high-pressure mercury lamps, metal halide lights as soon as possible to become the main stream of city landscape lighting area.

Typical LED driver solutions for LED area lighting power structure

LED drivers used for LED area lighting need to meet the some standards for power factor (PF) and harmonic content, like IEC61000-3-2 of EU International Electrical Union (IEC) standard has explicit specification for harmonic content of lighting applications with power consumption more than 25W – the total harmonic distortion (THD) should be less than 35%. However, production satisfied IEC61000-3-2 does not mean that they have a power factor that more than 0.9. According to relevant regulations of the United State, lighting devices or other electrical appliances should have a power factor no less than 0.9 and THD more than 20%.

 

Typical LED driver solutions for LED area lighting power structure

 

Most of area lighting applications are used outdoors. They may probably be subjected to all sorts of harsh environment, the overall service life will be definitely affected. These problems can be solved by improving the overall structure design, reducing the heat generation and increasing the power efficiency of LED drivers. Reducing heat dissipation can be realized by insolating LED heat resources and G24 LED drivers to enhance the stability of the entire system.

 

LED lighting products can be intelligently controlled. Traditional road lighting applications can realize automate control via timer and optical sensors. This kind of intelligent control is relatively complex and more likely failure. Intelligent controls for LED area lighting applications are mainly depended on PLC and wireless control technologies, which is more stable and flexible, such like time-based centralized control for brightness; brightness control based on traffic flow sensors; brightness control based on sensors used to detect people and vehicles. LED intelligent control technology is able to save more energy, having much less impacts on security. Double brightness control is a typical LED intelligent lighting control applications in LED area lighting industry. These lamps can automatically adjust self-brightness (two or more levels) in accordance with surrounding light conditions. This solution can be used in many places, like parks, gas stations, parking lots, stares, freezers. LEDs can be instantly turned on and off or adjusted according to actions or activities. Once detecting actions or activities, LED lamps with double brightness control systems can provide 100% brightness. The brightness will drop to only 20%-40% when no actions or activities are detected. Intelligent control makes energy-efficient LED lighting fixtures save more power.

High-powered LED area lighting applications for street and parking lots

With the enhancement of energy saving and environmental protection awareness, people are increasingly concerned about the energy consuming effects on the environment. According to statistics, among all electricity consumptions, around 20%-22% electricity was consumed by lighting applications. Improving energy efficiency of lighting products can contribute to the reduction of carbon dioxide emissions. Therefore, energy-efficient lighting is becoming a focal point.

 

High-powered LED area lighting applications for street and parking lots

 

From the view of application field, lighting includes multiple areas, house lighting, road lighting, residential lighting, industrial lighting, etc.. Sorted by power, LED lighting applications can be divided into low-powered indoor lighting applications and high-powered LED area lighting applications, such like LED wall wash lights, LED tunnel lights, LED street lights, LED parking lights, LED flood lights, etc..

 

High-powered LED area lighting applications have many challenges: lighting fixtures are not easily accessible, risks brought about by the fault of light sources, harsh outdoor climates and so on. Existing light sources used in high-powered area lighting applications are metal halide, high pressure sodium lamps (HPS), linear fluorescent and compact fluorescent lamps. There are a lot of limitations. For example, the CRI of HPS is very low (only 22). Objects under such light will completely loss their original color, which we also called color distortion. Traditional metal halide lamps have high energy loss (about 40%). Furthermore, the run-up time (from start to full brightness) is as long as 10 minute. Linear fluorescent lights have very weak cold temperature performances. Compact fluorescent lamps also have a long start time.

 

On the other hand, with the constant improvement of high-brightness white-ray LEDs in performance and cost, this kind of G24 LED chips have been widely used in high-powered LED area lighting applications and provide advantages that traditional technologies do not have. For example, consuming less power per lumen light, which is also known as luminous efficiency; better direction control; better color and quality, environmental protection, intelligent control on switching on/off, automatically adjust brightness according to the ambient light. In addition, LEDs are more reliable, reducing product cost and maintenance cost.

 

The main function of LED drivers is limiting the current flow in a variety of conditions, keeping LEDs away from current surges and other fault conditions. LED drivers also provide a certain level of protection, avoiding fire caused by electrical or mechanical shocks. For area lighting applications, the harsh climate brings temperature controlling difficulties to LED drivers. Also, drivers used in area lighting applications need to withstand 277VAC, 347VAC or even 480VAC in some conditions.