led test and aging test

If the consumers to describe the perfect light source characteristics, then you might hear in their description requires the lowest energy light output and color adjustable, long time to use a variety of desirable characteristics. Minimum input energy is efficiently input power is converted to lumen output, called efficacy; adjustment related to the dimming of light output with less light brightness, or may be regulated to increase the color of the lighting equipment, so as to simulate daytime relative to the status of the night; and by adjusting the bias current flowing through the LED light led test output can be maintained in a longer service life during.

led test and aging test

Incandescent lamps with energy efficiency is low and the service life is shorter; sodium lamps provide color choices are few and short life; less fluorescent lamps dimmable choice selection, service life is short. High brightness LED lights, which claims to have a good energy efficiency, long service life, easy to choose the color and dimming control and no ultraviolet (UV) rays. Thanks to intelligent control device design or LED driver electronics, the advantages of these claims have now been realized. Intelligent LED driver can be adjusted for brightness decay in use during the period, provides the driving characteristics to adjust the color and alternative sorting (binning) to obtain the desired color and brightness of the LED: the by using spectral tuning for different LED system led test  to get the The desired color and brightness.

The spectral tuning mixing several kinds of LED spectral energy distribution, such as the appropriate mix of red, green, and blue LED can produce white light. This RGB combination is also used to generate almost all colors of light. If the LED drive is not designed for adjusting a set of different LEDs, the designer must select from the separation of the LED in order to produce a specific color. Sorting manufacturers based on light-emitting lumens and color LED classification process, the example of Figure 1 shows a group of industry-standard LED classification criteria.

Sort by plotting rectangular area on the chromaticity diagram. A group containing the LED of the same class will be similar in color and brightness characteristics. However, in a large office or factory led test environment contains many lighting equipment, different classes may still result in uneven light color in a group of large-scale lighting equipment is obvious. Separation of LED design does not provide the method of changing the illumination device color; use the feedback to the tuning system and a set of different colors of LED spectral characteristics of the different LED compensating illumination system, it can be established in an office environment, so that the entire space uniform light. Spectral tuning can also compensate for other effects, such as the edge of the room window outward natural light or reflected into the room corridor lighting.

led lighting solutions and LM80

LED bulbs in the market there are two important questions:

The first identity is unclear. Found that up over half of the LED bulb LED light bulb according to ITRI test industry led lighting solutions, marked the actual luminous flux are lower than the more than 10% of the indicated value.

The second is the uneven quality. Currently on the market is no set of specifications to be able to make it clear that the relationship between the price and quality of the LED bulbs.Causing consumers often hold “apples and oranges” comparison, some more took a higher price, but did not buy a high quality product led lighting solutions, the case-by-good money for bad money is more and more serious, but also caused by Europe and the United States and other countries. highly concerned about the identity and quality of the LED lamps / bulbs.

led lighting solutions and LM80
In view of this, the Bureau of Energy, Ministry of Economic Affairs for LED bulbs also accelerated the Energy Label driven, in this matter, the author is a happy and sad at the same. Joy is that, at least in Taiwan is about to have a commonality standard, can provide consumers need to select LED bulbs. The worry is that consumers spend more money, buy LED bulbs that meet the “the Energy Label benchmark requirements project” really have a quality protection?

More official representative market norms, able to do something to do with the lamp life, it should be the case that the U.S. Environmental Protection Agency / Energy Star for LED bulbs / lamps published LM-80 specification. However, since the release of this specification, in North America has been found in a number of different voices, some reliability experts and even began to call, should immediately stop as the LM-80 lumen maintenance (L70) LED bulb or lamp life judgment only basis.

In fact, in 2006, the U.S. Department of Energy Solid State Lighting (SSL) Quality Working Group, invited 32 reliability experts, very in-depth discussion of estimation methods for reliability and service life of the LED. Considerations LED industry technical capacity, the working group decided, on behalf of the reliability of LED components and lighting will be the most significant, and also the most easily quantifiable indicators lumen maintenance (L70). Because the traditional incandescent light bulbs in the use of tungsten burned, the lamp life to LED bulbs in lumens recession is gradual and slow led lighting solutions, early in the recession, people in the visual feel of has been to wait until the light source the recession to initial light source of 70% (L70), people will feel to the bulb dims, this case will affect the illumination. Therefore, the Working Group recommends that the specification of LM-80 lumen maintenance (L70) as the sole judge basis.

 

display led and OLED

LED backlight LED  as the LCD backlight, LED backlit display LCD display backlight source is traditional CCFL cold cathode fluorescent tube (similar to fluorescent lamps) transition to LED (light emitting diode). LCD imaging principle can be understood as the external voltage is applied to the liquid crystal molecules are deflected just like a gate camel barrier backlight emits light permeability, thus the light projected on the color filters of different colors to form the image display led.

Backlight module transition from CCFL to LED Lights can bring many benefits, allows more uniform brightness of the display screen, lower power consumption, can be more lightweight and stylish appearance. However, commonly used in the market is a W-LED (white LED) backlight, in fact, this backlight is only the luminous components replaced. Enhance display very weak and did not even upgrade. LCD display to enhance significantly RGB-LED (tri-color LED) to enhance the display effect is more obvious, but high production costs, and therefore be applied to high-priced LCD TV. Merchant said LED display with white LED backlight display products, and ordinary liquid crystal display is the difference between the change of the backlight.

display led and OLED

LED display is set in one of the micro-electronics technology, computer technology, information processing, its colorful, wide dynamic range, high brightness, long life, stable and reliable work, etc., become the most advantage of the public media, LED The display has been widely used in large squares, commercials, sports venues, the dissemination of information, news releases, and securities transactions, to meet the needs of different environments display led.

LED display is a way through the to control semiconductor light-emitting diode display probably look from many usually red light-emitting diodes, by the bright lights off to show character. The display screen is used to display a variety of information, text, graphics, images, animation, quotes, video, video signal display led.

Along with the self-luminous OLED display without backlight, high contrast, thin thickness, wide viewing angle, fast response, can be used for a flexible panel, wide temperature range, the structure and the process is relatively simple, excellent characteristics, is considered to be emerging application technology for the next generation of flat panel displays.

 

warranty of diode led

LED has a unique advantage, but the LED is a fragile semiconductor products, LED products to be extra careful, I now summarize some LED Note attaches great importance to the process of using the.

(A) DC power supply should be used diode led

Some manufacturers in order to reduce the cost of the product using the RC Buck to LED product supply, which will directly affect the life of the LED products. Dedicated switching power supply (preferably a constant current source) to the supply of LED products will not affect the service life of the product, but the relatively high cost of the product.

(B) shall make anti-static measures

LED products to be used in the production process in the processing of certain anti-static measures, such as: table to be grounded, workers wear anti-static clothing, with anti-static ring, as well as with anti-static gloves, can install anti-static ion conditional fans, as well as to ensure the workshop humidity around 65%, in order to avoid the air is too dry to produce static electricity, especially the green LED is more easily damaged by static electricity. LED antistatic ability of different quality grades are not the same, high grade quality LED lights antistatic ability is stronger. May not have a lot of friends on the electrostatic know very well that I am here in more detail about the knowledge of static electricity: static essence remaining charge. The charge is all  diode led the physical quantities of the essential aspects of electrostatic phenomena called the ESD.

warranty of diode led

The amount of potential, electric field, current, etc. are generated due to the presence of the charge or the movement of the charge quantities. A lot of static electricity problems are caused because people do not have ESD awareness, even now there are many people suspected of ESD will damage electronic products. This is because the the most ESD damage occurred following the feeling of the people, because the perception of the human body electrostatic discharge voltage of about 3KV many electronic components can be damaged when a few hundred volts or tens of volts, usually electronic devices are ESD damage no clear boundaries, the components are mounted on the PCB, after re-testing, the results of a lot of problems, analysis quite difficult. Potential damage, that is, the use of sophisticated instruments it is difficult to measure its performance significantly change, so it is all electronic engineers and designers are skeptical ESD, in recent years, but experiments diode led confirmed that this potential damage after a certain period of time, electronic products The reliability decreased significantly.

 

led design for new led lights

LED lights with its unparalleled energy-saving, environmental protection, long life, high controllability technology advantages, in recent years become the world’s most promising high-tech one, officially opened the prelude to a comprehensive alternative to traditional lighting, semiconductor lighting technology innovation is changing centuries the history of traditional lighting. With the application of LED technology in the lighting field, LED lighting products in the world set off a storm of green energy saving, green lighting products industry as. Increasing energy consumption, and some even predicted: “in the next 10 years, LED lighting products will be the only product to replace the traditional high-pressure sodium lamps, incandescent lamps, fluorescent lamps led design, table lamps lighting LED lamps to be universal, not only need to substantially reduce costs, but also need to address the problem of energy efficiency and reliability, and how to solve these problems, share the design of high efficiency and high reliable LED lamps.

Do not use the bipolar power led design devices

led design for new led lights

Experts pointed out that the bipolar power devices are cheaper than the MOSFET, generally about 2 cents, so some designers use bipolar power devices in order to reduce the cost of LED driver, this will seriously affect the reliability of the circuit, because with LED drive circuit board temperature enhance effective working range of the bipolar device is rapidly shrinking, this will lead to device failure in the temperature rise which affects the reliability of the LED lamps, the correct approach is to choose MOSFET devices, the service life of the MOSFET devices much longer than bipolar devices.

Try not to use electrolytic capacitors

LED driver circuit Do not use electrolytic capacitors in the end? Supporters and opponents, supporters believe that the board temperature control, turn to reach the purpose to extend the life of electrolytic capacitors led design, for example, choose a life span of 105 degrees for a high temperature of 8000 hours electrolytic capacitor, electrolytic capacitor life estimation formula based on prevailing “temperature 10 degrees lower doubling of life expectancy, it is to work in an environment of 95 degrees life of 16,000 hours, 32,000 hours working life in an environment of 85 degrees in 75 Degree of working life of 64,000 hours, if the actual operating temperature is lower, then life will be longer! Seen in this light, as long as the selection of high-quality electrolytic capacitor drive power of life is not any impact.

 

led tube lights in lumen

In recent years, the strengthening of public awareness of energy saving LED lighting technology matures, to some extent, facilitated the initial formation of the LED lighting market, and there is a growing trend. LED lights on the market, however, has also exposed an intractable problem led tube lights, the LED’s dazzling and spot light directional problem.

For LED dazzling problems, the manufacturers are using a variety of methods, with brushed PC mask with frosted masks using special phosphor material, but these methods are not ideal, drawing mask can eliminate glare, but spot phenomenon is more serious, a slightly longer time in this lamp eye fatigue, long hours this lamp with the eyes, but also lead to eye astigmatism; while using frosted and milky white mask optical loss too much, is very poor.

LED lighting is a market has a bright future in the industry have suggested that engineers just formed in this market, concerned about the efficiency of LED lamps, the luminous flux and the life outside, do not ignore the problem of LED lighting comfort.

led tube lights in lumen

However, using optical diaphragm, eyes intuitive observation feeling of each LED is brighter, but not dazzling, the diaphragm LED fluorescent light becomes more uniform, and the viewing angle is significantly wider. This diaphragm works is to hash irradiation the diaphragm above LED point light source into surface light source uniform output so that you can solve the problem of glare spot and widen the illuminated area. Addition, the diaphragm transmittance rate of more than 90 control limited impact led tube lights.

Using optical diaphragm, not only can eliminate the LED spot specific, and can also widen the irradiation angle. Since the LED fluorescent lamp is a regular arrangement of two rows or three rows, so each point between the light source emits light there will be voids, so that within a certain distance on the generation of a flare; optical diaphragm, optical diaphragm point light source of the incident light is uniformly diffused become divergent light source emits light becomes very uniform, completely solve the spot to solve problems.

In addition, LED light-emitting directional strong irradiation angle of about 120 degrees, it is easy to produce lighting blind spot; optical film, optical film, the unique diffusion can light irradiation range expanded to about 180 degrees, so you can effectively eliminate lighting blind spot led tube lights.

LED fluorescent optical diaphragm, LED fluorescent lighting can make the same number in the same area of ​​space, the diaphragm LED fluorescent absence of irradiation blind spots, light uniformity, lighting effects are much more than ordinary LED fluorescent. And the required lighting area is larger, this advantage is more obvious.

LED industry is emerging industries advocated by the government

At present, Many places local government practices is required to see the operation of the machine in order to give the support of corporate commitment. Many enterprises forced to support start production, resulting in high water level pressure on the stock. In order to alleviate the pressure on the stock, the companies began to cut sale price, so that there is no profit at all, eventually leading to the loss-making; There are some enterprises in order to ease the pressure on the stock, the product credit out, resulting in a huge trade receivables, and increase the risk of corporate finance.

LED industry is emerging industries advocated by the government

Insiders analysis that the LED capacity surplus is not only because the strength of the market is enough, but also associated with a lot of irrational investment. Government support become the catalyst of this phenomenon. But the operation of the business need comprehensive consideration, such as sales channels, transportation, the supply industrial chain supporting facilities, labor costs, and personnel, etc.

At first, Sales channels, LED enterprises plant in somewhere, they need to consider the marketability of the product. Whether it is the international market or the local Chinese market? If the production base position shall not be ok, it will increase a considerable operating for enterprises.

Second, Transportation. If there is not convenient transportation line, the enterprise products to market cycle will be delay, which is not conducive to sales of the product and it will damage products from different degrees.

Third, Surrounding industrial chain. peripherals do not have a complete industrial chain, or the industry chain is not rich enough, so that it will increase the difficulty and cost of raw materials procurement.

Four, Talent. this is the core of the enterprise. The distribution of talent is regularly to be found. If enterprises where put into production can not find the right people, the core aspects of the production and R & D and sales is bound to bring trouble.

LED insider think that, LED industry is the emerging industries advocated by the government, but businesses should have long term plan in the operation of the project, a long-term view of the development of enterprises, because favorable government policies can not blindly invest in the LED industry. And presently, Capacity relative surplus resulted enormous pressure to the LED lights business, therefore, companies need more government support.

 

How to balance the dual leds light oriented enterprise policy support and the global market

In 2012, in mainland China LED industry is heavily farce, from the beginning of the Shida boss Paolu starting to the big vision photoelectric arrears door “event, LED industry always told us that the reality is so cruel. From an overall point of view, the Chinese mainland LED market share has increased, but the LED output value greatly climb, so that companies feel the pressure.

How to balance the dual leds light oriented enterprise policy support and the global market

The outside layman watch bustle and astir, insiders see way. Large leds light frequent collapse of LED industry indicated that the industry crisis is beyond the scope of normal reshuffle. In the final analysis, LED fire LED industry itself. LED products is energy saving and environmental protection. That is not fake, but this is not something that people invest in direct purpose and fundamental motives for the LED business, money is the last word!

Under the guidance of macroeconomic policy, Chinese mainland LED industry developed rapidly, but subject to the impact of price, technology, products, end markets are in a weak state. Even so, there are still many companies to switch to LED industry or many large LED enterprises continue to expand our production capacity to the market. Therefore, resulting in a greater squeeze, overcapacity situation appears. Thus many leds light companies face the embarrassment of riding a tiger. Especially, G24 LED in the upstream industry, on the competition market, capacity become part of the market competitiveness, companies need to have a larger scale, while the high cost of investment in equipment, resulting the risk encountered in the enterprise. In order to allow enterprises to operate normally, we only to accept the conditions of local governments to tempt to local into production.

LED inside reporters knows that to attract LED enterprises to place into production conditions generally have the following aspects:

First, the land supports, large leds light enterprises plant a larger area, in order to improve the industrial base of the coastal cities, small land support given by the government put into the general enterprise, and second-tier cities hope to bring this new industry, on the land, they were give support as a encourage enterprises to local production;

U.S. scientists have developed a new material warm white led lights

As we all know, LED (light emitting diode) lights have the advantage of energy efficient and longer life expectancy, but at present, LED lights are mainly in blue light, which hindered its popularity in the field of indoor lighting. Developed by scientists at the University of Georgia, USA Today, it is said to be the world’s first single phosphor and a single light-emitting unit warm white LED lights. The paper details about this material is published in the latest issue of Optical Science and Applications journal Nature Publishing Group.

U.S. scientists have developed a new material warm white led lights

The paper’s lead author, associate professor at the University of Georgia Pan Zhengwei (sound), said: “At present, the white LED lamp are mainly used on flash and auto headlights. But the emit light blue luminescent are less likable. especially in indoor lighting field. Our materials achieved a warm color temperature, while at the same time to achieve a realistic color reproduction. Earlier improved using a single phosphor LED lights failed to achieve this effect.

Pan Zhengwei said, there are two main indicators to measure the quality of artificial light. Correlated color temperature is used to measure the well-being of the light. For Indoor lighting, color temperature is lower than the temperature of 4000K (Kelvin), which is ideal. While correlated color temperature higher than 5000K, the light will emit light blue luminescent white LED lights. Another important indicator is the color reproduction, that is, the ability of the light source simulate natural light. The Reduction degree that reached more than 80 is ideal for indoor lighting, while below this value, the color will be very distortion.

Pan Zhengwei and his colleagues developed the material to meet these two conditions, correlated color temperature is controlled at below 4000K, and also color reproduction reaches 85.

Pan Zhengwei said outer layer of blue LED chip coated with phosphor of different colors, it will be able to issue a warm white light, which would then make a phosphor-based white LED lights. However, these raw materials in accordance with the precise ratio, it wastes money and labor, and eventually the light color will be different, because each raw material is not the same reaction to temperature change.

Doubt and Tension, two expression for LED industry

Doubt

In 2012, the net profit of some companies rely on government subsidies,which is more serious. The state subsidies occupy a large part of their profits; This can not help but provoke the questioned eyes of everyone. So the sustainability of this mode is also controversial.

The subsidies can be counted as corporate profits., The answer is yes! Listed companies Sanan Optoelectronics third quarter profit is 667 million yuan, including subsidies up to 328 million yuan, accounting for nearly half; On November 13, Sanan carried on the enormous financial to achieve the Taiwan Formosa Epitaxy, which is almost twice equity-it is the first private equity. And soon after followed came the news Sanan CDB borrowings of up to 5.5 billion; Look at BDO Runda, interim net profit is 120 million yuan in 2012, while government subsidies is up to 150 million yuan as much, compared to the three security I am afraid that surpasses it; the profits of the country star power subsidies accounted for approximately 25%.

In this regard, industry insiders questioned that, the national starting point is good, but excessive investment is precisely a big reason caused by industry overcapacity. From another perspective, the LED Lights, as a new LED industry, it is necessary to get support from the government, but whether it should be facing the end consumer subsidies? For Enterprises, enterprises who can obtain subsidies only account for a small part of the type of product. A small number of large enterprises are not always having everything if they have government funding. Government can give you a ride, but ultimately it depends on the enterprise’s own energy and strength.

Doubt and Tension, two expression for LED industry

Tension

In 2012, LED industry development is still facing many challenges. But influenced by the European debt crisis, the U.S. economic downturn and other factors, China LED companies exporting orders dropped sharply.

Lighting companies in particular, the industry began to centralized direction development, some of which have already accumulated enough strength to take advantage of this opportunity to develop a large-scale local lighting industry, and try to come out on top in the new round of competition in the industry, but the small and medium-sized enterprises who lack of core technology strength will face more severe survival problems.