2012年7月30日星期一

small led grow light and reducing cost


LED lights display used in many ways, the emerging field of LED display industry, the technical aspects of development tend to have many deficiencies. This article will discuss the key technical issues need to be resolved, attributed to "three high and one low", ie, high light efficiency, high color rendering, high reliability and low cost technology to achieve low cost and its essence is also a technical problem.
small led grow light and reducing cost
Of course, to solve these technical problems also need a series of measures displayed in the LED industry chain. Such as the use of new technologies, new structure, new processes, new materials. In this paper, stresses v. to take the technical route and its direction, and hope that through this article is described in the product innovation of the LED industry entrepreneurs.
The following from the "three high and one low" high light efficiency, high color rendering, high reliability and low cost:
High light efficiency
The luminous efficiency for the LED display can be said to be an important indicator of the energy saving effect, and effect of the luminous efficiency there to be strengthened in order to really to do to solve technical problems related to all aspects of the high light efficiency, from the industrial chain, and then how to achieve high light effect it? This article will specifically compete to explore the epitaxy, packaging, lighting, etc. to solve technical problems.
A. Improve the internal quantum efficiency and external quantum efficiency.
Two. To improve encapsulation efficiency of the light and reduce the junction temperature.
3. Improve the lighting of the light extraction efficiency.
High color rendering
LED display the quality of light and color, including color temperature, color, light and color fidelity, light color natural tones to identify the degree of visual comfort. Here we only discuss and resolve the problem of the color temperature and color. Production of high-color LED display light, will lose more light efficiency, and to take care of these two factors in the design. Of course, to improve the high color rendering must also consider the combination of the three primary colors RGB. Here I have three ways to:
A. Multi-primary color phosphors.
Two. RGB multi-chip combination.
3. Fluorescent powder and chips.
High reliability
Including the failure rate, life expectancy and other indicators. But in the application but there is a different understanding and elaboration. High reliability refers to the ability of the product under specified conditions and provisions within the time to complete the required function. LED fails categories have a serious failure to failure and parameters. Life is the value of the product reliability characterization. : Generally refers to the statistical average of a large number of components in terms of the life of the LED devices is the meaning of this description. But affect the LED street lights chip manufacturing, packaging, thermal resistance, heat and other factors curtain product reliability. Speaking of LED display products based on the implementation of comprehensive quality control for the 2:00:
A. Reduce the loss of efficiency.
Two. Extend the depletion time to failure.
Reduce product cost
Many consumers in the purchase of LED display at all times feel that price is too high, so the contention that this many LED spot display entrepreneurs have taken the appropriate measures to reduce costs in addition to mass production, mainly from the technical to take measures to reduce costs approach, ways. In epitaxial silicon, package, driver, heat, reduce costs, a fundamental solution to the cost of LED display products. Specific talk about the following four aspects:
A. Epitaxial silicon link to ways to reduce costs.
Two. The package links lower costs.
3. Lighting aspects of cost reduction methods.
4. Other ancillary cost reduction
These are mainly from the high light efficiency, high color rendering, high reliability and low cost of the four technology to solve the LED display technology and take corresponding measures, total Overall, through the adoption of new technologies, new processes, new structure, new materials and other measures to achieve a high luminous efficiency of LED display, high color rendering, high reliability and low-cost outside the deeper point of view, should be to improve the quality of energy efficiency and light color as the LED display higher, so the real people provide products on demand!

small led grow lights and print method


Lighting applications or backlighting applications, the light guide plate and the LED lights source with the best in the compatibility of the product quality and poor quality of the light guide plate for the entire LED products have an important impact, the most important performance in the brightness and uniformity. The same module, the light guide plate will have different effects, high-quality light guide plate transmittance significantly than low-quality high, but also to prevent the bright spot, dark areas appear.
small led grow lights and print method
The production of light guide material is plexiglass or PC material, but the market is more and are based on acrylic sheet, because it is the most excellent quality so far synthetic transparent material, with unparalleled high brightness, can improve the light use efficiency. Acrylic and then through a series of processing before they can be called the light guide plate, the processing of the main methods of network production.
Speaking of network production, familiar screen printing LGP, a large number of customers because of its low cost and used as a backlight. In fact, countries develop energy-saving environmental protection engineering, screen printing light guide plate manufacturers should follow the development trend of environmental protection, aligned with the environmental protection industry. Below the shortcomings of the production of silk screen light guide plate.
As we all know, the silk screen of the production of the light guide plate can not be separated from the ink, which is produced materials. But the ink is the biggest source of pollution of the printing industry, has reached hundreds of thousands of tons of emissions annually by the ink-induced global volatile organic compounds (VOC) contamination, these volatile organic compounds, the formation of a more serious greenhouse effect than carbon dioxide, and sunlight irradiation, the formation of oxides and photochemical smog, seriously pollutes the atmospheric environment, affect people's health.
LED products, not only energy saving, long life advantages. Long life is an important feature of the LED products, determine the LED light source, light guide plate is almost decided the life of the entire LED products. LED lighting process inevitably produces heat, heat ink for screen printing light guide plate will have been affected. A test of the industry experts in the use of screen printing LGP LED panel lights, lights for three months, resulting in a nearly one-third of the degree of light failure. This situation resulted mainly due to the lighting process, the heat generated by the LED so that the light guide plate of the ink volatile, deterioration of the stability of the light guide, so contrary to the view of the LED products durable.
In the screen printing process, you must also pay attention to the production environment. Strictly speaking, must be in a clean room for production, clean room is defined as having the air filter, allocation, optimization, structural materials and equipment room, is the basis of pollution control, clean room, the light guide plate of pollution-sensitive ink screen printing can not mass production. Production is completed, the application need to pay attention to the application environment humidity, UV screen printing outlets, rainy and sunny weather will speed up the phenomenon of light failure.
Admittedly, the design of the screen printing network technology is very mature, and the effect on the brightness and uniformity welcomed by many customers, but in view of the complexity of production processes and the requirements on the flatness of the acrylic sheet is very high (screen printing requirements of the acrylic sheet surface very flat, or can not be printed, so they use the extruded sheet, in order to ensure flatness) a lot of companies are beginning to transition to the direction of the laser scribing or laser dot design, this also causes the laser light guide plate products in the market and screen printing light guide plate to compete for market share reasons.

small led lamps and fire proof


With the rapid development of modern technology, LED lights display screen industry sustained rapid speed of growth, expanding industry, technology innovation, market share since 1993, continued to grow by an annual average growth rate of 40%, however, in 2012 Hong Kong Harbour Grand caught fire incident on April 2, knocked to the entire LED industry a wake-up call: the rapid growth of this industry, LED display screen safe application of technology to the remaining short board, LED productsstandardization and Standardization was again put on the agenda. In particular, LED display screen fire safety application techniques is the focus of today I would take you to see what factors will affect the display of fire safety issues.
small led lamps and fire proof
Display fire prevention technology is good or bad is closely associated with display fire raw materials, cabinet craft.
The fire main raw materials, including the display of these four aspects of the use of the screen inside the wire, power supply, external protection, structural fire protection materials and plastic kit:
The first point: in most display applications, the unit area of ​​the screen shows the greater the greater the power consumption, higher requirements on the power stability of the wire. Many wire products, in line with GB requirements of the wire to be able to guarantee its security and stability, requires three things: wire core copper conductive carrier, wire core cross-sectional area of ​​tolerance in the value of the standard range, wrapped wire core rubber insulation up to standard and flame retardant, compared to the copper clad aluminum wire core wire core cross-sectional area is small enough level of insulation rubber wire, power performance is more stable, less prone to short-circuit condition;
Second point: UL approved power products also chose the best choice when similar products, the effective conversion rate power load to ensure security and stability in the external ambient temperature of the hot case, can also work;
The third point: display external protective structure material on the market, higher fire rating display products are mostly fire-resistant aluminum composite panel, its fire resistance and excellent fire retardant is also strong, the core material Special Material oxygen aging properties is also very strong, melting temperature 135 ° C, decomposition temperature ≥ 300 ° C, the environmental performance of halogen, in line with SGS, flame retardant B-S1, d0, t0, reference standard the UL94 GB/8624-2006. General outdoor display screen products of the aluminum plate with high temperature, rain and hot and cold impact aging rapidly, season segment in a more humid climate, make it rain easily penetrate inside the screen body leading to electronic components caused by short fire;
The fourth point: the curtain fire raw materials, there is an important part of that is plastic kit, plastic kit modules available for the use of the mask bottom shell materials, the main use of raw materials with a flame retardant PC + fiberglass materials, not only has the resistance burning function better at high temperature and long-term use, no distortion, does not become brittle and crack, combined with the tightness of good glue to use, can effectively block the external environment of the rain in through causing a short circuit within the fire .
In addition to the internal raw materials will affect the fire effect, external configuration and design also very important, but the external configuration is mainly involved to fire prevention, heat in the display screen work at the same time, configure the row of fans and air conditioners cooling the inside of the screen body cooling, recommended every 8-10 square assembly 1P air conditioning to ensure that screen the body temperature is kept constant temperature is not configured in place of air conditioning or exhaust fans can cause uneven heat treatment, easily lead to elevated temperature caused by the screen within the security risks. A lot of LED down lights companies during the cabinet level of protection test simply to simulate the spray water testing in the external environment, pending research on the persistence and strength of the waterproofing effect, with the result in the display products used for some time after there seepage occurred, this is the outdoor display is easy to fire or short service life of the important reasons. In response to a lightning storm, the Screen device arrester is to avoid the lightning assault and burned an essential tool of the screen within the device, the lightning to ground impact without Screen.
Above belong to the display of internal reasons, of course we can not ignore the later maintenance process caused by human factors, in the follow-up maintenance work, for example, the operator did not follow a strict process flow operation (module screws did not matter, wire reverse polarity, conductive objects left over after the operation, etc.), and easily lead to the house on fire.
The exact cause of the fire events of the Hong Kong hotel display there is to be investigated, but not incident on Hong Kong's LED display product application to hold a negative attitude, while the entire industry standards has not been established, but the industry is doing better LED business or, for example, Chau Ming, Shenzhen City, display products have been the England Test Center BS476 building materials fire retardant test, display products to meet international certification standards within the LED industry leader, we should in line to lead exemplary corporate, high quality, strict specifications required, and guide the healthy development of the industry, thereby enhancing the competitiveness of the industry as a whole in the international arena and globalize.

smd high power led and dlp technology


Strong technology as a new big-screen video, LED lights source DLP splicing products have been one of the industry the focus of industrial innovation. Era light LED technology is not only a simple change of the light source technology, it will fundamentally change the practical performance of the DLP splicing products, or even create many new applications. LED light source DLP Video New in the end they will give industrial customers to bring a new surprise which unexpected?
Lower cost of ownership
smd high power led and dlp technology
The LED high bay light source used in DLP Video Wall product is the first significant change is the user's cost is significantly reduced. Although the use of LED technology will make the first investment of DLP Video Wall project increased by 30%, but the LED light source to achieve a life of 60,000 hours, is equivalent to about 20 times that of traditional mercury lamps. That is the whole life of the customers in the DLP Video Wall will save at least 20 bulb replacement costs. This fee is not only enough to offset the LED technology resulting from the rising cost of DLP splicing unit can save a lot of money invested.
Another feature of the LED light source technology is the three primary colors of light independently. This makes the DLP projection system to no longer need the splitter device of the color wheel. As a mechanical operation of the product, color wheel maintenance and replacement frequency is caused by the customer an important part of the cost. Although the color wheel components are not DLP Video Wall core supplies, but no color wheel, LED lighting products, the economy still can not be ignored.
The long-life LED light source also makes DLP Video Wall, a significant reduction in maintenance frequency. The annual maintenance number at least a 50% reduction. This will also serve as important "money" node, one of the important added value for customers purchasing LED light source products. In addition, as an efficient light source products, LED down light will also have a higher luminous efficiency, higher light utilization efficiency, which reflects the "low cost" feature of the other part of the conservation of electricity.
Higher system reliability
LED light source of the product itself is a solid cold light source products. Its high efficiency, low heat, solid-state form is not accidental damage. Traditional mercury lamp light source has the vulnerability of ordinary light bulbs, high product temperature in highlighting the work of state, is also easier because of accident damage, burning, or burst. The solid-state light-emitting LED light source features a significant increase in the stability of the light source.
With traditional mercury lamps products, LED light low-voltage DC pulse drive. The power supply section does not contain high-voltage high-current components, the power of life and stability are more controllable. Combination of the three primary colors of natural light-emitting LED light source, and no mechanical color wheel component splitting, making the LED light source part of the power supply, control and spectral three aspects go beyond the traditional mercury lamp stability.
LED light source, the three primary colors independent light-emitting characteristics of the work makes it even a "light bulb" fails, the machine is still in the state of the lack of color display. This is the traditional single-lamp DLP splicing unit once the light bulb burned, in sharp contrast to the situation of not work. The lack of color display characteristics, making the light accidents of LED light source can protect customers' losses to a minimum or even no loss. LED light source products and a simple single-lamp DLP splicing unit, its reliability is closer to the Lamps backup system.
Green environmentally friendly low-carbon
The LED light source technology is well-known green technology. The characteristics of the semiconductor manufacturing process, to make it easier the control of toxic metals, unlike the traditional mercury lamp, once the damage is likely to cause the leak of the toxic elements of the internal mercury lamp. As semiconductor components, LED light source can also be recycled, one of the important metal elements can re-enter the smelting aspects of regeneration.
In addition, LED light products or high luminous efficiency light source products.
In the same light conditions, with lower power consumption. Moreover, LED light source using digital pulse light, independent of the three primary colors, and only when the DLP light valve chip DMD certain colors of light, LED light source before work. This is very different to work with traditional mercury lamps continued to ignite. LED light source is not continuous, luminous valuable only when needed, to enable them to better meet the needs of the future economic development of low carbon environmental protection.
More gorgeous bright screen
The LED light source is a typical wide-gamut light source, its color effect is far more than the traditional mercury lamp products. Do not need color wheel for additional filtering characteristics, are also better able to protect the entire DLP-ray machine system can accurately restore the excellent color. The giant ocean LED light source DLP splicing products also has 100

smd led lamps, led and oled


The difference between LED lights and OLED
LED TV is the boundary illuminated LCD (liquid crystal display), around the screen a large number of light-emitting diodes, the light transmitted by an independent wire to the center of the screen. It makes the screen thinner, but also brought unpleasant viewing angle.
smd led lamps, led and oled
In contrast OLED (organic light emitting display) screen is able to light-emitting current through organic materials. Because in addition to the backlight, OLED screen performance is more superior than other competing products.
The benefits of OLED led down lights
The OLED TV to be able to provide higher density map and a clearer image, which means that the OLED screen can display three-dimensional images without sacrificing image resolution, as like most other TV. OLED TV to enjoy the natural scenery video like by the window concept, rather than watching a glowing box.
Not talking about color. OLED displays can artificially create all the colors of nature. Looked at the LCD screen and then look at the OLED screen, it feels like "The Wizard of Oz" Dorothy the first time you open the door to the Wonderland.
OLED screen contrast is almost unlimited, so watching the screen does not appear in the Blu-ray Disc "Dark Knight" color aliasing or black spots. OLED also overcomes the problem of motion blur, usually on the LCD device will see a quick flash of the screen characters appear annoying, horrible ghost. Alone, these advantages enough to make OLED screens become the game of choice for display.
OLED screen is not only the TV to become more compact and more thin, it can freely bend. Have not seen any this big screen, but I believe the near future, the TV hanging from the ceiling to.
What are the disadvantages?
OLED TV will be no firm offer, you can imagine that it is approximately twice the price of LCD HDTV. Also, their availability is probably years later, you have to consider replacing the blue OLED life of 14,000 hours (equivalent to eight hours a day to 5 years).
This TV, can not be used outdoors or in a strong light room too light to cover up or play down the television image. Also, long-term exposure to ultraviolet light will be substantial damage to organic diagram, the formation of the necrotic spot caused by the regrettable results equivalent to no longer worth the used car.
May have heard of OLED screens is the power consumption of less environmentally friendly products, but is not the case. OLE screen image blackish power consumption of only 40% of the LCD; image with a white background (the Windows desktop, web, play drama House MD, MD), the OLD power consumption of the screen under normal circumstances three times.
Have yet to become mainstream
We mixed the new OLED TV. Although it unmatched picture quality, OLED TV is not yet universal access. Involved in research and development before the technology immature, Sony only focus on the LED products screen on the LCD.
If the family wants to share a TV as a daily viewing purposes will exclude these expensive types. If a specialized room for watching movies and TV shows every day, not more than five hours, OLED TV is only worth considering.

solar energy led lighting and ppfc design


The development of high-power LED lighting solutions manufacturer currently experiencing the biggest design challenge is the thermal design and thermal overload protection, they must overcome 's LED lights source is sensitive to heat problems, and will cause excessive heat or improper application of the performance of the LED light source be discounted.
solar energy led lighting and ppfc design
Theory and practice has proven that LED performance and life expectancy is closely related to the PN junction temperature of the LED. When the LED chip junction temperature rise of 10 ° C, the luminous flux will decay to 1%, 50% reduction in the life of the LED, overcurrent, overvoltage and overheating will significantly reduce the performance and service life of the LED street light. Therefore, in addition to good thermal design, safe and reliable overheating protection must be considered.
Usually on the LED, about 20% of the input power is converted to light, 80% is converted to heat. This depends on many factors, fever may be related to the underlying irregular and phonon emission, seal materials. 90% of the total heat generated by the LED, by conduction transmission. Dissipation of heat from the LED junction, conduction is the thermal conductivity of the main channel, convection and radiation is only about 10% of all heat transfer.
Obviously, LED light source requires accurate power and thermal management systems, as compared with other light sources to provide electricity to the LED most of the conversion to heat. Without proper thermal management, heat will affect the LED life and color output. The same time, due to the LED driver devices are silicon devices, they will soon fail. This must be equipped with fail-safe backup overcurrent protection devices.
So why the success of high-power LED lighting design can not be separated from PPTC? Many people think that the LED driver can provide overcurrent and overtemperature protection is not necessary to add a PPTC device in the external, because it would add additional cost. But this is wrong, many of the LED driver is easy to be damaged due to DC voltage and polarity errors. LED driver outputs will damaged or destroyed due to short circuit. Although most LED drivers contain built-in security features include thermal shutdown, open LED and short circuit detection. However, to protect the integrated circuit (IC) and other sensitive electronic components, and may require additional overcurrent protective device. Therefore, only the PPTC (especially resettable PolySwitch PPTC) is to prevent overheating damage to the most appropriate solutions in the high-power LED down lights.
To illustrate this problem, we first look at a typical LED driver to provide what protection function. The most high-power LED constant current drive to provide the typical protection features include: thermal shutdown protection, overvoltage / overcurrent comparator, high-current MOSFET, the current size of the adjustment, a certain level of ESD protection. However, the thermal shutdown feature is just a self-protection function, it is difficult to be applied to the LED overheat designed to protect. Overvoltage / overcurrent protection characteristics of the need for external overvoltage protection circuit, turn off the power may cause other problems. High-current MOSFET failure modes are usually short-circuit, which is potentially unsafe factors. LED dimming with the current regulation characteristics may cause the LED over-temperature.
But the concept of the the PPTC the protection of high-power LED is different, it has the following four unique advantages:
1) failure mode is a high-impedance, even in the fault state, LED is safe.
2) PPTC can directly measure the temperature of the LED, so you can close protection.
3) PPTC can be achieved over temperature, overcurrent and overvoltage protection. Very easy to use, does not require an external circuit. LED, even in protected state can work.
4) allows designers to lower cost, dimming design, without worrying about security issues. Therefore outside of the LED driver with a PPTC device can achieve stronger security, and meet the most stringent safety standards and to achieve cost reduction.

solar energy street lights and led strips


First, what is LED strips?
Lights with LED lights use a special process of welding copper wire or strip of flexible circuit boards above, and then connect the power light-emitting, because of its light-emitting shape, such as a light band got its name. The first process is welded to the copper above the LED, and then put the PVC pipe or to use the device directly forming both round and flat like its title to distinguish between the number of copper wire and the lamp with the shape of two lines called second-tier, circular preceded round, that is, round the second-tier; flat in front with flat characters, that is flat second-tier. Later developed into a flexible printed circuit board that the FPC to do the carrier, the process easier, the quality is easier to control, longer life, better color and brightness gradually replace the older process, become the trend.
solar energy street lights and led strips
Round second-line conventional three-wire, round, flat line, flat line; colors red, green, blue, yellow, white, colorful. Diameter: 10mm --- 16mm widely used in building body contours, bridges, rails, hotels, Lin Yuan, dance halls, advertising decoration places.
Second, what's  the advantages of  led strips?
1, soft, like a wire, like curling.
2, able to cut and Yanjie.
3, light bulbs and circuit is completely encapsulated in flexible plastic, insulation, waterproof performance is good, safe to use.
4, the weather resistance.
Difficult to break, long service life.
6, easy to create graphics, text and other shapes; has been widely used in buildings, bridges, roads, gardens, courtyards, floors, ceilings, furniture, automotive, ponds, underwater, advertising, signs, signs, decorations and lighting.
how long is the lifespan?
LED constant current component, so different manufacturers to produce LED light with constant-current effect is not the same, of course, life will vary. Of course, if the poor light with the copper or the toughness of the flexible printed circuit board will also affect the life span of LED lights with.
What precautions four LED lights repair?
1, anti-static: LED bulbs is static-sensitive components, if not done in the maintenance of LED lights with anti-static measures, it will burn LED, resulting in waste. It should be noted that the iron must use anti-static soldering iron, maintenance personnel must also make anti-static measures (such as wearing a static ring and anti-static gloves, etc.)
2, the continuous high temperature: LED lights with two important components of the LED and the FPC are not continuous high temperature products. FPC in the sustained high temperatures or exceeds its withstand temperature, it will make the FPC cover film blistering, a direct result of the LED lamp with scrap. Same time, LED can not be sustained tolerance to high temperature, a long time under high temperature and time, its chips will be burned by the high temperature. Therefore, the iron used in the maintenance LED lights with temperature soldering iron to limit the temperature in a range of prohibited to easily change and set. In addition, even so, should also be noted that the residence time of the LED pin in the maintenance of iron not more than 10 seconds, if you exceed this time, it may burn out the LED chip.
3, weak points: a lot of LED lights with a bad pin at the short-circuit, real bad cause must be identified before servicing. Otherwise, the rush to replace the bad LED, once again the power will continue to cause the LED chip breakdown by short-circuit current. So, before the new LED lamps replacement, we must first find out the real causes of bad, the right medicine can do more with less.

solar led flood lights outdoor and lighting source


With the herd phenomenon of the market, as consumers, use LED lights remains to be calm, scientific analysis, the choice of the best cost-effective light sources and lamps, here are several basic performance of the LED:
1, the brightness of the LED brightness, different prices. LED lamps for LED should be consistent with the Laser Level Class I standards.
2, the antistatic ability antistatic ability LED, long life, and hence the price is high. The antistatic usually greater than 700V, the LED can be used for LED lighting.
Wavelength wavelength LED, the same color, such as requiring the same color, the price is high. No the LED spectrophotocolorimeter instrument manufacturer it is difficult to produce pure colors products.
4, the leakage current LED is one-way conductive light, if the reverse current is called leakage, the leakage current LED street lights, life is short, low prices.
solar led flood lights outdoor and lighting source
5, the use of different light angle of the LED emitting angle. Special light-emitting point of view, higher prices. If all diffusion angle, the higher prices.
6, critical to the quality of life is life, life light bad decision. Light decay, long life, long life and high price.
7-chip LED light chip, different chips, the price difference. The chip is more expensive in Japan, the United States, generally made in Taiwan and chip prices lower than the Japanese, the United States.
8, the size of the chip size chip to the side, the quality of large-chip LED is better than small chips. Prices are proportional to the chip size.
The colloid ordinary LED colloidal general epoxy resin, plus a more expensive price of the LED UV and fire retardant, high-quality outdoor LED lighting should be UV and fire. Each product will have different designs, different designs for different purposes, the reliability of LED lighting design include: electrical safety, fire safety, the application of environmental safety, mechanical safety, health and safety, safe use of time and other factors. From the electrical safety point of view, should comply with the relevant international and national standards.
LED is a new product, the Chinese national standards lag, but the national product qualification testing. LED lighting prices with the international safety certification (such as GS, CE, UL and so on) and the national product quality certification must be high, because these products in the security design is reliable. The attention of consumers is to carefully identify the authenticity of the certificate, certificate of international safety certification and the national product manufacturers are not many.
From health, the price of non-toxic materials designed to be high, especially in indoor LED lighting, do not cheap selection of LED lighting, odor, currently only a few LED manufacturers is produced using non-toxic materials, identify the directly with the nose, respectively, the smell of products than the lower price without the smell. Like lead, mercury, cadmium and other toxins need professionals. Look for environmental safety, reliable dust-proof design, the high price of materials, fire protection, UV protection, anti-low temperature cracking of LED products.