why do your led flat panel light quality and other homes vary greatly
With the LED chip to improve light efficiency, packaging technology continues to improve, and the development of LED lighting cooling technology, LED light source in the field of rapid expansion of lighting, LED flat panel lamp industry boom.LED flat light with uniform light, low glare, simple installation and many other advantages, good market prospects, leading the new trend of modern fashion indoor lighting. However, the current market, the quality of LED flat-panel light varies, some manufacturers regardless of product quality, blindly lower prices, vicious competition, seriously affected the healthy development of the industry.As the LED led flat panel ceiling drop troffer lights lamp has not yet introduced national standards, in 2014 China Electronics Industry Standardization Technology Association and the China Poly Industry common standards to promote the Foundation jointly announced the cross-strait common standard GT004-2012 “indoor general lighting led flat panel ceiling drop troffer lights lamp”, led flat panel ceiling drop troffer lights lamp Made safety and performance requirements, standardize the quality requirements of LED led flat panel ceiling drop troffer lights lamp, flat panel lamp manufacturers as a reference basis for production, but also makes the market management to follow the law. Cross-strait common standards with reference to the following on how to control the quality of LED led flat panel ceiling drop troffer lights lamp to explore.1, the structural characteristicsLED flat-panel light structure is unique compared with other lamps and lanterns. It is mainly composed of light source, light guide plate, diffusion plate, reflection paper, drive power and so on, more than other lamps, such as light guide plate, diffusion plate, The structure of the product.(1) LED light sourceLED flat panel light manufacturer in the use of LED light source are basically using SMD patch series, such as 3528,3014 and so on. LED led flat panel ceiling drop troffer lights lamp manufacturers face the market is dynamic, manufacturers will be based on the actual needs of customers to choose to meet the design requirements of the light source. LED light source of choice for product performance improvement is critical, is to improve the quality of LED flat light one of the important factors.(2) light guide plateThe role of light guide plate is LED light source of light through the optical technology into a surface light source, the side of the LED light refraction through the mesh to the light from the front evenly derived. At present, the main form of printing-type light guide plate, light guide plate will directly affect the quality of the product brightness and uniformity, requires a good light transmission performance.Light guide plate is the key point of led flat panel ceiling drop troffer lights lamp quality control, network design is not good, the overall luminous efficiency is poor, the light is not uniform, there will be bright on both sides of the middle of dark, light into the light band, visible dark areas, different Angle brightness inconsistencies and so on. To improve the efficiency of light guide plate mainly depends on the design of outlets, followed by the quality of the plate, should choose the high rate of qualified translucent plate.(3) a diffusion plateThe main role of diffusion plate is to light guide plate evenly derived, so that the distribution of light more evenly. When the light reaches the diffusion point, the reflected light will spread to all angles, and then emitted from the positive light guide plate, the use of a variety of density, the size of the proliferation of points, the light guide plate uniform light to improve the light guide plate brightness. But also play a role in fuzzy dot.Diffuser plate is generally used acrylic sheet or PC material, almost PS material. Acrylic low cost and light transmittance slightly higher than the PC, anti-aging performance is weak; PC price is slightly expensive, but strong anti-aging properties. Diffusion board can not be seen after the installation of outlets, and the transmittance to 90%. Acrylic light transmittance of 92%, PC is about 90%, PS is about 88%, manufacturers can be based on the demand for diffusion plate material selection, most manufacturers are using acrylic materials.(4) reflective paperReflective paper is the role of light guide plate under the overflow of light reflection, making the full use of LED light, as far as possible reflectivity close to 100% reflective paper, to maximize the use of light to improve the output of LED flat panel brightness, the general For the RW250.(5) rear coverThe main role is to seal the LED flat-panel light, the general use of aluminum, but also play a cooling effect.(6) drive powerThere are two kinds of LED drive power, one is the use of constant current power supply, this model is efficient, PF value of up to 0.95, cost-effective; second is to use constant voltage with constant current power supply, stable performance, but low efficiency, high cost, This power is mainly for export, the other has certification requirements. In fact the family is safe to use constant current power supply, because users are difficult to access to power, and the lamp body itself is safe low voltage.2, improve efficiencyPerformance level is an important indicator of the performance evaluation of LED flat panel lights. Luminous efficiency (luminousefficacy) is the luminous flux emitted by the light source and its power consumption ratio, the unit is lm W. Luminaire performance (luminaireefficacy) is the use of the lamp in the claimed conditions, the initial luminous flux emitted by the lamp and its power consumption ratio, the unit is lm W.“Light efficiency” for the evaluation of LED light source, “lamp performance” used to evaluate the LED lamps, LED light source efficiency and LED lighting efficiency that energy into light energy efficiency, is to describe energy-saving lighting products indicators, Is different. In accordance with GT004-2012 “indoor general lighting with led flat panel ceiling drop troffer lights lamp” standard, the measurement should be not more than 65% relative humidity, temperature 25 ℃ ± 1 ℃ without air convection environment, and should make led flat panel ceiling drop troffer lights lamp in a stable working condition .LED light source light efficiency in the light source flux is the bare light source (not installed in the state of the lamp) the luminous flux. LED luminous flux in the performance of light is the light source into the lamp, while using the required LED control device or LED control device power supply, the luminous flux emitted by the lamp. LED light source consumes less electric power than LED lamps consume electrical power. LED light source light efficiency is much greater than the lamp performance. One is because the LED into the lamp, the color temperature increases, reducing the light output; the other because the light into the light, the use of LED control device or power supply after the loss of the system; Third, light through the optical system after the loss of light, Factors will result in reduced luminous efficiency lamps. GT004-2012 “indoor general lighting with led flat panel ceiling drop troffer lights lamp” standard provides different color temperature of the lamp performance rating (the table below).LED led flat panel ceiling drop troffer lights lamp test found that improving performance must do the following two points: First, to choose high-efficiency, high brightness LED, both can improve performance, can also reduce costs, more importantly, improve the quality of LED flat-panel light. Second, the light emitted by the LED to make full use of, if only concerned about the brightness of the LED, but failed to improve the design of the optical path, effectively improve the utilization of light, LED led flat panel ceiling drop troffer lights lamp performance to enhance the effect is not.From the LED light source to the light guide plate, reflective plate, until the final led flat panel ceiling drop troffer lights lamp display the entire process, the utilization of light from the brightness indicators will be reduced by about 30%, LED flat light from the light guide plate to the final utilization rate of less than 70%. To improve the utilization of light, you need to choose good quality light guide plate, reflective paper and other materials, not only to meet the led flat panel ceiling drop troffer lights lamp design technical performance indicators, but also in the size of the specifications with each other. As the direct-type module thick, thin and beautiful does not meet the trend, therefore, the current mainly to the side light.The role of the light guide plate is to guide the light scattering direction, used to improve the brightness of the panel, and to ensure uniformity of panel brightness. Now the application of more and more thin light guide plate, the quality of the quality of the impact of LED flat panel light great, light guide plate light transmittance and optical uniformity indicator is the pros and cons of side light led flat panel ceiling drop troffer lights lamp performance improvement key.Light guide plate is the use of injection molding method of propylene pressed into a smooth surface of the plate, or the use of existing acrylic plate, light transmittance of 90% or more; and then with a high reflective and non-absorbing materials, light guide plate The bottom printed with the screen printed on the proliferation of points, reflective paper will overflow the bottom of the light reflected back to the light guide plate, used to improve the efficiency of light and positive brightness. After laboratory tests, the results show that LED professional manufacturers of led flat panel ceiling drop troffer lights lamp performance in the color temperature 5500K can reach 110lm W, but can reach the level of performance of the manufacturers are not many.3, good uniformityLED led flat panel ceiling drop troffer lights lamp is another important indicator of its luminous uniformity, cross-strait common standard GT004-2012 “indoor general lighting with led flat panel ceiling drop troffer lights lamp” proposed brightness uniformity (luminanceuniformity) requirements, refers to the light-emitting surface brightness and brightness minimum Arithmetic mean value.As the LED flat-panel light, the uneven light will lead to uniform brightness of the panel display, causing the perception of the human eye uncomfortable. According to GT004-2012 standard requirements, led flat panel ceiling drop troffer lights lamp brightness uniformity should be not less than 0.8. Test method is mainly based on the size of the screen size, select the appropriate test points, measured the brightness of each point.The square L, the long side of the rectangle L and the circle diameter D of not more than 20cm led flat panel ceiling drop troffer lights lamp, according to the following diagram (a) of the requirements of distribution; more than 20cm led flat panel ceiling drop troffer lights lamp according to figure (b) In the led flat panel ceiling drop troffer lights lamp light-emitting surface of the test spot diameter of 2cm ~ 3cm, the brightness of each point and the average brightness after subtracting the maximum, then the maximum brightness divided by the percentage of the average brightness uniformity. It is generally believed that uniformity of more than 80% of the perception of the human eye has little effect.Flat lamp brightness uniformity test is the first time in the standard indoor lighting on the surface brightness requirements. It reflects the characteristics of flat-panel lighting parameters, is one of the important characteristics of this type of lighting. In indoor lighting, surface lighting to create a soft lighting effect is simple and other stent lamps or grille lamps can not be replaced.Indoor lighting, fluorescent lamps with diffuser plate is also a surface luminous effect, has been used for many years, but not up to the level of led flat panel ceiling drop troffer lights lamp brightness uniformity. The reason is that fluorescent tubes are omnidirectional light source, can not adjust the optical system to achieve better brightness uniformity, and lamp performance is 40lm W level. The LED light source is a half-space light, in the lamp, the light utilization rate, lamp performance can reach 80lm W or more, while the brightness uniformity can reach a high level.The use of side-light structure LED flat light, LED light-emitting tube is arranged in the side of the light guide plate, lamp visual effect is better. At present, most domestic manufacturers still use printed light guide plate as the light guide components, the use of a variety of density, the proliferation of different sizes, the light guide plate uniform light, in order to obtain good light uniformity.From the test results, small size led flat panel ceiling drop troffer lights lamp brightness uniformity easily meet the requirements, even if a little deviation from the uniformity of the human eye is also not easy to feel out. Large areas of LED led flat panel ceiling drop troffer lights lamps, and sometimes due to the quality of light guide plate brightness unevenness occurs, there are process reasons caused by the light into the light band, or visible dark areas of local phenomenon. Therefore, the selection of the main raw materials such as light guide plate, diffusion plate and reflection paper should be evaluated in good quality, and the raw materials should be strictly controlled. The manufacturer should be equipped with necessary optical brightness meter and light transmittance testing instrument.4, the color differenceFrom the visual sensitivity of the human eye, the yellow and green color-sensitive, that is, these two colors a little bit volatile, the human eye can feel. The same production enterprises to produce LED led flat panel ceiling drop troffer lights lamps, different batches of products should not be obvious color, or users in the product is difficult to re-buy the same color after the failure of the product.The standard stipulates that the light color between samples of three led flat panel ceiling drop troffer lights lamps should be consistent, and the average color coordinate value of three samples should not exceed 0.004. At the end of the luminous flux maintenance test, the chromaticity of the LED panel light fixture should deviate from the initial value by 0.007 in the CIE1976 (u’v ‘) diagram.In the led flat panel ceiling drop troffer lights lamp lamps, commonly used colors are red, green, blue and white, measure the color of the unit is nm (nano), the color-sensitive people, as long as the color a little bit of volatility can be felt. To control the color, you must control the raw materials. In order to avoid the differences caused by different wavelengths of light, lighting production company should control the LED light source.
Such as green wavelength 525-530nm, separated by 5nm, yellow 580-585nm, separated by 5nm. While the red can be 620-628nm, separated by 8nm, the green wavelength can be separated by more than 5nm, the red even within 8nm will not be too obvious. However, to reduce chromatic aberration, to avoid long-term use due to some of the uncertainties, such as color drift, the same color wavelength control in the 2nm is appropriate. So the control of the color index is often important, because different people on the color discrimination ability is not the same.For white, usually with color temperature, warm white is generally 3000-3500K, is white 3500-5000K, cold white 5000K-6500K. General packaging manufacturers LED color temperature separated by 500K, also separated by 1000K, the internal temperature of the package for the color temperature error requirements are generally plus or minus 200K. Therefore, the color should be stable LED light source, the production process should be strictly controlled.Detection of LED led flat panel ceiling drop troffer lights lamp color, found that the choice of three different led flat panel ceiling drop troffer lights lamp samples for testing, different manufacturers of color products are not the same, there will be a certain gap, some LED flat-panel products color standards than the standard, after analysis that the main The reason is the manufacturer in the selection of LED light source failed to seriously and effective screening, the consistency of the optical performance of each LED is not good, resulting in different flat-panel lighting color is not the same, a large area of visual perception of poor installation, Uncomfortable feeling.To improve this common problem, first, to do a good job in supplier evaluation, select a relatively fixed vendor; the second is to LED products supplier consistency requirements to ensure continuity of supply and a variety of performance indicators are relatively stable; Third, the company itself should strengthen the LED incoming inspection, excluding chromatic aberration of the requirements of the LED, to ensure that produce consistent with the requirements of LED flat light.5, there are problemsAt present, the performance of LED devices continues to increase, its scope of application is also growing, LED lamps dimmable products are constantly innovating, application areas continue to expand. High-brightness white LED light efficiency continues to improve, the achievements of the contralateral LED led flat panel ceiling drop troffer lights lamp demand, which also contributed to the new LED led flat panel ceiling drop troffer lights lamp research and development, making new side-type LED flat-panel lights continue to emerge.However, LED led flat panel ceiling drop troffer lights lamp also has some problems.First, lamp performance, for the side into the LED flat-panel light, low efficiency is still an urgent problem to be solved. On the one hand, to achieve high brightness, we must increase the number of chips to improve power, but the energy-saving effect of poor performance, especially large-size led flat panel ceiling drop troffer lights lamp; the other hand, power increases, lighting equipment LED module operating temperature will increase, Affect the light decay and life, so how to choose high light efficiency of the LED light source needs comprehensive examination