Choosing the right source of light and finding a scientifically sensible light distribution is the key to improving illumination uniformity. Previously, the wall was washed with fluorescent lamps or metal halide lamps, and the illumination uniformity was not ideal. Fluorescent lamps are linear light sources that are not far off. Although the metal halide lamp is a point light source, the power of the single lamp is large and the spot is obvious. Therefore, we choose lamps with high-power LED as the light source. After special light distribution design as the wall washer, the uniformity of illumination will be greatly improved. Starting from theoretical analysis, we will study the needs of light distribution and seek reasonable light distribution of LED linear lamps that can evenly polish one wall. We strive to achieve the best balance between the efficiency and effectiveness of wall washers. The research method starts with a spot that is washed by a led light source on the wall. Then use the superposition method to study the wall washing effect of a row of LEDs. The DIALux software is used to simulate the calculation, and the light distribution data is improved according to the calculation result, so that the illumination uniformity of the illuminated surface is more than 0.9. How to use a LED linear luminaire to evenly brighten a wall? What kind of light distribution does the luminaire need? In the past, special studies in this area were rare. This paper starts with theoretical analysis, and combines theory with practice to explore the light distribution requirements of such lamps. 1, light distribution needs We know that the LED light source is the light distribution of all the LED particles in the lamp. So we started by studying the light distribution requirements of a single LED. First, we assume that the lens that determines the LED light distribution is axisymmetric that is easy to process, easy to ensure light uniformity and light quality. Figure 1 Single LED light distribution with narrow beam lens and its spot Figure 2 A plurality of LEDs with a narrow beam lens are superimposed to form a spot of the entire luminaire Secondly, the luminaire needs to have a yaw angle α that turns to the illuminated surface, so that the maximum intensity of the center of the luminaire is aligned with the farthest end of the illuminated surface, so that more light is directed to the farthest end to improve the uniformity. As shown below. Figure 3 calculation sketch Finding the light distribution curve is a function of the light intensity Iθ with respect to the angle θ. According to the cosine square inverse ratio law: Eθ=Iθ*cos3(90°-(α+θ))/h2(1) It is assumed that the distance h from the illuminated surface of the luminaire is constant, so when Iθ is inversely proportional to cos3 (90°-(α+θ)), namely: When Iθ=a/cos3 (90°-(α+θ)) (a is a constant), Eθ is kept constant. For the convenience of discussion, the yaw angle α of the luminaire is set to 10°. Because you want to find the shape of the light distribution curve, without losing the generality, let a be unit 1, you can get the following table: Table 1 light distribution curve calculation data table Based on the data of this table, the LED lens light distribution curve constructed as shown below. Figure 4 Single LED light distribution curve required for wall washers It is easy to know from formula (1) that when α is at other angles, the single LED light distribution curve required for the illuminated surface lamp can be uniformly washed, but the peaks are different, and the basic shapes of the curves are the same. Dual USB Charger,Round USB Charger,USB Charger Outlet,Round USB Charging Dongguan baiyou electronic co.,ltd , https://www.dgbaiyou.com
Solve the light distribution LED line type lamp to evenly brighten a wall
In the field of lighting engineering, it is sometimes necessary to illuminate a wall evenly. In order to achieve the purpose of concealing the luminaire, it is usually done by washing the wall.