• P.R.Yawale
• P.B.Pathakji
• V.G. Wagh
• P.B.Buchade
• A.D. Shaligram

Uniform, adequate and pleasant illumination over a certain target area is a common requirement in many applications.Light emitting diodes gradually becoming the first choice for many lighting applications because of luminance efficacy, compactness and durability. Illumination system consists of one or many light sources and used to create a visual environment for visibility of objects of variable sizes and shapes. LED lighting sources are composed of several individual LEDs mounted on a panel. Denser the LED array,more uniform is the illumination. However, high density of LEDs in an array is restricted due tothe thermal problem, available space and cost. High bright LEDs are intense point sources of light and create bright spots known as LED hotspots that are harmful to human eyes. Technical specifications to be considered for designing of lighting system are desirable intensity distribution, color, energy consumption, cost, effect on health, safety, ambient light effect, etc. To avoid these problems systematic approach is necessarythat provides an optimized design of illumination system. Different configurations of LED arrays such as circular, linear and square are used to obtain anuniform illumination. Therefore, it is important to obtain better uniform illumination using less number of LEDs. One of the ways to obtain anuniform illumination is to use diffusers. Diffusers are essential to distribute the light emitted by the LEDs evenly and reduce their glare. A vast of diffuser materials are available today those have a dramatic effect onillumination. A frosted glass positioned in front of the light source was the traditional method as a diffuser. The frosted glass has high absorption-coefficient and it blocks a large amount of the LED light. Also glass is bulky that increases the overall weight of the final device. Another problem is that glass materials cannot efficiently hide the point sources of light and can result in LED hotspots. In addition, glass is prone to crack during shipping and installation.To overcome these difficulties, plastics (acrylic and polycarbonates) are dominating the LED diffusers. Polycarbonate diffusers convert the point-shaped glary light from LEDs into homogeneous surface spread light with high luminous efficiency and excellent hotspot hiding. Acrylic gives good results, but adds weight, complexity and cost to the overall luminaire design. The acrylic and polycarbonate diffusers offer good uniformity but light efficiency of source is reduced during light diffusion action.Reflection and absorption by surrounding wall coatings, furniture and furnishing materials also affect the uniformity of light. This paper reports simulation results to find effect of different materialsabsorption and reflection properties on uniform illumination. Simulation was carried out using DIALux software. Selection of optimal diffuser material to obtain glare free uniform illumination for a specific application is also highlighted.

optical diffusers, uniformity, glare, DIALux, reflection and absorption coefficients

"Effect of Reflection and Absorption Properties of Materials in Designing Application Based Illumination System", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 5, page no.171-175, May - 2019, Available :http://www.jetir.org/papers/JETIRCP06029.pdf

"Effect of Reflection and Absorption Properties of Materials in Designing Application Based Illumination System", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 5, page no. pp171-175, May - 2019, Available at : http://www.jetir.org/papers/JETIRCP06029.pdf