luminous body, the surface is a yellow substance which the core portion of the semiconductor, professional called a PN semiconductor. Through the the PN structure semiconductor design, the current through it emits light. The light is issued at this time is a divergent direction. By the LED packaging technology, so that the light directed injection refraction, encapsulated by resin to form a LED lamp beads condenser results. Course, the LED Flashlight secondary condenser (light cup or lens), but also a very important way. Thus, not all of the light generated by the tube core can be released, which depends primarily on the quality of semiconductor material, the structure and geometry of the tube core inside the package structure and the encapsulating material, application requirements to improve the LED within the external quantum efficiency.
The following LED flashlight reflectors and lens to be a brief introduction:
Encapsulating resin lens converging the light refraction, and thereby control the angle of the light for the first time, the refractive index of the tube core and the refractive index of air is too large, resulting in the die within the total reflection critical angle is very small. Therefore, the appropriate first refraction critical angle of refraction through the large or too small, it is difficult to do a perfect secondary concentrator. Due to the high temperature of the LED light emission, the ideal state is to use aluminum alloy light cup, because as the temperature increases, the plastic optical glass is easily deformed, aging, shortened life expectancy. Secondary refraction of the lens, the LED flashlight light mostly along a straight line.