人的眼睛能看到的可見光按波長從長到短排列，依次為紅、橙、黃、綠、青、藍(lán)、紫。其中紅光的波長范圍為0.62～0.76μm；紫光的波長范圍為0.38～0.46μm。比紫光波長還短的光叫紫外線，比紅光波長還長的光叫紅外線。紅外線遙控就是利用波長為0.76～1.5μm之間的近紅外線來傳送控制信號的。
常用的紅外遙控系統(tǒng)一般分發(fā)射和接收兩個部分。發(fā)射部分的主要元件為紅外發(fā)光二極管。它實(shí)際上是一只特殊的發(fā)光二極管，由于其內(nèi)部材料不同于普通發(fā)光二極管，因而在其兩端施加一定電壓時，它便發(fā)出的是紅外線而不是可見光。目前大量使用的紅外發(fā)光二極管發(fā)出的紅外線波長為940nm左右，外形與普通 5發(fā)光二極管相同，只是顏色不同。紅外發(fā)光二極管一般有黑色、深藍(lán)、透明三種顏色。判斷紅外發(fā)光二極管好壞的辦法與判斷普通二極管一樣：用萬用表電阻擋量一下紅外發(fā)光二極管的正、反向電阻即可。紅外發(fā)光二極管的發(fā)光效率要用專門的儀器才能精確測定，而業(yè)余條件下只能用拉距法來粗略判定。 接收部分的紅外接收管是一種光敏二極管。
People's eyes can see the visible wavelength from long to short according to the arrangement, in order to red, orange, yellow, green, green, blue, violet. One of the red wavelengths for 0.62 ~ 0.76 muon m, Purple is 0.38 wavelength range ~ muon m. Purple is shorter than the wavelength of light called ultraviolet ray, red wavelengths of light is longer than that of infrared light. Infrared remote control is to use wavelength for 0.76 ~ 1.5 muon m between the near infrared to transfer control signal.
Commonly used infrared remote control system of general points transmit and receive two parts. The main component part for the launch of infrared light emitting diode. It is actually a special light emitting diode, due to its internal material differs from ordinary light emitting diode, resulting in its ends on certain voltage, it is a rather infrared light. Use of infrared light emitting diode the infrared wavelengths, for 940nm appearance and ordinary, just the same light emitting diode five different colors. Infrared light emitting diode generally have black and blue, transparent three colors. Judgement of infrared light emitting diode and judgment method, using a multimeter to ordinary diode electric block measure of infrared light emitting diode, reverse resistance. The infrared light emitting diode luminescence efficiency to use special instrument to measure precise, and use only spare conditions to pull away from roughly judgement. Receiving part of infrared receiving tube is a photosensitive diode.