• TOP
• Engineering References
• Wavelength of light and color temperature

9. Wavelength of light and color temperature

Light is a type of electromagnetic wave, and its color is determined by the wavelength. Visible light is between 380nm-800nm, and is divided into 7 colours (Violet, Indigo, Blue, Green, Yellow, Orange, Red). When selecting the LED, the colour can be known by knowing the central wavelength of light emission. Moreover, at present there are lot of interest on colour temperature by the popularization of White LED. The colour temperature shows relative strength of violet light and red light of a colour emitted light source. It is defined as ‘temperature of black body when same colour light as that light is radiated by the perfectly black body’ and its unit is K (Kelvin).