Abstract: The spectra of flash lamp by white LED of eleven mobile phone were obtained by combined type multifunction grating spectrometer (model number:WGD-3). The spectrum was composed of blue light band in the 400-460nm range and excitation band in the 460-610 range. The intensity of the blue band was strong, and the excitation light band was low. Due to the differences in material and technology of different types of mobile phone flash lamp LED, the spectra were slightly different. In the range of blue light band, the band at 440nm was the serious harm to the human eye, No. 1-4 mobile phone could not avoid the blue light strongest peak at central wavelength of 440nm. The green band near at 556nm was the most obvious of NO. 3 mobile phone. The relative intensity was defined as the ratio of the intensity of the central wavelength of the blue light and the intensity of the center wavelength of the excited light. The relative intensity of NO.5 mobile phone was stronger than other mobile phone. The intensity of the blue band was an important parameter, when satisfying the white light vision, we should minimize the intensity of blue light and reduce the injure of blue light.

Key words: Light Emitting Diode, White light, Blue light, Spectrum