WHITE LIGHT EMITTING DIODE (LED) LIGHTING DEVICE DRIVEN BY PULSE CURRENT

摘要

A white LED lighting device is driven by a pulse current, which consists of blue, violet or ultraviolet LED chips, blue afterglow luminescence materials A and yellow luminescence materials B. Wherein the weight ratio of blue afterglow luminescence materials A to yellow luminescence materials B is 10-70wt%:30-90wt%. The LED chips of the white LED lighting device are driven by the pulse current. The frequency of the pulse current is not less than 50Hz. Because of using afterglow luminescence materials, the light can be sustained when excitation light disappears, which can eliminate the influence of LED light output variation due to current fluctuation on the illumination. At the same time, the pulse current can make the LED chips at an intermittent work state in order to eliminate the problem of chips heating.