Apparatus for driving light emitting diode

摘要

The present invention relates to an apparatus for driving a light emitting diode. The apparatus for driving the light emitting diode according to the present invention comprises a rectifier circuit for accessing an Alternating Current (AC) voltage source to rectify an AC voltage of the AC voltage source, a light emitting diode array connected to an output side of the rectifier circuit and including a plurality of light emitting diode array blocks, and a charging/discharging circuit configured to be charged by a voltage output from the rectifier circuit, wherein the apparatus for driving the light emitting diode comprises a discharging switch, a block switch circuit, and a controller. The apparatus for driving the light emitting diode according to the present invention can apply a voltage equal to or larger than a driving voltage to intervals around a phase of 180 degrees in which the light emitting diode cannot be driven since a size of the voltage applied by the AC voltage source is smaller than or equal to the driving voltage, by using the charging/discharging circuit and the switch.

主权项

1. An apparatus for driving a light emitting diode, comprising:
a rectifier circuit connected to an AC voltage source and configured to full-wave rectify an AC voltage of the AC voltage source; a light emitting diode array connected to an output side of the rectifier circuit, the light emitting diode array including a plurality of light emitting diode array blocks; a charging/discharging circuit configured to be charged by a voltage outputted from the rectifier circuit; a discharging switch configured to connect or disconnect a route through which energy charged in the charging/discharging circuit is delivered to the light emitting diode array; a block switch circuit configured to adjust the number of the light emitting diode array blocks to which the voltage outputted from the rectifier circuit is delivered; and a controller configured to control the discharging switch and the block switch circuit so that in an A interval where an instantaneous value of the voltage outputted from the rectifier circuit is smaller than a predetermined value, the charging/discharging circuit is discharged after the light emitting diode array as a whole is turned off and so that in the A interval, at least one of the light emitting diode array blocks is turned on and then turned off after the light emitting diode array as a whole is turned off at least once, wherein the controller is configured to control the block switch circuit so that in a B interval where the instantaneous value of the voltage outputted from the rectifier circuit is equal to or larger than the predetermined value, the number of the light emitting diode array blocks being turned on is increased as the instantaneous value of the voltage outputted from the rectifier circuit becomes larger.