Patent ID: 8917028
Filing Date: 2014-12-23
Classification: H05B,Y02B

Abstract:
1. A driving circuit, comprising: a plurality of light-emitting units, wherein the light-emitting units are coupled with each other in series and are driven with an input voltage varying according to a frequency; a plurality of switches, wherein each switch has a preset voltage and an activation voltage and comprises a light-emitting end, a control end, and a setting end, the light-emitting ends are coupled with the light-emitting units, and the setting ends of the switches are coupled with each other; a voltage generating module coupled with the control ends of the switches and comprising a plurality of control units, wherein each control unit is respectively coupled between the adjacent control ends; the voltage generating module provides a plurality of control voltages to the switches, and each switch is driven to be activated or to be deactivated according to a relation of the preset voltage and a difference between the control voltage and the activation voltage when the input voltage drives the light-emitting units, the switches, and the control units; and a current setting module coupled between the setting ends of the switches and the voltage generating module, wherein the voltage generating module provides an operating bias voltage to the current setting module, and the voltage generating module controls the operating bias voltage to determine a light-emitting voltage of each light-emitting unit and the control voltages of the switches; wherein the voltage generating module includes an adjusting unit having a positive input end and a negative input end, wherein the negative input end is coupled with the current setting module.