Light-emitting device

摘要

A light-emitting device includes a power module, a first light-emitting module, a second light-emitting module, a third light-emitting module, and a control module. The power module is configured to rectify an AC voltage for providing a periodic driving voltage. The first, second, third light-emitting modules are connected in series. The control module is configured to make the first, second, third light-emitting modules being driven by the driving voltage in response to different driving stages in a cycle period of a driving voltage. An average-diode-junction-area of the first light-emitting module is different from an average-diode-junction-area of the second light-emitting module or an average-diode-junction-area of the third light-emitting module.

主权项

1. A light-emitting device comprising:
a power module for rectifying an AC voltage to provide a driving voltage, wherein the driving voltage is periodic; a first light-emitting module; a second light-emitting module, wherein the first light-emitting module and the second light-emitting module are electrically connected to each other in series; and a control module for making the first light-emitting module and the second light-emitting module be driven by the driving voltage in response to different driving stages in one cycle period of the driving voltage, wherein, in a first driving stage of the driving stages in the one cycle period of the driving voltage, the control module makes the first light-emitting module being driven by the driving voltage, and provides a first driving current to the first light-emitting module, and a first cross voltage is present across the first light-emitting module; in a second driving stage of the driving stages in the one cycle period of the driving voltage, the control module makes the first light-emitting module and the second light-emitting module being driven by the driving voltage, and provides a second driving current to the first light-emitting module and the second light-emitting module, and a second cross voltage is present across the first light-emitting module and the second light-emitting module, and the first driving current is different from the second driving current; and a product of the first cross voltage and the first driving current and a product of the second cross voltage and the second driving current are substantially identical, such that luminous fluxes of the first light-emitting module and the second light-emitting module in the first driving stage and the second driving stage are substantially identical.