US 8,786,202 B2Granted

Lighting device and method of controlling light emitted thereby

AssigneeLG Electronics Inc.

InventorNamjin Kim

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Abstract

A lighting device and a method of controlling a light emitted thereby are disclosed. A lighting device according to the present invention includes a rectifier unit configured to rectify an alternation current voltage to supply the rectified voltage to each of light emitting units, the light emitting units configured of a plurality of light emitting diodes connected with each other in series, a control unit configured to control each light emitting unit and a first switching element based on the input voltage and the first switching element configured to be switched on and off based on the control of the control unit, wherein the control unit controls to the first switching element switch on and off based on the input voltage to connect the first light emitting unit and the second light emitting unit alternatively in series and parallel.

Claims17

Dependent claims

A lighting device comprising:

a rectifier unit configured to rectify an alternation current voltage to supply the rectified voltage to a plurality of light emitting units;
the light emitting units configured of a plurality of light emitting diodes (LEDs) connected with each other in series;
a plurality of current sources connected with each of the light emitting units to control currents inputted to a corresponding light emitting unit;
a control unit configured to control the plurality of current sources and a first switching element based on levels of an input voltage via the rectifier unit;
and
the first switching element configured to be switched on and off based on the control of the control unit,
wherein the control unit controls the plurality of current sources and the first switching element based on the levels of the input voltage;
in a first voltage level, switching on the first switching element, controlling to saturate a first current level of the first current source, and controlling to saturate a first current level of the second current source,
in a second voltage level, switching on the first switching element, controlling to saturate a second current level of the first current source, and controlling to saturate a second current level of the second current source, and
in a third voltage level, switching off the first switching element, turning off the first current source, and controlling to maintain the second current level of the second current source.

7 more elements

A method of controlling a light emitted from a lighting device including a plurality of light emitting units configured of light emitting diodes (LEDs) connected in series, the method comprising:

rectifying an alternation current voltage input and supplying the rectified voltage to each of the light emitting units at a rectifier unit;
and
controlling a plurality of current sources connected to the plurality of light emitting units and a first switching element located between a first light emitting unit and a second light emitting unit based on levels of an input voltage at a control unit,
wherein the step of controlling change in the velocity of the light emitted is performed;
in a first voltage level, switching on the first switching element, controlling to saturate a first current level of the first current source, and controlling to saturate a first current level of the second current source,
in a second voltage level, switching on the first switching element, controlling to saturate a second current level of the first current source, and controlling to saturate a second current level of the second current source, and
in a third voltage level, switching off the first switching element, turning off the first current source, and controlling to maintain the second current level of the second current source.

4 more elements

Dependencies are inferred from the claim text.