Backlight for a display device
View Patent ↗A backlight comprising a plurality of lamps, an A/D converter connected to the lamps in parallel to convert an inputted alternating current into a direct current and to provide the converted direct current to the lamps, a current measuring unit connected to the lamps in parallel to measure currents outputted from the lamps, and a controlling unit to control a current value to be applied to the lamps according to a current value inputted from the current measuring unit.
1. A backlight comprising:
a plurality of lamps;
an A/D converter connected to the lamps in parallel to convert an inputted alternating current into a direct current and to provide the converted direct current to the lamps;
a current measuring unit connected to the lamps in parallel to measure currents outputted from the lamps, the current measuring unit including a plurality of transformers connected to each lamp for leveling currents inputted from the lamps; and
a controlling unit to control a current value to be applied to the lamps according to a current value inputted from the current measuring unit.
2. The backlight of claim 1 , further comprising a boost transformer to boost a current converted by the A/D converter to be applied to the lamps.
3. The backlight of claim 1 , wherein the current outputted from the plurality of transformers is inputted to the controlling unit in parallel.
4. The backlight of claim 1 , wherein the current measuring unit further includes a plurality of diodes each connected to a respective one of the lamps and passing over-currents outputted from the lamps.
5. The backlight of claim 4 , wherein the over-current is serially inputted to the controlling unit.
6. The backlight of claim 1 , wherein the lamps include one of a cold cathode fluorescent lamp (CCFL) and an external electrode fluorescent lamp (EEFL).
7. A liquid crystal display device comprising:
a liquid crystal panel having a plurality of pixels and displaying an image;
a plurality of lamps for providing light to the liquid crystal panel;
an A/D converter connected to the lamps in parallel to convert an inputted alternating current into a direct current and to provide the converted direct current to the lamps;
a current measuring unit connected to the lamps in parallel to measure currents outputted from the lamps, the current measuring unit includes a plurality of transformers connected to each lamp for leveling currents inputted from the lamps; and
a controlling unit to control a current value to be applied to the lamps according to a current value inputted from the current measuring unit.
8. The liquid crystal display device of claim 7 , further comprising a boost transformer to boost a current converted by the A/D converter to be applied to the lamps.
9. The liquid crystal display device of claim 7 , wherein the current outputted from the plurality of transformers is inputted to the controlling unit in parallel.
10. The liquid crystal display device of claim 7 , wherein the current measuring unit further includes a plurality of diodes each connected to a respective one of the lamps and passing over-currents outputted from the lamps.
11. The liquid crystal display device of claim 10 , wherein the over-current is serially inputted to the controlling unit.
12. The liquid crystal display device of claim 7 , wherein the lamps include one of a cold cathode fluorescent lamp (CCFL) and an external electrode fluorescent lamp (EEFL).