Patent ID: 7511695

Claim:
A backlight unit installed in the back of a display unit, comprising: lighting units, each lighting unit comprising: red, green, and blue light emitting diodes connected in series, and a temperature detecting unit to detect the temperature of the lighting unit, and a drive unit to control current supplied to the light emitting diodes according to the temperature of the lighting unit, so that each lighting unit keeps a uniform brightness even though each lighting unit changes in temperature, to adjust current to be supplied to the light emitting diodes by means of pulse width modulation, so as to keep at least the brightness of light emitted from each lighting unit uniform, to control the peak value of the current to be supplied to the light emitting diodes, so that the resolution of pulse width is the same for the red, green, and blue light emitting diodes, and to adjust the peak value of current to be supplied to the light emitting diodes in response to the detected temperature, wherein the lighting units are arranged in various positions at which the light emitting diodes keep a prescribed temperature.