Method of driving a light source, light source apparatus for performing the method and display apparatus having the light source apparatus

A light source apparatus comprising:

• a light source part configured for emitting a light;
• a voltage generating part configured for generating a variable driving voltage to drive the light source part;
• and
• a feedback part configured for adjusting the driving voltage using a first voltage outputted to a first end of the light source part and a second voltage sensed at a second end of the light source part, the first voltage being based on the driving voltage and the second voltage being based on a current passing through the light source part,
• wherein the first voltage is a divided voltage of the driving voltage as divided by a first resistor and a second resistor, and
• wherein the feedback part comprises:
• a reference voltage compensating circuit configured for generating a third voltage based on the first voltage and a supplied first reference voltage;
• a first differential amplifier configured for generating a fourth voltage based on the second voltage and the third voltage;
• and
• a comparator configured for comparing the fourth voltage to a supplied second reference voltage and for outputting a corresponding feedback signal.

A light source apparatus comprising:

• a light source part configured for emitting a light;
• a voltage generating part configured for generating a variable driving voltage to drive the light source part;
• and
• a feedback part configured for adjusting the driving voltage using a first voltage outputted to a first end of the light source part and a second voltage sensed at a second end of the light source part, the first voltage being based on the driving voltage and the second voltage being based on a current passing through the light source part,
• wherein the first voltage is a divided voltage of the driving voltage as divided by a first resistor and a second resistor, and
• wherein the feedback part comprises:
• a signal multiplying part configured for generating a multiplied voltage by multiplying the first voltage and the second voltage;
• a differential amplifier configured for generating a fourth voltage based on the multiplied voltage and a supplied reference voltage;
• and
• a comparator configured for comparing the fourth voltage to a supplied time-varying comparing signal and to output a digitized feedback signal based on the comparison.

A display apparatus comprising:

• a display panel configured for displaying an image;
• and
• a light source apparatus configured for providing a light to the display panel, the light source apparatus including:
• a light source part configured for emitting the light;
• a voltage generating part configured for generating a variable driving voltage to drive the light source part;
• and
• a feedback part configured for adjusting the driving voltage using a first voltage sensed at a first end of the light source part and a second voltage sensed at an opposed second end of the light source part, the first voltage being based on the driving voltage and the second voltage being based on a current passing through the light source part,
• wherein the first voltage is a divided voltage of the driving voltage as divided by a first resistor and a second resistor, and
• wherein the feedback part comprises:
• a reference voltage compensating circuit configured for generating a third voltage based on the first voltage and a supplied first reference voltage;
• a first differential amplifier configured for generating a fourth voltage based on the second voltage and the third voltage:
• and
• a comparator configured for comparing the fourth voltage to a supplied second reference voltage and for outputting a corresponding feedback signal.

A method of driving a light source, the method comprising:

• outputting a variable driving voltage to a light source part;
• sensing a first voltage that is substantially representative of a voltage drop developed across the light source part;
• sensing a second voltage that is substantially representative of a current passing through the light source part;
• developing a feedback controlling signal from the first and second sensed voltages that is substantially representative of a power consumption of the light source part;
• and
• adjusting the variable driving voltage based on the developed feedback controlling signal,
• wherein the first voltage is a linear function of the variable driving voltage, and
• wherein the developing the feedback controlling signal comprises:
• generating a third voltage based on the first voltage and a supplied first reference voltage;
• generating a fourth voltage based on the second voltage and the third voltage;
• comparing the fourth voltage to a time-varying comparing signal;
• and
• comparing the fourth voltage with the time-varying comparing signal.