Patent ID: 8305335

Claim:
A backlight lamp lighting control device comprising: a pulse width modulation (PWM) signal generating section for generating a PWM signal in accordance with a duty ratio externally inputted, and outputting the PWM signal to a PWM inverter for driving a lamp to light; a tube current detecting section for detecting a current flowing in the lamp, the PWM signal generating section generating the PWM signal based on a current, which is obtained by adjusting the current detected by the tube current detecting section in accordance with the duty ratio externally inputted, so that luminance displayed on a display panel will be substantially uniform over the entire display panel, and the current flowing in the lamp being adjusted in accordance with a change in the duty ratio externally inputted; and a duty correction section for correcting the duty ratio externally inputted, in accordance with the current thus adjusted, so that the luminance displayed on the display panel will be identical with luminance corresponding to the duty ratio externally inputted, the PWM signal being generated based on the current thus adjusted and the duty ratio thus corrected, wherein the amount by which a luminance ratio of the lamp is reduced by an increase in the current flowing in the lamp is greater than the amount by which the luminance ratio of the lamp increases due to a reduction in the duty ratio externally inputted, the luminance ratio of the lamp being defined as a luminance on a high voltage side of the lamp divided by a luminance on a low voltage side of the lamp.