| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide "a light control device and a light control method for a back light" which can discharge an output smoothing capacitor at light control OFF time in a short time with no sense of incompatibility in vision of a screen without causing any increase in cost. <P>SOLUTION: When a light control OFF command is made, an output smoothing capacitor C is discharged through an LED matrix by converting a light control PWM wave generated at light control ON time into a DC current which is equal in current amount per unit period to the light control PWM wave, and performing light control over the LED matrix according to the DC current generated by the conversion. Consequently, a dedicated short-circuit circuit need not be provided separately to suppress an increase in cost, the discharging is carried out in a short time through the LED matrix with small resistance, and even when the discharging is performed through the LED matrix, visual luminance is the same before and after the light control OFF command is made. <P>COPYRIGHT: (C)2012,JPO&INPIT |
