Patent ID: 9570018
Date: 2017-02-14
CPC Classifications: G09G,H03K

Claim:
1. A backlight driver comprising: a duty ratio detector for detecting a duty ratio of an input pulse width modulation (PWM) signal; a buffer for delaying a current duty ratio from the duty ratio detector by one frame, and outputting the delayed duty ratio as a previous duty ratio; a duty ratio filter for detecting a difference between the current duty ratio received from the duty ratio detector and the previous duty ratio received from the buffer, the duty ratio filter comprising: an input multiplexer for selecting one of the delayed duty ratio from the buffer and the selected duty ratio from the output multiplexer in response to a flag signal from the duty ratio determination signal, and outputting the selected duty ratio as the previous duty ratio for a next cycle of the input PWM signal; and a PWM generator for generating an output PWM signal obtained when a selected duty ratio from the duty ratio filter is reflected in an input synchronization signal, and outputting the output PWM signal to a backlight unit.