Adaptive Backlight Drive Frequency for Flicker Reduction

The patent applies dynamics by making the PWM frequency adaptive rather than fixed. The drive control unit dynamically adjusts the frequency based on the desired brightness level: using higher frequencies (500Hz or higher) when brightness is low to prevent flicker, and allowing lower frequencies when brightness is high where flicker is less perceptible. This dynamic frequency adjustment resolves the contradiction by optimizing flicker reduction only when necessary.

The patent changes the frequency parameter of the PWM drive signal based on brightness requirements. By varying the frequency parameter according to the duty ratio range (using 500Hz or higher for low brightness, and lower frequencies for high brightness), the system achieves both flicker reduction and wide brightness range coverage.

The drive control unit implements dynamic frequency selection based on operating conditions. Instead of requiring the drive circuit to handle extremely high frequencies across all brightness levels, the system dynamically selects appropriate frequency ranges, reducing the temporal resolution requirements of the drive circuit while maintaining flicker reduction effectiveness.

The patent applies partial action by using high frequencies (500Hz or higher) only when necessary (at low brightness levels where flicker is most noticeable), rather than maintaining excessively high frequencies at all times. This reduces the burden on the drive circuit while achieving sufficient flicker reduction.