System, methods, and devices, for inaudible enhanced PWM dimming

摘要

Systems and methods for inaudible enhanced pulse width modulation (PWM) backlight dimming are provided. By way of example, an electronic display backlight system according to the present disclosure may include a backlight element and backlight driver circuitry. The backlight driver circuitry may drive the backlight element at various brightness levels using at least two individual duty cycles that occur immediately after one another. The backlight driver circuitry may vary the individual duty cycles such that none will ever reach 100% unless all are 100%, thereby preventing the occurrence of audible noise that might otherwise arise if an “on” PWM period from one individual duty cycle continued into the next.

主权项

1. An electronic display backlight system comprising:
a backlight element; and backlight driver circuitry configured to cause the backlight element to be driven at various brightness levels by varying a first individual duty cycle of the backlight element over a first pulse width modulation clock cycle and a second individual duty cycle of the backlight element over a second pulse width modulation clock cycle, wherein the first pulse width modulation clock cycle and the second pulse width modulation clock cycle occur immediately after one another, and wherein the backlight driver circuitry is configured to vary the first individual duty cycle and the second individual duty cycle such that neither the first individual duty cycle nor the second individual duty cycle will ever reach 100% unless both are 100%.