Backlight system for a display

摘要

A method and system for modifying a pulse width modulation signal for controlling the backlit illumination intensity of a liquid crystal display. The modified pulse width modulated signal may be selected to operate with at least one pulse having a first duty cycle with the remaining pulses in the pulse width modulation signal having a second duty cycle across a selected number of pulses making up a given time period (i.e., frame). By utilizing more than one duty cycle for the pulses of the pulse width modulated signal to drive light sources in a display during a given frame, the overall number of backlit illumination intensities for the liquid crystal display may be increased. By distributing the differing pulse duty cycles within a group of pulses of within a frame, visible artifacts may be reduced.

主权项

1. An electronic device, comprising:
a display having a plurality of light emitting diodes (LEDs) adapted to generate light to illuminate a plurality of pixels in the display; a pulse width modulator adapted to generate a first pulse width modulated (PWM) signal at a first frequency; and display control logic adapted to:
modify at least one pulse of a series of pulses of the first PWM signal to generate a pulse waveform;increase an amount of time the at least one pulse is in an on state relative to an amount of time that other pulses of the series of pulses are in the on state;increase an amount of time that a second pulse of the series of pulses is in the on state relative to the amount of time that the other pulses of the series of pulses are in the on state;select a position of the first at least one pulse and the second at least one pulse in the series of pulses such that the first at least one pulse and the second at least one pulse are non-adjacent pulses in the series of pulses to minimize a possible occurrence of a visual artifact on the display; andtransmit the pulse waveform to the display.