Backlight controller, method for driving light sources, and display system

Abstract

The invention discloses a backlight controller, a method for driving light sources, and a display system. The backlight controller includes a feedback circuitry, a phase array circuitry, and an encoder circuitry. The feedback circuitry is coupled to the plurality of light source strings and generates a plurality of feedback signals indicative of a plurality of currents flowing through the plurality of light source strings respectively. The phase array circuitry receives a dimming control signal and receives a code signal indicative of a total number of operative light source strings among the plurality of light source strings, and generates a plurality of phase shift signals according to the code signal and the dimming control signal. The encoder circuitry is coupled to the phase array circuitry and receives the plurality of phase shift signals and the plurality of feedback signals, and generates a plurality of pulse width modulation signals to respectively control the operative light source strings. The backlight controller can detect the light source strings in service among a plurality of light source strings, provide automatic phaseshift regulation based on the total number of the light source strings in service, so as to optimize the burst mode light regulation and reduce the ripple current in power line.

Description

technical field [0001] The invention relates to a display system, in particular to a backlight controller and a method for driving a light source. Background technique [0002] Light Emitting Diodes (LED, Light Emitting Diodes) are more and more popular in the lighting industry, especially in the backlight fields of Liquid Crystal Display (LCD, Liquid Crystal Display), street lighting and household appliances. Compared with fluorescent light-emitting devices, LEDs have the advantages of low power consumption, small size and no use of harmful substances in light-emitting devices. In addition, the power supply for the LED operates at a relatively low voltage, which avoids problems caused by the high voltage of the power supply for fluorescent lamps. For example, a cold cathode fluorescent lamp (CCFL) may require more than 1000V of AC voltage to start and operate, while a single LED requires only 1V to 4V of DC voltage. [0003] To provide sufficient brightness, a display sys...

AI Technical Summary

Problems solved by technology

The challenge of using LEDs in lighting systems is to optimize the brightness of the LEDs based on the environment and the balanced current in the LEDs, thus prolonging the operating life of the LEDs

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