Redundant operation of a backlight unit of a display device under a shorted LED condition

摘要

Disclosed embodiments relate to techniques for operating a backlight unit of a display device in a redundant mode and a non-redundant mode in the event of a shorted LED failure condition. For instance, in a redundant mode, multiple LED strings arranged in an end-to-end configuration are each driven to provide a first quantity of light, such that the combined output from all LED strings is capable of providing a total light output corresponding to a maximum brightness setting for the display device. In the case that an LED on one of the strings fails due to a shorted LED failure condition, the remaining functional LEDs of the affected string may be driven to provide a second quantity of light, such that the combined output from the affected strings and the non-affected strings may still provide the same total light output for achieving the maximum brightness setting. The second quantity of light is greater than the first quantity.

主权项

1. A method comprising:
controlling at least one light-emitting diode (LED) string of a backlight unit in a first mode, wherein the LED string comprises a plurality of LEDs electrically connected in series, such that all of the LEDs of the LED string are controlled to each provide a first light output, wherein the combined first light output from all of the LEDs provides a target luminance output for the LED string; determining whether a shorted LED failure condition occurs in any of the LEDs in the LED string; and in response to detecting a shorted LED failure condition across at least one of the LEDs in the LED string, controlling at least one other LED string in a second mode to compensate for the shorted LED failure condition such that the remaining operational LEDs of the LED string are controlled to each provide the first light output, and LEDs of the at least one other LED string are each controlled to provide a second light output greater than the first light output, wherein the second light output of the LEDs of the at least one other LED string compensates for a difference between the target luminance output for the LED string and the combined first light output from the remaining operational LEDs of the LED string.