Backlight drive voltage control device, backlight drive voltage control method and television

A backlight drive voltage control device, comprising:

• a detecting unit connected to a controller, which detects the current states of the lamp strings of each of the divisions of the backlight sources of a liquid crystal screen, sends feedback signals to the controller according to the current states, and does not send to the controller the feedback signals corresponding to lamp strings selected by the controller which voltage adjustment amounts are larger than a threshold after receiving a closing feedback control signal from the controller;
• the controller connected to an AC to DC converter, which sends a voltage adjustment control signal to the AC to DC converter according to the feedback signals, and acquires the voltage adjustment amount of each lamp string according to the voltage adjustment control signal, selects lamp strings which voltage adjustment amounts are larger than the threshold, and sends the closing feedback control signal to the detecting unit;
• and
• the AC to DC converter which outputs corresponding voltages to the lamp strings according to the voltage adjustment control signal, so that the lamp strings work at a rated current.