Using a led driver as a led backlight inverter
For sure,you can use separate LED back-light.All you have to do is to built a circuit with variable PWM(pulse Width Modulation).I think you can implement a PWM varying circuit using an Arduino or with any other micro-controllers.The purpose of the PWM here is to control the brightness of the background LED.More or less,nothing else is much complicated in background LED.The background LED is just brighten or dimmed using PWM circuit.