Focus LCDs

Is it possible to adjust the brightness of a LED backlight on a LCD module?

Yes, that is the great thing about LEDs is that they are DC (Direct Current) driven and are adjustable without any complex circuitry like what is required for a AC driven backlight such as an EL or CCFL.

Yes. A resistor inline with BL+ or BL- will give a fixed intensity; a trim pot will provide manual control; a computer with a PWM port to a transistor switch will provide program control (use a large capacitor and a resistor as a low-pass filter to avoid rapid switching of the LED.) The transistor will introduce some voltage drop, hence the maximum brightness is reduced somewhat.

LCD is lit by a tube light in the rear and LED is lit with light emitting diodes as the name suggests.

LCD is lit by a tube light in the rear and LED is lit with light emitting diodes as the name suggests.