All laptops are comprised of numerous parts, but the LCD inverter plays an especially important role. The inverter is one of several key parts within a laptop's display; it helps to illuminate the screen. If an inverter wasn't installed in your laptop, you wouldn't be able to see anything on the display.
Normally, a notebook's screen will display windows and other user-controlled elements. But without a backlight, the viewing experience would be similar to looking at a film reel without a projector. The inverter allows for the laptop's display to be lit by providing power to the screen's backlight.
The LCD inverter can usually be found inside some area of the laptop's display. For example, the MacBook's inverter can be found inside the display hinge, while other manufacturers place it along the side of the screen.
Compared to the rest of the display, the inverter is a relatively small part. It's a rigid ribbon-like component one to two inches in length and plastic plugs -- which attach to the screen's own wires -- are set on each end.
As a sub-component of the display, inverters are fairly inexpensive. Since individual laptop components are usually stocked by third-party vendors, prices can vary greatly, depending on the laptop model or store.
Within the portion of the display's hardware dedicated to providing power, the inverter converts DC current into AC current. This transition makes it possible for the display to be powered. The small size of most inverters is also beneficial, because it allows for laptops to feature high-quality displays without having to produce a larger chassis.