Laptop monitors are built-in displays. They are similar to desktop monitors, except that you can adjust the resolution, brightness, and contrast using software or button controls. You cannot adjust the laptop monitor for height and distance because it is integrated into the lid of the case. You can connect a desktop monitor to a laptop, providing the user with multiple screens and increased functionality, as shown in the figure.
There are four types of laptop displays:
LED monitors use less power and have a longer lifespan than LCD monitors. Organic LED (OLED) technology is commonly used for mobile devices and digital cameras, but can also be found in laptop concept designs. OLED monitors will become more popular as the technology improves. Plasma displays are rarely found in laptops, because they consume a large amount of power.
On many laptops, a small pin on the laptop cover contacts a switch when the case is closed, called an LCD cutoff switch. The LCD cutoff switch helps conserve power by extinguishing the backlight and turning off the LCD. If this switch breaks or is dirty, the LCD remains dark while the laptop is open. Carefully clean this switch to restore normal operation.