A backlight is a form of illumination used in liquid-crystal displays (LCDs). As LCDs do not produce light by themselves—unlike, for example, cathode ray tube (CRT), plasma (PDP) or OLED displays—they need illumination (ambient light or a special light source) to produce a visible image. How to Set Your Dell Backlit Keyboard to Always On. Backlights illuminate the LCD from the side or back of the display panel, unlike frontlights, which are placed in front of the LCD. Backlights are used in small displays to increase readability in low light conditions such as in wristwatches, and are used in smart phones, computer displays and LCD televisions to produce light in a manner similar to a CRT display. A review of some early backlighting schemes for LCDs is given in a report Engineering and Technology History by Peter J. Wild.
Simple types of LCDs such as in pocket calculators are built without an internal light source, requiring external light sources to convey the display image to the user. Most LCD screens, however, are built with an internal light source. Such screens consist of several layers. The backlight is usually the first layer from the back. Light valves then vary the amount of light reaching the eye, by blocking its passage in some way. Most use a fixed polarizing filter and a switching one, to block the undesired light.
Dell Backlit Keyboard
Out of the box, a Dell laptop doesn’t let you set your backlit keyboard to always on. Dell has a dedicated driver that you can install to control the backlit keyboard. It’s called Dell Feature Enhancement Pack Application and you can download it from Dell’s website.
You don’t need to install all components in this driver. Select the Custom install option and install only the Keyboard and Devices component.
Once installed open Control Panel and go to Hardware and Sound. You will see an option called ‘Dell Keyboard Backlight Settings‘. Click it. In the window that opens, go to the Backlight tab.
Here you can change the timeout duration, or set it to always on by selecting the ‘Never‘ option.
The brightness slider at the bottom may or may not be of any use. It’s likely only useful on select laptops.
