Desk lamps are lamps which can be placed on a small surface such as a desk. One of the classic desk lamps has either a circular or rectangular base with a straight pillar coming from the center with a light bulb on top. These lamps usually have a small, tiltable shade to help direct the light and either a rotational switch or pull chain to turn it on and off.
In the early 1990s, a new take on this fairly standard group of desk lamps appeared. These lamps, rather than making use of a pull chain or switch, were made entirely of metal and controlled by simply tapping them at any point. These lamps remain popular, particularly with college students, because of both their "coolness" factor and their ease of use. Even in the dark, it is easy to simply reach over and tap the lamp anywhere on its body to get light, rather than fumbling around trying to find a switch or chain.
Many lamps also feature a flexible arm which the light itself is attached to. This allows the base to remain stationary while the light source has a wide range of motion, so the direction of the light can easily be shifted. The older style of flexible-arm lamps features a single-hinged arm with a spring and a rotating base, making for somewhat limited movement. Newer flexible lamps have arms with hundreds of small segments, allowing for very precise control over where the light is pointing.
Desk lamps may also make use of clamping bases rather than large flat bases. This type of lamp can be attached to the edge of a table or shelf. An adjustable clamp lets the user tighten the lamp firmly to whatever it is attached to.
Desk lamps make use of the range of light sources used in traditional lighting. Many people find full-spectrum lighting to be particularly beneficial in a lamp, as reading documents or staring at a computer screen is less tiring on the eyes in this more natural light. A number of integrated full-spectrum lamps exist, many of which are essentially large rectangles that can be carried with you for easy use. One side of the rectangle folds up, making an inverted L shape, with the light at the top shining down.
Perhaps the most famous desk lamp is the Tolomeo desk lamp. This designer Italian lamp became hugely popular during the dot-com boom in the United States for its functionality and attractive modern design. The lamp has a very heavy steel base, two arms and a fully swivelable head. Springs keep the lamp under constant tension.