Scroll wheel
From Wikipedia, the free encyclopedia
 |
This article does not cite any references or sources. (October 2006) Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. |
A scroll wheel (or mouse wheel) is a hard plastic or rubbery disc (the "wheel") on a computer mouse that is perpendicular to the mouse surface. It is normally located between the left and right mouse buttons. It is used, as the name suggests, for scrolling. It can also be used as a third mouse button by pressing on it. Some modern mice can scroll horizontally as well as vertically, using either a tilting scroll-wheel (introduced by Microsoft) or a scroll ball (found on Apple's Mighty Mouse). In many applications (e.g. Mozilla Firefox[1]), holding down the control key while rolling the scroll wheel causes the text size to increase or decrease, or an image in an image-editing or map-viewing program to zoom in or out, if such a feature is available.
The scroll wheel was invented in 1995 for the Genius EasyScroll mouse [2]. It first gained popularity in the late 1990s when operating systems had the feature built-in, and is notably one of the first additions to the basic two-button mouse design used for PCs that became a de-facto standard. It is also one of the first hardware elements (aside from high-speed modems) designed directly in response to the proliferation of the World Wide Web, where efficient mouse-only scrolling is most useful. Also, clicking a hyperlink with a third button or scroll wheel can create a tab in certain web browsers.
Scroll wheels are prevalent on modern computer mice. To many users, they have become an integral part of the hardware interface. However, non-wheeled mice are still available.
Scroll wheels can also be found on such handheld devices as portable digital audio players, PDAs, or BlackBerry devices. On the Apple iPod, the scroll wheel uses touch sensitive technologies from Synaptics (instead of being mechanical).
In the 21st century, scroll wheels started appearing on keyboards as well, particularly on Logitech and Microsoft models. It is usually located to the left of the caps lock key. The implementation of scroll wheels on laptop computers has generally faded, while touchpads are often made with the edges acting to scroll the page (rather than to move the cursor), partly making up for the lack of a scroll wheel. On recent Apple laptops, scrolling is achieved by touching and dragging two fingers on the touchpad at the same time.
In many first-person shooter (FPS) games, the scroll wheel can be used to change weapon.
