Computer mouse

Computer mouse
Name	Computer mouse
Caption	A modern Logitech wireless mouse
Inventor	Douglas Engelbart
Invented	1964
Released	1970s
Connectivity	USB, Bluetooth, PS/2, Serial
Related	Trackball, Touchpad, Graphics tablet

Computer mouse. A computer mouse is a hand-held pointing device that detects two-dimensional motion relative to a surface. This motion is typically translated into the movement of a cursor on a display, allowing for fine control of a graphical user interface. The device's name originates from its resemblance to the rodent, with the cord historically seen as a tail.

History

The first prototype was developed in the 1960s by Douglas Engelbart and his team at the Stanford Research Institute (SRI). This early device, constructed from a wooden shell with two metal wheels, was publicly demonstrated in 1968 at the "Mother of All Demos". The technology was later refined at Xerox PARC, leading to the incorporation of a mouse into the Xerox Alto, a pioneering personal computer. The mouse achieved mainstream popularity following its inclusion with the Apple Macintosh 128K in 1984, which popularized the graphical user interface. Subsequent innovations included the introduction of the optical mouse by companies like Microsoft and Logitech, which replaced mechanical tracking balls.

Operation

A mouse functions by tracking its movement across a surface and relaying this data to the host computer. Early mechanical mice used a rolling ball that turned orthogonal wheels connected to rotary encoders. Modern optical and laser mice use a small LED or laser to illuminate the surface, with a CMOS sensor capturing successive images; an onboard digital signal processor analyzes these images to determine direction and distance. This movement data is transmitted via the mouse's interface, and the computer's operating system translates it into corresponding cursor motion on the screen.

Types

Mice are primarily categorized by their motion detection technology. The mechanical ball mouse was dominant until largely supplanted by the optical mouse, which uses an LED and sensor. The laser mouse employs a lasar diode for higher sensitivity on a wider variety of surfaces. Other specialized types include the trackball, where the user rotates a stationary ball, and the gyroscopic or air mouse, which uses inertial sensors for motion detection in three dimensions. Gaming mice, produced by companies like Razer and SteelSeries, often feature high-precision sensors and customizable weights.

Connectivity and interfaces

Mice connect to computer systems through various interfaces. Early mice used dedicated serial ports or the bus mouse interface. The PS/2 connector, introduced on the IBM PS/2, became a standard before the widespread adoption of USB. Modern mice predominantly use USB, either wired or via a wireless RF dongle that communicates using protocols like Logitech Unifying or proprietary 2.4 GHz. Many contemporary devices also support direct Bluetooth connectivity, eliminating the need for a dedicated receiver.

Buttons and features

The standard mouse features at least two primary buttons (traditionally for selection and context menus) and a scroll wheel, pioneered by Microsoft with its IntelliMouse. Additional buttons are common, especially on gaming mice, and can be programmed for specific functions or macros. Some mice include features like adjustable dots per inch (DPI) sensitivity switching, onboard memory for profiles, and customizable RGB lighting. Ergonomic designs, such as vertical mice from companies like Logitech and Anker, aim to reduce user strain, while other models may incorporate touch-sensitive surfaces or gesture support.

Performance characteristics

Key performance metrics for a mouse include its resolution, often measured in DPI or the more accurate counts per inch (CPI), which indicates sensitivity. Polling rate, measured in Hz, determines how often the mouse reports its position to the computer, with higher rates reducing perceived lag. Tracking speed, measured in inches per second (IPS), and acceleration define the maximum physical speed the sensor can accurately track. For gaming, metrics like perfect control speed and sensor smoothing are critical, with top-tier sensors from manufacturers like PixArt being highly sought after. The choice of mouse feet material, such as PTFE, also affects glide friction and performance.

Category:Computer peripherals Category:Pointing devices Category:American inventions