The Types of Mice
An explanation of the varieties of computer mice
The computer mouse is one of the key components of a computer. The earliest known mention of the word mouse as a pointing device for computers was in 1965. The mouse, as we know it today, was invented by German engineer Douglas Englebart at SRI International in 1968. It was later developed by German company Telefunken. The Xerox alto was the first computers designed that used a mouse in 1973.
From those early days, computer mice have become smaller, cheaper, and more durable (since most mice don't use a trackball nowadays). Mice today can now be corded or wireless. They can also use a Bluetooth signal.
This article will explain three types of mice: ball, optical, and ergonomic.
The ball mouse is perhaps the most well-known variety of mice. It features the magnetic ball – usually called a wheel – that is controlled by two freely rotating rollers. The cursor's left-right motion is detected by one roller (called the X roller) and the forward-backward motion is detected by the other (the Y roller). A third spring-loaded roller pushes the ball up against the other two rollers. The mouse's driver software detects the motion of the cursor using X and Y axes on the screen.
Each roller has infrared light emitting diodes (LED) that detects wheel and ball movement. The light from the diodes is either passed freely or interrupted. Logic circuits interprets this as an indication as to which direction the ball is rotating.
Ball mice typically have a cord and are connected through a serial port. One would usually find them used with older computers.
Optical or Laser Mice
The optical mouse is the standard mouse used with modern-day computers. Instead of a ball, these mice feature several light emitting diodes and photodiodes to detect movement relative to the surface on which the mouse is placed. These mice can be both corded and wireless, unlike ball mice. The wireless variety is battery-powered with a USB connector.
Laser mice are somewhat similar to optical mice except it uses a laser light not LED and tend to work better with opaque surfaces. LED tends to work best on non-reflective surfaces.
These mice are used to provide maximum comfort to prevent hand strain injuries such as carpal tunnel syndrome and arthritis. They reduce discomfort by setting the arm and wrist to a more normal position. On a typical mouse, the two bones in the arm (ulna and radius) are twisted. With an ergonomic mouse, the mouse buttons are set on the side of the mouse rather than the top so the ulna and radius is neutral.