Diagram of a mechanical mouse.
<ol><li>Pulling the mouse turns the ball.</li>
<li>X and Y rollers grip the ball and transfer movement.</li>
<li>Optical encoding disks include light holes.</li>
<li>Infrared LEDs shine through the disks.</li>
<li>Sensors gather light pulses to convert to X and Y velocities.</li></ol>
<div style="display:inline-block;padding:0 3px;background-color:#BDC"><a href="//commons.wikimedia.org/wiki/File:Mouse-mechanism-cutaway.png" title="File:Mouse-mechanism-cutaway.png"><b>Original: </b></a></div> <div style="display:inline-block;padding:3px 0;"><a href="https://en.wikipedia.org/wiki/User:Jeremykemp" class="extiw" title="en:User:Jeremykemp">Jeremykemp</a></div> <div style="display:inline-block;padding:0 3px;background-color:#CCF">Vector: </div> <div style="display:inline-block;"><a href="//commons.wikimedia.org/wiki/User:Pbroks13" title="User:Pbroks13">Pbroks13</a></div>
Attribution
<a href="//commons.wikimedia.org/wiki/File:Mouse-mechanism-cutaway.png" title="File:Mouse-mechanism-cutaway.png">Mouse-mechanism-cutaway.png</a>