(^470) PC Hardware: A Beginner’s Guide
Optical Mouse
The optical mouse eliminates the mouse ball, replacing it with a optical sensors that track
themovementofthemouseagainstthebackgroundofthemousepadorwhicheverflatsur-
faceit’son.Figure18-24showsthebottomofanopticalmouse—noticetheballismissing.
Optical mice have been around for a few years. The older design for the optical mouse
required a highly reflective mousepad that had a printed grid on it. The real drawback to
this mouse, besides the fact it was slow, was that if you lost the mousepad, the mouse
would not work on a normal flat service that had a bit of texture or detail to it. Some
surfaces, such as glass, mirrors, or smooth, shiny, solid-color surfaces without detail, do
not work well with even the new optical mice.
The latest optical mouse designs include an optical process that captures images of
the surface underneath the mouse (called the mousing surface) at a rate of u pto 2,000
images per second. The mouse includes a digital signal processor (DSP) that analyzes
these images and is able to detect even the slightest movement. The optical system of the
mouse eliminates the need for a mousepad and works on virtually any flat surface except
those that are very shiny or reflective.
One real advantage to the optical mouse over the optomechanical mouse is that it does
not require internal cleaning. Because it has eliminated all moving parts, the optical mouse
does not pick u pdust and other debris that could clog u pthe o ptomechanical mouse and
require it to be regularly cleaned. Another advantage is that, according to manufacturer
claims, an optical mouse is at least 33 percent faster and many times more accurate than an
optomechanical mouse.Figure 18-24. The business side of an optical mouse. Photo courtesy of Logitech, Inc.