How Do Optical Mice Detect Movement?

[dimensionless]

How does an optical computer mouse know which way it is moving?

 

[fargoth]

from how stuff works:

most optical mice use a small, red light-emitting diode (LED) that bounces light off that surface onto a complimentary metal-oxide semiconductor (CMOS) sensor. In addition to LEDs, a recent innovation are laser-based optical mice that detect more surface details compared to LED technology. This results in the ability to use a laser-based optical mouse on even more surfaces than an LED mouse.

Here's how the sensor and other parts of an optical mouse work together:

* The CMOS sensor sends each image to a digital signal processor (DSP) for analysis.
* The DSP detects patterns in the images and examines how the patterns have moved since the previous image.
* Based on the change in patterns over a sequence of images, the DSP determines how far the mouse has moved and sends the corresponding coordinates to the computer.
* The computer moves the cursor on the screen based on the coordinates received from the mouse. This happens hundreds of times each second, making the cursor appear to move very smoothly.