The old fashioned mice worked via two wheels that are turned by a ball:
One represented the x-axis while the other represtened the y-axis. Turning one, would move the mouse in that specified direction. Moving both resulted in a combined and (somewhat) smooth movement of the mouse.
With the advent of Lasers and optics, we now more commonly use the 'Laser Mouse'. How do they work exactly? How does a laser light and moving of the device translate into those x and y values for movement on the screen?
Detailed explanations are welcomed.
Best Answer
Laser and optical mice essentially take hundreds of photos every second. They compare successive images to find a common point between them, and from that common point, calculate x and y offsets to send to the computer. The laser or LED merely act as a light source.
Of course this is a vast over simplification. There are a couple of methods for determining the common point, for instance.
As for moving to laser light from LEDs, that was done to get higher resolution images (finer control), as well as allowing mice to be used reliably on more surfaces.