Optical mouse contains LED. LED produces a red light that is emitted onto a surface. The light is reflected off the surface back to the CMOS sensor. The CMOS sensor sends each image that is reflected back to a DSP (Digital Signal Processor) for analysis.
DSP is able to detect both patterns and images and can determine if the mouse has moved, at what distance it has moved and at what speed.
DSP determine the coordinate and send to computer and will show the movement of the mouse.
Re: optical mouse
An optical mouse is an advanced computer pointing device that uses a light-emitting diode (LED), an optical sensor, and digital signal processing (DSP) in place of the traditional mouse ball and electromechanical transducer.The optical mouse takes microscopic snapshots of the working surface at a rate of more than 1,000 images per second. If the mouse is moved, the image changes. The tiniest irregularities in the surface can produce images good enough for the sensor and DSP to generate usable movement data. The best surfaces reflect but scatter light; an example is a blank sheet of white drawing paper.