Optical Technology
To understand what is involved with an optical sensor, you must first know how it works. Originally developed by Agilent Technologies, a subsidiary of HP, the system is complex even though it is not costly to mass-produce. A luminous red diode projects light onto a surface. At the same time, a simplified camera takes a shot of the surface at regular intervals. The images are then received by a sensor which, as in digital photography, can process a certain number of pixels to restore the image to the electronics in digital form. The chip then compares the digital images and uses the differences it records to calculate the movement of the mouse.
Up to now, there were two generally accepted criteria used to judge a sensor's performance. One was the number of images captured and analyzed per second, and the other was the resolution, meaning the number of shots that could be taken over a given distance. The first factor is easy to understand: the more measurements taken within an allotted time, the greater responsiveness and precision will be.
