I have already said everything I need to know about the mice, tak wiec przejdę teraz do urządzenia jakim jest mało popularny trackball. Well, a trackball (because that's his Polish name) it is very impractical for domestic use, nie wspominam nawet o próbie grania na tym w gry komputerowe gdyż wszelkie próby kończą się na ponownym podłączeniu swojego „gryzonia”. So why was this contraption even created if it is so horrible?. Well, the trackball is perfect for specialized applications such as: design work, control of industrial devices or medical devices, where great precision is required. It is worth mentioning that it was also used in laptops, where trackpads were later replaced.
The manipulator looks like an upside down ball mouse. At the moment, there are two motion translation mechanisms that divide trackballs into mechanical-optical and optical. In the case of the former, the operation is not much different from the outdated ball mice. Again we have a rubber ball two rollers and an infrared sensor, therefore I will not write about them. The case gets more interesting when it comes to optical manipulators. Here, the operation is based on the optical sensor registering a special pattern with which the ball is covered. The sensor consists of a light emitting diode, which emits infrared light. The light from the diode is projected onto the surface of the ball, this then reflects the beam onto the CCD where it is converted into electrical impulses ultimately recognized as motion.
In the history of pointing devices, there is mention of a light pen. You probably haven't heard of him, no wonder, it was used mainly in design. Jestem za to pewien że kojarzysz pistolet z Nintendo. I have shot ducks with him many times in "Duck Hunt". What am I going to. This gun is a twin similar design to the light pen. Surprised? I was too. The construction and principle of operation is not complicated. There is a photosensitive sensor at the end of the pen, when applied to the screen, it detects light, allowing the computer to locate the cursor position. Detection of the position is based on the registration of the operating frequency of the CRT monitor (so does not work on LCD screens) and comparing the obtained results with the data sent by the computer.