I purchased two old printers at a garage sale today in hopes of dismantling them and playing around with some stepper motors. After tearing both of them apart I discovered that there are no stepper motors. What all of them are controlled by is a translucent plastic ring with several "Dots/Dashes" around the outside. It also has what appears to be some type of sensor that reads the position of the ring.
I am wondering is there a relatively easy way of controlling these motors as they were intended with the plastic rings and sensors? My goal is to make them controllable like a stepper motor. I would like to know more about this system they use perhaps the proper name for it. Eventually I would like the motors to be controlled from my RaspberryPi.
After looking at one of the sensors with a high power magnifying glass I was able to obtain a manufacturer and track down exactly what it is. I was unable to locate a model though. Has anyone worked with a system like this? How does it work exactly to control position of a motor?