SHARP Printer Calculator module slow motion

Neat little device that I'm reverse engineering. The machine operates pretty quickly, so the slow motion helps.
From what I can tell, the entire printer uses a single DC motor to operate (no stepper motors!) and is free-spinning at a constant RPM. Through a somewhat complex transmission system, it uses an optical sensor and a wheel (similar to how a roller-ball mouse works) to determine the position of the character wheel. When the microcontroller determines the position of the wheel, it engages an actuator (or a clutch?) on or near the white cog to press the wheel against the paper and advance the carriage. The carriage return is simply the microcontroller releasing the spring-loaded carriage which snaps (violently!) to it's start position.