Abstract: A motion detector comprising a rotator member having at least one radially positioned member and being mounted for rotation from at least a first position to at least a second position; a detector member, preferably a Hall Effect sensor; and a magnet producing a magnetic field; wherein, the radially positioned member is characterized by altering the magnetic flux of the magnetic field when it moves into and out of proximity to the magnet; and wherein the detector member detects the alteration of the magnetic flux. The motion detector is preferably used to detect the speed, type, position, presence, and absence of a printer ribbon cartridge.

Abstract: A motion detector comprising a rotator member having at least one radially positioned member and being mounted for rotation from at least a first position to at least a second position; a detector member, preferably a Hall Effect sensor; and a magnet producing a magnetic field; wherein, the radially positioned member is characterized by altering the magnetic flux of the magnetic field when it moves into and out of proximity to the magnet; and wherein the detector member detects the alteration of the magnetic flux. The motion detector is preferably used to detect the speed, type, position, presence, and absence of a printer ribbon cartridge.

Abstract: A print head is attached to a stepper motor that moves the print head toward and away from the surface of a printing medium. During a gap setting operation, a controller controls the stepper motor to move the print head to a maximum distance away from the surface of the printing medium. A print wire actuator coil for the print wire used in the gap setting operation is then energized. The print head is then positioned over the printing medium and the controller controls the stepper motor to move the print head in towards the printing medium. When the energized print wire touches the printing medium, the print wire begins to be pushed back into the print head. As the wire is pushed back, an air gap between a yoke and a print wire armature is created. The opening of the air gap increases the amount of flux detected by a Hall sensor. When the output voltage of the Hall sensor reaches a predetermined level, the controller determines that the print wire has pressed the ribbon and printing medium against the platen.

Abstract: In a printer having multiple paper paths, each path is provided with a clutch and a tractor to advance paper between a printhead and a striker bar, the paper being selectively advanced along the paper paths. Each clutch has a timing pulley driven by a cog belt, in turn driven by a stepper motor. The input pulley and the output gear driving the tractor are synchronized during repeated engagement such that the clutch reengages the input and output elements at a rotational position corresponding to the rotational position of the input element when previously disengaged from the output element.