Abstract: In a printer, a sheet feeder includes a motor which is used for a plurality of mechanisms in common so as to make the printer lighter in weight and more compact in size. The sheet feeder can vary the feeding amount of the sheet in response to the printing operation. The sheet feeder also permits the manual operation of a sheet feed roller shaft by disconnecting power from a motor via a power switching mechanism. The power switching mechanism includes a clutch mechanism which has a gear for transmitting the power of the motor, and a clutch wheel. The clutch mechanism is used when feeding the sheet by the operation of the motor. The sheet feeding amount is varied by the operation of a partial gear which comes into contact selectively with a first or second feed cam. These feed cams have projections having different heights.

Abstract: A ribbon cartridge comprises a case, a sliding guide slidably mounted in the case, and an endless ink ribbon enclosed in the case. A greater part of the ribbon is enclosed in the case at a space between the sliding guide and an inlet side of the case. The sliding guide has a front guide plate at an inlet side thereof, and a rear guide plate at an outlet side. The front guide plate has a vertical inlet slit and the rear guide plate has an inclined outlet slit. The ink ribbon is engaged with both the slits so as to correct any twist thereof.

Abstract: A recording medium feeding apparatus for printer is disclosed wherein a web of a recording medium is fed and taken up by a take up reel. A web feeding mechanism and a reel driving mechanism are operated through a coupling means by a spring means in which energy is stored by a common driving means.

Abstract: A platen assembly for a print station apparatus, which comprises first and second indepently movable platen units for holding recording medium so as to compensate for thickness of the medium, a third platen unit interposed between the first and second platen units and independently movable from the first and second platen units, the third platen unit having a minimum length necessary for holding the centerfold of the medium, and first and second springs secured to the first and second platen units and biasing the third platen unit toward a guide of the print station apparatus.