Abstract: Dot-matrix printer for printing on a paper resting against a platen includes a bendable piezoelectric lamina which is supported along a first edge planar ferromagnetic member which is operatively connected to the bendable piezoelectric lamina at a region remote from the first edge, a dot print element mounted the movement of the bendable piezoelectric lamina along a line parallel to the plane of the planar ferromagnetic member, control means for generating first or second voltage signals for energizing the bendable piezoelectric lamina to cause the planar ferromagnetic member to assume a first or a second position, and electromagnetic means for applying a controllably variable magnetic force on the planar ferromagnetic member such that only when the planar ferromagnetic member is not in the first position is there sufficient force exerted by the dot print element to print on the record medium with the diameter of the dot being a function of the force.

Abstract: A ribbon cassette including a casing provided with an opening for receiving a photoelectric device. In the casing is a ribbon which passes from a supply reel to a take-up reel. A guide leads the ribbon past the photoelectric device. If the ribbon breaks, the ribbon is pulled away from the photoelectric device to cause a change in received light.

Abstract: Dot-matrix printer for printing on a paper resting against a platen includes a bendable piezoelectric lamina, means for fixedly supporting the bendable piezoelectric lamina along a first edge, a planar rerromagnetic member, means for operatively connecting the planar ferromagnetic member to the bendable piezoelectric lamina at a region remote from the first edge, a dot print element, means for mounting the dot element to be responsive to the movement of the bendable piezoelectric lamina in the region of the planar ferromagnetic member to extend along a line parallel to the plane of the planar ferromagnetic member, control means for generating first or second voltage signals for energizing the bendable piezoelectric lamina to cause the planar ferromagnetic member to assume a first or a second position, and electromagnetic means for applying a magnetic force on the planar ferromagnetic member such that only when the planar ferromagnetic member is not in the first position is there sufficient force exerted by th

Abstract: An ink ribbon cartridge for a printer comprising a storage reel for an ink ribbon, a take-up reel for the ink ribbon, drive wheels for longitudinally advancing the ink ribbon from the storage reel to the take-up reel for printing on the ribbon, and a pulley or roller which rides on the cam and which is coupled to a further pulley or roller, these parts cooperating for transversely displacing the ribbon during its longitudinal advance to offset the area of the ribbon utilized in printing.

Abstract: Apparatus and method for use with a tape cartridge of a printer to determine halt of tape feed from a supply reel to a take-up reel of the cartridge comprising reflective and non-reflective portions on the supply reel rotating therewith and an assembly including a light source and a sensor fixed in position to face the supply reel to cooperate with the reflective and non-reflective portions without mechanical contact therewith for producing a train of successive electrical output pulses as the supply reel rotates. Upon cessation of the output pulses the tape feed is halted. The system also provides a mechanical locking device for effecting positive locking of the supply reel at the end of tape feed.

Abstract: Reader-writer apparatus includes a common drive roller having a primary axis of rotation lying in a plane which divides a reading region from a writing region and a read follower roller positioned operatively opposite the common drive roller, has an axis of rotation parallel to the primary axis of rotation and is disposed on the read side of the region dividing plane; also, there is a similar write follower roller operatively opposite the common drive roller which has an axis parallel to the primary drive axis and is disposed on the write side of the region dividing plane. A master document feeder is positioned on the read side of the plane to guide a master document between the common drive roller and the read follower to a read site while a master document accepter also on the read side of the region dividing plane accepts a master document passing from the read site.

Abstract: A vibrating thermal printer transfers thermoplastic ink from a ribbon to a record medium by selectively heating resistive elements on a substrate of electrically conductive material. While the record medium and ribbon are passing the print head, the print head, by means of piezoelectric phenomenon, induces vibration in the head to facilitate the deposition of thermoplastic ink onto the paper. There is also shown the preheating of the ribbon to improve throughput.

Abstract: An envelope bin assembly for a printer comprising a bin member in which envelopes can be stacked in readiness for feed by an envelope feed roller of the printer, the bin member being engageable in a support of the printer such that the feed roller of the printer can engage the frontmost envelope in the stack to feed the same to a printing station of the printer. A pressure applying member is guidably supported for displacement in the bin member for applying pressure, under the action of gravity, to the stack of envelopes at the rear thereof thereby to press the frontmost envelope in the stack against the feed roller and bend the envelopes at the front of the stack around the feed roller to produce a fan effect at the lower edges of the envelopes by which the lower edges are spread apart to facilitate single feed of the frontmost envelope.

Abstract: Paper bail apparatus for a printer comprising a frame mounted on a non-circular paper bail shaft of a printer and rotatably supporting a pair of rollers for contact with the platen of the printer along two separate lines of contact which are circumferentially spaced on the platen and longitudinally offset from one another. The frame is made from plastic material and the rollers are snap-fit in the frame. The frame has a projection at an inlet guide for guidable entry of the paper between the rollers and the platen.

Abstract: An ink ribbon cartridge for a printer comprising a storage reel for an ink ribbon, a take-up reel for the ink ribbon, drive wheels for longitudinally advancing the ink ribbon from the storage reel to the take-up reel for printing on the ribbon and a pulley which rides on a cam for transversely displacing the ribbon during its longitudinal advance to produce a saw-tooth path of travel of the ribbon and offset the area of the ribbon utilized in printing.

Abstract: Sheet and envelope feeder apparatus for a printer comprising first and second trays for respective stacks of sheets of paper and first and second drive rollers for feeding sheets of paper from the respective trays to the printer where a printing operation is effected on at least one of the faces of the sheets of paper. A third tray is provided for envelopes and a third drive roller for feeding envelopes from the third tray to the printer. The first and second drive rollers are selectively driven by a first drive motor to feed the sheets of paper.

Abstract: Apparatus for releasably attaching a daisy print wheel to a splined shaft of an angular drive such that the print wheel can be driven in angular rotation with substantially no backlash. The apparatus comprises a splined hub fixed to the print wheel and slidably engageable with the splined shaft and a holder mounted on the hub for movement between a locking position in which the hub is locked on the splined shaft with interference fit and a released position in which the hub with the holder thereon is slidably removable from the splined shaft together with the print wheel. The hub includes a plurality of angular segments of cantilever formation which are pressed into the spaces between the splines on the drive shaft with interference fit by the engagement of the holder in its locking position. The holder is axially movable on the hub in traveling between the locking and release positions and is not normally removable from the hub.