Seiko Epson Corporation

Takashi Takeuchi

Akio Mitsuishi

Toshio Kuriyama

Masayuki Kumazaki

Osamu Koshiishi

A printer including an impact dot print head for driving a plurality of print wires mounted on the cantilevered end of print levers is provided. The print head includes a stopper positioned to be impacted by a print lever returning from a print position to an at rest position before a plunger on the lever impacts the magnetic core. A spring mounted on the lever biases it towards the print position. Magnetic flux of a permanent magnet attracts the plunger to the non-print position. An electromagnetic coil is energized to cancel the magnetic attraction of the plunger to the core to drive the wire towards the print position.

Impact dot print head and printer including same

A printer apparatus having a sheet feeding roller which rotates in the forward direction only when the platen rotates in the reversed direction, and a auxiliary sheet feeding roller rotating in the forward direction both when the platen rotates in the forward direction and when it rotates in the reverse direction, when the platen rotates in the forward direction, the printing sheet is nipped at a predetermined amount between the platen and the driven roller, and thereafter while the platen is rotated in the reverse direction sufficient for pushing the thus nipped sheet back while the auxiliary sheet feeding roller rotates in the forward direction to eliminate an undesirable skew, whereby the printing sheet is bent being pushed in front and in rear, and thereafter the platen is rotated in the forward direction again, to transport the printing sheet to a printing start position.

Printing apparatus and method of forward and reverse sheet feeding to

A printing head for a wire dot printer includes a plurality of printing levers connected to a corresponding plurality of printing wires. A plurality of guide holes are operable for guiding the distal ends of the printing wires beyond a nose of the printing head. Each guide hole corresponds to one of the plurality of printing levers. As viewed from the nose of the printing head, each printing lever extends radially from its corresponding guide hole and the inner ends of the printing levers form a zig-zag pattern. A plurality of plate springs provides the resilient force to push the printing levers and thereby the printing wires toward the nose of the printing head. A spacer for supporting the plate springs equalizes the effective length of each plate spring.

Print wire alignment in a wire dot printer

A printer utilizes an impact dot print head achieving higher drive acceleration and resultant velocity for driving a print wire without notable increase in the moment of inertia through the provision of magnetic influencing means on adjacent or opposite sides of the print wire lever fulcrum or rotation center. The length of the print wire actuating lever between the rotation center and the print wire connection on one side of the lever is longer than the length of the lever between the rotation center and the point of magnetic influence on the other side of the lever. Thus, angular moment for driving a print wire actuating lever can be increased without notable increase of the moment of inertia by employing a magnetic influencing means on opposite sides of the rotation center of the print wire actuating lever. Therefore, an increase in the speed of printing can be achieved in the employment of the disclosed magnetic influencing means without any accompanying problems due to increased inertial mass of the print wire operating mechanism.

Printer utilizing improved impact dot print head

An impact dot print head for printing without impact noise when returning to the non-printed position includes a base. An arm is mounted for movement between a non-print position and a print position. A print wire is mounted on the arm. A first device selectively drives the arm towards the print position by bias or magnetic force. A second device returns the arm to the non-print position and maintains the arm at that position without causing the arm to impact any member of the print head when returning to the print position. The second device uses balanced magnetic attraction or repulsion and/or bias forces to hold the arm out of contact with other parts of the printer other than at its point of mounting when at the non-print position.

Growing community of inventors

Suwa, Japan

Takashi Takeuchi