Abstract: A needle guide (5) is composed of a first guide wall (5a) and a second guide wall (5b) arranged at a distance x from each other. Each of these guide walls is formed with through holes through which needles penetrate and which extends parallel to the longitudinal direction of a needle bunch, the through holes of the first guide wall and the second guide wall for one needle is shifted from each other in the convergence direction of the needles with a shift amount ?n determined by the distance x and a convergence angle ?n of the needle.

Abstract: In order to restrain a flux loss for obtaining magnetic characteristic required for high-speed printing, a wire dot printer head has armature 4 having a pivot shaft serving as a center of a pivot and pivotably provided so as to oppose to plural cores formed on a yoke and an armature spacer provided on the yoke for forming a side magnetic path with respect to the armature, wherein, supposing that each of the saturated magnetic fluxes of the yoke, the armatures and the armature spacer is defined as A, B and C in this order, these components are formed to establish a relationship of A?B?C.

Abstract: An impact printer with a hammerbank having print hammers retained by a permanent magnet for impacting a print ribbon, and a mechanical driver for moving the hammerbank across print media. First and second coils for each hammer are wrapped around first and second pole pieces, one of which is asymmetrical to the other pole piece. One of the pole pieces can have a generally elongated longitudinal form with the coil wound around the longitudinal form and the other can have a generally arcuate form, with the coil wrapped on a portion between the ends thereof. The coil wrapped around the arcuately formed pole piece is thicker than the coil wrapped around the longitudinal pole piece. The result is to provide pole pieces and coils for an impact printer having differing spatial relationships that can be staggered, or formed asymmetrically for more compact coil and pole piece placement to improve printer efficiency.

Abstract: An impact line printer comprising a print ribbon wound on a pair of spools for traversal in two directions across a plurality of print hammers having tips for impacting the print ribbon to print on a media. A permanent magnet having two pole pieces having pole piece ends in adjacent relationship to the print hammers retains the print hammers until a coil in associated relationship with each pole piece releases the magnetic retention of the hammers. A magnetically permeable extension is longitudinally adjacent each hammer which acts as a magnetic shunt to permit more rapid printing rates and higher impacts. The extensions conduct and shunt magnetic flux from the hammers through the longitudinally adjacent extensions.

Abstract: A printing apparatus, which performs printing by using a full-line type printhead, prints an image in accordance with an attachment angle of the printhead, and automatically performs registration adjustment when using plural printheads. In the apparatus, an angle of the printhead relative to a transfer direction of a print medium is detected, image data received in raster format is divided into plural pixel blocks, the divided pixel blocks are stored into a memory, the order of reading the pixel blocks from the memory is determined based on the detected relative angle, and the read data is transmitted to the printhead and used for printing.

Abstract: A needle printing head comprising a support (11) able to axially guide a plurality of printing needles (15), each of which has one end attached to a mobile armature (16) of a corresponding actuation electromagnet (17) having a ferromagnetic core (18) provided with polar extensions. A separation element (30) is interposed between the mobile armatures (16) and the corresponding polar extensions. The separation element (30) is made of a metal material and comprises elements (33, 34) able to reduce the effects of the eddy currents which are generated by the energizing of every electromagnet (17).