Oki Electric Industry Co., Ltd.

Nippon Telegraph and Telephone Public Corporation

Mitsuo Iwama

Hiroshi Kikuchi

Minoru Isobe

Hirokazu Ando

Minoru Teshima

Tadasi Kodama

Yasuo Ohmori

Kazumasa Fukushima

Tsunematsu Takahashi

A printer head having a circular first yoke, a cylindrical permanent magnet fixed on the circular first yoke, a (n) number of electromagnets (n is an integer) positioned on a circle on the first yoke within the permanent magnet having predetermined angle intervals, a ring shaped second yoke fixed on the permanent magnet so that the upper surface of the second yoke is on the same plane as that of the upper surface of the electromagnets, a ring shaped spacer positioned on the second yoke, a disk shaped spring fixed on the spacer having a common outer ring and a (n) number of projections projected in the internal direction from the common outer ring, (n) number of armatures each fixed on each projection of the spring, (n) number of print needles each fixed to each armature so that a print needle is perpendicular to the plane of the spring, a circular yoke plate fixed on the spring having (n) number of radial slits for accepting the armatures and the width of each slit being narrower than the width of projection of the spring, a guide frame fixed on the yoke plate having a ring and a hollow cylindrical post positioned at the center of the ring, the post having a guide slit at the top of the guide frame for accepting the tops of the aligned print needles, a side hole at the side of the post at the extension of the guide slit being provided. And an oil felt being provided on the inner wall of the permanent magnet.

Printer head

A high operational speed print head for mosaic printing is provided which has a plurality of print needles positioned on a straight line, each being selectively driven toward a piece of paper through an ink ribbon. The printer head comprises a cylindrical permanent magnet ring magnetized in the axial direction; a circular bottom plate covering the bottom of the permanent magnet; and a plurality of electromagnets each having a center core and a coil wound around the core positioned on a circle on said bottom plate so as to be surrounded by the permanent ring magnet. A yoke provides a closed magnetic path with the permanent ring magnet, the bottom plate and each of the electromagnets. A plurality of moving bodies equal in number to the number of electromagnets are provided, each having at least an elongated armature overlying the core of the related electromagnet and composing a part of said closed magnetic path. A leaf spring supports the armature and is fixed to the yoke, and a print needle is mounted perpendicular to the elongated armature.

Printer head for serial dot printer

Growing community of inventors

Yokosuka, Japan

Mitsuo Iwama