Seiko Epson Corporation

Shigeki Mizuno

Motoyuki Niimura

Hiroshi Shirotori

Katsuhiko Nishizawa

Toshikazu Kotaka

Kenjiro Murakami

Norio Horaguchi

Hiroshi Ishida

Osamu Koshiishi

Yoshiaki Nakayama

Tatsumi Tsuboki

Kyoui Ko

Keiichi Kubota

Masaki Shimomura

Minoru Tanaka

Kazuhiko Yamamoto

Hiromi Mimura

Teturo Takahashi

A printer wherein a drive roller of a pair of sheet discharge rollers is made of rubber and a driven roller of the pair of sheet discharge rollers is made of synthetic resin; the leading end of a sheet is guided so as to be abutted against the drive roller earlier than the driven roller; the sheet that is in the course of being discharged is guided by a sheet discharge tray so as to come in slidable contact with an edge portion that is on a print head side of a sheet discharge opening. As a result, the printer can provide satisfactory printing conditions quickly with a simple structure and reduce noise leaking from the sheet discharge opening.

Printer

Printer having noise noise reduction structure

An impact dot printer designed to reduce noise, including a first cover, a second cover, and an overlap portion therebetween. The first cover is located above a print section, and may include sound wave reflecting plates, sheet guide plates, and a sound absorbing member, each reflecting plate, each sheet guide plate, and the sound absorbing member being arranged close to the print section. The second cover is rotatable relative to the first cover and forms a printed sheet discharge path together with the first cover. The second cover also has sound wave reflecting plates and sheet guide plates. Each sheet guide plate is designed to be projected farther from the associated cover than the corresponding reflecting plate on said cover. The distance between adjacent sheet guide plates is made smaller than the width of the smallest sheet to be used in the printer. The overlap portion between the first and second covers is arranged so that essentially no opening is provided between the first and second covers when viewed from the top or side.

Impact dot printer with noise suppression

In a serial impact printer, a printing head having an impact wire pin array of two arrangement lines is mounted on a carriage in such a way that the pin arrangement lines are inclined by an angle .theta. with respect to the virtual vertical direction. The respective wire pins in the array are driven at timings different delay time by delay time according to the inclination angle .theta.. The control circuit for determining the drive timings comprises a circuit for turning on the respective wire pins at the delay time intervals and a circuit for turning off the respective wire pins in sequence at the delay time intervals after a predetermined time has elapsed. It is desirable that the inclination angle .theta. satisfies the following formula:

Printing head and its drive timing control circuit for impact printer

The present invention provides an impact dot printer free from the missing of dots. An impact dot printer for recording dots on a recording medium comprises a printer wire having a printer end, a guide member for supporting the printing wire, an ink ribbon which contains an ink composition comprising a dye and a solvent and is positioned between the printing end of the printing wire and the recording medium. The printer also has a lubricant containg an oil component in the guide member for permitting the printing wire to be easily moved. The solubility of the solvent for the dye in the oil component of the lubricant is more than 400 g/100 g of oil.

Ink ribbon with wire lubricant in a wire impact printer

An impact dot head of a printer provided with a plurality of printing wires. The top end guide and/or the nose formed with protrusions at the sides thereof and with holes for slidably guiding the tips of the printing wires. The top end guide is inserted into a hole and grooves of a nose. The protrusions are then deformed to interlock within the apertures in one of the nose and top end guide, so that the respective end surfaces of the top end guide and the nose surface confronting the printing medium are in a predetermined relation, preferably essentially flush. Further, a method is provided for mass producing the impact dot head at a relatively low cost by using heat to deform the projections made of a thermoplastic resin.

Dot matrix printer with improved wire guide

An impact dot head for a printer includes a frame and a plurality of printing wires movably supported on the frame in a predetermined array. Each printing wire is bent by a different predetermined amount to be guided when moved. A plurality of armatures are respectively coupled to a respective one of the printing wires for moving the printing wires. A plurality of magnetic cores are respectively associated with each one of the armatures for selectively driving the armatures. Each of the armatures is driven by its respective magnetic core between a rest position and a printing position. A retaining member is supported on the frame and has a plurality of openings each of which is respectfully associated with one of the armatures. A plurality of coil springs each of which is supported in a respective one of the openings normally biases the armatures in the rest position. Each of the openings has a depth corresponding to the amount of bending of the printing wire associated therewith.

Printer with impact dot head

An impact dot print head for driving a printing wire is provided. An armature has a printing wire mounted at one end and is attached to a leaf spring at its other end. A ring-shaped primary magnet provides a magnetic force for maintaining the armature in a stand-by condition. A plurality of coil electromagnets provided for each respective armature. The coil magnets form a ring having an inner circumference. A ring-shaped magnetic member is provided within the diameter of the ring formed by the coil electromagnets to reduce the magnetic interference between adjacent electromagnetic coils during driving of the printing wires.

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Suwa, Japan

Shigeki Mizuno