Oki Data Corporation

Oki Electric Industry Co., Ltd.

Nec Corporation

Oki Daga Corporation

Kiyoshi Ikeda

Mitsuru Kishimoto

Noboru Ooishi

Hideyuki Kobayashi

Masahiko Shimosugi

Tatsuya Koyama

Shigenori Koido

Hirokazu Andou

Hiroshi Kikuchi

Takeo Fujii

Minoru Teshima

Katsuya Kamimura

Nobutoshi Chigira

Hiroyuki Ueki

Muto Eisaku

Yuko Mine

An ink jet recording apparatus is provided with a black head and a plurality of color heads. The black head has a predetermined number of first orifices aligned at predetermined intervals (e.g. 0.0169 mm) in a sub scanning direction (direction in which a print medium travels). The plurality of color heads eject different colored ink drops. Each color head has the predetermined number of second orifices aligned in the sub scanning direction perpendicular to the main scanning direction. The second orifices of adjacent color heads are aligned in a main scanning direction perpendicular to the sub scanning direction.

Ink jet recording apparatus

A dot data generator receives print data from a host apparatus and generates dot data from the print data. Dots have different diameters according to a gradation level. A drive frequency setting section sets a drive frequency in accordance with the print data. A drive signal generator generates a timing in timed relation with the drive frequency. A recording head is driven at the generated timing to form a plurality of dots on a print medium. An operation circuit determines a total drive time forming dots for each line in the main scanning direction. The drive frequency is set on a line-by-line basis in accordance with the total drive time. The timing may be delayed so that dots are formed always at accurate print positions irrespective of the scanning speed in the main scanning direction and in the sub scanning direction.

Recording apparatus

An ink Jet head includes first base second base which are made of a piezoelectric material. The first and second bases are formed with a plurality of first and second grooves in their surfaces, respectively, and are formed with first and second electrodes on their surfaces between the first grooves, respectively. The first and second bases also includes side surfaces intersecting the surfaces of the first and second bases, respectively. The electrodes are spaced apart from the side surfaces. The second base is placed on the first base so that the grooves in the first base and the grooves in the second base communicate with each other to define ink pressure chambers. An insulating layer is formed on the inner walls of the ink pressure chambers. An orifice plate having orifices is bonded to the side surfaces so that the ink chambers communicate with atmosphere through the orifices.

Ink jet head having electrode and non-electrode areas

A method of manufacturing a print head is for use with an ink Jet printer. The print head includes a plurality of parallel ink pressure chambers defined by a plurality of walls and a cover bonded on the top surfaces of the walls. The method includes the steps of forming a plurality of parallel grooves in a piezoelectric element, the grooves being bounded by a plurality of parallel walls aligned in a row; and applying an adhesive either to the top surfaces of the walls or to a surface of a cover in registration with top surfaces of the walls, the adhesive being applied by screen printing, the adhesive being applied by moving a squeegee in a direction perpendicular to a direction in which the grooves extend.

Method of manufacturing a print head for use with an ink jet printer

An ink jet head has a plurality of ink pressure chambers defined therein and a surface to which a plurality of ink pressure chambers open. An orifice plate having an orifice therein is bonded to the surface. When manufacturing the ink jet head, a coating of an insulating material is first formed on an inner wall of the ink pressure chambers and subsequently a re-dissolvable curingresin is applied to the ink jet head in an area from the inner walls to the surface. Then, the coating and the resin deposited on the surface are removed from the surface. Then, the resin deposited on the coating in the ink pressure chambers is dissolved to remove the resin from the inner wall. Finally, the orifice plate is bonded to the surface.

Ink jet head having an improved coating in an ink pressure chamber and a

An ink jet recording apparatus includes a printhead that ejects black ink drops and colored ink drops through a plurality of corresponding ink nozzles in accordance with print data. The printhead ejects ink drops when the printhead is moved to scan a recording medium in a forward direction and a reverse direction opposite to the forward direction. The forward and reverse directions are perpendicular to a direction in which the recording medium travels. A print data identifier separates the print data for a line into black print data and color print data. A print data selector supplies one of the black print data and color print data to the printhead when the printhead scans the recording medium in the forward direction, and the other of the black print data and color print data to the printhead when the printhead scans the recording medium in the reverse direction.

Ink jet recording apparatus and control method thereof

A method of adjusting an ink jet head having at least one polarized electromechanical transducer forming an ink pressure chamber from which ink drops are ejected when the electromechanical transducer is deformed. The method includes the steps of performing a first polarization operation where the electromechanical transducer is polarized into saturation in a first direction, and performing second polarization operation where the electromechanical transducer polarized by the first polarization operation is polarized in a second direction opposite to the first direction so that the electromechanical transducer is polarized to a predetermined level.

Method of adjusting electromechanical element of ink jet print head to

An ink jet recording apparatus has at least one ink chamber having an orifice through which ink drops are ejected, each ink drop having a variable amount of ink and being ejected at a timing corresponding to the amount of ink; and a controller for causing said ink chamber to eject ink drops therefrom in accordance with print data. The ink drop has an amount of ink in accordance with the level of gradation of the print data and is ejected at a timing in accordance with the amount of ink. The ink chamber may includes a plurality of ink chambers, i.e., black, yellow, magenta, and cyan. A black ink chamber is located at a first distance away from the print medium and ejects black ink drops along line k1. Color ink chambers of yellow, magenta, and cyan are aligned in a plane parallel to the surface of the print medium and oriented so that the color ink drops are ejected toward the print medium along lines k1, k3, and k4, respectively. The color ink chambers eject ink aiming at a point at which the ink drops are merged before they reach the print medium. The point is located at a second distance, which is shorter than the first distance away from the color ink chambers.

In a wire dot printer having a wire-dot print head provided with wire drive elements disposed in sequence, the energization of the respective wire drive elements is controlled in accordance with print data supplied for respective drive elements and a drive time signal supplied in common to a plurality of the drive elements. Detection is made, for each drive element, whether or not an adjacent drive element is energized, in accordance with the print data corresponding to the adjacent drive element, and the energization time for the particular drive element is controlled in accordance with the result of the detection.

Apparatus for driving adjacent elements in a wire-dot print head

Wire dot print head

In a wire dot print head, swinging members are formed of plate springs and armatures, which are attracted toward a core to resiliently deform a plate spring when an associated coil is not energized, and are released and moved forward when the coil is energized. The swinging members are swung about the forward tip ends of fulcrum members. A partition sheet is interposed between the rear surfaces of the swinging members and both the front ends of the cores and the front tip ends of the fulcrum members to interrupt transfer of grease, and to prevent direct contact of the cores and the fulcrum members with the armatures. The partition sheet includes a front plastic film, a metallic residual sheet, and a rear plastic film which are stacked in the stated order from the front side to the rear side of the print head. The front film is bonded to the metallic residual sheet over the entire surface of the metallic residual sheet. By bonding the front film and the metallic residual sheet, migration of the grease from the rear side to the front side of the partition sheet is prevented, and adhesion of the grease to the plate springs is also prevented. Moreover, because of the bonding, the metallic residual sheet is prevented from contacting the air and hence from rusting.

Wire dot print head having a bipartite partitioning sheet

An armature device of a printing head for use in a wire printer includes stylus having a free end to strike a recording medium, an armature connected to the stylus for reciprocating the stylus in a longitudinal direction thereof, a permanent magnet for generating a magnetic flux, a core for conducting the magnetic flux into the armature to form a magnetic path, a coil winding wound around the core for selectively substantially cancelling the magnetic flux, and a spring member having a free end supporting the armature for spring biasing the armature away from the core. The armature has a generally elongated shape, and a transverse groove formed in an end portion of the armature. The end portion of the armature has a first portion forming one wall of the groove and a second portion forming the other wall of the groove, the first and second portions opposing each other along the longitudinal direction of the armature. One of the walls is higher than the other wall. The stylus has a fixed end portion housed and bonded in the groove, with an end surface facing a bottom of the groove.

Armature of printing head for use in wire printer

A radio communications system has a node station centrally located in a covering area and a plurality of remote substations. The system comprises a plurality of transceivers in the node station, and a plurality of substation transceivers respectively located in the substations corresponding respectively to the node station transceivers to establish a plurality of pairs of two-way radio links therebetween. The covering area is divided into a plurality of concentric zones, each of the zones being assigned a pair of particular frequencies or a pair of particular polarization planes. Each zone has one or more substations. Transmission power level of each of the node station transceivers and each of the substation transceivers is adjusted so that fine-weather reception field strength at each end of those radio links having a greater length is greater than fine-weather reception field strength at each end of those radio links having a smaller length, there being a linear relationship between the field stength at each end of each radio link and the length thereof. The minimum azimuth angular spacing between adjacent substations can be reduced by a factor of 1/4 to allow a greater number of substations to be accommodated in the system.

Radio communications system with reduced D/U ratio variations

A multi-direction time division multiplex communication apparatus for a central station in a multi-direction time division multiplex communication system in which the central station transmits signals meant for each of satellite stations in a time division multiplex broadcast mode, while each of the satellite stations after extraction of a clock extracts the signal meant for the own station and intermittently transmits signals from the own station after adjusting the signals to such a timing that, when the signals from the own station reach the satellite station, the signals do not overlap with signals reaching the central station from the other satellite stations and appear as orderly as a single sequence of time division multiplex signals. Despite any fluctuation of an absolute delay time which may occur during communication between the central and satellite stations due to variations in the ambient conditions, the central station selects the output of a particular code regenerator circuit which is operating responsive to a decision clock whose timing matches with the fluctuation, thereby allowing the system as a whole to hold a communication without having the error rate increased.

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Tokyo, Japan

Kiyoshi Ikeda