Hitachi Koki Co., Ltd.

Ricoh Printing Systems, Ltd.

Hitachi Printing Solutions, Ltd.

Hitachi, Ltd.

Kenichi Kugai

Nobuhiro Noto

Yoshitaka Akiyama

Nobuhiro Kurosawa

Kenji Yamada

Shigenori Suematsu

Hiroshi Takahagi

Takahiro Yamada

Hitoshi Kida

Satoru Tobita

Junshin Sakamoto

Takuji Torii

Yasuo Takano

Hirotaka Kobayashi

Kazuaki Akimoto

Susumu Saito

Akira Arimoto

Shinichi Sakamoto

Shigeo Moriyama

Takeshi Mochizuki

Takashi Sato

Yoshikane Matsumoto

Yutaka Shoji

Koji Takahashi

Kazuo Shimizu

Makoto Kurosawa

Takashi Nishimura

Ryuuichi Shimizu

Masato Miwa

Takao Matsuoka

Yoshimasa Kondo

Satoru Wada

Takahiro Kikuchi

Akira Kashimura

Keiji Watanabe

Takuji Toru

Masafumi Shimizu

A method for manufacturing an inkjet recording head includes an ejecting step, a measuring step, dividing step and applying step. The ejecting step ejects test ink droplets and print ink droplets from nozzles. The measuring step measures ejection results of the test ink droplets. The dividing step divides a plurality of nozzles into a plurality of groups based on the ejection results. The applying step applies a group-based polarizing voltage determined for each group to the piezoelectric elements belonging to a corresponding group to polarize the piezoelectric elements so that ejection results of the print ink droplets fall in a predetermined range.

Method for manufacturing inkjet recording head of inkjet recording device

A droplet ejecting device includes a nozzle unit, a piezoelectric member and a drive voltage generating unit. The piezoelectric member has a common electrode and a discrete electrode. A first differentiation by polarization voltage of a characteristic curve indicating change in a polarization of the piezoelectric member with respect to change in the polarization voltage has a plurality of extremal values including a first extremal value at a prescribed positive voltage Vbp that is the smallest polarization voltage among plus polarization voltages corresponding to the plurality of extremal values, and a second extremal value at a prescribed negative voltage Vbn that is the largest polarization voltage among minus polarization voltages corresponding to the plurality of extremal values. The drive voltage generating unit generates a drive voltage having a range between a first negative voltage Veand a first positive voltage Ve, and applies the drive voltage between the common electrode and the discrete electrode. Vbp, Vbn, Ve, and Veare set such that Vbn&#x3c;Ve&#x3c;0 and 0&#x3c;Ve&#x3c;Vbp.

Inkjet recording device, ejecting device provided therein, and method of calibrating ejection characteristic for droplet

The invention is to provide a multi-beam light source where the interval of core portions is reduced and the core portions are arranged on a straight line. The multi-beam light source includes a first substrate where a plurality of optical fibers each having a core portion and a clad portion surrounding the core portion coaxially are fixed at predetermined intervals, and a second substrate where a plurality of similar optical fibers are fixed at predetermined intervals. The first and second substrates are put and bonded on top of each other so that the core portion of each optical fiber on the second substrate is inserted between core portions of adjacent optical fibers on the first substrate, and the core portions of the optical fibers on the first and second substrate are arranged substantially on a straight line.

Multi-beam light source, method for manufacturing the same, light scanning unit using the same, and image forming apparatus using the same

An inkjet head includes a pair of support plates A, B and a diaphragm plate interposed between the support plates A, B. In this configuration, even when adhesion between the diaphragm plate and the support plate B is insecure, and when a piezoelectric element deforms a diaphragm toward a pressure chamber , that is, in a direction away from the support plate B, the support plate A prevents the diaphragm plate from peeling off the support plate B. Accordingly, the dimension and thus a deforming amount of the diaphragm is maintained uniform, whereby a uniform ink ejection performance is maintained.

Configuration of inkjet head realizing uniform ink ejection performance

An ink jet print head includes pressure chambers, nozzles, and ink channels in a one-to-one correspondence. A diaphragm forms a side of each pressure chamber. The ink channels are formed in a restrictor plate. Piezoelectric elements are attached to the diaphragm and to a piezoelectric element fixing plate, which supports the piezoelectric elements. A housing of the head is formed with a common ink channel for supplying ink to the ink channels and an internal space into which the piezoelectric elements and the piezoelectric element fixing plate are at least partially inserted. A cover is provided for covering the piezoelectric element fixing plate. The cover is connected to the housing and is provided with an internal space large enough to maintain a gap between the cover and the piezoelectric element fixing plate.

Ink jet print head and method of production thereof

An ink jet print head includes pressure chambers, a diaphragm forming a side of the pressure chambers, stacked piezoelectric elements, a piezoelectric element fixing plate, and a housing. The stacked piezoelectric elements are attached to the diaphragm in a one-to-one correspondence with pressure chambers. The piezoelectric element fixing plate is fixedly attached to and supports the stacked piezoelectric elements. The housing includes a common ink channel portion that supplies ink to the pressure chambers. The piezoelectric element fixing plate and the stacked piezoelectric elements are disposed at least partially in the space defined by the diaphragm and internal side walls of the ink channel portion with a gap existing between the piezoelectric element fixing plate and the internal side walls.

During a method for manufacturing an ink-jet print head, piezoelectric element bars are fixed to a base plate. Then, two corners of the piezoelectric element bars are cut. The bare are then diced to be separated into individual piezoelectric elements.

Method of manufacturing ink jet print head

To increase the size of dot printed on a print medium with an on-demand multi-nozzle ink jet head, at least two unit pulses are applied in succession to a piezoelectric element which varies the volume of an ink chamber. The unit pulse has a pulse width substantially equal to a period of Helmholtz natural oscillation determined based on dimensions, materials, and physical properties of an ink channel and the piezoelectric element and other components relating to oscillation. An off duration between adjacent unit pulses applied in succession to the piezoelectric element is preferably set one fifth to one fourth of the unit pulse width.

Drive method for an on-demand multi-nozzle ink jet head

An on-demand ink jet head includes a plurality of piezoelectric elements in alignment with one another with one end of each facing in the same direction. The end of each piezoelectric element is bonded by an adhesive material to a diaphragm which, together with a nozzle plate, forms a pressurizing chamber. To confine the fluid state adhesive material expelled out of the endmost piezoelectric elements, a dummy piezoelectric element is disposed outside each endmost piezoelectric element. The adhesive material, when dried, serves as a damper of the piezoelectric element for damping unwanted vibrations of the piezoelectric elements. By the provision of the dummy piezoelectric elements, the distribution of the adhesive material becomes substantially even between the piezoelectric elements, resulting in uniform operations of the piezoelectric elements.

Multi-nozzle ink jet head with dummy piezoelectric elements at both ends of a piezoelectric element array for controlling the flow of adhesive about the piezoelectric element array

A transfer belt for use in an electrophotographic apparatus for transporting an image support onto which a toner image formed on a surface of a photoconductor containing a photoconductive layer is transferred, and the transfer belt includes a surface layer formed from a coating liquid containing: a solvent; at least one kind of inorganic or organic fine particles dispersible in the solvent; and at least one kind of organic compound dissolved in the solvent. Also disclosed is an electrophotographic apparatus using the transfer belt.

Transfer belt and electrophotographic apparatus

A rotary sleeve 1 is integral with a rotary polygon mirror 14 forming a rotor section, one end portion of the rotary sleeve is formed into a magnet mounting section 15, on which a magnet yoke 3 and rotary magnets 4 are mounted. The rotary sleeve 1 has a bearing on its inner cylindrical surface 17 which is in the form of a through-hole.

Rotary polygon mirror motor

A rotary polygon mirror device comprises: a rotor including a polygon mirror secured to one end face of a cylinder, a central rod secured inside said cylinder in such a manner that the central rod is extended along the axis of the cylinder, and a thrust bearing magnet secured to the end face of the central rod, said magnet; and a casing coaxially surrounding the cylinder with a gap therebetween. In the device, the gap provides radial bearing means, and the cylinder and the casing are made equal in thermal expansion coefficient.

Dynamic pressure bearing and rotary polygon mirror device with the

In a print hammer assembly for a dot line printer, print pins are attached to the tip ends of print hammers alternately displaced toward left and right by a predetermined distance from a vertical center of the print hammer, wherein comb portions of a front yoke at both sides of the plunger are made to be an equal width. With such an arrangement, the print pins are not deformed horizontally due to imbalanced magnetic force applied to the associated print hammer at the time of magnetization of a permanent magnet.

Print hammer assembly for dot line printer

Print hammers in a printing head of a dot line printer for printing with an ink ribbon multiple dot lines in a single shuttling direction and for providing a character line by the combination of the multiple dot lines in accordance with reciprocal motions of the print head while feeding a printing sheet in a line to line direction include hammer springs and printing pins provided at the free tip end portions of the springs. The printing pins are positioned offset from one another in the shuttling direction to thus perform multiple dot line printings in the single shuttling motion. Each of the printing pins has a printing pin surface in abutment with the printing sheet through the ink ribbon. The printing pin surface has a polygonal shape defined by a combination of ridge lines. All ridge lines extend obliquely with respect to the shuttling direction for facilitating grinding of the printing pins.

Print hammers of printing head in dot line printer

A method of and apparatus for fabricating an article having an aspheric figure, wherein the three-dimensional positional relationship between a work and a grinding spindle as a processing tool is controlled in terms of a polar coordinate system. The grinding spindle extends in a plane which is perpendicular to the direction of rotation of said work and is made to swing along an arcuate path. The distance between the axis of rotation of the work and the axis of the swing of the grinding spindle is changed in relation to the rotational angular position of the work.

Growing community of inventors

Hitachinaka, Japan

Kenichi Kugai