Konica Corporation

Konica-Minolta Holdings, Inc.

Konishiroku Photo Industry Co., Ltd.

Konica Minolta, Inc.

Konica Minolta Ij Technologies, Inc.

Konica Technosearch Corp.

Kazuo Asano

Akiko Kitami

Shinichi Nishi

Kazuo Arai

Toru Terasaka

Hidetaka Ninomiya

Katsuaki Komatsu

Daisuke Ishibashi

Katuichi Kawabata

Yuko Nagasawa

Wataru Ishikawa

Yoshikazu Maekawa

Akihiko Tamura

Hiroaki Arakawa

Yoshio Takeuchi

Takashi Horiyama

Miki Horii

Shinich Nishi

Shin-ichi Nishi

Shozo Kikukawa

Chise Nishiwaki

A head maintenance device includes a wiping section which wipes a nozzle plane, on which a plurality of nozzles to eject ink are provided, of an inkjet head. The wiping section includes a wiping member including a cloth, an elastic body and a support, in the order named from a side where the wiping section comes into contact with the inkjet head. The cloth is moved parallel to the nozzle plane at a relative moving velocity of not less than RMV&#xd7;0.2 and not more than RMV&#xd7;0.9 with respect to the nozzle plane so as to wipe the nozzle plane.

Head maintenance device and inkjet recorder

An inkjet recording apparatus including: a recording head having a pressure chamber, and a pressure generation device to change a volume of the pressure chamber, wherein the recording head ejects an ink in the pressure chamber as an ink droplet from a nozzle by driving the pressure generation device based on drive signals; and a drive signal generating section to generate the drive signals, which include: an ejection pulse including a first pulse for expanding the volume of the pressure chamber and then contracting the volume; a preliminary pulse, to be applied immediately before the first pulse, for contracting the volume of the pressure chamber and then expanding the volume, and wherein the preliminary pulse is a rectangular wave having a pulse width of 2AL or greater, where AL is &#xbd; of an acoustic resonance cycle period of a pressure wave in the pressure chamber.

Inkjet recording apparatus

A method of forming an image containing the step of: ejecting droplets of an ink-jet ink containing water, a colorant and a polymer through a nozzle of an ink-jet head onto an image recording medium, wherein the polymer has a hydrophilic main chain and a plurality of side chains which are capable of cross-linking between the side chains by irradiation with an active energy ray; and a shearing stress is continuously applied to the ink-jet ink in an ink-jet head channel of the ink-jet head during the time when the ink-jet head is in a stand-by condition to eject the droplets of the ink-jet ink.

Image forming method

A liquid droplet ejecting apparatus having: a pressurizing device; a pressure generation chamber whose volume expands or contracts by a movement of the pressurizing device; a liquid droplet ejecting head having a nozzle communicating with the pressure generation chamber; and a drive signal generator which generates the drive signal for operating the pressurizing device, and causing to eject liquid droplets through the nozzle, wherein the drive signal comprises: an expansion pulse to expand the volume of the pressure generation chamber; a first contraction pulse following the expansion pulse to contract the volume; and a second contraction pulse after the first contraction pulse to contract the volume, wherein a pulse width of the expansion pulse is 0.7AL through 1.3AL, and a pulse width of the first contraction pulse is 0.3 AL through 1.5 AL, where AL is &#xbd; of an acoustic resonance period of the pressure generation chamber.

Liquid droplet ejecting apparatus and a method of driving a liquid droplet ejecting head

A driving method of a droplet ejection head having plural channels separated by sidewalls formed with piezoelectric material, the channels being divided into three groups; and an electric voltage pulse is applied to each of the groups sequentially in a time-sharing mode, and to generate a shear deformation of the sidewall, and liquid is ejected as a droplet from a nozzle, wherein applying process of the pulse includes: a first step for enlarging a volume of a channel; a second step for keeping the enlarged volume; a third step for reducing the volume; a fourth step for keeping the reduced volume; and a fifth step for enlarging the volume, wherein the third step starts when &#x3b1;/&#x3b2;&#x2266;&#x2153; is satisfied for the protruded pillar at an adjoining channel nozzle driven just before; where &#x3b1; denotes a width of the pillar, and &#x3b2; denotes a maximum width of the pillar.

Driving method of droplet ejection head

A method of driving a droplet jetting head comprising nozzle orifices to jet droplets, pressure generating chambers each of which can store liquid and communicate with one of the orifices, and pressurizing devices to change the pressures of the pressure generating chambers, comprising the steps of increasing the pressure in the pressure generating chamber by the pressurizing device and protruding liquid in the pressure generating chamber from the nozzle orifice as a droplet, and separating the liquid which protrudes from the nozzle orifice when &#x3b1;/&#x3b2; is equal to or less than 1/3 where &#x3b1;(&#x3bc;m) is the diameter (in micrometers) of an liquid pillar (protruded from the nozzle orifice) at the front end of the nozzle orifice and &#x3b2;(&#x3bc;m) is the maximum diameter (in micrometers) of the liquid pillar.

Method of driving a droplet jetting head

An inkjet recording head for ejecting ink in ink channels by deformation of the piezoelectric element, comprising: a partition wall, formed by making grooves in an actuator substrate made of a polarized piezoelectric element, for forming longitudinal side surface of a plurality of ink channels; a cover plate adhered on an upper surface of the partition wall to form a top surface of the plurality of ink channels; a nozzle plate, adhered on a front side surface of the actuator substrate, having a nozzle hole for ejecting ink, wherein the cover plate is made of a machinable ceramics, which has a higher thermal conductivity than that of the piezoelectric element, and where Lc and Lp respectively represent the linear thermal expansion coefficient of the cover plate and the piezoelectric element, the relationship of, |Lc&#x2212;Lp|&#x2266;5&#xd7;10/&#xb0; C. is satisfied, and a top plate having higher thermal conductivity than the cover plate is provided on the cover plate.

Inkjet recording head

An inkjet recording apparatus having a head that ejects ink droplets, a temperature detector that detects temperatures in the vicinity of the head, and a drive waveform controller that generates a drive waveform driving the head, wherein the drive waveform controller changes, based on temperature information coming from the temperature detector, the amplitude as temperature changes, according to the expression V=EXP(A/T+B) wherein V represents an amplitude of the drive waveform, T represents the temperature and A and B represent a constant.

Inkjet recording apparatus and control method of inkjet recording apparatus

A droplet ejection apparatus provided with: a drive signal generator for generating drive signals including a plurality of drive pulses; a drive pulse selector for selecting drive pulses in accordance with a print datum of each pixel; and a head for ejecting a droplet from a nozzle provided corresponding to a channel, by changing a volume of the channel according to the drive pulses selected, wherein, the drive signal includes a micro-vibration pulse as one of the drive pulses to generate a micro-vibration of meniscus in the nozzle in such a degree that the droplet is not ejected, said micro-vibration pulse being formed of rectangular waves which include at least one micro-vibration pulse having a pulse width of (2n) AL, where AL is &#xbd; of the acoustic resonance period of the channel, and n is an integer not smaller than 1.

Droplet ejection apparatus and its drive method

An inkjet recording head for ejecting ink, having a plurality of piezoelectric sidewalls to form a plurality of ink channels; a piezoelectric bottom plate; and a plurality of electrodes All of the ink channels are divided into two or more groups of ink channels composed of ink channels between which at least one ink channel is sandwiched;

An ink-jet recording apparatus in which an electromechanical converting device that changes a volume of an ink channel of a recording head is driven to make an ink droplet to jet from a nozzle, wherein before an ink droplet jetting operation is conducted, an ink meniscus of the ink channel is vibrated finely by repeating plural times a pushing out process so that a distance corresponding to a peak of the ink meniscus pushed out from a surface of the nozzle is equal to or more than a radius of the nozzle and a process for pulling in more toward the ink channel across a repose position, while the ink is prevented from jetting from the nozzle.

Ink-jet recording apparatus

An inkjet recording method having a step of ejecting an ink containing at least photo-polymerizing compound and a colorant from a nozzle of a recording head, which has a piezoelectric member, to form an image on a recording member. The inkjet recording method utilizes a piezoelectric function of the piezoelectric member, a diameter of the nozzle (R) is from 20 to 50 &#x3bc;m, and a length of the piezoelectric member in an ink ejecting direction (L) is from 2.0 to 5.0 mm.

Inkjet recording method

In an ink jet printer provided with a printing head having an ink chamber, a piezoelectric element and a nozzle tip; the printer is further provided with a drive signal generating circuit for generating drive signals corresponding to image information, a temperature sensor for measuring the temperature of the printing head; and a heating signal generating circuit for generating a heating signal on the basis of the temperature of the printing head measured by the temperature sensor. The piezoelectric element vibrates in response to the heating signal and generates heat so that the ink in the ink chamber is heated.

Ink jet printer

A metal complex compound is disclosed. The compound is represented by the following formula I or II: ##STR1##

Metal complex compound

A liquid crystal display device consisting essentially of a liquid crystal cell and a pair of polarizing plates disposed on the both sides of said liquid crystal cells is disclosed. The liquid crystal cell has a liquid crystal layer in which a nematic liquid crystal containing an optically active substance and forming a twisted structure is disposed between a pair of electrode substrates being oppositely disposed and each having an alignment layer, and said liquid crystal display device is characterized by satisfying Conditions (a) to (d); Condition (a): a twist angle .alpha. of the twisted structure in the liquid crystal layer is 220.degree. to 300.degree.; Condition (b): a pretilt angle .theta..sub.o made by a director of liquid crystal molecules contacting a face of the electrode substrate and the electrode substrate itself is not less than 25.degree.; Condition (c): a product, .DELTA.n.multidot.d, of a refractive anisotropy, .DELTA.n, of the nematic liquid crystal and a thickness, d, of the liquid crystal layer is 0.65 to 0.90 .mu.m; Condition (d): in the relation to the twist angle .alpha., angles .beta. and .gamma. made by polarizing axes of a pair of the polarizing plates and the directions of aligning treatments of the electrode substrates adjacent to the respective polarizing plates satisfy Equation (1);

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Hino, Japan

Kazuo Asano