Ricoh Printing Systems, Ltd.

Sony Corporation

Ricoh Company, Ltd.

Hitachi Koki Co., Ltd.

Hitachi Printing Solutions, Ltd.

Satoru Tobita

Yoshikane Matsumoto

Toshiharu Sumiya

Takahiro Yamada

Tomohiko Koda

Hitoshi Kida

Toshitaka Ogawa

Yoshitaka Akiyama

Masaru Tezuka

Koji Ishiwata

Ryouta Matsufuji

Kazushi Sato

Shinya Kobayashi

Osamu Machida

Tomohiko Kohda

Norimasa Sohgawa

Kenichi Kugai

Kunihiro Yamanaka

Takashi Satou

Ryo Kasahara

Naoko Kitaoka

Seiji Tanizawa

Ryohta Matsufuji

Hideaki Miyauchi

Shinya Tomita

Keiji Hirai

Hideaki Mamiya

Yoichiro Sako

Masahiro Kuwata

Kenji Yamada

Mamoru Okano

Takashi Sato

Makoto Kurosawa

Takuji Torii

Nobuhiro Noto

Shun Suzuki

Hiroyuki Yamauchi

Katsunori Kawasumi

Teruaki Higashihara

Yoshinari Suzuki

Hiroomi Kozawa

Katsuya Kawai

Roger Lagadec

Teruhito Noshiro

Nobuhiro Kurosawa

Hideyuki Makita

Keisuke Sekiguchi

Kazunobu Hayashi

Kaori Fujii

Youichi Hujita

Shuusuke Iwata

Tadashi Mimura

Yuji Ohmura

Masayuki Kinoshita

Takashi Kagami

Hiroyuki Hara, Deceased

Kazuyuki Hishida

Genichiro Kawamichi

A liquid discharge head includes a plurality of nozzles, a plurality of individual liquid chambers, a common liquid chamber, a deformable damper, and a damper chamber. The plurality of nozzles is arrayed in a nozzle array direction, to discharge liquid. The plurality of individual liquid chambers is communicated with the plurality of nozzles. The common liquid chamber supplies liquid to the plurality of individual liquid chambers. The deformable damper constitutes part of a wall face of the common liquid chamber. The damper chamber is disposed along the nozzle array direction with the damper interposed between the damper chamber and the common liquid chamber. The damper chamber extends to an outer area in the nozzle array direction than an individual liquid chamber of the plurality of individual liquid chambers at each end in the nozzle array direction.

Liquid discharge head, liquid discharge device, and liquid discharge apparatus

A liquid-jet head includes a channel plate forming an individual liquid chamber in communication with nozzles configured to eject liquid drops, a wall surface member forming a wall surface of the individual liquid chamber, and a drive unit disposed on the wall surface member side and configured to generate a pressure applied to a drive region inside the individual liquid chamber. In the liquid-jet head, a fluid resistance part is formed by disposing an island part in a liquid supply channel configured to supply a liquid to the individual liquid channel, and the island part includes a gradient part on the channel plate side, at least a part of the gradient part being formed such that the part of the gradient part faces the drive region inside the individual liquid chamber.

Liquid-jet head and image forming apparatus

A droplet ejecting apparatus includes a recording head including nozzles, liquid chambers communicating with the respective nozzles and storing ink, and actuators for applying pressure to the respective liquid chambers; and a print control unit configured to generate drive signals for driving the respective actuators to eject droplets from the nozzles. The drive signal includes a first contracting waveform component for ejecting a droplet and a second contracting waveform component for further contracting the liquid chamber after application of the first contracting waveform component but not ejecting a droplet. The second contracting waveform component is output at oscillation-damping timing at which a pressure wave generated by the first contracting waveform component is damped, in a condition where an environmental temperature is high, and is output at resonating timing at which resonance with the generated pressure wave occurs, in a condition where the environmental temperature is low.

Droplet ejecting apparatus and method for driving the same

An image forming apparatus includes a recording head and a driving waveform generator. The recording head has a nozzle, a liquid chamber, and a pressure generator. The driving waveform generator is connected to the pressure generator to generate and output a driving waveform including a plurality of driving pulses per driving cycle to eject a droplet from the nozzle. A last one of the driving pulses includes a first expansion waveform element, a first retaining waveform element, a first contraction waveform element, a second retaining waveform element, a second contraction waveform element, a third retaining waveform element, and a second expansion waveform element. The first contraction waveform element has a potential difference greater than a potential difference of the first expansion waveform element. The second contraction waveform element has a time period longer than a time period of the first contraction waveform element.

Image forming apparatus including recording head for ejecting liquid droplets

An image forming apparatus comprises a printing head unit, a driving waveform generator that generates and outputs a driving waveform having four or more driving pulses in chronological order per driving cycle, and a selector that selects and applies one of multiple driving pulses to a pressure generator to cause a printing head unit to selectively discharge a liquid droplet of three or more different sizes. The driving waveform includes three or more driving pulses at least having a final driving pulse to collectively discharge the biggest liquid droplet. The driving waveform includes a micro-driving pulse for discharging a smallest droplet within a time period of from about 2&#xd7;Tc to about 4&#xd7;Tc after the driving waveform starts being outputted when Tc represents a natural vibration period of a separate liquid chamber of the printing head unit.

Image forming apparatus with ink-jet printing system

A liquid ejection head is disclosed. The liquid ejection includes a flow channel plate, the flow channel plate being formed from one thin plate, the flow channel plate being formed with one or more pressure generating chambers, a fluid resistance section which supplies liquid to the pressure generating chamber, and a nozzle hole which opposes the pressure generating chamber. The flow channel plate is made of a metal material, and wherein the flow plate includes the pressure generating chamber which is formed of a groove-shaped indentation; the nozzle hole which is formed at one end in a longitudinal direction of the groove-shaped indentation; and the fluid resistance section which is formed at the other end in the longitudinal direction of the groove-shaped indentation. The pressure generating chamber, the nozzle head, and the fluid resistance section are formed such that they deform the thin plate in a thickness direction.

Liquid ejection head including flow channel plate formed with pressure generating chamber, method of manufacturing such liquid ejection head, and image forming apparatus including such liquid ejection head

A liquid ejection head includes nozzles, separate chambers, a common chamber, inlet portions, a filter unit, and ribs. Droplets of liquid are ejected from the nozzles. The separate chambers are communicated with the nozzles. The inlet portions are communicated with the corresponding separate chambers. Liquid is supplied from the common chamber to the separate chambers through the inlet portions. The filter unit is disposed between the inlet portions and the common chamber to filter liquid in an area across the separate chambers in a first direction in which the nozzles are arrayed. The ribs are disposed in the filter unit at intervals corresponding in size to at least two of the separate chambers in the first direction to partition the filter unit. The inlet portions are communicated in the first direction with each other in at least one portion of each of the inlet portions facing the filter unit.

Liquid ejection head, liquid-droplet ejection device, and image forming apparatus

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 disclosed inkjet head includes an ink channel unit formed by stacking a channel plate having a nozzle hole formed therein, a channel plate having a pressure chamber formed therein, and a channel plate having a restrictor formed therein and by bonding the channel plates together by diffusion bonding, which channel plates have substantially the same thickness; a pressure generating source attached to a surface of the ink channel unit and configured to generate pressure to jet ink; and a housing formed by stacking housing plates and by bonding the housing plates together by diffusion bonding and configured to hold the ink channel unit, which housing plates have substantially the same thickness as that of the channel plates.

Inkjet head and method of producing the same

An inkjet recording head includes a nozzle plate, chamber plate, and a diaphragm plate. The nozzle plate includes a plurality of nozzles for ejecting ink droplets, a plurality of connecting channels in communication with the nozzles and pressure chambers. The nozzles are formed in a row at a uniform pitch. The connecting channels extend from the nozzles alternately in opposite directions in a staggered formation and are offset a prescribed angle to a direction orthogonal to the row of nozzles. The chamber plate includes the pressure chambers, restrictors, and common ink chambers formed therein. Each pressure chamber has an elongated shape extending in a direction orthogonal to the row of nozzles. The pressure chambers are formed in rows, one on either side of the row of nozzles, so that the pressure chambers in one row oppose the corresponding pressure chambers in the other row. The diaphragm plate has a vibration plate that seals the pressure chambers.

Inkjet recording head

An ink jet head having: a common ink chamber for storing an ink supplied from an ink supply part; an ink supply path for supplying the ink stored in the common ink chamber; a pressure chamber to which the ink is supplied via the ink supply path; and a nozzle for discharging the ink in the pressure chamber in accordance with a pressure change in the pressure chamber. The components being constructed by stacking a plurality of thin plate members, wherein a plurality of the ink supply paths are arranged in parallel.

Ink jet head

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

An inkjet recording head includes a base member, an ink channel unit, a plurality of piezoelectric elements, and a dynamic vibration absorber. The ink channel unit is formed with a plurality of nozzle holes and a plurality of ink pressure chambers. The ink channel unit includes a diaphragm that defines part of each ink pressure chamber. Each piezoelectric element has one end fixed to the base member and another end attached to the diaphragm. Each piezoelectric element generates displacement in a displacement direction for deforming the diaphragm to eject ink droplets through a corresponding one of the plurality of nozzle holes. The dynamic vibration absorber is mounted on the base member for damping vibrations of the base member due to a resonance, the resonance occurring in a frequency range less than or equal to a predetermined frequency.

Inkjet recording head having dynamic vibration absorber

An ink jet recording head unit includes a plurality of nozzle elements, a plurality of piezoelectric elements and a driving unit. The plurality of piezoelectric elements is provided in one-to-one correspondence with the plurality of nozzle elements. Each piezoelectric element has a positive pole and a negative pole. Each piezoelectric element expands and contracts when a voltage potential difference between the positive pole and the negative pole is varied. The plurality of nozzle elements includes a first nozzle element and a second nozzle element adjacent to the first nozzle element. A first piezoelectric element and a second piezoelectric element correspond to the first nozzle element and the second nozzle element respectively. The driving unit controls the first piezoelectric element and the second piezoelectric element to expand and contract in a complementary manner.

Recording head for inkjet recording device

Growing community of inventors

Hitachinaka, Japan

Satoru Tobita