Nec Corporation

Fuji Xerox Co., Ltd.

Ryosuke Uematsu

Junichi Suetsugu

Kazuo Shima

Yoshihiro Hagiwara

Hitoshi Minemoto

Hitoshi Takemoto

Toru Yakushiji

Tadashi Mizoguchi

Minoru Yamada

Junichi Fujisawa

Yoshihiro Hagihara

Kazunori Shindo

Chiseki Yamaguchi

Toyoji Ushioda

Shinro Oikawa

Hiromichi Fukuchi

Yoshinobu Kariya

A developing unit includes a developer consumption calculator calculating consumptions of developer in zones and storing the consumption in each zone into a corresponding storage region; a consumption shift unit shifting the consumption stored in the storage region corresponding to each zone to a storage region corresponding to a zone located on a downstream side in a developer conveyance direction in response to the conveying of the developer by the circulation conveyance member; a supply amount setting unit setting a supply amount from a developer supply portion based on the consumption stored in the storage region corresponding to the zone corresponding to the developer supply position; and a developer supply controller controlling supply of the developer from the developer supply portion based on the set supply amount.

Developing unit, visualized image formation unit and image forming apparatus

An ink jet print head comprises a substrate formed with a heating resistor, an ink path defining member for defining an ink supply path, and a orifice plate, and in the orifice plate, there is formed an ink outlet at the position opposing the heating resistor. Further, a heating zone surrounding the heating resistor is formed at the position corresponding to the heating resistor of the ink supply path. The channel resistance of the ink supply path is set so that a relationship is established between a quantity q of the discharged ink drop, a sectional area A of the ink outlet, and a maximal projection h that a meniscus of the ink has when it projects from the ink outlet after it has restored the exit level from a retreat position it had after the drop of the ink had been discharged, such that 0<h<0.3 q/A. Consequently, there is obtained a high-speed printing of high quality without dispersion.

Ink jet print head

An electrostatic ink jet recording head of a drop-on-demand type has a head body defining an ink chamber for receiving liquid ink containing charged toner particles, a set of electrodes for migrating the liquid ink by electrophoresis and ejecting the liquid ink from an ejecting slit of the ink chamber, and an ink reservoir, disposed above the ink chamber, for circulating the liquid ink by gravity between the ink reservoir and the ink chamber. A flow resistance against the liquid ink in the flow path from the outlet port of the ink chamber to the ink reservoir is smaller than a meniscus force generated by meniscuses formed at the ejecting slit to effectively eject the liquid ink without a pump and without an ink leakage.

Electrostatic ink jet recording head having electrophoretic electrode and gravity ink reservoir

Liquid developer of different colors capable of being formed in a film shape are used to form developed images on a plurality of photosensitive drums . The developed images are successively transferred from the photosensitive drums onto an image carrier belt so as to be overlaid on one another while applying an electrostatic force. In the color developed image formed on the image carrier belt , the solid component ratio of the liquid developer is increased to form the color developed image into a film shape, which is transferred and fixed to a recording medium.

Color image formation apparatus using a liquid developer and color image formation method using a liquid developer

An electrostatic ink-jet recording device which provides stable printing by preventing too much charged toner from gathering around an ink discharge aperture even if the charged toner has not been discharged for a long time. If the charged toner is not to be discharged, the potential difference between the electrophoretic electrode and the discharge electrode is so controlled as to suppress electrophoretic movement of the charged toner toward the ink discharging aperture, or the potential difference is made zero. If the charged toner is to be discharged, the voltage applied to the discharge electrode is kept lower than the voltage applied to the electrophoretic electrode for a predetermined period of time before discharging a jet of the charged toner.

Ink-jet recording device for suppressing excess electrophoretic accumulation of charged particles

An electrostatic ink jet printing head comprises printing electrodes formed on the base film of a substrate. The printing electrodes have insulating coating films which coat the printing electrodes, respectively. Each of the printing electrodes has a main electrode portion formed on the base film and a protruding electrode portion which protrudes from the base film. A covering member covers the main electrode portion. The covering member has an internal surface defining, in cooperation with the main electrode portions and the base film, a ink receiving space which receives ink containing toner particles.

Simple electrostatic ink jet printing head having low cost

An inkjet recording apparatus includes an insulating support member having a major surface on which a plurality of ejection electrodes are formed with each of the ejection electrodes protruding from an ejection end of the insulating support member. Each of the ejection electrodes is coated with an insulating material. Further, a cover member is provided to cover the insulating support member to form ink chambers between them and an opening at an ejection end of the cover member. The ejection portion of each ejection electrode protrudes from the ejection end of the cover member through the opening. The ink is supplied from one ink chamber to the ejection electrodes and flows into the other ink chamber through the ejection electrodes.

Injet recording apparatus

A record head for an electrostatic ink jet recorder includes a head chip implemented as a laminate of alternating flat conductors and flat insulators and etched by an etching liquid reactive only to the material of the insulators. The conductors readily turn out ridges protruding from the head chip and having a high aspect ratio. The ridges each serve as an ejection electrode.

Method of producing a record head for an electrostatic ink jet recorder

A recording head includes an ink chamber storing ink containing electrified toner particles and having an ejection opening 7 at one end and an ejection electrodes for ejecting the toner particles from the ejection opening. A counter electrode 6 faces the ejection opening. The recording head also includes a toner, concentration detection sensor detects a potential of the ejection opening 7, and a control unit for deciding a detected toner concentration and controlling a voltage to be applied to the ejection electrodes. The surface potential nearby ejection opening or the toner concentration and a voltage applying time are made to previously correspond to each other and are stored in a ROM table. A stable printing quality is obtained by detecting the toner concentration near the ejection opening by the toner concentration detection circuit and controlling a voltage to be applied to the ejection electrodes corresponding to a detected value.

Electrostatic ink jet recording apparatus capable of realizing stable

In an electrostatic inkjet device having a plurality of ejection electrodes, when an ejection electrode is designated as an ejection dot, a potential of the ejection electrode is changed to an ejection level for a first time period. When the ejection electrode is not designated as an ejection dot, the potential of the ejection electrode is changed within a predetermined level different from a ground level such that ejection does not occur at the ejection electrode.

Method and apparatus for controlling inkjet ejection electrodes by

An electrostatic ink jet recording head has a laminate structure for an electrode assembly disposed in an ink chamber of a head body. The laminate structure includes a first base film, a plurality of patterned recording electrodes, a plurality of patterned control electrodes and a second base film. The recording electrodes and control electrodes are alternately arranged one by one as viewed perpendicular to the laminate. The tips of the recording electrodes are located ahead of the tips of the control electrodes toward the opposite electrode. In operation, the control electrodes located on both sides of a specified recording electrode are applied with a high voltage pulse to eject liquid ink from the meniscus in the vicinity of the specified recording electrode. The ink jet recording head can be manufactured at low costs and with a higher density.

Electrostatic ink jet recording head using control and recording

A head body is shaped to project toward an ink ejection side, and formed along the projection with an ink channel for circulating the ink, at the vertex of the front end of which an opening is formed for ejecting the ink from the ink channel. An ejection electrode is formed along the front end of the head body. Its front end reaches the opening. An electrophoresis electrode is secured in the ink channel at a position opposite to the opening, and supplied with a voltage for moving the toner particles in the ink flowing in the ink channel to the front end of the ejection electrode with the electrophoresis effect. An opposite electrode is positioned opposite to the ink ejection side. A drive circuit drives the opposite electrode when the electrophoresis electrode is driven, and generates voltage for attracting the toner particles toward the opposite electrode with Coulomb force that is generated by an electric field acting between the ejection electrode and the electrophoresis electrode, and the opposite electrode.

Ink-jet recording apparatus with improved ink density formation

An electrostatic ink jet according to the present invention includes a head body having an ink chamber for holding ink liquid containing charged particulate material; an ejection port provided at one end of that head body and connecting to the ink chamber; an ejection electrode arranged near this ejection port and fed with an ejection voltage of the same polarity as the charge characteristic of the charged particulate material; a counter electrode arranged opposite to the ejection port via a recording medium; and a pair of stirring electrodes. The stirring electrodes are arranged in the direction reverse to that of gravity in the ink chamber. The stirring electrodes are fed with a stirring voltage for shifting the charge particulate material in the direction reverse to the direction of gravity, and that stirring voltage is generated before the generation of the ejection voltage. As a result, the toner particulates are prevented from precipitating before the ejection of ink, and their concentration in the ink liquid in the ink chamber is generally uniformized.

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Tokyo, Japan

Ryosuke Uematsu