Nec Corporation

Tadashi Mizoguchi

Yoshihiro Hagiwara

Kazuo Shima

Hitoshi Minemoto

Hitoshi Takemoto

Toru Yakushiji

Junichi Suetsugu

Tomoya Saeki

Ryosuke Uematsu

Ryousuke Uematsu

Junichi Suetsucu

An ink jet printer has a plurality of ink ejection electrodes for receiving an ejecting voltage to eject an ink droplet, a pulse width generator for specifying the pulse width of each ejecting electrode to obtain a dot diameter of the ink droplet for gray-scale printing. The ejecting voltage Vej for each ejection electrode is divided into a plurality of unit pulses. Each unit pulse is supplied to a corresponding ejection electrode concurrently with unit pulses for other ejection electrodes. A combination of unit pulses for a single ejection electrode forms a single ink droplet having a dot diameter corresponding to the number of unit pulses, thereby achieving accurate gray-scale printing with a reduced circuit scale.

Electrostatic ink jet printer

An inkjet device ensuring reliable and stable ink ejection is disclosed. A plurality of ejection electrodes are arranged in a housing having an ink chamber containing ink including toner particles and a gate electrode plate is placed at a predetermined distance from the ejection electrodes. The gate electrode plate has a slit formed such that the ejection electrodes are directed to the slit and an ink drain coupled to the slit for draining ink from the slit.

Electrostatic inkjet head having an ink drain for draining ink from a slit

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

An electrostatic ink jet recorder of the type controlling charged toner particles contained in ink by using electrophoresis is disclosed. The recorder achieves a miniature and cost-effective configuration by reducing the number of drivers for driving ejection electrodes and auxiliary electrodes. The same amount of toner particles is ejected from all of ejection electrodes despite a scatter in the ejection electrode and a scatter in the position of the ejection electrode relative to auxiliary electrodes and a counter electrode.

Electrostatic ink jet recorder having ejection electrodes and auxiliary electrodes divided into groups

An electrostatic ink jet recording device includes a recording head having an ink chamber receiving therein liquid ink containing electrified toner particles and a plurality of recording electrodes for ejecting the toner particles from the liquid ink. Each of the recording electrodes is applied with a bias pulse train when the recording head resides in a printing area and a non-printing area, and a selected group of the recording electrodes are applied with a constant recording signal for ejection of toner particles. Undesirable ejection of the toner particles in the non-printing area is avoided by the application of the bias pulse train.

Control system for applying biasing and recording signals to recording electrodes of an electrostatic ink jet recording device

Light of a light emitting portion is received by a total of two light receiving portions disposed opposite to each other through a record medium. The surface condition of the record medium is detected corresponding to the amount of light reflected and the amount of light transmitted so as to determine whether the record medium placed is plain paper, coated paper, OHP film, or the like. By controlling the number of heating elements of a heater or turning on/off the heater, an optimum fixing condition is accomplished.

Electrostatic ink jet recording apparatus that adjusts the amount of heat based on the type of recording material

An ink jet recording head comprises a plurality of electrophoretic electrodes corresponding to a plurality of ejecting electrodes, and a pair of stirring electrodes disposed at both ends of the row of the ejecting electrodes. The stirring of the colored particles by the stirring electrodes prevents block of an ink jet slit by the concentrated colored particles, whereas individual control of the electrophoretic electrodes prevents undesirable ink ejection from non-specified ejecting electrode.

Ink jet recording head having ink stirring electrodes for dispersing ink

The quantity of toner particles in an ink is detected by a toner quantity detector. The quantity of toner particles is integrated for a predetermined time period by a controlling portion. The integrated value is compared with a reference value. When the integrated value is smaller than the reference value, a value is opened for a predetermined time period so as to supply a toner in a toner replenisher to an ink tank. Thus, a predetermined quantity of the toner is replenished to the ink tank. After the toner has been replenished, when the integrated value does not become larger than the reference value, a valve is opened for a predetermined time period under the control of the controlling portion so as to replenish a charge control agent from a charge control agent replenisher to the ink tank.

Toner quantity detection and replenishment system for an electrostatic

The electrostatic ink-jet recording head has a head member having a chamber for supplying and discharging ink, a head chip in which a plurality of continuous meniscus shapes are respectively formed on groove portions, a cover plate formed so as to expose a part of the corners of the groove and flange portions, and a protruded member on which pectinate protrusions are formed at the same intervals as those of the meniscus shapes formed on the head chip. A recording electrode is formed on each groove portion. Each protrusion of the protruded member is set on each groove portion of the head chip and moreover, formed so as to be protruded beyond the corner of the flange portion.

Electrostatic ink-jet recording head having a head chip provided with

An ink jet recording device comprises a recording head for ejecting pigmented ink in an ink chamber, an ink reservoir for circulating the pigmented ink between the ink chamber and the ink reservoir, and a replenishment tank for replenishing concentrated pigmented ink to the ink reservoir. The replenishment of the concentrated pigmented ink is effected by a piezoelectric element for reducing the volume of the replenishment tank upon receiving a driving signal. The concentration of colored particles in the concentrated pigmented ink is equal to the concentration of the colored particles in the ink droplet ejected from the ink chamber.

Ink jet recording device

An ink-jet printing apparatus, having (a) a plurality of ink-ejecting bars each having a pointed end, the pointed end being capable of moving toward a recording medium; (b) an ink reservoir for supplying to each of the ink-ejecting bars with ink including toner; (c) a counter electrode for drawing the toner in ink from a location faced to the pointed end of said ink-ejecting bar, said counter electrode and the ink ejecting bar interposing the recording member; and (d) recording electrodes for flying the toner in ink from the pointed end of each of the ink-ejecting bars.

Apparatus and method for ink-jet printing using extending ink-ejecting

An electrostatic ink jet recorder of the present invention includes a head for ejecting ink, an ink reservoir storing the ink, and an ink feed pipe and an ink discharge pipe for circulating the ink between the head and the ink reservoir. The head has a first ink chamber communicated to the ink feed pipe, a second ink chamber communicated to the ink discharge pipe, a third ink chamber positioned at a higher level than the first and second ink chambers for ejecting the ink for printing, a siphon pipe communicating the first and third ink chamber and having a suction opening below an ink level in the first ink chamber, and an ink outlet pipe having an outlet opening above an ink level in the second ink chamber for delivering the ink from the third ink chamber to the second ink chamber. Delicate pressure variation in the head ascribable to the movement of the head is reduced in order to maintain pressure inside the third ink chamber for ejection stable.

Electrostatic ink jet recorder

A precision ejection ink-jet printing apparatus to prevent self-ejection. Self-ejection is an ejection of coloring agent particles from an ink-ejection opening without an application of ejection voltage to an ejection electrode. The precision ejection ink-jet printing apparatus includes an ink chamber filled with a pigment type ink, an electrophoretic electrode for causing coloring agent particles in the pigment type ink to concentrate at ink ejection openings, a plurality of ejection electrodes for causing ejection of the coloring agent particles concentrated at the ink ejection openings toward a printing medium, and voltage controller for controlling a voltage to be applied to the electrophoretic electrode. The voltage controller gradually increases the applied voltage up to a predetermined target voltage. The gradual increase in voltage moderates the electrophoretic motion of the coloring agent particles, preventing self-ejection.

Precision ejection ink-jet printing apparatus

An electrostatic ink-jet printing head in which ink containing charged toner particles in an insulating solvent is supplied from an ink reservoir, an electric field is applied to the ink to generate an electrostatic force, and the electrostatic force causes the toner particles to be ejected from ink ejecting ports. The electrostatic ink-jet printing head comprises a head block including a head block main body which defines an ink chamber and also including a base film which is assembled on the head block main body. The base film has ink ejecting ports and has a plurality of projections extending from one edge of the ejecting port into the ejecting port. The ejecting ports, ejecting electrodes and ejecting projections are collectively formed on a base film by a TAB technique, and by bending the base film at the ejecting ports having projections according to the shape of the head block main body.

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Niigata, Japan

Tadashi Mizoguchi