Matsushita Electric Industrial Co., Ltd.

Dai Nippon Toryo Co., Ltd.

Akira Mizoguchi

Kiyoshi Yamamori

Masayoshi Miura

Yasutaka Hiromori

Tsunehiko Toyoda

Hiroshi Makishima

Noriaki Okamura

Kazufumi Suzuki

Hirofumi Yano

Yuetsu Ochiai

Shumi Kumagai

In order to prevent clogging of the nozzle of an ink jet writing head, a nozzle moistening device is provided which includes an elastic enclosure fluid-tightly engageable with the front face of the writing head when not in use, a source of water, and a capillary tube for transmitting water from the source to the enclosure by capillary action to permit evaporation of water in the enclosure to moisten the nozzle.

Ink jet writing apparatus having a nozzle moistening device

An ink jet writing head includes a housing shaped to provide an inner liquid chamber for containing ink therein, a piezoelectric transducer for generating short-duration pressure rises in the liquid in the inner chamber, and an outer liquid chamber which is separated by a dividing plate from the inner liquid chamber and connected thereto by a connecting channel formed in the dividing plate. The outer liquid chamber is of such an axial dimension that it may provide capillary action on the ink supplied from an ink supply source. The outer chamber is formed by an ink nozzle plate secured to a surface of the housing spaced from the dividing plate. The ink nozzle is axially aligned with the connecting channel to cause the ink in the outer chamber to leave the writing head in response to the pressure rise in the inner chamber. A spacer is provided in the other liquid chamber to maintain the axial dimension thereof at a predetermined value regardless of errors which might be produced during manufacture of the housing and assemblage of the writing head.

Ink jet writing head with spacer in capillary chamber

An original image field is successively scanned along each of parallel line paths to detect the image density of the scanned elemental picture area. A plurality of recurring sequences of binary digits or pulses is generated for each of the scanned line paths in synchronism with the scansion of each elemental picture area, thereby forming dot pattern conversion matrices corresponding in number to the number of discrete gradation steps or image densities with the pulses representing the dots in each matrix. The detected image density is used to select a corresponding one of the dot pattern matrices to represent the scanned area with a dot if the latter is present in a specified position in the corresponding matrix by allowing the selected recurring pulse sequence to be delivered to a recording unit which is moved with respect to a recording field in synchronism with the scansion of the original field.

Method of and system for reproducing or transmitting half-tone images

An ink ejection apparatus comprising an ink ejection unit having a liquid chamber connected to an ink container through a conduit and an air chamber connected to a source of pressurized air. Axially aligned discharge channels are provided to allow the ink in the liquid chamber to be discharged through the discharge channels. A piezoelectric transducer is mounted adjacent to the liquid chamber to generate rapid pressure increases therein to permit ejection of ink droplets to the atmosphere in response to electrical signals. The ink container is also supplied with the pressurized air from the air supply source so that there is a constant stream of air through the discharge channel and there is a static pressure balance between the air and liquid chambers when the air supply source is in operation. To eliminate the problem of pressure imbalance which could occur at the instant the air supply source is energized or de-energized, an arrangement is provided to impart a retarding action to the transitory variation of the pressure in the conduit.

Ink ejection apparatus

An ink composition for ink jet recording consisting essentially of a water-soluble wetting agent, water, a water-soluble dye and an oxygen absorber.

Ink composition for ink jet recording

A liquid ejection system comprises a writing head having a liquid chamber for containing liquid therein, a liquid discharge channel, an electromechanical transducer for generating pressure rises in the liquid in the liquid chamber for discharging the liquid through the liquid discharge channel, an air chamber having an air discharge channel coaxially aligned with the liquid discharge channel for discharging dry air from the air chamber along the passage of the ejected liquid. A humidifier, which is operative during the standby mode of the system, is provided to humidify the air supplied to the air chamber. A closing member is mounted with respect to the writing head and operative to close its air discharge channel during the standby mode to direct the humidified air through the exit side of the liquid discharge channel to maintain the liquidity of the liquid in the liquid discharge channel during the standby period and open the air discharge channel during the operational period to allow ejection of dry air simultaneously with liquid to a writing surface.

Liquid ejection system with air humidifying means operative during

Apparatus for applying droplets of colored liquid to a surface includes a chamber divided into a liquid chamber portion and an air chamber portion. The liquid chamber portion includes an intake channel connected to a liquid supply container and a discharge channel through which the liquid is discharged for deposition on the surface. A pressure producing means is in contact with the liquid chamber portion to produce periodic pressure increases in the liquid in the chamber portion to eject it through the discharge channel to the atmosphere in a series of droplets. The air chamber portion includes an intake channel connected to a source of pressurized air and a discharge channel axially aligned with the discharge channel of the liquid chamber portion to allow the air to be discharged therethrough to the atmosphere at a high speed. The liquid droplets are thus discharged through the two axially aligned discharged channels and accelerated by the stream of air along their passage to the surface.

Apparatus for applying liquid droplets to a surface by using a high

A writing unit for applying fluid droplets to a surface includes a chamber which is divided into an outer chamber portion and an inner chamber portion which are connected by a connecting channel. A discharge channel is connected to the outer chamber portion in alignment with the connecting channel. A piezoelectrical transducer is provided adjacent the inner chamber portion opposite to the outer chamber portion to produce short duration pressure increases to eject the liquid in the chamber from the discharge channel in pulsed jets to the surface. The inner and outer chamber portions are communicated to the atmosphere by respective vent passageways to withdraw the air in the chamber when the writing unit is first loaded with liquid and the bubbles introduced into the liquid in the chamber during normal operation. The vent passageways are closed during ink ejection process.

Ink ejection type writing unit

A writing mechanism for applying fluid droplets to a surface includes a chamber which is divided into an outer chamber portion and an inner chamber portion with a channel connecting the outer and inner chamber portions. The inner chamber portion is provided with a device which produces short duration pressure increases in the fluid in the chamber. The outer chamber portion is provided with an intermediate reservoir chamber which is in communication with an intake channel for the supply of liquid from a supply container and a discharge channel through which the liquid is discharged for deposition on the surface.

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Kawasaki, Japan

Akira Mizoguchi