Matsushita Electric Industrial Co., Ltd.

Tamotsu Kojima

Masayoshi Miura

Gen Oda

Kenji Akami

Hiroshi Naito

Kiyoshi Yamamori

Shigeyoshi Hasegawa

Sadashi Higuchi

Yuuji Mogi

An ink jet printer having a print head which comprises a front nozzle member having a front channel, a housing secured to the front nozzle member, and a rear nozzle member which defines with the housing a liquid chamber and further defines with the front nozzle member a laminar airflow chamber. The rear nozzle member has a forwardly projecting nozzle and a rear channel extending from the liquid chamber through the projecting nozzle in axial alignment with the front channel to form a meniscus at the front end. The airflow chamber is connected to an air supply for directing air to a point between the front and rear channels so that it creates a sharp pressure gradient along a path therebetween. A dead air region is created in a location adjacent the exit end of the rear channel to cause the meniscus to take a dome-like shape which is stabilized against vibrations and transients. An electric field gradient is established between the front channel and the meniscus to cause the latter to extend toward the front channel and expelled through the front channel.

Ink jet printer

An ink jet printer having a print head which comprises a front nozzle member having a front channel, a housing secured to the front nozzle member, and a rear nozzle member which defines with the housing a liquid chamber and further defines with the front nozzle member a laminar airflow chamber. The rear nozzle member has a forwardly projecting nozzle and a rear channel extending from the liquid chamber through the projecting nozzle in axial alignment with the front channel to form a meniscus at the front end. An electric field gradient is established between the front channel and the meniscus to cause the latter to extend toward the front channel and expelled through the front channel. A portion of the front nozzle member is rendered liquid-repellant to prevent the field distribution from being seriously disturbed by an ink layer formed on it by stray liquid particles.

An ink ejection recording apparatus is disclosed which comprises a plurality of ink ejection heads commonly connected to an ink tank, each of the ink ejection heads having an ink nozzle through which minute ink droplets are discharged in accordance with an electric signal and an air nozzle opposing to the ink nozzle and adapted for forming an air stream which accelerates the ink droplets towards a recording medium so as to record an image on the recording medium by means of the droplets. The ink ejection heads are arranged at different heights and the ink ejection heads have different levels of balance pressure so that the levels of the ink pressure acting on the ink nozzles of the ink ejection head are equalized in the operating state of the apparatus. Pressure relieving means are provided for relieving pneumatic pressure applied to the ink ejection heads and to the ink tank and being arranged such that relief of pressure from said ink tank is conducted after relief of pressure from said ink ejection heads.

Ink ejection recording apparatus having means for equalizing the static

An ink jet recording apparatus has an ink jet unit from which tiny independent ink droplets, suspended by a flow of air, are made to fly towards a recording medium, thereby recording information on the medium. The apparatus has a heat washing unit disposed at a position beyond one end of a recording medium mounting portion, so that the ink jet unit which has been moved to this position after completion of the recording operation is washed by the head washing unit which is movable towards and away from the ink jet unit at this position, whereby a high stability and reliability of the ink jet recording are ensured for a long period of time without suffering from clogging of nozzles or contamination of the recording medium. The stability and reliability are further enhanced by the simultaneous use of an ink mist suction unit which sucks ink mist around the ink jet unit and an anti-clogging unit which prevents clogging of the nozzles.

Ink jet recording apparatus with head washing device

In an ink jet printer, a print head comprises a front nozzle member having a front channel, a housing secured to the front nozzle member, and a rear nozzle member which defines with the housing a liquid chamber and further defines with the front nozzle member a laminar airflow chamber. The rear nozzle member has a forwardly projecting nozzle and a rear channel extending from the liquid chamber through the projecting nozzle in axial alignment with the front channel to form a meniscus at the front end. The airflow chamber is connected to an air supply for directing air to a point between the front and rear channels so that it creates a sharp pressure gradient along a path therebetween. A dead air region is created in a location adjacent the exit end of the rear channel to cause the meniscus to take a dome-like shape which is stabilized against vibrations and transients. An electric field gradient is established between the front channel and the meniscus to cause the latter to extend toward the front channel and expelled through the front channel. A portion of the front nozzle member is rendered liquid-repellant to prevent the field distribution from being seriously disturbed by an ink layer formed on it by stray liquid particles.

Ink jet printer and method for fabricating a nozzle member

In a nonimpact printer having a reciprocable printer head, ink is supplied to the head through a pair of identical, flexible conduits which are connected from first and second spaced apart outlets of an ink container. The container is not air tight with the outside so that it can act as a pressure absorber. Each of the first and second conduits have a sufficient length to allow the head to reciprocate along the length of a platen with end of each conduit moving therewith to cause pressure variations to occur in the conduits when the printer head varies its speed of movement. By virtue of the pressure absorbing action of the liquid container, the pressure variations are nullified and the printer head is supplied with constant pressure ink.

Growing community of inventors

Kawasaki, Japan

Tamotsu Kojima