Abstract: A method for preserving an ink jet head and an ink jet head unit which can prevent worsening of the ink discharging features when the ink jet head is preserved or stored before it is assembled to an ink jet recording apparatus. The preserving method and the ink jet head unit are characterized in that terminals connected respectively to a plurality of energy generating means for generating energy for discharging ink are all also connected to each other by conductive means such as a clip or conductive tape.

Abstract: A recording head comprises a liquid emission member having an orifice through which an ink is emitted, an electro-thermal converter element for generating a thermal energy which is utilized to emit the ink introduced into the liquid emission member, and a functional element disposed on a same substrate on which the electro-thermal converter element is disposed for driving and controlling the electro-thermal converter element.The functional element includes an NPN bipolar transistor for driving the electrothermal converter element and a CMOS transistor composed of an NMOS transistor and a PMOS transisfor for controlling an operation of the bipolar transistor.The NMOS transistor being formed in a P well diffusion layer in an N.sup.- type epitaxial growth layer which is grown on a surface of a P type semiconductor substrate.The PMOS transistor being formed in an N well diffusion layer in the N.sup.- type epitaxial growth layer which is grown on the surface of the P type semiconductor substrate.

Abstract: Disclosed is an ink jet apparatus having a head for forming an image picture on a recording paper, a subsidiary ink tank detachably coupled to the head for accommodating ink and air therein, and a carriage on which the head and the subsidiary ink tank are mounted and used for scanning the recording region. The subsidiary ink tank includes an opening to be coupled to a suction device for adjusting amounts of ink and air accommodated in the interior thereof, and a valve mechanism which assumes an open state when it is coupled to the suction device and a closed state when it is disconnected therefrom.

Abstract: An ink jet recording apparatus usable with an ink cartridge includes an ink cartridge mounting passage a plate for blocking the ink cartridge mounting passage and; a limiting member for preventing opening of the plate. The limiting member is disposed at each lateral end portion so that they are arranged in a chevron shape with an upward inclination, and when the ink cartridge is inserted in the ink cartridge passage, the limiting members contact to a front surface of the ink cartridge and are simultaneously rotated externally to release the blocking plate.

Abstract: An ink remaining amount detecting device, and an ink jet recording apparatus having such a device, for detecting when a predetermined amount of ink remains in an ink supply passage of an ink jet apparatus. This device includes a diaphragm, supporting member for fixedly supporting a circumference of the diaphragm, at least two pawl members having respective first ends fixed to a position substantially equidistant from the diaphragm's center, and extending away from the diaphragm to respective second ends constituting respective pawls, which have respective pawl end and base portions, the pawl members being resiliently flexible toward the center of the diaphragm.

Abstract: An ink jet recording method of applying, to a piezoelectric element serving as an energy generating member for ink droplet formation and emission, a first voltage pulse for retracting the meniscus in a direction opposite to the emitting direction prior to the ink droplet formation, and a second voltage pulse supplied in succession to the first voltage pulse for emitting an ink droplet. The first voltage pulse is controlled according to the circumferential temperature of the piezoelectric element in action.

Abstract: An ink jet recording apparatus for an ink jet recording apparatus includes a plurality of electrothermal transducer elements for producing thermal energy for ejections of recording liquid driving circuitry for supplying electric energy to the electrothermal transducer elements in accordance with data to be recorded and a control signal, wherein the plural electrothermal transducers are grouped into plural groups, and the groups are simultaneously driven by the driving device, wherein the electrothermal transducer elements in a group are supplied with electric power in a period between maximum expansion of a bubble in a previously driven group and expiration thereof.

Abstract: In a liquid injection recording method, the falling time of a voltage pulse applied to electromechanical converting means for generating energy for discharging liquid droplets to a recording medium is made longer under a high temperature environment than under a room temperature environment.

Abstract: An ink jet recording apparatus comprises a discharge port for discharging the ink, a storing portion for storing the ink therein, a cap for covering said discharging port, pump means communicated with said cap, a sucking tube for communicating said cap with said storing portion and a valve provided in said sucking tube.

Abstract: A multihead liquid emission recording apparatus comprises a plurality of liquid emission nozzles; a plurality of electromechanical conversion elements each provided for each of said plurality of liquid emission nozzles for jetting a recording liquid particle from each nozzle; and drive circuit means for driving each of said electromagnetic conversion elements by a voltage signal corresponding to its recording signal; wherein the change range of said drive signal for driving each of said electromagnetic conversion element is set such that the variation ranges of dot diameters on a recording medium formed by said recording liquid particle jetted out of each of said liquid emission nozzles become substantially the same.

Abstract: An apparatus for driving a liquid jet head comprises: a piezoelectric element which mechanically deforms responsive to an electric signal; a pressure chamber whose volume varies due to the deformation of such element; a discharge port communicated with such chamber; 1st and 2nd charging circuits to charge such element at the same polarity; a discharging circuit to discharge such element; and a control unit for making the 1st charging circuit operative prior to the operation of the 2nd charging circuit. A charge time constant of the 1st charging circuit is set to be sufficiently long that no droplet is emitted. A charge time constant of the 2nd charging circuit is set to be shorter to emit a droplet from the discharge port. The surface tension of the meniscus and the contractive force due to the contraction of the pressure chamber act multiplicatively, so that it is possible to record a droplet of a small dot diameter.