Ing C. Olivetti C., S.p.a.

Giandomenico Dagna

Alessandro Scardovi

Riccardo Brescia

Mario Buat

Giorgio Tadini

Enrico Manini

Franco Morin

Bruno Visentin

Nicolo Guglielmi

An ink jet printer is provided with an ink reservoir including a laminar substrate covered on the outer surface of a plurality of metal coatings forming individual electrodes associated with a plurality of nozzles. These latter are formed of holes passing through the substrate and the coatings. An additional metal coating is provided in the inner surface of the substrate and includes a portion to provide a common electrode and a plurality of portions connected with the coatings of the outer surface. The reservoir has a chamber for the evacuation of gases which form during the printing operation, the chamber having an associated Venturi pump acting as a vacuum source. The electrical energization circuit for the printer includes an adjustment member for effecting controlled variation in the energy of the pulses which cause the ejection of ink sprays through the printer nozzles.

High speed ink jet printer with improved electrical connection to the

The head comprises at least one nozzle (38) associated with two electrodes and carried by a holder (14) into which an ink cartridge (50) can be fitted. The cartridge is filled with ink and sealed after it has been filled. The cartridge terminates at one end with a cylindrical portion (60) which is closed by a diaphragm which can be ruptured upon insertion in the head. The diaphragm is ruptured by a tube (66) which projects within the holder and which communicates with the printing nozzles (38). The cylindrical portion (60) of the cartridge is offset with respect to the longitudinal axis of the cartridge to ensure correct insertion thereof. At the other end the cartridge is closed by a cover (87) having an aperture which is disposed above the free level (PL) of the ink and which is initially closed by a second diaphragm. The second diaphragm is ruptured by a movable suction conduit (102) which is manually fitted to the cartridge to lock the latter in position and to permit a pump to exhaust the gases which are formed during the printing operation. The printing head may comprise a holder having a plurality of housings in side-by-side relationship for the insertion of corresponding cartridges containing inks of different colors.

Ink jet print head cartridge assembly

An ink jet printer has a chamber for the evacuation of gases which form during the printing operation, the chamber having an associated Venturi pump acting as a vacuum source. The electrical energization circuit for the printer includes an adjustment member for effecting controlled variation in the energy of the pulses which cause the ejection of ink sprays through the printer nozzles.

Ink jet printer with gas evacuating arrangement

The device comprises a printing head (15) constituted by an insulating container (19) with a capillary nozzle (36). The electrically conductive ink is kept under circulation in the container via a feed tube (26, 23) and a return tube (27, 24) leading to a suction pump, in order to allow the formation of a convex meniscus at the exit aperture of the nozzle (36) and eliminate any vapor bubbles. A pulse generator creates a voltage of a predetermined value and duration between an electrode (37) external to the nozzle and an electrode (23) in contact with the ink, in order to create a state of excitation of the meniscus and partial vaporization of a layer of ink, such as to expel a plurality of ink particles. The head is mounted on a carriage movable transversely to the paper, which advances at each stroke reversal of the head.

Selective ink-jet printing device

The ink jet dot printer comprises a head mounted on a carriage movable along a platen supporting the paper and is formed by a plurality of tubes and piezoelectric transducer for ejecting the ink, which are supported by two parallel plates spaced from one another, between which a polymerizable resin is cast to form a single block. The tubes are aligned in a single row F--F' in a direction inclined with respect to the printing line, in such manner that the distance between the extreme tubes measured perpendicularly to the printing line is equal to the maximum height of the characters. On the outside of the front plate supporting the tubes there is fixed a thin plate bearing a row of nozzles, each of which is aligned with the corresponding ejector tube. The expulsion of the drops of ink is obtained by means of the compression exerted on the tubes by the piezoelectric transducers activated in parallel by electric pulses generated by an energizing circuit under the control of a driving logic circuit by means of which it is possible to vary the slope of the printed characters and obtain bidirectional printing at high speed.

Ink jet dot printer

In a capacitive keyboard using a polarized dielectric commonly called an electret, the keys are organized according to a matrix by rows and columns, the signals generated on the column conductors being of opposite polarity with respect to those generated on the row conductors. The movable armatures of the variable capacitors of the keys also act as bridging elements to allow the crossing of the row and column conductors and as snap elements.

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Ivrea, Italy

Giandomenico Dagna