Abstract: The invention relates to a method of impressing channels having a cross-sectional area of less than 1 mm.sup.2, notably less than 3000 .mu.m.sup.2, into the surface of an object, notably for the formation of damping channels of ink jet printer heads. The impression of channels having a small cross-sectional area can be performed with high precision by inserting a wire-shaped element (5) between the surfaces of the object (2) and of a plane die (1) in the position of the channel (3, 4, 12) to be formed, after which the die (1) is pressed until it contacts the surface of the object (2).

Abstract: The ink-jet printer contains an ink-jet nozzle (1) connected to a pressure chamber (5) which is recessed in a body (7) and is covered with a diaphragm (13, 15) on which a driving element (17) is fitted. The diaphragm contains an outer plate (13) on which the driving element (17) is fitted and an inner plate (15) provided with an oblong opening (19) which extends between the pressure chamber (5) and the ink-feed channel (11). The opening (19) forms a narrow passage with very accurately defined dimensions between the ink-feed channel (11) and the pressure chamber (5).

Abstract: A plate, through which several ink ducts extend, merges at a flat side of the plate into nozzles and at the opposite side into separated pressure chambers. The printing head has a diaphragm plate common to all pressure chambers, connected to a one-piece piezoceramic plate, which has an embossed part overlying each pressure chamber. Film electrodes are provided on each embossed part, extending above and beyond the area of the pressure chamber. Electrical connections are made to the film electrodes outside the area above the pressure chambers so that the mass of the electrical connections does not affect the resonant frequency.

Abstract: Nozzles are formed in a plate for an ink-jet printer by holding a metal foil tightly against the side of the plate from which the nozzle is to protrude, and then pressing and punching through the plate and the metal foil together, through an aperture of a pressing die into a cushion of a hard elastic material such as lead. The foil is made of an isotropic material which is harder than that of the nozzle plate, and is preferably an amorphous or microcrystalline metal.

Abstract: An ink jet printer comprising conical pressure chambers (2). The pressure chambers have to be filled with ink without inclusion of bubbles. To this end, the pressure chambers (2) are constructed as very flat cones, the ink being supplied to the base thereof via a supply duct (5) which opens into the cone envelope. The ink is discharged from the apex of the cone via a discharge duct. Under the influence of capillary forces, an air bubble is enclosed in the pressure chambers by the ink and is discharged via the apex.

Abstract: An ink jet printer comprising one or more nozzles which are connected, via a pressure chamber, to an ink supply duct. The pressure chamber comprises a wall which can be moved by means of an electromechanical converter in order to realize droplet-like ejection of ink from the nozzle. The converter continuously vibrates during operation. In front of each nozzle there is arranged a brake electrode which can be connected to a voltage as desired. When the voltage is switched off, the ejected ink droplet is incident on the record carrier, and when the voltage is switched on, the ink droplet is intercepted by the brake electrode and is withdrawn into the nozzle by the converter. Special interceptors for the ejected ink and deflection devices are no longer required.