Abstract: A droplet ejection device comprising a flow passage, a nozzle orifice formed in a wall of the flow passage, a circulation system for circulating a liquid through the flow passage, and an actuator system for generating a pressure wave in the liquid in the flow passage, wherein an obstruction member is arranged in the flow passage in a position opposite to the nozzle orifice and projecting towards the nozzle orifice.

Abstract: A droplet ejection device comprising a flow passage, a nozzle orifice formed in a wall of the flow passage, a circulation system for circulating a liquid through the flow passage, and an actuator system for generating a pressure wave in the liquid in the flow passage, wherein an obstruction member is arranged in the flow passage in a position opposite to the nozzle orifice and projecting towards the nozzle orifice.

Abstract: In a jetting device for ejecting droplets of a relatively hot fluid, a fluid chamber body is made of a heat resistant material and an inner surface of the fluid chamber body, the inner surface defining a fluid chamber of the jetting device, is wettable by the fluid. This configuration provides that no additional force needs to be applied for forcing the fluid into an orifice, i.e. a narrow tube leading towards a nozzle.

Abstract: In a jetting device for ejecting droplets of a relatively hot fluid, a fluid chamber body is made of a heat resistant material and an inner surface of the fluid chamber body, the inner surface defining a fluid chamber of the jetting device, is wettable by the fluid. This configuration provides that no additional force needs to be applied for forcing the fluid into an orifice, i.e. a narrow tube leading towards a nozzle.

Abstract: A method of making a number of adjacent ducts with a required duct side and duct spacing in a duct plate for an inkjet print-head. The method includes the steps of pressing a non-rotating toothed bit from a starting position into the duct plate, moving the bit and the duct plate relatively to one another in such manner that a first groove is cut in the duct plate and returning the bit and/or duct plate to the starting position. The bit is then moved relatively to the duct in a direction of the first groove in such a manner that a subsequent tooth of the bit situated next to the first tooth comes to lie just above the first groove. These steps are then repeated in such manner that the depth of the grooves correspond to the required duct depth.

Abstract: An inkjet array provided with a piezoelectric member and a member in the form of a plate opposite the piezoelectric member, the plate member having a surface which faces the piezoelectric member provided with a number of parallel elongated ink ducts, while the piezoelectric member is provided with a number of elongated parallel piezoelectric elements substantially rectangular in cross-section, each piezoelectric element being situated opposite an ink duct, the piezoelectric member being received in a recess in a baseplate which abuts the ink duct surface of the plate member containing the ink ducts, and which is fixed to the plate member.

Abstract: A printing device for reproducing information having movable image-forming element with a dielectric surface. An image-forming station is provided in which a magnetic roller having a rotatable electrically conductive non-magnetic sleeve is disposed near the surface of the image-forming element. An electric field between the image-forming element and the magnetic roller is generated in accordance with an information pattern. An electrically conductive magnetically attractable toner powder is placed in the zone between the magnetic roller and the image-forming element during generating of the electric field. A magnetic field formed in the zone by stationary ferromagnetic knife blade disposed inside the magnetic roller sleeve and the blade is held between like poles of two magnets at an angle of between 70.degree. and 85.degree. to the tangential plane to the sleeve.

Abstract: A method of producing a screened layer on an electrophotographic element by applying a homogeneous layer to a support and removing small areas from the layer by blasting it with particles having a diameter of between 5 and 1000 .mu.m.