Abstract: A device is provided for receiving a combination of two variable volume chambers and a plurality of valves for forming an ink supply circuit for an ink jet printing head. Such a device is formed by a solid one-piece block comprising a plurality of cavities which are disposed radially about a central housing receiving both a piston (P) and a pressure sensor (5). The piston (P) being formed by the stacking of at least two pieces of diameter O.sub.1 and O.sub.2 and two membranes clamped by two flanges, the whole defining two variable volume chambers. This device cooperates with a reservoir block having two compartments between which moves a link connected on one side to an eccentric and on the other to the piston for forming an extremely reliable and compact ink supply circuit.

Abstract: A high resolution printing method is disclosed, implemented in a printer in which a continuous ink jet is broken up into drops (G) in a charging electrode (6) where they are selectively charged electrostatically, said drops then pass between deflection electrodes (9), the appearance of a satellite drop (Sn) from a main drop is caused by application of an appropriate voltage in the charging electrode during formation of said main drop and the coalescence of a satellite drop thus formed intended for printing with the following main drop is prevented, also by application of a voltage to the charging electrode during the formation of said main drop.

Abstract: The invention provides a cell having a variable volume chamber and a fluid supply circuit for an ink jet printing head which is equipped therewith. The cell includes a variable volume chamber (1) connected to a pressure sensor (5) and to at least a pair of valves (7, 9) each associated with a restriction (8, 10). The variation of volume is obtained by means of a piston actuated by an eccentric (3) secured to the rotor of a stepping motor (4). The maximum pressure difference generated at the ends of the restrictions (8, 10) is used to measure the viscosity of the fluid which flows through the corresponding valves (7, 9).

Abstract: Disclosed is a cell having a variable volume chamber and a fluid supply circuit for an ink jet printing head which is equipped therewith, the cell including a variable volume chamber (1) connected to a pressure sensor (5) and to at least a pair of valves (7, 9) each associated with a restriction (8, 10); the variation of volume being obtained by a piston actuated by an eccentric (3) secured to the rotor of a motor (4).

Abstract: Ink jet printing head and replacement of bevel sticks in industrial tracers by an ink jet printing head provided with a set of deflection plates (3, 4, 5) so arranged and polarized that the electric field of deflection of droplets is orientable according to an angle which may vary from 0.degree. to 180.degree.. The applications cover particularly the field of industrial tracing techniques.

Abstract: The invention provides a fluid pressure regulator with integrated sensor, including a single block (1), the fluid flow section combining the regulator and the sensor (12). In another block (2) integrally secured to the first, is provided a control system formed by a stepper motor (6) acting on the order of an external automatic device, for closing an orifice (0) to a greater or lesser degree by means of a valve (10), a spring (9), a pusher (8) and a spool (7) so as to create a fluid leak (fr) for causing a fine variation of the operating pressure (pu). Sealing between the two blocks (1) and (2) is obtained by the presence of a membrane (3). The spool (7) acts on the pusher (8) through this membrane.

Abstract: The invention relates to a method for marking products in relation with an organization commissioned to check this marking both from the point of view of authenticity of the printed message and from the point of view of the number of these messages which have actually been printed. The printer (A) connected to the packaging chain (C) receives the control instructions either directly from a terminal (B) located in the premises of the checking organization or by means of a memory card programmed by this organization and supplied by this latter to the user. Recording of the number of messages is carried out either directly at the level of the terminal (B) on the premises of the checking party or by means of the memory card which contains a predetermined number of messages. When the card has been utilized, the user acquires another card. The invention applies in particular to checking of affixing of inland revenue stamps and makes it possible to guard against fraud in an effective manner.

Abstract: In a ink jet printing head, all essential elements are made integral with a monolithic part (2) acting as a base. Furthermore, the modulation body (10) cooperates with adjusting means (screw 84 and oblong holes 85) according to two angles (.alpha.) and (.beta.), situated in two perpendicular planes. The charge (71), charge-control (72l ) and deflexion (73, 74) electrodes are integral with a block (70). The electric isolation is provided particularly by means of a groove (89) and a web (90), thereby preventing any arc formation. The inventon can be applied to any ink jet printer.

Abstract: Such a device comprises a plurality of modules (1) each having a body (4) presenting an ink inlet (2) and a purging orifice (3), co-operating with the gun (5) of which the periphery carries two sets of O-rings respectively delimiting the ink supply chamber and the purge chamber. Said particular arrangement provides for the sealing while permitting a rotation (.alpha.) on 360.degree. of the gun and therefore a setting of the jet direction with respect to the axis of the nozzle ejecting the ink drops. Each of the modules (1) is further orientable about an axis (31) according to an angle (.beta.). The invention applies to the printing of multiple writing lines and to the optional covering of said lines.

Abstract: A printing head for equipping any printer of the continuous ink-jet type comprises a modulator element in which a body and an orientable cylindrical plate are incorporated in a modulator base. The orientable plate carries an ink-drop ejecting nozzle and is capable of optimizing the perpendicularity of the ink jet. The modulator element and an electrode-holder are rigidly fixed respectively to a casing and to a section of its cover which is pivotally mounted with respect to the modulator base. Slits formed in charging electrodes and charging-control electrodes can be positioned with respect to the axis of ejection of the ink jet.

Abstract: A charge detector forming part of a device for controlling the electrostatic charge applied to ink drops in an ink-jet printer comprises at least one internal conductive cylindrical rod connected to an electronic circuit and surrounded by an insulating sleeve. The sleeve is tightly fitted within an outer conductive cylinder which is connected to ground. A calibrated slot of predetermined length and width is formed so as to provide a passageway for the flow of ink drops through the detector. As each ink drop passes in front of the conductive cylindrical rod, a signal is induced and processed by the electronic circuit. The device also serves to control at least one ink-pressurizing pump with a view to ensuring constant flow velocity of the ink drops.

Abstract: A safety device for the conductive-fluid circulation system of an ink-jet printer consists of a sensor and an associated electronic circuit inserted between an ink-drop recovery trough and a recirculating pump. The level of turbulence of the fluid flow within a pipe segment of insulating material located between two conductive pipe segments is determined by the sensor by measuring the variation in conductivity in relation to variations in cross-sectional area of fluid within the insulating pipe segment and by delivering a control logic signal.

Abstract: The invention relates to a high stability printing liquid, intended more particularly for printing by ink jet.The ink is in the state of a micro-emulsion formed by a dispersing phase containing a group of inter-compatible constituents and a dispersed phase containing a second group of inter-compatible constituents, the constituents of the first and second groups being incompatible with one another. These two phases are separated by an interfacial liquid containing surfactant molecules in such a way that the dispersed phase is in the form of globules of 500 to 1000 Angstrom.The invention is more particularly applicable to printing by ink jet.