A device for measuring the flow rate and viscosity of ink sent to a print head of an ink jet printer comprises: a restriction of the diameter of a conduit for the flow of ink arranged in the path thereof defined by the conduit; a sensor for measuring the pressure difference (P.sub.in-P.sub.out) between the pressure of fluid upstream of the restriction and the pressure of ink downstream of the restriction; a viscous leak, creating a pressure drop by friction loss, the viscous leak being in series with the restriction, in the path of the ink defined by the conduit; a sensor for measuring the pressure difference (P.sub.inV-P.sub.outV) between the pressure of fluid upstream of the viscous leak and the pressure of ink downstream of the viscous leak; and a circuit for calculating the flow rate and viscosity of ink as a function of: (P.sub.in-P.sub.ou)t and (P.sub.inV-P.sub.outV).

A print head of a binary continuous jet printer comprising: a plurality of nozzles for producing a plurality of ink jets in a cavity delimited by lateral walls, an upper wall and a lower wall, a sorting unit for separating drops or sections of one or more of the jets intended for printing from drops or sections that do not serve for printing, a slot, which passes through the lower wall, enabling the exit of ink drops intended for printing, a gutter for recovering drops or sections not intended for printing, a conduit for injecting gas into the cavity, and for making this gas circulate, in the cavity, to the plurality of nozzles for producing a plurality of ink jets in the cavity, then to the gutter.

A valve comprises an orifice plate (1) having one or more orifices (4) through which a fluid may flow, and one or more piezo-electric elements (2). Each element (2) has a face positioned to contact the orifice plate at an orifice. Each element has a first state in which it abuts the plate to prevent flow of fluid through the associated orifice and a second state in which the face is spaced from the plate to allow flow through the associated orifice. A controller (50) selectively applies a first voltage to an elements to cause it to adopt the first state and applies a second voltage to the one or more elements to cause the elements to adopt the second state.

The invention relates to a print head of a binary continuous jet printer comprising: means for producing a plurality of ink jets in a cavity, delimited by lateral walls, and by an upper wall and a lower wall, means for separating drops or sections of one or more of said jets intended for printing from drops or sections that do not serve for printing, a slot, which passes through the lower wall, enabling the exit of ink drops intended for printing, a gutter for recovering drops or sections not intended for printing, means for injecting gas into the cavity, and for making this gas circulate, in the cavity, to the means for producing a plurality of ink jets in said cavity, then to the gutter.

A production system such as an inkjet printer system includes a plurality of communication distribution devices connected in a daisy chain arrangement. A plurality of secondary devices, such as printhead electronics boards for inkjet printheads, is connected to each of the communication distribution devices. A first communication distribution device which is connected to a system controller assigns a communication address to itself from a first set of communication address and assigns communication addresses to its connected secondary devices from a second set of communication addresses. It then communicates information to the next communication distribution device specifying the next available communication addresses. This process continues down the chain of communication distribution devices. The assigned communication addresses are then transmitted to the system controller. The assigned communication addresses enable the system controller to determine the relative physical locations of the communication distribution devices and secondary devices.

An inkjet printhead includes two groups of interleaved nozzles. First and second sets of drop-formation waveforms are associated with the groups of nozzles to selectively cause portions of a liquid jet to break off into drops. A timing delay device time-shifts the second-group waveforms relative to those associated with the first-group waveforms. A charging-electrode waveform having portions with first and second potentials is provided to a charging electrode. The waveform energies of the second-group waveforms is larger than the waveform energies of the corresponding first-group waveforms so that printing drops break off from the liquid jets while the charging-electrode is at the first potential, and non-printing drops break off from the liquid jets while the charging-electrode is at the second potential.

An inkjet printhead includes two groups of interleaved nozzles. First and second sets of drop-formation waveforms are associated with the groups of nozzles to selectively cause portions of a liquid jet to break off into drops. A timing delay device time-shifts the second-group waveforms relative to those associated with the first-group waveforms. A charging-electrode waveform having portions with first and second potentials is provided to a charging electrode. The waveform energies of the second-group waveforms is larger than the waveform energies of the corresponding first-group waveforms so that printing drops break off from the liquid jets while the charging-electrode is at the first potential, and non-printing drops break off from the liquid jets while the charging-electrode is at the second potential.

A continuous inkjet printer is provided comprising an ink supply system, a droplet generator configured to receive ink from the ink supply system and to produce a jet of ink for printing, a gutter configured to receive parts of the jet that are not required for printing, a gutter line connected to the gutter and configured to return unprinted ink to the ink supply system, a suction system comprising a Venturi having a suction port configured to apply a suction force to the gutter line, and a gutter flow rate control system configured to control a rate of flow of fluid along the gutter line based on temperature.

An inkjet printer includes an m number of data setters ranging from a first data setter to an m-th data setter, and an m number of print controllers ranging from a first print controller to an m-th print controller, where m is a natural number greater than or equal to 2. Upon receiving data for ink dots, an n-th data setter sets an n-th dot group including some or all of the ink dots, where n is a natural number in a range of from 2 to m. An n-th print controller causes the n-th dot group to be formed over an (n1) dot group. The first to the m-th data setters set the first to the m-th dot groups so that at least some of ink dots belonging to the first to the m-th dot groups overlap each other.

A droplet discharge apparatus to discharge droplets while moved by a user includes a head to discharge a droplet onto a recording medium, a sensor to detect a movement amount of the droplet discharge apparatus in a predetermined period, and a memory to store determination information indicating whether droplet discharging has been instructed for each pixel of the image data. The droplet discharge apparatus further includes a processor configured to accumulate the movement amount to calculate a total movement amount of the droplet discharge apparatus; instruct droplet discharging from the head based on the total movement amount and the image data; instruct droplet discharging only for an unprinted pixel for which the determination information indicates that droplet discharging has not been instructed; and rewrite the determination information of the unprinted pixel to indicate that droplet discharging has been instructed, based on a predetermined condition.