# US 8,783,806 B2 · Ink jet printer and method for depositing a protective layer on a substrate > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,783,806 B2 - Document ID: US8783806B2 - Status: Granted - Kind: B2 - Application number: 13/948,670 - Filed: 2013-07-23 - Published: 2013-11-21 - Granted: 2014-07-22 - Earliest claimed: 2008-12-30 - Assignees: M.G.I. USA, Inc. - Applicants: M.G.I USA, Inc. - Inventors: Edmond Abergel - Web page: https://patentgrep.com/patent/US8783806B2 ## CPC - B41J 29/38: Drives, motors, controls or automatic cut-off devices for the entire printing mechanism - B41J 2/04571: {detecting viscosity} - B41J 2/04581: {controlling heads based on piezoelectric elements} - B41J 2/04588: {using a specific waveform} - B41J 29/393: Devices for controlling or analysing the entire machine {; Controlling or analysing mechanical parameters involving printing of test patterns} - B41M 7/02: Dusting {, e.g. with an anti-offset powder for obtaining raised printing such as by thermogravure (B41M7/0027, B41M7/0036, B41M7/0045, B41M7/0054, B41M7/0072, B41M7/0081, B41M7/009 take precedence); Varnishing (devices for treating the surfaces of sheets, webs, or other articles in connection with printing B41F23/00, B41L23/00)} - B41J 2/175: Ink supply systems {; Circuit parts therefor} - B41J 2/17513: {Inner structure} - B41J 2/195: for monitoring ink quality - B41M 7/0072: {using mechanical wave energy, e.g. ultrasonics; using magnetic or electric fields, e.g. electric discharge, plasma} - B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS - B41M: PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING, (correction of typographical errors B41J; processes for applying transfer pictures or the like B44C1/16; fluid media for correction of typographical errors by coating C09D10/00; printing textiles D06P) ## Abstract A protective layer is applied to a substrate moving relative to an ink jet nozzle array. Each nozzle responds to a piezoelectric actuator. Shapes of ink droplets deposited by the nozzles on the substrate, to form the protective layer, are controlled by shapes of electric waveforms applied to the actuators. Shapes of the waveforms respond to at least one of: droplet viscosity and temperature, temperature of the substrate, desired thickness of the layer, type of substrate surface to which the droplets are applied, and relative to speed of the substrate and the ink jet nozzle array. ## Claims ### Claim 1 A method of applying a coating of covering ink to a substrate moving relative to an ink jet nozzle arrangement having a piezoelectric actuator for applying droplets of covering ink to the substrate, the method comprising controlling by a computer the shapes of the droplets by controlling the shape of an electric waveform applied to the piezoelectric actuator, said shape being controlled by selecting at least a number of plateaus of the electric waveform, in response to at least one of the following parameters: viscosity of the ink, composition of the covering ink, temperature of the covering ink, temperature of the substrate, desired thickness of the layer, type of substrate surface to which the droplets are applied, and relative speed of the substrate and the ink jet nozzle arrangement. ### Claim 2 (depends on 1) The method of claim 1 wherein the shape of said electric waveform is controlled in response to the viscosity and/or the temperature of the ink, detected as the ink flows from the ink container to the nozzle by at least one detector upstream from a heater included in the nozzle arrangement. ### Claim 3 (depends on 1) The method of claim 1 wherein the substrate surface type parameter includes chemical composition of the substrate and/or stiffness of the substrate. ### Claim 4 (depends on 1) The method of claim 1 wherein the waveform has (a) neutral value associated with the nozzle arrangement being at rest, (b) a first polarity relative to the neutral value for causing the nozzle arrangement to have a volume greater than the neutral value, and (c) a second polarity relative to the neutral value for causing the nozzle arrangement to have a volume less than the neutral value; the waveform first polarity having an intermediate substantially constant amplitude between the neutral value and a peak value, each peak value causing a droplet to be expelled from the nozzle arrangement, the intermediate value having an amplitude and/or duration dependent on the viscosity of the ink droplet. ### Claim 5 (depends on 1) The method of claim 1 further including maintaining the temperature of the covering ink at a predetermined temperature within the ink jet nozzle arrangement by said heater. ### Claim 6 (depends on 1) The method of claim 1 wherein the ink includes a photoinitiator and further including irradiating the covering ink applied to the substrate with radiation that activates the photoinitiator. ### Claim 7 (depends on 1) The method of claim 1 wherein the parameter includes the viscosity of the droplet of covering ink at the outlet of the nozzle. ### Claim 8 (depends on 1) The method of claim 1 wherein the parameter includes viscosity of the covering ink measured by a probe upstream from the piezoelectric actuator and/or from a heater heating the covering ink. ### Claim 9 Apparatus for applying a coating of covering ink to a substrate, comprising a transport mechanism for causing relative movement between the substrate and an ink jet nozzle arrangement, the ink jet nozzle arrangement having a piezoelectric actuator for applying droplets of covering ink to the substrate; a computer controlling a heater included in the nozzle arrangement heating the covering ink and an electric source for applying an electric waveform to the piezoelectric actuator, said waveform controlling the shapes of the droplets, said apparatus comprising a command device controlling the shape of the electric waveform by selecting at least a number of plateaus of the electric waveform, in response to at least one of the following parameters: viscosity of the covering ink, composition of the covering ink, temperature of the covering ink, temperature of the substrate, desired thickness of the layer, type of substrate surface to which the droplets are applied, and relative speed of the substrate and the ink jet nozzle arrangement. ### Claim 10 (depends on 9) The apparatus of claim 9 further including at least one detector upstream from the heater for detecting the viscosity of the ink and/or a detector for detecting temperature of the ink as the ink flows from the ink container to the nozzle and wherein said command device selects said number of plateaus in response to the viscosity and/or temperature of the covering ink measured by said detector. ### Claim 11 (depends on 9) The apparatus of claim 9 wherein the substrate surface type parameter includes chemical composition of the substrate and/or stiffness of the substrate. ### Claim 12 (depends on 9) The apparatus of claim 9 wherein the waveform has (a) neutral value associated with the nozzle arrangement being at rest, (b) a first polarity relative to the neutral value for causing the nozzle arrangement to have a volume greater than the neutral value, and (c) a second polarity relative to the neutral value for causing the nozzle arrangement to have a volume less than the neutral value; the waveform first polarity having an intermediate substantially constant amplitude between the neutral value and a peak value, each peak value causing a droplet to be expelled from the nozzle arrangement, the intermediate value having an amplitude and/or duration dependent on the viscosity of the ink droplet. ### Claim 13 (depends on 9) The apparatus of claim 9 further including a temperature detector for the ink flowing to the ink jet nozzle arrangement, and a temperature controller responsive to the temperature detector, the temperature controller being arranged for controlling the temperature of the ink flowing in the ink jet nozzle arrangement, wherein the computer controls the heater via the temperature controller. ### Claim 14 (depends on 9) The apparatus of claim 9 further including a memory storing information associated with the shapes of a plurality of the waveforms, an interface for controlling readout of said information in the memory in response to at least one of the parameters being entered into the interface, and a controller arranged to be responsive to the information readout of said memory for controlling the electric source for causing the electric source to derive a waveform having a shape determined by the readout information. ### Claim 15 (depends on 14) The apparatus of claim 14, wherein the interface includes an operator memory interface for enabling an operator to enter at least one of the parameters into the interface. ### Claim 16 (depends on 9) The apparatus of claim 9 wherein the parameter includes the viscosity of the droplet of covering ink at the outlet of the nozzle. ### Claim 17 (depends on 9) The apparatus of claim 9 wherein the parameter includes viscosity of the covering ink measured by a probe upstream from the piezoelectric actuator. ### Claim 18 A method of applying a coating of covering ink to a substrate moving relative to an ink jet nozzle arrangement having a piezoelectric actuator for applying droplets of covering ink to the substrate, the method comprising controlling by a computer the shapes of the droplets by controlling the shape of an electric waveform applied to the piezoelectric actuator, said shape being controlled by a preprogrammed command device with at least a memory correlating the composition of the varnish with the viscosity of the varnish and determining the temperature required by a heating resistance mounted in the nozzle, so that the varnish has a desired viscosity. ### Claim 19 (depends on 18) The method of claim 18 wherein said shape is further controlled by said command device in response to at least one of the following parameters: viscosity of the ink droplets, composition of the covering ink, temperature of the covering ink, temperature of the substrate, desired thickness of the layer, type of substrate surface to which the droplets are applied, and relative speed of the substrate and the ink jet nozzle arrangement. ### Claim 20 (depends on 18) The method of claim 18 wherein the shape of said electric waveform is controlled in response to the viscosity and/or the temperature of the ink, detected as the ink flows from the ink container to the nozzle by at least one detector upstream from a heater included in the nozzle arrangement. ### Claim 21 (depends on 18) The method of claim 18 wherein the substrate surface type parameter includes chemical composition of the substrate and/or stiffness of the substrate. ### Claim 22 (depends on 18) The method of claim 18 wherein the waveform has (a) neutral value associated with the nozzle arrangement being at rest, (b) a first polarity relative to the neutral value for causing the nozzle arrangement to have a volume greater than the neutral value, and (c) a second polarity relative to the neutral value for causing the nozzle arrangement to have a volume less than the neutral value; the waveform first polarity having an intermediate substantially constant amplitude between the neutral value and a peak value, each peak value causing a droplet to be expelled from the nozzle arrangement, the intermediate value having an amplitude and/or duration dependent on the viscosity of the ink droplet. ### Claim 23 (depends on 18) The method of claim 18 further including maintaining the temperature of the covering ink at a predetermined temperature within the ink jet nozzle arrangement by said heater. ### Claim 24 (depends on 18) The method of claim 18 wherein the ink includes a photoinitiator and further including irradiating the covering ink applied to the substrate with radiation that activates the photoinitiator. ### Claim 25 (depends on 18) The method of claim 18 wherein the parameter includes the viscosity of the droplet of covering ink at the outlet of the nozzle. ### Claim 26 (depends on 18) The method of claim 18 wherein the parameter includes viscosity of the covering ink measured by a probe upstream from the piezoelectric actuator and/or from a heater heating the covering ink. ### Claim 27 Apparatus for applying a coating of covering ink to a substrate, comprising a transport mechanism for causing relative movement between the substrate and an ink jet nozzle arrangement, the ink jet nozzle arrangement having a piezoelectric actuator for applying droplets of covering ink to the substrate; a computer controlling a heater included in the nozzle arrangement heating the covering ink and an electric source for applying an electric waveform to the piezoelectric actuator, said waveform controlling the shapes of the droplets, said electric waveform having a shape determined by a preprogrammed command device with at least a memory correlating the composition of the varnish with the viscosity of the varnish and determining the temperature required by a heating resistance mounted in the nozzle, so that the varnish has a desired viscosity. ### Claim 28 (depends on 27) The apparatus of claim 27 wherein said command device further controls the shape of the waveform in response to at least one of the following parameters: viscosity of the covering ink, composition of the covering ink, temperature of the covering ink, temperature of the substrate, desired thickness of the layer, type of substrate surface to which the droplets are applied, and relative speed of the substrate and the ink jet nozzle arrangement. ### Claim 29 (depends on 27) The apparatus of claim 27 further including at least one detector upstream from the heater for detecting the viscosity of the ink and/or a detector for detecting temperature of the ink droplets as the ink flows from the ink container to the nozzle and wherein said command device selects said number of plateaus in response to the viscosity and/or temperature of the covering ink measured by said detector. ### Claim 30 (depends on 27) The apparatus of claim 27 wherein the substrate surface type parameter includes chemical composition of the substrate and/or stiffness of the substrate. ### Claim 31 (depends on 27) The apparatus of claim 27 wherein the waveform has (a) neutral value associated with the nozzle arrangement being at rest, (b) a first polarity relative to the neutral value for causing the nozzle arrangement to have a volume greater than the neutral value, and (c) a second polarity relative to the neutral value for causing the nozzle arrangement to have a volume less than the neutral value; the waveform first polarity having an intermediate substantially constant amplitude between the neutral value and a peak value, each peak value causing a droplet to be expelled from the nozzle arrangement, the intermediate value having an amplitude and/or duration dependent on the viscosity of the ink droplet. ### Claim 32 (depends on 27) The apparatus of claim 27 further including a temperature detector for the ink flowing to the ink jet nozzle arrangement, and a temperature controller responsive to the temperature detector, the temperature controller being arranged for controlling the temperature of the ink flowing in the ink jet nozzle arrangement, wherein the computer controls the heater via the temperature controller. ### Claim 33 (depends on 27) The apparatus of claim 27 further including a memory storing information associated with the shapes of a plurality of the waveforms, an interface for controlling readout of said information in the memory in response to at least one of the parameters being entered into the interface, and a controller arranged to be responsive to the information readout of said memory for controlling the electric source for causing the electric source to derive a waveform having a shape determined by the readout information. ### Claim 34 (depends on 33) The apparatus of claim 33, wherein the interface includes an operator memory interface for enabling an operator to enter at least one of the parameters into the interface. ### Claim 35 (depends on 27) The apparatus of claim 27 wherein the parameter includes the viscosity of the droplet of covering ink at the outlet of the nozzle. ### Claim 36 (depends on 27) The apparatus of claim 27 wherein the parameter includes viscosity of the covering ink measured by a probe upstream from the piezoelectric actuator.