Inkjet Printing Inkjet Technology Fundamentals Rafi Bronstein Rafi
Inkjet Printing Inkjet Technology Fundamentals Rafi Bronstein Rafi. Bronstein@HP. com Mobile: 054 -531 -3760 Rafi Bronstein July, 2008
Inkjet Technology and Inkjet Printing Rafi Bronstein Rafi. Bronstein@HP. com 2008 Rafi Bronstein July, 2008
Course Syllabus n Inkjet technology history and fundamentals u Types on inkjet technologies u History of inkjet printing u Industrial applications n Most successful inkjet printing technologies u Continuous inkjet technologies u Drop-on-Demand inkjet technologies Rafi Bronstein l Thermal inkjet l Piezo inkjet l Novel ink ejection technologies July, 2008
Course Syllabus n Print head fabrication materials and processes n Print head designs and key vendors u Thermal inkjet u Piezo inkjet u Direct ink ejection n Piezo print head design parameters u Frequency, crosstalk, drop placement accuracy … Rafi Bronstein July, 2008
Course Syllabus n Printing inks and their composition u Ink types and properties n Inkjet printing substrates u Paper and coatings u Non-paper media n Basics of radiometry and basic color theory u Radiometry u Color systems and color management Rafi Bronstein July, 2008
Course Syllabus n Ink drying and curing technologies u Drying u Curing n Drop-on-demand ink droplet deflection techniques u Sony u Kodak u Others Rafi Bronstein July, 2008
Course Syllabus n Inkjet printing systems design n The printing industry n Digital printing and inkjet printing Rafi Bronstein July, 2008
Ink Jet Printing Methods Classification Rafi Bronstein July, 2008
Ink Jet Printing History (I) n 1878 – Lord Rayleigh n 1929 – Hansell, USP #1, 941, 001 Electrostatic Deflection Recorder n 1938 – Genschmer, USP #2, 151, 683 Spark Type Ink Ejector n 1946 – Hansell, USP #2, 512, 743 Jet Sprayer Actuated by n n n Piezoelectric 1958 – Winston, USP #3, 060, 429 Drop Jetting by Electrostatic Attraction 1962 – Naiman, USP #3, 179, 042 Sudden Steam Printer 1964 – Sweet, USP #3, 596, 275 Continuous Inkjet Printing 1966 – Hertz et al. USP #3, 416, 153 Modulation by Electrostatic Dispersion 1967 – Sweet et al. USP #3, 373, 437 Array of Continuous Ink Jets Rafi Bronstein July, 2008
Ink Jet Printing History (II) n 1970 – Kyser et al. USP #3, 946, 398 Drop-on-Demand Bend Mode n n n n Inkjet Apparatus 1970 – Zoltan, USP #3, 683, 212 Squeeze Tube Piezoelectric Inkjet 1972 - Stemme – USP #3, 747, 120 Bend Mode with Metal Diaphragm 1979 – Endo et al. GBP #2, 007, 162 Electrothermal Transducer (Bubble jet) 1982 – Howkins, USP #4, 459, 601 Piezoelectric Push Mode 1982 – Vaught et al. USP #4, 490, 728 Electrothermal Transducer (Thermal Inkjet) 1979 - 1985 – Fishbeck, USP #4, 032, 929 - USP #4, 584, 590 Shear Mode Transducer 1989 – Bartky et al. USP #4, 879, 568 Droplet Deposition Apparatus Rafi Bronstein July, 2008
Ink Jet Printing n Continuous n Drop-On-Demand (DOD) u Piezoelectric u Thermal (Bubble) inkjet n Others Rafi Bronstein July, 2008
Lord Rayleigh – Drop Formation Law (I) d P V L λ Emerging from an orifice liquid jet breaks-up into droplets. Because of the surface tension: • Droplets have random size • Droplets have random spacing Rafi Bronstein July, 2008
Lord Rayleigh – Drop Formation Law (II) d P L = K*ln(d/2α 0)V(ρd 3/σ)0. 5 V L λ = 4. 51 d; fs = V/4. 51 d λ α 0 – the initial disturbance ρ - the density of the fluid σ – the surface tension of the fluid L – break-up length fs – the frequency of spontaneous drop formation λ – wave length Rafi Bronstein July, 2008
Drop Formation – Ink Jet Basics n Can the drop size be controlled? n Can the spatial spacing of the drops be controlled? n Can the break-up length be controlled? n What would be the drop selection method? Rafi Bronstein July, 2008
Sweet-type Continuous Ink Jet Deflection Plates Pressure Charge Electrodes Gutter Substrate Rafi Bronstein July, 2008
Binary Continuous Ink Jet Deflection Plates Pressure Charge Electrodes Gutter Rafi Bronstein Substrate July, 2008
Is It So Simple? Viscosity Rafi Bronstein Density Change in Viscosity with pressure July, 2008
Drop Charging Methods Plate Charging (Sweet) Rafi Bronstein Tunnel Charging (S. Bahl? ) Plate Face Charging (S. Bahl? ) July, 2008
Drop Charge Requirements and Limits Drop charge limits: (Rayleigh limit) • Electric field between the electrodes • Conductive ink • Inductive charging • Charging voltage • Charging electrode shape • Jet break-up parameters Rafi Bronstein Q = Sq. Rt. (64π2ε 0 r 3σ); ε – free space permittivity σ – surface tension r – drop radius July, 2008
Drop Deflection Plates Pressure L Charge Electrodes Gutter Substrate • Electrostatic deflection field • Aerodynamic drag force • Neighboring drops repulsion Deflection on paper X = (q. E/m. V 2)L(D-(L/2)) Where q, m, and V are charge, mass and drop velocity. L- length of the deflection plate. D – distance from the plate edge to the substrate. Rafi Bronstein July, 2008
Density modulation (W. Lloyd & H. Taub) Substrate Mask Charge electrode Substrate Nozzle Charge electrode Mask V V Charge electrode Drop dispersion on mask/aperture V Rafi Bronstein July, 2008
Density modulation (H. Hertz) Deflection Plates Pressure Charge Electrodes Gutter Substrate • Variable number of drops per pixel Rafi Bronstein July, 2008
Key Inkjet Patents (I) Rafi Bronstein July, 2008
Key Inkjet Patents (II) Zoltan Rafi Bronstein July, 2008
Piezoelectric Materials Ceramics poling Rafi Bronstein July, 2008
Piezo effect and Piezoelectric Deformation Rafi Bronstein 0 - 0 + + - July, 2008
Piezoelectric Materials (I) Rafi Bronstein July, 2008
Piezo effect and Piezoelectric Deformation 0 - + 0 Rafi Bronstein + - July, 2008
Elements of Piezoelectric Inkjet technology Source: S. Negro and E. Smouse, Hewlett-Packard Inkjet Printing Technology: The State of the Art, 1999 Rafi Bronstein July, 2008
Key Inkjet Patents (III) Rafi Bronstein July, 2008
Drop-on-Demand Piezoelectric Inkjet Piezoceramic Membrane Manifold Pressure chamber Orifice Rafi Bronstein Inlet Orifice plate July, 2008
Drop Ejection Process: • Push-on • Draw-push Rafi Bronstein July, 2008
Forces Acting on Ink Drop VCarriage • Drop charge • Electric field of the substrate • Ejection frequency • Nozzle plate state • … VDrop Windspeed H Drug d daero Rafi Bronstein July, 2008
Elements of Thermal Inkjet (print head structure) Source: S. Negro and E. Smouse, Hewlett-Packard Inkjet Printing Technology: The State of the Art, 1999 Rafi Bronstein July, 2008
Elements of Thermal Inkjet (how it works) Source: S. Negro and E. Smouse, Hewlett-Packard Inkjet Printing Technology: The State of the Art, 1999 Rafi Bronstein July, 2008
Elements of Thermal Inkjet (drop ejection process) Source: S. Negro and E. Smouse, Hewlett-Packard Inkjet Printing Technology: The State of the Art, 1999 Rafi Bronstein July, 2008
Thermal Inkjet Configurations Source: S. Negro and E. Smouse, Hewlett-Packard Inkjet Printing Technology: The State of the Art, 1999 Rafi Bronstein July, 2008
Key Inkjet Patents (IV) Canon 1977 - 1988 Rafi Bronstein July, 2008
Key Inkjet Patents (V) HP Rafi Bronstein July, 2008
Key Inkjet Patents (VI) Fishbeck Rafi Bronstein July, 2008
Key Inkjet Patents (VI) Fishbeck Rafi Bronstein July, 2008
Key Inkjet Patents (VII) Rafi Bronstein July, 2008
Key Inkjet Patents (VIII) Bibl Micro. Fab Rafi Bronstein July, 2008
Key Print Head Characteristics n Resolution n Drop ejection frequency n Drop volume n Drop speed u Array pitch u Drop speed uniformity across the array u Operating temperature range u Physical size and weight Rafi Bronstein July, 2008
Print Head Resolution – Print Resolution n Pitch between two neighboring nozzles u Actual resolution u Linear array u Two dimensional array n Electronic resolution u Minimal printable distance between two successive dots Rafi Bronstein July, 2008
Drop Ejection Frequency n Minimal time between two successive drop ejection cycles u System resonance u Fixed frequency u Plurality of ink ejection frequencies n Defines throughput Rafi Bronstein July, 2008
Drop Speed n The speed at which the drop leaves the orifice u Aerodynamic resistance u Multi drop grey scale printing u Ejection force u Ink parameters n Defines printing speed n Drop speed variations Rafi Bronstein July, 2008
Effect of Drop Speed Variations Rafi Bronstein July, 2008
Drop Volume n The volume of the ejected drop (picoliter; nanogram) u u Drop volume variation as function of ejection frequency n Defines amount of ink on the substrate and accordingly image color gamut Rafi Bronstein July, 2008
Tektronix Print head US Pat. No. 5, 155, 498 Rafi Bronstein July, 2008
Drive Signal Form US Pat. No. 5, 155, 498 Rafi Bronstein July, 2008
Various Drop Formation Wait Periods. Signal of Fig. 2. US Pat. No. 5, 155, 498 Rafi Bronstein July, 2008
Drop Flight Speed with Signal of Fig. 2. US Pat. No. 5, 155, 498 Rafi Bronstein July, 2008
Another Form of Drive Signal US Pat. No. 5, 155, 498 Rafi Bronstein July, 2008
Print Head Pressure Changes with Drive Signals of Figs. 6 -7. US Pat. No. 5, 155, 498 Rafi Bronstein July, 2008
Crosstalk Between the Channels Rafi Bronstein July, 2008
Drop Volume as Function of Ejection frequency US 5, 274, 400 (HP) Rafi Bronstein July, 2008
XAAR XJ 500/360. VEEjet. Rafi Bronstein July, 2008
Q&A n Do you have any questions? Rafi Bronstein July, 2008
Thank you Rafi Bronstein July, 2008
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