HP Scitex FB6100 Printing Technologies - Page 22

Repeating this process and then slicing the wafer into die produces complete, integrated printhead structures with features that are defined and aligned together with sub-micron precision. With thousands of identical drop generators on each printhead,62 SPT processes deliver high print quality at high productivity with consistent drop volumes, drop speeds, and drop trajectories. Because the SPT process can define and produce very small physical features, ink filters can be placed in the ink supply for each drop generator. These are seen as "pillars" in the figure. Integral ink filters improve printhead reliability by preventing unwanted particles in the ink from clogging the drop generators. The epoxy materials used in SPT resist chemical interaction with aqueous inks to give reliable performance and long operational life in commercial print production environments. HP's portfolio of HP Designjet printers with aqueous inks and HP Latex Inks is based on two SPT platforms: printheads with 0.88-inch and 4.25-inch nozzle arrays. These are described in the following table. HP Designjet Printer Array Length Number of Colors/Printhead Ink Type Colors Drop Volumes (pl) Nozzles per Color69 Total Nozzles Nozzles per Inch HP 70 / HP 73 63 Z2100, Z3200 0.88 in. 2 HP Vivera pigment inks C lc M lm Y lg G pK mK R Gn B E 4, 6 67 1,056 Z2100: 8,448; Z3200: 12,672 HP 91 Z6100 0.88 in. / 1.70 in 64 HP 72 T610, T620, T770,T1100, T1200 0.88 in. 2 2 HP Vivera pigment inks C lc M lm Y lg pK mK HP Vivera inks C M Y pK mK G 66 4, 6 67 6, 9 68 1,056 1,056 16,896 6,336 1,200 HP 789 L25500 0.88 in./ 1.70 in64 2 HP Latex Inks C lc M lm Y K 12 1,056 12,792 HP 786 L65500 4.25 in.65 2 HP Latex Inks C lc M lm Y K 12 5,280 31,680 In addition to the thermal inkjet structure built on silicon die, "printhead" also describes complete assembly that includes the drop ejecting component mounted on a "backend" that provides ink pressure regulation, electrical interconnection, ink supply, and mechanical registration. Printheads printing two colors of ink have two independent pressure regulators in the backend assembly. HP Thermal Inkjet printheads feature a snap-out/snap-in design for simple and quick user replacement requiring no tools, handling of ink tubes, or a time-consuming and expensive service call. Inserting the printhead into its slot in the printer carriage makes ink and electrical connections and registers the printhead against mechanical stops. HP's T-, Z-, and L-series Designjet printers print a test plot whenever a printhead is replaced, and the plot is automatically scanned by an optical sensor on the print carriage to perform an automatic color-to-color alignment without requiring manual mechanical adjustments. 62 For example, an HP 70 Thermal Inkjet printhead has 2,112 nozzles on a single die. 63 See the Printer Data Sheet for the printheads and ink colors available for in each printer. 64 Effective print swath with overlap between sets of printheads in HP Double Swath technology. 65 Effective print swath with overlap between printhead chips. 66 Matte Black (mK) is pigment-based; Photo Black (pK), Gray (G), and C, M, and Y inks are dye-based. 67 Drop volumes for the HP 70, HP 73, and HP 91 printheads: 4pl for lc, lm, lg, pK, G, and E; 6pl for C, M, Y, mK, R, Gn, and B. 68 Drop volumes for the HP 72 printheads: 6pl for C, M, pK, and G; 9pl for Y and mK. 69 Nozzles per color on each printhead. Total nozzles per printhead is "Number of Colors/Printhead" X "Nozzles per Color". 22