Inkjet printing refers to any system of characters, codes or other graphic patterns formed by ejecting drops of ink onto a printing surface . The concept of inkjet dates back to the 1860s, when Lord Kelvin developed the first practical jet machine for pattern generation. Early commercialization was in the 1950s tape Recorder area in oscilloscopes. Since the 1960s, the development of inkjet technology has mainly focused on computer output, with scientists such as Hellmuth Hertz in Europe (Lund Institute, Sweden) and Richard Sweet (Stanford University) and Steven Zoltan (Brush Instruments) in the United States.
Current commercial products range from printers for direct-encoding packaging, to high-speed-low-resolution direct mail printers (from Diconix), to graphic arts-quality color plotters (from Iris Graphics), to graphic arts-quality color plotters (from Hewlett Packard). To address this range of applications, several variants of this technique have been developed. Each method involves cost, speed, reliability, and print quality, determined by the interplay between hardware and supplies.
Inkjet printing capabilities include:
• Generates streams or drops of ink under pressure
• Ejects ink from nozzle holes
• Control of droplet size and uniformity
• Control which droplets reach the paper
• Droplets are placed on the recording surface
The control of these processes depends on several design variables such as nozzle size, firing rate, droplet
Deflection method and ink viscosity. Changing any variable usually requires adjusting other variable system variables, making R&D slow and expensive.
Inkjet printers fall into two basic categories: continuous jet (simultaneous) and pulse jet (drop-on-demand). Most early development occurred in the area of serial jets, but more recently the focus has shifted to the less complex (and therefore less costly) drop-on-demand approach.
