This article needs additional citations for verification. Chodowiecki Basedow Tafel 21 c Z. Inkjet printing is a type of computer printing that recreates a digital image by propelling droplets of ink onto paper, plastic, or other substrates. The concept of inkjet printing originated in the 20th century, and the epson T30 Resetter Software was first extensively developed in the early 1950s.
The emerging ink jet material deposition market also uses inkjet technologies, typically printheads using piezoelectric crystals, to deposit materials directly on substrates. Images produced on inkjet printers are sometime sold under other names since the term is associated with words like “digital”, “computers”, and “everyday printing”, which can have negative connotations in some contexts. In 1867, Lord Kelvin patented the syphon recorder, which recorded telegraph signals as a continuous trace on paper using an ink jet nozzle deflected by a magnetic coil. In CIJ technology, a high-pressure pump directs liquid ink from a reservoir through a gunbody and a microscopic nozzle, creating a continuous stream of ink droplets via the Plateau-Rayleigh instability. The more highly charged droplets are deflected to a greater degree.
Only a small fraction of the droplets is used to print, the majority being recycled. CIJ is one of the oldest ink jet technologies in use and is fairly mature. A print head will contain several such nozzles, and will be moved across the page as paper advances through the printer. Hewlett-Packard, and Lexmark, use the thermal inkjet process.
In the thermal inkjet process, the print cartridges consist of a series of tiny chambers, each containing a heater, all of which are constructed by photolithography. Piezoelectric printing nozzle of an EPSON C20 printer. A DOD process uses software that directs the heads to apply between zero and eight droplets of ink per dot, only where needed. Piezo inkjet technology is often used on production lines to mark products. The basic problem with inkjet inks is the conflicting requirements for a coloring agent that will stay on the surface vs.
Desktop inkjet printers, as used in offices or at home, tend to use aqueous inks based on a mixture of water, glycol and dyes or pigments. While aqueous inks often provide the broadest color gamut and most vivid color, most are not waterproof without specialized coating or lamination after printing. Most Dye-based inks, while usually the least expensive, are subject to rapid fading when exposed to light or ozone. Color is achieved with pigments rather than dyes for excellent fade-resistance. There are two main design philosophies in inkjet head design: fixed-head and disposable head. Each has its own strengths and weaknesses.
The idea is that because the head need not be replaced every time the ink runs out, consumable costs can be made lower and the head itself can be more precise than a cheap disposable one, typically requiring no calibration. Fixed head designs are available in consumer products, but are more likely to be found on industrial high-end printers and large format plotters. The disposable head philosophy uses a print head which is supplied as a part of a replaceable ink cartridge. Every time a cartridge is exhausted, the entire cartridge and print head are replaced with a new one. Most high-volume Hewlett-Packard inkjet printers use this setup, with the disposable print heads used on lower volume models. A similar approach is used by Kodak, where the printhead intended for permanent use is nevertheless inexpensive and can be replaced by the user. The primary cause of inkjet printing problems is ink drying on the printhead’s nozzles, causing the pigments and dyes to dry out and form a solid block of hardened mass that plugs the microscopic ink passageways.
Most printers attempt to prevent this drying from occurring by covering the printhead nozzles with a rubber cap when the printer is not in use. Abrupt power losses, or unplugging the printer before it has capped the printhead, can cause the printhead to be left in an uncapped state. To combat this drying, nearly all inkjet printers include a mechanism to reapply moisture to the printhead. Typically there is no separate supply of pure ink-free solvent available to do this job, and so instead the ink itself is used to remoisten the printhead. The printer attempts to fire all nozzles at once, and as the ink sprays out, some of it wicks across the printhead to the dry channels and partially softens the hardened ink. Some printers use a supplemental air-suction pump, using the rubber capping station to suck ink through a severely clogged cartridge. The suction pump mechanism is frequently driven by the page feed stepper motor: it is connected to the end of the shaft.