ink jet printers

Two main design philosophies operate in inkjet head design. Each has strengths and weaknesses.

The fixed-head philosophy provides an inbuilt print head (often referred to as a Gaither Head) that is designed to last for the whole life of the printer. 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. On the other hand, if the head is damaged, it is usually necessary to replace the entire printer. Epson have traditionally used fixed print heads featuring micropiezo technology. These print heads are available in consumer products and are typically more accurate in dot placement than comparable thermal printers.

Other fixed head designs are more likely to be found on industrial high-end printers and large format plotters and use piezo inkjet heads. Because development of these heads requires a large investment in research and development, there are only a few companies offering them: Kodak VersamarkTrident, Xaar, Spectra (Dimatix), Hitachi / Ricoh, HP Scitex, Brother, Konica Minolta, Seiko Epson, and ToshibaTec (a licensee of Xaar).

Hewlett-Packard has introduced a fixed-head thermal inkjet printer with its newer printer models such as the HP Photosmart 3310.

The disposable head philosophy uses a print head which is a part of the replaceable ink cartridge. Every time a cartridge is exhausted, the entire cartridge and print head are replaced with a new one. This adds to the cost of consumables and makes it more difficult to manufacture a high-precision head at a reasonable cost, but also means that a damaged print head is only a minor problem: the user can simply buy a new cartridge. Hewlett-Packard has traditionally favoured the disposable print head, as did Canon in its early models.

An intermediate method does exist: a disposable ink tank connected to a disposable head, which is replaced infrequently (perhaps every tenth ink tank or so). Most high-volume Hewlett-Packard inkjet printers use this setup, with the disposable print heads used on lower volume models.

Canon now uses (in most models) replaceable print heads which are designed to last the life of the printer, but can be replaced by the user if they should become clogged. For models with "Think Tank" technology, the ink tanks are separate for each ink color.

Posted in: Inkjet head design on วันอาทิตย์ที่ 5 สิงหาคม พ.ศ. 2550 at ที่ 01:50