Ink Cartridges September 07, 2007 09:47 by John Sollars
An ink cartridge is the most obvious component of any ink jet printer. It actually contains the ink and is the part that most people will replace on a regular basis. Each cartridge will contain between one and five different colours of ink and certain manufacturers will also include a chip, print head and electronic contacts to communicate with the printer.
How Ink Cartridges Work
There are three basic types of inkjet printer all using different technologies. HP were the inventors of the technology and they along with Lexmark and Dell use a thermal inkjet technology. Inside the cartridge there is a heating element with a tiny metal plate or resistor. In response to a signal from the printer a tiny current is passed through the resistor which heats it up which vapourises the ink bubble surrounding the plate. As this process occurs the total volume of the ink exceeds that of the nozzle and an ink droplet is forced out of the nozzle onto the paper. This process takes a matter of milliseconds and in a colour cartridges happens for each individual colour.
Epson went down a different route and use a piezoelectric crystal. When the printer signals to the print head to print some ink, instead of heating up the area of ink, the Piezo Crystal expands which essentially squeezes the droplet of ink out of the cartridges. With Epsons latest print head technology the size of the ink droplet is measured in nanolitres (which is 10 to the minus 9 of a litre!).
And Finally Canon independently developed the Bubblejet technology. Canon's proprietary "Bubble Jet" printing technology is a world renowned, using special heating elements (micro-heaters) to eject ink from microscopic print nozzles. It was an accidental discovery during the 1970's at Canon's Research Centre in Japan, when a soldering iron came into contact with the needle of a syringe that was filled with ink. A researcher noticed that ink suddenly spurted from the needle. This led to the development of Bubble Jet printing, a high-speed, high quality ink jet printing technology.
