May 31, 2007 – Epson announced today the development of a piezo print head nearly half the size of current heads and yielding greater dpi. The new Micro Piezo head produces 360 dots per inch—twice that of Epson’s current print heads and the greatest in the industry for piezo heads. But the key is that they are able to maintain droplet size, thereby achieving the same or better quality with a unit half the size. This will result in smaller, faster piezo printers, a boon for Epson. Reducing the size of the piezo element required the development of a whole new manufacturing process as the current mechanical process was not up to the task. Using photolithographic techniques (the same used to manufacture circuits on semiconductor chips), Epson’s researchers were able to shrink the size of the piezo from sixteen layers to a single thin layer, which results in a smaller print head. This reduction in head size will allow Epson to produce smaller, faster printers.
|Graphic courtesy of 'Epson's Next Generation Micro Piezo Print Head Boasts Macro Potential,' Technology Newsline, Epson|
In Micro Piezo technology, voltage is applied to the piezo, thin quartz or ceramic layers. This layer distorts in response, creating vibrations that cause the ink in the chamber below to be jetted out via the nozzles. Precise control of the distortion and vibration allow for tight control of droplet size. Epson is able to vary the amount of distortion thus resulting in varied droplet size. The piezo technology also allows for faster ink spraying than thermal inkjet technology because in the latter, the ink needs to be boiled before being sprayed, which takes time. Another advantage of the piezo heads is their ability to use either dye and pigment inks, while thermal inkjet printers are relegated to one or the other.
More information can be found in Epson's press release.