Secrets Behind the Development of Epson's Micro Piezo Technology (Part 2)

Micro Piezo print heads contain a piezo element. When this piezo
changes shape, it generates mechanical pressure that forces the
ink out.


The birth of the Micro Piezo print head

The previous efforts of Epson's engineers had resulted in a piezo element that could only move 0.1 μm when 100 volts was applied. However, the groundbreaking new piezo element moved as much as 1 μm with only 30 volts. This was a major breakthrough. Achieving such a big movement with a lower voltage meant generating sufficient power to fire ink straight and accurately. A low voltage also meant it was possible to make the driving circuits smaller, which would allow designers to create a smaller printer.

The Epson MX-80 was a best-selling SIDM printer in its day.The first sample of the actuator
using the new piezo element

After a long series of experiments and prototypes using the new piezo element as an actuator, Epson's engineering team decided on the structure for their new print head. Their next priority was to make the print head viable for volume production and commercialize an inkjet printer using the new head. To achieve this as quickly as possible, Epson's executives formed an emergency project team that gathered staff from various parts of the company. Minoru Usui, now Epson's global president, was given the important task of heading up the project.

Epson Stylus ColorEpson Stylus Color

Despite having to overcome a series of challenges, the team was in 1993 able to launch the first printer containing the new print head. This was the Epson Stylus 800, a monochrome inkjet that was the first Micro Piezo inkjet printer to be launched. The following year, the team went a stage further with the Epson Stylus Color, the world's first 720-dpi printer. Despite a price of more than $1,000 in the currency of the time, the product was a huge hit thanks to the high-resolution and stunning quality of the printouts. These products firmly established Epson as a major player in the market for personal printers.

Expanding applications and ongoing evolution

Since the first Micro Piezo printers were launched, Epson continued to develop its technology to meet the growing market demands for printers with better print quality, speed and compact design.

In 2007, Epson successfully commercialized the Micro Piezo TFP (Thin Film Piezo) print head. Manufactured using semiconductor processes, the piezo element used as the actuator was formed as a thin film on a silicon wafer. This allowed denser arrangement of the nozzles on the new print head, ensuring even greater print quality and print speeds. Epson employed the new print head on its range of large-format printers.

Epson global president, Minoru UsuiEpson global president, Minoru Usui

Looking back at the development process, Usui commented, "Other types of inkjets were on the market before our piezo-type inkjets. I knew we had to create a standout product, and therefore set about developing a print head that would help us achieve this. One of the main characteristics of piezo-based inkjets compared to our competitors' thermal systems is a greater ink choice. In addition to regular inks, we went on to develop pigment inks, solvent inks and specialist inks for a wide range of industrial applications. Piezo-based print heads are also extremely durable so we were able to develop applications for the office, an environment in which durability is key."

From the very start of the development process, Usui realized that the basic structure of the Micro Piezo print head made it suitable for commercial and industrial applications. Two decades later Micro Piezo technology is used in a wide range of applications, from printing photos and office documents to specialized digital on-demand printing.

Next-generation print head

Twenty years after the development of the first Micro Piezo inkjet printer, Epson has announced the development of the next-generation print head that will provide the platform for future Epson inkjet printers. The new print head was created by combining Epson's twenty years of expertise in inkjet printing and the latest MEMS manufacturing technologies. The company plans to deploy the new print head first in business inkjet printers for the office and in industrial printing systems.

But the evolution of Epson's core Micro Piezo technology will not stop here. Epson will continue to drive technological advances as it seeks to create new value for its customers.