For professionals and consumers alike, inkjet printing technologies have made producing full color high quality photographs, documents, and fine art reproductions easier, cleaner, and more affordable.
Today, there are two primary types of inkjet print head technologies in use: Piezo (Epson Printers) and Thermal (Canon and HP Printers). In this blog we will be exploring the main difference between the two, as well as some advantages and disadvantages of both.
How does Epson’s Micro Piezo print head work?
In the Epson Micro Piezo print head, microscopic piezoelectric elements (like crystals and ceramics) are built behind the print nozzles. When an electrical charge is applied to them, these elements bend backward, forcing precise amounts of ink onto the substrate (see Diagram 1). Because electrical charges can be turned on and off like a switch, there is a vast amount of control over the rate of ink being ejected through the nozzle while also creating perfectly spherical dots at different droplet sizes.
How does the Canon’s Thermal Print head work?
Thermal inkjet technology uses heat, (didn’t see that coming!) as opposed to electricity, to force ink from the print head to the substrate. Conceptually similar to the way water bubbles when boiled, thermal inkjet technology works by electrifying microscopic resistors behind the print nozzle, creating an intense heat that vaporizes the ink to create a bubble that expands so rapidly the ink literally explodes onto the paper. After ejecting ink, the chamber then cools quickly to allow more ink to refill the chamber and the process is repeated.
Fun Fact: The ink in a thermal print head is, for a nanosecond, close to a million degrees centigrade – hotter than the surface of the sun!
|Precise and Variable Droplet Sizes Can use wide range of inks due to low temperature (solvent, UV, pigment, dye) Droplet sizes down to 1.5 picoliter Run longer due to cooler temperature
|Less Expensive Print Heads More Print Heads Per Printer
|More Expensive Heads Fewer Print Heads Per Printer
|Only 2 different droplet sizes Larger droplet size Limited ink options due to extreme heat Need to be replaced more often due to high heat
Each print head has its advantages and disadvantages. Based purely on a print quality comparison, the Epson wins. Since the Micro Piezo print head can be controlled more precisely and is able to vary droplet sizes, it provides a sharper, grain-free print, with smoother tonal transitions. The Micro Piezo print head is ideal for photo and fine-art reproduction.