Inkjet printers have arguably been the kings of the printing industry, ever since the first Inkjet printer was manufactured, by Hewlett-Packard (HP) in 1976, from a concept created in the 1950s.
They’re used everywhere for almost all purposes, from printing documents in offices to colorful photos. But, how do they work? What makes them so special? Why are they so loved by everyone?
Development of Inkjet Printers
The functioning system of early typewriters played a good part in the development of inkjet printers. Typewriters have metal types or metal letters, which push on a ribbon full of ink when they’re hit on the keyboard. The ink is pushed out on the paper, typing out the letters that were clicked.
Since only one page could be printed at a time and mistakes were irreversible, this method wasn’t very efficient. That’s why, with upgrading technology, people moved onto impact printing methods for better results.
There were various methods of impact printing, each using a different form of technology for printing. The common characteristic of these methods was the fact that it involved paper being stricken by the ink ribbon to create letterings and designs on the paper, thus the name- Impact printing.
For example, the golf ball technology used a metal ball that had letters and numbers on its surface. By rotating at high speed, it would reach the desired letter and hit against the ink ribbon, which would then cause the letter to be printed on the paper.
The most popular form of impact printing was the dot-matrix technology. This technology uses lots of metal pins or spikes that hit the ink ribbon in specific patterns to create different alphanumeric characters.
However, even though impact printing is much more productive than typewriters, they were still very prone to being damaged often and maintenance was tough. This is when non-impact printers came in and revolutionized printing for good!
Non-impact printing functions opposite of the impact printers, in the way that they don’t come in contact with the pages while printing, and use ink nozzles or toners to print.
Inkjet printers were the first non-impact printers to be developed, and even though almost all printers nowadays print in the non-impact printing methods, inkjet devices are still the best and most useful ones out there, with only laser printers giving a good fight.
Inkjet printers have minute ink-sprays or nozzles that shoot tiny droplets of ink onto the paper and create certain shapes, letters, and designs according to the printing commands.
These are created using dots just like the dot-matrix printers, but, for inkjet printers, the dots are much smaller and thinner, and almost invisible in the output.
Different nozzles of the inkjet printers can come with different kinds of technologies, like the Bubble Jet technology and Piezoelectric technology. While their mechanisms are different, the results are always of the highest quality.
Bubble Jet technology vs Piezoelectric technology
Bubble Jet Technology
Also known as Thermal bubble technology, there are slight differences among the technology integrated by different brands, like HP and Canon. But, these steps pretty much sum up the processes.
- The electric circuit system in the printer receives commands from the computer.
- It determines the nozzles will be used to print a certain character, like “S”, which may require hundreds of nozzles.
- The circuit supplies a small electric current through tiny resistors inside the nozzles required to print a certain character.
- The current causes the temperature of the resistor to rise, which vaporizes the ink and creates an ink bubble.
- The ink bubble keeps on getting larger, which pushes some ink out onto the paper.
- After expanding to its limit, the bubble bursts, and forces the ink out, to form a crisp, clear dot.
- Since there’s a difference in pressure because of one less ink bubble, more ink moves inside the nozzle, for the next printing job.
Hundreds of nozzles (300-600) carry out these processes at the same time to produce a character. The print head then adjusts itself in the right position to print the next character.
This technology is patented by Epson and is slightly different from the Bubble Jet with its use of pressure to print. The nozzle works with three components: ink tanks, ink guns, and piezoelectric crystals.
- A tiny droplet of ink always stays at the edge of the ink gun.
- The electric circuit system of the printer energizes contacts on the piezoelectric crystal upon receiving commands from the computer.
- The excited piezoelectric crystal exerts pressure towards the ink guns and pushes against the membrane between them.
- The membrane in turn creates more pressure on the ink gun.
- With enough force applied to the ink dispenser, the tiny ink droplet is pushed onto the paper.
This process is repeated thousands of times forming crystal clear characters and designs.
What Are The Parts Of An Inkjet Printer?
Inkjet printers may have a small and compact design, but they have several components working to give you the best quality output.
Inside The Printer
- Ink Cartridges: Needless to say, the ink cartridges contain the ink used to print on paper. They can be monochrome or color, or a mixture of both.
- Print head: Print heads are the key to excellent prints on paper. They contain hundreds or thousands of tiny nozzles that spray small droplets of ink onto the paper.
- Internal Stepper Motors: Stepper motors control the movement of the print head and ink cartridges according to the printing commands, and also enable bidirectional printing.
- Belt and Stabilizer Bars: The belt attaches the print head to the stepper motors tightly, while the stabilizer bars help the print head and ink cartridges to move accurately.
Outside The Printer
- Paper Trays: The input paper tray is where you load the paper you want to print on. These also have adjustable clippers for papers of different sizes.
- On the other hand, the output paper tray is where the printed paper comes out.
- Some printers come with an additional input tray, specially designed for different types of paper.
- External Stepper motors, Plastic Gears, and Rollers: The plastic gears and stepper motors work together to control rollers and ensure proper entry of paper into the printer, along with precise movements inside.
- Connectivity: Apart from wireless connections, printers can also be connected with wires. Most printers come with parallel and USB ports. Lots of printers have Ethernet ports as well, while some even have Memory Card slots. Smart printers come with LCD touchscreens as well.
How Does The Printing Take Place?
Have you ever wondered what processes take place once you hit “Print” on your computer? Let’s have a look!
- The printer software on your computer receives the command and sends the data through a USB cable, or over Wi-Fi.
- The information is stored in the buffer memory of the printer, which can range from 16 KB to 16 MB, for a greater number of printing commands.
- The external stepper motor stimulates the gears to turn the rollers for the paper to move into the printer.
- Once the paper reaches an accurate position, the internal stepper motor triggers the movement of the print head and ink cartridges.
- The stepper motor stops for a fraction of a second, when the print head sprays the ink droplets accordingly over the page, creating the desired characters.
- The stepper motor repeats the same process as it moves the print head all around the paper, and printing is finished.
- The external stepper motors stimulate the plastic gears again, but this time the rollers pull the paper out of the printer in the output tray, giving you an outstanding printout.
Inkjet printers are upgrading in technology every day to deliver printouts of higher quality and precision for you. Starting from additional functionalities with the printers to better nozzle technologies, inkjet printers are still the leading printing technology in the world.