How A Print Cartridge Works - Adding a Little Color to Your World!
Printing in the modern age is as simple as a mouse click. In seconds, all your effort can be paid off in a beautiful, crisp rendering of your work on fresh new paper.
But it may surprise you to know just how complicated this process actually is.
Like many things in the modern era, print cartridges are often used but rarely understood. When they break down, most of us scratch our heads in confusion.
If we’re really technically inclined, we may give the printer a good smack to see if we can intimidate it into printing off a few more pages.
Finally, there’s no longer a reason to scratch yourself silly. Put your fixin’ hammer away, because we’re going to tell you all about print cartridges and how they work.
The basic premise of a printer cartridge is simple: supply the means to transfer media from a file to a medium. In this case, the medium is most often a piece of paper. In layman’s terms, the purpose of a print cartridge is to print. Simple, right?
Let’s start with color basics.
The primary colors on the color spectrum are Blue, Yellow, and Red. By using these three colors in various amounts, virtually any color can be created. By mixing all three of the colors together in equal amounts on a print page, you can make black, where the absence of these colors on a print page creates white.
Now, you are probably saying to yourself, “That’s all well and good, but my print cartridge doesn’t have red, yellow and blue!”
That’s true; in fact you’d be hard pressed to find a print head that did. There’s a very good reason for that.
In other mediums, such as television for an example, color is created by the mixing of different amounts of red, blue, and green (blue + yellow). This is because television projects light out to your eyes, making the color variations more realistic.
The process of color television is known as a color additive process. The different colors are added together in various amounts to create new color variations.
Printing colors onto a page is a different story.
Light is reflected off of the paper and back to your eyes. (Note how this is different from television, where the light is projected to your eyes.) In a spot that looks green, for example, the paper absorbs all of the spectrum colors except green, which is reflected back into your eyes, causing you to see green.
However, the color is naturally muted by this process, meaning that true-to-life colors are extremely difficult to recreate.
It is because of this that your print cartridge contains those funny color variations known as Cyan, Magenta, and Yellow. Printing color onto paper is known as a color subtractive process, because the colors are removed to make new color variations instead of being added.
Cyan is a mixture of blue and green (minus red), Magenta is a mixture of blue and red (minus green), and Yellow is artificially created as green and red (minus blue).
In this way, realistic colors can be reproduced without dumping copious amounts of colored ink onto a page and soaking it. The colors aren’t true-to-life, but in some cases they can come very close.
As an aside, the combination of Cyan, Magenta, and Yellow (in theory) makes black. However, because of the random nature of mixing ink on paper, it often creates a muddy brown color instead. For this reason, most color printers come with a separate cartridge for black ink.
So as not to be confused with the “B” of the “RGB” color format (meaning red, green, and blue), black is often given the “K” descriptor, essentially completing the four-color “CMYK” (meaning Cyan, Magenta, Yellow, and Black) coding format.
Inkjets: Blasting Ink onto Your Page
Inkjet print cartridges, come in two basic types: the CIJ (Continuous Ink Jet) and the DOD (Drop On Demand) cartridge.
The CIJ print cartridge lets out a constant stream of ink from its source. These devices are used mainly for printing postage labels and “best before” dates on perishables. These are high-speed printers for industrial applications.
The DOD printer system is probably what most people are interested in, however. It is the standard inkjet printing system for home printers.
DOD is also known as impulse printing. It works by using a thermal reaction to heat the ink. When the ink gets hot enough, vapors form in the print head and then force their way through the printing jets.
This heating process can happen extremely quickly, and the size of the jet nozzles depend on the resolution capabilities of the print head. Generally, the smaller the nozzles, the smaller the ink droplets on the page, and the higher quality the picture is going to be.
The ink is generally mixed on the page in this way, with a first layer of color being applied and then a second layer almost simultaneously. Printer reactions can be measured in microseconds in many cases, so even if it seems your printer is slow, the reactions going on inside the print cartridge are not.
Another type of pulse printer was developed in the 1980's that made use of an electrostatic attachment that forced the ink out onto the paper. However, this process can be very messy, and the electrostatic print head never had any viable commercial success.
Lighting the Way to Clean Copy
Laser printing works much differently than inkjet printing.
In a laser printer, the image is created with toner and electrostatic energy. Electrostatic energy is the electricity you get from leaving your clothes in the dryer. It is also the same electricity that causes lightning.
In a laser printer, a drum assembly that carries a positive electrostatic charge is used to create an electrostatic image. This image is created with the help of a laser which directs a beam at every dot on the page. These dots are changed into negatively charged areas, effectively recreating an exact copy of the image with electrostatic energy.
Positively charged toner is applied to the drum which sticks to the negatively charged areas. It is then rolled over a sheet of paper, recreating the image there. Finally, the paper with the loose toner is run through a set of superheated rollers that melt the toner onto the paper, creating the copied image perfectly on the paper.
A print cartridge for a laser printer is often a self contained unit, with the toner, assembly drum and developer built into a single component. The developer consists of a series of negatively charged beads that roll through the toner compartment. These beads pick up the toner and then release it on the electrostatic image of the drum assembly, where it is ready to be applied to paper.
In recent years, the amount of waste created by disposable print cartridges has lead to environmental problems. Toner can be hazardous if it leaks into groundwater or soil. Because of this, many companies now provide refilling packages that will extend the life of a printer cartridge. Each type of cartridge has its own method for refilling, however, so it’s important to follow the directions carefully.
Hopefully, this article has helped you understand how printers work a little better. But if you still need more information about them, why not check out some websites by companies who actually make printers and print cartridges? Companies like Hewlett Packard, IBM, Canon, Apple, Epson and Compaq all make affordable printers and print cartridges. Their web sites are packed with great information covering just about anything you may need.
About The Author
Bill Schnarr is a successful freelance writer providing tips and advice for consumers purchasing printer ink online, printer ink cartridges and business contract templates. His numerous articles offer moneysaving tips and valuable insight on typically confusing topics.
This article on the "How A Print Cartridge Works" reprinted with permission.
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