What is a Printer?
A printer is a peripheral (external device) that connects to a computer or network that generates physical copies of digital documents, images, or graphics. Printers convert digital data into physical output using different mediums, such as paper or plastic using inkjet, laser, thermal or other printing technologies.
Printers can vary in function from basic single-purpose models to multifunction printers (MFPs) that combine printing with scanning, copying, and faxing capabilities. Commonly found in offices, schools, and homes, printers play a key role in document management, enabling users to create hard copies for record-keeping, sharing, or offline access.
The Evolution of Printers
It may be hard to believe but computer printers, or at least the concept of computer printers, dates back around 200 years. English polymath Charles Babbage designed the first recognised mechanical computer, the Difference Engine in the 1820s. While this fact is fairly widely known, did you know that Babbage also invented a mechanical printer that attached to the Difference Engine?
The next innovation in what would later become the computer printer came about in 1868 with the invention of the typewriter and QWERTY keyboard by American inventor and publisher, Christopher Soles. A direct line can be drawn between typewriters and ribbon-based dot matrix or single line printers.
The first true computer printer was not released for nearly a century. In 1953, American business machine manufacturer Remington-Rand released a high-speed printer for use with the Universal Automatic Computer (UNIVAC).
Once the first computer printer was released, the floodgates of innovation seemed to open. Four years after the UNIVAC printer, IBM marketed the first dot matrix printer and a year later Hewlett-Packard (HP) entered the printer market.
In 1968, Shinshu Seiki Co., a company that would become Epson, developed the first mini (desktop) printer. Unbelievably, in 1971 the laser printer was invented before the inkjet printer by Xerox engineer Gary Starkweather.
A year later in 1972, the first thermal printers, designed to be handheld units for use in retail.
1976 saw Hewlett-Packard develop the first inkjet printer, while IBM released the first high speed laser printer. The years between 1976 and 1988 saw multiple companies iterating on both inkjet and laser technologies to create the kinds of desktop printers we have today.
The next revolution in printing didn’t occur until 1992 when Stratasys, Inc. introduced its first 3D printer. The printer utilised FDM (Fused Deposition Modelling) technology developed and patented by Stratasys co-founder S. Scott Crump.
Stratasys essentially maintained a monopoly on 3D printing until 2009 when S. Scott Crump’s parent for Fused Deposition Modelling expired, allowing other companies to use the technology to create 3D printers for commercial and eventually home use.
Types of Printer
While all printers share similarities – they all turn digital data into physical form using some sort of medium such as inkjet or laser toner cartridges, the difference between different types of printers can be rather stark.
Dot Matrix Printers
A dot matrix printer is what is referred to as an impact printer. Impact printers create images or text on paper by striking a ribbon against the paper with small pins or “dots.” These printers use a print head that moves horizontally across the page, with each pin in the print head independently controlled to produce a dot at the correct location. By activating the pins in pattern, dot matrix printers can create characters, graphics, and other designs on paper.
Although their print quality is generally lower than inkjet or laser printers, and typically monochrome, dot matrix printers are cost-effective and have a lower operating cost since they use simple ink ribbons and are more mechanical in nature.
Although generally outmoded by modern printer technology, dot matrix printers are still used today due to their ability to handle multipart forms, making them popular in industrial and office settings where continuous printing is necessary. They can also print on carbon-copy paper and other specialty materials, unlike most inkjet or laser printers, and are typically used for invoices, receipts, or shipping forms in situations where multiple copies are needed at once.
Laser Printers
Laser printers produce text and images by using a laser beam to transfer and fuse toner onto paper. The process begins with a positively charged drum, or photoreceptor. A laser scans across the drum, creating a negatively charged image pattern of the text or graphic being printed. This negatively charged image attracts positively charged toner particles, causing them to adhere to the areas where the laser has made an impression.
Once the toner is on the drum in the correct pattern, the paper, which is given a negative charge by the printer, is rolled against the drum, pulling the positively charged toner particles onto the page. The toner is then fused, or permanently bonded, to the paper through heat and pressure as it passes through a fuser assembly. This process results in a high-resolution, smudge-free image or text.
Laser printers are fast, accurate, and efficient, particularly in high-volume printing environments. Laser printers are often used in offices and settings in which print quality and consistency are important. Compared to many inkjet printers, laser printers typically have a lower cost per page, as toner cartridges usually last longer and don’t dry out over time.
Thermal Printers
A thermal printer applies heat to special heat-sensitive paper or ribbon to create graphics or an image. Unlike other printers, thermal printers work without ink or toner, making them the perfect choice for quick, low-maintenance printing, such as labels or barcodes.
There are two primary types of thermal printing technologies: direct thermal printing and thermal transfer printing.
Direct Thermal Printing: Direct thermal printers use a thermal printhead to apply heat directly to specially coated thermal paper. When heated, thermal paper darkens, creating text or images. Direct thermal printers are typically used for receipts, shipping labels, and tickets, as the process is straightforward and inexpensive. Direct thermal prints can fade over time and are sensitive to heat and sunlight.
Thermal Transfer Printing: In thermal transfer printing, the printhead heats a wax or resin-based ribbon, which transfers ink onto the surface of the paper or other materials. This process produces more durable and long-lasting prints than direct thermal printing, making thermal transfer printers suitable for barcodes, labels, and other applications requiring resistance to fading.
Thermal printers are popular in retail, logistics, healthcare, and other industries due to overall reliability and low operational costs.
Inkjet Printers
Inkjet printers work by propelling minuscule droplets of ink from a cartridge through a series of nozzles or printheads onto the paper. The ink droplets are precisely directed, allowing the printer to produce detailed, high-resolution images and text, using one of two main printing technologies: thermal inkjet or piezoelectric.
Thermal Inkjet Printers: These inkjet printers work by heating the ink inside the cartridge, which causes it to form bubbles. The bubbles expand and force the ink out through the nozzles, resulting in tiny droplets on the paper.
Piezoelectric Inkjet Printers: These inkjet printers use a piezoelectric crystal behind each nozzle that changes shape when an electric current is applied. This shape change creates pressure that pushes the ink through the nozzle without heating it, which can result in greater control over droplet size and placement.
Inkjet printers are popular for home and office use due to their affordability, relatively compact size, and ability to print vibrant colours. They are particularly well-suited for printing photographs and documents that need high-quality colour reproduction.
Inkjet printers generally have a slower printing speed than laser printers and may require regular maintenance to prevent ink from drying and clogging the nozzles.
3D Printers
A 3D printer creates three-dimensional objects by layering materials based on digital designs. The process, commonly called additive manufacturing, works by adding material layer by layer, in contrast to traditional manufacturing methods that typically involve removing material to achieve a desired shape or outcome. 3D printers use materials such as plastic, resin, metal, or even biological substances, depending on the type of printer and its application.
The process begins with a digital 3D model designed in computer-aided design (CAD) software. This design is then processed by the printer’s software, which “slices” the model into thin horizontal layers. The printer follows these layers as instructions to build the object from the ground up. Fused Deposition Modelling (FDM), one of the most common 3D printing methods, involves heating a thermoplastic filament and extruding it through a nozzle, which moves in precise paths to build each layer. Another popular method, Stereolithography (SLA), uses a laser to cure liquid resin layer by layer into a solid object.
Photo Printers
Designed to produce high-quality photographic prints, typically on glossy or specialised photo paper, photo printers differ from standard printers as they use specific ink formulations and printing techniques to deliver sharper images, enhanced colour accuracy, and finer detail. There are two main types of photo printers: inkjet and dye-sublimation.
Inkjet Photo Printers: The most common type of photo printer, Inkjet photo printers spray tiny droplets of ink onto the paper in a highly controlled pattern to create the image. They often include a wider colour range than standard inkjet printers by incorporating extra inks, such as light cyan and light magenta, which allow for smoother gradients and more realistic skin tones.
Dye-sublimation (dye-sub) Photo Printers: These photo printers use heat to transfer dye onto specially coated paper in successive layers. The layers are typically yellow, magenta, cyan, and a protective coating. This process results in a continuous tone, which provides a smoother colour transition compared to the tiny dots visible in inkjet prints. Dye-sub prints are durable, water-resistant, and smudge-proof as soon as they are printed.
LED Printers
An LED printer works similarly to a laser printer, but instead of using a laser beam, it uses an array of light-emitting diodes (LEDs) to create images on the photoconductor drum. This technology was first developed as a more efficient and reliable alternative to traditional laser printing, especially for high-speed, high-volume environments like offices.
In an LED printer, the row of LEDs shines light on the photosensitive drum to form the desired image. When light from the LEDs hits the drum, it creates a static charge pattern that attracts toner particles in the shape of the image. The charged areas pick up toner, which is then transferred to paper and fused using heat and pressure to create the final print.
One significant advantage of LED printers is their simplicity: without moving parts in the light-emitting array, they’re generally more durable and have fewer mechanical issues than laser printers. In addition, LED printers can be very fast, making them suitable for bulk printing tasks. Since the entire line of LEDs flashes at once, this removes the need for scanning across the drum as with a laser beam, enabling quicker print times.
LED printers are also known for high colour accuracy and precision, especially for text and line work, though they may be less ideal for photo-realistic colour prints compared to inkjet options.
