Obscure Tech: Ever Heard of LED Printers?

Image credit: Wikimedia Commons

For many, printers are either the inkjet or laser type. The few who have been exposed to older tech may also know of the dot matrix printers. However, not many are aware of another printer technology that offers a number of advantages: the LED printer. This printer technology is largely unknown to consumers, but it’s actually a commonly used technology.

What Are LED Printers?

LED printers are fundamentally similar to laser printers. Some would even classify them as a type of laser printer. They use powdered toner instead of liquid ink. Just like laser printers, they employ photosensitive drums to transfer the toner to the paper. Their printouts are warm stacks of paper that make you want to handle them with extra care.

As the phrase implies, LED printers employ light emitting diodes to operate. They are distinguished from laser printers in their use of an LED bar as the light source in the printhead. An LED bar is employed in the xerography process to produce pulse-flashes on a page that create the image on the print drum as it moves.

It’s difficult to ascertain the origin of the LED printer or who invented it. Oki Electric Industry claims to be the maker of the first LED printer, which was said to have been created back in 1981. The company offered in 1986 a commercial LED printer called OPP 6220. It was a compact 240 dpi monotonic printer capable of outputting 16 prints per minute.

How Do LED Printers Work?

LED printers operate in the same way as laser printers do. They use powdered toner instead of ink. They employ a photosensitive drum (also known as the organic photoconductor or OPC drum) to transfer the toner to the paper along with a charged roller (also referred to as the primary charge roller or PCR) or a corona wire to supply a negative charge to the paper before it rolls under the OPC drum. There’s also a fusing component that binds the toner into the paper. This fusing component is what makes the prints warm after they come out of the laser or LED printer.

Image credit: Wikimedia Commons

The texts or images are created because of the pulsing light aimed at the OPC drum. The light creates portions of the OPC drum that are more positively charged (compared to the rest of the drum), which make them attract the toner from the toner barrel, which is negatively charged. This results in patterns formed by the toner on the OPC drum that are then transferred line by line to the paper.

As mentioned, what makes LED printers different is the use of light emitting diodes as the light source instead of laser. LED printers employ fixed arrays of tiny LEDs aimed at the photosensitive drum instead of one laser module with a rotating mirror that reflects the light onto the OPC drum.

This setup results in a faster printing process, especially when comparing color printing from traditional laser and LED printers. However, because of the inherent inconsistencies of the light produced by the tiny LEDs, the output may not be as precise as what traditional laser printers are able to deliver. This slightly inferior precision or inconsistency, nevertheless, is mostly unnoticeable to the naked eye.

Advantages of LED Printers

LED printers are considered to be more efficient and reliable compared to traditional laser printers. This advantage is largely due to the minimal number of moving parts. Since the unit does not employ a rotating laser head, it does not suffer as much mechanical wear and tear. This means it can last longer and is not prone to damages when subjected to shocks or movements.

Additionally, LED printers can output prints faster because of the way they are set up. The light from the LED  arrays are directly beamed to the OPC drum, which is a way faster process compared to having just a single laser light source that is then pulsed numerous times line-by-line on the photosensitive drum.

Moreover, LED printers tend to use less power. LEDs are more power-efficient compared to LED light sources. Also, the elimination of a moving part in the laser module means that LED printers don’t have to use electricity for it. It’s worth noting that motors use considerably more power than light-generating devices.

Prevalence of LED Printers

LED printers are not that popular; that’s why it is featured in this post. However, it may not be that out of reach for most consumers. A quick search on Amazon for laser printers would show results that include LED printers in them. You can find them labeled as “digital printers” (which are included in the results for the keyword “laser printer”) or printers that provide “laser printer quality results.”

You will notice these printers based on their print speeds. LED printers usually have similar monochrome and color print speeds. Traditional laser printers have slower page per minute outputs for their color prints. 

Also, color LED printers have a distinctive arrangement of their toner cartridges. They are stacked neatly on the top part of the unit so the paper efficiently passes through the drums from one color to the other. The Canon ImageCLASS LBP612CDW Color Laser Printer on Amazon, for example, has its toner cartridges arranged similar to how it looks like in the LED printer from Brother with the model HL3140CW. The LBP612CDW is apparently an LED printer but is labeled as a laser printer by Amazon.

Image: Screenshot of an Amazon product comparison page

The Takeaway

Printing technology has advanced significantly over the years. Consumers are enjoying 3D printers now, and there’s a bunch of unusual but impressive printers out in the market. LED printing is largely an obscure technology but it’s not difficult to obtain one. Also, their prices are not that different from laser printers. Some are even cheaper in relation to their specs. It’s not going to be a bad idea to consider getting an LED printer if you are planning to replace your old device with something as capable and even more reliable than a standard laser printer.