Understanding today’s digital print technology requires knowing how an image is transferred to paper. In simple terms, a light source creates an electrostatic image of tiny dots, which is converted to a toner image, before being fused onto the paper.
The light source is the core of the digital printing process and is driven by two technologies—laser technology and LED technology.
LED versus laser technology
Printers today use a number of print technologies, with electro photographic and inkjet having majority market share.
Ricoh uses electro photographic laser printing in printers and multifunction products (MFPs). Within this process, the image on the photoconductor drum is created by a laser light source. In LED printers, the same image is created using an LED light source.
In this briefing paper we will look how both these technologies work, how they differ, and what the immediate benefits of LED printing for your customers are.
What is LED print technology?
Light-emitting diode (LED) printing is an electro photographic process that uses a matrix of LEDs as its light source.
These LEDs are mounted in rows, known as arrays, along the digital print head, and they cover the entire width of the organic photoconductor (OPC) drum.
Is this technology new?
LED print technology has been around for a while. Initially examples of LED printers had some design limitations that proved to be problematic. Light intensity and timing accuracy varied from LED to LED— which meant image quality also varied.
Recent developments have enabled this technology to be more consistent and cost-effective.
Selling LED printers
Due to their simpler design, LED printers are more compact than their laser counterparts. They also use significantly less power and are quieter.
LED print heads produce smaller dot sizes, resulting in highly accurate output with fine detail. Also, because printing occurs one line at a time, impressive colour print speeds are achieved, which are as fast as black and white.
How does LED differ from laser?
How is it different from laser print technology?
The light source in a laser printer uses a combination of rotating mirrors and lenses to create an image by scanning from one end of a line to another.
In comparison, the LED print head illuminates the drum by emitting an entire line of dots at the same time.
Laser print technology
Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. Laser technology relies on elaborate combinations of rotating mirrors and lenses that must remain aligned throughout the life of the device. A single light source creates an image by scanning from one end of a line to another, and zigzagging down to the next line—rendering each dot individually in sequence.
LED print technology
LEDs are tiny semiconductors that emit pulses of light. These LEDs are mounted in rows —known as arrays— along the digital LED print head, and they cover the entire width of the drum.
The LEDs are individually turned on and off according Laser printing is a complex process that requires seven steps:
Why LED printing?
Colour LED printing
Colour devices have four rows of LEDs—one each for cyan, magenta, yellow, and black toners—which allows colour documents to be printed at the same speed as black and white.
A 600 dpi LED printer will have 600 LEDs per inch over the required page width, and a 1,200 dpi LED printer will have 1,200 LEDs per inch. To create a printed document, the digital LED printhead illuminates the drum by simultaneously emitting an entire line of dots. This method is significantly different from a laser printhead, which writes the dots in a one-at-a-time sequence. For a square inch of printing, LED diodes in a 1,200 dpi device, will only scan the raster image 1,200 times as opposed to a laser beam that will scan the image 1,440,000 times. The result— LED printers can print high-resolution images as fast as low resolution images.
Benefits to the customer
LED printing has many benefits for customers, especially those wishing to convert black and white printers to colour.
- Fast, high-resolution colour—Colour and high-resolution speeds are as fast as those of black and white, and low resolution
- Sharp images—Not only do documents print faster at high-resolutions, the small dot size created by the LED technology is responsible for razor sharp print quality
- Quiet operation—Customers can place this quiet printer anywhere. Energy-efficient—Less power is consumed by LED printers
- Cost savings on consumables—Because the toner cartridges and drums can be replaced separately, LED printers can help customers reduce their total cost of ownership (TCO)
- Compact and light—LED printers are compact and lighter than their laser counterparts, making them easier to fit into tight spaces
- Reliability — The printhead in an LED printer is solid-state, with few moving parts—making it easy to maintain
- Straight paper path—LED printers have a straight paper path, enabling reliable thick paper support, and minimising paper jams.