inkjet printing

There are two main types of inkjet printer technology: piezo with liquid ink and solid ink, and thermal inkjet.

Piezo inkjets fire liquid ink typically through 180 nozzles per inch, which is a low nozzle density. They offer good drop modulation, but print quality diminishes the higher the printing speed. With solid ink, sticks of wax-like ink are melted in a heater, drops are fired across the page and the ink hardens in place.

Easy to use, they offer vivid colours and a choice of media types but the drawbacks include long warm-up time, high power consumption and no closed-loop control to deal with clogged nozzles. Dot size limitations also mean compromising on image detail and printout stability is poor.

HP Inkjets use thermal inkjet technology (TIJ). These printers have a high nozzle density of 600 nozzles per inch and use HP PhotoREt precision technology to deliver better image quality. HP Business Inkjets also use dual processor technology to deliver higher performance. This enables easier printing of complex documents and fast processing of 2400 dpi data for photo-quality printing.

A heater ensures the ink is quick drying.

laser printing

dry electro photographic process

There are 2 printing sub-technologies that both use the same method known as dry electro photographic process: Laser and LED (light emitting diode) technology. These processes are based on the physical law that opposite charges attract and equal charges repel.

LED printers have a fixed single row of light emitting diodes mounted at a 90-degree angle. A low powered light from an LED creates an image of the printer dot.

Variable dot size is limited and dot replacement is restricted, which can inhibit resolution enhancement. Over time an individual LED can experience a different amount of wear and therefore the strength of each LED may vary as a result.

This give rise to a poor quality print effect called vertical streaking.

HP LaserJets use a single, high quality light source for the drum. The application, through drum scanning, of advanced resolution and colour halftoning technology enable better image quality.

There are two types of laser technology, both used for HP Colour LaserJets:

Four-pass

Colour laser printers using four-pass technology are generally smaller and less expensive, making them good for small and medium sized businesses.

They are ideal if you need to print some documents in colour, but do not need large volume colour output and high speeds.

In-line

In-line laser technology delivers much faster colour printing speeds making it more suitable for users needing high-volume and high-performance, for whom purchase price may be less of an issue. These printers do still offer a low total cost-of-ownership and are therefore suitable for most office environments.

Leading the way

Print quality is a crucial factor for business customers. HP is constantly evolving and developing new technologies to enhance your experiences and help drive down the costs of colour printing.

hp PhotoREt IV

This advanced HP-developed printhead technology offers a print resolution from an inkjet printer that is as good as a traditional photograph. Unlike conventional inkjet printing, which typically places up to two drops of ink per dot, producing up to 8 different colours per dot, HP PhotoREt IV allows the printer to layer, not two, but 32 drops of ink accurately per dot, generating more than 3,500 directly printable colours. This means that flesh tones and other colours are far more natural and transitions from colour to colour are much smoother.

Stunning image quality is matched by superior performance. Hp Inkjet printers provide up to 50% faster firing times and use twice as many colour nozzles as other inkjet printer - 524 nozzles* each firing 36,000 drops of ink per second to deliver over 70 million drops per second. Furthermore no special papers are required; dramatic, rich-colour results will be achieved on both plain and photo paper. HP Printers deliver professional photo-quality results at a speed to satisfy even the busiest user.

hp ImageREt 2400 and 8-bit contone

With accurate colour control, precise toner blending, 2400 dpi quality and millions of pattern free colours, HP Colour LaserJets use this technology for photo-realistic printing with no compromises. 8-bit contone ensures superior image detail by delivering four times more data per pixel than 1-bit binary and 2-bit contone, used by competitor products.

Other sophisticated features include:

• smart calibration giving users consistent output from first to last print
• trapping technology which hides any colour plane mis-registration and transitions between halftones
• smart edge enhancement identifies text edges and applies special half toning to sharpen them
• smart chip technology tracks ink and print usage and informs the user in time for re-ordering
• advanced tone technology delivers the second generation of chemically grown toner with smaller, uniform toner particles enabling the printer to achieve best print quality

understanding speed definitions

Speed is always an important factor in choosing the right printer. To make it easier to decide whether to buy an HP Business Inkjet or an HP Colour LaserJet we have developed page per minute speed comparisons over a suite of documents.

the context

Traditional inkjet marking systems mark a point at a time, with high variability depending on content. Usually a "draft speed" is quoted to reflect their best capabilities. Laser printers mark a line at a time with lower variability according to content. "Engine speed" is quoted to measure their performance. For easier comparison we quote "laser-like speeds" for HP Business Inkjets. These ratings have been carefully measured and are equivalent to the page per minute speed you can expect from an HP Colour LaserJet printer.

you can rely on HP

With two outstanding and compatible technologies for colour printing, HP give you the widest possible choice. Both Inkjet and LaserJet technologies are constantly being improved and developed to give better print quality, higher performance, superior reliability and ease-of-use. We can help to match your specific needs with our extensive range of products, ensuring you choose exactly the right HP colour printer.

*figures based on the hp business inkjet 3000 series