Get ready for the speed demons

High speed, decent quality and low cost. Pick any two. That’s been your choice in the decade and a half or so since modern commercial inkjets appeared. But now there are single-pass print heads approaching commercial reality that may offer top colour quality with speeds and prices to blow today’s inkjets and even production-speed laser presses out of the water. Maybe even wide format will go single-pass, affordably. These new heads still face serious technical challenges, but they certainly aren’t science fiction. 

HP is already releasing commercial systems based on its Edgeline head technology. But Australian developer Silverbrook Research is showing prototype fast printers using its Memjet single-pass heads, whose low prices will be revolutionary if they ever reach the market. “Conventional wisdom is that you cannot have high speed, quality colour and low cost all at once,” says Bill McGlynn, CEO of the new Memjet home and office print head manufacturing company. “This technology turns that notion on its head, making page-wide colour printing practical and cost-effective. We believe this breakthrough technology will change the printing industry by eliminating the cost and performance barriers of colour, and by allowing both incumbents and non-incumbents to compete on a new playing field.”

HP’s new Edgeline heads first appeared late last year in its commercial photographic printers. Photosmart Express Station photo kiosks for retail locations can knock out 20 6-colour 4 x 6 inch prints in 2 minutes, while the Photosmart pm1000 Microlab printer plugs into a retailer’s existing photofinishing system and can output a print every five seconds. 

Now it has just announced its first pair of multifunction office printer/copier/scanners (CM8050 and CM8060) with Edgeline heads, rated at 40 and 50 colour ppm, for volumes around 50,000 pages per month. It’s being cagey about prices, but something under £10,000 seems likely. HP says that Edgeline is designed to handle “high-volume workloads for businesses that require high print speeds, outstanding print quality and reliability, and a low cost of operation.” It plans to use Edgeline in future light production and industrial printers.

Gary Cutler, vice president of digital printing technology at HP, says Edgeline technology will introduce radical changes in print quality, performance, reliability and cost of operation - taking ink-based, page-wide printing to “astonishing” new levels. “Edgeline represents the best in ink and laser technology,” he says. “How big a deal is this? This is a $30 billion market opportunity that allows us to build our portfolio and complement our current laser and industrial printing businesses. For me, it’s one of the most exciting steps we’ve ever made in creating breakthrough solutions for customers. This is gonna be huge for HP.” The heads can be used with several types of paper motion systems: drum-based, moving platen, and roll-toroll. The print heads are arrayed across the width of the page, says Randi Dunn-Williams, HP solution strategist. “This allows us to print pages in one or two passes, instead of having a scanning head technology or a contact writing system — resulting in brilliant images at up to 71 pages per minute.”

“We’ve used HP’s scalable print technology to create the Edgeline pens and printheads, which are all built with photolithographic processes at sub-micron precision,” says HP’s Steve Rasmussen, senior mechanical engineer. Each 108 mm wide head prints two colours and has 10,560 nozzles, arranged to give 1,200 nozzles per inch.

“Our ink formulation allows us to jet ink out of our nozzles really fast and we create prints that are fast drying, accurate and very high quality on many different kinds of paper,” says Steve Rasmussen, senior mechanical engineer. “More nozzles contribute to better speed, quality, accuracy and reliability, giving us laser-like text and colour images that only our ink can deliver.”

Bruce Zignego, research and development director at HP, says Edgeline’s biggest economic value to customers will be in devices that will print millions of pages. “That will allow customers to benefit from the total cost of ownership that will be the lowest in the industry,” he says. “This is a powerful engine!”

More controversially, on 21 March at the Global Ink Jet Printing Conference in Prague, Australian inventor Kia Silverbrook stood up in front of an audience of some of the leading developers worldwide and talked about a very fast, very low cost single-pass head technology called Memjet. What’s more, he took along some working prototypes. A video sequence on the company’s website shows wide format, photo, document and label Memjet prototypes printing at remarkable speeds. There’s been some scepticism about the videos in on-line forum discussions. However Lyra Research, an independent US analyst that ran a webcast for Silverbrook in late March, says it has seen these prototypes operating and that the videos represent reality.

According to Silverbrook’s figures, Memjet can print high res full-colour at astonishing speeds. Up to 1,600 x 1,600 dpi A4 documents can be printed at one page per second, 4 x 6 inch photo prints at 30 per minute, or 6 inches (15 cm) per second on a 1.3 m wide format printer. Draft modes of 1,600 x 800 dpi can double those speeds. Heads will cost a fraction of the price of current singlepass head configurations, notably HP’s Edgeline,

Silverbrook predicts. This means they’ll be affordable even in home/office devices. The company says a Memjet-based 60 ppm A4 office printer could cost less than £150. Ink costs will also be lower than today’s systems, so it will “help eliminate the price penalty for printing colour.” Ink for 4 x 6 in photo prints will cost about 0.01p per copy. Apparently it’s dye based and used with microporous paper for near-instant drying, though one of the Silverbrook patents also mentions a ‘fixative agent’ that could perhaps go in the fifth nozzle channel.

The first commercial systems will be in photo kiosks, just like HP, and not low-cost in devices. Photo-Me International, the large France-based company that produces photo booths and kiosks, says it will start trials with Memjet based kiosks in customer sites in France by Q3, followed by rollout to other countries.

‘Mem’ stands for ‘micro electronic machine,’ a term for small mechanical devices produced by the same fabrication technology that’s used for microchips. To make the heads, Silverbrook has licensed its technology to three Memjet start-up companies (for office, photo and label applications). They’ll manufacture heads and components and supply them to printer manufacturers.

Memjet heads are modular, being comprised of 100 mm wide ‘chip’ arrays with interlocking wedge-shaped ends that can be butted together seamlessly and synchronised to form continuous arrays of virtually any width. The chips have five rows of nozzles, each of which can have a different colour if needed. Ink droplets of 1.4 picolitres are generated. An A4-wide array contains 11 of the 100 mm chips. Silverbrook says that arrays of 2 m or wider are possible. It is also talking about narrower format reel-fed models to compete with today’s digital production presses. 

Although publicity-shy, Silverbrook Research has been in existence since the mid-1990s and now claims to employ 300 people, based in Balmain, a suburb of Sydney in Australia. It been granted about 1,400 US patents and says there are 2,000 more in the pipeline (though not all are Memjet-related).

If Silverbrook’s technology can be shown to work reliably at the prices claimed, it will change the face of digital printing, from desktop to wide format. However, its claims are viewed very sceptically by other printhead developers, many of whom were present in Prague. We spoke to a few, who preferred to remain anonymous, but their general response can be summarised as “if it was that easy we’d have done it already.” The MD of one flatbed inkjet maker said he’d heard Silverbrook making similar claims in 1998. “I’d be surprised if it’s commercial within another ten years,” he said. “Edgeline on the other hand is a proper commercial product. It’s not as impressive as Silverbrook’s claims, but it is real.”

A manager of an established print head manufacturer said the challenge isn’t so much building the page-wide arrays, but how to maintain them. Even the high cost single- pass drop-on-demand presses (ie the Dotrix and Screen TruePress Jet 520) face a maintenance challenge, he claims. With moving-head printers a few blocked nozzles aren’t critical because they can be compensated for in subsequent passes. Not so with a single-pass system. “We have a new architecture that’s built for high reliability. We’re seeing this in the labs but it’s not out in the field yet,” he said, predicting it will be ready for a Dotrix-style production press in about 18 months.

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