|By Ralph Grabowski, June 17, 2014||
Article first appeared
The biggest surprise around HP's announcement last week of its sort-of-new page-wide technology for large-format inkjet printers was not the page-wide printing; it was that the new printers would not ship for another 12-18 months.
As it turned out, the long delay in shipping was a surprise only for the CAD editors attending. We were the minority among the 36 or so North American journalists HP flew to San Diego, USA. All of the others write about the print industry, which takes a longer-term view than us impatient, we-want-it-now CAD journalists. HP's pr firm explained it like this (notice that they consider 12-18 months "soon"):
We have introduced something so disruptive that is important for our customers to know [about] it so they make the right buying decision as soon as possible. By informing customers today that the new HP Large Format PageWide Technology will be available soon, they can make their own decisions with all the information; whether is it worth to renew their current equipment with existing technology and commit to another 3-5 years with LED technology in many cases, or wait until PageWide Technology is available soon and enjoy all its benefits.
Next's years printer is shown this year in figure 1.
|Figure 1: HP's new page-wide inkjet printer with its eight ink cartridges|
Most inkjet printers work in two dimensions: the print head moves side to side, as the paper moves perpendicularly, jerkily. HP showed us a printhead that is as wide as the paper. This means that only the paper moves. And the paper moves much faster, because it no longer needs to wait for the printhead to finish its sideways travel.
Page-wide printing is not, however, new. We have experienced it for several decades with laser printers, and today it is the norm for large-format LED printers. Essentially, LED printers are like laser printers, but they use a wide, stationary array of blue LED lights, instead of a scanning laser. This is great for monochrome prints (which CAD users capitalize on), but not as efficient for color.
Furthermore, PageWide is not new to HP's line of inkjet printers. Last year, the company introduced its first page-wide inkjet printhead in its Officejet Pro X model. By eliminating the delay from the printhead moving side to side, this printer outputs 70 pages a minute (in office print mode, as measured by HP).
So was there anything new to last Tuesday's announcement? What's new is that HP figured out how to modularize the page-wide printhead: they can stick two, three, ten in a row, each one being five inches wide. Eight gets you an E-size (A0) printer.
One of the techies on the stage said that HP could conceivable keep going, and have modules 20 or 40 wide. More Intriguingly, he let it slip that printers could also have two or three rows, but then stopped himself. Additional rows for additional colors or special coatings, I suppose.
Speaking of additional colors, HP introduced a new color: red. In the real world, red is a vibrant color, but in the printing world, colors are faked by combining various amounts of ink colored cyan (light blue), yellow, magenta (pink), and black. (Red is made from 15% Cyan, 100% Yellow, 100% Magenta, and 0% blacK.) In the samples HP provided, CYMK red looked orangier than the new pure red. So now top end inkjet printer owners have to buy eight print cartridges: light magenta, light yellow, light cyan, and red - in addition to the original four.
Inkjets are called that because they jet ink at paper. The problem is how to throw tiny amounts of ink consistently and quickly. HP's method involves heating the ink by sending a 1-microsecond electrical pulse to a resistor. The heat causes a bubble to form in the ink-filled chamber, which forces out a drop 6 picoliters in size at a speed of 225 mph (10 meters per second) over a distance of 1mm. The bubble collapses, drawing more ink into the head. The process lasts 10 microseconds.
One gram of ink is good for 170 million droplets. HP ink is made of pigments, water solvent, and other stuff. After landing on the paper, the water evaporates.
The 8.575" page-wide printhead in the Pro X has ten offset "dies," and each one is overlapped by 30 nozzles so that a seamless print line is formed (see figure 2). Each die has 4224 nozzles, 1056 for each one of the CMYK colors. Data that controls the on-off operation of the 4000+ nozzles is fed at a rate of 100 megabits per second through ten data paths. When you go through the math (width times nozzles, divided by 4 colors, minus overlaps), the resulting resolution is 1200dpi.
|Figure 2: HP's Pro X page-wide printhead module consists of ten offset dies|
When it comes to next year's large-format page-wide inkjet printers that print on paper up to 40" wide, HP uses eight 5" printhead modules. The resolution is lower at 600dpi, because half the nozzles are reserved for backup, in case their neighbors plug up. Now, this puzzled me, because HP boasted about the integrated printhead cleaner, and a new technology that keeps nozzles from drying out. The new technology is a simple change to the shape of the nozzle (its output end is extended slightly) so that the ink forms a concave, non-evaporating, viscous layer through surface tension. I guess the idea is higher reliability through redundancy.
HP execs insisted to us that because color prints just as fast as monochrome, they have no intention of releasing a monochrome version of the new printer.
I was prepared to not be excited by yet another large-format printer-plotter announcement. After all, what could be new after 30 years? This is a class of product I began reviewing in the 1980s as technical editor at CADalyst magazine. Back then, HP already was the undisputed leader of pen plotters, significantly ahead of the competition in speed and accuracy. (The nearest competitor was Mutoh of Japan, as I recall.) For example, they managed to coax a hair-raising connection speed of 19,200 bits per second with the computer (over the then-standard serial connection), whereas competitors were managing half that speed.
Well, last week HP managed to foil my skepticism with its page-wide inkjet printhead that prints as fast in color as in monochrome (they say). Then HP let me down by delaying the product launch by more than a year. My spirits will be lifted if HP announces a price that keeps to their promise of lowering costs. Current pricing for large-format printers ranges roughly between $10,000 and $14,000. (By contrast, the HP DraftMaster of the late 1980s was around $18,000, and used ink pens for plotting - nasty for doing renderings.)
The reason behind faster printing (and for color-only printing, instead of a monochrome option, and for the new pure-red color) is, of course, to sell ever more ink. During one session, HP allowed that their definition of a "high value customer" is one who spends 14x more on ink than average. Printing faster means printing more, and so using up more ink; printing monochrome prints in color means using up ink cartridges at an uneven rate. When Tenlinks.com editor Roopinder Tara asked about being locked in HP's ink prison, and if ink could be sourced from other suppliers, HP's response was significant: sure, you can buy HP ink direct from us or from our distributors.
There is no way other than The HP Way; buying ink from a cheaper, non-monopoly source is out of the question.
https://ssl.www8.hp.com/us/en/large-format-printers/designjet-printers/overview.html (this page has a video briefly showing the early pen plotters)
[Disclosure: HP paid my airfare, accommodation, ground transportation, and meals.]
|Ralph Grabowski, TenLinks senior editor, is one of the leading CAD journalists and authors, with over a 100 books and many hundreds of articles. His upFront.eZine may be the industry’s longest running newsletter. Ralph holds a civil engineering degree. More…|
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