ARCHITECTURES: Printers crank out new SoC requirements

It goes without saying that this is a cost-sensitive segment. Much as razors are a platform for repeat purchases of razor blades, home printers exist to sell ink. The printers themselves are sold at giveaway prices to create continuous demand for high-margin, proprietary inkjet or dye-sublimation cartridges.

This puts both price and integration pressure on the makers of printer SoC devices. To the extent possible, the active circuitry in the printer needs to be packed into a single, inexpensive chip. Printer SoCs have become small marvels of CPU, pixel processor, motor control and scanner/printer interface hardware.

The crunch comes as home users begin to see their printer less as a PC peripheral than as an alternative to the one-hour photo place. Consumers, market research suggests, are becoming increasingly interested in printing their digital photos at home. But this group is not particularly amenable to the arcane user interfaces of programs like Photoshop. So there is a growing market for home photo-quality printers that can stand alone, attaching directly to a camera and doing their own image preparation.

As Zoran Corp. product-marketing manager William Queen observed, "You can get much better photo-manipulation features and a more flexible user interface in PC-based software, but there's a growing market for simplicity."

Most home users won't be comparing the results from their standalone printer with those from Photoshop. But they will compare home-printed shots with the photos they had done at the grocery store, and that's a problem.

"In minilabs, you have very sophisticated algorithms running on Pentiums," Queen said. "Today, the standalone printer will offer a little brightness and contrast adjustment and some other simple manipulations, but problematic images won't look great in comparison to what you'd get from the minilab.

"In the near future, though, you will see sharpness, tone matching and accurate red-eye correction on the home printers as well. They are going to begin closing the gap with minilab results."

All of this will require more horsepower than just an ARM7 and a rasterization state machine. "Most of the algorithms on these printers are going to be running on a DSP core, not on the CPU," Queen said.

That's where Zoran, with its proprietary DSP hardware, comes in. In its first attack on this market need, the company has introduced the Quatro 4050 SoC, for extreme-entry-level printers, and the 4200, offering a wider selection of peripheral interfaces. Both provide motor and lamp driver outputs as well as outputs for dye-sublimation or inkjet print heads.

Both chips also offer an integrated analog front end (AFE) for the scanner. Pulling precision analog functions onto the SoC without resorting to an analog process module — and without creating serious noise problems for the analog circuitry — jacks up the die size requirements, Queen acknowledged, but "even with the added die area, the integrated AFE is very low in cost compared with discrete components. If you are aiming at a $200 price point for a complete multifunction peripheral, you just can't afford a discrete AFE anymore."

With scanner quality rising and home printers competing with minilabs, stand by for higher clock rates, more powerful image processing and bigger memory. But all will have to be handled within a bill of materials that recognizes the real end product isn't the razor; it's the blades.