The Inkjet-Printer Pen

The pen of the future will use inkjet technology to deliver a multitude of colours from its tip, according to recent filings from prolific patenter Silverbrook Research in Balmain, Australia.

Inkjet printer heads are now cheaply mass-produced and small enough to fit into the stem of a pen in place of a nib or ballpoint. Silverbrook's pen body is about as thick as a fountain pen, with a battery-powered microelectromechanical print head near the tip that pumps out fine jets of ink from a replaceable cartridge.

A smooth roller point at the tip of the pen holds the jet at a fixed distance from the paper and pressing the point onto the paper switches the jet on and off. Varying the pressure varies the thickness of the line by controlling the number of jets that pump ink - a hard push makes a thick line and vice versa.

The roller point can also sense the direction of movement over the page and make the jet change shape to mimic the behaviour of a pen nib. And if the cartridge has separate chambers of cyan, magenta, yellow and black ink, a switch on the side of pen will allow writing and drawing to be done in a rainbow of colours.

Read more about the inkjet pen design, here.

Double delay for pirates

Much effort is going into ways of making computer game and movie discs hard to copy, to foil copyright pirates. The latest, and perhaps the cleverest, comes from Philips. It exploits two unrelated features that already exist in the current DVD standard, in the new Blu-ray disc and also the Universal Media Disc, used by the PlayStation Portable games console.

Most disc pressings now spread a recording across a two layers on a single side, and there is a little-used provision for barcoding discs with etched marks near the centre hole.

Philips' scheme involves recording matching digital flags in the two layers of the same disc, while using the barcode to define the time delay between the two marks. A player reads the barcode to learn the defined delay, and then checks the actual delay by quickly focusing on one layer after the other.

Even if a pirate copies a game or movie to a dual layer disc, there is virtually no chance of getting the marks in the different layers to have the same delays as the original. And if the timings don't match, the disc won't play.

The new system relies on existing features, so it can be made to work with existing games consoles, which are programmed by the game being played, and the same applies to the new Blu-ray systems. It can also work with computers that incorporate programmable software to play games or movies.

Read more about the disc-pirate foiler here (pdf format).

Tagged by laser

More and more items are being labelled with radio frequency identity (RFID) tags. These can be read wirelessly and from a distance - but singling out one item in a crowded warehouse, supermarket or library is getting ever harder. The solution is a form of laser guidance, according to a patent application filed by NewScientist.com user, Dan Steinberg of Virginia, US.

His idea is to make the RFID reader very directional and able to shine a laser beam of light at the tags it finds, like a sniper's sight.

RFID tags respond to an interrogating radio signal from a reader device by sending back a signal with an identifying code that displays on the reader's screen. If the interrogating radio signal is beamed out broadly and there are a lot of tags in range, the reader may display a bewildering list of IDs.

So the new reader is more like a handheld flashlight which transmits its interrogating signal through a narrow aperture in an absorptive plate. Only tags directly in of the beam the reader receive enough signal to respond.

Once a response is received, the reader emits a thin beam of laser light in the direction of the received signal. This marks the tagged item, and if it is in a box or behind a partition the spot shows where to look for it.