Samsung gets a lot of grief (and lawsuits) for imitating other firms’ good ideas. In the case of active-stylus-based mobile computing, though, they have led the way with their extensive Note product line. With over 40 million units sold, a combination of large screen and note-taking capability has made the Note tablet one of the most popular high-end mobile devices. It’s bigger sibling, the Note 10.1, has remained a niche product for die-hards like me, but definitely has a loyal following.
By using an active stylus in the Note, Samsung achieves several major advantages over a passive-stylus-based version. First, it is easy for applications to tell the difference between the pen and touch. That means that you can rest your hand or accidentally touch the screen while writing with the pen and not have it mess up your ink. Second, you get very high resolution to enable precision note-taking and drawing. Third, it is possible to detect the stylus even when it is only hovering over the display, allowing for some cool added features. Finally, you also get pressure-sensitivity, allowing more accurate modelling of different drawing and painting tools.
Wacom EMR-powered styli create a resonance from the magnetic field provided by the sensor boardFor the active stylus in the Note, Samsung — and later Microsoft — turned to leading tablet vendor Wacom to add the necessary sensing layer. Wacom uses Electro-Magnetic Resonance (EMR) technology to generate a small magnetic field that creates a resonance in the pen’s other wise passive (non-powered) circuitry. Along with position, the sensor board receives data including the pen’s speed, angle and writing pressure.
The downside of EMR is that it requires a separate layer of small antennas and a lower shield to block interference from other components. This can add as much as a millimetre to the thickness, as well as to the weight and cost of Wacom-power devices — although the newest generation of Note products show that even EMR-equipped displays are getting thinner and lighter over time. A separate controller is also needed to turn the magnetic fields on and off based on pen location. Since fingers and capacitive styli don’t have the same resonant circuits, the EMR sensor doesn’t see them at all.
Wacom also has their own active-stylus tablets now — the Cintiq Companion product line. Cintiqs are clearly the king of stylus-based input. They’ve delivered high-quality pressure-sensitive input on a screen for years — but high-cost and dependence on PCs made them a special-purpose tool for well-heeled creatives. Now Wacom has extended the Cintiq product line to mobile, or at least portable, devices, with its Cintiq Companion products, available in both Windows 8 and Android versions. Their large size and high price tag will keep them out of the hands of all but a few, though.