Netbooks: Swivel Touchscreen Does Not Equal Tablet PC

T91_StylusWrtiting_withScreenshot-728-75A lot of people are very interested in the new netbooks that are getting touchscreen capability. The Asus T91 is attracting a lot of attention as a “Tablet PC” with netbook pricing. Since the convertible nature of the T91 means the screen can be swiveled around into a slate form, one could make the assumption that this device (or any other convertible) would be good for inking on the screen. I hear from people all the time wanting to know if these types of devices will be good for inking and I need to set the record straight. The correct answer to that question is: almost certainly not.

Slate Tablet PCs are great for writing on the screen — the form factor screams for that ability. Taking notes in a meeting or writing out emails is a natural use for these convertible devices, but the fact is that there are some things that prevent most devices from doing this well. Netbooks have passive digitizers that are built for touch input; operating the netbook with fingertips is pretty natural and especially effective for slate devices. The problem sets in when writing on the screen is desired.

Microsoft developed Windows XP Tablet Edition to power Tablet PCs with an active digitizer. These are the screens that require a special pen for writing on the digitizer screen with accuracy. The special digitizer is needed because touchscreen (passive or resistive) digitizers are less resolute than needed for good ink recognition on the screen. Touchscreens also react to any touch on the screen, so when you set your hand on the screen to write on it, the digitizer interprets the hand as it would the pen and produces what is called “vectoring.” Instead of nice ink appearing where you are writing, you get a bunch of scribbles produced from the simple act of setting the hand down on the screen. That’s why Tablet PCs of old used the special digitizers, which ignored touch completely.

Today, touchscreens have become common and folks like to drive their PC with the finger. These use the same passive digitizers built for touch and being used in convertible netbooks. Inking will not work on them for the reasons already noted. To produce a convertible netbook that works with touch and provides good inking requires special attention by the OEM. Those wanting a good inking experience are being confused by Microsoft’s incorporation of the Tablet Edition into premium versions of Vista, and now Windows 7. The expectation is that any convertible netbook running Windows 7 will be a good Tablet PC, and that is false. It requires special technology in addition to the OS to handle inking.

Dual digitizers can be used, one for touch and one for inking, but this is prohibitively expensive and not for the netbook crowd. Another method is to use a “hard” passive digitizer that ignores random touches by the hand on the screen. This is used by the expensive Fujitsu P1630 Tablet PC. It works well for inking but not so well for touch. The last method is to use a “soft” touchscreen that incorporates special “palm rejection” software. It can be manipulated easily by fingertip but is effective for inking as well. This software “sees” the hand when it rests on the screen but ignores it, expecting ink to be produced with a stylus.

This last method has been used successfully in the Intel Classmate convertible netbook we evaluated, which is only slightly more expensive than the average netbook. While the method worked very well and produced a good touch experience along with good inking, it required special software produced by Intel especially for the Classmate. While it demonstrates that other OEMs could duplicate this effort, it’s highly unlikely that they will do so, either from a lack of expertise or a desire to keep the netbook costs down. It’s unlikely any convertible netbooks are using this technique, which means they won’t do inking well at all.

Convertible netbooks are probably going to start appearing in greater numbers as they seem to be a hot item with those who follow the netbook space. Having a netbook that can work as a laptop and also as a handheld slate is pretty useful. They make for good web tablets operated by touch when in slate mode. Just remember that touch operation is generally as far as it goes. Don’t expect the ability to write notes on the screen or you’ll likely just be disappointed.

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