Thursday, March 27, 2008

Different types of screens on a Tablet PC

If you're thinking about moving to a paperless system, you're probably considering a tablet PC. Make sure you know about the types of screens that are currently available for these computers, since this may affect your purchasing decision.

  1. Active digitizer (may be referred to as "Wacom or Penabled digitizer") - these types of screens require a special type of electromagnetic 'pen' for screen input. They will not respond to touch. Most of the pens are made by Wacom and they have buttons to various mouse clicks and eraser functions. Furthermore, some pens have an 'eraser' so that you can erase your digital writing on the screen. Active digitizer screens are pressure-sensitive, so you can draw a light or dark line depending on how hard you press. You can also hover the pen over the screen and move the mouse around. Handwriting recognition is most accurate if you're using an active digitizer. Be warned: replacing a pen can cost between $20 to over $50, so make sure you don't lose any pens. You need the pen for screen input, so you'll want to have a spare.
  2. Passive digitizer (also referred to as a "touch screen") - these screens can be activated by the touch of a finger, fingernail, or any plastic 'pen.' Hence, they do not require any special pens. If you happen to lose or misplace your pen, you can use anything to write on the screen. Just make sure you don't scratch the screen. Most screens are very touch sensitive, so if you rest your hand on the screen, that may disrupt your pen input signals. The result is called 'vectoring' - and you will end up with unintended lines all over the place because of the mixed pen/hand signals. Fujitsu has some touch screen tablets that require extra pressure for touch input. These screens are not as touch-sensitive as other devices. The result becomes less (or practically no) vectoring problems. However, you won't be able to input using your soft fingerpads, so grab a plastic pen or use your fingernails and risk scratching the screen.
  3. MultiTouch (not to be confused with Apple's MultiTouch) - these screens combine an active digitizer with a passive digitizer. You essentially get the best of both worlds. When the screen detects the active pen is working, then touch becomes disabled and you get no vectoring. If the pen is not used, then the screen becomes a passive digitizer so that you can tap on the screen and use your fingers to input. Apple's MultiTouch allows you to use two fingers on the surface simultaneously. It's just a matter of time before this feature is available for Tablet PCs.
So what's the best option for healthcare? MultiTouch offers the best of both worlds, so you can switch between active vs. passive digitizer modes. However, MultiTouch devices are generally significantly more expensive. For professional healthcare use, I would strongly recommend a MultiTouch because you don't want to be in a position when you're unable to input data because you left your active pen in another room. Avoid Passive Digitizers (unless you get a Fujitsu) if you plan to use the tablet with a pen. You don't want to deal with the frustrating problems associated with vectoring. Most full-size tablets use an Active Digitizer or MultiTouch. True touch-screen devices are generally only found on GPS devices, PDAs/Smartphones, UMPCs, or really tiny tablets.

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