A digital pen is a battery-operated writing instrument that allows the user to digitally capture a handwritten note or drawing. Typically, a digital pen comes with a Universal Serial Bus (USB) cradle to let the user upload the handwritten notes to a personal computer (PC). The pen looks like a regular ball-point pen and can be used as such, but requires special digital paper if the user wishes to digitally capture what he has written. A page of digital paper, which can be purchased in traditional pad or sticky-note size, has small dots on it that allow the pen to "see" what has been written.
Here's how it works: When the user is done writing on his digital paper, he puts a checkmark in the "save" box. The pen vibrates or beeps to confirm that it knows the box has been checked and that the user is done with that page and wishes to save it. Typically, a digital pen can store up to 40 pages of saved digital paper in its memory. Only pages that have been checked will be saved. Most pens save the handwritten data as an image file (GIF or JPEG, depending on the pen's manufacurer) although some digital pens use a proprietary file format. When the user wants to upload his saved notes from the pen, he docks the pen in its USB cradle. The cradle automatically senses the pen's presence, opens the accompanying software application on the user's PC, and transfers the saved files to a specified folder.
Many digital pens come with handwriting recognition software that allows the user to import their handwritten notes into typed text. Some of the newer high-end digital pens are wireless, taking advantage of Bluetooth technology. These pens do not require a docking station, but instead send the captured notes or drawings directly the the user's PC or cell phone.