Digital pen

A digital pen is an input device that turns handwritten or drawn strokes into digital data, which can then be used in different software applications. It works alongside a graphics tablet, tablet computer, smartphone, or digital notebook. Once the handwriting is captured and digitized, the result can appear on a screen.

Common protocols for digital pens include Microsoft Pen Protocol (MPP, formerly N-trig), Wacom AES 1.0 and 2.0, Wacom EMR, Universal Stylus Initiative (USI), Apple Pencil Active Projected Capacitive (APC), and Bluetooth. Examples of such pens are the Microsoft Surface Pen (MPP), Samsung S Pen (Wacom EMR), Google Pixelbook Pen (Wacom AES), and Apple Pencil (APC).

Active

Digital pens fall into several technology groups. Active pens, like N-trig's DuoSense Pen, contain electronic components whose signals are picked up by a device's built-in digitizer and sent to its controller, relaying data on location, pressure, button presses, and other functions. Active Electrostatic (AES) pens are battery-powered styluses that actively communicate with a touchscreen by emitting a weak electrical signal detected by the digitizer, offering high precision.

Positional

Position-based pens detect the tip's location during writing. Some models appear on graphics tablets from Wacom and on tablet computers using Wacom's Penabled technology. Electromagnetic Resonance (EMR) pens contain a circuit that resonates with the tablet's digitizer.

Camera

Accelerometer-based pens detect movement and contact with the writing surface. Camera-based pens use special digital paper to detect where the stylus touches, as seen in NeoLAB or Anoto technology. Trackball pens use a sensor on the pen to detect the motion of a trackball.

Smart pen

A smart pen shares the basic traits of a digital pen but adds features like voice recording or a text scanner. It is generally larger and more feature-rich than an active pen. Digital pens usually have internal electronics, touch sensitivity, input buttons, memory for storing handwriting data, and transmission capabilities. Smartphone pens have become a popular tool for note-taking, drawing, or creating digital art on a device.