The invention provides for an optical imaging pen configured to capture and decode infrared (IR) position tags from a page. The pen includes a force sensor photodiode configured to sense when a nib of the pen is in contact with the page, and an LED configured to project IR radiation onto a portion of the page when the nib is in contact therewith. The pen also includes an image sensor configured to image the portion of the page when the nib is in contact therewith by receiving reflected IR radiation, and at least one orthogonal accelerometer configured to sense motion of the pen by sensing acceleration in x and y directions and integrating with respect to time to produce an instantaneous velocity. The pen further includes a controller arranged in signal communication with the accelerometer, photodiode and image sensor, said controller configured to control the photodiode and image sensor to capture, decode and encrypt the tags into digital ink data, and to include the instantaneous velocity of the pen into the digital ink data.