Patent ID: 7936343

Claim:
A sensing device for sensing a position relative to a surface, the surface having coded data in a machine readable form and visible information for unaided human interpretation, the coded data having an array of separate data portions, each of the data portions respectively encoding data indicative of a position of the data portion on the surface, a plurality of the data portions encoding data indicative of respective positions in a region of the surface, the region being at least partially coincident with the visible information, the sensing device including: a retractable nib for interacting with the surface; a retraction mechanism for slidably retracting and extending the nib relative to a housing of the sensing device; a force sensor coupled to the retractable nib, said force sensor sensing a nib force applied to the surface by the nib; an image sensor and processor configured for: sensing at least one of the data portions when placed in an operative position relative to the surface; determining if the sensed data portion is within the region; determining if the sensed data portion contains control data indicating the sensing device to capture continuous nib force readings; generating, using the sensed data portion, digital ink at least partially indicative of: a position of the nib relative to the surface; an orientation of the sensing device relative to the data portion; generating force data as continuous nib force readings only if the sensed data portion contains said control data; and a communicator configured to communicate the digital ink and the force data to a computer system, wherein said image sensor generates said digital ink only when said sensed nib force exceeds a predetermined threshold.