Patent ID: 7451115

Claim:
A method of enabling payment of bills, said method comprising the steps of: providing a bill containing: (A) information relating to a requested payment; and (B) coded data printed as a collection of tags, each tag identifying: (i) an identity of the bill, and (ii) a location of the tag on the bill; interacting with a zone of the bill using an optically imaging pen, said pen comprising an image sensor, a processor and a nib; capturing, using the image sensor, an image of a tag within the zone; computing, in the processor, the position of the nib on the bill using: (i) the tag location identified in the imaged tag, (ii) an observed perspective distortion on the imaged tag, and (iii) a known spatial relationship between the pen's physical axis containing the nib and the pen's optical axis containing the image sensor, said axes being different from each other; transmitting indicating data from the pen to a computer system, said indicating data being indicative of the identity of the bill and a position of the nib relative to the bill; and identifying, in the computer system, at least one parameter relating to a requested payment associated with said zone, using the indicating data and a map of the bill maintained in the computer system.