Optically imaging stylus for interacting with substrate having imageable position-coding pattern

Abstract

An optically imaging stylus for interacting with a substrate having an imageable position-coding pattern identifying a plurality of locations on the substrate. The stylus includes: a nib; an image sensor; and a processor configured for: (i) inferring a perspective transform using perspective-distorted features of the imaged position-coding pattern; (ii) determining a rotational orientation of the stylus relative to the position-coding pattern; (iii) acquiring and decoding coded data contained in the imaged position-coding pattern, the decoded coded data identifying an imaged location on the substrate; (iv) calculating a nib position using: the imaged location, the perspective transform and the determined rotational orientation, the nib position being different than the imaged location; and (v) generating digital ink identifying the nib position.

1 . An optically imaging stylus for interacting with a substrate having an imageable position-coding pattern, said position-coding pattern identifying a plurality of locations on the substrate, said stylus comprising:
 a stylus body;   
       a nib for interacting with the substrate; 
       an image sensor for imaging an area of the position-coding pattern; and 
       a processor configured for: 
       (i) inferring a perspective transform using perspective-distorted features of the imaged position-coding pattern, said features being perspective-distorted due to a tilt of the stylus; 
       (ii) determining, from the imaged position-coding pattern, a rotational orientation of the stylus relative to the position-coding pattern; 
       (iii) acquiring and decoding coded data contained in the imaged position-coding pattern, the decoded coded data identifying an imaged location on the substrate; 
       (iv) calculating a nib position using: the imaged location, the perspective transform and the determined rotational orientation, said nib position being different than the imaged location; and 
       (v) generating digital ink identifying the nib position. 
     
     
         2 . The optically imaging stylus of  claim 1 , further comprising a force sensor for detecting a nib force. 
     
     
         3 . The optically imaging stylus of  claim 2 , wherein the processor is configured to interpret said nib force as an indication of contact between the nib and the substrate. 
     
     
         4 . The optically imaging stylus of  claim 1 , wherein said stylus contains a unique identity. 
     
     
         5 . The optically imaging stylus of  claim 1 , wherein said digital ink comprises a plurality of nib positions representing handwritten input on the substrate. 
     
     
         6 . The optically imaging stylus of  claim 1 , wherein said image sensor is offset from said nib. 
     
     
         7 . The optically imaging stylus of  claim 1 , further comprising a transceiver for communicating the digital ink to a computer system, such that the computer system can interpret the digital ink and perform an action in response to the interaction with the substrate. 
     
     
         8 . The optically imaging stylus of  claim 1 , wherein said nib is a non-marking stylus nib. 
     
     
         9 . The optically imaging of  claim 1 , wherein said image sensor comprises an infrared filter. 
     
     
         10 . An imaging system comprising:
 a substrate having an imageable position-coding, said position-coding pattern identifying a plurality of locations on the substrate; and
 an optically imaging stylus for interacting with the substrate, said stylus comprising: 
   
       a nib for interacting with the substrate; 
       an image sensor for imaging an area of the position-coding pattern; and 
       a processor configured for: 
       (i) inferring a perspective transform using perspective-distorted features of the imaged position-coding pattern due to a tilt of the stylus; 
       (ii) determining from the imaged position-coding pattern a rotational orientation of the stylus relative to the position-coding pattern; 
       (iii) acquiring and decoding coded data contained in the imaged position-coding pattern, the decoded coded data identifying an imaged location on the substrate; 
       (iv) calculating a nib position using: the imaged location, the perspective transform and the determined rotational orientation, said nib position being different than the imaged location; and 
       (v) generating digital ink identifying the nib position. 
     
     
         11 . The imaging system of  claim 10 , wherein the position-coding pattern is printed on the substrate. 
     
     
         12 . The imaging system of  claim 11 , wherein the position-coding pattern is printed with an infrared absorbing ink. 
     
     
         13 . The imaging system of  claim 10 , wherein the stylus further comprises a force sensor for detecting a nib force. 
     
     
         14 . The imaging system of  claim 13 , wherein the processor is configured to interpret said nib force as an indication of contact between said nib and said substrate. 
     
     
         15 . The imaging system of  claim 10 , wherein said stylus contains a unique identity. 
     
     
         16 . The imaging system of  claim 10 , wherein said digital ink comprises a plurality of nib positions representing handwritten input on the substrate. 
     
     
         17 . The imaging system of  claim 10 , wherein said image sensor is offset from said nib. 
     
     
         18 . The imaging system of  claim 10 , wherein said stylus further comprises a transceiver for communicating the digital ink to a computer system, such that the computer system can interpret the digital ink and perform an action in response to the interaction with the substrate.