Electronic pen and method for recording of handwritten information

Abstract

An electronic pen for recording of handwritten or hand-drawn information has a control unit and a memory. The control unit registers pen movements across at least one base, stores a plurality of digital pen strokes in the memory as a function of said movements, and supplies a set of the digital pen strokes for processing. The digital pen strokes include a first type, which is processed as graphical information constituting the information to be recorded, and a second type, which is processed as instructions for the processing of digital pen strokes of the first type. The electronic pen also has session-determining means adapted to detect a current working session of the pen. The control unit indicates, for the processing of the set of digital pen strokes, the working session during which the respective digital pen strokes have been input.

1 . (canceled) 
   
   
       2 . An electronic pen for recording of handwritten or hand-drawn information, comprising:
 a memory; and   a control unit configured to register pen movements across at least one base during a plurality of unique working sessions formed sequentially in time, and to store the registered pen movements as a plurality of digital pen strokes in the memory;   wherein the control unit is further configured to
 detect a current working session of the pen for each digital pen stroke in the plurality of digital pen strokes, wherein the control unit is operable to detect the same current working session for more than one of the digital pen strokes; and 
 store session information in the memory identifying the current working session for said each digital pen stroke. 
   
   
   
       3 . The electronic pen as claimed in  claim 2 , wherein the control unit is configured to generate the session information each time one of said working sessions is initiated. 
   
   
       4 . The electronic pen as claimed in  claim 3 , further comprising a session counter which is stored in the memory, and wherein the control unit is configured to increment the session counter each time one of said plurality of working sessions is initiated. 
   
   
       5 . The electronic pen as claimed in  claim 4 , wherein said session information comprises a current value of the session counter. 
   
   
       6 . The electronic pen as claimed in  claim 4 , wherein the control unit is configured to store each digital pen stroke in association with a respective current value of the session counter. 
   
   
       7 . The electronic pen as claimed in  claim 2 , further comprising a timer configured to generate a sequence of time values, wherein the control unit is further configured to store each pen stroke in association with a respective time value. 
   
   
       8 . The electronic pen as claimed in  claim 7 , wherein the session information comprises a time value derived from the timer by the control unit each time one of the plurality of working sessions is initiated. 
   
   
       9 . The electronic pen as claimed in  claim 2 , further comprising a session-determining module which is connected to the control unit and configured to detect an initiation of each of the plurality of working sessions. 
   
   
       10 . The electronic pen as claimed in  claim 9 , wherein the session-determining module comprises a mechanical, optical, electrical or magnetic switch. 
   
   
       11 . The electronic pen as claimed in  claim 10 , further comprising a pen body and a protective cap, said switch being placed so as to detect that the protective cap is removed from the pen body. 
   
   
       12 . The electronic pen as claimed in  claim 2 , wherein the control unit is further configured to select a set of digital pen strokes in the memory based on the session information, and supply the selected set of digital pen strokes for processing. 
   
   
       12 . The electronic pen as claimed in  claim 12 , wherein the control unit is further configured to supply the session information of the selected set of digital pen strokes. 
   
   
       14 . The electronic pen as claimed in  claim 2 , wherein the plurality of digital pen strokes is one of a first type, which is processed as graphical information, and a second type, which are processed as instructions for processing the digital pen strokes of the first type, and wherein the control unit is configured to supply a first set of digital pen strokes of the first type, and to supply a second set of digital pen strokes of the second type, wherein the control unit is configured to identify a set of relevant working sessions based on the session information associated with the first set of digital pen strokes, and to select the second set of digital pen strokes based of the session information associated with first set of digital pen strokes. 
   
   
       15 . The electronic pen as claimed in  claim 14 , wherein the second set of digital pen strokes is selected to originate from the same working session(s) as the first set of digital pen strokes. 
   
   
       16 . The electronic pen as claimed in  claim 14 , wherein the control unit is further configured to supply the session information of the first and second sets of digital pen strokes. 
   
   
       17 . The electronic pen as claimed in  claim 14 , wherein the control unit is further configured to register the digital pen strokes of said first type from a first base, and register digital pen strokes of said second type from a second base. 
   
   
       18 . The electronic pen as claimed in  claim 17 , in which said base comprises a position-coding pattern. 
   
   
       19 . The electronic pen as claimed in  claim 14 , in which said second type of digital pen strokes represents at least one property of said first type of digital pen strokes. 
   
   
       20 . The electronic pen as claimed in  claim 19 , wherein said property includes at least one of the following: a visual graphic property; temporal or spatial resolution for the digital pen strokes; a background for the digital pen strokes; a context to which the pen or its user belongs; and an indication of restricted access to the digital pen strokes. 
   
   
       21 . The electronic pen as claimed in  claim 14 , in which said second type of digital pen strokes represents at least one command for affecting an interpretation of the digital pen strokes of said first type. 
   
   
       22 . The electronic pen as defined in  claim 21 , wherein said interpretation of the digital pen strokes of said first type includes character recognition and wherein said command serves to interpret one or more of the digital pen strokes as a text, a sequence of characters, a sequence of digits, a sequence of upper-case characters, a sequence of lower-case characters, or an address for electronic communication. 
   
   
       23 . The electronic pen as defined in  claim 21 , wherein said interpretation of the digital pen strokes of said first type includes geometrical object recognition and wherein said command serves to interpret one or more of the digital pen strokes as an ideal geometrical shape. 
   
   
       24 . The electronic pen as defined in  claim 21 , wherein said interpretation of the digital pen strokes of said first type includes character recognition and wherein said command serves to define a page format parameter such as page break, page column or page margin. 
   
   
       25 . The electronic pen as claimed in  claim 12 , further comprising a transmitter for communication with a remote processing device, wherein the control unit is configured to supply the selected set of digital pen strokes to said remote processing device for processing therein. 
   
   
       26 . The electronic pen as claimed in  claim 2 , wherein the control unit is configured to process the selected set of digital pen strokes. 
   
   
       27 . The electronic pen as defined in  claim 2 , wherein the plurality of digital pen strokes is one of a first type, which is processed as graphical information, and a second type, which represents at least one property of the digital pen strokes of the first type, each digital pen stroke being associated with a respective time value, wherein the control unit is further configured to identify a set of relevant working sessions based on the session information associated with a selected first set of digital pen strokes of the first type, and to select a second set of digital pen strokes of the second type based of the session information associated with the selected first set, and wherein the control unit is further configured to assign said at least one property to the digital pen strokes in the selected first set, based on the time values of the digital pen strokes in the selected first and second sets, and wherein the control unit is further configured, based on said session information, to detect that a certain digital pen stroke is indicated as having been input during a different working session than a preceding digital pen stroke and, as a consequence of this, to restore the property for successive digital pen strokes of the first type to an initial or default state. 
   
   
       28 . The electronic pen as defined in  claim 2 , which is de-activated between said working sessions. 
   
   
       29 . A method, in an electronic pen, for recording of handwritten or hand-drawn information, said method comprising:
 registering pen movements across at least one base during a plurality of unique working sessions formed sequentially in time,   storing the registered pen movements as a plurality of digital pen strokes in a memory of the electronic pen;   detecting a current working session of the electronic pen for each digital pen stroke in the plurality of digital pen strokes, wherein the same current working session may be detected for more than one of the digital pen strokes; and   storing session information in the memory identifying the current working session for said each digital pen stroke.   
   
   
       30 . A computer-readable medium storing a set of instructions which, when executed by a processor in an electronic pen, performs a method for recording of handwritten or hand-drawn information, said method comprising:
 registering pen movements across at least one base during a plurality of unique working sessions formed sequentially in time,   storing the registered pen movements as a plurality of digital pen strokes in a memory of the electronic pen;   detecting a current working session of the electronic pen for each digital pen stroke in the plurality of digital pen strokes, wherein the same current working session may be detected for more than one of the digital pen strokes; and   storing session information in the memory identifying the current working session for said each digital pen stroke.