Abstract:
An information management system comprises a coordinate acquiring device for specifying a position on a paper sheet and a content server for storing data. The content server stores document data, event data, and stroke information. When the coordinate acquiring device specifies the position of the stoke information on the paper sheet concerning the document data, the content server retrieves event data relevant to the stroke information corresponding to the specified position, judges whether or not the user who has specified the position of the stroke information can read the retrieved event data, and transmits the event data if the user is judged to be able to read the event data.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to an information management system for managing a document or the like, and more particularly, to a technology for managing access to a document under management. 
       BACKGROUND OF THE INVENTION 
       [0002]    In recent years, as a result of advancement of a digital technology, it has become possible to digitize hand-written information written on paper with ease. 
         [0003]    Currently, a computer manages only an electronic document obtained by digitizing a paper document. Under this condition, hand-written information wrote to the paper document is not managed digitally, which makes it impossible to effectively use the hand-written information. 
         [0004]    As a technology for solving this problem, there is known an electronic meeting system disclosed in JP 2000-092048 A. In the electronic meeting system disclosed in JP 2000-092048 A, management of a meeting material converted into electronic data and preparation work necessary for holding a meeting are semiautomatically performed. To this end, the technology includes the steps of: registering a meeting material in a meeting server before a meeting starts and automatically creating an attribute file of the meeting material; managing the meeting material; automatically creating a meeting index based on information extracted from the attribute file; automatically distributing the material and the meeting index to every participant&#39;s terminal before the meeting starts; converting a memo inputted through a keyboard during the meeting into a minutes format and creating the minutes; creating a list of contents registered in the meeting server; and automatically distributing an added material to every participant&#39;s terminal. Accordingly, it is possible to semiautomatically perform the management of the electronized meeting material and the preparation work necessary for holding a meeting such as the creation of the meeting index and the automatic distribution of the meeting material. 
         [0005]    In addition, in a customer management system disclosed in JP 07-334570 A, a barcode or a customer code, which can be mechanically read by an OCR or the like, is previously printed on an application form to be issued and distributed based on a customer master. Then, by using the application form returned from a person who wishes to attend, the customer code is mechanically read to be obtained by an automatic data entry device using an optical reading method, a method of extracting the customer code by software from a facsimile reception signal, or the like. After that, the application of the customer is registered in the customer master. At the time of attendance, the customer code is mechanically read from a participant card, and is received/registered. Therefore, the registration can be processed speedily and mechanically, so the issuing of the participant card and a meeting schedule list useful for reservation of a hall, processing of analyzing the participant, or the like can be performed timely based on the registered customer master. Accordingly, it is possible to speedily perform the registration of application for the attendance reservation at the meeting such as a seminar and the reception register processing at the time of the attendance. 
         [0006]    Also, a pen-type input device (digital pen) that digitally obtains a path of a pen tip is put to practical use. The digital pen inputs the obtained pen tip path into a computer. Examples of the digital pen include the “Anoto pen” developed by Anoto AB in Sweden. Details of the digital pen are described in WO 01/71473 A1. The digital pen has an advantage in that it is possible even for a user who is not used to using a keyboard or a mouse to use the pen easily, and is therefore expected to be applied to application tasks in an electronic government and other fields. 
       SUMMARY OF THE INVENTION 
       [0007]    In the related technologies described above, in a case where a plurality of users participate in any one of a plurality of meetings that are being held simultaneously, it has been unable to find out which meeting each of the users have participated in. Therefore, it is difficult to determine which video information each user&#39;s handwritten memo should be linked to. 
         [0008]    When each user&#39;s handwritten memo is made public widely, any person can access the video information linked to the handwritten memo. However, it may be necessary to place a limitation on those who can view the information depending on the importance of the information. Therefore, it becomes necessary to set access limitations (securities) for the link information includes in the handwritten memo and for the video information, for instance, to permit only a specific user to access the video information from the handwritten memo. 
         [0009]    When the user writes a memo in correspondence with a given scene and topic, the writing of the memo often lags behind the scene. Therefore, it is necessary to set a link to an appropriate position of a video related to the memo even in a case where an write time period of the memo becomes out of synchronization. 
         [0010]    Further, it is necessary to link a handwritten memo to the corresponding position (scene) of a video even in a case where a viewed video is not continuously played back due to pausing or fast-forwarding thereof. 
         [0011]    An information management system according to one embodiment of this invention includes: a coordinate pointing device for identifying a location on a paper medium; and a content server for storing data, the content server storing document data used for the event, event data, and stroke information, the stroke information including coordinates of the location identified by the coordinate pointing device and a time at which the location is identified. In the information management system, the content server is configured to: retrieve, when the coordinate pointing device identifies the location of the stroke information, the event data related to the stroke information corresponding to the identified location; judge whether or not the user who has created the stroke information is allowed to view the retrieved event data; and transmit the event data in a case where the identified user is allowed to view the event data as a result of the judgment. 
         [0012]    Further, the content server is configured to: identify the coordinate pointing device which has identified the location related to the stroke information based on the stroke information; identify the user who operated the identified coordinate pointing device when the stroke information was generated; and judge whether or not the identified user is allowed to view the retrieved event data based on security information set for the user who operated the identified coordinate pointing device and security information set for the event data. 
         [0013]    Further, the content server is configured to: compare the coordinate pointing device which has generated the stroke information and the coordinate pointing device which has designated the location related to the stroke information; judge, when the two coordinate pointing devices are identical, whether or not the identified user is allowed to view the retrieved event data based on the security information set for the user who operated the coordinate pointing device and the security information set for the event data; and judge, when the two coordinate pointing devices are mutually different, whether or not the identified user is allowed to view the retrieved event data without using at least one of the security information set for the user who operated the coordinate pointing device and the security information set for the event data. 
         [0014]    Further, the content server is configured to: identify a stroke set generated during a time period having an overlap with a generation time period for the identified stroke information; identify the stroke information that has started to be written first out of identified stroke sets generated during the time period having an overlap; and transmit the event data corresponding to the time at which the identified first stroke information was generated. 
         [0015]    According to this invention, it is possible to effectively use the event data associated with the handwritten information while setting a security for each user. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a conceptual drawing illustrating a process of a document management system according to embodiments of this invention. 
           [0017]      FIG. 2  is a block diagram of a configuration of the document management system according to a first embodiment of this invention. 
           [0018]      FIG. 3  is a block diagram of a content server according to the first embodiment. 
           [0019]      FIG. 4  is a block diagram of an information terminal according to the first embodiment. 
           [0020]      FIG. 5  is a block diagram of a event information input device according to the first embodiment. 
           [0021]      FIG. 6  is a diagram of a configuration of event information stored in the content server according to the first embodiment. 
           [0022]      FIG. 7  is a diagram of a configuration of media view information stored in the content server according to the first embodiment. 
           [0023]      FIG. 8A  is a diagram of a configuration of distributed material information stored in the content server according to the first embodiment. 
           [0024]      FIG. 8B  is a diagram of a configuration of handwritten memo-related information stored in the content server according to the first embodiment. 
           [0025]      FIG. 9  is an explanatory diagram of obtainment of coordinates on paper by a digital pen according to the first embodiment. 
           [0026]      FIG. 10  is an explanatory diagram of a document registered in the content server according to the first embodiment. 
           [0027]      FIG. 11  is an explanatory diagram of the document on which information has been written with the digital pen according to the first embodiment. 
           [0028]      FIG. 12A  shows an example of a stroke set according to the first embodiment. 
           [0029]      FIG. 12B  is a diagram of a configuration of stroke set information stored in the content server according to the first embodiment. 
           [0030]      FIG. 12C  is a diagram of a configuration of stroke coordinate information stored in the content server according to the first embodiment. 
           [0031]      FIG. 13  is a diagram of a configuration of user information stored in the content server according to the first embodiment. 
           [0032]      FIG. 14  is a flowchart of written-data accumulating processing according to the first embodiment. 
           [0033]      FIG. 15  is a flowchart of processing of generating a link set from a handwritten memo to each type of information obtained during the meeting according to the first embodiment. 
           [0034]      FIG. 16  is a flowchart of processing of determining time information of the stroke set according to the first embodiment. 
           [0035]      FIG. 17  is a flowchart of processing of retrieving various kinds of information obtained during the meeting based on a handwritten memo according to the first embodiment. 
           [0036]      FIG. 18  is an explanatory diagram of a content viewer according to the first embodiment. 
           [0037]      FIG. 19  is a flowchart of written-data accumulating processing according to a second embodiment of this invention. 
           [0038]      FIG. 20  is an explanatory diagram of a meeting attendance form according to the second embodiment. 
           [0039]      FIG. 21  is a flowchart of written-data accumulating processing according to a third embodiment of this invention. 
           [0040]      FIG. 22  is a flowchart of written-data accumulating processing according to a fourth embodiment of this invention. 
           [0041]      FIG. 23  is an explanatory diagram of a meeting attendance form according to the fourth embodiment. 
           [0042]      FIG. 24  is a flowchart of processing of retrieving various kinds of information obtained during the meeting based on a handwritten memo according to a fifth embodiment of this invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0043]    Description will be made of embodiments of this invention with reference to the drawings. 
         [0044]      FIG. 1  is a conceptual drawing illustrating processing of a document management system according to embodiments of this invention. 
         [0045]    First, processing of an information accumulation phase will be described. The information accumulation phase is executed mainly during a meeting, and causes a content server to accumulate information involved in the meeting. 
         [0046]    At the start of an event (e.g., meeting), a camera set in a meeting room starts to record a video of the event. The content server acquires through a network the video of the event taken by the camera, and stores the video of the event ( 1 ). An attendant (user of a digital pen) at the meeting uses the digital pen to write a memo or the like related to contents of the meeting on a distributed material (or one&#39;s own notebook) during the meeting ( 1 ′). 
         [0047]    The digital pen establishes a connection with an information terminal used by the user, and transfers stroke information written during the meeting to the information terminal ( 2 ). It should be noted that the transfer of the stroke information from the digital pen to the information terminal may be performed after the meeting, instead of during the meeting. 
         [0048]    Upon reception of the stroke information from the digital pen, the information terminal transmits the stroke information to the content server. The content server accumulates stroke information in handwritten characters ( 3 ). 
         [0049]    Second, processing of an information access phase will be described. The information access phase is executed after the meeting, and causes the content server to provide the user with information necessary for the user. 
         [0050]    After the meeting, by using the digital pen, the user selects the handwritten memo on the distributed material (or on one&#39;s own notebook) to thereby request electronic information related to the handwritten memo ( 4 ). The digital pen establishes a connection with the information terminal used by the user, and transfers a location of the selected handwritten memo (location designated by the user with the digital pen) to the information terminal. 
         [0051]    The information terminal transmits the location selected by the user with the digital pen to the content server to request retrieval of the handwritten memo at the designated location ( 5 ). 
         [0052]    Upon reception of the request for the retrieval of the handwritten memo, the content server retrieves the electronic information related to the handwritten memo (e.g., video recorded during the event) with a writer and write time of the handwritten memo as search keys ( 6 ). It may be judged at the same time whether or not the user who has requested the electronic information has a right to view the retrieved electronic information. 
         [0053]    Then, the content server transmits the retrieved video to the requesting source information terminal ( 7 ). 
         [0054]    After that, the information terminal displays the electronic information transmitted from the content server. 
         [0055]    According to this invention, the user can obtain the electronic information related to the handwritten memo by selecting the handwritten memo. 
       First Embodiment 
       [0056]      FIG. 2  is a block diagram of a document management system according to a first embodiment of this invention. 
         [0057]    The document management system comprises a content server  11 , information terminals  12 , digital pens  14 , an event information input device  15 , a network  17 , and a location information server  19 . 
         [0058]    The content server  11 , the information terminals  12 , the event information input device  15 , and the location information server  19  are connected to one another through the network  17 . Each of the information terminals  12  is connected to one or more digital pens  14 . The information terminals  12  and the digital pens  14  may be connected by a wire using a universal serial bus (USB) protocol or the like. Alternatively, the information terminals  12  and the digital pens  14  may be connected wirelessly using Bluetooth, a wireless LAN, a mobile telephone system, infrared rays, or the like. 
         [0059]    The content server  11  manages contents for each event, and transmits requested contents to the information terminal  12 . It should be noted that the contents include a document, audio, and video related to an event. The document represents all of information printed and displayed on a paper medium. 
         [0060]    The information terminal  12  is a computer device used by each person, and transfers information received from the digital pen  14  to the content server  11 . The information terminal  12  also displays the information received from the content server  11 . 
         [0061]    As in the case of an ordinary pen, with the digital pen  14 , it is possible to write characters, figures, and the like on a paper medium. Also, the digital pen  14  comprises a micro-camera at its tip end and obtains a dot pattern of a position on the paper that comes into contact therewith. Further, the digital pen  14  holds a pen ID set in advance. The digital pen  14  further comprises a communication interface for connection with the information terminal  12  in a wired or wireless manner. 
         [0062]    For instance, as shown in  FIG. 9 , the digital pen  14  obtains dot pattern information printed on a document. Thus, it is possible to identify coordinates on the paper from the dot pattern information obtained by the digital pen  14 . 
         [0063]    Further, the digital pen  14  may transmit, through a mobile telephone system or a wireless LAN system instead of the information terminal  12 , the identified absolute coordinates, a time at which the dot pattern has been obtained, and the pen ID directly to the content server  11 . 
         [0064]    The event information input device  15  is a computer device set in the meeting room, and creates information (e.g., video, image, audio, and/or slide) related to an event. The event information input device  15  also registers the contents including the document and the created video in the content server  11  in association with the event. 
         [0065]    In addition, the event information input device  15  may establish a connection with the digital pen  14  during the meeting, obtain information such as absolute coordinates identified by the digital pen  14 , and transmit the obtained information to the content server  11 . 
         [0066]    The location information server  19  is a computer device including a CPU, a memory, and a storage device, and holds a database in which the coordinates on a paper medium are associated with an amount by which a dot pattern of the paper medium is displaced from a reference point. Based on the dot pattern of the paper medium, the location information server  19  also provides the coordinates on the paper medium. 
         [0067]    It should be noted that the document management system of this embodiment may be equipped with a printer. In response to an instruction sent from the information terminal  12 , the printer prints the content such as a document. 
         [0068]      FIG. 3  is a block diagram of the content server  11  according to the first embodiment of this invention. 
         [0069]    The content server  11  comprises a CPU  111 , a memory  112 , a storage device  113 , and a data communication unit  118 . 
         [0070]    The CPU  111  performs various kinds of processing by invoking and executing various kinds of programs stored in the storage device  113 . 
         [0071]    The memory  112  has a work area in which data used by the CPU  111  in the various kinds of processing is stored temporarily. 
         [0072]    The storage device  113  is constituted by a nonvolatile storage medium (e.g., magnetic disk drive). The storage device  113  stores an event management program  114 , a document management program  115 , a pen data management program  116 , and a user management program  117 . Those programs are loaded into the memory  112 , and are then executed by the CPU  111 , thereby performing the various kinds of processing. 
         [0073]    The storage device  113  stores event information  21 , media view information  28 , document information  22  and  23 , stroke information  24 , and user information  27 . 
         [0074]    The event management program  114  manages information including the event information  21  (shown in  FIG. 6 ) and the media view information  28  (shown in  FIG. 7 ). The document management program  115  manages the document information  22  and  23  (shown in  FIGS. 8A and 8B , respectively). The stroke set management program  116  manages the stroke information  24  (shown in  FIG. 12B ). The user management program  117  manages the user information  27  (shown in  FIG. 13 ). 
         [0075]    The data communication unit  118  is network interface. The network interface is a LAN card that is capable of performing communication using a TCP/IP protocol, for instance. The content server  11  is capable of communicating with a device connected to the network  17 , such as the information terminal  12 . 
         [0076]      FIG. 4  is a block diagram of the information terminal  12  according to the first embodiment of this invention. 
         [0077]    The information terminal  12  comprises a CPU  121 , a memory  122 , a pen data input unit  123 , an operation input unit  124 , a data display unit  125 , and a data communication unit  126 . 
         [0078]    The CPU  121  invokes and executes various programs stored in a storage device (not shown), thereby performing various kinds of processing. 
         [0079]    The memory  122  has a work area in which data used by the CPU  121  in the various kinds of processing is stored temporarily. Also, the memory  122  temporarily stores data sent from the content server  11 , the digital pen  14 , and the like. 
         [0080]    The pen data input unit  123  communicates with the digital pen  14  in a wired manner or a wireless manner and collects information on coordinates and the like obtained by the digital pen  14 . 
         [0081]    The operation input unit  124  is a keyboard, for instance, and is used by a user to input information. 
         [0082]    The data display unit  125  is composed of a liquid crystal display, for instance, and displays contents such as a document obtained from the content server  11 . 
         [0083]    The data communication unit  126  is a network interface such as a LAN card that is capable of performing communication using a TCP/IP protocol. With this construction, it becomes possible for the information terminal  12  to communicate with the content server  11  through the network  17 . 
         [0084]    It should be noted that the pen data input unit  123  and the data communication unit  126  may be a single interface. 
         [0085]      FIG. 5  is a block diagram of the event information input device  15  according to the first embodiment. 
         [0086]    The event information input device  15  comprises a CPU  151 , a memory  152 , an operation recording unit  153 , a video input unit  154 , an audio input unit  155 , a data display unit  156 , a pen data input unit  157 , a signature authentication unit  158 , a signature database (DB)  158 A, and a data communication unit  159 . 
         [0087]    The CPU  151  invokes and executes various programs stored in a storage device (not shown), thereby performing various kinds of processing. 
         [0088]    The memory  152  has a work area in which data used by the CPU  151  in the various kinds of processing is stored temporarily. Also, the memory  152  temporarily stores data sent from the content server  11 , the digital pen  14 , and the like. 
         [0089]    The operation recording unit  153  records an operation performed with respect to the document management system during the meeting. Examples of the recorded operation include an operation (operation such as rewind or fast forward for a video used during the meeting) performed on a keyboard by a presenter. 
         [0090]    The video input unit  154  collects video data taken during the meeting by the camera set in the meeting room. 
         [0091]    The audio input unit  155  collects audio data recorded during the meeting by a microphone set in the meeting room. 
         [0092]    The data display unit  156  is constituted by a large-screen display device such as a projector set in the meeting room, and displays data used during the meeting. Examples of the displayed data include a presentation material used by the presenter and a document obtained from the content server  11 . 
         [0093]    The pen data input unit  157  communicates with the digital pen  14  in a wired manner or a wireless manner, and collects information including coordinates and the like obtained by the digital pen  14 . 
         [0094]    The signature authentication unit  158  authenticates a meeting attendant based on his/her signature to verify his/her identification. To this end, the signature authentication unit  158  uses the signature DB  158 A in which the signature of the meeting attendant is registered in advance. The signature DB  158 A may be stored in the event information input device  15 , or may be stored in another device (e.g., content server  11 ) connected to the network  17 . Alternatively, it is possible to separately provide a signature database server. 
         [0095]    The data communication unit  159  is a network interface. Examples of the network interface include a LAN card that allows communications using a TCP/IP protocol. This allows the event information input device  15  to communicate with the content server  1 i via the network  17 . 
         [0096]      FIG. 6  is a diagram of a configuration of the event information  21  stored in the content server  11  according to the first embodiment. 
         [0097]    The event information  21  includes an event ID  210 , an event name  211 , a date and time  212 , a place  213 , a registered attendant count  214 A, a registered attendant  214 B, an unregistered attendant count  215 A, an unregistered attendant  215 B, a distributed material  216 , an additional information item count  217 A, an additional information item  217 B, an in-event action count  218 A, an in-event action  218 B, a media view count  219 A, and a media view ID  219 B. In the event information  21 , one record is generated each time an event such as a meeting takes place. 
         [0098]    The event ID  210  is a unique identifier of an event. For instance, the event management program  114  determines the event ID  210  automatically according to an arbitrary rule, and records the event ID  210  in the event information  21 . 
         [0099]    The event name  211  is a name of the event. 
         [0100]    The date and time  212  is a start date and time and end date and time of the event. 
         [0101]    The place  213  is a place where the event is held. 
         [0102]    The registered attendant count  214 A is the number of attendants at the event who have been registered in advance. It should be noted that the number of recorded registered attendants  214 B is equal to the registered attendant count  214 A. 
         [0103]    Recorded as the registered attendant  214 B is a unique user ID of each registered attendant at the event and presence/absence thereof. 
         [0104]    The unregistered attendant count  215 A is the number of attendants at the event who have not been registered in advance. It should be noted that the number of recorded unregistered attendants  215 B is equal to the unregistered attendant count  215 A. 
         [0105]    Recorded as the unregistered attendant  215 B is a unique user ID of each unregistered attendant at the event. It should be noted that, as will be described later, the unregistered attendant  215 B is identified by an ID of the digital pen  14  used by the attendant or a signature of the attendant. 
         [0106]    By recording a registered attendant, an absentee who has planned to participate (registered absentee), and an unregistered attendant in a manner distinguishable from one another as described above, it is possible to provide the system with security based on a level of each individual. For instance, the system may prohibit the absentee from viewing a video of the meeting, or may prohibit the unregistered attendant from viewing the distributed material. 
         [0107]    The distributed material  216  corresponds to an ID of the dot pattern used for a material distributed at the event. The example shown in the drawing indicates that 50 different dot patterns of 150.100.10.1 to 150.100.10.50 are used for the event as the distributed material. 
         [0108]    During the event and/or after the event, when writing is made on a distributed material with the digital pen  14 , the event is identified by a distributed material ID of a corresponding document on which characters and the like have been written. 
         [0109]    The additional information item count  217 A is the number of additional information items related to the event. It should be noted that the number of recorded additional information items  217 B is equal to the additional information item count  217 A. 
         [0110]    The additional information item  217 B is an information item such as a video, image, audio, or slide related to the event. To be specific, examples of the information item recorded as the additional information item  217 B include video data obtained by photographing the event, audio data obtained by recording the event, and a slide used at the event. Recorded as the additional information item  217 B are a type of additional information item, a file name of the additional information item, and a content security set for the additional information item. 
         [0111]    The in-event action count  218 A is the number of actions performed during the event. It should be noted that the number of recorded in-event actions  218 B is equal to the in-event action count  218 A. 
         [0112]    The in-event action  218 B is a detail of the action performed during the event. The in-event action  218 B includes an ID of a document related to the action (corresponding document ID), a type of action, and a time at which the action is performed. It should be noted that the time is represented as a relative time with the start time of the event as a reference. 
         [0113]    To be specific, a first data item of the in-event action  218 B indicates that a presenter turned a material whose document ID was “DC028428” from page 1 to page 2 at the relative time of 5 minutes and 11.33 seconds (5 minutes and 11.33 seconds after the start of the meeting). A second data item of the in-event action  218 B indicates that projection of a material whose document ID was “DC028438” started at the relative time of 8 minutes and 41.03 seconds. A third data item of the in-event action  218 B indicates that the presenter pointed at a position of coordinates (115.0,50.0)-(145.0,90.0) on the material whose document ID was “DC028438” at the relative time of 15 minutes and 21.43 seconds. 
         [0114]    The media view count  219 A is the number of times that video data obtained by video-recording the event. It should be noted that the number of recorded media view IDs  219 B is equal to the media view count  219 A. 
         [0115]    The media view ID  219 B is an identifier of information on viewing the video data obtained by video-recording the event, and has a link to media view information  28  (shown in  FIG. 7 ). 
         [0116]      FIG. 7  is a diagram of a configuration of the media view information  28  stored in the content server  11  according to the first embodiment. 
         [0117]    The media view information  28  includes a media view ID  281 , a user ID  282 , a view unit count  283 , and a view unit  284 . In the media view information  28 , one record is generated each time a user views a content. 
         [0118]    The media view ID  281  is a unique identifier for identifying the event. For instance, the event management program  114  determines the media view ID  281  each time a content is viewed, and records the media view ID  281  in the media view information  28 . 
         [0119]    The user ID  282  is an ID of a user who viewed the content. 
         [0120]    The view unit count  283  is the number of continuous playback durations of the viewed content. In other words, a duration in which the viewer has continuously viewed the content without stop is set as a view unit. Recorded as the view unit count  283  is the number of view units. It should be noted that the number of recorded view units  284  is equal to the view unit count  283 . 
         [0121]    The view unit  284  is detailed information on a view unit. To be specific, recorded as the view unit  284  are a storage location of a viewed content (“Media URL” serving as a file name including a path name), a position of a content at which viewing of one unit thereof started (“start pos” expressed by a relative time from the head of the content), a time at which viewing of the one unit started (“media start”), and a time at which the viewing of the one unit ended (“media end”). 
         [0122]    For instance, a first data item of the view unit count  283  indicates that a portion of a video file “MV001023.mov” stored at “file://contentsLibrary/Conference” was started to be viewed from the position 34.12 seconds from the head of the file started at 12:00 and 14.14 seconds and ended at 12:00 and 14.24 seconds. 
         [0123]    Next, description will be made of document information stored in the content server  11  according to the first embodiment. The document information includes distributed material information  22  and handwritten memo-related information  23 . 
         [0124]      FIG. 8A  is a diagram of configuration of the distributed material information  22  out of the document information stored in the content server  11  according to the first embodiment. 
         [0125]    The distributed material information  22  includes a document ID  220 , a dot pattern ID  221 , an owner user ID  222 , a corresponding event  223 , an electronic file  224 , a document size  225 , a document security level  226 , a stroke set count  227 , and a stroke set ID  228 . 
         [0126]    The document ID  220  is a unique identifier of a document. It should be noted that documents owned by different persons are recognized as different documents even when the documents have the same information, and are therefore assigned with different document IDs  220 , generating different records of the distributed material information  22 . Documents to be distributed to different users are normally printed along with different dot patterns before distribution thereof. 
         [0127]    The dot pattern ID  221  is an identifier of a dot pattern printed on the document. 
         [0128]    The owner user ID  222  is a unique identifier of a user who owns the document. 
         [0129]    The corresponding event ID  223  is a unique identifier of an event associated with the document. Normally recorded as the corresponding event ID  223  is the event ID of the meeting where the document is distributed, and the corresponding event ID  223  corresponds to the event ID 2   10  of the event information  21 . 
         [0130]    The electronic file  224  is a file name of electronic data of the document. 
         [0131]    The document size  225  indicates a size of paper suitable for printing the document. Stored as the document size  225  are coordinates of an upper left-hand corner of an area of the paper and coordinates of a lower right-hand corner thereof. In the example shown in the drawing, the document size  225  is expressed in millimeters with the upper left-hand corner being an origin point. 
         [0132]    The document security level  226  indicates how confidential the document is. As will be described later, based on the document security level  226  and a security level  276  of a user (shown in  FIG. 13 ), it is determined whether or not the user can view the document. 
         [0133]    The stroke set count  227  is the number of stroke sets written on the document with the digital pen  14 . It should be noted that the number of recorded stroke set IDs  228  is equal to the stroke set count  227 . 
         [0134]    The stroke set is a group of mutually related lines (strokes), and is obtained by using, for instance, layout analysis in character recognition. In the layout analysis, the mutually related lines are identified based on times when the lines were written and/or locational relationships between the lines. Thus, the stroke set is obtained. In other words, strokes written at close times and close locations constitute one stroke set. 
         [0135]    The stroke set ID  228  is a unique identifier of a stroke set written on the document, and has a link to handwritten memo-related information (shown in  FIG. 8B ) and the stroke information  24  (shown in  FIG. 12B ). 
         [0136]      FIG. 8B  is a diagram of configuration of the handwritten memo-related information  23  out of the document information stored in the content server  11  according to the first embodiment. 
         [0137]    The handwritten memo-related information  23  includes a stroke set ID  230 , a related information item count  231 , and a related information item  232 . In the handwritten memo-related information  23 , one record is generated for each stroke set. 
         [0138]    The stroke set ID  230  is a unique identifier of the stroke set, which is the same as a stroke set ID  241  of stroke data (shown in  FIG. 12B ). 
         [0139]    The related information item count  231  is the number of information items associated with the stroke set. It should be noted that the number of recorded related information items  232  is equal to the related information item count  231 . 
         [0140]    The related information item  232  is data related to the stroke set. To be specific, examples of the data include a video data when the stroke set was written, a presentation material used by an explainer when the stroke set was written, and a distributed material on which the stroke set was written. 
         [0141]    For instance, a related information item described as a first data item of the related information item  232  is a video data (“Movie”) whose file name is “MV001023.mov”, and includes data obtained at time instants during a time period from 10:00 and 50.0 seconds to 10:12 and 00.0 seconds out of time instants when the stroke set was written. It should be noted that the time period during which the stroke set was written extends from 10:00 and 50.0 seconds to 10:12 and 00.0 seconds, so all the data recorded as the related information items exists within the entire time period from the start to the end of writing of the stroke set. 
         [0142]    In addition, a security level (“View Security”) at which the stroke set is viewed is “02”. Further, when the stroke set was written, a user has rewound the video by 3.0 seconds. 
         [0143]    It should be noted that in a case where a state of progress of an information item recorded as the related information item is grasped when the stroke set is written, a location (page number and line number) on information item at the time is recorded. The state of progress of the information item is identified by a location thereon pointed by a presenter. 
         [0144]    Further, when the data item recorded as the related information item is a paper information item on which the stroke set has been written, the location (page number and line number) where the stroke set has been written is recorded. 
         [0145]      FIG. 9  is an explanatory diagram of obtainment of relative coordinates on paper by the digital pen  14  according to the first embodiment of this invention. 
         [0146]    The digital pen  14  comprises a CPU, a memory, a processor, a communication interface, a camera  141 , a battery, and a writing pressure sensor. Also, the digital pen  14  comprises a pen tip with which it is possible to write characters, symbols, and the like on paper with ink or graphite. 
         [0147]    The digital pen  14  is used together with a sheet  20  on which dots  203  for location detection have been printed. Here, the dots  203  will be described by magnifying a part  201  of the sheet  20 . On the sheet  20 , a plurality of small dots  203  have been printed. Those dots  203  have been printed at locations displaced from intersections (reference points)  202  of virtual lattice lines upwardly, downwardly, rightwardly, or leftwardly. 
         [0148]    When a character or a figure is written on the paper with the digital pen  14 , the written character or the like remains on the paper in such a manner that visual recognition is possible. When detecting that the pen tip has come into contact with the paper using the writing pressure sensor, the digital pen  14  photographs the dots  203  printed on the paper with the camera  141 . For instance, the digital pen  14  photographs an area including six by six dots  203 . 
         [0149]    The digital pen  14  obtains absolute coordinates, at which the dot pattern exists, from the photographed dot pattern. Those absolute coordinates are coordinates at which the dot pattern exists in a vast plane area. The vast plane area is an entire area in which arrangement of dot patterns without overlapping is possible. 
         [0150]    The digital pen  14  transmits the obtained absolute coordinates to the information terminal  12 . The information terminal  12  transmits the absolute coordinates transmitted from the digital pen  14  to the content server  11 . 
         [0151]    The content server  11  transmits the absolute coordinates obtained from the digital pen  14  to the location information server  19 . The location information server  19  identifies the location (dot pattern ID) of the paper in the vast plane area and coordinates (relative coordinates) on the paper medium based on the absolute coordinates transmitted from the content server  11  and transmits the identified dot pattern ID and relative coordinates to the content server  11 . 
         [0152]    In the manner described above, the content server  11  obtains the dot pattern ID and the relative coordinates from the dot pattern photographed by the digital pen  14 . 
         [0153]    By obtaining information on contact locations of the pen tip at predetermined timings (e.g., periodically), it is possible to grasp a movement of the pen tip. 
         [0154]    In other words, the digital pen  14  transmits the absolute coordinates corresponding to the photographed dot pattern, a photographed time of the dot pattern, and the pen ID to the information terminal  12 . 
         [0155]    The content server  11  obtains the relative coordinates from the location information server  19  based on the absolute coordinates obtained by the digital pen  14 . The content server  11  obtains a path (stroke information) of the pen tip from the obtained relative coordinates and the time at which the dot pattern has been photographed. 
         [0156]    It should be noted that the location information server  19  may be included in the content server  11  instead of being provided separately. 
         [0157]    Also, it is not required for the digital pen  14  to use the location information server  19  in order to identify the dot pattern ID and the relative coordinates. For instance, the sheet is identified based on a two-dimensional barcode or an IC tag embedded in the sheet  20 . In addition, it is possible to identify locations (relative coordinates) on the sheet using a tablet. It should be noted that one of the sheet identification using a μ-chip or the like and the location identification on the sheet using the tablet may be combined with the absolute coordinate identification by the location information server  19 . In this case, it becomes possible to alleviate a load of processing in which the document management system identifies the dot pattern ID and the relative coordinates. 
         [0158]      FIG. 10  is an explanatory diagram of a document  31  registered in the content server  11  according to the first embodiment. 
         [0159]    The user registers the document (distributed material)  31  as shown in this drawing in the content server  11  in association with an event at which the document  31  has been distributed. 
         [0160]    The document  31  is attached with a dot pattern different from another document. In other words, when contents of respective documents are printed, dot patterns different for each of the documents are printed. Further, the documents having different dot patterns have different document IDs  220  and are distributed to different users. 
         [0161]    It should be noted that the distributed material  31  may be a document created electronically by document creation software or the like, or may be obtained by converting a handwritten document into an electronic format. 
         [0162]      FIG. 11  is an explanatory diagram of the document  31  on which information has been written with the digital pen  14  according to the first embodiment. 
         [0163]    This drawing indicates a state where information has been written on the document illustrated in  FIG. 10  by using the digital pen  14 . 
         [0164]    The user annotates information (character, symbol, or the like)  311  on the document  31  with the digital pen  14  during an event (or after the event). During the action, the digital pen  14  periodically obtains absolute coordinates of a location (contact location of a pen tip thereof) where the character or the like has been written and a time when the absolute coordinates are measured. Subsequently, the digital pen  14  transmits the obtained absolute coordinates and obtainment times to the content server  11 . 
         [0165]    The content server  11  makes an inquiry to the location information server  19  to identify a dot pattern ID and relative coordinates which correspond to the absolute coordinates included in the received stroke information, while identifying a document ID based on the dot pattern ID. 
         [0166]    Then, the content server  11  determines a stroke of the written information based on the identified relative coordinates and the measurement time, and creates stroke coordinate information  25  (shown in  FIG. 12C ). Then, the identified document ID is used to create a new stroke set information  24  (shown in  FIG. 12B ). 
         [0167]      FIG. 12A  shows an example of a stroke set  26  according to the first embodiment of this invention. 
         [0168]    The stroke set  26  is a set of strokes of characters “Tokyo”  311  shown in  FIG. 11  written with the digital pen  14 . In this embodiment, as shown in the drawing, an upper left-hand corner is set as an origin, a horizontal direction is set as an X axis, and a vertical direction is set as a Y axis, thereby determining locations of the strokes. 
         [0169]    As described above, the stroke set is a group of mutually related lines (strokes) and is identified based on a write time of the lines and/or location relations among the lines. 
         [0170]      FIG. 12B  is a construction diagram of the stroke set information  24  stored in the content server  11  according to the first embodiment. 
         [0171]    It should be noted that, in the drawing, stroke set information for the stroke set  26  shown in  FIG. 12A  is illustrated. 
         [0172]    The stroke set information  24  includes, a stroke set ID  241 , a pen ID  242 , an initial write date and time  243 , a corresponding rectangle coordinate  244 , a number of strokes  245 , and stroke information  246 . 
         [0173]    The stroke set ID  241  is a unique identifier of the stroke set. 
         [0174]    The pen ID  242  is an identifier of the digital pen  14  used to annotate the stroke set. 
         [0175]    The initial write date and time  243  is a date and time of initial writing of the stroke set. 
         [0176]    The corresponding rectangle area  244  is a rectangle area including the stroke set. The corresponding rectangle area  244  include coordinates (relative coordinates) on a document, on which the stroke set has been written, and is expressed by a coordinate of an upper left-hand corner of the rectangular area and a coordinate of a lower right-hand corner. 
         [0177]    The number of strokes  245  is the number of lines (strokes) included in the stroke set. Pieces of stroke information  246 , whose number is equal to the number of strokes  245 , are recorded. 
         [0178]    The stroke information  246  includes the number of sampling points  246 A and serial numbers  246 B. 
         [0179]    The number of sampling points  246 A is the number of relative coordinates that constitute a corresponding stroke, which has been obtained by the digital pen  14 . 
         [0180]    Each serial number  246 B is a unique identifier of the relative coordinates constituting the stroke obtained by the digital pen  14 , and is a link to the stroke coordinate information  25  (shown in  FIG. 12C ). 
         [0181]      FIG. 12C  is a construction diagram of the stroke coordinate information  25  stored in the content server  11  according to the first embodiment. 
         [0182]    The stroke coordinate information  25  includes a serial number  251 , an X coordinate  252 , a Y coordinate  253 , and an obtainment time  254 . 
         [0183]    The serial number  251  is a unique identifier of the relative coordinate obtained by the digital pen  14 . 
         [0184]    The X coordinate  252  is a relative coordinate in a direction of the X axis shown in  FIG. 12A  and is expressed in units of millimeters, for instance. 
         [0185]    The Y coordinate  253  is a relative coordinate in a direction of the Y axis shown in  FIG. 12A  and is expressed in units of millimeters, for instance. 
         [0186]    The obtainment time  254  expresses an obtainment time of the relative coordinates by the digital pen  14 . It should be noted that in the example shown in the diagram, in the obtainment time field  254 , an elapsed time from an initial write time  242  is recorded. 
         [0187]      FIG. 13  is a construction diagram of the user information  27  stored in the content server  11  according to the first embodiment. 
         [0188]    The user information  27  includes, a user ID  271 , a name  272 , a section  273 , a position  274 , a possession pen ID  275 , and a security level  276 . 
         [0189]    The user ID  271  is a unique identifier of the user. 
         [0190]    The name  272  is the name of the user. 
         [0191]    The section  273  is a section to which the user belongs. 
         [0192]    The position  274  is a position of the user. 
         [0193]    The possession pen ID  275  is a unique identifier of the digital pen  14  possessed by the user. 
         [0194]    The document security level  276  is a right of the user to access a confidential document. As will be described later, it is determined whether or not the user can view the document based on the security level  276  of the user and the security level  226  (shown in  FIG. 8A ) of the document. 
         [0195]    Next, description will be made of the processing of the document management system according to the first embodiment. 
         [0196]      FIG. 14  is a flowchart of written-data accumulating processing according to the first embodiment. 
         [0197]    The first embodiment will be described by taking an example case where the user uses the digital pen  14  that is personally dedicated to the user and a distributed material prepared by a organizer of the meeting. In other words, in the first embodiment, the content server  11  can identify the user based on the pen ID of the digital pen and can also identify the user based on the document ID of the distributed material. 
         [0198]    It should be noted that there can be  4  patterns depending on which of personally-dedicated use and shared use the digital pen is put to and on which of a distributed material and one&#39;s own material an writing sheet is. Processings in the other patterns will be described later as a second embodiment to a fourth embodiment. 
         [0199]    During the event, an attendant (user) at the meeting uses the digital pen  14  to annotate a memo or the like on the distributed material (S 101 ). In this step, the digital pen  14  periodically photographs a dot pattern during writing (during detection by the writing pressure sensor), and obtains the absolute coordinates of a position where the writing has been conducted. 
         [0200]    After that, the user connects the digital pen  14  to the information terminal  12 , and transmits the absolute coordinates obtained by the digital pen  14 , the times at which the absolute coordinates were obtained, and the pen ID, from the digital pen  14  to the information terminal  12  (S 102 ). 
         [0201]    Upon reception of the absolute coordinates, the times at which the absolute coordinates were obtained, and the pen ID, from the digital pen  14 , the information terminal  12  transmits the received data to the content server  11  (S 103 ). 
         [0202]    The content server  11  generates the stroke coordinate information  25  and the stroke set information  24  from the absolute coordinates obtained by the digital pen  14  (S 104 ). 
         [0203]    To be specific, the content server  11  determines an arbitrary coordinate origin point, and generates the stroke coordinate information  25  from differences between the coordinate origin point and the respective coordinates and the times at which the coordinates were obtained. After that, the content server  11  identifies a set of mutually related lines (stroke set) based on the times when the lines were written and/or the locational relationships between the lines, and generates the stroke set information  24 . 
         [0204]    After that, the content server  11  identifies the event ID of the meeting based on a distributed material dot pattern (S 105 ). To be specific, the content server  11  transmits the absolute coordinates obtained by the digital pen  14  to the location information server  19 . The location information server  19  identifies the dot pattern ID and the relative coordinates based on the absolute coordinates transmitted from the content server  11 , and transmits the dot pattern ID and the relative coordinates to the content server  11 . The content server  11  searches the event information  21  with the obtained dot pattern ID as a search key to identify an event including the dot pattern ID. 
         [0205]    Subsequently, the content server  11  searches the user information  27  with the pen ID obtained from the digital pen  14  as a search key to identify the user who possesses the digital pen (S 106 ). 
         [0206]    Then, the content server  11  judges whether or not the user ID of the identified user is included as the registered attendant  214 B (S 107 ). 
         [0207]    When the identified user ID is not included as the registered attendant  214 B, the content server  11  judges that the user is an unregistered attendant, increments the unregistered attendant count  215 A, and registers the user in the unregistered participant field  215 B (S 108 ). 
         [0208]    On the other hand, when the identified user ID is included in the registered attendant  214 B, the user is found to be a registered attendant, so the content server  11  updates the presence/absence data of the corresponding user in the registered attendant field  214 B to “present” (S 109 ). 
         [0209]    After that, when the user requests viewing of a content, the content server  11  generates the media view information  28  (S 110 ). It should be noted that media view information is also generated while the video of the meeting is recorded. Therefore, it is possible to associate a stroke set with the content in Step S 123  of  FIG. 15 . 
         [0210]    Subsequently, the content server  11  generates the handwritten memo-related information  23  (S 111 ). To be specific, the content server  11  identifies a time period corresponding to the stroke set information  24  generated in Step S 104 , a document that was being used during the time period, a video that was being recorded during the time period, and audio data that was being recorded during the time period. Then, the content server  11  registers the identified data as related information items in the handwritten memo-related information  23 . It should be noted that  FIG. 15  will be used to describe detailed processing of generating the handwritten memo-related information. 
         [0211]    Subsequently, based on the security level  276  (shown in  FIG. 13 ) of the user and the security level  226  (shown in  FIG. 8A ) of the document, the content server  11  determines whether or not the user can view the document, and sets a meeting information access right (S 112 ). 
         [0212]      FIG. 15  is a flowchart of processing of generating a link set from a handwritten memo to each type of information obtained during the meeting according to the first embodiment, showing details of the processing of Step S 111  shown in  FIG. 14 . 
         [0213]    First, stroke sets generated in Step S 104  of  FIG. 14  are extracted one by one (S 121 ). 
         [0214]    Second, it is judged whether or not there is any stroke set left unprocessed (S 122 ). As a result, when there is an unprocessed stroke set, the processing advances to Step S 123 . On the other hand, when there is no unprocessed stroke set, the handwritten memo-related information  23  has been generated for every stroke set, so the processing is ended. 
         [0215]    In Step S 123 , the media view information  28  is searched to identify a content that was being viewed during the time when the stroke set was written. It should be noted that the time period during which the stroke set was written is obtained from the initial write date and time denoted as reference numeral  243  in  FIG. 12B  within the stroke set information and a maximum value of the obtainment times denoted as reference numeral  254  in  FIG. 12C  within the stroke coordinate information. 
         [0216]    After that, an overlapping range between a viewing duration of the identified content and a time period during which the stroke set was generated is extracted. Then, a playback range of the content corresponding to the stroke set is determined (S 124 ). 
         [0217]    The playback range is determined simply by extracting an overlapping range between an write time period of the stroke set and the viewing duration of the content. Further, the viewing duration of the content added with a predetermined time period before and after (for instance, one minute each before and after) the writing of the stroke set may be set as the playback duration. Further, the playback duration may be determined by the view unit of the content which includes the write time period of the stroke set. Further, times at which scenes within the content are changed may be detected to set as the playback duration a time period which includes the write time period of the stroke set and which is defined between the detected positions at which the scenes are changed. 
         [0218]    In this step, the initial write time of the stroke set may be used as it is, but time information of the content corresponding to the stroke set may be determined by a method shown in  FIG. 16 , and may be used instead. 
         [0219]    Lastly, the related information item  232  is registered, and the handwritten memo-related information  23  is generated (S 125 ). 
         [0220]      FIG. 16  is a flowchart of processing of determining time information of the stroke set according to the first embodiment, showing details of the processing of Step S 124  shown in  FIG. 15 . 
         [0221]    First, the stroke set for which the playback range of a content is to be determined is determined (S 131 ). 
         [0222]    After that, the distributed material information  22  of the distributed material corresponding to the event information  21  on the meeting in which the user participated is accessed. Then, it can be judged whether or not the user is allowed to access the distributed material based on the document security level  226  of the distributed material and the security level  276  of the user. When the access is allowed, based on the security level of the user and View Security of the stroke set, it is further judged whether or not reference to a stroke set of another user is allowed (S 132 ). As a result of the judgment, when the reference to the stroke set of the another user is allowed, the processing advances to Step S 133 , and information on the stroke set of the another user is also used to determine the playback duration of the content. On the other hand, when the reference to the stroke set of the another user is not allowed, the processing advances to Step S 135 . 
         [0223]    In Step S 133 , the stroke set which was written by a participant at the same meeting and which has an overlap in write time period range is extracted. 
         [0224]    To be specific, the stroke set information  24  is searched with the write time period of the stroke set as a search key to identify the stroke set having an overlap in write time period. The user information  27  is then searched with the pen ID  242  of the stroke set as a search key to identify the user who written the stroke set. The event information  21  is then searched with the user ID  271  of the identified user and the write time period of the stroke set as search keys to identify the event which the user attended. Then, another user who attended the event is identified. 
         [0225]    After that, the user information  27  is searched with the identified user ID as a search key to identify a digital pen possessed by the attendant user. The stroke set information  24  is then searched with the possession pen ID  275  of the identified digital pen and the write time period of the stroke set as search keys to identify stroke sets which were written by the attendant at the same meeting and which have an overlap in write time period. 
         [0226]    After that, of the identified stroke sets having an overlap in write time period, the initial write date and time  243  of the stroke set that has started to be written first is set as time instant information ( 1 ) (S 134 ). 
         [0227]    Subsequently, the stroke set is converted into a text to generate text data (S 135 ). 
         [0228]    Then, it is judged whether or not the generated text data exists in a video, audio, slide, and the like in the vicinity of the write time period range of the stroke set. When the text data exists in the data, a time instant at which the text data existed is set as time instant information ( 2 ) (S 136 ). 
         [0229]    In this step, pattern matching using graphic data may be used in addition to matching using text data. 
         [0230]    After that, the time information of the stroke set is determined based on the time information ( 1 ) and the time information ( 2 ) (S 137 ). Then, the playback range of the content is determined based on the determined time information (Step S 124  of  FIG. 15 ). 
         [0231]    To be specific, the earlier one of the time information ( 1 ) and the time information ( 2 ) may be set as the time information of the stroke set. Alternatively, of the time information ( 1 ) and ( 2 ), the one closer to the initial write date and time of the stroke set may be selected. Further, the user may choose one of the time information ( 1 ) and the time information ( 2 ). 
         [0232]      FIG. 17  is a flowchart of processing of retrieving various kinds of information obtained during the meeting based on a handwritten memo according to the first embodiment. It should be noted that  FIG. 17  shows a case where users use sheets having the same dot pattern, for instance, a case where the distributed materials have the same dot pattern or a case where the users have notebooks having the same dot pattern. 
         [0233]    In other words,  FIG. 17  shows a case where paper on which a user annotates with the digital pen is insufficient to identify the user who possesses the document. It should be noted that a case of different dot patterns will be described as the fifth embodiment of this invention with reference to  FIG. 24 . 
         [0234]    First, the user designates a handwritten memo written on a paper medium with the digital pen possessed by the user (S 141 ). At this time, the digital pen  14  photographs a dot pattern at a position of the designation to obtain the absolute coordinates of the designated position. 
         [0235]    After that, the user connects the digital pen  14  to the information terminal  12 , and transmits the absolute coordinates obtained by the digital pen  14 , the time at which the absolute coordinates were obtained, and the pen ID, from the digital pen  14  to the information terminal  12  (S 142 ). 
         [0236]    Upon reception of the absolute coordinates, the time at which the absolute coordinates were obtained, and the pen ID, from the digital pen  14 , the information terminal  12  transmits the received data to the content server  11  (S 143 ). 
         [0237]    The content server  11  uses the pen ID of the digital pen  14  to identify the stroke set (S 144 ). 
         [0238]    To be specific, the content server  11  searches the stroke set information  24  with the pen ID as a search key to extract the stroke set that was written with the digital pen  14 . 
         [0239]    Further, the content server  11  transmits the absolute coordinates obtained by the digital pen  14  to the location information server  19 . The location information server  19  identifies the dot pattern ID and the relative coordinates based on the absolute coordinates transmitted from the content server  11 , and transmits the dot pattern ID and the relative coordinates to the content server  11 . The content server  11  collates the obtained relative coordinates with the extracted stroke set to identify the designated handwritten memo (stroke set ID). 
         [0240]    After that, the content server  11  references the handwritten memo-related information  23  of the identified stroke set ID to identify the related information item. 
         [0241]    Subsequently, the content server  11  searches the user information  27  with the pen ID of the digital pen  14  as a search key to identify the user who possesses the digital pen. 
         [0242]    After that, the content server  11  judges whether or not the user has a right to view the related information item (S 145 ). The right is defined by the document security level denoted by reference numeral  226  in  FIG. 8A  of the identified distributed material, right information defined based on the security level denoted by reference numeral  276  in  FIG. 13  of the user, and the security information (View Security) specified in the related information item. 
         [0243]    When it is judged that the user does not have the right to view the information item related to the stroke set, the content server  11  examines the right of the next related information item. On the other hand, when it is judged that the user has the right to view the information item related to the stroke set, the content server  11  reads out the related information item, and transmits the related information item to the information terminal  12  (S 146 ). 
         [0244]    After that, the information terminal  12  outputs the related information item transmitted from the content server  11  (S 147 ). 
         [0245]    Each processing of the first embodiment has been described above with the content server  11  as a main subject. However, the content server  11  may store various kinds of information and provide the stored information via the network  17 . In other words, a management server may be provided separately from the content server  11  in order to execute processing of retrieval, judgment, or the like. 
         [0246]      FIG. 18  is an explanatory diagram of a content viewer  120  according to the first embodiment. 
         [0247]    The content viewer  120  is constituted by software running on the information terminal  12 , and operates a content sent from the content server  11  when the user views the content. 
         [0248]    The content viewer  120  has a display screen  121 . Displayed on the display screen is the content sent from the content server  11 . 
         [0249]    The display screen  121  is provided in its lower part with a time scale bar  122 . The time scale bar  122  is provided with a marker  123 . The marker  123  moves within the time scale bar  122 , indicating a state of progress of the viewed content. In addition, the user can change a viewing position by moving the marker  123 . 
         [0250]    Provided below the time scale bar  122  are an open button  124  for opening a content file, a volume bar  129 , the fast-forward button  128 , a rewind button  127 , a stop button  126 , and a play button  125 . 
         [0251]    As described above, the times at which the user operates those buttons are transmitted to the content server  11 , and recorded in the content server  11 . For instance, the operations of the play button  125  and the stop button  126  are recorded in the view unit  284  of the media view information  28 . Similarly, the operations of the fast-forward button  128  and the fast-forward button  127  are recorded in the related information item  232  of the handwritten memo-related information  23 . 
       Second Embodiment 
       [0252]      FIG. 19  is a flowchart of written-data accumulating processing according to the second embodiment of this invention. 
         [0253]    The second embodiment will be described by taking an example case where the user uses the personally-dedicated digital pen  14  and the user&#39;s own paper medium (e.g., notebook). In other words, in the second embodiment, the content server  11  can identify the user based on the pen ID of the digital pen but cannot identify the user based on the document ID. It should be noted that the description of the second embodiment will be given to parts different from the first embodiment described above, while description of the same parts, which are denoted by the same reference symbols, will be omitted. 
         [0254]    First, before the event starts (or during the event), an attendant (user) at the meeting uses the digital pen  14  to check or write his/her name in a meeting attendance form  30  (shown in  FIG. 20 ) (S 151 ). 
         [0255]    During the event, the user uses the digital pen  14  to annotate a memo or the like on the user&#39;s own paper medium such as in a notebook (S 152 ). After that, the user connects the digital pen  14  to the information terminal  12 , and transmits the absolute coordinates obtained by the digital pen  14 , the times at which the absolute coordinates were obtained, and the pen ID, from the digital pen  14  to the information terminal  12  (S 102 ). 
         [0256]    The information terminal  12  transmits the data received from the digital pen  14  to the content server  11  (S 103 ). 
         [0257]    The content server  11  generates the stroke coordinate information  25  and the stroke set information  24  from the absolute coordinates obtained by the digital pen  14  (S 104 ). 
         [0258]    The processing of Steps S 102  to S 104  is the same as that in the first embodiment described above. 
         [0259]    Subsequently, the content server  11  identifies the event ID of the meeting based on the dot pattern ID corresponding to the meeting attendance form  30  (S 153 ). The meeting attendance form  30  (its dot pattern ID) is previously registered in correspondence with the event ID of the meeting. For instance, it is registered in the distributed material  216  of the event information  21 . 
         [0260]    It should be noted that the meeting attendance form may be substituted by any other document that allows identification of the meeting (that is insufficient to identify the owner of the document in the second embodiment). For instance, the second embodiment can be applied to a case of using the distributed materials whose owners cannot be identified. 
         [0261]    After that, the content server  11  identifies the user who possesses the digital pen (S 106 ). Then, depending on whether or not the identified user is included as the registered attendant  214 B, the content server  11  registers the user in the unregistered participant field  215 B or the registered attendant field  214 B (S 107  to S 109 ). 
         [0262]    Then, the content server  11  generates the media view information  28  (S 110 ), generates the handwritten memo-related information  23  (S 111 ), and sets the meeting information access right (S 112 ). 
         [0263]    The processing of Steps S 106  to S 112  is the same as that in the first embodiment described above. 
         [0264]      FIG. 20  is an explanatory diagram of the meeting attendance form  30  according to the second embodiment. 
         [0265]    The meeting attendance form  30  is printed along with a specific dot pattern. Used for the meeting attendance form  30  is a dot pattern of the dot pattern ID included as the distributed material  216  of the event information. Therefore, when the user designates an arbitrary position on the meeting attendance form  30 , the content server  11  can identify the dot pattern ID corresponding to the meeting attendance form  30 , and can further identify the meeting (event ID). 
         [0266]    The meeting attendance form  30  includes a place  301  of the event, a date and time  302 , a registerer  303 , and a non-registered attendant  304 . The user who attends at the event fills in the meeting attendance form  30 . 
         [0267]    The place  301  is shown as a blank box. The user uses the digital pen  14  to fill in the box with a place where the event is held. 
         [0268]    The date and time  302  is shown as a blank box. The user uses the digital pen  14  to fill in the box with a date and time when the event is held. 
         [0269]    The content server  11  uses a character recognition technology to recognize characters written in the place  301  and the date and time  302  with the digital pen  14  and converts the characters into text data. The resultant text data of the place where the event is held is registered as the place  213  of the event information, and the resultant text data of the date and time when the event is held is registered as the date and time  212  of the event information. 
         [0270]    It should be noted that the place where the event is held may be registered by providing the place  301  with a plurality of areas associated with places where events are held and allowing the user to choose the area. Similarly, the date and time when the event is held may be registered by providing the date and time  302  with a plurality of areas associated with dates and times when events are held and allowing the user to choose the area. 
         [0271]    The registerer  303  is provided with an expected attendant&#39;s name  303 A and a check field  303 B. The user designates the check field  303 B corresponding to one&#39;s own name with the digital pen  14 . For instance, this explanatory diagram shows a state where Mr./Ms. Yamada has checked for his/her presence. The content server  11  identifies the attendant based on relative coordinates designated with the digital pen  14 . Then, the content server  11  updates the presence/absence data of the registered attendant field  214 B of the identified user into “present”. 
         [0272]    The unregistered person  304  is provided with fields to be filled in with an unexpected attendant&#39;s name. The user fills in the unregistered person  304  with a section of a company to which the user belongs and his/her own name when his/her own name is not found as the registerer  303 . The content server  11  searches the user information  27  with the pen ID of the digital pen  14  as a search key to identify the attendant, the digital pen  14  being used to fill in the unregistered person  304  with his/her own name and the section to which the user belongs. Then, the content server  11  increments the unregistered attendant count  215 A, and registers the user ID of the identified attendant in the unregistered participant field  215 B. 
       Third Embodiment 
       [0273]      FIG. 21  is a flowchart of written-data accumulating processing according to the third embodiment of this invention. 
         [0274]    The third embodiment will be described by taking an example case where the user uses the shared-use digital pen  14  and a distributed material prepared by a host of the meeting. In other words, in the third embodiment, the content server  11  cannot identify the user based on the pen ID of the digital pen, but can identify the user based on the document ID of the distributed material. It should be noted that the description of the third embodiment will be given to parts different from the first and second embodiments described above, while description of the same parts, which are denoted by the same reference symbols, will be omitted. 
         [0275]    Before the event starts (or during the event), an attendant (user) at the meeting uses the digital pen  14  to write his/her signature on the distributed material (S 161 ). 
         [0276]    The user uses the digital pen  14  during the event to annotate a memo or the like on the distributed material (S 101 ). After that, the user connects the digital pen  14  to the information terminal  12 , and transmits the absolute coordinates obtained by the digital pen  14 , the times at which the absolute coordinates were obtained, and the pen ID, from the digital pen  14  to the information terminal  12  (S 102 ). 
         [0277]    The information terminal  12  transmits the data received from the digital pen  14  to the content server  11  (S 103 ). 
         [0278]    The content server  11  generates the stroke coordinate information  25  and the stroke set information  24  from the absolute coordinates obtained by the digital pen  14  (S 104 ). 
         [0279]    After that, the content server  11  identifies the event ID of the meeting based on a distributed material dot pattern (S 105 ). 
         [0280]    The processing of Steps S 101  to S 105  is the same as that in the first embodiment described above. 
         [0281]    Subsequently, the content server  11  identifies the user by the signature written on the distributed material in Step S 161  (S 162 ). To be specific, the content server  11  subjects the stroke data of the signature to the pattern matching with signatures registered in the signature DB  158 A, to thereby identify the user ID of the user corresponding to the signature. 
         [0282]    Then, depending on whether or not the identified user is included as the registered attendant  214 B, the content server  11  registers the user in the unregistered participant field  215 B or the registered attendant field  214 B (S 107  to S 109 ). Then, the content server  11  generates the media view information  28  (S 110 ), generates the handwritten memo-related information  23  (S 111 ), and sets the meeting information access right (S 112 ). The processing of Steps S 107  to S 112  is the same as that in the first embodiment described above. 
       Fourth Embodiment 
       [0283]      FIG. 22  is a flowchart of written-data accumulating processing according to the fourth embodiment of this invention. 
         [0284]    The fourth embodiment will be described by taking an example case where the user uses the shared-use digital pen  14  and the user&#39;s own medium (e.g., notebook). In other words, in the fourth embodiment, the content server  11  cannot identify the user based on the pen ID of the digital pen and cannot either identify the user based on the document ID. It should be noted that the description of the fourth embodiment will be given to parts different from the first to third embodiments described above, while description of the same parts, which are denoted by the same reference symbols, will be omitted. 
         [0285]    First, before the event starts (or during the event), an attendant (user) at the meeting uses the digital pen  14  to write his/her signature on the meeting attendance form  30  (shown in  FIG. 23 ) (S 171 ). 
         [0286]    During the event, the user uses the digital pen  14  to annotate a memo or the like on the user&#39;s own paper medium such as in a notebook (S 152 ). After that, the user connects the digital pen  14  to the information terminal  12 , and transmits the absolute coordinates obtained by the digital pen  14 , the times at which the absolute coordinates were obtained, and the pen ID, from the digital pen  14  to the information terminal  12  (S 102 ). 
         [0287]    The information terminal  12  transmits the data received from the digital pen  14  to the content server  11  (S 103 ). 
         [0288]    The content server  11  generates the stroke coordinate information  25  and the stroke set information  24  from the absolute coordinates obtained by the digital pen  14  (S 104 ). 
         [0289]    The processing of Steps S 102  to S 104  is the same as that in the first embodiment described above. 
         [0290]    Subsequently, the content server  11  identifies the event ID of the meeting based on the dot pattern ID corresponding to the meeting attendance form  30  (S 153 ). The meeting attendance form  30  (its dot pattern ID) is previously registered in correspondence with the event ID of the meeting. 
         [0291]    It should be noted that the meeting attendance form may be substituted by any other document that allows identification of the meeting (that is insufficient to identify the owner of the document in the fourth embodiment). For instance, the fourth embodiment can be applied to a case of using the distributed materials (along with the same dot pattern) whose owners cannot be identified. 
         [0292]    Subsequently, the content server  11  identifies the user by the signature written on the meeting attendance form  30  in Step S 171  (S 162 ). To be specific, the content server  11  subjects the stroke data of the signature to the pattern matching with signatures registered in the signature DB  158 A, to thereby identify the user ID of the user corresponding to the signature. 
         [0293]    After that, depending on whether or not the identified user is included as the registered attendant  214 B, the content server  11  registers the user in the unregistered participant field  215 B or the registered attendant field  214 B (S 107  to S 109 ). Then, the content server  11  generates the media view information  28  (S 110 ), generates the handwritten memo-related information  23  (S 111 ), and sets the meeting information access right (S 112 ). The processing of Steps S 107  to S 112  is the same as that in the first embodiment described above. 
         [0294]      FIG. 23  is an explanatory diagram of a meeting attendance form  30  according to the fourth embodiment. 
         [0295]    The meeting attendance form  30  is printed along with a specific dot pattern. Used as the dot pattern of the meeting attendance form  30  is a dot pattern corresponding to the dot pattern ID of the meeting included as the distributed material  216  of the event information. Therefore, when the user designates an arbitrary position on the meeting attendance form  30 , the content server  11  can identify the dot pattern ID corresponding to the meeting attendance form  30 , and can further identify the meeting (event ID). 
         [0296]    The meeting attendance form  30  is filled in by the user who attends at the event. The meeting attendance form  30  includes the place  301  of the event, the date and time  302 , and an attendant  305 . 
         [0297]    The place  301  and the date and time  302  are the same as those of the first embodiment described above. 
         [0298]    An attendant  305  is provided with fields to be filled in with an attendant&#39;s name. The user fills in the attendant  305  with a section of a company to which the user belongs and his/her own name. 
         [0299]    The content server  11  uses the signature DB  158 A to identify the user ID of the user corresponding to the signature. Then, the content server  11  updates the presence/absence data of the registered attendant field  214 B of the identified user into “present”. Alternatively, the content server  11  registers the user ID of the identified attendant in the unregistered participant field  215 B. 
       Fifth Embodiment 
       [0300]      FIG. 24  is a flowchart of processing of retrieving various kinds of information obtained during the meeting based on a handwritten memo according to the fifth embodiment of this invention. 
         [0301]    Unlike the first embodiment described above, the fifth embodiment will be described by taking an example case where users use sheets having different dot patterns, for instance, a case where all the distributed materials have different dot patterns or a case where the users have notebooks having different dot patterns. In other words, the description will be made for a case where paper on which a user annotates with the digital pen allows identification of the user who possesses the document. 
         [0302]    It should be noted that the description of the fifth embodiment will be given to parts different from the first embodiment described above, while description of the same parts, which are denoted by the same reference symbols, will be omitted. 
         [0303]    First, the user designates a handwritten memo written on the distributed material with the digital pen possessed by the user (S 181 ). At this time, the digital pen  14  photographs a dot pattern in a position of the designation to obtain the absolute coordinates of the designated position. 
         [0304]    After that, the user connects the digital pen  14  to the information terminal  12 , and transmits the absolute coordinates obtained by the digital pen  14 , the time at which the absolute coordinates were obtained, and the pen ID, from the digital pen  14  to the information terminal  12  (S 182 ). 
         [0305]    Upon reception of the absolute coordinates, the time at which the absolute coordinates were obtained, and the pen ID, from the digital pen  14 , the information terminal  12  transmits the received data to the content server  11  (S 143 ). 
         [0306]    The content server  11  identifies the distributed material based on the absolute coordinates obtained by the digital pen  14  (S 184 ). 
         [0307]    To be specific, the content server  11  transmits the absolute coordinates obtained by the digital pen  14  to the location information server  19 . The location information server  19  identifies the dot pattern ID and the relative coordinates based on the absolute coordinates transmitted from the content server  11 , and transmits the dot pattern ID and the relative coordinates to the content server  11 . The content server  11  searches the distributed material information  22  with the obtained dot pattern ID as a search key to identify a distributed material using the dot pattern ID. 
         [0308]    Then, the content server  11  extracts the stroke set included in the distributed material information  22  of the identified distributed material ID. Further, the content server  11  collates the obtained relative coordinates obtained from the location information server  19  with the corresponding rectangle coordinates  244  of the extracted stroke set to identify the designated handwritten memo (stroke set ID). 
         [0309]    Subsequently, the content server  11  searches the user information  27  with the pen ID of the digital pen  14  as a search key to identify the user who possesses the digital pen. 
         [0310]    After that, the content server  11  judges whether or not the user has a right to view the related information item (S 145 ). 
         [0311]    When it is judged that the user does not have the right to view the information item related to the stroke set, the content server  11  examines the next related information item. On the other hand, when it is judged that the user has the right to view the information item related to the stroke set, the content server  11  reads out the related information item, and transmits the related information item to the information terminal  12  (S 146 ). 
         [0312]    After that, the information terminal  12  outputs the related information item transmitted from the content server  11  (S 147 ). 
       INDUSTRIAL APPLICABILITY 
       [0313]    This invention is useful for a system for managing information recorded on a paper medium as electronic data, in particular, suitable for a document management system.