Abstract:
In an information data management apparatus, an available capacity for storage is ensured when information data is input and that information data is to be stored in a data storage unit. A process of reducing or compressing data is carried out on at least one of predetermined information data and summary data that indicates succinctly the contents of the predetermined information data. The predetermined information data and summary data are stored in correspondence in the data storage unit. The other data not subjected to reduction or compression remains in the data storage unit in the intact state. By presenting and confirming the other data left, the user can perceive the contents of corresponding information data succinctly when the other data is summary data. When the other data is information data, the details of the contents of the information data can be acquired.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to an information management apparatus, an information management method, a recording medium recorded with an information management program, and a program product. Particularly, the present invention relates to an information management apparatus and method to store and organize information efficiently even in the case where the medium into which information is to be stored is of small capacity, a recording medium recorded with an information management program, and a program product.  
           [0003]    2. Description of the Background Art  
           [0004]    Users can now obtain information of interest using information processing terminals with portable communication cap ability such as a portable cellular phone. The services providing such information include the recently-increasing PUSH type service in which the information transmission source provides a client with information at an arbitrary timing in addition to the so-called PULL type service in which a server responds to an information request from a client according to HTTP (Hyper-Text Transfer Protocol).  
           [0005]    By means of the PUSH type service, information can be provided to the client immediately at a predetermined time or when information is generated at the information provider source even if the client does not transmit an information acquisition request. The provided information includes various types of information such as video and audio as well as text information, resulting in an increase in the information size.  
           [0006]    The resource including a memory of the aforementioned conventional information terminal is limited in capacity due to its portability. The entire data that is to be received may not be stored in the memory if the amount of the data is too large. In the case where data is to be newly received when there is no more empty space in the incorporated memory, the reception is denied, or the data already stored in the incorporated memory is deleted partially or entirely according to a predetermined procedure depending upon each information terminal to allow storage of the newly received data in the empty region obtained as a result of delete.  
           [0007]    In the case where the data is deleted in the order of, for example, the least recently received order according to the aforementioned data delete procedure, the oldest data will be deleted irrespective of whether the data is of importance or of interest to the user, or whether the content of the data has already been confirmed by the user. To solve this disadvantage, various approaches set forth below are afforded. “Receiver For Radio Calling” disclosed in Japanese Patent Laying-Open No. 9-224270 ensures a region to store new data by deleting the oldest message with the lowest priority.  
           [0008]    “Selective Call Receiver And Message Storage/Delete Method” disclosed in Japanese Patent Laying-Open No. 9-238373 ensures a storage region for a new message by erasing the message with the lowest level of importance from the stored messages. Both of these approaches are disadvantageous in that a message, once deleted, cannot be confirmed thereafter since the entire message is deleted from the storage region.  
           [0009]    In “Reception Data Management System” disclosed in Japanese Patent Laying-Open No. 11-196180, determination is made whether the received data has been confirmed by the user to define the data to be deleted or compressed in order to ensure a storage region for new data. However, the determination function is set in advance only at the system side. The user cannot set the parameter for determination. Although the received data includes two types of data differing in size, respective contents thereof can be set only at the system side.  
           [0010]    In “Radio Transfer Apparatus Having Improved Operation During The Period Of Time When Network Is Available, And Transmission Method Thereof” disclosed in Japanese Patent Laying-Open No. 2000-148572, the channel resource is ensured by protecting the contents of a reserved cache memory from consolidation or refresh. However, protection is applied only on a reserved cache memory. Data stored in other cache memories will become the object of consolidation and refresh.  
         SUMMARY OF THE INVENTION  
         [0011]    An object of the present invention is to provide an information management apparatus and information management method that can confirm the contents of information that becomes the subject of reduction even if the information already stored is reduced for the purpose of ensuring a capacity for information storage, an information management method, a recording medium recorded with an information management program, and a program product.  
           [0012]    Another object of the present invention is to provide an information management apparatus that can specify information that is to become the subject of reduction in a variable manner as desired, an information management method, a recording medium recorded with an information management program, and a program product.  
           [0013]    According to an aspect of the present invention, an information management apparatus includes a data storage unit where various data is stored, and an output unit to present information including contents stored in the data storage unit. The information management apparatus includes an information data input unit to input information data, a summary data generation unit generating summary data that can indicate succinctly the contents of the information data input through the information data input unit, and a manager unit storing the information data input through the information data input unit and the summary data generated by the summary data generation unit in correspondence in the data storage unit.  
           [0014]    The manager unit includes a data reduction unit. When the capacity of the information data input through the information data input unit and corresponding summary data is insufficient in the data storage unit, the data reduction unit reduces the data size of either predetermined information data or summary data stored in the data storage unit in correspondence until an available capacity for storage is ensured. At this stage, the predetermined information data and summary data is selected according to a criterion set in a variable manner.  
           [0015]    Since the predetermined information data and summary data that is to become the subject of data reduction can be selected according to a criterion set in a variable manner, the data that is the subject of reduction can be selected according to the user&#39;s demand. Thus, the usability is improved.  
           [0016]    Since the amount of data for at least one of predetermined information data and summary data stored in correspondence with each other is reduced in ensuring an empty region to store input information data into the data storage unit, the other data not subject to reduction remains in the data storage unit intact. By presenting and confirming the other data at the output unit, the contents of the corresponding information data can be confirmed succinctly in the case where the other data is summary data. In the case where the other data is information data, the contents can be identified in detail.  
           [0017]    The information management apparatus can apply a restore process to result in the original data amount in order to present the predetermined information or predetermined summary data subjected to data reduction via the output unit.  
           [0018]    Since a restore process is carried out to result in the original data amount when the predetermined information data or summary data that is subjected to data reduction is to be presented and confirmed via the output unit, the contents in a state prior to reduction can be confirmed.  
           [0019]    The data reduction unit in the information management apparatus of the present aspect can reduce in stages the amount of data of at least one of predetermined information data and summary data until a capacity available for storage is ensured. This data reduction carried out in a stepped manner until an available capacity for storage is ensured avoids the problem that more data than needed is reduced.  
           [0020]    In the information management apparatus of the present aspect, summary data may indicate a portion of the contents of the information data. Also, summary data may indicate the feature of the information data. By presenting and confirming summary data at the output unit, the contents or feature of information data corresponding to the summary data can be perceived.  
           [0021]    In the information management apparatus of the present application, data reduction can be effected by deleting at least one of the predetermined information data and summary data from the data storage unit.  
           [0022]    Since at least either the predetermined information data or summary data already stored is deleted when information data is input and is to be stored in the data storage unit, an empty region sufficient for storage can be obtained promptly.  
           [0023]    In the information management apparatus of the present aspect, data reduction can be effected by compressing at least one of predetermined information data and summary data in the data storage unit.  
           [0024]    When input information data is to be stored in the data storage unit, at least either the predetermined information data or summary data already stored can be compressed to ensure an empty region. In this case, the aforementioned restore process is a decompress process of compressed data.  
           [0025]    In the case where the available capacity for storage is still insufficient even if all the predetermined information and summary data in the data storage unit are compressed in the information management apparatus of the present aspect, at least one of predetermined information data and summary data stored in correspondence in the data storage unit can be deleted until an available capacity for storage is ensured.  
           [0026]    In the case where all the data stored in the data storage unit are compressed, further available capacity can be ensured by deleting at least one of the predetermined image data and summary data.  
           [0027]    In the information management apparatus of the present aspect, deletion of at least one of the predetermined information data and summary data can be carried out stepwise until an available capacity for storage is ensured. This prevents data from being deleted excessively.  
           [0028]    The information management apparatus of the present aspect can include an importance level determination unit to determine the level of importance of information data corresponding to summary data based on a predetermined guideline that is set in a variable manner. The criterion can correspond to the level of importance determined by the importance level determination unit.  
           [0029]    The predetermined information data or summary data that becomes the subject of reduction (deletion or compression) can be determined based on a corresponding level of importance.  
           [0030]    The level of importance is determined based on a predetermined guideline that is set in a variable manner. The user can set a predetermined guideline in a variable manner to alter the importance to a desired level. As a result, the predetermined information data or predetermined summary data that becomes the subject of reduction (deletion or compression) can be set as desired by the user.  
           [0031]    The information management apparatus of the present invention further includes a guideline set unit that is operated by an external source to set a predetermined guideline in a variable manner. In setting a predetermined guideline in a variable manner, the user only has to operate the guideline set unit from an external source.  
           [0032]    The level of importance corresponding to the predetermined information data and summary data is lower than the level of importance of the newly input information data. Therefore, data having a level of importance lower than that of the newly input information data can be set as more likely to be chosen for reduction.  
           [0033]    In the information management apparatus of the present aspect, the manager unit includes an insufficient capacity determination unit. The insufficient capacity determination unit compares the available capacity in the data storage unit with the total size of the information data newly input by the information data input unit and corresponding summary data to determine insufficient capacity based on the comparison result.  
           [0034]    The summary data generation unit in the information management apparatus of the present aspect generates summary data from the contents of information data based on data obtained according to a predetermined condition. The predetermined condition is set in a variable manner.  
           [0035]    By setting the predetermined condition in a variable manner, the contents of the summary data can be altered as desired by the user. For example, the user can alter the setting so that only information of higher requirement is included in the summary data.  
           [0036]    The information management apparatus of the present aspect further includes a condition set unit operated by an external source to set a predetermined condition in a variable manner. In setting a predetermined condition in a variable manner, the user only has to operate the condition set unit from an external source.  
           [0037]    When an available capacity is to be ensured in storing input information data into the data storage unit, compression is effected on at least one of predetermined summary data and predetermined information data stored in correspondence. Therefore, the other data not subjected to compression can be left in the data storage unit in the intact format. By presenting and confirming the other data at the output unit, the contents of the corresponding information data can be perceived succinctly when the other data is summary data. When the other data is information data, the contents of the information data can be perceived in detail.  
           [0038]    In order to present the compressed information via the output unit in the information management apparatus of the present aspect, a decompression process is effected on the relevant information. In the case where the compressed predetermined information data or summary data is to be presented and confirmed via the output unit, the contents can be perceived in detail since the decompression process is carried out to obtain the original data.  
           [0039]    The compression unit of the information management apparatus of the present aspect can compress the data amount of at least one of predetermined information data and summary data in a stepped manner. Since the available capacity for storage can be ensured while carrying out compression stepwise, excessive compression can be avoided.  
           [0040]    According to another aspect of the present invention, an information management method includes an information data input step of entering information data, a summary data generation step of generating summary data that can indicate the contents of the input information data succinctly, and an organization step of storing, in correspondence, information data input at the information data input step and summary data generated at the summary data generation step into a data storage unit prepared in advance having stored contents presented via an output unit prepared in advance. The organization step includes a data reduction step. In the case where the data storage unit lacks sufficient capacity to store information data newly input through the information data input step and corresponding summary data, the data of at least one of predetermined information data and summary data stored in correspondence in the data storage unit is reduced until available capacity for storage is ensured in the data reduction step. In the present aspect, the predetermined information data and summary data are selected according to a criterion set in a variable manner.  
           [0041]    Since the predetermined information data and summary data that is to become the subject of reduction is selected according to a criterion set in a variable manner, the subject of data reduction can be selected as desired by the user. Thus, the usability is improved.  
           [0042]    In the case where an available capacity is to be ensured in storing input information data into the data storage unit, the data of at least one of predetermined summary data and predetermined information data stored in correspondence is reduced. Therefore, the other data not subjected to reduction can be left in the data storage unit in the intact state. By presenting and confirming that other data at the output unit, the contents of the corresponding information data can be perceived succinctly when the other data is summary data. When the other data is information data, the contents thereof can be perceived in detail.  
           [0043]    According to a further aspect of the present invention, an information management method includes an information data input step of entering information data, a summary data generation step of generating summary data that can indicate succinctly the contents of information data input through the information data input step, and an organization step of storing, in correspondence, information data input at the information data input step and summary data generated at the summary data generation step in a data storage unit prepared in advance, having the stored contents presented via an output unit prepared in advance. The organization step includes a compression step. In the case where the capacity to store the information data newly input at the information data input step and corresponding summary data is insufficient in the data storage unit, at least one of the predetermined information data and summary data stored in correspondence in the data storage unit is compressed until an available capacity for storage is ensured at the compression step. In the present aspect, the predetermined information data and summary data are selected according to a criterion set in a variable manner.  
           [0044]    Since the predetermined information data and summary data that becomes the subject of compression can be selected according to a criterion set in a variable manner, the data of interest of compression can be selected as desired by the user. Thus, the usability is improved.  
           [0045]    In the case where an available capacity is to be ensured in storing input information data in the data storage unit, compression is effected on at least one of the predetermined summary data and predetermined information data stored in correspondence. Therefore, the other data not subjected to compression can be left in the data storage unit in the intact format. By presenting and confirming that other data at the output unit, the contents of the corresponding information data can be perceived succinctly when the other data is summary data. When the other data is information data, the contents of the information data can be perceived in detail.  
           [0046]    According to still another aspect of the present invention, a recording medium is machine-readable. An information management program to execute the above-described information management method through the machine is recorded in the recording medium.  
           [0047]    According to a still further aspect of the present invention, a program product executes the above-described information management method through a computer.  
           [0048]    The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0049]    [0049]FIG. 1 is a block diagram of an information data management apparatus according to a first embodiment of the present invention.  
         [0050]    [0050]FIG. 2 is a flow chart of an information data acquisition process in the information data management apparatus of FIG. 1.  
         [0051]    [0051]FIG. 3 shows a specific example of summary data extracted by the summary data extraction unit of FIG. 1.  
         [0052]    [0052]FIG. 4 is a flow chart of an importance level determination process according to the first embodiment.  
         [0053]    [0053]FIG. 5 is a flow chart of a storing process of summary data, information data, and importance level data according to the first embodiment.  
         [0054]    [0054]FIG. 6 shows an example of a screen displayed to set the importance level according to the first embodiment.  
         [0055]    [0055]FIG. 7 shows an example of summary data extracted when the information data is electronic mail data in the first embodiment.  
         [0056]    [0056]FIG. 8 shows the case where information data is electronic mail data with an attached file in the first embodiment.  
         [0057]    [0057]FIG. 9 shows an example of a screen notifying the user of data deletion in the first embodiment.  
         [0058]    [0058]FIG. 10 shows an example of a screen to prompt the user to confirm data deletion in the first embodiment.  
         [0059]    [0059]FIG. 11 shows a structure of an information data management apparatus according to a second embodiment of the present invention.  
         [0060]    [0060]FIG. 12 is a flow chart of an information data acquisition process of the second embodiment.  
         [0061]    [0061]FIG. 13 is a flow chart of an information data confirmation process of the second embodiment.  
         [0062]    [0062]FIG. 14 shows an appearance of an information processor according to a third embodiment of the present invention.  
         [0063]    [0063]FIG. 15 shows a structure of the function of the information processor of FIG. 14.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0064]    Embodiments of the present invention will be described hereinafter with reference to the drawings.  
         [0065]    First Embodiment  
         [0066]    A first embodiment of the present invention will be described based on an information data management apparatus  100 . FIG. 1 is a block diagram of information data management apparatus  100 . Information data management apparatus  100  is incorporated in an information processor  1  having communication capability with an external source and information processing capability via the Internet  200 . Information data management apparatus  100  includes a data input unit  101 , a summary data extraction unit  102 , a data storage manager unit  103 , an importance level determination unit  104 , a data storage unit  105 , a user presentation unit  106 , a user designation unit  107 , a condition set unit  108  and a criterion set unit  109 .  
         [0067]    Data input unit  101  includes a data input capability. According to the data input capability, applied data is input, and then output as information data  3   i  (i=1, 2, 3, . . . , n). Applied data includes, but not limited to, data received at information processor  1  through Internet  200 , and data applied through a user input  300  corresponding to an operation to input data using, for example, a keyboard not shown of information processor  1 .  
         [0068]    Summary data extraction unit  102  has the extraction capability to enter information data  3   i  output from data input unit  101  to extract summary data  5   i  (i=1, 2, 3, . . . , n) from information data  3   i.    
         [0069]    Data storage unit  105  is a memory of a type in which information of a plurality of types is stored. Data storage unit  105  has information data  3   i , summary data  5   i  and importance level data  8   i  that will be described afterwards stored in correspondence with each other.  
         [0070]    User presentation unit  106  has the capability to present user with information via an output unit that has the capability to output information by, for example, display or print out or audio, of information processor  1 . When information read out from data storage unit  105  is input, user presentation unit  106  outputs the input information via the output unit to present the user with the input information.  
         [0071]    User designation unit  107  enters instructions and requests applied by the user through a keyboard or the like of information processor  1 . User designation unit  107  outputs a request to browse specific information data  3   i  or summary data  5   i  in data storage unit  105 , when such a request is input, to data storage manager unit  103 .  
         [0072]    Data storage manager unit  103  has the capability to administer the available capacity of data storage unit  105 , the capability to delete data, the capability to store information data  3   i  and summary data  5   i  in correspondence in data storage unit  105 , and the capability to read out and output to user presentation unit  106  desired information from data storage unit  105  in response to a request from user designation unit  107 .  
         [0073]    Importance level determination unit  104  determines the level of importance of corresponding information data  3   i  based on applied summary data  5   i  to output importance level data  8   i  according to the determination result.  
         [0074]    [0074]FIG. 2 is a flow chart of an information data acquisition process in information data management apparatus  100  shown in FIG. 1. The process when information data  3   i  is input to information data management apparatus  100  of FIG. 1 will be described with reference to the flow chart of FIG. 2.  
         [0075]    Externally applied data is input by data input unit  101 , and output to summary data extraction unit  102  as information data  3   i . Summary data extraction unit  102  receives information data  3   i  to extract summary data  5   i  from received information data  3   i  (step S 201  (step abbreviated to S hereinafter) and S 202 ). Extracted summary data  5   i  and corresponding information data  3   i  are applied to data storage manager unit  103 . Data storage manager unit  103  receives the applied summary data  5   i  and information data  3   i , and outputs received summary data  5   i  to importance level determination unit  104 .  
         [0076]    [0076]FIG. 3 shows a specific example of summary data  5   i  extracted by summary data extraction unit  102  of FIG. 1. Summary data  5   i  includes a portion of corresponding information data  3   i  or data representing a feature of corresponding information data  3   i , and can indicate the contents of corresponding information data  3   i  succinctly. The amount of data of summary data  5   i  is smaller than that of corresponding information data  3   i . Summary data  5   i  includes pointer data  4 , extracted data  6  and flag data  7 . Pointer data  4  is the information to specify and designate corresponding information data  3   i . Extracted data  6  indicates the data per se extracted from corresponding information data  3   i . Flag data  7  includes at least one flag, referred to by importance level determination unit  104  to determine the level of importance of corresponding information data  3   i . The user can perceive the contents of summary data  5   i  via user presentation unit  106 . Here, four summary data  51 - 54  are exemplified.  
         [0077]    In the case where corresponding information data  3   i  is data stored in a file, pointer data  4  indicates the file name thereof. When corresponding information data  3   i  is stored in data storage unit  105 , pointer data  4  can use a pointer to designate information data  3   i  in data storage unit  105 .  
         [0078]    By utilizing the format of corresponding information data  3   i , extracted data  6  indicates contents extracted from the relevant information data  3   i . In the case where corresponding information data  3   i  is electronic mail, a From field indicating the information of the transmission source of the relevant electronic mail or a Reply-To Field indicating information of an address or a Subject field indicating the subject of the mail is extracted and set as extracted data  6 . In the case where From field is extracted, the party to send a reply for corresponding information data  3   i  (electronic mail) can be inferred by referring to summary data  5   i . In the case where Subject field is extracted, the contents of the body of corresponding information data  3   i  (electronic mail) can be estimated by referring to summary data  5   i.    
         [0079]    Thus, even in the case where information data  3   i  is deleted from data storage unit  105  and only summary data  5   i  can be reviewed, presentation of a From field and a Subject field in extracted data  6  in summary data  5   i , in the case of mail, allows the user to at least confirm the dispatcher and subject of the mail. Summary data  5   i  can be used for presentation to the user as well as in other processes in information data management apparatus  100 . For example, determination of an importance level that will be described afterwards can be made using flag data  7  in summary data  5   i.    
         [0080]    In the case where corresponding information data  3   i  is Web data, URL (Uniform Resource Locator) data is extracted from the relevant information data  3   i  and set as extracted data  6 . Therefore, the corresponding information data  3   i  (web data) can be accessed again based on the URL data obtained by referring to summary data  5   i.    
         [0081]    In the present example, flag data  7  includes flags A, B, C and D. The value of flag A indicates whether protection on deletion of corresponding information data  3   i  is to be set or not. Flag A takes value 1 when protection is set and value 0 when protection is not set. The value of flag B indicates whether corresponding information data  3   i  has not yet been referred to by the user, or already referred to by the user. Flag B takes the value of  1  when corresponding information data  3   i  is not yet referred and the value of 0 when already referred. Flag C indicates the type of corresponding information data  3   i  by a value of 2 bits. Flag C takes the value of 11 when information data  3   i  indicates the schedule, the value of 10 when information data  3   i  is electronic mail, the value of 01 when information data  3   i  is web data, and the value of 00 for other cases. Flag D indicates the date of receiving corresponding information data  3   i  via the Internet  200 , or the date input by user input  300 , or a date of update. By handling the type of information data  3   i  in a manner similar to those of other items, the level of importance (priority) referred to for determination of deletion can be set arbitrarily based on the data type, as will be described afterwards.  
         [0082]    Referring to FIG. 2 again, importance level determination unit  104  receives summary data  5   i  and refers to flag data  7  in received summary data  5   i  to execute an importance level determination process set forth below according to the flow chart of FIG. 4.  
         [0083]    First, determination is made whether  1  is set in flag A in the input summary data  5   i  (S 401 ). In the case where flag A takes the value of 1, “a” is set in corresponding importance level data  8   i  since corresponding information data  3   i  is protected data designated by the user so as not to be deleted (S 402 ). In the case where flag A takes the value of 0, control proceeds to identify the value of flag B (S 403 ). In the case where flag B takes the value of 1, “b” is set in corresponding importance level data  8   i  since corresponding information data  3   i  is information not yet read (S 404 ). In the case where flag B takes the value of 0, control proceeds to identify control proceeds to identify the value of flag C (S 405 - 407 ).  
         [0084]    In the case where flag C takes the value of 11, “c” is set in corresponding importance level data  8   i  since corresponding information data  3   i  is schedule data (S 408 ). In the case where flag C takes the value of  10 , “d” is set in corresponding importance level data  8   i  since corresponding information data  3   i  is electronic mail data (S 409 ). In the case where flag C takes the value of 01, “e” is set in corresponding importance level data  8   i  since corresponding information data  3   i  is Web data (S 410 ). In the case where flag C takes the value of 00, “f” is set in corresponding importance level data  8   i  since corresponding information data  3   i  is other data (S 411 ).  
         [0085]    Importance level data  8   i  having respective values set as described above is output to data storage manager unit  103  (S 412 ). Thus, the importance level determination process ends.  
         [0086]    The level of importance of information data  3   i  becomes lower in the order of value a, b, c, d, e and f of importance level data  8   i . When there are a plurality of information data  3   i  having the same value for importance level data  8   i , the level of importance is determined based on the reception date or input date or update date indicated by corresponding flag D. In other words, a lower level of importance is defined for information data  3   i  in proportion to an older least recent) reception date or input date or update date.  
         [0087]    A lower level of importance in importance level data  8   i  for information data  3   i  has been set in the order of schedule data, electronic mail data, Web data, and other data. However, the setting order is not limited thereto. For example, a determination method of the level of importance can be implemented so that a certain electronic mail, for example, that has importance level data  8   i  higher than the schedule data or lower than Web data is included.  
         [0088]    As an alternative to the importance level determination through importance level determination unit  104 , the user can directly determine and specify the level of importance.  
         [0089]    Referring to FIG. 2 again, following the above-described importance level determination process, data storage manager unit  103  executes a storing process to set summary data  5   i , information data  3   i  and importance level data  8   i  in correspondence (S 204 ). The storing process of summary data  5   i , information data  3   i  and importance level data  8   i  will be described according to the flow chart of FIG. 5. It is assumed that information data  3   i  and summary data  5   i  and importance level data  8   i  corresponding thereto are stored, ‘m’ each, in data storage unit  105 .  
         [0090]    Data storage manager unit  103  inputs summary data  5   i  and corresponding information data  3   i  from summary data extraction unit  102  and also importance level data  8   i  corresponding to the input information data  3   i  from importance level determination unit  104  (S 499 ). Value ‘m’ is set to the control variable ‘J’ of the process (S 500 ) The total size of the input information data  3   i  and summary data  5   i  is compared with the available capacity in data storage unit  105  (S 501 ).  
         [0091]    In the case where the comparison result indicates that the total size of the input information data  3   i  and summary data  5   i  is smaller than the available capacity in data storage unit  105 , the input importance level data  8   i  is sorted and stored in data storage unit  105  in the order of the plurality of importance level data  8   i  stored in data storage unit  105 . Then, the input information data  3   i  and summary data  5   i  are stored in data storage unit  105  in correspondence with the sorted importance level data  8   i  (S 502  and S 503 ). Thus, the process ends.  
         [0092]    In the case where the total size of the input information data  3   i  and summary data  5   i  is greater than the available capacity in data storage unit  105 , determination is made whether the value of the input importance level data  8   i  is lower than the value of the Jth importance level data  8   i  stored in data storage unit  105  (S 504 ).  
         [0093]    When the determination result indicates that the value of the input importance level data  8   i  is lower, the input information data  3   i , summary data  5   i  and importance level data  8   i  will not be stored in data storage unit  105 , and the process ends. In contrast, when the value of the Jth importance level data  8   i  stored in data storage unit  105  is lower, information data  3   i  corresponding to that Jth importance level data  8   i  is deleted from data storage unit  105  (S 505 ). Following this deletion of one information data  3   i , the value of m is updated to m=m−1 (S 506 ). Control returns to S 501 , and the subsequent process is repeated until the input information data  3   i  and summary data  5   i  are stored in data storage unit  105 . Then, the process by data storage manager unit  103  ends.  
         [0094]    In the present first embodiment, deletion of information data  3   i  from data storage unit  105  is executed in order to ensure a region in data storage unit  105  to store the newly input data. However, since summary data  5   i  corresponding to the deleted information data  3   i  still retains in data storage unit  105 , the contents indicating the deleted information data  3   i  succinctly (pointer data  4 , extracted data  6  and flag data  7 ) can be perceived by referring to the relevant summary data  5   i . Accordingly, the contents of relevant information data  3   i  can be inferred.  
         [0095]    Although the subject of deletion is information data  3   i  here, corresponding summary data  5   i  can be deleted instead.  
         [0096]    In the case where the data to infer the contents of the deleted information data  3   i  is not required, information data  3   i  and corresponding summary data  5   i  can be deleted simultaneously instead of deleting only information data  3   i  as in FIG. 5. Such deletion designation can be specified at the user side via user designation unit  107 .  
         [0097]    The data to be deleted does not necessarily have to be determined according to the determination process based on importance level data  8   i . For example, information data  3   i  corresponding to electronic mail from a certain mail address can be deleted with priority. Such a designation can be carried out at the user side via user designation unit  107 .  
         [0098]    Also, the present embodiment can be implemented in which summary data  5   i  is generally not stored. Only in the case where the available capacity in data storage unit  105  is insufficient, summary data  5   i  is extracted for determination of the level of importance.  
         [0099]    The types of flags included in flag data  7  of summary data  5   i  is not limited to those described above. A flag that indicates the dispatch source of corresponding information data  3   i  or a flag indicating whether a particular text train is included or not can be employed. Also, the type of flag set depending upon the type of information data  3   i  can be altered. Furthermore, by allowing the user who is using information data management apparatus  100  to set the value of importance level data  8   i  and the flag, data management that is more conformable to the user&#39;s request can be implemented. Such a user request can be designated by the user via a criterion set unit  109 .  
         [0100]    Accordingly, the level of importance can be altered as desired by the user. For example, the user who wishes to have mail data saved above all can raise the priority of flag C through the setting using, for example, a screen  400  shown in FIG. 6 directed to importance level setting. The user who merely wishes to delete data from the oldest data can raise the priority of flag D.  
         [0101]    An example of a screen displayed via the output unit of information processor  1  to set importance level data  8   i  (priority) as to the four determination criteria corresponding to the aforementioned flags A, B, C and D in information data processor  1  is shown in FIG. 6. The four determination criteria include the items of “deletion protection”  314 , “unread/read”  315 , “data type”  316 , and “received date•updated date”  317 . In screen  400  of FIG. 6 for information data  3   i , list buttons  305 ,  306 ,  307 ,  308  and buttons  310 ,  311 ,  312 ,  313  corresponding to display areas  301 ,  302 ,  303 ,  304 , respectively, to display a desired determination criterion specified by the user are provided. Here, the level of importance priority) for the determination criterion displayed in each of display areas  301 ,  302 ,  303  and  304 , in order, is determined.  
         [0102]    The user operates respective list buttons  305 ,  306 ,  307  and  308  to display, in a list format, the labels of the four determination criteria relating to corresponding display areas  301 ,  302 ,  303  and  304 , respectively. FIG. 6 corresponds to the case where list button  305  is operated to display determination criterion list  309 . The user specifies the desired type of determination criterion from the displayed determination criterion list, whereby the specified determination criterion is displayed on the corresponding display area. In FIG. 6, deletion protection  314  is specified as the determination criterion from the determination criterion list  309 , i.e. as the determination criterion desired by the user to be set with the highest level of importance. Thus, the desired determination criterion selectively specified from determination criterion list  309  displayed by operating respective list buttons  305 - 308  is displayed in respective display areas  301304  is provided.  
         [0103]    Buttons  310 - 313  function to display a screen for setting (not shown), when operated, in the case where a criterion to set the level of importance in further detail for the determination criterion displayed in each of corresponding display areas  301 - 304 . For example, when “data type”  316  is displayed in display area  303 , an operation on button  312  causes display of a screen to set in further detail the level of importance based on the data type such as electronic mail, Web data, schedule data and the like. In the case where, for example, “received date•updated date”  317  is displayed in display area  303 , an operation on button  312  causes display of a screen to set in further detail the level of importance based on the ascending/order/descending order of the received date.  
         [0104]    The determination criterion to set the level of importance is not limited to that described above. A complicated structure such as a tree structure can be implemented. Furthermore, particular data can be specified by a combination of a plurality of conditions.  
         [0105]    [0105]FIG. 7 shows an example of summary data Si extracted when information data  3   i  is electronic data. Since electronic mail is transferred to the mail address mainly used by information data management apparatus  100  from a plurality of mail addresses here, it is assumed that there are present a user UA who requires a “To field” indicating the address of the electronic mail, and a user UB who requires the contents of the body of the electronic mail to look into the contents per se.  
         [0106]    It is assumed that a mail body  601  corresponding to information data  3   i  includes a To field  801  indicating the information of destination, a From field  802  indicating information of the dispatcher, a Subject field  803  indicating the subject of the mail, a Date field  804  indicating the date of transmission, a Message-ID field  805  indicating a message ID, a Mine-Version field  806 , a Content-Type field  807  indicating the mail format, a Content-Transfer-Encoding field  806  indicating the character code of the mail, and a mail main text  809 . Summary data extraction unit  102  extracts summary data  602  and  603  including extracted data  6  as summary data  5   i  from mail body  601  in response to the request of users UA and UB, respectively.  
         [0107]    Summary data  602  and  603  include Date field  804 , From field  802  and Subject field  806  in common to extracted data  6 . The field included in summary data  602  as extracted data  6  unique to user UA includes To field  801 . The field included in summary data  603  as extracted data  6  unique to user UB includes mail text (partial)  810  which is a portion of mail main text  809 . This mail main text (partial)  810  may be just the several ten to several hundred characters from the beginning of mail main text  809 , or a summary of mail main text arranged by some means indicating the feature of the described contents in mail main text  809 .  
         [0108]    In the present embodiment, data of less importance to newly input data for storage into data storage unit  105  is deleted from data storage unit  105 . An application set forth below is also allowed. The data deleted from data storage unit  105  is transferred to and stored in a memory region (not shown) in information data management apparatus  100  other than data storage unit  105  or transferred to another apparatus differing from information data management apparatus  100  to be stored in a memory region of another apparatus.  
         [0109]    In the present embodiment, data deletion is effected for each information data  3   i  or summary data  5   i . Alternatively, only a portion of information data  3   i  can be deleted. Also, the amount of data to be deleted can be altered according to the determined level of importance.  
         [0110]    For example, an example of a data structure in the case where information data  3   i  is electronic mail data attached with a file is shown in FIG. 8. In FIG. 8, a header  620  including To field  801 , From field  802 , Subject field  803 , Data field  804 , Message-Id field  805 , Mine-Version field  806 , Content-Type field  807  and Content-Transfer-Encoding field  808 , and mail main text  809  are included in mail body  601  of information data  3   i  in FIG. 8. A text file  641  and an image file  642  are attached to this electronic mail.  
         [0111]    An approach can be taken in which, when the electronic mail of FIG. 8 is the subject of deletion in order to ensure an available capacity in data storage unit  105 , the entire electronic mail of FIG. 8 is not deleted. At least one of attached text file  641  and image file  642  is deleted to leave mail main unit  601 . As an alternative approach, deletion can be effected in a stepped manner to ensure an available capacity by first deleting one of the attached text file  641  and image file  642 , and then deleting the other file when still an available capacity is not sufficient, and then further deleting mail main text  809  when still an available capacity cannot be achieved.  
         [0112]    In the case where data compression is effected that will be described afterwards in order to ensure an empty region in data storage unit  105 , data can be compressed in a stepped manner, similarly to the stepped deletion described above. Deletion and compression of such a stepped manner can be applied also to summary data  5   i.    
         [0113]    In the present invention, the user can be notified of data deletion, when executed. FIG. 9 shows an example of a screen displayed at the output unit of information processor  1  to notify the user that data deletion has been completed. In a screen  401  of FIG. 9, a window  420  appears in which a message is displayed notifying the user that data of the lowest level of importance has been deleted, identifying the deleted data.  
         [0114]    A screen  402  of FIG. 10 requesting the user to confirm deletion may be displayed at the output unit of information processor  1 . In screen  402  of FIG. 10, a window  430  is displayed including a message asking whether deletion of the data of the lowest level of importance is permitted or not, identifying the relevant data, and buttons  432  and  433  to allow or not allow, respectively, deletion. The user can confirm the message displayed in window  430  and operate button  432  in the case deletion is allowed, whereby data is actually deleted. In the case where deletion of the relevant data is not desired and deletion is not permitted, button  433  is operated. Therefore, deletion of required data can be prevented.  
         [0115]    In a similar manner for the data compression process carried out to ensure an available capacity in data storage unit  105 , an approach can be taken to display a screen notifying the user that data has been compressed or a screen asking the user whether data compression is allowed or not.  
         [0116]    In the present embodiment, determination of the level of importance is carried out when the available capacitance in data storage unit  105  is insufficient. However, the timing of determination is not limited thereto. For example, determination can be carried out at a constant cycle, or when the user operates the determination criterion of the importance level, or at an arbitrary time specified by the user.  
         [0117]    Second Embodiment  
         [0118]    A second embodiment will be described hereinafter. In contrast to the previous first embodiment in which an available capacity is ensured by deleting selected data from data storage unit  105 , a process of compressing selected data is carried out together with such data deletion in the second embodiment.  
         [0119]    The form of summary data  5   i , the importance level determination method and data deletion method in the second embodiment are similar to those of the first embodiment. Therefore, illustration and description thereof will not be repeated.  
         [0120]    [0120]FIG. 11 shows a structure of an information data management apparatus  700  of the second embodiment. In FIG. 11, components corresponding to those of information data management apparatus  100  of the first embodiment have the same reference characters allotted, and description thereof will not be repeated.  
         [0121]    Information data management apparatus  700  includes a data input unit  101 , a summary data extraction unit  102 , a data storage manager unit  710 , an importance level determination unit  104 , a data storage unit  105 , a user presentation unit  106 , a user designation unit  107 , a condition set unit  108 , a criterion set unit  109 , an information data compression unit  706 , an information data decompression unit  707 , and an information data compression determination unit  708 .  
         [0122]    Information data compression unit  706  has a capability to compress information data  3   i . Information data decompression unit  707  has a capability to decompress the compressed information data  3   i . Information data compression determination unit  708  determines whether information data  3   i  in data storage unit  105  specified by data storage manager unit  710  is compressed or not. User designation unit  107  has a capability to accept a confirmation request of desired information data  3   i  from the user to instruct data storage manager unit  710  to confirm the relevant desired information data  3   i .  
         [0123]    [0123]FIG. 12 is a flow chart of an information data acquisition process of the second embodiment. The process carried out after information data management apparatus  700  receives information data  3   i  via the Internet  200  or user input  300  will be described with reference to FIG. 12. The extraction feature of summary data  5   i  by summary data extraction  102  and the determination of importance level data  8   i  by importance level determination unit  104  are similar to those of the first embodiment. Therefore, description thereof will not be repeated. It is assumed that importance level data  8   i  is sorted and stored in the ascending order in data storage unit  105 , and information data  3   i  and summary data  5   i  are stored in data storage unit  105  corresponding to the sorted importance level data  8   i.    
         [0124]    Externally applied information data  3   i  is input at data input unit  101 , and output to summary data extraction unit  102  (S 801 ). Upon entry of information data  3   i  at summary data extraction unit  102 , summary data  5   i  is extracted from the input information data  3   i  (S 802 ). The extracted summary data  5   i  and corresponding information data  3   i  are output to data storage manager unit  710 . Data storage manager unit  710  receives information data  3   i  and summary data  5   i , and outputs summary data  5   i  to importance level determination unit  104 .  
         [0125]    Importance level determination unit  104  receives summary data  5   i  and refers to flag data  7  in summary data  5   i  to determine importance level data  8   i  (S 803 ), in a manner similar to that described before. As a result of the determination, importance level data  8   i  is output to data storage manager unit  710 .  
         [0126]    When determination is made that the total size of input information data  3   i  and corresponding summary data  5   i  is smaller than the available capacity in data storage unit  105  (YES in step S 804 ), data storage manager unit  710  sorts the input importance level data  8   i  in an appropriate order among all importance level data  8   i  stored in data storage unit  105 , and then stores the input information data  3   i  and summary data  5   i  in data storage unit  105  in correspondence with the sorted importance level data  8   i  (S 805  and S 806 ). Thus, the process ends.  
         [0127]    When determination is made that the total size of input information data  3   i  and summary data  5   i  is larger than the available capacity in data storage unit  105  (NO at S 804 ), information data  3   i  with the lowest value of corresponding importance level data  8   i  is selected from all the information data  3   i  stored in data storage unit  105  (S 807 ). Determination is made whether selected information data  3   i  is already compressed or not by information data compression determination unit  708  (S 808 ). When the determination result indicates that information data  3   i  is not compressed, the relevant information data  3   i  in data storage unit  105  is compressed by information data compression unit  706  (S 809 ). Then, control returns to S 804 , and the subsequent process is repeated.  
         [0128]    In the case where the relevant information data  3   i  is already compressed, determination is made whether the value of importance level data  8   i  corresponding to the selected information data  3   i  takes the highest value or not (S 810 ). If determination is made that the value is not the highest, information data  3   i  corresponding to importance level  8   i  that takes the next highest value to importance level data  8   i  of the previous selected information data  3   i  is selected (S 812 ). The process of S 808  and et seq. is likewise carried out for selected information data  3   i.    
         [0129]    In the case where select information data  3   i  has the highest value of corresponding importance level data  8   i , a deletion process of information data  3   i  is carried out (S 811 ) as shown in the first embodiment since an available capacity that allows storage of input data could not be ensured in data storage unit  105  even if compression is repeated. Thus, an available capacity is provided.  
         [0130]    According to the flow chart of FIG. 12, the compression process of information data  3   i  in data storage unit  105  is repeated until an available capacity that allows storage of the input data is ensured in data storage unit  105 , or until all information data  3   i  in data storage unit  105  is compressed. In the case where the available capacity to allow storage cannot be ensured even if the compression process on information data  3   i  is executed, the deletion process of information data  3   i  as shown in the first embodiment is carried out to acquire an available capacity.  
         [0131]    In the second embodiment, information data  3   i  is compressed. Alternatively, corresponding summary data  5   i  can be compressed instead of information data  3   i . Further alternatively, both information data  3   i  and corresponding summary data  5   i  can be compressed. The designation for such compression can be input by the user through user designation unit  107 . In all the cases where compressed data is specified and read out according to user designation unit  107  and presented to the user by user presentation unit  106 , a decompression process is carried out by information data decompression unit  707 .  
         [0132]    [0132]FIG. 13 is a flow chart of an information data confirmation process of the second embodiment.  
         [0133]    When the user of information data management apparatus  700  specifies an appropriate information data  3   i  stored in data storage unit  105  and requests browsing of the desired information data  3   i  via user designation unit  107 , user designation unit  107  receives and provides the relevant request to data storage manager unit  710  (S 901 ).  
         [0134]    In response to input of such a request, data storage manager unit  710  designates information data compression determination unit  708  to effect determination relating to compression of desired information data  3   i . Information data compression determination unit  708  identifies the relevant information data  3   i  in data storage unit  105  and provides the determination result to data storage manager unit  710 . Based on the input determination result, when determination is made that desired information data  3   i  is not compressed (NO at S 902 ), the relevant information data  3   i  is read out from data storage unit  105  (S 905 ). Then, control proceeds to S 904  that will be described afterwards.  
         [0135]    When determination is made that the desired information data  3   i  is compressed (YES at S 902 ), data storage manager unit  710  outputs a decompression designation to information data decompression unit  707 . Information data decompression unit  707  reads out the relevant information data  3   i  from data storage unit  105  and applies decompression thereon. The decompressed data is output to data storage manager unit  710  (S 903 ).  
         [0136]    Data storage manager unit  710  provides to user presentation unit  106  the input desired information data  3   i  read out from data storage unit  105 . User presentation unit  106  receives and outputs desired information data  3   i  to present the relevant data to the user (S 904 ).  
         [0137]    By the above-described procedure, the contents of desired information data  3   i  can be perceived irrespective of whether the desired information data  3   i  is compressed or not.  
         [0138]    Third Embodiment  
         [0139]    A third embodiment of the present invention will be described here. In the third embodiment, a recording medium recorded with a program to execute the above-described process through a computer is shown.  
         [0140]    [0140]FIG. 14 is an appearance of an information processor  1  according to a third embodiment of the present invention. FIG. 15 shows the functional block of information processor  1  of FIG. 14. Information processor  1  incorporates the function according to the above-described information data management apparatus  100  or  700 .  
         [0141]    Referring to FIGS. 14 and 15, information processor  1  includes a monitor  110  of a CRT (Cathode Ray Tube) or liquid crystal, a keyboard  150 , a mouse  160 , a pen tablet  170 , a CPU (Central Processing Unit) to control information processor  1  per se in a centralized manner, a memory  124  constituted by a ROM (Read Only Memory) or an RAM (Random Access Memory), a hard disc  126 , a FD (Flexible Disc) drive device  130  mounted with a detachable FD  132  to access the mounted FD  132 , a CD-ROM (Compact Disc Read Only Memory) drive device  140  mounted with a detachable CD-ROM to access the mounted CD-RAM  142 , and a communication interface  180  to establish communication connection between a communication network  182  including the Internet  200  and information processor  1 . Communication connection is established between each of these components via a bus.  
         [0142]    A magnetic tape device having a detachable cassette type magnetic tape mounted to access the mounted magnetic tape can be provided in information processor  1 .  
         [0143]    Monitor  110  corresponds to user presentation unit  106 . Keyboard  150 , mouse  160  and pen tablet  170  correspond to user designation unit  107 , condition set unit  108 , and criterion set unit  109 , respectively. User input through user designation unit  107 , condition set unit  108  and criterion set unit  109  can be realized by specification of desired data through manipulation of the input unit by the user from the displayed data in monitor  110 . Data storage unit  105  can be provided in memory  124 , hard disc  126 , or a FD  132  inserted in FD drive device  130 .  
         [0144]    As the recording medium of the third embodiment, the memory required to carry out the process in information processor  1  such as the ROM of memory  124  per se may be the program medium. Alternatively, the recording medium may be a program medium readable by insertion of a magnetic tape, FD  132  and CD-ROM  142  which are recording media where a program reader such as a magnetic tape device, a FD drive device  130  and CD-ROM drive device  140  not shown are provided as an external memory device. In all cases, the stored program may be of a structure that is accessed and executed by CPU  122 . Alternatively, the program may be of the scheme that is temporarily read out and then loaded into a predetermined program area of information processor  1 , for example the program storage area of RAM of memory  124 , to be read and executed by CPU  122 . It is assumed that the program for such loading is prestored in information processor  1 .  
         [0145]    The above-described program medium is a recording medium that is formed detachable from the body of information processor  1 . It may be a medium that carries a program in a non-volatile manner. For example, it may be a tape system such as a magnetic tape or cassette tape, a disc system including a magnetic disc such as FD  132  and hard disc  126 , or an optical disc such as CD-ROM  142 /MO (Magnetic Optical Disc)/MD (Mini Disc)/DVD (Digital Versatile Disc), a card system such as an IC card including memory card/optical card, or a semiconductor memory formed of a mask ROM, EPROM (Erasable and Programmable ROM), EEPROM (Electrically EPROM), and flash ROM.  
         [0146]    Since information processor  1  adapts a structure that allows communication connection with a communication network  182  including the Internet  200 , a program can be down-loaded through communication network  182 . In such a case, the program for down loading is prestored in the body of information processor  1 , or installed into the body of information processor  1  from another recording medium.  
         [0147]    The contents stored in the recording medium are not limited to a program, and may be data instead.  
         [0148]    Although a desk top type computer as shown in FIG. 14 is exemplified as information processor  1  in the present embodiment, a portable computer such as a note type or lap top type computer or a mobile terminal can also be employed. Also, information processor  1  may be a terminal such as a cellular phone mainly based on a communication function rather than an information processing function.  
         [0149]    Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.