Patent Publication Number: US-7716718-B2

Title: Electronic device network system and data receiver search method using electronic device network system

Description:
This Nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2003/020937 filed in Japan on Jan. 29, 2003, the entire contents of which are hereby incorporated by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to electronic device network systems in which data is transmitted from one electronic device to another for data output in a network of electronic devices. The invention also relates to data receiver search methods using such electronic device network systems. 
     BACKGROUND OF THE INVENTION 
     With the rapid advancement of information processing devices and Internet environment, there has been ongoing development of OA devices that use not only conventional techniques for LAN environment but also various techniques for the Internet. 
     Such OA devices may be used not only individually but also in combination by combining their functions. The OA devices may be external devices for computer apparatuses, or may be computer apparatuses used as external devices. That is, such OA devices are now regarded as advanced information processing devices for providing services in supporting office work. 
     With the advancement of information processing devices as above, new integrative interface specifications known as BMLinkS® was developed by the OA System Devices Committee in May of 1998. 
     In a printing system under BMLinkS® standards, a host computer transmits print data to a storage server and stores the print data therein, and the stored print data in the storage server is transmitted to a printer for a print job. 
     In another printing system in which information processing devices and printers are disposed at discrete locations on a network, a search is made for a printer that outputs print data, so that the print data can be transmitted to the printer for a print job, as disclosed in Japanese Unexamined Publication for Patent Application No. 214872/1995 (Tokukaihei 07-214872; published on Aug. 15, 1995) (“Publication 1” hereinafter). 
     In the printing system disclosed in Publication 1, a search is made for a function (paper size, double-sided printing, sorting, etc.) and/or a format (bitmap, printer language, etc.) that are suitable for a print job, so that the print job can be carried out according to these functions and formats. 
     With the rapid spreading of networks and the Internet, printing systems as disclosed in Publication 1 are highly convenient and have many applications. 
     However, the printing system disclosed in Publication 1 does not take into account protection (security) of print data. Thus, the printing system is prone to data leakage in printing secret documents, imposing limitations on its applications. 
     In light of the problem of print data leakage, there have been proposed printing systems in which password is entered to output or delete print data, as disclosed in Japanese Unexamined Publication for Patent Application No. 021022/1998 (Tokukaihei 10-021022; published on Jan. 23, 1998) (“Publication 2” hereinafter), and No. 301058/1999 (Tokukaihei 11-301058; published on Nov. 2, 1999) (“Publication 3” hereinafter). 
     For example, the data output control system disclosed in Publication 2 solves the problem of data leakage by providing a security print mode in which a printer server is prevented from outputting print data to a printer unless an ID or password is verified in the print server. 
     While this ensures security by causing users to enter an ID or password, use of printers in the security print mode is prohibited for users who do not know the ID or password. 
     SUMMARY OF THE INVENTION 
     The present invention was made in view of the foregoing problem, and it is an object of the present invention to provide an electronic device network system that allows a user to transmit data through a transmission route according to a user&#39;s desired security level, and to provide a data receiver search method using such an electronic device network system, taking into account protection (security) of data between electronic devices in a network. 
     In order to achieve the foregoing object, an electronic device network system of the present invention includes: an electronic device for transmitting data via a network; a plurality of storing means for storing data transmitted from the electronic device; and a plurality of external devices for acquiring data from the storing means and processing the acquired data, the network connecting the electronic device, the storing means, and the external devices to one another, wherein the electronic device, at least one of the plurality of storing means, and at least one of the external devices each have a security function. 
     With this structure, in transmitting data from an electronic device to an external device via a storing means, a user selects a storing means and external device that have security functions corresponding to a user&#39;s desired security level, thereby safely and conveniently transmitting data to the storing means and external device. 
     That is, the electronic device network system of the present invention is a network system connecting an electronic device, a plurality of storing means for storing various data, and a plurality of external devices for acquiring the stored data in the storing means and processing the acquired data. The electronic device network system complies with the BMLinkS® standards, for example. 
     The electronic device is realized by a host PC or scanner, for example, and transmits data to a storing means and external device via a network. 
     The storing means is realized, for example, by a storage server in a network. A plurality of storage servers have different security levels. 
     The external device is realized, for example, by a printer or MFP (Multi-Function Printer), and processes the transmitted data. 
     In the electronic device network system of the present invention, a security function is rendered to the electronic device, at least one of the storing means, and at least one of the external devices. 
     For example, the security function may be an encryption protocol used in data communications, or it may be realized by a network combining an intranet and the Internet. The security level may be tiered into three levels 0, 1, and 2, for example. Note that, as the term is used herein, security level is 0 when data is transmitted and received without taking into account data security. 
     This enables a user to set a security level according to the importance of transmitted data. Based on the security level so set, the user is able to search for a data transmission route to an external device, thereby safely and securely transmitting the data to a desired storing means or external device. 
     For example, when the user wishes to transmit important data, the data is transmitted through a data transmission route that combines a storing means of a high security level and an external device of a security level that enables the data to be acquired from the storing means of a high security level and to be outputted. This solves the problem of data leakage to a third party. 
     Thus, in order to safely transmit important data, the user simply selects a storing means and external device of a desired security level without entering an ID or password. As a result, an electronic device network system is realized that ensures data safety. 
     As the term is used herein, “security function” refers to a data protecting function for preventing unauthorized access to data in a network so as to protect the data contents (document, image, etc.). Examples of security functions include: 
     unauthorized access preventing function for preventing:
         unauthorized access to a network;   unauthorized access to a device (electronic device, storing means, external device) on a network; and   unauthorized access to predetermined data stored in a device (electronic device, storing means, external device) on a network;       

     tampering preventing function for preventing tampering of data by an unauthorized user; 
     leakage preventing function for preventing unauthorized reading of data by an unauthorized user; and 
     data protecting function for preventing data from being destroyed or made unusable. 
     It is preferable that the leakage preventing function is rendered to the electronic device, at least one of the storing means, and at least one of the external devices. It is particularly preferable that these devices and means have a function of transmitting and receiving encrypted data. 
     In order to achieve the foregoing object, the present invention provides a data receiver search method using an electronic device network system that includes: an electronic device for transmitting data via a network; a plurality of storing means for storing data transmitted from the electronic device; and a plurality of external devices for acquiring data from the storing means and processing the acquired data, the network connecting the electronic device, the storing means, and the external devices to one another, and the electronic device, at least one of the plurality of storing means, and at least one of the external devices each having a security function, the method searching for a storing means and an external device whose respective security functions match a security level set by a user, when the electronic device transmits data. 
     In an electronic device network system that complies with the BMLinkS® or other specifications in which a plurality of electronic devices, storing means, and external devices are disposed at discrete locations on a network, the method searches for a storing means and external device that are suitable for a user&#39;s desired security level, thereby enabling a user to search a plurality of storing means and external devices and find therefrom a storing means and external device that can be used to safely transmit data. 
     Thus, in order to safely transmit important data, the user simply selects a storing means and external device of a desired security level without entering an ID or password. As a result, an electronic device network system is realized that ensures data safety. 
     In order to achieve the foregoing object, a data receiver search system of the present invention includes: a plurality of storing means with different security levels for storing data; a plurality of external devices for acquiring data from the storing means and processing the acquired data; an electronic device connected to the storing means and the external devices via a network; and a search device, connected to the electronic device, for searching for a storing means that satisfies a predetermined condition, the electronic device including: a transmission section for transmitting data to the storing means; and a setting section for enabling a user to set a security level for transmitted data, the search device including a search section for searching for a storing means according to the security level set in the setting section, so that the transmitted data is received by the storing means so searched. 
     Thus, a user only needs to set a security level according to the importance of transmitted data in order to search the network for a storing means whose security level correspond to a user&#39;s desired security level. The user is therefore able to transmit data on a route that includes a storing means whose security function satisfies the user&#39;s desired security level. 
     For a fuller understanding of the nature and advantages of the invention, reference should be made to the ensuing detailed description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating structures of a host PC, a storage, a printer, and a search server in a printing system according to one embodiment of the present invention. 
         FIG. 2  is a block diagram illustrating a schematic structure of the printing system shown in  FIG. 1 . 
         FIG. 3(   a ) through  FIG. 3(   d ) are views illustrating the contents of stored data in respective information storing sections of the host PC, the storage, the printer, and the search server. 
         FIG. 4(   a ) through  FIG. 4(   c ) are block diagrams illustrating data transmission routes for different security levels. 
         FIG. 5  is a flowchart representing procedures for searching for a transmission route of print data when the search is made by giving priority to security level in the printing system of  FIG. 1 . 
         FIG. 6(   a ) through  FIG. 6(   d ) are views illustrating the display contents displayed by the host PC when print data is outputted according to the method in the flowchart of  FIG. 5 . 
         FIG. 7  is a flowchart representing procedures for searching for a transmission route of print data when the search is made by giving priority to printer in the printing system of  FIG. 1 . 
         FIG. 8(   a ) through  FIG. 8(   d ) are views illustrating the display contents displayed by the host PC when print data is outputted according to the method in the flowchart of  FIG. 7 . 
         FIG. 9  is a flowchart representing procedures for searching for a transmission route of print data when the search is made by giving priority to storage in the printing system of  FIG. 1 . 
         FIG. 10(   a ) through  FIG. 10(   d ) are views illustrating the display contents displayed by the host PC when print data is outputted according to the method in the flowchart of  FIG. 9 . 
         FIG. 11  is a flowchart representing procedures for searching for a transmission route of print data when the print data is obtained by searching for a storage using a printer in the printing system of  FIG. 1 . 
         FIG. 12  is a block diagram illustrating a network structure constituting a printing system according to another embodiment of the present invention. 
         FIG. 13(   a ) through  FIG. 13(   d ) are views illustrating the contents of stored data in respective information storing sections of the host PC, the storage, the printer, and the search server. 
         FIG. 14(   a ) through  FIG. 14(   c ) are block diagrams illustrating transmission routes of print data according to security level. 
         FIG. 15  is a block diagram illustrating an internal structure of a scanner in a scanner system according to yet another embodiment of the present invention. 
         FIG. 16(   a ) through  FIG. 16(   d ) are views illustrating the contents of stored data in respective information storing sections of the host PC, the storage, the printer, and the search server. 
         FIG. 17(   a ) through  FIG. 17(   f ) are block diagrams illustrating transmission routes of print data according to security level. 
         FIG. 18  is a flowchart representing procedures for searching for a transmission route when data is transmitted from the scanner to a host PC in the scanner system of  FIG. 15 . 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     First Embodiment 
     Referring to  FIG. 1  through  FIG. 11 , the following will describe a printing system according to an electronic device network system and a data receiver search method using the electronic device network system in one embodiment of the present invention. 
     The printing system of the present embodiment includes a plurality of host PCs (electronic devices), a plurality of storages (storing means), and a plurality of printers (external devices), which are connected to one another through the Internet. 
     Specifically, as shown in  FIG. 2 , the printing system includes four host PCs (host HA 11 , host HB 12 , host HC 13 , and host HD 14 ), three storages (storage SA 21 , storage SB 22 , and storage SC 23 ), four printers (printer PA 31 , printer PB 32 , printer PC 33 , and printer PD 34 ), and a search server (search means, search device)  41 . 
     The host PCs  11  through  14  are realized by common computers, for example, such as a personal computer and workstation, and are used to transmit print data to the printers  31  through  34 . 
     The storages  21  through  23  are for storing various data transmitted from the host PCs  11  through  14 . In the present embodiment, the storages  21  through  23  are used to temporarily store the print data transmitted from the host PCs  11  through  14 . The storages  21  through  23  also output the stored print data to the printers  31  through  34 , as required. 
     The printers  31  through  34  output the print data transmitted from the storages  21  through  23 , or that directly transmitted from the host PCs  11  through  14 . That is, the printers  31  through  34  carry out a print job. 
     The search server  41  searches the storages  21  through  23  or the printers  31  through  34  for a necessary storage or printer. The search is made according to various functions of the storages  21  through  23  and printers  31  through  34 . For example, for a print job of data requiring double-sided printing, the search server  41  searches the printers  31  through  34  for a printer with a double-sided printing function. The search server  41  is also able to search the storages  21  through  23  and the printers  31  through  34  according to their security levels. 
     Next, description is made below as to the security function rendered to each of the host PCs  11  through  14 , each of the storages  21  through  23 , and each of the printers  31  through  34 . 
     In the printing system of the present embodiment, three kinds of data protecting functions, “encryption protocol 2.0,” “encryption protocol 1.0,” and “no encryption protocol” are rendered to each of the host PCs  11  through  14 , each of the storages  21  through  23 , and each of the printers  31  through  34 . With these data protecting functions, three security levels “high,” “medium,” and “low” are realized. 
     The cryptosystem used here may be a common key cryptosystem, a public key cryptosystem, or a hybrid of these cryptosystems. Among these cryptosystems, the hybrid cryptosystem is most preferable, in which data is encrypted by a common key cryptosystem and is sent after a common key is encrypted by a public key cryptosystem, as in the SSL protocol. 
     Note that, the encryption protocol is not the only way to render the security functions. For example, the security functions may be rendered by combining an intranet and the Internet, as will be described in the Second Embodiment, or by encrypting data using encrypting means before it is transmitted, as will be described in the Third Embodiment. 
     Referring to  FIG. 1 , the following more specifically describes the host PCs  11  through  14 , the storages  21  through  23 , the printers  31  through  34 , and the search server  41  in regard to their structures. 
     As illustrated in  FIG. 1 , the storages  21  through  23  each include a communications section  211 , a control section  212 , a storage information storing section  213 , an encryption/decryption section  214 , and a print data storing section  215 . 
     The communications section  211  is an interface for sending and receiving data to and from the external devices. 
     The control section  212  is a central unit, controlling the entire device. 
     The storage information storing section  213  stores storage information, examples of which include security level and user fee. The information stored in the storage information storing section  213  may be displayed using display means (not shown) to enable a user to confirm the stored information. 
     The encryption/decryption section  214  protects the stored print data in the storages  21  through  23 . Specifically, the encryption/decryption section  214  carries out an encryption process so that the transmitted data from the host PCs  11  through  14  are not easily read out by a third party. The encryption/decryption section  214  also carries out a decryption process for decrypting the encrypted print data into a readable form. 
     The print data storing section  215  stores the print data processed by the encryption/decryption section  214 . 
     The printers  31  through  34  each include a communications section  311 , a control section  312 , a printer information storing section  313 , an encryption/decryption section  314 , an image forming section  315 , and a search section  316 . 
     The communications section  311  is an interface for sending and receiving data in and from the external devices. 
     The control section is a central unit, controlling the entire device. 
     The printer information storing section  313  stores the printer information (for example, security level, printer function) characterizing the printer. The information stored in the printer information storing section  313  may be displayed using display means (not shown) to enable a user to confirm the stored information. 
     The encryption/decryption section  314 , as with the encryption/decryption section  214  of the storages  21  through  23 , carries out an encryption process for the print data, and a decryption process for decrypting the encrypted print data into a readable form. 
     The image forming section  315  develops an image from the print data decrypted by the encryption/decryption section  314 . 
     The search section  316  searches for a storage that contains data to be processed by the printer. 
     The host PCs  11  through  14  each include a communications section (transmitting section)  111 , a control section  112 , a host information storing section  113 , an encryption/decryption section  114 , a search driver  115 , and a printer driver  116 . 
     The communications section  111  is an interface for sending and receiving data in and from the external devices. 
     The control section  112  is a central unit, controlling the entire device. 
     The host information storing section  113  stores host information, such as security level, characterizing the host PC. Note that, the information stored in the host information storing section  113  may be displayed using display means (not shown) to enable a user to confirm the stored information. 
     The encryption/decryption section  114 , as with the encryption/decryption sections  213  and  214 , carries out an encryption process for print data, and a decryption process for decrypting the encrypted print data into a readable form. 
     The search driver  115  is driving means for driving the search server  41 . Using the search server  41 , the search driver  115  searches the host PCs  11  through  14  for a desired host PC. With the search driver  115 , the setting section for enabling a user to set a security level is realized on software. That is, the search driver  115  causes a computer (not shown) to operate as the setting section. Another function of the search driver  115  is to command the search server  41  to search for a device whose security level satisfies a user&#39;s desired security level. 
     Using applications installed in the host PCs  11  through  14 , the printer driver  116  causes user data to be converted into print data for respective printers, or causes a target printer to carry out a print job under desired print conditions (the number of copies, paper size, etc.). The printer driver  116  also serves to cause print data (print job) to be stored in the storages  21  through  23 . 
     The search server  41  includes a communications section  411 , a control section  412 , a device information storing section  413 , and a search section  414 . 
     The communications section  411  is an interface for sending and receiving data in and from the external devices. 
     The control section  412  is a central unit, controlling the entire device. 
     The device information storing section  413  stores information concerning all devices on the network, including, for example, security levels of the printers and storages, and print functions of the printers. The information stored in the device information storing section  413  may be displayed using a display section (not shown) of the host PC to enable a user to confirm the stored information. 
     The search section  414  searches the host PCs  11  through  14 , the storages  21  through  23 , or the printers  31  through  34  according to the search conditions specified by a user, so that a device (host PC, storage, or printer) with a user&#39;s desired security level is found based on the device information acquired from the respective devices on the network and stored in the device information storing section  413 . 
       FIG. 3(   a ) through  FIG. 3(   d ) show types of information stored in the respective information storing sections  113 ,  213 ,  313 , and  413  of the storages  21  through  23 , the printers  31  through  34 , the host PCs  11  through  14 , and the search server  41 . 
     The storage information storing section  213  provided in each of the storages  21  through  23  stores information including “storage name,” “storage fee,” and “security level (data protecting functions),” as shown in  FIG. 3(   a ). 
     In the storage SA 21 , security level is “high,” and the encryption protocol level is 2.0, with which print data can be encrypted before it is transmitted. The storage SA 21  also has a backup function that is turned on in times of server trouble. 
     In the storage SB 22 , security level is “medium,” and the encryption protocol level is 1.0, with which print data can be encrypted before it is transmitted. 
     In the storage SC 23 , security level is “low,” and there is no data protection. 
     That is, the printing system of the present embodiment provides three storages of different security levels for data protection. 
     As the term is used herein, security level is “high” when the storage offers high data protection safety in terms of both network and data itself. For example, the security level of a storage is “high” when it is connected only to devices (personal computers, printers, etc.) on an intranet in a company. 
     As the term is used herein, security level is “medium” when the storage offers high safety in terms of data itself but poses safety problems in terms of network. For example, the security level of a storage is “medium” when it is installed in a company but may be connected to external devices on the Internet. 
     As the term is used herein, the security level of a storage is “low” when the data protection safety involves some danger in terms of network and data itself. For example, the security level of a storage is “low” when it provides free access on the Internet. 
     Note that, as to a printing system with storages having security functions, more detailed description will be given in the Second Embodiment below in conjunction with its applications on an intranet, the Internet, and a combination of these networks. 
     As noted above, the storages  21  through  23  have different security levels. Accordingly, user fees are different for these different security levels. For example, user fees are priced 200 Yen, 100 Yen, and 0 Yen (free) in a descending order of security levels. 
     The printer information storing section  313  provided in each of the printers  31  through  34  stores information, including “printer name,” “data protecting function” indicative of a security level of the printers  31  through  34 , “location” where the printer is installed, and “print function” of the printer, as shown in  FIG. 3(   b ). 
     The printer PA 31  has encryption protocol levels 2.0 and 1.0. In addition, the printer PA 31  has a decrypting function, so that the print data can be stocked and remain encrypted until it is printed. The security level is “top secret.” 
     In the printer PB 32  has encryption protocol levels 2.0 and 1.0, and the security level is “high.” 
     In the printer PC 33 , the encryption protocol level is 1.0, and the security level is “medium.” 
     The printer PD 34  offers no data protection, and the security level is “low.” 
     As noted above, the information stored in the printer information storing section  313  includes “location” where the printer is installed, and “print function” of the printer, such as color printing, double-sided printing, and stapling. These information may be displayed in a display section (not shown) of the printer, or may be confirmed at the host PC via the search server  41 . 
     The host information storing section  113  provided in each of the host PCs  11  through  14  stores information, including “host name,” and “data protecting function” indicative of a security level of the host PCs  11  through  14 , as shown in  FIG. 3(   c ). 
     In the present embodiment, the host PCs  11  through  14  all have encryption protocol levels 2.0 and 1.0, so that the print data can be encrypted before it is transmitted. Further, the host PCs  11  through  14  can accommodate any of the security levels “high,” “medium,” and “low.” 
     The device information storing section  413  of the search server  41  stores information including “storage name,” “available printer,” and “security level.” 
     The information stored in the search server  41  may be acquired by gathering printer information from the printers  31  through  34 , and storage information from the storages  21  through  23 . Alternatively, the search server  41  may store information that has been created beforehand. 
     With the device information storing section  413  in the search server  41 , the printing system of the present embodiment is able to select a device (storages  21  through  23 , printers  31  through  34 ) according to the necessary security level for the print data. 
     The search server  41  may additionally be provided with a route search section (route search means) (not shown), which, according to the security level, searches print routes linking storages and printers as shown in  FIG. 4(   a ) through  FIG. 4(   c ). 
     For example, when the user&#39;s desired security level is “high” or higher (“high” or “top secret”), the search server  41  searches for a print route that links the storage SA 21  with the printer PA 31  or printer PB 32 , as shown in  FIG. 4(   a ). 
     As another example, when the user&#39;s desired security level is “medium,” the search server  41  searches for a print route that links the storage SB 22  with the printer PA 31 , printer PB 32 , or printer PC 33 , as shown in  FIG. 4(   b ). 
     Further, when the user&#39;s desired security level is “low,” the search server  41  searches for a print route that links the storage SC 23  with any one of the printers  31  through  34 , as shown in  FIG. 4(   c ). 
     In this manner, the printing system of the present embodiment enables an optimum transmission route to be easily searched according to the user&#39;s desired security level, thereby enabling the printers  31  through  34  to output the print data transmitted from the host PCs  11  through  14  by taking into account data protection security. 
     Referring to  FIG. 5  and  FIG. 6(   a ) through  FIG. 6(   d ), the following describes how print data are transmitted according to the security level in the printing system of the present embodiment. 
       FIG. 6(   a ) through  FIG. 6(   d ) schematically illustrate displayed contents in the host PCS  11  through  14  during a print process. 
     To transmit print data from the host PCs  11  through  14 , the search driver  115  of the host PCs  11  through  14  is activated in step S 1  of the flowchart shown in  FIG. 5 . With the search driver  115  activated, the host PCs  11  through  14  are connected to the search server  41  in S 2 . 
     In response, the host PCs  11  through  14  carry out display as shown in  FIG. 6(   a ), enabling a user to select a search category (search condition). 
     Here, if the user would like a search according to a security level, a “security” button is pressed in S 3 . 
     Then, the host PCs  11  through  14  carry out display as shown in  FIG. 6(   b ), enabling the user to select a security level as he or she desires (security level for the print data). In the display shown in  FIG. 6(   b ), a “high” security level is selected. 
     For example, when a “high” security level is selected in S 4 , a list of storages is displayed in S 5  according to their security levels, as shown in  FIG. 6(   c ). 
     In S 6 , the user selects one of the storages SA through SC in the display of  FIG. 6(   c ). In the example of  FIG. 6(   c ), storage SA is selected. 
     With a storage selected by the user in S 6 , available printers are displayed in S 7  according to the selected storage and the security level, as shown in  FIG. 6(   d ). 
     If the location and print functions of the available printers in the display do not meet the user demand, i.e., if Yes in S 8 , the sequence may be repeated from S 3 . 
     On the other hand, if the functions of the available printers meet the user demand, i.e., if No in S 8 , a storage fee is charged in S 9  and print data is created in S 10 . In S 11 , the print data is transmitted to the selected storage using an encryption protocol. 
     In the printing system of the present embodiment, the print data is transmitted from the host PC to the storage in the manner described above. This enables the print data to be transmitted through a route according to the security level of the print data, thereby realizing a printing system that is safe to use in terms of data protection. 
     Referring to the flowchart of  FIG. 7 , the following will describe how a transmission route of print data is determined by giving priority to the location of the printer used to output the print data, according to the printing system of the present embodiment. 
     In the transmission method of print data described above, a print route is determined by giving priority to the security level. In an alternative transmission method described below, a search for a print route linking printers and storages is made by giving priority to the location of the printer used to output the print data. 
     To transmit print data from the host PCs  11  through  14 , the search driver  115  of the host PCs  11  through  14  is first activated in S 21  of  FIG. 7 . With the search driver  115  activated, the host PCs  11  through  14  are connected to the search server  41  in S 22 . 
     In response, the host PCs  11  through  14  carry out display as shown in  FIG. 8(   a ), enabling a user to select a search category (search condition). Here, if the user would like a search that prioritizes a printer used to output the print data, a “printer” button is pressed in S 23 . 
     Then, the host PCs  11  through  14  carry out display as shown in  FIG. 8(   b ), enabling the user to enter search conditions in S 24 , including the location and function of the printers, for example. In the display shown in  FIG. 8(   b ), printer location (address) is selected. 
     For example, when the printer location (address) selected by a user is “Nara” prefecture, a list of printers located in Nara prefecture is displayed in S 25 , as shown in  FIG. 8(   c ). In addition to the printer locations, the list also displays print functions and security levels of the respective printers. 
     From the list, the user in S 26  selects a printer of a desired location and with print functions and a security level that fulfill the print data. Note that, when the list does not contain a printer that meets the user demand in S 26 , the sequence may return to S 23  to select a search category again and start over the process. 
     With a printer selected in S 26 , an output process of the print data is carried out in S 27 . The output process of S 27  is carried out by either one of the following two methods. In the first method, the print data is transmitted and outputted from the printers  31  through  34  after once stored in the storages  21  through  23 . In the second method, the print data is directly transmitted and outputted from the printers  31  through  34  by bypassing the storages  21  through  23 . 
     Among these two methods, the second method is described first in which the print data is directly transmitted and outputted from the printers  31  through  34  by bypassing the storages  21  through  23 . 
     In this case, in S 33 , the user is charged for using the selected printer, and print data is created in S 34 . Then, the print data is sent in S 35  to the selected one of the printers  31  through  34 , and a print job is carried out for the print data. 
     The first method is described below in which the print data is transmitted and outputted from the printers  31  through  34  after once stored in the storages  21  through  23 . 
     In this case, the user selects a button “output to storage” in the display shown in  FIG. 8(   c ). In response, the host PCs  11  through  14  display a list of available storages  21  through  23  for the selected one of the printers  31  through  34  (S 28 ), as shown in  FIG. 8(   d ). From the list, the user in S 29  selects a storage with a security level and fee that fulfill the print data. If the list does not contains a storage that meets the user demand in S 29 , the sequence may return to S 23  to select a search category again and start over the process. 
     With a storage selected in S 29 , the user is charged for using the selected printer and storage in S 30 , and print data is created in S 31 . In S 32 , the print data is transmitted to the selected storage. 
     The printing system of the present embodiment transmits print data from the host PCs  11  through  14  to the storage or printer according to either one of the first and second methods, thereby outputting the print data from a printer of a desired location. Further, according to the importance of print data, the printing system of the present embodiment selects an optimum route from a plurality of print data transmission routes with different security levels, thereby providing a printing system that has good operability and is safe to use in terms of data protection of print data. 
     Referring to the flowchart of  FIG. 9 , the following describes how a transmission route of print data is determined by giving priority to the respective functions of the storages when searching the storages. 
     To transmit print data from the host PCs  11  through  14 , the search driver  115  of the host PCs  11  through  14  is first activated in S 41  of  FIG. 9 . With the search driver  115  activated, the host PCs  11  through  14  are connected to the search server  41  in S 42 . 
     In response, the host PCs  11  through  14  carry out display as shown in  FIG. 10(   a ), enabling a user to select a search category (search condition). 
     Here, if the user would like a search that prioritizes the security level of a storage, a “storage” button is pressed in S 43 . 
     Then, the host PCs  11  through  14  carry out display as shown in  FIG. 10(   b ), enabling the user to enter search conditions for the storages  21  through  23  in S 44 , including “name” and “security” of the storages  21  through  23 , for example. In the display shown in  FIG. 10(   b ), the “name” of the storages  21  through  23  is selected. 
     For example, when the storage SC 23  is selected, a list is displayed in S 25 , as shown in  FIG. 10(   c ). If the storage SA 21  is selected in S 45 , a list as illustrated in  FIG. 10(   b ) is displayed. 
     From the list of  FIG. 10(   c ) or  FIG. 10(   d ), the user determines whether the requirements of the print data are met by the available printers for the storages SA 21  through SA 23 , the security level determined by combinations (route) of storages and printers, and the user fee for the print job. If the displayed conditions fulfill the requirements of the print data, the user presses an “OK” button in the display of  FIG. 10(   c ) or  FIG. 10(   d ), and selects a storage in S 46 . 
     If the list does not contain available printers, security level, or user fee that fulfill the user demand, the sequence may return to S 43  to select a search category again and start over the process. 
     With a storage selected in S 46 , the user is charged for a storage fee in S 47 , and print data is created in S 48 . The print data is sent to the selected storage in S 49 . 
     In the printing system of the present embodiment, the print data is transmitted from the host PCs  11  through  14  to the storages  21  through  23  in the manner described above. This enables the print data to be transmitted to a storage of a desired security level and stored therein. Further, according to the importance of print data, the printing system enables an optimum route to be selected from a plurality of transmission routes with different security levels, thereby providing a printing system that has good operability and is safe to use in terms of data protection. 
     Further, in the printing system of the present embodiment, a storage with a desired security level may be searched from the printers  31  through  34  using the search server  41 , so as to acquire print data stored in the storage so searched. Referring to the flowchart of  FIG. 11 , the following describes how the storages  21  through  23  are searched from the printers  31  through  34 . 
     In order to start a search for print data from a given printer, the search driver (not shown) of the printers  31  through  34  is first activated in S 61  of  FIG. 11 . With the search driver activated, the printer is connected to the search server  41  in S 62 . 
     In response, the printer carries out display as shown in  FIG. 10(   a ), enabling a user to select a search category (search condition). 
     Here, if the user would like a search according to a storage, a “storage” button is pressed in S 63 . 
     Then, the printer carries out display as shown in  FIG. 10(   b ), enabling the user to enter search conditions for the storages in S 64 , including “name” and “security level” of the storages, for example. In S 65 , the printer displays a search result, enabling the user to select a storage that stores target print data in S 66 . The sequence may return to S 63  if the user needs to select a search condition again. 
     If the user selects a storage containing target print data in S 66 , it is determined in S 67  whether the print data is suitable for a print job in the printer. Namely, it is determined in S 67  whether the desired print data stored in the storage is suitable for the printer in terms of security. 
     If the print data is determined to be printable in S 67  (Yes), the print data is acquired from the selected storage. A print job is carried out for the print data in S 69 , and a user fee is charged in S 70  before the process is finished. 
     On the other hand, if the print data is determined to be unprintable in S 67  (No), the display section displays a message in S 71 , indicating that the print data is unprintable. In S 72 , the user can choose whether to search for an available printer again. If the user chooses to carry out a search again (Yes), a search for available printers is made in S 73 . On the other hand, the process is finished if the user chooses not to carry out a search again (No). 
     As described, in the printing system of the present embodiment, print data stored in a storage cannot be transmitted to a printer if the storage and the printer have different security levels and when the security level of the printer is lower than that of the storage. 
     This prevents the stored print data of the storage from being erroneously outputted from a printer whose security level is lower than that of the print data, thereby ensuring security for the print data. 
     As noted above, the print data stored in a storage is prevented from being transmitted to a printer when the security levels of the storage and printer do not match. In this case, a search may be made for a storage whose security level matches that of the storage, using the search section  316  of the printer operated by the user. This enables the user to quickly find a printer with a matching security level, and output the print data from the printer if the location, functions, and other conditions of the printer are satisfied. 
     Note that, in the described embodiment, the host PCs do not have security levels. However, the present invention is not just limited to this implementation, and security levels may also be set for the host PCs as for the storages and printers. 
     Second Embodiment 
     Referring to  FIG. 12  through  FIG. 14(   c ), the following will describe a printing system according to an electronic device network system and a data receiver search method using the electronic device network system in another embodiment of the present invention. Note that, for convenience of explanation, elements which are functionally equivalent to those described with reference to the drawings in the foregoing First Embodiment are given the same reference numerals and explanations thereof are omitted here. 
     A printing system of the present embodiment is used in basically the same network environment as that of the First Embodiment. However, the printing system of the present embodiment differs from that of the First Embodiment in that the printing system is connected to a network via an intranet, which is used for communications in a confined area as in a company. 
     In a network environment of the printing system of the present embodiment, the host HA 11 , the storage SA 21 , and the printer  31  are connectable only to an intranet  60 , as shown in  FIG. 12 . 
     The host HB 12 , the storage SB 22 , and the printer  32  are connectable to the intranet  60  and an Internet  61 . A search server  41  is connectable to host PCs and printers on the intranet  60  and the Internet  61 . 
     Further, a host HC 13 , a host HD 14 , a printer PC 33 , a storage SC 23 , and a printer PD 34  are connectable only to the Internet  61 . 
     In the printing system of the present embodiment, some of the devices on the intranet  60  are connected to a network  62  (shaded area in  FIG. 12 ) that is connectable both to the intranet  60  and the Internet  61 . For data protection (security), these devices are connected to the other devices on the intranet  60  via a router (access control means)  42  which constitutes a data security system. Further, for data protection (security), the devices on the network  62  (shaded area in  FIG. 12 ) that is defined by both the Internet  61  and the intranet  60  are connected to the devices on the Internet  61  via a firewall (access control means)  43  which constitutes a data security system. 
     As shown in  FIG. 13(   a ), the host information storing section  113  of the host PCs  11  through  14  stores information of storages available to the host PCs  11  through  14 . The host information storing section  113  also stores locations of the storages. The availability of the storages is determined by a network structure, as shown in  FIG. 12 . For example, the host HC 13  is also connectable to the storage SB 22  on the intranet  60 . 
     As shown in  FIG. 13(   b ), the printer information storing section  313  of the printers  31  through  34  stores information of storages available to the printers  31  through  34 . As with the host PCs  11  through  14 , the availability of the storages is determined by a network structure, as shown in  FIG. 12 . For example, the printer PC 33  is also connectable to the storage SB 22 . The printer information storing section  313  also stores locations of the printers, and information concerning print functions, including color printing, double-sided printing, and stapling, for example. The stored information may be displayed through a display section of each printer, or may be confirmed at each host PC via the search server  41 . 
     As shown in  FIG. 13(   c ), the storage information storing section  213  of the storages  21  through  23  stores information of hosts and printers available to the storages  21  through  23 . The storage information storing section  213  also stores locations of these hosts and printers. The availability of hosts and printers is indicated by the network structure of  FIG. 12 . The storage SB 22  is connectable to the host HC 13  and the printer PC 33  on the Internet  61 . 
     As shown in  FIG. 13(   d ), the device information storing section  413  of the search server  41  stores hosts HA through HD and printers PA through PD available to the storages SA through SC. The device information storing section  413  also stores security levels for the print jobs carried out by the printers via the hosts and storages. 
     With the search server  41  provided with the device information storing section  413 , the printing system of the present embodiment is able to set a security level according to the importance of the print data. The print data is then processed by selected devices (storages and printers) corresponding to the security level of the print data being processed. 
     As shown in  FIG. 13(   d ), the printing system of the present embodiment provides three print routes (combinations of storages, hosts, and printers) for print data of different security levels. 
     As the term is used herein, security level is “high” when the printing system offers high data protection safety in terms of both network and data itself. For example, the security level of a print route in the printing system is high when the print route links only devices on the intranet  60  in a company. 
     As the term is used herein, security level is “medium” when the printing system offers high safety in terms of data itself but poses safety problems in terms of network. For example, the security level of a print route in the printing system is medium when the print route may be linked to hosts, printers, and storages on the Internet  61  outside the company, in addition to hosts and printers installed in the company. 
     As the term is used herein, the security level of a print route is “low” when the data protection safety involves some danger in terms of network and data itself. For example, the security level of a print route is “low” when the print route links devices that offer free access on the Internet  61 . 
     The host HA 11 , the storage SA 21 , and the printer PA 31  all have a high security level because these devices are on the intranet  60  and cannot be accessed via the Internet  61  from devices on the Internet  61 . 
     The host HB 12 , the storage SB 22 , and the printer PB 32  are on the intranet  60  and the Internet  61 , and are connectable to devices on the intranet  60  and the Internet  61 . The host HB 12 , the storage SB 22 , and the printer PB 32  are accessible via the Internet  61  from devices on the internet  61 , but access thereto is limited by the firewall  43  that connects the host HB 12 , the storage SB 22 , and the printer PB 32  to the Internet  61 . Therefore, the security levels for these devices are “medium” and are higher than the security levels of devices connected to the Internet  61  without the firewall  43 . 
     The printer PD 34 , the host HC 13 , the host HD 14 , the storage SC 23 , and the printer PC 33  are connected to the Internet  61  without the firewall  43 , and are accessible via the Internet  61  from any devices on the Internet  61 . Accordingly, the security levels of these devices are “low.” 
     In the printing system of the present embodiment, the search server  41  may additionally be provided with a route search section (route search means) (not shown), which, according to the security level, searches print routes linking storages and printers as shown in  FIG. 14(   a ) through  FIG. 14(   c ). 
     For example, when the user&#39;s desired security level is “high,” the search server  41  searches for a print route that links the host HA 11  or HB 12 , the storage SA 21 , and the printer PA 31  or PB 32 , as shown in  FIG. 14(   a ). 
     As another example, when the user&#39;s desired security level is “medium,” the search server  41  searches for a print route that links: one of the hosts HA 11 , HB 12 , and HC 13 ; the storage SC 23 ; and one of the printers PA 31 , PB 32 , and PC 33 , as shown in  FIG. 14(   b ). 
     Further, when the user&#39;s desired security level is “low,” the search server  41  searches for a print route that links: one of the hosts HB 12 , HC 13 , and HD 14 ; the storage SC 23 ; and one of the printers PC 33  and PD 34 , as shown in  FIG. 14(   c ). 
     In this manner, with the search function, the printing system of the present embodiment enables an optimum print route to be easily searched according to the user&#39;s desired security level, thereby enabling the user to select a print route more efficiently. 
     Note that, as in the First Embodiment, the printing system of the present embodiment is also able to transmit print data according to the security level. The manner in which the print data is transmitted according to the security level is already described in the First Embodiment, and further explanations thereof are omitted here. 
     Third Embodiment 
     Referring to  FIG. 15  through  FIG. 18 , the following will describe a scanner system according to an electronic device network system and a data receiver search method using the electronic device network system in yet another embodiment of the present invention. Note that, for convenience of explanation, elements which are functionally equivalent to those described with reference to the drawings in the foregoing First Embodiment are given the same reference numerals and explanations thereof are omitted here. 
     A scanner system of the present embodiment includes scanners (electronic devices)  51  through  54  as illustrated in  FIG. 15 , in addition to the host PCs (external devices)  11  through  14 , the storages  21  through  23 , the printers  31  through  34 , and the search server (search means)  41  as shown in  FIG. 1 . In the present embodiment, scan data are transmitted from the scanners  51  through  54  to the host PCs. In this respect, the present embodiment differs from the foregoing First and Second Embodiments in which print data are transmitted from the host PCs to the printers  31  through  34 . 
     The scanners  51  through  54  each include a communications section  511 , a control section  512 , a scanner information storing section  513 , an encryption section  514 , a search section  515 , an operation section  516 , and an image reading section  517 . 
     The communications section  511  is an interface for sending and receiving data to and from the external devices. 
     The control section  512  is a central unit, controlling the entire device. 
     The scanner information storing section  513  stores scanner information, examples of which include the locations, functions, and security levels of the scanners. The information stored in the scanner information storing section  513  may be displayed using display means (not shown) to enable a user to confirm the stored information. 
     The encryption section  514  protects scan data. Specifically, the encryption section  514  encrypts scan data so that the scan data will not be read easily by a third party. 
     The search section  514  searches the storages and printers on a network according to security levels or other conditions. 
     The operation section  516  is used by a user to directly operate a scanner, and receives user instructions. 
     The image reading section  517  serves as a scanner to read documents and capture document images as image data. 
       FIG. 16(   a ) through  FIG. 16(   d ) show types of information stored in the respective information storing sections  113 ,  213 ,  313 , and  413  of the storages  21  through  23 , the printers  31  through  34 , the host PCs  11  through  14 , and the search server  41 . 
     The storage information storing section  213  provided in each of the storages  21  through  23  stores information including “storage name,” “storage fee,” and “security level (data protections),” as shown in  FIG. 16(   a ). 
     For example, in the storage SA 21 , security level is “high,” and the encryption protocol level is 2.0, with which print data can be encrypted before it is transmitted. 
     In the storage SB 22 , security level is “medium,” and the encryption protocol level is 1.0, with which print data can be encrypted before it is transmitted. 
     In the storage SC 23 , security level is “low,” and there is no data protection. 
     That is, the scan system of the present embodiment provides three storages of different security levels for data protection, as described with reference to  FIG. 3  in the First Embodiment. 
     The scanner information storing section  513  provided in each of the scanners  51  through  54  stores information, including “printer name,” “data protection” indicative of the security levels of the scanners  51  through  54 , “location” where the scanner is installed, and “scanner functions” of the scanner, as shown in  FIG. 16(   b ). 
     A scanner ScA 51  has encryption protocol levels 2.0 and 1.0. In addition, the scanner ScA 51  has an encrypting function. The security level is “top secret.” 
     A scanner ScB 52  has encryption protocol levels 2.0 and 1.0, and the security level is “high.” 
     In a scanner ScC 53 , the encryption protocol level is 1.0, and the security level is “medium.” 
     A scanner ScD 54  offers no data protection, and the security level is “low.” 
     As noted above, the scanner information stored in the scanner information storing section  513  includes “location” where the scanner is installed, and “scanner functions” of the printer, such as color printing, black-and-white printing, and resolutions. These information may be displayed in a display section (not shown) of the scanner, or may be confirmed at the host PC via the search server  41 . 
     The host information storing section  113  provided in each of the host PCs  11  through  14  stores information, including “host name,” “data protection” indicative of the security levels of the host PCs  11  through  14 , and information concerning the presence or absence of data encryption/decryption functions, as shown in  FIG. 16(   c ). 
     In the present embodiment, the host PCs  11  through  14  all have encryption protocol levels 2.0 and 1.0, so that the scan data can be encrypted before it is transmitted. Further, the host PCs  11  through  14 , including the host HD 14  with no encryption protocol, can accommodate any of the security levels “high,” “medium,” and “low.” 
     The device information storing section  413  of the search server  41  stores information concerning routes, the presence or absence of encryption protocol, the presence or absence of data encryption, and security level, as shown in  FIG. 16(   d ). 
     The information stored in the search server  41  may be acquired by gathering scanner information from the scanners  51  through  54 , storage information from the storages  21  through  23 , and host information from the host PCs  11  through  14 . Alternatively, the search server  41  may store information that has been created beforehand. 
     With the device information storing section  413  in the search server  41 , the scanner system of the present embodiment is able to select a device (storages  21  through  23 , host PCs  11  through  14 ) from the scanners  51  through  54  according to the necessary security level for the scanner data. 
     The search server  41  may additionally be provided with a route search section (route search means) (not shown), which, according to the security level, searches data transmission routes linking scanners, storages, and host PCs as shown in  FIG. 17(   a ) through  FIG. 17(   f ). 
     For example, when the user&#39;s desired security level is “top secret,” the search server  41  may search for a transmission route that links the scanner ScA 51 , the storage SA 21 , and the host HA 11 , and that allows data to be transmitted in an encrypted form, as shown in  FIG. 17(   a ). 
     Specifically, the scanner first encrypts scan data. The scan data, in its encrypted form, is transmitted with encryption protocol 2.0 from the storage. The encrypted scan data is decrypted at the host PC when it is used. 
     When the user&#39;s desired security level is “high,” the search server  41  may search for a transmission route that links the scanner ScA 51 , the scanner ScB 52 , the storage SA 21 , and the hostHA 11  or HB 12 , as shown in  FIG. 17(   b ). 
     Specifically, the scanner first transmits data with encryption protocol 2.0, and the data is stored in the storage. When using data, the data is decrypted in the storage and transmitted with encryption protocol 2.0 to the host PC. 
     Alternatively, when the user&#39;s desired security level is “high,” the search server  41  may search for a transmission route that links the scanner ScA 51 , the storage SB 22 , and the host HA 11  or HB 13 , and that allows data to be transmitted in an encrypted form, as shown in  FIG. 17(   c ). 
     Specifically, the scanner first encrypts scan data, and transmits the encrypted scan data with encryption protocol 1.0. The scan data, in its encrypted form, is stored in the storage. When using data, the scan data is transmitted with encryption protocol 1.0 and decrypted at the host PC. 
     When the user&#39;s desired security level is “medium,” the search server  41  may search for a transmission route that links: one of the scanners ScA 51 , ScB 52 , and ScC 54 ; the storage SB 22 ; and one of the hosts HA 11 , HB 12 , and HC 13 , as shown in  FIG. 17(   d ). 
     Specifically, the scanner first transmits scan data with encryption protocol 1.0, and the encrypted scan data is stored in the storage. When using data, the scan data is transmitted with encryption protocol 1.0. 
     Alternatively, when the user&#39;s desired security level is “medium,” the search server  41  may search for a transmission route that links the scanner ScA 51 , the storage SB 23 , and the host HA 11  or HB 13 , and that allows data to be transmitted in an encrypted form, as shown in  FIG. 17(   e ). 
     Specifically, the scanner first encrypts scan data, and transmits the encrypted scan data with no security. The encrypted scan data is then stored in the storage, and is transmitted with no security. When using data, the encrypted scan data is decrypted. 
     When the user&#39;s desired security level is “low,” the search server  41  may search for a transmission route that links: one of the scanners ScA 51  through ScD 54 ; the storage SC 23 ; and one of the hosts HA 11  through HD 14 , as shown in  FIG. 17(   f ). 
     Specifically, the scan data is first transmitted with no security, and is stored in the storage. The scan data is then transmitted to the host PC with no security. 
     In this manner, the scanner system of the present embodiment enables a data transmission route to be easily searched according to the security level, thereby transmitting data from a scanner to a host PC, taking into account security for data protection. 
     To transmit scan data from the scanners  51  through  54 , the search section  515  of the scanners  51  through  54  is first activated in S 81  of  FIG. 18 . With the search section  515  activated, the scanners  51  through  54  are connected to the search server  41  in S 82 . 
     Here, if a user would like a search according to the security level, a “security” button is pressed in S 83 . 
     For example, when a “high” security level is selected in S 84 , storages are displayed in S 85  according to their security levels. 
     In S 86 , the user selects one of the three storages. 
     With a storage selected in S 86 , available host PCs are displayed in S 87  according to the selected storage and the security level. 
     If the locations and functions of the available host PCs in the display do not meet the user demand, i.e., if Yes in S 88 , the sequence may be repeated from S 83 . 
     On the other hand, if the security levels or other conditions of the available host PCs meet the user demand, i.e., if No in S 88 , a storage fee is charged in S 89 , and scan is started in S 90 . The scan data is then encrypted with an encryption protocol, and the encrypted scan data is transmitted to the storage in S 91 . 
     In the scanner system of the present embodiment, the scan data is transmitted from the scanner to the storage in the manner described above. This enables the scan data to be transmitted on a route according to the security level of the scan data, thereby realizing a scanner system that is safe to use in terms of data protection. 
     Note that, the data may be transmitted from the host PC to the storage and printer as in the First and Second Embodiments. Alternatively, the data may be transmitted from an electronic device, such as a scanner, to the storage, host PC, and other external devices, as in the present embodiment. 
     Further, the number of available transmission routes for a user can be increased by combining the encrypted data with the protection functions of communicated data, such as the encryption protocol rendered to each of the scanners, storages, and host PCs, as shown in  FIG. 17(   a ),  FIG. 17(   c ), and  FIG. 17(   e ). 
     It should be appreciated that the electronic device network systems described in the foregoing First through Third Embodiments are merely one example of the present invention, and the present invention is not just limited to these implementations. For example, the present invention is also applicable to a printing system having larger numbers of host PCs, storages, and printers. Further, other than the printing system, the electronic device network system of the present invention may be applied to a network using an electronic device such as a scanner, not a printer, as described in the Third Embodiment. 
     Further, in the First through Third Embodiments, the electronic device (host PC, scanner), external device (printer, host PC), and storing means (storage) each have its own security level. However, the present invention is not just limited thereto. For example, a user may set his or her security level, and it may be combined with the electronic device, external device, and storing means, etc. In this way, for highly secret data, only a limited number of users can have access to devices with a “top secret” security level, enabling the electronic device network system to be structured with improved security. 
     It should be appreciated that the present invention is not just limited to the foregoing embodiments, and the invention may be varied in many ways within the scope of the claims. Further, the technical means described in the foregoing embodiments may be suitably combined to constitute a new embodiment, and all such combinations of the technical means are intended to fall within the scope of the present invention. 
     In one aspect of the invention, the present invention is a printing system including a plurality of storages for storing print data transmitted from a host PC, and a plurality of printers for acquiring the print data from the storages and printing the acquired print data, wherein the storages have different security levels, and the printing system further includes search means for searching for a storage storing the print data, according to the security level of the print data specified by a user. 
     In one aspect of the invention, the present invention is a printing system including a plurality of storages for storing print data transmitted from a host PC, and a plurality of printers for acquiring the print data from the storages and printing the acquired print data, wherein the printing system further includes: a first search means for searching for a storage storing the print data, according to the security level of the print data specified by a user; a display means for displaying a security level of the storage that was selected based on the result of search by the search means; and a second search means for searching for acquiring the print data from the storage and searching for an available printer. 
     In an electronic device network system of the present invention, an electronic device, at least one of a plurality of storing means, and at least one of a plurality of external devices each have a security level. 
     When transmitting data from the electronic device to the external devices via the storing means, the electronic device network system enables the user to select a storing means and an external device whose security functions correspond to a desired security level of the user, thereby transmitting the data to the storing means and the external device more safely and more easily. 
     Thus, when transmitting important data requiring security, the user simply selects a storing means and an external device whose security levels match the user&#39;s security level, without entering an ID or password. As a result, an electronic device network system is realized that ensures data security. 
     The electronic device network system preferably includes a search means for searching the electronic device, storing means, and external devices according to the security levels of the respective security functions of the electronic device, storing means, and external devices. 
     Thus, the user only needs to set a security level according to the importance of transmitted data in order to search the network for a storing means and external device whose security levels correspond to the user&#39;s security level. The user is therefore able to transmit data on a route linking a storing means and external device whose security functions provide the user&#39;s desired security level. 
     The electronic device network system preferably includes a search means for searching for an external device according to the location or functions of the external device. 
     This enables the user to search for an external device according to the location or functions of the external device used to output data, enabling the user to more easily select from the network an external device that fulfills the user demand. 
     For example, when the user prefers a particular location of data output, a search for an external device is made first based on locations of the external devices. Based on the search result, a further search is made according to the security levels, functions, and other criteria of the external devices, thereby searching for an external device that meets the user demand. 
     When the transmitted data requires special processing, a search for an external device is made based on functions of the external devices, enabling a more refined search. 
     It is preferable that the search means searches for a data transmission route from the electronic device to the storing means or external device. 
     This enables the user to search for a transmission route of data from the electronic device to the external device via the storing means, based on his or her desired security level, or the locations, functions, and other criteria of the external devices. 
     For example, when the user&#39;s desired security level for the transmitted data is “high,” a search is made for a storing means and external device whose security functions provide a “high” or higher security level. The transmission route linking the storing means and external device so searched is displayed as the search result. 
     This is more efficient in finding a transmission route that matches the desired security level, as compared with finding a transmission route by combining a storing means and an external device that are separately searched according to the user&#39;s desired security level. 
     It is preferable that the external device includes a search section for searching for a storing means whose security level corresponds to the security level of the external device making the search. 
     This enables the user operating the external device to search for a storing means whose security function is suitable for data transmission to the user&#39;s external device, thereby enabling the user operating the external device to directly acquire necessary data from the storing means storing the data. In this way, the security of output data can be ensured even for data acquired by the external device from the storing means. Further, by searching for a storing means that can transmit data to the external device operated by the user, it is ensured that the security levels are matched to enable the stored data in the storing means to be acquired by the external device making the search. 
     It is preferable that the respective security functions of the electronic device, the storing means, and the external device are determined depending on whether the electronic device, the storing means, and the external device belong to which of a plurality of networks that are connected to one another via access control means. 
     For example, three security levels can be set for a user in a company when a company&#39;s intranet that is connected to the Internet via access control means such as a router or firewall is combined with the Internet that has free access. More specifically, a “high” security level is set for devices that are connectable only to the intranet in the company, a “medium” security level is set for devices that are connectable to both the intranet and the Internet, and a “low” security level is set for devices that are connectable to only the Internet. 
     For important print data, the user may send the data using a device that is connectable only to the intranet in the company and output the data from this device. In this way, the data will not be leaked to external devices that are connectable only to the Internet, thereby outputting data safely and securely. 
     The firewall may prohibit access from devices with particular addresses, or may prohibit communications that uses a port with a specific number, or may prohibit access from particular types of software. The firewall may be realized by hardware (firewall server, etc.) or software (firewall software). 
     The external device is preferably an image forming device. 
     In this way, the storing means and external devices on a network may be searched, and the print data transmitted from the electronic device such as a host PC can be transmitted to a storing means and image forming device whose security levels match a user&#39;s desired security level. As a result, a printing system can be realized that ensures data security. 
     The electronic device is preferably a scanner. 
     In this way, a scanner system is realized in which image data or other types of data read by the scanner is safely transmitted to the storing means, external devices, and other types of electronic devices. 
     In a data receiver search method using an electronic device network system according to the present invention, the electronic device, storing means, and external device each have a security function, and method searches for a storing means and an external device whose respective security functions match a security level set by a user, when the electronic device transmits data. 
     The method is for an electronic device network system that accommodates, for example, BMLinkS®, in which a plurality of electronic devices, storing means, and external devices are installed at discrete locations on a network. In the system, the method searches for a suitable storing means and external device according to a user&#39;s desired security level, thus easily finding a storing means and external device to which data can be safely sent to, by searching the storing means and external devices on a network. Thus, for important data requiring security, the user simply selects a storing means and an external device whose security levels match his or her security level, without entering an ID or password. As a result, an electronic device network system is realized that ensures data security. 
     It is preferable that a search for an external device is made according to the location or functions of the external device. 
     This enables the user to search for an external device based on the location or functions of the external device, enabling the user to more easily select from the network an external device that fulfills the user demand. For example, when the user prefers a particular location of data output, a search for an external device is made first based on locations of the external devices. Based on the search result, a further search is made according to the security levels, functions, and other criteria of the external devices, thereby searching for an external device that meets the user demand. 
     When the transmitted data requires special processing, a search for an external device is made based on functions of the external devices, enabling a more refined search. 
     It is preferable that a search is made for a data transmission route from the electronic device to the storing means or external device. 
     This enables the user to search for a transmission route of data from the electronic device to the external device via the storing means, based on his or her desired security level, or the locations, functions, and other criteria of the external devices. For example, when the user&#39;s desired security level for the transmitted data is “high,” a search is made for a storing means and external device whose security functions provide a “high” or higher security level. The transmission route linking the storing means and external device so searched is displayed as the search result. This is more efficient in finding a transmission route that matches the desired security level, as compared with finding a transmission route by combining a storing means and an external device that are separately searched according to the user&#39;s desired security level. 
     It is more preferable that transmission of data to the electronic device, the storing means, and the external devices is prohibited when the respective security levels of the electronic device, the storing means, and the external device do not match the security level set by the user. 
     In this way, when the user transmits important data requiring security, the data will not be transmitted erroneously to a storing means or external device that provides free access. As a result, it is ensured that the data is transmitted more securely to a desired external device with required security functions. 
     It is preferable that, when stored data in a storing means needs to be outputted from an external device but an external device and a storing means storing necessary data have different security levels so that the data is prevented from being transmitted from the storing means to the external device, a search is made for an external device whose security level matches the security level of the storing means storing the necessary data. 
     This is preferable because it enables the search means to search for an external device that can output necessary data stored in a storing means, when the security level of the external device currently used by the user does not match the security level of the storing means storing the necessary data. As a result, the user is able to always grasp available external devices for data output, and output necessary data from an external device whose security level is suitable for the print data. 
     The invention being thus described, it will be obvious that the same way may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.