Abstract:
There is disclosed a communication apparatus that operates as a client of a first server having a referral function for referring the communication apparatus to a second server that performs an operation requested by the communication apparatus. The communication apparatus comprises a requesting unit that sends, to the first server or the second server that manages information about a user of the communication apparatus, a request for the operation for applying a use restriction of one or more functions of the communication apparatus, a setting unit that determines whether to enable or disable a referral using the referral function, and a use restricting unit that applies the use restriction of one or more functions of the communication apparatus according to a response to the request sent from the requesting unit and the determination by the setting unit.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a communication device such as an image forming apparatus including a copier, a printer, a scanner, a facsimile, a complex device, and a multifunction device, and an information processing apparatus including a personal computer; a communication method; and a recording medium.  
         [0003]     2. Description of the Related Art  
         [0004]     In recent year, complex devices and multifunction devices having copy, printer, scanner, and facsimile functions have been available in the market. The complex devices can print images on paper when used as copiers or printers, scan images from originals when used as copiers or scanners, and send and receive images to and from other communication apparatuses through telephone lines when used as facsimiles.  
         [0005]     &lt;Patent Document 1&gt; Japanese Patent Laid-Open Publication No. 2002-084383  
         [0006]     &lt;Patent Document 2&gt; Japanese Patent Laid-Open Publication No. 2004-122778  
         [0007]     Some of the functions of the complex devices and multifunction devices use “user information”. For example, when the complex devices and the multifunction devices are used as scanners or facsimiles, “user information” such as mail address and facsimile telephone numbers is used. Although the complex devices and the multifunction devices generally have management functions for managing such user information, it would be useful for the complex devices and the multifunction devices to have acquisition functions for acquiring such user information from “servers”. LDAP (Lightweight Directory Access Protocol) servers are a typical example of such “servers”.  
         [0008]     In LDAP, persons and organizations are recognized as “objects”. Information about an individual object is stored in an entry for information management. The entry contains an “object class”, which is information about the type of the object, and an “attribute” which is information about object characteristics. The attribute consists of “attribute types” such as c (country), o (organization), ou (organization unit), cn (common name), sn (last name), givenName (first name), uid (user ID), userPassword (user password), mail (mail address), and facsimileTelephoneNumber (facsimile telephone number), and “attribute values” such as c:Japan/o:Ricoh/ou:R&amp;D division/cn:Taro Suzuki/sn:Suzuki/givenName:Taro. Each entry has a hierarchical structure according to its object class. A distinguished name (DN) of the entry is formed from hierarchically ordered relative distinguished names (RDNs) from its attributes (identification attributes).  
         [0009]     Various requests and responses are exchanged between LDAP servers and LDAP clients. LDAP supports authentication related operations (e.g. bind, unbind), query related operations (e.g. search, compare), update related operations (add, delete, modify), referrals (a function where an LDAP server refers an LDAP client to another LDAP server), and chaining (a function where an LDAP server contacts another LDAP server). For example, if an LDAP client sends a search request for a search operation to an LDAP server, the LDAP server sends a response (search result) to the LDAP client using referrals and chaining as necessary.  
         [0010]     As information processing functions of complex devices and multifunction devices have become more sophisticated, more and more complex devices and multifunction devices are configured to support user authentication. Examples of the user authentication supported by the complex devices and the multifunction devices include “local authentication” performed by the complex devices and the multifunction devices, and “remote authentication” performed by authentication servers (e.g. LDAP authentication and NT authentication performed by LDAP servers and NT servers).  
         [0011]     Also, as information processing functions of complex devices and multifunction devices have become more sophisticated, more and more complex devices and multifunction devices are configured to support use restriction operations. It would be convenient if use restrictions of the functions of the complex devices and the multifunction devices could be enforced a per-user group basis (e.g. permission to use the devices is granted to users belonging to a company but not granted to users not belonging to the company). For instance, in the case of complex devices and multifunction devices that use LDAP authentication, users may be divided into groups based on their LDAP attributes such that use restrictions may be set in the devices on a per-user group basis. If so, although the user groups can be customized in detail, it is difficult for an operator unfamiliar with LDAP attribute to divide the users into groups. Therefore, there has been a demand for a method of easily grouping users and setting use restrictions on a per-user group basis.  
       SUMMARY OF THE INVENTION  
       [0012]     The present invention may solve at least one problem described above.  
         [0013]     According to an aspect of the present invention, there is provided a method of easily grouping users and enforcing use restrictions on a per-user group basis so as to restrict use of functions of a “communication apparatus” such as an image forming apparatus and an information processing apparatus.  
         [0014]     According to another aspect of the present invention, there is provided a communication apparatus operating as a client of a first server having a referral function for referring the communication apparatus to a second server that performs an operation requested by the communication apparatus, the communication apparatus comprising a requesting unit that sends, to the first server or the second server that manages information about a user of the communication apparatus, a request for the operation for applying a use restriction of one or more functions of the communication apparatus, a setting unit that determines whether to enable or disable a referral using the referral function, and a use restricting unit that applies the use restriction of one or more functions of the communication apparatus according to a response to the request sent from the requesting unit and the determination by the setting unit.  
         [0015]     According to still another aspect of the present invention, there is provided a communication method performed by a communication apparatus operating as a client of a first server, the first serer having a referral function for referring the communication apparatus to a second server that performs an operation requested by the communication apparatus, the method comprising a requesting step of sending, to the first server or the second server that manages information about a user of the communication apparatus, a request for the operation for applying a use restriction of one or more functions of the communication apparatus, a setting step of determining whether to enable or disable a referral using the referral function, and a use restricting step of applying the use restriction of one or more functions of the communication apparatus according to a response to the request sent in the requesting step and the determination in the setting step.  
         [0016]     According to a further aspect of the present invention, there is provided a recording medium storing a program executable by a communication apparatus operating as a client of a first server having a referral function for referring the communication apparatus to a second server that performs an operation requested by the communication apparatus, the program comprising a requesting instruction for sending, to the first server or the second server that manages information about a user of the communication apparatus, a request for the operation for applying a use restriction of one or more functions of the communication apparatus, a setting instruction for determining whether to enable or disable a referral using the referral function, and a use restricting instruction for applying the use restriction of one or more functions of the communication apparatus according to a response to the request sent according to the requesting instruction and the determination according to the setting instruction.  
         [0017]     According to another further aspect of the present invention, there is provided a communication method for use in a first server having a referral function for referring a communication apparatus to a second server that performs an operation requested by the communication apparatus, and in the communication apparatus operating as a client of the first server, the method comprising a requesting step of causing the communication apparatus to send, to the first server or the second server that manages information about a user of the communication apparatus, a request for the operation for applying a use restriction of one or more functions of the communication apparatus, a setting step of causing the communication apparatus to determine whether to enable or disable a referral using the referral function, and a use restricting step of causing the communication apparatus to apply the use restriction of one or more functions of the communication apparatus according to a response to the request sent in the requesting step and the determination in the setting step. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is a block diagram illustrating a software configuration of a multifunction device according to an embodiment of the present invention;  
         [0019]      FIG. 2  is a block diagram illustrating a hardware configuration of a multifunction device according to an embodiment of the present invention;  
         [0020]      FIG. 3  is a schematic diagram illustrating a network including a multifunction device according to an embodiment of the present invention;  
         [0021]      FIG. 4  is a conceptual diagram illustrating information management by LDAP servers and NT servers;  
         [0022]      FIGS. 5A-5C  are tables showing examples of use restriction setting and referral setting;  
         [0023]      FIGS. 6A-6C  are screens used for use restriction setting and referral setting;  
         [0024]      FIG. 7  is a sequence diagram illustrating a first example of the process flow of authentication (LDAP authentication);  
         [0025]      FIG. 8  is a sequence diagram illustrating a second example of the process flow of authentication (LDAP authentication);  
         [0026]      FIG. 9  is a sequence diagram illustrating a third example of the process flow of authentication (NT authentication);  
         [0027]      FIG. 10  is a sequence diagram illustrating a fourth example of the process flow of authentication (NT authentication);  
         [0028]      FIG. 11  is a flowchart illustrating a use restriction operation;  
         [0029]      FIG. 12  is a sequence diagram illustrating steps taken when an authentication operation and a use restriction operation are separately performed;  
         [0030]      FIG. 13  is a sequence diagram illustrating steps taken when an authentication operation and a use restriction operation are jointly performed;  
         [0031]      FIGS. 14A-14C  show examples of an authentication screen, a copier application screen, and a scanner application screen;  
         [0032]      FIG. 15  is a sequence diagram illustrating a modified example of  FIGS. 12 and 13 ;  
         [0033]      FIG. 16  is a flowchart showing a color copying charging operation;  
         [0034]      FIG. 17  is a flowchart showing a monochrome copying charging operation; and  
         [0035]      FIGS. 18A-18C  show examples of an authentication screen, a request screen, and a restriction screen. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0036]      FIG. 1  is a block diagram illustrating a software configuration of a multifunction device  101  according to an embodiment of the present invention. The multifunction device  101  comprises various applications  111 , various platforms  112 , and an operating system  113 .  
         [0037]     The applications  111  include a copier application  121  having a copy function, a printer application  122  having a printer function, a scanner application  123  having a scanner function, and a facsimile application  124  having a facsimile function.  
         [0038]     The platforms  112  include a communication management module  131  for communication management, a document management module  132  for document management, an engine management module  133  for engine management, an operations panel management module  134  for operations panel management, a memory management module  135  for memory management, an authentication management module  136  for authentication management, a user information management module  137  for user information management, and a system management module  138  for system management.  
         [0039]      FIG. 2  is a block diagram illustrating a hardware configuration of the multifunction device  101  according to an embodiment of the present invention. The multifunction device  101  further comprises an imaging unit  201 , a printing unit  202 , a facsimile control unit  203 , a CPU  211 , an ASIC  212 , a RAM  213 , a ROM  214 , a HDD  215 , a NIC  221 , and an operations panel  222 .  
         [0040]     The imaging unit  201  scans images from originals. The printing unit  202  prints images on paper. The facsimile control unit  203  controls the facsimile functions. The CPU  211  is an integrated circuit that processes various information items. The ASIC  212  is an integrated circuit that processes various images. The RAM  213  is a memory (volatile memory) within the multifunction device  101 . The ROM  214  is a memory (nonvolatile memory). The HDD  215  is storage within the multifunction device  101 . The NIC  221  is a communication unit as a network interface of the multifunction device  101 . The operations panel  222  is an operations display unit as a user interface of the multifunction device  101 .  
         [0041]     The applications  111 , the platforms  112 , and the operating system  113  of  FIG. 1  are stored in the ROM  214  and the HDD  215  of  FIG. 2 .  
         [0042]      FIG. 3  is a schematic diagram illustrating a network including the multifunction device  101  according to an embodiment of the present invention. The multifunction device  101  is connected to an LDAP server  301 A, an LDAP server  301 B, an LDAP server  301 C, an NT server  302 A, an NT server  302 B, and an NT server  302 C over the network.  
         [0043]     The LDAP servers  301  and the NT servers  302  store information about, for example, members of an R&amp;D division as shown in  FIG. 4 . The LDAP server  301 A and the NT server  302 A manage information about, for example, members of a PF development group of the R&amp;D division. The LDAP server  301 B and the NT server  302 B manage information about, for example, members of a C&amp;F development group of the R&amp;D division. The LDAP server  301 C and the NT server  302 C consolidate the information about the members of the R&amp;D division.  
         [0044]     In this embodiment, the NT server  302 A corresponds to a domain controller (DC) for a domain for the PF development group of the R&amp;D division. The NT server  302 B corresponds to a domain controller (DC) for a domain for the C&amp;F development group of the R&amp;D division. The NT server  302 C corresponds to a domain controller (DC) for a domain for the R&amp;D division. The NT servers  302 A,  302 B, and  302 C include Active Directory (AD). Accordingly, the LDAP servers  301 A,  301 B, and  301 C and the NT servers  302 A,  302 B, and  302 C support “LDAP” as a communication protocol.  
         [0045]     Moreover, both the LDAP servers  301  and the NT servers  302  support LDAP referrals. For example, when the multifunction device  101  sends a request for an operation to the LDAP server  301 A or the NT server  302 A, the LDAP server  301 A or the NT server  302 A refers the multifunction device  101  to another server (the LDAP server  301 B or  301 C, or the NT server  302 B or  302 C) depending on the result of the operation.  
         [0046]     In the multifunction device  101 , use restrictions of the functions of the multifunction device  101  can be imposed (use restriction setting). Further, in the multifunction device  101 , LDAP referrals for authentication operations for performing operations of restricting the use of the functions of the multifunction device  101  can be enabled or disabled (referral setting).  
         [0047]      FIGS. 5A-5C  are tables showing examples of the use restriction setting and the referral setting. In the multifunction device  101 , the use restriction and the referral settings may be made for the multifunction device  101  as shown in  FIG. 5A . In an alternative embodiment, the use restriction setting and the referral setting may be made on a per-function basis of the multifunction device  101  as shown in  FIG. 5B . In a further alternative embodiment, the use restriction setting and the referral setting may be made on a per-user basis of the multifunction device  101  as shown in  FIG. 5C . In a further alternative embodiment, the use restriction setting and the referral setting may be made on the per-function basis and on the per-user basis of the multifunction device  101  (i.e., for each combinations of the items in  FIG. 5B  and the items  FIG. 5C ). If the settings are made on the per-function basis, “use restriction setting: permitted, referral setting: enabled” may be applied to one function while “use restriction setting: not permitted, referral setting: disabled” may be applied to another function. If the settings are made on a per-user basis, “use restriction setting: permitted, referral setting: enabled” may be applied to one user while “use restriction setting: not permitted, referral setting: disabled” may be applied to another user.  
         [0048]      FIGS. 6A-6C  are screens used for use restriction setting and referral setting.  FIG. 6A  shows a selection screen used for selecting whether to set use restrictions. When “YES” is selected in the screen of  FIG. 6A , the screen switches to the screens of  FIGS. 6B and 6C . The screens of  FIGS. 6B and 6C  are setting screens used for the use restriction setting and the referral setting on the per-function basis. When the use restriction setting and the referral setting are made on the per-function basis and “OK” is pressed, the authentication management module  136  applies the use restriction setting and the referral setting on the per-function basis to the multifunction device  101 .  
         [0049]     The following describes operations of authenticating users of the multifunction device  101  and operations of restricting the use of the functions of the multifunction device  101 . The multifunction device  101  sends the LDAP servers  301  and the NT servers  302 , which manage information about the users of the multifunction device  101 , requests for, for example, authentication operations for performing operations of restricting the use of the functions of the multifunction device  101 . The following describes the case where a member of the C&amp;F development group of the R&amp;D division attempts to use the multifunction device  101  owned by the PF development group of the R&amp;D division.  
         [0050]      FIG. 7  is a sequence diagram illustrating a first example of the process flow of authentication (LDAP authentication).  
         [0051]     First, the authentication management module  136  sends a user authentication request to the LDAP server  301 A together with authentication information (user name and password) of the user of the multifunction device  101  input to the multifunction device  101  (SlOl). In response to the user authentication request, the LDAP server  301 A returns an error message to the authentication management module  136  (S 102 ). In this step, the LDAP server  301 A refers the multifunction device  101  to the LDAP server  301 B as the destination of the authentication request. Then, the authentication management module  136  saves the authentication result at the time referrals are disabled as “authentication failed” (S 103 ).  
         [0052]     Then, the authentication management module  136  sends the user authentication request to the LDAP server  301 B together with the authentication information (user name and password) of the user of the multifunction device  101  input to the multifunction device  101  (S 111 ). In response to the user authentication request, the LDAP server  301 B sends an authentication certificate to the authentication management module  136  (S 112 ). Then, the authentication management module  136  sends an acquisition request for user identification information of the user to the LDAP server  301 B (S 113 ). In response to the acquisition request for user identification information of the user, the LDAP server  301 B sends the user identification information (user ID) of the user to the authentication management module  136  (S 114 ). Then, the authentication management module  136  saves the authentication result at the time referral are enabled as “authentication successful” (S 115 ).  
         [0053]     Subsequently, the authentication management module  136  sends the user information management module  137  an acquisition request for use restriction information indicating the use restrictions of the functions of the multifunction device  101  together with the user identification information and the authentication information (user ID, user name, and password) of the user (S 121 ). In response to the acquisition request for use restriction information indicating the use restrictions of the functions of the multifunction device  101 , the user information management module  137  sends the authentication management module  136  the use restriction information (the use restriction settings shown in  FIGS. 5B, 6B , and  6 C), which is stored in the multifunction device  101 , indicating the use restrictions of the functions of the multifunction device  101  (S 122 ). In this step, the referral settings shown in  FIGS. 5B, 6B , and  6 C are sent together with the use restriction settings shown in  FIGS. 5B, 6B , and  6 C. If the use restriction settings or the referral settings cannot be acquired, the user identification information and the authentication information of the user may be saved in the multifunction device  101  (S 123 , S 124 , and S 125 ). Saving the user identification information and the authentication information of the user allows the multifunction device  101  to create the entry for the user in advance in case use restriction settings and referral settings are made on a per-user basis.  
         [0054]     Then, the authentication management module  136  performs operations of restricting the use of the functions of the multifunction device  101  based on the authentication result, the use restriction settings, and the referral settings (S 131 ). The operations performed in step S 131  are described below in greater detail with reference to  FIG. 11 . In an alternative embodiment, steps S 113  and S 114  may be omitted. If steps S 113  and S 114  are omitted, the user identification information may be unnecessary in step S 121 , and accordingly steps S 123 , S 124 , and S 125  may be omitted.  
         [0055]      FIG. 8  is a sequence diagram illustrating a second example of the process flow of authentication (LDAP authentication).  
         [0056]     First, the authentication management module  136  sends a user authentication request to the LDAP server  301 A together with authentication information (user name and password) of the user of the multifunction device  101  input to the multifunction device  101  (S 201 ). In response to the user authentication request, the LDAP server  301 A returns an error to the authentication management module  136  (S 202 ). In this step, the LDAP server  301 A refers the multifunction device  101  to the LDAP server  301 B as the destination of the authentication request.  
         [0057]     Then, the authentication management module  136  determines whether to send the authentication request to the LDAP server  301 B based on whether the referral setting is “enabled” or “disabled” (S 211 ). If the referral setting is “enabled”, the authentication management module  136  sends the user authentication request to the LDAP server  301 B together with the authentication information of the user of the multifunction device  101  input to the multifunction device  101  (S 212 ). In response to the user authentication request, the LDAP server  301 B sends an authentication certificate to the authentication management module  136  (S 213 ). Then, the authentication management module  136  sends an acquisition request for user identification information of the user to the LDAP server  301 B (S 214 ). In response to the acquisition request for user identification information of the user, the LDAP server  301 B sends the user identification information (user ID) of the user to the authentication management module  136  (S 215 ). If the referral setting is “disabled”, operations of steps S 212 , S 213 , S 214 , and S 215  are not performed, thereby making the processing in the second example faster than the processing in the first example.  
         [0058]     Subsequently, the authentication management module  136  sends the user information management module  137  an acquisition request for use restriction information indicating the use restrictions of the functions of the multifunction device  101  together with the user identification information and the authentication information (user ID, user name, and password) of the user (S 221 ). In response to the acquisition request for use restriction information indicating the use restrictions of the functions of the multifunction device  101 , the user information management module  137  sends the authentication management module  136  the use restriction information (the use restriction settings shown in  FIGS. 5B, 6B , and  6 C), which is stored in the multifunction device  101 , indicating the use restrictions of the functions of the multifunction device  101  (S 222 ). In this step, the referral settings shown in  FIGS. 5B, 6B , and  6 C are sent together with the use restriction settings shown in  FIGS. 5B, 6B , and  6 C. If the use restriction settings or the referral settings cannot be acquired, the user identification information and the authentication information of the user may be saved in the multifunction device  101  (S 223 , S 224 , and S 225 ). Saving the user identification information and the authentication information of the user allows the multifunction device  101  to create the entry for the user in advance in case use restriction settings and referral settings are made on a per-user basis.  
         [0059]     Then, the authentication management module  136  performs operations of restricting the use of the functions of the multifunction device  101  based on the authentication result, the use restriction settings, and the referral settings (S 231 ). The operations performed in step S 231  are described below in greater detail with reference to  FIG. 11 . In an alternative embodiment, steps S 214  and S 215  may be omitted. If steps S 214  and S 215  are omitted, the user identification information may be unnecessary in step S 221 , and accordingly steps S 223 , S 224 , and S 225  may be omitted.  
         [0060]      FIG. 9  is a sequence diagram illustrating a third example of the process flow of authentication (NT authentication).  
         [0061]     First, the authentication management module  136  sends a user authentication request to the NT server  302 A (DC or AD) together with authentication information (user name and password) of the user of the multifunction device  101  input to the multifunction device  101  (S 301 ). In response to the user authentication request, the NT server  302 A sends an authentication certificate to the authentication management module  136  (S 302 ). Then, the authentication management module  136  sends an acquisition request for user identification information of the user to the NT server  302 A (S 303 ). In response to the acquisition request for user identification information of the user, the NT server  302 A returns an error to the authentication management module  136  (S 304 ). In this step, the NT server  302 A refers the multifunction device  101  to the NT server  302 B as the destination of the acquisition request for user identification information. Then, the authentication management module  136  saves the authentication result at the time referrals are disabled as “authentication failed” (S 305 ).  
         [0062]     Then, the authentication management module  136  sends the acquisition request for user identification information of the user to the NT server (AD)  302 B (S 311 ). In response to the acquisition request for user identification information of the user, the NT server  302 B sends the user identification information (user ID) of the user to the authentication management module  136  (S 312 ). Then, the authentication management module  136  saves the authentication result at the time referrals are enabled as “authentication successful” (S 313 ).  
         [0063]     Subsequently, the authentication management module  136  sends the user information management module  137  an acquisition request for use restriction information indicating the use restrictions of the functions of the multifunction device  101  together with the user identification information and the authentication information (user ID, user name, and password) of the user (S 321 ). In response to the acquisition request for use restriction information indicating the use restrictions of the functions of the multifunction device  101 , the user information management module  137  sends the authentication management module  136  the use restriction information (the use restriction settings shown in  FIGS. 5B, 6B , and  6 C), which is stored in the multifunction device  101 , indicating the use restrictions of the functions of the multifunction device  101  (S 322 ). In this step, the referral settings shown in  FIGS. 5B, 6B , and  6 C are sent together with the use restriction settings shown in  FIGS. 5B, 6B , and  6 C. If the use restrictions setting or the referral settings cannot be acquired, the user identification information and the authentication information of the user may be saved in the multifunction device  101  (S 323 , S 324 , and S 325 ). Saving the user identification information and the authentication information of the user allows the multifunction device  101  to create the entry for the user in advance in case use restriction settings and referral settings are made on a per-user basis.  
         [0064]     Then, the authentication management module  136  performs operations of restricting the use of the functions of the multifunction device  101  based on the authentication result, the use restriction settings, and the referral settings (S 331 ). The operations performed in step S 331  are described below in greater detail with reference to  FIG. 11 . In an alternative embodiment, the user identification information may be unnecessary in step S 321 , and accordingly steps S 323 , S 324 , and S 325  may be omitted.  
         [0065]      FIG. 10  is a sequence diagram illustrating a fourth example the process flow of authentication (NT authentication).  
         [0066]     First, the authentication management module  136  sends a user authentication request to the NT server  302 A (DC or AD) together with authentication information (user name and password) of the user of the multifunction device  101  input to the multifunction device  101  (S 401 ). In response to the user authentication request, the NT server  302 A sends an authentication certificate to the authentication management module  136  (S 402 ). Then, the authentication management module  136  sends an acquisition request for user identification information of the user to the NT server  302 A (S 403 ). In response to the acquisition request for user identification information of the user, the NT server  302 A returns an error to the authentication management module  136  (S 404 ). In this step, the NT server  302 A refers the multifunction device  101  to the NT server  302 B as the destination of the acquisition request for user identification information.  
         [0067]     Then, the authentication management module  136  determines whether to send the acquisition request for user identification information to the NT server (AD)  302 B based on whether the referral setting is “enabled” or “disabled” (S 411 ). If the referral setting is “enabled”, the authentication management module  136  sends the acquisition request for user identification information of the user to the NT server  302 B (S 412 ). In response to the acquisition request for user identification information of the user, the NT server  302 B sends the user identification information (user ID) of the user to the authentication management module  136  (S 413 ). If the referral setting is “disabled”, operations of steps S 412  and S 413  are not performed, thereby making the processing in the fourth example faster than the processing in the third example.  
         [0068]     Subsequently, the authentication management module  136  sends the user information management module  137  an acquisition request for use restriction information indicating the use restrictions of the functions of the multifunction device  101  together with the user identification information and the authentication information (user ID, user name, and password) of the user (S 421 ). In response to the acquisition request for use restriction information indicating the use restrictions of the functions of the multifunction device  101 , the user information management module  137  sends the authentication management module  136  the use restriction information (the use restriction settings shown in  FIGS. 5B, 6B , and  6 C), which is stored in the multifunction device  101 , indicating the use restrictions of the functions of the multifunction device  101  (S 422 ). In this step, the referral settings shown in  FIGS. 5B, 6B , and  6 C are sent together with the use restriction settings shown in  FIGS. 5B, 6B , and  6 C. If the use restriction settings or the referral settings cannot be acquired, the user identification information and the authentication information of the user may be saved in the multifunction device  101  (S 423 , S 424 , and S 425 ). Saving the user identification information and the authentication information of the user allows the multifunction device  101  to create the entry for the user in advance in case use restriction settings and referral settings are made on a per-user basis.  
         [0069]     Then, the authentication management module  136  performs operations of restricting the use of the functions of the multifunction device  101  based on the authentication result, the use restriction settings, and the referral settings (S 431 ). The operations performed in step S 431  are described below in greater detail with reference to  FIG. 11 . In an alternative embodiment, the user identification information may be unnecessary in step S 421 , and accordingly steps S 423 , S 424 , and S 425  may be omitted.  
         [0070]      FIG. 11  is a flowchart illustrating a use restriction operation. The use restriction operation of  FIG. 11  corresponds to the use restriction operations in step S 131 , S 231 , S 331 , and S 431  of  FIGS. 7, 8 ,  9 , and  10 .  
         [0071]     The authentication management module  136  refers to the referral setting of one function of the multifunction device  101  (S 501 ). If the referral setting of the function is “enabled”, the authentication result at the time referrals are enabled is acquired (S 502 ). On the other hand, if the referral setting of the function is “disabled”, the authentication result at the time referrals are disabled is acquired (S 503 ). In the examples of  FIG. 7  and  FIG. 9 , the authentication results saved step S 115  and step S 313  correspond to the authentication results acquired in step S 502 , and the authentication results acquired in step S 103  and step S 305  correspond to the authentication results acquired in step S 503 . In the examples of  FIG. 8  and  FIG. 10 , the acquisition of the authentication results of step S 502  and S 503  are already substantially performed as in steps S 211  and S 411 .  
         [0072]     The referral setting in this example is as shown in Table A of  FIG. 11 . This setting is the same as the setting shown in  FIG. 5B . The authentication results at the time referrals are enabled and disabled are as shown in Table B of  FIG. 11 . The authentication results shown in Table B are the same as the authentication results in the examples of  FIGS. 7, 8 ,  9 , and  10 . Accordingly, the authentication results acquired in steps S 502  and S 503  are as shown in Table C of  FIG. 11 .  
         [0073]     The authentication management module  136  then refers to the authentication results acquired in steps S 502  and S 503  (S 511 ). If the authentication result of the function is “failed”, the use “not permitted” is applied (use restriction B). On the other hand, if the authentication result is “successful”, the use restriction setting of the function is referred to (S 512 ). If the use restriction setting of the function is “not permitted”, the use “not permitted” is applied (use restriction B). On the other hand, if the use restriction setting of the function is “permitted”, the use “permitted” is applied (use restriction A). Theses operations are performed for each of the functions of the multifunction device  101  (S 513 ).  
         [0074]     The use restriction setting in this example is as shown in Table D of  FIG. 11 . This setting is the same as the use restriction setting shown in  FIG. 5B . Accordingly, the use restrictions to be applied to the functions of the multifunction device  101  are as shown in Table E of  FIG. 11 .  
         [0075]     In the authentication operations shown in  FIGS. 7, 8 ,  9 , and  10  and the use restriction operation shown in  FIG. 11 , the use restriction operations for the functions of which referral settings are “enabled” are performed according to the authentication result from the LDAP server  301 A (NT server  302 A) and the authentication result from the LDAP server  301 B (NT server  302 B). On the other hand, the use restriction operations for the functions of which referral settings are “disabled” are performed according to authentication result from the LDAP server  301 A (NT server  302 A), but regardless of the authentication result from the LDAP server  301 B (NT server  302 B). In this embodiment, the authentication result from the LDAP server  301 A (NT server  302 A), which manages the information about the members of the PF development group, is “successful” only when the user is a member of the PF development group. That is, by setting the use restriction setting and the referral setting of one function to “permitted” and “disabled”, respectively, the use permission of that function is given only to the members of the PF development group. As described above, the multifunction device  101  is configured such that users can be divided into groups by only setting “enabled” or “disabled” in the referral setting. Further, the use restrictions can be imposed on a per-user group basis by only setting “permitted” or “not permitted” in the use restriction setting. The multifunction device  101  is advantageous because LDAP servers and NT serves generally manage user information on a user group basis (on a per-company basis, on a per-division basis, on a per-location basis, etc.).  
         [0076]     As described above, if the referral setting is enabled, the multifunction device  101  performs operations of restricting the use of the functions of the multifunction device  101  according to the response to the authentication request sent from the LDAP server  301 B (NT server  302 B) to which the LDAP server  301 A (NT server  302 A) referred the multifunction device  101 . On the other hand, if the referral setting is disabled, the multifunction device  101  performs operations of restricting the use of the functions of the multifunction device  101  regardless of the response to the authentication request sent from LDAP server  301 B (NT server  302 B) to which the LDAP server  301 A (NT server  302 A) referred the multifunction device  101 .  
         [0077]      FIG. 12  is a sequence diagram illustrating steps taken when an authentication operation and a use restriction operation are performed separately by individual applications. The following describes the case where the copier application  121  having the copy function and the scanner application  123  having the scanner function are present.  
         [0078]     When the multifunction device  101  is started, the copier application  121  shows an authentication screen (S 601 ). Then, the authentication information of a user who attempts to use the multifunction device  101  is input (S 602 ), so that the copier application  121  sends the authentication management module  136  a query for the use restrictions of the functions of the multifunction device  101  (S 603 ). Then, the authentication management module  136  performs one of the authentication operations of  FIGS. 7, 8 ,  9  and  10 , and the use restriction operation of  FIG. 11  for the copy function of the copier application  121  (S 604 ). The authentication management module  136  sends the copier application  121  a use restriction of the corresponding function of the multifunction device  101  to be applied, indicating “copy function: permitted” (S 605 ). Upon reception of the use restriction of the corresponding function of the multifunction device  101  to be applied, indicating “copy function: permitted”, the copier application  121  shows a copier application screen (S 606 ).  
         [0079]     When a scanner button on the operations panel  222  is pressed (S 611 ) in order to switch from the copier application screen (copy function) to a scanner application screen (scanner function), the scanner application  123  sends the authentication management module  136  a query for the use restrictions of the functions of the multifunction device  101  (S 612 ). Then, the authentication management module  136  performs one of the authentication operations of  FIGS. 7, 8 ,  9  and  10 , and the use restriction operation of  FIG. 11  for the scanner function of the scanner application  123  (S 613 ). The authentication management module  136  sends the scanner application  123  a use restriction of the corresponding function of the multifunction device  101  to be applied, indicating “scanner function: not permitted” (S 614 ). Upon reception of the use restriction of the corresponding function of the multifunction device  101  to be applied, indicating “scanner function: not permitted”, the scanner application  123  shows a scanner application screen (use-not-permitted screen) (S 615 )  
         [0080]     It is to be noted that the queries in step S 603  and S 612  are sent together with the authentication information input in the authentication screen. The authentication screen may be therefore shown again when switching the screens (functions).  
         [0081]      FIG. 13  is a sequence diagram illustrating steps taken when an authentication operation and a use restriction operation are performed jointly by all the applications. The following describes the case where the copier application  121  having the copy function and the scanner application  123  having the scanner function are present.  
         [0082]     When the multifunction device  101  is started, the authentication management module  136  shows the authentication screen (S 701 ). Then, the authentication information of a user who attempts to use the multifunction device  101  is input (S 702 ), so that the authentication management module  136  performs one of the authentication operations of  FIGS. 7 and 9 , and the use restriction operation of  FIG. 11  for the copy function of the copier application  121  (S 703 ).  
         [0083]     When a copy button on the operations panel  222  is pressed (S 711 ) in order to switch to the copier application screen (copy function) the copier application  121  sends the authentication management module  136  a query for the use restrictions of the functions of the multifunction device  101  (S 712 ). The authentication management module  136  sends the copier application  121  a use restriction of the corresponding function of the multifunction device  101  to be applied, indicating “copy function: permitted” (S 713 ). Upon reception of the use restriction of the corresponding function of the multifunction device  101  to be applied, indicating “copy function: permitted”, the copier application  121  shows a copier application screen (S 714 ).  
         [0084]     If the scanner button on the operations panel  222  is pressed (S 721 ) in order to switch to the scanner application screen (scanner function), the scanner application  123  sends the authentication management module  136  a query for the use restrictions of the functions of the multifunction device  101  (S 722 ). The authentication management module  136  sends the scanner application  123  a use restriction of the corresponding function of the multifunction device  101  to be applied, indicating “scanner function: not permitted” (S 723 ). Upon reception of the use restriction of the corresponding function of the multifunction device  101  to be applied, indicating “scanner function: not permitted”, the scanner application  123  shows the scanner application screen (use-not-permitted screen) (S 724 ).  
         [0085]     In place of sending queries for the use restriction of the corresponding functions of the multifunction device  101  from the copier application  121  and the scanner application  123  to the authentication management module  136  and returning the use restriction to be applied from authentication management module  136 , the authentication management module  136  may deliver tickets to the copier application  121  and the scanner application  123 .  
         [0086]      FIGS. 14A-14C  show examples of the authentication screen, the copier application screen, and the scanner application screen (use-not-permitted screen) of  FIGS. 12 and 13 ;  
         [0087]      FIG. 15  is a sequence diagram illustrating a modified example of  FIGS. 12 and 13 .  
         [0088]     When the multifunction device  101  is started, the copier application  121  shows an authentication screen (S 801 ). Then, the authentication information of a user who attempts to use the multifunction device  101  is input (S 802 ), so that the copier application  121  sends a user authentication request to the authentication management module  136  (S 803 ). Then, the authentication management module  136  performs one of the authentication operations of  FIGS. 7, 8 ,  9  and  10  for the copy function of the copier application  121  (S 804 ). In response to the user authentication request, the authentication management module  136  sends the copier application  121  the authentication result at the time referrals are enabled, which is “authentication successful” and the authentication result at the time referrals are disabled, which is “authentication failed” (S 805 ).  
         [0089]     When a start button on the operations panel  222  is pressed (S 811 ) in a color copying mode, the copier application  121  performs a color copying charging operation (S 812 ) and then performs a color copying operation (S 813 ). When a start button on the operations panel  222  is pressed (S 821 ) in a monochrome copying mode, the copier application  121  performs a monochrome copying charging operation (S 822 ) and then performs a monochrome copying operation (S 823 ).  
         [0090]      FIG. 16  is a flowchart showing the color copying charging operation of step S 812 .  
         [0091]     The authentication management module  136  refers to the authentication result at the time referrals are disabled (S 11 ). If the authentication result at the time referrals are disabled is “successful”, the authentication management module  136  charges a server corresponding to the LDAP server  301 A or the NT server  302 A (S 12 ). If the authentication result at the time referrals are disabled is “failed”, the authentication management module  136  refers to the authentication result at the time referrals are enabled (S 13 ). If the authentication result at the time referrals are enabled is “successful”, a request screen that requests insertion of coin (fee) is displayed (S 14 ). If the authentication result at the time referrals are enabled is “failed”, a restriction screen that indicates that the use is not permitted is displayed (S 15 ).  
         [0092]      FIG. 17  is a flowchart showing a monochrome copying charging operation of step S 822 .  
         [0093]     The authentication management module  136  refers to the authentication result at the time referrals are disabled (S 21 ). If the authentication result at the time referrals are disabled is “successful”, the authentication management module  136  charges a server corresponding to the LDAP server  301 A or the NT server  302 A (S 22 ). If the authentication result at the time referrals are disabled is “failed”, the authentication management module  136  refers to the authentication result at the time referrals are enabled (S 23 ). If the authentication result at the time referrals are enabled is “successful”, the authentication management module  136  charges a server corresponding to the LDAP server  301 B or the NT server  302 B (S 24 ). If the authentication result at the time referrals are enabled is “failed”, the request screen that requests insertion of coin (fee) is displayed (S 25 ).  
         [0094]      FIGS. 18A-18C  show examples of the authentication screen, the request screen, and the restriction screen of  FIGS. 15, 16 , and  17 .  
         [0095]     The present application is based on Japanese Priority Application No. 2005-002652 filed on Jan. 7, 2005, with the Japanese Patent Office, the entire contents of which are hereby incorporated by reference.