Patent Publication Number: US-2011058208-A1

Title: Print system in which a terminal uses a print device through the internet

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The disclosures herein relate to a technology by which a terminal device uses a printer device through the Internet to print. 
     2. Description of the Related Art 
     A solution that allows easy operations to automate the setup of network information in a printer driver and a printer device operable by the printer driver is already known in the art. 
     As an example of a related-art technology, Japanese Patent No. 3958283 discloses a configuration in which an RFID reader transmits network information and a printer driver stored in a hard drive as attachments to an email based on information retrieved from an RFID card. A personal computer receives the email, and installs the printer driver in a storage device, followed by setting up a network environment according to the network information. 
     As another example of a related-art technology, Japanese Patent Application Publication No. 2006-238199 discloses a system in which an information processing apparatus has a print setting means that automatically makes settings necessary to use a printer device through the Internet to print. 
     In the related-art technologies described above, no consideration is given to the fact that a firewall is usually provided at the border between the Internet and a local network connected thereto. Further, no discussion is made with respect to the case in which a terminal device (e.g., mobile terminal) connected to the Internet is connected to a printer device such as a printer. Because of this, it would be difficult to use the configurations of these related-art technologies in a real environment. Since communication is performed through the Internet, security needs to be ensured. However, this is not discussed, either. 
     With respect to a case in which a terminal device downloads a driver through the Internet, and uses a printer device through the Internet to print, solutions to date have a problem in that no sufficient measure has been taken against changes that may be made to firewall settings at the border between networks. Further, there is a problem in that no sufficient measures have been taken against the illegal access or tampering of print data by unauthorized users and the unauthorized use of a printer. 
     Accordingly, it may be desirable to adapt a secure print environment provided in a local network to a configuration in which a terminal device performs printing through the Internet. 
     SUMMARY OF THE INVENTION 
     In one embodiment, a print system in which a terminal uses a print device through the Internet to cause the print device installed in a local network to print includes: a user checking unit configured to check whether a user is a user authorized to use the print device in the local network; an operation page providing unit configured to provide an accessible operation page to the user upon determining that the user is a user authorized to use the print device; and a print controlling unit configured to cause the print device to print according to access control information associated with the user in response to a print request received through the Internet, the print request being made by the terminal by using a printer driver of the print device, the terminal being situated outside the local network, and the printer driver being installed by use of the operation page. 
     In one embodiment, a print control apparatus of a print system in which a terminal uses a print device through the Internet to cause the print device installed in a local network to print includes: a user checking unit configured to check whether a user is a user authorized to use the print device in the local network; an operation page providing unit configured to provide an accessible operation page to the user upon determining that the user is a user authorized to use the print device; and a print controlling unit configured to cause the print device to print according to access control information associated with the user in response to a print request received through the Internet, the print request being made by the terminal by using a printer driver of the print device, the terminal being situated outside the local network, and the printer driver being installed by use of the operation page. 
     In one embodiment, a method of controlling printing performed by a print control apparatus of a print system in which a terminal uses a print device through the Internet to cause the print device installed in a local network to print includes: a user checking step of checking whether a user is a user authorized to use the print device in the local network; an operation page providing step of providing an accessible operation page to the user upon determining that the user is a user authorized to use the print device; and a print controlling step of causing the print device to print according to access control information associated with the user in response to a print request received through the Internet, the print request being made by the terminal by using a printer driver of the print device, the terminal being situated outside the local network, and the printer driver being installed by use of the operation page. 
     According to at least one embodiment, provision is made to adapt a secure print environment provided in a local network to a configuration in which a terminal device performs printing through the Internet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects and further features of embodiments will be apparent from the following detailed description when read in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic diagram of the entire configuration of a print system according to an embodiment; 
         FIG. 2  is a drawing illustrating the apparatus configuration of the print system according to the embodiment; 
         FIG. 3  is a block diagram illustrating a first functional configuration of the print system according to the embodiment; 
         FIG. 4  is a drawing illustrating the hardware configuration of a print manager; 
         FIG. 5  is a drawing illustrating the data structure of an authorized printer user list according to the first functional configuration illustrated in  FIG. 3 ; 
         FIG. 6  is a flowchart illustrating the process of providing a notice of an operation page according to the first functional configuration illustrated in  FIG. 3 ; 
         FIG. 7  is a flowchart illustrating the process of generating a print queue at a terminal according to the first functional configuration illustrated in  FIG. 3 ; 
         FIG. 8  is a flowchart illustrating a print process according to the first functional configuration illustrated in  FIG. 3 ; 
         FIG. 9  is a block diagram illustrating a second functional configuration of the print system according to the embodiment; 
         FIG. 10  is a drawing illustrating the data structure of an access control list according to the second functional configuration illustrated in  FIG. 9 ; 
         FIG. 11  is a drawing illustrating the data structure of an authorized printer user list according to the second functional configuration illustrated in  FIG. 9 ; 
         FIG. 12  is a flowchart illustrating the process of providing a notice of an operation page according to the second functional configuration illustrated in  FIG. 9 ; 
         FIG. 13  is a flowchart illustrating a print process according to the second functional configuration illustrated in  FIG. 9 ; 
         FIG. 14  is a drawing illustrating an example of a displayed email transmitted from a print manager; and 
         FIG. 15  is a drawing illustrating an example of an operation page that is used for installing a printer driver. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following, embodiments of the present invention will be described with reference to the accompanying drawings.  FIG. 1  is a schematic diagram of the entire configuration of a print system according to an embodiment. In a print system  1000  illustrated in  FIG. 1 , a terminal  10  is connected to the Internet  100 , and is capable of freely accessing Web pages. A printer  20  installed in a local area network  200  is connected to an Internet communication line through a firewall  30 . The terminal  10  may not be able to reference the address of the printer  20 . 
       FIG. 2  is a drawing illustrating the apparatus configuration of the print system according to the embodiment. The terminal  10  and the printer  20  are the same as those illustrated in  FIG. 1 . The local area network  200  illustrated in  FIG. 2  includes a Web server  40 , a mail server  50 , a print manager  60 , and an IC-card reader  70  in addition to the printer  20 . 
     The Web server  40  and the mail server  50  are both connected to the firewall  30 . The print manager  60  is connected to the Web server  40  and the mail server  50 . The print manager  60  is also connected to the printer  20 . Moreover, the IC-card reader  70  is connected to the printer  20 . 
     The terminal  10  sets a print queue internally by operating an operation page provided by the Web server  40 . The terminal  10  uses the print queue to send print data to the Web server  40 . 
     The firewall  30  has general security settings made thereto. According to such security settings, for example, typical print-related communication cannot pass through while communication for making Web pages available to the public and communication for transferring emails are allowed to pass through. 
     The Web server  40  makes an operation page available to the public, so that the terminal  10  can make a print queue by use of the operation page. The Web server  40  receives print data from the terminal  10 , and transfers the received print data to the print manager  60 . In response to a request from the print manager  60 , the Web server  40  returns the address of an operation page that is to be made available to the public. 
     The mail server  50  serves to transfer the address of the Web server  40  to the terminal  10  in response to a request from the print manager  60 . 
     The print manager  60  performs the management and control of users who use the printer  20 . The print manager  60  may use user information retrieved from an IC card, for example, to determine whether the user is authorized to use the printer  20 . When the user is an authorized user to use the printer  20 , the print manager  60  sends, through the mail server  50  to the terminal  10 , the address of an operation page made available to the public by the Web server  40 . The user has been authorized to use the printer  20  in advance by using an IC card. Upon being recognized to be an authorized user, the user accesses the received address of the operation page to display the operation page at the terminal  10  to request printing. The print manager  60  converts print data produced by the terminal  10  in response to a user print request into commands decodable by the printer  20 . 
     The printer  20  interprets the commands to print on a paper medium. The IC-card reader  70  retrieves user information from an object carried by the user. The user information read by the IC-card reader  70  is supplied to the print manager  60  via the printer  20 . The IC-card reader  70  may be installed at any location in the local area network  200  as long as the IC-card reader  70  can provide user information to the print manager  60 . 
       FIG. 2  shows an apparatus configuration in which the Web server  40  and the mail server  50  are provided separately from the print manager  60 . As illustrated in  FIG. 3 , for example, the system may be configured such that the print manager  60  includes the functions of the Web server  40  and the mail server  50 .  FIG. 3  is a block diagram illustrating a first functional configuration of the print system according to the embodiment. 
     The terminal  10  includes a general Web browser  11 , an application  12 , and a mail client  13 . It is assumed that a conventional print function (e.g., Web Point&amp;Print) may be used to create a server print queue  14 . 
     The Web browser  11  can open an operation page of the print manager  60 . 
     The mail client  13  can receive and open email sent from the print manager  60 . 
     The print manager  60  has a Web server function and a mail server function in addition to a print control function for controlling the printer  20  for printing. The print manager  60  includes an access control unit  61 , a printer management unit  62 , a URL issuing unit  63 , a mail transmitting unit  64 , an operation-page generating unit  65 , an operation-page displaying unit  66 , a print-data receive unit  67 , and a print drawing unit  68 . The URL issuing unit  63  and the mail transmitting unit  64  correspond to the mail server function, and the operation-page generating unit  65  and the operation-page displaying unit  66  correspond to the Web server function. 
     The access control unit  61  performs user authentication by using user information read by the IC-card reader  70  to determine whether the user is authorized to use the printer  20 . The user information includes a user ID identifying a user, a user email address, and access control information. The access control information includes a printer name for identifying a printer  20  usable by the user and print functions permitted to be used with respect to the printer  20 . When the user is determined to be an authorized user to use the printer  20 , the access control unit  61  registers the user&#39;s user ID, email address, and access control information in an authorized printer user list  62   a  together with the data indicative of the present time. 
     The authorized printer user list  62   a  lists valid periods on a user-ID-specific basis with respect to users determined to be authorized printer users where the valid periods indicate periods during which printing is permitted. The authorized printer user list  62   a  is stored in a memory area  69 . Upon expiration of a valid period, the user information is deleted. 
     The printer management unit  62  manages one or more printer drivers  62   p  that are installed in advance in the print manager  60  and stored in the memory area  69 . In response to a request from the access control unit  61 , the printer management unit checks the print functions permitted to be used based on the access control information specified by the user information. The printer management unit  62  then creates print queues in the memory area  69  by attaching the access control information to the printer drivers  62   p  based on the check results. An interface to access the print queues to be used is made available to the public on the operation page. A printer driver  62   p  may be configured as a common driver usable by all the model types. In this case, installing one common driver is sufficient, and there is no need to install plural drivers for respective printer model types. 
     The URL issuing unit  63  issues a URL that specifies the address of the operation page in response to a request from the printer management unit  62 . The URL issuing unit  63  provides the email address included in the user information and the issued URL to the mail transmitting unit  64 . The valid period of the issued URL may be managed by use of the authorized printer user list  62   a.    
     The mail transmitting unit  64  attaches the URL issued by the URL issuing unit  63  to email, and sets the destination of the email to the user email address, thereby transmitting the email to a mail server to which the terminal  10  is connected. 
     In response to a request from the printer management unit  62 , the operation-page generating unit  65  creates an interface for the print queues to which the access control information linked to the printer drivers  62   p  is attached. 
     The operation-page displaying unit  66  displays the operation page upon request from the terminal  10 . The operation page may be a Web page. The operation page provides the functions used to create a print queue at the terminal  10 . The period for displaying the page corresponding to the URL requested by the terminal  10  may be limited to the valid period. In such a case, the operation-page displaying unit  66  refers to the authorized printer user list  62   a  to acquire the valid period of the requested URL, and then compares the valid period with the present time to control display on the terminal  10 . 
     The print-data receive unit  67  receives a print request from the print queue  14  of the terminal  10 . The print request from the terminal  10  may be made by using the IPP (Internet Printing Protocol), for example. Encryption (e.g., HTTPS) using SSL may be utilized. The print request includes print data and setting information specified by the user regarding the print operation. The print-data receive unit  67  notifies the printer management unit  62  of the print request. The printer management unit  62  checks whether there is a print queue required by the print request, and also checks whether the setting information conforms to the print functions permitted for the print queue. Based on the check results, the print-data receive unit  67  uses the print drawing unit  68  to draw the print data according to the permitted print functions. 
     The print drawing unit  68  has the drawing function for existing printer drivers. The print drawing unit  68  uses the print data to generate image data according to the print functions permitted to the user as specified by the request from the print-data receive unit  67 . The print drawing unit  68  further controls a print unit  21  of the printer  20  through the permitted print functions to print the image data. 
     A user permitted to use only duplex printing may request one-side printing. In such a case, duplex printing is performed without regard to the user intention through the controls as described above. 
     The printer  20  includes the print unit  21  having general print functions, and also includes a user information recording unit  22  that can record user information read from an IC card  72 . 
     The IC-card reader  70  includes a user information reading unit  71  for reading user ID information and a user email address recorded in an object carried by a user such as the IC card  72   
       FIG. 4  is a drawing illustrating the hardware configuration of a print manager. The print manager  60  illustrated in  FIG. 4  may be a computer, and includes a CPU (Central Processing Unit)  31 , a memory unit  32 , a display unit  33 , an output unit  34 , an input unit  35 , a communication unit  36 , a storage device  37 , and a driver  38 , which are connected to a system bus B. 
     The CPU  31  controls the print manager  60  in accordance with programs stored in the memory unit  32 . The memory unit  32  may be a RAM (Random Access Memory) and a ROM (Read Only Memory), and store programs executed by the CPU  31 , data subjected to processing by the CPU  31 , data obtained through processing by the CPU  31 , etc. Part of the memory area of the memory unit  32  is allocated as a work area used by the CPU  31 . 
     The display unit  33  displays various types of information under the control of the CPU  31 . The output unit  34  may includes a printer or the like, and is used to output various types of information in response to administrator&#39;s instruction. The input unit  35  may include a mouse and keyboard, and is used by an administrator to enter various types of information necessary for the operation of the print manager  60 . 
     The communication unit  36  has one or more communication protocols used for the Internet, a LAN (Local Area Network), etc. The communication unit  36  serves to control communication between the printer and an external apparatus connected through the Internet, a LAN, or the like. 
     The storage device  37  may be a hard-disk drive unit, which stores programs and data used in various types of processing. Programs for implementing operations performed by the print manager  60  are supplied to the print manager  60  through a recording medium  39  such as a CD-ROM (Compact Disk Read Only Memory). When the recording medium  39  having programs stored therein is mounted in the driver  38 , the driver  38  reads the programs from the recording medium  39 , so that the programs are installed in the storage device  37  through the system bus B. One or more of the programs installed in the storage device  37  are loaded to cause the CPU to perform processing. The recording medium for storing programs is not limited to a CD-ROM, but may be any type of computer-readable medium. The programs implementing the operations of the present embodiment may alternatively be downloaded by the communication unit  36  through a network to be installed in the storage device  37 . The print manager  60  may support USB (Universal Serial Bus). In such a case, the programs may alternatively be installed from an external storage device connected through a USB cable. The print manager  60  may support a flash memory such as an SD card. The programs may alternatively be installed from such a memory card. 
     The functional blocks  61  through  68  of the print manager  60  illustrated in  FIG. 3  are implemented by the CPU  31  executing respective programs. The memory area  69  of the print manager  60  may be provided in the memory unit  32  and/or the storage device  37 . 
       FIG. 5  is a drawing illustrating the data structure of a authorized printer user list according to the first functional configuration illustrated in  FIG. 3 . As illustrated in  FIG. 5 , the authorized printer user list  62   a  includes a user ID  5   a , authentication management information  5   b , URL management information  5   c , and access control information  5   d  separately for each user who is authorized to be a printer user. 
     The user ID  5   a  and the authentication management information  5   b  are registered when the access control unit  61  authenticates a user as a printer authorized user. The user ID  5   a  uniquely identifies each user. The authentication management information  5   b  indicates the date and time of registration. Alternatively, the authentication management information  5   b  indicates the date and time of expiration of authentication. 
     The URL management information  5   c  indicates a URL issued by the URL issuing unit  63  and the date and time of issuance. Alternatively, the date and time may indicate the valid period of the URL. When the valid period of a URL is not an item to be controlled, the date and time of issuance may be omitted. 
     The access control information  5   d  is access control information read from the IC card  72 . The access control information  5   d  includes a printer name identifying a printer and print functions the user is authorized to use. The access control information  5   d  is used to control print requests arriving from inside or outside the local area network  200 . 
       FIG. 6  is a flowchart illustrating the process of providing a notice of an operation page according to the first functional configuration illustrated in  FIG. 3 . In  FIG. 6 , a user who would like to use the printer  20  holds a carried item such as an IC card over the IC card reader to which the printer  20  is connected (S 401 ). 
     The user information reading unit  71  of the IC-card reader  70  reads user information from the IC card (S 402 ). The user information includes a user ID, a user email address, and access control information. 
     The printer  20  transfers the acquired user information to the print manager  60  (S 403 ). The printer  20  may record the user information. When print data is supplied from the user, the printer  20  may request the user to enter his/her user ID, and may perform printing upon authenticating the user as a printer authorized user by use of the recorded user information. Such authentication at the time of printing makes it possible to prevent the printout from being taken by an unauthorized user. Time may also be recorded in order to provide a mechanism by which to prohibit printing after the passage of a predetermined time period. 
     When the print manager  60  receives the user information from the printer  20 , the access control unit  61  checks based on the user information whether the user carrying the IC card is a user authorized to use the printer  20  (S 404 , S 405 ). If the user is not a legitimate user, or is not a user authorized to print by use of the printer  20 , the request is denied, and the procedure comes to an end (S 411 ). The operation panel of the printer  20  may display an indication that the information provided by the IC card is not valid. 
     The printer management unit  62  manages plural printer drivers. In the first functional configuration, all the printer drivers  62   p  of the printers  20  managed by the print manager  60  are installed in the print manager  60 . Disclosure of printer functions may be controlled by use of each user&#39;s access control information on a printer specific basis. In such a case, plural print queues may be installed with respect to a single printer driver. The printer management unit  62  refers to the user information to check the user&#39;s access control information (S 406 ). For example, such a control procedure may be used that the administrator can use all the functions of the printer  20  while general users cannot use color printing. Based on the check results, print queues to which the access control information linked to the printer drivers  62   p  are generated (S 407 ). These queues are automatically deleted upon passage of a predetermined time period. 
     The operation-page generating unit  65  generates an operation page for making the generated print queues available to the public (S 408 ). The operation-page displaying unit  66  prepares to display the operation page that is to be made public. 
     The URL issuing unit  63  generates a URL of the operation page to be displayed in response to a request from the printer management unit  62  (S 409 ). This generated URL is a unique combination of a print queue to be displayed and access control information. For example, the printer  20  having a printer name “A” may be identified as “http://www.xxx.yyy.zzz/printers/printer_a?color=0” where a print queue a is used with a monochrome setting. It may not be desirable to disclose access control information and printer information in a form that is easily recognizable to unauthorized users. In consideration of this, the portion relating to the settings of the printer  20  may be encrypted by use of a hash function as in the following example: “http://www.xxx.yyy.zzz/printers/hgdfxf2df4d”. 
     The mail transmitting unit  64  attaches the generated URL to email, and sends the email to an email address obtained from the user information (S 410 ). 
     In the following, a description will be given of a print queue generating process that generates the print queue  14  at the terminal  10  upon receiving the email from the print manager  60 .  FIG. 7  is a flowchart illustrating the process of generating a print queue at the terminal according to the first functional configuration illustrated in  FIG. 3 . 
     The mail client  13  of the terminal  10  receives the email sent from the print manager  60 , and displays the received email (S 501 ). 
     The user operates the displayed operation page to generate the print queue  14  at the terminal (S 503 ). The mechanism that creates at the terminal  10  a print queue corresponding to a print queue at the server such as the print manager  60  may be implemented by use of Web Point&amp;Print of Windows (registered trademark), for example. Since the Web browser  11  and the operation-page generating unit  65  exchange data through HTTP communication, proper operations can be performed even under the presence of general security mechanisms such as the firewall  30 . 
     In the following, a description will be given of a print process to print at the printer  20  from the application  12  of the terminal  10 .  FIG. 8  is a flowchart illustrating a print process according to the first functional configuration illustrated in  FIG. 3 . In  FIG. 8 , a user starts a print process through the print queue  14  by use of the application  12  (S 601 ) 
     The Print-Data Receive Unit  67  of the Print manager  60  receives the print request inclusive of print data. The print-data receive unit  67  then queries the printer management unit  62  whether there is a print queue specified by the print request (S 602 , S 603 ). Here, a print queue is a time-limited print queue. Print queues are automatically deleted upon passage of a certain time period because the indefinite disclosure of queues would create network vulnerability. 
     If there is no queue, the print manager  60  denies and cancels the user request, and brings the print process to an end (S 607 ). If there is a print queue, the print drawing unit  68  generates commands processable by the printer  20  (S 604 ). The print drawing unit  68  may change setting information contained in the print request in accordance with the access control information attached to the print queue, and may then generate image data by use of the print data contained in the print request. The print drawing unit  68  then controls the print unit  21  of the printer  20  to print the image data according to the setting information conforming to the permitted print functions. 
     The printer  20  receives commands from the print manager  60  (S 605 ), and starts printing on a paper sheet (S 606 ). The printer  20  may use the recorded user information to authenticate the user ID of the user who has come to take a printout, thereby producing the printout only upon successful authentication. 
     The first functional configuration illustrated in  FIG. 3  creates print queues to which access control information linked to the printer driver  62   p  is attached, and controls a print process based on the access control information corresponding to the created print queues. In the following, a description will be given of another configuration by which a print process requested from outside the local area network  200  is controlled without using print queues. 
       FIG. 9  is a block diagram illustrating a second functional configuration of the print system according to the embodiment. In  FIG. 9 , the same or similar functions as those of the first functional configuration illustrated in  FIG. 3  are referred to by the same numerals, and a description thereof will be omitted. The second functional configuration illustrated in  FIG. 9  differs from the first functional configuration illustrated in  FIG. 3  in that an access control list  61   b  created by the administrator in advance is stored in the memory area  69  in addition to a authorized printer user list  62   b . Further, a printer driver  62   p  usable in common for various types of models is stored in the memory area  69 . In the second functional configuration, the user information read from an IC card  72   b  carried by a user includes a user ID and an email address. User&#39;s access control information is obtained from the access control list  61   b.    
     In a print manager  60   b , as in the first functional configuration illustrated in  FIG. 3 , the URL issuing unit  63  and the mail transmitting unit  64  correspond to the mail server function, and the operation-page generating unit  65  and the operation-page displaying unit  66  correspond to the Web server function. 
     The access control unit  61  refers to the access control list  61   b  to perform authentication by using user information read by the IC-card reader  70  to determine whether the user is authorized to use the printer  20 . The user information includes a user ID identifying a user and a user email address. When the user is determined to be an authorized user to use the printer, the access control unit  61  registers the user&#39;s user ID and email address in the authorized printer user list  62   b  together with the data indicative of the present time. 
     The access control list  61   b  is a list that associates printer information indicative of usable printers with print functions permitted to be used with the usable printers on a user-ID-specific basis. The access control list  61   b  is prepared in advance by the administrator, and is stored in the memory area  69  of the print manager  60   b.    
     The authorized printer user list  62   b  lists valid periods on a user-ID-specific basis with respect to users determined to be authorized printer users where the valid periods indicate periods during which printing is permitted. The authorized printer user list  62   b  is stored in the memory area  69 . 
     The printer management unit  62  manages one printer driver  62   p  that is installed in advance in the print manager  60   b  and stored in the memory area  69 . In response to a request from the access control unit  61 , the printer management unit  62  uses the user ID contained in the user information to refer to the access control list  61   b , thereby checking the print functions permitted to the user. The operation page discloses an interface to the printer driver  62   p  and the permitted print functions. 
     The URL issuing unit  63  issues a URL that specifies the address of the operation page in response to a request from the printer management unit  62 . The URL issuing unit  63  provides the email address included in the user information and the issued URL to the mail transmitting unit  64 . The valid period of the issued URL may be managed by use of the authorized printer user list  62   b.    
     The mail transmitting unit  64  attaches the URL issued by the URL issuing unit  63  to an email, and specifies the user email address, thereby transmitting the email to a mail server to which the terminal  10  is connected. 
     In response to a request from the printer management unit  62 , the operation-page generating unit  65  creates an interface to the print queue of the printer driver  62   p.    
     The operation-page displaying unit  66  displays the operation page upon request from the terminal  10 . The operation page may be a Web page. The operation page provides the functions used to create a print queue at the terminal  10 . The period for displaying the page corresponding to the URL requested by the terminal  10  may be limited to the valid period. In such a case, the operation-page displaying unit  66  refers to the authorized printer user list  62   b  to acquire the valid period of the requested URL, and then compares the valid period with the present time to control display on the terminal  10 . 
     The print-data receive unit  67  receives a print request from the print queue  14  of the terminal  10 . The print request from the terminal  10  may be made by using the IPP (Internet Printing Protocol), for example. Encryption (e.g., HTTPS) using SSL may be utilized. The print request includes a user ID for identifying a user, print data, and setting information specified by the user regarding the print operation. The print-data receive unit  67  notifies the printer management unit  62  of the print request. The printer management unit  62  uses the user ID to refer to the authorized printer user list  62   b , thereby checking whether the user is a user authorized to use the printer. When the check results indicate that the user is an authorized printer user, the print-data receive unit  67  causes the print drawing unit  68  to print the print data in accordance with the permitted print functions. 
     The print drawing unit  68  has the drawing function for existing printer drivers. The print drawing unit  68  refers to the access control list  61   b  by using the user ID specified in the request supplied from the print-data receive unit  67 , thereby checking whether the setting information is consistent with the print functions permitted to the user. Based on the check results, the print drawing unit  68  uses the print data to generate image data according to the permitted print functions. The print drawing unit  68  further controls the print unit of the printer  20  through the permitted print functions to print the image data. 
     A user permitted to use only duplex printing may request one-side printing. Even in such a case, duplex printing is performed without regard to the user intention through the controls as described above. 
     The print manager  60   b  has the hardware configuration illustrated in  FIG. 4 . The functional blocks  61  through  68  of the print manager  60   b  illustrated in  FIG. 9  are implemented by the CPU  31  executing respective programs. The memory area  69  of the print manager  60   b  may be provided in the memory unit  32  and/or the storage device  37 . 
       FIG. 10  is a drawing illustrating the data structure of an access control list according to the second functional configuration illustrated in  FIG. 9 . The access control list  61   b  illustrated in  FIG. 10  includes printer information indicative of usable printers and access control information on a user-ID-specific basis. In the illustrated example, a user having the user ID “User01” is authorized to use the printer “A”. Upon using this printer “A”, color printing is permitted (Color=1), but only duplex printing (Duplex=2) is allowed. 
     The permission to use color printing (Color=1) indicates that the user can select either color printing or black-&amp;—white printing. An indication of no color printing (Color=0) indicates that black-&amp;-white printing is performed since color printing is not permitted. 
     The indication of duplex printing (Duplex=2) means that the user is not allowed to use one-side printing. Even if the user makes a setting to use one-side printing, duplex printing is forcibly used. 
       FIG. 11  is a drawing illustrating the data structure of an authorized printer user list according to the second functional configuration illustrated in  FIG. 9 . As illustrated in  FIG. 11 , the authorized printer user list  62   b  includes a user ID  11   a , authentication management information  11   b , and URL management information  11   c  separately for each user who is authorized to be a printer authorized user. In the second functional configuration, each user&#39;s access control information is managed by use of the access control list  61   b , and is not listed in the authorized printer user list  62   b.    
     The user ID  11   a  and the authentication management information  11   b  are registered when the access control unit  61  performs user authentication. The user ID  11   a  uniquely identifies each user. The authentication management information  11   b  indicates the date and time of registration. Alternatively, the authentication management information  11   b  indicates the date and time of expiration of authentication. 
     The URL management information  11   c  indicates a URL issued by the URL issuing unit  63  and the date and time of issuance. Alternatively, the date and time may indicate the valid period of the URL. When the valid period of a URL is not an item to be controlled, the date and time of issuance may be omitted. 
       FIG. 12  is a flowchart illustrating the process of providing a notice of an operation page according to the second functional configuration illustrated in  FIG. 9 . In  FIG. 9 , a user who would like to use the printer  20  holds a carried item such as an IC card over the IC card reader to which the printer  20  is connected (S 421 ). 
     The user information reading unit  71  of the IC-card reader  70  reads user information from the IC card (S 422 ). The user information includes a user ID and a user email address. 
     The printer  20  transfers the acquired user information to the print manager  60  (S 423 ). The printer  20  may record the user information. When print data is supplied from the user, the printer  20  may request the user to enter his/her user ID, and may perform printing upon authenticating the user as a printer authorized user by use of the recorded user information. Such authentication at the time of printing makes it possible to prevent the printout from being taken by an unauthorized user. Time may also be recorded in order to provide a mechanism by which to prohibit printing after the passage of a predetermined time period. 
     When the print manager  60  receives the user information from the printer  20 , the access control unit  61  uses the user information to refer to the access control list  61   b , thereby checking whether the user carrying the IC card is a user authorized to use the printer  20  (S 424 , S 425 ). If the user is not a legitimate user, or is not a user authorized to print by use of the printer, the request is denied, and the procedure comes to an end (S 430 ). The operation panel of the printer  20  may display an indication that the information provided by the IC card is not valid. 
     In the second functional configuration, one printer driver  62   p  usable in common for various models of printers  20  managed by the print manager  60  is installed in the print manager  60  and managed by the printer management unit  62 . Disclosure of printer functions may be controlled by use of each user&#39;s access control information on a printer specific basis. In such a case, plural print queues may be installed with respect to a single printer driver. The printer management unit  62  refers to the user information to check the user&#39;s access control information (S 426 ). For example, such a control procedure may be used that the administrator can use all the functions of the printer  20  while general users cannot use color printing. 
     The operation-page generating unit  65  generates an operation page for making the generated print queues available to the public (S 427 ). The operation-page displaying unit  66  prepares to display the operation page that is to be made public. 
     The URL issuing unit  63  generates a URL of the operation page to be displayed in response to a request from the printer management unit  62  (S 428 ). Any URL may suffice as long as it is unique. For example, a random number may be used to generate “http://www.xxx.yyy.zzz/printers/604927”. The random number portion may be encrypted by use of a predetermined algorithm using a hash function or the like as in the following example: “http://www.xxx.yyy.zzz/printers/hgdfxf2df4d”. 
     The mail transmitting unit  64  attaches the generated URL to email, and sends the email to an email address obtained from the user information (S 429 ). 
     The print queue generating process at the terminal according to the second functional configuration of  FIG. 9  is the same as the print queue generating process at the terminal according to the first functional configuration of  FIG. 7  previously described, and a description thereof will be omitted. 
       FIG. 13  is a flowchart illustrating a print process according to the second functional configuration illustrated in  FIG. 9 . In  FIG. 13 , a user starts a print process through the print queue  14  by use of the application  12  (S 621 ) 
     The print-data receive unit  67  of the print manager  60  receives the print request inclusive of print data. The print-data receive unit  67  then queries the printer management unit  62  whether the user ID specified by the print request is registered as that of an authorized printer user (S 622 , S 623 ). The printer management unit  62  refers to the authorized printer user list  62   b  to check whether the user ID is registered. If the user ID is a registered ID, the printer management unit  62  refers to the access control list  61   b  to acquire access control information associated with the user ID. The printer management unit  62  notifies the print-data receive unit  67  of the presence/absence of user-ID registration, and also notifies of the access control information if the user ID is already registered. 
     If the user ID is not registered as that of an authorized printer user, the print manager  60  denies and cancels the user request, and brings the print process to an end (S 627 ). If the user ID is already registered as that of an authorized printer user, the print drawing unit  68  generates commands processable by the printer  20  (S 624 ). The print drawing unit  68  may change setting information contained in the print request in accordance with the access control information corresponding to the user ID received from the printer management unit  62 , and may then generate image data by use of the print data contained in the print request. The print drawing unit  68  then controls the print unit  21  of the printer  20  to print the image data according to the setting information conforming to the permitted print functions. 
     The printer  20  receives commands from the print manager  60  (S 625 ), and starts printing on a paper sheet (S 626 ). The printer  20  may use the recorded user information to authenticate the user ID of the user who has come to take a printout, thereby producing the printout only upon successful authentication. 
     In the following, a description will be given of an example of a screen displayed at the terminal  10 .  FIG. 14  is a drawing illustrating an example of a displayed email transmitted from a print manager. In  FIG. 14 , an email display screen  14   a  displayed at the terminal  10  shows the contents of an email, which is transmitted from the mail transmitting unit  64  to the user email address after the user is authenticated based on user information read by the IC-card reader  70 . 
     The email display screen  14   a  shows the user email address in a destination field  14   b , and indicates successful authentication by the print manager  60  in a subject field  14   c . The contents of this email include an address  14   d  indicative of the URL of an operation page that is used for installing a printer driver. The address  14   d  is the URL generated by the URL issuing unit  63 . 
     When the user accesses the address  14   d , an operation page  15   a  as illustrated in  FIG. 15  is displayed by the Web browser  11 .  FIG. 15  is a drawing illustrating an example of an operation page that is used for installing a printer driver. In  FIG. 15 , the Web browser  11  shows in a URL field  15   b  the address  14   d  that the user has accessed from the email display screen  14   a . The operation page  15   a  shows a list of printers for which printer drivers can be installed. 
     The operation page  15   a  displays a message  15   c  prompting the user to install a printer driver, an operation button  15   d  for initiating installation upon clicking, and access control information  15   e  assigned to the user. 
     In the embodiments described heretofore, security measures can be applied to a print request arriving from outside the local area network  200  similarly to the manner in which security measures are applied to a print request generated within the local area network  200 . Namely, only a user who is authorized to use a printer in the local area network  200  can send an acceptable print request from outside the local area network  200 . Further, printing is performed in accordance with the access control information assigned to the user. 
     The local area network  200  may be formed within a corporation. Employees may be registered as authorized printer users in the local area network  200  of the corporation. In such a case, an employee on a business trip can use the terminal  10  to access the local area network  200  through the Internet  100 , and can print to the printer  20  installed in the local area network  200 . 
     Inside the local area network  200 , the authorized printer user list  62   b  may be referred to in order to check whether the user is registered as an authorized printer user. This arrangement properly prevents the printer  20  from being exposed to an unauthorized access coming from outside. 
     Moreover, even when a user registered on the authorized printer user list  62   b  issues a print request, printing is performed in accordance with the access control information assigned to the user. Accordingly, security measures imposed on print requests originating inside the local area network  200  are invariably applied to all print requests. 
     Further, the present invention is not limited to these embodiments, but various variations and modifications may be made without departing from the scope of the present invention. 
     The present application is based on Japanese priority applications No. 2009-207260 filed on Sep. 8, 2009 and No. 2010-127294 filed on Jun. 2, 2010, with the Japanese Patent Office, the entire contents of which are hereby incorporated by reference.