Patent Publication Number: US-2011063663-A1

Title: Method for printing document of mobile terminal through printer, and mobile terminal therefor

Description:
PRIORITY 
     This application claims priority under 35 U.S.C. §119(a) to an application filed in the Korean Industrial Property Office on Sep. 15, 2009 and assigned Serial No. 10-2009-0087112, the contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an apparatus and method for printing a document of a mobile terminal, and more particularly to an apparatus and method for enabling a user to print the document through a printer, via wireless communication of the mobile terminal, and without requiring a separate printer setup procedure. 
     2. Description of the Related Art 
     Generally, in order for a desktop personal computer (hereinafter, referred to as a computer) to print a document via a printer, a document file, application software capable of reading the document, and driver software suitable for the particular printer model and the operating system are requested. Therefore, when the user issues a document output request, a computer reads and analyzes a document file through application software and generates, through a Graphical Device Interface (GDI) a document image that has a form suitable for a printer to which the document image is to be output. After reading and analyzing the document, the computer transmits data of the document image to the printer through a printer driver, thereby printing the document. 
     Unlike desktop personal computer environments such as described above, a mobile terminal such as a cellular phone cannot use the same application software as that used in the computer. Since mobile terminals are designed to be carried by users, the performance of mobile terminals is lower than the performance of desktop personal computers, and mobile terminal operating systems are different from desktop computer operating systems in most cases. More specifically, mobile terminals are more limited than desktop personal computers, with respect to implementing application software. Therefore, such mobile environments, dedicated viewer software capable of only viewing documents is used to check various documents. 
     In order to output a document stored in a mobile terminal, the mobile terminal connects to a computer. To this end, indirect and direct connection schemes are used. The indirect connection scheme includes directly inserting an external storage device into the mobile terminal, copying a desired document into the external storage device, bringing the copied document of the external storage device into the computer, and then outputting the copied document. The direct connection scheme includes outputting the document using a separate data cable or a wireless local area connection scheme. However, using an external storage device or a data cable is inconvenient for a user because the user must perform a connection task, and using a wireless local area connection scheme requires the user to be aware of the way of using software for wireless connection. 
     As described above, a conventional mobile terminal uses dedicated viewer software in order to read a computer document. However, when using dedicated viewer software, since the number of formats for documents has already been determined, a user of the mobile terminal cannot view a corresponding document if the mobile terminal does not have the same viewer software for supporting a document format of document software, as that in the computer. Document formats may frequently change due to version upgrades according to enhancement of functions of document software. Therefore, if dedicated viewer software is not rapidly updated, the dedicated viewer software may not be used with updated document formats. Although dedicated viewer software is used to address the above-described absence of mobile versions of document-related software, such dedicated viewer software cannot support all document formats used by computers. It is also necessary to install a printer driver in order to print a document. However, since mobile terminals have no fixed printer for usage, unlike computers, a mobile terminal must find and install a suitable printer driver every time a document is to be printed. Even in the above-described method of connecting a mobile terminal and a computer, a user passes through a setup procedure of inputting, step-by-step, information for a wireless communication connection in order to establish a wireless local area communication, which is inconvenient. It is inefficient for a user to input pieces of information items, one-by-one, which is very inconvenient for users who must frequently change setup due to frequent movement. 
     Therefore, a need exists for a method for enabling a mobile terminal to simply establish a wireless connection with a printer when the mobile terminal is located near the printer, and to print a desired document, even without installing a printer driver for document printing. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made to solve at least the above-mentioned problems occurring in the prior art, and the present invention provides an apparatus and method for printing documents of a mobile terminal, even without application software corresponding to each document and a separate printer setup procedure, such as installing a printer driver or other similar procedures. 
     In addition, the present invention provides an apparatus and method for enabling the user to easily connect a mobile terminal to a printer using a wireless communication function of the mobile terminal, and to print documents of the mobile terminal using the printer. 
     In accordance with an aspect of the present invention, there is provided a method for printing, by a printer, a document of a mobile terminal, the printer being connected with at least one computer. The method includes acquiring document support information from at least one computer connected with the printer; performing a wireless auto-connection procedure with the mobile terminal; receiving a print request including an output target document from the connected mobile terminal; selecting a computer to output the output target document by referring to the acquired document support information when receiving the print request; and printing the output target document in response to a print instruction issued by the selected computer. 
     In accordance with another aspect of the present invention, there is provided a method for printing, by a mobile terminal, a document of the mobile terminal through a printer connected with at least one computer. The method includes performing a wireless auto-connection procedure with the printer, wherein the printer manages document information in which a computer available for output according to each document type is mapped; and transmitting a print request including an output target document to the printer in order for the printer to select a target computer by making reference to the document information when a connection with the printer is completed. 
     In accordance with another aspect of the present invention, there is provided a mobile terminal for outputting a document of the mobile terminal through a printer connected with at least one computer. The mobile terminal includes a wireless auto-setup module for performing a wireless auto-connection procedure with the printer, wherein the printer manages document information in which a computer available for output according to each document type is mapped; a discovery module for performing a discovery operation with the connected printer; a Graphical User Interface (GUI) for providing a print menu, the print menu being used for selecting a target document to be output and selecting a print option; and a printing agent module for, when the output target document and print option are appointed through the print menu, transmitting a print request including the output target document to the printer for enabling the printer to select a target computer by referring to the document information. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a block diagram illustrating a system for network printing according to an embodiment of the present invention; 
         FIG. 2  is a flowchart illustrating a printing procedure according to an embodiment of the present invention; 
         FIG. 3  is an operational flowchart further illustrating a discovery and printable document registration procedure illustrated in  FIG. 2 , according to an embodiment of the present invention; 
         FIGS. 4 and 5  are operational flowcharts further illustrating a wireless auto-connection procedure illustrated in  FIG. 2  according to an embodiment of the present invention; and 
         FIG. 6  is an operational flowchart further illustrating a discovery and document output procedure between a mobile terminal and a printer illustrated in  FIG. 2 , according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Hereinafter, various embodiments of the present invention are described with reference to the accompanying drawings. In the following description, the same elements are designated by the same reference numerals although they are shown in different drawings. In addition, in the following description of the present invention, a detailed description of known functions and configurations incorporated herein are omitted where a detailed description thereof may make the subject matter of the present invention unclear. 
     The present invention provides a method for printing a document of a mobile terminal, even without a separate printer setup procedure. To this end, an embodiment of the present invention includes performing a wireless auto-connection between a mobile terminal and a printer located near the mobile terminal, and when the mobile terminal transmits a document to be printed to the printer, allowing the printer to find a computer capable of outputting the document and to transmit the document to the computer. Thereafter the printer prints the document in response to a print instruction received from the computer. Accordingly, the user can print various documents stored in the mobile terminal wherever a printer is located, even without information of the printer. 
       FIG. 1  is a block diagram illustrating a system for network printing according to an embodiment of the present invention. As illustrated in  FIG. 1 , a system for printing a document of a mobile terminal includes a mobile terminal  10 , a printer  20  for printing documents, and at least one computer  30 ,  40 , and  50  connected with the printer  20  by a local area network (LAN). 
     The mobile terminal  10 , which may be a cellular phone or another similar device, performs a wireless connection operation with the adjacent printer  20  using a wireless local area communication scheme, and transmits a document to be printed to the printer  20  while sending a print request when the mobile terminal  10  is connected with the printer  20 . The mobile terminal  10  includes a wireless auto-setup module  102 , a discovery module  104 , a printing agent module  106 , and a Graphical User Interface (GUI)  108 . 
     The wireless auto-setup module  102  functions configure a wireless auto-connection between the mobile terminal  10  and the printer  20 . 
     The discovery module  104  finds a printer located near the mobile terminal  10 . The discovery module  104  multicasts a printer discovery request, and then obtains a name, an Internet Protocol (IP) address, port information, etc. of a printer targeted for connection from a response to the discovery request when receiving the response. In the present example, the mobile terminal  10  obtains information form the printer  20 . The information of the printer  20 , obtained as described above, is used to transmit a document to be printed to the printer  20 . 
     The printing agent module  106  communicates with a printing manager module  114  of the printer  20 , and transmits/receives and manages various state information of the printer  20 . More specifically, the printing agent module  106  manages state information of the wirelessly-connected printer  20 , such as an online state, an offline state, a power on/off state, a paper feed state, etc. The printing agent module  106  also issues a document print request to the printer  20 , and checks whether a document to be printed can be printed by inquiring the printer  20  for information about whether the printer  20  can print the document and receiving a response to the inquiry. The printing agent module  106  requests and acquires information on various attributes, e.g., the number of copies, a paper type, a page, color/black &amp; white, etc., that are used in printing. The printing agent module  106  transmits acquired attribute information to the GUI  108 . When print option information and a print target document is selected by the user through the GUI  108 , the printing agent module  106  transmits the print option information together with the print target document to the printer  20 . 
     Based on attribute information received from the printing agent module  106 , the GUI  108  provides a user with information on the state of a wirelessly-connected printer, a selected number of copies, a selected paper, whether the printer can print a document, and other configurable print options. The user can also select a print-target document through the GUI  108 . 
     The printer  20  includes a wireless auto-setup module  110 , a discovery module  112 , and the printing manager module  114 . 
     The wireless auto-setup module  110  configures a wireless auto-connection with the mobile terminal  10 , similarly to the wireless auto-setup module  102  of the mobile terminal  10 . Such a wireless auto-connection procedure will be described in detail hereinbelow. 
     Similarly to the discovery module  104  of the mobile terminal  10 , the discovery module  112  provides a response including information on its own name. IP address, port, etc. upon receiving the discovery request from the mobile terminal  10 . 
     The printing manager module  114  manages target computers  30 ,  40 , and  50  capable of outputting documents through the current printer  20  in the form of a table by mapping the computers  30 ,  40 , and  50  according to types of documents. Such a table may have a structure as illustrated in Table 1 below, but the present invention is not limited thereto. 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                 Target 
                   
                 Output 
                   
               
               
                   
                 Type of 
                 computer 
                 Software 
                 available/ 
                 Allocated 
               
               
                 No. 
                 document 
                 address 
                 version 
                 unavailable 
                 area (Free) 
               
               
                   
               
             
            
               
                 1 
                 doc 
                 192.168.0.10 
                 7.0 
                 Output 
                 115 GB 
               
               
                   
                   
                   
                   
                 available 
               
               
                 2 
                 doc 
                 192.168.0.15 
                 5.0 
                 Output 
                  50 MB 
               
               
                   
                   
                   
                   
                 unavailable 
               
               
                 3 
                 xls 
                 192.168.0.110 
                 7.0 
                 Output 
                 663 MB 
               
               
                   
                   
                   
                   
                 available 
               
               
                 4 
                 ppt 
                 192.168.0.10 
                 7.0 
                 Output 
                 115 GB 
               
               
                   
                   
                   
                   
                 available 
               
               
                 5 
                 gul 
                 192.168.0.20 
                 12   
                 Output 
                 800 MB 
               
               
                   
                   
                   
                   
                 available 
               
               
                 . 
                 . 
                 . 
                 . 
                 . 
               
               
                 . 
                 . 
                 . 
                 . 
                 . 
               
               
                 . 
                 . 
                 . 
                 . 
                 . 
               
               
                   
               
            
           
         
       
     
     As shown in Table 1, contents of the table include document support information, such as a type of each document (i.e., a file extension), a network address of each computer connected with the printer  20  in a local area network, a version of each document software installed in each computer, information regarding whether document output is available, and information regarding a document storage area allocated to each computer, etc. 
     The printing manager module  114  also receives a document requested for printing by the user, from the printing agent module  106  of the mobile terminal  10 , finds a computer capable of outputting the received document by referring to a table such as Table 1, and then transmitting the received document to the found computer. 
     As described above, a printer auto-connected with a mobile terminal prints a document to be printed through a computer corresponding to the document among computers connected with the printer by a network, so that the mobile terminal can print a desired document, without installing a printer driver and application software corresponding to each document. 
     The first computer  30  includes a discovery module  120 , a print control module  122 , a document control module  124 , and a storage  126 . The following description of the configuration of the first computer  30  is provided as an example; the configuration and operation of the second and third computers  40  and  50  are the same as those of the first computer  30 . 
     The discovery module  120  performs a discovery operation of the first computer  30  to find the printer  20 . The discovery module  120  also registers information regarding types of documents that the first computer  30  can output, a network address, an area allocated to accommodate documents, etc., which are collected by the document control module  124  of the first computer  30  that is a local computer, with the printing manager module  114  of the printer  20 . 
     The document control module  124  searches for document software installed in the first computer  30 , and manages types of documents that can be output by the first computer  30 . In the present example, information managed by the document control module  124  includes a type of each document (i.e., a file extension), a name of each software, a version of each software, an installation position of each software, etc. Such management information may have a table structure as illustrated in Table 2 below, but the present invention is not limited thereto. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                 Type of 
                   
                   
                   
               
               
                 No. 
                 document 
                 Name 
                 Version 
                 Position of software 
               
               
                   
               
             
            
               
                 1 
                 doc 
                 MS Word 
                 7.0 
                 C:\Program Files\Word.exe 
               
               
                 2 
                 xls 
                 MS Excel 
                 7.0 
                 C:\Program Files\Excel.exe 
               
               
                 3 
                 ppt 
                 MS PowerPoint 
                 7.0 
                 C:\Program Files\Powerpoint.exe 
               
               
                 4 
                 gul 
                 HunMinJeongEum 
                 12   
                 C:\Program Files\Hun.exe 
               
               
                 5 
                 hwp 
                 Hangul2007 
                 2007    
                 C:\Program Files\Hwp.exe 
               
               
                 . 
                 . 
                 . 
                 . 
                 . 
               
               
                 . 
                 . 
                 . 
                 . 
                 . 
               
               
                 . 
                 . 
                 . 
                 . 
                 . 
               
               
                   
               
            
           
         
       
     
     The document control module  124  also receives an output target document and an output option set by the user from the printing manager module  114  of the printer  20 , and stores the received output target document and output option in the storage  126 . In addition, the document control module  124  performs document security-related operations, such as deletion, copy protection, modulation protection, etc., or a document 
     The print control module  122  applies the received output option through an output function of document software, and controls the printer  20  to print the document. 
       FIG. 2  is a diagram schematically illustrating a printing procedure according to an embodiment of the present invention. More specifically.  FIG. 2  illustrates a procedure in which, when the mobile terminal  10  wirelessly auto-connects with the printer  20  and transmits a document to be printed to the printer  20 , the printer  20  finds a computer corresponding to the document and requests the found computer to print the document. 
     Referring to  FIG. 2 , when the printer  20  is powered on, the printer  20  performs a discovery operation of searching for one or more computers  30  and  40  connected by a LAN using a predetermined discovery protocol, identifies documents that can be output from the searched computers  30  and  40 , and registers documents that can be output from each computer  30  and  40  in steps  200  and  205 . The procedure of performing a discovery operation between the printer and the computer and registering documents that can be output in steps  200  and  205  is described detail hereinbelow with reference to  FIG. 3 . 
     In step  210 , a wireless auto-connection procedure is performed between the mobile terminal  10  and the printer  20 . According to an embodiment of the present invention, a method for easily achieving a wireless connection is provided for improving convenience for a user. Such a wireless auto-connection procedure is described hereinbelow with reference to  FIGS. 4 and 5 .  FIGS. 4 and 5  are flow diagrams explaining a wireless auto-connection procedure in  FIG. 2  according to an embodiment of the present invention. 
     When the mobile terminal  10  and the printer  20  have been connected with each other through step  210 , a discovery operation is performed in step  215 . Through the discover operation, the mobile terminal  10  can obtain attribute information of the printer  20 , and can report a state of the printer  20  based on the obtained attribute information. When the user of the mobile terminal  10  has selected a print option and a document to be printed, the mobile terminal  10  transmits the document to be printed to the printer  20  in step  220 . In the present example, a print option selected by the user is transmitted, together with the document, and the printer  20  finds a computer capable of outputting the document by referring to a table such as Table 1. If the printer  20  has found the second computer  40  as a computer corresponding to the document (i.e., capable of outputting the document), the printer  20  transmits the document to the second computer  40  in step  225 . The second computer  40  transmits an output instruction to the printer  20  in step  230 , so that the printer  20  prints the document. 
     As described above, according to an embodiment of the present invention, the printer  20  directly finds a target computer suitable for document output among computers connected with the printer  20  by a LAN, and requests the found computer to output a document. Accordingly, the mobile terminal  10  is not required to install a separate printer driver to use the printer  20 , and can print various types of documents stored in the mobile terminal  10  because a print request is sent to a computer having application software corresponding to a document to be printed, among computers connected with the printer  20  by a LAN. 
     In order to print various types of documents, as described above, the printer  20  should be aware of information regarding documents supported by each computer  30 ,  40 , and  50 . For this reason, according to an embodiment of the present invention, a procedure of performing a discovery operation between a printer and a computer and registering documents that can be output is provided, as described in steps  200  and  205 . Such a procedure is described as follows with reference to  FIG. 3 , wherein an operation performed between the printer  20  and the first and second computers  30  and  40  is explained as an example. 
     In step  300 , the discovery module  112  of the printer  20  multicasts a request signal for requesting each computer  30  and  40  to provide information regarding documents that can be output by the first and second computers  30  or  40 , to the computers  30  and  40  connected by a LAN using a discovery protocol. The printer  20  transmits such a request in order to identity document output support information for each of the first and second computers  30  and  40 . The request is transmitted to the discovery modules  120  and  130  of the first and second computers  30  and  40 , respectively. Each discovery module  120  and  130  inquires each document control module  124  and  134 , respectively, about a list of printable documents in steps  305  and  310 , so that each of document control modules  124  and  134  acquires application information in steps  315  and  320 , respectively. The application information represents document information, including types of documents supported by each computer, the version of document software installed in each computer, whether output is available or unavailable, and a document allocation area that can be accommodated. Thereafter, when each document control module  124  and  134  transmits the document information to each discovery module  120  and  130  in steps  335  and  340 , each discovery module  120  and  130  generates and transmits a response message including the document information to the printer  20  in steps  345  and  350 . In the present example, the response message includes a network address, in addition to the document information. 
     As described above, each computer  30  and  40  provides the printer  20  with document support information, including types and versions of documents supported by the computer, a document allocation area that can be accommodated, whether output is available or unavailable, a network address, etc., using a discovery protocol, in advance in response to a printable document information request. If a third computer  50  is powered on after the discovery operation has been completed, the discovery module of the third computer  50  may directly register information regarding documents supported by the third computer  50  with a previously registered printer  20 . 
     When the printer  20  receives response messages including each piece of document information from each of first and second computers  30  and  40  through the aforementioned steps, the printer  20  generates a table such as Table 1 based on each piece of received document information. The table is used to find a computer that can output a document received from the mobile terminal  10 . 
     According to an embodiment of the present invention, a method for enabling the user to easily connect the mobile terminal  10  and the printer  20  using a Wireless Auto Setup procedure, i.e. a wireless auto-connection setup procedure is provided. Such a wireless auto-connection procedure corresponding to step  210  in  FIG. 2  is described in detail as follows with reference to  FIGS. 4 and 5 . 
       FIG. 4  is a diagram illustrating a wireless auto-connection procedure using a Wireless Fidelity (WiFi) scheme among wireless local area communication schemes, wherein a Service Set IDentifier (SSID) is required for WiFi communication between the mobile terminal  10  and the printer  20 , a security key is required for authentication and encryption, an IP address must be set for IP communication, and a Wired Equivalent Privacy (WEP) key value is required, since authentication and encryption are performed in a WEP scheme. According to an embodiment of the present invention, a scheme of automatically generating and setting up all the information required for wireless connection is used. Specifically, an SSID, a security key, an IP address are automatically generated using the same information input by a user between the mobile terminal  10  and the printer  20 . According to alternative embodiments of the present invention, random information may be used instead of the same information. In this case, the random information may be a random number that is randomly generated in the mobile terminal  10  and the printer  20 . Through this procedure, it is possible to conveniently and automatically connect the mobile terminal  10  to the printer  20  without requiring a user to input each piece of information for wireless LAN connection every time. Due to the characteristics of random information that changes for every connection attempt, it is possible to obtain a more enhanced security characteristic. 
     Referring to  FIG. 4 , the mobile terminal  10  and the printer  20  execute the same wireless connection software, in which a WiFi connection setup begins in the mobile terminal  10  and the printer  20 , respectively, according to a user input. When initiation of such a wireless LAN auto-connection procedure is requested, the printer  20  generates and displays random information that is used in common with the mobile terminal  10 , on a display unit of the printer  20  for the wireless auto-connection, in step  400 . The mobile terminal  10  displays a random number on the display unit of the printer  20 , and receives user input of the random number of the printer  20  in step  405 . Such a random number is used to generate and set up information required for a wireless auto-connection. Specifically, as shown in steps  410  and  415 , an SSID, a WEP, etc. is automatically generated and set up with the respective random numbers using the same hash function, thereby completing a WiFi connection. 
       FIG. 5  is a diagram illustrating a wireless auto-connection procedure using a BLUETOOTH® (BT) scheme among wireless local area communication schemes, wherein each of the mobile terminal  10  and printer  20  generates a device name and a Personal Identification Number (PIN) code with a random number, such as in  FIG. 4 , using the same hash function. When a Bluetooth connection setup begins in the mobile terminal  10  and the printer  20 , the printer  20  generates and outputs a random number in step  500 , and then the user sees and inputs the random number through the mobile terminal  10  in step  505 . Then, the printer  20  performs a device name setup procedure and a PIN code auto-generation/setup procedure using the random number in steps  510  and  515 , respectively, while the mobile terminal  10  performs a printer discovery operation and a PIN code auto-generation/setup procedure using the random number in steps  520  and  525 , respectively. Accordingly, the user is only required to input a random number in order to automatically achieve a wireless connection between the mobile terminal  10  and the printer  20 . 
     Hereinafter, a discovery and document output procedure between the mobile terminal and the printer, which corresponds to steps  215  to  230  in  FIG. 2 , is described in detail as follows with reference to  FIG. 6 . 
     Referring to  FIG. 6 , a user may begin a network printing function through a “print” menu provided by the GUI  108 . When such a beginning request is input to the mobile terminal  10 , the discovery module  104  of the mobile terminal  10  executes a discovery protocol in step  600 , thereby requesting a printer discovery from the discovery module  112  of the printer  20 . For such a request, the discovery module  104  of the mobile terminal  10  multicasts a DISCOVERY_PRINTER message. Upon receiving such a DISCOVERY_PRINTER message, the printer  20  transmits a RESPONSE_PRINTER message, which is a response message including printer information, such as its own printer name, IP address, port information, etc., to the discovery module  104  of the mobile terminal  10  in step  605 . The discovery module  104  transmits the printer information, which has been acquired through such a discovery procedure, to the printing agent module  106  in step  610 . 
     The GUI  108  transmits a PRINTING_CAPABILITY_REQUEST message for requesting attribute information of the printer  20  from the printing agent module  106  in step  615 . Such an attribute information request is used to prepare a “print” menu, which enables the user to check the state of a printer, and then to configure a desired option. 
     Accordingly, the printing agent module  106  transmits the PRINTING_CAPABILITY_REQUEST message to the printing manager module  114  of the printer  20  in step  620  in order to request attribute information. The printing manager module  114  responds by transmitting a PRINTING_CAPABILITY_RESPONSE message corresponding to the attribute information request in step  625 . Such a response message includes attribute information requested by the mobile terminal  10 . Here, the attribute information represents various information related to printing, and includes types of printable documents, the state of the printer  20 , and information on various options which can be set. 
     Upon receiving the PRINTING_CAPABILITY_RESPONSE message, the printing agent module  106  transfers the PRINTING_CAPABILITY_RESPONSE message to the GUI  108 , in step  630 . The GUI  108  provides a “print” menu based on received attribute information. Such a “print” menu includes various option functions, including state information of the printer, types of printable documents, color/black &amp; white setup options, horizontal/vertical setup options, etc. When a print target document and various print options have been appointed through the use of the “print” menu, the GUI  108  transmits the print target document to the printing agent module  106  using a SELECT_DOCUMENT message in step  635 . The printing agent module  106  combines and transmits the document and the appointed print options through the use of a PRINT_REQUEST message in step  640 . 
     Through such a PRINT_REQUEST message, the print target document, which has been combined together with the appointed print options, is transmitted to the printing manager module  114  of the printer  20 . The printing manager module  114  selects a computer capable of outputting the document by referring to a table such as Table 1 in step  642 . More specifically, the printer  20  compares a type of a received document, a capacity of the received document, a right of use, etc. with corresponding information in a document-computer mapping table such as Table 1, and selects a computer capable of outputting the received document. When the printer  20  selects the first computer  30 , the printing manager module  114  transmits a PRINT_REQUEST message to the document control module  124  of the first computer  30  in step  650 , thereby transmitting the document and print options to the document control module  124 . 
     Upon receiving the PRINT_REQUEST message, the document control module  124  stores the document in a local storage area of the storage  126  in step  655 , and then notifies the print control module  122  of the position of the stored document and the print options through the use of the PRINT_REQUEST message, in step  660 . The print control module  122  executes an application corresponding to the document or an output API of the application by applying the application or output API to print options, by making reference to a document-application table such as Table 2, so that the printing manager module  114  of the printer  20  can print the document. Accordingly, the print control module  122  transmits a PRINT message including a print image to the printing manager module  114  in step  665 , so that actual printing is executed through a printer driver. 
     According to an embodiment of the present invention, a user can print various documents stored in a mobile terminal wherever a printer is located. In addition, the user can print a document of the mobile terminal without information of the printer, and can immediately obtain a printed document, because a document print instruction is issued in a state where the mobile terminal is located near the printer. Accordingly, it is not necessary for the user to find a document application and to install a printer driver suitable for a corresponding printer every time a document is printed, so that the convenience of the user is enhanced. In addition, according to an embodiment of the present invention, a method for simply achieving a wireless connection between a mobile terminal and a printer is provided, so that the user can easily connect the mobile terminal and the printer. 
     While the present invention has been shown and described with reference to certain embodiments thereof; it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Accordingly, the scope of the invention is not to be limited by the above embodiments but by the claims and the equivalents thereof.