Patent Publication Number: US-2013229673-A1

Title: Wireless communication apparatus and communication method

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a wireless communication apparatus, and a communication method. 
     2. Description of the Related Art 
     In recent years, there is known a technique in which an apparatus such as a mobile communication terminal or MFP (Multi-Function Printer) includes a short distance wireless communication unit to transmit/receive data such as an image (for example, Japanese Patent Laid-Open No. 2010-006016). There has been also proposed a technique of switching over, among a plurality of communication units, from a first communication unit to a second communication unit as needed in consideration of the communication speed and operability (for example, Japanese Patent Laid-Open No. 2007-166538). 
     The first communication unit is, for example, an NFC (Near Field Communication) unit as a low-speed communication unit in which it is possible to readily, uniquely identify a communication party. On the other hand, the second communication unit is, for example, a Bluetooth® or wireless LAN (WLAN) unit as a high-speed communication unit. There has been proposed a printer which improves the convenience by executing authentication processing and the like by the first communication unit, and transferring a large amount of data by the second communication unit. 
     The techniques disclosed in Japanese Patent Laid-Open Nos. 2010-006016 and 2007-166538, however, do not consider externally transmitting data from an apparatus such as an MFP with a small-capacity memory. 
     For example, when transferring image data read by a scanner of an MFP or the like to an external apparatus using the short distance wireless communication, that communication may be disabled while transmitting the image data. In this case, the MFP needs to hold the image data until connection is established again, or to discard the image data. This may spoil the user convenience, and reduce the usable area of the memory of the MFP. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is conceived as a response to the above-described disadvantages of the conventional art. 
     For example, a wireless communication apparatus, and a communication method according to one embodiment of this invention are capable of efficiently using an apparatus with a small-capacity memory even if communication is disabled during data transfer. 
     According to one aspect of the present invention, there is provided a wireless communication apparatus. The apparatus comprises a wireless communication unit configured to be able to communicate with a communication device according to each of a first wireless communication method and a second wireless communication method that has a communicable range wider than that in the first communication method. The apparatus further comprises a reception unit configured to receive a request for executing predetermined processing and information for performing wireless communication according to the second wireless communication method with an output destination of data obtained by executing the predetermined processing, by performing wireless communication according to the first wireless communication with the communication device in the wireless communication unit, and an execution unit configured to execute the predetermined processing upon receiving the request. The apparatus also comprises an output unit configured to output the data obtained by executing the predetermined processing by the execution unit, to the output destination, by performing wireless communication according to the second wireless communication method with the output destination in the wireless communication unit, based on the information received by the reception unit. 
     According to another aspect of the present invention, there is provided a method applicable to the above-mentioned apparatus. The method comprises: wirelessly communicating with a communication device according to each of a first wireless communication method and a second wireless communication method that has a communicable range wider than that in the first wireless communication method; receiving a request for executing predetermined processing, and information for performing wireless communication according to the second wireless communication method with an output destination of data obtained by executing the predetermined processing, by performing wireless communication according to the first wireless communication with the communication device; and executing the predetermined processing upon receiving the request; and outputting the data obtained by executing the predetermined processing, to the output destination, by performing wireless communication according to the second wireless communication method with the output destination, based on the received information. 
     According to still another aspect of the present invention, there is provided a non-transitory computer readable storage which stores a computer program for executing the above method. 
     The embodiment according to the invention is particularly advantageous since it is possible to transfer image data obtained by a scanner apparatus to an information processing apparatus using high-speed WLAN. Furthermore, even if communication is interrupted while transferring the image data, the image data is transferred to an alternative apparatus such as a server apparatus, and then the information processing apparatus can acquire the image data from the server apparatus via a network. 
     This enables to efficiently use the scanner apparatus with a small-capacity memory. 
     Further features of the present invention will become apparent from the following description of exemplary embodiment(s) (with reference to the attached drawings). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing the overall configuration of a network system capable of performing short distance wireless communication according to an exemplary embodiment of the present invention. 
         FIG. 2  is a front view showing a mobile communication terminal. 
         FIGS. 3A and 3B  are views each schematically showing the outer appearance of an MFP apparatus. 
         FIGS. 4A and 4B  are block diagrams showing the concept of a passive mode in NFC communication. 
         FIGS. 5A and 5B  are block diagrams showing the concept of an active mode in NFC communication. 
         FIG. 6  is a block diagram showing the arrangement of a mobile communication terminal  200 . 
         FIG. 7  is a block diagram showing the schematic arrangement of an MFP  300 . 
         FIG. 8  is a block diagram showing the detailed arrangement of an NFC unit. 
         FIG. 9  is a block diagram showing the internal structure of the non-volatile memory (flash memory) of the MFP. 
         FIG. 10  is a block diagram showing the internal structure of the non-volatile memory (flash memory) of the mobile communication terminal  200 . 
         FIG. 11  is a flowchart for causing the NFC unit to operate as an initiator. 
         FIG. 12  is a sequence chart showing the sequence of performing data exchange in the passive mode. 
         FIG. 13  is a sequence chart showing the sequence of performing data exchange in the active mode. 
         FIG. 14  is a sequence chart showing the sequence of performing push-type communication in which the MFP takes initiative for transferring, to the mobile communication terminal, image data obtained by reading an image original using the scanner function of the MFP. 
         FIG. 15  is a sequence chart showing the sequence of performing pull-type communication in which the mobile communication terminal takes initiative for transferring, to itself, image data obtained by reading an image original using the scanner function of the MFP. 
         FIG. 16  is a flowchart illustrating processing executed by the mobile communication terminal from a time when an application of the mobile communication terminal is activated until communication with the MFP ends. 
         FIG. 17  is a flowchart illustrating processing executed by the MFP from a time when the mobile communication terminal is detected until communication with it ends. 
         FIG. 18  is a view showing an example of a screen for making settings for a scanner apparatus, which is displayed by the application of the mobile communication terminal. 
         FIG. 19  is a view showing an example of a screen for making detailed settings for the scanner apparatus, which is displayed by the application of the mobile communication terminal. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     An exemplary embodiment of the present invention will now be described in detail in accordance with the accompanying drawings. It should be noted that the relative arrangement of components and the like set forth in the embodiment do not limit the scope of the present invention unless it is specifically stated otherwise. 
     In this specification, the terms “print” and “printing” not only include the formation of significant information such as characters and graphics, but also broadly includes the formation of images, figures, patterns, and the like on a print medium, or the processing of the medium, regardless of whether they are significant or insignificant and whether they are so visualized as to be visually perceivable by humans. 
     Also, the term “print medium” not only includes a paper sheet used in common printing apparatuses, but also broadly includes materials, such as cloth, a plastic film, a metal plate, glass, ceramics, wood, and leather, capable of accepting ink. 
     In the embodiment, a case in which after specifying a communication party and performing authentication by low-speed communication using a short distance wireless communication method, the communication is switched over to a high-speed communication to transmit image data will be described. More specifically, a method of performing, for a target, authentication by short distance wireless communication such as NFC (Near Field Communication) which does not require a power supply, and then switching the communication to another communication protocol to communicate image data will be explained. 
       FIG. 1  is a block diagram showing the configuration of a network system using short distance wireless communication according to an exemplary embodiment of the present invention. The system has a basic configuration in which a server apparatus  101 , a mobile communication terminal (information processing apparatus)  200 , and a multi-function printer (to be referred to as an MFP or printing apparatus hereinafter)  300  are connected to each other via a network  100 . 
     The server apparatus  101  includes a storage unit for image data to be printed, and a processor for managing user IDs and executing an image processing application. The mobile communication terminal  200  implements at least two types of wireless communication protocols with different authentication methods and different communication speeds. The mobile communication terminal need only be an apparatus capable of handling files of print targets, for example, a personal information terminal such as a PDA (Personal Digital Assistant), a mobile phone, a smart phone, or a digital camera. The MFP  300  is a multi-function printer including a display unit and operation panel through which various settings can be made, and having a printer function of using an inkjet printer or the like as a printer engine, a scanner function of reading an original placed on a document table, a FAX function, and a telephone function. 
     The network  100  and server apparatus  101  are connected by wired LAN, and the network  100  and MFP  300  are connected by wired LAN or wireless LAN (to be referred to as WLAN hereinafter). The network  100  and mobile communication terminal  200  are connected by WLAN. Since both the mobile communication terminal  200  and the MFP  300  have a WLAN function, they can perform peer to peer (to be referred to as P2P hereinafter) communication by authenticating each other. 
       FIG. 2  is a front view showing the mobile communication terminal  200  such as a smart phone. The smart phone indicates a multi-function mobile phone including a camera, network browser, and mail function in addition to a mobile phone function. 
     Referring to  FIG. 2 , an NFC unit  201  performs communication using NFC. Actually, communication can be performed when the user moves the NFC unit  201  close to within about 10 cm of the NFC unit of the other communication party. A WLAN unit  202  is used to perform communication using WLAN, and is arranged within the terminal. Note that the coverage of WLAN is wider than that (about 10 cm) of NFC. A display unit  203  is formed from an LCD display on which an operation unit  204  with an electrostatic touch-panel operation mechanism is arranged. The operation unit  204  detects user operation information. As a typical operation method, the display unit  203  displays button-shaped menus, and when the user touches the operation unit  204 , an event associated with the button portion is issued to execute processing. A power key  205  is used to turn on/off the power. 
       FIGS. 3A and 3B  are views each schematically showing the outer appearance of the MFP  300 .  FIG. 3A  is a perspective view showing the outer appearance and  FIG. 3B  is a plan view showing the MFP. 
     A document table  301  is a transparent glass table and is used to place an original to be read by the scanner. A document cover  302  is used to prevent reading light from externally leaking at the time of reading by the scanner. A printing paper insert port  303  is used to set paper sheets of various sizes. The paper sheets set in the printing paper insert port  303  are conveyed to a printing unit (printer engine) one by one, undergo desired printing, and are discharged from a printing paper discharge port  304 . 
     As shown in  FIG. 3B , an operation display unit  305  and an NFC unit  306  are arranged on the document cover  302 . The operation display unit  305  includes keys for various operations and an LCD display, with which it is possible to perform an operation and make settings for the MFP  300 . The NFC unit  306  is a unit used to perform short distance wireless communication, and the NFC unit is a place, close to which the user actually moves the mobile communication terminal  200 . An effective communicable distance is about 10 cm from the NFC unit  306 . A WLAN antenna  307  is used for WLAN communication, and is embedded in the document cover  302 . 
     The NFC unit is used for low-speed communication, and the WLAN unit is used for high-speed communication. 
     NFC communication will be described next. For near field communication using an NFC unit, an apparatus which generates an RF (Radio Frequency) field (magnetic field) to start communication will be referred to as an initiator hereinafter. An apparatus which communicates with the initiator in response to an instruction sent by the initiator will be referred to as a target hereinafter. The communication modes of the NFC unit include a passive mode and active mode. In the passive mode, the target responds to an instruction sent by the initiator by performing load modulation. On the other hand, in the active mode, the target responds to an instruction sent by the initiator with an RF field generated by the target itself. 
       FIGS. 4A and 4B  are block diagrams showing the concept of the passive mode in NFC communication. 
       FIG. 4A  shows a case in which an initiator  401  transmits data  404  to a target  402  in the passive mode. The initiator  401  generates an RF field (magnetic field)  403 . The initiator  401  modulates the RF field  403  to transmit the data  404  to the target  402 .  FIG. 4B  shows a case in which a target  406  transfers data  408  to an initiator  405  in the passive mode. Similarly to  FIG. 4A , the initiator  405  generates an RF field  407 . The target  406  performs load modulation for the RF field  407  to transmit the data  408  to the initiator  405 . 
       FIGS. 5A and 5B  are block diagrams showing the concept of the active mode in NFC communication. 
       FIG. 5A  shows a case in which an initiator  501  transmits data  504  to a target  502  in the active mode. The initiator  501  generates an RF field  503 . The initiator  501  modulates the RF field  503  to transmit the data  504  to the target  502 . Upon completion of the data transmission, the initiator  501  stops generating the RF field  503 .  FIG. 5B  shows a case in which a target  506  transmits data  508  to an initiator  505  in the active mode. The target  506  generates an RF field  507 . The target  506  transmits the data  508  with the RF field  507  generated by itself. Upon completion of the data transmission, the target  506  stops generating the RF field  507 . 
       FIG. 6  is a block diagram showing the arrangement of the mobile communication terminal  200 . 
     The mobile communication terminal  200  includes a main board  601  for controlling the apparatus as a whole, a WLAN unit  617  for performing WLAN communication, an NFC unit  618  for performing NFC communication, and a BT unit  621  for performing BT communication using Bluetooth®. Note that although  FIG. 6  shows a mobile communication terminal as the communication party of the NFC unit  618  or BT unit  621 , the communication party is not limited to this. For example, the NFC unit or BT unit can communicate with any apparatus implementing the same communication protocol, as a matter of course. Furthermore, a WLAN unit may be arranged instead of the BT unit  621  to perform high-speed wireless communication using a protocol conforming to, for example, IEEE802.1X or IEEE802.11n. The WLAN unit  617 , NFC unit  618 , and BT unit  621  will be collectively referred to as a communication unit hereinafter. 
     A CPU  602  of the main board  601  serves as a system control unit for controlling the mobile communication terminal  200  as a whole. A ROM  603  stores control programs, an embedded operating system (OS) program, and the like to be executed by the CPU  602 . In this embodiment, each control program stored in the ROM  603  performs software control such as scheduling or task switching under the management of the embedded OS stored in the ROM  603 . A RAM  604  is formed from an SRAM or the like. The RAM  604  stores program control variables, setting values registered by the user, management data for the mobile communication terminal  200 , and the like, and also is used as various work buffer areas. 
     An image memory  605  is formed from a DRAM or the like, and temporarily stores image data received via the communication unit or image data read out from a data storage unit  612  for processing by the CPU  602 . A non-volatile memory  622  is formed from a flash memory or the like, and stores data to be saved even after power-off. Examples of the data are telephone directory data and information of devices connected in the past. Note that the memory structure is not limited to that shown in  FIG. 6 . The image memory  605  and RAM  604  may share a memory, or data may be backed up in the data storage unit  612 . Although the DRAM is used in this embodiment, the present invention is not limited to this, and a hard disk, a non-volatile memory, or the like may be used. 
     A data conversion unit  606  performs analysis of a page description language (PDL) and the like, and data conversion such as color conversion and image conversion. A telephone unit  607  controls a telephone line, and processes voice data input/output through a speaker/microphone unit  613 , thereby implementing communication by telephone. An operation unit  608  controls a signal generated by the operation unit  204  described with reference to  FIG. 2 . A GPS (Global Positioning System)  609  acquires the current latitude and longitude. A display unit  610  electronically controls display contents of the display unit  203  described with reference to  FIG. 2 , and can display various input operations, the operation state and status of the MFP  300 , and the like. 
     A camera unit  611  has a function of electronically recording and encoding an image input via a lens. An image captured by the camera unit  611  is saved in the data storage unit  612 . The speaker/microphone unit  613  implements a function of inputting or outputting voice for the telephone function, an alarm notification function, and the like. A power supply unit  614  includes a portable battery, and controls the power supply. Power supply states include a battery empty state corresponding to a zero battery level, a power off state before the user presses the power key  205 , an active state (power-on state) in which the apparatus is normally activated, and a power-saving state in which the apparatus is activated but in a power-saving mode. 
     The mobile communication terminal  200  integrates three (3) wireless communication units as communication units for performing data communication with another device such as an MFP, and can perform wireless communication by WLAN, NFC, and Bluetooth®. The communication unit converts data into a packet, and transmits the packet to another device such as mobile terminals  200 A,  200 B. The communication unit also converts a packet from another external device into data, and transmits the converted data to the main board  601 . The WLAN unit  617 , NFC unit  618 , and BT unit  621  are connected by bus cables  615 ,  616 , and  620 , respectively. The WLAN unit  617 , NFC unit  618 , and BT unit  621  implement communication conforming to the respective specifications. The NFC unit will be described in detail later. 
     The above-described components  603  to  614 ,  617 ,  618 ,  621 , and  622  are connected to each other via a system bus  619  managed by the CPU  602 . 
       FIG. 7  is a block diagram showing the schematic arrangement of the MFP  300 . 
     The MFP  300  includes a main board  701  for controlling the apparatus as a whole, a WLAN unit  717  for performing WLAN communication, an NFC unit  718  for performing NFC communication, and a BT unit  719  for performing BT communication. Note that although  FIG. 7  shows mobile communication terminals  200 C,  200 D as the communication party of the NFC unit  718  or BT unit  719 , the communication party is not limited to this. For example, the NFC unit or BT unit can communicate with any apparatus implementing the same communication protocol, as a matter of course. Furthermore, a WLAN unit may be arranged instead of the BT unit  719  to perform high-speed wireless communication using a protocol conforming to, for example, IEEE802.1X or IEEE802.11n. The WLAN unit  717 , NFC unit  718 , and BT unit  719  will be collectively referred to as a communication unit hereinafter. 
     A CPU  702  of the main board  701  serves as a system control unit for controlling the MFP  300  as a whole. A ROM  703  stores control programs, an embedded operating system (OS) program, and the like to be executed by the CPU  702 . In this embodiment, each control program stored in the ROM  703  performs software control such as scheduling or task switching under the management of the embedded OS stored in the ROM  703 . 
     A RAM  704  is formed from an SRAM or the like. The RAM  704  stores program control variables, setting values registered by the user, management data for the MFP  300 , and the like, and also is used as various work buffer areas. A non-volatile memory  705  is formed from a flash memory or the like, and stores data to be saved even after power-off. More specifically, the non-volatile memory  705  stores network connection information, user data, and the like. An image memory  706  is formed from a DRAM or the like, and stores image data received via the communication unit, image data processed by an encoding/decoding processing unit  712 , and image data acquired from a memory card via a memory card controller (not shown). Like the memory structure of the mobile communication terminal  200 , the memory structure is not limited to this. A data conversion unit  707 , for example, performs analysis of page description language (PDL) data and the like, and conversion of image data into print data. 
     An image signal generated when a reading unit  710  controlled by a reading control unit  708  causes a CIS image sensor to optically read an original undergoes various image processes such as binarization processing and half-toning processing via an image processing control unit (not shown), thereby outputting high-resolution image data. 
     An operation unit  709  and a display unit  711  represent the operation display unit  305  described with reference to  FIGS. 4A and 4B . The encoding/decoding processing unit  712  executes encoding/decoding processing and resizing processing for the image data (JPEG, PNG, or the like) handled by the MFP  300 . 
     A paper feed unit  714  holds printing media such as printing paper sheets. The paper feed unit  714  can perform a paper feed operation under the control of a print control unit  716 . Especially, the paper feed unit may include a plurality of paper feed units to hold a plurality of kinds of printing paper sheets in one apparatus. In this case, the print control unit  716  controls to select a paper feed unit to feed printing paper sheets. 
     The print control unit  716  converts image data to be printed into high-resolution image data by executing, via the image processing control unit (not shown), various image processes such as smoothing processing, printing density correction processing, and color correction, and outputs the obtained image data to a printing unit  715 . The print control unit  716  periodically reads out information in the printing unit  715  to update status information stored in the RAM  704 . More specifically, the print control unit  716  updates the ink residual of an ink tank, the state of a printhead, and like. 
     Similarly to the mobile communication terminal  200 , the MFP  300  integrates three (3) wireless communication units. Each function is the same as that of the mobile communication terminal  200 , and a description thereof will be omitted. Note that the WLAN unit  717 , NFC unit  718 , and BT unit  719  are connected by bus cables  720 ,  721 , and  722 , respectively. 
     The above-described components  702  to  719  are connected to each other via a system bus  723  managed by the CPU  702 . 
     The WLAN unit shown in  FIGS. 6 and 7  can perform high-speed wireless communication conforming to, for example, IEEE802.1X or IEEE802.11n. 
       FIG. 8  is a block diagram showing the detailed arrangement of the NFC unit used as the NFC unit  618  or NFC unit  718 . 
     An NFC unit  800  includes an NFC controller  801 , an antenna unit  802 , an RF unit  803 , a transmission/reception control unit  804 , an NFC memory  805 , and a device connection unit  807 . A power supply  806  is provided outside the NFC unit  800 . The antenna unit  802  receives/transmits a radio wave or a carrier from/to another NFC device. The RF unit  803  has a function of modulating/demodulating an analog signal into/from digital signal. The RF unit  803  includes a synthesizer to identify the frequency of a band or a channel and control the band or channel using frequency assignment data. The transmission/reception control unit  804  performs control concerning transmission/reception, including assembling and disassembling of a transmission/reception frame, preamble addition and detection, and frame identification. The transmission/reception control unit  804  also controls the NFC memory  805  to input/output various data and programs. 
     The NFC memory  805  is formed from a non-volatile memory. When the NFC unit operates in the active mode, it receives power via the power supply  806 , and communicates with another device via the device connection unit  807  or communicates with another NFC device existing within coverage by a carrier transmitted/received via the NFC controller  801 . To the contrary, when the NFC unit operates in the passive mode, it receives a radio wave from another NFC device via the antenna unit  802 , and receives power from the other NFC device by electromagnetic induction. The NFC unit then communicates with the other NFC device by modulating the carrier, thereby transmitting/receiving data including information stored in the NFC memory  805 . 
       FIG. 9  is a block diagram showing the internal structure of the non-volatile memory (flash memory)  705  of the MFP  300 . 
     Referring to  FIG. 9 , reference numeral  901  denotes an entire flash memory. User data  902  stores information about the user, including a FAX number, a communication history, and network information. A list  903  of apparatuses connected in the past stores a list of apparatuses to which the MFP  300  has been connected so far. If, for example, the MFP  300  communicated with a smart phone using NFC, the identifier of the smart phone is stored. If P2P communication with a smart phone was performed via WLAN, identification information for WLAN connection is stored. More specifically, if WPS (Wi-Fi Protected Setup) is used for WLAN connection, WPS Credential authentication information is stored. 
     If the MFP  300  was connected to a smart phone by Bluetooth®, OOB authentication information is stored. If the MFP  300  was connected to the server apparatus  101  via the network  100 , the network information of the server apparatus  101  is stored. Setting information  906  stores the setting information of the MFP  300 . For example, menu items such as a print mode, correction information of an inkjet printhead, and the like are stored. Other  907  stores another non-volatile information. 
       FIG. 10  is a block diagram showing the internal structure of the non-volatile memory (flash memory)  622  of the mobile communication terminal  200 . 
     Referring to  FIG. 10 , reference numeral  1001  denotes an entire non-volatile memory. A printer list  1002  stores a list of printers to which the mobile communication terminal  200  has been connected so far. A printer A  1003  is an example of the printer. Network connection information  1004  stores network connection information when the printer A was connected to a network. If, for example, the printer A was connected via LAN, the address of the connection destination and authentication information are stored. A unit-specific information  1005  stores information about the printer, for example, information of the printing resolution and the number of inks used of the printer. 
     A printer-specific application  1006  stores an application for performing processing (conversion of image data into a format conforming to the specifications of the printer, band processing control, communication control, and the like) specific to the printer. This information is downloaded via the network  100  or saved when the terminal is connected to the printer for the first time. A printer B  1008  is an example of another printer. User data  1009  stores data about the user, for example, a telephone number  1010  and an image server address  1011 . 
       FIG. 11  is a flowchart when the NFC unit operates as an initiator. 
     In step S 1101 , every NFC unit operates as a target, and stands by for an instruction from an initiator. In step S 1102 , the NFC unit can switch over to an initiator in response to a request from an application for controlling communication conforming to the NFC specifications. If the NFC unit responds to the request to switch over to an initiator, the process advances to step S 1103  in which the application selects one of the active mode and the passive mode, and determines the transmission rate. 
     In step S 1104 , the initiator detects the existence of an RF field output from an apparatus other than itself. If an external RF field exists, the initiator does not generate the RF field of its own; otherwise, the process advances to step S 1105  in which the initiator generates the RF field of its own. 
     By executing the above steps, the NFC unit starts the operation as the initiator. 
       FIG. 12  is a sequence chart showing the sequence of performing data exchange in the passive mode. A case will be described in which an NFC unit (first NFC unit)  1201  operates as an initiator and an NFC unit (second NFC unit)  1202  operates as a target. 
     In step S 1201 , the NFC unit  1201  performs single device detection to specify the NFC unit  1202 . In step S 1202 , the NFC unit  1201  transmits, as an attribute request, the identifier of its own, the bit transmission rate of transmission/reception, the effective data length, and the like. This attribute request has general purpose bytes which can be arbitrarily selected and used. Upon receiving an effective attribute request, the NFC unit  1202  transmits an attribute response in step S 1203 . Note that transmission from the NFC unit  1202  is performed by load modulation, and data transmission by load modulation is represented by a dotted arrow in  FIG. 12 . 
     Upon confirming an effective attribute response, the NFC unit  1201  can transmit a parameter selection request, and change the parameters of a subsequent transmission protocol in step S 1204 . Parameters included in the parameter selection request are the transmission rate and effective data length. Upon receiving an effective parameter selection request, the NFC unit  1202  transmits a parameter selection response, and changes the parameters in step S 1205 . Note that steps S 1204  and S 1205  may be omitted if the parameters are not changed. 
     In step S 1206 , the NFC unit  1201  and the NFC unit  1202  exchange data by sending a data exchange request and a data exchange response. With the data exchange request and response, it is possible to transmit, as data, information for an application of the communication party. If the data size is large, the data can be divided and transmitted. 
     Upon completion of the data exchange, the NFC unit  1201  transmits one of a selection cancellation request and a release request in step S 1207 . If the NFC unit  1201  transmits the selection cancellation request, the NFC unit  1202  transmits a selection cancellation response in step S 1208 . Upon receiving the selection cancellation response, the NFC unit  1201  releases the attributes indicating the NFC unit  1202 , and the process returns to step S 1201 . On the other hand, if the NFC unit  1201  transmits the release request, the NFC unit  1202  transmits a release response to return to the initial state in step S 1208 . Upon receiving the release response, the NFC unit  1201  can return to the initial state since the target has been completely released. 
       FIG. 13  is a sequence chart showing the sequence of performing data exchange in the active mode. A case will be described in which an NFC unit (first NFC unit)  1301  operates as an initiator and an NFC unit (second NFC unit)  1302  operates as a target. 
     In step S 1301 , the NFC unit  1301  transmits, as an attribute request, the identifier of its own, the bit transmission rate of transmission/reception, the effective data length, and the like. Upon receiving an effective attribute request, the NFC unit  1302  transmits an attribute response in step S 1302 . Note that transmission from the NFC unit  1302  is performed by an RF field generated by itself. Upon completion of data transmission, therefore, both the NFC units stop generating RF fields. 
     Upon confirming an effective attribute response, the NFC unit  1301  can transmit a parameter selection request, and change the parameters of a transmission protocol in step S 1303 . Parameters included in the parameter selection request are the transmission rate and effective data length. Upon receiving an effective parameter selection request, the NFC unit  1302  transmits a parameter selection response, and changes the parameters in step S 1304 . Note that similarly to the passive mode, steps S 1303  and S 1304  may be omitted if the parameters are not to be changed. 
     In step S 1305 , the NFC unit  1301  and the NFC unit  1302  exchange data by sending a data exchange request and a data exchange response. With the data exchange request and response, it is possible to transmit, as data, information for an application. If the data size is large, the data can be divided and transmitted. 
     Upon completion of the data exchange, the NFC unit  1301  transmits one of a selection cancellation request and a release request in step S 1306 . If the NFC unit  1301  transmits the selection cancellation request, the NFC unit  1302  transmits a selection cancellation response in step S 1307 . Upon receiving the selection cancellation response, the NFC unit  1301  releases the attributes indicating the NFC unit  1302 . After that, the NFC unit  1301  transmits an activation request to another target with a known identifier in step S 1308 . Upon receiving the activation request, the target transmits an activation response in step S 1309 , and the process returns to step S 1301 . On the other hand, if the NFC unit  1301  transmits the release request, the NFC unit  1302  transmits a release response, and returns to the initial state in step S 1309 . Upon receiving the release response, the NFC unit  1301  can return to the initial state since the target has been completely released. 
     The communication rate of NFC is relatively as low as several hundred bps. Therefore, authentication and the like are performed using NFC, and a large amount of data is transmitted using higher-speed WLAN, thereby achieving efficient data transfer. 
       FIG. 14  is a sequence chart showing the sequence of performing data transfer while switching between NFC and WLAN.  FIG. 14  shows an example of so-called push-type communication in which the MFP  300  takes initiative for transferring, to the mobile communication terminal  200 , image data generated by reading an image original using the scanner function of the MFP  300 . 
     In step S 1401 , to establish NFC communication with the MFP  300 , the NFC unit  618  serves as an initiator to detect the NFC unit  718  as a target. If the NFC unit  718  has been correctly detected, the NFC unit  718  transmits a detection response in step S 1402 . Note that in the example shown in  FIG. 14 , the mobile communication terminal  200  serves as an initiator. In fact, however, the MFP  300  may become an initiator based on an input through the operation display unit  305  or the like. Upon correctly receiving the detection response, in step S 1403  the NFC unit  618  transmits an attribute request for performing NFC communication. Upon receiving the attribute request, the NFC unit  718  returns an attribute response in step S 1404 . With the attribute request and response, the NFC_IDs of the initiator and target are transmitted, and the communication parties are specified by the NFC_IDs. 
     In step S 1405 , mutual authentication is performed, thereby enabling to pass an encryption key for data encryption. Note that if, for example, it is not necessary to pass an encryption key, this mutual authentication need not be performed. In step S 1406 , the NFC unit  618  requests information about a communication protocol available in the MFP  300 , to the NFC unit  718 . This request contains information about a communication protocol available in the mobile communication terminal. Upon receiving the request, the NFC unit  718  can recognize that the mobile communication terminal can use WLAN communication. In step S 1407 , the NFC unit  718  responds to the request received in step S 1406  with the information about the communication protocol available in itself. Both the apparatuses, therefore, can identify the communication protocol available with each other. 
     Assume that the mobile communication terminal serving as the initiator has determined that it is possible to perform data transfer at speed using the recognized WLAN communication protocol higher than that with NFC, and thus communication is performed by switching over to WLAN. Note that the MFP may determine switch-over to WLAN. 
     In this case, in steps S 1408  and S 1409 , for example, the apparatuses exchange information necessary for WLAN communication, such as addresses for specifying the communication parties. The process then advances to step S 1410 , in which the NFC unit  618  transmits a request to switch over from the NFC communication to the WLAN communication. Upon receiving the switch-over request, the NFC unit  718  responds to it in step S 1411 . 
     Upon receiving a correct switch-over response, the NFC unit  618  is switched over to the WLAN unit  617  in step S 1412 , and the NFC unit  718  is switched over to the WLAN unit  717  in step S 1413 . After the switch-over operations, the NFC unit  618  transmits a release request in step S 1414 . Upon receiving the release request, the NFC unit  718  transmits a release response in step S 1415 , thereby terminating NFC communication. 
     Processing in step S 1416  and subsequent steps executes WLAN communication based on the information for WLAN communication exchanged in steps S 1408  and S 1409 . 
     In step S 1416 , the WLAN unit  717  confirms with the WLAN unit  617  whether or not data transfer is possible. The contents to be confirmed here include, for example, the capacity of free space to save image data to be transferred to the mobile communication terminal  200 . Upon receiving the confirmation request, the WLAN unit  617  transmits an acknowledgement in step S 1417 . If a correct acknowledgement has been received, and it has been determined that data transfer is possible, the WLAN unit  717  transmits, to the WLAN unit  617 , image data generated by the scanner function of the MFP  300  in step S 1418 . This processing enables to transfer a large amount of data using a higher-speed communication protocol. 
       FIG. 15  is a sequence chart showing the sequence of performing so-called pull-type communication in which the mobile communication terminal  200  takes initiative for transferring, to itself, image data generated by reading an image original using the scanner function of the MFP  300 . Note that the same step in  FIG. 15  as that in  FIG. 14  has the same reference symbol, and a description thereof will be omitted. 
     Referring to  FIG. 15 , after switching over from NFC communication to WLAN communication, the WLAN unit  617  transmits a request for acknowledgement of data acquisition to the WLAN unit  717  in step S 1416 ′. The contents to be confirmed here include a data size of data to be transferred by the MFP  300 . Upon receiving the request for acknowledgement of transfer data, the WLAN unit  717  transmits a response in step S 1417 ′. If a correct response has been received, and it has been determined in consideration of the free space of the mobile communication terminal  200  that data transfer is possible, the WLAN unit  617  requests image data in step S 1418 ′. Upon receiving a correct request, the WLAN unit  717  transmits the requested image data in step S 1419 ′. 
       FIG. 16  is a flowchart illustrating processing executed by the mobile communication terminal from a time when an application of the mobile communication terminal is activated until communication with the MFP ends. Assume that the application has, for example, a user interface used by the user to input settings as shown in  FIG. 18 , and a function of causing the NFC unit of the mobile communication terminal to operate as an initiator. 
     In step S 1601 , the user uses the application of the mobile communication terminal to make settings for the scanner function of the MFP  300  and send an instruction to the scanner function. The settings and instruction are transmitted to the MFP. The settings include settings for a reading function such as the reading resolution of a scanner, and address settings used for transferring image data obtained by an image reading operation. Upon completion of the setting operation, a detection request/response, attribute request/response, and the like are transmitted/received using NFC communication to detect the MFP  300  in step S 1602 . Note that either the mobile communication terminal or MFP may serve as an initiator in this case. Upon detecting the MFP, the reading settings determined in step S 1601  are transmitted to the MFP in step S 1603 . 
     In step S 1604 , the transfer destination of the image data determined in the reading settings is checked. If the image data is to be transferred to the mobile communication terminal, the process advances to step S 1605 . On the other hand, if the image data is to be transferred to an apparatus other than the mobile communication terminal, for example, the server apparatus  101 , the process releases the target to terminate the communication. Note that the transfer destination of the image data has been decided in advance in the mobile communication terminal or MFP, it is not necessary to execute the processing in step S 1604 . 
     In step S 1605 , it is checked whether or not the image data is transferred using a communication method other than the NFC, such as WLAN. If the communication method is switched over from NFC communication to another communication method, the process advances to step S 1606 . If NFC communication continues, the process advances to step S 1607 . Note that the communication method of transferring the image data may be selected by the user in step S 1601 , may be automatically selected by the mobile communication terminal or MFP, or may have been decided in advance. 
     In step S 1606 , the communication method is switched over according to the sequence shown in  FIG. 14  or  15 . Note that since the sequence from a time when communication starts until mutual authentication is performed ends in step S 1602 , the processing of requesting information about an available WLAN protocol in step S 1406  and subsequent steps is executed. If the mobile communication terminal or MFP cannot use the set communication method, the user is notified of it or alternative processing of selecting another available communication method is executed. If the communication method has been successfully switched over to that other than NFC communication, the NFC communication may be terminated. 
     Upon completion of the above processing, in step S 1607  the process stands by for completion of processing of reading an image original by the scanner function of the MFP. Upon completion of the reading processing, the process advances to step S 1608  by receiving a processing end notification or the like. In step S 1608 , the image data of the read image original is received. At this time, communication for receiving the image data is performed by the NFC communication or the communication method to which the NFC communication has been switched over in step S 1606 . Upon completion of reception of the image data, the communication is terminated. Note that if the communication is interrupted while receiving the data, error processing is executed. For example, the user is notified of the error by displaying it on the screen of the mobile communication terminal. 
       FIG. 17  is a flowchart illustrating processing executed by the MFP from a time when the mobile communication terminal is detected until communication ends.  FIG. 17  shows processing in which the mobile communication terminal activates the scanner function of the MFP using NFC communication to transfer the image data of a read image original to the mobile communication terminal or server apparatus according to the NFC communication protocol or another communication protocol. 
     In step S 1701 , the MFP receives the settings for the scanner function, which have been decided by the user in step S 1601  of  FIG. 16 . These settings include settings for the reading function such as the reading resolution of the scanner, and settings for addresses to which the image data obtained by an image reading operation is transferred. In step S 1702 , the received settings are decoded to check the transfer destination of the image data. If the image data is directly transferred to the mobile communication terminal, the process advances to step S 1703 ; otherwise, the process advances to step S 1704 . Note that if the mobile communication terminal or MFP has decided in advance the transfer destination of the image data, it is not necessary to execute the processing in step S 1702 . 
     In step S 1703 , it is determined whether or not the communication method for transferring the image data is switched over from the NFC communication to another method. If the communication method is switched over, the process advances to step S 1704 ; otherwise, the process advances to step S 1705 . In step S 1704 , the communication method is switched over according to the sequence shown in  FIG. 14  or  15 . Especially, if it is determined in step S 1702  that the image data is not transferred to the mobile communication terminal, communication with the mobile communication terminal is disconnected, thereby starting communication with the specified transfer destination of the image data. If the MFP or the transfer destination of the image data cannot use the set communication method, the user of the mobile communication terminal is notified of it or alternative processing of selecting another available communication method is executed. If the communication method has been successfully switched over to that other than the NFC communication, the NFC communication may be terminated. 
     In step S 1705 , the scanner function of the MFP is used to read an image original. Upon completion of the reading processing, the mobile communication terminal is notified of it, and the process advances to step S 1706 . Note that although the image reading processing is executed after switching over the communication method in this example, the communication method may be switched over after or in parallel with the image reading processing. 
     In step S 1706 , the MFP transmits the image data to the specified transfer destination according to the specified communication protocol. The transfer destination and communication protocol have been decided in advance or in reading settings. Furthermore, in step S 1707 , the MFP monitors whether or not a transmission error has occurred, for example, whether or not the transfer destination moves out of coverage in wireless communication. If an error has occurred in communication with the transfer destination, the communication may be interrupted while transferring the image data. The process, therefore, advances to step S 1708 , in which the MFP performs transfer control to transmit the image data to an alternative server apparatus. By including, as an alternative destination, the address of another transfer destination such as a server apparatus in the settings received in step S 1701 , it is possible to transfer the remaining image data to the other transfer destination when communication with the transfer destination selected first fails. Note that the address of another transfer destination to which the image data is transmitted may be included in the settings, or may have been determined in advance by the MFP. 
     If no transmission error has occurred, the MFP terminates the communication upon completion of transfer of the image data. Even if a transmission error has occurred, the MFP terminates the communication upon completion of transfer of the image data to the alternative server apparatus. If the image data has been transferred to a transfer destination (for example, the server apparatus) other than the mobile communication terminal, the MFP may request the server apparatus serving as the alternative transfer destination to notify, with email or the like, the mobile communication terminal that transfer of the image data is complete. 
       FIG. 18  is a view showing an example of a screen for making settings, in step S 1601  of  FIG. 16 , upon executing an application of the mobile communication terminal, for a scanner apparatus (or an MFP having a scanner function) for performing an image reading operation. The application has, for example, a user interface used by the user to input data, and a function of causing the NFC unit to operate as an initiator. 
       FIG. 19  is a view showing an example of a screen for making detailed settings for a scanner apparatus (or an MFP having a scanner function), to which the screen moves on when a detailed setting key  1805  shown in  FIG. 18  is selected in step S 1601  of  FIG. 16 . 
     As shown in  FIG. 18 , a color mode selection key  1802 , a reading mode selection key  1803 , an image save destination selection key  1804 , the detailed setting key  1805 , a reading start key  1806 , and an end key  1807  are displayed on a setting screen  1801 . The color mode selection key  1802  can be used to, for example, select an item associated with a reading color such as color or monochrome. The reading mode selection key  1803  can be used to, for example, select the type of image original to be read such as a document or photograph. The image save destination selection key  1804  is used to set the transfer destination of image data obtained by reading an image original. In this example, the mobile communication terminal, a server apparatus to which the mobile communication terminal can be connected, and the like are displayed as options. It is also possible to add or delete options of the transfer destination of the image data. 
     When the detailed setting key  1805  is selected, the screen moves on from the setting screen  1801  to a detailed setting screen  1901  shown in  FIG. 19 . When the reading start key  1806  is selected, the mobile communication terminal becomes an initiator in NFC communication, and starts to detect the scanner apparatus (in this embodiment, the MFP) as the communication party. When the end key  1807  is selected, the application ends. Before terminating the application, a message for reconfirming it and selection keys may be displayed. Note that the keys and display contents on the setting screen  1801  are merely illustrative, and the items, display contents, and positions may be arbitrarily changed. Furthermore, items common to general scanner apparatuses may be set on this screen, and the screen may be changed according to the scanner apparatus set on the screen shown in  FIG. 19  (to be described later). 
     Detailed settings for the scanner apparatus (in this embodiment, the MFP) will be described with reference to  FIG. 19 . 
     A reading apparatus selection key  1902 , a reading resolution selection key  1903 , a key  1904  for selecting an alternative transfer destination in the event of a transfer failure, an image transfer completion notification selection key  1905 , and a key  1906  for returning to abbreviated setting are displayed on the detailed setting screen  1901 . The reading apparatus selection key  1902  is used to select a scanner apparatus (in this embodiment, an MFP) as the communication party to which the contents set on the screen are transmitted. Apparatuses with which have been communicated in the past are displayed as options here, and the user can add a new option from the displayed apparatuses. To add a new option, for example, a scanner apparatus or MFP may be recognized by performing NFC communication or the like in addition to transmission of the settings, or the user may search for scanner apparatuses on the Web site and select one of them. If the selected scanner apparatus is different from that with which has been actually communicated, the user may be notified of the error and instructed to change the item, or processing of reading an image original may be executed according to settings similar to the input settings. The reading resolution selection key  1903  can be used to select the reading resolution of the scanner apparatus. Since this setting may be different for each apparatus, only selectable settings for the selected apparatus may be presented as options to the user. 
     The key  1904  for selecting an alternative transfer destination in the event of a transfer failure can be used to select a transfer destination different from that selected in  FIG. 18  for transmitting the remaining image data even in a case where communication is interrupted before starting to transfer the image data or while transferring the image data. For example, the mobile communication terminal, a server apparatus to which the mobile communication terminal can be connected, and the like are displayed as options. It is also possible to add or delete options of the transfer destination of the image data, or no alternative transfer destination may be set. 
     The image transfer completion notification selection key  1905  can be used to select, when the image data is transferred to an apparatus other than the mobile communication terminal, whether or not to send a notification that transfer of the image data is complete. Assume that it is selected that such notification is sent. In this case, if the mobile communication terminal has recognized that transfer is complete, for example, if the mobile communication terminal has correctly received the image data, a notification need not be sent. When the key  1906  for returning to abbreviated setting is selected, the displayed screen returns from the detailed setting screen  1901  to the setting screen  1801  shown in  FIG. 18 . Note that the keys and display contents on the detailed setting screen  1901  are merely illustrative, and the items, display contents, and positions may be arbitrarily changed. 
     According to the above-described embodiment, it is possible to use high-speed WLAN to transfer, to the mobile communication terminal, image data obtained by executing the scanner function of the MFP. Furthermore, even if communication is interrupted while transferring the image data, for example, the MFP can transfer the image data to an alternative apparatus such as a server apparatus, and then the mobile communication terminal can acquire the image data from the server apparatus via a network. 
     This arrangement can prevent a large amount of image data from being stored in the MFP with a relatively small-capacity memory for a long time, thereby enabling to efficiently use the MFP. On the other hand, even if the mobile communication terminal operating with a battery power supply cannot receive image data because the battery has run out, it can acquire the desired image data from the server apparatus after the battery is exchanged or the battery is recharged. 
     Note that a case in which the MFP transmits scanned data has been described in the above embodiment, the present invention is not limited to this, and the MFP may transmit various data. For example, the present invention is applicable to a case where image data stored in either an internal memory of the MFP or an external memory attached to the MFP is transmitted. In this case, the MFP  300  receives information, such as a file name, which identifies data to be transmitted from the mobile communication terminal  200  by NFC communication, and transmits the identified data based on the information by WLAN. 
     Furthermore, a case in which the MFP transmits data to the server by WLAN has been described in the above embodiment. The present invention, however, is not limited to this, and various wireless communication methods such as Bluetooth® can be used. Also, the MFP may transmit data to the server by wired communication. 
     Aspects of the present invention can also be realized by a computer of a system or apparatus (or devices such as a CPU or MPU) that reads out and executes a program recorded on a memory device to perform the functions of the above-described embodiment(s), and by a method, the steps of which are performed by a computer of a system or apparatus by, for example, reading out and executing a program recorded on a memory device to perform the functions of the above-described embodiment(s). For this purpose, the program is provided to the computer for example via a network or from a recording medium of various types serving as the memory device (e.g., computer-readable medium). 
     While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2012-048616, filed Mar. 5, 2012, which is hereby incorporated by reference herein in its entirety.