Abstract:
An information processing apparatus includes an authenticator that authenticates a user, an operation acceptor that, during a period in which an operating user is logged in, accepts an operation by the operating user, a setter that sets a setting value, a log-out detector that detects log-out of the operating user, a setting value maintainer that, in the case where the log-out is detected, associates a setting value, which is set at a time point at which the log-out is detected, with the operating user, and a recoverer that, in the case where the operating user associated with the setting value stored is authenticated, sets a setting value to the setting value stored in the setting value maintainer, wherein the setting value maintainer, in the case where a user different from the operating user associated with the setting value stored is authenticated, does not delete the stored setting value.

Description:
[0001]    This application is based on Japanese Patent Application No. 2016-060141 filed with Japan Patent Office on Mar. 24, 2016, the entire content of which is hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    Field of the Invention 
         [0003]    The present invention relates to an information processing apparatus, a setting continuation method and a non-transitory computer-readable recording medium encoded with a setting continuation program. More specifically, the present invention relates to an information processing apparatus that automatically detects the log-out of a user, a setting continuation method performed in the information processing apparatus and a non-transitory computer-readable recording medium encoded with a setting continuation program. 
         [0004]    Description of the Related Art 
         [0005]    In recent years, a technology for authenticating a user based on authentication information received from a portable device when an information processing apparatus becomes communicable with the portable device carried by the user has been known, and this technology can be applied to an information processing apparatus such as an MFP (Multi Function Peripheral). Because the user is authenticated by the MFP only by being close to the MFP  100  while carrying the portable device, an operation performed by the user for authentication can be simplified. 
         [0006]    However, the user sometimes moves away from the MFP temporarily in the middle of an operation of the MFP. For example, it includes the case where the user carries sheets of paper to fill a tray in the MFP from another location or the case where the user forgets to bring a document for copying and returns to a desk to fetch the document. In this case, at a time point at which the MFP can no longer communicate with the portable device carried by the user, the MFP determines that the user is logged out and executes a log-out process. Generally, when executing the log-out process, the MFP changes a setting value, which is set by that time point, to a default value, so that the user must restart settings from the beginning at a time point at which the user logs in again. 
         [0007]    Japanese Patent Laid-Open No. 2014-191402 discloses an information processing apparatus including a pseudo-log-out execution means that, in the case where a user requests to log out, cancels a process of log-out and creates a pseudo-log-out state by preventing an user operation and viewing of a screen while maintaining a log-in session, and a log-in request process means that, in the case where the user requests to log in after pseudo-log-out, confirms whether a pseudo-logged-out user matches the user who requests to log in, characterized in that the log-in request process means, in the case where the pseudo-logged-out user and the user who requests to log in are different from each other, requests an OS to execute a log-out process of the pseudo-logged-out user and a log-in process of the user who requests to log in. 
         [0008]    However, in the case where another user logs in, the information processing apparatus described in Japanese Patent Laid-Open No. 2014-191402 executes the log-out process. Thus, in the case where the other user logs in, there is a problem that the setting value is erased. Meanwhile, in the case where the user sets the setting value and then allows the MFP to execute a process, the setting value is no longer necessary. In the case where the user allows the MFP to execute a process and then requests to log out, the unnecessary setting value is kept stored. Thus, there is a problem that a default setting value is not displayed in the case of the next log-in request. 
       SUMMARY OF THE INVENTION 
       [0009]    According to one aspect of the present invention, an information processing apparatus includes a hardware processor that executes a process, the hardware processor includes an authenticator configured to authenticate a user, an operation acceptor configured to, during a period in which an operating user authenticated by the authenticator is logged in, accept an operation by the operating user, a setter configured to set a setting value used for execution of a process in accordance with the accepted operation, a log-out detector configured to detect log-out of the operating user, a setting value maintainer configured to, in the case where the log-out is detected by the log-out detector, associate a setting value, which is set by the setter at a time point at which the log-out is detected by the log-out detector, with the operating user for storage, and a recoverer configured to, in the case where the operating user associated with the setting value stored in the setting value maintainer is authenticated by the authenticator, set a setting value to the setting value stored in the setting value maintainer, wherein the setting value maintainer is configured not to, in the case where a user different from the operating user associated with the setting value stored by the setting value maintainer is authenticated by the authenticator, delete the stored setting value. 
         [0010]    According to another aspect of the present invention, an information processing apparatus comprising a hardware processor that executes a process, the hardware processor includes an authenticator configured to authenticate a user, an operation acceptor configured to, during a period in which an operating user authenticated by the authenticator is logged in, accept an operation by the operating user, a setter configured to set a setting value used for execution of a process by a process executor in accordance with the accepted operation, a log-out detector configured to detect log-out of the operating user, a setting value maintainer configured to, in the case where the log-out is detected by the log-out detector with the operation by the operating user authenticated by the authenticator not completed, associate a setting value, which is set by the setter at a time point at which the log-out is detected by the log-out detector, with the operating user for storage, and configured not to, in the case where the log-out is detected by the log-out detector with the operation by the operating user authenticated by the authenticator completed, store the setting value set by the setter, and a recoverer configured to, in the case where the operating user associated with the setting value stored by the setting value maintainer is authenticated by the authenticator, set a setting value to the setting value stored by the setting value maintainer. 
         [0011]    According to yet another aspect of the present invention, a setting continuation method includes an authentication step of authenticating a user, an operation acceptance step of, during a period in which an operating user authenticated in the authentication step is logged in, accepting an operation by the operating user, a setting step of setting a setting value used for execution of a process by an information processing apparatus in accordance with the accepted operation, a log-out detection step of detecting log-out of the operating user, a setting value maintaining step of, in the case where the log-out is detected in the log-out detection step, associating a setting value, which is set in the setting step at a time point at which the log-out is detected in the log-out detection step, with the operating user for storage, and a recovery step of, in the case where the operating user associated with the setting value stored in the setting value maintaining step is authenticated in the authentication step, setting a setting value to the setting value stored in the setting value maintaining step, wherein the setting value maintaining step includes a step of, in the case where a user different from the operating user associated with the setting value stored in the setting value maintaining step is authenticated in the authentication step, not deleting the stored setting value. 
         [0012]    According to yet another aspect of the present invention, a setting continuation method includes an authentication step of authenticating a user, an operation acceptance step of, during a period in which an operating user authenticated in the authenticator is logged in, accepting an operation by the operating user, a setting step of setting a setting value used for execution of a process by an information processing apparatus in accordance with the accepted operation, a log-out detection step of detecting log-out of the operating user, a setting value maintaining step of, in the case where the log-out is detected in the log-out detection step with the operation by the operating user authenticated in the authentication step not completed, associating a setting value, which is set in the setting step at a time point at which the log-out is detected in the log-out detection step, with the operating user for storage, and in the case where the log-out is detected in the log-out detection step with the operation by the operating user authenticated in the authentication step completed, not storing the setting value set in the setting step; and a recovery step of, in the case where the operating user associated with the setting value stored in the setting value maintaining step is authenticated in the authentication step, setting a setting value to the setting value stored in the setting value maintaining step. 
         [0013]    The foregoing and other features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a diagram showing an overview of an image forming system in one embodiment of the present invention; 
           [0015]      FIG. 2  is a diagram showing one example of a range of an antenna included in an MFP; 
           [0016]      FIG. 3  is a block diagram showing one example of a hardware configuration of the MFP; 
           [0017]      FIG. 4  is a block diagram showing one example of functions of a CPU included in the MFP; 
           [0018]      FIG. 5  is a flow chart showing one example of a flow of a setting continuation process; 
           [0019]      FIG. 6  is a flow chart showing one example of a flow of an operation acceptance process; and 
           [0020]      FIG. 7  is a flow chart showing one example of a flow of a repetition operation acceptance process. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    Embodiments of the present invention will be described below with reference to drawings. In the following description, the same parts are denoted with the same reference characters. Their names and functions are also the same. Thus, a detailed description thereof will not be repeated. 
         [0022]      FIG. 1  is a diagram showing an overview of an image forming system in one embodiment of the present invention. Referring to  FIG. 1 , the image forming system  1  includes Multi-Functional Peripherals (hereinafter referred to as “MFPs”)  100 ,  100 A,  100 B,  100 C, an authentication server  200  and a portable device  250  that are respectively connected to a network  2 . The MFP  100 ,  100 A,  100 B,  100 C have the same configuration and functions, so that the MFP  100  will be taken as an example in the description here, unless otherwise specified. 
         [0023]    The MFP (Multi Function Peripheral)  100  is one example of an information processing apparatus, includes a scanner for scanning a document, an image forming unit for forming an image on a recording medium such as a sheet of paper based on image data, and a facsimile machine, and includes an image scanning function, a copying function and a facsimile transmission reception function. While the MFP  100  is described as an example of the information processing apparatus in the present embodiment, the information processing apparatus may be a printer or a facsimile machine each having an image forming function. 
         [0024]    The network  2  is a Local Area Network (LAN), either wired or wireless. Further, the network  2  is not limited to the LAN and may be a Wide Area Network (WAN), the Internet or the like. The MFP  100 ,  100 A,  100 B,  100 C can communicate with one another via the network  2 , and each of the MFPs  100 ,  100 A,  100 B,  100 C can communicate with the authentication server  200  via the network  2 . 
         [0025]    The authentication server  200  is a general computer. The hard configuration and the functions of the authentication server  200  are known. Therefore, a description thereof will not be repeated. 
         [0026]    The MFP  100  includes an antenna  118 A, which is an electrode laid on a floor surface in a predetermined range in its vicinity. The portable device  250  includes at least a memory and a data communication unit that performs human body communication with each of the MFPs  100 ,  100 A,  100 B,  100 C. The portable device  250  stores unique device identification information assigned to the portable device  250  in the memory. When a user who carries the portable device  250  is present on the antenna  118 A of the MFP  100 , the portable device  250  can perform the human body communication with the MFP  100  via a body of the user and the antenna  118 A. 
         [0027]    The portable device  250  is attached to a nameplate worn by the user or a card, for example. As long as including a communication unit for the human body communication, the portable device  250  may be a device for an exclusive purpose, or may be incorporated in a PDA (Personal Digital Assistant), a mobile phone or the like. 
         [0028]    As a human body communication technology, various types of methods such as a current method for allowing a weak current to flow in a human body when a person touches an electrode and modulating the current for transmission of information, an electric field method for giving a change in the electric field along a surface of the human body for communication, an acoustic wave method for using an ultrasonic wave as a transmission medium have been developed. However, the human body communication technology is not limited to them. The case where the electric field method is used is described here as an example of the human body communication technology. 
         [0029]    When becoming communicable with the portable device  250 , the MFP  100  receives device identification information for identifying the device from the portable device  250  and transmits an authentication request including the device identification information to the authentication server  200 . The device identification information received from the portable device  250  is the authentication information for authenticating the user. 
         [0030]    Users permitted to use each of the MFPs  100 ,  100 A,  100 B,  100 C are registered in the authentication server  200 . The authentication server  200  performs authentication of a user based on an authentication request received from any of the MFPs  100 ,  100 A,  100 B,  100 C and returns a result of authentication. As for an operation of the authentication server  200 , the case where an authentication request is received from the MFP  100  will be described here as an example. In the authentication server  200 , a user record, which associates the user identification information for identifying a user permitted to use the MFP  100  with the device identification information of the portable device  250  assigned to the user, is stored in advance. In response to the reception of the authentication request from the MFP  100 , if the user record including the device identification information included in the authentication request is stored, the authentication server  200  authenticates the user associated with the device identification information by the user record. If the user record including the device identification information included in the authentication request is not stored, the authentication server  200  does not authenticate the user based on the device identification information. The authentication server  200  returns a result of authentication to the MFP  100 , which has transmitted the authentication request. The result of authentication indicating that the user is authenticated includes the device identification information included in the authentication request and the user identification information of the authenticated user. 
         [0031]      FIG. 2  is a diagram showing one example of a range of the antenna included in the MFP.  FIG. 2  is a diagram of the MFP  100  as viewed from above. Referring to  FIG. 2 , the antenna  118 A is laid on a floor surface close to an operation panel  160  and a front side of a main body of the MFP  100 . 
         [0032]    The antenna  118 A is laid close to the front surface of the MFP  100 . A positional relationship between the antenna  118 A and the main body of the MFP  100  depends on an environment in which the MFP  100  is provided. The antenna  118 A may be arranged on a floor surface on which a user who operates the MFP  100  can be positioned in the case where the user operates the operation panel  160 . 
         [0033]      FIG. 3  is a block diagram showing one example of a hardware configuration of the MFP. Referring to  FIG. 3 , the MFP  100  includes a main circuit  110 , a document scanning unit  130  for scanning a document, an automatic document feeder  120  for transporting a document to the document scanning unit  130 , an image forming unit  140  for forming a still image, which is output by the document scanning unit  130  when the document scanning unit  130  scans a document, on a sheet of paper or other medium, a paper feed unit  150  for supplying a sheet of paper to the image forming unit  140 , an operation panel  160  as a user interface and the antenna  118 A. 
         [0034]    The automatic document feeder  120  automatically transports a plurality of documents set on a document feed tray to a predetermined document scanning position set on a platen glass of the document scanning unit  130  one by one, and discharges the document of which a document image is scanned by the document scanning unit  130  onto a document discharge tray. 
         [0035]    The document scanning unit  130  includes a light source that irradiates the document transported to the document scanning position with light, and an optoelectronic transducer that receives the light reflected by the document, and scans the document image according to a size of the document. The optoelectronic transducer converts the received light into image data, which is an electric signal, and outputs the image data to the image forming unit  140 . The paper feed unit  150  transports a sheet of paper stored in the paper feed tray to the image forming unit  140 . 
         [0036]    The image forming unit  140  forms an image by a well-known electrophotographic method, and forms an image on the sheet of paper transported by the paper feed unit  150  based on print data on which a data process is performed, print data that is externally received or print data stored in the HDD  116 . The data process includes various data processes such as shading correction performed on the image data received from the document scanning unit  130 . The image forming unit  140  discharges the sheets of paper on which images are formed onto the document discharge tray. 
         [0037]    The main circuit  110  includes a CPU  111 , a communication interface (I/F) unit  112 , a ROM (Read Only Memory)  113 , a RAM (Random Access Memory)  114 , an EEPROM (Electrically Erasable and Programmable ROM)  115 , a hard disc drive (HDD)  116  as a mass storage device, a facsimile unit  117 , a human body communication unit  118  for performing the human body communication and an external storage device  119  on which a CD-ROM (Compact Disc-Read Only Memory)  119 A is mounted. 
         [0038]    The CPU  111  is connected to the automatic document feeder  120 , the document scanning unit  130 , the image forming unit  140 , the paper feed unit  150  and the operation panel  160 , and controls the entire MFP  100 . The ROM  113  stores a program executed by the CPU  111  and necessary data for execution of the program. The RAM  114  is used as a work area when the CPU  111  executes a program. Further, the RAM  114  temporarily stores a still image continuously sent from the document scanning unit  130 . 
         [0039]    The operation panel  160  is provided close to the front surface of the MFP  100  and includes a display unit  160 A and an operation unit  160 B. The display unit  160 A is a display device such as a liquid crystal display device (LCD) and an organic ELD (Electroluminescence Display) and displays instruction menus to users, information of acquired image data and the like. The operation unit  160 B includes a plurality of keys and accepts input of an instruction of each type, characters, numbers and the like corresponding to the keys by the operation of the user. The operation unit  160 B further includes a touch panel provided on the display unit  160 A. 
         [0040]    The communication I/F unit  112  is an interface for connecting the MFP  100  to the network  2 . The CPU  111  communicates with the PC  200  and the other MFPs  100 A,  100 B,  100 C via the communication I/F unit  112 , and transmits and receives data. Further, the communication I/F unit  112  communicates with another computer connected to the Internet via the network  2 , and transmits and receives data. 
         [0041]    The facsimile unit  117  is connected to the Public Switched Telephone Networks (PSTN) to transmit facsimile data to or receive facsimile data from the PSTN. The facsimile unit  117  stores the received facsimile data in the HDD  116  or outputs the received facsimile data to the image forming unit  140 . The image forming unit  140  prints the facsimile data received from the facsimile unit  117  on a sheet of paper. Further, the facsimile unit  117  converts the data stored in the HDD  116  into the facsimile data and transmits the facsimile data to a facsimile device connected to the PSTN. 
         [0042]    The human body communication unit  118  is connected to the antenna  118 A. In the case where a user who carries the portable device  250  is present on the antenna  118 A, the human communication unit  118  uses the antenna  118 A and a body of the user as communication mediums and communicates with the portable device  250  via the antenna  118 A and the body of the user. 
         [0043]    The external storage device  119  is mounted with the CD-ROM  119 A. The CPU  111  can access the CD-ROM  119 A via the external storage device  119 . The CPU  111  loads the program recorded in the CD-ROM  119 A, which is mounted on the external storage device  119 , into the RAM  114  for execution. The program executed by the CPU  111  is not limited to the program recorded in the CD-ROM  119 A, and the program stored in the HDD  116  may be loaded into the RAM  114  for execution. In this case, another computer connected to the network  2  may rewrite the program stored in the HDD  116  of the MFP  100 , or may additionally write a new program therein. Further, the MFP  100  may download a program from another computer connected to the network  2  and store the program in the HDD  116 . The program referred to here includes not only a program directly executable by the CPU  111  but also a source program, a compressed program, an encrypted program and the like. 
         [0044]    The medium for storing the program executed by the CPU  111  is not limited to the CD-ROM  119 A. It may be an optical disc (MO (Magnetic Optical Disc)/MD (Mini Disc)/DVD (Digital Versatile Disc)), an IC card, an optical card, or a semiconductor memory such as a mask ROM, an EPROM (Erasable Programmable ROM) or an EEPROM (Electrically EPROM). 
         [0045]      FIG. 4  is a block diagram showing one example of the functions of the CPU included in the MFP. The functions shown in  FIG. 4  are the functions realized by the CPU  111  in the case where the CPU  111  included in the MFP  100  executes a setting continuation program stored in the ROM  103 , the EEPROM  115 , the HDD  116  or the CD-ROM  119 A. 
         [0046]    Referring to  FIG. 4 , the CPU  111  includes a communication control portion  51  for controlling the human body communication unit  118 , a log-in management portion  53  that manages a user who is logged in, an operation acceptance portion  55  that controls the operation unit  160 B, a setting portion  57  that sets a setting value, a display control portion  59  that controls the display unit  160 A, a process execution portion  61  that executes a process in accordance with the setting value, a setting value maintaining portion  63 , a recovery portion  65 , an extension portion  67  and a count portion  69  that counts an elapsed time period from the time when the user logs out. 
         [0047]    The communication control portion  51  controls the human body communication unit  118  and allows the human body communication unit  118  to communicate with the portable device  250 . Specifically, the communication control portion  51  allows the human body communication unit  118  to regularly output a transmission request of the device identification information. When the human body communication unit  118  receives the device identification information transmitted by the portable device  250 , which has received the transmission request, the communication control portion  51  accepts the device identification information from the human body communication unit  118 . Only when a user who carries the portable device  250  is present on the antenna  118 A, the human body communication unit  118  can communicate with the portable device  250 . Therefore, when accepting the device identification information from the human body communication unit  118 , the communication control portion  51  detects that the user who carries the portable device  250  is present on the antenna  118 A. When accepting the device identification information from the human body communication unit  118 , the communication control portion  51  outputs the accepted device identification information to the log-in management portion  53 . 
         [0048]    Further, after the human body communication unit  118  receives the device identification information, the communication control portion  51  continuously allows the human body communication unit  118  to regularly output the transmission request of the device identification information, and accepts the device identification information from the human body communication unit  118  each time the human body communication unit  118  receives the device identification information transmitted by the portable device  250 , which has received the transmission request. Thus, the communication control portion  51  can detect that the user who carries the portable device  250  is no longer present on the antenna  118 A. In other words, the communication control portion  51  can detect that the user who carries the portable device  250  is present on the antenna  118 A. During a period in which the device identification information is accepted from the human communication unit  118 , the communication control portion  51  outputs the device identification information to the log-in management portion  53  each time the communication control portion  51  accepts the device identification information from the human body communication unit  118 . 
         [0049]    The log-in management portion  53  includes a user authentication portion  71  and a log-out detection portion  73 . The user authentication portion  71  authenticates the user who carries the portable device  250  based on the device identification information received from the communication control portion  51 . The user authentication portion  71  includes a first authentication portion  75 , a second authentication portion  77  and a user storage portion  79 . 
         [0050]    In response to reception of the device identification information from the communication control portion  51 , the first authentication portion  75  transmits an authentication request including the device identification information received from the communication control portion  51  to the authentication server  200  via the communication I/F unit  112 . As described above, in the case where authenticating the user by using the device identification information included in the authentication request, the authentication server  200  that receives the authentication request returns a result of authentication including the user identification information and the device identification information. In the case where not authenticating the user, the authentication server  200  returns a result of authentication indicating that the user is not authenticated. In the case where the communication I/F unit  112  receives a result of authentication including the user identification information and the device identification information from the authentication server  200 , the first authentication portion  75  outputs a set of the user identification information and the device identification information included in the result of authentication to the user storage portion  79  and the log-out detection portion  73 , and outputs the user identification information to the operation acceptance portion  55  and the extension portion  67 . 
         [0051]    In response to reception of the set, of the user identification information and the device identification information, from the first authentication portion  75 , the user storage portion  79  stores the set, of the user identification information and the device identification information, in the RAM  114 . When receiving a deletion instruction from the count portion  69 , described below, the user storage portion  79  deletes a set, of user identification information and device identification information, including the user identification information that is the same as the user identification information included in the deletion instruction from among sets, of user identification information and device identification information, stored in the RAM  114 . In other words, the user storage portion  79  stores the set, of the user identification information and the device identification information, included in the result of authentication received from the first authentication portion  75  until receiving the deletion instruction from the count portion  69 . 
         [0052]    The log-out detection portion  73  detects the log-out of the user who has been authenticated by the user authentication portion  71 . After receiving the set, of the user identification information and the device identification information, from the first authentication portion  75 , when no longer receiving the same device identification information from the communication control portion  51 , the log-out detection portion  73  detects the log-out of the user specified by the user identification information that makes a set with the device identification information. In the case where detecting the log-out of the user, the log-out detection portion  73  outputs a set, of the user identification information of the logged-out user and the device identification information, to the second authentication portion  77  and outputs the user identification information of the logged-out user to the setting portion  57 , the count portion  69  and the setting value maintaining portion  63 . 
         [0053]    In the case where receiving the device identification information from the communication control portion  51 , if the device identification information, which is the same as the device identification information received from the communication control portion  51 , is stored in the RAM  114  by the user storage portion  79 , the first authentication portion  75  does not transmit the authentication request to the authentication server  200 . 
         [0054]    In response to reception of the device identification information from the communication control portion  51 , the second authentication portion  77  authenticates the user based on the set, of the user identification information and the device identification information, stored in the RAM  114  by the user storage portion  79 . Specifically, after receiving the set, of the user identification information of the logged-out user and the device identification information, from the log-out detection portion  73 , in the case where receiving the same device identification information for the first time, the second authentication portion  77  determines whether a set, of the user identification information and the device identification information, including the device identification information that is the same as the device identification information received from the communication control portion  51  is stored in the RAM  114  by the user storage portion  79 . If the set, of the user identification information and the device identification information, including the device identification information that is the same as the device identification information received from the communication control portion  51  is stored in the RAM  114 , the second authentication portion  77  authenticates the user specified by the user identification information. If the set, of the user identification information and the device identification information, including the device identification information that is the same as the device identification information received from the communication control portion  51  is not stored in the RAM  114 , the second authentication portion  77  does not authenticate the user. 
         [0055]    In the case where authenticating the user, the second authentication portion  77  outputs the set, of the user identification information of the authenticated user and the device identification information, to the log-out detection portion  73 , and outputs the user identification information of the authenticated user to the recovery portion  65 , the operation acceptance portion  55  and the extension portion  67 . Because the first authentication portion  75  requests the authentication server  200  to perform authentication, the time is required for transmission of the authentication request, and also a processing time period is required for the authentication performed by the authentication server  200 . The second authentication portion  77  performs the authentication based on the set, of the user identification information and the device identification information, stored in the RAM  114  by the user storage portion  79 . Therefore, between the time required for the authentication performed by the first authentication portion  75  and the time required for the authentication performed by the second authentication  77 , the time required for the authentication performed by the second authentication portion  77  is shorter. Therefore, the authentication is performed by the second authentication portion  75  until a predetermined time period elapses since the user authenticated by the first authentication portion  75  logs out from the MFP  100 , so that the response time can be reduced. 
         [0056]    The count portion  69  counts an elapsed time period from the time when the user logs out. When the elapsed time period from the time of the log-out is a threshold value or more, the count portion  69  outputs the deletion instruction to the user storage portion  79 . The deletion instruction includes the user identification information of the user who has not been logged in in a predetermined time period or more since the time of the log-out. 
         [0057]    The extension portion  67  changes the threshold value used by the count portion  69  to a value increased by a time period during which a user who is other than the logged-out user is logged in. In the case where the threshold value is changed by the extension portion  67 , when the elapsed time period from the time of the log-out of the user is the changed threshold value or more, the count portion  69  outputs the deletion instruction to the user storage portion  79 . 
         [0058]    Specifically, the extension portion  67  receives the user identification information of the logged-in user from any of the first authentication portion  75  and the second authentication portion  77  included in the user authentication portion  71 . In response to reception of the user identification information of the logged-in user from any of the first authentication portion  75  and the second authentication portion  77 , the extension portion  67  outputs an extension start instruction including the user identification information of the logged-in user to the count portion  69 . 
         [0059]    In response to reception of the user identification information of the logged-out user from the log-out detection portion  73 , the count portion  69  starts counting a time count corresponding to the user identification information. In the case where receiving the extension start instruction from the extension portion  67 , the count portion  69  temporarily stops counting the time count corresponding to the user identification information that is different from the user identification information included in the extension start instruction. Further, in the case where receiving the user identification information of the logged-out user from the log-out detection portion  73 , the count portion  69  restarts counting the time count corresponding to the user identification information, which is different from the user identification information of the logged-out user, received from the log-out detection portion  73  among the time counts for which the counting is temporarily stopped. In the case where a time count value of the time count is the threshold value or more, the count portion  69  outputs a deletion instruction, including the user identification information corresponding to the time count, to the user storage portion  79  and the setting value maintaining portion  63 . 
         [0060]    For example, in the case where a user A logs out, the count portion  69  receives user identification information of the user A from the log-out detection portion  73 . In response to the reception of the user identification information of the user A from the log-out detection portion  73 , the count portion  69  starts counting a time count A corresponding to the user A. Thereafter, in the case where a user B logs in, the extension portion  67  outputs an extension start instruction including user identification information of the user B to the count portion  69 . In response to the reception of the extension start instruction including the user identification information of the user B, the count portion  69  temporarily stops counting the time count A corresponding to the user A. A time count value at this time point is T 1 . Next, when the user B logs out, the count portion  69  receives the user identification information of the user B from the log-out detection portion  73 . In response to the reception of the user identification information of the user B from the log-out detection portion  73 , the count portion  69  starts counting a time count B corresponding to the user B, cancels the temporary stop of counting of the time count A corresponding to the user A, and starts counting from the time count value T 1 . Thus, a value of the threshold value is increased by a period during which the count portion  69  temporarily stops counting the time count A. When the time count value of the time count A is the predetermined threshold value or more, the count portion  69  outputs a deletion instruction including the user identification information of the user A to the user storage portion  79 . 
         [0061]    The operation acceptance portion  55  is connected to the operation unit  160 B and accepts an operation of inputting to the operation unit  160 B by the user. The operations accepted by the operation acceptance portion  55  include an operation of pressing any of the hard keys included in the operation unit  160 B and an operation of designating a position on the touch panel included in the operation unit  160 B. The operations accepted by the operation unit  160 B includes a setting operation of setting a setting value, an execution instruction operation of giving an instruction to execute a process, an end instruction operation of giving an instruction to end a repetition process, and a screen switch operation of switching the operation screens. The operation acceptance portion  55  determines the operation that is accepted after the input of the user identification information of the logged-in user from any of the first authentication portion  75  and the second authentication portion  77  included in the user authentication portion  71  as an operation performed by the user who is identified by the user identification information. In the case where accepting the execution instruction operation, the operation acceptance portion  55  outputs a set, of the execution instruction operation and the user identification information, to the process execution portion  61 . In the case where accepting the end instruction operation, the operation acceptance portion  55  outputs a set, of the end instruction operation and the user identification information, to the process execution portion  61 . 
         [0062]    The display control portion  59  controls the display unit  160 A and displays an operation screen in the display unit  160 A. In response to acceptance of the screen switch operation by the operation acceptance portion  55 , the display control portion  59  displays the operation screen specified by the screen switch operation in the display unit  160 A. The operation screen includes a setting value display region in which a setting value is displayed. The user can operate the operation unit  160 B in accordance with the operation screen displayed in the display unit  160 A and change the setting value displayed in the setting value display region included in the display screen. 
         [0063]    In response to reception of the user identification information of the logged-out user from the log-out detection portion  73 , the setting portion  57  sets the setting value to a default setting value. The setting portion  57  sets the setting value based on the setting operation accepted by the operation acceptance portion  55 . Specifically, the setting portion  57  determines the setting value based on the operation accepted by the operation acceptance portion  55  and changes the set setting value to the determined setting value. 
         [0064]    The process execution portion  61  controls at least one of the document scanning unit  130 , the automatic document feeder  120 , the image forming unit  140 , the paper feed unit  150 , the HDD  116 , the facsimile unit  117  and the external storage device  119  and executes a process. In response to acceptance of the execution instruction operation by the operation acceptance portion  55 , the process execution portion  61  executes a process defined by the execution instruction operation based on a setting value set by the setting portion  57 . The processes executable by the process execution portion  61  include a one-off process which is executed once for one execution instruction operation and a repetition process of repeating a one-off process until the end instruction operation is accepted. 
         [0065]    In the case where receiving a set, of the user identification information and the execution instruction operation, from the operation acceptance portion  55 , if the process specified by the execution instruction operation is a one-off process, the process execution portion  61  outputs an end instruction including the user identification information received from the operation acceptance portion  55  to the setting value maintaining portion  63 . If the process specified by the execution instruction operation is a repetition process, the process execution portion  61  does not output the end instruction to the setting value maintaining portion  63 . In the case where receiving a set, of the user identification information and the execution instruction operation, from the operation acceptance portion  55 , if the process specified by the execution instruction operation is a repetition process, in response to next reception of a set, of the user identification information and the end instruction operation, from the operation acceptance portion  55 , the process execution portion  61  outputs an end instruction including the user identification information received from the operation acceptance portion  55  to the setting value maintaining portion  63 . 
         [0066]    In response to reception of the user identification information of the logged-out user from the log-out detection portion  73 , the setting value maintaining portion  63  stores a set, of the user identification information and the setting value set by the setting portion  57 , in the RAM  114 . When receiving a deletion instruction from the count portion  69 , the setting value maintaining portion  63  deletes the set, of the user identification information and the setting value, including the user identification information that is the same as the user identification information included in the deletion instruction from among sets, of the user identification information and the setting value stored in the RAM  114 , from the RAM  114 . In other words, the setting value maintaining portion  63  stores a set, of the setting value that had been set by the user (who logs out afterwards) before the user logs out and the user identification information of the logged-out user, until an elapsed time period from the time of the log-out is the threshold value or more. 
         [0067]    In the case where receiving user identification information of a user who is authenticated by the second authentication portion  77 , the recovery portion  65  determines whether a set, including the user identification information that is the same as the user identification information received from the second authentication portion  77 , is present among sets, of the user identification information and the setting value, stored by the setting value maintaining portion  63 . If the setting value, which makes the set with the user identification information that is the same as the user identification information received from the second authentication portion  77 , is stored in the RAM  114  by the setting value maintaining portion  63 , the recovery portion  65  updates a setting value that is set by the setting portion  57  with the setting value. 
         [0068]      FIG. 5  is a flow chart showing one example of a flow of a setting continuation process. The setting continuation process is a process executed by the CPU  111  in the case where a setting continuation program stored in the ROM  103 , the EEPROM  115 , the HDD  116  or the CD-ROM 119 A is executed by the CPU  111  included in the MFP  100 . 
         [0069]    Referring to  FIG. 5 , the CPU  111  determines whether the MFP  100  has become communicable with the portable device  250  (step S 01 ). The process waits until the MFP  100  becomes communicable with the portable device  250  (NO in the step S 01 ). If the MFP  100  is communicable with the portable device  250  (YES in the step S 01 ), the process proceeds to the step S 02 . In other words, the setting continuation process is a process that is executed in response to the MFP  100  being communicable with the portable device  250 . 
         [0070]    In the step S 02 , the CPU  111  acquires the device identification information received from the portable device  250 , and the process proceeds to the step S 03 . The process from the step S 03  to the step S 10  will be described below. 
         [0071]    In the step S 11 , the CPU  111  transmits the authentication request to the authentication server  200 , and the process proceeds to the step S 12 . The authentication request includes the device identification information acquired in the step S 02 . The authentication server  200  stores a user table that associates the user identification information of the user who is permitted to use the MFP  100  with the device identification information of the portable device  250  that is assigned to the user. In the case where the authentication server  200  receives the authentication request, if the device identification information, which is the same as the device identification information included in the authentication request, is stored in the user table, the authentication server  200  authenticates the user identified by the user identification information associated with the device identification information. If the device identification information, which is the same as the device identification information included in the authentication request, is not stored in the user table, the authentication server  200  does not authenticate the user. In the case where the authentication is successful, the authentication server  200  returns a result of authentication including the user identification information of the authenticated user and the device identification information. In the case where the authentication is unsuccessful, the authentication server  200  returns a result of authentication indicating the authentication failure. 
         [0072]    In the step S 12 , the process branches in accordance with the result of authentication returned from the authentication server  200 . If the result of authentication indicates the authentication success, the process proceeds to the step S 14 . If not, the process proceeds to the step S 13 . In the step S 13 , the user is notified of an error, and the process returns to the step S 01 . For example, the CPU  111  notifies the user of the error by displaying an error message, indicating that the user is not authorized to use the MFP  100 , in the display unit  160 A. 
         [0073]    In the step S 14 , a setting value is set to a default value, and the process proceeds to the step S 15 . In the step S 15 , the CPU  111  stores a set, of the user identification information and the device identification information, included in the result of authentication received from the authentication server  200  in the step S 12  in the RAM  114 , and the process proceeds to the step S 16 . 
         [0074]    In the step S 16 , counting of a time count of another user is temporarily stopped, and the process proceeds to the step S 17 . In the step S 17 , the operation acceptance process is executed, and the process returns to the step S 01 . Details of the time count of the other user and the operation acceptance process will be described below. 
         [0075]      FIG. 6  is a flow chart showing one example of a flow of the operation acceptance process. The operation acceptance process is a process executed in the step S 17  of  FIG. 5 . Referring to  FIG. 6 , the CPU  111  displays an operation screen in the display unit  160 A (step S 21 ). One operation screen among a plurality of operation screens stored in the HDD  116  is displayed in the display unit  160 A. The operation screen defined by the setting value among the plurality of operation screens is displayed. 
         [0076]    In the step S 22 , whether an operation is accepted is determined. If the operation is accepted by the operation unit  160 B, the process proceeds to the step S 23 . If not, the process proceeds to the step S 32 . In the step S 23 , the process branches depending on the accepted process. In the case where a screen transition operation is accepted, the process proceeds to the step S 24 . In the case where a setting operation is accepted, the process proceeds to the step S 26 . In the case where an execution instruction operation is accepted, the process proceeds to the step S 28 . 
         [0077]    In step S 24 , an operation screen specified by the screen transition operation is determined, and the process proceeds to the step S 25 . In the step S 25 , the determined operation screen is displayed in the display unit  160 A, and the process returns to the step S 22 . In the step S 26 , a setting value specified by the setting operation is set, and the process proceeds to the step S 27 . In the step S 27 , a setting flag is set to “1”, and the process returns to the step S 22 . The setting flag is a flag indicating whether an operation by the user is completed. In the case where the operation by the user is completed, “0” is set. In the case where the operation by the user is not completed, “1” is set. 
         [0078]    In the step S 28 , the CPU  111  executes the process specified by the execution instruction operation in accordance with the setting value, and the process proceeds to the step S 29 . In the step S 29 , whether the process specified by the execution instruction operation is the repetition process is determined. If the process is the repetition process, the process proceeds to the step S 30 . If not, the process proceeds to the step S 31 . In the step S 30 , a repetition operation acceptance process is executed, and the process returns to the step S 22 . In the step S 31 , the setting flag is set to “0”, and the process returns to the step S 22 . 
         [0079]    In the step S 32 , whether the MFP  100  is communicable with the portable device  250  is determined. If the MFP  100  is communicable with the portable device  250 , the process returns to the step S 22 . If not, the process proceeds to the step S 33 . In the step S 33 , whether the setting flag is set to “1” is determined. If the setting flag is set to “1”, the process proceeds to the step S 34 . If not, the process proceeds to the step S 36 . 
         [0080]    In the step S 34 , the CPU  111  associates the setting value that is set at that time point with the user for storage, and the process proceeds to the step S 35 . Specifically, a set, of the setting value and the user identification information of the user who is permitted to log in, is stored in the RAM  114 . In the step S 35 , the CPU  111  starts counting a time count T corresponding to the user who is permitted to log in, and the process proceeds to the step S 36 . In the step S 36 , the temporary stop, performed in the step S 26  of  FIG. 5 , of counting of a time count corresponding to another user is canceled, and the process returns to the setting continuation process. 
         [0081]    Returning to  FIG. 5 , when acquiring the device identification information from the portable device  250  in the step S 02 , the CPU  111 , in the step S 3 , determines whether the device identification information, which is the same as the device identification information received from the portable device  250  in the step S 02 , is stored in the RAM  114 . In the step S 03 , the device identification information stored in the RAM  114  is the device identification information of the portable device  250  assigned to the user authenticated by the authentication server  200 . In the step S 03 , if the device identification information, which is the same as the device identification information received from the portable device  250  in the step S 02 , is stored in the RAM  114 , the process proceeds to the step S 04 . If not, the process proceeds to the step S 11 . 
         [0082]    In the step S 04 , the user is specified, and the process proceeds to the step  505 . The CPU  111  specifies the user identified by the user identification information that makes a set with the device identification information received from the portable device  250  as the authenticated user based on the set, of the device identification information and the user identification information, stored in the RAM  114 . 
         [0083]    In the step S 05 , a time count value of the time count T corresponding to the user is acquired. In the step S 35  shown in  FIG. 6 , the CPU  111  starts counting the time count T when the MFP  100  can no longer communicate with the portable device  250 . In other words, the time count T corresponding to the user is an elapsed time period from the time when the user logs out from the MFP  100 . However, in the step S 14  in the setting continuation process and the step S 36  of the operation acceptance process that are executed for another user, counting of the time count T is temporarily stopped during a time period in which the other user is logged in. Thus, the CPU  111  does not count the time period in which the other user is logged in. 
         [0084]    In the next step S 06 , whether the time count value of the time count T corresponding to the user is the threshold value TH or more is determined. If the time count value of the time count T is the threshold value TH or more, the process proceeds to the step S 07 . If not, the process proceeds to the step S 10 . In the step S 10 , the setting value is restored, and the process proceeds to the step S 16 . Specifically, the CPU  111  reads out a set, including the user identification information that is the same as the user identification information of the user specified in the step S 04 , among the sets of the user identification information and the setting value stored in the RAM  114 , and sets the setting value included in the read set as the setting value. 
         [0085]    In the step S 07 , the device identification information that is the same as the device identification acquired in the step S 02  is deleted from the RAM  114 , and the process proceeds to the step S 08 . A set, including the device identification information that is the same as the device identification information acquired in the step S 02 , among sets of the device identification information and the user identification information stored in the RAM  114  is deleted from the RAM  114 . 
         [0086]    In the step S 08 , whether a setting value is stored is determined. In the step S 34  of the operation acceptance process shown in  FIG. 6 , a set, of the user identification information and the setting value, is sometimes stored in the RAM  114 . If a set, of the user identification information and the setting value, including the user identification information that is the same as the user identification information of the user specified in the step S 04  is stored in the RAM  114 , the process proceeds to the step S 09 . If not, the step S 09  is skipped, and the process proceeds to the step S 11 . In the step S 09 , a setting value is deleted, and the process proceeds to the step S 11 . Specifically, a set, including the user identification information that is the same as the user identification information of the user specified in the step S 04 , among sets of the user identification information and the setting value stored in the RAM  114  is deleted from the RAM  114 . 
         [0087]      FIG. 7  is a flow chart showing one example of a flow of the repetition operation acceptance process. The repetition operation acceptance process is a process executed in the step S 30  of  FIG. 6 . Referring to  FIG. 7 , the CPU  111  determines whether the execution instruction operation is accepted (step S 41 ). If the execution instruction operation is accepted, the process proceeds to the step S 42 . If not, the process proceeds to the step S 43 . In the step S 42 , the CPU  111  executes a process specified by the execution instruction operation in accordance with a setting value stored in the RAM  114 , and the process returns to the step S 41 . 
         [0088]    In the step S 43 , whether the end instruction operation is accepted is determined. If the end instruction operation is accepted, the process proceeds to the step S 44 . If not, the process proceeds to the step S 45 . In the step S 44 , the setting flag is set to “0”, and the process returns to the operation acceptance process. 
         [0089]    In the step S 45 , whether the MFP  100  is communicable with the portable device  250  is determined. If the MFP  100  is communicable with the portable device  250 , the process returns to the step S 41 . If not, the process proceeds to the step S 46 . The process from the step S 46  to the step S 50  is the same as the process from the step S 33  to the step S 36 . Thus, a description thereof will not be repeated. 
       First Modified Example 
       [0090]    In the above-mentioned embodiment, the MFP  100  treats the device identification information of the portable device  250  as the authentication information of the user registered as the user who uses the portable device  250 . When becoming communicable with the portable device  250  by the human body communication, the MFP  100  authenticates the user based on the device identification information received from the portable device  250  and permits the log-in of the user during a period in which the MFP  100  is communicable with the portable device  250 . When being no longer capable of communicating with the portable device  250 , the MFP  100  determines that the user has logged out. 
         [0091]    The MFP  100  in the first modified example uses short-range communication as a communication method for the portable device  250  and the MFP  100  to communicate with each other instead of the human body communication. As a short-range communication device, a device that communicates by using a communication method in accordance with the BLE (Bluetooth (trademark) Low Energy) standards can be used. In this case, when a distance between the MFP  100  and the portable device  250  is a communicable distance or less, the MFP  100  communicates with the portable device  250 . The communicable distance is several meters. Further, as the short-range communication device, a communication method of NFC (Near Field Communication) may be used. In this case, a communicable distance is several tens of centimeters. 
       Second Modified Example 
       [0092]    Further, in the MFP  100 , a proximity sensor may be provided close to the operation panel  160  and a side surface of the main body of the MFP  100 . The MFP  100  may detect a user who is present close to the operation panel  160  and the side surface of the main body of the MFP  100 , display a log-in screen in the display unit  160 A, authenticate the user by accepting a user ID and a password input in the operation unit  160 B by the user, and detect the log-out of the user in response to non-detection of the user by the proximity sensor. In this case, the MFP  100  does not need the human body communication unit  118 . As the proximity sensor, an infrared sensor, a camera or the like can be used. 
         [0093]    As described above, when the user A logs out, the MFP  100  in the present embodiment stores a setting value, which is set before the log-out, in the RAM  114 . In the case where another user B logs in, the MFP  100  does not delete the setting value stored in the RAM  114  for the user A. When the user B logs out, the MFP  100  stores the setting value for the user B. Therefore, in the case where the user A logs in again, the MFP  100  reads out the setting value stored in the RAM  114  for setting. Therefore, in the case where logging in the MFP  100  again, the user A can continue with the operation, which the user A had conducted before logging out. Similarly, in the case where logging in the MFP  100  again, the user B can continue with the operation, which the user B had conducted before logging out. Therefore, the MFP  100  can allow each of the plurality of users to continue with an operation, which he/she had conducted before logging out. 
         [0094]    Further, when the user A logs out with an operation of inputting to the MFP  100  by the user A not completed, the MFP  100  stores the setting value, which is set by the time of the log-out, in the RAM  114 . In the case where the user A logs in again, the MFP  100  reads out the setting value stored in the RAM  114  for setting. A state where the operation of inputting to the MFP  100  by the user A is not completed includes a state where the user A is in the middle of inputting the setting value. In the case of a one-off process, the state where the operation of inputting to the MFP  100  by the user A is not completed includes a state before an execution instruction operation is input. In this case, in the case where logging in the MFP  100  again, the user A can continue with the setting of the setting value for execution of the one-off process. Further, in the case of a repetition process, the state where the operation of inputting to the MFP  100  by the user A is not completed is a state before a plurality of one-off processes end and a state before the end instruction operation of giving an instruction to end the repetition process is input. In this case, in the case where logging in the MFP  100  again, the user A can continuously execute the repetition process. 
         [0095]    When the user A who operates the MFP  100  logs out from the MFP  100  with the operation of inputting to the MFP  100  completed, the MFP  100  does not store the setting value in the RAM  114 . Further, when the user A logs out, the MFP  100  stores the setting value in the RAM  114  until a time period defined by a threshold value elapses since the log-out. In the case where the user A logs in after the time period defined by the threshold value has elapsed since the log-out, the setting value is not stored in the RAM  114 . In this case, the MFP  100  sets a setting value to a default setting value. Therefore, the user A can set a new setting value from the default setting value, thereby being able to easily determine the setting value. 
         [0096]    Further, when the user A logs out, the MFP  100  stores the setting value, which is set by the time of the log-out, in the RAM  114  until a predetermined time period elapses since the user A logs out. The MFP  100  starts counting a time period during which the setting value is stored in the RAM  114  when the user A logs out. Specifically, each time the user A logs out, the MFP  100  resets a time count T and starts counting the time count T. Therefore, even in the case where the user A repeats to log in and log out several times, the user A can continue with an operation, which the user A had conducted before the last log-out as long as the user A logs in before a time period of the threshold value elapses since the log-out. 
         [0097]    When the user A logs out, the MFP  100  stores the setting value in the RAM  114  until a time period defined by the threshold value elapses since the log-out. In the case where the other user B logs in, the MFP  100  increases the threshold value for the user A by a time period during which the other user B is logged in. Therefore, even in the case where the other user B uses the MFP  100 , the user A can continue with the operation, of setting a setting value for the one-off process, which the user A had conducted before logging out. Further, the user A can allow the MFP  100  to continuously execute the repetition process, which the user A had allowed the MFP  100  to execute before logging out. 
         [0098]    Further, after authenticating the user by the authentication server  200 , the MFP  100  does not use the authentication server  200  and performs authentication by the second authentication portion  75  until a predetermined time period elapses since the log-out of the user. Therefore, the authentication performed during a period from the time when the user authenticated by the authentication server  200  logs out until the time when the predetermined time period elapses is simplified, so that the time required for authentication can be reduced. 
         [0099]    While the MFP  100  has been described as one example of the information processing apparatus in the above-mentioned embodiment, the present invention may of course be identified as a setting continuation method for allowing the MFP  100  to execute the setting continuation process shown in  FIGS. 5 to 7  and a setting continuation program for allowing the CPU  111  that controls the MFP  100  to perform the setting continuation method. 
         [0100]    Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.