Abstract:
An authentication apparatus comprising: display means for displaying first specification information that specifies a user; and reception means for receiving second specification information different from the first specification information; wherein user authentication is performed using the first specification information displayed on the display means and the second specification information received by the reception means, the authentication apparatus being characterized by comprising: a table that sets forth a correspondence relation between identification information for identifying an external device and the first specification information; detection means for detecting presence or absence of an external device the identification information of which is stored, by means of wireless communication; means for obtaining the identification information from the external device when the presence of the above-mentioned external device is detected; means for reading, from the table, first specification information corresponding to the obtained identification information; and means for displaying the read-out first specification information.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This Nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2005-313233 filed in Japan on Oct. 27. 2005, the entire contents of which are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to an authentication apparatus and an image forming apparatus in which a login name is inputted automatically.  
         [0004]     2. Description of Related Art  
         [0005]     In the prior art, a device is presently well known that logs in to a server apparatus connected to a network, thereby acquires authentication, and then performs communication with this server apparatus. The most general login procedure used at this time is that a user inputs a login name and a password imparted to a person to be authenticated, so that authentication is performed. Alternatively, without the use of a server apparatus, authentication means is provided in a device itself so that authentication is performed.  
         [0006]     On the other hand, in the area of image forming apparatuses such as a digital combined machine, an image forming system is known that can perform wireless communication with an IC tag (see, for example, Japanese Patent Application Laid-Open No. 2000-318269 and No. 2001-22230).  
         [0007]     In the authentication system described above, the procedure of inputting a login name and a password one by one is employed generally. Nevertheless, it is very tedious that both of the login name and the password need be inputted at each time of authentication. Thus, it has been desired that users&#39; convenience is improved with ensuring security.  
         [0008]     On the other hand, in the prior art image forming system that performs wireless communication with an IC tag, applications have been proposed like a printing completion reporting system and communication with an MFP-installed cartridge. Nevertheless, these approaches do not satisfy the above-mentioned desire.  
       BRIEF SUMMARY OF THE INVENTION  
       [0009]     The present invention has been devised in view of this situation. An object of the present invention is to provide an authentication apparatus and an image forming apparatus in which when an external device such as an IC tag is detected, a login name is inputted automatically so that users&#39; convenience is improved, and in which a password is used so that security is ensured.  
         [0010]     An authentication apparatus according to the present invention is an authentication apparatus comprising: display means for displaying first specification information that specifies a user; and reception means for receiving second specification information different from said first specification information; wherein user authentication is performed using the first specification information displayed on said display means and the second specification information received by said reception means, said authentication apparatus being characterized by comprising: a table that sets forth a correspondence relation between identification information for identifying an external device and said first specification information; detection means for detecting presence or absence of an external device the identification information of which is stored, by means of wireless communication; means for obtaining said identification information from said external device when the presence of said external device is detected; means for reading, from said table, first specification information corresponding to said obtained identification information; and means for displaying the read-out first specification information on said display means.  
         [0011]     In this present invention, when the presence of an external device the identification information of which is stored is detected, the identification information is obtained from the external device. Then, first specification information corresponding to the obtained identification information is displayed on the display means so that convenience is improved.  
         [0012]     An authentication apparatus according to the present invention is characterized by comprising: means for determining whether said detection means has detected the absence of said external device within a predetermined time after said first specification information is displayed; and means for bringing said first specification information displayed on said display means into a non-display state, when it is determined that the absence of said external device is detected within said predetermined time after said first specification information is displayed.  
         [0013]     In this present invention, when the absence of an external device is detected within a predetermined time after first specification information is displayed, the first specification information displayed on the display means is brought into a non-display state so that security is improved.  
         [0014]     An authentication apparatus according to the present invention is characterized by comprising: means for determining whether second specification information is received within a predetermined time after said first specification information is displayed; and means for bringing said first specification information displayed on said display means into a non-display state, when it is determined that the second specification information is not received within said predetermined time.  
         [0015]     In this present invention, when second specification information is not received within a predetermined time after first specification information is displayed, the first specification information displayed on the display means is brought into a non-display state so that security is improved.  
         [0016]     An authentication apparatus according to the present invention is characterized in that said detection means comprises: means for transmitting a predetermined signal to the outside; and means for receiving a reply signal returned in response to the transmitted signal; and detects the presence or absence of said external device based on the received reply signal.  
         [0017]     In this present invention, a predetermined signal is transmitted to the outside. Then, based on a reply signal returned in response to the transmitted signal, the presence or absence of an external device is determined. Thus, the presence or absence of an external device is detected based on the autonomous operation of the authentication apparatus.  
         [0018]     An authentication apparatus according to the present invention is characterized by comprising: means for determining whether a predetermined condition is satisfied, when said detection means detects the presence of said external device; and means for stopping display on said display means when it is determined that said condition is not satisfied.  
         [0019]     In this present invention, when the presence of an external device is detected, it is determined whether a predetermined condition is satisfied. Then, when the condition is not satisfied, the display on the display means is stopped so that the situation of displaying the first specification information is restricted according to the condition.  
         [0020]     An authentication apparatus according to the present invention is characterized in that said condition is defined concerning a receiving condition of said reply signal.  
         [0021]     In this present invention, the receiving condition of the reply signal transmitted from the external device is defined as the condition for displaying the first specification information. Thus, the determination whether the first specification information is to be displayed is performed based on the receiving condition such as the intensity (the receiving level) of the reply signal and the continuation time length of the reply signal.  
         [0022]     An authentication apparatus according to the present invention is characterized by further comprising means for receiving setting of said condition.  
         [0023]     In this present invention, setting of the condition for displaying the first specification information is allowed to be received. Thus, the condition can be optimized depending on the installation condition of the authentication apparatus.  
         [0024]     An authentication apparatus according to the present invention is characterized in that plural kinds of said correspondence relations are defined, and that priority for displaying the first specification information on said display means is defined for each of the first specification information.  
         [0025]     In this present invention, a plurality of correspondence relations between the identification information and the first specification information are defined. Then, priority for displaying the first specification information is defined for each of the first specification information. This allows distinction between a case that the first specification information is to be displayed automatically and a case that the first specification information is not to be displayed automatically.  
         [0026]     An authentication apparatus according to the present invention is characterized in that the first specification information is displayed in accordance with said priority when said detection means detects a plurality of external devices are detected.  
         [0027]     In this present invention, when a plurality of external devices are detected, first specification information is displayed in accordance with the priority. Thus, even when a plurality of users each carrying an external device such as an IC card are present, one piece of first specification information is solely displayed on the display means.  
         [0028]     An authentication apparatus according to the present invention is characterized by comprising: means for connecting an external authentication apparatus for storing a table that sets forth a correspondence relation between first specification information for specifying a user and second specification information; means for transmitting the first and the second specification information to the external authentication apparatus connected to the above-mentioned means; and means for receiving an authentication result transmitted from said external authentication apparatus, and by performing user authentication based on the received authentication result.  
         [0029]     In this present invention, the first specification information for specifying a user and the second specification information are transmitted to the external authentication apparatus so that user authentication is performed.  
         [0030]     An authentication apparatus according to the present invention is characterized by comprising: a table that sets forth a correspondence relation between first specification information for specifying a user and second specification information; and means for determining whether when second specification information is received by said reception means, first specification information corresponding to the received second specification information is stored in said table; and by performing user authentication based on the determination result obtained by the above-mentioned means.  
         [0031]     In this present invention, the table that sets forth a correspondence relation between the first specification information for specifying a user and the second specification information is provided so that user authentication is performed with reference to the table.  
         [0032]     An authentication apparatus according to the present invention is characterized in that said table is encrypted and that when said table is to be referred to, means for decrypting the encrypted table and volatile storage means for storing the decrypted table are used.  
         [0033]     In this present invention, the table is stored in an encrypted manner. Then, when the table is to be referred to, the encrypted table is decrypted, and then the decrypted table is stored in the volatile storage means. This improves security.  
         [0034]     An authentication apparatus according to the present invention is characterized by comprising: means for receiving image data; means for forming an image on a sheet based on the received image data; and an authentication apparatus according to any one of the above-mentioned inventions; and in that said authentication apparatus performs user authentication when the image data is received.  
         [0035]     In this present invention, the means for receiving image data and the means for forming an image on a sheet based on the received image data are provided so that when image data is received, user authentication is performed. Thus, the use of the apparatus is allowed only for authorized users.  
         [0036]     According to the present invention, when the presence of an external device the identification information of which is stored is detected, the identification information is obtained from the external device. Then, first specification information corresponding to the obtained identification information is displayed on the display means. Thus, even when user authentication is performed using the first specification information indicating a login name and the second specification information indicating a password, the user oneself need not input both. This improves convenience. Further, even when the first specification information is displayed, the second specification information is inputted by the user oneself This ensures security.  
         [0037]     According to the present invention, when the absence of an external device is detected within a predetermined time after first specification information is displayed, the first specification information displayed on the display means is brought into a non-display state. Thus, when it is determined that the user has left the place, the first specification information can be brought into a non-display state. Thus, the possibility is reduced that the first specification information assigned to a specific user could be known to unspecified persons. This improves security.  
         [0038]     According to the present invention, when second specification information is not received within a predetermined time after first specification information is displayed, the first specification information displayed on the display means is brought-into a non-display state. Thus, when it is determined that the user does not intend to use the apparatus, the first specification information can be brought into a non-display state. Thus, the possibility is reduced that the first specification information assigned to a specific user could be known to unspecified persons. This improves security.  
         [0039]     According to the present invention, a predetermined signal is transmitted to the outside. Then, based on a reply signal returned in response to the transmitted signal,.the presence or absence of an external device is determined. Thus, the presence or absence of an external device can be detected based on the autonomous operation of the authentication apparatus. Detection techniques employable for this purpose include: wireless communication using an IC tag; Bluetooth; and infrared communication.  
         [0040]     According to the present invention, when the presence of an external device is detected, it is determined whether a predetermined condition is satisfied. Then, when the condition is not satisfied, the display on the display means is stopped. This permits setting of a condition for restricting the displaying of the first specification information.  
         [0041]     According to the present invention, the receiving condition of a reply signal transmitted from the external device is defined as the condition for displaying the first specification information. Thus, the determination whether the first specification information is to be displayed is performed based on the receiving condition such as the receiving level and the continuation time length of the reply signal.  
         [0042]     According to the present invention, setting of the condition for displaying the first specification information is allowed to be received. Thus, the condition can be optimized depending on the installation condition of the authentication apparatus.  
         [0043]     According to the present invention, a plurality of correspondence relations between the identification information and the first specification information are defined. Then, priority for displaying the first specification information is defined for each of the first specification information. This allows distinction between a case that the first specification information is to be displayed automatically and a case that the first specification information is not to be displayed automatically.  
         [0044]     According to the present invention, when a plurality of external devices are detected, first specification information is displayed in accordance with the priority. Thus, even when a plurality of users each carrying an external device such as an IC card are present, one piece of first specification information is solely displayed in accordance with the priority rule.  
         [0045]     According to the present invention, first specification information for specifying a user and second specification information are transmitted to the external authentication apparatus so that user authentication is performed. Thus, the first and the second specification information can be managed by a single apparatus.  
         [0046]     According to the present invention, a table is provided that sets forth a correspondence relation between the first specification information for specifying a user and the second specification information. Then, user authentication is performed with reference to the table. This permits user authentication even in the case of absence of the function of connection to a communication network.  
         [0047]     According to the present invention, the table is stored in an encrypted manner. Then, when the table is to be referred to, the encrypted table is decrypted, and then the decrypted table is stored in the volatile storage means. This improves security.  
         [0048]     According to the present invention, the means for receiving image data and the means for forming an image on a sheet based on the received image data are provided so that when image data is received, user authentication is performed. Thus, the use of the apparatus is allowed only for authorized users.  
         [0049]     The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0050]      FIG. 1A and 1B  are schematic diagrams describing an operation of a digital combined machine according to an embodiment of the present invention;  
         [0051]      FIG. 2  is a block diagram describing a configuration of an authentication system employing a digital combined machine;  
         [0052]      FIG. 3  is a conceptual diagram showing an example of a user management table;  
         [0053]      FIG. 4  is a schematic diagram showing an example of an operation panel;  
         [0054]      FIG. 5  is a conceptual diagram showing an example of an authentication table;  
         [0055]      FIG. 6  is a flow chart describing a procedure of processing performed by a digital combined machine;  
         [0056]      FIG. 7  is a flow chart describing a procedure of processing performed by a digital combined machine;  
         [0057]      FIG. 8  is a conceptual diagram showing a table that sets forth a receiving level and a continuation time length;  
         [0058]      FIG. 9  is a conceptual diagram showing an example of a user management table that sets forth priority of login names to be displayed;  
         [0059]      FIG. 10  is a flow chart describing a procedure of processing performed by a digital combined machine;  
         [0060]      FIG. 11  is a flow chart describing a procedure of processing performed by a digital combined machine;  
         [0061]      FIG. 12  is a block diagram describing a configuration of an authentication system according to an embodiment of the present invention;  
         [0062]      FIG. 13  is a conceptual diagram showing an example of an authentication table; and  
         [0063]      FIG. 14  is a flow chart describing an operation of a digital combined machine at the time of power on. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0064]     A mode in which an image forming apparatus according to the present invention is applied to a digital combined machine is described below in detail with reference to the drawings.  
       Embodiment 1  
       [0065]      FIG. 1A  is a schematic diagram describing an operation of a digital combined machine according to an embodiment of the present invention. In the figure, numeral  100 A indicates a digital combined machine having: a scanner function of optically reading an image of a manuscript; a copy function of forming an image onto a sheet such as a paper sheet and an OHP film based on the image data read and obtained from the manuscript; an image transmission function of transmitting the image data read and obtained from the manuscript, to the outside via a communication network; and a printer function of receiving a print job transmitted from the outside and then performing image formation. In the present embodiment, user authentication is performed for the functions such as such as the scanner function, the copy function, and the image transmission function where the digital combined machine  100 A is operated directly. Then, only when the user authentication has been successful, the use of these functions is allowed.  
         [0066]     In the user authentication, a login name assigned to each user and a password set up by each user are used. From the perspective of users&#39; convenience, the login name is inputted automatically, while from the perspective of security, the password is manually inputted by a user oneself. For the purpose of the automatic input of the login name, an IC card  10  is used in which an IC chip is embedded. When a user carrying an IC card  10  is present near the digital combined machine  100 A, based on information obtained from the IC card  10 , a login name assigned to the user is extracted so that the extracted login name is displayed on an operation panel  106  (see  FIG. 1B ). In contrast, when a user carrying an IC card  10  is not present near the digital combined machine  100 A, no user name is displayed (see FIG.  1 A). In the state that a login name is displayed, when the user inputs merely the password, user authentication is performed so that convenience is improved. Further, since the password need be inputted by the user oneself, security degradation is avoided.  
         [0067]      FIG. 2  is a block diagram describing a configuration of an authentication system employing the digital combined machine  100 A. The digital combined machine  100 A has a CPU  101 . The CPU  101  reads and executes a control program stored in advance in a ROM  103 , thereby controls various kinds of hardware connected via a bus  102 , and thereby causes the entire apparatus to serve as an authentication apparatus and an image forming apparatus according to the present invention.  
         [0068]     A management section  105  is composed of a nonvolatile semiconductor memory. A part of the storage area is used as a user management table  105   a .  FIG. 3  is a conceptual diagram showing an example of the user management table  105   a . In the user management table  105   a , identification numbers each for identifying an IC card (e.g., an IC card  10 ) and login names each for specifying a user are stored in a manner corresponding to each other. Each identification number is identification information for identifying an IC card, and may be composed of a numerical value having an appropriate number of digits or alternatively a combination of alphabetical characters, numeric characters, and the like. Each login name is used as first specification information for specifying a user, and is defined uniquely for each user by a manager of the present system or by the user oneself.  
         [0069]     The operation panel  106  receives an operation instruction from a user, and displays information to be reported to a user.  FIG. 4  is a schematic diagram showing an example of the operation panel  106 . The operation panel  106  includes: a display section  106   a  for displaying information to be reported to a user; and an operation section  106   b  for receiving an operation instruction from a user. The display section  106   a  includes, for example, a liquid crystal display unit and thereby displays information such as an operation guide to a user, a setting value received through the operation section  106   b , and an error message. The operation section  106   b  includes a plurality of hardware keys. The hardware keys provided in the operation section  106   b  include: a numerical keypad used for numerical input; a clear key for clearing an inputted setting value; an end key for terminating various kinds of setting; a color copy key for issuing a start instruction for color copy; and a monochrome copy key for issuing a start instruction for monochrome copy. Here, a touch panel may be provided on the display section  106   a  so that a selection operation may be received in correspondence to a displayed operation guide.  
         [0070]     A wireless communication IF  107  is an interface for performing wireless communication with the IC card  10 . The IC card  10  includes in the inside: an antenna circuit fabricated by printing a conductor pattern on an insulating substrate; and an IC chip connected to the antenna circuit. In the IC card  10 , electric power is supplied to the antenna circuit from a signal transmitted from the wireless communication IF  107 . The IC chip supplied with the electric power through the antenna circuit generates a reply signal based on data of the identification number stored in advance in an internal memory in the chip, and then transmits the generated reply signal to the outside through the antenna circuit. On the other hand, the wireless communication IF  107  includes: a signal generating circuit for generating a signal to be transmitted to the IC card  10 ; an antenna circuit for transmitting the generated signal to the outside and receiving a reply signal from the IC card  10 ; and a receiving circuit for extracting the identification number of the IC card  10  from the reply signal received through the antenna circuit. When receiving a reply signal from the IC card  10 , the wireless communication IF  107  extracts the identification number of the IC card  10  from the reply signal, and then notifies the identification number to the CPU  101 .  
         [0071]     A communication IF  108  is an interface for connection to a communication network N such as a local area network and the Internet network. An authentication server  200 A is connected to this communication network N so that the digital combined machine  100 A can transmit and receive various kinds of information to and from the authentication server  200 A via the communication IF  108 . Information transmitted from the digital combined machine  100 A to the authentication server  200 A includes: a login name corresponding to identification information (first specification information) obtained by the wireless communication IF  107 ; and a password (second specification information) received through the operation panel  106 . Further, information received by the digital combined machine  100 A from the authentication server  200 A is information concerning an authentication result indicating whether a user has successfully been authenticated based on the transmitted login name and password.  
         [0072]     An image reading section  110  includes (not shown): a light source for projecting light onto a manuscript to be read; an image sensor such as a CCD (Charge Coupled Device); and an AD converter. An image of a manuscript located at a predetermined reading position is formed on the image sensor so that the image is converted into an analog electric signal. Then, the obtained analog signal is AD-converted by the AD converter. After that, correction is performed on the digital signal obtained by AD conversion, with taking into consideration the orientation property of the light source at the time of manuscript reading, sensitivity inhomogeneity of the image sensor, and the like, so that image data of digital format is generated.  
         [0073]     An image formation section  111  includes, for example (not shown): an electrostatic charger for electrostaically charging a photosensitive drum at a predetermined potential; a laser writing unit for emitting laser light according to image data received from the outside and thereby generating an electrostatic latent image on the photosensitive drum; a developing unit for supplying toner to the electrostatic latent image formed on the photosensitive drum surface and thereby causing the latent image to be visible; and a transfer unit for transferring the toner image formed on the photosensitive drum surface onto a paper sheet. Thus, the image formation section  111  records an image desired by a user onto a paper sheet by electrophotography.  
         [0074]     Here, in the present embodiment, image formation is performed by electrophotography using a laser writing unit. Instead, the image formation may be performed by an inkjet method, a heat transfer method, or a sublimation method.  
         [0075]     An HDD  112  has a magnetic recording medium and can accumulate image data processed internally. The accumulated image data is read out, for example, when an instruction is issued through the operation panel  106 . Thus, when printing processing need be re-executed because of a failure in the printing processing, an insufficient number of outputted copies, or the like, the accumulated image data can be read out so that the printing processing can be executed.  
         [0076]     The internal configuration of the authentication server  200 A is described below. The authentication server  200 A has a CPU  201 . This CPU  201  is connected via a bus  202  to hardware including a ROM  203 , a RAM  204 , a communication IF  205 , and a storage section  206 . The CPU  201  uploads onto the RAM  204  a control program stored in advance in the ROM  203 , then executes the program, and thereby controls the operation of the entire apparatus so as to perform user authentication.  
         [0077]     The communication IF  205  is an interface for connection to the communication network N, and allows various kinds of information to be transmitted to and received from the digital combined machine  100 A. Information received by the authentication server  200 A via the communication IF  205  is a login name (first specification information) and a password (second specification information) transmitted from the digital combined machine  100 A. Further, information transmitted by the authentication server  200 A via the communication IF  205  is information concerning the result of user authentication performed based on the received login name and password.  
         [0078]     The storage section  206  includes an HDD device or a nonvolatile semiconductor memory. A part of the storage area of the storage section  206  is used as an authentication table  206   a .  FIG. 5  is a conceptual diagram showing an example of the authentication table  206   a . The authentication table  206   a  sets forth a correspondence relation between each login name serving as the first specification information and each password serving the second specification information. As described above, each login name is information defined uniquely for each user by a manager of the present system or by each user oneself. Each password is information set up by each user oneself, and may be composed of a numerical value having an appropriate number of digits or alternatively a combination of alphabetical characters, numeric characters, and the like.  
         [0079]     When receiving a login name and a password through the communication IF  205 , the authentication server  200 A refers to the authentication table  206   a  in the storage section  206  and thereby performs user authentication. That is, the CPU  201  of the authentication server  200 A searches the authentication table  206   a  and thereby determines whether the received login name is registered in the authentication table  206   a . When the login name is registered in the authentication table  206   a , the CPU  201  refers to the authentication table  206   a  and thereby determines whether the received login name and password is an authorized combination. When it is determined as an authorized combination, successful authentication of the user is reported. In contrast, when it is determined that the received login name is not registered in the authentication table  206   a , or alternatively when it is determined that the combination of the received login name and password is not an authorized combination, unsuccessful authentication of the user is reported.  
         [0080]     The procedure of processing performed by the digital combined machine  100 A is described below.  FIG. 6  is a flow chart describing a procedure of processing performed by the digital combined machine  100 A. First, the CPU  101  of the digital combined machine  100 A determines whether the wireless communication IF  107  has received a signal having a receiving level of a predetermined value or higher (step S 11 ). When it is determined that a signal having a receiving level of the predetermined value or higher is not received (S 11 : NO), the CPU  101  waits until a signal having a receiving level of the predetermined value or higher is received.  
         [0081]     When it is determined that the wireless communication IF  107  has received a signal having a receiving level of the predetermined value or higher (S 11 : YES), the CPU  101  determines whether the receiving of the signal has continued for a predetermined time (step S 12 ). When it is determined that the receiving of the signal has not continued for the predetermined time (S 12 : NO), the CPU  101  returns the processing to step S 11 .  
         [0082]     When the receiving of the signal having a receiving level of the predetermined value or higher has continued for the predetermined time (S 12 : YES), the wireless communication IF  107  obtains from the signal the identification number for identifying the IC card  10  (step S 13 ). The obtained identification number is notified to the CPU  101 .  
         [0083]     When receiving the identification number, the CPU  101  refers to the user management table  105   a  in the management section  105 , and thereby determines whether a corresponding login name is present (step S 14 ). When it is determined that a corresponding login name is not present (S 14 : NO), the CPU  101  terminates the processing in the present flow chart. At that time, a screen for receiving the input of a login name and a password is displayed on the display section  106   a  of the operation panel  106 . Thus, the user can manually input the login name and the password by a method of operating the operation panel  106 .  
         [0084]     When it is determined that a corresponding login name is present (S 14 : YES), the CPU  101  reads a login name corresponding to the identification number of the IC card  10  from the user management table  105   a , and then displays the login name on the display section  106   a  of the operation panel  106  (step S 16 ). After displaying the login name on the display section  106   a , the CPU  101  determines whether a password has been inputted through the operation panel  106  (step S 17 ). When a password is not yet inputted (S 17 : NO), the CPU  101  waits until a password is inputted.  
         [0085]     When it is determined that a password has been inputted through the operation panel  106  (S 17 : YES), a login name read from the user management table  105   a  based on the identification number of the IC card  10  and the password inputted through the operation panel  106  are transmitted to the authentication server  200 A via the communication network N (step S 18 ).  
         [0086]     After transmitting the login name and the password, the CPU  101  determines the successfulness or unsuccessfulness of the authentication of the user based on an authentication result transmitted from the authentication server  200 A (step S 19 ). When the authentication of the user is determined as unsuccessful (S 19 : NO), the CPU  101  terminates the processing in the present flow chart. At that time, the screen for receiving the input of a login name and a password may be re-displayed on the display section  106   a  so that a login name and a password may be received by means of an input operation through the operation panel  106 . On the other hand, when the authentication of the user is determined as successful (S 19 : YES), the CPU  101  goes into a standby state where the use of the original functions such as a scanner function and a copy function of the digital combined machine  100 A is permitted (step S 20 ).  
         [0087]     Here, in the present embodiment, user authentication has been performed when the original functions such as a scanner function and a copy function are to be used. Instead, user authentication may be performed only when a particular function is to be used.  
       Embodiment 2  
       [0088]     In Embodiment 1, after the login name has been displayed on the display section  106   a  on the operation panel  106 , password input has been waited. Instead, after the displaying of the login name, when a signal in a predetermined receiving condition is not received from the IC card  10 , that is, when the user carrying an IC card  10  is determined as having left the vicinity of the digital combined machine  100 A, the login name displayed on the display section  106 a may be brought into a non-display state.  
         [0089]      FIG. 7  is a flow chart describing a procedure of processing performed by the digital combined machine  100 A. The digital combined machine  100 A performs the processing from step S 21  to step S 26  in the same manner as Embodiment 1. That is, when a signal is received from an IC card having an identification number registered in the user management table  105   a , a login name corresponding to the identification number is read from the user management table  105   a . Then, the read-out login name is displayed on the display section  106   a.    
         [0090]     Then, the CPU  101  determines whether a password has been inputted through the operation panel  106  (step S 27 ). When a password is not yet inputted (S 27 : NO), the CPU  101  determines whether a signal received through the wireless communication IF  107  has a receiving level of a predetermined value or lower (step S 28 ). When it is determined that the receiving level is higher than the predetermined value (S 28 : NO), the CPU  101  returns the processing to step S 27 . Further, when it is determined that the receiving level is at or below the predetermined value (S 28 : YES), the CPU  101  determines whether that state has continued for a predetermined time (step S 29 ). When it is determined that the state has not continued for the predetermined time (S 29 : NO), the CPU  101  returns the processing to step S 27 . When the state that the receiving level is at or below the predetermined value has continued for the predetermined time (S 29 : YES), the CPU  101  brings into a non-display state the login name displayed on the display section  106   a  (step S 30 ), and then returns the processing to step S 21 .  
         [0091]     When it is determined that a password has been inputted at step S 27  (S 27 : YES), a login name read from the user management table  105   a  based on the identification number of the IC card and the password inputted through the operation panel  106  are transmitted to the authentication server  200 A via the communication network N (step S 31 ).  
         [0092]     After transmitting the login name and the password, the CPU  101  determines the successfulness or unsuccessfulness of the authentication of the user based on an authentication result transmitted from the authentication server  200 A (step S 32 ). When the authentication of the user is determined as unsuccessful (S 32 : NO), the CPU  101  terminates the processing in the present flow chart. At that time, the screen for receiving the input of a login name and a password may be re-displayed on the display section  106   a  so that a login name and a password may be received by means of an input operation through the operation panel  106 . On the other hand, when the authentication of the user is determined as successful (S 32 : YES), the CPU  101  goes into a standby state where the use of the original functions such as a scanner function and a copy function of the digital combined machine  100 A is permitted (step S 34 ).  
         [0093]     As such, in the present embodiment, when a login name is displayed on the display section  106   a , the receiving condition of the signal received by the wireless communication IF  107  is checked so that when it is determined that the user carrying the IC card has left the vicinity of the digital combined machine  100 A, displaying of the login name is stopped. This avoids that the user name is left in a displayed state, and hence improves security.  
         [0094]     Further, as for the threshold values for the receiving level and the continuation time length which are set up for the check of the receiving condition of the wireless communication IF  107 , the values before the display of the login name may differ from those during the display of the login name. For example, the table shown in the conceptual diagram of  FIG. 8  may be held in the management section  105  so that adopted threshold values may be changed depending on the situation whether the login name is displayed or not. Further, these threshold values may be set up depending on the installation condition of the individual digital combined machine  100 A. In this case, a threshold value for the receiving level and a threshold value for the continuation time length may be received through the operation panel  106  so that the table shown in  FIG. 8  may be updated.  
         [0095]     Further in the present embodiment, when the login name has been displayed on the display section  106   a , the receiving condition of the signal received by the wireless communication IF  107  has been checked so that when the user carrying an IC card  10  has been determined as having left the vicinity of the digital combined machine  100 A, the displaying of the login name has been stopped. Instead, the displaying of the login name may be stopped when a password is not inputted within a predetermined time after the login name is displayed. In this case, at the time that the login name is displayed, time counting is started in a built-in timer of the CPU  101 . Then, when a predetermined time has elapsed in a state that no password is inputted, the login name displayed on the display section  106   a  may be brought into a non-display state.  
       Embodiment 3  
       [0096]     In the embodiments described above, when an identification number of the IC card has been obtained, in the case that a login name corresponding to the identification number has been registered in the user management table  105   a , the login name has been displayed on the display section  106   a  on the operation panel  106 . Instead, priority may be set up in order that a user whose login name is to be displayed automatically should be distinguished from a user whose login name is not to be displayed automatically.  
         [0097]      FIG. 9  is a conceptual diagram showing an example of a user management table that sets forth priority of login names to be displayed. In the present embodiment, in place of the user management table  105   a , a user management table  105   b  that sets forth a correspondence relation between the identification number, the login name, and the priority as shown in  FIG. 9  is stored in the management section  105 . The priority is defined as a numerical value. A higher priority is assigned to a greater numerical value.  
         [0098]      FIGS. 10 and 11  are flow charts describing a procedure of processing performed by the digital combined machine  100 A. The digital combined machine  100 A performs the processing from step S 41  to step S 43  in the same manner as Embodiment 1. That is, the digital combined machine  100 A receives a signal transmitted from an IC card, and then obtains the identification number.  
         [0099]     When the identification number is obtained, it is determined whether a login name corresponding to the identification number is present in the user management table  105   b  (step S 44 ). When it is determined that a login name corresponding to the identification number is not present (S 44 : NO), the CPU  101  terminates the processing in the present flow chart. At that time, a screen for receiving the input of a login name and a password is displayed on the display section  106   a  of the operation panel  106 . Thus, the user can manually input the login name and the password by a method of operating the operation panel  106 .  
         [0100]     When it is determined that a login name corresponding to the identification number is present (S 44 : YES), the CPU  101  determines whether the priority set up to the login name is higher than a predetermined priority level (step S 46 ). In the present embodiment, when the priority is higher than the predetermined priority level, the login name is automatically displayed on the display section  106   a . When the priority is lower than the predetermined priority level, a login name is inputted manually. Thus, at step S 46 , when it is determined that the priority is lower than the predetermined priority level (S 46 : NO), the CPU  101  determines whether a login name has been inputted through the operation panel  106  (step S 47 ). When it is determined that a login name is not inputted (S 47 : NO), the CPU  101  waits until a login name is inputted.  
         [0101]     When it is determined at step S 47  that a login name has been inputted (S 47 : YES), or alternatively when it is determined at step S 46  that the priority is higher than the predetermined priority level (S 46 : YES), the CPU  101  displays the login name on the display section  106   a  (step S 48 ). For example, when the predetermined priority level is set at  150 , “OO TARO” is solely displayed automatically among the login names shown in  FIG. 9 . The other login names “ΔΔ HANAKO” and “×× JIRO” are displayed when each login name is inputted manually by the user.  
         [0102]     After displaying the login name on the display section  106   a , the CPU  101  determines whether a password has been inputted through the operation panel  106  (step S 49 ). When a password is not yet inputted (S 49 : NO), the CPU  101  waits until a password is inputted. When it is determined that a password has been inputted through the operation panel  106  (S 49 : YES), a login name read from the user management table  105   a  based on the identification number of the IC card  10  and the password inputted through the operation panel  106  are transmitted to the authentication server  200 A via the communication network N (step S 50 ).  
         [0103]     After transmitting the login name and the password, the CPU  101  determines the successfulness or unsuccessfulness of the authentication of the user based on an authentication result transmitted from the authentication server  200 A (step S 51 ). When the authentication of the user is determined as unsuccessful (S 51 : NO), the CPU  101  terminates the processing in the present flow chart. At that time, the screen for receiving the input of a login name and a password may be re-displayed on the display section  106   a  so that a login name and a password may be received by means of an input operation through the operation panel  106 . On the other hand, when the authentication of the user is determined as successful (S 51 : YES), the CPU  101  goes into a standby state where the use of the original functions such as a scanner function and a copy function of the digital combined machine  100 A is permitted (step S 53 ).  
       Embodiment 4  
       [0104]     In the embodiments described above, the digital combined machine  100 A has managed the user management table  105   a , while the authentication server  200 A has managed the authentication table  206   a . Instead, both tables may be managed in an encrypted state in the server, and then may be downloaded at the time of power on of the digital combined machine.  
         [0105]      FIG. 12  is a block diagram describing a configuration of an authentication system according to an embodiment. A digital combined machine  100 B has a CPU  101 . The CPU  101  is connected via a bus  102  to hardware including a ROM  103 , a RAM  104 , an operation panel  106 , a wireless communication IF  107 , a communication IF  108 , an encryption and decryption processing section  109 , an image reading section  110 , an image formation section  111 , and an HDD  112 . Here, the hardware configuration other than the encryption and decryption processing section  109  is the same as that of Embodiment 1, and hence the description is omitted.  
         [0106]     The encryption and decryption processing section  109  performs encryption and decryption of electronic data. Electronic data to be decrypted in the encryption and decryption processing section  109  is an authentication table  206   b  transmitted from the authentication server  200 B described later. Electronic data to be encrypted is data in which new contents of registration is added in order to update the authentication table  206   b . For the purpose of encryption and decryption of the electronic data, the encryption and decryption processing section  109  includes: an input buffer for temporarily holding target data; an arithmetic circuit for performing an arithmetic operation according to predetermined decryption algorithm or encryption algorithm on the data held in the input buffer; and an output buffer for holding the arithmetic operation result obtained by the arithmetic circuit. The CPU  101  extracts the arithmetic operation result from the output buffer, and thereby obtains decrypted data or encrypted data.  
         [0107]     The authentication server  200 B is described below. The authentication server  200 B has a CPU  201 . This CPU  201  is connected via a bus  202  to a ROM  203 , a RAM  204 , a communication IF  205 , and a storage section  206  that stores the authentication table  206   b.    
         [0108]      FIG. 13  is a conceptual diagram showing an example of the authentication table  206   b . In the present embodiment, the identification number for identifying an IC card, the login name serving as the first specification information for specifying a user, and the password serving as the second specification information are managed collectively in the authentication table  206   b . This authentication table  206   b  is stored in an encrypted state in the storage section  206 . When a transmission request is issued from the digital combined machine  100 B, the CPU  201  of the authentication server  200 B reads the encrypted authentication table  206   b  from the storage section  206 , and then transmits the read-out authentication table  206   b  to the digital combined machine  100 B.  
         [0109]      FIG. 14  is a flow chart describing an operation of the digital combined machine  100 B at the time of power on. When the digital combined machine  100 B is turned on the power(step S 61 ), warming-up is performed (step S 62 ), so that a state ready for receiving data is established in each hardware section. After the warming-up, the CPU  101  requests the authentication server  200 B for the authentication table  206   b  (step S 63 ). Specifically, an instruction that indicates that the authentication table  206   b  should be transmitted is transmitted to the authentication server  200 B via the communication network N.  
         [0110]     After requesting the authentication table  206   b , the CPU  101  determines whether the authentication table  206   b  has been received (step S 64 ). When it is determined that the authentication table  206   b  is not yet received (S 64 : NO), the CPU  101  waits until the authentication table  206   b  is received. When it is determined that the authentication table  206   b  has been received (S 64 : YES), the received authentication table  206   b  is decrypted by the encryption and decryption processing section  109  (step S 65 ). Then, the decrypted authentication table  206   b  is stored in the RAM  104  (step S 66 ).  
         [0111]     The authentication table  206   b  stored in the RAM  104  sets forth a correspondence relation between the identification number and the login name and a relation between the login name and the password. Thus, when the identification number of an IC card is obtained, a login name corresponding to the identification number can be read and then displayed on the display section  106   a  on the operation panel  106 . Then, when a password is inputted through the operation panel  106 , the processing (authenticating processing) of determining whether the password is an authorized password can be performed.  
         [0112]     As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within metes and bounds of the claims, or equivalence of such metes and bounds thereof are therefore intended to be embraced by the claims.