Abstract:
A processing apparatus capable of improving the degree of security protection without requiring a user to perform any additional operations, the processing apparatus determining whether or not a logged-in user is the same person as a user who pressed input confirmation button to confirm contents of input information by comparing first fingerprint information obtained when the user logged in and second fingerprint information obtained when the input confirmation button was pressed, and carrying out processing based on the contents of the input and confirmed information if the user&#39;s identity is confirmed.

Description:
[0001]     This application is based on Japanese Patent Application No. 2005-200285 filed in Japan on Jul. 8, 2005, the entire content of which is hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a processing apparatus that executes processing in accordance with instructions provided by the user, as well as to a control method therefor.  
         [0004]     2. Description of the Related Art  
         [0005]     An image processing apparatuses termed an MFP (Multifunction Peripherals) that includes the functions of a copying machine, network printer, scanner, fax and document server has become widely used in recent years.  
         [0006]     The increasing number of different functions possessed by this type of image processing apparatus has led to its being shared by a number of users, which has created demand for security measures or management of the charging of fees for the use thereof. Consequently, users of such an image processing apparatus are sometimes required to perform user authentication. This prevents the unauthorized use of the image processing apparatus and enables the status of use thereof to be tracked for each user.  
         [0007]     There are three main methods of user authentication: Memory-based authentication, ownership authentication and biometric authentication. In the memory-based authentication method, a user seeking user authentication enters into the image processing apparatus via keyboard a user ID and password that are known only to the user. In the ownership authentication method, the user carries a storage medium such as a USB token or IC card on which key information issued only to the user is stored, and the user when seeking user authentication places the storage medium in the image processing apparatus for reading of this key information. In the biometric authentication method, a user seeking user authentication has the image processing apparatus read a unique physical characteristic of the user such as his fingerprint or iris. The image processing apparatus performs user authentication using the information input or read via the above methods. Recently, increased attention has been paid to the biometric authentication method, which does not require the user to memorize a password or carry a storage medium.  
         [0008]     Japanese Laid-Open Patent Applications 2002-44313 and 2002-108487 disclose image processing apparatuses that use fingerprint-based authentication. According to the image processing apparatus of Japanese Laid-Open Patent Application 2002-44313, information regarding an operation regularly executed by each individual is registered in advance in association with the person&#39;s fingerprint information. As a result, even if such operation comprises the configuration of a complex image processing function, the user can execute it via a simple one-touch operation.  
         [0009]     According to the image processing apparatus described in Japanese Laid-Open Patent Application 2002-108487, the user&#39;s fingerprint information and password are registered in advance, and when fingerprint-based authentication fails, the user logs in using the password.  
         [0010]     However, when using the conventional art methods disclosed in these patent documents, if an authenticated user leaves the image processing apparatus while it is running, an unauthorized user could then use it without the user&#39;s permission. This is undesirable from a security standpoint, and entails the possibility of the user incurring erroneous charges.  
         [0011]     Accordingly, a method is often used in which the user is logged out automatically when the image processing apparatus is not operated for a preset period of time. However, in this method, where the preset period is long, the degree of security obtained is minimal. Where the preset length of time is short, on the other hand, the user may often be logged out involuntarily. If that happens, the user must repeat the login operation and occasionally reproduce his entire work from the beginning, which is burdensome.  
         [0012]     While a system can be employed in which the user logs out manually each time he leaves the image processing apparatus, he must then log in upon his return to the image processing apparatus to resume work. This method as well is therefore burdensome for the user. In addition, the user may forget to log out before leaving the image processing apparatus.  
         [0013]     In addition to image processing apparatuses such as MFPs, other types of processing apparatuses shared by multiple users, such as personal computers and workstations, also entail the above problems.  
       Object and Summary  
       [0014]     An object of the present invention is to provide an improved processing apparatus and control method therefor that resolve the various problems identified above.  
         [0015]     Another object of the present invention is to improve the degree of security protection for a processing apparatus without requiring the user to perform any additional operations.  
         [0016]     These and other objects are attained by providing a processing apparatus having the configuration described below:  
         [0017]     an input button used to input information;  
         [0018]     an input confirmation button used to confirm the contents of said input information;  
         [0019]     a first obtaining unit that obtains at the time of the user&#39;s login to said processing apparatus first fingerprint information comprising information regarding the user&#39;s fingerprint;  
         [0020]     a storage device that stores said first fingerprint information obtained by said first obtaining unit;  
         [0021]     a second obtaining unit that obtains second fingerprint information comprising information regarding the fingerprint of the finger used to press said input confirmation button;  
         [0022]     a determination unit that, after the user has logged into said processing apparatus, determines whether or not the user who pressed said input confirmation button to confirm the contents of said input information is identical to the user who logged into said processing apparatus, by comparing (i) said second fingerprint information obtained by said second obtaining unit when said input confirmation button was pressed in order to confirm the contents of said information input via said input button and (ii) said first fingerprint information stored in said storage device; and  
         [0023]     a controller that, when the user&#39;s identity is confirmed by said determination unit, executes control of the various components of said processing apparatus to carry out processing based on the contents of said input and confirmed information. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]     These and other objects and features of the present invention will become clear from the following description taken in conjunction with the preferred embodiments thereof with reference to the accompanying drawings, in which:  
         [0025]      FIG. 1  is a drawing showing an example of the configuration of a system using an image forming apparatus;  
         [0026]      FIG. 2  is a drawing showing an example of the hardware configuration of the image forming apparatus;  
         [0027]      FIG. 3  is a drawing showing an example of the configuration of an operation panel;  
         [0028]      FIG. 4  is an explanatory drawing showing an example of the hardware configuration of a fingerprint reader and an example of the sequence of operations performed during fingerprint reading;  
         [0029]      FIG. 5  is a drawing showing an example of the functional configuration of the image forming apparatus;  
         [0030]      FIG. 6  is a drawing showing an example of a user information table;  
         [0031]      FIG. 7  is a drawing showing an example of a login screen;  
         [0032]      FIG. 8  is a flow chart regarding the sequence of operations of the overall operation of the image forming apparatus; and  
         [0033]      FIG. 9  is a flow chart showing the sequence of operations performed when identities do not match. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0034]      FIG. 1  is a drawing showing an example of the configuration of a system using an image forming apparatus  1 .  FIG. 2  is a drawing showing an example of the hardware configuration of the image forming apparatus  1 .  FIG. 3  is a drawing showing an example of the configuration of an operation panel  10 f.  FIG. 4  is a drawing to describe an example of the hardware configuration of a fingerprint reader  10 k and an example of the sequence of operations performed during fingerprint reading.  
         [0035]     The image forming apparatus  1  is connected to a terminal device  2  over a communication circuit  3  as shown in  FIG. 1 . The Internet, an intranet, public circuits or dedicated lines are used for the communication circuit  3 .  
         [0036]     An application program and a driver that serve the image forming apparatus  1  are installed in the terminal device  2 . The terminal device  2  may comprise a personal computer, workstation or PDA (Personal Digital Assistant).  
         [0037]     The image forming apparatus  1  is a processing apparatus that possesses various functions, including the functions of a copying machine, scanner, fax, network printer and document server. It is sometimes called an MFP. The ‘network printer’ function is a function by which image data is received from the terminal device  2  and an image is printed on paper. It may be called a ‘network printer function’ or ‘PC print function’. The ‘document server’ function is a function where a storage area termed a ‘box’ or ‘personal box’ and equivalent to a folder or directory in a personal computer is provided to each user to enable the user to save document data such as an image file in the storage area. This function is sometimes referred to as a ‘box function’.  
         [0038]     As shown in  FIG. 2 , the image forming apparatus  1  comprises a CPU  10 a, a RAM  10 b, a ROM  10 c, a hard disk  10 d, a control circuit  10 e, an operation panel  10 f, a scanner  10 g, a printer  10 h, a communication interface  10 j and fingerprint readers  10 kA,  10 kB.  
         [0039]     The scanner  10 g is a device that optically reads images such as photos, letters/characters, drawings and graphs/charts present in the original document and generates image data.  
         [0040]     The printer  10 h prints images onto paper in accordance with user instructions based on the image data read by the scanner  10 g or sent from the terminal device  2  or the like.  
         [0041]     The communication interface  10 j comprises a NIC (Network Interface Card) or modem and enables communication with other devices.  
         [0042]     The control circuit  10 e is a circuit to control such devices as the hard disk  10 d, scanner  10 g, printer  10 h, communication interface  10 j, operation panel  10 f and fingerprint readers  10 kA,  10 kB.  
         [0043]     The operation panel  10 f comprises a display TD and an operation button unit SB having a plurality of operation buttons as shown in  FIG. 3 .  
         [0044]     The operation button unit SB comprises a plurality of input buttons SB 1  that enable input of numbers, letters/characters or other symbols, an input confirmation button SB 2  that enables confirmation of the contents of user input performed using the input button SB 1  or the display TD, a sensor that recognizes the pressing of the input button SB 1  or the input confirmation button SB 2 , a transmission circuit that transmits signals indicating the recognized input button SB 1  or input confirmation button SB 2  to the CPU  10 a, and the like. In order to permit reading of the user&#39;s fingerprint by the fingerprint reader  10 kA described below, the surface of the input confirmation button SB 2  comprises flat glass that is transparent to light of the wavelength emitted by the light source of the fingerprint reader  10 kA.  
         [0045]     The display TD is a touch panel display that displays such screens as a screen to provide messages or instructions to the user operating this image forming apparatus  1 , a screen using which the user inputs desired types of processing and processing parameter values, a screen that displays images formed by the image forming apparatus  1 , the results of operations or processes or the like. It also detects the position on the display touched by the user and sends to the CPU  10 a a signal indicating the result of such detection.  
         [0046]     In the example shown in  FIG. 3 , a plurality of input buttons SC 1  having such button names as ‘Normal paper’, ‘One-sided paper’ and ‘Auto-detect’ are displayed on the display TD, and when the user presses one of the input buttons SC 1 , the display TD detects the position on the display TD pressed by the user and transmits to the CPU  10 a a signal indicating which of the input buttons SC 1  was pressed. In the example of  FIG. 3 , the input confirmation button SC 2  having the button name ‘OK’ is displayed on the display TD. This input confirmation button SC 2 , like the input confirmation button SB 2 , is a button used to confirm the contents of information input via user operation of the input button SB 1  or SC 1 . In addition, a flat glass panel that is transparent to light having the wavelength emitted by the light source of the fingerprint reader  10 kB is used on the display screen of the display TD for reading of the user&#39;s fingerprint by the fingerprint reader  10 kB described below.  
         [0047]     The user inputs into the image forming apparatus  1  information specifying the type of processing desired or applicable parameter values by operating the input button SB 1  or SC 1 . For example, the buttons may be used to execute a print or other job, view information stored in the image forming apparatus  1 , change screens on the display TD or change various configuration settings.  
         [0048]     If there is no error in the contents of the input information, the information is confirmed by making selection using the input confirmation button SB 2  or SC 2 . When this is done, the CPU  10 a controls the various components of the image forming apparatus  1  to execute processing in accordance with the confirmed contents.  
         [0049]     As described above, the operation panel  10 f fulfills the role of a user interface for a user who directly operates the image forming apparatus  1 .  
         [0050]     The fingerprint reader  10 kA comprises such components as a light source  10 k 1 , an optical system  10 k 2  and an imaging element  10 k 3 , as shown in  FIG. 4 . The light source  10 k 1  is an LED (Light-Emitting Diode), and emits light toward the fingerprint of the finger of a user who presses the surface of the input confirmation button SB 2 . The optical system  10 k 2  comprises a lens, an aperture and mirrors, for example. The various components of the optical system  10 k 2  are disposed such that the light emitted from the light source  10 k 1  strikes the finger of a user who presses the surface of the input confirmation button SB 2  and the reflected light reaches the imaging element  10 k 3  and forms an image of the fingerprint thereon. The imaging element  10 k 3  is an image sensor such as a CCD (Charge-Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor), and generates fingerprint image data by converting the formed fingerprint image into electrical signals. The fingerprint reader  10 kA reads the fingerprint of a user who presses the input confirmation button SB 2  in this way.  
         [0051]     The fingerprint reader  10 kB has the same configuration as the fingerprint reader  10 kA, and reads the fingerprint of a user who presses the input confirmation button SC 2 . In place of the optical system-based fingerprint reader shown in  FIG. 4 , this fingerprint reader may be based on a semiconductor or on pressure-sensitivity or heat-sensitivity.  
         [0052]     The fingerprint readers  10 kA,  10 kB are used in order to prevent unauthorized persons from using the image forming apparatus  1  without permission even if the user who is logged in to the image forming apparatus  1  is away from the location of the image forming apparatus  1 . These fingerprint readers  10 kA,  10 kB may be collectively termed the ‘fingerprint reader  10 k’ herein.  
         [0053]      FIG. 5  is a drawing showing an example of the functional configuration of the image forming apparatus  1 .  FIG. 6  is a drawing showing an example of a user information table TB 1 .  FIG. 7  is a drawing showing an example of a login screen HG 1 .  
         [0054]     The hard disk  10 d in  FIG. 2  stores, among other things, programs and data used to execute the various functions of a fingerprint data obtaining controller  101 , an access controller  102 , a fingerprint data storage unit  103 , a user match determination unit  104 , a fingerprint data deletion unit  105 , a job execution unit  106  and a user information storage unit  107 , as shown in  FIG. 5 . These programs are read into the RAM  10 b where necessary and are executed by the CPU  10 a. All or part of these programs and data may be stored in the ROM  10 c. Alternatively, all or part of the functions shown in  FIG. 5  may be realized through a control circuit  10 e.  
         [0055]     The user information storage unit  107  stores and manages the user information table TB 1  shown in  FIG. 6 . Stored in the user information table TB 1  is data indicating the user ID, password and login status of each user. A user pertaining to a record for which the flag in the ‘login status’ field is up, i.e., a record for which the ‘login status’ value is ‘0’, is a user that is logged into the image forming apparatus  1 . In the example shown in  FIG. 6 , the user having a user ID of ‘B002’ is logged in to the image forming apparatus  1 . The ‘login status’ value is updated as appropriate when the user logs into or out of the image forming apparatus  1 .  
         [0056]     When no user is logged in, the login screen HG 1  shown in  FIG. 7  is displayed on the display TD. In order for a user to log into the image forming apparatus  1 , the user enters his user ID and password via this login screen HG 1  and presses the input confirmation button SC 2  or the input confirmation button SB 2  (see  FIG. 3 ) to confirm the contents of the input information.  
         [0057]     When this is done, the access controller  102  determines based on the confirmed user ID and password and the data in the user information table TB 1  whether or not the user who made the input is an authorized user. If the user is recognized as an authorized user, that user is logged into the image forming apparatus  1 . From that moment until the user logs out, the user can use the image forming apparatus  1 . The access controller  102  executes logout processing described below.  
         [0058]     During login processing, first, the password corresponding to the input-confirmed user ID is read out from the user information table TB 1 . If the read-out password matches the input-confirmed password, the image forming apparatus  1  confirms that the current user is an authorized user and permits the user to log into the image forming apparatus  1 . A flag is then raised in the login status field of the record for that user ID in the user information table TB 1 . In this embodiment, the user authentication method comprises the memory-based authentication method based on a user ID and password but may comprise an ownership authentication method or other method.  
         [0059]     The fingerprint data obtaining controller  101  carries out processing to obtain fingerprint data DTF indicating information pertaining to the fingerprint of the user operating the operation panel  10 f. This processing is executed according to the following sequence, for example. In  FIG. 4 , when the fingerprint data obtaining controller  101  detects the pressing of the input confirmation button SB 2  (as indicated by the encircled number ‘ 1 ’ in the drawing), it commands the fingerprint reader  10 kA to read the fingerprint of the finger that pressed the input confirmation button SB 2 . When this is done, the light source  10 k 1  of the fingerprint reader  10 kA emits light toward the input confirmation button SB 2  (encircled numbers ‘ 3 ’ and ‘ 4 ’). This light reflects off of the finger pressed against the input confirmation button SB 2  and is received by the imaging element  10 k 3  (encircled numbers ‘ 5 ’ and ‘ 6 ’). When this occurs, an image of the fingerprint is formed on the imaging element  10 k 3 . The imaging element  10 k 3  generates fingerprint image data by converting the image into electrical signals and transmits this image data to the fingerprint data obtaining controller  101  (encircled number ‘ 7 ’). In  FIG. 4 , the chain-dot line indicates the movement of the signals, while the dashed line indicates the movement of the light.  
         [0060]     Where the user presses the input confirmation button SC 2 , user fingerprint image data is generated by the fingerprint reader  10 kB and is sent to the fingerprint data obtaining controller  101 . The sequence of operations for fingerprint reading in this case is identical to the sequence followed by the fingerprint reader  10 kA. In this way, the input confirmation buttons SB 2 , SC 2  are used not only to confirm the contents of input information, but also as imaging instruction means during fingerprint imaging.  
         [0061]     The fingerprint data obtaining controller  101  obtains the image data sent from the fingerprint reader  10 kA or the fingerprint reader  10 kB as fingerprint data DTF for the user operating the operation panel  10 f. Here, the image data for the fingerprint image may itself be used as the fingerprint data DTF, or information pertaining to a specific characteristic point on the fingerprint (i.e., the position, orientation, type or other aspect of the characteristic point) may be extracted from the fingerprint image and this information may be used as the fingerprint data DTF.  
         [0062]     When the user inputs a user ID or other information from the login screen HG 1  and presses the input confirmation button SB 2  or SC 2  in order to confirm the contents of the input information, the fingerprint data storage unit  103  stores the fingerprint data DTF obtained by the fingerprint data obtaining controller  101  until a command to delete this information is issued by the access controller  102 .  
         [0063]     When user login to the image forming apparatus  1  is completed, a screen to specify the type of processing, applicable parameter values or the like is displayed on the display TD. Here, the user enters the contents of the processing that he wants the image forming apparatus  1  to execute by operating the input buttons SB 1  or SC 1  of the operation panel  10 f. When input is completed, the user presses the input confirmation button SB 2  or SC 2  to confirm the contents of the input information. This causes a command for the execution of processing to be issued by the user to the image forming apparatus  1 . In this case as well, the fingerprint data DTF for the finger pressed against the input confirmation button SB 2  or SC 2  is obtained by the fingerprint data obtaining controller  101 . The fingerprint data DTF obtained at the time of confirmation of the contents of the processing (i.e., at the time the command to execute such processing is issued) is stored temporarily in the RAM  10 b or the like without being saved in the fingerprint data storage unit  103 . After such data is used for processing by the user match determination unit  104  described below, it is immediately deleted. In the discussion below, the fingerprint data DTF stored in the fingerprint data storage unit  103  at the time of login may be referred to as the ‘login fingerprint data DTF  1 ’, while the fingerprint data DTF stored in the RAM  10 b or the like when a processing command is issued may be referred to as the ‘processing command fingerprint data DTF 2 ’.  
         [0064]     When a command to execute processing is issued by a user, the user match determination unit  104  calls out the login fingerprint data DTF 1  from the fingerprint data storage unit  103  and determines, based on the processing command fingerprint data DTF 2  obtained at the time such command was issued and the called-out login fingerprint data DTF 1 , whether or not the user who issued the processing command is the logged-in user. For example, it determines that there is a match if the degree of similarity between the characteristic point indicated by the login fingerprint data DTF 1  and the characteristic point indicated by the processing command fingerprint data DTF 2  equals or exceeds a threshold value a, and determines that there is no match if such degree of similarity does not reach the threshold value a.  
         [0065]     Where a match is determined to exist, the job execution unit  106  is notified of such determination, while if a match is determined not to exist, the access controller  102  is notified of such determination.  
         [0066]     When notification of a match is received, the job execution unit  106  controls the various components of the image forming apparatus  1  such that processing is executed in accordance with the processing contents input by the user, as in the prior art.  
         [0067]     When notification of the absence of a match is received, the access controller  102  logs out the currently logged-in user and notifies the fingerprint data deletion unit  105  that logout has occurred. The user is also logged out and logout notification is issued where the user logs out on his own or where a prescribed period of time elapses without operation of the image forming apparatus  1 .  
         [0068]     When logout notification is received from the access controller  102 , the fingerprint data deletion unit  105  deletes the login fingerprint data DTF 1  stored in the fingerprint data storage unit  103 .  
         [0069]     The entire sequence of operations executed by the image forming apparatus  1  between user login and logout will now be described with reference to a flow chart.  
         [0070]      FIG. 8  is a flow chart pertaining to the entire series of operations executed by the image forming apparatus  1 , while  FIG. 9  is a flow chart pertaining to ‘no-match’ processing. The processes represented in these flow charts are controlled by the CPU  10 a.  
         [0071]     When no one is logged into the image forming apparatus  1 , the login screen HG 1  is displayed on the display TD. When a user wishing to use the image forming apparatus  1  inputs his user ID and password via the login screen HG 1  and presses the input confirmation button SB 2  or SC 2 , the image forming apparatus  1  reads the fingerprint image for the finger that pressed the input confirmation button SB 2  or SC 2  and obtains login fingerprint data DTF 1  (# 1 ), and executes the user authentication process (# 2 ). If the user is recognized as an authorized user as a result of the user authentication process, the user is logged in. If the user is not recognized, a message indicating login denial is displayed on the display TD and the user is barred from using the image forming apparatus  1 .  
         [0072]     When login is completed, the image forming apparatus  1  saves the login fingerprint data DTF 1  obtained in step # 1  (# 3 ).  
         [0073]     The user for whom login is confirmed then inputs the contents of the desired processing using the input buttons SB 1  or SC 1 . When input is completed, the user presses the input confirmation button SB 2  or SC 2  with the same finger used for login in order to confirm the input processing contents and enable the image forming apparatus  1  to execute such processing (# 4 ).  
         [0074]     When this is done, the image forming apparatus  1  reads the fingerprint of the finger that pressed the input confirmation button SB 2  or SC 2  and obtains the processing command fingerprint data DTF 2  (# 5 ). By comparing the fingerprint information indicated by the recently obtained processing command fingerprint data DTF 2  with the login fingerprint data DTF 1  stored in step # 3 , the image forming apparatus  1  then determines whether or not the logged-in user is the same person as the user who specified the processing contents (i.e., the user who issued the processing execution command) (# 6 ). In other words, if the degree of similarity between the two fingerprint data sets equals or exceeds a threshold value a, the image forming apparatus  1  determines that the users are the same person, while if the degree of similarity does not reach the threshold value a, the image forming apparatus  1  determines that the users are different persons.  
         [0075]     If the two users are determined to be identical (YES in # 7 ), processing is executed based on the user-input processing contents in the same manner as in the prior art (# 9 ). If the user then logs out after the execution of processing (YES in # 10 ), the login fingerprint data DTF 1  stored in step # 3  is deleted and the currently logged-in user is logged out (# 12 ). Where the logout operation is not performed (NO in # 10 ), the operations including and subsequent to step # 4  are repeated each time a processing execution command is issued by the user.  
         [0076]     If it is determined in step # 7  that the two users are different persons, however (NO in step # 7 ), the issued processing command is denied. The login fingerprint data DTF 1  stored in step # 3  is then deleted (# 11 ) and the currently logged-in user is logged out (# 12 ).  
         [0077]     Incidentally, it may occur that while the currently logged-in user is away from the image forming apparatus  1 , another user operates the image forming apparatus  1  to issue a processing command without knowing that the first user is already logged into the image forming apparatus  1 . However, in this case, because the fingerprint of the currently logged-in user naturally does not match the fingerprint of the other user, the issued processing command is denied. When this occurs, the other user must naturally re-perform from the start the operations necessary to issue the processing command after logging in once more to the image forming apparatus  1 , which is burdensome. In addition, there may be cases where a user match may be determined not to exist due to problems with the reading of a fingerprint. When immediate logout occurs in this instance, the user also must log in once more and perform the necessary operations, which is burdensome.  
         [0078]     Accordingly, a construction may be adopted wherein if the users are determined to be different persons (NO in # 7 ), no-match processing is executed (# 8 ), the login fingerprint data DTF 1  is deleted and logout is performed where necessary. The no-match processing is carried out via the sequence of operations shown in  FIG. 9 .  
         [0079]     A message prompting the user to answer the question of whether or not the user currently operating the image forming apparatus  1  is different from the logged-in user is displayed on the display TD (# 81 ).  
         [0080]     If an answer indicating that the users are different persons is returned (YES in # 82 ), a message prompting the user to answer the question of whether or not the set parameter values input via the input button SB 1  or SC 1 , such as the paper size and the magnification, should be retained is displayed on the display TD (# 83 ).  
         [0081]     If an answer indicating that the set parameter values should be retained is returned (YES in # 84 ), the set parameter values information indicating those set parameter values is stored in the RAM  10 b or the like. Proceeding to step # 11  in  FIG. 8 , the login fingerprint data DTF 1  for the currently logged-in user is deleted (# 11 ) and that user is logged out from the image forming apparatus  1  (# 12 ). As a result, the other user who operated the image forming apparatus  1  without the knowledge of the currently logged-in user can log into and use the image forming apparatus  1 . In addition, after login, a screen that reproduces the parameter values previously set by the other user is displayed based on the set parameter values information stored in the RAM  10 b.  
         [0082]     If an answer indicating that the users are not different persons (i.e., that they are the same person) is returned, on the other hand (NO in # 82 ), the CPU  10 a returns to step # 5  in  FIG. 8  and retries fingerprint reading. However, the number of retries is counted (# 86 ), and if the number of retries has exceeded a prescribed number (YES in # 87 ), because this may indicate that a different person is improperly attempting to use the image forming apparatus  1 , subsequent retry attempts are denied and the currently logged-in user is logged out from the image forming apparatus  1  (# 12 ). When this occurs, the login fingerprint data DTF 1  is also deleted (# 11 ).  
         [0083]     According to this embodiment, when a user logs into the image forming apparatus  1 , information regarding the fingerprint of the user performing the login operation is obtained. Furthermore, when a processing command is issued, information regarding the fingerprint of the user performing the command issuance operation is obtained. The information regarding these two fingerprints is compared, and if it is determined that the currently logged-in user is the same user who issued the processing command, the processing related to that command is executed. In this way, even if a logged-in user leaves the image forming apparatus  1  without logging out, unauthorized use of the image forming apparatus  1  by a different person can be prevented. In other words, a scheme whereby the image forming apparatus  1  can be continuously used by only the logged-in and authenticated user can be provided, enabling security to be improved.  
         [0084]     The login fingerprint data DTF 1  stored in the fingerprint data storage unit  103  is saved only for the period of time that the user is logged in. The processing command fingerprint data DTF 2  obtained upon the issuance of a processing command is deleted immediately after it is used to determine whether or not a user match exists. Therefore, because there is less danger than exists in the prior art of unauthorized disclosure of the login fingerprint data DTF 1  and the processing command fingerprint data DTF 2 , which comprise sensitive personal information, the user can permit his fingerprint to be read by the image forming apparatus  1  without security concerns.  
         [0085]     Fingerprint-based authentication in this embodiment is carried out in order to confirm whether or not a user seeking to carry out processing is the same person as the currently logged-in user. User authentication to determine whether or not the user using the image forming apparatus  1  is an authorized user is already complete at the time of login. Therefore, the threshold value a pertaining to the degree of matching, which is employed at the time of fingerprint verification, can be set to a value lower than that used for normal user authentication, thereby allowing user authentication to be performed more easily.  
         [0086]     Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.  
         [0087]     The descriptions of this embodiment used an image forming apparatus such as an MFP as an example, but the present invention may be applied in a different type of processing apparatus such as a personal computer or a workstation that can be used by a plurality of users. In this case, a fingerprint reader may be connected to the apparatus via a USB or other connection and this fingerprint reader may be used as an input confirmation button. Alternatively, the fingerprint reader may be disposed in a mouse button.  
         [0088]     In the above embodiment, while the risk of unauthorized outside disclosure of fingerprint information, which is sensitive personal information, is reduced by the fact that the user fingerprint information obtained at the time of login is deleted upon logout, thereby giving the user peace of mind, there may be cases in which, depending on the environment in which the image forming apparatus  1  is used or the purpose of use, a more secure user authentication process is desired. In this case, user authentication may be carried out via fingerprint verification. To accomplish this, fingerprint information for each user is registered in a database in advance. User authentication is carried out by comparing the user fingerprint information obtained at the time of login with the fingerprint information registered in the database. Furthermore, it is acceptable if the fingerprint information obtained at the time of execution of user-specified processing is compared with the fingerprint information for the currently logged-in user among all logged-in users registered in the database, or with the fingerprint information obtained at the time of login.  
         [0089]     All or part of the configuration of the image forming apparatus  1 , the processing contents, the sequence of operations, the table contents, the user authentication method or the like may be changed within the essential scope of the invention.