Patent Publication Number: US-2018046849-A1

Title: Authentication device, image processing apparatus, and authentication method

Description:
INCORPORATION BY REFERENCE 
     This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2016-158374 filed on Aug. 12, 2016, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     The present disclosure relates to authentication devices, image processing apparatuses, and authentication methods. 
     Generally, an image processing apparatus such as an image forming apparatus or an image reading apparatus includes a touch panel in which an operation panel and a display portion are integrated. In this case, when the image processing apparatus performs an authentication process, a password input through an operation performed on the operation panel is checked against a pre-registered password. 
     Meanwhile, there are cases where input information required for the authentication process is input by a handwriting operation performed on the operation panel. For example, it has been known that, in the authentication process, a trajectory of a handwriting operation performed on the operation panel is detected, and the detected trajectory is checked against a trajectory represented by pre-registered data in a pattern recognition process. 
     In the above-described case, the following operations are required: a screen call operation such as tapping an input start button displayed on the display portion; a handwriting operation performed on a handwriting input screen that is displayed on the display portion in response to the screen call operation; and an authentication start operation for starting the authentication process by deleting the handwriting input screen. 
     In the authentication process described above, it is troublesome for a user to perform the authentication start operation after the password input operation or the handwriting operation. 
     In addition, in the authentication process based on checking of a password, input of a long password is required to enhance the security. However, an operation of inputting a long password is troublesome. 
     Meanwhile, in the authentication process based on checking of the trajectory of a handwriting operation, if a strict matching condition is adopted for the checking in order to enhance the security, authentication failure may occur excessively frequently. 
     On the other hand, in checking the trajectory of the handwriting operation, if an approximation condition having a relatively wide allowable range is adopted, a handwriting operation having a complicated trajectory is required in order to enhance the security. It is troublesome to perform the handwriting operation having the complicated trajectory. 
     An objective of the present disclosure is to provide an authentication device capable of performing a high-security authentication process by a simple operation, an image processing apparatus including the authentication device, and an authentication method using the authentication device. 
     SUMMARY 
     An authentication device according to one aspect of the present disclosure includes an operation panel, a registered handwriting procedure acquiring portion, a long-pressing detecting portion, a handwriting detecting portion, and a handwriting authentication portion. The operation panel is capable of detecting a multi-touch operation. The registered handwriting procedure acquiring portion acquires information of a registered handwriting procedure from a storage portion in which the information of the registered handwriting procedure has been stored in advance. The registered handwriting procedure represents a handwriting procedure including a trajectory of a handwriting operation performed on the operation panel and at least one of a time, a speed, and a number of strokes of the handwriting operation. The long-pressing detecting portion detects a long-pressing operation performed on the operation panel. The handwriting detecting portion detects the handwriting procedure in the handwriting operation performed on the operation panel, during a period in which the long-pressing operation is continuously detected. The handwriting authentication portion determines whether or not the detected handwriting procedure satisfies a predetermined approximation condition with respect to the acquired registered handwriting procedure, thereby determining whether authentication has succeeded or failed. 
     An image processing apparatus according to another aspect of the present disclosure includes an image processing portion and the above-described authentication device. The image processing portion includes one or both of an image reading portion configured to read an image of a document sheet and an image forming portion configured to form an image on a sheet. 
     An authentication method according to still another aspect of the present disclosure includes acquiring information of a registered handwriting procedure from a storage portion in which the information of the registered handwriting procedure has been stored in advance. The registered handwriting procedure represents a handwriting procedure including a trajectory of a handwriting operation performed on an operation panel capable of detecting a multi-touch operation and at least one of a time, a speed, and a number of strokes of the handwriting operation. Further, the authentication method includes detecting a long-pressing operation performed on the operation panel. Further, the authentication method includes detecting the handwriting procedure in the handwriting operation performed on the operation panel, during a period in which the long-pressing operation is continuously detected. Further, the authentication method includes determining whether or not the detected handwriting procedure satisfies a predetermined approximation condition with respect to the acquired registered handwriting procedure, thereby determining whether authentication has succeeded or failed. 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description with reference where appropriate to the accompanying drawings. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of an image processing apparatus according to an embodiment. 
         FIG. 2  is a flowchart showing an example of procedure of an authentication information registration process in the image processing apparatus according to the embodiment. 
         FIG. 3  is a flowchart showing an example of procedure of a login process in the image processing apparatus according to the embodiment. 
         FIG. 4  shows an example of an authentication information registration screen in the image processing apparatus according to the embodiment. 
         FIG. 5  shows an example of an authentication information registration screen on which a virtual keyboard is displayed, in the image processing apparatus according to the embodiment. 
         FIG. 6  shows an example of an authentication information registration screen on which a handwriting operation is performed, in the image processing apparatus according to the embodiment. 
         FIG. 7  shows an example of a login screen in the image processing apparatus according to the embodiment. 
         FIG. 8  shows an example of a login screen on which a handwriting frame is displayed, in the image processing apparatus according to the embodiment. 
         FIG. 9  shows an example of a login screen on which a handwriting operation is performed, in the image processing apparatus according to the embodiment. 
         FIG. 10  shows an example of a login screen on which a handwriting authentication error occurs, in the image processing apparatus according to the embodiment. 
         FIG. 11  shows an example of a login screen on which a virtual keyboard is displayed, in the image processing apparatus according to the embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the following embodiments are examples embodying the present disclosure, and, by nature, do not limit the technical scope of the present disclosure. 
     [Configuration of Image Processing Apparatus  10 ] 
     As shown in  FIG. 1 , an image processing apparatus  10  according to an embodiment includes a touch panel unit (TPU)  1 , an image reading portion  2 , an image forming portion  3 , a data storage portion  4 , a control portion  5 , and the like. The TPU  1  includes an operation panel  1   a  and a display portion  1   b  which are integrated with each other. 
     The operation panel  1   a  is a panel capable of detecting a multi-touch operation. For example, a capacitive, resistive, or optical operation panel  1   a  may be adopted. The display portion  1   b  is a panel-like display device such as a liquid crystal panel. 
     The image reading portion  2  is a device executing an image scanning process of reading an image of a document sheet. For example, the image reading portion  2  includes: a platen glass on which a document sheet is placed; a light source that emits light toward the document sheet; a mechanism that causes the light source to move along the platen glass; a line sensor that receives reflected light from the document sheet and outputs image data; and the like. 
     The image forming portion  3  is a device that executes a printing process of forming an image on a sheet by a predetermined method such as electrophotography or ink jetting. For example, the image forming portion  3  forms, on the sheet, an image represented by image data obtained by the image reading portion  2 . 
     In the present embodiment, the image reading portion  2  and the image forming portion  3  form an image processing portion  200 . Alternatively, the image processing portion  200  may include only one of the image reading portion  2  and the image forming portion  3 . 
     The data storage portion  4  is a non-transitory computer-readable memory. For example, a hard disk drive, a flash memory, or the like is adopted as the data storage portion  4 . 
     The control portion  5  executes various types of calculation and data processing, and controls various electronic devices included in the image processing apparatus  10 . The control portion  5  is capable of exchanging data and control signals with the TPU  1 , the image reading portion  2 , the image forming portion  3 , and the data storage portion  4  via a bus  6 . 
     The control portion  5  includes a user interface (UI) control portion  51  that controls the TPU  1 , an image reading control portion  52  that controls the image reading portion  2 , an image formation control portion  53  that controls the image forming portion  3 , and the like. The UI control portion  51  controls the TPU  1 , and executes an authentication information registration process, a login process, and the like which are described later. 
     For example, the control portion  5  is implemented by a processor that executes a program stored in the data storage portion  4  or the like in advance. The processor is a microprocessor unit (MPU), a digital signal processor (DSP), or the like. 
     When the UI control portion  51  detects that a predetermined scan start operation is performed on the TPU  1 , the image reading control portion  52  causes the image reading portion  2  to execute the image scanning process. In addition, when the UI control portion  51  detects that the predetermined copy start operation is performed on the TPU  1 , the image reading control portion  52  causes the image reading portion  2  to execute the image scanning process, and the image formation control portion  53  causes the image forming portion  3  to execute the printing process. 
     The UI control portion  51  includes a registration control portion  51   a,  a touch operation detecting portion  51   b,  a character string input control portion  51   c,  an ID overlap check portion  51   d,  a handwriting frame display control portion  51   e,  a handwriting detecting portion  51   f,  a detection result display control portion  51   g,  a login control portion  51   h,  a registration information acquiring portion  51   i,  a handwriting authentication portion  51   j,  a password authentication portion  51   k,  and the like. 
     The login process is a process of determining whether or not to allow a user to use the image processing apparatus  10 , on the basis of input authentication information that is input through the TPU  1 . The login process is an example of an authentication process. The authentication information registration process is a process of causing the data storage portion  4  to store registered authentication information  4   x  to be compared to the input authentication information, in advance of the login process. 
     In the image processing apparatus  10 , the TPU  1  and the UI control portion  51  form an authentication device  100  that executes the login process. The authentication device  100  determines whether authentication for use of the image processing portion  200  has succeeded or failed. 
     In the conventional general authentication device, there are cases where input information required for the login process is input by a handwriting operation performed on the operation panel  1   a . For example, it has been known that, in the login process, a trajectory of a handwriting operation performed on the operation panel  1   a  is detected, and the detected trajectory is checked against a trajectory represented by pre-registered data in a pattern recognition process. 
     In the above-described case, the following operations are required: a screen call operation such as tapping an input start button displayed on the display portion  1   b;  a handwriting operation performed on a handwriting input screen that is displayed on the display portion  1   b  in response to the screen call operation; and an authentication start operation for starting the login process by deleting the handwriting input screen. 
     In the login process described above, it is troublesome for the user to perform the authentication start operation after a password input operation or a handwriting operation on the TPU  1 . 
     In addition, in the login process based on checking of a password, input of a long password is required to enhance the security. However, an operation of inputting a long password is troublesome. 
     Meanwhile, in the log-in process based on checking of the trajectory of a handwriting operation, if a strict matching condition is adopted for the checking in order to enhance the security, authentication failure may occur excessively frequently. 
     On the other hand, in checking the trajectory of the handwriting operation, if an approximation condition having a relatively wide allowable range is adopted, a handwriting operation having a complicated trajectory is required in order to enhance the security. It is troublesome to perform the handwriting operation having the complicated trajectory. 
     The authentication device  100  according to the present embodiment is capable of performing the login process with high security by a simple operation. Hereinafter, the authentication information registration process and the login process by the authentication device  100  will be described. 
     [Authentication Information Registration Process] 
     First, an example of procedure of the authentication information registration process by the authentication device  100  will be described with reference to a flowchart shown in  FIG. 2 . In the following description, S 101 , S 102 , . . . represent identification characters for respective steps performed by the UI control portion  51 . 
     When a predetermined registration start operation is performed on the operation panel  1   a  or an operation button (not shown), the registration control portion  51   a  of the UI control portion  51  causes an authentication information registration screen g 0  to be displayed (refer to  FIG. 4 ). Thus, the authentication information registration process is started. 
     As shown in  FIG. 4 , the authentication information registration screen g 0  includes a user ID input frame g 01 , a password input frame g 02 , a “handwriting” icon g 03 , a “register” icon g 04 , a “cancel” icon g 05 , and the like. 
     The user ID input frame g 01  represents an area that accepts an operation of inputting a user ID such as a user name. The password input frame g 02  represents an area that accepts an operation of inputting a password corresponding to the user ID. The “handwriting” icon g 03  is an icon to be operated when an operation of inputting a handwritten drawing g 100  described later is performed (refer to  FIG. 6 ). 
     &lt;Step S 101 &gt; 
     When the authentication information registration screen g 0  is displayed on the display portion  1   b,  the touch operation detecting portion  51   b  detects a touch operation performed on the operation panel  1   a . At this time, the touch operation detecting portion  51   b  detects the touch operation on the operation panel  1   a  while distinguishing among predetermined five types of touch operations corresponding to the authentication information registration screen g 0 . 
     The five types of touch operations include: an operation of touching the user ID input frame g 01 ; an operation of touching the password input frame g 02 ; an operation of pressing the “handwriting” icon g 03  long; an operation of touching the “register” icon g 04 ; and an operation of touching the “cancel” icon g 05 . 
     The long-pressing operation is an operation of continuously touching a certain position on the operation panel  1   a  for a time period equal to or longer than a predetermined long-pressing period. The touch operation detecting portion  51   b  repeats the process in step S 101  until detecting any of the five types of touch operations. 
     Upon detecting the operation of touching the user ID input frame g 01 , the touch operation detecting portion  51   b  advances the process to step S 102 . Upon detecting the long-pressing operation performed on the handwriting icon g 03 , the touch operation detecting portion  51   b  advances the process to step S 106 . Upon detecting the operation of touching the password input frame g 02 , the touch operation detecting portion  51   b  advances the process to step S 109 . 
     Upon detecting the operation of touching the “register” icon g 04 , the touch operation detecting portion  51   b  advances the process to step S 111 . Upon detecting the operation of touching the “cancel” icon g 05 , the touch operation detecting portion  51   b  ends the authentication information registration process. 
     &lt;Step S 102 &gt; 
     In step S 102 , the character string input control portion  51   c  causes the display portion  1   b  to display a virtual keyboard g 00  for inputting a character string (refer to  FIG. 5 ). 
     &lt;Step S 103 &gt; 
     Further, the character string input control portion  51   c  sets a character string representing the user ID, in accordance with a key touch operation performed in the area of the virtual keyboard g 00  on the operation panel  1   a . Hereinafter, the user ID obtained through the key touch operation performed on the virtual keyboard g 00  is referred to as an input user ID. 
     &lt;Step S 104 &gt; 
     Subsequently, the ID overlap check portion  51   d  determines whether or not the input user ID is an unregistered ID that does not match a registered user ID already stored in the data storage portion  4 . 
     Upon determining that the input user ID is an unregistered ID, the ID overlap check portion  51   d  advances the process to step S 101  with the storage of the input user ID being maintained. On the other hand, upon determining that the input user ID is not an unregistered ID, the ID overlap check portion  51   d  advances the process to step S 105 . 
     &lt;Step S 105 &gt; 
     In step S 105 , the ID overlap check portion  51   d  discards the input user ID set in step S 103 , and advances the process to step S 101 . 
     &lt;Step S 106 &gt; 
     In step S 106 , the handwriting frame display control portion  51   e  causes the display portion  1   b  to display a handwriting frame g 1  representing an input area for a handwritten drawing g 100  (refer to  FIG. 6 ). The handwritten drawing g 100  represents the trajectory of the handwriting operation. In the example shown in  FIG. 6 , the handwriting frame display control portion  51   e  causes a grid g 10  serving as a guide for the position of the handwriting operation to be displayed in the handwriting frame g 1 . 
     &lt;Step S 107 &gt; 
     Further, the handwriting detecting portion  51   f  executes a handwriting detection process during a period in which the long-pressing operation on the handwriting icon g 03  is continuously detected. The handwriting detection process is a process of detecting the handwriting operation performed in the handwriting frame g 1  on the operation panel  1   a.    
     The handwriting operation is a multi-stroke slide-touch operation on the operation panel  1   a , and a trajectory g 11  of the multi-stroke slide-touch operation represents the handwritten drawing g 100 . 
     The user performs the long-pressing operation on the handwriting icon g 03  with a first finger  91  that is a finger of his/her one hand, and simultaneously performs the handwriting operation with a second finger  92  that is a finger of the other hand (refer to  FIG. 6 ). The first finger  91  is a finger that first touches the operation panel  1   a , and the second finger  92  is a finger that touches the operation panel  1   a  during a period in which the first finger  91  touches the operation panel  1   a.    
     In the UI control portion  51 , the touch operation detecting portion  51   b  detects the long-pressing operation performed on the operation panel  1   a  (S 101 ), and the handwriting detecting portion  51   f  detects the handwriting operation performed on the operation panel  1   a  during the continuation of the long-pressing operation (S 107 ). 
     In the handwriting detection process, the handwriting detecting portion  51   f  detects a handwriting procedure of the handwriting operation. The handwriting procedure includes the trajectory g 11  of the handwriting operation, and at least one of the time, the speed, and the number of strokes of the handwriting operation. The handwriting procedure is a part of the authentication information, and substitute information for the password. 
     In the present embodiment, the handwriting procedure includes the trajectory g 11  of the handwriting operation, and at least one of the time, the speed, and the number of strokes of the handwriting operation. For example, the handwriting procedure detected by the handwriting detecting portion  51   f  may include the trajectory g 11  of each stroke in the handwriting operation, one or both of the time and the speed of each stroke in the handwriting operation, and the number of strokes of the handwriting operation. 
     For example, even when a slide-touch operation that is not apart from the operation panel  1   a  continues, the handwriting detecting portion  51   f  detects a position at which the speed of the slide-touch operation becomes zero, as an end position of one stroke and a start position of next one stroke. 
     In the following description, the handwriting procedure of the handwriting operation, which is detected by the handwriting detecting portion  51   f,  is referred to as a detected handwriting procedure. 
     Further, in step S 107 , the detection result display control portion  51   g  causes the display portion  1   b  to display the result of the detection by the handwriting detecting portion  51   f.  In the example shown in  FIG. 6 , the detection result display control portion  51   g  causes the display portion  1   b  to display, as the result of the detection by the handwriting detecting portion  51   f,  the trajectory g 11  of each stroke of the handwriting operation, an arrow g 12  indicating the moving direction of the trajectory g 11  of each stroke, and a stroke order g 13 . 
     &lt;Step S 108 &gt; 
     Meanwhile, the touch operation detecting portion  51   b  monitors whether or not the long-pressing operation on the handwriting icon g 03  continues. The touch operation detecting portion  51   b  allows the process in step S 107  by the handwriting detecting portion  51   f  during the continuation of the long-pressing operation on the handwriting icon g 03 . The touch operation detecting portion  51   b  determines that a time point at which the long-pressing operation on the handwriting icon g 03  is no longer detected is an end time point of the handwriting operation. 
     At least when the long-pressing operation on the handwriting icon g 03  is no longer detected, the handwriting frame display control portion  51   e  deletes the handwriting frame g 1  from the authentication information registration screen g 0  on the display portion  1   b , and advances the process to step S 101 . At this time, the process is advanced from step S 108  to step S 101  with the storage of the detected handwriting procedure being maintained. 
     Also when the state in which the handwriting operation in the handwriting frame g 1  is not detected, continues for a predetermined time or more, the handwriting frame display control portion  51   e  may delete the handwriting frame g 1  from the authentication information registration screen g 0  on the display portion  1   b  and advance the process to step S 101 . 
     &lt;Step S 109 &gt; 
     In step S 109 , the character string input control portion  51   c  causes the display portion  1   b  to display the virtual keyboard g 00  for inputting a character string. 
     &lt;Step S 110 &gt; 
     Further, the character string input control portion  51   c  sets the password in accordance with a key touch operation performed in the area of the virtual keyboard g 00  on the operation panel  1   a . Hereinafter, the password obtained through the key touch operation on the virtual keyboard g 00  is referred to as an input password. 
     The character string input control portion  51   c  advances the process to step S 101  with the storage of the input password being maintained. 
     &lt;Step S 111 &gt; 
     When a touch operation on the “register” icon g 04  is detected, the registration control portion  51   a  determines whether or not predetermined essential information has already been input in steps S 103 , S 107 , and S 110 . The essential information includes the input user ID obtained in step S 103 , and at least one of the detected handwriting procedure obtained in step S 107  and the input password obtained in step S 110 . 
     Upon determining that the essential information has already been input, the registration control portion  51   a  advances the process to next step S 112 ; otherwise, the registration control portion  51   a  causes the display portion  1   b  to display a specified error notification, and then advances the process to step S 101 . 
     &lt;Step S 112 &gt; 
     In step S 112 , the registration control portion  51   a  causes the data storage portion  4  to store the registered authentication information  4   x  in which the input user ID obtained in step S 103  is associated with one or both of the detected handwriting procedure and the input password which are obtained in steps S 107  and S 110 , respectively. Thereafter, the registration control portion  51   a  ends the authentication information registration process. 
     The registered authentication information  4   x  includes a registered user ID  4   a  corresponding to the input user ID obtained in step S 103 , and one or both of a registered handwriting procedure  4   b  corresponding to the detected handwriting procedure obtained in step S 107  and a registered password  4   c  corresponding to the input password obtained in step S 110 . 
     [Login Process] 
     Next, an example of procedure of the login process by the authentication device  100  will be described with reference to a flowchart shown in  FIG. 3 . In the following description, S 201 , S 202 , . . . represent identification characters for respective steps performed by the UI control portion  51 . 
     When the image processing apparatus  10  is started up, the login control portion  51   h  of the UI control portion  51  causes a login screen g 2  to be displayed (refer to  FIG. 7 ). Thus, the login process is started. 
     As shown in  FIG. 7 , the login screen g 2  includes a user ID input frame g 21 , a password input frame g 22 , a “login” icon g 23 , and the like. The login control portion  51   h  that causes the display portion  1   b  to display the login screen g 2  including the password input frame g 22  is an example of an input frame display control portion. 
     The user ID input frame g 21  represents an area that accepts an operation of inputting the user ID to be used in the login process. The password input frame g 22  represents an area that accepts an operation of inputting a password, corresponding to the user ID, to be used in the login process. 
     &lt;Step S 201 &gt; 
     When the login screen g 2  is displayed on the display portion  1   b , the touch operation detecting portion  51   b  detects a touch operation performed on the operation panel  1   a . At this time, the touch operation detecting portion  51   b  detects the touch operation on the operation panel  1   a  while distinguishing among predetermined four types of touch operations corresponding to the login screen g 2 . 
     The four types of touch operations include: an operation of touching the user ID input frame g 21 ; a short-pressing operation performed on the password input frame g 22 ; a long-pressing operation performed on the password input frame g 22 ; and an operation of touching the “login” icon g 23 . The long-pressing operation is an operation of continuously touching an area corresponding to the password input frame g 22  on the operation panel  1   a  for a time period equal to or longer than the long-pressing period described above. 
     On the other hand, the short-pressing operation is a touch operation shorter in time than the long-pressing operation, and performed on the area corresponding to the password input frame g 22  on the operation panel  1   a . The touch operation detecting portion  51   b  repeats the process at step S 201  until detecting any of the four types of touch operations. 
     Upon detecting the operation of touching the user ID input frame g 21 , the touch operation detecting portion  51   b  advances the process to step S 202 . Upon detecting the long-pressing operation performed on the password input frame g 22 , the touch operation detecting portion  51   b  advances the process to step S 204 . Upon detecting the short-pressing operation performed on the password input frame g 22 , the touch operation detecting portion  51   b  advances the process to step S 211 . 
     Upon detecting the operation of touching the “login” icon g 23 , the touch operation detecting portion  51   b  advances the process to step S 214 . 
     The touch operation detecting portion  51   b  that detects the long-pressing operation performed on the password input frame g 22  in step S 201  is an example of a long-pressing detecting portion that detects the long-pressing operation performed on the operation panel  1   a.    
     In addition, the touch operation detecting portion  51   b  that detects the short-pressing operation performed on the area corresponding to the password input frame g 22  on the operation panel  1   a  in step S 201  is an example of a short-pressing operation detecting portion. 
     &lt;Step S 202 &gt; 
     In step S 202 , the login control portion  51   h  selects the user ID to be used in the login process from the registered user IDs  4   a  included in the registered authentication information  4   x,  in accordance with a selection operation performed in an area of the user ID input frame g 21  on the operation panel  1   a . Hereinafter, the registered user ID  4   a  selected in step S 202  is referred to as a selected user ID. 
     In step S 202 , the registration information acquiring portion  51   i  acquires all the registered user IDs  4   a  from the data storage portion  4 , and the login control portion  51   h  causes the display portion  1   b  to display all the registered user IDs  4   a  as selection candidates. 
     &lt;Step S 203 &gt; 
     Further, the registration information acquiring portion  51   i  acquires, from the data storage portion  4 , the registered handwriting procedure  4   b  and the registered password  4   c  corresponding to the selected user ID. Thereafter, the login control portion  51   h  advances the process to step S 201 . 
     The registration information acquiring portion  51   i  that executes the process in step S 203  is an example of a registered handwriting procedure acquiring portion that acquires information of the registered handwriting procedure  4   b  from the data storage portion  4  in which the information of the registered handwriting procedure  4   b  representing the handwriting procedure has been stored in advance. 
     In addition, the registration information acquiring portion  51   i  that executes the process in step S 203  is also an example of a registered password acquiring portion that acquires the registered password  4   c  from the data storage portion  4  in which the registered password  4   c  associated with the information of the registered handwriting procedure  4   b  has been stored in advance. 
     &lt;Step S 204 &gt; 
     When the long-pressing operation on the password input frame g 22  is detect, the login control portion  51   h  determines whether or not the selected user ID has already been accepted in the process in step S 202 . Upon determining that the selected user ID has already been accepted, the login control portion  51   h  advances the process to next step S 205 ; otherwise, the login control portion  51   h  causes the display portion  1   b  to display a specified error notification, and advances the process to step S 201 . 
     &lt;Step S 205 &gt; 
     In step S 205 , the handwriting frame display control portion  51   e  causes the display portion  1   b  to display the handwriting frame g 1  representing an input area for the handwritten drawing g 100  (refer to  FIG. 8 ). The process in step S 205  is executed when the long-pressing operation on the password input frame g 22  is detected. 
     &lt;Step S 206 &gt; 
     Further, similarly to step S 107  in  FIG. 2 , the handwriting detecting portion  51   f  executes the handwriting detection process during a period in which the long-pressing operation on the password input frame g 22  is continuously detected. At this time, the handwriting detecting portion  51   f  detects the handwriting procedure of the handwriting operation performed on the area represented by the handwriting frame g 1  on the operation panel  1   a , during a period in which the handwriting frame g 1  is displayed on the display portion  1   b.    
     The user performs the handwriting operation with his/her second finger  92  while performing the long-pressing operation on the password input frame g 22  with his/her first finger  91  (refer to  FIG. 9 ). 
     Also in the handwriting detection process in step S 206 , the handwriting detecting portion  51   f  detects the handwriting procedure including the trajectory g 11  of the handwriting operation and at least one of the time, the speed, and the number of strokes of the handwriting operation. 
     Further, in step S 206 , the detection result display control portion  51   g  causes the display portion  1   b  to display the result of the detection by the handwriting detecting portion  51   f.  In the example shown in  FIG. 9 , the detection result display control portion  51   g  causes the display portion  1   b  to display, as the result of the detection by the handwriting detecting portion  51   f,  the trajectory g 11  of each stroke of the handwriting operation, the arrow g 12  indicating the moving direction of the trajectory g 11  of each stroke, and the stroke order g 13  of each stroke. 
     &lt;Step S 207 &gt; 
     Further, the handwriting authentication portion  51   j  determines whether or not the handwriting procedure detected in step S 206  satisfies a predetermined approximation condition with respect to the registered handwriting procedure acquired in step S 203 , thereby determining whether authentication has succeeded or failed. 
     For example, the approximation condition includes: a trajectory approximation condition as an approximation condition for the trajectory g 11  of each stroke in the handwriting operation; and a temporal approximation condition as an approximation condition for the time of each stroke in the handwriting operation. In addition, regarding the approximation condition, it is an essential condition that the number of strokes of the handwriting operation is the same between the detected handwriting procedure and the registered handwriting procedure. 
     For example, the trajectory approximation condition includes, as an essential condition, a condition that, between the detected handwriting procedure and the registered handwriting procedure, a deviation of each of a start position and an end position of the trajectory g 11  of each stroke in the handwriting operation is within a predetermined allowable positional deviation range. 
     Likewise, the temporal approximation condition may include, as an essential condition, a condition that, between the detected handwriting procedure and the registered handwriting procedure, a difference in time of each stroke in the handwriting operation is within a predetermined allowable time difference range. 
     Further, in the present embodiment, each time the trajectory g 11  of each stroke in the handwriting operation and one or both of the time and the speed of each stroke are detected by the handwriting detecting portion  51   f,  the handwriting authentication portion  51   j  determines whether or not the result of the detection for each stroke satisfies the approximation condition with respect to the registered handwriting procedure  4   b  (S 207 ). In addition, the handwriting authentication portion  51   j  determines that the approximation condition is not satisfied when the number of the detected strokes exceeds the number of the strokes in the registered handwriting procedure. 
     Upon determining that the result of the detection for each stroke does not satisfy the approximation condition with respect to the registered handwriting procedure  4   b,  the handwriting authentication portion  51   j  determines that authentication has failed. When the determination results in “authentication failed”, the handwriting authentication portion  51   j  causes the display portion  1   b  to display a specified error notification g 3 , and advances the process to step S 201 . In this case, the detection result obtained in step S 206  is discarded. 
       FIG. 10  shows a case where the handwriting authentication portion  51   j  determines that the trajectory g 11  of the second stroke in the detected handwriting procedure does not satisfy the approximation condition with respect to that of the second stroke in the registered handwriting procedure  4   b,  and causes the display portion  1   b  to display an error notification g 3  on the login screen g 2 . 
     The handwriting authentication portion  51   j  executes, in step S 209  described later, a final determination process as to whether authentication has succeeded or failed. This final determination process by the handwriting authentication portion  51   j  as to whether authentication has succeeded or failed includes a process of determining whether or not the approximation condition regarding the number of strokes of the handwriting operation is satisfied. 
     &lt;Step S 208 &gt; 
     On the other hand, the touch operation detecting portion  51   b  monitors whether or not the long-pressing operation on the password input frame g 22  continues. The touch operation detecting portion  51   b  allows the process in step S 206  by the handwriting detecting portion  51   f  during a period in which the long-pressing operation on the password input frame g 22  continues. The touch operation detecting portion  51   b  determines that a time point at which the long-pressing operation on the password input frame g 22  is no longer detected is an end time point of the handwriting operation. 
     At least when the long-pressing operation on the password input frame g 22  is no longer detected, the handwriting frame display control portion  51   e  deletes the handwriting frame g 1  from the login screen g 2  on the display portion  1   b , and advances the process to step S 209 . 
     Also when the state in which the handwriting operation in the handwriting frame g 1  is not detected, continues for a predetermined time or more, the handwriting frame display control portion  51   e  may delete the handwriting frame g 1  from the login screen g 2  on the display portion  1   b  and advance the process to the step S 209 . 
     &lt;Step S 209  That Follows Step S 208 &gt; 
     In step S 209  that follows step S 208 , the handwriting authentication portion  51   j  executes the final determination process as to whether authentication has succeeded or failed. Specifically, the handwriting authentication portion  51   j  determines that authentication has succeeded when all the detection results for the respective strokes satisfy the approximation condition with respect to the registered handwriting procedure  4   b  and the total number of the strokes detected matches the number of the strokes in the registered handwriting procedure; otherwise, the handwriting authentication portion  51   j  determines that authentication has failed. 
     Upon finally determining that authentication has succeeded, the handwriting authentication portion  51   j  advances the process to next step S 210 ; otherwise, the handwriting authentication portion  51   j  causes the display portion  1   b  to display a specified error notification and then advances the process to step S 201 . 
     &lt;Step S 210 &gt; 
     In step S 210 , the image reading control portion  52  and the image formation control portion  53  each shift to the operating mode, thereby completing the login process. With this, the image processing apparatus  10  becomes capable of executing the image scanning process by the image reading portion  2  and the printing process by the image forming portion  3 . 
     &lt;Step S 211 &gt; 
     On the other hand, when the touch operation detecting portion  51   b  detects the short-pressing operation performed on the password input frame g 22  in step S 201 , the login control portion  51   h  determines whether or not the selected user ID has already been accepted in the process in step S 202 . Upon determining that the selected user ID has already been accepted, the login control portion  51   h  advances the process to next step S 212 ; otherwise, the login control portion  51   h  causes the display portion  1   b  to display a specified error notification, and advances the process to step S 201 . 
     &lt;Step S 212 &gt; 
     In step S 212 , the character string input control portion  51   c  causes the display portion  1   b  to display the virtual keyboard g 00  for inputting a character string.  FIG. 11  shows the login screen g 2  on which the virtual keyboard g 00  is displayed by the short-pressing operation performed on the password input frame g 22  with the first finger  91 . 
     &lt;Step S 213 &gt; 
     Further, the character string input control portion  51   c  sets the input password in accordance with a key touch operation performed in the area of the virtual keyboard g 00  on the operation panel  1   a . The key touch operation in the area of the virtual keyboard g 00  on the operation panel  1   a  is an example of a character string input operation. 
     The process in step S 213  is executed when the short-pressing operation on the password input frame g 22  is detected. The character string input control portion  51   c  that performs the process in step S 213  is an example of a password input portion that specifies the input password in accordance with the character string input operation performed on the operation panel  1   a.    
     The character string input control portion  51   c  advances the process to step S 201  with the storage of the input password being maintained. 
     &lt;Step S 214 &gt; 
     In step S 201 , when the touch operation detecting portion  51   b  detects an operation of touching the “login” icon g 23 , the login control portion  51   h  determines whether or not the user ID and the password which are necessary for the password authentication process have already been accepted in the processes in steps S 202  and S 213 . 
     Upon determining that the user ID and the password necessary for the password authentication process have already been accepted, the login control portion  51   h  advances the process to next step S 215 ; otherwise, the login control portion  51   h  causes the display portion  1   b  to display a specified error notification, and advances the process to step S 201 . 
     &lt;Step S 215 &gt; 
     In step S 215 , the password authentication portion  51   k  executes the password authentication process, and advances the process to step S 209 . In the password authentication process, the password authentication portion  51   k  checks the input password set in step S 213  against the registered password  4   c  corresponding to the selected user ID obtained in step S 203 , thereby determining whether authentication has succeeded or failed. The password authentication portion  51   k  determines that authentication has succeeded when the input password matches the registered password  4   c;  otherwise, the password authentication portion  51   k  determines that authentication has failed. 
     &lt;Step S 209  That Follows Step S 215 &gt; 
     In step S 209  that follows step S 215 , the password authentication portion  51   k  advances the process to step S 210  described above when determining that authentication has succeeded in the password authentication process; otherwise, the password authentication portion  51   k  causes the display portion  1   b  to display a specified error notification and then advances the process to step S 201 . 
     In the present embodiment, the user performs the handwriting operation with his/her second finger  92  in accordance with the pre-registered procedure, while performing long-pressing on the handwriting icon g 03  with his/her first finger  91 . When the user takes his/her first finger  91  off the handwriting icon g 03 , the operation for the login process is completed. This operation is simpler than the operation of touching the “login” icon g 23  after inputting the password. 
     The handwriting detecting portion  51   f  detects the handwriting procedure including the trajectory g 11  of the handwriting operation performed on the operation panel  1   a , and at least one of the time, the speed, and the number of strokes of the handwriting operation. This handwriting procedure includes a lot of information even if the handwriting operation is an operation of expressing a relatively simple trajectory g 11 . Therefore, a high-security authentication process is realized by the simple handwriting operation. 
     The detection result display control portion  51   g  causes the display portion  1   b  to display the result of the detection by the handwriting detecting portion  51   f . Thus, the user is allowed to perform the handwriting operation required for the authentication process more reliably by operational feeling with his/her second finger  92  and visual recognition of the detected handwriting procedure. 
     The authentication device  100  is applicable to both the handwriting authentication process and the password authentication process, depending on the preference of the user. In addition, the password input frame g 22  of the login screen g 2  is shared by the short-pressing operation for inputting the input password and the long-pressing operation for the handwriting operation. Thus, a simple login screen g 2  can be adopted. 
     The detected handwriting procedure and the registered handwriting procedure each include the number of strokes of the handwriting operation performed on the operation panel  1   a , and one or both of the operation time for each stroke and the operation speed for each stroke. In this case, the handwriting authentication portion  51   j  can determine whether or not the detection result of the handwriting procedure for each stroke of the handwriting operation satisfies the approximation condition with respect to the registered handwriting procedure. Thus, it is easy to determine whether or not the approximation condition is satisfied. 
     In addition, each time the trajectory g 11  of each stroke in the handwriting operation and one or both of the time and the speed of each stroke are detected by the handwriting detecting portion  51   f,  the handwriting authentication portion  51   j  determines whether or not the detection result for each stroke satisfies the approximation condition with respect to the registered handwriting procedure. Then, upon determining that the detection result for each stroke does not satisfy the approximation condition with respect to the registered handwriting procedure, the handwriting authentication portion  51   j  determines that authentication has failed. 
     Therefore, when an inappropriate handwriting procedure is detected in the middle of the handwriting operation, the handwriting authentication portion  51   j  can promptly provide a determination result of “authentication failed”, without waiting for the end of the handwriting operation. 
     At least when the long-pressing operation on the operation panel  1   a  is no longer detected, the handwriting frame display control portion  51   e  deletes the handwriting frame g 1  from the display portion  1   b  (S 208 ), and the handwriting detecting portion  51   f  detects the handwriting procedure of the handwriting operation performed on the area represented by the handwriting frame g 1  on the touch panel, during a period in which the handwriting frame g 1  is displayed on the display portion  1   b  (S 206 ). Therefore, an extra operation for generating an event to end the handwriting operation, for example, an operation of touching an “operation confirmation” icon displayed in response to the handwriting frame g 1 , is not necessary. 
     It is to be understood that the embodiments herein are illustrative and not restrictive, since the scope of the disclosure 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.