Patent Publication Number: US-11042335-B2

Title: Image forming system which continues image formation of confidential document under condition that presence of executor is confirmed

Description:
INCORPORATION BY REFERENCE 
     The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2018-220832, filed on Nov. 27, 2018. The contents of this application are incorporated herein by reference in their entirety. 
     BACKGROUND 
     The present disclosure relates to an image forming system including an image forming apparatus such as a printer, a copier, or a multifunction peripheral. 
     A technique has been proposed for a case in which an image of a confidential document is formed (printed) through an image forming apparatus over a network. The confidential document is for example an important document, and requires security protection. According to the technique, authentication information of a user attached to confidential print data is sent to the image forming apparatus and printing is output under a condition that the user is authenticated. 
     SUMMARY 
     An image forming system according to an aspect of the present disclosure includes: an image forming apparatus which performs image formation of a received confidential document; and an authentication server which authenticates, based on biometric information, an executor who is to operate the image forming apparatus to perform the image formation. The image forming apparatus and the authentication server are connected through a network. The image forming apparatus includes: confidential document storage which stores the received confidential document therein; a biometric information reading section which reads and acquires biometric information of the executor; a biometric information sending section which sends the biometric information acquired by the biometric information reading section to the authentication server; a confidential image forming section which starts the image formation of the confidential document when the executor has been authenticated by the authentication server; biometric information storage which stores therein the biometric information acquired by the biometric information reading section as comparison biometric information; and an authentication section which executes presence confirmation of the executor by acquiring biometric information through the biometric information reading section and comparing the biometric information to the comparison biometric information during the image formation of the confidential document. The confidential image forming section continues the image formation of the confidential document under a condition that the presence of the executor is confirmed by the authentication section and suspends the image formation of the confidential document when the presence of the executor is not confirmed by the authentication section within a prescribed period. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a system configuration diagram illustrating a general configuration of an image forming system according to an embodiment of the present disclosure. 
         FIG. 2A  is a sequence diagram which describes a printing preparation operation in the image forming system illustrated in  FIG. 1 . 
         FIG. 2B  is a continuation of the sequence diagram illustrated in  FIG. 2A . 
         FIG. 2C  is a continuation of the sequence diagram illustrated in  FIG. 2B . 
         FIG. 3A  is a flowchart describing a confidential printing operation in the image forming apparatus illustrated in  FIG. 1 . 
         FIG. 3B  is a continuation of the flowchart illustrated in  FIG. 3A . 
         FIG. 3C  is a continuation of the flowchart illustrated in  FIG. 3B . 
     
    
    
     DETAILED DESCRIPTION 
     The following describes an embodiment of the present disclosure in detail with reference to the accompanying drawings. In the following embodiment, configuration indicating the same functions is labeled with the same reference signs. 
     Referring to  FIG. 1 , an image forming system according to the present embodiment includes a client terminal  1 , a document server  2 , an executor terminal  3 , an image forming apparatus  4 , and an authentication server  5  connected to each other through a network  6  such as a local area network (LAN). 
     The document server  2  is an information processing device which includes a processor such a central processing unit (CPU), read-only memory (ROM), random-access memory (RAM), and the like, and operates under program control. The document server  2  includes non-volatile storage such as semiconductor memory or a hard-disk drive (HDD), and stores therein a confidential document  21  in a state where access authority has been set. 
     The document server  2  functions as a password generating section  22 , an encrypted file generating section  23 , a password sending section  24 , and an encrypted file sending section  25 . The password generating section  22  generates a one-time password (hereafter referred to as an encryption password) which encrypts a confidential printing file including the confidential document  21 , and generates a one-time password (hereafter referred to as an access password) for accessing the encrypted file. The encrypted file generating section  23  generates the encrypted file by encrypting the confidential printing file using the encryption password. The password sending section  24  sends the encryption password and the access password to the executor terminal  3 . The encrypted file sending section  25  sends the encrypted file authenticated with the access password to the image forming apparatus  4 . 
     The client terminal  1  is an information processing device operated under program control, such as a personal computer used by a printing client A. The printing client A has authority to access the confidential document  21  stored on the document server  2 . 
     The executor terminal  3  is an information processing device operated under program control, such as a personal computer used by a printing executor B. The printing executor B is requested to print the confidential document  21  by the printing client A. 
     The image forming apparatus  4  is a copier including a print function. The image forming apparatus  4  includes an operation section  41 , a document reading section  42 , storage  43 , an image forming section  44 , a communication section  45 , a biometric information reading section  46 , and a controller  7 . 
     The operation section  41  is a user interface including various operation keys or a touch panel in which a transparent pressure sensor is provided on a surface of a liquid-crystal display panel. The operation section  41  functions as an input section, a display section, and an audio output section. 
     The document reading section  42  is a scanner which reads a document image. The document reading section  42  reads a document image by irradiating a document with light and receiving light reflected by the document. The document is fed by an unillustrated document feeder device or placed on platen glass by a user. 
     Examples of the storage  43  include semiconductor memory or an HDD. 
     The image forming section  44  records an image on recording paper. The image forming section  44  includes a photosensitive drum, a charger, an exposure section, a developing section, a transfer section, a cleaner, and a fixing section, for example. 
     The communication section  45  has a function of sending and receiving various data between the client terminal  1 , the document server  2 , the executor terminal  3 , and the authentication server  5  over the network  6 . 
     The biometric information reading section  46  reads and acquires the biometric information of the printing executor B. The biometric information reading section  46  is constituted by various sensors or cameras. The biometric information reading section  46  acquires one or more of the following as the biometric information of the printing executor B: a fingerprint image, an iris image, a retinal image, a vein image, and a facial image. 
     The controller  7  is an information processor such as a microcomputer including a processor such as a CPU, ROM, RAM, and the like. A control program for controlling operation of the image forming apparatus  4  is stored in the ROM. The processor of the controller  7  reads out the control program stored in the ROM and loads the control program in the RAM to control the entire apparatus according to instruction information. 
     The controller  7  functions as a confidential file acquiring section  71 , a biometric information sending section  72 , a decrypting section  73 , a confidential printing section  74 , and an authentication section  75  by executing the control program. 
     The confidential file acquiring section  71  sends a file request to the document server  2  upon receiving a confidential print job. The confidential print job is equivalent to an example of a “confidential image forming job”. The confidential print job is sent from the executor terminal  3 . The file request includes a file address, an access password, and a function list of the image forming apparatus  4 . The confidential file acquiring section  71  receives an encrypted file from the document server  2  and stores the encrypted file in the storage  43 . 
     The biometric information sending section  72  sends the biometric information acquired by the biometric information reading section  46  and a user ID specifying the printing executor B to the authentication server  5 . The biometric information sending section  72  stores the biometric information acquired by the biometric information reading section  46  in the storage  43  as comparison biometric information. 
     The decrypting section  73  decrypts the encrypted file into a confidential printing file using the encryption password. The confidential printing file includes the confidential document  21  and a printing profile. The printing profile is equivalent to an example of an “image formation profile”. 
     The confidential printing section  74  prints the confidential document  21  with the settings of the printing profile. 
     The authentication section  75  causes the biometric information reading section  46  to acquire biometric information during printing. The authentication section  75  compares the biometric information acquired by the biometric information reading section  46  with the comparison biometric information stored in the storage  43 . The authentication section  75  compares the biometric information to the comparison biometric information and performs presence confirmation of the printing executor B. 
     The authentication server  5  is an information processing device which includes a processor such as a CPU, ROM, RAM, and the like, and is operated under program control. The authentication server  5  includes non-volatile storage such as semiconductor memory or an HDD, and stores authentication information  51  and output device information  52  therein. 
     The authentication information  51  is information for authenticating whether or not the printing executor B operating the image forming apparatus  4  is a person for whom the comparison biometric information is stored in the storage  43 . The comparison biometric information to be compared to the biometric of the printing executor B acquired by the biometric information reading section  46 , such as a fingerprint image, an iris image, a retinal image, a vein image, or a facial image, is registered as the authentication information  51 . 
     The output device information  52  is information about the image forming apparatus  4  through which printing of the confidential document  21  is permitted. A media access control (MAC) address or an internet protocol (IP) address specifying the image forming apparatus  4  is registered in the output device information  52 . 
     The authentication server  5  compares the biometric information received from the image forming apparatus  4  to the authentication information  51 . The authentication server  5  functions as an authentication section  53  which sends the comparison result to the image forming apparatus  4 . 
     A printing preparation operation is described in detail with reference to  FIGS. 2A to 2C . The printing preparation operation is performed before the printing executor B requested to print the confidential document  21  from the printing client A starts printing through the image forming apparatus  4 .  FIG. 2A  is a sequence diagram which describes the printing preparation operation in the image forming system  100 .  FIG. 2B  is a continuation of the sequence diagram illustrated in  FIG. 2A .  FIG. 2C  is a continuation of the sequence diagram illustrated in  FIG. 2B . 
     The client terminal  1  receives a designation of the confidential document  21  to be printed and a designation of various printing settings through operation of the printing client A (Step S 101 ). The designation of various printing settings includes items such as printing unit quantity, size, and color or monochrome. 
     Next, the client terminal  1  generates a printing profile from designated printing settings (Step S 102 ). The client terminal  1  sends a confidential printing preparation request for the designated confidential document  21  to the document server  2  (Step S 103 ). The confidential printing preparation request includes the printing profile generated by the client terminal  1 . 
     Upon receiving the confidential printing preparation request, the document server  2  generates a confidential printing file (Step S 104 ). 
     Next, the document server  2  functions as the password generating section  22 . The document server  2  generates an encryption password which encrypts the confidential printing file. Then, the document server  2  functions as the encrypted file generating section  23 . The document server  2  generates an encrypted file in which the confidential printing file has been encrypted by secret key cryptography (Step S 105 ). Secret key cryptography is a method in which the same password is used for encryption and decryption. The password to be used is the encryption password generated by the document server  2 . 
     Next, the document server  2  functions as the password generating section  22 . The document server  2  generates the access password for accessing the encrypted file (Step S 106 ). 
     The document server  2  also functions as the password sending section  24 . The document server  2  sends the file address, the encryption password, and the access password of the encrypted file to the client terminal  1  (Step S 107 ). 
     Having received the file address, the encryption password, and the access password, the client terminal  1  receives, through operation by the printing client A, a designation of the printing executor B to perform printing (Step S 108 ). For example, the client terminal  1  accesses the authentication server  5 . The client terminal  1  may then receive the designation of the printing executor B from among candidates with biometric information registered in the authentication information  51 . 
     Next, the client terminal  1  sends a printing request to the executor terminal  3  of the printing executor B (Step S 109 ). The printing request includes the file address, the encryption password, and the access password. Note that the printing request may be delivered to the printing executor B via facsimile, postal mail of a paper medium, or the like. 
     Next, the printing executor B who has received the printing request operates the executor terminal  3  to send a confidential print job and a user ID specifying themselves (the printing executor B) to the image forming apparatus  4  which performs printing (Step S 110 ). The confidential print job includes the file address, the encryption password, and the access password. 
     The controller  7  of the image forming apparatus  4  which has received the confidential print job functions as the confidential file acquiring section  71 . The confidential file acquiring section  71  sends a file request to the document server  2  (Step S 111 ). The file request includes the file address, the access password, and a function list of the image forming apparatus  4 . 
     Having received the file request, the document server  2  specifies the encrypted file according to the file address and determines whether or not the image forming apparatus  4  has a biometric authentication function needed for confidential printing according to the function list (Step S 112 ). 
     When the image forming apparatus  4  has the biometric authentication function needed for confidential printing in Step S 112 , the document server  2  determines whether or not printing can be performed based on the printing profile according to the function list (Step S 113 ). 
     When printing can be performed according to the printing profile in Step S 113 , the document server  2  determines whether or not the image forming apparatus  4  is registered in the output device information  52  of the authentication server  5  based on the MAC address or the IP address of the image forming apparatus  4  (Step S 114 ). 
     When the image forming apparatus  4  is registered in the output device information  52  in Step S 114 , the document server  2  functions as the encrypted file sending section  25 . The document server  2  sends the encrypted file which has been authenticated with the access password to the image forming apparatus  4  (Step S 115 ). 
     The confidential file acquiring section  71  stores the received encrypted file and encryption password in the storage  43  in association with the user ID designating the printing executor B (Step  116 ). The image forming apparatus  4  enters standby to perform confidential printing. Therefore, the image forming apparatus  4  completes the preparation operation for confidential printing. 
     Note that when a negative determination is made in any of Steps S 112  to S 114 , the document server  2  denies transmission of the confidential printing file. Then, the document server  2  notifies the executor terminal  3  that transmission has been denied. Therefore, the printing executor B returns to Step S 110  and selects another image forming apparatus  4  to which the confidential print job is to be sent. 
     Next, a confidential printing operation performed by the printing executor B through the image forming apparatus  4  is described in detail with reference to  FIGS. 3A to 3C .  FIG. 3A  is a flowchart describing the confidential printing operation in the image forming apparatus  4  illustrated in  FIG. 1 .  FIG. 3B  is a continuation of the flowchart illustrated in  FIG. 3A .  FIG. 3C  is a continuation of the flowchart illustrated in  FIG. 3B . 
     The biometric information reading section  46  determines whether biometric information has been acquired. When an encrypted file is temporarily saved in the storage  43 , the controller  7  functions as the biometric information sending section  72 . When the encrypted file is temporarily saved in the storage  43 , the biometric information reading section  46  enters standby to acquire biometric information (Step S 201 ). 
     When biometric information is acquired in Step S 201 , the biometric information sending section  72  sends the acquired biometric information and the user ID specifying the printing executor B to the authentication server  5  (Step S 202 ). The biometric information sending section  72  also stores the acquired biometric information in the storage  43  as comparison biometric information (Step S 203 ). 
     Next, the controller  7  determines whether or not the biometric information matches the user ID specifying the printing executor B to perform confidential printing based on an authentication result from the authentication server  5  (Step S 204 ). 
     When the biometric information matches the user ID specifying the printing executor B in Step S 204 , the controller  7  functions as the decrypting section  73 . The decrypting section  73  decrypts the encrypted file into a confidential printing file using the encryption password (Step S 205 ). 
     Next, the controller  7  functions as the confidential printing section  74 . The confidential printing section  74  starts printing of the confidential document  21  with the settings of the printing profile (Step S 206 ). Note that because the printing profile is also encrypted before printing of the confidential document  21  is started, falsification of the printing profile can be prevented. As a result, the confidential document  21  is printed as intended by the printing client A. 
     When printing of the confidential document  21  starts in Step S 206 , the controller  7  functions as the authentication section  75 . The authentication section  75  causes the biometric information reading section  46  to acquire biometric information. Then, the authentication section  75  performs presence confirmation of the printing executor B by comparing the comparison biometric information stored in the storage  43  to the acquired biometric information (Step S 207 ). Furthermore, the authentication section  75  determines whether or not the presence of the printing executor B has been confirmed (Step S 208 ). 
     When the presence of the printing executor B has been confirmed in Step S 208 , the confidential printing section  74  continues printing of the confidential document  21  (Step S 209 ). The confidential printing section  74  then determines whether or not printing has completed (Step S 210 ). 
     When the printing is not completed in Step S 210 , the authentication section  75  returns to Step S 207  to perform presence confirmation of the printing executor B. The authentication section  75  performs Steps S 207  to S 210  at a prescribed interval (an interval of several seconds, for example). Therefore, printing of the confidential document  21  continues under the condition that the printing executor B is present in the immediate vicinity of the image forming apparatus  4 . Accordingly, an image of the confidential document  21  is formed in a state in which the image forming apparatus  4  has confirmed that the printing executor B is in the immediate vicinity of the image forming apparatus  4 . As a result, security can also be ensured during image formation. 
     When printing is completed in Step S 210 , the controller  7  deletes the confidential printing file, the encryption password, and the comparison biometric information from the storage  43  (Step S 211 ). The controller  7  then sends a printing completion notification to the client terminal  1  notifying that printing of the confidential document  21  has been completed (Step S 212 ), and the confidential printing process ends. 
     When the presence of the printing executor B is not confirmed in Step S 208  because biometric information cannot be acquired by the biometric information reading section  46  or does not match the comparison biometric information stored in the storage  43 , the confidential printing section  74  suspends printing of the confidential document  21  (Step S 213 ). Furthermore, the confidential printing section  74  outputs a warning from the operation section  41  by sound or display (Step S 214 ). 
     Note that the warning of Step S 214  may be output when the controller  7  has determined that printed matter is remaining. The controller  7  determines whether or not printed matter is remaining based on, for example, an imaging result of a camera which captures an image of printed matter output from the image forming apparatus  4  or a measurement result of a scale which measures the weight of printed matter. 
     Next, the authentication section  75  performs presence confirmation of the printing executor B (Step S 215 ). The authentication section  75  determines whether or not the presence of the printing executor B can be confirmed within a prescribed period (Step S 216 ). 
     When the presence of the printing executor B can be confirmed within the prescribed period in Step S 216 , the confidential printing section  74  restarts printing (Step S 217 ). The process returns to Step S 207  and the authentication section  75  performs presence confirmation of the printing executor B. 
     When the presence of the printing executor B cannot be confirmed within the prescribed period in Step S 216 , the confidential printing section  74  ends printing (Step S 218 ). The controller  7  then deletes the confidential printing file, the encryption password, and the comparison biometric information from the storage  43  (Step S 219 ). The controller  7  then sends a partial printing completion notification to the client terminal  1  (Step S 220 ) and ends the confidential printing operation. The partial printing completion notification is a notification which notifies that printing of the confidential document  21  has been partially completed. Note that by including information of pages for which printing has been completed in the printing partial completion notification, duplicate printing of the pages for which printing has been completed can be favorably avoided. 
     When the biometric information does not match the printing executor B in Step S 204 , the controller  7  deletes the encrypted file and the encryption password from the storage  43  (Step S 221 ). The controller  7  then sends a non-printing notification to the client terminal  1  (Step S 222 ) and ends the confidential printing operation. The non-printing notification is a notification which notifies that printing of the confidential document  21  has not been performed. 
     Note that when the biometric information does not match the printing executor B in Step S 204 , reauthentication may be performed a preset designated number of times. Reauthentication means that the controller  7  determines whether or not biometric information matches the user ID specifying the printing executor B to perform confidential printing. 
     Note that according to the present embodiment, the biometric information reading section  46  and the authentication section  75  are used to authenticate biometric information, but a smartphone including a fingerprint authentication function or a facial authentication function may also be used as the biometric information reading section  46  and the authentication section  75 . In this case, the Global Positioning System (GPS), a beacon, a mounted camera, an indoor camera, ultrasonic measurement, or the like may be used to determine that the distance between the image forming apparatus  4  and the smartphone is less than a designated distance. 
     According to the present disclosure as described above, the image forming system  100  includes the image forming apparatus  4  which performs image formation of the received confidential document  21  and the authentication server  5  which authenticates, based on biometric information, the printing executor B who is to operate the image forming apparatus  4  to perform the image formation. The image forming apparatus  4  and the authentication server  5  are connected through the network  6 . The image forming apparatus  4  includes: the storage  43  which functions as confidential document storage that stores the received confidential document  21  therein; the biometric information reading section  46  which reads and acquires the biometric information of the printing executor B; the biometric information sending section  72  which sends the biometric information acquired by the biometric information reading section  46  to the authentication server  5 ; the confidential printing section  74  which is a confidential image forming section that starts the image formation of the confidential document  21  when the printing executor B has been authenticated by the authentication server  5 ; the storage  43  which functions as biometric information storage that stores therein the biometric information acquired by the biometric information reading section  46  as comparison biometric information; and the authentication section  75  which performs presence confirmation of the printing executor B by acquiring the biometric information through the biometric information reading section  46  and comparing the biometric information to the comparison biometric information during the image formation of the confidential document  21 . The confidential printing section  74  continues the image formation of the confidential document  21  under a condition that the presence of the printing executor B is confirmed by the authentication section  75  and suspends the image formation of the confidential document  21  when the presence of the printing executor B is not confirmed by the authentication section  75  within a prescribed period. 
     Through this configuration, security can also be ensured during printing because the image formation of the confidential document  21  is performed in a state in which the image forming apparatus  4  has confirmed that the printing executor B is present in the immediate vicinity of the image forming apparatus  4 . 
     Furthermore, according to the present embodiment, the confidential printing section  74  deletes the confidential document  21  from the confidential document storage when the presence of the printing executor B is not confirmed by the authentication section  75  within the prescribed period. 
     Through this configuration, leakage of the confidential document  21  can be prevented and the security of the confidential document  21  can be ensured when image formation of the confidential document  21  is partially completed. 
     Furthermore, according to the present embodiment, the image forming apparatus  4  includes the operation section  41  which functions as a warning output section that outputs a warning when the presence of the printing executor B is not confirmed by the authentication section  75 . 
     Through this configuration, separation of the printing executor B from the image forming apparatus  4  can be prevented and the security of the confidential document  21  can be ensured. 
     Furthermore, according to the present disclosure, the image forming system  100  includes: the document server  2  which encrypts the confidential document  21  and the printing profile (image formation profile) as an encrypted file and generates the access password for the encrypted file and the encryption password that decrypts the encrypted file; and the executor terminal  3  which sends the access password to the image forming apparatus  4  as a confidential print job (confidential image formation job). The document server  2  and the executor terminal  3  are connected through the network  6 . The image forming apparatus  4  includes: the confidential file acquiring section  71  which, upon receipt of the confidential print job, receives the encrypted file and the encryption password from the document server  2  by sending the access password to the document server  2  and stores the encrypted file and the encryption password in the confidential document storage; and the decrypting section  73  which decrypts the encrypted file into the confidential document  21  and the printing profile using the encryption password when the printing executor B has been authenticated by the authentication server  5 . The confidential printing section  74  starts the image formation of the confidential document  21  based on the printing profile when the printing executor B has been authenticated by the authentication server  5 . 
     Through this configuration, the printing profile of the confidential document  21  can be set in advance by the printing client A who requests the printing executor B to print the confidential document  21 . 
     Note that the present disclosure is not limited to the above embodiment, and it is clear that the embodiment can be variously altered within a scope of the technical idea of the present disclosure. Aspects of the above elements of configuration, such as number, position, and shape, are not limited to the above embodiment. The aspects may be any number, position, shape, or the like suitable to implement the present disclosure. Note that elements of configuration which are the same are labeled with the same reference signs in the drawings.