JP5239482B2 - Communication apparatus, program, and image forming apparatus - Google Patents

Description

  The present invention relates to a communication device, a program, and an image forming apparatus.

In general offices and the like, a system is constructed in which a terminal device such as a personal computer and an image forming apparatus such as a printer are connected in a network environment to share or use the image forming apparatus. In such a system, signals are frequently transmitted from an unspecified terminal device or the like to the image forming apparatus via the network. For this reason, even if the received signal does not need to be processed by the image forming apparatus, the CPU in the image forming apparatus is activated each time a signal is received, resulting in unnecessary power consumption. Therefore, there is a demand for reduction in power consumption in the image forming apparatus caused by unspecified signals from the network.
For example, in Patent Document 1, when the printer shifts from the normal mode to the sleep mode, the status monitor (printer status management program) of the host computer stops the polling operation to the printer, and the printer changes from the sleep mode to the normal mode. A technology is described in which the status monitor of the host computer resumes the polling operation to the printer when it has been migrated, and the polling operation to the printer of the status monitor on the host computer is stopped or resumed according to the status of the printer. ing.

JP 2006-215686 A

Here, in general, a terminal device that transmits a signal to a device such as an image forming apparatus connected to a communication line such as a network does not have a function of interpreting that the device is in a power saving state. Also included. For this reason, such a terminal device continues, for example, polling access even if a device connected to the communication line is in a power saving state. As a result, there is a problem that the CPU in the device in the power saving state is activated, and the reduction of power consumption does not proceed.
An object of the present invention is to reduce power consumption in a device connected to a communication line.

According to the first aspect of the present invention, there is provided a receiving unit that receives a signal transmitted via a communication line, and one of a plurality of acceptance restriction levels that restricts acceptance of the signal received by the receiving unit. Receiving restriction setting means for setting the acceptance restriction level, and acceptance processing means for performing acceptance processing of the signal according to the acceptance restriction level set by the acceptance restriction setting means, and the acceptance restriction setting means The reception restriction level set by the above is realized by changing a power supply state to the reception processing means .

According to a second aspect of the present invention, the acceptance restriction level includes a communication prohibition mode that is a first communication mode that maintains low power consumption, an encryption mode that is a second communication mode, and a third communication mode. The communication apparatus according to claim 1, wherein the communication apparatus has a sleep communication mode.
According to a third aspect of the present invention, in the communication prohibition mode, the communication apparatus according to the second aspect is characterized in that the network and the reception unit are blocked and reception of all the signals is prohibited.
The invention according to claim 4 is the communication apparatus according to claim 2, wherein the encryption mode only accepts an encrypted signal.
The invention according to claim 5 is the communication apparatus according to claim 2, wherein the sleep communication mode accepts all signals transmitted to the communication apparatus.
The invention according to claim 6 is characterized in that the acceptance restriction setting means sets the acceptance restriction level different for each predetermined time period for the signal received by the receiving unit. 1 is a communication apparatus.
According to a seventh aspect of the present invention, the acceptance limit setting means is configured to reject acceptance of all the signals received by the receiving unit, acceptance of the signals encrypted with a predetermined secret key, and all The communication apparatus according to claim 1, wherein the acceptance restriction level including acceptance permission of the signal is set.
In the invention according to claim 8 , the acceptance restriction setting means changes the acceptance restriction level setting based on an instruction from a user, and changes the acceptance restriction level setting to the acceptance restriction setting means. It further comprises user authentication means for authenticating the user, wherein the acceptance restriction setting means changes the acceptance restriction level setting when there is an instruction from the user authenticated by the user authentication means. The communication device according to claim 1.
The invention described in claim 9 further includes a history information storage unit that stores history information when the setting of the acceptance restriction level is changed by the acceptance restriction setting means. It is a communication apparatus of description.

According to the tenth aspect of the present invention, there is provided a receiving function for receiving a signal transmitted to a computer via a communication line, and one of a plurality of acceptance restriction levels for restricting acceptance of the received signal. a receiving limit setting function for setting the acceptance limit level, to realize a receiving processing function of performing acceptance processing of the signal corresponding to the receiving restriction level set, the receiving restriction level set by the receiving limit setting function Is realized by changing the power supply state to the acceptance processing function .

According to an eleventh aspect of the present invention, the function of setting the acceptance limit level has a function of setting the acceptance limit level different for each predetermined time period for the received signal. The program according to item 10 .
The invention according to claim 12 further includes a function of changing the setting of the acceptance restriction level based on an instruction from a user, and a function of authenticating the user who performs the setting change of the acceptance restriction level. 11. The program according to claim 10 , wherein the function for changing the restriction level setting changes the setting of the acceptance restriction level when there is an instruction from the authenticated user.
According to a thirteenth aspect of the present invention, there is provided the program according to the tenth aspect, further comprising a function of storing history information when the setting of the acceptance restriction level is changed in a history information storage unit.

According to a fourteenth aspect of the present invention, there is provided a communication unit that is connected to a communication line and performs signal communication with the communication line, and the image received when the signal received by the communication unit is image data. An image forming unit that forms an image based on data, and a signal processing unit that processes the signal received by the communication unit, wherein the communication unit receives a signal transmitted via the communication line A reception unit, an acceptance restriction setting unit that sets one acceptance restriction level among a plurality of acceptance restriction levels for restricting acceptance of the signal received by the reception unit, and the acceptance restriction setting unit. An acceptance processing means for performing acceptance processing of the signal according to the acceptance restriction level set; and a signal transfer means for forwarding the signal permitted to be accepted by the acceptance processing means to the signal processing section , Acceptance system Said receiving restriction level set by the setting means is an image forming apparatus characterized by being realized by changing the power supply state to said receiving processing means and said signal transfer means.

According to a fifteenth aspect of the present invention, the acceptance limit setting unit outputs the signal when the power supply to the control unit that controls the operation of each unit provided in the image forming apparatus is stopped. 15. The image forming apparatus according to claim 14, wherein the acceptance restriction level is set.
According to a sixteenth aspect of the present invention, in the image forming apparatus according to the fourteenth aspect, the acceptance restriction setting means sets the acceptance restriction level according to the frequency of image formation in the image forming unit. is there.
The invention according to claim 17 is characterized in that the acceptance limit setting means classifies the frequency of the image formation in the image forming unit by a time zone and sets the acceptance limit level according to the time zone. The image forming apparatus according to claim 16 .
According to an eighteenth aspect of the present invention, when the acceptance restriction setting unit cancels the acceptance restriction level for refusing acceptance of all the signals received by the receiving unit, the image forming apparatus is connected to the communication line. 15. The image forming apparatus according to claim 14 , further comprising identification information notification means for notifying the identification information.

According to the first aspect of the present invention, it is possible to reduce the power consumption of the device connected to the communication line compared to the case where the present invention is not adopted.
According to claim 2 of the present invention, it is possible to set a plurality of communication modes having different security levels while reducing power consumption compared to the case where the present invention is not adopted.
According to the third aspect of the present invention, compared with a case where the present invention is not adopted, the control unit is not activated and the power consumption can be kept low.
According to the fourth aspect of the present invention, a certain degree of security is ensured as compared with the case where the present invention is not adopted, and for example, when a notification that a packet is combined is received, a power supply unit for the control unit The power consumption can be reduced by starting the power supply from.
According to the fifth aspect of the present invention, for example, in the sleep mode, power is supplied to the function unit of the communication unit, for example, so that the print job can be performed while reducing the power consumption of the connected image forming apparatus, for example. Yes.
According to the sixth aspect of the present invention, since the reception restriction level is set corresponding to the difference in signal reception frequency for each time zone, the apparatus connected to the communication line is compared with the case where the present invention is not adopted. The security function for the signal received via the communication line can be enhanced while reducing the power consumption in the network.
According to the seventh aspect of the present invention, it is possible to set a security function at a level corresponding to the usage status of the equipment such as the usage frequency of the equipment connected to the communication line for the signal received via the communication line.

According to claim 8 of the present invention, since only the authenticated user can change the setting of the acceptance restriction level, compared with the case where the present invention is not adopted, the device that receives a signal through the communication line The security function can be kept high.
According to claim 9 of the present invention, it is possible to verify the possibility of information leakage in a device that receives a signal via a communication line.

According to the tenth aspect of the present invention, it is possible to reduce the power consumption of the device connected to the communication line compared to the case where the present invention is not adopted.
According to the eleventh aspect of the present invention, since the reception restriction level is set corresponding to the fact that the reception frequency of the signal is different for each time zone, the device connected to the communication line is compared with the case where the present invention is not adopted. The security function for the signal received via the communication line can be enhanced while reducing the power consumption in the network.
According to the twelfth aspect of the present invention, since only an authenticated user can change the setting of the acceptance restriction level, in the device that receives a signal through the communication line as compared with the case where the present invention is not adopted. The security function can be kept high.
According to the thirteenth aspect of the present invention, it is possible to verify the possibility of information leakage in a device that receives a signal via a communication line.

According to the fourteenth aspect of the present invention, it is possible to reduce the power consumption of the device connected to the communication line compared to the case where the present invention is not adopted.
According to the fifteenth aspect of the present invention, compared to a case where the present invention is not adopted, the image forming apparatus maintains the power saving state in the image forming apparatus and receives a signal transmitted via the communication line. Security functions can be strengthened.

According to the sixteenth aspect of the present invention, it is possible to set an acceptance limit for a signal received via a communication line in accordance with a use state of the image forming apparatus, and compared with a case where the present invention is not adopted, While reducing power consumption, it is possible to enhance the security function for signals received via a communication line.
According to the seventeenth aspect of the present invention, since the reception limit level is set corresponding to the fact that the reception frequency of the signal in the image forming apparatus differs for each time zone, the communication line is compared with the case where the present invention is not adopted. The security function for the signal received via the communication line can be strengthened while reducing the power consumption of the device connected to the.
According to the eighteenth aspect of the present invention, when the identification information of the image forming apparatus itself is changed while the signal acceptance is rejected, the identification information is notified to the device connected to the communication line. be able to.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram illustrating an example of a communication system to which an image forming apparatus according to the present embodiment is connected. In the communication system shown in FIG. 1, for example, client devices 2A to 2C (hereinafter simply referred to as “client device 2”), which are examples of external devices installed in a user's work space (for example, a desk), Image forming apparatuses 3A to 3C (hereinafter simply referred to as “images”) which are examples of image forming apparatuses that form images on a medium (paper) such as recording paper based on image data generated and stored by the client apparatuses 2A to 2C. Are collectively connected to each other via a network 1 such as a LAN (Local Area Network), a WAN (Wide Area Network), or the Internet, which is an example of a communication line. The communication line may include a telephone line and a satellite communication line (for example, a spatial transmission line in digital satellite broadcasting).
The network 1 is connected to an external network 5 via a gateway 4 that is an example of a relay device.
In general, a plurality of client apparatuses 2 and a plurality of image forming apparatuses 3 can be connected on the network 1, but in the configuration shown in FIG. 1, as an example, three client apparatuses 2A to 2C are respectively provided. And three image forming apparatuses 3A to 3C are connected.

The client device 2 connected to the network 1 uses, for example, a personal computer (PC), and creates and stores image data including documents, figures, photographs, and the like. Then, when printing the created image data or the stored image data, the client apparatus 2 converts the image data into a print job that is a print command for any of the image forming apparatuses 3A to 3C and outputs the print job. The data constituting the print job (print job data) is attribute data which is information for setting various printing functions and specifying any of the image forming apparatuses 3A to 3C for performing printing in addition to the image data. It is comprised including.
The print job output from the client apparatus 2 is transmitted to any of the image forming apparatuses 3A to 3C via the network 1.

Next, the configuration of the image forming apparatus 3 will be described.
FIG. 2 is a block diagram illustrating the configuration of the image forming apparatus 3 according to the present embodiment. As shown in FIG. 2, the image forming apparatus 3 includes a control unit 10 that controls the operation of the entire image forming apparatus 3 according to a predetermined processing program, and a communication unit 20 that performs communication with the network 1. Yes. Also, an image processing unit 30 that performs analysis of a print job transmitted from the client apparatus 2 via the network 1 and performs various processes on image data included in the print job, and operations when various processes are performed in the image processing unit 30 An image processing storage unit 31 used as a storage memory and an image output unit 32 that forms an image on a sheet based on image data that has been subjected to various processes by the image processing unit 30 are provided. As the image output unit 32, for example, an electrophotographic image forming engine is used. In addition, the image processing unit 30 and the image output unit 32, and other functional units as necessary function as an image forming unit.

Here, the communication unit 20 and the image processing unit 30 are connected to the external bus 41. The control unit 10 is connected to the external bus 41 via the bus bridge 43. Thereby, the control unit 10, the communication unit 20, and the image processing unit 30 transmit and receive signals to and from each other via the external bus 41 and the bus bridge 43.
Further, the image forming apparatus 3 includes a power supply unit 50 as an example of a power supply unit that converts, for example, 100 V power supplied from a commercial power source into a predetermined voltage (for example, 24 V, 12 V, and 5 V). Power of a predetermined voltage is supplied to each functional unit. The image forming apparatus 3 also includes an external storage unit 60 that stores various data such as various programs and image data.

  The control unit 10 is an example of a control unit, and as illustrated in FIG. 2, a CPU (Central Processing Unit) 101 that performs arithmetic processing when controlling the entire image forming apparatus 3 and processing executed by the CPU 101. A RAM (Random Access Memory) 102 in which programs are stored, a ROM (Read Only Memory) 103 in which data such as setting values used in a processing program executed by the CPU 101 are stored, and various data and information are stored. SRAM (Static Random Access Memory), non-volatile memory (NVM) 104 such as flash memory, an input device (not shown) for receiving various inputs from the user such as a keyboard and a touch panel, a liquid crystal display, etc. An interface (I / F) 105 that transmits and receives data to and from a display device (not shown) or the like is provided. These are connected to each other via an internal bus 42 connected to the bus bridge 43.

  A processing program executed by the control unit 10 is provided by being loaded into the RAM 102 from, for example, a hard disk (HDD) as the external storage unit 60, for example, when the image forming apparatus 3 is started up. As another provision form, there is a form that is stored in the ROM 103 in advance and loaded from the ROM 103 to the RAM 102 for provision. Further, when the rewritable ROM 103 such as an EEPROM is provided, after the control unit 10 is assembled, only the program is provided, installed in the ROM 103, and loaded from the ROM 103 to the RAM 102 to be provided. . Further, there is a form in which a program is transmitted to the control unit 10 via a network such as the Internet and installed in the RAM 102 of the control unit 10. Furthermore, there exists a form provided in the state stored in storage media, such as CD-ROM.

  The control unit 10 is also an example of a signal processing unit, and processes a signal (packet) received by the communication unit 20 via the network 1. For example, if the received packet is related to a print job, it is sent to the image processing unit 30. When the received packet is a packet that does not need to be processed by the control unit 10, the control unit 10 performs processing such as discarding the packet.

Further, the control unit 10 controls the operation mode of the image forming apparatus 3. FIG. 3 is a diagram for explaining an operation mode set in the image forming apparatus 3 of the present embodiment. As shown in FIG. 3, each image forming apparatus 3 has “image forming operation mode”, “standby mode”, “low power mode”, and “sleep” as operation modes in order to enhance the power saving effect during operation. Mode "is selectively set.
The image forming operation mode is an operating state in which the image output unit 32 executes an image forming operation on a sheet relating to image data. The standby mode is an operation state corresponding to on-demand with respect to input of image data, and shifts to an image forming operation mode according to the input of image data. In the image forming operation mode or a standby mode equivalent thereto, power is supplied from the power supply unit 50 to all the functional units in the image forming apparatus 3, and on-demand for input of image forming operation power, image data, and the like. Electric power for responding to is supplied.

The low power mode is an operation state set when, for example, there is no input of image data or the like even after the first period has elapsed. In the low power mode, power supply from the power supply unit 50 to at least an image forming engine (for example, a functional unit that performs an image forming operation including a fixing device) of the image output unit 32 is stopped. On the other hand, power supply to functional units other than the image forming engine of the image output unit 32 such as the control unit 10 and the communication unit 20 is continued.
The sleep mode is an operation state set when there is no input of image data or the like even after the second period, which is longer than the first period, has elapsed. In the sleep mode, only power supply from the power supply unit 50 to the communication unit 20 is continued, and power supply to other functional units including the CPU 101 of the control unit 10 is stopped. Thereby, the power saving effect higher in the sleep mode than in the low power mode can be obtained.

Subsequently, the communication unit 20 is an example of a communication unit and a communication device, and includes a transmission / reception unit 21 that transmits and receives signals, an A / D conversion unit 22 that converts an analog signal into a digital signal, and predetermined packets for transmission and reception A packet processing unit 23 that performs the above processing, an address information storage unit 24 that stores identification information (address information) of the image forming apparatus 3 itself, an encryption processing unit 25 that decrypts an encrypted packet, and a packet that is temporarily stored A packet storage unit 26 and a D / A conversion unit 27 that converts a digital signal into an analog signal are provided.
The transmission / reception unit 21 is an example of a reception unit (reception unit), is connected to the network 1, and receives a signal transmitted from the network 1. Then, the received signal is sent to the A / D converter 22. In addition, the signal analogized by the D / A converter 27 is transmitted to the transmission destination via the network 1.
The A / D conversion unit 22 is an example of a reception processing unit that performs a signal (packet) reception process, and converts a signal received by the transmission / reception unit 21 from the network 1 from an analog signal to a digital signal. As a result, the analog signal is converted into a packet composed of a data string represented by “0” and “1” and sent to the packet processing unit 23.

The packet processing unit 23 is an example of a reception processing unit that performs a signal (packet) reception process, and an image formation in which the destination address of the packet acquired from the A / D conversion unit 22 is stored in the address information storage unit 24. It is determined whether or not it matches the address information (identification information) such as the MAC (Medium Access Control) address of the device 3 itself. A packet whose destination address does not match the MAC address of the image forming apparatus 3 itself is discarded.
Further, the packet processing unit 23 sends a packet whose destination address matches the MAC address of the image forming apparatus 3 itself to the packet storage unit 26 and temporarily stores it.
Further, when the packet stored in the packet storage unit 26 is decrypted by the encryption processing unit 25, the packet processing unit 23 reads the packet decrypted by the encryption processing unit 25 from the packet storage unit 26, and the control unit 10 Send to. The packet processing unit 23 here functions as a signal transfer means for transferring a signal (packet).

  In addition, the packet processing unit 23 performs processing for adding address information such as the MAC address of the image forming apparatus 3 itself stored in the address information storage unit 24 to the packet created by the control unit 10. Further, the encryption processing unit 25 encrypts the packet created by the control unit 10 as necessary. Then, the address information and the like are added, and the encrypted packet is sent to the D / A conversion unit 27 as necessary.

The encryption processing unit 25 has a function of decrypting a packet encrypted with a predetermined secret key based on, for example, IPsec (Security Architecture for Internet Protocol), with a predetermined public key paired with the secret key. Further, it has a function of encrypting a packet created by the control unit 10 with this secret key.
That is, the encryption processing unit 25 acquires a packet destined for the image forming apparatus 3 itself stored in the packet storage unit 26 from the packet storage unit 26 and tries to decrypt it with a predetermined public key. If the packet can be decrypted with a predetermined public key, the packet is decrypted, and the decrypted packet is stored in the packet storage unit 26. Further, the packet processing unit 23 is notified that the packet has been decoded. On the other hand, if the packet cannot be decrypted with a predetermined public key, the packet processor 23 is notified that the packet is not decrypted.
The encryption processing unit 25 encrypts the packet created by the control unit 10 with a predetermined secret key in accordance with an instruction from the packet processing unit 23.

  The D / A converter 27 converts the packet acquired from the packet processor 23 from a digital signal to an analog signal. Then, the analog signal is sent to the transmission / reception unit 21.

  In the image forming apparatus 3 according to the present embodiment, when the sleep mode is set as the operation mode, power consumption is reduced and security is ensured when a signal transmitted via the network 1 is received. In addition, a plurality of communication modes having different security levels are set in the communication unit 20. That is, communication modes having different acceptance restriction levels for restricting acceptance of signals received by the transmission / reception unit 21 to a plurality of stages are set. Then, as an example of a plurality of communication modes set by the communication unit 20, the image forming apparatus 3 has a “communication prohibition mode” having the highest security level, an “encryption communication mode” having a moderate security level, and a security level having the highest security level. The three stages of “sleep communication mode” with low are applied. Then, the control unit 10, which is an example of an acceptance restriction setting unit, sets one of the “communication prohibition mode”, “encryption communication mode”, and “sleep communication mode” to the frequency of use of the image forming apparatus 3 ( The signal reception setting in the communication unit 20 is changed in accordance with the selected communication mode.

The control unit 10 classifies the use frequency of the image forming apparatus 3 by, for example, a time zone. For example, one day is divided into three time zones according to the frequency of use of the image forming apparatus 3. As a specific example, the first time zone is, for example, from 23:00 to 7:00 in the next morning, when the office where the image forming apparatus 3 is installed becomes unmanned and the frequency of use of the image forming apparatus 3 is extremely low. Also, the second time zone is set at a relatively low frequency of use of the image forming apparatus 3, for example, 7:00 to 9:00 and 21:00 to 23:00. Furthermore, the third time zone is, for example, from 9:00 to 21:00 when the image forming apparatus 3 is used relatively frequently.
And the control part 10 sets the communication mode from which a security level differs for every time slot | zone in the communication part 20 when the sleep mode is set as an operation mode. FIG. 4 is a diagram illustrating an example of a communication mode set in the communication unit 20 for each time period. As shown in FIG. 4, for example, when the sleep mode is set in the first time zone, the control unit 10 sets the communication mode in the communication unit 20 to the communication prohibition mode with the highest security level. To do. Further, when the sleep mode is set in the second time zone, the control unit 10 sets the communication mode in the communication unit 20 to an encryption communication mode having a moderately high security level. Further, when the sleep mode is set in the third time zone, the control unit 10 sets the communication mode in the communication unit 20 to the sleep communication mode with the lowest security level.

  In this case, each time zone may be configured / changed by the user. Different time zones may be set depending on the day of the week. In particular, different time zones may be set on holidays and holidays. At this time, the control unit 10 may be configured to automatically determine the day of the week or holiday based on an RTC (Real Time Clock) and a country identification code.

Subsequently, each communication mode set in the communication unit 20 will be described.
First, the communication prohibition mode set in the first time zone (23:00 to 7:00 the next morning) will be described. In the first time zone (23:00 to 7:00 in the next morning), the frequency of use of the image forming apparatus 3 is extremely low, and a print job is rarely transmitted. On the other hand, a polling packet for requesting transmission of status information of the image forming apparatus 3 using, for example, SNMP (Simple Network Management Protocol) is transmitted via the network 1. The status information here refers to various types of information necessary for image formation such as the size and type of paper set in the image forming apparatus 3 and information on the remaining amount of developer. In addition, since the office or the like where the image forming apparatus 3 is installed is unattended during the first time zone, for example, a function of leaking image data or the like from the external storage unit 60 in the image forming apparatus 3 or an external storage unit It is also a time zone that is unprotected against packets including software having a function of falsifying and erasing the image data in 60.
Therefore, in the first time zone (from 23:00 to 7:00 in the next morning), the control unit 10 blocks the communication mode in the communication unit 20 when the sleep mode is set between the network 1 and the communication unit 20. The communication prohibit mode is set to prohibit the acceptance of all packets.

That is, in the communication prohibition mode, power supply to the A / D conversion unit 22 provided in the communication unit 20 is stopped. As a result, all signals received by the transmission / reception unit 21 are not converted into digital signals by the A / D conversion unit 22, and the received signals are sent to the packet processing unit 23 and subsequent functional units. There is nothing. As a result, the communication unit 20 and the network 1 are disconnected. As a result, in the state where the sleep mode is set as the operation mode, the control unit 10 (CPU 101) is not activated even if a packet that does not need to be processed, such as a polling packet using SNMP, is transmitted. The power consumption of the image forming apparatus 3 is kept low.
In addition, since a packet including software having a leakage function of image data or the like, a software having a function of tampering / deleting image data or the like is not accepted, high security is ensured.
Note that when the A / D converter 22 cuts off the signal, power supply to a clock circuit that supplies a clock to the A / D converter 22 may be stopped.

Next, in the second time zone (7 o'clock to 9 o'clock and 21 o'clock to 23 o'clock) in which the encryption mode is set, relatively few print jobs are transmitted via the network 1. On the other hand, for example, a polling packet for requesting transmission of status information of the image forming apparatus 3 using SNMP is transmitted.
Therefore, in the second time zone (7 o'clock to 9 o'clock and 21 o'clock to 23 o'clock), the control unit 10 determines the communication mode in the communication unit 20 when the sleep mode is set as an encrypted signal. Set the encryption mode to accept only.

  That is, in the encryption mode, power is supplied to the communication unit 20 and functional units such as the A / D conversion unit 22, the packet processing unit 23, and the cryptographic processing unit 25 are operated. As a result, a signal from a specific client device 2 that transmits a packet encrypted with a secret key that is paired with a predetermined public key provided in the encryption processing unit 25 is accepted. On the other hand, a packet that is not encrypted with a private key that is paired with a predetermined public key provided in the cryptographic processing unit 25 is not accepted. Thereby, a certain degree of high security is ensured, and only a print job from a specific client device 2 is executed.

FIG. 5 is a flowchart illustrating an example of a procedure of packet processing performed in the communication unit 20 when the control unit 10 sets the encryption communication mode in the communication unit 20. In the communication unit 20 in which the encryption communication mode is set, when the transmission / reception unit 21 receives a signal (step 101), the received signal is converted into a packet including a data string digitized by the A / D conversion unit 22. Conversion is performed (step 102). Then, the packet is sent to the packet processing unit 23 (step 103).
The packet processing unit 23 determines whether or not the destination MAC address described in the MAC header of the packet for the acquired packet matches the MAC address of the image forming apparatus 3 itself stored in the address information storage unit 24 (step). 104). If the destination MAC address of the packet matches the MAC address of the image forming apparatus 3 itself (step 105), the packet is stored in the packet storage unit 26 (step 106). On the other hand, if the destination MAC address of the packet does not match the MAC address of the image forming apparatus 3 itself (step 105), the packet is discarded (step 107).

  Next, when the packet is stored in the packet storage unit 26, the encryption processing unit 25 reads the packet stored in the packet storage unit 26 (step 108). Then, the encryption processing unit 25 attempts to decrypt the packet using a predetermined public key (step 109). When the packet can be decrypted with a predetermined public key (step 110), the packet is decrypted, and the decrypted packet is stored in the packet storage unit 26 (step 111). Further, it notifies the packet processing unit 23 that the packet has been decoded (step 112). On the other hand, when the packet cannot be decrypted with the predetermined public key (step 110), the packet processor 23 is notified that the packet is not decrypted (step 113).

When receiving the notification that the packet has been decoded in step 112, the packet processing unit 23 generates a return instruction signal that instructs the control unit 10 (CPU 101) to start supplying power from the power supply unit 50. Then, the control unit 10 is returned from the sleep mode (step 114). After returning the control unit 10 from the sleep mode, the packet processing unit 23 reads the decoded packet from the packet storage unit 26 (step 115), and sends the read packet to the control unit 10 (step 116). The control unit 10 performs predetermined processing on the transmitted packet. For example, if the packet is a print job, the packet (print job) is sent to the image processing unit 30.
On the other hand, when the notification that the packet is not decoded is received in Step 113, the packet processing unit 23 deletes the packet stored from the packet storage unit 26 (Step 117).

Subsequently, in the third time zone (9:00 to 21:00) in which the sleep communication mode is set, for example, a polling packet for requesting transmission of status information of the image forming apparatus 3 using SNMP is transmitted. The use frequency of the forming apparatus 3 is high, and many print jobs for the image forming apparatus 3 are transmitted.
Therefore, in the third time zone (9:00 to 21:00), the control unit 10 sets the communication mode in the communication unit 20 when the sleep mode is set to all the transmissions to the image forming apparatus 3. Set to sleep communication mode to accept signals.

  That is, in the sleep communication mode, power is supplied to all functional units in the communication unit 20 except the cryptographic processing unit 25, and functional units other than the cryptographic processing unit 25 are operated. As a result, the packet processing unit 23 sends all packets whose destination MAC address matches the MAC address of the image forming apparatus 3 itself stored in the address information storage unit 24 to the control unit 10. As a result, the communication unit 20 transmits the unencrypted packet transmitted from the client device 2 connected to the network 1 in addition to the packet encrypted with the predetermined secret key transmitted from the specific client device 2. Also accept polling packets.

  In this way, in the sleep communication mode, all packets from the client apparatus 2 transmitted to the image forming apparatus 3 are accepted. However, in the third time zone (9:00 to 21:00), the frequency of use of the image forming apparatus 3 is high and the time during which the sleep mode is set in the image forming apparatus 3 is small. In addition, there is a high possibility that a packet from the client apparatus 2 transmitted to the image forming apparatus 3 is a print job. Therefore, when the sleep mode is set in the image forming apparatus 3, even if all signals from the client apparatus 2 transmitted to the image forming apparatus 3 are accepted, this is a factor that increases the power consumption. It's hard to fall. On the other hand, for example, if only encrypted packets are accepted by setting the encryption communication mode even in the third time zone, the amount of packets to be decrypted increases because the use frequency of the image forming apparatus 3 is high. Processing time. In addition, the power consumption in the cryptographic processing unit 25 increases. Therefore, when the sleep mode is set in the third time zone, the sleep communication mode is set in the communication unit 20. In this case, the power consumption in the image forming apparatus 3 is reduced by setting the operation mode to the sleep mode.

FIG. 6 is a flowchart illustrating an example of a procedure of packet processing performed in the communication unit 20 when the control unit 10 sets the sleep communication mode in the communication unit 20. In the communication unit 20 in which the sleep communication mode is set, when the transmission / reception unit 21 receives a signal (step 201), the received signal is converted into a packet including a data string digitized by the A / D conversion unit 22. Conversion is performed (step 202). Then, the packet is sent to the packet processing unit 23 (step 203).
The packet processing unit 23 determines whether or not the destination MAC address described in the MAC header of the packet for the acquired packet matches the MAC address of the image forming apparatus 3 itself stored in the address information storage unit 24 (step). 204). If the destination MAC address of the packet matches the MAC address of the image forming apparatus 3 itself (step 205), the packet is stored in the packet storage unit 26 (step 206). On the other hand, if the destination MAC address of the packet does not match the MAC address of the image forming apparatus 3 itself (step 205), the packet is discarded (step 207).

  Next, when the packet is stored in the packet storage unit 26, the packet processing unit 23 generates a return instruction signal instructing the start of power supply from the power supply unit 50 to the control unit 10 (CPU 101). Is returned from the sleep mode (step 208). After the control unit 10 returns from the sleep mode, the packet processing unit 23 reads the packet from the packet storage unit 26 (step 209), and sends the read packet to the control unit 10 (step 210). The packet processing unit 23 here functions as a signal transfer means for transferring a signal (packet). The control unit 10 performs predetermined processing on the transmitted packet. For example, if the packet is a print job, the packet (print job) is sent to the image processing unit 30. If the packet is encrypted, the control unit 10 decrypts it with a predetermined public key.

As described above, in the image forming apparatus 3 of the present embodiment, when the operation mode is set to the sleep mode, the security level varies depending on the time zone corresponding to the use frequency of the image forming apparatus 3 in the communication unit 20. Set multiple communication modes. Thereby, the power consumption in the image forming apparatus 3 is reduced, and the security of the image forming apparatus 3 when a signal transmitted via the network 1 is received is ensured.
The communication mode set in the communication unit 20 by the control unit 10 is not limited to the “communication prohibited mode”, the “encrypted communication mode”, and the “sleep communication mode”, and any communication mode having different signal reception settings. May be set.

  By the way, in the control part 10 of this Embodiment, the use frequency of the image forming apparatus 3 is divided by a time zone, for example, and the case where each communication mode corresponding to each time slot divided in the communication part 20 is set is demonstrated. did. However, as a method of making each communication mode correspond to the frequency of use of the image forming apparatus 3, for example, the image forming apparatus 3 measures the transmission frequency of a print job transmitted to itself, and the measured transmission frequency of the print job is used. Accordingly, the communication mode setting in the communication unit 20 may be changed. For example, when the print job transmission frequency is high, the communication unit 20 is set to the sleep communication mode when the sleep mode is set. On the other hand, when the sleep mode in which the print job is not transmitted for, for example, one hour is continued, the communication unit 20 is set to the communication inhibition mode.

  In addition, when the control unit 10 sets the communication unit 20 to the communication prohibition mode or the encryption communication mode, the control unit 10 sets the communication prohibition mode or the encryption communication mode for the client device 2 connected to the network 1. You may comprise so that the notification to the effect may be performed. Thus, for example, when the communication prohibit mode is set, the client apparatus 2 recognizes that the image forming apparatus 3 does not accept the print job, and the print job is transmitted while avoiding the communication prohibit mode setting time. Done. For example, when the encryption communication mode is set, it is understood that the image forming apparatus 3 only accepts an encrypted print job in the client apparatus 2, and the client apparatus 2 has a predetermined secret key. Thus, the encrypted print job is transmitted.

Further, the client device 2 may be configured to instruct the control unit 10 of the image forming apparatus 3 to set the communication prohibition mode and the encryption communication mode. In that case, the control unit 10 of the image forming apparatus 3 may accept an instruction to set the communication prohibition mode or the encryption communication mode, for example, on condition that user authentication is performed by inputting a user name or a password.
Furthermore, the input of an input device (not shown) such as a touch panel of the image forming apparatus 3 is forcibly set in the communication prohibit mode or the encryption communication mode, or the communication prohibit mode or the encryption communication mode is forced to the sleep communication mode. It may be configured to make a general change. Also in that case, the control unit 10 may accept an input of setting / changing of the communication prohibition mode and the encryption communication mode, for example, on the condition of user authentication by inputting a user name and a password. Further, input of setting / changing of the communication prohibition mode and the encryption communication mode may be accepted on condition that user authentication is performed by a security card or the like.
The user authentication as described above is performed by the control unit 10 that functions as an example of a user authentication unit.
Then, setting instructions for the communication prohibition mode and the encryption communication mode from the client device 2, the forced setting of the communication prohibition mode or the encryption communication mode from the input device (not shown), and the sleep communication mode from the communication prohibition mode or the encryption communication mode. When a forced change is made, from the viewpoint of ensuring security, history information such as setting instruction time, setting / change contents, and user name is logged in the NVM 104 of the control unit 10 ( log) may be stored. In that case, from the viewpoint of ensuring security, the log (history information) stored in the NVM 104 is disclosed only to the user having the management authority of the network 1, and only the user having the management authority deletes the log. It may be configured.

  Further, when the image forming apparatus 3 is provided with a facsimile function or a copy function, the operation of the facsimile function or the copy function may be limited in accordance with the communication mode set in the communication unit 20. Good. For example, when the communication prohibition mode is set in the communication unit 20, the operation of the facsimile function or the copy function is set to be stopped.

In addition, when the communication unit 20 returns from the communication prohibition mode to the encryption communication mode or the sleep communication mode, the control unit 10 that functions as the identification information notification unit transmits an ARP (Address Resolution Protocol) obvious from the communication unit 20 to the network 1. You may comprise so that a packet may be transmitted. That is, the image forming apparatus 3 itself transmits an ARP packet for obtaining a MAC address, which is an example of identification information, from an IP (Internet Protocol) address, which is an example of identification information of the image forming apparatus 3 itself. A MAC address is returned to the image forming apparatus 3 itself. Thereby, the client apparatus 2 on the network 1 reads the ARP packet transmitted via the network 1. When the MAC address of the image forming apparatus 3 has been changed, the client apparatus 2 rewrites the MAC address of the image forming apparatus 3.
Further, when the communication unit 20 returns from the communication prohibition mode to the encryption communication mode or the sleep communication mode, the control unit 10 functioning as the identification information notification unit sends the communication unit 20 to the gateway 4 connected to the network 1. You may comprise so that the ARP packet which described the IP address of the gateway 4 may be transmitted. That is, by transmitting an ARP packet for obtaining the MAC address of the gateway 4 to the network 1, the gateway 4 returns the MAC address of the gateway 4 to the image forming apparatus 3. At that time, the ARP table in the gateway 4 is rewritten by the gateway 4 reading the MAC address and IP address of the image forming apparatus 3 described in the ARP packet.

  As described above, in the image forming apparatus 3 of the present embodiment, when the sleep mode is set as the operation mode, the communication unit 20 has a plurality of security levels different from each other according to the use frequency of the image forming apparatus 3. Set the communication mode. Thereby, the power consumption in the image forming apparatus 3 is reduced, and the security of the image forming apparatus 3 when a signal transmitted via the network 1 is received is ensured.

1 is a schematic configuration diagram illustrating an example of a communication system to which an image forming apparatus according to an exemplary embodiment is connected. 1 is a block diagram illustrating a configuration of an image forming apparatus. It is a figure explaining the operation mode set with an image forming apparatus. It is the figure which showed an example of the communication mode set to a communication part for every time slot | zone. It is the flowchart which showed an example of the procedure of the packet process performed in a communication part, when a control part sets encryption communication mode to a communication part. It is the flowchart which showed an example of the procedure of the packet process performed in a communication part, when a control part sets sleep communication mode to a communication part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Network, 2 (2A-2C) ... Client apparatus, 3 (3A-3C) ... Image forming apparatus, 4 ... Gateway, 10 ... Control part, 20 ... Communication part, 21 ... Transmission / reception part, 22 ... A / D conversion , 23 ... packet processing unit, 24 ... address information storage unit, 25 ... encryption processing unit, 26 ... packet storage unit, 27 ... D / A conversion unit, 30 ... image processing unit, 32 ... image output unit, 101 ... CPU , 102 ... RAM, 103 ... ROM, 104 ... NVM, 105 ... interface (I / F)

Claims (18)

A receiving unit for receiving a signal transmitted via a communication line;
An acceptance restriction setting means for setting one acceptance restriction level among a plurality of acceptance restriction levels for restricting acceptance of the signal received by the receiving unit;
An acceptance processing means for performing acceptance processing of the signal according to the acceptance restriction level set by the acceptance restriction setting means ,
The communication apparatus according to claim 1, wherein the acceptance restriction level set by the acceptance restriction setting means is realized by changing a power supply state to the acceptance processing means . The acceptance restriction level includes a communication prohibit mode that is a first communication mode that maintains low power consumption, an encryption mode that is a second communication mode, and a sleep communication mode that is a third communication mode. The communication device according to claim 1. The communication apparatus according to claim 2, wherein the communication prohibition mode cuts off a network and the reception unit and prohibits reception of all the signals. 3. The communication apparatus according to claim 2, wherein the encryption mode accepts only an encrypted signal. The communication apparatus according to claim 2, wherein the sleep communication mode accepts all signals transmitted to the communication apparatus.   The communication apparatus according to claim 1, wherein the acceptance restriction setting unit sets the acceptance restriction level different for each predetermined time period with respect to the signal received by the reception unit.   The acceptance restriction setting means includes acceptance refusal of all the signals received by the receiving unit, acceptance acceptance of the signal encrypted with a predetermined secret key, and acceptance acceptance of all the signals. The communication apparatus according to claim 1, wherein an acceptance restriction level is set. The acceptance restriction setting means is configured to change a setting of the acceptance restriction level based on an instruction from a user, and to authenticate the user who performs the setting change of the acceptance restriction level with respect to the acceptance restriction setting means. In addition,
The communication apparatus according to claim 1, wherein the acceptance restriction setting unit changes the setting of the acceptance restriction level when there is an instruction from the user authenticated by the user authentication unit.   The communication apparatus according to claim 1, further comprising a history information storage unit that stores history information when the setting of the acceptance restriction level is changed by the acceptance restriction setting unit. On the computer,
A receiving function for receiving a signal transmitted via a communication line;
An acceptance restriction setting function for setting one acceptance restriction level among a plurality of acceptance restriction levels for restricting acceptance of the received signal;
An acceptance processing function for performing acceptance processing of the signal according to the set acceptance restriction level ;
The program according to claim 1, wherein the acceptance restriction level set by the acceptance restriction setting function is realized by changing a power supply state to the acceptance processing function . 11. The program according to claim 10, wherein the function of setting the acceptance restriction level has a function of setting the acceptance restriction level that differs for each predetermined time period with respect to the received signal. A function of changing the setting of the acceptance restriction level based on an instruction from the user, and a function of authenticating the user of changing the setting of the acceptance restriction level;
11. The program according to claim 10 , wherein the function for changing the setting of the acceptance restriction level changes the setting of the acceptance restriction level when there is an instruction from the authenticated user. 11. The program according to claim 10 , further comprising a function of storing history information when the setting of the acceptance restriction level is changed in a history information storage unit. A communication unit connected to the communication line and performing signal communication with the communication line;
An image forming unit that forms an image based on the image data when the signal received by the communication unit is image data;
A signal processing unit for processing the signal received by the communication unit,
The communication unit is
A receiving unit that receives a signal transmitted via the communication line;
An acceptance restriction setting means for setting one acceptance restriction level among a plurality of acceptance restriction levels for restricting acceptance of the signal received by the receiving unit;
An acceptance processing means for performing acceptance processing of the signal according to the acceptance restriction level set by the acceptance restriction setting means;
Signal transfer means for transferring the signal permitted to be accepted by the acceptance processing means to the signal processing unit ;
The image forming apparatus according to claim 1, wherein the acceptance restriction level set by the acceptance restriction setting means is realized by changing a power supply state to the acceptance processing means and the signal transfer means . The acceptance restriction setting unit sets the acceptance restriction level of the signal when the operation state is shifted to an operation state where power supply to a control unit that controls the operation of each unit provided in the image forming apparatus is stopped. The image forming apparatus according to claim 14, wherein: The image forming apparatus according to claim 14, wherein the acceptance restriction setting unit sets the acceptance restriction level according to a frequency of image formation in the image forming unit. 17. The image formation according to claim 16, wherein the acceptance limit setting unit classifies the frequency of the image formation in the image forming unit by a time zone, and sets the acceptance limit level according to the time zone. apparatus. Identification information notification for notifying the communication line of identification information of the image forming apparatus when the acceptance restriction setting means cancels the acceptance restriction level for refusing acceptance of all the signals received by the receiving unit. 15. The image forming apparatus according to claim 14 , further comprising means.

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