JP2010125692A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve energy saving effect in an environment utilized from a host device on a network. <P>SOLUTION: In an image forming apparatus 1, a CPU 12 transmits the equipment information of its own apparatus saved in a RAM 13 to a host device 2, or the CPU 12 detects the equipment information of its own apparatus to transmit to the host device 2 when receiving inquiries about the equipment information of its own apparatus from the host device 2 in case of a first on-state of a power source and a second on-state of a power source. Further, a network control 15 transmits the equipment information of its own apparatus saved in a ROM 14 referable even in a third on-state of a power source to the host device 2, or transmits that the network control 15 can not transmit the equipment information of its own apparatus to the host device 2 when receiving inquiries about the equipment information of its own apparatus from the host device 2 in case of the third on-state of a power source. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus including a facsimile machine, a printer, a copying machine, and a multifunction machine.

Conventionally, in the energy saving mode, when an external device connected via a network inquires about the device information of the own device, the sub CPU detects the device information of the own device and notifies the external device (for example, the image forming device) And Patent Document 1).
In addition, the device information of the own device is stored in the storage means before shifting to the energy saving state, and when there is an inquiry about the device information of the own device from an external device connected via the network in the energy saving state, the above There has been an image forming apparatus (for example, see Patent Document 2) that notifies device information stored in a storage unit to an external apparatus.
JP 2004-34488 A JP 2005-119203 A

However, when there is an inquiry about the device information of the device itself in the energy saving state, there is a problem that the energy saving effect cannot be obtained by returning from the energy saving state to the normal state each time.
Further, even if only the sub CPU operates and responds in the energy saving state as in the technique described in Patent Document 1, the power consumption is increased by driving the sub CPU, and the energy saving effect is not obtained. There was a problem.

Further, as in the technique described in Patent Document 2, when there is an inquiry about the device information of the own device in the energy saving state, the device information stored in the storage unit before returning to the energy saving state is returned. Then, since this device information is stored in the storage means before shifting to the energy saving state, the transition time to energy saving is delayed.
For example, if device information is stored in a RAM with high power consumption as a storage means, the power of the RAM cannot be reduced, and further power consumption cannot be reduced. Manufacturing costs also increase.

Furthermore, in order to respond to all device information inquiries, a RAM having a large RAM capacity for storing all the device information is required. The forming apparatus cannot reduce power consumption unless it operates with a small amount of RAM.
Also, in order to acquire all device information and store it in the storage means before shifting to the energy saving state, the time in the energy saving state is shortened by the time required to acquire and store the device information.
The present invention has been made in view of the above points, and an object thereof is to improve the energy saving effect in an environment used from a host device on a network.

  In order to achieve the above-mentioned object, the present invention achieves the above object by receiving means for receiving image data from a host device via a network, image forming means for forming an image based on image data received by the receiving means, and image forming In an image forming apparatus including a control unit that controls image formation by the unit, power is supplied to the image forming unit and the control unit in a first power-on state, and power is supplied to the control unit. In the second power-on state in which power supply to the image forming unit is cut off, the control unit receives the inquiry about the device information of the own device from the host device. The device information of the own device stored in the first storage means included in the means is transmitted to the host device, or the control means detects the device information of the own device and In the third power-on state in which the power supply to the image forming unit and the control unit is both cut off, when an inquiry about the device information of the own device is received from the host device, The receiving unit cannot transmit the device information of the own device stored in the second storage unit that can be referred to even in the third power-on state, or the receiving unit cannot transmit the device information of the own device. There is provided an image forming apparatus configured to transmit information to the host device.

  A receiving unit that receives image data from the host device via the network; an image forming unit that forms an image based on the image data received by the receiving unit; and a second unit that controls image formation by the image forming unit. In the image forming apparatus having one control means, the power is supplied to the first control means in the first power-on state in which power is supplied to the image forming means and the first control means. In the second power-on state in which the supply of power to the image forming unit is interrupted, the first control unit receives the first device information query from the host device when the first control unit receives an inquiry about the device information of the host device. The device information of the own device stored in the first storage means included in the control means is transmitted to the host device, or the first control means detects the device information of the own device and the host In the third power-on state in which the power supply to the image forming unit and the first control unit are both cut off, when an inquiry about the device information of the own device is received from the host device The second control means not included in the third power-on state transmits the device information of the own device stored in the second storage means that can be referred to even in the third power-on state to the host device. Alternatively, the image forming apparatus may be configured to transmit information indicating that the apparatus information of the own apparatus cannot be transmitted to the host apparatus.

Further, in the image forming apparatus as described above, the device information that is stored in advance in the second storage unit and is transmitted in response to the inquiry from the host device in the third power-on state is the MIB object. Good.
Of the MIB objects stored in advance in the second storage unit, information indicating the state of the image forming apparatus may be fixed to a value that the host apparatus does not determine as an error.
Further, the MIB object stored in advance in the second storage means may be limited to information that cannot be rewritten from the host device.
The response contents to the inquiry of the device information from the host device are the response contents in the first power-on state or the second power-on state and the response contents in the third power-on state. It should be different.

Further, when the host device requests rewriting of device information stored in the second storage means in the third power-on state, an error indicating that writing cannot be performed is returned to the host device. Good.
Further, when the host device requests a part of the device information stored in the second storage means, it is preferable to return information indicating that the requested information does not exist to the host device. .
Further, in the third power-on state, if there is an inquiry about the device information of the own device from a host device registered in advance in the own device, the second power-on state is changed from the third power-on state. Alternatively, it is preferable to shift to the first power-on state.
The host device registered in advance in the own device may be registered by the IP address input from the own device.
Furthermore, the host device registered in advance in the own device may be registered by an IP address input from another host device connected via the network.

  The image forming apparatus according to the present invention can improve the energy saving effect in an environment used from a host device on a network.

Hereinafter, the best mode for carrying out the present invention will be specifically described with reference to the drawings.
[Example 1]
1 to 3 are block diagrams showing a functional configuration of Embodiment 1 of the image forming apparatus according to the present invention.
The image forming apparatus 1 is an apparatus including a facsimile machine, a printer, a copier, and a multifunction machine, and is connected to a host apparatus 2 including a personal computer via a network 3 so as to be capable of data communication.

The image forming apparatus 1 includes a controller 10 and an image forming unit 20, and the image forming unit 20 includes a plotter 21 and a scanner 22.
The plotter 21 is a printing device that prints and outputs an image based on image data as a result of image processing from the controller 10 on a medium such as paper.
The scanner 22 is an image reading device that scans an image of information recorded on a medium such as paper and transfers the image data to the controller 10.
The controller 10 includes a power supply control unit 11, a CPU 12, a RAM 13, a ROM 14, a network control unit 15, an image processing unit 16, and an operation unit 17.
The power supply control unit 11 controls supply and cut-off of power by a power supply (not shown because it is publicly known) to the image forming unit 20 by the first power supply control signal, and the CPU 12, RAM 13, and image processing unit by the second power supply control signal 16 and the operation unit 17, and controls the supply and interruption of power by the power source to the control part A that controls the image forming unit 20.

The CPU 12 is a microcomputer that controls each unit mounted on the controller 10 and the plotter 21 and the scanner 22 of the image forming unit 20, and functions as the control unit.
The RAM 13 is a volatile memory that provides a work area in which the CPU 12 reads and writes information for performing various control operations, and stores a first status including an MIB. The function of the first storage unit Fulfill.
The ROM 14 is a non-volatile memory in which a second status including a program and MIB, which are procedures for the CPU 12 to perform various control operations, is stored, and functions as the second storage unit.

The network control unit 15 is connected to the network 3 that is a communication network including a local area network and the Internet, and functions as a network control unit that controls data communication with the host device 2 via the network 3.
The image processing unit 16 functions as an image processing unit that forms image data as original information to be output to the plotter 21 of the image forming unit 20.
The operation unit 17 is an input display device including an input device that receives input of user operation information and a display device that displays various types of information to the user.
In the first embodiment, the configuration example in which the operation unit 17 is provided in the control portion A of the controller 10 is shown. However, for example, the image forming unit 20 and other portions are provided outside the control portion A. You may do it.

  In the image forming apparatus 1 of the first embodiment, the program executed by the CPU 12 is stored in the ROM 14 which is a nonvolatile memory. However, in order to execute the program at high speed, the program stored in the ROM 14 is volatile. It moves to RAM13 which is memory and performs. The ROM 14 can be directly accessed from the network control unit 15.

In FIG. 1, the power from the power source is supplied to all the parts inside the image forming apparatus 1 of the first embodiment, that is, the power is supplied to each part in the image forming unit 20 and the control part A. The first power-on state is shown.
In the image forming apparatus 1 according to the first embodiment, the CPU 12 decodes all packets received from the host device 2 via the network 3 in the first power-on state.
When the decrypted packet is an inquiry about the device information of the own device, if the device information is information stored in the RAM 13 in advance, the CPU 12 displays the first status including the MIB stored in the RAM 13. Read and output a response packet including the first status to the network control unit 15.
Then, the network control unit 15 transmits the response packet received from the CPU 12 to the host device 2 via the network 3.

Further, the CPU 12 has the device information inquired by the packet received from the host device 2 being information including the state of the image forming apparatus 1, for example, the state of the paper and the state of the toner, and information not stored in the RAM 13 in advance. In this case, necessary device information is acquired from the image forming unit 20 via the image processing unit 16.
The device information is temporarily stored in the RAM 13 and processed into information conforming to the MIB object standard, and a response packet including the processed information is output to the network control unit 15.
Then, the network control unit 15 transmits a response packet from the CPU 12 to the host device 2 via the network 3.

FIG. 2 shows a second power-on state in which power is supplied to the control portion A of the image forming apparatus 1 of Embodiment 1 but power supply to the image forming unit 20 is interrupted. ing.
In the image forming apparatus 1 according to the first exemplary embodiment, the CPU 12 instructs the power supply control unit 11 to cut off the power supply to the image forming unit 20 when there is no job using the image forming unit 20 for a predetermined period of time. The first power instruction signal is sent.
When the power supply control unit 11 receives the first power supply instruction signal from the CPU 12, the power supply from the power supply is cut off to the image forming unit 20 by the first power supply control signal.
Thus, the image forming apparatus 1 shifts to the energy saving state. The rectangular frame of the image forming unit 20 in FIG. 2 is hatched to indicate that the power is cut off.

In the second power-on state, the CPU 12 decodes all packets received from the host device 2 via the network 3.
When the decrypted packet is an inquiry about the device information of the own device, if the device information is information stored in the RAM 13 in advance, the CPU 12 displays the first status including the MIB stored in the RAM 13. Read and output a response packet including the first status to the network control unit 15.
Then, the network control unit 15 transmits a response packet from the CPU 12 to the host device 2 via the network 3.

Further, the CPU 12 has the device information inquired by the packet received from the host device 2 being information including the state of the image forming apparatus 1, for example, the state of the paper and the state of the toner, and information not stored in the RAM 13 in advance. In this case, a first power supply instruction signal for instructing the power supply control unit 11 to resume power supply to the image forming unit 20 is sent.
When the power supply control unit 11 receives the first power supply instruction signal from the CPU 12, the power supply control unit 11 resumes power supply from the power supply to the image forming unit 20 by the first power supply control signal.
Thus, the image forming apparatus 1 returns from the energy saving state to the normal state in which image formation is possible.

When the CPU 12 confirms that the image forming unit 20 has returned from the energy saving state, the CPU 12 acquires necessary device information from the image forming unit 20 via the image processing unit 16, temporarily stores the device information in the RAM 13, and stores the MIB object. To the network control unit 15 and output a response packet including the processed information.
Then, the network control unit 15 transmits a response packet from the CPU 12 to the host device 2 via the network 3.
Thereafter, when the state in which there is no job using the image forming unit 20 continues for a predetermined time, the CPU 12 instructs the power supply control unit 11 to cut off the power supply to the image forming unit 20. Send a signal.
When the power supply control unit 11 receives the first power supply instruction signal from the CPU 12, the power supply from the power supply is again cut off to the image forming unit 20 by the first power supply control signal, and the image forming apparatus 1 again receives the second power supply signal. Return to the power-on state.

FIG. 3 shows a third power-on state that shifts when certain conditions are satisfied after the transition to the second power-on state in the image forming apparatus 1 according to the first embodiment.
For example, when a job that needs to be operated does not occur for a certain period in any of the units including the image forming unit 20 of the image forming apparatus 1 in the second power-on state, the CPU 12 instructs the power control unit 11 to The first power supply instruction signal for instructing to cut off the power supply to the control part A is sent.
When receiving the first power instruction signal from the CPU 12, the power control unit 11 cuts off the power supply from the power source to each part of the control part A by the second power control signal, and also controls the CPU 12, RAM 13, and image of the control part A. The network control unit 15 is notified that the power supply to each unit of the processing unit 16 and the operation unit 17 has been cut off.
In this way, the image forming apparatus 1 shifts to the third power-on state (sleep state).

In the third power-on state, the network control unit 15 decodes all packets received from the host device 2 via the network 3. However, the packets that can be decoded by the network control unit 15 are a few types of packets including, for example, a pin (Ping), an arp (ARP), and a simple network management protocol (SNMP).
The ROM 14 stores a second status for returning a fixed value in advance in response to an inquiry from the host device 2.

If the packet received via the network 3 cannot be decoded, the network control unit 15 sends a second power supply instruction signal for instructing the power supply control unit 11 to resume power supply to the control part A.
When receiving the second power supply instruction signal from the network control unit 15, the power supply control unit 11 resumes power supply to the CPU 12, the RAM 13, the image processing unit 16, and the operation unit 17 of the control part A by the second power supply control signal.
Thereafter, the CPU 12 whose power supply has been resumed receives and decodes the packet that could not be decoded from the network control unit 15, and performs processing according to the contents of the packet.
When the packet received from the host device 2 via the network 3 is an SNMP packet for inquiring about the device information of the own device, a response packet including an MIB object stored in advance in the ROM 14 is sent via the network control unit 15. To the host device 2.

When the inquiry about the device information inquires about the state of the image forming apparatus 1, for example, the state of paper or toner, the MIB object stored in the ROM 14 shows an error regardless of the actual state of the image forming apparatus 1. Since a value that does not generate a warning is set, the process of resuming the power supply to the control part A and the image forming unit 20 of the image forming apparatus 1 and acquiring the actual state of the image forming apparatus is not performed.
Further, when the packet transmitted by the host device 2 requests to rewrite the MIB object, the host device 2 does not rewrite the ROM 14 at all and responds to the host device 2 that the MIB object cannot be rewritten. Is transmitted by the network control unit 15.

Further, when the MIB object corresponding to the object identifier (OID) of the SNMP packet indicated by the packet transmitted by the host device 2 is not stored in the ROM 14, the network control unit 15 determines that the host device 2 In response, a notification that the MIB object is not supported is transmitted.
In this way, even if the device information inquiry packet is received from the host device 2 when the third power-on state (sleep state) is entered, it is not necessary to cancel the sleep state of the image forming apparatus 1. The power consumption of the image forming apparatus 1 can be reduced.

Further, rewriting the MIB object with the SNMP packet is regarded as an error.
Accordingly, it is possible to prevent further transmission of the SNMP packet from the host device 2 in advance, and it is possible to prevent the return to the second power-on state for rewriting the MIB object and to maintain the low power consumption state. can do.
Further, when an inquiry about an MIB object not stored in the ROM 14 is received, a response indicating that it is not supported is transmitted.
Therefore, it becomes possible to prevent further transmission of the SNMP packet from the host apparatus 2 in advance, and to prevent returning to the second power-on state for referring to the MIB object, and to maintain the low power consumption state. can do.

In addition, an error is transmitted to the originally rewritable MIB object in the third power-on state.
Furthermore, when an MIB object that should originally be supported but is not stored in the ROM 14 in the third power-on state, an error or no support is returned.
Therefore, the host apparatus 2 can recognize that the image forming apparatus 1 connected to the network 3 is in the third power-on state (sleep state).

If the image forming apparatus connected to the network is notified that it has shifted to the low power consumption mode by unicast or multicast and has returned, the notification can be handled even if such notification is made. A host device that is effective for the host device but cannot handle the notification is in a state of receiving an unnecessary packet that cannot be processed even if the notification packet is received.
As a result, if the image forming device frequently switches to and returns to the low power consumption mode, unnecessary packets will fly over the network, causing unnecessary increase in network traffic and network performance. It will be a factor to reduce.

The image forming apparatus 1 according to the first embodiment responds only to the host apparatus that has transmitted the packet.
Further, the response is originally limited to the category supported by the host device, but if the host device understands the meaning of the response, the image forming apparatus is in the sleep state. Thus, it is possible to perform control to prevent transmission of a packet that causes the host apparatus to cancel the sleep state of the image forming apparatus inadvertently without generating unnecessary packets on the network.

In an image forming apparatus to which the present invention is not applied, even if the image forming apparatus is connected to a network and is in a sleep state, a packet for an OS including Windows (registered trademark) to periodically acquire a status about the state of the apparatus To send a status response every time.
Then, the image forming apparatus connected to the network returns from the sleep state even when there is no job such as printing, and power consumption increases.
In order to respond to all device information inquiries, it is necessary to store the MIB database on the RAM, and in that case, a large amount of RAM capacity is required.
Then, an image forming apparatus that wants to reduce power consumption during sleep cannot reduce power consumption unless it operates with a small amount of RAM.
Furthermore, if device information is acquired and stored in the storage device during sleep, the sleep time is shortened by the time required for acquiring and storing the device information.

In the image forming apparatus according to the first embodiment, the return to the normal state can be prevented for the response to the device information inquiry at the time of sleep, so that the sleep state can be secured for a long time.
Further, since the MIB RAM area can be reduced, it is possible to further reduce power consumption.
Furthermore, since device information is not acquired immediately before the transition to sleep, it is possible to immediately transition to sleep.

[Example 2]
4 to 6 are block diagrams showing a functional configuration of the image forming apparatus according to the second embodiment of the present invention. Portions common to FIGS. 1 to 3 are denoted by the same reference numerals.
In the image forming apparatus 1 according to the second embodiment, in addition to the CPU (first control unit) 12, a newly provided CPU (second control unit) 31 is stored in the ROM (second storage unit) 14. Is different from the above-described first embodiment in that a response to the device information inquired of the host apparatus 2 is made via the network control unit 15.
In addition, the CPU 31 instructs the power supply control unit 11 to cut off the supply of power to the image forming unit 20 and the control part B and to restart the supply by the power supply instruction signal.
Further, the control portion B is provided with a ROM (third storage means) 30 referred to by the CPU 12, and a RAM (fourth storage means) 32 used as a work area by the CPU 31 during operation.

That is, in order to change from the first power-on state to the second power-on state, the CPU 12 notifies the CPU 31 of a request for changing the power-on state.
The CPU 31 that has received the notification notifies the power control unit 11 of a power instruction signal.
Then, the first power control signal operates to cut off the power supply from the power source to the image forming unit 20 and shift to the second power-on state.
Similarly, the transition from the second power-on state to the third power-on state causes the CPU 31 that has received the notification from the CPU 12 to notify the power control unit 11 of the power instruction signal. Then, the third power-on state is entered in the same manner as described above.
Further, the transition from the third power-on state to the second power-on state is performed when the CPU 31 that detects the establishment of the transition condition notifies the power control unit 11 of a power instruction signal.
In addition, the transition to the first power-on state is performed by the CPU 12 that has detected that the condition that requires the transition to the first power-on state is established, and the CPU 31 that has received the notification notifies the power control unit 11. This is done by notifying the power supply instruction signal.

In the image forming apparatus 1 according to the second embodiment, the program executed by the CPU 12 is stored in the ROM 30. In order to execute the program at high speed, the program stored in the ROM 30 is stored in the RAM 13, which is a volatile memory. After moving, it is executed on the RAM 13.
Alternatively, the ROM 30 may not be provided on the assumption that the program is executed in the RAM 13, and the program executed by the CPU 12 may be stored in the ROM 14.
The ROM 14 can be accessed from the CPU 31.

In FIG. 4, the power from the power source is supplied to all the parts inside the image forming apparatus 1 of the second embodiment, that is, the power is supplied to each part in the image forming unit 20 and the control part B. The first power-on state is shown.
In the image forming apparatus 1 according to the second embodiment, the CPU 12 decodes all packets received from the host apparatus 2 via the network 3 in the first power-on state.
When the decrypted packet is an inquiry about the device information of the own device, if the device information is information stored in the RAM 13 in advance, the CPU 12 displays the first status including the MIB stored in the RAM 13. Read and output a response packet including the first status to the network control unit 15.
Then, the network control unit 15 transmits a response packet from the CPU 12 to the host device 2 via the network 3.

Further, the CPU 12 has the device information inquired by the packet received from the host device 2 being information including the state of the image forming apparatus 1, for example, the state of the paper and the state of the toner, and information not stored in the RAM 13 in advance. In this case, necessary device information is acquired from the image forming unit 20 via the image processing unit 16, and the device information is temporarily stored in the RAM 13 and processed into information conforming to the MIB object standard. Is output to the network control unit 15.
Then, the network control unit 15 transmits a response packet to the host device 2 via the network 3.
Note that the CPU 31 does not need to operate in the first power-on state, and may be in a sleep state or a clock stop state. By doing so, a power saving effect can be obtained.

FIG. 5 shows a second power-on state in which power is supplied to the control part B of the image forming apparatus 1 of Embodiment 2 but power supply to the image forming unit 20 is interrupted. ing.
In the image forming apparatus 1 according to the second embodiment, when there is no job that uses the image forming unit 20 for a predetermined time, the CPU 12 notifies the CPU 31 of the change in the power-on state and receives the notification. The CPU 31 sends a power instruction signal for instructing the power control section 11 to cut off the power supply to the image forming section 20.
When the power supply control unit 11 receives a power supply instruction signal from the CPU 31, the power supply from the power supply is cut off to the image forming unit 20 by the first power supply control signal.
Thus, the image forming apparatus 1 shifts to the energy saving state. 5 shows that the rectangular frame of the image forming unit 20 in FIG. 5 is hatched to interrupt the power.

In the second power-on state, the CPU 12 decodes all packets received from the host device 2 via the network 3.
When the decrypted packet is an inquiry about the device information of the own device, if the device information is information stored in the RAM 13 in advance, the CPU 12 displays the first status including the MIB stored in the RAM 13. Read and output a response packet including the first status to the network control unit 15.
Then, the network control unit 15 transmits a response packet from the CPU 12 to the host device 2 via the network 3.

Further, the CPU 12 has the device information inquired by the packet received from the host device 2 being information including the state of the image forming apparatus 1, for example, the state of the paper and the state of the toner, and information not stored in the RAM 13 in advance. In this case, the CPU 31 is instructed to change the power-on state by controlling the power instruction signal.
Receiving the instruction, the CPU 31 sends a power instruction signal for instructing the power supply control unit 11 to resume power supply to the image forming unit 20.
When the power supply control unit 11 receives the power supply instruction signal from the CPU 31, the power supply control unit 11 resumes power supply from the power supply to the image forming unit 20 by the first power supply control signal.
Thus, the image forming apparatus 1 returns from the energy saving state to the normal state in which image formation is possible.

When the CPU 12 confirms that the image forming unit 20 has returned from the energy saving state, the CPU 12 acquires necessary device information from the image forming unit 20 via the image processing unit 16, temporarily stores the device information in the RAM 13, and stores the MIB object. To the network control unit 15 and output a response packet including the processed information.
The network control unit 15 transmits a response packet from the CPU 12 to the host device 2 via the network 3.

Thereafter, when the state where there is no job using the image forming unit 20 continues for a predetermined time, the CPU 12 controls the CPU 31 to change the power-on state by controlling the power instruction signal.
Receiving the instruction, the CPU 31 sends a power instruction signal for instructing the power control unit 11 to cut off the power supply to the image forming unit 20.
When the power supply control unit 11 receives the power supply instruction signal from the CPU 31, the power supply from the power supply is again cut off by the first power supply control signal to the image forming unit 20, and the image forming apparatus 1 again receives the second power supply. Return to the input state.

In the first power-on state and the second power-on state, if the CPU 31 enters a sleep state or a clock stop state within a range where it can accept a power control instruction from the CPU 12, further power saving effect can be obtained. Is obtained.
In the above description, the transition from the third power-on state to the second power-on state and the transition from the second power-on state to the third power-on state are the CPUs 31 that have received notification from the CPU 12. However, the CPU 12 may control the transition from the second power-on state to the third power-on state.

FIG. 6 shows a third power-on state that shifts when certain conditions are satisfied after the transition to the second power-on state in the image forming apparatus 1 of the second embodiment.
For example, in the second power-on state, if any job including the image forming unit 20 of the image forming apparatus 1 does not occur for a certain period of time, the CPU 12 turns on the power to the CPU 31. Instruct to change.
Upon receiving the instruction, the CPU 31 sends a power instruction signal for instructing the power supply control unit 11 to cut off the power supply to the control part B.
When the power supply control unit 11 receives the power supply instruction signal from the CPU 31, the power supply from the power supply to the CPU 12, RAM 13, image processing unit 16, operation unit 17, and ROM 30 of the control part B is performed by the second power supply control signal. Cut off.
In this way, the image forming apparatus 1 shifts to the third power-on state (sleep state).

In the third power-on state, the CPU 31 decodes all packets received from the host device 2 via the network 3.
However, the packets that can be decoded by the CPU 31 are, for example, some types of packets including Ping, ARP, and SNMP.
The ROM 14 stores a second status for returning a fixed value in advance in response to an inquiry from the host device 2.
When the packet received by the network control unit 15 via the network 3 cannot be decoded, the CPU 31 sends a power supply instruction signal for instructing the power supply control unit 11 to resume power supply to the control part B.
When the power supply control unit 11 receives the power supply instruction signal from the CPU 31, the power supply to the CPU 12, the RAM 13, the image processing unit 16, the operation unit 17, and the ROM 30 of the control part B is resumed by the second power supply control signal.

Thereafter, the CPU 12 whose power supply has been resumed receives and decodes the packet that could not be decoded by the CPU 31, and performs processing according to the contents of the packet.
If the processing cannot be completed in the second power-on state, the CPU 12 instructs the CPU 31 to transition to the first power-on state.
The CPU 31 controls the power supply instruction signal so that the power supply control unit 11 controls the first power supply control signal to resume power supply to the image forming unit 20 and return to the first power-on state.
Thereafter, the CPU 12 performs processing using the device information acquired from the image forming unit 20.
When the packet received from the host device 2 via the network 3 is an SNMP packet for inquiring about the device information of the own device, a response packet including an MIB object stored in advance in the ROM 14 is sent via the network control unit 15. To the host device 2.

When the inquiry about the device information inquires about the state of the image forming apparatus 1, for example, the state of paper or toner, the MIB object stored in the ROM 14 shows an error regardless of the actual state of the image forming apparatus 1. Or a value that does not generate a warning is set, the process of resuming power supply to the control part B and the image forming unit 20 of the image forming apparatus 1 and acquiring the actual state of the image forming apparatus is not performed.
Further, when the packet transmitted by the host device 2 requests to rewrite the MIB object, the host device 2 does not rewrite the ROM 14 at all and responds to the host device 2 that the MIB object cannot be rewritten. Is transmitted from the CPU 31 via the network control unit 15.

Further, when the MIB object corresponding to the object identifier (OID) of the SNMP packet indicated by the packet transmitted from the host device 2 is not stored in the ROM 14, the CPU 31 passes through the network control unit 15. The host device 2 is notified that the MIB object is not supported.
In this way, even if the device information inquiry packet is received from the host device 2 when the third power-on state (sleep state) is entered, it is not necessary to cancel the sleep state of the image forming apparatus 1. The power consumption of the image forming apparatus 1 can be reduced.

Further, by making an error in rewriting the MIB object with the SNMP packet, it becomes possible to prevent further transmission of the SNMP packet from the host device 2 in advance, and the second power-on state for rewriting the MIB object. Can be prevented and the low power consumption state can be maintained.
Further, by transmitting a response indicating that the MIB object not stored in the ROM 14 is not supported when an inquiry about the MIB object is received, it is possible to prevent further transmission of the SNMP packet from the host device 2 in advance. It is possible to prevent the return to the second power-on state for referring to the MIB object, and to maintain the low power consumption state.

In addition, an error is transmitted to the rewritable MIB object in the third power-on state, and it is stored in the ROM 14 in the third power-on state even though it is an MIB object that should have been originally supported. When referring to a MIB object that does not exist, the host apparatus 2 responds that it is in error or not supported, whereby the image forming apparatus 1 connected to the network 3 is in the third power-on state (sleep state). I can recognize that.
If the image forming apparatus connected to the network is notified that it has shifted to the low power consumption mode by unicast or multicast and has returned, the notification can be handled even if such notification is made. It is effective for the host device.
However, the host device that cannot handle the notification is in a state where it receives an unnecessary packet that cannot be processed even if the notification packet is received, and the image forming apparatus frequently shifts to and returns to the low power consumption mode. If it is repeated, unnecessary packets will fly over the network, causing the network traffic to increase unnecessarily and reducing the network performance.

In the image forming apparatus 1 according to the second embodiment, the response is made only to the host apparatus that has transmitted the packet, and the response is originally limited to the category supported by the host apparatus.
Therefore, any host apparatus that understands the meaning of this response can recognize that the image forming apparatus has shifted to the sleep state, so that the host apparatus may inadvertently cancel the sleep state of the image forming apparatus. It is possible to perform control to prevent unnecessary packet transmission without generating unnecessary packets on the network.

In the image forming apparatus according to the second embodiment, the return to the normal state can be prevented for the response to the device information inquiry at the time of sleep, so that the sleep state can be secured for a long time.
Further, since the MIB RAM area can be reduced, it is possible to further reduce power consumption.
Furthermore, since device information is not acquired immediately before the transition to sleep, it is possible to immediately transition to sleep.

Next, when the host device 2 manages device information of the image forming apparatus 1 which is a network device connected to the network, it is performed by referring to the MIB using SNMP.
The host device 2 that manages the network device is called an SNMP manager, and the managed image forming device 1 is called an SNMP agent.
The basic operation is that the SNMP manager requests device information from the SNMP agent, and the SNMP agent acquires the requested device information and responds to the SNMP manager.
The host apparatus 2 determines the status of the image forming apparatus 1 being monitored from the acquired MIB contents. Each piece of information stored in the MIB is called an object. In this description, as already described above, the term MIB object is used.

MIB objects are managed in a tree structure for each element of device information, and an identifier called an object ID (hereinafter abbreviated as “OID”) is assigned to each MIB object.
The OID is a number delimited by periods, for example, 1.3.6.2.1.1.6.
The host device 2 specifies an OID for the image forming apparatus 1 to acquire device information and change settings.
As described above, the host apparatus 2 acquires a MIB object from the image forming apparatus 1, and displays the MIB object on the monitor (not shown) connected to the host apparatus 2 on the status of the image forming apparatus 1. The current state of the image forming apparatus 1 can be confirmed by notifying the information to another PC (not shown) or referring to the contents of the MIB object.

The host apparatus 2 needs to periodically collect device information in order to grasp the real-time state of the image forming apparatus 1, but the image forming apparatus 1 turns on the power to the image forming unit 20. All the real-time device information of the image forming apparatus 1 cannot be obtained unless the first power-on state is established.
When the image forming apparatus 1 is in the first power-on state or the second power-on state, the power consumption is originally so low regardless of any MIB object inquiry from the host device 2. Therefore, there is no significant impact on power consumption.
However, since power is not supplied to most parts of the image forming apparatus 1 in the third power-on state, the power consumption state is very low.
Therefore, maintaining the third power-on state where the power consumption of the image forming apparatus 1 has been reduced to the utmost is extremely important in reducing power consumption. The power consumption cannot be kept low if the power supply state 3 is changed to the second power-on state or the first power-on state.

For example, in the technology described in Patent Document 1 that is a publicly known technology, two types of statuses are held, and one status is a status for responding at the time of sleep when the power consumption of the device is low, and the device transitions to the sleep state. Stored in storage means before.
Another status is a fixed status. When this status is fixed, the user is inquired whether it is really necessary.
However, since a MIB object generally has a size of 1 Mbyte to 2 MByte, if a large-capacity RAM for storing a MIB object of this size is built in a semiconductor such as an ASIC, the cost of the ASIC is increased. It is not suitable for installation in a new product.

Further, if a DRAM such as SDRAM is mounted on the board as an external memory instead of being built in the ASIC or the like, the power consumption becomes high.
Then, it is necessary to save the device information of the image forming unit in the storage unit before transitioning to the sleep state, and the transition to the sleep state is possible even though it is desired to transition to the sleep state with low power consumption as soon as possible. It will be a factor to prevent.
Further, when another fixed status is responded, if the display is made to inquire whether the user really needs the information, the host device that manages the image forming apparatus is often a server. Since the user does not always operate, even if the above inquiry is displayed, the subsequent operation cannot be performed.
Therefore, it stops in a state where the inquiry is displayed, and the device information of the image forming apparatus cannot be acquired.

As described above, in the conventional image forming apparatus, when device information such as the status of the image forming apparatus is acquired before going to sleep and stored in the RAM or the like in order to inquire device information from the host device, the device enters sleep. For this reason, the preparation time becomes longer and the capacity of the RAM increases, resulting in an increase in power consumption.
Normally, a RAM of about 2 Mbytes is required to store the MIB object. However, when 2 Mbytes of RAM are required, it is impossible to install the memory in a device such as an ASIC from the viewpoint of cost. If a DRAM such as an attached SDRAM is mounted, the power consumption increases.

Therefore, in the image forming apparatus 1 according to the first and second embodiments, first, the ROM 14 is a non-volatile memory with low power consumption in order to solve the above-described problems.
The ROM 14 stores the MIB object of the image forming apparatus 1.
Further, it is not an MIB object stored in the ROM 14 in the first power-on state or the second power-on state, but an MIB object or volatile memory created based on device information acquired from the image forming unit 20. The MIB object stored in the RAM 13 is transmitted to the host device 2.
Furthermore, when it is in the third power-on state, it is desired to reduce the power consumption for as long as possible. Therefore, the MIB object stored in advance in the ROM 14 is transmitted to the host device 2.

Further, in the third power-on state, if a MIB object that cannot be obtained correctly unless a transition to the first power-on state or the second power-on state is requested, a warning is given by the host device 2 side. Alternatively, a value that is fixed in advance so as not to be handled as an error is stored in the ROM 14, and the value is transmitted to the host device 2.
For example, in the case of an OS such as Windows (registered trademark), when the host apparatus 2 determines that the collected MIB object is in a warning or error state, the device information is frequently inquired until the state changes, so the sleep state is maintained. It becomes difficult to do.
Therefore, the MIB object that can acquire the correct state only in the first power-on state or the second power-on state is set to a value that does not cause an error or a warning when it is received by the host device 2 and is stored in the ROM 14. It is.
In the third power-on state, the CPU 31 or the network control unit 15 responds with a value stored in advance in the ROM 14 to eliminate the need to make a transition from the third power-on state and sleep with low power consumption. It becomes possible to maintain the state.

FIG. 7 is a diagram illustrating an example of the MIB object.
This MIB object represents a sample of the MIB tree defined in RFC1213.
RFC-1156 defines the first standard MIB as MIB-1, and 114 types of managed objects are defined. However, in order to make OID assignment simple and easy to understand, eight groups (System, Interfaces, at: Address Translation, ip, icmp, tcp, udp, egp).
In RFC 1213 after that, 57 types of managed objects are newly added, and MIB-2 is defined in which 171 types of managed objects are classified into 11 types.

The eleven groups are System, interface, and at: address translation, ip, icmp, tcp, udp, egp, oim, transmission, and snmp.
For example, in the System group, settings related to the system of the image forming apparatus 1 are managed, and the breakdown is sysDescr: entity information, sysObjectID: vendor OID, sysUpTime: elapsed time since the last initialization, sysContact : Node administrator information, sysName: domain name, sysLocation: physical location of the node, sysService: a service provided by Entity.
These pieces of information can be managed based on the OID.

In the Interfaces group, settings related to the hardware interface possessed by the image forming apparatus 1 are managed.
The number of interfaces held by the image forming apparatus 1 is stored in the first object ifNumber, and a table row for storing settings is added according to the number of interfaces.
The description of the breakdown is omitted because it is publicly known.
For example, when referencing ifType, when the host device 2 managing the image forming apparatus 1 transmits a GET-SNMPv2-SMI packet (OID is interfaces) of the OID of the system, it is specified by the GET-SNMPv2-SMI packet. The OID of ifNumber and the OID of ifTable, which are OID information that belongs to an OID (interfaces) that can be managed by the image forming apparatus 1, are returned to the host apparatus 2.

At this time, the value belonging to the ifNumber OID is the number of IFs, but the value belonging to the ifTable OID is the number of objects held as a layer below it. In the case of FIG. 7, it is 22 from ifIndex to ifSpecific.
Here, since the host apparatus 2 can recognize that the connected image forming apparatus 1 holds the object “ifType” as a management target, if the “type” is specified in the OID of the GET-SNMPv2-SMI packet and then transmitted, The value of ifType can be acquired from the image forming apparatus 1.
By performing such control, the host apparatus 2 can refer to and operate the management target object of the image forming apparatus 1 connected to the network 3.
Thus, since the MIB object is stored in the ROM of the nonvolatile memory with low power consumption, the power consumption can be further reduced.
Further, it is not necessary to prepare an external DRAM externally, and since it is not necessary to incorporate a large capacity DRAM in the ASIC, it is possible to develop an inexpensive device with low power consumption.

Next, the MIB object can be rewritten from the host device 2 for setting change.
However, MIB objects need to be stored in the RAM of the volatile memory in order to rewrite, but if stored in the RAM, the power consumption cannot be lowered, and a product with low cost and low power consumption can be developed. Disappear.
Therefore, only the non-rewritable MIB object is stored in the ROM 14, and when the MIB object is rewritten in the third power-on state, an error response to the MIB object rewrite is returned to the host device 2. To do.

In this way, even if the MIB object is rewritten in the third power-on state, it is not necessary to make a transition to the first power-on state or the second power-on state, and the image forming apparatus 1 The power consumption can be kept low.
Therefore, since the rewritable MIB object is not stored, the ROM 14 required in the third power-on state may be a non-volatile memory, and product development with low cost and low power consumption is possible.

Next, in response to a device information inquiry from the host device 2, the current device information of the image forming apparatus 1 should always be referred to as a MIB object, but in order to perform such an operation, Even when the third power-on state is entered, the apparatus must transition to the first power-on state or the second power-on state to perform the device information acquisition process for the image forming apparatus 1.
However, when such an operation is performed, it is impossible to satisfy the desire to keep the power consumption of the image forming apparatus 1 low for a long period of time.
The third power-on state means that there is no job that uses the image forming unit 20 and power supply to the image processing unit 16 should not be necessary in the first place.

In addition, when there is an inquiry about device information from the host device 2 in the third power-on state, even if it is not the correct device information of the real image forming apparatus 1 at that time, it is not handled as an error or warning. In most cases, there is no problem if a simple MIB object is responded.
As described above, when all responses are made to the inquiry of the device information from the host device 2 in the third power-on state, the state transition to the first power-on state or the second power-on state is required. The low power consumption state in the image forming apparatus 1 cannot be maintained for a long time.
Accordingly, when the image forming apparatus 1 is in the first power-on state or the second power-on state, the image forming apparatus 1 acquires the correct device information at that time and responds to the host device 2, but when in the third power-on state, Even if the inquiry content is the same MIB object, the correct device information is not acquired, but an arbitrary fixed value prepared in advance in the ROM 14 is returned to the host device 2 so that the consumption of the image forming apparatus 1 Electric power can be further reduced.

FIG. 8 is a flowchart showing processing at the time of network packet reception in the image forming apparatus 1.
In step (indicated by “S” in the figure), when a network packet is received from the host device, in step 2, the network control unit 15 in the case of the first embodiment and the CPU 31 in the case of the second embodiment are turned on. It is determined whether or not the state is the third power-on state.
When not in the third power-on state, the CPU 31 or the network control unit 15 does not perform any further processing, and the CPU 12 makes subsequent determinations.
The content of the received packet is inspected, and if it is a MIB inquiry, it is determined in step 9 whether or not the image forming unit 20 is necessary.

If the image forming unit 20 is not required, in step 12, the CPU 12 performs a process of transmitting the MIB object stored in the RAM 13 to the host device 2 via the network control unit 15, and ends this process.
If it is determined in step 9 that the image forming unit 20 is necessary, the process proceeds to the first power-on state in step 10. In step 11, the current device information is received from each unit including the image forming unit 20. The process of acquiring and transmitting the MIB object based on the device information to the host apparatus 2 via the network control unit 15 is performed, and this process is terminated.
Next, when the CPU 31 or the network control unit 15 determines in step 2 that the current power-on state is the third power-on state, the CPU 31 or network control unit 15 receives from the host device 2 in step 3. It is determined whether the received packet is a device information inquiry.

If it is not a device information inquiry, it is determined in step 7 whether or not the CPU 12 is necessary. If it is determined that the processing by the CPU 12 is necessary, the process proceeds to the second power-on state in step 8 and the subsequent processing is as follows. The CPU 12 is caused to perform this.
If it is determined in step 9 that the image forming unit 20 is necessary, the process proceeds to the first power-on state in step 10. In step 11, the current device information is received from each unit including the image forming unit 20. The process of acquiring and transmitting the MIB object based on the device information to the host apparatus 2 via the network control unit 15 is performed, and this process is terminated.
If the image forming unit 20 is not necessary, in step 12, the CPU 12 performs a process of transmitting the MIB object stored in the RAM 13 to the host device 2 via the network control unit 15, and ends this process.

If it is determined in step 3 that the device information is inquired, in step 4, the corresponding device information is acquired from the ROM 14. In step 5, a packet including the MIB object of the device information is transmitted to the host device 2. End the process.
If it is determined in step 7 that the CPU 12 is not required, in step 6, the CPU 31 or the network control unit 15 responds to the host device 2 and ends this processing.
In this way, the third power-on state can be maintained for a long time, so that a product with low power consumption can be developed.

Next, in order to rewrite the value of the MIB object, a RAM is required. However, when the RAM is mounted, the cost increases and the power consumption also increases.
Processing when the host apparatus 2 requests to rewrite the MIB object will be described.
When receiving the network packet from the host device 2, the CPU 31 or the network control unit 15 determines whether or not it is in the third power-on state.
If the state is other than the third power-on state, the CPU 12 performs all the subsequent processing.
In the third power-on state, the CPU 31 or the network control unit 15 checks whether the received packet is a MIB object rewrite request.

If it is not a MIB object rewrite request, the corresponding MIB object stored in advance in the ROM 14 is transmitted to the host device 2.
Further, when a MIB object rewrite request is made, the packet shown in FIG. 9 is transmitted and responded.
The packet shown in FIG. 9 stores data of SNMP version 40, community name 41, and protocol data unit (PDU) 42.
The PDU 42 includes a PDU type 43, a request identifier 44, an error status 45, an error position number 46, and MIB information 47.
Then, the SNMP error status 45 is responded as “No Such Name” or “Error”. In the figure, 48 indicates an empty area.

In this way, since rewriting of the MIB object is not accepted in the third power-on state, the image forming apparatus 1 can be maintained in the low power consumption state for a long time.
However, rewriting of these MIB objects is accepted in the first power-on state or the second power-on state.

FIG. 10 is a flowchart showing processing when rewriting an MIB object.
A part of this process is common to the process of FIG. 8, so the description of the common part is simplified.
When a network packet is received from the host device 2, the CPU 31 in the case of the second embodiment or the network control unit 15 in the case of the first embodiment first checks whether or not the third power-on state is established. . (S21, 22)
When it is not in the third power-on state, it is determined whether or not the image forming unit 20 is necessary based on the received network packet. (S28)
This determination may also be made by the CPU 31 or the network control unit 15.

If it is determined that the image forming unit 20 is not necessary, the CPU 12 performs a MIB object rewriting process, and returns to the original state when the process is completed. (S31)
If it is determined that the image forming unit 20 is necessary, the first power-on state is entered so that the image forming unit 20 can be used. (S29)
The case where the image forming unit 20 is required is, for example, when acquisition of a MIB object that acquires the state of the image forming apparatus 1 occurs.
After shifting to the first power-on state, processing such as rewriting of the MIB object requested from the host apparatus 2 including the image forming unit 20 is performed. (S30)

Next, a case where the third power-on state is established when the network packet arrives from the host device 2 will be described.
If the third power-on state is determined in S22, the CPU 31 or the network control unit 15 determines whether or not the network packet is a MIB object rewrite in S23.
If the MIB object is to be rewritten, in S24, the MIB object is a rewritable MIB object in the sleep mode in order to avoid an increase in power consumption of the image forming apparatus 1 due to returning from the sleep state. However, the error status is transmitted to the host device 2 to complete the process.

By performing this operation, it is possible to maintain the sleep state even when the MIB object is rewritten during the sleep.
If the network packet received from the host device 2 is not a MIB object rewrite, the CPU 31 or the network control unit 15 determines whether the CPU 12 needs a necessary process. (S26)
If it is determined that the CPU 12 is not necessary, the CPU 31 or the network control unit 15 transmits a response to the host device 2 (S25). If the CPU 12 determines that it is necessary, the process shifts to the second power-on state. (S27)
After shifting to the second power-on state, the CPU 12 determines whether the image forming unit 20 is a necessary process. (S28)

If it can be determined that the image forming unit 20 is not necessary, the CPU 12 performs a process such as transmitting a response to the host device 2 (S31). If the image forming unit 20 determines that it is necessary, the image forming unit 20 shifts to the first power-on state. Processing including the forming unit 20 is performed. (S29, 30)
In this way, even when the image forming apparatus 1 receives a network packet for rewriting the MIB object from the host apparatus 2, it is possible to prevent the sleep from the sleep state.

FIG. 11 is a sequence diagram illustrating an example of data exchange between the image forming apparatus 1 and the host apparatus 2.
11A shows a sequence when the image forming apparatus 1 is in the first power-on state or the second power-on state, and FIG. 11B shows the image forming apparatus 1 in the third power-on state. The sequence at the time of is shown.
“Get Request” in the figure is a signal for requesting information acquisition of an object of a specified OID.
In addition, “Get Next Request” in the figure is a signal for requesting acquisition of information on the next object in the hierarchy of the specified OID.
Further, “Set Request” in the figure is a signal for requesting information change of the object of the designated OID.
Furthermore, “Get Response” in the figure is a response signal to the request from the manager.

The area surrounded by the broken line frame C in FIG. 3 is not originally in the first power-on state or the second power-on state in which the image forming apparatus 1 is supplied with power from the power source to the image forming unit 20. 4 shows a communication part for accessing an MIB object that cannot respond correctly to a request from the host device 2.
As shown to (a) of the figure, in the 1st power-on state or the 2nd power-on state, the image forming apparatus 1 receives “Get Request”, “Get Next Request”, and “Set Request” from the host device 2. No error response is returned for each signal.

However, in the third power-on state, the image forming apparatus 1 responds to a request to rewrite the MIB object by “Set Request” from the host device 2 in the first power-on state or the second power-on state. Since it is necessary to make a state transition to a state, the low power consumption state cannot be maintained.
Therefore, as shown in FIG. 5B, when the image forming apparatus 1 receives “Set Request” indicated by an arrow 50 in the figure from the host apparatus 2 in the third power-on state, an arrow 51 in the figure. Returns “No Such Name” or “Error” in “Get Response”.
Therefore, the image forming apparatus 1 can prevent the subsequent “Set Request” command from the host apparatus 2 from being transferred, and can maintain the third power-on state with reduced power consumption.
In this way, it is possible to develop a low-cost and low-power-consumption device by not permitting rewriting of MIB objects.

FIG. 12 is a sequence diagram illustrating another example of data exchange between the image forming apparatus 1 and the host apparatus 2.
12A shows a sequence when the image forming apparatus 1 is in the first power-on state or the second power-on state, and FIG. 12B shows the image forming apparatus 1 in the third power-on state. The sequence at the time of is shown.
The area surrounded by the broken line frame C in FIG. 3 is not originally in the first power-on state or the second power-on state in which the image forming apparatus 1 is supplied with power from the power source to the image forming unit 20. 4 shows a communication part for accessing an MIB object that cannot respond correctly to a request from the host device 2.

The host apparatus 2 refers to the MIB object held by the image forming apparatus 1 using “Get Request” and “Get Next Request”.
As shown in FIG. 5A, the image forming apparatus 1 responds to “Get Request” and “Get Next Request” from the host device 2 in the first power-on state and the second power-on state. Always returns a “Get Response” response normally.

However, in the third power-on state, for example, in response to the third “Get Next Request”, a response “Get Response” indicating that the next MIB object exists is returned to the host device 2. Then, further transmission of “Get Next Request” or “Get Request” is transmitted from the host device 2 at this point or when the time has elapsed from this point in time, The inquiry packet of the MIB object that cannot return a correct value unless it shifts to the area C, that is, the first power-on state or the second power-on state will be transmitted.
As described above, when the image forming apparatus 1 makes a response to the “Get Next Request” from the host apparatus 2 that the next MIB object exists, the update from the host apparatus 2 is performed based on the response. Inquiries about device information occur, and it becomes difficult to maintain the sleep state.

Therefore, in order to prevent transmission of the transmission packet from the host apparatus 2 described above, the image forming apparatus 1 receives “Get Request from the host apparatus 2 in the third power-on state, as shown in FIG. As a response to “Get Next Request”, “Get Response” is used to prevent access from the host apparatus 2 to the MIB object that is considered to require the state transition to the first or second power-on state. The response is made with a notification that the corresponding MIB object does not exist.
For example, in response to “Get Next Request” indicated by an arrow 52 in the figure, “Get Response” indicated by an arrow 53 in the figure responds with a notification that the corresponding MIB object does not exist.
In this way, the image forming apparatus 1 can reduce the number of inquiries from the host apparatus 2 in advance by limiting the response to the “Get Next Request” from the host apparatus 2, and maintain the sleep state. Is possible.

Next, normally, a large number of host devices are connected to the image forming apparatus 1 in the network, and all the host devices 2 periodically transmit SNMP packets that are device information inquiry packets of the image forming apparatus 1. .
FIG. 13 is a block diagram illustrating a configuration example of a network.
FIG. 13 assumes a network environment in which a plurality of host devices 4, 5, and 7 are connected to the network 3. For example, 100 host devices are connected to the network 3, and Each host apparatus periodically sends an SNMP packet to one image forming apparatus 1.

For example, assuming that each host apparatus transmits an SNMP packet once every 300 seconds, the image forming apparatus 1 receives the SNMP packet once every 3 seconds, and the third packet is sent to respond to the SNMP packet. When there is a transition from the first power-on state to the first power-on state or the second power-on state, there is also a time for the power-on and other state transitions. The power consumption of the image forming apparatus 1 cannot be reduced.
For this reason, an error occurs with respect to writing to an SNMP packet from a host device that is likely to change to the first or second power-on state, for example, the host devices 4 and 5 surrounded by the broken line frame 6 in the figure. As for “Get Request” and “Get Next Request”, notification that the MIB object does not exist prevents the transition to the first or second power-on state in advance, and the power consumption can be reduced.

However, if such a response is made, the consumables of the image forming apparatus 1 are managed via the network, and when the replenishment is necessary, a user who has introduced a system for supplying supplies supplies the image forming apparatus 1 with respect to the use destination. Since the correct state cannot be grasped, there is a possibility that inconvenience due to lack of consumables such as toner, ink, paper, etc. at the moment when the image forming apparatus 1 is actually used may be lost. is there.
As described above, when managing consumables at the usage destination by inquiring device information from a remote location, the user is inconvenienced if current correct consumable information cannot be obtained.
On the other hand, if a device information inquiry related to consumables inquiries from a host device that is not intended for consumables management is received, it becomes difficult to maintain the sleep state.

Therefore, the host apparatus 2 that manages consumables of the image forming apparatus 1 is registered in the image forming apparatus 1 in advance, and only the response to the SNMP packet from the host apparatus 2 is in the third power-on state. Even in such a case, the inconvenience as described above can be eliminated by shifting to the first power-on state or the second power-on state and transmitting the correct device information as the MIB object.
In this way, by responding correctly only to device information inquiries from the host device that manages the user's consumables, the sleep state is maintained to the maximum while correctly managing the consumables of the customer's device. It becomes possible.

Next, unless the host device 2 that manages the consumables of the image forming apparatus 1 as described above is identified, eventually, responses to SNMP packets from all the host devices 2 must be made.
That is, the host device 2 cannot be identified unless the host device 2 that manages the consumables is designated by any method.
Therefore, the source IP address included in the header of the network packet is registered in advance from the menu of the operation unit 17 of the image forming apparatus 1, and the network packet received by the network control unit 15 in the third power-on state. The MIB object that may require a transition to the first or second power-on state when the IP address registered in the operation unit 17 is checked. By normally performing all of the above responses, it is possible to manage consumables of the image forming apparatus 1 from a remote place while maintaining low power consumption for a long time.

  In this way, consumables are managed by designating the IP address of the host device 2 by the menu of the operation unit 17 of the image forming apparatus 1 and comparing it with the IP address included in the header of the received packet. Since it is possible to determine whether or not it is a device information inquiry from the host device 2 that is present, it is possible to manage the user's image forming apparatus while maintaining the sleep state to the maximum.

Next, the host device 2 that manages the consumables of the image forming apparatus 1 as described above is not necessarily installed in the same building as the image forming apparatus 1, and is physically located at a remote place. Sometimes it is installed.
When the consumables management host device 2 is installed in a remote place, the person who manages the host device 2 cannot directly operate the operation unit of the image forming apparatus 1.
Further, it is not known when the IP address of the host device 2 installed at a remote location will change due to the circumstances of the remote location.
For example, when a change is made to a person in the building where the image forming apparatus 1 is set when the host apparatus 2 is replaced, the consumables cannot be managed from the host apparatus 2 due to an operation error. There is a possibility of becoming.

Moreover, device information for consumables management is often acquired in the middle of the night to avoid disturbing daytime work, and it is not possible to immediately confirm whether the set values requested and set are as requested. .
In this way, the host device 2 cannot be identified unless the host device 2 that manages the consumables is designated by some method.
Further, when going to operate the operation unit of the image forming apparatus 1 for setting, the convenience is poor when the image forming apparatus 1 is installed at a remote location.

Therefore, an image is formed by connecting to the image forming apparatus 1 from a remote location via the network 3 by a web browser (Web Browser), and setting and registering the IP address of the host apparatus 2 in the image forming apparatus 1 via the web browser. Whether the device information inquiry from the host device 2 that manages the consumables is specified by designating the IP address from the menu of the operation unit of the device 1 and comparing it with the IP address included in the header of the received packet. Therefore, it is possible to manage the user's image forming apparatus 1 while maintaining the sleep state to the maximum.
Further, since it is possible to set from a remote location, the system administrator can also set from a remote location, and even a user who is not familiar with the image forming apparatus 1 who actually uses the image forming apparatus 1 can set it. It is also possible to prevent errors and the like.

  The image forming apparatus according to the present invention can be applied to all apparatuses that perform image formation, including facsimile machines, printers, copiers, and multifunction machines.

1 is a block diagram showing a functional configuration of Embodiment 1 of an image forming apparatus according to the present invention. FIG. FIG. 2 is a block diagram showing a functional configuration of the image forming apparatus according to the first embodiment of the present invention. FIG. 2 is a block diagram showing a functional configuration of the image forming apparatus according to the first embodiment of the present invention. It is a block diagram which shows the function structure of Example 2 of the image forming apparatus of this invention. FIG. 6 is a block diagram showing a functional configuration of a second embodiment of the image forming apparatus according to the present invention.

FIG. 6 is a block diagram showing a functional configuration of a second embodiment of the image forming apparatus according to the present invention. It is a figure which shows an example of a MIB object. It is a flowchart figure which shows the process at the time of the network packet reception in the image forming apparatus of the Example of this invention. 6 is a diagram illustrating an example of data contents of a packet transmitted from the image forming apparatus according to the embodiment of the present invention to a host device. FIG.

FIG. 5 is a flowchart illustrating processing when the image forming apparatus according to the embodiment of the present invention rewrites an MIB object. FIG. 3 is a sequence diagram illustrating an example of data exchange between the image forming apparatus and the host apparatus according to the embodiment of this invention. FIG. 6 is a sequence diagram illustrating another example of data exchange between the image forming apparatus and the host apparatus according to the embodiment of the present invention. It is a block diagram which shows the structural example of the network of the Example of this invention.

Explanation of symbols

1: Image forming device 2: Host device 3: Network 10: Controller 11: Power source control unit 12, 31: CPU 13, 32: RAM 14, 30: ROM 15: Network control unit 16: Image processing unit 17: Operation unit 20 : Image forming unit 21: Plotter 22: Scanner 40: SNMP version 41: Community name 42: Protocol data unit 43: PDU type 44: Request identifier 45: Error status 46: Error position number 47: MIB information 48: Empty area

Claims (11)

Receiving means for receiving image data from a host device via a network; image forming means for forming an image based on image data received by the receiving means; and control means for controlling image formation by the image forming means; In an image forming apparatus comprising:
In the first power-on state in which power is supplied to the image forming unit and the control unit, power is supplied to the control unit, but power supply to the image forming unit is interrupted. In the second power-on state, when the device information inquiry of the host device is received from the host device, the control unit stores the device of the host device stored in the first storage unit included in the control unit. The information is transmitted to the host device, or the control unit detects the device information of its own device and transmits it to the host device, and the supply of power to the image forming unit and the control unit is both shut off. In the case of the power-on state, when the device information inquiry of the self-device is received from the host device, the receiving device is stored in the second storage means that can be referred to even in the third power-on state. of Transmits the vessel information to the host device, or an image forming apparatus wherein the receiving means is characterized in that it can not send the device information of its own device and to transmit to the host device. A receiving unit that receives image data from a host device via a network, an image forming unit that forms an image based on image data received by the receiving unit, and a first control that controls image formation by the image forming unit An image forming apparatus comprising:
When power is supplied to the image forming unit and the first control unit, and when power is supplied to the first control unit, power is supplied to the image forming unit. In the case of the second power-on state that is shut off, when receiving an inquiry about the device information of the host device from the host device, the first control unit stores the first storage unit included in the first control unit. The stored device information of the own device is transmitted to the host device, or the first control unit detects the device information of the own device and transmits the device information to the host device, to the image forming unit and the first control unit. In the third power-on state in which the power supply of both is interrupted, the second control means not included in the third power-on state when receiving an inquiry about the device information of the own device from the host device Is the third power source The device information of the own device stored in the second storage means that can be referred to even in the on state is transmitted to the host device, or the fact that the device information of the own device cannot be transmitted is transmitted to the host device. An image forming apparatus.   3. The device information stored in advance in the second storage means and transmitted in response to an inquiry from the host device in the third power-on state is a MIB object. The image forming apparatus described.   The information indicating the state of the image forming apparatus among the MIB objects stored in advance in the second storage unit is fixed to a value that the host apparatus does not determine as an error. The image forming apparatus described.   4. The image forming apparatus according to claim 3, wherein the MIB object stored in advance in the second storage means is only information that cannot be rewritten from the host apparatus.   The response content to the inquiry of the device information from the host device is different between the response content in the first power-on state or the second power-on state and the response content in the third power-on state. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   When the host device requests rewriting of device information stored in the second storage unit in the third power-on state, an error indicating that writing is not possible is returned to the host device. The image forming apparatus according to claim 6.   When the host device requests a part of device information stored in the second storage unit, the host device returns information indicating that the requested information does not exist. Item 7. The image forming apparatus according to Item 6.   In the third power-on state, if there is an inquiry about the device information of the own device from a host device registered in advance in the own device, the second power-on state or the second power-on state from the third power-on state The image forming apparatus according to claim 1, wherein the image forming apparatus is shifted to a first power-on state.   The image forming apparatus according to claim 9, wherein the host apparatus registered in advance in the own apparatus registers by an IP address input from the own apparatus.   The image forming apparatus according to claim 9, wherein the host apparatus registered in advance in the self apparatus is registered by an IP address input from another host apparatus connected via a network.

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