141, the sheet feeding unit 142, and the sheet discharge unit 143 of the printer device 104.

The power supply control for respective blocks can also be achieved by, for example, constituting the first power switch 310 from two systems. In the sleep state, only a relay switch of one system connected to a block to shut off is turned OFF and a relay switch of the other system is kept ON. In the shutdown state, the relay switches of both systems are turned OFF. A power supply control signal in this case is not a binary signal but a multi-value control signal corresponding to the power state. In the power states, such as the sleep state and the shutdown state, the power supply is performed by such a control. In this control, the power controller 303 may perform a multi-value control on the first power switch 310 to supply the electric power to the blocks connected to the controller 103. In this control, the CPU 340 of the controller 103 may perform a multi-value control of the first power switch 310 by notifying the power controller 303 to supply the electric power to the blocks connected to the controller 103.

A reboot process in the image forming apparatus 101 (power supply in rebooting the power controller) will be described. The CPU 340 of the controller 103 receives a reboot event in the standby state after the image forming apparatus 101 is activated. The reboot event is issued from an application running on the CPU 340 or issued from the computer 109 via the LAN 108, for example. After receiving the reboot event, the CPU 340 performs a process to end the application and a process to store the information stored in the memory 341 into the hard disk 106.

The CPU 340 performs termination processes on the scanner device 102, the printer device 104, the FAX device 107, the finisher device 150, and a peripheral device. After the completion of the processes, the CPU 340 notifies the power controller 303 of the completion and transitions to the power-off state. In the power-off state, the power controller 303 turns off the first power switch 310 to the fourth power switch 313. As a result, the power supply to the controller 103, the printer device 104, the scanner device 102, the FAX device 107, and the finisher device 150 is cut off. The power controller 303 preferably waits until the analog signal of the power source 301 completely drops off. Further, the image forming apparatus 101 may shorten the signal waiting time by transition to a reset state instead of the power-off state.

Then, after the transition to the power-off state, the power controller 303 turns ON the first power switch 310 to the fourth power switch 313. Thus, the controller 103, the printer device 104, the scanner device 102, the FAX device 107, and the finisher device 150 are energized. The CPU 340 performs an initialization process of the peripheral device and performs activation processes of the scanner device 102, the printer device 104, the FAX device 107, the finisher device 150, the peripheral device.

A sleep transition process in the image forming apparatus 101 (controller 103) will be described. The sleep transition process is a process in which the image forming apparatus 101 transitions to the sleep state when it is determined that the active state in which the image forming apparatus 101 is not used continues for a predetermined period by using an automatic sleep timer. The CPU 340 of the controller 103 notifies the power controller 303 of the transition to the sleep state. This notification changes the power supply to the controller 103. As described above, the power supply control for respective blocks can also be achieved by, for example, constituting the first power switch 310 from two systems. In the sleep state, only a relay switch of one system connected to a block to shut off is turned OFF and a relay switch of the other system is kept ON. At this time, the CPU 340 can also transition to the sleep state by notifying the power controller 303 to turn off the second power switch 311 and stopping the power supply from the power source 301 to the operation unit 105 by the power controller 303.

The CPU 340 can also transition to the sleep state by the CPU 305 of the operation unit 105 performing notification to set the operation panel and the peripheral device to the power saving state by serial communications. Similarly, the scanner device 102 and the printer device 104 can also transition to the sleep state.

The sleep state of the image forming apparatus 101 will be described. The sleep state is a state in which an activation time can be shortened than that of a normal activation while reducing the power consumption.

For example, the image forming apparatus 101 enters into the sleep state when a predetermined time elapses in a state where the image forming apparatus 101 is not used (i.e., when the user does not operate the image forming apparatus 101), when the touch panel or a power saving key on the operation unit 105 is pressed, or when a preset time is reached. In the sleep state, for example, the electric power is supplied to the memory 341, an interruption controller (not illustrated), the USB host controller 208, the USB device controller 210, the network controller 211, and the RTC 212 of the controller 103. The electric power is also supplied to the power saving key of the operation unit 105, a part of the FAX device 107, and various sensors.

First, the power supply in returning from the sleep state in the image forming apparatus 101 will be described. A return factor from the sleep state depends on the system configuration of the image forming system 100. The following description is an example. The power controller 303 starts power supply in response to one or more interruptions from, for example, the network, the RTC 212 that detects a timer and an alarm, and the FAX device 107 that detects an incoming call or off-hook during the sleep state. Other interruptions occur from a soft switch, various sensors, and a USB that detects communication.

Specific examples of other interruptions include opening and closing of a cover of a front door of the printer device 104, insertion and removal of a print sheet of a multi manual sheet feeding unit of the printer device 104, opening and closing of a pressure plate of the scanner device 102, and detection of a document by an automatic document feeder of the scanner device 102. Further, other interruptions include card detection of an NFC card reader, detection of a human sensor, off-hook of a FAX handset, and FAX reception.

The power controller 303 notifies the CPU 340 of an interruption cause. When receiving a notification from the power controller 303, the CPU 340 performs a process for returning the state of the software to the normal state, that is, a sleep return process for returning from the sleep state.

Next, the sleep return process in the image forming apparatus 101 will be described. The power controller 303 receives an event handler of pressing the power saving key, which is one of the sleep return factors, during the sleep state. Accordingly, the power controller 303 turns ON the first power switch 310 to return the CPU 340 from the sleep state. At this time, for example, the power controller 303 performs the multi-value control of the first power switch 310 to supply the electric power to the respective blocks of the controller 103. The power controller 303 can also cause the CPU 340 to return from the sleep state by issuing an interruption signal to the CPU 340. The CPU 340 notifies the power controller 303 to turn on the second power switch 311 to the fourth power switch 313. Thus, the electric power is supplied to the scanner device 102, the printer device 104, and the operation unit 105. Although the power supply to the FAX device 107 or the like is not illustrated, it can be prepared as a signal (not illustrated).

Although the sleep return factor in the above description is the pressing of the power saving key, it may be a network packet. In this case, when receiving the network packet during the sleep state, the power controller 303 turns ON the first power switch 310 to return the CPU 340 from the sleep state. When the power controller 303 interprets the network packet and determines that the packet is a print job, the CPU 340 notifies the power controller 303 to turn ON the fourth power switch 313. This supplies the electric power to the printer device 104. In this case, the process can be performed without supplying the electric power to the operation unit 105 and the scanner device 102. That is, when the user does not use the touch panel, the power supply to the operation unit 105 is unnecessary. When no print job is generated or when it is unnecessary to obtain device information, the electric power may not be supplied to the printer device 104 and the scanner device 102.

The CPU 340 transitions to the sleep state again when, for example, the copy or the print job via the network is completed. At this time, the CPU 340 notifies the power controller 303 of the transition to the sleep state. The power controller 303 turns OFF the second power switch 311 to the fourth power switch 313 to stop the power supply to the components other than the controller 103. At this time, for example, the power controller 303 can set the CPU 340 to an interruption signal waiting state, perform the multi-value control of the first power switch 310 to turn OFF the blocks of the controller 103, and then set the CPU 340 to the sleep state.

When the main power switch 110 is turned OFF, the power controller 303 notifies the CPU 340 of the turn-off. The power controller 303 performs the multi-value control of the first power switch 310 to turn off the powers of the CPU 221 of the sub board 220 and the memory 223. The power controller 303 sets the memory 341 of the main board 200 to a self-refresh state in which a refresh rate is lowered to save power. Thus, the controller 103 can be brought into a suspended state. The suspended state is a power saving state in which the memory is energized to hold the state, and can be used in the sleep state and a high-speed activation mode.

When the main power switch 110 is turned ON, the power controller 303 releases the memory 341 of the main board 200 from the self-refresh state, and turns ON the power of the CPU 221 and the memory 223 of the sub board 220 to activate them. Thus, the controller 303 can be returned from the suspended state. The trigger to transition to the suspended state or return from the suspended state is not limited to the ON/OFF operation of the main power switch 110, and may be, for example, a software event.

FIG. 4 is a view illustrating an example of a UI screen displayed on the operation unit of the image forming apparatus. The UI screen (an operation screen) 400 shown in FIG. 4 is displayed on the operation unit 105 of the image forming apparatus 101. The UI screen 400 is displayed in response to a notification from the CPU 340 of the controller 103 to the CPU 305 of the operation unit 105. The UI screen 400 includes a label field 410, an ON key 420, an OFF key 430, a user notification field 440, a cancel key 450, and an OK key 460. In the label field 410, a function such as an automatic turn-off in an offline state is displayed.

Hereinafter, the offline state and the automatic turn-off will be described. As described above, the image forming apparatus 101 is configured to be connectable with of the networks, such as the wired LAN, the wireless LAN, the USB host (USB device), and the FAX device 107. Then, when the image forming apparatus 101 is communicably connected to at least one of the wired LAN, the wireless LAN, the USB host (USB device), and the FAX device 107, it is determined that the image forming apparatus 101 is in a connected state in which the image forming apparatus 101 is connected to the network. This connected state may be referred to as online (an online state).

In contrast, when the image forming apparatus 101 is not communicably connected to any of the wired LAN, the wireless LAN, the USB host (USB device), and the FAX device 107, it is determined that the image forming apparatus 101 is in a disconnected state in which the image forming apparatus 101 is not connected to the network. The disconnected state may be referred to as the offline (offline state). In this way, the image forming apparatus 101 determines whether it is in the online, that is, in the connected state or in the offline, that is, in the disconnected state (a determination step). The CPU 340 of the main board 200 is responsible for this determination.

Although the CPU 340 functions as a determination unit that determines whether the apparatus is in the connected state or the disconnected state in this embodiment, this is not limiting. For example, a part functioning as the determination unit may be provided separately from the CPU 340. Further, as a result of the determination by the CPU 340, when it is determined that the apparatus is in the disconnected state, it is possible to perform a shutoff control for forcibly shutting off the power source of the image forming apparatus 101. The shutoff control may be referred to as the automatic turn-off or the shutdown. The CPU 340 of the main board 200 is responsible for the shutoff control. Although the CPU 340 functions as a power control unit that performs the shutoff control in this embodiment, this is not limiting. For example, a part functioning as the power control unit may be provided separately from the CPU 340.

The ON key 420 validates the function displayed in the label field 410. The OFF key 430 invalidates the function displayed in the label field 410. In this way, the ON key 420 and the OFF key 430 function as an operation unit that allows an operation for selecting whether the function displayed in the label field 410 is valid or invalid, and a switching control unit that performs a switching control for switching between the valid and invalid states of the function.

In the user notification field 440, for example, a warning “Power consumption will increase if OFF is selected.” is displayed. The user notification field 440 may display, for example, numerical values from “1” to “10” to be selectable. In this case, a message such as “Power consumption increases as the value increases” or “Power consumption increases as the value decreases” may be displayed in the user notification field 440. Further, when the numerical values include “0”, a message of “Power consumption increases when the value is “0“or as the value increases.” may be displayed. Further, when one choice is selected, sub-choices belonging to the selected choice may be displayed. A warning may then be displayed when the sub-choices are displayed.

The cancel key 450 is used to cancel the setting state on the UI screen 400. The OK key 460 is used to fix the setting state on the UI screen 400. The CPU 340 can save the setting state on the UI screen 400 in the storage device (a memory unit), such as the HDD 106, the nonvolatile memory 205, or the flash disk 207. The CPU 340 can change the setting state on the UI screen 400 in response to an operation by a user or an administrator or a notification from the computer 109 via the LAN 108.

In using an image forming apparatus that is not connected to a network and is not being operated remotely from the outside, it may be settled that the image forming apparatus is not used until a user approaches the image forming apparatus. In this image forming apparatus, since a power source is kept ON even though it is settled that the image forming apparatus is not used, power consumption is wasted accordingly. In view of this issue, the image forming apparatus 101 in this embodiment is configured to be able to reduce such waste of power consumption. The configuration and operation will be described below.

FIG. 5 is a flowchart illustrating the automatic turn-off process executed in the image forming apparatus 101. The program based on the flowchart illustrated in FIG. 5 is started from the standby state in which the CPU 340 of the main board 200 can receive a print job or a sleep transition event that is a trigger of transition to the sleep state. The CPU 305 of the operation unit 105 starts a sleep transition timer when a user last operates the image forming apparatus 101. Then, when the operation unit 105 receives no operation from a user during a predetermined period from the start of the sleep transition timer, the CPU 305 issues the sleep transition event to the CPU 340. Further, when a power saving key of the operation unit 105 is operated, the CPU 305 issues the sleep transition event to the CPU 340. Further, when a sleep event or a job event is received from the computer 109 via the LAN 108, the sleep transition event is issued to the CPU 340.

As shown in FIG. 5, in a step S501, the CPU 340 confirms that the use of the image forming apparatus 101 is completed, and determines whether the sleep transition event that is a trigger of transition from the normal state to the sleep state is received. The sleep transition event corresponds to, for example, an operation of an automatic sleep key or the power saving key. As a result of the determination in the step S501, when it is determined that the sleep transition event is received, the process proceeds to a step S502. On the other hand, as a result of the determination in the step S501, when it is determined that no sleep transition event is received, the process waits in the step S501.

The CPU 340 starts transition to the sleep state in the step S502 and proceeds with the process to a step S503.

In the step S503, the CPU 340 determines whether a predetermined process (for example, a copy job) based on an execution instruction from the computer 109 is executing. As a result of the determination in the step S503, when it is determined that the job is executing, the process waits in the step S503. Thus, the CPU 340 is in the standby state until the job execution is completed. When receiving a sleep reset event as an event other than a job, the CPU 340 can transition to a state of canceling the state waiting for completion of the job execution. On the other hand, as a result of the determination in the step S503, when it is determined that the job is not executing, the process proceeds to a step S504.

In the step S504, the CPU 340 determines whether the network is in the disconnected state. As a result of the determination in the step S504, when it is determined that the network is in the disconnected state, the process proceeds to a step S505. On the other hand, as a result of the determination in the step S504, when it is determined that the network is not in the disconnected state, that is, the network is in the connected state, the process ends. Thus, the transition to the sleep state is completed.

In the step S505, the CPU 340 starts the operation of an offline timer (a timer) and proceeds with the process to a step S506. The offline timer is built in the main board 200, for example.

In the step S506, the CPU 340 determines whether the sleep reset event for returning from the sleep state is received. The sleep reset event corresponds to, for example, a print job, sensor recovery, an operation of the power saving key, etc. As a result of the determination in the step S506, when it is determined that the sleep reset event is received, the process proceeds to a step S507. On the other hand, as a result of the determination in the step S506, when it is determined that no sleep reset event is received, the process proceeds to a step S508.

The CPU 340 resets the offline timer, i.e., returns the operation of the offline timer to an initial state in the step S507 and ends the process.

In the step S508, the CPU 340 determines whether the network is in the disconnected state. As a result of the determination in the step S508, when it is determined that the network is in the disconnected state, the process proceeds to a step S509. On the other hand, as a result of the determination in the step S508, when it is determined that the network is not in the disconnected state, the process proceeds to the step S507.

In the step S509, the CPU 340 determines whether the offline timer expires, i.e., whether the offline timer expires. As a result of the determination in the step S509, when it is determined that the operation of the offline timer expires, the process proceeds to a step S511. On the other hand, as a result of the determination in the step S509, when it is determined that the operation of the offline timer is not expired, the process proceeds to a step S510.

The CPU 340 waits for a certain time (e.g., 1 second) in the step S510 and sequentially executes the steps from the step S506.

In the step S511, the CPU 340 determines whether network is in the disconnected state. As a result of the determination in the step S511, when it is determined that the network is in the disconnected state, the process proceeds to a step S512. On the other hand, as a result of the determination in the step S511, when it is determined that the network is not in the disconnected state, the process ends.

In the step S512, the CPU 340 performs the automatic turn-off.

As described above, in the image forming apparatus 101, it is determined whether the network is in the disconnected state in the step S504 after the job execution is completed (No in the step S503) during the transition to the sleep state (the step S502). Note that this determination is not necessarily performed during the transition to the sleep state, and may be performed after the transition to the sleep state is completed. When it is determined that the network is in the disconnected state (Yes in the step S504), the offline timer is started. When the offline timer expires (Yes in the step S509), it is determined again whether the network is in the disconnected state (the step S511). When it is determined that the network is in the disconnected state again (Yes in the step S511), the automatic turn-off is performed (the step S512).

When it is determined that the network is in the connected state in any of the determinations of whether the network is in the disconnected state (No in the step S504 or S511), the automatic turn-off is not performed.

As described above, when the image forming apparatus 101 is not connected to the network and is not operated remotely from the outside, it may be settled that the image forming apparatus is not used until a user approaches the image forming apparatus 101. In such a use state, the automatic turn-off process can prevent the power source 301 of the image forming apparatus 101 from being kept ON. This can reduce waste of the power consumption in the image forming apparatus 101. When it is determined that the network is not in the disconnected state, that is, the network is in the connected state (No in the step S508) before the offline timer expires (No in the step S509), the offline timer is reset (the step S507). This can reduce an unnecessary operation of the offline timer, that is, countdown. When the transition from the sleep state to the normal state is completed before the offline timer expires, the offline timer may be reset. Instead of resetting the offline timer, for example, the operation of the offline timer may be canceled or stopped.

Hereinafter, a second embodiment will be described with reference to FIG. 6. Differences from the above-described embodiment will be described, and the description of the same matters will be omitted. The image forming apparatus 101 may be installed in a library, for example. In this case, when the image forming apparatus 101 is in a network disconnected state, the automatic turn-off that is unexpected by a user of the image forming apparatus 101 in the library may be performed. Further, unexpected automatic turn-off may be performed after firmware of the image forming apparatus 101 that is already in operation is updated. Therefore, the image forming apparatus 101 in this embodiment is configured to be able to reduce this phenomenon. The configuration and operation will be described below.

When the offline timer is always enabled, the issue in that the image forming apparatus 101 suddenly performs the automatic turn-off arises in an environment in which the image forming apparatus 101 is used in a library or the like by unspecified number of people in the network disconnected state. Therefore, when the automatic turn-off in the environment in which the network is in the disconnected state becomes a trouble, the CPU 340 can set the offline timer to be disabled from a local UI or a remote UI. This can prevent sudden automatic turn-off of the image forming apparatus 101.

In addition, when the offline timer is always enabled, the issue in that the image forming apparatus 101 suddenly performs the automatic turn-off arises in a case where firmware of the image forming apparatus 101 used in a city like a library in the network disconnected state is upgraded (updated). Therefore, the CPU 340 stores information about an installation date on which the image forming apparatus 101 has been installed in the library. And if the installation date of the image forming apparatus 101 is prior to reference date, the operation of the offline timer is not started even if the firmware is upgraded so that the automatic turn-off is reduced.

FIG. 6 is a flowchart illustrating an automatic turn-off process executed in the image forming apparatus according to the second embodiment. In the flowchart shown in FIG. 6, the steps S501 to S504 are sequentially executed as in the flowchart shown in FIG. 5. Then, as a result of the determination in the step S504, when it is determined that network is in the disconnected state, the process proceeds to a step S601.

In the step S601, the CPU 340 determines whether the offline timer is set to invalid. Note that the setting of the offline timer to invalid is performed on a screen (not shown) displayed on the operation unit 105, for example, and is stored in a storage device (a memory unit), such as the HDD 106, the nonvolatile memory 205, or the flash disk 207. The CPU 340 can change the invalid setting of the offline timer, that is, set to valid, in response to an operation by a user or an administrator or a notification from the computer 109 via the LAN 108.

Then, as a result of the determination in the step S601, when it is determined that the offline timer is set to invalid, the process ends, similarly to the case where it is determined that network is not in the disconnected state in the step S504. On the other hand, as a result of the determination in the step S601, when it is determined that the offline timer is not set to invalid, the process proceeds to a step S602.

In the step S602, the CPU 340 determines whether the installation date (date) on which the image forming apparatus 101 has been installed in the library (a predetermined location) is prior to a predetermined reference date. The installation date is stored in, for example, the storage device. Further, at least one of a production date on which the image forming apparatus 101 was produced and a setting date on which the operating conditions of the image forming apparatus 101 were set may be used instead of the installation date. Then, as a result of the determination in the step S602, when it is determined that the installation date is prior to the reference date, the process ends. As a result, the offline timer does not operate, and the automatic turn-off is disabled, and thus the execution of the automatic turn-off is prevented. On the other hand, as a result of the determination in the step S602, when it is determined that the installation date is not prior to the reference date, that is, the installation date is behind the reference date, the process sequentially executes the steps after the step S505. This starts the operation of the offline timer and enables the automatic turn-off, and thus the automatic turn-off can be executed. By such a control, when the unexpected execution of the automatic turn-off becomes a trouble, it is possible to prevent the unexpected execution of the automatic turn-off.

Hereinafter, a third embodiment will be described with reference to FIG. 7. Differences from the above-described embodiments will be described, and the description of the same matters will be omitted. In this embodiment, the image forming apparatus