Image forming apparatus, control method for image forming apparatus, and program

Abstract

To enable the improvement of usability by suppressing an occurrence of a situation or the like in which an operation state cannot be returned regardless of the existence of a return instruction from a user during a retry of power saving processing, the power saving processing cannot be completed, or the like in the case that the power saving processing such as suspension continues to lead a failure.SOLUTION: An image forming apparatus 101 inhibits suspension (transition from a power supply state D to a power supply state C and transition from a power supply state E to a power supply state B) (S511 of Figure 5), and makes a return to an original power state (S512 of Figure 5) in the case of failing in deep sleep processing (the transition from the power supply state D to the power supply state C) (in the case of No in S503 of Figure 5). Also, it performs shutdown (S611) in the case of failing in end processing (the transition from the power supply state E to the power supply state B) (in the case of No in S604). Further, it performs shutdown (S611) in the case that the suspension is inhibited (in the case of Yes in S602).SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to power control of an image forming apparatus.

Background Art

[0002] An image forming apparatus uses a suspend technique to achieve low power consumption by stopping peripheral devices and putting the CPU into a stopped state (OFF or WFI (Wait For Interrupt)) while keeping the memory powered on. When the image forming apparatus is not in use, it performs a suspend process and transitions to a sleep state from the standby state. Conversely, when the image forming apparatus receives an event notification for sleep resume from the sleep state, it performs a resume process and returns to the standby state.

[0003] Also, an image forming apparatus uses a hibernation technique to achieve low power consumption by saving the information in the memory and registers to a non-volatile storage device and turning off the peripheral devices and the CPU. Suspension and hibernation are used appropriately according to the user's usage and convenience, contributing to power saving of the image forming apparatus.

[0004] In Patent Document 1, a technique is proposed to shut down when a specific error notification is received from a drive unit such as a scanner or a printer during the suspend process.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Image forming apparatuses consist of multiple components that make up the system. Therefore, if a hardware failure occurs, various problems can arise with power-saving processes such as suspending or hibernating.

[0007] Power-saving processes such as suspend and hibernation involve shutting down the device. If a part of the device malfunctions and causes a delay in processing, the suspend process may take a long time, potentially resulting in users being unable to use the system for an extended period.

[0008] For example, during the suspend process of a non-volatile memory device, if writing to some blocks does not complete immediately, the system may be forced to wait until a timeout occurs. In this case, the non-volatile memory device may be stopped by stopping the write operation to the faulty block or by recovering the faulty block through read / write operations. However, if the blocks in the non-volatile memory device are not recovered, and the non-volatile memory device fails to detect the block abnormality, the suspend retry process will cause a wait of several minutes, resulting in reduced convenience for the user, such as being unable to use the system during that time. If the device suspend fails, the entire system suspend may fail, leading to delays in user response.

[0009] Furthermore, power-saving processes such as suspend and hibernation involve stopping processes. If a process is performing system processing at this time, the process suspension can take time, potentially resulting in users being unable to use the system for extended periods. For example, a network transmission and reception process performs a series of communication protocol operations, sending a transmit buffer to the counterpart device and receiving a response in the receive buffer. During this process, the transmit and receive buffers become busy, and the suspension process for the process and the device drivers it uses fails until the sending and receiving of buffers is complete. As a result of the process suspension failure, the entire system fails to suspend, leading to delays in user response.

[0010] As mentioned above, when power-saving processes such as suspend or hibernation fail, even though continued failure is possible, retries to the power-saving process are performed, leading to issues such as delays in user response or the process not completing at all.

[0011] This invention was made to solve the above-mentioned problems. The objective of this invention is to solve problems caused by the continuous failure of power saving processes such as suspend, and to provide a mechanism that suppresses situations such as the inability to return to an operational state even when a user commands a return to the operational state during a retry of the power saving process, or the inability to complete the power saving process. [Means for solving the problem]

[0012] The present invention relates to an image forming apparatus that transitions between a plurality of power states, including a suspend state, and the transition to the suspend state predetermined number of times If it fails, The transition to the aforementioned suspend state is prohibited, It has a control means for performing a shutdown. Furthermore, the number of times the transition to the suspend state has failed is initialized in accordance with the occurrence of a different startup than a watchdog reset. It is characterized by doing so. [Effects of the Invention]

[0013] According to the present invention, the problems that arise when power-saving processes such as suspend repeatedly fail can be solved, and situations such as the inability to return to an operational state even when a user commands a return to the power-saving process to retry, or the failure to complete the power-saving process can be suppressed. As a result, usability can be improved. [Brief explanation of the drawing]

[0014] [Figure 1] A diagram illustrating the configuration of the image forming system shown in this embodiment. [Figure 2] A diagram showing the configuration of the controller included in the image forming apparatus of this embodiment. [Figure 3] A diagram illustrating the power supply configuration of the image forming apparatus according to this embodiment. [Figure 4] A diagram illustrating the power state and state transitions of the image forming apparatus according to this embodiment. [Figure 5] Flowchart for explaining the operation of the image forming apparatus according to the first embodiment. [Figure 6] Flowchart for explaining the operation of the image forming apparatus according to the first embodiment. [Figure 7] Flowchart for explaining the operation of the image forming apparatus according to the second embodiment. [Figure 8] Flowchart for explaining the operation of the image forming apparatus according to the third embodiment. [Figure 9] Flowchart for explaining the operation of the image forming apparatus according to the third embodiment. [Figure 10] Flowchart for explaining the operation of the image forming apparatus according to the third embodiment. [Figure 11] Flowchart for explaining the operation of the image forming apparatus according to the fourth embodiment. [Figure 12] Flowchart for explaining the operation of the image forming apparatus according to the fourth embodiment. [Figure 13] Flowchart for explaining the operation of the image forming apparatus according to the fourth embodiment.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. 〔First Embodiment〕 <Configuration of the System> FIG. 1 is a diagram for explaining an example of the configuration of an image forming system showing an embodiment of the present invention. In the present embodiment, a multifunction peripheral having a printing function, a scanner function, a data communication function, etc. will be described as an example.

[0016] In FIG. 1, the image forming apparatus 101 is configured to be able to receive jobs from the computer 109 via the LAN 108. The number of connected computers may be 1 or more.

[0017] In the image forming apparatus 101, the scanner 102 optically reads an image from a document and converts it into a digital image. The printer 104 outputs the digital image to a paper device called paper. The operation unit 105 is equipped with a touch panel and hard keys for receiving settings for the apparatus from the user and displaying the processing status. The hard disk (HDD) 106 stores digital images, control programs, etc. The HDD 106 is a non-volatile storage device and may also be an SSD (Solid State Drive) or eMMC (embedded Multi Media Card). The fax machine 107 sends and receives digital images over a telephone line, etc. The controller 103 is connected to the scanner 102, printer 104, operation unit 105, hard disk 106, and fax machine 107, and executes jobs on the image forming apparatus 101 by issuing instructions to each module.

[0018] The image forming apparatus 101 can also receive input and output of digital images from the computer 109 via the LAN 108, issue jobs, and give instructions to the equipment. The scanner device 102 includes a document feeding unit 121 that can automatically and sequentially replace stacks of documents, and a scanner unit 122 that can optically scan documents and convert them into digital images. The image data converted by the scanner unit 122 is transmitted to the controller 103.

[0019] The printer device 104 has a paper feeding unit 142 that can sequentially feed one sheet of paper at a time from a stack, a marking unit 141 for printing image data on the fed paper, and a paper output unit 143 for ejecting the printed paper. The finisher device 150 performs processing such as paper ejection, sorting, stapling, punching, and cutting on the paper devices output from the paper output unit 143 of the printer device 104 of the image forming apparatus 101.

[0020] Furthermore, the image forming apparatus 101 has a power switch 110 for controlling the power supply. When this power switch is turned off, the image forming apparatus 101 waits for the software and hardware to finish processing and then stops supplying power to all parts except those necessary to detect when the power switch is turned on.

[0021] <System Functions> The following describes an example of a job (function) that the image forming apparatus 101 can perform. [Copy function] The image forming apparatus 101 has a copying function that records images read from the scanner device 102 onto the hard disk 106 and simultaneously prints them using the printer device 104. [Image transmission function] The image forming apparatus 101 includes an image transmission function that transmits images read from the scanner device 102 to the computer 109 via the LAN 108. [Image saving function] The image forming apparatus 101 has an image storage function that records images read from the scanner device 102 onto the hard disk 106 and transmits or prints the images as needed. [Image printing function] The image forming apparatus 101 includes an image printing function that analyzes, for example, a page description language transmitted from the computer 109 and prints it using the printer device 104.

[0022] <Configuration of the operating unit 105> The operation unit 105 is connected to the controller 103. The operation unit 105 has an LCD touch panel, power saving buttons, copy buttons, cancel buttons, reset buttons, a numeric keypad, a user mode key, etc., and provides a user interface for operating the image input / output system. These keys include hardware keys and software keys displayed on the LCD, and the presence of hardware keys is not mandatory.

[0023] <Block diagram of controller 103> Next, Figure 2 will be used to explain the block diagram of the controller 103 and its peripheral devices. Figure 2 shows an example of the configuration of the controller 103. The controller 103 has a main board 200 and a sub-board 220.

[0024] The Mainboard 200 is a so-called general-purpose CPU system. The mainboard 200 has a CPU 340 that controls the entire board, a boot ROM 202 that contains the boot program, and memory 341 that the CPU uses as work memory. The mainboard 200 also has a bus controller 204 that has a bridging function with an external bus, non-volatile memory 205 that is not erased even when the power is lost, and a watchdog timer (WDT) 230 that resets the controller 103. The CPU 340 controls the WDT 230.

[0025] The main board 200 also includes a disk controller 206 for controlling the storage device, and a flash disk 207 such as an SSD or eMMC, which is a relatively small-capacity storage device made of semiconductor devices. Furthermore, the main board 200 includes a USB controller 208 capable of controlling USB, a real-time clock (RTC) 272, and the like. External devices such as a USB memory stick 209, control unit 105, and hard disk 106 are connected to the main board 200.

[0026] Subboard 220 consists of a relatively small general-purpose CPU system and image processing hardware, etc. The sub-board 220 includes a CPU 221 that controls the entire board, a memory 223 that the CPU uses as work memory, a bus controller 224 that has a bridging function with an external bus, and a non-volatile memory 225 that is not erased even when the power is cut off. Furthermore, the sub-board 220 includes an image processing processor 227 and a device controller 226 for real-time digital image processing.

[0027] The scanner device 102 and printer device 104, which are connected to the outside of the controller 103, exchange digital image data via the device controller 226. Paper devices ejected from the printer device 104 are processed by the finisher device 150. The fax device 107 is directly controlled by the CPU 221.

[0028] Note that this diagram is a block diagram and has been simplified. For example, CPU340, CPU221, etc., include many CPU peripheral hardware components such as chipsets, bus bridges, and clock generators, but these are simplified in this explanation as they are unnecessary for the level of detail, and this block configuration does not limit the present invention.

[0029] The operation of controller 103 will be explained below using image copying using a paper device as an example. When the user commands image copying from the operation unit 105, the CPU 340 sends an image reading command to the scanner device 102 via the CPU 221. The scanner device 102 optically scans the paper document, converts it into digital image data, and inputs it to the image processing processor 227 via the device controller 226. The image processing processor 227 performs a DMA transfer to the memory 223 via the CPU 221 to temporarily store the digital image data. When the CPU 340 confirms that a certain amount or all of the digital image data has been stored in the memory 223, it issues an image output command to the printer device 104 via the CPU 221. The CPU 221 informs the image processing processor 227 of the address of the image data in the memory 223. The image data on the memory 223 is transmitted to the printer device 104 via the image processing processor 227 and the device controller 226 according to a synchronization signal from the printer device 104. The printer device 104 prints the digital image data onto the paper device. When printing multiple copies, the CPU 340 saves the image data from memory 223 to the hard disk 106. For the second and subsequent copies, it is possible to send image data to the printer device 104 from the hard disk 106 or memory 223 without receiving image data from the scanner device 102.

[0030] <Power configuration> Figure 3 is a block diagram illustrating the power supply configuration of the image forming apparatus 101. The following explanation, using Figure 3, will describe the configuration of the power supply 301, power control unit 303, controller 103, operation unit 105, scanner device 102, and printer device 104 in the image forming apparatus 101, focusing on the parts related to the present invention.

[0031] The power control unit 303 is constantly supplied with power from the power supply 301 via the power line. However, because it consumes only a small amount of power, when the power is turned off, only the power control unit 303 is energized, and power control is performed. In the image forming apparatus 101, when the power switch 110 is pressed, the power control unit 303 detects this. Upon detecting that the power switch 110 has been pressed, the power control unit 303 controls the power switch P310 to supply power to the CPU 340 of the controller 103. Similarly, the power control unit 303 controls the power switch Q311 to supply power to the CPU 305 of the operation unit 105, the power switch R312 to supply power to the scanner device 102, and the power switch L313 to supply power to the printer device 104.

[0032] Furthermore, the CPU 340 of the controller 103 can also control the power switch Q311 to supply power to the CPU 305 of the operation unit 105 from the power supply 301 by notifying the power control unit 303. Similarly, the CPU 340 can also individually supply power to the scanner device 102 by controlling the power switch R312 and to the printer device 104 by controlling the power switch L313 from the power supply 301. At this time, it is also possible to individually control the power supply of the marking unit 141, paper feed unit 142, and paper output unit 143 of the printer device 104, but this is outside the scope of this discussion and will be omitted.

[0033] The power supply for each block as shown in Figure 3 can be achieved, for example, by configuring the power switch P310 into two systems, and in the sleep state, turning off only the power switch connected to the block whose power is to be turned off, while leaving the other system on. In the shutdown state, both power switches are turned off. In this case, the power control signal is not binary, but a multi-level control signal corresponding to the power supply state. Although such a description is omitted in this example, the aforementioned power states, including the sleep state and shutdown state, are powered by this type of control. This control can be implemented in any form, whether the power control unit 303 performs multi-level control of the power switch P310 to supply power to each block of the controller 103, or the CPU 340 of the controller 103 notifies the power control unit 303 to perform multi-level control of the power switch P310 to supply power to each block of the controller 103. In this embodiment, power switches P310, Q311, R312, and L313 are relay switches, but they are not limited to relay switches; for example, silicon switches may also be used.

[0034] <Power states and power state transitions> Figure 4 illustrates the five power states and state transitions of the system in this embodiment. First, let's explain the five power states. The five power states are arranged in order from lowest to highest power consumption: Power State A < Power State B < Power State C < Power State D < Power State E.

[0035] Power state A is one of the states where the power switch is OFF, and corresponds to the cold-off state. In this power state, power is supplied to the functional parts that receive the signal notification when the power switch is ON. Power state B is one of the states where the power switch is OFF, and corresponds to the off state that enables fast recovery from fast startup modes, also known as suspend or hibernation. In this power state, power is supplied to the functional parts that receive the signal notification when the power switch is ON, and in the case of suspend, to functional parts such as memory.

[0036] Power state C is one of the states where the power switch remains ON, and corresponds to a deep sleep state. In this power state, power is supplied to functional parts such as the CPU and memory used for interrupt waiting (WFI) and suspend. Note that both power states B and C belong to the suspend state.

[0037] Power state D is one of the states where the power switch remains ON, corresponding to a light sleep state. In this power state, the UI screen is turned off, and power is supplied to the functional parts that use the CPU and memory.

[0038] Power state E is the standby or operating state with the power switch ON. In this power state, the UI screen is turned ON, power is supplied to the CPU and memory, and power is supplied to the functional parts being used, such as the printer, scanner, and facsimile. At this time, the control unit 105 is assumed to be ON, but it may be OFF during printing, etc.

[0039] The following describes the power transitions between the five power states. <Power supply at startup: State transition from power state A to power state E> When the operator wants to use the image forming apparatus 101 from power state A, they turn on the power switch 110. This starts the startup process for the image forming apparatus 101.

[0040] The following describes the startup process of the image forming apparatus 101. When the power control unit 303 detects that the power is ON from the power switch 110, it turns on the power switches (310, 311, 312, 313) using a power switch control signal. As a result, power is supplied from the power supply 301 to the entire device, namely the controller 103, the operation unit 105, the scanner device 102, and the printer device 104, via each DC power supply path. In other words, the device transitions to power state E. When power is supplied to the controller 103, the printer device 104, the scanner device 102, etc., their respective CPUs begin initialization operations.

[0041] At this time, the power supply to the controller 103 may be controlled in more detail by the power switch P310, the operating unit 105 by the power switch Q311, the scanner device 102 by the power switch R312, and the printer device 104 by the power switch L313. For example, the controller 103 can divide the power switch into multiple parts to separate the power supply to the main board 200 and the sub-board 220, or to separate the network controller 211 of the main board 200. This allows for different power supplies for, for example, sleep mode and fast startup mode. Also, in the printer device 104, for example, the power supply to the CPU and the paper feed unit 142, marking unit 141, and paper output unit 143 can be separated, but the details are omitted here.

[0042] When power is supplied, the CPU 340 of the controller 103 performs hardware initialization. Hardware initialization includes register initialization, interrupt initialization, registration of device drivers at kernel startup, and initialization of the control unit 105. Next, the CPU 340 of the controller 103 performs software initialization. Software initialization includes calling initialization routines for each library, starting processes and threads, starting software services that communicate with the printer device 104 and scanner device 102, and drawing on the control unit 105. Finally, the CPU 340 of the controller 103 transitions to a standby state.

[0043] <Power supply in standby mode: Power state E> Next, we will explain the power supply to the image forming apparatus 101 in its normal state, when the printer device 104 and scanner device 102 are not in use. The normal state is not simply a state where all units are powered. The normal state also includes, for example, a state where power is not supplied to the printer device 104 when printing is not in progress, or a state where power is not supplied to the scanner device 102 when the operation unit 105 is not lit and it is known that the user is not in front of the image forming apparatus 101. The normal state also includes a waiting state in which power is supplied to the necessary parts in order to speed up the completion of printing by the printer device 104 or the completion of scanning by the scanner device 102. The waiting state includes, for example, a state in which the paper feed unit 142 and paper output unit 143 do not operate the motors or polygons for printing, or a state in which the marking unit 141 does not temperature control the transfer unit for printing. The waiting state also includes a state in which the scanner unit 122 does not operate the home position detection for scanning.

[0044] <Power supply during printing: Power state E> Next, we will explain the power supply in the image forming apparatus 101 when the printer device 104 or scanner device 102 are in use in printing mode, such as copying or PDL printing. This section explains how to turn the printer device 104 on and off using the image printing function. The CPU 340 of the controller 103 receives data from the computer 109 via the LAN 108 into the memory 341. The CPU 340 analyzes the received data and, if it is to execute the image printing function, generates a print job. The CPU 340 then notifies the power control unit 303, which switches the power switch L313 to supply power from the power supply 301 to the printer device 104. Furthermore, the CPU 340 executes the print job when the printer device 104 becomes available. The CPU 340 sends data to the CPU 221 of the sub-board 220 via the memory 341, the bus controller 204, and the bus controller 224 of the sub-board 220. Furthermore, the CPU 221 sends data to the printer device 104 via the image processing processor 227 and the device controller 226. The printer device 104 prints the received data and, upon completion of printing, notifies the CPU 340 of the result. When printing is complete, the CPU 340 uses the power control unit 303 to turn off the power switch L313 using a power control signal, thereby turning off the power to the printer device 104.

[0045] <Power supply in standby mode: State transitions between power state E, power state D, and power state C> CPU340 transitions from power state E to power state D upon completion of jobs such as printing or scanning, or after a certain period of time has elapsed since the end of user operations (S442). Furthermore, when the system finishes using CPU340, such as for network responses, it transitions from power state D to power state C (S432). Subsequently, in power state C, if CPU340 receives a notification such as the reception of a network packet, it transitions to power state D (S431). If the network packet is a job, CPU340 transitions from power state D to power state E (S441) and executes the job.

[0046] <Power supply during sleep transition: State transition from power state D to power state C> Next, we will explain the sleep transition process of controller 103. When the CPU 340 remains in an active state for a certain period of time without being used by the user, such as when a user's copy or network print job is completed, the CPU 340 transitions to a sleep state via an auto-sleep timer. The CPU 340 notifies the power control unit 303 of the transition to the sleep state and changes the power supply to the controller 103. The CPU 340 controls the power control unit 303 to use multi-level control of the power switch P310 to turn off each block of the controller 103, puts the CPU 340 into an interrupt signal waiting state, and puts the CPU 340 into a sleep state. As mentioned above, power supply to each block can be achieved, for example, by configuring the power switch P310 with two systems, and in the sleep state, turning off only the power switch connected to the block whose power is to be turned off, while leaving the other on.

[0047] At this time, the CPU 340 notifies the power control unit 303, which then turns off the power switch Q311 using a power control signal, thereby cutting off the power supply from the power supply 301 to the operation unit 105 and transitioning to sleep mode. Alternatively, the CPU 340 notifies the CPU 305 of the operation unit 105 via serial communication or other means, which then puts the operation panel and peripherals into a power-saving state, causing the operation unit 105 to transition to sleep mode.

[0048] Also at this time, as described above, the CPU 340 notifies the power control unit 303, which then turns off the power switches (312, 313) using a power control signal, stopping the power supply to the scanner device 102 and the printer device 104. If no print jobs have been generated or if it is not necessary to acquire device information, the printer device 104 and the scanner device 102 do not need to be powered except for parts necessary for sleep recovery, such as sensors.

[0049] <Power supply during sleep mode: Power state C> Next, we will explain the sleep state of the image forming apparatus 101. Sleep mode refers to the CPU's WFI (Wait For Interrupt) standby state or suspend state, which allows for faster startup times compared to normal startup while reducing power consumption. The system enters sleep mode when a certain period of time has passed without user operation, when the touch panel or power-saving key on the control unit 105 is pressed, or when a set time is reached. In sleep mode, power is supplied to the controller 103's memory 341, interrupt controller, network controller 211, RTC 212, USB controller 208, etc. Power is also supplied to the power-saving key on the control unit 105, part of the fax machine, various sensors, etc. However, since the factors for waking from sleep mode vary depending on the system, the power supply in sleep mode is not limited to this configuration.

[0050] This section describes the software's behavior when the system resumes from sleep mode. The power supply control unit 303 starts supplying power when it receives one or more interrupts during sleep mode, such as network, RTC (Real-Time Clock) which detects timers and alarms, FAX which detects incoming calls and off-hooks, soft switches, various sensors, and USB which detects insertion / removal and communication. The power supply control unit 303 notifies the CPU 340 of the cause of the interrupt, and the CPU 340, upon receiving this notification, performs a process to return the software state to the normal state, i.e., a sleep recovery process.

[0051] <Power supply upon resuming from sleep: State transition from power state C to power state D> Next, we will explain the sleep wake-up process for controller 103. When the power control unit 303 receives a power saving key press event handler, which is a sleep wake-up event, during sleep mode, it turns on the power switch P310 and wakes the CPU 340 of the controller 103 from sleep mode. At this time, for example, the power control unit 303 can also wake the CPU 340 from sleep mode by multi-level control of the power switch P310 to supply power to each block of the controller 103 and issuing an interrupt signal to the CPU 340. Note that this sequence is outside the scope of this paper and will be omitted. The CPU 340 notifies the power control unit 303, and the power control unit 303 turns on the power switches (311, 312, 313) and supplies power to the operation unit 105, scanner device 102, and printer device 104. Note that power supply to devices such as the fax device 107 is not shown in the diagram, but it can also be provided as an unshown signal.

[0052] <Power supply in fast startup mode: Power state B> Next, we will describe the high-speed startup mode state of the image forming apparatus 101. Fast startup mode refers to a suspend or hibernation state that allows for faster startup times than normal startup while reducing power consumption. The system transitions to high-speed startup mode when the user turns off the power switch or when it receives termination notification from applications or servers inside or outside the image forming apparatus. In fast startup mode, power is supplied to the memory 341 of the controller 103 and the interrupt controller that receives the power switch ON interrupt. On the other hand, power is saved in fast startup mode by de-energizing or resetting devices that are not used as recovery factors, such as the network controller 211, RTC 212, USB controller 208, power saving keys on the operation unit 105, part of the fax machine 107, and various sensors. However, since the recovery factors from fast startup mode vary depending on the system, the power supply in fast startup mode is not limited to this configuration.

[0053] This section describes the software's behavior when resuming from fast boot mode. When the power control unit 303 receives an interrupt indicating that the power switch 110 is ON during fast startup mode, it begins supplying power. The power control unit 303 notifies the CPU 340 of the cause of the interrupt, and the CPU 340, upon receiving this notification, performs the process of returning the software state to a normal state, namely, the process of returning from fast startup mode, the process of returning from hibernation, and the process of resuming from suspend.

[0054] <Flowchart Explanation> In the first embodiment, if deep sleep processing fails, a power saving prohibition flag is set, and suspend processing (i.e., transition to power state C or power state B) is prohibited. This configuration will be explained in detail below using a flowchart. Figures 5 and 6 are flowcharts showing an example of the operation of the image forming apparatus of the first embodiment, and most succinctly represent the features of this embodiment. For example, these processes are realized by the CPU 340 loading a program stored in the HDD 106 into the memory 341 and executing it.

[0055] First, let's explain using the flowchart in Figure 5. The process shown in the flowchart of Figure 5 corresponds to a deep sleep process (transition process from power state D to power state C). This process is triggered by the CPU 340 when a sleep process occurs, such as the completion of printing or scanning, or a certain period of time after the user has finished using the image forming apparatus, i.e., the start of the transition from power state D to power state C (S432).

[0056] First, the CPU 340 checks whether a power saving disabling flag is set (S501). For example, the power saving disabling flag is stored in memory 341, and for example, when the power of the image forming apparatus 101 is turned off, the power saving disabling flag becomes unset. If the power saving prohibition flag is set (Yes in S501), CPU340 will not transition to power state C and will terminate the processing of this flowchart.

[0057] On the other hand, if the power saving prohibition flag is not set (No in S501), the CPU340 performs the transition process to power state C (S502). Next, CPU340 checks whether the transition process to power state C in S502 failed (S503). If successful (No in S503), the transition to power state C is completed, and the processing of this flowchart ends.

[0058] On the other hand, if the transition process to power state C in S502 fails (if the result is Yes in S503), the CPU 340 sets the power saving prohibition flag (S511), returns the power state to power state D (S512), and terminates the processing of this flowchart.

[0059] The following explanation will use the flowchart in Figure 6. The process shown in the flowchart of Figure 6 corresponds to the termination process (transition process from power state E to power state B). This process is initiated by the CPU 340 when a termination event occurs, i.e., when the power switch 110 is turned OFF or when a termination notification is received from the application, which triggers the transition from power state E to power state B (S422).

[0060] CPU340 checks whether the power switch 110 (power SW) is turned OFF (S601). Turning the power SW OFF can also be done by checking whether a termination notification has been received from the application. If the power SW is not turned OFF (S601 is No), CPU340 continues to check whether the power SW is turned OFF. On the other hand, if the power switch is turned OFF (if S601 is answered with Yes), CPU340 proceeds to process S602.

[0061] In S602, the CPU 340 checks whether the power saving prohibition flag is set. If the power saving prohibition flag is set (Yes in S602), the CPU 340 performs a transition process to power state A in order to cold off by shutdown (S611). As a result, the image forming apparatus 101 shuts down and enters the cold-off state.

[0062] On the other hand, if the power saving prohibition flag is not set (No in S602), CPU340 proceeds to process S603. In S603, CPU340 initiates the transition process to power state B in order to perform suspend or hibernation. Then, CPU340 checks whether the transition process to power state B in S603 failed (S604). If it did not fail (No in S604), CPU340 completes the transition to power state B, and the processing of this flowchart ends.

[0063] On the other hand, if the transition process to power state B in S603 fails (if the answer is Yes in S604), the CPU 340 performs the transition process to power state A in order to shut down and cold off (S611). As a result, the image forming apparatus 101 shuts down and enters a cold-off state. If the transition process to power state B in S603 fails (if the answer is Yes in S604), the system may be configured to return to the original power state E.

[0064] In image forming apparatuses, the transition process to sleep mode may fail. If an attempt is made to perform a shutdown process after a failure to transition to sleep mode, the transition process to any of the fast startup modes, such as suspend or hibernation, which cuts off power and the clock of devices that are not recovery factors and lowers the power to a level lower than sleep mode, will also fail. Therefore, in the first embodiment, if the image forming apparatus 101 fails to transition to power state C during deep sleep processing, it prohibits transitions to power state C and power state B. This prevents repeated retries to transition to power state C and power state B, and prevents situations where the apparatus cannot return to an operational state even if a user commands it to resume operation during retries. Furthermore, if the image forming apparatus 101 fails to perform deep sleep processing as described above, it automatically shuts down without transitioning to power state B during the shutdown process, which would normally transition to power state B, a fast recovery-enabled power state in fast startup mode. It also automatically shuts down if the transition to power state B fails during the shutdown process. Thus, the above configuration ensures that the power is reliably turned off. As a result, in cases where power-saving processes such as suspend or hibernation are likely to fail repeatedly, it is possible to prevent situations where the power-saving process is repeatedly retried, resulting in delays in user response or the power-saving process not being completed. Furthermore, it is possible to prevent situations where the system cannot return to an operational state even if a user commands it to resume operation during power-saving process retries.

[0065] [Second Embodiment] In the process shown in Figure 6 of the first embodiment, power-off can be guaranteed by automatically shutting down if suspend fails. In this configuration of the first embodiment, since the system shuts down without returning to the original power state, if the termination process performed by the application during suspend and the termination process during shutdown are different, data may be logically corrupted. In contrast, in the process shown in Figure 7 of the second embodiment, if the transition to power state B, which is suspend, fails, the system first returns to power state E, which is the original power state, and then automatically transitions to power state A, which is the shutdown state. This allows the application to terminate as well, and data protection is possible.

[0066] Figure 7 is a flowchart showing an example of the operation of the image forming apparatus of the second embodiment, and most succinctly represents the features of this embodiment. These processes are realized by the CPU 340 loading a program stored in the HDD 106 into memory 341 and executing it. The processes shown in the flowchart of Figure 7 are started by the CPU 340 when a termination event occurs, i.e., a transition from power state E to power state B (S422), triggered by the power switch 110 being turned OFF or a termination notification being received from the application.

[0067] First, the processes in S701-S704 and S711 are the same as those in S601-S604 and S611 in Figure 6, so their explanation will be omitted, and the explanation will focus on the differences from Figure 6. In the second embodiment, if the transition process to power state B fails (if Yes in S704), the CPU 340 sets the power saving prohibition flag (S721) and returns to power state E (S723). Upon returning to power state E, the CPU 340 continues the termination process as it has already received the termination notification and checks whether the power saving prohibition flag has been set (S702). In this case, since the power saving prohibition flag was set in S721, the CPU 340 determines Yes in S702 and performs the transition process to power state A (S711). By first returning to the original power state, power state E, and then transitioning to the shutdown state, power state A, the application can be terminated before being shut down. Note that the power saving prohibition flag may also be a flag that instructs a transition to power state A.

[0068] As described above, according to the second embodiment, if the image forming apparatus 101 fails to transition to a power-saving state such as suspend, it can return to its original power state, thereby ensuring that the application termination process is performed and the apparatus shuts down during the termination process. This allows the application to be terminated before shutdown, thus protecting the data.

[0069] [Third Embodiment] In the third embodiment, if the sleep process fails, the settings stored in the non-volatile memory are changed to prohibit the sleep process and fast startup process, and the user is notified. Conversely, if the phenomenon of failure to transition to power saving mode due to maintenance or other reasons is resolved, the settings stored in the non-volatile memory are restored to their original values, and the sleep process and fast startup process are permitted, and the user is notified in this case as well. This configuration will be explained below using a flowchart. Figures 8, 9, and 10 are flowcharts showing an example of the operation of the image forming apparatus of the third embodiment, and most succinctly represent the features of this embodiment. These processes are achieved by the CPU 340 loading a program stored in the HDD 106 into the memory 341 and executing it.

[0070] The flowchart in Figure 8 will be explained below. The process shown in the flowchart of Figure 8 corresponds to a deep sleep process (transition process from power state D to power state C). This process is triggered by the CPU 340 when a deep sleep process occurs, i.e., when a transition from power state D to power state C (S432) begins, such as when printing or scanning is completed, or after a certain period of time has passed since the user finished using the image forming apparatus.

[0071] First, the CPU 340 checks whether the power saving setting stored in the non-volatile memory is power saving disabled (S801). The power saving setting is stored in, for example, the HDD 106 or the non-volatile memory 205, and the setting information such as "power saving disabled" or "power saving enabled" is stored as the power saving setting. If the power saving setting is set to disable power saving (Yes in S801), CPU340 will not transition to power state C and will terminate the processing of this flowchart.

[0072] On the other hand, if the power saving setting is set to allow power saving (No in S801), the CPU 340 starts the process of transitioning to power state C (S802). Next, CPU340 checks whether the transition process to power state C in S802 failed (S803). If successful (No in S803), CPU340 completes the transition to power state C, and the processing of this flowchart ends.

[0073] On the other hand, if the transition process to power state C in S802 fails (if S803 is Yes), the CPU 340 proceeds to S811. In the S811, CPU340 changes the power saving setting to power saving disabled. In S812, CPU340 returns to power state D. Furthermore, the CPU 340 transitions to power state E (S813), changes the display unit of the operation unit 105 from a hidden state due to sleep to a displayed state, notifies (for example, by displaying on the display unit) that the power saving setting has been changed to power saving disabled (S814), and terminates the processing of this flowchart.

[0074] Furthermore, the notification method described in S814 above is not limited to display on the display unit; it can also be performed simultaneously using multiple notification methods, such as sending notifications to an external server or a designated email address, or recording and saving in a log that the transition to power state C failed. Any notification method that can notify users or service personnel is acceptable. Further details are omitted as they are outside the scope of this paper.

[0075] Furthermore, the data (power saving settings) stored in the aforementioned non-volatile memory device will not be lost if the information from the non-volatile memory device is loaded into memory (e.g., memory 341), modified, and saved to the non-volatile memory device before the power to the memory is cut off. Also, it is not always necessary to read from or write to the non-volatile memory device when accessing the power saving settings, but this is outside the scope of this discussion and will be omitted.

[0076] Next, we will explain the flowchart in Figure 9. The flowchart in Figure 9 corresponds to the termination process (transition process from power state E to power state B). This process is initiated by the CPU 340 when a termination event occurs, such as when the power switch 110 is turned OFF or when a termination notification is received from the application, i.e., when the transition occurs from power state E to power state B (S422).

[0077] CPU340 checks whether the power switch 110 (power SW) is turned OFF (S901). Turning the power SW OFF can also be done by checking whether a termination notification has been received from the application. If the power SW is not turned OFF (S901 is No), CPU340 continues to check for the power SW being OFF as in S901. On the other hand, if the power switch is turned OFF (if S901 is answered with Yes), CPU340 proceeds to process S902.

[0078] In S902, the CPU340 checks whether the power saving setting stored in the non-volatile memory is set to power saving disabled. If the power saving setting is set to power saving disabled (Yes in S902), the CPU340 performs a transition process to power state A in order to perform a cold-off by shutdown (S912).

[0079] On the other hand, if the power saving setting is set to allow power saving (No in S902), CPU340 starts the transition process to power state B in order to suspend or hibernate (S903). Next, CPU340 checks whether the transition process to power state B in S903 failed (S904). If successful (No in S904), CPU340 completes the transition to power state B and terminates the processing of this flowchart.

[0080] On the other hand, if the transition to power state B fails (if S904 is Yes), CPU340 proceeds to S911. In the S911, the CPU340 changes the power saving setting to power saving disabled. In addition, in S912, the CPU 340 undergoes a transition process to power state A because it is cold-off due to shutdown (S912). Alternatively, as in the second embodiment, the transition process to power state A may be performed after returning to the original power state.

[0081] The flowchart in Figure 10 will be explained below. The flowchart in Figure 10 begins when the CPU 340 detects a maintenance operation. For example, it begins when it detects hardware replacement, such as a controller or non-volatile memory device, during the power-off process. It also begins when it detects that a device has entered maintenance mode or that maintenance mode has been released. Furthermore, it begins when it detects that the service technician's work mode has been released. There are several other timings and methods for detecting a device that has failed to shut down and whose power state transition has failed (S803, S904), and its recovery, but these are outside the scope of this discussion and will be omitted in detail. In the flowchart in Figure 10, maintenance is considered complete when an event occurs that resolves the phenomenon of failure to transition to power saving mode due to maintenance or other reasons.

[0082] The CPU 340 determines whether the maintenance of the image forming apparatus 101 is complete (S1001). If the maintenance is not complete (No in S1001), the CPU 340 continues to check for maintenance completion. On the other hand, if maintenance is complete (if the answer to S1001 is Yes), CPU340 proceeds to process S1002.

[0083] In S1002, CPU340 checks whether the power saving setting for the non-volatile memory device has been changed to power saving disabled (i.e., the processes in S811 and S911 have been performed). If the power saving setting has not been changed to power saving disabled (i.e., No in S1002), CPU340 terminates this flowchart.

[0084] On the other hand, if the power saving setting has been changed to power saving disabled (if the answer is Yes in S1002), the CPU 340 changes the power saving setting of the non-volatile memory device to power saving enabled (S1003) and notifies that the setting has been changed to power saving enabled (S1004).

[0085] The notification method of S1004 described above can perform multiple actions simultaneously, such as notifying an external server and recording and saving failures, and is not limited to displaying information on the display unit of the operation unit 105, but this is outside the scope of this paper and will be omitted. Furthermore, while the power saving settings are being changed, it is possible to mask and prohibit the user from changing the settings from the control unit 105 or computer 109, or to notify the user when they attempt to change the power saving settings. However, these are outside the scope of this paper and will be omitted.

[0086] As described above, according to the third embodiment, if the image forming apparatus 101 fails to transition to a power-saving state such as suspend, it can disable the power-saving settings to prohibit the transition to a power-saving state such as suspend and notify the user. Conversely, if the phenomenon of failure to transition to a power-saving state is resolved due to maintenance or other reasons, it can enable the power-saving settings to allow the transition to a power-saving state such as suspend and notify the user.

[0087] [Fourth Embodiment] During the process of entering a power-saving state such as suspend (suspend process) or resuming (resume process), a device failure or other issue may cause the suspend or resume process to fail, resulting in a watchdog reset (hereinafter referred to as "WDT reset"). In the fourth embodiment, in this case, power-saving settings are disabled to prevent the transition to a power-saving state, and the system operates in fail-safe mode. This configuration will be explained below using a flowchart.

[0088] Figures 11, 12, and 13 are flowcharts showing an example of the operation of the image forming apparatus of the fourth embodiment, and most succinctly represent the features of this embodiment. These processes are achieved by the CPU 340 loading a program stored in the HDD 106 into the memory 341 and executing it.

[0089] The flowchart in Figure 11 will be explained below. CPU340 initiates the startup process, which involves transitioning from power state A, also known as the power-off state or cold-off state, to power state E, also known as the power-on state or standby state. First, CPU340 determines whether it is booting after a WDT reset (S1101). If it is booting after a WDT reset (S1101 is Yes), CPU340 proceeds with the boot process. On the other hand, if the boot is not after a WDT reset (the answer in S1101 is No), the CPU 340 sets the value of the variable REBOOT_COUNT, which represents the number of WDT reboots, to "0" (S1102). Note that REBOOT_COUNT is stored, for example, in HDD 106 or non-volatile memory 205.

[0090] The flowchart in Figure 12 will be explained below. CPU340 initiates a transition process from power state D, which is a shallow sleep state, to power state C, which is a deep sleep state where the system is in suspend mode or has power to peripherals turned off and is waiting for an interrupt (Wait For Interrupt, hereafter referred to as "WFI").

[0091] When deep sleep processing begins, CPU340 checks whether the power saving setting of the non-volatile memory is in the power saving disabled state (S1201). If it is in the power saving disabled state (Yes in S1201), CPU340 does not transition to the power saving state and does not repeatedly reset the WDT, so this flowchart terminates. On the other hand, if power saving is not prohibited (if the answer to S1201 is No), CPU340 continues processing and proceeds to S1202.

[0092] In S1202, CPU340 checks if REBOOT_COUNT is greater than 3 (S1202). If REBOOT_COUNT is not greater than 3 (No in S1202), CPU340 determines that the WDT reset has not been repeated many times and increments REBOOT_COUNT by 1 (S1204). Subsequently, CPU340 continues the transition process to power state C, which is deep sleep (S1205). It should be noted that when the transition to power state C (deep sleep) is completed (S1205), the CPU340 may also complete the resume process or the transition to power state E (shallow sleep) upon receiving a power saving recovery event. However, this is outside the scope of this discussion and will be omitted. Furthermore, when the process in S1205 is completed, that is, when power-saving processes such as suspend are successful, the CPU340 decreases REBOOT_COUNT by 1 (S1206). In other words, if power-saving processes such as suspend fail due to a device failure or other reason, and a WDT reset occurs, REBOOT_COUNT will remain increased by 1.

[0093] Furthermore, if REBOOT_COUNT is greater than 3 (Yes in S1202), CPU340 determines that the WDT reset has been repeated multiple times and sets the power saving setting for the non-volatile memory device to power saving disabled (S1211). Subsequently, CPU340 returns to power state D, which is a shallow sleep state (S1212).

[0094] The flowchart in Figure 13 is explained below. The process shown in the flowchart of Figure 13 corresponds to the termination process (transition process from power state E to power state B). This process is initiated by the CPU 340 when a termination event occurs, i.e., when the power switch 110 is turned OFF or when a termination notification is received from the application, which triggers the transition from power state E to power state B (S422).

[0095] CPU340 checks whether the power switch 110 (power SW) is turned OFF (S1301). Turning the power SW OFF can also be done by checking whether a termination notification has been received from the application. If the power SW is not turned OFF (S1301 is No), CPU340 continues to check whether the power SW is turned OFF. On the other hand, if the power switch is turned OFF (if the answer to S1301 is Yes), CPU340 proceeds to process S1302.

[0096] In S1302, the CPU 340 checks whether the power saving prohibition flag is set. If the power saving prohibition flag is set (Yes in S1302), the CPU 340 performs a transition process to power state A in order to cold off by shutting down (S1312). As a result, the image forming apparatus 101 shuts down and enters the cold-off state.

[0097] On the other hand, if the power saving prohibition flag is not set (No in S1302), CPU340 checks whether REBOOT_COUNT is greater than 3 (S1303). If REBOOT_COUNT is not greater than 3 (No in S1302), CPU340 determines that the WDT has not been reset multiple times and increments REBOOT_COUNT by 1 (S1304). Subsequently, CPU340 continues the transition process to power state B in order to suspend or hibernate (S1305). Note that at the time of the transition to power state B (S1305), the transition to power state B could be completed, and then the transition to power state A, which is the resume process, could be completed by turning on the power switch, but this is outside the scope of this discussion and will be omitted. When the process in S1305 described above is completed, that is, when power saving processes such as suspend or hibernation are successful, CPU340 decreases REBOOT_COUNT by 1 (S1306). In other words, if power saving processes such as suspend fail due to a device failure or other reason and a WDT reset occurs, REBOOT_COUNT will remain incremented by 1.

[0098] Additionally, if REBOOT_COUNT is greater than 3 (Yes in S1302), CPU340 determines that the WDT has been reset multiple times and sets the power saving setting to power saving disabled (S1311). Subsequently, CPU340 performs a transition process to power state A, which is a power-off or cold-off state (S1312).

[0099] Note that while REBOOT_COUNT, which determines that a WDT reset has been attempted multiple times, is set to 3, this number can be changed arbitrarily. In other words, any configuration that determines that a WDT reset has been attempted multiple times after a predetermined number of suspend or similar failures is acceptable. Furthermore, REBOOT_COUNT is used in the same way for both deep sleep processing (transition from power state D to power state C) and fast shutdown processing (transition from power state E to power state B). However, it is also possible to check the number of consecutive WDT activations using separate variables, but this is outside the scope of this discussion and will be omitted. In the fourth embodiment, as in the third embodiment, if the phenomenon of failure to transition to power saving mode due to maintenance or other reasons is resolved by the process shown in Figure 10, the power saving settings may be changed to enable mode to allow transition to power saving states such as suspend. Also, in the same manner as in the third embodiment, user notification may be given when transitioning to power saving states such as suspend is prohibited or permitted.

[0100] As described above, according to the fourth embodiment, the image forming apparatus 101 can operate in fail-safe mode by prohibiting the transition to the power-saving state if the watchdog timer is reset multiple times when transitioning to the power-saving state.

[0101] As described above, each embodiment can solve the problems that arise when power-saving processes such as suspend repeatedly fail. For example, it is possible to suppress situations such as the inability to return to an operational state even when a user commands the system to resume operation during a retry of the power-saving process, or the failure to complete the power-saving process, thereby improving usability.

[0102] It should be noted that the structure and content of the various data described above are not limited to those mentioned, and it goes without saying that they can be composed of various structures and contents depending on the use and purpose. Although one embodiment has been described above, the present invention can take the form of, for example, a system, apparatus, method, program, or storage medium. Specifically, it may be applied to a system consisting of multiple devices, or to an apparatus consisting of a single device. Furthermore, any configurations combining the above embodiments are also included in the present invention.

[0103] (Other embodiments) The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions. Furthermore, the present invention may be applied to a system consisting of multiple devices or to a device consisting of a single device. The present invention is not limited to the embodiments described above, and various modifications (including organic combinations of each embodiment) are possible based on the spirit of the invention, and these are not excluded from the scope of the invention. That is, all configurations that combine the above-described embodiments and their modified forms are included in the present invention. [Explanation of symbols]

[0104] 101 Image forming apparatus 102 Scanner device 103 Controller 104 Printer device 110 Power switch 301 Power supply 303 Power Control Unit 340 CPU

Claims

1. An image forming apparatus that transitions between multiple power states, including a suspend state, The system has a control means that, if the transition to the suspend state fails a predetermined number of times, prohibits the transition to the suspend state and shuts down the system. The image forming apparatus is characterized in that the number of times the transition to the suspend state has failed is initialized in accordance with the occurrence of a startup different from a watchdog reset.

2. The image forming apparatus according to claim 1, characterized in that the control means returns to the original state and then shuts down if the transition to the suspend state fails.

3. The plurality of power states include at least the suspend state and the sleep state, The system has setting means for setting a prohibition on transitioning from the sleep state to the suspend state if the transition from the sleep state to the suspend state fails, The image forming apparatus according to claim 1, characterized in that the control means performs a shutdown when the prohibition of transition to the suspend state is set.

4. The aforementioned plurality of power states include at least the suspend state and the normal state, The system has setting means for setting a prohibition on transitioning to the suspended state if the transition from the normal state to the suspended state fails, The image forming apparatus according to claim 1, characterized in that the control means performs a shutdown when the prohibition of transition to the suspend state is set.

5. A control method for an image forming apparatus that transitions between multiple power states, including a suspend state, The system includes a step of prohibiting the transition to the suspend state and shutting down if the transition to the suspend state fails a predetermined number of times. A control method for an image forming apparatus, characterized in that the number of times the transition to the suspend state has failed is initialized in accordance with the occurrence of a startup different from a watchdog reset.

6. A program for causing a computer to execute the control method of claim 5.

Images