Control method for image processing device, image processing device

Abstract

When a lower-level device is connected to a USB host controller via a USB hub, each device is reliably started up in response to a wake-up event occurring in the lower-level device. [Solution] When the image processing device 10 is operating in normal mode, the control device 5 outputs a command to a lower-level device 8 connected to the USB host controller 7 via one or more USB hubs to set a remote wake-up function. When the suspend condition is met, the control device 5 outputs a global suspend command to the USB host controller 7 and further transitions the image processing device 10 from normal mode to suspend mode. When the suspended USB host controller 7 receives a remote wake-up notification from the lower-level device 8 which was started in response to a wake-up event, the control device 5 transitions the image processing device 10 back to normal mode.

Description

Technical Field

[0001] The present invention relates to a control method for an image processing apparatus including a USB host controller and an image processing apparatus.

Background Art

[0002] An image processing apparatus such as an image forming apparatus, an image reading apparatus, or a multifunction peripheral has a function of shifting from a normal mode to a standby mode when a standby condition is satisfied.

[0003] The standby mode is an operation mode with less power consumption than the normal mode. For example, the standby condition is that a standby time during which no operation or processing request is received exceeds a predetermined time.

[0004] The image processing apparatus may include a USB interface. The image processing apparatus can exchange data with an external device such as a storage device directly connected to the USB interface or connected via a USB hub.

[0005] Also, it is known that the image processing apparatus shifts from the normal mode to the standby mode when it does not receive a status response request from a host device connected to the USB interface (see, for example, Patent Document 1). In this case, the USB interface is a USB device controller, and the host device includes a USB host controller.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Incidentally, the image processing device may include the USB host controller and be connected to a lower-level device via a USB hub.

[0008] When the image processing device transitions from the normal mode to the sleep mode, the USB host controller of the image processing device, the USB hub, and the USB device controller of the lower-level device are suspended, thereby increasing power saving efficiency.

[0009] The image processing device, which includes the USB host controller, outputs a command to the lower-level device to set a remote wake-up function, and then suspends the USB host controller.

[0010] A typical host device outputs a selective suspend command to the USB hub and the lower-level device before suspending the USB host controller. The USB hub and the lower-level device suspend when they receive the selective suspend command.

[0011] Then, when a wake-up event occurs in the lower-level device, the USB device controller of the lower-level device starts up, and the started USB device controller outputs a resume notification to the USB hub.

[0012] Furthermore, after the USB hub is activated in response to the resume notification, the USB device controller of the lower-level device outputs a remote wake-up notification to the USB host controller via the USB hub.

[0013] The USB host controller, which is in suspend mode, starts up when it receives notification of the remote wake-up.

[0014] However, if the USB hub suspends in response to the selective suspend command, the USB hub may fail to start up depending on the timing of the wake-up event in the lower-level device.

[0015] The object of the present invention is to provide a control method for an image processing apparatus and an image processing apparatus that enable each device to be reliably started up in response to a wake-up event occurring in a lower-level device equipped with a USB device controller when the lower-level device is connected to the USB host controller of the image processing apparatus via a USB hub. [Means for solving the problem]

[0016] A control method for an image processing apparatus according to one aspect of the present invention is a method for controlling an image processing apparatus comprising a USB host controller. The control method includes, when the image processing apparatus is operating in normal mode, the control device outputting a command to set a remote wake-up function to a lower-level device connected to the USB host controller via one or more USB hubs. The control method further includes, when predetermined suspend conditions are met, the control device outputting a global suspend command to the USB host controller, and further transitioning the image processing apparatus from normal mode to a suspend mode which consumes less power than normal mode. The control method further includes, when the suspended USB host controller is started up after receiving a remote wake-up notification from the lower-level device which was started up in response to a wake-up event, the control device transitioning the image processing apparatus from the suspend mode to normal mode.

[0017] An image processing apparatus according to another aspect of the present invention comprises an image processing unit that performs image processing, a USB host controller, and a control device that implements the control method. [Effects of the Invention]

[0018] According to the present invention, when a lower device including a USB device controller is connected to a USB host controller of an image processing apparatus via a USB hub, it is possible to provide a control method for an image processing apparatus and an image processing apparatus in which each device can be surely activated in response to the occurrence of a wake-up event in the lower device.

Brief Description of the Drawings

[0019] [Figure 1] FIG. 1 is a block diagram showing the configuration of an image processing apparatus according to an embodiment. [Figure 2] FIG. 2 is a flowchart of a standby process in the image processing apparatus according to the embodiment. [Figure 3] FIG. 3 is a flowchart of a normal return process in the image processing apparatus according to the embodiment. [Figure 4] FIG. 4 is a flowchart of an abnormal return process in the image processing apparatus according to the embodiment. [Figure 5] FIG. 5 is a flowchart of a standby process in a host apparatus according to a reference example. [Figure 6] FIG. 6 is a flowchart of a normal return process in a host apparatus according to a reference example. [Figure 7] FIG. 7 is a flowchart of a failure example of a return process in a host apparatus according to a reference example.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following embodiments are an example of embodying the present invention and do not limit the technical scope of the present invention. [[ID=********************]]

[0021] [Configuration of Image Processing Apparatus 10] The image processing apparatus 10 according to the embodiment can execute various image processes such as an image forming process, an image reading process, and an image transmitting process. For example, the image processing apparatus 10 is a printer, a copier, a facsimile apparatus, or a multifunction machine.

[0022] In the example shown in Figure 1, the image processing device 10 comprises an image forming unit 1, an image reading unit 2, a user interface device 3, a communication device 4, a control device 5, and a secondary storage device 6. Furthermore, the image processing device 10 includes a USB host controller 7, which is the host-side USB interface. Note that USB is a registered trademark.

[0023] The image processing device 10 can communicate with other devices, such as information processing terminals, via a network. The network includes LANs (Local Area Networks) and the Internet.

[0024] The image forming unit 1 performs the image forming process using a predetermined method such as electrophotography or inkjet. The image forming process is the process of forming an image on the sheet 91.

[0025] The image forming unit 1 includes a sheet transport mechanism for transporting the sheet 91 and a printing device for forming an image on the sheet 91.

[0026] The image reading unit 2 performs the image reading process. The image reading process is the process of reading the image of the document 92. The image reading unit 2 includes an optical scanning mechanism that scans light across the document 92 and an image sensor that receives reflected light reflected from the document 92.

[0027] The image sensor outputs data of the scanned image. The scanned image is an image read from the original document 92.

[0028] The user interface device 3 includes an operating device 3a and a display device 3b. The operating device 3a is a device that accepts human input. For example, the operating device 3a includes operation buttons and a touch panel. The display device 3b is capable of displaying information. For example, the display device 3b includes a display panel such as a liquid crystal panel.

[0029] The communication device 4 is a communication interface device that communicates with other devices, such as the information processing terminal, through the network. The control device 5 performs all data transmission and reception with the other devices through the communication device 4.

[0030] The image forming unit 1 performs the image forming process based on the data of the read image or the received print data. The received print data is data included in the print request received from the information processing terminal via the communication device 4.

[0031] Furthermore, the communication device 4 is capable of performing the image transmission process. The image transmission process is the process of transmitting the data of the read image to a specified destination via the network.

[0032] The USB host controller 7 is an interface that can connect to a USB interface-compatible lower-level device 8, such as a flash memory, SSD (Solid State Drive), or camera. The lower-level device 8 is equipped with a USB device controller 8x, which is the USB interface on the device side.

[0033] Furthermore, the process of recording the data of the read image obtained by the image reading unit 2 into a storage device such as the SSD is also an example of the image processing that the image processing device 10 can perform. In addition, the image formation process based on the image data stored in the storage device such as the SSD is also an example of the image processing.

[0034] In this embodiment, the image forming unit 1 and the image reading unit 2 are examples of multiple image processing units that each perform different types of image processing.

[0035] The image processing device 10 can switch between a normal mode and a sleep mode, which consumes less power than the normal mode. Specifically, the image forming unit 1, the image reading unit 2, the user interface device 3, and the control device 5 can switch between the normal mode and the sleep mode.

[0036] For example, in the aforementioned standby mode, the power supply to some devices in the image forming unit 1, image reading unit 2, user interface device 3, and control device 5 is stopped, while other devices operate with only some functions necessary for startup enabled.

[0037] In the normal mode, the image processing device 10 can perform the image processing in response to a request for image processing. On the other hand, when the image processing device 10 receives a request for image processing in the pause mode, it transitions from the pause mode to the normal mode and then performs the image processing.

[0038] The control device 5 performs various calculations, data processing, and controls various electrical devices provided by the image processing device 10. The control device 5 includes a CPU 51 and RAM (Random Access Memory) 52, among others.

[0039] The secondary storage device 6 is a computer-readable, non-volatile storage device. The secondary storage device 6 can store computer programs and various types of data. For example, an SSD and / or a hard disk drive may be used as the secondary storage device 6.

[0040] The secondary storage device 6 stores the computer program executed by the CPU 51 and the data referenced by the CPU 51. The CPU 51 is an example of a processor.

[0041] The CPU 51 is a processor that performs various data processing and control operations by executing the computer program stored in the secondary storage device 6.

[0042] It is also conceivable that other processors, such as a DSP, could perform the data processing and control in place of the CPU 51.

[0043] RAM52 is a computer-readable volatile memory device. RAM52 primarily stores the computer program executed by CPU51 and the data that CPU51 outputs and references during the execution of the computer program.

[0044] The CPU 51 includes a plurality of processing modules that are realized by executing the computer program. The plurality of processing modules in the CPU 51 include a device management unit 5a and a job control unit 5b, etc.

[0045] The device management unit 5a executes control to transition the image processing device 10 from one of the normal mode and the sleep mode to the other. In the following description, the transition of the image processing device 10 from the sleep mode to the normal mode is referred to as "startup." On the other hand, the transition of the image processing device 10 from the normal mode to the sleep mode is referred to as "sleep."

[0046] The device management unit 5a starts the image processing device 10 when a recovery event occurs while the operating mode of the image processing device 10 is in the aforementioned sleep mode.

[0047] For example, the recovery event may be the detection of an operation on a recovery button (not shown) included in the operating device 3a. Alternatively, if the image processing device 10 includes a human presence sensor (not shown), the recovery event may be the detection of a person by the human presence sensor.

[0048] Furthermore, the device management unit 5a executes a pause process when the pause condition is met while the operating mode of the image processing device 10 is in the pause mode. The pause process is a process that transitions the operating mode of the image processing device 10 from the normal mode to the pause mode.

[0049] For example, the pause condition may include a condition that the image processing device 10 remains in a state where it does not perform the image processing and does not receive any requests for the image processing for a predetermined period of time. The pause condition may also include a condition that an operation on a pause button (not shown) included in the operating device 3a is detected.

[0050] The job control unit 5b controls the image forming unit 1, the image reading unit 2, and the communication device 4. The job control unit 5b causes some or all of the image forming unit 1, the image reading unit 2, and the communication device 4 to execute jobs corresponding to requests input through the operating device 3a or the communication device 4.

[0051] The job includes some or all of the multiple types of image processing. In this embodiment, the job includes an image reading job, a print job, and a copy job.

[0052] The image reading job is the image reading process performed by the operation of the image reading unit 2. The print job is the image forming process performed by the operation of the image forming unit 1. The copy job includes the image reading process and the image forming process performed by the operation of the image reading unit 2 and the image forming unit 1. That is, the job includes one or more types of image processing.

[0053] Incidentally, in the image processing device 10, the USB host controller 7 may be connected to a lower-level device 8 via one or more USB hubs 80 (see Figure 1).

[0054] When the image processing device 10 transitions from the normal mode to the sleep mode, the USB host controller 7 of the image processing device 10, the USB hub 80, and the USB device controller 8x of the lower-level device 8 are suspended, thereby further enhancing power saving.

[0055] The image processing device 10, which includes a USB host controller 7, outputs a command to the USB device controller 8x of the lower-level device 8 to set the remote wake-up function, and then suspends the USB host controller 7.

[0056] A typical host device outputs a selective suspend command to the USB hub 80 and the lower-level device 8 before suspending the USB host controller 7. The USB hub 80 and the lower-level device 8 suspend when they receive the selective suspend command.

[0057] Then, when a wake-up event occurs in the lower-level device 8, the USB device controller 8x of the lower-level device 8 starts up, and the started USB device controller 8x outputs a resume notification to the USB hub.

[0058] Furthermore, after the USB hub 80 starts up in response to the resume notification, the USB device controller 8x of the lower-level device 8 outputs a remote wake-up notification to the USB host controller 7 via the USB hub 80.

[0059] The USB host controller 7, which is in suspend mode, starts up when it receives the notification for the remote wake-up.

[0060] However, if the USB hub 80 suspends in response to the selective suspend command, the USB hub 80 may fail to start up depending on the timing of the wake-up event occurring in the lower-level device 8.

[0061] The following describes an example of the pause and resume processing procedures performed by the host device 10x in the reference example, referring to the flowcharts shown in Figures 5-7. The host device 10x corresponds to a conventional general image processing device.

[0062] The host device 10x includes a USB host controller 7x and a control device 5x. In the host device 10x, the USB host controller 7x corresponds to the USB host controller 7 of the image processing device 10, and the control device 5x corresponds to the control device 5 of the image processing device 10.

[0063] In the example shown in Figures 5-7, the primary USB hub 80a is connected to the USB host controller 7x, the secondary USB hub 80b is connected to the primary USB hub 80a, and the USB device controller 8x of the lower-level device 8 is connected to the secondary USB hub 80b.

[0064] [Hibernation process on host device 10x] The following describes an example of the procedure for the pause process executed by the control device 5x of the host device 10x in the reference example, with reference to the flowchart shown in Figure 5.

[0065] The pause process shown in Figure 5 is a process to switch the operating mode of the host device 10x from the normal mode to the pause mode.

[0066] The control device 5x executes the pause process when the pause condition of the host device 10x is met.

[0067] The processing performed by the USB host controller 7x, primary USB hub 80a, secondary USB hub 80b, and USB device controller 8x shown in Figure 6 is in accordance with the USB standard.

[0068] Before the aforementioned sleep condition for the host device 10x is met, or when the aforementioned sleep condition for the host device 10x is met, the control device 5x sets the remote wake-up function on the USB device controller 8x of the lower-level device 8.

[0069] Specifically, the control device 5x outputs a command to set the remote wake-up function to the USB device controller 8x via the USB host controller 7x, the primary USB hub 80a, and the secondary USB hub 80b. As a result, the remote wake-up function is set on the USB device controller 8x.

[0070] When the USB device controller 8x is set to the remote wake-up function, it executes a remote wake-up notification process when it starts up from a suspended state. The remote wake-up notification process is the process of outputting a remote wake-up notification to the USB host controller 7x.

[0071] When the remote wake-up function is set on the USB device controller 8x and the sleep condition is met, the control device 5x executes the following multiple processes included in the sleep process.

[0072] First, the control unit 5x outputs a selective suspend command to the USB device controller 8x of the lower-level device 8 via the USB host controller 7x, the primary USB hub 80a, and the secondary USB hub 80b.

[0073] The USB device controller 8x suspends when it receives the selective suspend command. When suspending, the USB device controller 8x outputs a suspend notification to the control unit (not shown) of the lower device 8. As a result, the lower device 8 enters a hibernation state.

[0074] Furthermore, the control device 5x outputs the selective suspend command to the secondary USB hub 80b via the USB host controller 7x and the primary USB hub 80a.

[0075] The secondary USB hub 80b suspends when it receives the selective suspend command.

[0076] Furthermore, the control device 5x outputs the selective suspend command to the primary USB hub 80a via the USB host controller 7x.

[0077] The primary USB hub 80a suspends when it receives the selective suspend command.

[0078] Furthermore, the control device 5x outputs the selective suspend command to the USB host controller 7x.

[0079] The USB host controller 7x suspends when it receives the selective suspend command.

[0080] Furthermore, the control device 5x causes the host device 10x to switch from the normal mode to the sleep mode.

[0081] When the pause process shown in Figure 5 is executed, and the pause conditions are met, the USB device controller 8x, the USB host controller 7x, and all USB hubs 80 will suspend, and the host device 10x will enter the pause mode.

[0082] [Recovery process in host device 10x] Next, with reference to the flowchart shown in Figure 6, an example of a normal recovery process procedure performed by the control device 5x of the host device 10x in the reference example will be described.

[0083] The recovery process is a process to switch the operating mode of the host device 10x from the sleep mode to the normal mode.

[0084] The recovery process shown in Figure 7 is executed when a wake-up event occurs in the lower device 8 while the operating mode of the host device 10x is the sleep mode and all USB hubs 80 and the USB device controllers 8x of the lower device 8 are in a suspended state.

[0085] The processing performed by the USB host controller 7x, primary USB hub 80a, secondary USB hub 80b, and USB device controller 8x shown in Figure 7 is in accordance with the USB standard.

[0086] When the wake-up event occurs in the lower-level device 8, the USB device controller 8x wakes up.

[0087] When the USB device controller 8x wakes up, it sends a resume notification to the secondary USB hub 80b.

[0088] The secondary USB hub 80b wakes up upon receiving the resume notification. When the secondary USB hub 80b wakes up, it outputs the resume notification to the primary USB hub 80a.

[0089] The primary USB hub 80a wakes up upon receiving the resume notification. When the primary USB hub 80a wakes up, it outputs the resume notification to the USB host controller 7x.

[0090] The USB host controller 7x wakes up upon receiving the resume notification. When the USB host controller 7x wakes up, it outputs a wake-up notification to the control unit 5x.

[0091] When the control device 5x receives the wake-up notification, it causes the host device 10x to switch from the sleep mode to the normal mode.

[0092] When the host device 10x transitions to the normal mode, the control device 5x sets the remote wake-up function on the USB device controller 8x of the lower-level device 8. Note that if the remote wake-up function setting shown in Figure 5 is performed in advance, the setting of the remote wake-up function shown in Figure 6 may be omitted.

[0093] [Example of recovery process failure on host device 10x] Next, with reference to the flowchart shown in Figure 7, we will explain an example of a failure in the recovery process in the host device 10x in the reference example.

[0094] The process shown in Figure 7 is the process that occurs when the wake-up event occurs in the lower-level device 8 while the secondary USB hub 80b is suspended due to the pause process shown in Figure 5.

[0095] In the processes shown in Figure 7 and Figure 5, the process up to the point where the control device 5x outputs the selective suspend command to the secondary USB hub 80b is the same.

[0096] If the wake-up event occurs in the lower-level device 8 while the secondary USB hub 80b is suspended, the USB device controller 8x wakes up and outputs a resume notification to the secondary USB hub 80b.

[0097] When the USB device controller 8x outputs a resume notification to the secondary USB hub 80b, the secondary USB hub 80b may be in the middle of suspending. In this case, congestion occurs in the secondary USB hub 80b, and the secondary USB hub 80b cannot wake up.

[0098] If the secondary USB hub 80b fails to wake up, the primary USB hub 80a and USB host controller 7x also fail to wake up, resulting in the recovery process failing.

[0099] The control device 5 of the image processing device 10 executes a process to avoid the failure of the recovery process as shown in Figure 7.

[0100] The following describes an example of the pause and resume processing procedures performed by the image processing device 10, with reference to the flowcharts shown in Figures 2-4.

[0101] The pause and resume processes shown in Figures 2-4 are examples of processes that implement a control method for the image processing device 10. The pause and resume processes shown in Figures 2-4 are performed when the lower-level device 8 is connected to the USB host controller 7 via one or more USB hubs 80.

[0102] In the example shown in Figures 2-4, the primary USB hub 80a is connected to the USB host controller 7, the secondary USB hub 80b is connected to the primary USB hub 80a, and the USB device controller 8x of the lower-level device 8 is connected to the secondary USB hub 80b.

[0103] In the pause process and the recovery process described below, the processes executed by the control device 5 are, for example, processes executed by the device management unit 5a of the CPU 51.

[0104] [Pause processing in the image processing device 10] The following describes an example of the pause process procedure performed by the control device 5x of the image processing device 10, with reference to the flowchart shown in Figure 2.

[0105] The pause process shown in Figure 2 is a process for switching the operating mode of the image processing device 10 from the normal mode to the pause mode.

[0106] The processing performed by the USB host controller 7, primary USB hub 80a, secondary USB hub 80b, and USB device controller 8x shown in Figures 2-4 is in accordance with the USB standard.

[0107] When the image processing device 10 is operating in the normal mode, the control device 5 sets the remote wake-up function to the USB device controller 8x of the lower-level device 8.

[0108] Before the aforementioned sleep condition for the image processing device 10 is met, or when the aforementioned sleep condition for the image processing device 10 is met, the control device 5 sets the remote wake-up function on the USB device controller 8x of the lower-level device 8.

[0109] Specifically, the control device 5 outputs a command to set the remote wake-up function to the USB device controller 8x via the USB host controller 7, the primary USB hub 80a, and the secondary USB hub 80b. As a result, the remote wake-up function is set on the USB device controller 8x.

[0110] When the USB device controller 8x is set to the remote wake-up function, it executes a remote wake-up notification process when it starts up from a suspended state. The remote wake-up notification process is the process of outputting a remote wake-up notification to the USB host controller 7.

[0111] When the remote wake-up function is set on the USB device controller 8x and the sleep condition is met, the control device 5 executes the following multiple processes included in the sleep process.

[0112] Furthermore, when the image processing device 10 is operating in the normal mode, the control device 5 executes the following pause process when the pause condition for the image processing device 10 is met.

[0113] In the aforementioned suspension process, first, the control device 5 outputs a global suspend command to the USB host controller 7.

[0114] When the USB host controller 7 receives the global suspend command, it outputs the global suspend command to the primary USB hub 80a connected to the lower side and then suspends the device.

[0115] After outputting the global suspend command, the control device 5 switches the image processing device 10 from the normal mode to the pause mode.

[0116] On the other hand, when the primary USB hub 80a receives the global suspend command, it outputs the global suspend command to the secondary USB hub 80b connected to the lower side and then suspends.

[0117] Furthermore, when the secondary USB hub 80b receives the global suspend command, it outputs the global suspend command to the USB device controller 8x connected to the lower side and then suspends.

[0118] Furthermore, when suspending, the USB device controller 8x outputs a suspend notification to the control unit (not shown) of the lower-level device 8. This causes the lower-level device 8 to enter a hibernation state.

[0119] When the pause process shown in Figure 2 is executed, and the pause conditions are met, the USB device controller 8x, the USB host controller 7, and all USB hubs 80 will suspend, and the host device 10x will enter the pause mode.

[0120] [Recovery process in image processing device 10] Next, with reference to the flowchart shown in Figure 2, an example of the normal recovery process procedure performed by the control device 5 of the image processing device 10 will be described.

[0121] The recovery process shown in Figure 2 is a process for switching the operating mode of the image processing device 10 from the pause mode to the normal mode.

[0122] The recovery process shown in Figure 2 is executed when the operating mode of the image processing device 10 is the pause mode and all USB hubs 80 and the USB device controllers 8x of the lower-level devices 8 are in a suspended state, and a wake-up event occurs in the lower-level device 8.

[0123] When the wake-up event occurs in the lower-level device 8, the USB device controller 8x wakes up.

[0124] When the USB device controller 8x wakes up, it outputs a resume notification to the secondary USB hub 80b.

[0125] The secondary USB hub 80b wakes up upon receiving the resume notification. When the secondary USB hub 80b wakes up, it outputs the resume notification to the primary USB hub 80a.

[0126] The primary USB hub 80a wakes up upon receiving the resume notification.

[0127] The USB device controller 8x of the lower-level device 8 outputs a remote wake-up notification to the USB host controller 7 when the secondary USB hub 80b and the primary USB hub 80a wake up.

[0128] The USB host controller 7 wakes up when it receives a remote wake-up notification from the USB device controller 8x. When the USB host controller 7 wakes up, it outputs a wake-up notification to the control device 5.

[0129] When the control device 5 receives the wake-up notification, it switches the image processing device 10 from the sleep mode to the normal mode.

[0130] In other words, when the suspended USB host controller 7 is activated after receiving notification of the remote wake-up from the lower-level device 8 which was activated in response to the wake-up event, the control device 5 switches the image processing device 10 from the hibernation mode to the normal mode.

[0131] When the image processing device 10 transitions to the normal mode, the control device 5 sets the remote wake-up function on the USB device controller 8x of the lower-level device 8. Note that if the remote wake-up function setting shown in Figure 2 is performed in advance, the setting of the remote wake-up function shown in Figure 3 may be omitted.

[0132] [Unusual recovery process in image processing device 10] Next, the unusual recovery process in the image processing device 10 will be explained with reference to the flowchart shown in Figure 4.

[0133] The process shown in Figure 4 is the process that occurs when the wake-up event occurs in the lower-level device 8 while the secondary USB hub 80b and USB device controller 8x are suspended due to the pause process shown in Figure 2.

[0134] In the processes shown in Figure 7 and Figure 2, the process up to the point where the secondary USB hub 80b outputs the global suspend command to the USB device controller 8x is the same.

[0135] If the wake-up event occurs in the lower-level device 8 while the secondary USB hub 80b and USB device controller 8x are suspended, the USB device controller 8x cancels the suspension and outputs a resume notification to the secondary USB hub 80b.

[0136] On the other hand, the secondary USB hub 80b ignores the resume notification because the USB host controller 7 is in a suspended state when it receives the resume notification, and therefore ignores the resume notification until it is suspended.

[0137] Furthermore, the secondary USB hub 80b detects the resume notification after suspending and wakes up. When the secondary USB hub 80b wakes up, it outputs the resume notification to the primary USB hub 80a.

[0138] In the process shown in Figure 4 and the recovery process shown in Figure 3, the process after the secondary USB hub 80b outputs the resume notification to the primary USB hub 80a is the same.

[0139] On the other hand, when the image processing device 10 is in the sleep mode and the recovery event occurs in the image processing device 10, the control device 5 causes the image processing device 10 to switch from the sleep mode to the normal mode.

[0140] Furthermore, when the image processing device 10 transitions to the normal mode, the control device 5 outputs a notification of the resume mode to the USB host controller 7.

[0141] The USB host controller 7 wakes up upon receiving the resume notification and outputs the resume notification to the primary USB hub 80a.

[0142] The primary USB hub 80a wakes up upon receiving the resume notification and outputs the resume notification to the secondary USB hub 80b.

[0143] The secondary USB hub 80b wakes up upon receiving the resume notification and outputs the resume notification to the USB device controller 8x.

[0144] The USB device controller 8x wakes up upon receiving the resume notification and notifies the lower device 8's control unit (not shown) of the wake-up. As a result, the lower device 8 starts up.

[0145] In the image processing device 10, when a lower-level device 8 equipped with a USB device controller 8x is connected to a USB host controller 7 via a USB hub 80, each device can be reliably started up in response to the occurrence of the wake-up event in the lower-level device 8.

[0146] [Notes on the invention] The following is an overview of the invention extracted from the above-described embodiments. Note that each configuration and processing function described below can be selected and combined as desired.

[0147] <Note 1> A method for controlling an image processing device equipped with a USB host controller, When the image processing device is operating in normal mode, the control device executes a process to output a command to set the remote wake-up function to a lower-level device connected to the USB host controller via one or more USB hubs. The control device, when predetermined suspend conditions are met, outputs a global suspend command to the USB host controller, and further transitions the image processing device from the normal mode to a suspend mode that consumes less power than the normal mode. A method for controlling an image processing device, comprising: when the suspended USB host controller is started up after receiving a remote wake-up notification from the subordinate device which was started up in response to a wake-up event, the control device transitions the image processing device from the hibernation mode to the normal mode.

[0148] <Note 2> An image processing unit that performs image processing, USB host controller and An image processing apparatus comprising a control device that implements the control method for the image processing apparatus described in Appendix 1 above. [Explanation of symbols]

[0149] 1: Image forming unit 2: Image reading unit 3: User Interface Device 5: Control device 7: USB Host Controller 7x: USB host controller 8: Lower-level devices 8x: USB device controller 10: Image processing device 80: USB Hub 80a: Primary USB hub 80b: Secondary USB hub

Claims

1. A control method for an image processing apparatus equipped with a USB host controller, When the image processing device is operating in normal mode, the control device executes a process to output a command to set the remote wake-up function to a subordinate device connected to the USB host controller via one or more USB hubs. The control device, when predetermined suspend conditions are met, outputs a global suspend command to the USB host controller, and further transitions the image processing device from the normal mode to a suspend mode that consumes less power than the normal mode. The control device, when predetermined suspend conditions are met, outputs a global suspend command to the USB hub and suspends the USB host controller, and further switches the image processing device from the normal mode to a suspend mode that consumes less power than the normal mode. A method for controlling an image processing device, comprising: when the suspended USB host controller is started up after receiving a remote wake-up notification from the subordinate device which was started up in response to a wake-up event, the control device transitions the image processing device from the hibernation mode to the normal mode.

2. An image processing unit that performs image processing, USB host controller and An image processing apparatus comprising a control device that implements the control method for the image processing apparatus described in claim 1.

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