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

Abstract

To provide an image forming apparatus and the like that can efficiently execute image formation on and image deletion from a sheet without impairing convenience of a user.SOLUTION: An image forming apparatus has a normal power state in which it can perform image formation on a sheet, a sleep state in which it makes a transition to the normal power state when there is a request for image formation, and a suspended state in which it does not make a transition to the normal power state even if there is a request for image formation, and the image forming apparatus comprises: a power control program 602 for causing the image forming apparatus to make a transition from the normal power state to the sleep state in response to satisfaction of a condition for transition to the sleep state, and causing the image forming apparatus to make a transition from the normal power state to the suspended state when a condition for transition to the suspended state is satisfied; and a printer control program 605 for performing image deletion from the sheet within a period from when the condition for transition to the suspended state is satisfied until when the image forming apparatus makes a transition from the normal power state to the suspended state.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus, a control method for an image forming apparatus, and a program. [Background technology]

[0002] In recent years, with the rise in environmental awareness, there is a demand for reusing sheets printed by an image forming apparatus. In response to this demand, for example, an image forming apparatus is known that supports normal printing on a sheet using a normal toner, decolorizing toner printing on a sheet using a decolorizing toner, and further supports decolorizing of the decolorizing toner on a sheet. Such an image forming apparatus cannot simultaneously perform image formation (normal printing or decolorizing toner printing on a sheet) and image erasure (decolorizing of the decolorizing toner on a sheet). Therefore, a user needs to perform image formation on a sheet and image erasure in separate time periods. Therefore, Patent Document 1 discloses an image forming apparatus that operates image erasure during a non-use period. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-281864 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the image forming apparatus disclosed in Patent Document 1 starts the image forming operation if there is a request for image formation even if the image erasure is in operation. In this regard, for each function of normal printing, color erasing toner printing, and color erasing on a sheet, it may take a significant amount of time to transition from a state in which one function can be realized to a state in which another function can be realized. Therefore, when the image forming apparatus disclosed in Patent Document 1 is in the middle of an image erasure operation and there is an unexpected request for image formation from a user, if it takes a significant amount of time to transition to a state in which image formation is possible, there is a problem that the convenience for the user is impaired.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide an image forming apparatus, a control method for the image forming apparatus, and a program that can efficiently form and erase images on a sheet without impairing user convenience. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the image forming apparatus of the present invention is an image forming apparatus having a first state in which an image can be formed on a sheet, a second state in which the image forming apparatus transitions to the first state when a request for image formation is made, and a third state in which the image forming apparatus does not transition to the first state even when a request for image formation is made, and is characterized in that the image forming apparatus is equipped with a first transition means for transitioning the image forming apparatus from the first state to the second state when a transition condition for the second state is satisfied, a second transition means for transitioning the image forming apparatus from the first state to the third state when a transition condition for the third state is satisfied, and an erasure means for erasing an image on a sheet from when the transition condition for the third state is satisfied until the image forming apparatus transitions from the first state to the third state. Effect of the Invention

[0007] According to the present invention, image formation and image erasure can be efficiently performed on a sheet without impairing user convenience. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a hardware block diagram illustrating a configuration of the image forming apparatus. [Diagram 2] FIG. 2 is a hardware block diagram showing a configuration of an image forming apparatus in a sleep state. [Diagram 3] FIG. 2 is a hardware block diagram showing a configuration of an image forming apparatus in a suspended state. [Figure 4] 2 is a diagram showing transitions between power states (normal power state, sleep state, suspended state, and power-off state) in an image forming apparatus. [Diagram 5] FIG. 2 is a diagram showing a suspend setting screen (hereinafter, abbreviated as "suspend setting screen") in the image forming apparatus. [Figure 6] FIG. 4 is a diagram showing various programs stored in a ROM of the image forming apparatus. [Figure 7] 6 is a flowchart showing a process flow when the image forming apparatus transitions from a normal power state to a sleep state or a suspended state. [Figure 8] FIG. 2 is a diagram showing an image erasing setting screen (hereinafter abbreviated as "image erasing setting screen") in the image forming apparatus. [Figure 9] 6 is a flowchart showing a process flow when the image forming apparatus transitions from a sleep state to a normal power state. [Figure 10] 10 is a flowchart showing a process flow when the image forming apparatus transitions from a suspended state to a normal power state. [Figure 11] 6 is a flowchart showing a process flow when the image forming apparatus transitions from a normal power state to a sleep state or a power-off state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Each embodiment of the present invention will be described in detail below with reference to the drawings. However, the configurations described in each of the following embodiments are merely examples, and the scope of the present invention is not limited by the configurations described in each embodiment. For example, each part constituting the present invention can be replaced with any configuration that can exert a similar function. In addition, any configuration may be added. In addition, any two or more configurations (features) of each embodiment can be combined.

[0010] First Embodiment The first embodiment will be described below with reference to FIGS. 1 to 10. FIG. 1 is a hardware block diagram showing the configuration of an image forming apparatus 100. The image forming apparatus 100 is a multifunction peripheral to which the present invention is applied. The multifunction peripheral is realized as an MFP (Multifunction Peripheral) in which multiple functions such as a print function and a scan function are integrated. The present invention may be applied to a printer, a copier, or the like, although it is different from the first embodiment. The image forming apparatus 100 has a controller 101, a storage 102, an operation unit 103, a printer unit 104, a scanner unit 105, a FAX unit (Facsimile unit) 106, a power switch 107, and the like. The controller 101 controls the storage 102, the operation unit 103, the printer unit 104, the scanner unit 105, and the FAX unit 106 of the image forming apparatus 100.

[0011] The controller 101 includes a central processing unit (CPU) 111, a read only memory (ROM) 112, a random access memory (RAM) 113, and a storage I / F 114. The controller 110 further includes an operation unit I / F 115, a printer I / F 116, a scanner I / F 117, a universal serial bus (USB)-host I / F 118, a network I / F 119, and a system bus 120. The system bus 120 is a transmission path for the CPU 111 to access other devices such as the ROM 112, and is also a transmission path for devices to access each other. The CPU 111 controls peripheral devices of the CPU 111 and performs data arithmetic processing. The CPU 111 loads various programs stored in the ROM 112 into the RAM 113 and executes them. The CPU 111 includes a built-in timer. However, the timer may be provided separately from the CPU 111.

[0012] The RAM 113 is a memory used by the CPU 111 as a work memory. The storage I / F 114 is connected to the storage 102. The storage 102 stores various programs and data (databases, image files, etc.) required for the image forming apparatus 100 to operate. The storage 102 is, for example, an external storage device such as a hard disk drive (HDD) or a solid state drive (SSD). The storage 102 may be an embedded multi media card (eMMC) built into the controller 101. The operation unit I / F 115 is connected to the operation unit 103. The operation unit I / F 115 transmits an instruction input by a user via the operation unit 103 to the CPU 111. In the first embodiment, the operation unit 103 includes, for example, a display, a keyboard, a hard key, a touch sensor, etc.

[0013] The printer unit 104 is connected to the printer I / F 116. The printer unit 104 forms an image on a sheet based on image data received from the printer I / F 116. The printer unit 104 also erases an image on a sheet according to an instruction from the controller 101. In the first embodiment, image formation on a sheet includes normal printing on the sheet using normal toner (non-erasable toner) and erasable toner printing on the sheet using erasable toner (erasable toner). Image erasure on a sheet includes erasing of the erasable toner on the sheet. The printer unit 104 cannot simultaneously form an image on a sheet and erase an image on the sheet. The printer unit 104 can form an image on a sheet when the image forming apparatus 100 is in a normal power state described later.

[0014] The printer unit 104 has a function of switching the type of output toner used when printing on a sheet between normal toner and decolorizing toner in accordance with an instruction from the controller 101. The printer unit 104 also has a function of adjusting the image forming process, such as the sheet conveying speed and the fixing roller temperature, based on the type of output toner. Furthermore, the printer unit 104 switches the fixing roller temperature and the removal roller temperature between normal printing on a sheet using normal toner, decolorizing toner printing on a sheet using decolorizing toner, and further decolorizing the decolorizing toner on a sheet.

[0015] The printer unit 104 also has a printing tray and an erasing tray. Sheets used for normal printing using normal toner and for erasing toner printing using erasing toner are set in the printing tray. Sheets printed with erasing toner, that is, sheets used for erasing the color of the erasing toner on the sheet (hereinafter referred to as "erasing sheets") are set in the erasing tray (tray). The printer unit 104 also has a sensor for detecting the sheet set in the printing tray and a sensor for detecting the erasing sheet set in the erasing tray.

[0016] The scanner unit 105 is connected to the scanner I / F 117. When the scanner unit 105 reads an image on a document and generates image data, it transmits the image data to the scanner I / F 117. The scanner I / F 117 stores the image data in the storage 102. The USB-Host I / F 118 communicates with a USB device communicatively connected to the USB-Host of the image forming apparatus 100. In the first embodiment, the controller 110 and the FAX unit 106 are connected. The FAX unit 106 transmits FAX data to the FAX line 121 based on image data received via the USB-Host I / F 118. The FAX unit 106 also generates image data based on FAX data received from the FAX line 121, and transfers the image data to the storage 102 via the USB-Host I / F 118. The USB-Host I / F 118 can also be connected to an external USB device 122. In the first embodiment, the external USB device 122 includes a USB memory and a USB keyboard.

[0017] A network cable such as a LAN (Local Area Network) cable 123 is connected to the network I / F 119. The network I / F 119 communicates with other devices (for example, a PC 124 or a server device 125) connected to the network so as to be able to communicate with each other via the LAN. The PC 124 can transmit and receive image data and can operate the image forming apparatus 100 via a Web browser. The power switch 107 is connected to the controller 101. When the power switch 107 is in an on state, power is supplied to at least a part of the controller 101. The image forming apparatus 100 has an appropriate termination process for software and hardware, and even if the power switch 107 is turned off, power supply to each part is not immediately stopped. When the power switch 107 is in an off state, power supply to parts other than those necessary to turn the power switch 107 on again is stopped. The power switch 107 may be configured as a power key selectably displayed on a display of the operation unit 103, or may be installed as a hard key on the main body of the operation unit 103 or the image forming apparatus 100.

[0018] The image forming apparatus 100 can transition to a normal power state (ACPI S0 state), a sleep state (ACPI S3 state), a suspend state (ACPI S3 state), and a power off state (ACPI S5 state). FIG. 2 is a hardware block diagram showing the configuration of the image forming apparatus 100 in a sleep state (second state) (first power saving state) (power saving state). When the CPU 111 issues a notification of transition to the sleep state, as shown in FIG. 2, it stops the supply of power to the ROM 112, the storage I / F 114, the storage 102, the printer I / F 116, and the printer unit 104. The CPU 111 further stops the supply of power to the scanner I / F 117 and the scanner unit 105. The RAM 113 may be in a self-refresh mode. In the first embodiment, an example in which the CPU 111 stops the supply of power is shown, but a power control circuit for stopping the supply of power may be provided.

[0019] FIG. 3 is a hardware block diagram showing the configuration of the image forming apparatus 100 in the suspended state (third state) (second power saving state). When the CPU 111 notifies the transition to the suspended state, as shown in FIG. 3, it stops the supply of power to the ROM 112, the storage I / F 114, the storage 102, the operation unit I / F 115, and the operation unit 103. The CPU 111 further stops the supply of power to the printer I / F 116, the printer unit 104, the scanner I / F 117, the scanner unit 105, the USB-Host I / F 118, the FAX unit 106, and the network I / F 119. The RAM 113 may be in a self-refresh mode. In addition, in the image forming apparatus 100 in the normal power state (first state), power is supplied to each device in FIG. 2 and FIG. 3. Therefore, the image forming apparatus 100 in the sleep state consumes less power than the image forming apparatus 100 in the normal power state. Similarly, the image forming apparatus 100 in the suspended state consumes less power than the image forming apparatus 100 in the normal power state. Note that a hardware block diagram showing the configuration of the image forming apparatus 100 in the normal power state is omitted since it is the same as that in FIG. 1. Also, the image forming apparatus 100 in a power-off state (third state) (not shown) performs a shutdown process, and is configured such that power is not supplied to each device in FIG. 2 and FIG. 3. However, since the power-off state is the S5 state of ACPI, the image forming apparatus 100 in the power-off state consumes only the power required for powering on. Therefore, the above-mentioned state in which the power switch 107 is off corresponds to the power-off state.

[0020] FIG. 4 is a transition diagram of each power state (normal power state, sleep state, suspended state, power off state) in the image forming apparatus 100. 401 indicates that the image forming apparatus 100 transitions from the normal power state to the sleep state. In the normal power state, the image forming apparatus 100 transitions to the sleep state when a predetermined time has elapsed without receiving a predetermined access from the PC 124 or the server device 125 and without the operation unit 103 accepting a user operation. 402 indicates that the image forming apparatus 100 transitions from the sleep state to the normal power state. In the sleep state, the image forming apparatus 100 transitions to the normal power state when a predetermined access is received from the PC 124 or the server device 125 or when the operation unit 103 accepts a user operation. This point will be described in detail in the explanation of step S901 shown in the flowchart of FIG. 9 to be described later. 403 indicates that the image forming apparatus 100 transitions to the suspended state from the normal power state. 404 indicates that the image forming apparatus 100 transitions from the normal power state to the power off state. In the first embodiment, the image forming apparatus 100 transitions from the normal power state to the suspended state or the power off state in accordance with a power off instruction. The power off instruction is an off operation of the power switch 107, a remote off instruction from an external device such as the PC 124, an off instruction issued from a timer at a specified time, or an off instruction issued from a timer after a predetermined time has elapsed. In the image forming apparatus 100, a user can set in advance whether the image forming apparatus 100 transitions to the suspended state or the power off state when the image forming apparatus 100 receives a power off instruction. As a result, the image forming apparatus 100 transitions to a preset state (suspended state or power off state) in accordance with the power off instruction.

[0021] FIG. 5 is a diagram showing a suspend setting screen in the image forming apparatus 100. The suspend setting screen in FIG. 5 has an ON button 501 and an OFF button 502, and is displayed on the display of the operation unit 103. Whether the user touches the ON button 501 or the OFF button 502 in the suspend setting screen in FIG. 5 is detected by a touch sensor of the operation unit 103. In the suspend setting screen in FIG. 5, for example, the ON setting is performed by the user touching the ON button 501, and the OFF setting is performed by the user touching the OFF button 502. When the image forming apparatus 100 is set to ON, it transitions from the normal power state to the suspended state in accordance with a power-off instruction, and when the image forming apparatus 100 is set to OFF, it transitions from the normal power state to the power-off state in accordance with a power-off instruction. Note that the image forming apparatus 100 may determine whether to transition from the normal power state to the suspended state or the power-off state according to the operation time of the power switch 107. For example, when the power switch 107 is pressed for a long time, the image forming apparatus 100 transitions from the normal power state to the power off state, and when the power switch 107 is pressed for a short time, the image forming apparatus 100 transitions from the normal power state to the suspend state.

[0022] Returning to the description of FIG. 4, 405 indicates that the image forming apparatus 100 moves from the suspended state to the normal power state. When the power switch 107 is pressed in the suspended state, the image forming apparatus 100 moves to the normal power state. 406 indicates that the image forming apparatus 100 moves from the power-off state to the normal power state. When the power switch 107 is pressed in the power-off state, the image forming apparatus 100 moves to the normal power state. As described above, the image forming apparatus 100 in the power-off state consumes only the power required for power-on. On the other hand, the image forming apparatus 100 in the suspended state consumes more power than the image forming apparatus 100 in the power-off state. Therefore, the time required for the image forming apparatus 100 to move from the suspended state to the normal power state is shorter than the time required for the image forming apparatus 100 to start up from the power-off state to the normal power state. In addition, the image forming apparatus 100 executes a shutdown process (including an application termination process and an operating system termination process) before transitioning to the power-off state. However, the shutdown process is not executed when the image forming apparatus 100 transitions to a suspended state.

[0023] FIG. 6 is a diagram showing various programs stored in the ROM 112 of the image forming apparatus 100. As described above, the various programs stored in the ROM 112 of the image forming apparatus 100 are expanded in the RAM 113 and executed by the CPU 111. The OS (Operating System) 601 is a program that manages various processes and memory resources, and controls the controller 101. The power control program 602 is a program that communicates with each unit and controls the power of each device of the image forming apparatus 100. In addition, the power control program 602 determines whether a transition condition to a sleep state is satisfied, and if it determines that the transition condition to a sleep state is satisfied, notifies the printer control program 605 of a power saving transition and notifies the OS 601 of a sleep state transition. Similarly, the power control program 602 determines whether a transition condition to a suspend state is satisfied, and if it determines that the transition condition to a suspend state is satisfied, notifies the printer control program 605 of a power saving transition and notifies the OS 601 of a suspend state transition. In addition, the power control program 602 determines whether the conditions for transitioning to the power off state have been met, and if it determines that the conditions for transitioning to the power off state have been met, notifies the printer control program 605 of the transition to the power off state and notifies the OS 601 of the transition to the power off state.

[0024] The storage control program 603 is a program for controlling the storage 102 via the storage I / F 114. The operation section control program 604 is a program for controlling the operation section unit 103 via the operation section I / F 115. The printer control program 605 is a program for controlling the printer unit 104 via the printer I / F 116. The scanner control program 606 is a program for controlling the scanner unit 105 via the scanner I / F 117. The USB control program 607 is a program for controlling USB devices (including the external USB device 122) connected via the USB-Host I / F 118. The network control program 608 is a program for transmitting and receiving packets to and analyzing packets from a LAN connected via the network I / F 119.

[0025] FIG. 7 is a flowchart showing a process flow when the image forming apparatus 100 transitions from a normal power state to a sleep state or a suspend state. The process flow (control method of the image forming apparatus) shown in the flowchart of FIG. 7 is realized by the CPU 111 (computer) expanding various programs stored in the ROM 112 into the RAM 113 and executing them. In the flowchart of FIG. 7, first, in step S701, the power control program 602 determines whether the transition condition to the sleep state or the transition condition to the suspend state is satisfied. If the power control program 602 determines that the transition condition to the sleep state or the transition condition to the suspend state is satisfied, the process proceeds to step S702. On the other hand, if the power control program 602 determines that the transition condition to the sleep state or the transition condition to the suspend state is not satisfied, the process returns to step S701. The transition condition to the sleep state is that a predetermined time has elapsed without receiving a predetermined access from the PC 124 or the server device 125 and without the operation unit 103 accepting a user operation. The condition for transitioning to the suspend state is that the image forming apparatus 100 receives a power-off instruction and is set to ON on the suspend setting screen of FIG. 5, or the power switch 107 is pressed briefly.

[0026] In step S702, the power control program 602 notifies the printer control program 605 of a power saving transition. Furthermore, in step S702, the power control program 602 determines whether the transition destination from the normal power state is a sleep state or a suspend state. In this process, if the transition condition determined to be satisfied in step S701 is a transition condition for a sleep state, it is determined that the transition destination from the normal power state is a sleep state. On the other hand, if the transition condition determined to be satisfied in step S701 is a transition condition for a suspend state, it is determined that the transition destination from the normal power state is a suspend state. Then, if the power control program 602 determines that the transition destination from the normal power state is the suspend state, the process proceeds to step S703. On the other hand, if the power control program 602 determines that the transition destination from the normal power state is a sleep state, the process proceeds to step S708.

[0027] In step S703, the power control program 602 determines whether the image erasure setting is enabled. If the power control program 602 determines that the image erasure setting is enabled, the process proceeds to step S704. On the other hand, if the power control program 602 determines that the image erasure setting is disabled, the process proceeds to step S707. FIG. 8 is a diagram showing an image erasure setting screen in the image forming apparatus 100. In the image erasure setting screen in FIG. 8, the user can set the image erasure setting to enabled or disabled. The image erasure setting screen in FIG. 8 has an ON button 801 and an OFF button 802, and is displayed on the display of the operation unit 103. In the image erasure setting screen in FIG. 8, whether the user touches the ON button 801 or the OFF button 802 is detected by a touch sensor of the operation unit 103. In this way, in the image erasure setting screen in the operation unit 103 (operation means), for example, when the user touches the ON button 801, the image erasure setting is set to enabled, and when the user touches the OFF button 802, the image erasure setting is set to disabled.

[0028] Returning to the description of Fig. 7, in step S704, the printer control program 605 (determination means) determines whether or not an erasing sheet is present in the erasing tray of the printer unit 104. This determination is made based on the detection result of the sensor of the printer unit 104. If the printer control program 605 determines that an erasing sheet is present in the erasing tray of the printer unit 104, the process proceeds to step S705. On the other hand, if the printer control program 605 determines that an erasing sheet is not present in the erasing tray of the printer unit 104, the process proceeds to step S707.

[0029] In step S705, a preparation process for image erasure is performed. In the preparation process for image erasure, the printer control program 605 controls the printer unit 104 to start driving the toner removal roller, and confirms that the surface temperature of the toner removal roller has reached a temperature (removal roller temperature) at which the decolorizing toner can be erased. In step S706, an image erasure process is performed (erasing process). In the image erasure process, the printer control program 605 (erasing means) controls the printer unit 104 to start erasing the decolorizing toner on the sheet. The erasing of the decolorizing toner on the sheet is performed on the decolorizing sheet in the decolorizing tray of the printer unit 104, and is performed until all the decolorizing sheets in the decolorizing tray are used up. In this way, the erasing of the decolorizing toner on the sheet, that is, the image erasure on the sheet is performed. Then, when the image erasure on the sheet is completed, the printer control program 605 notifies the power control program 602 that it is possible to transition to a suspended state. Then, the process proceeds to step S707.

[0030] In step S707, the power control program 602 (second transition means) notifies the OS 601 of the transition to the suspended state, and stops the power supply to each unit and the I / F of each unit (second transition step). As a result, for example, as shown in FIG. 3, the power to the ROM 112, the storage I / F 114, the storage 102, the operation unit I / F 115, the operation unit 103, the printer I / F 116, and the printer unit 104 is turned off. Furthermore, the power to the scanner I / F 117, the scanner unit 105, the USB-Host I / F 118, the FAX unit 106, and the network I / F 119 is turned off. Then, the OS 601 puts the CPU 111 into a WFI (Wait For Interrupt) state. In this way, the image forming apparatus 100 transitions from the normal power state to the power saving state of the suspended state. After that, the flowchart in FIG. 7 ends.

[0031] On the other hand, in step S708, the power control program 602 (first transition means) notifies the OS 601 of a transition to the sleep state, and stops the power supply to each unit and its I / F (first transition process). As a result, for example, as shown in FIG. 2, the power is turned off to the ROM 112, the storage I / F 114, the storage 102, the printer I / F 116, the printer unit 104, the scanner I / F 117, and the scanner unit 105. Then, the OS 601 puts the CPU 111 into the WFI state. In this way, the image forming apparatus 100 transitions from the normal power state to the power saving state of the sleep state. After that, the flowchart in FIG. 7 ends.

[0032] FIG. 9 is a flowchart showing a process flow when image forming apparatus 100 transitions from a sleep state to a normal power state. The flowchart in FIG. 9 is implemented by CPU 111 expanding various programs stored in ROM 112 into RAM 113 and executing them. In step S901, CPU 111 determines whether or not there is a request for image formation from the user. If CPU 111 determines that there is a request for image formation from the user, it returns from the WFI state. Thereafter, the process proceeds to step S902. On the other hand, if CPU 111 determines that there is no request for image formation from the user, the process returns to step S901. Note that CPU 111 may regard the following cases (1) to (3), for example, as a request for image formation from the user. (1) When the image forming apparatus 100 receives a predetermined access from the PC 124 or the server apparatus 125. (2) When the operation unit 103 receives a user operation. (3) When a sheet is set in scanner unit 105.

[0033] In step S902, CPU 111 performs a sleep return process. In the sleep return process, CPU 111 starts supplying power to each unit and its I / F, making each available. The units and I / F to which power is supplied are the units and I / F to which power was turned off in step S708 above in order for image forming apparatus 100 to transition to the sleep state. As a result, image forming apparatus 100 transitions from the sleep state to a normal power state in which image formation on a sheet is possible. Thereafter, the flowchart in FIG. 9 ends.

[0034] Fig. 10 is a flowchart showing a process flow when image forming apparatus 100 transitions from a suspended state to a normal power state. The flowchart in Fig. 10 is implemented by CPU 111 expanding various programs stored in ROM 112 into RAM 113 and executing them. In step S1001, CPU 111 determines whether power switch 107 has been pressed. If CPU 111 determines that power switch 107 has been pressed, the system returns from the WFI state. The process then proceeds to step S1002. On the other hand, if CPU 111 determines that power switch 107 has not been pressed, the process returns to step S1001.

[0035] In step S1002, CPU 111 performs a suspend recovery process. In the suspend recovery process, CPU 111 starts supplying power to each unit and its I / F, making each available. The units and I / F to which power is supplied are the units and I / F to which power was turned off in step S707 above in order for image forming apparatus 100 to transition to the suspended state. As a result, image forming apparatus 100 transitions from the suspended state to a normal power state in which image formation on sheets is possible. Thereafter, the flowchart in FIG. 10 ends.

[0036] As described above, in the sleep state, the image forming apparatus 100 according to the first embodiment transitions to a normal power state in which image formation on a sheet is possible when there is a request for image formation, as shown in FIG. 9. As a result, even if a request for image formation is made suddenly by a user, the image forming apparatus 100 in the sleep state can perform image formation in response to the request. On the other hand, in the suspended state, the image forming apparatus 100 does not transition to a normal power state in which image formation on a sheet is possible even if there is a request for image formation, as shown in FIG. 10. Therefore, even if a request for image formation is made by a user, the image forming apparatus 100 in the suspended state cannot perform image formation in response to the request. Therefore, in the image forming apparatus 100, as shown in FIG. 7, image erasure on a sheet is performed between when the transition condition to the suspended state is satisfied and when the image forming apparatus transitions to the suspended state, thereby avoiding the loss of user convenience in response to the request for image formation. As a result, the image forming apparatus 100 can efficiently perform image formation and image erasure on a sheet without impairing user convenience.

[0037] In the image forming apparatus 100 according to the first embodiment, if the user sets the image erasure setting to be enabled on the image erasure setting screen in FIG. 8, the image is erased from the sheet, and if the user sets the image erasure setting to be disabled, the image is not erased from the sheet. In this way, in the image forming apparatus 100, the user can set whether or not the image is erased from the sheet during the period from when the transition condition to the suspended state is satisfied until the transition to the suspended state. In the image forming apparatus 100 according to the first embodiment, as shown in FIG. 7, if an erasure sheet is present in the erasure tray of the printer unit 104, the image is erased from the sheet. In contrast, if an erasure sheet is not present in the erasure tray of the printer unit 104, the image is not erased from the sheet. In this way, the image forming apparatus 100 can avoid unnecessary preparations for image erasure from the sheet.

[0038] <Second embodiment> The second embodiment will be described below with reference to FIG. 11. Here, the differences from the first embodiment will be mainly described. FIG. 11 is a flowchart showing a process flow when the image forming apparatus 100 transitions from a normal power state to a sleep state or a power-off state. The process flow shown in the flowchart of FIG. 11 is realized by the CPU 111 expanding various programs stored in the ROM 112 into the RAM 113 and executing them. In the flowchart of FIG. 11, first, in step S1101, the power control program 602 determines whether a transition condition to the sleep state or a transition condition to the power-off state is satisfied. If the power control program 602 determines that the transition condition to the sleep state or the transition condition to the power-off state is satisfied, the process proceeds to step S1102. On the other hand, if the power control program 602 determines that the transition condition to the sleep state or the transition condition to the power-off state is not satisfied, the process returns to step S1101. The transition condition to the sleep state is that a predetermined time has elapsed without receiving a predetermined access from the PC 124 or the server device 125 and without the operation unit 103 accepting a user operation. The condition for transitioning to the power-off state is that the image forming apparatus 100 receives a power-off instruction and is set to OFF on the suspend setting screen of FIG. 5, or that the power switch 107 is pressed and held down.

[0039] In step S1102, the power control program 602 determines whether the destination of the transition from the normal power state is a sleep state or a power-off state. In this process, if the transition condition determined to be satisfied in step S1101 is the transition condition for the sleep state, it is determined that the destination of the transition from the normal power state is the sleep state. On the other hand, if the transition condition determined to be satisfied in step S1101 is the transition condition for the power-off state, it is determined that the destination of the transition from the normal power state is the power-off state. Then, if the power control program 602 determines that the destination of the transition from the normal power state is the power-off state, it notifies the printer control program 605 of a power-off transition. Then, the process proceeds to step S1103. On the other hand, if the power control program 602 determines that the destination of the transition from the normal power state is the sleep state, it notifies the printer control program 605 of a power-save transition. Then, the process proceeds to step S1108.

[0040] Steps S1103 to S1106 are similar to steps S703 to S706 described above, and therefore their description will be omitted. In step S1107, the power control program 602 notifies the OS 601 of a transition to a power-off state. This causes a shutdown process to be performed, and for example, the power to each device in FIG. 2 and FIG. 3 is turned off. In this manner, the image forming apparatus 100 transitions from the normal power state to a power-off state (ACPI S5 state). Thereafter, the flowchart in FIG. 11 ends. Also, step S1108 is similar to step S708 described above, and therefore its description will be omitted. After the process of step S1108 is performed, the flowchart in FIG. 11 ends.

[0041] As described above, in the image forming apparatus 100 according to the second embodiment, in the sleep state, as shown in FIG. 9, when there is a request for image formation, the image forming apparatus 100 according to the second embodiment transitions to a normal power state in which image formation on a sheet is possible, as in the first embodiment. As a result, even if a request for image formation is made suddenly by a user, the image forming apparatus 100 in the sleep state can perform image formation in response to the request. On the other hand, in the power-off state (S5 state of ACPI), the image forming apparatus 100 consumes only the power required for power-on, and does not transition to a normal power state in which image formation on a sheet is possible, even if there is a request for image formation. Therefore, in the image forming apparatus 100, as shown in FIG. 11, image erasure on a sheet is performed between when the transition condition to the power-off state is satisfied and when the image forming apparatus transitions to the power-off state, thereby avoiding the loss of user convenience in response to a request for image formation. As a result, the image forming apparatus 100 can efficiently perform image formation and image erasure on a sheet without impairing user convenience.

[0042] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, the normal power state, sleep state, suspend state, and power off state are not limited to their respective names, and may be states corresponding to each of them. In the first embodiment, as an application example of the present invention, the image forming apparatus 100 when transitioning from the normal power state to the sleep state or suspend state as shown in FIG. 7 has been described. In the second embodiment, as an application example of the present invention, the image forming apparatus 100 when transitioning from the normal power state to the sleep state or power off state as shown in FIG. 11 has been described. However, the application examples of the present invention are not limited to these, and may be, for example, the image forming apparatus 100 when transitioning from the normal power state to the sleep state, suspend state, or power off state as shown in FIG. 4.

[0043] The present invention can also be realized by supplying a program that realizes one or more functions of each of the above-mentioned embodiments to a system or device via a network or a storage medium, and having one or more processors of a computer in the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0044] The disclosure of each embodiment includes the following configurations, methods, and programs. (Configuration 1) An image forming apparatus having a first state in which an image can be formed on a sheet, a second state in which the apparatus transitions to the first state when an image formation request is received, and a third state in which the apparatus does not transition to the first state even when an image formation request is received, a first transition means for transitioning the image forming apparatus from the first state to the second state in response to a condition for transitioning to the second state being satisfied; a second transition means for transitioning the image forming apparatus from the first state to the third state when a transition condition for the third state is satisfied; and an erasing means for erasing an image on a sheet from the time when a transition condition to the third state is satisfied until the image forming apparatus transitions from the first state to the third state. (Configuration 2) The first state is a normal power state, 2. The image forming apparatus according to configuration 1, wherein the second state and the third state are a first power saving state and a second power saving state in which power consumption is less than that in the normal power state. (Configuration 3) The first state is a normal power state, the second state is a power saving state in which less power is consumed than in the normal power state; 2. The image forming apparatus according to claim 1, wherein the third state is a power-off state in which only power required for power-on is consumed. (Configuration 4) A setting unit is provided that allows a user to set whether or not to execute the erasing unit, The image forming apparatus according to any one of configurations 1 to 3, characterized in that the erasing means is executed when the setting means sets the erasing means to be executed, and is not executed when the setting means sets the erasing means not to be executed. (Configuration 5) A determination unit is provided to determine whether a sheet is present in the tray used by the erasing unit, The image forming apparatus according to any one of configurations 1 to 4, characterized in that the erasing means is executed when the determination means determines that a sheet is present in the tray, and is not executed when the determination means determines that a sheet is not present in the tray. (Method 1) A method for controlling an image forming apparatus having a first state in which an image can be formed on a sheet, a second state in which the apparatus transitions to the first state when an image formation request is received, and a third state in which the apparatus does not transition to the first state even when an image formation request is received, a first transition step of transitioning the image forming apparatus from the first state to the second state in response to a condition for transitioning to the second state being satisfied; a second transition step of transitioning the image forming apparatus from the first state to the third state when a transition condition for the third state is satisfied; a control method for an image forming apparatus, comprising: an erasing process for erasing an image on a sheet from when a transition condition to the third state is satisfied until the image forming apparatus transitions from the first state to the third state. (Program 1) A program for causing a computer to execute each of the means of the image forming apparatus according to any one of configurations 1 to 5. [Explanation of symbols]

[0045] 100 Image forming device 602 Power control program (first transition means) (second transition means) 605 Printer control program (deletion means)

Claims

1. An image forming apparatus having a first state in which an image can be formed on a sheet, a second state in which the apparatus transitions to the first state when an image formation request is received, and a third state in which the apparatus does not transition to the first state even when an image formation request is received, a first transition means for transitioning the image forming apparatus from the first state to the second state in response to a condition for transitioning to the second state being satisfied; a second transition means for transitioning the image forming apparatus from the first state to the third state when a transition condition for the third state is satisfied; an erasing means for erasing an image on a sheet from the time when a transition condition to the third state is satisfied until the image forming apparatus transitions from the first state to the third state.

2. the first state is a normal power state; 2. The image forming apparatus according to claim 1, wherein the second state and the third state are a first power saving state and a second power saving state in which power consumption is less than that in the normal power state.

3. the first state is a normal power state; the second state is a power saving state in which less power is consumed than in the normal power state, 2. The image forming apparatus according to claim 1, wherein the third state is a power-off state in which only power required for power-on is consumed.

4. a setting means for allowing a user to set whether or not to execute the erasing means, 2. The image forming apparatus according to claim 1, wherein the erasing means is executed when the setting means sets the erasing means to be executed, and is not executed when the setting means sets the erasing means not to be executed.

5. a determination means for determining whether a sheet is present in a tray used by the erasing means, 2. The image forming apparatus according to claim 1, wherein the erasing means is executed when the determination means determines that a sheet is present in the tray, and is not executed when the determination means determines that a sheet is not present in the tray.

6. A method for controlling an image forming apparatus having a first state in which an image can be formed on a sheet, a second state in which the apparatus transitions to the first state when a request for image formation is received, and a third state in which the apparatus does not transition to the first state even when a request for image formation is received, comprising: a first transition step of transitioning the image forming apparatus from the first state to the second state in response to a condition for transitioning to the second state being satisfied; a second transition step of transitioning the image forming apparatus from the first state to the third state when a transition condition for the third state is satisfied; a control method for an image forming apparatus, comprising: an erasing process for erasing an image on a sheet from the time when a transition condition to the third state is satisfied until the image forming apparatus transitions from the first state to the third state.

7. 2. A program for causing a computer to execute each unit of the image forming apparatus according to claim 1.

Images