Image formation device

Abstract

To provide an image formation device which can execute preparation operation according to a mode of an image formation device.SOLUTION: When detecting opening operation of a front cover 2a during an off mode, a sub CPU 92 of a printer 1 stores a flag CFG1=1. When switching the printer 1 from the off mode to a normal mode, the sub CPU 92 turns an off mode flag to be OFFFG=0 (S207). In start processing, the sub CPU 92 switches it to the off mode (S19) in the case of OFFFG=1 (S11: NO), and executes preparation operation (S13) in the case of OFFFG=0 (S11: YES). In the start processing, the sub CPU 92 executes the preparation operation (S13) in the case of flag CFG1=1 (S14: YES), and does not execute the preparation operation in the case in which the flag CFG1 is not 1 (S14: NO).SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present application relates to a technique for performing a preparatory operation in an image forming apparatus. [Background technology]

[0002] The following Patent Document 1 describes an image forming apparatus that determines whether to perform a preparatory operation when a power supply unit is started. The preparatory operation is, for example, an operation for preparing the apparatus, such as a new product detection operation for determining whether to replace a developing cartridge. When the image forming apparatus of Patent Document 1 detects a rise in the AC voltage of the AC power supply when the power supply is resumed after the power supply from the AC power supply to the power supply unit is stopped, the image forming apparatus stores the rise history in a register. When the rise history is stored in the register, or when the front cover is opened during the period when the supply of the AC voltage is stopped, the image forming apparatus executes the preparatory operation. Also, when the rise history is not stored in the register and the front cover is not opened during the period when the supply of the AC voltage is stopped, the image forming apparatus does not execute the preparatory operation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-173547 A Summary of the Invention [Problem to be solved by the invention]

[0004] The image forming device of Patent Document 1 has an off mode for reducing power consumption in addition to a normal mode for performing normal operations. The image forming device of Patent Document 1 may uniformly perform preparatory operations based on the start-up history and the determination result of whether the cover is open or not when the power supply unit starts operating, regardless of whether the mode before the power supply unit starts operating is the normal mode or the off mode. Therefore, there is room for improvement in the determination process for performing the preparatory operations.

[0005] The present application has been proposed in view of the above-mentioned problems, and has an object to provide an image forming apparatus that can execute a preparatory operation according to the mode of the image forming apparatus. [Means for solving the problem]

[0006] In order to achieve the above object, an image forming apparatus of the present application includes a main body housing, a cover that covers an opening formed in the main body housing, a cover detection unit that detects an opening operation of the cover, an image forming unit that forms an image on a sheet, a control unit, a power supply unit to which a power cable connectable to an external power source is connected and that supplies driving power to the image forming unit based on power supplied from the power cable, and a non-volatile memory, wherein the control unit executes a normal mode in which power is supplied from the power supply unit to the image forming unit, and a normal mode process that executes a preparatory operation of the image forming unit based on detection of an opening operation of the cover by the cover detection unit, the normal mode process storing an off mode flag in the non-volatile memory when switching from the normal mode to an off mode that reduces power consumption compared to the normal mode, and an off mode process that executes the off mode, and when an opening operation of the cover is detected by the cover detection unit, stores a first flag in the non-volatile memory, and the control unit executes the off mode to switch from the off mode to the off mode. When switching to the normal mode, the control unit executes an off mode process that deletes the off mode flag in the nonvolatile memory, and a startup process that switches to the normal mode or the off mode when the control unit is started up. In the startup process, in a first case in which the control unit starts up in response to the start-up of the power supply unit due to the power cable being connected to the external power supply, (a) if the off mode flag is stored in the nonvolatile memory, the control unit controls to transition to the off mode, and (b) if the off mode flag is not stored in the nonvolatile memory, the control unit executes the preparatory operation and transitions to the normal mode. In a second case in which the control unit starts up in response to switching from the off mode to the normal mode by the off mode process, (c) if the first flag is stored in the nonvolatile memory, the control unit executes the preparatory operation and transitions to the normal mode, and (ii) if the first flag is not stored in the nonvolatile memory, the control unit transitions to the normal mode without executing the preparatory operation.

[0007] According to this, in the start-up process, in the first case where the control unit starts up with the start-up of the power supply unit by connecting the power cable to an external power supply, if the off mode flag is stored, the control unit does not execute the preparatory operation and transitions to the off mode. On the other hand, in the case where the off mode flag is not stored, the control unit executes the preparatory operation and executes the preparatory operation for transitioning to the normal mode. During the off mode, the control unit can execute the preparatory operation at the timing of switching from the off mode to the normal mode without executing the preparatory operation. Also, in the second case where the control unit starts up with the switching from the off mode to the normal mode by the off mode process, if the first flag is stored, that is, if the opening operation of the cover is detected during the off mode, the control unit executes the preparatory operation. On the other hand, if the first flag is not stored, the control unit does not execute the preparatory operation. Therefore, the control unit can execute the preparatory operation when the cover is opened during the off mode. As a result, the preparatory operation can be executed in response to the switching between the normal mode and the off mode of the image forming apparatus and the opening and closing of the cover.

[0008] The control unit may be configured such that, if the state before starting the off mode processing is the off mode, after starting the off mode processing, the control unit stores a second flag in the non-volatile memory, and if, during the startup processing, the off mode flag is not stored in the non-volatile memory and the second flag is stored in the non-volatile memory, the control unit performs the preparatory operation to transition to the normal mode, if the off mode flag and the second flag are not stored in the non-volatile memory and the first flag is stored in the non-volatile memory, the control unit performs the preparatory operation to transition to the normal mode, and if the off mode flag, the second flag, and the first flag are not stored in the non-volatile memory, the control unit transitions to the normal mode without performing the preparatory operation.

[0009] According to this, if the state before the start of the off mode process is the off mode, for example, if the power cable is disconnected and inserted during the off mode, and the device is started again and the off mode is maintained, the second flag is stored in the off mode process after the start, so that the preparatory operation is executed when switching to the normal mode in the startup process. In other words, in such a situation, the preparatory operation is executed assuming that there is a high possibility that a developing cartridge or the like has been replaced. Therefore, by using the second flag as a flag indicating that the power cable has been disconnected and inserted, if the power cable has been disconnected and inserted during the off mode, the preparatory operation can be executed when switching from the off mode to the normal mode. Also, even if the second flag is not stored, the first flag indicating the detection of the cover opening operation is stored, so that the preparatory operation is executed in the startup process. Therefore, even if the power cable has not been disconnected and inserted, the preparatory operation can be executed in response to the cover being opened. And, if the first and second flags are not stored in the startup process, the preparatory operation is not executed. Therefore, the conditions for executing the preparatory operation can be set by the first and second flags.

[0010] The device may further include a volatile memory, and the control unit, in the startup process, when the first case occurs and the off mode flag is stored in the non-volatile memory, controls to store the second flag in the volatile memory and then transition to the off mode, and in the off mode process, when the second flag is stored in the volatile memory, does not detect the cover opening operation by the cover detection unit, and when the second flag is not stored in the volatile memory, detects the cover opening operation by the cover detection unit, and when the cover opening operation is detected by the cover detection unit, stores the first flag in the volatile memory, and when switching from the off mode to the normal mode, stores information of the second flag and the first flag stored in the volatile memory in the non-volatile memory.

[0011] According to this, in the start-up process, in the first case and when the off mode flag is stored in the non-volatile memory, the second flag is stored in the volatile memory, and then the device transitions to the off mode. Then, in the off mode process, when the second flag is stored, detection of the cover opening operation is not performed, so that unnecessary detection operations during the off mode can be reduced. Even if the cover opening operation is not detected during the off mode, the second flag stored in the volatile memory during the off mode can be stored in the volatile memory, so that the preparatory operation can be performed when transitioning to the normal mode. Also, when the second flag is not stored, the fact that the cover opening operation was detected during the off mode is stored in the first flag of the volatile memory, and then re-stored in the non-volatile memory, so that the preparatory operation can be performed.

[0012] Furthermore, the device may further include a second control unit separate from the control unit, and the second control unit may start up the control unit during the startup process, and if the off mode flag is not stored in the non-volatile memory, execute control of parts other than the image forming unit by the second control unit, and if the off mode flag is stored in the non-volatile memory, switch the second control unit to a suspended state.

[0013] According to this, when the off mode flag is not stored, that is, when the printer is in the normal mode, the control unit controls the image forming unit, and the second control unit controls the units other than the image forming unit. Also, in the off mode, the control unit executes necessary control, so that the second control unit can be switched to a suspended state, thereby saving power.

[0014] In addition, the second control unit may be configured to determine whether or not a condition for switching from the normal mode to the off mode is met while the second control unit is executing control of a unit other than the image forming unit, and if it determines that the condition for switching from the normal mode to the off mode is met, to execute an instruction to the control unit to switch to the off mode.

[0015] According to this, the second control unit, in the normal mode, monitors the condition for switching from the normal mode to the off mode, and can switch the control unit to the off mode based on determining that the condition is met.

[0016] The printer may further include a power switch, and when at least one of the conditions of detecting pressing of the power switch and the condition of not accepting a print job for a predetermined period of time is satisfied in the normal mode, the second control unit may determine that the condition for switching from the normal mode to the off mode is satisfied and execute an instruction to the control unit to switch to the off mode.

[0017] According to this, in normal mode, the second control unit determines the conditions for switching from normal mode to off mode, such as a condition for detecting the pressing of the power switch or a condition for not accepting a print job, and can switch the control unit to off mode if the condition is met.

[0018] The apparatus may further include a power switch, and the control unit may execute the startup process when it detects that the power switch is pressed during the off mode process.

[0019] According to this, in the off mode, the control unit can determine the condition for detecting the pressing of the power switch as a condition for executing the startup process, and can execute the startup process if the condition is met. Effect of the Invention

[0020] According to the image forming apparatus of the present application, the preparatory operation can be performed according to the mode of the image forming apparatus. [Brief description of the drawings]

[0021] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a color laser printer according to an embodiment of the present application. [Diagram 2]FIG. 2 is a block diagram showing a control configuration of the color laser printer of FIG. [Diagram 3] 10 is a flowchart showing the contents of a main CPU startup process executed by the main CPU. [Figure 4] 11 is a flowchart showing the contents of a sub-CPU startup process executed by the sub-CPU; [Diagram 5] 13 is a flowchart showing the contents of a sub-CPU process executed by the sub-CPU. [Figure 6] 13 is a flowchart showing the contents of a sub CPU off mode process executed by the sub CPU. [Figure 7] FIG. 11 is a diagram showing the correspondence between steps executed in each process and flags in the steps. [Figure 8] 13 is a diagram showing steps to be executed in each process when the power cable is unplugged and plugged in during the off mode, and the correspondence between flags in the steps. FIG. [Figure 9] FIG. 13 is a diagram showing steps to be executed in each process when a power cable is unplugged and plugged in during normal mode, and the correspondence between flags in the steps. [Figure 10] 13A and 13B are diagrams showing steps executed in each process when the front cover is opened or closed in the off mode, and the correspondence between flags in the steps. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] A color laser printer, which is an embodiment of the image forming apparatus of the present application, will be described below with reference to FIG. 1. FIG. 1 shows a cross-sectional view of the schematic configuration of a color laser printer (hereinafter, printer) 1 according to this embodiment. Printer 1 is a so-called tandem type laser printer that uses four color toners. In the following description, the description will be based on the direction as seen by a user using printer 1, as shown in FIG. 1. That is, the right side in FIG. 1 will be referred to as the "front", the left side as the "rear", the upper side as the "upper", the lower side as the "lower", the near side as the "left" and the far side as the "right".

[0023] As shown in FIG. 1, the printer 1 includes a main body housing 2, a paper feed section 10, and an image forming section 20. The main body housing 2 is generally box-shaped. The main body housing 2 houses the paper feed section 10, the image forming section 20, and the like. An output tray 5 is formed on the top surface of the main body housing 2. The printer 1 outputs the sheets S on which images have been formed in a stacked state onto the output tray 5. A front cover 2a is provided on the front surface of the main body housing 2. The front cover 2a is a cover that opens and closes an opening 2b formed on the front surface of the main body housing 2. The front cover 2a can be rotated forward, for example, around a rotation shaft 2c provided at the bottom end, from a position where the opening 2b shown in FIG. 1 is closed to a position where the opening 2b is opened (opened).

[0024] The paper feed unit 10 includes a paper feed tray 11 in which sheets S are stored, a pickup roller 12, a separation pad 13, a pressure plate 14, and various rollers. The sheets S are, for example, standard sheets such as A4 size. The sheets S are not limited to paper media such as plain paper and thick paper, but may be other recording media such as OHP film. The paper feed tray 11 is detachably attached to the lower part of the main body housing 2. The pressure plate 14 is provided in the paper feed tray 11. A displacement mechanism (not shown) is provided below the pressure plate 14. The displacement mechanism displaces the pressure plate 14 to an inclined state so that the front side is higher prior to image formation. As a result, the sheets S stored in the paper feed tray 11 are brought toward the pickup roller 12 by the pressure plate 14, separated one by one by the pickup roller 12 and the separation pad 13, and transported to the image forming unit 20 by various rollers. The sheet S discharged from the paper feed tray 11 is conveyed along the conveying path R by the image forming unit 20, the discharge rollers 65, etc., and is discharged onto the discharge tray 5.

[0025] The image forming unit 20 is provided in the approximate center of the inside of the main body housing 2, and includes developing cartridges 30C, 30M, 30Y, and 30K, an exposure unit 40, a transfer unit 50, and a fixing unit 60. The developing cartridges 30C, 30M, 30Y, and 30K accommodate cyan, magenta, yellow, and black toners, respectively. The four developing cartridges 30C to 30K are provided in the order of developing cartridges 30K, 30Y, 30M, and 30C from the front to the rear of the printer 1. The developing cartridges 30C to 30K can be removed and replaced by opening the front cover 2a and removing them through an opening 2b of the main body housing 2.

[0026] The developing cartridge 30C includes a photosensitive drum 31, a charger 32, and a toner cartridge 33C. The other developing cartridges 30M, 30Y, and 30K have different toner colors, but are otherwise similar in configuration to the developing cartridge 30C. For this reason, the following description will mainly focus on the developing cartridge 30C, and descriptions of the other developing cartridges 30M, 30Y, and 30K will be omitted as appropriate.

[0027] The charger 32 is, for example, a Scorotron type charger including a charging wire 32a and a grid portion 32b. The charger 32 uniformly charges the surface of the photoconductor drum 31 positively before forming an electrostatic latent image on the surface of the photoconductor drum 31 during image formation. The device for charging the photoconductor drum 31 is not limited to a Scorotron type charger, and may be other devices such as a roller-type charging roller. Furthermore, the polarity for charging the photoconductor drum 31 is not limited to positive charging, and may be negative charging.

[0028] The toner cartridge 33C includes a toner storage chamber 33a, an agitator 33e, a supply roller 33b, a developing roller 33f, and a layer thickness regulating blade 33d. The toner storage chamber 33a stores cyan toner. The agitator 33e agitates the toner stored in the toner storage chamber 33a. The supply roller 33b is provided in the toner storage chamber 33a and rotates by a driving force transmitted from a motor (not shown) provided in the main body housing 2. The supply roller 33b supplies the toner supplied from the toner storage chamber 33a to the developing roller 33f. The photosensitive drum 31 rotates, for example, in a clockwise direction in FIG. 1. The developing roller 33f is provided diagonally behind and below the supply roller 33b and is in contact with the supply roller 33b. The developing roller 33f is also disposed downstream of the charger 32 in the rotation direction of the photosensitive drum 31. The developing roller 33f rotates by receiving a driving force from a motor (not shown) provided in the main body housing 2. A positive voltage is applied to the roller shaft of the developing roller 33f. The toner supplied to the developing roller 33f is carried on the developing roller 33f as the developing roller 33f rotates. The layer thickness regulating blade 33d is provided so as to be in pressure contact with the developing roller 33f from above, and regulates the thickness of the toner adhering to the outer peripheral surface of the developing roller 33f to a constant value. The toner cartridges 33M, 33Y, and 33K of the other colors (magenta, yellow, and black) shown in FIG. 1 have the same configuration as the toner cartridge 33C.

[0029] The exposure unit 40 is provided at the top inside the main body housing 2, and includes a laser light source, a polygon mirror, a lens, a reflecting mirror, etc. (not shown). A laser beam emitted from the laser light source is deflected by a polygon mirror, etc., and is emitted from the exposure unit 40. The exposure unit 40 exposes the surface of the photoconductor drum 31 by emitting a light beam shown by a dashed line in FIG. 1 to the surface of the photoconductor drum 31. As a result, an electrostatic latent image is formed on the surface of the photoconductor drum 31. The toner carried on the development roller 33f moves to the electrostatic latent image on the photoconductor drum 31 due to the potential difference between the development roller 33f and the electrostatic latent image formed on the photoconductor drum 31, and forms a toner image.

[0030] The transfer unit 50 is disposed at a position above the position of the paper feed unit 10 and below the position of the developing cartridge 30C. The transfer unit 50 transports the sheet S fed by the paper feed unit 10 toward the discharge tray 5. The transfer unit 50 includes a drive roller 51, a driven roller 52, a conveyor belt 53, and a plurality of (four in this embodiment) transfer rollers 54. The conveyor belt 53 is, for example, an endless belt formed by shaping a belt in a loop, and is stretched between the drive roller 51 located below the rear end side of the developing cartridge 30C and the driven roller 52 located below the front end side of the developing cartridge 30K.

[0031] Each of the multiple transfer rollers 54 is disposed at a position facing each photoconductor drum 31 in the vertical direction, with paper transport surface 53A, which is the outer circumferential surface of transport belt 53, sandwiched therebetween, and is in contact with transport belt 53 from the rear side of paper transport surface 53A. A negative transfer voltage is applied to each of the multiple transfer rollers 54 in accordance with the transport timing of sheet S, thereby transferring the toner image carried on the surface of photoconductor drum 31 to sheet S transported along paper transport surface 53A.

[0032] The fixing unit 60 is provided downstream in the transport direction from the position of the transfer unit 50. The fixing unit 60 includes a heating roller 61 that heats the sheet S, and a pressure roller 62 that sandwiches the sheet S between the heating roller 61. The image forming unit 20 transports the sheet S, on which the toner image has been transferred, to the fixing unit 60. The fixing unit 60 thermally fixes the toner image transferred to the sheet S to the sheet S by transporting the sheet S between the heating roller 61 and the pressure roller 62. The sheet S on which the image has been printed is discharged to the discharge tray 5 by discharge rollers 65.

[0033] (Printer 1 control configuration) Next, the control configuration of the printer 1 will be described with reference to Fig. 2. As shown in Fig. 2, in addition to the above-mentioned configuration, the printer 1 includes a power supply unit 71, a DC / DC converter 72, a main board 73, a power switch 74, a USBIF (abbreviation of interface) 75, a network IF 76, and a cover switch 77. The power supply unit 71 includes a power cable 71A connected to a commercial power source 81, which is an external power source. The power supply unit 71 includes, for example, an AC / DC circuit, and functions as a power source that converts AC voltage supplied from the commercial power source 81 via the power cable 71A into DC voltage and supplies it to each unit of the printer 1, such as the image forming unit 20. The DC voltage is an example of driving power.

[0034] The power supply unit 71 starts up in response to the power cable 71A being connected to the commercial power supply 81, and stops in response, for example, to the user unplugging the power cable 71A from the commercial power supply 81. The DC / DC converter 72 transforms the DC voltage supplied from the power supply unit 71 and supplies the transformed voltage to the main board 73.

[0035] The main board 73 is a control board that controls the printer 1 in an integrated manner, and includes an SoC 85, a ROM 86, a RAM 87, and a non-volatile memory 88. The SoC 85 is a system on a chip that includes a main CPU 91, a sub CPU 92, an external IF 93, and a volatile memory 94. The SoC 85 is connected to the power switch 74, the USB IF 75, the network IF 76, the cover switch 77, the paper feed unit 10, the image forming unit 20, and the like via the external IF 93. The USB IF 75 is a communication interface that can communicate in accordance with the USB standard. The network IF 76 is, for example, a wired interface such as a LAN interface, or a wireless interface that executes communication in accordance with the Wi-Fi (registered trademark) standard. The device that controls the printer 1 is not limited to an SoC, and may be another device such as an ASIC (Application Specific Integrated Circuit).

[0036] The ROM 86 stores various control programs and various setting information for controlling the printer 1. As shown in FIG. 2, the ROM 86 stores a main CPU program MPG and sub-CPU programs SPG1 and SPG2. The RAM 87 is, for example, a DRAM, and is used as a working area for reading out various control programs and a storage area for temporarily storing image data based on a print job. The non-volatile memory 88 is, for example, an NVRAM, and is used to store an off mode flag OFFFG and a flag CFG1. The volatile memory 94 of the SoC 85 is, for example, an SRAM, and is used to store a flag CFG2. The main CPU 91 and the sub-CPU 92 execute processing according to the control programs (main CPU program MPG, sub-CPU programs SPG1 and SPG2) read from the ROM 86 and signals input from various sensors, and control each part of the printer 1 while storing the processing results in the RAM 87 and the non-volatile memory 88.

[0037] The storage medium for storing the main CPU program MPG and the sub-CPU programs SPG1 and SPG2 is not limited to the ROM 86, but may be an NVRAM, HDD, SSD, etc. The storage medium for storing the main CPU program MPG may be an external storage medium such as a USB memory, or may be a storage medium such as a CD-ROM or DVD-ROM.

[0038] The printer 1 of this embodiment has a normal mode and an off mode. The normal mode is, for example, a mode in which all the functions of the printer 1 can be used in normal operation. In the normal mode, the SoC 85 is in a state in which the main CPU 91 and the sub-CPU 92 are activated. In the normal mode, the main CPU 91 executes the main CPU program MPG to control the USBIF 75 and the network IF 76. The main CPU 91 acquires a print job from an external device via the USBIF 75 and the network IF 76, and executes generation of image data based on the print job (rasterization, etc.). In the normal mode, the sub-CPU 92 executes the sub-CPU program SPG1, controls the image forming unit 20 and the paper feed unit 10, etc. based on the image data generated by the main CPU 91, and executes printing of the image data. In other words, in the normal mode, the main CPU 91 executes control other than that executed by the sub-CPU 92 (such as control of the image forming unit 20). The main CPU 91 and the sub-CPU 92 may execute each other's control instead depending on the conditions. In the normal mode, the power supply unit 71 supplies a DC voltage of 24 V to each unit of the printer 1, such as the image forming unit 20. In addition, the DC / DC converter 72 converts the DC voltage of 24 V supplied from the power supply unit 71 to 3.3 V and supplies the voltage to the SoC 85.

[0039] The off mode is, for example, a power saving mode in which the power consumption of the printer 1 is reduced compared to the normal mode. The sub CPU 92 executes the sub CPU program SPG2 in the off mode to execute control in the off mode. In the off mode, the sub CPU 92 reduces the power consumption by lowering the clock frequency. In the off mode, the sub CPU 92 puts the main CPU 91 into a suspended state (stopped state). This causes the main CPU 91 to enter a state in which it does not accept print jobs from external devices such as a PC via the USBIF 75 or the network IF 76. In addition, the sub CPU 92 controls the power supply unit 71 in the off mode to reduce the DC voltage output from the power supply unit 71. For example, the power supply unit 71 supplies a DC voltage of 6V in the off mode. The DC / DC converter 72 generates a DC voltage of 3.3V from the DC voltage of 6V supplied from the power supply unit 71 and supplies it to the SoC 85. The sub CPU 92 executes control in the off mode based on the power supplied from the DC / DC converter 72. In addition, in the off mode, the image forming unit 20, the paper feeding unit 10, etc. are not supplied with the 24V necessary for driving, and are therefore in a stopped state.

[0040] The above-mentioned control contents in the normal mode and the off mode are merely examples. For example, the power supply unit 71 may completely stop supplying power to the image forming unit 20 and the like in the off mode. Also, the sub-CPU 92 may operate at the same clock frequency as in the normal mode in the off mode without lowering the clock frequency. Also, when the main CPU 91 receives a print job from an external device via the USBIF 75 or the like in the off mode, it may return from the suspended state and execute the generation of image data.

[0041] The cover switch 77 has a contact that opens and closes in conjunction with the opening and closing of the front cover 2a, for example. The cover switch 77 is supplied with power in both the normal mode and the off mode. The sub-CPU 92 inputs contact information of the cover switch 77 in both the normal mode and the off mode, and determines whether the front cover 2a is opened or closed based on the contact information.

[0042] The processes executed by the main CPU 91 and the sub CPU 92 will be described with reference to Figures 3 to 6. The values ​​stored in the non-volatile memory 88 and the volatile memory 94 and the reasons for them will be described with reference to Figures 7 to 10, based on the steps executed in each process in Figures 3 to 6 and the corresponding relationships of the flags in those steps.

[0043] (Main CPU startup process) Next, the main CPU startup process executed by the main CPU 91 will be described with reference to Fig. 3. There are two cases in which the main CPU 91 executes the main CPU startup process. (1) When the printer 1 is in the normal mode or the off mode, the power cable 71A is unplugged and then reconnected to the commercial power source 81, thereby starting up the power supply unit 71 (first case). (2) When the power cable 71A is connected to the commercial power source 81, the printer 1 is switched from the off mode to the normal mode by pressing the power switch 74 (second case).

[0044] In the first case, when power cable 71A is connected to commercial power supply 81, power supply unit 71 starts up. When power supply unit 71 starts up, DC / DC converter 72 also starts up and a direct current voltage of 3.3 V is supplied to SoC 85. With the supply of a direct current voltage of 3.3 V, main CPU 91 starts up. The second case is as follows: For example, when a user wants to use the printer 1 to print on a sheet S, the user can switch the printer 1 from the off mode to the normal mode by pressing and holding the power switch 74 of the printer 1. Then, in the sub CPU off mode process in FIG. 6 described later, the sub CPU 92 determines that the power switch 74 has been pressed (S205: YES), and starts up the main CPU 91 from the off mode.

[0045] After executing the main CPU program MPG to start up the system of the printer 1, the main CPU 91 starts the main CPU startup process shown in Fig. 3. In the following description, the main CPU 91 and sub-CPU 92 which execute the control programs (main CPU program MPG, sub-CPU programs SPG1, SPG2) may be described simply by their CPU names. For example, the statement "the main CPU 91 reads the sub-CPU program SPG1 from ROM 86 and stores it in RAM 87" means "the main CPU 91 executes the main CPU program MPG, and reads the sub-CPU program SPG1 from ROM 86 and stores it in RAM 87 according to the instructions of the main CPU program MPG."

[0046] In addition, the off mode flag OFFFG in the following description is a flag for the main CPU 91 and sub CPU 92 to determine whether to transition to normal mode or off mode. A "0" in the off mode flag OFFFG indicates an instruction to transition to normal mode, and a "1" in the off mode flag OFFFG indicates an instruction to transition to off mode. When the printer 1 is in normal mode, a "0" in the off mode flag OFFFG is stored in the non-volatile memory 88. When the printer 1 is in off mode, a "1" in the off mode flag OFFFG is stored in the non-volatile memory 88.

[0047] As described above, since an alternative value is set in the off mode flag OFFFG, the state in which the off mode flag OFFFG is set to the value "0" indicating the normal mode can be regarded as the state in which the off mode flag OFFFG is not set to the value "1" indicating the off mode. Therefore, the state in which the off mode flag OFFFG is set to the value "0" is an example of the state in which the off mode flag of the present application is deleted. Note that the above-mentioned relationship between the flags and their values ​​is merely an example. For example, the off mode flag OFFFG may be set to "1" indicating the off mode.

[0048] 3, when the main CPU 91 starts the processing of FIG. 3, in step (hereinafter simply referred to as "S") 1, the main CPU 91 reads the sub-CPU program SPG1 from the ROM 86 and stores it in the RAM 87. The main CPU 91 causes the sub-CPU 92 to read the sub-CPU program SPG1 stored in the RAM 87, starts up the sub-CPU 92 (S2), and executes the sub-CPU start-up processing of S3.

[0049] After executing S3 and causing the sub CPU 92 to start the sub CPU startup process shown in FIG. 4, the main CPU 91 determines whether the off mode flag OFFFG is stored as "0" in the non-volatile memory 88 (S4).

[0050] When the main CPU 91 determines that the off mode flag OFFFG is stored as "0" in the non-volatile memory 88 (S4: YES), it starts main control (S5). When the off mode flag OFFFG is "0", this is an instruction to transition to the normal mode, so the main CPU 91 switches to the normal mode in S5. For example, the main CPU 91 instructs the paper feed unit 10 and the image forming unit 20 to supply DC voltage from the power supply unit 71, starts the network IF 76 to enable communication, and accepts a print job via the network IF 76. When the main CPU 91 accepts a print job, it executes printing based on the print job using the paper feed unit 10 and the image forming unit 20.

[0051] After switching to the normal mode, the main CPU 91 judges whether or not the condition for switching to the off mode is satisfied (S6). As the condition for switching from the normal mode to the off mode, for example, at least one of the following conditions can be adopted: a condition for detecting the pressing of the power switch 74; and a condition for not accepting a print job for a predetermined time. The pressing of the power switch 74 means, for example, that the power switch 74 is pressed (pressed and held) for a period of time equal to or longer than a preset time. The condition for switching from the normal mode to the off mode is not limited to the above condition, and may be, for example, a condition for accepting an instruction to switch to the off mode by a user's operation instruction. While the condition for switching to the off mode is not satisfied (S6: NO), the main CPU 91 maintains the normal mode and repeatedly executes the judgment process of S6 in the normal mode. On the other hand, when the main CPU 91 judges that the condition for switching to the off mode is satisfied (S6: YES), it executes an instruction to the sub CPU 92 to switch to the off mode (S7), and ends the process shown in FIG. 3.

[0052] Furthermore, if the main CPU 91 determines in S4 that the off mode flag OFFFG is not stored as "0" in the non-volatile memory 88 (S4: NO), this indicates an instruction to transition to the off mode, so that the state is switched to the suspended state (S9) and the state is stopped to reduce power consumption, etc. When the main CPU 91 switches to the suspended state (S9), it ends the processing shown in FIG.

[0053] (Sub-CPU startup process) Next, the sub-CPU startup process executed by the sub-CPU 92 will be described with reference to Fig. 4. When the sub-CPU 92 starts the sub-CPU startup process based on an instruction from the main CPU 91 in S3 of Fig. 3, it determines in S11 of Fig. 4 whether the off mode flag OFFFG is stored as "0" in the non-volatile memory 88. If the sub-CPU 92 determines that the off mode flag OFFFG is stored as "0" in the non-volatile memory 88 (S11: YES), that is, when switching to the normal mode, it determines whether the flag CFG1 is stored as "2" in the non-volatile memory 88 (S12).

[0054] The flag CFG1 is set to a value of "0," "1," or "2," and is stored in the non-volatile memory 88. The flag CFG1 is set to "0" to indicate the initial state. The flag CFG1 is set to "1," which allows the sub-CPU 92 to determine that the front cover 2a has been opened while the printer 1 is in the off mode. The flag CFG1 is set to "2," which allows the sub-CPU 92 to determine that the power cable 71A has been unplugged from the commercial power source 81 while the printer 1 is in the normal mode or off mode.

[0055] If the sub-CPU 92 determines that the flag CFG1 is stored as “2” in the non-volatile memory 88 (S12: YES), the sub-CPU 92 executes preparatory operations (S13) because the power cable 71A was unplugged from the commercial power source 81 before executing the sub-CPU startup process of FIG. 4.

[0056] The preparatory operation is, for example, an operation for preparing for printing, a correction process, etc. When the power cable 71A is disconnected from the commercial power source 81, the user may have replaced the developing cartridges 30C to 30K, and it is preferable to perform the preparatory operation before printing in the normal mode. In particular, the printer 1 of this embodiment does not have an auxiliary power source such as a battery that can supply power even when the power cable 71A is disconnected from the commercial power source 81. For this reason, when the power cable 71A is disconnected from the commercial power source 81, it is difficult for the printer 1 to supply power to a detection circuit for detecting whether the developing cartridges have been replaced by the user. As a result, when the developing cartridges 30C to 30K are replaced or the like when the power cable 71A is disconnected from the commercial power source 81, it is difficult for the printer 1 of this embodiment to detect that the developing cartridges have been replaced or the like when the power cable 71A is disconnected from the commercial power source 81. Similarly, when the front cover 2a described later is opened, the developing cartridges 30C to 30K may have been replaced or the like. Therefore, the sub-CPU 92 performs the preparatory operation in such a case.

[0057] The preparation operation may include, for example, a new product detection process or a process for warming the fixing unit 60. The new product detection process is a process for detecting replacement of the developing cartridges 30C to 30K. The method for determining whether the developing cartridges 30C to 30K have been replaced is not particularly limited, but for example, a method using a mechanical mechanism may be adopted. Specifically, a gear that rotates when the developing cartridges 30C to 30K are replaced (removed) may be provided, and the presence or absence of replacement may be determined based on the rotational position of the gear. Alternatively, the replacement of the developing cartridges 30C to 30K may be determined by reading an IC chip provided in the developing cartridges 30C to 30K. For example, when the sub-CPU 92 detects that at least one of the developing cartridges 30C to 30K has been replaced by the new product detection process, the sub-CPU 92 executes a correction operation for correcting image forming conditions such as a development bias and a charging bias.

[0058] Furthermore, if printing is performed immediately before the fixing unit 60 is warmed up, the heating roller 61 and the pressure roller 62 may deteriorate. For this reason, the sub-CPU 92 performs, for example, a process of warming the fixing unit 60 to a preheating temperature as a preparatory operation. The contents of the preparatory operation are not limited to the above. For example, the sub-CPU 92 may perform a process of driving the agitator 33e of the developing cartridges 30C to 30K and agitating the toner as a preparatory operation. Alternatively, the sub-CPU 92 may perform, for example, a process of checking the operation of the motors of the driving sources, a process of checking for failures, a test process of image formation, and the like as a preparatory operation.

[0059] Furthermore, when the sub CPU 92 determines in S12 that the flag CFG1 is not stored as "2" in the non-volatile memory 88 (S12: NO), it determines whether or not the flag CFG1 is stored as "1" in the non-volatile memory 88 (S14). When the sub CPU 92 determines that the flag CFG1 is stored as "1" in the non-volatile memory 88 (S14: YES), that is, before the sub CPU startup process of FIG. 4 is executed, the sub CPU 92 executes S13 because it corresponds to the case where the front cover 2a has been detected to be opened while the printer 1 is in the off mode. As described above, before the sub CPU startup process of FIG. 4 is executed, if the front cover 2a is opened while the printer 1 is in the off mode, there is a possibility that the development cartridges 30C to 30K have been replaced. Therefore, the sub CPU 92 executes the preparation operation of S13. After executing S13, the sub CPU 92 starts the sub CPU process shown in FIG. 5 (S20).

[0060] On the other hand, when the sub-CPU 92 determines that the flag CFG1 is not stored as "1" in the non-volatile memory 88 (S14: NO), it starts sub-CPU processing (S20). Therefore, the sub-CPU 92 does not execute preparatory operations if the power cable 71A has not been inserted or removed from the commercial power source 81 and the front cover 2a has not been opened or closed while the printer 1 is in the off mode. This allows power saving by omitting the preparatory operations, and suppresses the progression of deterioration of components such as toner that occurs when excessive preparatory operations are executed.

[0061] Furthermore, when the sub CPU 92 determines in S11 that the off mode flag OFFFG is not stored as "0" in the non-volatile memory 88 (S11: NO), it reads the sub CPU program SPG2 for the off mode from the ROM 86 and stores it in the volatile memory 94 of the SoC 85 (S15). Next, the sub CPU 92 reads the sub CPU program SPG2 from the volatile memory 94 and executes it (S16). As a result, the sub CPU 92 switches the program to be executed from the sub CPU program SPG1 for the normal mode to the sub CPU program SPG2, and starts the off mode process.

[0062] Next, the sub CPU 92 stores "2" in the flag CFG2 of the volatile memory 94 (S17). Next, the sub CPU 92 stores "1" in the off mode flag OFFFG of the non-volatile memory 88 (S18). After executing S18, the sub CPU 92 starts the sub CPU off mode processing of FIG. 6 (S19).

[0063] (About S17) In S17, flag CFG2 is stored as "2" in volatile memory 94. This flag is used to determine whether or not the sub-CPU 92 is executing the sub-CPU off mode processing in FIG. 6 via the route from S15 to S18 in FIG. 4. (About S18) In S18, the off mode flag OFFFG is stored as "1" in the non-volatile memory 88 so that when the power cable 71A is unplugged from the commercial power source 81 during the sub-CPU off mode processing of Fig. 6, the sub-CPU 92 determines in the sub-CPU startup processing of Fig. 4 that the sub-CPU 92 is in the off mode. If the sub-CPU 92 is in the off mode when the power cable 71A is unplugged from the commercial power source 81, the sub-CPU 92 transitions to the off mode, which is the state when the power cable 71A is unplugged in the sub-CPU startup processing of Fig. 4.

[0064] (Regarding sub-CPU processing) Next, the sub-CPU processing will be described with reference to Fig. 5. The sub-CPU processing is processing executed by the sub-CPU 92 after a positive determination is made in S11, i.e., in normal mode, as shown in Fig. 4. When the sub-CPU 92 executes S20 in Fig. 4 and starts the sub-CPU processing in Fig. 5, it stores "2" in the flag CFG1 of the non-volatile memory 88 in S101.

[0065] The sub-CPU 92 determines whether or not the front cover 2a has been opened based on the contact information of the cover switch 77 (S102). If the sub-CPU 92 determines that the front cover 2a has been opened (S102: YES), it determines whether or not the front cover 2a has been closed based on the contact information of the cover switch 77 (S110).

[0066] The sub-CPU 92 repeatedly executes the determination process of S110 until it detects that the front cover 2a is closed (S110: NO). When the sub-CPU 92 determines that the front cover 2a is closed (S110: YES), it executes a preparatory operation (S111) similar to S13 in FIG. 4. After executing S111, the sub-CPU 92 executes S102. This allows the preparatory operation to be executed in the normal mode in response to the opening and closing of the front cover 2a, that is, when there is a possibility that the developing cartridges 30C to 30K have been replaced.

[0067] Furthermore, when the sub-CPU 92 determines in S102 that the front cover 2a is closed (S102: NO), it determines whether or not a print command has been received (S103). A print command is a command to instruct the printer 1 to print, and is, for example, a command from the main CPU 91 to form image data based on a print job received via the USB IF 75 or the network IF 76. Alternatively, the print command may be a command based on a copy operation or the like on an operation unit (not shown) of the printer 1.

[0068] When the sub-CPU 92 receives a print command (S103: YES), it controls the image forming unit 20 and the paper feed unit 10 based on the print command to execute the print process (S104), and executes S105. On the other hand, when the sub-CPU 92 does not receive a print command (S103: NO), it executes S105. In S105, the sub-CPU 92 judges whether or not it has received an instruction to switch to the off mode from the main CPU 91. This switching instruction is the instruction of S7 in FIG. 3. While the sub-CPU 92 does not receive a switching instruction, it makes a negative judgment in S105 (S105: NO), and repeatedly executes the process from S102. As a result, the sub-CPU 92 receives a print command in the normal mode and executes the print process as appropriate.

[0069] When the sub CPU 92 receives the switching instruction (S105: YES), it prepares to switch from the normal mode to the off mode in S106 and thereafter. The sub CPU 92 reads the sub CPU program SPG2 for the off mode from the ROM 86 and stores it in the volatile memory 94 (S106). The sub CPU 92 executes the sub CPU program SPG2 in the volatile memory 94 (S107). As a result, the sub CPU 92 switches the program to be executed from the sub CPU program SPG1 for the normal mode to the sub CPU program SPG2.

[0070] The sub CPU 92 performs initialization by storing "0" in the flag CFG2 of the volatile memory 94 (S108). The sub CPU 92 stores "1" in the off mode flag OFFFG of the non-volatile memory 88 (S109). The sub CPU 92 starts the sub CPU off mode process (S112).

[0071] (About S101) In S101, the flag CFG1 stored in the non-volatile memory 88 is stored as "2" so that the sub-CPU 92 can determine, in the sub-CPU startup processing of FIG. 4, that the power cable 71A has been unplugged from the commercial power source 81 during the processing of S102 to S105 in the sub-CPU processing of FIG. 5.

[0072] (About S108) In S108, flag CFG2 is stored in volatile memory 94 as "0" to determine whether or not the sub-CPU 92 is going through the sub-CPU processing of FIG. 5 in the sub-CPU off mode processing of FIG. 6 described below.

[0073] (About S109) In S109, the off mode flag OFFFG is stored as "1" in the non-volatile memory 88 so that when the power cable 71A is unplugged from the commercial power source 81 during the sub-CPU off mode processing in Fig. 6 described later, the sub-CPU 92 determines in the sub-CPU startup processing in Fig. 4 that the mode is off. If the mode is off when the power cable 71A is unplugged from the commercial power source 81, the sub-CPU 92 transitions to the off mode, which is the state when the power cable 71A is unplugged in the sub-CPU startup processing in Fig. 4.

[0074] (Sub-CPU off mode processing) Next, the sub-CPU off mode process will be described with reference to FIG. 6. The sub-CPU off mode process is a process executed by the sub-CPU 92 in the off mode. When the sub-CPU 92 starts the sub-CPU off mode process in S19 of FIG. 4 or S112 of FIG. 5, it executes various power saving settings in S201 of FIG. 6. The sub-CPU 92 executes the power saving settings for switching to the off mode described above. Specifically, the sub-CPU 92 controls the power supply unit 71, for example, to reduce the output voltage of the power supply unit 71 from 24V to 6V. In addition, the sub-CPU 92 stops the supply of DC voltage from the power supply unit 71 to the paper feed unit 10, the image forming unit 20, the USBIF 75, and the network IF 76. In addition, the sub-CPU 92 may lower the clock frequency compared to the normal mode.

[0075] Next, the sub CPU 92 determines whether or not the flag CFG2 is stored as "2" in the volatile memory 94 (S202). The sub CPU 92 checks whether or not the flag CFG2 is stored as "2" in the volatile memory 94 in order to determine whether or not the sub CPU off mode process in Fig. 6 is to be executed via S19 in Fig. 4.

[0076] When the sub-CPU 92 determines that the flag CFG2 is stored as "2" in the volatile memory 94 (S202: YES), it executes S205.

[0077] On the other hand, when the sub CPU 92 determines that the flag CFG2 is not stored as "2" in the volatile memory 94 (S202: NO), that is, when the flag CFG2 is stored as "0" or "1" in the volatile memory 94, the sub CPU 92 proceeds to S203. The sub CPU 92 determines whether the front cover 2a is opened or not based on the contact information of the cover switch 77 (S203). When the sub CPU 92 determines that the front cover 2a is not opened (S203: NO), the sub CPU 92 executes S205. When the sub CPU 92 determines that the front cover 2a is opened (S203: YES), the sub CPU 92 stores "1" in the flag CFG2 of the volatile memory 94, which indicates that the front cover 2a is opened (S204). After executing S204, the sub CPU 92 executes S205.

[0078] In S205, the sub-CPU 92 determines whether the power switch 74 has been pressed and held by the user. The condition for canceling the off mode is, for example, a condition in which the power switch 74 is pressed (pressed and held) by the user for a period of time equal to or longer than a preset time. Note that the condition for canceling the off mode is not limited to the above-described condition in which the power switch 74 is operated, and may be a condition in which another switch is operated.

[0079] The sub-CPU 92 repeatedly executes the process from S202 until the user presses down the power switch 74 and the condition for canceling the off mode is met (S205: NO). Therefore, during the off mode, if the flag CFG2 is "2", the sub-CPU 92 does not monitor whether the front cover 2a is opened or closed, but if the flag CFG2 is "0" or "1", it monitors whether the front cover 2a is opened or closed.

[0080] When the sub-CPU 92 determines that the power switch 74 has been pressed and held by the user (S205: YES), it writes the information of the flag CFG2 in the volatile memory 94 to the flag CFG1 in the non-volatile memory 88 (S206). This allows the information of the flag CFG2 that the sub-CPU 92 stored during the off mode to be stored in the flag CFG1. The sub-CPU 92 stores "0" in the off mode flag OFFFG in the non-volatile memory 88 (S207).

[0081] When the sub CPU 92 executes S207, for example, the sub CPU 92 controls the power supply unit 71 to change the output voltage from 6V to 24V, and starts the main CPU 91 (S208). The main CPU 91 starts up, reads the main CPU program MPG from the ROM 86, executes it, and starts the main CPU startup process of FIG. 3. Since "0" is stored in the off mode flag OFFFG in S207, the main CPU 91 makes an affirmative determination in S4 (S4: YES), executes S5 and subsequent steps, and switches to the normal mode. In addition, the sub CPU 92 executes the sub CPU startup process of FIG. 4 in conjunction with the execution of S3, and since "0" is stored in the off mode flag OFFFG, makes an affirmative determination in S11 (S11: YES), and executes a preparation operation as appropriate. The sub CPU 92 executes S20 and starts the process of FIG. 5, thereby transitioning to the normal mode. In addition, the image forming unit 20, the paper feed unit 10, etc. are started up by being supplied with a DC voltage of 24 V from the power supply unit 71, and are capable of image formation under the control of the sub-CPU 92, that is, are capable of performing normal operations.

[0082] (Flags stored in non-volatile memory and volatile memory) Next, a description will be given of the steps executed in the processes shown in Figures 3 to 6 and the setting values ​​of the flags stored in the non-volatile memory 88 and the volatile memory 94. Figure 7 shows the correspondence between the steps executed in each process and the flags in those steps.

[0083] When the main CPU 91 is in a suspended state, the sub CPU 92 starts processing when the user presses the power switch 74 (S205: YES) in the sub CPU off mode processing of FIG. 6, and starts up the main CPU 91 from the off mode state (S208).

[0084] In the initial state, the power cable 71A is connected to the commercial power source 81 and the front cover 2a is closed, the non-volatile memory 88 stores the off mode flag OFFFG as "0" (indicating transition to normal mode) and the flag CFG1 as "0" (initial state), and the volatile memory 94 stores the flag CFG2 as "0" (initial state). The following explanation will be given assuming this.

[0085] First, when the power switch 74 is pressed by the user, the main CPU 91 starts the process from S1 in Fig. 3, starts the sub-CPU 92 (S3), and then starts the normal mode process from S5 onwards. As shown in Fig. 7, in the initial state, since the off mode flag OFFFG is "0", control is performed to transition to the normal mode, and the sub-CPU 92 judges S11: YES in Fig. 4, and since the flag CFG1 is "0" (initial state), judges S12: NO and S14: NO, and executes S20. The values ​​of each flag are maintained. No preparatory operation is performed.

[0086] 5, and in S101, changes the flag CFG1 stored in the non-volatile memory 88 from "0" to "2." The off mode flag OFFFG is stored as "0" in the non-volatile memory 88. The value of "0" is stored as the flag CFG2 in the volatile memory 94.

[0087] In S102 to S105, the values ​​of the flags in S101 are maintained. When the sub CPU 92 receives an instruction to switch to the off mode from the main CPU 91 (S105: YES), it sets the flag CFG2 stored in the volatile memory 94 to "0" in S108, and changes the off mode flag OFFFG stored in the nonvolatile memory 88 to "1" in S109.

[0088] The sub-CPU 92 executes S112 and starts the process of FIG. 6. In the example shown in FIG. 7, the front cover 2a has not been opened or closed, so the flag CFG2 stored in the volatile memory 94 is maintained at "0". When the user presses the power switch 74 (S205: YES), the sub-CPU 92 sets the value of the flag CFG1 to "0", which is the value of the flag CFG2 (S206), sets the off mode flag OFFFG to "0", and stores it in the non-volatile memory 88 (S207). As a result, the off mode flag OFFFG and the flag CFG1 return to the same value as the initial state (both "0"). As long as the power cable 71A is connected to the commercial power source 81 and the front cover 2a is closed, the above-mentioned flow is repeatedly executed.

[0089] (Preparation process when power cable 71A is unplugged during off mode) Next, the values ​​of the flags in the steps up to the execution of the preparation process of FIG. 4 when the power cable 71A is unplugged or plugged in during the off mode will be described with reference to FIG.

[0090] The setting values ​​of each flag on the left side of Fig. 8 indicate the setting values ​​of each flag in each step of Fig. 7. In the off mode, the sub-CPU 92 repeatedly executes the processes from S202 to S205 in Fig. 6. A case will be described in which the power cable 71A is disconnected from the commercial power source 81 and then reconnected.

[0091] As shown in the lower left of FIG. 8, while the processes of S202 to S205 in FIG. 6 are repeatedly executed, the non-volatile memory 88 stores the off mode flag OFFFG as “1” and the flag CFG1 as “2”, and the volatile memory 94 stores the flag CFG2 as “0”.

[0092] In S109 of FIG. 5, the off mode flag OFFFG is stored as “1” in the nonvolatile memory 88, and in S101 of FIG. 5, the flag CFG1 is stored as “2” in the nonvolatile memory 88, and the setting values ​​stored as each flag in the nonvolatile memory 88 are maintained in the processing of S202 to S205 of FIG. 6.

[0093] In this state, when the power cable 71A is unplugged from the commercial power source 81, the flag CFG2 stored in the volatile memory 94 is erased. In the non-volatile memory 88, the off mode flag OFFFG continues to be stored as "1" and the flag CFG1 continues to be stored as "2".

[0094] Thereafter, when the user connects the power cable 71A to the commercial power source 81, the power supply unit 71 starts up, and the main CPU 91 starts up and starts the process of FIG.

[0095] The main CPU 91 switches to the suspend state (S4: NO→S9) because the off mode flag OFFFG is stored as “1” in the non-volatile memory 88. In addition, the flag CFG2 is stored in the volatile memory 94, so the value becomes indefinite (is reset) when the power cable 71A is disconnected or reconnected.

[0096] As indicated by the arrow in FIG. 8, in S11 in FIG. 4, in the non-volatile memory 88, the off mode flag OFFFG is stored as "1" and the flag CFG1 is stored as "2", and in the volatile memory 94, the flag CFG1 is indefinite.

[0097] Since the off mode flag OFFFG stored in the non-volatile memory 88 is "1", the sub-CPU 92 makes a negative determination in S11 (S11: NO), and executes the sub-CPU program SPG2 to switch to the off mode (S19).

[0098] In the first case where the main CPU 91 and the sub CPU 92 start up with the start-up of the power supply unit 71 by connecting the power cable 71A to the commercial power supply 81, since the off mode flag OFFFG is stored as "1" in the non-volatile memory 88 in Fig. 4 (S11: NO), the process proceeds to the off mode process (S19) without executing the preparatory operation in S13 in Fig. 4. The flow described above is an example of the case (A) described in the claims of the present application.

[0099] Further, the sub-CPU 92 stores "2" in the flag CFG2 of the volatile memory 94 and "1" in the off mode flag OFFFG of the non-volatile memory 88 (S17, S18). In either case of switching from the normal mode to the off mode shown in S109 of Fig. 5, or from the off mode to the off mode shown in S18 of Fig. 4, i.e., maintaining the off mode, the sub-CPU 92 stores "1" in the off mode flag OFFFG. Therefore, when the power cable 71A is disconnected from the commercial power source 81 in the off mode, "1" is always stored in the off mode flag OFFFG in the non-volatile memory 88, and the main CPU 91 and the sub-CPU 92 maintain the off mode after startup (S4: NO, S11: NO).

[0100] 6, and because the flag CFG2 is "2", a negative determination is made in S202 (S202: NO), and S203 is not executed. That is, when the power cable 71A is unplugged from the off mode and plugged back in, the sub-CPU 92 does not execute the process of detecting whether the front cover 2a is opened or closed.

[0101] When switching to normal mode (S205: YES), the sub-CPU 92 executes S206 and S207, sets the off mode flag OFFFG in the non-volatile memory 88 to "0", sets flag CFG1 to "2", and stores "2" as flag CFG2 in the volatile memory 94.

[0102] Thereafter, since the flag CFG1 is "2", the sub-CPU 92 makes an affirmative determination in S12 of FIG. 4 (S12: YES) and executes the preparatory operation (S13). That is, if the power cable 71A is unplugged or plugged in during the off mode, the preparatory operation is executed. In other words, if "2" is stored in the flag CFG2 in S17 and maintained until switching to the normal mode, an affirmative determination is made in S12 and the preparatory operation can be executed. Therefore, it is not necessary to change the flag CFG2 during the off mode (to monitor the opening and closing of the front cover 2a). Unnecessary opening and closing detection processing during the off mode can be omitted.

[0103] In the second case where the main CPU 91 and the sub CPU 92 start up as the sub CPU 92 switches from the off mode to the normal mode (S205: YES, S206, S207), and since the off mode flag OFFFG is stored as "0" (S11: YES) and the flag CFG1 is stored as "2" (S12: YES) in the non-volatile memory 88 in Fig. 4 (not as "1"), the preparatory operation of S13 in Fig. 4 is performed, and then the mode transitions to the normal mode (S20). Note that the flow described above is an example of the case (ii) described in the claims of the present application.

[0104] (Preparation process when power cable 71A is unplugged during normal mode) Next, the values ​​of each flag in each step up to the execution of the preparation process (S13) in FIG. 4 when the power cable 71A is unplugged or plugged in during normal mode will be described with reference to FIG. 9. The setting values ​​of each flag on the left side of FIG. 9 indicate the setting values ​​of each flag in each step in FIG. 7. During normal mode, the sub-CPU 92 repeatedly executes the processes from S102 to S105 in FIG. 5. A case will be described where the power cable 71A is unplugged or plugged in from the commercial power source 81 at this time.

[0105] 5 are repeatedly executed, the off mode flag OFFFG stored in the nonvolatile memory 88 is stored as "0", the flag CFG1 is stored as "2", and the flag CFG2 is stored as "0" in the volatile memory 94. As shown by the arrow in FIG 9, when the power cable 71A is unplugged from the commercial power source 81 in this state, the flag CFG2 stored in the volatile memory 94 is erased. The off mode flag OFFFG continues to be stored as "0" and the flag CFG1 continues to be stored as "2" in the nonvolatile memory 88.

[0106] Thereafter, when the user connects the power cable 71A to the commercial power source 81, the power supply unit 71 starts up, and the main CPU 91 starts up and starts the process of FIG.

[0107] Since the off mode flag OFFFG is stored as "0" in the non-volatile memory 88 (S4: YES), the main CPU 91 starts main control in the normal mode (S5). Since the off mode flag OFFFG stored in the non-volatile memory 88 is "0" and the flag CFG1 is "2", the sub-CPU 92 executes preparatory operations in the process of FIG. 4 (S11: YES, S12: YES, S13). This allows the preparatory operations to be executed when the power cable 71A is unplugged or plugged in during the normal mode. After the preparatory operations are executed, the normal mode is executed (S20).

[0108] In the first case where the main CPU 91 and sub-CPU 92 start up with the start-up of the power supply unit 71 by connecting the power cable 71A to the commercial power supply 81, the off mode flag OFFFG is stored as "0" in the non-volatile memory 88 in Fig. 4 (S11: YES), so the sub-CPU process (S20), which is the normal mode, is executed after executing the preparatory operation in S13 in Fig. 4. The flow described above is an example of the case (ii) described in the claims of the present application.

[0109] (Preparation process when the front cover 2a is opened or closed during the off mode and the mode is switched from the off mode to the normal mode) Next, the process when the front cover 2a is opened or closed during the off mode and the printer 1 switches from the off mode to the normal mode will be described with reference to Fig. 10. The setting values ​​of the flags on the left side of Fig. 10 indicate the setting values ​​of the flags in each step of Fig. 7. During the off mode, the sub-CPU 92 repeatedly executes the processes from S202 to S205 in Fig. 6. The case where the front cover 2a is opened or closed at this time will be described.

[0110] As shown in the lower left of Fig. 10, while the processes from S202 to S205 in Fig. 6 are repeatedly executed, the off mode flag OFFFG is "1", the flag CFG1 is "2", and the flag CFG2 is "0". Therefore, the sub CPU 92 makes a negative determination in S202 in Fig. 6 (S202: NO), and determines whether the front cover 2a is open or closed in S203. As shown by the arrow in Fig. 10, when the front cover 2a is opened or closed in this state, the sub CPU 92 makes a positive determination in S203 (S203: YES), and stores "1" in the flag CFG2 (S204). In response to the switch from the off mode to the normal mode (S205: YES), the sub CPU 92 stores the value "1" of the flag CFG2 in the flag CFG1 in the non-volatile memory 88 (S206), and stores "0" in the off mode flag OFFFG (S207).

[0111] In response to S208, the main CPU 91 executes S3, and since the off mode flag OFFFG is stored as "0" and the flag CFG1 is stored as "1" in the non-volatile memory 88 in the process of FIG. 4, the sub-CPU 92 executes the preparatory operation (S11: YES, S12: NO, S14: YES, S13). As a result, if the front cover 2a is opened or closed during the off mode, the preparatory operation can be executed. Then, after the preparatory operation is executed, the normal mode is executed. In this way, the main CPU 91 and the sub-CPU 92 can update each flag in response to the mode, the insertion or removal of the power cable 71A, and the opening or closing of the front cover 2a, and execute the preparatory operation at an appropriate timing based on each flag.

[0112] In the second case where the main CPU 91 and the sub CPU 92 start up as the sub CPU 92 switches from the off mode to the normal mode (S205: YES, S206, S207), and since the off mode flag OFFFG is stored as "0" (S11: YES) and the flag CFG1 is stored as "1" (S12: NO, S14: YES) in the non-volatile memory 88 in Fig. 4, the preparatory operation of S13 in Fig. 4 is performed, and then the normal mode (S20) is entered. The flow described above is an example of the case (III) described in the claims of the present application.

[0113] As described above, according to the present embodiment, the following effects are obtained. (1) The printer 1 of this embodiment includes a main body housing 2, a front cover 2a that covers an opening 2b formed in the main body housing 2, a cover switch 77 that detects an opening operation of the front cover 2a, an image forming unit 20 that forms an image on a sheet S, a sub-CPU 92, a power supply unit 71 to which a power cable 71A connectable to a commercial power source 81 is connected and that supplies driving power to the image forming unit 20 based on the power supplied from the power cable 71A, and a non-volatile memory 88. The sub-CPU 92 executes a normal mode process in which power is supplied from the power supply unit 71 to the image forming unit 20, and a preparatory operation of the image forming unit 20 is executed based on the detection of the opening operation of the front cover 2a by the cover switch 77, and when switching from the normal mode to an off mode that reduces power consumption compared to the normal mode, an off mode flag OFFFG="1" is stored in the non-volatile memory 88 (S109) (see FIG. 5). The sub-CPU 92 also executes off mode processing to execute the off mode, and when the opening operation of the front cover 2a is detected by the cover switch 77, the sub-CPU 92 stores flag CFG1="1" (an example of the first flag of the present application) in the non-volatile memory 88, and when switching from the off mode to the normal mode, deletes the off mode flag OFFFG="1" in the non-volatile memory 88 (sets it to "0", S207) (see FIG. 6). The sub-CPU 92 also executes sub-CPU startup processing to switch to the normal mode or the off mode at startup. In the sub-CPU startup process, in the first case where the sub-CPU 92 starts up in response to the start-up of the power supply unit 71 by connecting the power cable 71A to the commercial power supply 81, (i) if the off mode flag OFFFG="1" is stored in the non-volatile memory 88 (S11: NO), the sub-CPU 92 controls the transition to the off mode (S19). In the sub-CPU startup processing, in the first case where the sub-CPU 92 starts up in response to the start-up of the power supply unit 71 by connecting the power cable 71A to the commercial power supply 81, if (b) the off mode flag OFFFG="0" is stored in the non-volatile memory 88 (S11: YES), the sub-CPU 92 executes preparatory operations (S13) and transitions to normal mode (sub-CPU processing). In addition, in the second case where the sub-CPU 92 starts up in response to switching from the off mode to the normal mode by the off mode processing, (c) if flag CFG1="1" is stored in the non-volatile memory 88 (S14: YES), the sub-CPU 92 executes preparatory operations (S13) and transitions to the normal mode (sub-CPU processing). In addition, in the second case where the sub-CPU 92 starts up in response to switching from the off mode to the normal mode by the off mode processing, (ii) if the flag CFG1="1" is not stored in the non-volatile memory 88 (S14: NO), the sub-CPU 92 does not perform the preparatory operation of S13 and transitions to the normal mode (sub-CPU processing).

[0114] According to this, in the first case in the sub-CPU startup process, when the sub-CPU 92 starts up with the power supply unit 71 starting up due to the power cable 71A being connected to the commercial power supply 81, and the off mode flag OFFFG="1" is stored in the non-volatile memory 88, the sub-CPU 92 transitions to the off mode without performing any preparatory operations. On the other hand, in the sub-CPU startup process, when the off mode flag OFFFG="0" is stored in the non-volatile memory 88, the sub-CPU 92 executes preparatory operations and prepares to transition to the normal mode. During the off mode, the preparatory operations are not executed, and the preparatory operations can be executed at the timing of switching from the off mode to the normal mode. In addition, in the second case where the sub-CPU 92 is started in response to switching from the off mode to the normal mode by the off mode process, if the flag CFG1="1" is stored in the non-volatile memory 88, that is, if the opening operation of the front cover 2a is detected during the off mode, the sub-CPU 92 executes the preparatory operation. On the other hand, if the flag CFG1="1" is not stored in the non-volatile memory 88 during the sub-CPU startup process, the sub-CPU 92 does not execute the preparatory operation. Therefore, the preparatory operation can be executed when the front cover 2a is opened during the off mode. As a result, the preparatory operation can be executed in response to switching between the normal mode and the off mode of the printer 1, opening and closing of the front cover 2a, and insertion and removal of the power supply unit 71.

[0115] (2) Furthermore, if the state before starting the off mode process is the off mode, the sub CPU 92 stores flag CFG1="2" (an example of the second flag of the present application) in the non-volatile memory 88 after starting the off mode process (S11: NO, S17, S202: YES, S206). Furthermore, if the off mode flag OFFFG="0" is stored in the non-volatile memory 88 and flag CFG1="2" is stored in the non-volatile memory 88 during the sub CPU startup process (S11: YES, S12: YES), the sub CPU 92 executes a preparatory operation and transitions to the normal mode (S13, S20).

[0116] According to this, if the state before starting the off mode processing is off mode, for example, if the power cable 71A is unplugged and plugged in during off mode and the device is started again and the off mode is maintained, the flag CFG1="2" is stored in the off mode processing after the start, and preparatory operations are performed when switching to normal mode. In other words, in such a situation, the preparatory operation is executed assuming that there is a high possibility that the developing cartridges 30C to 30K have been replaced. Therefore, by using the flag CFG1="2" as a flag indicating that the power cable 71A has been unplugged or plugged in, if the power cable 71A has been unplugged or plugged in during the off mode, the preparatory operation can be executed when switching from the off mode to the normal mode.

[0117] Furthermore, if the off mode flag="1" and flag CFG1="2" are not stored in the non-volatile memory 88 during the sub-CPU startup process, and flag CFG1="1" is stored in the non-volatile memory 88 (S11: YES, S12: NO, S14: YES), the sub-CPU 92 executes preparatory operations and transitions to normal mode (S13, S20). According to this, even if flag CFG1="2" is not stored, by storing flag CFG1="1" which indicates the detection of the opening operation of the front cover 2a, the preparatory operations can be executed during the sub-CPU startup process. Therefore, even if the power cable 71A is not inserted or removed from the commercial power source 81, the preparation operation can be performed in response to the opening of the front cover 2a. In addition, during the sub-CPU startup process, if the off mode flag OFFFG="0" and the flag CFG1="2" and "1" are not stored in the non-volatile memory 88 (S11: YES, S12: NO, S14: NO), the sub-CPU 92 does not perform preparatory operations. According to this, if the power cable 71A is not inserted or removed, or the front cover 2a is not opened or closed, the preparatory operation is not executed. Therefore, the conditions for executing the preparatory operation can be set by the flag CFG1.

[0118] (3) In addition, in the sub-CPU startup process, if the first case occurs and the off mode flag OFFFG="1" is stored in the non-volatile memory 88 (S11: NO), the sub-CPU 92 stores the flag CFG2="2" in the volatile memory 94 (S17) and then controls to transition to the off mode (S19). In the off mode process of Fig. 6, if the flag CFG2="2" is stored in the volatile memory 94 (S202: YES), the sub-CPU 92 does not execute detection of the opening operation of the front cover 2a by the cover switch 77 (S203), and if the flag CFG2="2" is not stored in the volatile memory 94 (S202: NO), it executes detection of the opening operation of the front cover 2a by the cover switch 77 (S203), and if the opening operation of the front cover 2a is detected by the cover switch 77 (S203: YES), it stores the flag CFG2="1" in the volatile memory 94 (S204). When switching from the off mode to the normal mode, the sub-CPU 92 stores the information of the flag CFG2 stored in the volatile memory 94 in the flag CFG1 of the non-volatile memory 88 (S206).

[0119] According to this, in the sub-CPU startup process, in the first case, if the off mode flag OFFFG="1" is stored in the non-volatile memory 88, the flag CFG2="2" is stored in the volatile memory 94, and then the mode transitions to the off mode. Then, in the off mode process, if the flag CFG2="2" is stored, the detection of the opening operation of the front cover 2a is not performed, so that unnecessary detection operations during the off mode can be reduced. Even if the opening operation of the front cover 2a is not detected during the off mode, the flag CFG2="2" stored in the volatile memory 94 during the off mode (S17) is stored in the non-volatile memory 88, so that the preparatory operation can be performed when transitioning to the normal mode. Also, if the flag CFG2="2" is not stored, the fact that the opening operation of the front cover 2a was detected during the off mode is stored as the flag CFG2="1" in the volatile memory 94, and then re-stored in the flag CFG1 in the non-volatile memory 88, so that the preparatory operation can be performed.

[0120] (4) In addition, when the main CPU 91 (sub-CPU 92) is started, the main CPU 91 starts the sub-CPU 92 (S2, S3), and if the off mode flag OFFFG="1" is not stored in the non-volatile memory 88 (S4: YES), the sub-CPU 92 executes control other than that of the image forming unit 20 (control of the USBIF 75 and the network IF 76) (S5). If the off mode flag OFFFG="1" is stored in the non-volatile memory 88 (S4: NO), the main CPU 91 switches to a suspended state (S9).

[0121] According to this, when the off mode flag OFFFG="1" is not stored in the non-volatile memory 88, that is, when the normal mode is being performed, the sub CPU 92 executes control of the image forming unit 20, and the main CPU 91 executes control of components other than the image forming unit 20. Also, during the off mode, the sub CPU 92 executes necessary control, so that the main CPU 91 can be switched to a suspended state, thereby achieving power saving.

[0122] (5) Furthermore, while the sub-CPU 92 is controlling the components other than the image forming unit 20, i.e., in the normal mode, the main CPU 91 determines whether or not the condition for switching from the normal mode to the off mode is satisfied (S6). If the main CPU 91 determines that the condition for switching from the normal mode to the off mode is satisfied (S6: YES), it instructs the sub-CPU 92 to switch to the off mode (S7). Thus, the main CPU 91 monitors the condition for switching from the normal mode to the off mode in the normal mode, and can switch the sub-CPU 92 to the off mode based on the determination that the condition is satisfied.

[0123] (6) Furthermore, when at least one of the conditions for detecting the pressing of the power switch 74 and the condition for not accepting a print job for a predetermined period of time is satisfied in the normal mode (S6: YES), the main CPU 91 determines that the condition for switching from the normal mode to the off mode is satisfied, and instructs the sub-CPU 92 to switch to the off mode (S7). According to this, in the normal mode, the main CPU 91 determines the condition for switching from the normal mode to the off mode, that is, the condition for detecting the pressing of the power switch 74 or the condition for not accepting a print job, and can switch the sub-CPU 92 to the off mode based on the satisfaction of the condition.

[0124] (7) Furthermore, if the sub-CPU 92 detects pressing of the power switch 74 (S205: YES) during the sub-CPU off mode process of Fig. 6, it executes the startup process (S208, S3). This allows the sub-CPU 92 to determine the condition for detecting pressing of the power switch 74 as a condition for executing the startup process during the off mode, and execute the startup process when the condition is met.

[0125] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. For example, in the above embodiment, the cover switch 77 is used as the cover detector of the present application, but the method of detecting the opening and closing of the front cover 2a is not limited to this. For example, the opening operation of the front cover 2a may be detected using a sensor such as a proximity sensor or an infrared sensor. Although the commercial power supply 81 is used as the external power supply in the present invention, a DC power supply may also be used. In the above embodiment, the main CPU 91 determines whether to switch from the normal mode to the off mode, but the sub-CPU 92 in the normal mode may determine this.

[0126] Also, the storage destinations of the off mode flag OFFFG and the flags CFG1 and CFG2 in the above embodiment are merely examples. For example, a volatile memory 94 may be mounted outside the SoC 85 on the main board 73 to store the flag CFG2. Also, the configuration of the printer 1 in the above embodiment is just an example. The printer 1 does not need to include the USB IF 75 or the network IF 76. The printer 1 may also include a user interface such as a touch panel. The printer 1 may also have modes other than the normal mode and the off mode. For example, the printer 1 may have a power saving mode (such as a sleep mode) that consumes more power than the off mode but is capable of receiving image data, etc. In the above embodiment, a color printer that forms a color image on a sheet S is used as the image forming apparatus of the present application, but the present application is not limited to this. The image forming apparatus of the present application may be, for example, a monochrome printer that forms a monochrome image on a sheet S. The image forming apparatus is not limited to a printer, and may be, for example, a multifunction machine that has a scan function and a fax function in addition to a print function. The image forming apparatus may be a scanner that has only a scan function, or a fax machine that has only a fax function. Therefore, the configuration of the image forming unit is appropriately changed depending on the functions of the image forming apparatus. [Explanation of symbols]

[0127] 1 printer (image forming apparatus), 2 main body housing, 2b opening, 2a front cover (cover), 20 image forming section, 71 power supply section, 71A power cable, 74 power switch, 77 cover switch (cover detection section), 81 AC power supply (external power supply), 88 non-volatile memory, 91 main CPU (second control section), 92 sub CPU (control section), CFG1 flag (first flag, second flag), OFFFG off mode flag, S sheet.

Claims

1. An image forming unit that forms an image on a sheet, Control unit and A power supply unit is connected to an external power supply via a power cable, and supplies drive power to the image forming unit based on the power supplied from the power cable. Non-volatile memory and Equipped with, The control unit, A normal mode process that performs a normal mode in which power is supplied from the power supply unit to the image forming unit, wherein when switching from the normal mode to an off mode that reduces power consumption compared to the normal mode, the normal mode process stores an off mode flag in the non-volatile memory. Off-mode processing to perform the off-mode, comprising: off-mode processing to delete the off-mode flag of the non-volatile memory when switching from the off-mode to the normal mode; The startup process involves switching to either the normal mode or the off mode when the control unit is started, Execute, In the aforementioned startup process, In the first case, when the power supply unit starts up due to the power cable being connected to the external power supply, the control unit starts up, (i) If the off-mode flag is stored in the non-volatile memory, control is performed to transition to the off-mode without executing the preparation operation of the image forming unit. (b) If the off-mode flag is not stored in the non-volatile memory, the preparation operation of the image forming unit is performed to switch to the normal mode. Image forming apparatus.

2. Furthermore, the main body housing, A cover that covers the opening formed in the main body housing, A cover detection unit that detects the opening operation of the cover, Equipped with, The control unit, In the normal mode processing described above, the image forming unit performs a preparation operation based on the detection of the cover opening operation by the cover detection unit. In the off-mode process that executes the off-mode described above, if the cover opening operation is detected by the cover detection unit, the first flag is stored in the non-volatile memory. In the aforementioned startup process, In the second case in which the control unit is activated in conjunction with the switching from the off mode to the normal mode due to the off mode processing, (h) If the first flag is stored in the non-volatile memory, the preparation operation is performed and the system switches to normal mode. (ii) If the first flag is not stored in the non-volatile memory, the system transitions to the normal mode without performing the preparation operation. The image forming apparatus according to claim 1.

3. The control unit, If the state before starting the off-mode processing is the off-mode state, after starting the off-mode processing, the second flag is stored in the non-volatile memory. In the aforementioned startup process, If the off-mode flag is not stored in the non-volatile memory and the second flag is stored in the non-volatile memory, the preparation operation is performed to transition to the normal mode. If the off-mode flag and the second flag are not stored in the non-volatile memory, and the first flag is stored in the non-volatile memory, the preparation operation is performed to transition to the normal mode. The image forming apparatus according to claim 2, wherein if the off-mode flag, the second flag, and the first flag are not stored in the non-volatile memory, the apparatus transitions to the normal mode without performing the preparation operation.

4. Furthermore, it is equipped with volatile memory, The control unit, In the aforementioned startup process, In the first case described above, and if the off-mode flag is stored in the non-volatile memory, the second flag is stored in the volatile memory, and then the system is controlled to transition to the off-mode. In the aforementioned off-mode processing, If the second flag is stored in the volatile memory, the cover detection unit does not detect the opening of the cover; if the second flag is not stored in the volatile memory, the cover detection unit detects the opening of the cover; and if the cover detection unit detects the opening of the cover, the first flag is stored in the volatile memory. The image forming apparatus according to claim 3, wherein when switching from the off mode to the normal mode, the information of the second flag and the first flag stored in the volatile memory is stored in the non-volatile memory.

5. Furthermore, it includes a second control unit separate from the aforementioned control unit, The second control unit is, In the startup process, the control unit is started, The image forming apparatus according to claim 1, wherein if the off-mode flag is not stored in the non-volatile memory, the second control unit performs control other than that of the image forming unit, and if the off-mode flag is stored in the non-volatile memory, the second control unit is switched to a suspend state.

6. The second control unit is, The image forming apparatus according to claim 5, wherein while the second control unit is performing control other than that of the image forming unit, it determines whether the conditions for switching from the normal mode to the off mode are met, and if it determines that the conditions for switching from the normal mode to the off mode are met, it issues an instruction to the control unit to switch to the off mode.

7. Furthermore, it is equipped with a power switch, The second control unit is, The image forming apparatus according to claim 6, wherein in the normal mode, if at least one of the following conditions is met—that the power switch is pressed down, and that the apparatus does not accept print jobs for a predetermined period of time—it is determined that the conditions for switching from the normal mode to the off mode have been met, and an instruction is given to the control unit to switch to the off mode.

8. Furthermore, it is equipped with a power switch, The control unit, The image forming apparatus according to claim 1, wherein when the pressing of the power switch is detected during the off-mode processing, the startup processing is executed.

Images