JP2017199054A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus capable of properly managing a power supply mode by a main CPU in which power is shut off in an OFF mode.SOLUTION: An electronic apparatus comprises: a sub-microcomputer 9 in which power is supplied in all power supply modes and monitors an operation on a power switch 52; and a mode storage part 72 which is under the control of a main CPU 71, and stores the power supply modes as mode information. The sub-microcomputer 9 asserts an OFF mode notice signal when instructed by the main CPU 71 to make a transition to the OFF mode, and starts supply of power to the main CPU 71 on detecting an ON operation on the power switch 52 in the OFF mode to actuate the main CPU 71. The main CPU 71 makes a transition to a ready mode when the OFF-mode notice signal is asserted and the mode information represents the "OFF mode", and makes a transition to the OFF mode when the OFF-mode notice signal is negated and the mode information represents the "OFF mode".SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic apparatus such as an image forming apparatus that shifts to a mode in which only the operation of a power switch is monitored (hereinafter referred to as an off mode) by turning off a power switch that is a soft switch.

  In an image forming apparatus having an off mode, when a power switch is turned on, a power is supplied to a device that realizes each function (copy function, print function, FAX function, network function, etc.). When the power switch is turned off in the ready mode, the power supply to the device that realizes each function is stopped, and the power switch is turned off to monitor the operation of the power switch.

  The image forming apparatus also includes a main CPU that performs image processing and controls the entire apparatus, and an engine CPU that controls a printing unit (an engine unit that executes a print job) in response to an instruction from the main CPU. There is something. In such an image forming apparatus, the operation of the power switch in the off mode is monitored by an engine CPU that consumes less power than the main CPU.

  Therefore, in the off mode, the power supply state is such that power is supplied only to the engine CPU. When the power supply is cut off and turned on again in the off mode due to a power failure or insertion / removal of the AC plug, the engine CPU is restarted. At this time, by storing mode information for distinguishing between “off mode” and “other than off mode” in the non-volatile memory controlled by the engine CPU, the engine CPU can store the power before the power supply is cut off. It is comprised so that it may return to a power supply state (for example, refer patent document 1). Thereby, when a power failure or an instantaneous power failure occurs in the ready mode such as when waiting for FAX, it is possible to return to the standby state without the user's operation. In addition, when the power switch is turned off to set the off mode to return to the off mode when the AC plug is inserted / removed, even if the off mode is used when the apparatus is moved, a natural behavior is obtained.

JP, 2015-170332, A

  However, in the prior art, the main CPU has not been able to monitor the transition to the off mode due to the operation of the power switch, and there is a risk that the main CPU may transition to the off mode during data handling such as during firmware update or startup. For example, if the mode is shifted to the off mode during the firmware update, there is a risk that the firmware may be damaged and the system cannot be started.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electronic device capable of appropriately managing a power supply mode by a main CPU whose power is cut off in an off mode. The purpose is to do.

The electronic device according to the present invention includes, as a power supply mode, a ready mode in which power is supplied to a main CPU that controls the entire apparatus, and an off mode in which power to the main CPU is shut off and only the operation of a power switch is monitored. An electronic device that is supplied with power in all the power supply modes, monitors the operation of the power switch, and manages a power supply unit that supplies power to the main CPU; and And a non-volatile memory that stores the power supply mode as mode information. When the microcomputer is instructed to shift from the main CPU to the off mode in the ready mode, the main CPU The off mode notification signal to be output to the output signal is asserted, and the power switch on operation is detected in the off mode. Then, the power supply to the main CPU is started and started, and the off-mode notification signal is negated by the power-off to the microcomputer, and the main CPU is in the asserted state of the off-mode notification signal, When the mode information is “off mode”, the mode is shifted to the ready mode. When the off mode notification signal is negated and the mode information is the “off mode”, the mode is shifted to the off mode. It is characterized by that.
Furthermore, in the electronic device of the present invention, when the mode information is “non-off mode”, the main CPU may shift to the ready mode regardless of the off mode notification signal.
Furthermore, in the electronic device of the present invention, the off-mode notification signal may be an open collector output.
Furthermore, in the electronic device of the present invention, the electronic device includes an engine unit that is supplied with power in the ready mode and is turned off in the off mode, and the drive signal of the engine unit is gated with the off mode notification signal, When the off-mode notification signal is negated, the engine unit may not be driven as an initial value.

  According to the present invention, the main CPU determines the power supply mode based on the off mode notification signal asserted by the instruction to shift to the off mode and negated by the interruption of the power supply to the microcomputer and the mode information at the time of startup. Therefore, the power supply mode can be appropriately managed by the main CPU whose power is shut off in the off mode.

It is a block diagram which shows schematic structure of embodiment of the electronic device which concerns on this invention. FIG. 2 is a mode transition diagram illustrating a power supply mode included in the image forming apparatus illustrated in FIG. 1. 3 is a transition table illustrating a power state determination operation by the main CPU illustrated in FIG. 1.

Next, embodiments of the present invention will be specifically described with reference to the drawings.
The electronic apparatus according to the present embodiment is an image forming apparatus 1. Referring to FIG. 1, a document reading unit 2, a document feeding unit 3, a recording unit 4, an operation unit 5, a main control unit 7, An engine control unit 8 and a sub-microcomputer 9 are provided. The operation unit 5 is provided with a liquid crystal display unit 51, a power switch 52, and operation buttons 53. The user operates the operation unit 5 to input an instruction, thereby performing various settings of the image forming apparatus 1 and executing various functions such as image formation. The liquid crystal display unit 51 indicates the state of the image forming apparatus 1, displays the image forming status and the number of copies, and functions as a touch panel for setting the document size, duplex printing, black and white reversal, magnification setting, density setting, etc. Various settings can be made. The power switch 52 is a software switch that stops the supply of power to a device that realizes each function and instructs the shift to the off mode in which only the power switch 52 is turned on. The operation button 53 includes a start button that the user instructs to start image formation, a stop / clear button that is used when image formation is stopped, and other settings that are used when setting various settings of the image forming apparatus 1 to default. A reset button, a numeric keypad and the like are provided.

  The document reading unit 2 includes a scanner, a platen glass, and a document reading slit. When reading a document placed on the platen glass, the document reading unit 2 moves the scanner to a position facing the platen glass, reads the document placed on the platen glass while scanning, and acquires image data. The acquired image data is output to the recording unit 4. Further, when the original reading unit 2 reads the original fed from the original feeding unit 3, the original reading unit 2 moves the scanner to a position facing the original reading slit, and feeds the original by the original feeding unit 3 through the original reading slit. The document is read in synchronization with the operation to acquire image data, and the acquired image data is output to the recording unit 4.

  The document feeding unit 3 includes a document placing unit and a document transport mechanism, and feeds the documents placed on the document placing unit one by one by the document transport mechanism to the document reading unit 2.

  The recording unit 4 includes a photosensitive drum, a charging unit, an exposure unit, a development unit, a transfer unit, a fixing unit, and the like. The recording unit 4 performs an image forming process including charging, exposure, development, transfer, and fixing on the recording paper P. Record the toner image.

  The main control unit 7 is an information processing unit including a main CPU 71, a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The ROM stores a control program for controlling the operation of the image forming apparatus 1. The main CPU 71 reads out a control program stored in the ROM and develops the control program in the RAM, thereby controlling the entire apparatus. In addition, the main control unit 7 includes a mode storage unit 72 that stores mode information for distinguishing between “off mode” and “other than off mode”. The mode storage unit 72 is a non-volatile memory under the control of the main CPU 71 and can be configured by, for example, an EEPROM mounted on the main CPU 71. In the present embodiment, the mode information is composed of 1 bit in which “off mode” is “0” and “other than off mode” is “1”. Further, the main control unit 7 includes an ASIC dedicated to image processing and functions as an image processing unit 73 that performs various image processing (enlargement / reduction, density conversion, data format conversion, etc.) on the image data.

  The main control unit 7 is connected to the liquid crystal display unit 51 and the operation button 53 of the operation unit 5, the communication unit 11, and the storage unit 12. The main control unit 7 controls the entire apparatus according to the operation of the liquid crystal display unit 51 and the operation button 53 and also controls the display operation of the liquid crystal display unit 51. The communication unit 11 has a function of receiving a print job or the like from a user terminal such as a personal computer via a network such as a LAN. The storage unit 12 is a storage unit such as a semiconductor memory or an HDD (Hard Disk Drive), and includes image data acquired by reading a document by the document reading unit 2 as print data, a print job received by the communication unit 11, and the like. Is memorized.

  The engine control unit 8 controls the document reading unit 2, the document feeding unit 3, and the recording unit 4 that function as an engine unit that receives an instruction from the main control unit 7 and executes a print job. The engine control unit 8 is an information processing unit including an engine CPU 81, a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The ROM stores a control program for controlling the operation of the engine unit. The engine CPU 81 reads the control program stored in the ROM and develops the control program in the RAM, thereby controlling the engine unit based on an instruction from the main control unit 7.

  The sub-microcomputer 9 is an information processing unit including a microcomputer, and is connected to the main control unit 7, the power switch 52, and the power supply unit 10. The power supply unit 10 receives power supply from a commercial power supply (not shown) and generates a power supply (voltage) necessary for operating each unit of the image forming apparatus 1. The sub-microcomputer 9 is a control unit for power management that monitors the operation of the power switch 52 and manages power from the power supply unit 10 to each unit. The control performed by the sub-microcomputer 9 itself includes a control for starting power supply from the power supply unit 10 to the main CPU 71 when the power switch 52 is turned on or started in the off mode, and an instruction to shift to the off mode by the main CPU 71. Then, only the control for asserting the off mode notification signal is performed. Management of power supply from the other power supply unit 10 to each unit is actually managed by the main CPU 71, and the sub-microcomputer 9 communicates with the main CPU 71 of the main control unit 7 and follows the instructions of the main CPU 71. Accordingly, even when the power switch 52 is turned off, the sub-microcomputer 9 only notifies the main CPU 71 of the operation of the power switch 52, and the main CPU 71 manages the power supply from the power supply unit 10 to each unit. Therefore, when the power switch 52 is turned off, the sub-microcomputer 9 shuts off the power supply between the main control unit 7 and the engine control unit 8 under the control of the main CPU 71.

  The off mode notification signal is a signal output from the sub-microcomputer 9 to the main CPU 71 of the main control unit 7. The sub-microcomputer 9 asserts the off-mode notification signal when the main CPU 71 is instructed to shift to the off mode, and negates the off-mode notification signal when the main CPU 71 is instructed to return to the ready mode. Further, when the power to the sub-microcomputer 9 is temporarily cut off due to a power failure or insertion / removal of the AC plug with the off-mode notification signal asserted, the off-mode notification signal is negated. Since the off mode notification signal is output to the main CPU 71 whose power is shut off in the off mode, it is an open collector output so that no wraparound occurs.

Next, the power supply mode in the image forming apparatus 1 will be described in detail with reference to FIG.
As illustrated in FIG. 2, the image forming apparatus 1 includes a ready mode, a sleep mode in which power consumption is reduced as compared with the ready mode, and an off mode in which power consumption is further reduced as compared with the sleep mode.

  The ready mode is a normal mode in which power is supplied to each unit that realizes each function (copy function, print function, network function, etc.) of the image forming apparatus 1. In the ready mode, the power supply unit 10 supplies normal power to each unit of the image forming apparatus 1.

  In the ready mode, the main CPU 71 counts the unused time that has passed without the image forming apparatus 1 being used. Via the power supply unit 10. Alternatively, the main CPU 71 also instructs the power supply unit 10 via the sub-microcomputer 9 to shift to the sleep mode even when the sleep mode shift instruction is received from the operation unit 5.

  In the sleep mode, the power supply unit 10 restricts power supply to each unit connected to the main control unit 7 and the engine control unit 8. Further, the main CPU 71 and the engine CPU 81 operate in a clock low speed mode in which the operation clock is lowered to reduce power consumption.

  In the ready mode or the sleep mode, the main CPU 71 measures the unused time that has passed without the image forming apparatus 1 being used, and when the unused time exceeds the off transition time, the main CPU 71 shifts from the ready mode or the sleep mode to the off mode. Thus, the power supply unit 10 is instructed via the sub-microcomputer 9. Alternatively, the main CPU 71 also instructs the power supply unit 10 through the sub-microcomputer 9 to shift to the off mode even when the power switch 52 is turned off via the sub-microcomputer 9. The main CPU 71 updates the mode information in the mode storage unit 72 to “0” (“off mode”) when shifting to the off mode.

  In the off mode, the power supply unit 10 cuts off power supply to each unit including the main CPU 71 and the engine CPU 81 and supplies power only to the sub-microcomputer 9. That is, the off mode is a mode in which only the operation of the power switch 52 is monitored by the sub-microcomputer 9. Since the functions of the sub-microcomputer 9 are limited as described above, the power consumption is much smaller than that in the clock low speed mode of the main CPU 71 and the engine CPU 81.

  Next, the power supply state determination operation by the main CPU 71 will be described in detail with reference to FIG.

  When the power supply is started, the main CPU 71 determines a power supply mode by checking an off mode notification signal and mode information in the mode storage unit 72 at the time of booting, and determines a power supply mode to be shifted.

  When the off mode notification signal is asserted and the mode information in the mode storage unit 72 is “0” (“off mode”), the transition from the ready mode or the sleep mode to the off mode is performed normally. It is determined that the sub-microcomputer 9 has accepted the on operation of the power switch 52 in the off mode without shutting off the power to the image forming apparatus 1 due to a power failure or insertion / removal of the AC plug. Therefore, the main CPU 71 recognizes that it is a transition to the ready mode when the off mode notification signal is asserted and the mode information in the mode storage unit 72 is “0” (“off mode”). The power supply unit 10 is instructed via the sub-microcomputer 9 to shift to the ready mode. The main CPU 71 updates the mode information in the mode storage unit 72 to “1” (“other than the off mode”) when shifting to the ready mode.

  When the off mode notification signal is negated and the mode information in the mode storage unit 72 is “0” (“off mode”), the transition from the ready mode or the sleep mode to the off mode is performed normally. It is determined that the power to the image forming apparatus 1 has been cut off due to a power failure or insertion / removal of the AC plug. Therefore, when the off mode notification signal is negated and the mode information in the mode storage unit 72 is “0” (“off mode”), the main CPU 71 recognizes that it is a transition to the off mode. The power supply unit 10 is instructed via the sub-microcomputer 9 to shift to the off mode.

  When the off-mode notification signal is asserted and the mode information in the mode storage unit 72 is “1” (“other than off-mode”), it is determined as an irregular case that cannot be considered in normal operation. Therefore, the main CPU 71 recognizes that it is a transition to the ready mode when the off mode notification signal is asserted and the mode information in the mode storage unit 72 is “1” (“other than the off mode”). The power supply unit 10 is instructed via the sub-microcomputer 9 to shift to the ready mode.

  When the off-mode notification signal is negated and the mode information in the mode storage unit 72 is “1” (“other than off-mode”), an image is displayed due to a power failure or AC plug insertion / removal during the ready mode or the sleep mode. It is determined that the power to the forming apparatus 1 has been cut off. Therefore, the main CPU 71 recognizes that it is the transition to the ready mode when the off mode notification signal is negated and the mode information in the mode storage unit 72 is “1” (“other than the off mode”). The power supply unit 10 is instructed via the sub-microcomputer 9 to shift to the ready mode.

  When the off mode notification signal is negated and the mode information in the mode storage unit 72 is “0” (“off mode”), the mode is automatically shifted to the off mode from the time of power activation. In the automatic transition to the off mode, it is not preferable that the engine unit (the document reading unit 2, the document feeding unit 3, the recording unit 4) is driven and the motor or the fixing unit is driven. Therefore, the engine unit drive signal is gated by the off-mode notification signal, and the engine unit is configured not to be driven as an initial value when the off-mode notification signal is negated. As a result, settings other than the return from the off mode that the engine unit is not driven as an initial value, and the setting that drives the engine unit in hardware when returning from the off mode can be made. Without setting software, the motor and fixing of the engine can be driven quickly, and the startup time can be shortened.

As described above, in the present embodiment, as the power supply mode, the ready mode in which power is supplied to the main CPU 71 that controls the entire apparatus, the power to the main CPU 71 is shut off, and only the operation of the power switch 52 is performed. The image forming apparatus 1 is an electronic device having an off mode to be monitored, and is supplied with power in all power supply modes, monitors the operation of the power switch 52, and supplies power to the main CPU 71. A sub-microcomputer 9 that manages the power supply mode, and a mode storage unit 72 that is a nonvolatile memory that stores the power supply mode as mode information. The sub-microcomputer 9 is in the ready mode from the main CPU 71. When an instruction to shift to the off mode is given, an off mode notification signal output to the main CPU 71 is assigned. When the on operation of the power switch 52 is detected in the off mode, the supply of power to the main CPU 71 is started and activated, and the off mode notification signal is negated by the power interruption to the sub-microcomputer 9, and When the off mode notification signal is asserted and the mode information is “off mode”, the CPU 71 shifts to the ready mode, the off mode notification signal is negated, and the mode information is “off mode”. And switch to off mode.
With this simple and low-cost configuration, the power supply mode can be appropriately managed by the main CPU 71 whose power is shut off in the off mode. That is, when power is cut off and turned on again due to a power failure or insertion / removal of an AC plug, it is possible to return to the power supply mode before the power supply is cut off by checking the off mode notification signal and mode information. Therefore, the user experience is not impaired. Further, since the function of the sub-microcomputer 9 that monitors the operation of the power switch 52 can be limited, the power consumption of the sub-microcomputer 9 can be significantly reduced compared with the low-speed clock mode of the main CPU 71, and the off mode Power consumption can be suppressed.

Furthermore, according to the present embodiment, when the mode information is “other than the off mode”, the main CPU 71 shifts to the ready mode regardless of the off mode notification signal.
With this configuration, the power supply mode can be appropriately managed by the main CPU 71 whose power is shut off in the off mode.

Furthermore, according to the present embodiment, the off-mode notification signal is an open collector output.
With this configuration, there is no wraparound to the main CPU 71 whose power is shut off in the off mode.

Further, according to the present embodiment, the engine unit (the document reading unit 2, the document feeding unit 3, the recording unit 4) that is supplied with power in the ready mode and is turned off in the off mode is provided. The driving signal is gated by the off-mode notification signal, and the engine unit is not driven as an initial value when the off-mode notification signal is negated.
With this configuration, by using the off-mode notification signal, the driving of the engine unit can be stopped when the main CPU 71 performs the power state determination operation. Therefore, when the power is reapplied to shift to the off mode, no sound or vibration is generated due to driving of the motor or sensor in the engine unit, and the user's feeling of use is not impaired.

  Note that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Original reading part 3 Original feeding part 4 Recording part 5 Operation part 7 Main control part 8 Engine control part 9 Sub microcomputer 10 Power supply part 11 Communication part 12 Storage part 51 Liquid crystal display part 52 Power switch 53 Operation button 71 Main CPU
72 Mode storage unit 73 Image processing unit 81 Engine CPU

Claims (4)

The power supply mode is an electronic device having a ready mode in which power is supplied to a main CPU that controls the entire apparatus, and an off mode in which power to the main CPU is shut off and only the operation of a power switch is monitored. ,
A power source is supplied in all the power supply modes, monitoring the operation of the power switch, and managing a power supply unit that supplies power to the main CPU;
A nonvolatile memory that is under the control of the main CPU and stores the power supply mode as mode information;
When the microcomputer is instructed to shift from the main CPU to the off mode in the ready mode, the microcomputer asserts an off mode notification signal to be output to the main CPU and turns on the power switch in the off mode. When detected, start to start supplying power to the main CPU,
The off mode notification signal is negated by shutting off power to the microcomputer,
When the off-mode notification signal is asserted and the mode information is “off mode”, the main CPU shifts to the ready mode, the off-mode notification signal is negated, and the mode information is When in the “off mode”, the electronic apparatus is shifted to the off mode.   2. The electronic apparatus according to claim 1, wherein when the mode information is “non-off mode”, the main CPU shifts to the ready mode regardless of the off mode notification signal.   The electronic device according to claim 1, wherein the off-mode notification signal is an open collector output. An engine unit that is supplied with power in the ready mode and shuts off in the off mode;
4. The drive signal of the engine unit is gated by the off-mode notification signal, and the engine unit is not driven as an initial value when the off-mode notification signal is in a negated state. Electronic equipment.

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