JP5645793B2 - Electric apparatus and image forming apparatus provided with the same - Google Patents

Description

  The present invention relates to an electric device or an image forming apparatus that switches a load for supplying electric power.

  For example, image forming apparatuses such as multifunction peripherals and printers include various apparatuses such as a sheet conveying apparatus, a sheet feeding apparatus, a document reading apparatus, a printing apparatus, a substrate and a circuit for performing control and image processing, and the like. A combination of various electrical loads. The image forming apparatus functions by supplying electric power to these loads. An auxiliary power supply (for example, a storage battery or a fuel cell) that supplies power to various loads may be mounted on the image forming apparatus for the purpose of allowing the image forming apparatus to handle a large amount of power instantaneously.

  For example, Patent Literature 1 discloses a main power supply unit that supplies power supplied from a commercial power supply to a plurality of loads, a plurality of auxiliary power supply units that supply power to a plurality of loads, and a main power supply unit or a plurality of auxiliary power supplies. An image forming apparatus is described that includes a power source switching unit that selectively switches power supply from a unit to a plurality of loads, and a control unit that controls the power source switching unit according to an operation mode of the plurality of loads.

JP 2008-170682 A

  For example, the image forming apparatus is configured by combining a plurality of loads such as various apparatuses, substrates, circuits, and elements as described above. Then, from the viewpoint of power saving, power supply capability, etc., among the plurality of loads, the load for supplying power may be sequentially switched, and some of the plurality of loads may be selected to supply power. .

  Here, switching of the load for supplying power may make the driving of the load unstable. For example, if the load being supplied with power is sensitive to voltage fluctuations and there is a variation in the timing of switching the load to which power is supplied, driving the load (load before switching) from which power supply will be stopped in the future May become unstable. If the driving becomes unstable, operation, processing stoppage, delay, and unnecessary signals may be output, which may hinder accurate and proper operation of an apparatus such as an image forming apparatus. Therefore, it is necessary to prevent the driving of the load from becoming unstable by switching the load for supplying power and to prevent problems in processing and driving.

  Note that the invention described in Patent Document 1 includes the main power supply means and a plurality of auxiliary power supply means as described above. However, there is no mention or suggestion of a problem caused by switching of a load that supplies power. Therefore, switching of the load for supplying power cannot cope with the problem that the drive of the load may become unstable.

  In view of the above problems, the present invention makes it possible to reduce the instability of driving of a load due to switching of a load to which power is supplied without providing a board or circuit having a dedicated circuit for stabilizing voltage at high cost. Therefore, it is an object to easily prevent, maintain a stable load drive, and ensure the normal operation of the device.

  In order to achieve the above object, an electrical device according to claim 1 is configured to switch a plurality of loads, a power supply unit that supplies power to the loads, and connection and disconnection between the loads and the power supply unit, and the plurality of loads. A first switch for switching the load for supplying power, a capacitor for storing power and supplying power to the connected load, and among the plurality of loads, the load connected to the capacitor. The load includes a second switch that connects the load and the capacitor, the driving of which becomes unstable with the switching of the load connected to the power supply unit by the first switch.

  According to this configuration, the second switch switches the load connected to the capacitor among the plurality of loads, and the load and the capacitor whose driving becomes unstable due to the switching of the load connected to the power supply unit by the first switch. Connecting. Thereby, even if it switches the load which supplies the electric power from a power supply part, the drive of each load does not become unstable. In this way, since the drive of the load is kept stable (being stabilized), normal operation of the device is guaranteed. In addition, since power is not supplied to a load that is not used, a high power saving effect can be obtained.

  Further, since the capacitor is provided and the connection destination of the capacitor is simply switched, it is not necessary to provide a substrate and a circuit including a dedicated circuit for stabilizing the voltage with respect to a high-cost load corresponding to fluctuations in power consumption. Therefore, instability of the drive of the load accompanying switching of the load for supplying power can be prevented at a low cost. Further, as compared with the case where a dedicated circuit for voltage stabilization is provided, it is possible to easily prevent the driving of the load from becoming unstable, and to shorten the development period of the electric device.

Further, in the first aspect of the invention, the first switch switches a power supply destination before the driving of the load is completed, and the first switch is connected to the power source unit when the driving becomes unstable. By switching the load to be connected, the power supply from the power supply unit is stopped before driving is completed, and the second switch is the power supply from the power supply unit to be stopped from now on The load and the capacitor are connected before switching the load for supplying power from the power supply unit, and when the driving of the load in which power supply from the power supply unit is stopped is completed, the load from the power supply unit is completed. It was decided to connect the load and the capacitor where power supply was started .

  A load for supplying power may be switched in accordance with a timing at which a load for starting power supply (a load after switching) should start driving. In other words, while switching the power supply destination without waiting for the completion of the operation of the load for which power supply is stopped (load before switching), the load before switching is driven until completion of the period using the energy stored in the load. Sometimes. In such a case, along with the switching of the load for supplying power by the first switch, the load for which the power supply is stopped may become unstable before the drive is completed. Therefore, according to this configuration, when the first switch switches the load connected to the power supply unit, the second switch connects the load to which power supply is stopped and the capacitor. As a result, even if the load for supplying power is switched so that the load after switching is prioritized, the load for which power supply is stopped (the load before switching) is stably driven until the operation is completed. Can do.

According to a second aspect of the present invention, a plurality of loads, a power supply unit that supplies power to the loads, and switching between connection and disconnection between the loads and the power supply unit are switched, and power is supplied from among the plurality of loads. A first switch for switching the load, a capacitor for storing power and supplying power to the connected load, and switching the load connected to the capacitor among the plurality of loads, and the power supply unit The load that becomes unstable when the load to be connected is switched by the first switch and the second switch that connects the capacitor, and the load that becomes unstable is the first switch Is the load from which power supply from the power supply unit is started by switching the load connected to the power supply unit, and the second switch is The load that stops the power supply from the source unit and the capacitor are connected to charge the capacitor, and according to the switching of the power supply destination from the power supply unit, or the power supply destination from the power supply unit Before the switching, the load and the capacitor where the power supply from the power supply unit is started are connected .

  The voltage applied to the load may decrease when power supply to the load is started in consideration of the power and current supply capacity of the power supply and the amount of current flowing into the load when the power supply starts. . Therefore, according to this configuration, when the first switch switches the load to be connected to the power supply unit, the second switch connects the load and the capacitor from which power supply is started. Thereby, the temporary fall of the voltage applied to load is prevented, and a load can be driven correctly and reliably.

In the first or second aspect of the invention, the second switch connects the load being supplied with power and the capacitor being driven, and the capacitor is charged via the load being supplied with power and being driven. It was decided to.

  According to this configuration, the second switch connects the load supplied with electric power and the driving capacitor, and the capacitor is charged via the load supplied with electric power and being driven. As a result, the capacitor can be charged at the stage before switching of the load for supplying power. In addition, the fully charged capacitor can supply power to the load so that the drive does not become unstable when the load for supplying power is switched.

According to a third aspect of the present invention, an image forming apparatus includes the electric device according to the first or second aspect .

  According to this configuration, power supply to various loads included in the image forming apparatus can be switched so that the drive does not become unstable. In addition, since power is not supplied to a load that is not used, a high power saving effect can be obtained. Therefore, it is possible to provide an image forming apparatus that has a high power saving effect and is guaranteed to operate normally. In addition, instability of driving of the load accompanying switching of the load for supplying power can be prevented at low cost and easily, so that the manufacturing cost of the image forming apparatus and the development period can be shortened.

  According to the present invention, it is possible to prevent the driving of the load from becoming unstable by switching the load for supplying power, and normal operation of the device is guaranteed. Further, in order to prevent the drive of the load from becoming unstable, it is possible to dispense with a board including a dedicated circuit for stabilizing the voltage at a high cost, and it can be done easily and inexpensively.

1 is a schematic front cross-sectional view illustrating an example of a multifunction machine. 2 is a block diagram illustrating an example of a hardware configuration of a multifunction peripheral. FIG. It is a block diagram which shows an example of the switching of the electric power supply to load, and the connection destination of a capacitor. It is explanatory drawing explaining the connection of the capacitor to the load from which electric power supply is stopped. It is explanatory drawing for demonstrating the connection of the capacitor to the load where electric power supply is started. It is a block diagram for demonstrating an example of switching of the load which supplies electric power.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In the following description, a multifunction peripheral 101 (corresponding to an image forming apparatus) including the electric device 100 according to the present embodiment will be described as an example. However, each element such as configuration and arrangement described in this embodiment does not limit the scope of the invention and is merely an illustrative example.

(Schematic configuration of the multifunction machine 101)
First, an outline of the multifunction peripheral 101 according to the embodiment will be described with reference to FIG. FIG. 1 is a schematic front cross-sectional view illustrating an example of the multifunction machine 101.

  The multifunction machine 101 according to the present embodiment includes a reading unit 1 including an original conveying unit 1a and an image reading unit 1b at an upper portion. The document conveying unit 1a conveys the documents stacked on the document tray 11 one by one to the reading position (feed reading contact glass 12) of the image reading unit 1b. A plurality of documents to be copied or scanned are placed on the document tray 11. Further, the document conveying portion 1a can be opened upward by a fulcrum (not shown) provided on the back side of the sheet. Then, by lifting the document conveying portion 1a, a document such as a book can be placed on the placement reading contact glass 13 on the upper surface of the image reading portion 1b.

  As shown by a broken line in FIG. 1, an operation panel 2 that accepts a print setting input such as copying and displays various types of information is provided above the front. As indicated by a broken line in FIG. 1, the operation panel 2 is provided above the front surface of the multifunction machine 101. The operation panel 2 includes a touch panel type liquid crystal display unit 21. The liquid crystal display unit 21 displays a status such as an error in the multi-function peripheral 101, and various settings including keys and buttons for setting the function of a job executed by the multi-function peripheral 101 such as paper size, enlargement / reduction, and density setting. Display the screen for Keys and buttons pressed by the touch panel or the like are recognized by the operation panel 2. The operation panel 2 is provided with hard keys such as a numeric keypad 22 for inputting numbers and the like, and a start key 23 for instructing start of job execution. The user sets the multifunction machine 101 by using the liquid crystal display unit 21 and various hard keys.

  An image reading unit 1b, a sheet feeding unit 3a, a conveyance path 3b, an image forming unit 4a, a fixing unit 4b, and the like are provided in the housing of the multifunction machine 101.

  The image reading unit 1b reads a document and generates image data. A contact glass (two types of contact glass 12 for feeding reading and contact glass 13 for mounting reading) is provided on the upper surface of the image reading unit 1b, and the horizontal direction (in FIG. ), And an optical system member (all not shown) such as a lens and an image sensor (for example, CCD) are provided. For example, when reading a document continuously conveyed by the document conveying portion 1a, a moving frame is fixed below the feed reading contact glass 12, and reflected light of the document is guided to a lens and an image sensor. When reading the document placed on the placement reading contact glass 13, the moving frame is moved in the horizontal direction to guide the reflected light of the document to the lens and the image sensor.

  The image reading unit 1b uses these optical system members to irradiate the original with light, and A / D converts the output value of each pixel of the image sensor that receives the reflected light of the original to generate image data. The multifunction machine 101 performs printing (copy function) based on the read image data, transmission of the obtained image data (scan function, FAX function), and the like.

  Two sheet feeding cassettes 31a and 31b are stacked in a vertical direction as the sheet feeding unit 3a that stores and supplies image forming sheets. The paper supply unit 3a is a variety of (for example, plain paper, copy paper, recycled paper, etc.) and a plurality of (for example, about 500 to 1000) sheets of each size (for example, A4, A3, B4, B5, letter size, etc.). ) Load and store.

  The paper feed cassettes 31a and 31b are respectively provided with paper feed rollers 32a and 32b that are driven to rotate and feed paper one by one to the transport path 3b. Next, the transport path 3b is a path for transporting paper in the apparatus. In the conveyance path 3b, a plurality of conveyance roller pairs 33 (in FIG. 1, a total of six of 33a to 33f from the upstream side are shown) that rotate and rotate during conveyance of the sheet, and the conveyed sheet of the image forming unit 4a. A registration roller pair 34 or the like is provided that waits in front and feeds the paper in accordance with toner image formation.

  The image forming unit 4a forms an image (toner image) on the sheet fed from the sheet feeding unit 3a based on the image data, and transfers the toner image onto the conveyed sheet. As the image data, image data of a document acquired by the image reading unit 1b, image data transmitted from a computer 200 (see FIG. 2) connected to the multifunction machine 101, or the like is used.

  The image forming unit 4a includes a photosensitive drum 41 supported so as to be rotatable in the direction of the arrow shown in FIG. 1, a charging device 42, an exposure device 43, a developing device 44, and a transfer roller disposed around the photosensitive drum 41. 45, a cleaning device 46, and the like. The toner image formation and transfer process will be described. The photosensitive drum 41 is provided substantially at the center of the image forming unit 4a and is driven to rotate in a predetermined direction. The charging device 42 charges the photosensitive drum 41 to a predetermined potential. The exposure device 43 outputs laser light L based on the image data, scans and exposes the surface of the photosensitive drum 41, and forms an electrostatic latent image according to the image data.

  The developing device 44 supplies toner to the electrostatic latent image formed on the photosensitive drum 41 and develops it. The transfer roller 45 is in pressure contact with the photosensitive drum 41 to form a nip. Then, the registration roller pair 34 makes a timing and causes the sheet to enter the nip. When the nip between the paper and the toner image enters, a predetermined voltage is applied to the transfer roller 45, and the toner image on the photosensitive drum 41 is transferred to the paper. The cleaning device 46 removes the toner remaining on the photosensitive drum 41 after the transfer.

  The fixing unit 4b fixes the toner image transferred to the paper. The fixing unit 4b in the present embodiment is mainly composed of a heating roller 47 and a pressure roller 48 that incorporate a heating element. The heating roller 47 and the pressure roller 48 are pressed to form a nip. When the sheet passes through the nip, the toner is melted and heated, and the toner image is fixed on the sheet. The sheet after toner fixing is discharged to the discharge tray 35.

(Hardware configuration of MFP 101)
Next, a hardware configuration of the multifunction machine 101 according to the embodiment will be described with reference to FIG. FIG. 2 is a block diagram illustrating an example of a hardware configuration of the multifunction machine 101.

  First, the main control unit 5 is configured as a combined substrate with various elements, circuits, and the like. The main control unit 5 is a part that controls the operation of the multifunction machine 101. For example, the main control unit 5 includes a main CPU 51, a storage unit 52, an image processing unit 53, and the like as parts for performing calculations and processing. The main CPU 51 is an arithmetic processing unit of the main control unit 5, and performs various processes, calculations, and controls based on data and programs stored in the storage unit 52. The storage unit 52 is configured by combining, for example, a nonvolatile storage device (flash ROM or HDD) and a volatile storage device (for example, RAM). The storage unit 52 stores data, programs, image data, and the like required for various controls such as job execution. The storage unit 52 may be provided outside the main control unit 5.

  The image processing unit 53 performs image processing on the image data generated by the image reading unit 1b and image data input from the outside. For example, the image processing unit 53 includes an ASIC dedicated to image processing and an image processing memory. The image data after image processing can be sent to the exposure device 43 for printing (copy function, printer function), stored in the storage unit 52 (scanner function), or externally transmitted from the communication unit 54 described later. It can also be transmitted to (computer 200, FAX apparatus 300, etc.) (scanner function, FAX function). The image processing unit 53 may be functionally realized by the main CPU 51 or the storage unit 52. The image processing that can be performed by the image processing unit 53 is diverse, such as enlargement / reduction processing, density change, and the like.

  The reading unit 1 includes an image reading unit 1b and a document conveying unit 1a. The image reading unit 1b is provided with a reading control unit 10b that controls components and circuits included in the image reading unit 1b. The reading control unit 10b is provided as, for example, a substrate or a circuit including a memory including a program and data required for controlling the CPU and the image reading unit 1b. When the reading control unit 10b receives an instruction to read a document from the main control unit 5, the reading control unit 10b controls the image sensor, the lamp, and the like, and transmits the generated image data to the main control unit 5 and the like. Actually control.

  Similarly, the document transport unit 1a is provided with a document transport control unit 10a for controlling components and circuits included in the document transport unit 1a. The document conveyance control unit 10a is also provided as a substrate or a circuit including a memory including programs and data required for control of the CPU and the image reading unit 1b, for example. When the document transport control unit 10a receives an instruction to execute document transport from the main control unit 5, the document transport control unit 10a controls various rotating bodies to transport the documents one by one toward the reading position.

  A print engine unit 4 is provided for printing on the multifunction machine 101. The print engine unit 4 includes the paper feed unit 3a, the conveyance path 3b, the image forming unit 4a, the fixing unit 4b, and the like. In the print engine unit 4, an engine control unit 40 that receives an instruction from the main control unit 5 and actually controls the operation of the print engine unit 4 is provided. The engine control unit 40 includes, for example, a CPU and a memory for storing programs and data used for printing. The engine control unit 40 controls members included in the print engine unit 4 such as paper feeding, conveyance, toner image formation, and temperature control of the fixing unit 4b.

  Next, an operation panel 2 is provided for accepting and displaying setting input in the multifunction machine 101. In the operation panel 2, a panel control unit 20 that receives an instruction from the main control unit 5 and actually controls the operation panel 2 is provided. The panel control unit 20 includes, for example, a CPU, various programs, a memory for storing image data for display, and data for accepting input. The panel control unit 20 performs display control on the liquid crystal display unit 21, recognition processing of keys pressed on the liquid crystal display unit 21 by obtaining coordinates pressed from the output of the touch panel, and recognition of pressing of various hard keys. The members included in the operation panel 2 are controlled.

  The multifunction machine 101 is provided with a communication unit 54. The communication unit 54 includes an I / F unit 55 including a connector, a socket, a communication circuit, and a chip for connecting a communication line with an external computer 200 (for example, a personal computer or a server), the FAX apparatus 300, or the like. A communication control unit 56 that performs control is included. The communication control unit 56 communicates with the external computer 200 and the FAX apparatus 300 via the I / F unit 55 and a network, a line, a cable, and the like. For example, the data received by the communication unit 54 is delivered to the main control unit 5. Through the communication via the communication unit 54, printing data can be received from the computer 200 or the FAX apparatus 300 (printer function, scan function). Image data can be transmitted to the computer 200 or the FAX apparatus 300.

(Switching the load that supplies power)
Next, an outline of switching of a load for supplying electric power in the electric device 100 included in the multi-function peripheral 101 according to the embodiment will be described with reference to FIGS. FIG. 3 is a block diagram illustrating an example of switching power supply to the load and switching the connection destination of the capacitor 9. FIG. 4 is an explanatory diagram for explaining the connection of the capacitor 9 to a load whose power supply is stopped. FIG. 5 is an explanatory diagram for explaining the connection of the capacitor 9 to the load where power supply is started.

  First, the multifunction peripheral 101 has loads (portions that are driven by power supply, operate and process) such as the main control unit 5, the reading unit 1, the print engine unit 4, the operation panel 2, and the communication unit 54. Provided. In addition, various control units (main CPU 51, reading control unit 10b, document conveyance control unit 10a, engine, etc.) are also provided in each part of the main control unit 5, reading unit 1, print engine unit 4, operation panel 2, communication unit 54, and the like. A load such as a circuit board or a circuit such as a control unit 40 or a panel control unit 20) is provided. In other words, the multifunction machine 101 is configured by combining a plurality of large and small loads.

  In order to supply electric power to these various loads, a power supply unit 6 is provided in the multifunction machine 101. The power supply unit 6 is provided with one or a plurality of power conversion circuits 61 in order to supply power with various voltages to appropriate loads. For example, the power conversion circuit 61 includes a rectifier circuit, a transformer, a booster circuit, a step-down circuit, and the like. A voltage for a motor (for example, DC 24 V) in the multi-function peripheral 101, a voltage for various control units, and a circuit drive (for example, DC5V, 3.3V, 1.8V, etc.). And the power supply part 6 supplies electric power with the voltage according to each load.

  In the multifunction machine 101 according to the present embodiment, for example, for a plurality of alternatively used loads, power is supplied only to the load to be used, and supply of power to the unused load is stopped. In other words, among the plurality of loads, the load for supplying power is switched in a predetermined order. Thereby, supply of the electric power to the load which is not used can be stopped, and useless electric power consumption can be eliminated.

  With reference to FIG. 3, an outline of switching of a load for supplying power will be described. In FIG. 3, two types of blocks (first substrate unit 71 and second substrate unit 72) provided in the image processing unit 53 will be described as an example of the load used alternatively. In addition, the 1st board | substrate part 71 and the 2nd board | substrate part 72 may be made into another board | substrate, and may be provided as another block on the same board | substrate. Further, in this description, an example of switching the power supply destination to two blocks will be described, but three or more blocks may be provided, and the power supply destination is supplied so that power is supplied to the block to be used. This can be explained in the same manner in terms of switching.

  For example, the first substrate unit 71 is a part in which the circuits in charge of the first half of the series of predetermined image processing flows are combined, and the second substrate unit 72 is the circuit in charge of the second half of steps. It may be a combined part. For example, the first substrate unit 71 can be a portion in which circuits for performing basic image processing such as various corrections on the image data read or received by the reading unit 1 are combined. Further, based on the image data processed by the first substrate unit 71 and stored in the storage unit 52 by the first substrate unit 71, final image data formation such as zoom (enlargement / reduction), density conversion, etc. is performed. A portion where the circuits are gathered can be used as the second substrate portion 72.

  The first substrate unit 71 is a circuit that compresses image data, and the second substrate unit 72 is a circuit that decompresses image data. Based on the relationship that is not used at the same time, the first substrate unit 71 and the second substrate unit are used. The parts 72 may be distinguished. Also, instead of distributing all of the circuits included in the image processing unit 53 to either the first substrate unit 71 or the second substrate unit 72, some of the circuits are separated from the first substrate unit 71 and the second substrate unit 72. A portion (circuit) in which power supply is continued regardless of switching of a load for supplying power may be provided. Thus, the content and mode of the load to which power supply is switched can be determined as appropriate.

  A first switch 81 is provided to switch the load (first substrate unit 71, second substrate unit 72) that supplies power. For example, the first switch 81 is a semiconductor or a mechanical switch. The first switch 81 includes one terminal connected to the power supply unit 6. The first switch 81 includes a terminal connected to the first substrate unit 71 and a terminal connected to the second substrate unit 72. For example, the first switch 81 switches a load connected to a terminal connected to the power supply unit 6 based on the control signal.

  For example, the main CPU 51 grasps the progress of image processing by the image processing unit 53 and the switching timing of the first switch 81 based on the notification from the image processing unit 53 and the state of the storage unit 52. Then, for example, the main CPU 51 gives a control signal to the first switch 81 to switch the load for supplying power. A control circuit that supplies a control signal to the first switch 81 and switches a load that supplies power at an appropriate timing is provided separately, and power is supplied by a separately provided control circuit instead of the main CPU 51. The load to be switched may be switched.

  A capacitor 9 is provided for supplying power to the first substrate unit 71 and the second substrate unit 72 in an auxiliary manner. The capacitor 9 has, for example, a capacitance of several μF or more (depending on the power required for driving the load).

  A second switch 82 for connecting the capacitor 9 and the first substrate unit 71 or the second substrate unit 72 is provided. For example, the second switch 82 is a semiconductor or a mechanical switch. When the load to which the first switch 81 supplies electric power is switched, the second switch 82 connects the capacitor 9 to the load whose driving becomes unstable with the switching. For example, the main CPU 51 controls the second switch 82 to control the connection between the load and the capacitor 9. In other words, the second switch 82 switches the load connected to the capacitor 9 based on the control signal.

  As described above, the electric device 100 according to the present embodiment includes, for example, loads such as the first substrate unit 71 and the second substrate unit 72, the power supply unit 6, the first switch 81, the second switch 82, and the capacitor. 9, and other switch control elements such as the main CPU 51 can be considered to be included in the electric device 100.

  Next, the aspect which connects the capacitor 9 to the load (load before switching) from which electric power supply is stopped is demonstrated using FIG. First, the uppermost timing chart and the second timing chart from the top in FIG. 4 show switching of driving of the loads (first substrate unit 71 and second substrate unit 72) (switching of the period to be used). As shown in FIG. 4, the first substrate unit 71 and the second substrate unit 72 are used alternatively. In addition, a part of period which uses the 1st board | substrate part 71 and the 2nd board | substrate part 72 may be covered.

  The timing chart in the third stage from the top in FIG. 4 shows the power supply switching timing by the first switch 81.

  As shown in FIG. 4, there is a case where it is desired to ensure that the load can be used from the beginning of the section in which the load is used. In this case, shortly before the drive period of the load for stopping power supply (load before switching) is completed, power supply to the load after switching is started, and the load before switching is stored in the load until then. It is driven until the period is completed by the energy that has been obtained.

  In the example of FIG. 4, the period up to time T <b> 2 is the period for driving the first substrate unit 71, and the load to be driven at time T <b> 2 shifts to the second substrate unit 72. In addition, due to switching of the load to be used, in the example of FIG. 4, the period up to time T4 is the period for driving the second substrate unit 72, and the load driven at time T4 shifts (switches) to the first substrate unit 71.

  In order to drive the load (second substrate unit 72) reliably from time T2, it is necessary in advance to surely drive the load after actually starting the supply of power to the load (second substrate unit 72). The first switch 81 switches the power supply destination to the second substrate unit 72 at a time T1 that goes back from the time T2 by a predetermined time Δ1. Further, the first switch 81 switches the power supply destination to the first substrate unit 71 at a time T3 that goes back from the time T4 by a predetermined time Δ1 required for driving the load with certainty.

  In FIG. 4, the power supply is switched in such a manner that the switching time of the load for supplying power can be ignored. For example, in the case of a mechanical switch, no power is supplied to any load. May be. Therefore, a predetermined time Δ1 can be determined in consideration of the time required for switching the load for supplying power.

  For example, the main CPU 51 grasps the processing status of the substrate unit to be used (driven) (the processing status in the first substrate unit 71 and the second substrate unit 72, or determines in advance from the switching point of the previous power supply destination. A control signal for switching the power supply destination by the first switch 81 at a time earlier than a predetermined time Δ1 (for example, time T1 or time T3 in FIG. 4) with respect to the first control signal. Issue to switch 81. For example, data indicating a predetermined time Δ1 is stored in the storage unit 52, and the main CPU 51 uses the data. And the 1st switch 81 switches the load which receives electric power according to a control signal.

  As described above, since the power supply destination is switched before the driving of the load for which the power supply is stopped (the load before the switching) is completed, the driving of the load before the switching may become unstable. For example, a voltage drop may stop before the operation is completely completed, or an unnecessary signal may be output to the outside.

  Therefore, as illustrated in FIG. 4, the second switch 82 connects the capacitor 9 with the load (load before switching) from which power supply is stopped before switching the load that supplies power. Then, the second switch 82 connects the capacitor 9 and the load before switching at least until the driving of the load before switching is completed after switching of the load for supplying power. Thus, the capacitor 9 is used as an auxiliary power source. For this reason, the capacity of the capacitor 9 may be a capacity that can supply necessary charges until the driving of the load before switching is completed after switching of the load for supplying power.

  On the other hand, charging cannot be performed while the capacitor 9 is connected to a load whose power supply is stopped. Therefore, when driving of the load for which power supply is stopped (load before switching) is completed, the second switch 82 connects the capacitor 9 to the load for which power supply has been started (load after switching). The capacitor 9 is charged via a load that is supplying power.

  FIG. 4 illustrates an example of the storage state of the capacitor 9 when such a connection of the capacitor 9 is performed. For example, when the power supply destination is switched from the first substrate unit 71 to the second substrate unit 72 at the time T1, the main CPU 51 connects the capacitor to the second switch 82 at a time before the time T1. 9 and the first substrate 71 are connected. Then, the main CPU 51 supplies power from the capacitor 9 to the first substrate unit 71 from time T1 to time T2. Thereby, the first substrate unit 71 is stably driven until the driving period is completed.

  In this case, as shown in FIG. 4, the capacitor 9 starts to discharge at the time point T1. Then, the potential Vc0 of the capacitor 9 decreases. Therefore, an instruction is given to the second switch 82 to connect the load for which power supply has been started (the load after switching) and the capacitor 9 (for example, time T5 in FIG. 4). By switching the connection destination of the capacitor 9, charging of the capacitor 9 is started. Therefore, when the power supply destination is switched from the switched load to the next load, the main CPU 51 switches the load connected to the capacitor 9 to the second switch 82 so that the charging of the capacitor 9 is completed.

  The timing for switching the connection of the capacitor 9 is predetermined. For example, data indicating the switching time (switching timing) of the capacitor 9 is stored in the storage unit 52. The main CPU 51 uses this data to instruct the second switch 82 to switch the connection of the capacitor 9.

  Next, another aspect of the connection of the capacitor 9 will be described with reference to FIG. First, when a load that supplies power is switched, a drop in voltage applied to the load that has started supplying power may occur due to a current flowing into the load. For example, when an attempt is made to pass a current through the load beyond the capacity of the power supply unit 6, a voltage drop may occur.

  When such a power drop occurs, it may be lower than the voltage required to drive the load without problems. For this reason, there is a possibility that the operation of the load for which power supply has been started (the load after switching) becomes unstable for some time.

  Therefore, if the capacitor 9 is connected to a load that has started supplying power (a load after switching) according to switching of the load that supplies power, the operation of the load after switching becomes unstable due to a voltage drop. Can cope with it. Therefore, the case where the capacitor 9 is connected to the load that has started supplying power will be described with reference to FIG.

  First, the timing chart from the top to the third stage in FIG. 5 is the same as that in FIG.

  The second switch 82 connects the capacitor 9 and the load that will stop power supply from before the load to be supplied is switched. Thereby, the capacitor 9 is charged. And the 2nd switch 82 connects the capacitor 9 to the load (load after switching) which starts electric power supply according to switching of an electric power supply destination. Thus, the capacitor 9 is used as an auxiliary power source for supplying sufficient power to the load after switching. Thereby, the operation | movement of the load after switching can be stabilized. And the capacity | capacitance of the capacitor | condenser 9 should just be a capacity | capacitance which can supply the electric charge of the grade which stabilizes the drive of the load after switching after switching of the load which supplies electric power.

  Specifically, in the example of FIG. 5, the power supply destination is switched from the first substrate unit 71 to the second substrate unit 72 at time T1, and from the second substrate unit 72 to the first substrate unit 71 at time T3. In response to this switching, the second switch 82 connects the capacitor 9 to the second substrate unit 72 at time T1 and connects the capacitor 9 to the first substrate unit 71 at time T3. In other words, the second switch 82 connects the load (the first substrate unit 71 and the second substrate unit 72) and the capacitor 9 similarly to the switching of the power supply destination. Then, the driving of the load whose power supply is started at time T1 or time T3 is stabilized. Note that the second switch 82 may cause the capacitor 9 to start supplying power to the load immediately before switching the power supply destination.

  Then, as shown in FIG. 5, when the drive of the load (capacitor after switching, for example, the second substrate unit 72) connected to the capacitor 9 is stabilized along with the switching of the power supply destination, the capacitor 9 is switched to the load after switching. And the potential Vc0 of the capacitor 9 rises. The second switch 82 connects the capacitor 9 to the first substrate unit 71 in accordance with the switching of the power supply destination to the next load (for example, the first substrate unit 71).

  Data describing the timing when the capacitor 9 is connected is stored in the storage unit 52, for example. The main CPU 51 uses this data to instruct the second switch 82 to switch the connection of the capacitor 9.

  As shown in FIGS. 4 and 5, by using the capacitor 9, it is possible to stabilize the driving of the load where the power supply is stopped, and it is possible to stabilize the driving of the load where the power supply is started. . For this reason, data (data indicating how to connect the capacitor 9 to which load) is stored in the storage unit 52 in advance, and the main CPU 51 determines the timing and procedure for connecting the capacitor 9 to the load. The second switch 82 is controlled based on data defining the timing and procedure for connecting the capacitor 9 to the load.

  For example, in the case of the first substrate unit 71 and the second substrate unit 72 shown in FIGS. 4 and 5, “When the power supply destination is switched from the first substrate unit 71 to the second substrate unit 72, the second switch 82 is a capacitor. 9 is connected to the first substrate unit 71 to complete the driving of the first substrate unit 71 → the second substrate unit 72 is connected to the capacitor 9 to charge the capacitor 9 → the second substrate unit 72 is transferred to the first substrate unit 71 Timing to connect the capacitor 9 to the load with emphasis on stabilization of the drive in the first substrate unit 71, such as “when the power supply destination is switched, the capacitor 9 is also connected to the first substrate unit 71”. And a procedure can be determined in advance.

(Switching the load that supplies power)
Next, another example of switching the load for supplying power according to the present embodiment will be described with reference to FIG. FIG. 6 is a block diagram for explaining an example of switching of a load for supplying power.

  In the above description, the example in which the power supply destination is switched in units of blocks of the board provided in the image processing unit 53 has been described with reference to FIGS. However, according to the present invention, the load is not only a circuit, a board, or an element, but a single load in which a plurality of loads such as the reading unit 1, the image processing unit 53, and the print engine unit 4 are combined is 1 in this embodiment. Can be treated as one load unit.

  Therefore, assuming that the reading unit 1, the image processing unit 53, and the print engine unit 4 are one load, switching of a load for supplying power and connection of the capacitor 9 will be described.

  First, as described above, the power supply unit 6 generates a plurality of types of voltages in the power conversion circuit 61 in order to supply power to these various loads with appropriate voltages. The voltage generated by the power supply unit 6 is applied to each load (reading unit 1, image processing unit 53, print engine unit 4) via the first switch 81. In FIG. 6, there is one connection line from the power supply unit 6 to each load. However, when a plurality of types of voltages need to be supplied, a plurality of power supply lines from the power supply unit 6 to each load are provided. (For example, for driving a motor or for driving a control unit)

  In the multifunction peripheral 101 of the present embodiment, the reading unit 1, the image processing unit 53, and the print engine unit 4 are alternatively used along the flow of image data. For example, when image data is generated by reading an original, power is supplied to the reading unit 1. As a result, the reading unit 1 supplies power to the reading control unit 10b and the like, and the reading unit 1 starts and reads a document and generates image data. When the image data obtained by reading by the reading unit 1 is stored in the storage unit 52, the supply of power to the reading unit 1 is stopped and the power supply destination is switched to the image processing unit 53. As a result, the image processing unit 53 is activated. Then, when image processing in the image processing unit 53 is performed and image processed image data used for printing is stored in the storage unit 52, supply of power to the image processing unit 53 is stopped. Subsequently, the power supply destination is switched to the print engine unit 4. The print engine unit 4 is activated when power is supplied to the engine control unit 40 and the like, and printing is performed.

  As described above, when copying based on a document, the first switch 81 supplies power only to a load to be used, and stops supplying power to a load that is not used. Specifically, in the case of copying one page, the power supply destination is switched in the order of reading unit 1 → image processing unit 53 → print engine unit 4. It is possible to stop the supply of power to the load that is not used and eliminate unnecessary power consumption.

  Note that the configuration of the multifunction machine 101 is complicated and has various parts. For example, the print engine unit 4 may not have to stop supplying power to all of the print engine units 4 such as maintaining the temperature of the fixing unit 4b. Therefore, instead of turning on / off the entire power supply of each load of the reading unit 1, the image processing unit 53, and the print engine unit 4, the first switch 81 includes the reading unit 1, the image processing unit 53, The supply of power may be sequentially switched only for a part of each load of the print engine unit 4. In other words, power supply to a part of each load may be continued.

  For example, the main control unit 5 (main CPU 51), based on notifications from the reading unit 1, the image processing unit 53, the print engine unit 4 and the state of the storage unit 52, the processing progress status and the switching timing of the first switch 81. To figure out. Then, for example, the main CPU 51 gives a control signal to the first switch 81 to switch the load for supplying power. It should be noted that a control circuit that provides a control signal to the first switch 81 and switches a load for supplying power at an appropriate timing is provided separately in the main control unit 5 or the like, so that a control provided separately from the main CPU 51 is not provided. A load for supplying power may be switched by a circuit.

  A capacitor 9 is provided to supplementarily supply power to each load (reading unit 1, image processing unit 53, print engine unit 4). Note that the capacity of the capacitor 9 needs to be larger than when the load is the first substrate unit 71 or the second substrate unit 72 described above.

  A second switch 82 is provided for connecting the capacitor 9 and each load (reading unit 1, image processing unit 53, print engine unit 4). For example, the second switch 82 is a semiconductor or a mechanical switch. The second switch 82 connects the capacitor 9 to the load whose driving becomes unstable with the switching when the load to which the first switch 81 supplies power is switched. For example, the main CPU 51 of the main control unit 5 controls the second switch 82 to control connection between each load and the capacitor 9.

  As described above, the load is regarded as the reading unit 1, the image processing unit 53, and the print engine unit 4, and the electric device 100 according to the present embodiment is configured by the power supply unit 6, the first switch 81, the second switch 82, and the capacitor 9. Is configured. It can be considered that the electric device 100 includes a switch control element such as the main CPU 51.

  It should be noted that the procedure, method, advantage, and the like of the connection of the capacitor 9 for switching the load for supplying power are the same as those described with reference to FIGS. For example, data for determining the power supply switching timing of each load (reading unit 1, image processing unit 53, print engine unit 4), data for determining the timing and procedure for connecting the capacitor 9 to the load (which load Data indicating how to connect the capacitor 9) to the storage unit 52. Then, the main control unit 5 (main CPU 51) switches the load to which power is supplied based on the predetermined data stored in the storage unit 52, and sets the timing and procedure for connecting the capacitor 9 to the load. Based on this, the second switch 82 is controlled to stabilize the operation of each load.

  In this way, the electrical apparatus 100 according to the present embodiment includes a plurality of loads (for example, the first substrate unit 71, the second substrate unit 72, the image reading unit 1b, the image processing unit 53, the print engine unit 4, etc.), The power supply unit 6 that supplies power to the load, the connection between the load and the power supply unit 6 is switched, and the first switch 81 that switches the load that supplies power among a plurality of loads is stored and connected. The capacitor 9 that supplies power to the load and the load connected to the capacitor 9 among the plurality of loads are switched, and the drive becomes unstable as the load connected to the power supply unit 6 is switched by the first switch 81. And a second switch 82 for connecting the load and the capacitor 9.

  Thereby, even if the load for supplying power from the power supply unit 6 (for example, the first substrate unit 71, the second substrate unit 72, the image reading unit 1b, the image processing unit 53, the print engine unit 4, etc.) is switched. The drive of each load does not become unstable. In this way, since the drive of the load is kept stable (being stabilized), normal operation of the device is guaranteed. In addition, since power is not supplied to a load that is not used, a high power saving effect can be obtained. Further, since the capacitor 9 is provided and only the connection destination of the capacitor 9 is switched, it is not necessary to provide a substrate and a circuit provided with a dedicated circuit for stabilizing the voltage with respect to a high-cost load corresponding to fluctuations in power consumption. Therefore, instability of the drive of the load accompanying switching of the load for supplying power can be prevented at a low cost. Further, as compared with the case where a dedicated circuit for stabilizing the voltage is provided, it is possible to easily prevent the driving of the load from becoming unstable, and to shorten the development period of the electric device 100.

  Further, the load for supplying power may be switched in accordance with the timing at which the load for starting power supply (the load after switching) should start driving. In other words, while switching the power supply destination without waiting for the completion of the operation of the load for which power supply is stopped (load before switching), the load before switching is driven until completion of the period using the energy stored in the load. Sometimes. In such a case, along with the switching of the load for supplying power by the first switch 81, the load for which the power supply is stopped may become unstable before the drive is completed. Therefore, the second switch 82 includes a load (for example, the first substrate unit 71, the second substrate unit 72, the image reading unit 1 b, the image processing unit 53, the print engine unit 4, etc.) connected to the power supply unit 6 by the first switch 81. ) Is switched, the capacitor 9 is connected to a load to which power supply is stopped. As a result, even if the load for supplying power is switched so that the load after switching is prioritized, the load for which power supply is stopped (the load before switching) is stably driven until the operation is completed. Can do.

  In addition, the voltage applied to the load decreases when power supply to the load is started in consideration of the power supply capability of the negative power supply and current, and the magnitude of the current flowing into the load at the start of power supply. Sometimes. Therefore, the second switch 82 includes a load (for example, the first substrate unit 71, the second substrate unit 72, the image reading unit 1 b, the image processing unit 53, the print engine unit 4, etc.) connected to the power supply unit 6 by the first switch 81. ), The capacitor 9 is connected to the load from which power supply will be started. Thereby, the temporary fall of the voltage applied to load is prevented, and a load can be driven correctly and reliably.

  The second switch 82 is supplied with electric power and is being driven (for example, the first substrate unit 71, the second substrate unit 72, the image reading unit 1b, the image processing unit 53, the print engine unit 4, etc.) and the capacitor 9. And the capacitor 9 is charged via the load being supplied with power. Thereby, the capacitor 9 can be charged in the stage before switching the load for supplying power. In addition, the fully charged capacitor 9 can supply power to the load so that the drive does not become unstable when the load for supplying power is switched.

  In addition, the image forming apparatus (for example, the multifunction machine 101) includes the electric device 100 described above. Accordingly, various loads included in the image forming apparatus (for example, the first substrate unit 71, the second substrate unit 72, the image reading unit 1b, the image processing unit 53, the print engine unit 4 and the like) are provided so that the driving does not become unstable. ) Can be switched to supply power. In addition, since power is not supplied to a load that is not used, a high power saving effect can be obtained. Therefore, it is possible to provide an image forming apparatus that has a high power saving effect and is guaranteed to operate normally. In addition, instability of driving of the load accompanying switching of the load for supplying power can be prevented at low cost and easily, so that the manufacturing cost of the image forming apparatus and the development period can be shortened.

  The embodiment of the present invention has been described above, but the scope of the present invention is not limited to this, and various modifications can be made without departing from the spirit of the invention.

  For example, in the above description, the blocks in the image processing unit 53, the reading unit 1, and the print engine unit 4 are exemplified as loads, but the loads are not limited to these. For example, one device may be treated as a unit of load, such as an optional device such as the multifunction peripheral 101 main body or a post-processing device. The load may be a single chip or circuit.

  The present invention can be used for an electrical apparatus and an image forming apparatus including a plurality of loads whose power supply is individually controlled.

100 electrical equipment 101 multifunction peripheral (image forming apparatus)
1 Reading unit (an example of load) 4 Print engine unit (an example of load)
53 Image processing unit (an example of load) 6 Power supply unit 71 First substrate unit (an example of load) 72 Second substrate unit (an example of load)
81 First switch 82 Second switch 9 Capacitor

Claims (3)

Multiple loads,
A power supply for supplying power to the load;
A first switch that switches between connecting and disconnecting the load and the power source, and switching the load that supplies power among the plurality of loads;
A capacitor for storing electric power and supplying electric power to the connected load;
Among the plurality of loads, the load connected to the capacitor is switched, and the load that is unstable in driving due to the switching of the load connected to the power supply unit by the first switch is connected to the capacitor. 2 switches, and
The first switch switches the power supply destination before the driving of the load is completed,
The load that is unstable in driving is the load in which power supply from the power supply unit is stopped before driving is completed by switching the load connected to the power supply unit by the first switch.
The second switch connects the load to which the power supply from the power supply unit is to be stopped and the capacitor from before the switching of the load for supplying power from the power supply unit. When the driving of the load whose power supply has been stopped is completed, the load is connected to the capacitor where the power supply from the power supply unit is started and the capacitor .   Multiple loads,
  A power supply for supplying power to the load;
  A first switch that switches between connecting and disconnecting the load and the power source, and switching the load that supplies power among the plurality of loads;
  A capacitor for storing electric power and supplying electric power to the connected load;
  Among the plurality of loads, the load connected to the capacitor is switched, and the load that is unstable in driving due to the switching of the load connected to the power supply unit by the first switch is connected to the capacitor. 2 switches, and
  The load that becomes unstable in driving is the load from which power supply from the power supply unit is started by switching the load that the first switch connects to the power supply unit.
  The second switch connects the load that stops power supply from the power supply unit and the capacitor to charge the capacitor, and according to switching of a power supply destination from the power supply unit, or An electrical apparatus comprising: connecting the load and the capacitor where power supply from the power supply unit is started before switching the power supply destination from the power supply unit. An image forming apparatus comprising an electrical device according to claim 1 or 2.

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