JP5377426B2 - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that detects attachment/detachment of a paper cassette even in power-saving mode, such as sleep mode, where supply of power to a control unit of an engine control unit or the like is stopped to minimize power consumption. <P>SOLUTION: The image forming apparatus having normal mode and power-saving mode that consumes less power than the normal node includes: a detection unit for detecting that the image forming apparatus has been operated; a control unit for detecting that the image forming apparatus has been operated on the basis of a signal from the detection unit; a power source unit that supplies power to the control unit in normal mode, and does not supply power to the control unit in power-saving mode; and a monitoring unit that gives an instruction to the power source unit to supply power in normal mode when a restoration factor is determined on the basis of a signal from the detection unit. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a multifunction machine, a printer, and a facsimile machine having a power saving mode such as a sleep mode.

  In general, an image forming apparatus such as a copying machine, a multifunction peripheral, or a printer supplies, for example, power to each part (for example, a fixing heater) of the image forming apparatus and maintains a printable state, for example, In addition, the image forming unit has a power saving mode such as a sleep mode in which power supply to many components is stopped to save power. For example, the mode of the image forming apparatus is switched from the normal mode to the power saving mode when there is no operation for the image forming apparatus for a predetermined time or when the power saving key is pressed. For example, when an operation or input is performed on the image forming apparatus, or when printing is performed based on image data or setting data received from a network or the like, the image forming apparatus returns from the power saving mode to the normal mode. Printing etc. are done.

  For example, Patent Document 1 includes a sleep mode and a cassette opening / closing detection unit that detects opening / closing of the cassette even in the sleep mode. When the cassette opening / closing detection unit detects the opening / closing of the cassette, An image forming apparatus configured to operate and detect the remaining amount of paper in a cassette is described. With this configuration, the remaining amount information of the printer main body is accurately provided to the user in any state of the apparatus (see Patent Document 1: Claim 1, Claim 2, Paragraph [0035], etc.).

JP 2002-172832 A

  For example, if the paper cassette is attached or removed or the cover is opened or closed, it is possible that some operation such as paper replenishment or replacement has been performed on the image forming apparatus. It is necessary to grasp changes and state changes. For example, the image forming apparatus is provided with a control unit such as an engine control unit that controls paper conveyance and toner image formation. For example, the control unit is connected to a sensor or the like for detecting the attachment / detachment of the paper cassette or the opening / closing of the cover, and detects the attachment / detachment of the paper cassette to grasp the state change of the paper cassette.

  Here, in order to be able to grasp the state change of the image forming apparatus such as paper replenishment or replacement even in the power saving mode, it is necessary not to completely stop the power supply to the control unit such as the engine control unit. is there. Therefore, conventionally, even in the power saving mode, power supply is continued to a control unit such as the engine control unit, or power supply is intermittently performed to temporarily drive the engine control unit. However, if power is supplied to the engine control unit or the like even in the power saving mode in order to detect an operation to the image forming apparatus such as attachment / detachment of a paper cassette, the power consumed in the power saving mode cannot be reduced (reduction). There is a problem that I cannot.

  Here, in the image forming apparatus described in Patent Document 1, the CPU 26 of the image processing unit 22 always monitors opening and closing of the cover (see Patent Document 1: Paragraph [0033] and the like). Therefore, the image processing unit 22 is operating regardless of the normal mode or the power saving mode, and it is difficult to reduce the power consumption in the power saving mode. Therefore, the invention described in Patent Document 1 cannot cope with the above problem. In particular, since the image processing unit generally handles large data such as image data, a CPU having a high calculation processing speed is often mounted. However, such a CPU generally consumes a large amount of power. Therefore, the power consumption of the CPU 26 in the image forming apparatus of Patent Document 1 may be large, and it is difficult to reduce the power consumption in the power saving mode.

  In the image forming apparatus described in Patent Document 1, a switch 27 is provided for the cassette, and the CPU 26 detects opening and closing based on ON / OFF of the switch 27 (see Patent Document 1: Paragraph [0032] and the like). . Then, as the number of sheet cassettes attached to the image forming apparatus is larger, such as when the sheet cassettes are stacked, the more input / output ports in the CPU 26 and the number of signal lines between the switch and the CPU 26 are necessary. Therefore, there is an aspect that the manufacturing cost of the image forming apparatus increases.

  In view of the above problems, the present invention makes it possible to detect the insertion and removal of the paper cassette even in the power saving mode, and in the power saving mode, the power supply to the control unit such as the engine control unit is stopped to reduce the power consumption as much as possible. The challenge is to lower it.

In order to achieve the above object, an image forming apparatus according to claim 1 is an image forming apparatus having a normal mode and a power saving mode in which power consumption is reduced as compared with the normal mode, and the image forming apparatus is operated. In order to detect the failure, the state of the image forming apparatus and a plurality of detection units provided are confirmed, and the operation of the image forming apparatus is detected based on a signal from the detection unit. The detection is performed by the control unit, the power supply unit that supplies power to the control unit in the normal mode, the power supply unit that does not supply power to the control unit in the power saving mode, and the control unit that is stopped in the power saving mode. determine a cut-off portion, based on a signal from the detecting unit due to the operation to the image forming apparatus is performed, that return factor from the power saving mode to the normal mode has occurred that prevents the transmission of signals from the Department And, when it is determined that the return factor occurs, and a monitoring section that gives an instruction for supplying power in the normal mode to the power unit, the detecting unit, by operating the image forming apparatus, ON and OFF switches The signal line from the detection unit toward the monitoring unit is branched toward the control unit, and the blocking unit is a transistor provided between a branch point and the control unit, and the control unit and the control unit A voltage is applied between the collectors of the transistors via the switch unit. In the power saving mode, the switch unit is opened and no bias is applied to the transistor, thereby detecting the control unit. In the normal mode, the transistor is closed and a bias is applied to the transistor .

  According to this configuration, the monitoring unit that monitors whether the return factor from the power saving mode to the normal mode has occurred is provided, and when the image forming apparatus is operated such as the attachment / detachment of the sheet feeding unit, the return factor has occurred. A signal indicating that is transmitted to the monitoring unit. As a result, the image forming apparatus returns from the power saving mode to the normal mode. As a result, in the power saving mode, not only the image forming mechanism but also the attachment / detachment of the paper feeding unit is detected, so that it is not necessary to drive the control unit such as the engine control unit. That is, in the power saving mode, power supply to the control unit can be stopped.

Here, the monitoring unit mainly has a function of monitoring the occurrence of a return factor from the power saving mode to the normal mode, and may have a smaller function than the control unit. Therefore, the monitoring unit can be configured more simply than the control unit, and the power consumption of the monitoring unit can be smaller than that of the control unit. In the power saving mode, power is supplied to the monitoring unit without driving the control unit, thereby detecting power consumption (standby power) in the power saving mode while detecting that the image forming apparatus has been operated. Can be reduced. In other words, it is not necessary to drive the control unit in order to check the state change of the image forming apparatus. Further, when the signal from the detection unit is also input to the control unit, the power supply of the control unit is stopped in the power saving mode. When a signal from the detection unit is input to the control unit in this stopped state, the part of the control unit that receives the signal from the detection unit may be damaged. For example, when a signal from the detection unit is input to the CPU, a voltage is applied to the CPU port while the CPU is stopped. However, according to this structure, since the interruption | blocking part is provided, the voltage (electric power) from a detection part is not input with respect to a control part in power saving mode. Thereby, it is possible to avoid the electric power from going around to the control unit in the power saving mode. The blocking unit is a transistor provided between the branch point and the control unit. Since the transistor is not biased in the power saving mode, it is possible to reliably prevent the power from flowing to the control unit in the power saving mode. Can do.

  According to a second aspect of the present invention, in the first aspect of the present invention, each signal line from the plurality of detection units to the monitoring unit is input to an OR circuit, and the output of the OR circuit is the monitoring unit. To be entered.

  According to this configuration, for example, when there are a plurality of signal lines for transmitting a signal from the detection unit to the monitoring unit, such as when a plurality of sheet feeding units are provided and a detection unit is provided in the cassettes A and B, Each signal line is input to an OR circuit. Then, the output of the OR circuit is input to the monitoring unit. Thereby, the number of input ports in the interface in the monitoring unit can be reduced. Therefore, the configuration of the monitoring unit can be simplified, and the manufacturing cost of the monitoring unit and the image forming apparatus can be suppressed.

According to a third aspect of the present invention, in the first or second aspect of the present invention, paper used for printing is stored, paper is supplied at the time of printing, and at least a paper remaining amount sensor is provided, which is removable from the image forming apparatus. One or a plurality of sheet feeding units, and one detection unit is provided for the sheet feeding unit to detect the removal and attachment of the sheet feeding unit. After returning from the power mode, the state of the paper feeding unit is checked based on the output of the sensor.

  According to this configuration, the control unit checks the state of the sheet feeding unit based on the output of the sensor when returning from the power saving mode. Therefore, the sheet feeding unit is detached (removed and attached) in the power saving mode. When the control unit returns, the control unit can confirm the state change such as the remaining amount of paper in the paper feeding unit.

According to a fourth aspect of the present invention, in the first to third aspects of the present invention, the control unit is an engine control unit that controls an image forming mechanism for conveying paper and forming an image.

  According to this configuration, the control unit is an engine control unit that controls the image forming mechanism for conveying paper and forming an image. Therefore, in the power saving mode, the power supply to the engine control unit is stopped. Power saving can be achieved. Even in the normal mode, for example, when an abnormal operation is performed such as when the paper feeding unit is removed during printing, toner image formation can be stopped quickly.

According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, there is provided one or a plurality of covers that are openable and closable so that the inside of the image forming apparatus is exposed when the cover is opened. It is also provided for detecting the opening and closing of the cover.

  For example, the cover of the image forming apparatus is opened and closed for member replacement, maintenance, etc., and when the cover is opened and closed, there is a high possibility that some operation is performed on the image forming apparatus. Therefore, according to this configuration, since the detection unit is for detecting opening and closing of the cover, the control unit can be returned when the cover is opened. Thereby, it is possible to grasp the state change of the image forming apparatus one by one.

  According to the present invention, it is possible to stop power supply to a control unit such as an engine control unit and reduce power consumption as much as possible in the power saving mode. Even in the power saving mode, it is possible to detect the attachment / detachment of the paper cassette, the opening / closing of the cover, and the like. When detected, the image forming apparatus returns from the power saving mode to the normal mode, and the state of the sheet in the sheet feeding unit is quickly confirmed.

1 is a schematic cross-sectional view illustrating a schematic configuration of a multifunction machine according to an embodiment. FIG. 3 is an enlarged schematic cross-sectional view of an image forming unit according to an embodiment. 1 is a block diagram illustrating an example of a hardware configuration of a multifunction machine according to an embodiment. It is explanatory drawing for demonstrating the return from the power saving mode which concerns on embodiment. An example of the interruption | blocking part which concerns on embodiment is shown, (a) is a circuit diagram of the state from which the cassette was removed by power saving mode, (b) is a circuit diagram of the state by which the cassette was removed by normal mode. 6 is a flowchart illustrating an example of state transition control between a normal mode and a power saving mode in the multifunction peripheral according to the embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In this embodiment, an electrophotographic tandem color multifunction peripheral 100 (corresponding to an image forming apparatus) will be described as an example. The multi-function device 100 has a printable normal mode and a power saving mode (for example, a sleep mode) that reduces power consumption compared to the normal mode. However, each element such as configuration and arrangement described in the present embodiment is merely an illustrative example without limiting the scope of the invention.

(Schematic configuration of image forming apparatus)
First, an outline of the multifunction peripheral 100 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a multifunction peripheral 100 according to an embodiment of the present invention. FIG. 2 is an enlarged schematic cross-sectional view of the image forming unit 3b according to the embodiment of the present invention.

  As shown in FIG. 1, an MFP 100 according to this embodiment is provided with an operation panel 1 (shown by a broken line in FIG. 1 and corresponding to a detection unit) at the upper front. A document cover 101 is provided at the top, and an image reading unit 102 (scanner) is provided below the document cover 101. Further, the main body is provided with a cassette 2A (corresponding to a paper feeding unit), a cassette 2B (corresponding to a paper feeding unit), a conveyance path 3a, an image forming unit 3b, an intermediate transfer unit 4a, a fixing unit 4b, and the like.

  In order to facilitate maintenance such as removal of paper when a jam (paper jam) occurs, a side cover C1 (corresponding to a cover) that can be opened and closed is provided on the left side surface of the multifunction peripheral 100 main body to expose the conveyance path 3a and the like. Provided. And side cover sensor S1 which detects opening and closing of the side cover C1 is provided. The output of the side cover sensor S1 (corresponding to the detection unit) is switched between the open state and the closed state of the side cover C1. For example, the side cover sensor S1 uses a spring switch or an interlock switch that contacts a part of the upper end of the side cover C1. In the MFP 100 of this embodiment, a front cover (corresponding to a cover, not shown) can be opened and closed for replacement of a toner container. A front cover sensor S2 (corresponding to a detection unit) for detecting opening and closing of the front cover is also provided (see FIG. 3). That is, the multifunction device 100 can be opened and closed, and has one or more covers that expose the inside of the image forming apparatus when opened, and sensors as detection units are provided for the covers to detect opening and closing of the covers. To do.

  The operation panel 1 is provided at the upper front of the multifunction machine 100. The operation panel 1 includes a touch panel type liquid crystal display unit 11. The liquid crystal display unit 11 can display the state of the multi-function device 100 (for example, error occurrence and mode) and a setting screen. In addition, the operation panel 1 grasps the pressed position by the touch panel and accepts various inputs from the user. The operation panel 1 also includes a numeric keypad 12 for inputting numbers, a start key 13 for instructing the start of work such as copying, and a power saving key 14 for instructing transition to a power saving mode.

  The document cover 101 can be lifted with a fulcrum provided on the back side in FIG. The user lifts the document cover 101 and places the document on the contact glass 103 on the upper surface of the image reading unit 102. The image reading unit 102 reads a document and generates image data. In the image reading unit 102, an optical system member (not shown) such as an exposure lamp, a mirror, a lens, and an image sensor (for example, CCD) is provided. These optical members irradiate the original with light, and A / D convert the output value of each pixel of the image sensor that receives the reflected light of the original to generate image data. The multi-function device 100 can print based on the image data obtained by reading (copy function).

  Next, the cassette 2 can be attached and detached for paper supply, paper replacement, and the like. The multi-function device 100 is provided with two cassettes 2 (in FIG. 1, the upper one is labeled as cassette 2A, and the lower one is labeled as cassette 2B). Each cassette 2 can accommodate a plurality of sheets of various sizes (copy sheets, label sheets, etc.) and sizes (A size, B size sheets, etc.). The cassette 2A and the cassette 2B may be the same, and the same members are denoted by the same reference numerals and can be described in the same manner.

  In each cassette 2, the paper is placed on the placement plate 21. One end of the mounting plate 21 is rotatably attached to the lower surface of the cassette 2, and the other end on the downstream side in the sheet conveying direction is urged upward by a motor, a spring (not shown), or the like. Each cassette 2 is provided with a paper feed roller 22. The paper feed roller 22 is rotated by a drive mechanism (not shown) such as a motor, and feeds the paper to the transport path 3a.

  In the MFP 100 according to the present embodiment, an attachment / detachment detection sensor S3 for detecting attachment / detachment of the cassette 2A and an attachment / detachment detection sensor S4 for detecting attachment / detachment of the cassette 2B are provided. For example, the attachment / detachment detection sensors S3 and S4 are switches (for example, spring type or interlock type) that are in contact with the side surfaces of the cassettes 2A and 2B on the back side (rear side of the multifunction machine 100). When pulled out, the ON / OFF state changes. The attachment / detachment detection sensors S3 and S4 are not limited to switch type sensors, and may be any sensor that can detect attachment / detachment of the cassettes 2A and 2B, such as an optical sensor.

  Each cassette 2 is provided with a plurality of sensors such as a remaining sheet sensor S5, a sheet presence sensor S6, and a sheet size sensor S7. First, the remaining sheet sensor S5 in each cassette 2 is an optical sensor that irradiates light on the lower surface of the mounting plate 21 on which the paper in the cassettes 2A and 2B is mounted. The output changes according to. Based on the output of the remaining sheet sensor S5, the remaining amount of the sheet is detected. Note that the remaining paper amount sensor S5 is not limited to the one that obtains the inclination angle, and a plurality of optical sensors arranged in the height direction may be used as long as the remaining amount of paper can be detected.

  The sheet presence / absence sensor S6 is, for example, a reflection type optical sensor, which irradiates light from below to a through hole (not shown) provided in the mounting plate 21 and receives the reflected light. For example, if there is a sheet, the light is reflected by the sheet, and the reflected light is received by the sheet presence sensor S6. If there is no paper, no light is reflected by the paper, so the paper presence sensor S6 hardly receives reflected light. Accordingly, the output of the sheet presence / absence sensor S6 changes depending on the presence / absence of paper, and the presence / absence of paper is detected based on this change. The sheet presence / absence sensor S6 may be, for example, an ultrasonic sensor in addition to the optical sensor, as long as it can grasp the presence / absence of the sheet in the sheet feeding unit.

  Furthermore, each cassette 2 is also provided with a paper size sensor S7 for detecting the paper size. For example, the cassettes 2 </ b> A and 2 </ b> B are provided with a rear end regulation guide 23 that regulates the rear end of the paper and is slidable according to the paper size. Each cassette 2 is provided with a pair of width restriction guides 24 that are slidable in accordance with the paper size, and are provided as a pair to restrict the paper in the width direction (front and back directions with the multifunction peripheral 100). For example, the paper size sensor S7 includes a variable resistor connected to the rear end regulation guide 23 and the width regulation guide 24, and outputs a different voltage depending on the slide position of each regulation guide, and the output of the paper size sensor S7. Based on the above, the size of the paper stored in the paper supply unit is grasped.

  The transport path 3 a is a path for transporting the paper supplied from the cassette 2 </ b> A or the cassette 2 </ b> B to the discharge tray 31. The transport path 3a is provided with a plurality of transport roller pairs 32 that are driven to rotate and transport the paper during printing. In addition, the conveyance path 3a is provided with a pair of registration rollers 33 and the like for waiting the sheet in front of the intermediate transfer unit 4a and feeding the sheet in time. Further, for example, a plurality of paper passage sensors S8 for detecting the passage of paper can be provided in the transport path 3a (for example, a transmission type optical sensor, S8A on the front side of the registration roller pair 33, and the fixing unit 4b. (S8B is attached to the entrance portion, and S8C is attached to the downstream side of the fixing portion 4b).

  Further, the multifunction peripheral 100 includes an image forming unit 3b including an image forming unit 34 for four colors and an exposure device 35 as a part for forming a toner image based on image data of an image to be formed. Further, the multifunction machine 100 includes an intermediate transfer unit 4a as a part for transferring a toner image onto a sheet. First, an image forming unit 34Bk (black), an image forming unit 34Y (yellow), an image forming unit 34C (cyan), and an image forming unit 34M (magenta) are arranged in the image forming unit 3b from the left in FIG. The One exposure device 35 is disposed below the exposure device 35.

  Here, the image forming units 34Bk to 34M will be described with reference to FIG. Each of the image forming units 34Bk to 34M has basically the same configuration except that the color of the toner image to be formed is different. Therefore, in the following description, the symbols for identifying colors, Bk (black), Y (yellow), C (cyan), and M (magenta), are omitted unless otherwise specified. Only one image forming unit 34 is shown.

  First, each photosensitive drum 36 provided in each image forming unit 34 has a photosensitive layer made of amorphous silicon or the like, and carries a toner image on its peripheral surface. Each photosensitive drum 36 is driven to rotate counterclockwise at a predetermined speed by a driving device (not shown). Each charging device 37 charges the photosensitive drum 36 at a constant potential.

  The exposure device 35 below each image forming unit 3b (see FIG. 1) converts the input color-separated image signal into an optical signal by a laser output unit (not shown), and the converted optical signal. Can be output for four colors. Then, the exposure device 35 performs scanning exposure of each charged photosensitive drum 36 to form an electrostatic latent image.

  Each developing device 38 stores a developer containing toner (the image forming unit 34Bk is black, 34Y is yellow, 34C is cyan, and 34M is magenta). Each developing device 38 faces each photoconductive drum 36 and supplies toner. Each cleaning device 39 cleans and removes transfer residual toner and the like on the surface of the photosensitive drum 36.

  Returning to FIG. The intermediate transfer unit 4a receives the primary transfer of the toner image on each photosensitive drum 36, and performs secondary transfer onto the paper. The intermediate transfer unit 4a includes one primary transfer roller 41 (a total of four rollers 41Bk to 41M) provided for each photosensitive drum 36, an intermediate transfer belt 42, a drive roller 43, driven rollers 44 and 45, and a secondary transfer. It comprises a roller 46, a belt cleaning device 47, and the like. Each primary transfer roller 41 sandwiches each photosensitive drum 36 and an endless intermediate transfer belt 42, and a predetermined voltage is applied during primary transfer. The intermediate transfer belt 42 is stretched around each roller and rotates around the paper surface clockwise in FIG. The secondary transfer roller 46 sandwiches the intermediate transfer belt 42 with the driving roller 43.

  The toner images of the respective colors formed by the image forming units 34 are superposed with no timing and sequentially superimposed, and are primarily transferred to the intermediate transfer belt 42. The superimposed toner images are transferred to a sheet by a secondary transfer roller 46 to which a predetermined voltage is applied. The residual toner on the intermediate transfer belt 42 after the secondary transfer is removed and collected by the belt cleaning device 47.

  The fixing unit 4b heats and presses the toner image secondarily transferred onto the paper to fix it. The fixing unit 4b mainly includes a heating roller 48 incorporating a heater and a pressure roller 49 pressed against the heating roller 48. The paper on which the toner image has been transferred passes through the nip between the heating roller 48 and the pressure roller 49 and is heated and pressurized, and as a result, the toner image is fixed on the paper. The fixed sheet is discharged to the discharge tray 31 and printing is completed.

(Hardware configuration of MFP 100)
Next, based on FIG. 3, the hardware configuration of the multifunction peripheral 100 according to the embodiment of the present invention will be described. FIG. 3 is a block diagram illustrating an example of a hardware configuration of the multifunction peripheral 100 according to the embodiment of the present invention. In FIG. 3, the power supply relationship is indicated by white arrows, the flow of image data is indicated by shaded arrows, and the flow of signals such as control is indicated by solid arrows.

  As shown in FIG. 3, the multifunction peripheral 100 according to the present embodiment includes a main control unit 5 configured by combining an internal control board, various elements, circuits, and the like. The main control unit 5 controls each part of the multifunction peripheral 100 and is provided in the main body.

  For example, the main control unit 5 includes a CPU 51 as a central processing unit, a ROM 52 and a RAM 53 for storing and developing control programs and data, a time measuring unit 54 for measuring time required for control, and the like. . The main control unit 5 includes an I / F unit 55 (interface unit, hereinafter the same) for communicating with the engine control unit 6, an I / F unit 56 for communicating with the monitoring unit 7, An I / F unit 57 for communicating with the operation panel 1 and the HDD 50 as a mass storage device is provided. As a result, the main control unit 5 is connected to the HDD 50 and the operation panel 1, and contents inputted by exchanging data with the HDD 50 and pressing various keys such as the liquid crystal display unit 11 and the power saving key 14 are controlled by the main control. Is transmitted to the unit 5. For example, the main control unit 5 can be provided with an image processing unit 58. The image processing unit 58 includes, for example, an ASIC as a dedicated circuit for image processing, a high-speed memory, and the like, and performs image processing on image data (for example, enlargement, reduction, density change, etc.).

  In addition, an engine control unit 6 for actually controlling the configuration for carrying paper and forming a toner image is provided in the multifunction machine 100. That is, the engine control unit 6 controls the image forming mechanism 10 for conveying paper and forming an image. The engine control unit 6 is connected to an image forming mechanism 10 for conveying paper and forming (printing) an image. The engine control unit 6 receives an instruction from the main control unit 5 and controls the operation of the image forming mechanism 10. The image forming mechanism 10 includes, for example, a cassette 2A, a cassette 2B, a conveyance path 3a, an image forming unit 3b, an intermediate transfer unit 4a, a fixing unit 4b, and the like. That is, the multifunction peripheral 100 is provided with an image forming mechanism 10 for conveying paper and forming an image.

  For example, the engine control unit 6 includes a CPU 61 as a central processing unit, and a ROM 62 and a RAM 63 for storing and developing a program and data for controlling the actual image forming mechanism 10. The engine control unit 6 has an I / F unit 64 for communicating with and controlling the image forming mechanism 10. The engine control unit 6 includes an I / F unit 65 for communicating with the main control unit 5 and the monitoring unit 7.

  The CPU 61 also detects the cassettes 2A and 2B and the conveyance path 3a sensors (detachment detection sensors S3 and S4, front cover sensor S2, side cover sensor S1, paper remaining amount sensor S5, paper presence sensor S6, paper size sensor S7, Paper passage sensor S8 and the like). For example, some or all of the sensors may be connected to the I / F unit 64 in the engine control unit 6. Thereby, the engine control unit 6 can grasp the attachment / detachment of the cassettes 2A and 2B, the opening and closing of the respective covers, the state of the sheets contained in the cassettes 2A and 2B (presence / absence, remaining amount, size, etc.), the conveyance state of the sheets, and the like. . For example, necessary data such as a table for grasping the attachment / detachment of the cassettes 2A and 2B, opening / closing of the respective covers, the state of the sheets accommodated in the cassettes 2A and 2B, the conveyance state of the sheets, and the like are stored in the ROM 62. deep.

  A monitoring unit 7 is provided in the multifunction device 100. The monitoring unit 7 functions as, for example, a communication interface with the outside, and monitors whether a return factor that causes the MFP 100 to return to the normal mode from the power saving mode has occurred. Then, the monitoring unit 7 recognizes the necessity of returning the multifunction peripheral 100 from the power saving mode to the normal mode. For example, the monitoring unit 7 includes a CPU 71 as a central processing unit, a ROM 72 and a RAM 73 for storing and developing monitoring programs and data in communication and power saving modes. In addition, the monitoring unit 7 includes a return factor monitoring unit 74 that receives an input of a return signal generated when an operation is performed on the multifunction peripheral 100.

  The monitoring unit 7 has an I / F unit 75 as a communication interface with an external computer 200 (for example, a personal computer). For example, the I / F unit 75 has a plurality of types of connectors and sockets. As a result, the multifunction device 100 and the computer 200 are communicably connected directly (for example, via a USB connection) or via a network. Accordingly, the multi-function device 100 can receive and print data such as print setting data and image data from the computer 200 (printer function). Further, for example, a modem function can be incorporated in the I / F unit 75, and the multifunction peripheral 100 and the counterpart FAX apparatus 300 are communicably connected via a public line or the like. As a result, the multifunction peripheral 100 can transmit and receive image data and the like to and from the counterpart FAX apparatus 300 (FAX function). The monitoring unit 7 has an I / F unit 76 as a communication interface with the main control unit 5 and the engine control unit 6.

(Normal mode and power saving mode)
Next, a normal mode and a power saving mode in the multifunction peripheral 100 according to the embodiment of the present invention will be described with reference to FIG.

  The MFP 100 according to the present embodiment has a normal mode that keeps the MFP 100 in a printable state. In the normal mode, the power supply unit 8 supplies power to the main control unit 5, the engine control unit 6, the image forming mechanism 10, the monitoring unit 7, and the like. In FIG. 3, the supplied power is indicated by white arrows.

  The power supply unit 8 is connected to a commercial power supply, for example. In the power supply unit 8, a plurality of circuits and elements (not shown) such as a rectifier circuit, a transformer, and a DC / DC converter are arranged to generate various voltages. For example, the power supply unit 8 includes a motor driving voltage (for example, DC 24V, supplied to the image forming mechanism 10) for rotating various rotating bodies such as the photosensitive drum 36, the main control unit 5, the engine control unit 6, A DC voltage (for example, 5V, 3.3V, etc.) for the monitoring unit 7 is generated and supplied.

  For example, in the normal mode, communication is performed between the image forming mechanism 10, the engine control unit 6, and the main control unit 5. Further, the engine control unit 6 performs control such as confirming the output of each sensor, turning on / off the heater of the fixing unit 4b, and maintaining the fixing unit 4b at a fixable temperature. Thus, even in a standby state where printing is not performed in the normal mode, a certain amount of power is consumed by the image forming mechanism 10, the main control unit 5, the engine control unit 6, and the like.

  However, from the viewpoint of energy saving, not only the instantaneous maximum power consumption but also the magnitude of the power consumption in the standby state is becoming a point for consideration when the consumer selects the multifunction device 100. Therefore, the multifunction device 100 according to the present embodiment has a fixed time (for example, several minutes to several tens of minutes since the printing is completed. For example, the time measuring unit 54 measures time), when no operation or input is performed on the multifunction device 100 or the power saving key. For example, when 14 is pressed, the mode is changed from the normal mode to the power saving mode.

  In the power saving mode of the multifunction peripheral 100 according to this embodiment, power is supplied to the monitoring unit 7, but power supply to the main control unit 5, the engine control unit 6, and the image forming mechanism 10 is stopped. That is, the power supply unit 8 supplies power to the engine control unit 6 in the normal mode, and does not supply power to the engine control unit 6 in the power saving mode. As a result, power consumption in the standby state of the multifunction device 100 is reduced. As described above, in the MFP 100, the power supply destination, the generated voltage, the current capacity, and the like in the normal mode and the power saving mode are different. Therefore, in the power supply unit 8, a power saving power control unit 81 and a normal power control unit 82 are provided. The power saving power control unit 81 operates in the power saving mode, and the normal power control unit 82 operates in the normal mode. Each power control unit controls the operation of circuits and elements in the power supply unit 8, and controls voltage generation and power supply in each mode.

  In addition, in order to use as a trigger when returning from the power saving mode, in the multi-function device 100 of the present embodiment, the power supply unit 8 includes, for example, the front cover sensor S2 and the side cover in addition to the monitoring unit 7 even in the power saving mode. Electric power is supplied to the sensor S1, the desorption detection sensors S3 and S4, and the operation panel 1. In the power saving mode, the display of the liquid crystal display unit 11 may be turned off.

(Return from power saving mode)
Next, an example of return from the power saving mode in the multifunction peripheral 100 according to the embodiment of the present invention will be described with reference to FIG. FIG. 4 is an explanatory diagram for explaining return from the power saving mode according to the embodiment of the present invention.

  For example, the main control unit 5 gives the power supply unit 8 an instruction to shift from the normal mode to the power saving mode. Upon receiving this instruction, the normal power control unit 82 stops the power supply control, and the power saving power control unit 81 performs the power supply control. Thereby, it shifts to the power saving mode.

  The monitoring unit 7 is connected to a network or the like, and is provided with an I / F unit 75 that receives various data such as image data from the outside addressed to the own device. For example, when print setting data or image data is received from the external computer 200 (printer function), the multifunction peripheral 100 needs to be returned to the normal mode. Also, for example, when image data or the like is received from the counterpart FAX apparatus 300 (FAX function), it is necessary to return the multifunction peripheral 100 to the normal mode. In other words, the fact that the I / F unit 75 has received image data or the like destined for the multi-function peripheral 100 is regarded as a return factor from the power saving mode.

  In addition, when the user operates the operation panel 1, the user intends to use the multifunction device 100. In addition, when the cassettes 2A and 2B are attached / detached, there is a possibility that the paper state in each cassette 2 has changed, such as the remaining paper amount and paper size, and it is necessary to check the paper state. . In addition, for the maintenance of the multifunction peripheral 100, the front cover and the side cover C1 may be opened and closed. Therefore, in the present embodiment, the input to the operation panel 1, the attachment / detachment of each cassette 2, and the opening / closing of each cover are factors for returning from the power saving mode to the normal mode.

  Therefore, the outputs from the operation panel 1, the attachment / detachment detection sensors S3 and S4, the side cover sensor S1, and the front cover sensor S2 are input to the return factor monitoring unit 74 as a signal (return signal) indicating that a return factor has occurred. The That is, in order to detect that an operation has been performed on the image forming apparatus, a plurality of detection units are the operation panel 1, the attachment / detachment detection sensors S3 and S4, the side cover sensor S1, the front cover sensor S2, and the like. At this time, outputs from the operation panel 1, the attachment / detachment detection sensors S3 and S4, the side cover sensor S1, and the front cover sensor S2 are input to the OR circuit 83, and a signal from one output terminal from the OR circuit 83 is a cause of the return. Input to the monitoring unit 74. That is, each signal line from the plurality of sensors to the monitoring unit 7 is input to the OR circuit 83, and the output of the OR circuit 83 is input to the monitoring unit 7. In this configuration, the attachment / detachment detection sensors S3 and S4 output High when the cassette 2 is removed. Further, the side cover sensor S1 and the front cover sensor S2 output High when each cover is opened. Further, the operation panel 1 outputs High when input is made.

  Thereby, the interface of the return factor monitoring unit 74 is simplified, and the monitoring unit 7 can be simplified. This simplification realizes cost reduction of the monitoring unit 7 and power consumption reduction by simplifying the circuit configuration of the monitoring unit 7.

  Then, triggered by reception of image data or the like addressed to the MFP 100 at the I / F unit 75 or input of a return signal to the monitoring unit 7, the monitoring unit 7 causes a return factor and changes from the power saving mode to the normal mode. Judge that it should return to. When the monitoring unit 7 determines that it should return from the power saving mode to the normal mode, it instructs the power supply unit 8 to switch from the control by the power saving power control unit 81 to the control by the normal power control unit 82. Thereby, supply of electric power is started to the image forming mechanism 10, the main control unit 5, and the engine control unit 6, and the main control unit 5 and the engine control unit 6 are activated.

  After startup, for example, the engine control unit 6 confirms the output of the remaining sheet sensor S5, the sheet size sensor S7, etc., and confirms the state of the sheet in each cassette 2. Thereby, even if there is a change in the state of the paper in each cassette 2 even in the power saving mode, it is immediately grasped. That is, the multi-function device 100 stores paper used for printing, supplies paper during printing, has at least a sensor for detecting the remaining amount of paper, and has one or more cassettes 2 that can be detached from the image forming apparatus. One detection unit is provided for the cassette 2 to detect the removal and attachment of the cassette 2 (desorption detection sensors S3 and S4), and the engine control unit 6 is used when returning from the power saving mode. Based on the sensor output, the state of the cassette 2 is confirmed.

  Here, in order to detect the opening / closing of each cassette 2 and each cover without providing the monitoring unit 7, the engine control unit 6 periodically checks the outputs of the attachment / detachment detection sensors S3, S4, etc. However, it is necessary to continue power supply to the engine control unit 6 or to intermittently supply power to drive the engine control unit 6 temporarily. Therefore, conventionally, in the power saving mode, the power supply to the engine control unit 6 is continued or the power supply is temporarily resumed, and the power supply to the main control unit 5 cannot be completely stopped.

  In order to perform various controls, the engine control unit 6 is provided with a number of elements, circuits, and interfaces such as the CPU 61, and those that operate at high speed such as various controls and transmission of image data are used. In general, elements and interfaces that operate at high speed consume more power than low-speed elements and interfaces. If it does so, if the engine control part 6 is driven, fixed electric power will be consumed (for example, several W-several tens W). Therefore, in order to reduce the power consumption, it is better not to drive the engine control unit 6 at all in the power saving mode.

  Therefore, in the present embodiment, the monitoring unit 7 collectively grasps that any of a plurality of types of return factors has occurred. The monitoring unit 7 only needs to detect the occurrence of a return factor in addition to the function as a network interface, and the function is limited compared to the main control unit 5 and the engine control unit 6. Basically, only the presence / absence of a return signal from a data monitor or sensor that flows through the network 200 is confirmed. Therefore, the power consumption of the monitoring unit 7 can be less than that of the engine control unit 6 and the like. Therefore, the power consumption of the monitoring unit 7 is less than a few watts (for example, about 1 to 2 W). Therefore, in the MFP 100 according to the present embodiment, it is possible to stop the power supply to the engine control unit 6 in the power saving mode while always detecting the occurrence of the return factor such as the detachment of the cassette 2, and the high power saving. An effect is obtained.

  Here, even in the normal mode, in order to detect the attachment / detachment of each cassette 2 and the opening / closing of each cover, the CPU 61 of the engine control unit 6 outputs the outputs of the attachment / detachment detection sensors S3, S4, the side cover sensor S1, and the front cover sensor S2. Is entered. That is, the engine control unit 6 confirms the state of the image forming apparatus and detects that an operation has been performed on the image forming apparatus based on signals from the sensors. However, since the power supply to the engine control unit 6 is stopped in the power saving mode, the CPU 61 and the like of the engine control unit 6 are not driven. Then, in the power saving mode, when each cassette 2 is removed or each cover is opened or closed, a voltage is applied to the port of the CPU 61 that is not driven. In other words, there is a possibility that the CPU 61 and the like of the engine control unit 6 are destroyed due to the wraparound of power to the engine control unit 6 in the power saving mode. This also applies to the main controller 5 to which the output of the operation panel 1 is input.

  Therefore, in the multi-function device 100 of the present embodiment, a blocking unit 9 is provided between signal lines from each sensor (desorption detection sensors S3 and S4, side cover sensor S1, and front cover sensor S2) to the engine control unit 6. In the power saving mode, the blocking unit 9 blocks signal transmission from each sensor to the CPU 61 and prevents voltage application to the port of the CPU 61. On the other hand, the blocking unit 9 does not block signal transmission from each sensor to the CPU 61 in the normal mode. In other words, the shut-off unit 9 prevents the signal transmission from each sensor from being transmitted to the engine control unit 6 whose power supply is stopped in the power saving mode.

(Blocking part 9)
Next, based on FIG. 5, an example of the interruption | blocking part 9 which concerns on embodiment of this invention is demonstrated. FIG. 5 is a circuit diagram illustrating an example of the blocking unit 9 according to the embodiment of the present invention. FIG. 5A is a state in which the cassette 2 is removed in the power saving mode, and FIG. 5B is a state in which the cassette 2 is in the normal mode. Shows the state where is removed. In this description, the desorption detection sensor S3 will be described as an example, but the configuration of the blocking unit 9 and each sensor in the desorption detection sensor S4, the front cover sensor S2, and the side cover sensor S1 is the same. Explained.

  First, the attachment / detachment detection sensor S3 is, for example, a spring-type switch. One end of the attachment / detachment detection sensor S3 is connected to the ground, and the other end is connected to a signal line L1 to the OR circuit 83. When the cassette 2A is removed, the attachment / detachment detection sensor S3 is opened, and the signal line L1 to the ground and the OR circuit 83 is not connected. On the other hand, the attachment / detachment detection sensor S3 is closed when the cassette 2A is attached, and the ground and the signal line L1 to the OR circuit 83 are connected. In the case of the front cover sensor S2 and the side cover sensor S1, each sensor is opened when the cover is opened.

  The signal line L1 from the desorption detection sensor S3 to the OR circuit 83 is branched to transmit the output of the desorption detection sensor S3 to the engine control unit 6. The branched signal line L2 is connected to the base of an npn transistor 91 (corresponding to the blocking unit 9). A voltage Vcc1 (for example, supplied from the power supply unit 8) is applied between the attachment / detachment detection sensor S3 and the base of the transistor 91 via the resistor R1. Thereby, if the cassette 2A is removed, a voltage is applied to the base of the transistor 91 (current flows).

  The ground of the transistor 91 is connected to the emitter, and the engine control unit 6 is connected to the collector. A voltage Vcc2 is connected between the engine control unit 6 and the collector of the transistor 91 via a resistor R2 and a switch unit 92.

  Then, as shown in FIG. 5A, in the power saving mode, the switch unit 92 is opened. Thus, the voltage Vcc2 is not applied to the transistor 91, and the bias voltage (collector-emitter voltage) is not applied to the transistor 91. Accordingly, the engine control unit 6 is insulated from the desorption detection sensor S3. That is, each sensor (desorption detection sensors S3, S4, each cover sensor) is switched ON and OFF by an operation on the image forming apparatus, and a signal line from each sensor to the monitoring unit 7 is sent to the engine control unit 6. The blocking unit 9 is a transistor 91 provided between the branch point and the engine control unit 6, and the transistor 91 is not biased in the power saving mode. As a result, no voltage is applied to the port of the CPU 61 of the engine control unit 6 in the power saving mode regardless of whether the attachment / detachment detection sensor S3 is opened or closed. When the cassette 2A is removed, the switch is opened, and the signal line L1 is in a high state.

  On the other hand, as shown in FIG. 5B, in the normal mode, the switch unit 92 is closed. Thus, the transistor 91 is in a state where the voltage Vcc2 is applied. Further, when the cassette 2A is removed in the normal mode, the transistor 91 is turned on, and the voltage input to the CPU 61 of the engine control unit 6 becomes almost ground. Therefore, in the normal mode, the CPU 61 can determine that the cassette 2 has been removed if the port for the attachment / detachment detection sensor S3 is at the low level.

  On the other hand, when the cassette 2A is attached in the normal mode, the potential of the base of the transistor 91 becomes substantially 0 V (almost ground), and the transistor 91 is turned off. If it does so, the voltage input into CPU61 of the engine control part 6 will be in a High state by the voltage Vcc2. Therefore, in the normal mode, the CPU 61 can determine that the cassette 2 is attached if the port for the attachment / detachment detection sensor S3 is at a high level.

  5 (a) and 5 (b) show an example in which the monitoring unit 7 performs opening / closing control of the switch unit 92. However, the main control unit 5 and the engine control unit 6 perform control of the switch unit 92. Also good. For example, the switch unit 92 is composed of a transistor, the voltage Vcc2 is connected to the collector of the transistor, and the emitter is connected to the resistor R2. The main control unit 5 and the engine control unit 6 are connected to the base of the transistor. If in the power saving mode, the main control unit 5 and the engine control unit 6 are not supplied with power, so that the transistors are not turned on. On the other hand, in the normal mode, the main control unit 5 and the engine control unit 6 apply a voltage to the base of the transistor 91 (flow current). As described above, the main control unit 5 and the engine control unit 6 can perform opening / closing control of the switch unit 92.

(Transition control between normal mode and power saving mode)
Next, an example of state transition control between the normal mode and the power saving mode in the MFP 100 according to the embodiment of the present invention will be described with reference to FIG. FIG. 6 is a flowchart illustrating an example of state transition control between the normal mode and the power saving mode in the multifunction peripheral 100 according to the embodiment of the present invention.

  First, the start shown in FIG. 6 is, for example, when the main power supply of the multifunction peripheral 100 is turned on in the present invention. After the main power supply is turned on, the normal power control unit 82 of the power supply unit 8 starts operating (step # 1), and power is supplied to the main control unit 5, the engine control unit 6, and the image forming mechanism 10 to enter the normal mode. (Step # 2). After the warm-up, for example, the multifunction device 100 maintains the temperature of the fixing unit 4b at the fixing control temperature and maintains the printable state (step # 3). In the normal mode here, the state of paper (remaining amount, size, etc.) of each cassette 2 is periodically checked. Next, the main control unit 5 confirms whether or not a predetermined time has passed after the power-saving key 14 on the operation panel 1 is pressed, the operation or input to the multi-function device 100 has been lost, and the like. It is confirmed whether the mode should be shifted to the power mode (step # 4).

  If the printable state should still be maintained (No in step # 4), for example, the process returns to step # 2. On the other hand, if the mode is shifted to the power saving mode (Yes in step # 4), the main control unit 5 instructs the power source unit 8 to shift to the power saving mode mode (step # 5). As a result, in the power supply unit 8, power supply control is performed by the power saving power control unit 81, and power supply to the main control unit 5, the engine control unit 6, and the image forming mechanism 10 is stopped (step # 6). . As a result, the multi-function device 100 enters the power saving mode (step # 7). In this power saving mode, the monitoring unit 7 confirms whether a factor for returning from the power saving mode to the normal mode has occurred (step # 8).

  Then, the monitoring unit 7 confirms whether or not it is necessary to return to the normal mode since a return factor has occurred (step # 9). If it is not necessary to return to the normal mode (No in Step # 9), for example, the process returns to Step # 6. On the other hand, if it is necessary to return to the normal mode (Yes in Step # 9), the monitoring unit 7 instructs the power supply unit 8 to switch to the control by the normal power control unit 82 (Step # 10). Thereafter, for example, the process returns to step # 1. That is, the monitoring unit 7 determines that a factor for returning from the power saving mode to the normal mode has occurred based on a signal from each sensor when an operation is performed on the multifunction peripheral 100, and the factor for returning occurs. If it is determined that the power supply unit 8 is in the normal mode, the power supply unit 8 is instructed to supply power in the normal mode.

  In this way, the monitoring unit 7 is provided for monitoring whether or not a factor for returning from the power saving mode to the normal mode has occurred, and an image forming apparatus (for example, a multifunction peripheral) such as attachment / detachment of a sheet feeding unit (cassette 2A, cassette 2B) is provided. 100), a signal indicating that a return factor has occurred is transmitted to the monitoring unit 7. As a result, the image forming apparatus returns from the power saving mode to the normal mode. Thus, in the power saving mode, it is not necessary to drive the control unit (for example, the engine control unit 6) as well as the image forming mechanism. That is, in the power saving mode, power supply to the control unit can be stopped. Here, the monitoring unit 7 mainly functions to monitor the occurrence of a return factor from the power saving mode to the normal mode. For example, the monitoring unit 7 may have a smaller function than the engine control unit 6. Therefore, the monitoring unit 7 can have a simpler configuration than the engine control unit 6 and the like, and the power consumption of the monitoring unit 7 can be smaller than that of the engine control unit 6 and the like. In the power saving mode, for example, the engine control unit 6 or the like is not driven, and power is supplied to the monitoring unit 7 to detect that the image forming apparatus has been operated, and the power consumption in the power saving mode is detected. Electric power (standby power) can be reduced. In other words, it is not necessary to operate the engine control unit 6 and the like temporarily and periodically in order to check the state change of the image forming apparatus.

  In addition, for example, when a plurality of paper feed units (cassette 2A, cassette 2B) are provided and detection units (for example, attachment / detachment detection sensors S3, S4) are provided for the cassettes 2A, 2B, a signal from the detection unit is sent. Even if there are a plurality of signal lines for transmission to the monitoring unit 7, each signal line is input to the OR circuit 83. Then, the output of the OR circuit 83 is input to the monitoring unit 7. Thereby, the number of input ports in the interface in the monitoring unit 7 can be reduced. Therefore, the configuration of the monitoring unit 7 can be simplified, and the manufacturing cost of the monitoring unit 7 and the image forming apparatus can be suppressed. Further, when a signal from the detection unit is also input to the control unit (for example, the engine control unit 6), the power supply to the engine control unit 6 and the like is stopped in the power saving mode. If a signal from the detection unit is input to the engine control unit 6 or the like in this stopped state, the part of the engine control unit 6 or the like that receives the signal from the detection unit may be damaged. For example, when a signal from each sensor is input to the CPU 61, a voltage is applied to the port of the CPU 61 when the CPU 61 is stopped. However, since the blocking unit 9 is provided, the voltage (power) from the detection unit is not input to the engine control unit 6 and the like in the power saving mode. Thereby, it is possible to avoid the electric power from wrapping around the engine control unit 6 or the like in the power saving mode.

  In addition, the engine control unit 6 and the like check the state of the paper feeding unit (cassette 2A, cassette 2B) when returning from the power saving mode, so when returning from the power saving mode, for example, the engine control unit 6 Thus, it is possible to confirm the state change such as the remaining amount of paper in the paper feeding unit. In addition, since the engine control unit 6 and the like control the image forming mechanism 10 for conveying paper and forming an image, in the power saving mode, the power supply to the engine control unit 6 and the like is stopped to save power. Can be achieved. Even in the normal mode, for example, when an abnormal operation is performed such as when the paper feeding unit is removed during printing, toner image formation can be stopped quickly.

  In addition, for example, a cover (side cover C1 or the like) of the image forming apparatus (for example, the multifunction peripheral 100) is opened and closed for member replacement or maintenance in the apparatus, and when the cover is opened and closed, some operation is performed on the image forming apparatus. There is a high possibility. Therefore, since the detection unit (for example, the side cover sensor S1) is for detecting the opening and closing of the cover, the engine control unit 6 and the like can be returned when the cover is opened. Thereby, it is possible to grasp the state change of the image forming apparatus one by one. The shut-off unit 9 is a transistor 91 provided between the branch point and the engine control unit 6, and the transistor 91 is not biased in the power saving mode, so that it can be reliably transferred to the engine control unit 6 in the power saving mode. It is possible to prevent the electric power from sneaking around.

  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.

  The present invention is applicable to an image forming apparatus having a power saving mode and a normal mode.

100 MFP (image forming apparatus) 1 Operation panel (detection unit)
2 (2A, 2B) Cassette (paper feeding unit) 6 Engine control unit (control unit)
7 Monitoring unit 8 Power supply unit 83 OR circuit 9 Blocking unit 91 Transistor (blocking unit 9) 10 Image forming mechanism C1 Side cover (cover) S1 Side cover sensor (detection unit)
S2 Front cover sensor (detector) S3 Desorption sensor (detector)
S4 Desorption detection sensor (detection unit) S5 Paper remaining amount sensor

Claims (5)

An image forming apparatus having a normal mode and a power saving mode for reducing power consumption than the normal mode,
A plurality of detection units provided to detect that an operation has been performed on the image forming apparatus;
A controller that checks the state of the image forming apparatus and detects that an operation has been performed on the image forming apparatus based on a signal from the detector;
A power supply unit that supplies power to the control unit in the normal mode and does not supply power to the control unit in the power saving mode;
A blocking unit that prevents transmission of a signal from the detection unit to the control unit in which power supply is stopped in a power saving mode;
Based on a signal from the detection unit when an operation is performed on the image forming apparatus, it is determined that a factor for returning from the power saving mode to the normal mode has occurred, and when it is determined that the factor for returning has occurred, A monitoring unit that gives an instruction to perform power supply in a mode to the power supply unit ,
The detection unit is switched between ON and OFF by an operation on the image forming apparatus.
The signal line from the detection unit toward the monitoring unit is branched toward the control unit,
The blocking unit is a transistor provided between a branch point and the control unit,
A voltage is applied between the control unit and the collector of the transistor via a switch unit,
The switch unit is in an open state in the power saving mode and is in a state in which no bias is applied to the transistor, so that the control unit is insulated from the detection unit, and is closed in the normal mode. An image forming apparatus, wherein a bias is applied to the transistor .   The image forming apparatus according to claim 1, wherein each signal line from the plurality of detection units to the monitoring unit is input to an OR circuit, and an output of the OR circuit is input to the monitoring unit. . Contains paper used for printing, supplies paper at the time of printing, has at least a paper remaining amount sensor, and has one or more paper feed units that can be detached from the image forming apparatus,
One detection unit is provided for the paper supply unit, and detects the removal and attachment of the paper supply unit.
Wherein the control unit after returning from the power saving mode, based on the output of the sensor, the image forming apparatus according to claim 1 or 2, characterized in that to check the status of the paper feed unit. Wherein the control unit conveys the sheet, the image forming apparatus according to any one of claims 1 to 3, characterized in that an engine control unit for controlling the image forming mechanism for forming an image. One or more covers that are openable and closable and that expose the interior of the image forming apparatus when opened;
The detection unit is also provided with respect to the cover, the image forming apparatus according to any one of claims 1 to 4, characterized in that for detecting the opening and closing of the cover.

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