JP5836242B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus having a heater for drying and dehumidifying paper.

  In order to prevent curling and wrinkling of paper, and to prevent double feeding due to moisture adsorbing between papers, a heater may be installed in the paper storage portion of the image forming apparatus. The heater generates heat when energized and consumes a certain amount of power. Due to the recent increase in awareness regarding energy saving, it is preferable to suppress the power consumption of the heater in the paper feeder as much as possible. Therefore, Patent Document 1 describes a technique for reducing power consumption according to the state in the paper feeding device.

  Specifically, Patent Document 1 includes a paper feed cassette, a determination unit that determines the amount of print medium replenished in the paper feed cassette, and a heater control that controls a heater for dehumidifying the inside of the paper feed cassette. If the determination unit determines that the amount is small, after the print medium is replenished to the paper cassette, the heater is turned on after a predetermined time delay, and the determination unit determines that the amount is large In this case, there is described a printing apparatus in which the heater is turned on after a predetermined time longer than a predetermined time after the printing medium is supplied to the paper feed cassette. Based on the fact that it is not necessary to remove the moisture immediately after the print medium is packed with a packing material to make it less susceptible to moisture and removed from the packing material and replenished to the paper cassette. The timing to turn on the cassette heater is changed according to the state of the paper feed cassette before the medium is replenished and the amount of the replenished print medium. An attempt is made to suppress power consumption by the cassette heater (see Patent Document 1: Claim 1, paragraphs [0025], [0061], etc.).

JP 2011-102173 A

  The image forming apparatus has a power saving mode in which power supply is reduced and power consumption is reduced for a part (for example, a part that performs printing) constituting the image forming apparatus. In the power saving mode, the power consumption is suppressed as compared with the normal mode. For example, the normal mode is a mode in which power is supplied to all parts of the image forming apparatus, and the image forming apparatus is kept in a job executable state.

  Conventionally, in a power saving mode or a state where the main power supply is turned off, the necessity of energizing the heater is determined, and energization to a control circuit or the like that performs energization ON / OFF is stopped. In order to avoid deterioration of the paper quality, the heater for dehumidifying the paper may be kept energized (on) in the power saving mode or when the main power is turned off. However, even though the paper is sufficiently dehumidified, the heater may continue to be energized in the power saving mode or when the main power is turned off. Therefore, there is a problem that wasteful power may be consumed in the power saving mode or when the main power supply is turned off.

  On the other hand, it is also conceivable to keep the energization of the heater for dehumidifying the sheet stopped in the power saving mode or in a state where the main power is turned off. However, until the power supply control (ON / OFF control) to the heater by the control circuit is resumed after the power supply to the heater is stopped, the power saving mode is canceled, the main power is turned on again, etc. It may elapse for a long time. For example, there may be a period of time from the end of work until the start of the next morning (for example, dozens of hours) or consecutive holidays (for example, several days). In this case, if the energization of the heater for dehumidifying the paper is kept stopped, there is a problem that the paper absorbs moisture and the quality of the paper may not be maintained.

  Here, the invention described in Patent Document 1 energizes the heater after one or a few hours depending on the amount of supplied paper (see Patent Document 1: Paragraphs [0025] to [0029]). It does not deal with the power supply control of the heater in the power mode or when the main power of the image forming apparatus is turned off. Further, in the invention described in Patent Document 1, it is necessary to continue energization to a control circuit and a switch portion for controlling and judging energization and shut-off of the heater for several hours after paper replenishment. May be weak.

  The present invention has been made in view of the above-described problems of the prior art, and is a heater that dehumidifies a sheet while maintaining the quality of the sheet and reducing the power consumption of the image forming apparatus such as the power saving mode. This prevents unnecessary power consumption and saves power.

  Therefore, the image forming apparatus has a main switch for operating the main power on and off, a humidity detector for storing and supplying paper, and detecting the humidity in the space for storing the paper, and dehumidifying the paper. And a second heater for dehumidifying the paper separately from the first heater, and the humidity in the sheet feeding unit based on the output of the humidity detection unit. A recognition unit that recognizes; a first switch unit that controls energization to the first heater; a second switch unit that controls energization to the second heater; and power to the first heater and the second heater. A normal mode in which power is supplied to a predetermined supply stop portion in the image forming apparatus while the main power of the image forming apparatus is turned on, and a predetermined power saving mode transition condition When satisfied A power supply having a power saving mode in which power is not supplied to the stop portion, and returning to the normal mode and restarting the power supply to the supply stop portion when the return condition to the normal mode is satisfied in the power saving mode And in the normal mode, the first switch unit supplies power to the first heater such that the higher the humidity recognized by the recognition unit is, the larger the output of the first heater is. The second switch unit stops supplying power to the second heater. In the power saving mode, the first switch unit stops supplying power to the first heater, and the power supply unit is predetermined. After supplying power to the humidity detection unit and the recognition unit, the power supply to the humidity detection unit and the recognition unit is stopped while it is necessary for the recognition unit to recognize humidity at a given cycle, Previous The second switch unit is in a state of supplying power to the second heater if the humidity recognized by the recognition unit exceeds a predetermined threshold value, and supplies power to the second heater if the humidity is less than the threshold value. It was decided to be in a stopped state.

  According to the present invention, when the power consumption of the image forming apparatus is reduced, the supply and stop of the power to the second heater are switched according to the humidity state, so that the quality of the sheet is maintained. In addition, the heater for dehumidifying the paper is not left on (the power is kept on) in a state where the power consumption of the image forming apparatus is reduced, and wasteful power consumption can be prevented and power saving can be achieved.

1 is a schematic front sectional view 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 electric power supply system of a multifunction device. 3 is a block diagram illustrating an example of a portion that detects an operation on a multifunction peripheral. FIG. It is explanatory drawing which shows an example of arrangement | positioning of the heater for paper dehumidification. It is a block diagram which shows an example of the electric power supply system | strain to each heater. It is a timing chart which shows an example of the waveform of various signals in normal mode. It is a timing chart which shows an example of the waveform of various signals in a power saving mode and a main power supply cutoff state. 6 is a flowchart illustrating an example of a flow of dehumidification control of a sheet in a power saving mode and a main power supply cut-off state.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. However, each element such as configuration and arrangement described in each embodiment does not limit the scope of the invention and is merely an illustrative example.

(Schematic configuration of MFP 100)
First, the outline of the image forming apparatus according to the embodiment will be described with reference to FIG. In this description, an electrophotographic multifunction peripheral 100 will be described as an example of the image forming apparatus. FIG. 1 is a schematic front sectional view of the multifunction machine 100.

  The multifunction peripheral 100 according to the present embodiment is provided with a document conveying unit 51 and an image reading unit 2 at the top. In addition, an operation panel 3 that receives various settings such as copying and transmission and displays the state of the multifunction device 100 is provided above the front surface of the multifunction device 100 (a position indicated by a broken line in FIG. 1). Further, the MFP 100 main body is provided with a paper feed unit 4, a transport unit 5, an image forming unit 6, a fixing unit 7, and the like.

  The image reading unit 2 reads a document and generates image data. Further, contact glass (two kinds of contact glass 21 for feeding reading and contact glass 22 for mounting reading) is provided on the upper surface of the image reading unit 2, and the horizontal direction (in the left-right direction in FIG. 1) is provided inside the contact glass. And an optical system member (all not shown) such as a moving frame (including an exposure lamp and a mirror), a lens, and an image sensor (for example, a CCD) are provided. For example, when reading a document continuously conveyed by the document conveying unit 51, a moving frame is fixed below the feed reading contact glass 21, and reflected light of the document is guided to a lens and an image sensor. Further, when reading the document placed on the placement reading contact glass 22, 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 2 uses these optical system members to irradiate the original with light, A / D converts the output value of each pixel of the image sensor that receives the reflected light of the original, and generates image data. For example, the multi-function device 100 can print based on the read image data (copy function).

  A sheet feeding unit 4 that accommodates and supplies image forming sheets is provided below the multifunction peripheral 100. In addition, the sheet storage unit 4 as an optional device for expansion can be stacked further downward (for example, about 3 to 4 stages) to increase the sheet accommodation capacity. The portion of the paper supply unit 4 that accommodates paper can be removed as a cassette 41 for paper supply and paper size change.

  In the cassette 41 of the paper feed unit 4, a plurality of (for example, 500, plain paper, copy paper, recycled paper, etc.) and a plurality of sheets (for example, A4, A3, B4, B5, letter size, etc.) of each size (for example, 500). Load up to about 1000 sheets). In the cassette 41, a paper placement plate 42 on which a bundle of paper is placed is provided. The paper feed unit 4 is provided with a paper feed roller 43 that contacts the uppermost paper and feeds the paper by feeding it out.

  In addition, a heater for dehumidifying and feeling the sheet is provided on the upper surface of the sheet in the sheet feeding unit 4 (above the sheet placing plate 42). The heater may be provided below the paper.

  Further, as will be described in detail later, a temperature / humidity sensor 44 for confirming the humidity is provided in the sheet feeding unit 4 when the heater is turned on / off (to control the supply and stop of power to the heater). Provided. For example, the temperature / humidity sensor 44 is provided below the paper placement plate 42. By using the temperature / humidity sensor 44, the humidity in the paper feeding unit 4 can be measured and detected.

  Next, the transport unit 5 is a path for transporting paper in the apparatus. The transport unit 5 is provided with a transport roller pair 51 that is rotationally driven when transporting the paper, a registration roller pair 52 that waits for the transported paper in front of the image forming unit 6, and sends out the toner image formation timing. . A discharge tray 53 is also provided for receiving paper discharged from the discharge port.

  The image forming unit 6 forms an image (toner image) on the sheet fed from the sheet feeding unit 4 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 2 or transmission image data from a computer 200 (see FIG. 2) connected to the multifunction peripheral 100 is used. The image forming unit 6 includes a photosensitive drum 61 that is rotatably supported, a charging device 62, an exposure device 63, a developing device 64, a transfer roller 65, a cleaning device 66, and the like disposed around the photosensitive drum 61.

  The toner image formation and transfer process will be described. The photosensitive drum 61 is rotationally driven in a predetermined direction. The charging device 62 above the photosensitive drum 61 is charged to a predetermined potential. The exposure device 63 outputs a laser beam based on the image data, and scans and exposes the surface of the charged photosensitive drum 61 to form an electrostatic latent image corresponding to the image data.

  The developing device 64 supplies toner to the electrostatic latent image formed on the photosensitive drum 61 and develops it. The transfer roller 65 below the photosensitive drum 61 is pressed against the photosensitive drum 61 to form a nip. Then, the registration roller pair 52 is timed to cause 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 65, and the toner image on the photosensitive drum 61 is transferred to the paper. The cleaning device 66 removes toner and dirt remaining on the photosensitive drum 61 after the transfer.

  The fixing unit 7 fixes the toner image transferred to the paper. The fixing unit 7 in the present embodiment is mainly composed of a heating roller 71 and a pressure roller 72 that incorporate a heating element. The heating roller 71 and the pressure roller 72 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 53.

(Hardware configuration of MFP 100)
Next, an example of a hardware configuration of the multifunction peripheral 100 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 peripheral 100.

  First, a main control unit 8 a is provided in the main body of the multi-function device 100 as a part that controls the operation of the multi-function device 100. The main control unit 8a is a substrate, and includes, for example, a CPU 81 as a part that performs control. The main control unit 8a supervises the overall control of the multifunction peripheral 100. For example, a block that performs overall control, a block that performs communication control, and a block that performs image processing are provided in the main control unit 8a.

  The main control unit 8a has a storage unit 82. The storage unit 82 can store image data and the like in addition to programs and data for controlling the multifunction peripheral 100. For example, the storage unit 82 is a combination of volatile and nonvolatile storage devices such as RAM, ROM, HDD, and flash ROM. Based on the program and data stored in the storage unit 82, the CPU 81 controls the multifunction peripheral 100 by executing arithmetic processing and transmitting and receiving control signals.

  Also, an engine control unit 8b (recognition) that controls operations and processes related to printing such as ON / OFF of a motor that rotates various rotating bodies, paper feeding, paper conveyance, toner image formation, and the like when performing image formation and paper conveyance. Equivalent to the part). The engine control unit 8b is communicably connected to the main control unit 8a and the like, and based on an instruction from the main control unit 8a, the print engine unit 101 (paper feeding unit 4, conveyance unit 5, image forming unit 6, fixing unit 7) related to printing. Etc.) is actually controlled. For example, the engine control unit 8b has an engine CPU 83 as an arithmetic processing unit. The engine control unit 8b has an engine storage unit 84 (e.g., equivalent to a flash ROM, RAM, or storage unit) that stores a program and data for controlling a control target. In addition, a chip, a microcomputer, various circuits, elements, and the like may be mounted on the engine control unit 8b.

  The main control unit 8a is communicably connected to the document conveyance unit 51, the image reading unit 2, and the like, and causes the document conveyance unit 51 and the image reading unit 2 to read a document and generate image data. The main controller 8a is communicably connected to the operation panel 3. As a result, the contents of the settings and inputs made on the operation panel 3 are transmitted to the main controller 8a. The main control unit 8a gives an instruction to each unit included in the multi-function device 100 so that each unit operates in accordance with the set content.

  Further, the main control unit 8a is connected to the communication unit 85. The communication unit 85 communicates with the computer 200 (for example, a personal computer or a server) or the counterpart FAX apparatus 300 via a network, a cable, or a communication network. As a result, the MFP 100 receives image data and the like from the computer 200 and prints them (printer function), stores the image data read by the image reading unit 2 in the storage unit 82, and transmits the image data to the computer 200. (Scanner function), image data can be transmitted / received to / from an external FAX apparatus 300 (FAX function).

  In addition, a power supply unit 9 is provided in the multifunction device 100. The power supply unit 9 generates various voltages necessary for operating the multi-function device 100 (necessary for supplying to each unit in the multi-function device 100) and supplies the various voltages (details will be described later).

(Power supply system)
Next, an example of the power supply system of the multifunction peripheral 100 according to the embodiment will be described with reference to FIG. FIG. 3 is a block diagram illustrating an example of the power supply system of the multifunction peripheral 100.

  First, the multifunction device 100 is provided with a power supply unit 9 as a portion that generates various voltages and supplies power to each portion of the multifunction device 100. The multifunction device 100 is connected to a commercial power source by an outlet or a power cord. For example, the power supply unit 9 is connected to a commercial power supply via a main switch 102 for operating the main power supply of the multifunction peripheral 100 to be turned on and off. For example, the main switch 102 is provided on the side surface of the multifunction peripheral 100 or the like.

  For example, the power supply unit 9 includes a switching power supply unit 91. The switching power supply unit 91 is a switching power supply circuit that generates a DC voltage by switching. The switching power supply unit 91 includes a coil, a capacitor, a semiconductor switch, and a backflow prevention diode, and receives a supply of electric power from a commercial power supply to generate a constant DC voltage (for example, DC 24V for driving a motor).

  The power supply unit 9 is provided with a secondary power supply unit 92 that steps down the voltage generated by the switching power supply unit 91 and generates a DC voltage for driving an electronic circuit in a CPU, memory, ASIC, or the like. The secondary power supply unit 92 generates a voltage for driving elements provided in the main control unit 8a and the engine control unit 8b, such as DC5V, 3.3V, 2.5V, 1.8V, 1.2V, and the like.

  Then, power is supplied from the power supply unit 9 to the document conveying unit 51, the operation panel 3, the image reading unit 2, the main control unit 8a, the engine control unit 8b, the print engine unit 101, the communication unit 85, and the like.

  Further, the power supply unit 9 controls the supply and stop of power to the document conveying unit 51, the operation panel 3, the image reading unit 2, the main control unit 8a, the engine control unit 8b, the print engine unit 101, the communication unit 85, and the like. A power supply switching unit 93 is provided. For example, the power supply switching unit 93 includes a plurality of semiconductor switches, and supplies and stops the voltage generated by the switching power supply unit 91 and the voltage generated by the secondary power supply unit 92 to each unit.

  A power control unit 90 provided in the power supply unit 9 controls ON / OFF (supply or stop) of power supply to each unit by the power supply switching unit 93. Further, the power control unit 90 recognizes that the operation of turning on the main power of the multifunction peripheral 100 has been performed or the operation of shutting off has been performed by operating the main switch 102.

(Normal mode and power saving mode)
Next, an example of the normal mode and the power saving mode in the multifunction peripheral 100 according to the embodiment will be described with reference to FIGS. 3 and 4. FIG. 4 is a block diagram illustrating an example of a portion that detects an operation on the multifunction peripheral 100.

  First, when the main power is turned on by the main switch 102MS of the multifunction peripheral 100, the power control unit 90 of the power supply unit 9 operates the switching power supply unit 91 and the secondary power supply unit 92. Then, the power control unit 90 controls the power supply switching unit 93 to transfer the generated voltage (power) to each unit (the document conveyance unit 51, the operation panel 3, the image reading unit 2, and the main control unit 8a) of the multifunction machine 100. Engine control unit 8b, print engine unit 101, communication unit 85, etc.).

  Then, a start-up process (warm-up process) is performed in each unit of the multifunction peripheral 100. For example, when the main power is turned on, the main program is read from the storage unit 82, the main control unit 8a and the engine control unit 8b are started, and the fixing unit 7 is warmed up. Then, the multifunction device 100 is activated in the normal mode.

<Transition from normal mode to power saving mode>
Next, transition from the normal mode to the power saving mode will be described with reference to FIG. In the normal mode, the power supply unit 9 supplies power to all parts of the multifunction peripheral 100, and in principle, can immediately execute all functions and jobs. However, even when the multifunction device 100 is not used (standby state), constant power is consumed by the main control unit 8a, the engine control unit 8b, the print engine unit 101 (for example, temperature maintenance control of the fixing unit 7), and the like. The Therefore, the multifunction peripheral 100 according to the present embodiment has a power saving mode in which power consumption is reduced compared to the normal mode.

  When the conditions for shifting from the normal mode to the power saving mode are satisfied (when satisfied), the power supply unit 9 (multifunction device 100) shifts the power supply mode from the normal mode to the power saving mode. Transition conditions can be determined arbitrarily. For example, the transition condition to the power saving mode may be that the power saving key provided on the operation panel 3 and instructing the transition to the power saving mode is pressed.

  Further, for example, after the MFP 100 is started or after the job is completed, there is no operation or input (input to the operation panel 3, input of print data to the communication unit 85, etc.) to the MFP 100 (operation). The transition condition to the power saving mode is that a predetermined power saving mode transition time (for example, several minutes) elapses. For example, the time measuring unit 86 provided in the main control unit 8a measures the transition time to the predetermined power saving mode.

  A plurality of operation detection units that detect operations and inputs to the multifunction device 100 are provided in the multifunction device 100. For example, as shown in FIG. 4, in the multifunction peripheral 100, as an operation detection unit, a communication unit 85, a touch panel unit 31, an insertion / removal detection sensor 45, a cover open / close detection sensor 54, a document placement detection sensor 11, an open / close detection sensor. 12 etc. are provided.

  The communication unit 85 detects the input of print data from the computer 200 or the like, and notifies the main control unit 8a when the print data is received. The touch panel unit 31 detects an operation on the operation panel 3 by the user, and notifies the main control unit 8a when there is an operation.

  The insertion / removal detection sensor 45 detects insertion / removal of the cassette 41, and the output changes between when the cassette 41 is attached and when it is removed (for example, an interlock switch that contacts the cassette 41, see FIG. 1).

  The cover open / close detection sensor 54 detects opening / closing of a cover (for example, the left side cover 100c) of the multi-function device 100 provided for jam processing, maintenance, etc., and outputs when the cover is open and when the cover is closed. Change (for example, an interlock switch in contact with the optical sensor or the cover, see FIG. 1).

  The document placement detection sensor 11 is a sensor for detecting the presence or absence of a document on the placement tray 13 of the document transport section 51, and the output changes depending on whether the document is placed or not. (For example, a reflection type optical sensor, see FIG. 1).

  The open / close detection sensor 12 is a sensor for detecting whether or not the document conveying section 51 is lifted for copying or the like, and the output changes between when the document is placed and when the document is not placed ( For example, a reflective optical sensor, see FIG.

  Outputs of these operation detection units are input to the main control unit 8a. Accordingly, the main control unit 8a recognizes whether or not there is an operation on the multifunction peripheral 100, and the main control unit 8a recognizes whether or not the power saving mode transition condition is satisfied. When the main control unit 8a recognizes that the power saving mode transition condition is satisfied, the main control unit 8a instructs the power supply unit 9 to enter the power saving mode.

  In response to this instruction, the power supply unit 9 controls the power supply switching unit 93 to determine a predetermined supply stop portion (for example, the document conveying unit 51, the operation panel 3, the image reading unit 2, the engine control unit 8b, the print engine). The power supply to the part 101) is stopped. It should be noted that the part operated in the power saving mode (the part supplying power) can be arbitrarily determined.

  In the MFP 100 according to the present embodiment, an operation detection unit that detects that the condition for returning from the power saving mode to the normal mode is satisfied (the condition for canceling the power saving mode is satisfied), and an operation detection unit Is supplied to the main control unit 8a which recognizes that the return condition is satisfied even in the power saving mode (see FIG. 4). In the main control unit 8a, power is supplied only to necessary blocks, and power supply to unnecessary blocks is stopped.

《Release power saving mode / Power saving mode → Normal mode》
Next, cancellation of the power saving mode (returning to the normal mode) will be described with reference to FIG. First, in the power saving mode, the portion where power is supplied is limited. Therefore, the various functions (copy, scan, print, FAX, etc.) of the multifunction device 100 cannot be used.

  Therefore, when the return condition is satisfied in the multifunction peripheral 100 of the present embodiment, the multifunction peripheral 100 returns from the power saving mode to the normal mode, and returns to a state where various functions of the multifunction peripheral 100 can be used.

  In the multifunction device 100 of the present embodiment, when an operation or input is performed on the multifunction device 100, the main control unit 8a determines that the return condition is satisfied. The main control unit 8a recognizes that there has been an operation and an input to the multifunction device 100 based on the output of each operation detection unit.

  When recognizing that the return condition is satisfied, the main control unit 8a instructs the power supply unit 9 to return to the normal mode. In response to this instruction, the power control unit 90 causes the secondary power supply unit 92 to generate various voltages. The power control unit 90 of the power supply unit 9 controls the power supply switching unit 93 so that power is supplied to all parts of the multifunction peripheral 100.

  Thereby, the power supply to the supply stop portion is resumed. As a result, the start-up and warm-up processing is performed at the portion where the power supply is resumed, and the multifunction peripheral 100 returns to the normal mode.

(Dehumidification in paper feed unit 4)
Next, the dehumidification of the sheet in the sheet feeding unit 4 will be described with reference to FIG. FIG. 5 is an explanatory diagram showing an example of the arrangement of heaters for dehumidifying the paper.

  When paper is placed in a humid environment, the paper absorbs moisture. If the amount of moisture absorbed by the paper increases, wrinkles may occur. In addition, due to moisture absorption, a wavy state may occur, and wrinkles and folds may easily occur during paper conveyance. Further, wrinkles may occur due to water evaporation during fixing. In addition, when moisture enters between paper sheets (particularly coated paper whose surface is coated for color printing), the paper sheets adsorb each other, and double feeding of the paper sheets may occur.

  In order to maintain the quality of the paper, the multifunction peripheral 100 according to the present embodiment is provided with a heater for dehumidifying and feeling the paper. As a result, it is possible to prevent paper wrinkles and double feeds.

  Specifically, in the multifunction peripheral 100 of the present embodiment, two heaters are provided for one paper feed unit 4. As shown in FIG. 5, the first heater H <b> 1 and the second heater H <b> 2 are provided for the paper feed unit 4 separately from the first heater H <b> 1. FIG. 5 is a schematic view of the cassette 41 as viewed from above.

  As shown in FIG. 5, the second heater H <b> 2 is provided so as to surround the first heater H <b> 1 when viewed in the vertical direction, and the shape of the second heater H <b> 2 is a square shape. The first heater H1 is provided inside the second heater H2 and at a position closer to the center of the paper than the second heater H2.

  The first heater H1 and the second heater H2 are planar heating elements including heating wires, and generate heat when energized. The first heater H1 is provided with a first switch unit S1 for controlling energization. In the example of FIG. 5, a transistor is used as an example of the first switch unit S1.

  The second heater H2 is provided with a second switch part S2 for controlling energization. The second switch unit S2 is a switch that maintains an ON state or an OFF state once receiving an instruction from the engine control unit 8b. For example, the second switch unit S2 can be configured by a logic circuit, a transistor, or the like.

(Power supply system to each heater)
Next, an example of a power supply system to the first heater H1 and the second heater H2 will be described with reference to FIG. FIG. 6 is a block diagram showing an example of a power supply system to each heater.

  Electric power from the commercial power source is input to the power source unit 9, and the switching power source unit 91 generates a voltage having a predetermined voltage value (for example, DC 24V for driving the motor) as described above. And the switching power supply part 91 supplies electric power to the 1st heater H1 via 1st switch part S1.

  On the other hand, the power supply unit 9 is provided with a half-wave rectification unit 94. For example, the half-wave rectification unit 94 is a circuit (a general half-wave rectification circuit) in which a plurality of diodes are combined. And the half wave rectification part 94 carries out the half wave rectification of the alternating current supplied from a commercial power supply, and outputs it. The half-wave rectification unit 94 supplies power to the second heater H2 via the second switch unit S2.

  Further, the output of the temperature / humidity sensor 44 provided in the paper feed unit 4 is input to the engine control unit 8b. For example, the temperature / humidity sensor 44 includes a temperature detection body (for example, a thermistor) and a humidity detection body (for example, a polymer humidity sensor).

  The engine control unit 8b receives the output of the temperature detection sensor (temperature sensor) out of the temperature / humidity sensor 44, and recognizes the temperature of the temperature / humidity sensor 44 installation location (in the sheet feeding unit 4) based on the output value. The engine control unit 8b recognizes the temperature by referring to the data indicating the temperature with respect to the output of the temperature detection detector stored in the engine storage unit 84.

  Further, the engine control unit 8b receives the output of the detection body (humidity sensor) for detecting humidity in the temperature / humidity sensor 44, and the temperature / humidity sensor 44 installation location (in the paper feeding unit 4) based on the temperature recognized as the output value. Recognize the relative humidity. The engine storage unit 84 stores data indicating the relative humidity at each temperature with respect to the output of the humidity detecting body. The engine control unit 8b refers to the data stored in the engine storage unit 84 and recognizes the relative humidity. In this description, an example in which relative humidity is obtained as humidity will be described. However, an absolute humidity sensor may be installed to obtain absolute humidity.

  For example, the engine control unit 8b controls energization to the first heater H1 and the second heater H2. In other words, the engine control unit 8b controls ON / OFF of the first switch unit S1 and the second switch unit S2. In the following description, an example in which the engine control unit 8b recognizes humidity and controls the energization of the first heater H1 and the second heater H2 will be described. However, portions other than the engine control unit 8b may obtain humidity and control energization of the first heater H1 and the second heater H2. For example, the main control unit 8a may obtain the humidity based on the output of the temperature / humidity sensor 44 and control the energization of the first heater H1 and the second heater H2. Alternatively, a sheet feeding control board (sheet feeding control unit) is provided in the sheet feeding unit 4, and the provided sheet feeding control unit obtains humidity based on the output of the temperature / humidity sensor 44, and the first heater H 1 and the second heater H 2. May be controlled.

  And the engine control part 8b outputs the signal which instruct | indicates ON / OFF of 1st switch part S1. For example, when power is applied to the first heater H1 (when heat is generated), the engine control unit 8b outputs a signal (for example, a high level signal) indicating that the first switch unit S1 is in the ON state, A signal (for example, a low level signal) indicating that the switch unit S1 is in the OFF state is output.

  Further, the engine control unit 8b outputs a signal for instructing ON / OFF of the second switch unit S2. For example, when the engine control unit 8b supplies power to the second heater H2 (when generating heat), the engine control unit 8b outputs a signal indicating that the second switch unit S2 should be turned on to supply power to the second heater H2. When stopping, a signal indicating that the second switch section S2 should be turned off is output.

(Dehumidification of paper in normal mode)
Next, dehumidification of the paper in the normal mode will be described with reference to FIGS. FIG. 7 is a timing chart showing an example of waveforms of various signals in the normal mode.

  First, the uppermost chart in FIG. 7 shows a voltage waveform (sine wave, for example, 50 Hz or 60 Hz) of a commercial power source. The second chart is an example of the output waveform of the half-wave rectification unit 94.

  The third chart in FIG. 7 shows the output waveform of the switching power supply unit 91 when the main power supply is turned on in the normal mode. When the main power supply is turned on by the main switch 102, the switching power supply unit 91 continues to output a voltage having a certain magnitude.

  The fourth chart in FIG. 7 is a zero cross signal based on the voltage waveform of the commercial power supply. As shown in FIG. 6, the power supply unit 9 is provided with a zero cross signal generation unit 95. The zero-cross signal generator 95 is a signal that is high when the voltage value of the commercial power supply is 0 ± αV (for example, α may be several V or 1 V or less, such as 0.5 to 0.6 V). Is generated.

  The fifth chart in FIG. 7 shows the ON / OFF state of the first switch unit S1. The high level in the fifth chart of FIG. 7 indicates a state in which the first switch unit S1 supplies power from the switching power supply unit 91 to the first heater H1, and the low level indicates that the first switch unit S1 supplies power. The state which has stopped the electric power supply to the 1st heater H1 is shown.

  The lowermost chart in FIG. 7 shows the ON / OFF state of the second switch unit S2 (whether or not the second heater H2 can be energized). The High level in the lowermost chart in FIG. 7 indicates that the second switch unit S2 can supply power to the second heater H2, and the Low level indicates that the second switch unit S2 does not supply power to the second heater H2. Indicates a (cannot) state. As shown in the lowermost chart of FIG. 7, the second heater H2 is not energized in the normal mode (the second heater H2 is not used).

  In the normal mode, the engine control unit 8b controls the first switch unit S1 to supply power to the first heater H1 so that the output of the first heater H1 increases as the recognized humidity increases. On the other hand, the engine control unit 8b controls the second switch unit S2 to stop the supply of power to the second heater H2 in the normal mode.

  Here, the engine control unit 8b controls the first switch unit S1 to increase the power supply time to the first heater H1 within a unit time as the humidity recognized by the recognition unit is higher. The example of FIG. 7 shows an example in which the engine control unit 8b switches ON / OFF of energization to the first heater H1 based on the edge of the zero cross signal.

  The unit time is a time that can be arbitrarily determined. For example, assuming 1 second as a unit time, if the frequency of the commercial power supply is 50 Hz, 100 cycles of the zero cross signal is the unit time. And the time which the electric power to 1st heater H1 is continued within unit time is lengthened among 100 periods, so that the recognition part which the recognition part recognized. For example, the engine storage unit 84 stores data in which the time for supplying power to the first heater H1 per unit time is determined for the recognized humidity. The engine control unit 8b refers to the data stored in the engine storage unit 84, determines the energization time for the first heater H1 within a unit time, and supplies and stops power to the first heater H1 in the normal mode. To control.

  For example, when 1 second is defined as a unit time, if the ON / OFF of energization to the first heater H1 is switched for each edge of the zero cross signal, the engine control unit 8b is set in 1% increments (about 0. 0 at 60 Hz). The duty ratio for energizing the first heater H1 is controlled in increments of 8%. The engine control unit 8b increases the duty ratio as the recognized humidity increases, and increases the output of the first heater H1 as the humidity increases.

  If the humidity recognized by the engine control unit 8b is lower than a predetermined reference humidity (if it is recognized that the paper is sufficiently dry), the engine control unit 8b does not have the first heater H1 at all within a unit time. You may make it not supply electric power to.

  Thus, in the normal mode in which power is also supplied to the engine control unit 8b and the like, fine energization control is performed on the heater (first heater H1) that dehumidifies the paper.

(Dehumidification of paper in power saving mode and main power shut-off)
Next, the dehumidification of the paper in the power saving mode and the main power supply cutoff state will be described with reference to FIG. FIG. 8 is a timing chart showing an example of waveforms of various signals in the power saving mode and the main power supply cutoff state.

  First, the top chart in FIG. 8 shows a voltage waveform (sine wave, for example, 50 Hz or 60 Hz) of a commercial power source. The second chart is an example of the output waveform of the half-wave rectification unit 94.

  Further, the third chart in FIG. 8 shows the output waveform of the switching power supply unit 91 in the main power supply cutoff state. In the power saving mode, the switching power supply 91 is driven to supply power to the operation detection unit, the main control unit 8a, and the like (in the power saving mode, the power output from the switching power supply 91 is in the normal mode). Less than). Further, the switching power supply unit 91 may be driven even in the main power supply cut-off state.

  The fourth chart in FIG. 8 shows energization to the first heater H1 (ON / OFF of the first switch unit S1) (similar to FIG. 7). Then, as shown in the fourth chart of FIG. 8, the first heater H1 is not energized in the power saving mode or the main power cut-off state. In other words, the first heater H1 is not used in the power saving mode or the main power supply cut-off state. On the other hand, the lowermost chart in FIG. 8 shows the ON / OFF state of the second switch unit S2 (whether or not the second heater H2 can be energized, as in FIG. 7).

  First, for example, when entering the power saving mode or the main power shut-off state, the engine control unit 8b should recognize the humidity, check whether the recognized humidity exceeds a threshold value, and supply power to the second heater H2. Confirm whether or not.

  If the recognized humidity exceeds a predetermined threshold, the engine control unit 8b determines that dehumidification by the second heater H2 is necessary, and controls the second switch unit S2 to supply power to the second heater H2. The supply state.

  On the other hand, when the recognized humidity is equal to or lower than the threshold value and the engine control unit 8b determines that dehumidification by the second heater H2 is not necessary, the engine control unit 8b controls the second switch unit S2 to control the second heater The power supply to H2 is stopped.

  When the predetermined period T1 has elapsed since the power saving mode or the main power cut-off state has elapsed, or when the engine control unit 8b temporarily supplies power to the engine control unit 8b or the temperature / humidity sensor 44, the engine control unit 8b When a predetermined period T1 has elapsed since the humidity was recognized and the necessity of energization of the second heater H2 was determined, the power supply unit 9 (power control unit 90) controls the power supply switching unit 93. The engine control unit 8b recognizes the humidity, determines the necessity of drying by the second heater H2, and supplies power to the temperature / humidity sensor 44 and the engine control unit 8b while it is necessary to switch the state of the second switch unit S2. Then, the power supply to the temperature / humidity sensor 44 and the engine control unit 8b is stopped.

  For example, as shown in the third chart of FIG. 8, when the operation of the switching power supply unit 91 is stopped in the main power supply cut-off state, power is supplied to the engine control unit 8b and the temperature / humidity sensor 44 to In order to perform typical humidity recognition, the switching power supply unit 91 may be temporarily driven.

  As described above, in the power saving mode or the main power shut-off state, power is periodically and temporarily supplied to the engine control unit 8b and the temperature / humidity sensor 44, and periodically and temporarily engine control unit 8b and the temperature / humidity sensor. 44 starts and operates.

  When the power recognized by the engine control unit 8b that has been temporarily restored exceeds the threshold when the power saving mode or the main power supply is cut off, the engine control unit 8b determines that dehumidification by the second heater H2 is necessary. The engine control unit 8b controls the second switch unit S2 so that the power from the half-wave rectification unit 94 is input to the second heater H2. At this time, half-wave rectified power is supplied to the second heater H2, and the second switch H2 is configured so that the maximum output of the second heater H2 is smaller than the maximum output of the first heater H1. To supply power.

  On the other hand, when the recognized humidity is equal to or lower than the threshold value and the engine control unit 8b determines that dehumidification by the second heater H2 is not necessary, the engine control unit 8b controls the second switch unit S2 to the second heater H2. The power supply is stopped.

  As described above, in the power saving mode or the main power shut-off state, power is temporarily supplied to the engine control unit 8b and the temperature / humidity sensor 44 at a predetermined cycle T1, and the engine control unit 8b recognizes the humidity. Then, it is determined whether or not energization to the second heater H2 is necessary, and the state of the second switch unit S2 is switched.

  Here, the “predetermined period T1” is a time that can be appropriately determined. The “predetermined period T1” can be determined in consideration of the output of the second heater H2 and the like. For example, the “predetermined period T1” can be about 1 hour. The “predetermined period T1” may be several tens of minutes or several hours. Further, the setting may be made on the operation panel 3.

  Here, after entering the power saving mode or the main power shut-off state, or first, power is temporarily supplied to the engine control unit 8b and the temperature / humidity sensor 44, and the engine control unit 8b supplies the second heater H2. A timer unit 96 may be provided for detecting whether or not a predetermined period T1 has elapsed since it is determined whether energization is necessary (see FIGS. 3 and 6; the timer unit 96 includes a power saving mode, Even if the main power supply is cut off, power is supplied and driven). Note that the power control unit 90 may be operated even in the power saving mode or the main power supply cut-off state, and the power control unit 90 may be used as the timer unit 96 in which a predetermined cycle T1 elapses.

  Then, the timer unit 96 notifies the power control unit 90 and the power supply switching unit 93 of a signal indicating that the predetermined period T1 has elapsed, and temporarily supplies power to the engine control unit 8b and the temperature / humidity sensor 44. Supply.

(Flow of paper dehumidification control in power saving mode and main power shut-off state)
Next, an example of the flow of dehumidification control of the paper in the power saving mode and the main power supply cutoff state will be described with reference to FIG. FIG. 9 is a flowchart showing an example of the flow of dehumidification control of the paper in the power saving mode and the main power supply cut-off state.

  First, the start of FIG. 9 is when the power saving mode transition condition is satisfied, or when the main switch 102 is pressed to shut off the main power supply of the multifunction peripheral 100 (to turn off the main power supply).

  When shifting to the power saving mode or the main power shut-off state, the engine control unit 8b recognizes the humidity based on the output of the temperature / humidity sensor 44 (step # 1). Then, the engine control unit 8b determines whether it is necessary to dehumidify the sheet by the second heater H2 based on whether or not the recognized humidity exceeds a threshold value (step # 2).

  If the paper needs to be dehumidified (Yes in step # 2), the engine control unit 8b turns on the second switch unit S2 and maintains the state in which power is supplied to the second heater H2 (step # 3). ). On the other hand, if it is not necessary to dehumidify the sheet (No in step 2 #), the engine control unit 8b turns off the second switch unit S2 and maintains the state in which the power supply to the second heater H2 is stopped (step #). 4).

  Then, the multi-function device 100 shifts to or maintains the power saving mode or the main power shut-off state (when looping) (step # 5). At the time of shifting to the power saving mode, the power supply unit 9 stops the power supply to the predetermined supply stop part, and the part other than the predetermined supply stop part (the main control unit 8a, the operation detection unit, the second Continue to supply power to heater H2 etc. On the other hand, when the main power supply is cut off, the power supply unit 9 may supply power to the second heater H2, but the power supply to the supply stop portion, the main control unit 8a, and the operation detection unit is also stopped.

  Then, when the return condition is satisfied or the main switch 102 is operated to turn on the main power, and when it should be started in the normal mode (when the mode should be shifted to the normal mode, Yes in step # 6), this The flow ends (end). Then, the power supply unit 9 controls the power supply switching unit 93 to supply power to all parts of the multifunction device 100, start activation and warm-up processing, and activate the multifunction device 100 in the normal mode.

  On the other hand, when it is not necessary to start in the normal mode (No in step # 6), the timer unit 96 shifts to the power saving mode or the main power shut-off state, or the previous engine control unit 8b and the temperature and humidity It is confirmed whether or not a predetermined cycle T1 has elapsed since the time point at which the temporary power supply to the sensor 44 and the necessity of dehumidification by the second heater H2 were confirmed (step # 7).

  If the period T1 has not elapsed (No in step # 7), the flow returns to step # 5. On the other hand, if the cycle T1 has elapsed (Yes in step # 7), the power supply unit 9 temporarily resumes power supply to the engine control unit 8b and the temperature / humidity sensor 44 (step # 8).

  Then, the engine control unit 8b recognizes the humidity based on the output of the temperature / humidity sensor 44 (step # 9). Then, the engine control unit 8b determines whether it is necessary to dehumidify the sheet by the second heater H2 based on whether or not the recognized humidity exceeds a threshold value in advance (step # 10).

  If the paper needs to be dehumidified (Yes in step # 10), the engine control unit 8b turns on the second switch unit S2 and maintains the state in which power is supplied to the second heater H2 (step # 11). ). On the other hand, if it is not necessary to dehumidify the sheet (No in step # 10), the engine control unit 8b turns off the second switch unit S2 and maintains the state where the power supply to the second heater H2 is stopped (step #). 12).

  After step # 11 and step # 12, power supply unit 9 stops supplying power to engine control unit 8b and temperature / humidity sensor 44 (step # 13). The timer unit 96 starts counting time (step # 14). Then, the flow returns to step # 5.

  In this manner, the image forming apparatus (multifunction peripheral 100) according to the present embodiment includes the main switch 102, the sheet feeding unit 4, the recognition unit (engine control unit 8b), the first switch unit S1, and the second switch unit. The switch part S2 and the power supply part 9 are included. The main switch 102 is for operating the main power on and off. The paper feed unit 4 stores and supplies paper, and a humidity detection unit (temperature / humidity sensor 44) for detecting humidity in a space for storing paper, a first heater H1 for dehumidifying the paper, In addition to the first heater H1, a second heater H2 for dehumidifying the paper is included. The recognition unit recognizes the humidity in the paper feeding unit 4 based on the output of the humidity detection unit. The first switch unit S1 controls energization to the first heater H1. The second switch unit S2 controls energization to the second heater H2. The power supply unit 9 supplies power to the first heater H1 and the second heater H2, and the power supply unit 9 is in the state where the main power of the image forming apparatus (multifunction device 100) is turned on. A normal mode in which power is supplied to a predetermined supply stop portion of the power supply, and a power saving mode in which power is not supplied to the supply stop portion when a predetermined power saving mode transition condition is satisfied, When the return condition to the normal mode is satisfied in the power saving mode, the normal mode is restored and the power supply to the supply stop portion is resumed. In the normal mode, the first switch unit S1 supplies power to the first heater H1 such that the higher the humidity recognized by the recognition unit is, the larger the output of the first heater H1 is, and the second switch unit S2 The supply of power to the second heater H2 is stopped. In the power saving mode, the first switch unit S1 stops supplying power to the first heater H1, and the power source unit 9 is necessary for the recognition unit to recognize the humidity at a predetermined cycle T1. After supplying power to the humidity detection unit and the recognition unit, the power supply to the humidity detection unit and the recognition unit is stopped, and the second switch unit S2 allows the humidity recognized by the recognition unit to exceed a predetermined threshold. If the power is supplied to the second heater H2, the power supply to the second heater H2 is stopped.

  As a result, when the power consumed by the image forming apparatus (multifunction device 100) is being reduced (in the power saving mode), the power to the second heater H2 is periodically changed according to the humidity state. Can be switched between supply and shutdown. Therefore, as in the prior art, the heater for dehumidifying the paper is not left on (the power is kept on) during the power saving mode, and wasteful power consumption can be eliminated. Further, during the power saving mode, the power supply to the heater is not maintained in a stopped state, and the quality of the paper in the paper supply unit 4 can be maintained.

  Further, when the power consumed by the image forming apparatus (multifunction device 100) is being reduced (in the power saving mode), the portion for detecting the humidity is temporarily activated to the second heater H2. When the humidity detection is performed to determine the necessity of power supply for the second heater and the necessity for energization of the second heater H2 is determined, the humidity detection unit (temperature / humidity sensor 44) and the recognition unit (engine control unit 8b) ) Is stopped. Therefore, in a state where power consumption is reduced, power supply to the humidity detection unit and the recognition unit is minimized, and power is not consumed wastefully.

  When the main power supply of the image forming apparatus (multifunction peripheral 100) is shut off by an operation on the main switch 102, the first switch unit S1 stops supplying power to the first heater H1, and the power supply unit 9 Humidity detection is performed after power is supplied to the humidity detection unit (temperature / humidity sensor 44) and the recognition unit while the recognition unit (engine control unit 8b) needs to recognize humidity at a predetermined cycle T1. The second switch unit S2 is in a state of supplying power to the second heater H2 if the humidity recognized by the recognition unit exceeds a predetermined threshold, and the recognition unit recognizes the second switch unit S2. If the humidity is less than the threshold, the power supply to the second heater H2 is stopped.

  As a result, when the power consumed by the image forming apparatus (multifunction device 100) is being reduced (main power OFF state), the power to the second heater H2 is periodically changed according to the humidity state. Supply and stop are switched. Therefore, as in the prior art, while the main power is turned off, the heater for dehumidifying the paper is not left on (energized), and wasteful power consumption can be eliminated. Further, while the main power is turned off, the power supply to the heater is not maintained in a stopped state, and the quality of the paper in the paper feeding unit 4 can be maintained.

  The power source unit 9 is connected to a commercial power source, generates a voltage of a certain magnitude based on the commercial power source, and supplies power to the first heater H1, and a half of the power input from the commercial power source. A half-wave rectification unit 94 that performs wave rectification and supplies power to the second heater H2, and the first switch unit S1 has a higher humidity recognized by the recognition unit (engine control unit 8b) within a unit time. The power supply time to the first heater H1 is lengthened. As a result, when the main power of the image forming apparatus (multifunction device 100) is turned on and in the normal mode, fine output control of the first heater H1 is performed according to the detected humidity, and the inside of the paper feeding unit 4 is controlled. Humidity can be kept in an appropriate state. On the other hand, since the half-wave rectification unit 94 supplies power to the second heater H2, when the power consumption in the image forming apparatus is reduced, the first heater H1 within a unit time with respect to the second heater H2. Do not perform detailed output control to adjust the power supply to the. In the state where the power consumption in the image forming apparatus is reduced, the second switch unit S2 only switches between supplying and stopping power at a predetermined cycle T1. Therefore, when the power consumption in the image forming apparatus is reduced, it is not necessary to keep the recognition unit that controls the second switch unit S2 in operation, and a high power saving effect can be obtained.

  Further, the second heater H2 is provided so as to surround the first heater H1 when viewed from above and below, and the first heater H1 is provided closer to the center of the paper than the second heater H2. Accordingly, the first heater H1 that performs dehumidification in the normal mode is provided at the center position, and the paper can be dehumidified efficiently. Further, since the second heater H2 is provided outside the first heater H1, the sheet is not easily heated. Therefore, even if the power saving mode and the main power supply stop state are prolonged and the energization of the second heater H2 is prolonged, the sheet does not become high temperature, so that the sheet quality is maintained.

The second switch unit S2 supplies power to the second heater H2 so that the maximum output of the second heater H2 is smaller than the maximum output of the first heater H1. Thus, Ru output of the second heater H2 is suppressed.

  Next, another embodiment will be described. In the above-described embodiment, the example in which the engine control unit 8b recognizes the humidity and controls the energization to the first heater H1 and the second heater H2 has been described. However, the humidity recognition and the connection to each heater are performed in parts other than the engine control unit 8b. You may make it perform electricity supply control. In this case, when the power saving mode and the main power supply are shut off, power is periodically and temporarily supplied to the portion that performs humidity recognition and energization control to each heater.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  The present invention can be used in an image forming apparatus including a heater in a paper feeding unit.

100 MFP (image forming apparatus) 102 Main switch 4 Paper feed unit 44 Temperature / humidity sensor (humidity detection unit)
8b Engine control part (recognition part) 9 Power supply part 91 Switching power supply part 94 Half wave rectification part H1 1st heater H2 2nd heater S1 1st switch part S2 2nd switch part T1 Period

Claims (4)

A main switch for operating the main power on and off;
In order to dehumidify the paper separately from the first heater for storing and supplying the paper and detecting the humidity in the space for storing the paper, the first heater for dehumidifying the paper, and the first heater A sheet feeding unit including a second heater,
A recognition unit for recognizing humidity in the sheet feeding unit based on an output of the humidity detection unit;
A first switch for controlling energization to the first heater;
A second switch unit for controlling energization to the second heater;
A normal mode in which power is supplied to the first heater and the second heater, and power is supplied to a predetermined supply stop portion in the image forming apparatus in a state where main power of the image forming apparatus is turned on. And a power saving mode that does not supply power to the supply stop portion when a predetermined power saving mode transition condition is satisfied, and when the return condition to the normal mode is satisfied in the power saving mode, A power supply unit that returns to normal mode and resumes power supply to the supply stop portion, and
In the normal mode, the first switch unit supplies power to the first heater so that the higher the humidity recognized by the recognition unit is, the larger the output of the first heater is, and the second switch unit Stop supplying power to the second heater;
When in the power saving mode, the first switch unit stops supplying power to the first heater, and the power source unit is required for the recognition unit to recognize humidity at a predetermined cycle while the power supply unit is required to recognize humidity. After supplying power to the humidity detection unit and the recognition unit, the power supply to the humidity detection unit and the recognition unit is stopped, and the second switch unit has a predetermined threshold for the humidity recognized by the recognition unit. the a state to supply power to the second heater if exceeded, Ri Do a state of stopping the power supply to the second heater if less than or equal to the threshold value,
The power supply unit is connected to a commercial power supply, generates a voltage of a certain magnitude based on the commercial power supply, and supplies a power to the first heater, and a half-wave rectification of the power input from the commercial power supply And a half-wave rectifier for supplying power to the second heater,
The image forming apparatus according to claim 1, wherein the first switch unit increases the power supply time to the first heater within a unit time as the humidity recognized by the recognition unit increases.
A main switch for operating the main power on and off;
In order to dehumidify the paper separately from the first heater for storing and supplying the paper and detecting the humidity in the space for storing the paper, the first heater for dehumidifying the paper, and the first heater A sheet feeding unit including a second heater,
A recognition unit for recognizing humidity in the sheet feeding unit based on an output of the humidity detection unit;
A first switch for controlling energization to the first heater;
A second switch unit for controlling energization to the second heater;
A normal mode in which power is supplied to the first heater and the second heater, and power is supplied to a predetermined supply stop portion in the image forming apparatus in a state where main power of the image forming apparatus is turned on. And a power saving mode that does not supply power to the supply stop portion when a predetermined power saving mode transition condition is satisfied, and when the return condition to the normal mode is satisfied in the power saving mode, A power supply unit that returns to normal mode and resumes power supply to the supply stop portion, and
In the normal mode, the first switch unit supplies power to the first heater so that the higher the humidity recognized by the recognition unit is, the larger the output of the first heater is, and the second switch unit Stop supplying power to the second heater;
When in the power saving mode, the first switch unit stops supplying power to the first heater, and the power source unit is required for the recognition unit to recognize humidity at a predetermined cycle while the power supply unit is required to recognize humidity. After supplying power to the humidity detection unit and the recognition unit, the power supply to the humidity detection unit and the recognition unit is stopped, and the second switch unit has a predetermined threshold for the humidity recognized by the recognition unit. If it exceeds, it will be in a state of supplying power to the second heater, and if it is less than the threshold, it will be in a state of stopping power supply to the second heater,
The second heater is provided so as to surround the first heater when viewed from above and below,
Wherein the first heater is an image forming apparatus you and which are located at a position closer to the center of the sheet than the second heater. A main switch for operating the main power on and off;
In order to dehumidify the paper separately from the first heater for storing and supplying the paper and detecting the humidity in the space for storing the paper, the first heater for dehumidifying the paper, and the first heater A sheet feeding unit including a second heater,
A recognition unit for recognizing humidity in the sheet feeding unit based on an output of the humidity detection unit;
A first switch for controlling energization to the first heater;
A second switch unit for controlling energization to the second heater;
A normal mode in which power is supplied to the first heater and the second heater, and power is supplied to a predetermined supply stop portion in the image forming apparatus in a state where main power of the image forming apparatus is turned on. And a power saving mode that does not supply power to the supply stop portion when a predetermined power saving mode transition condition is satisfied, and when the return condition to the normal mode is satisfied in the power saving mode, A power supply unit that returns to normal mode and resumes power supply to the supply stop portion, and
In the normal mode, the first switch unit supplies power to the first heater so that the higher the humidity recognized by the recognition unit is, the larger the output of the first heater is, and the second switch unit Stop supplying power to the second heater;
When in the power saving mode, the first switch unit stops supplying power to the first heater, and the power source unit is required for the recognition unit to recognize humidity at a predetermined cycle while the power supply unit is required to recognize humidity. After supplying power to the humidity detection unit and the recognition unit, the power supply to the humidity detection unit and the recognition unit is stopped, and the second switch unit has a predetermined threshold for the humidity recognized by the recognition unit. If it exceeds, it will be in a state of supplying power to the second heater, and if it is less than the threshold, it will be in a state of stopping power supply to the second heater,
Said second switch unit images forming apparatus you and supplying power to the second heater so that the maximum output of the second heater is smaller than the maximum output of the first heater. When the main power of the image forming apparatus is shut off by an operation on the main switch,
The first switch unit stops power supply to the first heater;
The power supply unit supplies power to the humidity detecting unit and the recognizing unit while being necessary for the recognizing unit to recognize humidity at a predetermined cycle, and then the humidity detecting unit and the recognizing unit. Power supply to
The second switch unit is in a state of supplying power to the second heater if the humidity recognized by the recognition unit exceeds a predetermined threshold value, and if the humidity recognized by the recognition unit is equal to or less than the threshold value. the image forming apparatus according to any one of claims 1 to 3, characterized in that in a state of stopping the power supply to the second heater.

Images