JP2005174589A - Heating device, fixing device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reconcile the quick start-up of an exothermic temperature of a heating member when the electric current supply of a device returns and the maintenance of effects of sufficient electric power saving and energy saving even when an image forming device is provided with a function such as an energy saving mode function. <P>SOLUTION: The main control part 202 controls a capacitor charger 203, and charges a capacitor CP1 when needed. A sub-control part manages the energy saving mode of a digital copier, and energizing is stopped to the main control part 202 in shifting to the energy saving mode. However, a charge control circuit 10 compares a voltage S1 between terminals of the capacitor CP1 and a prescribed reference value S2 by a comparison circuit 3, and when the voltage S1 between the terminals is below the reference value S2, outputs a control signal S11 to direct the capacitor charger 203 to carry out the charging of the capacitor CP1 by taking the AND of an output signal of the comparison circuit 3 by an AND circuit 4 and an energy saving signal S3 which shows shifting into the energy saving mode. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat generating device including a heat generating member that generates heat with charging power of a capacitor, a fixing device, and an image forming apparatus including the fixing device.

  In Patent Documents 1 to 3, a heat generating member (fixing heater) of a fixing device used in an electrophotographic image forming apparatus can be charged using an electric double layer capacitor in addition to power supply from a commercial power source. There has been disclosed a technique for enhancing the power saving effect by using an auxiliary power source to enable rapid start-up.

  In addition, in an electrophotographic image forming apparatus and other electronic devices, energization to the power load in the apparatus is limited to a minimum circuit only when it is not used for a certain period of time when it is in a standby state. And what is equipped with the function of what is called an energy saving mode which aims at power saving and energy saving is known (refer patent document 4).

JP 2000-315567 A JP 2002-357966 A JP 2003-140484 A JP 2002-304088 A

  In an electrophotographic image forming apparatus, as described above, when the temperature of the fixing device is to be rapidly raised by a rechargeable auxiliary power source using a capacitor such as an electric double layer capacitor, the power of the capacitor is Since it is impossible to quickly raise the fixing temperature in a lowered state, a predetermined control device controls the charger to charge the capacitor when the charging power of the capacitor drops to a predetermined level or more. There is a need.

  However, when such an image forming apparatus has the above-described energy saving mode, power is also supplied to a control device (such as a microcomputer) that controls charging by the battery charger when the energy saving mode is entered. If stopped, the battery is not charged during the transition to the energy saving mode. In this case, when the charge amount of the battery has decreased considerably immediately before the transition to the energy saving mode, or when the battery has spontaneously discharged for a long period of the energy saving mode, the energy saving mode There is a problem that when the battery is restored from the state, the amount of charge of the capacitor is insufficient, and the fixing temperature of the fixing device cannot be raised rapidly.

  In this case, it is possible to quickly start up the fixing temperature of the fixing device by maintaining the power supply to the above-mentioned control device even when the mode is changed to the energy saving mode. Even after the transition, the above-described control device also consumes electric power, so that there is a problem that it is not possible to sufficiently save power and energy.

  The present invention relates to a fixing device or other heat generating device of an image forming device, and the device has functions such as an energy saving mode for limiting power supply of the device and saving power and energy when a predetermined condition is satisfied. Even when the power supply of the device is restored, the rapid rise of the heat generation temperature of the heat generating member when the power supply of the apparatus is restored is compatible with the maintenance of sufficient power saving and energy saving effects.

  The present invention includes a capacitor, a charger that charges the capacitor, a heat generating member that generates heat when supplied with charging power of the capacitor, a terminal voltage detection circuit that detects a voltage between terminals of the capacitor, and the detection voltage A control device for controlling the charger and charging the battery based on the power supply, and when a predetermined condition is satisfied, the supply of power to a part of the power load of the device including the control device is stopped, and this Power control means for performing control to release the stop when a predetermined condition is satisfied while in the stopped state, and controlling the charger based on the detected voltage when in the stopped state And a charging control means for charging.

  From another aspect, the present invention relates to a fixing member that fixes and fixes the toner image by pressurizing and heating a medium on which a toner image is formed, a capacitor, and the capacitor that receives power from a commercial power source. A charger that charges, a heat generating member that generates heat upon receiving supply of charging power of the capacitor, heats the fixing member, a terminal voltage detection circuit that detects a voltage between terminals of the capacitor, and the detection voltage based on the detection voltage A control device that controls the charger and charges the battery, and when a predetermined condition is satisfied, the supply of power to a part of the power load of the device including the control device is stopped and is in this stopped state. Power control means for controlling to release the stop when a predetermined condition is satisfied, and charge control for charging the battery by controlling the charger based on the detected voltage when in the stopped state Means, A fixing device comprising.

  According to the present invention, when a predetermined condition is satisfied, the supply of power to a part of the power load of the device including the control device that controls the charging of the battery is stopped, When the control of the power saving mode for canceling the stop is performed when the above condition is satisfied, the charging of the battery can be controlled even when power is not supplied to the control device by executing this control. it can. Therefore, even immediately after the return from the power saving mode or the like is achieved, the heat generation of the heat generating member can be rapidly started using sufficient charging power of the battery.

  The best mode for carrying out the present invention will be described.

  FIG. 1 is a longitudinal sectional view of a digital copying machine 1 according to the present embodiment. The digital copying machine 1 implements the image forming apparatus of the present invention, and is a so-called multifunction machine. That is, the digital copying machine 1 has a copying function and other functions, such as a printer function and a facsimile function, and the copying function, the printer function, and the facsimile are operated by operating an application switching key of an operation unit (not shown). It is possible to select the functions by switching them sequentially. Thus, the copy mode is selected when the copy function is selected, the print mode is selected when the printer function is selected, and the facsimile mode is selected when the facsimile mode is selected.

  Next, the schematic configuration of the digital copying machine 1 and the operation in the copy mode will be described. In FIG. 1, in an automatic document feeder (hereinafter referred to as ADF) 101, a document placed on a document table 102 with an image surface facing upward is pressed when a start key on an operation unit (not shown) is pressed. Then, the sheet is fed to a predetermined position on the document table 102 made of contact glass by the feeding belt 104. The ADF 101 has a count function that counts up the number of documents every time a document is fed. After the image information is read by the image reading device 106, the document on the contact glass 105 is discharged onto the paper discharge tray 108 by the feeding belt 104 and the discharge roller 107.

  When the document set detector 109 detects that the next document is present on the document table 102, the lowermost document on the document table 102 is similarly contacted by the feed roller 103 and the feed belt 104. It is fed to a predetermined position on the glass 105. After the image information is read by the image reading device 106, the original on the contact glass 105 is discharged onto the paper discharge tray 108 by the feeding belt 104 and the discharge roller 107. Here, the feeding roller 3, the feeding belt 4, and the discharging roller 7 are driven by a conveyance motor.

  When selected, the first paper feeding device 110, the second paper feeding device 111, and the third paper feeding device 112 feed the stacked transfer paper, and the transfer paper is photosensitized by the vertical conveyance unit 116. It is transported to a position where it contacts the body 117. For example, a photosensitive drum is used as the photosensitive member 117, and is rotated by a main motor (not shown).

  Image data read from the document by the image reading device 106 is subjected to predetermined image processing by an image processing device (not shown) and then converted into optical information by a writing unit 118, and a charging device (not shown) is provided on the photosensitive drum 117. Are uniformly charged and then exposed to light information from the writing unit 118 to form an electrostatic latent image. The electrostatic latent image on the photosensitive drum 117 is developed by the developing device 119 to become a toner image. A printer engine that forms an image on a medium such as paper by an electrophotographic system is configured by the writing unit 118, the photosensitive drum 117, the developing device 119, and other well-known devices around the photosensitive drum 117 (not shown). .

  The conveyance belt 120 serves as a sheet conveyance unit and a transfer unit, and a transfer bias is applied from a power source. The conveyance belt 120 is conveyed on the photosensitive drum 117 while conveying the transfer sheet from the vertical conveyance unit 116 at a constant speed with the photosensitive drum 117. The toner image is transferred onto the transfer paper. The transfer paper is fixed with a toner image by a fixing device 121 and is discharged to a paper discharge tray 123 by a paper discharge unit 122. The photosensitive drum 117 is cleaned of residual toner by a cleaning device (not shown) after the toner image is transferred.

  The above operation is an operation for copying an image on one side of a sheet in a normal mode. When an image is copied on both sides of a transfer sheet in a duplex mode, one of the paper feed trays 113 to 115 is copied. The transfer paper that is further fed and has an image formed on the surface as described above is switched to the double-sided paper feed path 124 side by the paper discharge unit 122 instead of the paper discharge tray 123 side, and switched back by the reversing unit 125 Then, the front and back sides are reversed and conveyed to the duplex conveying unit 126.

  The transfer paper transported to the double-sided transport unit 126 is transported to the vertical transport unit 116 by the double-sided transport unit 126, transported to the position where it abuts on the photoconductive drum 117 by the vertical transport unit 116, and is transferred onto the photoconductive drum 117. The toner image formed in the same manner as above is transferred to the back surface, and the toner image is fixed by the fixing device 121, whereby double-sided copying is performed. This double-sided copy is discharged to the paper discharge tray 123 by the paper discharge unit 122.

  Further, when the transfer paper is reversed and discharged, the transfer paper that is switched back by the reversing unit 125 and turned upside down is not conveyed to the duplex conveying unit 126 but is discharged via the reverse discharge conveyance path 127. The paper is discharged to the paper discharge tray 123 by the unit 122.

  In the print mode, image data from the outside is input to the writing unit 118 instead of the image data from the above-described image processing apparatus, and an image is formed on the transfer paper as described above.

  Further, in the facsimile mode, the image data from the image reading device 106 is transmitted to the other party by a facsimile transmission / reception unit (not shown), and the image data from the other party is received by the facsimile transmission / reception unit, instead of the image data from the image processing device described above. As a result, the image is formed on the transfer paper as described above.

  Further, the digital copying machine 1 includes a large-sized sheet supply device (hereinafter referred to as LCT), a finisher that performs sorting, punching, stapling, etc., a mode for reading a document, setting of a copy magnification, and paper feeding And an operation unit for setting the stage, setting the post-processing by the finisher 12, and displaying to the operator.

  Next, the configuration of the fixing device 121 will be described with reference to FIG. As shown in FIG. 2, the fixing device 121 implements the heat generating device and the fixing device of the present invention. A pressure roller 302 made of an elastic member such as silicon rubber is attached to a fixing roller 301 that is a heated object. It is pressed with a constant pressure by a pressing means (not shown). In many cases, the fixing member and the pressure member are generally in the form of a roller, but for example, one or both of them may be configured in an endless belt shape. In the fixing device 121, heaters HT1 and HT2 are provided at arbitrary positions. For example, the heaters HT1 and HT2 are disposed inside the fixing roller 301, and heat the fixing roller 301 that is an object to be heated from the inside.

  The fixing roller 301 and the pressure roller 302 are rotationally driven by a driving mechanism (not shown). A temperature sensor (such as a thermistor) TH11 is in contact with the surface of the fixing roller 301 and detects the surface temperature (fixing temperature) of the fixing roller 301. The sheet 307, which is a medium such as transfer paper carrying the toner 306, is heated and pressed by the fixing roller 301 and the pressure roller 302 when passing through the nip portion between the fixing roller 301 and the pressure roller 302. 306 is fixed.

  The fixing heater HT <b> 2 is a main heater (main heater) that is turned on when the predetermined target temperature Tt that serves as a reference for the fixing roller 301 has not been reached and heats the fixing roller 301. The fixing heater HT1, which is a heat generating member, is turned on when the main power supply of the copying machine 1 is turned on, when it is started up after returning from the energy saving mode described later, and when the fixing device 121 is warmed up. And an auxiliary heater (auxiliary heater) for heating the fixing roller 301.

  FIG. 3 is a diagram showing a configuration of a power supply control system of the copying machine 1 mainly including the fixing device 121. The power supply control system shown in FIG. 3 includes a main power supply SW201 for turning on / off the supply of AC power supply (commercial AC power supply) PS and a microcomputer, and a control unit serving as a control device that controls each part of the power supply circuit 200 and others. 202, a capacitor CP1 serving as an accumulator serving as an auxiliary power source for the fixing heater HT1, a capacitor charger 203 serving as a charger for charging the capacitor CP1, and a DC power generation circuit for generating a DC power source for the copying machine 1 204, an AC heater driving circuit 205 that supplies AC power to the AC fixing heater HT2, an input current detection circuit 206 that detects an input current input from an AC power source, an interlock switch 207, and a capacitor CP1. And a capacitor charging / discharging circuit 208 for supplying DC power to the fixing heater HT1.

  The AC power supply PS supplies AC power to the AC heater driving circuit 205, the DC power supply generation circuit 204, and the capacitor charger 203 via the main power supply SW201 and the input current detection circuit 206.

  The control unit 202 mainly controls each unit of the power supply circuit 200 and controls operations of the capacitor charger 203, the AC heater driving circuit 205, and the capacitor charging / discharging circuit 208. Specifically, the control unit 202 sends a control signal S11 to the capacitor charger 203 to control the charging operation of the capacitor CP1 by the capacitor charger 203. The control unit 202 also sends control signals S13 and S14 to the capacitor charge / discharge circuit 208 to control the ON / OFF operation of the fixing heater HT1 by the capacitor charge / discharge circuit 208. The control unit 202 also sends control signals S18 and S19 to the AC heater drive circuit 205 to control the ON / OFF operation of the fixing heater HT2 by the AC heater drive circuit 205. Further, the control unit 202 estimates the number of documents set on the ADF 101 based on the detection signal input from the slit sensor 111, the estimated number of documents, the number of copies set by the operation unit 150, and each operation mode ( Based on the time required for printing per sheet in the high-speed mode and the low-speed mode), the time required for the copy job for each operation mode is predicted.

  The input current detection circuit 206 is provided between the main power supply SW201, the AC heater drive circuit 205, the DC power supply generation circuit 204, and the capacitor charger 203, and the input current of the AC power supply input via the main power supply SW201. And the detection current S17 is output to the control unit 202. This input current varies according to the operating states of the AC heater drive circuit 205, the DC power supply generation circuit 204, the capacitor charger 203, and the image forming apparatus.

  The DC power generation circuit 204 is used for the power supply Vcc used mainly in the control system inside the image forming apparatus, mainly for the drive system, and the medium-high voltage power supply based on the AC power input via the main power SW201. Power supply Vaa is generated and output to each unit.

  The interlock switch 207 is a switch that is turned ON / OFF in conjunction with a cover of the copying machine 1 (not shown). A drive member that can be touched when the covers of the copying machine 1 are opened. In the case of having a member, the power supply is shut off so that the operation of the driving member is stopped or the voltage application to the applying member is stopped when the cover is opened. A part of the power supply Vaa generated by the DC power generation circuit 204 is input to the interlock switch 207, and is input to the capacitor charging / discharging circuit 208 and the AC heater driving circuit 205 via the interlock switch 207.

  The AC heater driving circuit 205 turns on / off the AC fixing heater HT2 in response to control signals S18 and S19 input from the control unit 202.

  Capacitor charger 203 is connected to capacitor CP1 and charges capacitor CP1 based on control signal S11 input from control unit 202.

  Capacitor CP1 is composed of a large-capacity capacitor such as an electric double layer capacitor. The capacitor CP1 is connected to the capacitor charger 203 and the capacitor discharge circuit 208, and is charged by the capacitor charger 203. The charged electric power is fixed to the fixing heater HT1 by ON / OFF control of the capacitor charge / discharge circuit 208. To be supplied.

  Capacitor charge / discharge circuit 208 discharges the electric power stored in capacitor CP1 in accordance with control signals S13 and S14 input from control unit 202, and turns fixing heater HT1 on and off.

  The thermistor TH11 is provided in the vicinity of the fixing roller 151, and outputs a detection signal S16 corresponding to the surface temperature of the fixing roller 151 to the control unit 202. Since the resistance value of the thermistor TH11 changes depending on the temperature, the control unit 202 detects the surface temperature of the fixing roller 151 from the detection signal S16 using the temperature change of the resistance value.

  FIG. 4 is a diagram showing a configuration of the AC heater driving circuit 205 of FIG. The AC heater driving circuit 205 includes a filter FIL21 that removes noise from the input AC power supply, a safety protection fixing relay RL21 that is turned ON / OFF according to a control signal S19 input from the control unit 202, and a safety The protection fixing relay RL21 includes a back-up prevention diode D21 and a heater ON / OFF circuit 220 that turns on / off the AC fixing heater HT2 based on a control signal S18 input from the control unit 202. ing.

  The AC power source PS is connected to one end side of the fixing heater HT2 via the filter FIL21 and a safety-protecting fixing relay RL21. The other end of the fixing heater HT2 is connected to the heater ON / OFF circuit 220.

  The heater ON / OFF circuit 220 turns on the triac TRI21 for turning on / off the AC power supply and the gate of the triac TRI21, and the photocoupler PC21 for insulating the signal from the control unit 202 on the secondary side. A transistor TR21 for driving the light emitting side LED of the photocoupler PC21, a noise absorbing snubber circuit including a capacitor C21 and a resistor R21, a noise absorbing inductor L21, a resistor R22 which is a continuity prevention resistor, It comprises resistors R23 and R24 which are current limiting resistors of the photocoupler PC21.

  In the AC heater driving circuit 205 configured as described above, the AC fixing heater HT2 is turned on when power is supplied in a state where both the safety-protecting fixing relay RL21 and the gate of the transistor TR21 are turned on.

  The control unit 202 turns on / off the control signal S18 supplied to the gate of the transistor TR21 of the heater ON / OFF circuit 220 in the state where the control signal S19 supplied to the fixing relay RL21 for safety protection is turned on, thereby AC fixing. The heater HT2 is turned on / off.

  FIG. 5 is a diagram showing a configuration of the capacitor charger 203 of FIG. The capacitor charger 203 includes an NF (noise filter) 211 that removes noise from the input AC voltage, an inrush prevention circuit 212 for preventing an inrush current, and an AC power supply PS that is input through the inrush prevention circuit 212. A diode bridge DB that rectifies the voltage, a capacitor C100 that smoothes the rectified AC voltage, a FET controller 213 that controls the switching of the FET 214 to control the charging operation of the capacitor CP1 (see FIG. 3), and a transformer T100. FET 214 to be turned ON / OFF, transformer T100 that boosts the input voltage, rectifying / smoothing circuit 215 that rectifies and smoothes the output on the secondary side of the transformer T100 and converts it into a DC output, and a current detector 216 that detects a current value. An overvoltage was not applied to the voltage detector 217 for detecting the voltage value and the capacitor CP1. It includes an overvoltage detecting unit 218 for detecting an overvoltage, and a diode D100 to prevent back flow from the capacitor CP1, and an insulating element 219.

  The AC voltage input from the AC power supply PS is noise-removed by the noise filter 211, rectified by the diode bridge DB via the inrush current prevention circuit 212, and smoothed by the capacitor 100, and the DC voltage obtained by the transformer 100 is Input to the primary side of T100. The FET control unit 213 starts switching control of the FET 214 in order to charge the capacitor CP1 when the control signal S11 input from the control unit 202 (see FIG. 3) is turned on. The FET control unit 213 performs switching control of the FET 214 based on each detection signal input from the current detection unit 216, the voltage detection unit 217, and the overvoltage detection unit 218, and performs constant current control for charging the capacitor CP1. Perform constant voltage control or constant power control. In general, it is desirable to charge the capacitor CP1 with a constant current, but it is possible to shorten the charging time by charging with constant power control.

  The transformer T100 is turned ON / OFF by the FET 214, boosts its primary side input, and outputs it from the secondary side. The secondary output of the transformer T100 is rectified and smoothed by the rectifying / smoothing circuit 215, and output to the capacitor CP1 via the diode D100. The secondary output of the transformer T100 after rectification / smoothing is detected by the current detection unit 216, the voltage detection unit 217, and the overvoltage detection unit 218, respectively. Input to the unit 213.

  FIG. 6 is a diagram showing a configuration of the capacitor charge / discharge circuit 208 of FIG. As shown in FIG. 6, the capacitor charge / discharge circuit 208 detects a charge / discharge switch 231, a safety fixing relay RL <b> 11, a reverse relay prevention diode D <b> 11 of the fixing relay RL <b> 11, and a voltage across the capacitor CP <b> 1. And a both-end voltage detection circuit 232.

  A charge / discharge switch 231 and a safety protection fixing relay RL11 are connected to both ends of the capacitor CP1. The charging / discharging switch 231 is turned on / off by a control signal S13 input from the control unit 202. Similarly, the fixing relay RL11 for safety protection is turned on / off by a control signal S14 input from the control unit 202.

  When both the charging / discharging switch 231 and the safety protection fixing relay RL11 are turned on, the electric charge accumulated in the capacitor CP1 is discharged to the fixing heater HT1, and electric power is supplied.

  The both-end voltage detection circuit 232 detects the both-end voltage of the capacitor CP1 and outputs the voltage signal S15 to the control unit 202. The control unit 202 constantly monitors the voltage signal S15 to monitor the charge state of the capacitor CP1.

  FIG. 7 is a diagram showing a schematic configuration of the control unit 202 of FIG. As shown in FIG. 7, the control unit 202 includes a CPU 241, a memory 242, and the like.

  The CPU 241 is connected to a memory 242 for storing a program and data for controlling the copying machine 1, and controls the printer engine and the power supply circuit 200 based on the program stored in the memory 242.

  The CPU 241 includes a voltage signal (analog signal) S15 representing the voltage across the capacitor CP1 detected by the voltage detection circuit 232 across the capacitor charge / discharge circuit 208, a thermistor TH11 for detecting the surface temperature of the fixing roller 151, and a resistor R41. The detection signal (analog signal) S16 divided by the resistance value, the detection current (analog signal) S17 in which the input current detection circuit 206 detects the input current of the apparatus are input.

  Further, the CPU 241 turns on / off the control signal S11 for turning on / off the charging of the capacitor CP1, the control signal S13 for turning on / off the charging / discharging switch 231, and the fixing relay RL11 for safety protection via the IO port. A control signal S14, a control signal S18 for turning on / off the heater ON / OFF circuit 220, a control signal S19 for turning on / off the fixing relay R21 for safety protection, and the like are output (see also FIG. 3).

  Further, the CPU 241 is configured to control the operation unit 150 and monitors the input of the KEY 163 provided on the operation unit 150. The DRV 243 is a driver that drives the LCD 11, and the DRV 244 is a driver that drives the LED 162, and is driven and controlled by the CPU 241.

  FIG. 8 is a block diagram for explaining the operation of the DC power supply generation circuit 204 and the like. When the main power SW 201 is turned on, AC power is supplied to the DC power generation circuit 204, and DC power is generated by DC control units (configured by converters) 251 and 252 of the DC power generation circuit 204. The DC power output from the DC control unit 252 is supplied to the aforementioned control unit (main control unit) 202, and the DC power output from the DC control unit 251 is supplied to the sub-control unit 253 (the operation unit 150, which will be described later). Is also supplied to the charging control circuit 10).

  The sub-control unit 253 is a control device that includes a microcomputer and manages the energy saving mode. That is, the digital copying machine 1 has a so-called energy saving mode function. In this digital copying machine 1, when a predetermined condition is satisfied, that is, when a certain time has passed in a standby state where the digital copying machine 1 is not used, only a part of the power load is energized. , A function of stopping power supply to most other power loads including the main control unit 202 to save power and energy is provided. In this case, when the predetermined condition is satisfied after the supply of power to most of the power loads is stopped, that is, when a certain condition is satisfied, such as when the user touches the operation key of the operation unit 150, The supply of power to each power load that has been stopped is restarted.

  In this example, the sub-control unit 253 saves energy when a certain condition for shifting to the power saving mode is satisfied, such as when a predetermined time has elapsed in the standby state where the digital copying machine 1 is not used. The signal S3 is output to stop the DC output of the DC control unit 252 (power control means). The DC control unit 251 that supplies DC power to the sub-control unit 253 always outputs DC power. As a result, the main control unit 202 is stopped, so that the output of the control signals S11, S13, S14, S18, and S19 described above is eliminated, and various sensors such as the thermistor TH11, the capacitor charger 203, the AC heater driving circuit 205, etc. Each load stops operating. Therefore, power saving and energy saving can be achieved. After the transition to the energy saving mode in this manner, when the sub control unit 253 detects that the predetermined key switch of the operation unit 150 is operated by the power key input detection unit 254, the sub control unit 253 detects the energy saving signal S3. Is released and the converter 252 starts supplying power to the main control unit 202 again (power control means), so that it is possible to supply power to each load necessary for the digital copying machine 1 to perform its original function. It becomes. Other conditions for returning from the energy saving mode include detection that a document is set on the document table 102, detection of FAX reception when the digital copying machine 1 is equipped with a FAX transmission / reception function, and detection of reception of a printer job. It may be.

  As described above, in the energy saving mode of the digital copying machine 1, the main control unit 202 that consumes a large amount of power is also stopped after shifting to the energy saving mode, and only the sub-control unit 253 that manages the energy saving mode is operating. It can be said that the power saving effect is great.

  However, when not in the energy saving mode, the main control unit 202 controls the capacitor charger 203 by the control signal S11 when necessary based on the detection voltage S15 detected by the both-end voltage detection circuit 232 as described above. Charging CP1. Specifically, when the detection voltage S15 falls below a predetermined reference value, it is determined that the amount of charge of the capacitor CP1 is insufficient, and the capacitor CP1 is charged.

  However, since the control signal (charge signal) S11 is not output when the main control unit 202 is stopped, the capacitor CP1 is not charged after shifting to the power saving mode. Then, when the charge amount of the capacitor CP1 is insufficient at the time of shifting to the power saving mode, or when the capacitor CP1 spontaneously discharges due to a long duration of the power saving mode, the capacitor CP1 is switched after the transition. When the amount of charge is insufficient, the fixing roller 301 cannot be rapidly heated even if the digital copying machine 1 performs image formation after returning from the power saving mode, and the start of image formation is delayed. There is a problem that the user waits for a long time until the start of image formation.

  Therefore, after the transition to the power saving mode, it is necessary to be able to charge the capacitor CP1 while stopping energization to the main control unit 202 that consumes a large amount of power. Below, the means for that is demonstrated.

  FIG. 9 is a circuit diagram of the charging control circuit 10 that enables the capacitor CP1 to be charged while stopping energization to the main control unit 202 that consumes a large amount of power after shifting to the power saving mode.

  The charging control circuit 10 is a circuit that realizes a charging control means, and operates with the sub-control unit 253 and the DC power output from the DC control unit 251 even after the transition to the energy saving mode, and the terminal voltage (charging voltage) of the capacitor CP1 is connected in series. The above-described voltage detection circuit 232 for dividing and detecting the voltage by resistors R1 and R2 connected to the voltage, and the voltage detection signal S15 by the voltage detection circuit 232 are divided by a predetermined power supply voltage by resistors R3 and R4. A comparison circuit 3 for comparing with a predetermined reference voltage S2 is provided. Thereby, it can be determined whether the charging voltage of the capacitor CP1 is low enough to require charging.

  When the charging voltage of the capacitor CP1 is low enough to require charging, the comparison circuit 3 outputs an H level signal (a signal indicating that the detection voltage S1 is lower than the reference voltage S2) to the AND circuit 4 (first signal). . The AND circuit 4 is also input with the energy saving signal S3 (H level signal) described above, that is, a signal (second signal) indicating that the energy saving mode has been entered, and the energy saving signal S3 is at the H level and is in the energy saving mode. When the output signal of the comparison circuit 3 is at H level and the charging voltage of the capacitor CP1 is low enough to require charging, the AND circuit 4 takes the AND and outputs the control signal S5 (H level signal). Output to the circuit 5.

  The OR circuit 5 takes the OR of the control signal S14 and the control signal S5, and outputs the above-described control signal S11 instructing the capacitor charger 203 to perform charging of the capacitor CP1 (in FIG. 3, from the control unit 202). The control signal S11 is directly output to the capacitor charger 203, but in actuality, it is output via the OR circuit 5).

  As described above, the charging control circuit 10 performs the charging of the capacitor CP1 when the charging voltage of the capacitor CP1 becomes too low even in the energy saving mode in which the main control unit 202 does not charge the capacitor CP1, so that the energy saving is performed. The fixing roller 301 can always be rapidly heated after returning from the mode, and image formation is started quickly, and the user does not have to wait for a long time until the start of image formation, which is convenient. When charging is performed by the control signal S11, when the voltage S15 reaches a predetermined reference value, a circuit (not shown) that determines that the charging amount has reached full and stops charging the capacitor CP1 is The battery charger 203 is provided.

  FIG. 10 is a circuit diagram illustrating another configuration example of the charging control circuit 10. 10, circuit elements having the same reference numerals as those in FIG. 9 are the same as those of the charging control circuit 10 in FIG. 9, and detailed description thereof is omitted. The charge control circuit 10 shown in FIG. 10 is different from that shown in FIG. 9 in that a permission / prohibition signal S 7 (third signal) is input to the AND circuit 4. The permission / inhibition signal S7 is always output as an H level signal from the operation unit 150, but becomes an L level signal when the user operates a predetermined key on the operation unit 150. At this time, the AND circuit 4 outputs an L level signal, the capacitor charger 203 does not charge the capacitor CP1 even if the charging voltage of the capacitor CP1 drops after the transition to the energy saving mode.

  That is, when the digital copying machine 1 is not used for a long time such as a weekend or a long holiday, even if the charging voltage of the capacitor CP1 is lowered when the mode is shifted to the energy saving mode, the charging of the capacitor CP1 is unnecessary. Yes, such charging is a waste of power. In this case, if the user performs a predetermined key operation on the operation unit 150, this is an instruction from the user for prohibiting charging of the capacitor CP1 (accepting means), and the permission / inhibition signal S7 is The L level state is maintained and a signal indicating that there has been an instruction from the user to prohibit charging of the capacitor CP1, charging to the capacitor CP1 by the charging control circuit 10 is prohibited, thereby saving power. be able to. When the user performs a predetermined key operation on the operation unit 150 again at the end of a weekend or long vacation, the permission / prohibition signal S7 returns to the H level, and the capacitor CP1 in the energy saving mode can be charged. It becomes.

  FIG. 11 is a circuit diagram illustrating another configuration example of the charging control circuit 10. 11, circuit elements having the same reference numerals as those in FIG. 10 are the same as those in the charge control circuit 10 in FIG. 10, and detailed description thereof is omitted. The charge control circuit 10 in FIG. 11 is different from that in FIG. 10 in that the AND circuit 4 is provided in the subsequent stage of the OR circuit 5. Accordingly, when the user performs a predetermined key operation on the operation unit 150 and the permission / prohibition signal S7 is at the L level, even if the user is not in the energy saving mode, that is, by the control signal S14 output by the control unit 202, Since charging of the capacitor CP1 is prohibited, the user can operate the operation unit 150, and when necessary, charging of the capacitor CP1 is absolutely prohibited to save power.

  FIG. 12 is a circuit diagram illustrating another configuration example of the charging control circuit 10. 12, circuit elements having the same reference numerals as those in FIG. 9 are the same as those in the charge control circuit 10 in FIG. 9, and detailed description thereof is omitted. The charge control circuit 10 of FIG. 12 is different from that of FIG. 9 in that a timer signal S8 is input to the AND circuit 4 instead of the permission / prohibition signal S7. The sub-control unit 253 has a clock function and a timer function, and always outputs the timer signal S8 as an H level signal, but changes the timer signal S8 to the L level when a predetermined time zone is reached (time determination means). ). That is, the timer signal S8 is a signal indicating that the current time is in a predetermined time zone. As a result, in a predetermined time zone (nighttime or the like), even when the mode is shifted to the energy saving mode and the charging of the capacitor CP1 is insufficient, the charging of the capacitor CP1 is prohibited, and unnecessary charging is not performed. In this way, power can be saved.

  FIG. 13 is a circuit diagram illustrating another configuration example of the charging control circuit 10. 13, circuit elements having the same reference numerals as those in FIG. 9 are the same as those in the charging control circuit 10 in FIG. The charge control circuit 10 of FIG. 13 is different from that of FIG. 9 in that the resistor R2 (or the resistor R1 or both of the resistors R1 and R2) constituting the both-end voltage detection circuit 232 is composed of a variable resistor. It is. As a result, the performance of the capacitor CP1 changes with time, and the time required to charge to the same voltage level is prolonged. Therefore, even if the capacitor CP1 has to be charged early, the service person can By adjusting the resistance value of the variable resistor described above, the value of the reference voltage S2 can be adjusted (variable means), and charging to the capacitor CP1 after shifting to the energy saving mode can be started early. it can. Of course, at least one of the resistors R3 and R4 may be a variable resistor, and the reference voltage input to the comparison circuit 3 may be variable.

  FIG. 14 is a circuit diagram illustrating another configuration example of the charging control circuit 10. 14, circuit elements having the same reference numerals as those in FIG. 9 are the same as those in the charge control circuit 10 in FIG. 9, and detailed description thereof is omitted. The charge control circuit 10 of FIG. 14 is different from that of FIG. 9 in that the control signal S11 is also output to the operation unit 150 based on the output signal of the AND circuit 4. Thereby, when the control signal S11 is at the H level, the operation unit 150 can notify the user that the capacitor CP1 has been charged after the transition to the energy saving mode by a predetermined means such as turning on the LED. (Notification means).

  Next, as another embodiment, a case will be described in which the function of each charging control circuit 10 described above is realized by processing performed by another local control unit, in this example, the sub control unit 253. FIG. 15 is a block diagram showing a hardware configuration in this case. In the following description, members having the same reference numerals as those in FIGS. 8 to 14 are circuit elements similar to those described above, and thus detailed description thereof is omitted.

  In this example, the main control unit 202 outputs a control signal to the sub control unit 253, and the sub control unit 253 controls the capacitor charger 203 to control the capacitor CP1 when not in the energy saving mode.

  The voltage detection signal S15, the permission / inhibition signal S7, and the timer signal S8 are also input to the sub-control unit 253, and when in the energy saving mode, the sub-control unit 253 performs the process shown in the flowchart of FIG. This process implements a charge control means. That is, when it is in the energy saving mode (Y in Step S1), when it is determined that the voltage S15 across the capacitor CP1 is lower than the preset reference value S2 (Y in Step S2), the permission / prohibition signal S7, it is determined whether or not the timer signal S8 (in this example, the timer signal S8 is an internal signal of the sub-control unit 253) is at the L level (steps S3 and S4). (Y in step S3, Y in S4) When the control signal S14 instructing charging of the capacitor CP1 is output from the control unit 202 (Y in step S5), the control signal S14 is canceled (step S6). Control signal S11 is output to charger 203 to charge capacitor CP1 (step S7). In step S7, the control signal S11 is also output to the operation unit 150 at the same time to notify the user that the charging of the capacitor CP1 is being performed as in the example described above with reference to FIG. ).

  When it is determined that the voltage S15 across the capacitor CP1 is greater than or equal to the reference value S2 (N in step S2), or when both the enable / disable signal S7 and the timer signal S8 are at the H level (N, in step S3). N in S4), charging in step S7 is not performed.

  FIG. 17 is a flowchart of the reference value S2 setting process executed by the sub-control unit 253 and the like. That is, when a service person or the like performs a predetermined key operation on the operation unit 150 and designates a predetermined value as the value of the reference value S2 (Y in step S11), the nonvolatile memory (not shown) is used as the value of the reference value S2. (Variable means) (step S12). In the process of FIG. 16 described above, the determination in step S2 is performed using the reference value S2 set in this way.

  By performing the processing as described above, the function of the above-described charging control circuit 10 can be executed by a local control unit such as the sub-control unit 253.

1 is a longitudinal sectional view of a digital copying machine according to an embodiment. 2 is an explanatory diagram of a fixing device. FIG. FIG. 2 is a circuit diagram of a power supply control system of a digital copying machine mainly including a fixing device. It is a circuit diagram of an AC heater drive circuit. It is a circuit diagram of a capacitor charger. It is a circuit diagram of a capacitor charging / discharging circuit. It is a circuit diagram of a main control part. It is a circuit diagram explaining functions, such as a sub-control part. It is a circuit diagram of a charge control circuit. It is a circuit diagram of the other structural example of a charge control circuit. It is a circuit diagram of the other structural example of a charge control circuit. It is a circuit diagram of the other structural example of a charge control circuit. It is a circuit diagram of the other structural example of a charge control circuit. It is a circuit diagram of the other structural example of a charge control circuit. It is a circuit diagram in the case of implement | achieving the function of a charge control circuit by the process which a sub control part performs. It is a flowchart of the process which a sub control part performs. It is a flowchart of the process which a sub control part performs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 3 Comparison circuit 4 AND circuit 121 Fixing device, heat generating device 202 Control device 203 Charger 232 Terminal voltage detection circuit 253 Power control means CP1 Power storage device HT1 Heating member

Claims (19)

A capacitor,
A charger for charging the battery;
A heat generating member that generates heat upon receipt of charging power from the battery;
A terminal voltage detection circuit for detecting a voltage between terminals of the capacitor;
A control device for controlling the charger based on the detected voltage and charging the capacitor;
When a predetermined condition is satisfied, supply of power to a part of the power load of the apparatus including the control device is stopped, and when the predetermined condition is satisfied while in the stopped state, the stop is stopped. Power control means for performing control to cancel,
Charge control means for controlling the charger based on the detected voltage and charging the battery when in the stopped state;
A heating device equipped with. The control device performs charging of the battery when the detected voltage falls below a predetermined reference value,
The charge control means charges the battery when the detected voltage is lower than a predetermined reference value.
The heat generating device according to claim 1. Comprising a receiving means for receiving an instruction to prohibit charging of the battery from a user;
The charging control unit prohibits charging of the battery when receiving the prohibition instruction;
The heat generating device according to claim 1 or 2. Time determination means for determining whether or not the current time is in a predetermined time zone,
The charging control unit prohibits charging of the battery when receiving the prohibition instruction when the time determination unit determines that the current time is in the predetermined time zone,
The heat generating device according to any one of claims 1 to 3.   The heat generating device according to any one of claims 1 to 4, further comprising notification means for notifying a user that the storage battery is charged when the storage battery is charged by the charge control means. The control device performs charging of the battery when the detected voltage falls below a predetermined reference value,
The charge control means includes
A comparison circuit for comparing the detection voltage with a predetermined reference value;
An AND circuit that takes an AND of a first signal indicating that the detection voltage output by the comparison circuit is below a predetermined reference value and a second signal indicating that the detection voltage is in a stopped state;
The heating device according to claim 1, comprising: Comprising a receiving means for receiving an instruction to prohibit charging of the battery from a user;
The AND circuit takes an AND of the first signal, the second signal, and a third signal indicating that the prohibition instruction has been received.
The heat generating device according to claim 6. Time determination means for determining whether or not the current time is in a predetermined time zone,
The AND circuit takes an AND of the first signal, the second signal, and a fourth signal indicating that the time determination means determines that the current time is in the predetermined time zone,
The heat generating device according to claim 6.   9. A notifying means for notifying a user that the battery is to be charged when the battery is charged by the charge control means based on an output signal of the AND circuit. 9. The heat generating device according to one. A fixing member for fixing the toner image by pressurizing and heating the medium on which the toner image is formed;
A battery,
A charger that receives power from a commercial power source and charges the battery;
A heating member that generates heat and heats the fixing member in response to supply of charging power of the capacitor;
A terminal voltage detection circuit for detecting a voltage between terminals of the capacitor;
A control device for controlling the charger based on the detected voltage and charging the capacitor;
When a predetermined condition is satisfied, supply of power to a part of the power load of the apparatus including the control device is stopped, and when the predetermined condition is satisfied while in the stopped state, the stop is stopped. Power control means for performing control to cancel,
Charge control means for controlling the charger based on the detected voltage and charging the battery when in the stopped state;
A fixing device. The control device performs charging of the battery when the detected voltage falls below a predetermined reference value,
The charge control means charges the battery when the detected voltage is lower than a predetermined reference value.
The fixing device according to claim 10. Comprising a receiving means for receiving an instruction to prohibit charging of the battery from a user;
The charging control unit prohibits charging of the battery when receiving the prohibition instruction;
The fixing device according to claim 10 or 11. Time determination means for determining whether or not the current time is in a predetermined time zone,
The charging control means prohibits charging of the battery when receiving the prohibition instruction when the time determination means determines that the current time is in the predetermined time zone,
The fixing device according to claim 10.   14. The fixing device according to claim 10, further comprising notification means for notifying a user that the storage battery is to be charged when the storage battery is charged by the charge control means. The control device performs charging of the battery when the detected voltage falls below a predetermined reference value,
The charge control means includes
A comparison circuit for comparing the detection voltage with a predetermined reference value;
An AND circuit that takes an AND of a first signal indicating that the detection voltage output by the comparison circuit is below a predetermined reference value and a second signal indicating that the detection voltage is in a stopped state;
The fixing device according to claim 10. Comprising a receiving means for receiving an instruction to prohibit charging of the battery from a user;
The AND circuit takes an AND of the first signal, the second signal, and a third signal indicating that the prohibition instruction has been received.
The fixing device according to claim 15. Time determination means for determining whether or not the current time is in a predetermined time zone,
The AND circuit takes an AND of the first signal, the second signal, and a fourth signal indicating that the time determination means determines that the current time is in the predetermined time zone,
The fixing device according to claim 15.   18. The notification unit according to claim 15, further comprising a notification unit that notifies a user that the battery is to be charged when the battery is charged by the charge control unit based on an output signal of the AND circuit. The fixing device according to 1. An image forming apparatus that forms an image on a medium by electrophotography and includes the fixing device according to claim 10 as a fixing device.

Images