JP2010026037A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which suppresses failure due to power failure to the minimum by performing optimum control based on accumulation conditions of DC power of an accumulator means and the kind of a job which is being performed when detecting the power failure. <P>SOLUTION: The image forming apparatus includes the accumulator means, a charging means, a voltage detection means, a control means, a power failure detection means and a storage means. The accumulator means can accumulate the DC power to be supplied to the respective parts of an apparatus body. The charging means charges the accumulator means by using power from a commercial power supply. The voltage detection means detects both-end voltage of the accumulator means. The control means controls the apparatus body and performs any of a plurality of kinds of jobs. The power failure detection means detects stop of power supply from the commercial power supply. The storage means stores a control program for controlling the respective parts of the apparatus body. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus provided with a power storage unit in an electrophotographic or inkjet image forming apparatus.

  In a conventional electrophotographic image forming apparatus or inkjet image forming apparatus, power is supplied from an external power source such as a commercial AC power source, and each part is driven by the input power to generate a print output. Done. At that time, when the power supply from the outside is interrupted due to a power failure or the like during the execution of the print job, all processing operations are stopped at the time of the interruption. Therefore, if the power supply is stopped during job execution, all processing stops at that time, which may cause an accident or hinder the operation after power is restored. .

Therefore, a printing apparatus is disclosed in which a battery is provided in the main body of the apparatus, and in the event of a power failure, the paper is forcibly discharged by supplying power from the battery and the status data of the main body of the apparatus is stored, and the job can be resumed without any problems when the power failure is resolved. (For example, refer to Patent Document 1).
JP 2001-042707 A

  However, in Patent Document 1, no particular consideration is given to the power supply capability of the battery. For example, when the battery is a secondary battery type such as an electric double layer capacitor, charging is not sufficient when the power is shut off. A case can be assumed, and in this case, a problem may occur.

  Therefore, in view of the above problems, the object of the present invention is to perform the optimal control based on the accumulation state of DC power of the power storage means and the type of job being executed when a power failure is detected, thereby minimizing problems caused by the power failure. It is an object of the present invention to provide an image forming apparatus that can be reduced to the above.

  The image forming apparatus of the present invention includes a power storage unit, a charging unit, a voltage detection unit, a control unit, a power failure detection unit, and a storage unit.

  The power storage means can store DC power to be supplied to each part of the apparatus main body. The charging means charges the power storage means using electric power from a commercial power source. The voltage detection means detects the voltage across the power storage means. The control means controls the apparatus main body and executes one of a plurality of types of jobs. The power failure detection means detects the stop of power supply from the commercial power source. The storage means stores a control program for controlling each part of the apparatus main body.

  When a power failure is detected by the power failure detection means during execution of a job, the control means in the image forming apparatus of the present invention detects the DC power accumulation state of the power storage means by the voltage detection means, and the detection result Whether to continue the job being executed is determined based on the type of job being executed.

  In this configuration, the apparatus main body can operate even if a power failure occurs during execution of a job. However, depending on the state of accumulation of DC power in the power storage means and the type of job being executed, there are cases where sufficient operation of the apparatus main body cannot be expected. Therefore, when a power failure is detected, optimal control based on the DC power storage status of the power storage means and the type of job being executed makes it possible to minimize the malfunction of the device body due to the power failure. .

  In this configuration, the storage unit stores a first threshold value indicating a minimum effective voltage value at which the apparatus main body can continue the print job being executed, and the control unit is executing the print job while executing the print job. When a power failure is detected by the power failure detection means, the DC power storage state of the power storage means is detected by the voltage detection means. If the voltage across the power storage means is equal to or higher than a first threshold, Preferably, it is determined to continue the print job, and if the voltage across the power storage means is less than the first threshold value, it is determined to interrupt the print job being executed.

  In this configuration, a first threshold value indicating whether or not the apparatus main body can continue the print job is stored in the storage unit, and the first threshold value is compared with the DC power storage state of the power storage unit. By determining whether or not the print job can be executed, it is possible to minimize the malfunction of the apparatus main body due to a power failure.

  The image forming apparatus of the present invention preferably further includes a paper feeding unit, a photoconductor, a transfer unit, a fixing unit, and a temperature detection unit.

  The paper feeding unit loads the recording medium and feeds the recording medium to the apparatus main body. The photoreceptor carries an image on the surface. The transfer unit transfers the image on the surface of the photoreceptor to a recording medium. The fixing unit fixes the image transferred onto the recording medium by the transfer unit onto the recording medium. The temperature detection unit detects a surface temperature of the fixing unit.

  The storage means has a minimum effective temperature at which the fixing unit can fix the image transferred onto the recording medium in all the recording media from the paper feeding unit to the fixing unit. 2 is stored, and when the power failure is detected by the power failure detection means during execution of the print job, the control means detects the DC power storage state of the power storage means by the voltage detection means. If the voltage across the power storage means is equal to or higher than the first threshold, the surface temperature of the fixing unit is detected by the temperature detection unit, and if the surface temperature of the fixing unit is equal to or higher than the second threshold, execution is in progress. If the surface temperature of the fixing unit is lower than the second threshold value or the voltage across the power storage means is lower than the first threshold value, the print job being executed is interrupted. Prefer to decide There.

  With this configuration, in the electrophotographic image forming apparatus, can the image transferred onto these recording media be fixed on the recording medium in all the recording media having the fixing unit from the paper feeding unit to the fixing unit? The second threshold value indicating the threshold value is stored in the storage means, and the second threshold value and the surface temperature of the fixing unit are compared to determine whether or not to execute the print job, thereby causing a malfunction of the apparatus main body due to a power failure. Can be minimized.

  In this configuration, when a power failure is detected by the power failure detection means during execution of a print job, the control means detects the DC power accumulation state of the power storage means by the voltage detection means, If the voltage at both ends is equal to or higher than the first threshold, the surface temperature of the fixing unit is detected by the temperature detection unit, and if the surface temperature of the fixing unit is equal to or higher than the second threshold, paper is fed from the paper feeding unit. It is determined that image formation is continued until image formation on all the recording media is completed, and that all recording media fed from the paper feed unit are discharged, and the surface temperature of the fixing unit is the second. Of the recording medium fed from the paper feed unit, the image formation is continued until the image formation on the recording medium reaching the transfer unit is completed and the paper feed unit feeds the recording medium. All done It decided to discharge the recording medium, if the voltage across less than the first threshold value of the accumulator unit, decides to immediately stop the image formation on a recording medium preferable.

  In this configuration, the second threshold value and the surface temperature of the fixing unit are compared to determine whether or not to continue image formation on the recording medium, thereby minimizing the malfunction of the apparatus main body due to a power failure. .

  The storage means has a minimum effective temperature at which the image transferred onto the recording medium can be fixed on the recording medium in all the recording media from the transfer section to the fixing section. A third threshold value is stored, and when the power failure is detected by the power failure detection means during execution of a print job, the control means detects the DC power storage state of the power storage means by the voltage detection means. If the voltage across the power storage means is equal to or higher than a first threshold, the surface temperature of the fixing unit is detected by the temperature detection unit, and if the surface temperature of the fixing unit is equal to or higher than a third threshold, Of the recording media fed from the paper feeding unit, the image formation is continued until the image formation on the recording medium reaching the transfer unit is completed, and all the recording media fed from the paper feeding unit are discharged. Do If the surface temperature of the fixing unit is lower than the third threshold value, it is determined to immediately stop the image formation on the recording medium and to discharge all the recording media fed from the paper feeding unit. If the voltage across the power storage means is less than the first threshold, it is preferable to immediately stop image formation on the recording medium.

  In this configuration, a third threshold value indicating a threshold value indicating whether or not the image transferred on the recording medium can be fixed on the recording medium in all the recording media from the transfer section to the fixing section is stored. By storing the third threshold value and the surface temperature of the fixing unit to determine whether or not to continue image formation on the recording medium, the malfunction of the apparatus main body due to a power failure is minimized. Is possible.

  In this configuration, the storage means stores a fourth threshold value indicating a minimum effective voltage value at which a job other than the print job being executed by the apparatus main body can be continued, and the control means is not a print job. When a power failure is detected by the power failure detection means while the job is being executed, the DC power storage state of the power storage means is detected by the voltage detection means, and the voltage across the power storage means is greater than or equal to a fourth threshold value. If there is, it is decided to complete the execution of the ongoing job and shift to the standby state. If the voltage across the power storage means is less than the fourth threshold, the job execution is interrupted and the standby state is shifted to. It is preferable to decide to do so.

  In this configuration, the storage unit stores a fourth threshold value indicating whether the apparatus main body can continue a job other than the print job being executed, and the fourth threshold value and the DC power of the power storage unit are stored. It is possible to minimize the malfunction of the apparatus main body due to a power failure by determining whether or not the print job can be executed by comparing with the storage status of the device.

  When the power failure is detected, the image forming apparatus according to the present invention can perform the optimal control based on the accumulation state of the DC power of the power storage unit and the type of the job being executed, thereby minimizing the trouble caused by the power failure. it can.

  Hereinafter, an image forming apparatus according to the best embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention.

  The image forming apparatus (apparatus main body) 100 forms a monochrome image on a predetermined sheet (recording medium) in accordance with image data received from the outside. The image forming apparatus 100 includes an exposure unit 13, a developing device 15, a photoconductor 17, a charger 19, a cleaner unit 21, a fixing unit 40, a paper feed tray (paper feed unit) 25, and a paper feed extending upward from the paper feed tray 25. The conveyance path 27, the paper conveyance path 27 from the end of the paper feed conveyance path 27 through the registration roller 29, the transfer belt 45 and the fixing unit 40 to the discharge roller 95, the discharge tray 33, and the like.

  The charger 19 is a charging means for uniformly charging the surface of the photoconductor 17 to a predetermined potential. As shown in FIG. 1, a charger-type charger is used. A brush-type charger may be used.

  The exposure unit 13 includes, for example, an EL or LED writing head in which light emitting elements are arranged in an array in addition to a method using a laser scanning unit (LSU) including a laser irradiation unit 35 and a reflection mirror 37 as shown in FIG. There is also a method using. Further, the exposure unit 13 employs a two-beam technique that uses a plurality of laser beams to reduce the speed of irradiation timing in order to perform high-speed printing processing.

  The photosensitive member 17 uniformly charged by the charger 19 is exposed according to the input image data, thereby forming a latent electrostatic image corresponding to the image data on the surface of the photosensitive member 17. .

  The developing unit 15 visualizes the electrostatic latent image formed on the photoreceptor 17 with toner. The cleaner unit 21 removes and collects toner remaining on the surface of the photoconductor 17 after the developed image is transferred.

  The toner visualized on the photoconductor 17 as described above is transferred onto the paper conveyed through the paper conveyance path 31. The transfer mechanism (transfer unit) 39 for this purpose is a mechanism for applying an electric field having a polarity opposite to the charge of the toner to transfer the toner onto the paper. For example, when the electrostatic image has a charge of (−) polarity, the polarity applied to the transfer mechanism 39 is (+) polarity.

The transfer mechanism 39 includes a transfer belt 45 that is bridged by a driving roller 41, a driven roller 43, and other rollers, and has a predetermined resistance value (range of 1 × 10 ⁹ Ω · cm to 1 × 10 ¹³ Ω · cm). . The contact portion 47 between the photosensitive member 17 and the transfer belt 45 is provided with an elastic conductive roller 49 that is a roller different from the drive roller 41 and the driven roller 43 and can apply a transfer electric field. The elastic conductive roller 49 has elasticity. As a result, the photoreceptor 17 and the transfer belt 45 are not in line contact with each other but are in surface contact with each other with a predetermined width (referred to as a transfer nip). As a result, the transfer efficiency to the conveyed paper can be improved.

  Further, on the downstream side of the transfer area of the transfer belt 45, a static elimination roller 51 is provided for neutralizing the sheet charged by the voltage applied when passing through the contact portion 47 and smoothly transporting to the next process. Has been. The neutralizing roller 51 is disposed on the back surface of the transfer belt 45.

  The transfer mechanism 39 is provided with a cleaning unit 53 and a charge removal mechanism 55 for removing toner from the transfer belt 45 and discharging the transfer belt 45. The static elimination mechanism 55 includes a method of grounding through the apparatus or a method of positively applying a polarity opposite to the polarity of the transfer electric field. The toner transferred onto the paper by the transfer mechanism 39 is conveyed to the fixing unit 40.

  The fixing unit 40 includes a heating roller (fixing unit) 408 and a pressure roller 410, and a sheet peeling claw 412, a thermistor (temperature detection unit) 406, and a roller surface cleaning member 65 are arranged on the outer periphery of the heating roller 408. Has been. Further, a first heater 402 and a second heater 404 for heating the surface of the roller to a predetermined temperature (fixing set temperature: approximately 170 ° C. to 200 ° C.) are arranged on the inner peripheral portion of the heating roller 408. Yes. On the other hand, a sheet peeling claw 414 is disposed on the outer periphery of the pressure roller 410.

  The fixing unit 40 heats and melts unfixed toner on the conveyed paper at the pressure contact portion (called a fixing nip portion) between the heating roller 408 and the pressure roller 410 at the surface temperature of the heating roller 408, Further, the unfixed toner on the paper is fixed on the paper by a throwing action by the pressure contact force of the pressure roller 410.

  The paper feed tray 25 is a tray on which sheets used for image formation are stacked. Here, the paper feed tray 25 is provided on the lower side and the side wall surface of the image forming unit. The image forming apparatus 100 is provided with a plurality of paper feed trays 25 that can store 500 to 1500 sheets of standard size paper for the purpose of performing high-speed printing processing. On the other hand, on the side surface of the image forming apparatus 100, a large-capacity paper feed cassette 73 capable of storing a large amount of a plurality of paper types and a manual feed tray 75 mainly used for printing of an irregular size are disposed.

  The paper discharge tray 33 is disposed on the side opposite to the manual feed tray 75 of the apparatus. However, instead of the paper discharge tray 33, a post-processing device (staple, punch processing, etc.) of discharged paper or a multi-stage discharge is provided. It is also possible to arrange a paper tray as an option.

  The image forming apparatus 100 includes a control unit 300. The control unit 300 includes a main control unit (control unit) 30, a ROM (storage unit) 34 that stores a control program that is a processing procedure executed by the main control unit 30, a RAM 36 that provides a work area for work, and a control unit. It is composed of a non-volatile memory that backs up and holds necessary data, an output circuit including a driver for driving a load such as a sensor, a solenoid, and a lamp.

  Next, a paper conveyance process corresponding to the processing mode of the image forming apparatus 100 will be described in detail. The main control unit 30 selects a sheet that meets the print request from the plurality of paper feed trays 25 and is conveyed to the registration roller 29 by the conveyance roller 93 in the conveyance path. The paper that has reached the registration roller 29 under the control of the main control unit 30 is temporarily stopped. The main control unit 30 re-rotates the registration roller 29 at a timing at which the leading edge of the paper and the image information on the photoconductor 17 are matched, whereby the paper is conveyed to the transfer mechanism 39. The toner corresponding to the image information is transferred onto the paper by the transfer mechanism 39, and then the paper is guided to the fixing unit 40 to fix the transferred toner onto the paper. Thereafter, the paper is discharged to the paper discharge tray 33.

  The main control unit 30 controls the transport method from the fixing unit 40 to the paper discharge tray 33 according to the printing mode (such as copier mode, printer mode or FAX mode) and the printing processing method (single-sided printing or double-sided printing). To do. In the normal copier mode, since the user performs an operation in the vicinity of the apparatus, the sheet conveyance control is often performed so that the printing surface is discharged upward. This is called “face-up discharge”. On the other hand, in each mode of the printer and FAX, “face-down discharge” that aligns the page order of discharged sheets is often used because the user is not in the vicinity of the apparatus.

  Therefore, the image forming apparatus 100 has a mechanism capable of switching between face-up discharge and face-down discharge according to the printing mode. This switching mechanism arranges a plurality of transport paths and a plurality of branching claws until the paper that has passed through the fixing unit 40 is discharged to the paper discharge tray 33, thereby discharging the paper according to the print mode. Configured to do.

  FIG. 2 is a block diagram of the image forming apparatus according to the embodiment of the present invention.

  The image forming apparatus 100 includes a main switch 52. The main switch 52 is configured to set the first connection unit 10 that switches on / off the power supply from the commercial power supply 20 to a conductive state or a non-conductive state.

  The image forming apparatus 100 includes a main control unit 30. The main control unit 30 is connected to the ROM 34, the RAM 36, the transport unit 46, the image forming unit 38, the display unit 48, the operation unit 44, the image reading unit 42, the fixing driving unit 18, and the switching control unit 32.

  The ROM 34 stores a plurality of programs necessary for the operation of the main control unit 30. The RAM 36 is a volatile memory that temporarily holds data. The conveyance unit 46 conveys the paper along a conveyance path provided inside the image forming apparatus 100. The image forming unit 38 performs an electrophotographic image forming process on the paper conveyed by the conveying unit 46. The display unit 48 displays information to be notified to the user. The operation unit 44 receives an input operation from the user. The image reading unit 42 reads an image of a document placed on a document table and generates image data. The fixing driving unit 18 controls the fixing unit 40 based on a signal from the main control unit 30. The fixing unit 40 fixes the toner image attached to the sheet to the sheet by heat and pressure.

  The switching control unit 32 is configured to set the connection state of the second connection unit 12, the third connection unit 14, and the fourth connection unit 16 based on a signal from the main control unit 30.

  The second connection unit 12 is connected to the commercial power supply 20 via the first connection unit 10. A rectification unit 22 and a voltage adjustment unit 28 are disposed following the second connection unit 12. The rectifying unit 22 includes a diode bridge 222. The voltage adjustment unit 28 includes a switching oscillation unit 282, a transformer 284, and a voltage conversion unit 286. The voltage adjustment unit 28 converts electric power from the commercial power source 20, and controls system circuits such as the main control unit 30 and the switching control unit 32, and an image. DC power is supplied to drive system circuits such as the forming unit 38 and the image reading unit 42.

  The third connection unit 14 is connected to the commercial power supply 20 via the first connection unit 10. A charging unit (charging unit) 24 and a power storage unit (power storage unit) 26 are arranged following the third connection unit 14. The charging unit 24 rectifies AC power from the commercial power source 20 and causes the power storage unit 26 to store DC power. The power storage unit 26 includes an electric double layer capacitor that can be charged by the charging unit 24.

  The fourth connection unit 16 is disposed between the power storage unit 26 and the voltage adjustment unit 28. A voltage detection unit (voltage detection means) 50 for detecting the electric power stored in the power storage unit 26 is provided at the subsequent stage of the fourth connection unit 16. The voltage detection unit 50 is connected to the main control unit 30 and outputs a detection result to the main control unit 30.

  FIG. 3 is a detailed block diagram of the image forming apparatus according to the embodiment of the present invention.

  The second connection unit 12 switches between conduction / non-conduction between the commercial power source 20 and the rectification unit 22 and controls on / off of power supply from the commercial power source 20 to the rectification unit 22. The second connection unit 12 includes a relay switch 122 and a relay coil 124. The relay switch 122 is disposed between the first connection unit 10 and the diode bridge 222. The relay coil 124 is disposed between the voltage conversion unit 286 and the switching control unit 32. When the switching control unit 32 selectively energizes the relay coil 124, on / off of the relay switch 122 is controlled.

  The third connection unit 14 switches between conduction / non-conduction between the commercial power source 20 and the charging unit 24 and controls on / off of power supply from the commercial power source 20 to the charging unit 24. The third connection unit 14 includes a relay switch 142 and a relay coil 144. The relay switch 142 is disposed between the first connection unit 10 and the charging unit 24. The relay coil 144 is disposed between the voltage conversion unit 286 and the switching control unit 32. When the switching control unit 32 selectively energizes the relay coil 144, ON / OFF of the relay switch 142 is controlled.

  The fourth connection unit 16 switches conduction / non-conduction between the power storage unit 26 and the voltage adjustment unit 28, and controls on / off of power supply from the power storage unit 26 to the voltage adjustment unit 28. The fourth connection unit 16 includes an FET 162. The gate of the FET 162 is connected to the switching control unit 32. The switching control unit 32 controls the voltage applied to the gate of the FET 162, whereby the power supply from the power storage unit 26 to the voltage adjustment unit 28 is controlled.

  In order to detect a power failure of the commercial power supply 20, a power failure detection unit (power failure detection means) 200 is provided. When the power failure detection unit 200 detects a power failure of the commercial power supply 20, the detection result is notified to the main control unit 30. The power failure detection unit 200 detects the AC waveform of the commercial power supply 20 and monitors the presence or absence of the AC waveform.

  The fixing drive unit 18 includes a triac 184, a triac 186, and a triac drive circuit 182. The triac 184 is disposed between the first connection unit 10 and the first heater 402. The triac 186 is disposed between the first connection unit 10 and the second heater 404. The triac drive circuit 182 controls the conduction states of the triac 184 and the triac 186 based on a signal from the main control unit 30.

  In the above configuration, the main control unit 30 detects the surface temperature of the heating roller 408 with the thermistor 406, and the first heater 402 and the first heater 402 so that the surface temperature of the heating roller 408 falls within the range of 170 ° C. to 200 ° C. The energization state to the second heater 404 is controlled. In addition, the main control unit 30 notifies the switching control unit 32 of the energization state of the first heater 402 and the second heater 404.

  The switching control unit 32 controls the connection state of the second connection unit 12, the third connection unit 14, and the fourth connection unit 16 based on the notification content from the main control unit 30. Specifically, when the triac 184 and the triac 186 are in a conductive state, the switching control unit 32 switches the second connection unit 12 and the third connection unit 14 to a non-conductive state and conducts the fourth connection unit 16. Switch to state. On the other hand, when the triac 184 and the triac 186 are in a non-conductive state, the switching control unit 32 switches the second connection unit 12 and the third connection unit 14 to a conductive state and sets the fourth connection unit 16 in a non-conductive state. Switch.

  As a result, while the first heater 402 and the second heater 404 are on, the voltage adjustment unit 28 is disconnected from the commercial power supply 20 and the electricity other than the fixing unit 40 is stored in the power storage unit 26 that has been charged in advance. Drive the circuit. Conversely, while the first heater 402 and the second heater 404 are off, the voltage adjusting unit 28 is connected to the commercial power source 20 and power is supplied from the commercial power source 20 to the electric circuits other than the fixing unit 40. At the same time, the power storage unit 26 is charged using power from the commercial power supply 20.

  According to the above, almost all 1.5 kw that can be supplied from the commercial power supply 20 can be supplied to the first heater 402 and the second heater 404. For this reason, it is easy to maintain the surface temperature of the heating roller 408 without the power consumption of the entire image forming apparatus 100 exceeding the predetermined power value of 1.5 kw. As a result, the image forming apparatus 100 can perform high-speed continuous printing.

  FIG. 4 is a diagram showing the configuration of the fixing unit in the image forming apparatus according to the embodiment of the present invention.

  As shown in FIG. 4A, the fixing unit 40 includes a heating roller 408, a pressure roller 410, a thermistor 406, and paper peeling claws 412 and 414. The heating roller 408 includes a first heater 402 and a second heater 404 inside. As shown in FIG. 4B, the first heater 402 and the second heater 404 are configured to have different heating characteristics.

  FIG. 5 is a flowchart showing the flow of the control means of the image forming apparatus according to the embodiment of the present invention.

  The following flow is executed in parallel with a main process such as print job execution as a sub process of the main control unit 30, and the control of the present invention is realized by transmitting a command from the sub process to the main process.

  Here, the first threshold value indicates the minimum effective voltage value at which the image forming apparatus 100 can continue the print job being executed, and the second threshold value is the value that the heating roller 408 heats from the paper feed tray 25. It is assumed that the minimum effective temperature at which an image transferred on these sheets of paper up to the roller 408 can be fixed on the sheet, and the third threshold value is that the heating roller 408 is transferred from the transfer mechanism 39 to the heating roller. In all the sheets up to 408, the minimum effective temperature at which the image transferred on these sheets can be fixed on the sheet is assumed, and the fourth threshold value is other than the print job being executed by the image forming apparatus 100 The minimum effective voltage value that can continue the job is assumed to be indicated.

  When the power failure detection unit 200 detects a power failure of the commercial power supply 20 (S10), the detection result is notified to the main control unit 30, and the second connection unit 12 and the third connection unit 14 are switched to the non-conducting state. 4 connection part 16 is switched to a conduction | electrical_connection state (S20). An inquiry is made to the main process, and if a job is being executed in the main process (S30), the voltage detection unit 50 detects the voltage Vc across the electric double layer capacitor (S40). An inquiry is made to the main process, and if the job being executed is a print job (S50), it is determined whether Vc is greater than or equal to the first threshold value V1 (S60). If Vc is equal to or higher than V1, the thermistor 406 detects the surface temperature T1 of the heating roller 408 (S70). It is determined whether or not T1 is equal to or higher than the second threshold value 180 ° C. (S80). If T1 is equal to or higher than 180 ° C., a command for prohibiting paper feeding from the new paper feeding tray 25 is transmitted to the main process ( S90). The main process stores the number of sheets already fed from the sheet feed tray 25, and continues image writing for the number of sheets already fed from the sheet feed tray 25. In this way, it is possible to perform printing on already fed paper, and it is not necessary to remove the white paper discharged from the paper discharge tray 33 without wasting paper. Next, an inquiry is made to the main process whether all the fed paper has been discharged to the main process and whether reception of print data and storage of the received data in the HDD has been completed (S100). When completed, a command is sent to the main process to shift the image forming apparatus 100 to a standby state (S110). When the main process receives the standby state transition command, it transmits an error notification to the PC, stores the state of the image forming apparatus 100 in the memory, and transitions to the standby state. In the standby state, the apparatus operation is stopped until the power is turned on again, that is, the power failure is resolved. When the power is turned on again, the main control unit 30 executes the start program, and the state of the image forming apparatus 100 before the power failure stored in the memory at that time is read from the memory and stored in the HDD. The suspended job is resumed using the print data.

  If T1 is less than 180 ° C. in S80, it is determined whether T1 is the third threshold value 170 ° C. or more (S120). If T1 is 170 ° C. or higher, a new page image formation prohibition command is transmitted to the main process (S130). As a result, the main process continues image formation for pages that are already being written, and stops new writing after the writing of the pages is completed. Since the already fed paper is discharged as white paper, the user needs to remove the discharged white paper.

  If T1 is less than 170 ° C. in S120, a command to immediately stop the image formation being executed is transmitted (S140). As a result, the toner image formation is interrupted in the middle of the page. When a sheet on which toner adheres while the surface temperature of the heating roller 408 is low passes through the heating roller 408, the toner remains on the heating roller 408 and the surface of the roller becomes dirty, so that the sheet is discharged with as little toner as possible. . In addition, since the already fed paper is ejected during printing or blank paper, the user needs to remove the ejected paper.

  If Vc is less than V1 in S60, it is determined that it is difficult to continue driving the motor or the like, and a command to immediately stop the image formation being executed is transmitted (S145). As a result, the toner image formation is interrupted in the middle of the page. At this time, by continuing to drive only the heating roller 408 and the pressure roller 410, it is possible to prevent the sheet from remaining in the fixing unit 40 and overheating the sheet.

  If the job being executed in S50 is not a print job, it is determined whether Vc is greater than or equal to the fourth threshold value V2 (S150). If Vc is equal to or higher than V2, a command for prohibiting new job execution is transmitted to the main process (S160). As a result, the main process continues for the job being executed and does not execute another job thereafter. Next, an inquiry is made to the main process as to whether the job being executed is completed (S170), and when the job is completed, a command for shifting to the standby state is transmitted to the main process (S110).

  If Vc is less than V2 in S150, it is determined that it is difficult to continue driving the control system component, and a command for forcibly stopping the job being executed is transmitted to the main process (S180).

  Finally, the description of the above-described embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a block diagram of an image forming apparatus according to an embodiment of the present invention. 1 is a detailed block diagram of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a diagram illustrating a configuration of a fixing unit in the image forming apparatus according to the embodiment of the present invention. 3 is a flowchart illustrating a flow of a control unit of the image forming apparatus according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10- 1st connection part 12- 2nd connection part 14- 3rd connection part 16- 4th connection part 17- Photoconductor 20- Commercial power supply 24- Charging part 25- Paper feed tray 26- Power storage part 30 -Main control unit 34-ROM
39-Transfer mechanism 50-Voltage detection unit 200-Power failure detection unit 406-Thermistor 408-Heating roller

Claims (6)

Power storage means capable of storing DC power to be supplied to each part of the apparatus body;
Charging means for charging the power storage means using electric power from a commercial power source;
Voltage detection means for detecting a voltage across the power storage means;
Control means for controlling the apparatus body and executing one of a plurality of types of jobs;
A power failure detection means for detecting stoppage of power supply from a commercial power source,
Storage means for storing a control program for controlling each part of the apparatus body;
With
When a power failure is detected by the power failure detection means during execution of the job, the control means detects the DC power accumulation status of the power storage means by the voltage detection means, and the detection result and the job being executed are detected. An image forming apparatus that determines whether or not to continue a job being executed based on a type. The storage means stores a first threshold value indicating a minimum effective voltage value with which the apparatus main body can continue a print job being executed,
When a power failure is detected by the power failure detection means during execution of a print job, the control means detects the DC power storage state of the power storage means by the voltage detection means, and the voltage across the power storage means If the threshold value is 1 or more, it is determined to continue the print job being executed, and if the voltage across the power storage means is less than the first threshold value, it is determined to interrupt the print job being executed. Item 2. The image forming apparatus according to Item 1. A paper feeding unit for loading the recording medium and feeding the recording medium to the apparatus main body;
A photoreceptor carrying an image on the surface;
A transfer portion for transferring an image of the surface of the photoreceptor to a recording medium;
A fixing unit for fixing the image transferred onto the recording medium by the transfer unit to the recording medium;
A temperature detection unit for detecting a surface temperature of the fixing unit;
Further comprising
The storage means has a minimum effective temperature at which the fixing unit can fix the image transferred onto the recording medium in all the recording media from the paper feeding unit to the fixing unit. 2 thresholds are stored,
When a power failure is detected by the power failure detection means during execution of a print job, the control means detects the DC power storage state of the power storage means by the voltage detection means, and the voltage across the power storage means If the surface temperature of the fixing unit is greater than or equal to a threshold value of 1, the surface temperature of the fixing unit is detected by the temperature detection unit, and if the surface temperature of the fixing unit is equal to or greater than a second threshold value, it is determined to continue the current print job. 3. The image according to claim 2, wherein if the surface temperature of the fixing unit is lower than a second threshold value or the voltage across the power storage unit is lower than the first threshold value, it is determined to interrupt the print job being executed. Forming equipment.   When a power failure is detected by the power failure detection means during execution of a print job, the control means detects the DC power storage state of the power storage means by the voltage detection means, and the voltage across the power storage means If the surface temperature of the fixing unit is equal to or greater than a threshold value of 1, the temperature detection unit detects the surface temperature of the fixing unit. If the surface temperature of the fixing unit is equal to or greater than a second threshold value, all the sheets fed from the sheet feeding unit are detected. It is determined to continue image formation until image formation on the recording medium is completed and to discharge all the recording media fed from the paper feeding unit, and the surface temperature of the fixing unit is less than a second threshold value. If there is, the image formation is continued until the image formation is completed on the recording medium that has reached the transfer unit among the recording media fed from the paper feeding unit, and all the media fed from the paper feeding unit Eject recording medium To determine that, if the voltage across said energy storage means is smaller than the first threshold value, the image forming apparatus according to claim 3, decide to immediately stop the image formation on the recording medium. The storage means has a third effective temperature indicating a minimum effective temperature at which the image transferred onto the recording medium can be fixed on the recording medium in all the recording media from the transfer section to the fixing section. Remembers the threshold of
When a power failure is detected by the power failure detection means during execution of a print job, the control means detects the DC power storage state of the power storage means by the voltage detection means, and the voltage across the power storage means If the surface temperature of the fixing unit is greater than or equal to a threshold value of 1, the temperature detection unit detects the surface temperature of the fixing unit, and if the surface temperature of the fixing unit is equal to or greater than a third threshold value, the recording medium fed from the sheet feeding unit Among them, it is determined to continue image formation until image formation on the recording medium that has reached the transfer section is completed and to discharge all recording media fed from the sheet feeding section. If the surface temperature is lower than the third threshold value, it is determined to immediately stop image formation on the recording medium and to discharge all the recording media fed from the paper feeding unit, and the voltage across the power storage means is First threshold If full, the image forming apparatus according to claim 3 or 4 determines to immediately stop the image formation on the recording medium. The storage means stores a fourth threshold value indicating a minimum effective voltage value at which a job other than a print job being executed by the apparatus main body can be continued.
When the power failure detection unit detects a power failure during execution of a job other than a print job, the control unit detects a DC power accumulation state of the power storage unit by the voltage detection unit, and detects both ends of the power storage unit. If the voltage is greater than or equal to the fourth threshold, it is decided to complete the execution of the ongoing job and shift to the standby state. If the voltage across the power storage means is less than the fourth threshold, job execution The image forming apparatus according to claim 1, wherein the image forming apparatus determines to interrupt the operation and shift to a standby state.

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