JP2017097249A - Fixing control device, image forming apparatus, fixing control method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve optimization of a power supplied to heating means that heats a fixing member at the start of supply of a power from a power source.SOLUTION: In an image forming apparatus 1, a fixing control part 110 detects a voltage of a power from an external power source PS with a voltage detector 81, and a heater control part 100 controls a duty ratio to turn on or off the power from the external power source PS to control the amount of power supplied to a fixing heater 30c. An arithmetic processing part 71, when the voltage of the power from the external power source PS detected by the voltage detector 81 falls below a predetermined voltage at the start of supply of a power from a power source to the fixing heater 30c, sets an upper limit of an on-duty control range controlled by the heater control part 100 to a predetermined upper limit or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fixing control device, an image forming apparatus, a fixing control method, and a program. More specifically, the present invention relates to a fixing control device, an image forming apparatus, a fixing control method, and a program for controlling power supplied to a heating unit of a fixing unit. .

  In an electrophotographic image forming apparatus, a recording agent image such as a toner image (hereinafter simply referred to as toner image) transferred onto a recording medium (hereinafter simply referred to as paper) such as paper or film. In order to fix the sheet on the sheet, the sheet is heated by the fixing unit.

  In general, the fixing unit heats a fixing member such as a fixing roller (hereinafter, appropriately referred to as a fixing roller) to a fixing temperature by a fixing heater, and fixes the toner image on the sheet to the sheet.

  In an electrophotographic image forming apparatus including a fixing unit having such a fixing heater, an inrush current may flow when power supply to the fixing heater is started during warm-up or printing. Voltage that causes the power supply voltage supplied to the image forming device to drop due to inrush current when the power cord wiring to the image forming device is in a poor power supply situation, such as a long wire such as a saddle or reel cable A descent may occur.

  When the power supply voltage drop occurs, the power supplied to the fixing heater decreases, causing the occurrence of fixing failure and the fixing roller does not rise to a predetermined fixing temperature. The image forming operation may be stopped.

  Conventionally, in an image forming apparatus including a fixing device that performs fixing by a heater unit and a power supply unit that supplies power to the heater unit, the power supply unit includes a voltage detection unit that detects an input voltage, and the heater. There is proposed an image forming apparatus that has a heater on / off switching unit that turns on / off the unit, and the heater on / off switching unit switches on / off of the heater unit based on a detection voltage result by the voltage detection unit when the heater is off. (See Patent Document 1).

  That is, in this conventional technique, the heater unit is switched on / off based on the detection voltage result when the heater is off.

  However, in the above prior art, since the heater unit is only switched on / off based on the detection voltage result when the heater is turned off, the power supply voltage is lowered due to the inrush current when the supply of power to the fixing heater is started. However, there is a need for improvement in improving the fixing accuracy and providing a stable operation.

  In view of the above, an object of the present invention is to improve the optimization of the power supply at the start of the supply of power to the heating means for heating the fixing member.

  In order to achieve the above object, the fixing control device according to claim 1 comprises a voltage detecting means for detecting the voltage of the input power supply power, a heating means for heating the fixing member by generating heat according to the amount of supplied power, Supply power amount control means for controlling the supply power amount to the heating means by controlling a duty ratio for turning on / off the input power supply power, and the voltage of the input power supply detected by the voltage detection means has a predetermined voltage. And an on-duty control means for setting the upper limit of the on-duty ratio by the supplied power amount control means to be equal to or lower than a predetermined upper limit value.

  According to the present invention, it is possible to improve the optimization of the supply power at the start of the supply of power to the heating means for heating the fixing member.

1 is a schematic configuration diagram of an image forming apparatus to which an embodiment of the present invention is applied. FIG. 3 is a block diagram of a main part of the image forming apparatus. The functional block diagram of a fixing control part. 5 is a flowchart showing fixing control processing. The figure which shows an example of the voltage change of the external power supply accompanying on-duty control. 6 is a flowchart showing a fixing control process with a power supply abnormality determination. 7 is a flowchart showing a fixing control process with determination of suitability for voltage detection function.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, since the Example described below is a suitable Example of this invention, various technically preferable restrictions are attached | subjected, However, The range of this invention is unduly limited by the following description. However, not all the configurations described in the present embodiment are essential constituent elements of the present invention.

  1 to 7 are diagrams showing an embodiment of a fixing control device, an image forming apparatus, a fixing control method, and a program according to the present invention. FIG. 1 shows a fixing control device, an image forming apparatus, and a fixing control according to the present invention. 1 is a schematic configuration diagram of an image forming apparatus 1 to which an embodiment of a method and a program is applied.

  In FIG. 1, the image forming apparatus 1 includes a main body housing 2 in which a paper feeding unit 10, a transport unit 20, a printer unit 40, and the like are housed, and a paper discharge tray 3 is provided on the upper part of the main body housing 2. Yes. Although not shown, the image forming apparatus 1 includes an operation display unit, and the operation display unit includes various operation keys and a display.

  The paper supply unit 10 includes a paper supply tray 11, a paper supply roller 12, a separation pad (not shown), and the like, and a plurality of sheets (recording medium) P are stored in the paper supply tray 11. The paper feed unit 10 separates the paper P in the paper feed tray 11 one by one by the paper feed roller 12 and the separation pad, and sends the paper P to the transport unit 20.

  The transport unit 20 includes a forward transport path 21, a double-sided transport path 22, a registration roller 23, a secondary transfer roller 24, a paper discharge roller 25, a double-sided roller 26, a registration sensor 27, a paper discharge sensor 28, a double-sided sensor 29, and a fixing unit. 30 and a plurality of conveyance rollers (not shown). The conveyance unit 20 conveys the paper P sent out from the paper supply unit 10 on the forward conveyance path 21 to the registration roller 23, and the registration sensor 27 detects the paper P conveyed to the registration roller 23. The image forming apparatus 1 temporarily stops the conveyance of the paper P by the registration roller 23, and then drives the registration roller 23 based on the detection result of the paper P by the registration sensor 27 and the toner image formation status in the printer unit 40. Control. The image forming apparatus 1 adjusts the timing of the paper P with the toner image formed by the printer unit 40, drives the registration roller 23, and conveys it to the secondary transfer roller 24. As will be described later, the transport unit 20 transfers the color toner image formed by the printer unit 40 onto the paper P transported from the registration roller 23 by the secondary transfer roller 24, and fixes the paper P to the fixing unit 30. Transport to.

  The fixing unit 30 includes a fixing roller (fixing member) 30a and a pressure roller 30b. The sheet P is sandwiched between the fixing roller 30a and the pressure roller 30b, and the sheet P is heated and heated while being conveyed. The toner image (recording agent image) on the paper P is fixed on the paper P. The fixing unit 30 conveys the paper P that has been fixed to the paper discharge roller 25.

  In the transport unit 20, when the paper discharge sensor 28 detects the paper P transported to the paper discharge roller 25 and the paper P performs double-sided image formation, the paper P is the paper P on which image formation on one side has been completed. Then, the paper discharge roller 25 is reversed at an appropriate timing and sent to the duplex conveying path 22. When the conveyance unit 20 sends the paper P to the double-sided conveyance path 22, the double-sided roller 26 conveys the paper P, and the double-sided sensor 29 detects the paper P conveyed on the double-sided conveyance path 22. The transport unit 20 transports the paper sent to the double-sided transport path 22 again from the double-sided transport path 22 to the registration roller 23, forms an image on the back surface of the paper P, and fixes it by the fixing unit 30 as described above. The paper is discharged onto the paper discharge tray 3 by the paper discharge roller 25.

  The printer unit 40 includes an intermediate transfer unit 41, process cartridges 42C, 42M, 42Y, and 42K for each color of C (cyan), M (magenta), Y (yellow), and K (black), an exposure unit 43, and a calibration unit. A sensor 44, a waste toner box 45, and the like are provided. The intermediate transfer unit 41 includes an intermediate transfer belt 51, a secondary transfer driving roller 52, a tension roller 53, transfer rollers 54Y, 54M, 54C, and 54K for CMYK colors. In the intermediate transfer unit 41, an intermediate transfer belt 51 formed in an endless belt-like ring shape is stretched between a secondary transfer driving roller 52 and a tension roller 53 that are stretched in a substantially horizontal direction. The secondary transfer driving roller 52 is disposed in contact with the secondary transfer roller 24 with the intermediate transfer belt 51 interposed therebetween.

  In the printer unit 40, CMYK process cartridges 42Y, 42M, 42C, and 42K are disposed along the intermediate transfer belt 51. The process cartridges 42Y, 42M, 42C, and 42K are respectively charged around the photoconductors 61Y, 61M, 61C, and 61K that are rotationally driven in the clockwise direction in FIG. 1, and charging rollers 62Y, 62M, 62C, and 62K, and developing / toner storage units. 63Y, 63M, 63C, 63K and cleaning units 64Y, 64M, 64C, 64K, etc. are accommodated in a cartridge case (not shown). Each of the process cartridges 42Y, 42M, 42C, and 42K is in contact with the photoconductors 61Y, 61M, 61C, and 61K facing the transfer rollers 54Y, 54M, 54C, and 54K for each color with the intermediate transfer belt 51 interposed therebetween. In the state, it is housed and mounted in the main body housing 2. In the printer unit 40, the intermediate transfer belt 51 is conveyed between the photosensitive members 61Y, 61M, 61C, and 61K of the process cartridges 42Y, 42M, 42C, and 42K and the transfer rollers 54Y, 54M, 54C, and 54K.

  Although not shown, the exposure unit 43 includes a polygon motor, a polygon mirror, an Fθ lens, a laser diode, a mirror, and the like. The exposure unit 43 emits the writing light for the process cartridges 42Y, 42M, 42C, and 42K for each color modulated based on the image data for each color from the laser diode to a polygon mirror that is rotationally driven by a polygon motor. The exposure unit 43 deflects the writing light in the main scanning direction by a polygon mirror, passes through an fθ lens, a mirror, and the like, and as indicated by broken line arrows in FIG. 1, each process cartridge 42Y, 42M, 42C. , 42K charging rollers 62Y, 62M, 62C, and 62K are uniformly irradiated to the photosensitive members 61Y, 61C, 61M, and 61K, and electrostatic latent images are formed on the photosensitive members 61Y, 61C, 61M, and 61K of the respective colors. Form.

  The printer unit 40 rotates the photoconductors 61Y, 61C, 61M, and 61K on which the electrostatic latent images are formed in the clockwise direction, and supplies the toner of each color to the photoconductor 61Y by the developing / toner storage units 63Y, 63M, 63C, and 63K. , 61C, 61M, and 61K to develop the electrostatic latent image. The printer unit 40 sequentially superimposes and transfers the color toner images on the intermediate transfer belt 51 by the transfer rollers 54Y, 54M, 54C, and 54K onto the photoreceptors 61Y, 61C, 61M, and 61K on which the toner images of the respective colors are formed. Form. The printer unit 40 further rotates the photoreceptors 61Y, 61C, 61M, and 61K that have completed the transfer of the toner images to remove residual toner by the cleaning units 64Y, 64M, 64C, and 64K. It is charged with 62M, 62C, 62K and used for image formation.

  The intermediate transfer belt 51 is driven to rotate counterclockwise by the secondary transfer driving roller 52, and is conveyed to the sheet P conveyed from the registration roller 23 between the secondary transfer driving roller 52 and the secondary transfer roller 24. Transfer the toner image.

  Note that the printer unit 40 retracts the transfer rollers 54Y, 54M, and 54C other than the black transfer roller 54K to positions separated from the photoreceptors 61Y, 61M, and 61C in the case of printing only black. Image formation.

  Further, the printer unit 40 forms a pattern image on the intermediate transfer belt 51 in order to perform calibration processing such as predetermined color misregistration correction processing and density adjustment processing, and this pattern image is detected by the calibration sensor 44. To do. For example, a reflection type optical sensor is used as the calibration sensor 44, and detects the position and density of the pattern image formed on the intermediate transfer belt 51 by the process cartridges 42Y, 42M, 42C, and 42K.

  The main part of the power supply system of the image forming apparatus 1 is configured as a block as shown in FIG. That is, the image forming apparatus 1 includes a control unit 70, a power supply unit 80, a paper feed / conveyance / printer unit 90, a fixing unit 30, a heater control unit 100, and the like.

  As described above, the fixing unit 30 includes a fixing roller (fixing member) 30a and a pressure roller 30b that are rotatably arranged. The fixing roller 30a is set in a predetermined standby state by a built-in fixing heater 30c. The temperature is controlled to the fixing temperature.

  As the fixing heater (heating means) 30c, for example, a halogen heater is used, and heat is generated according to the energization amount to heat the fixing roller 30a.

  The fixing unit 30 is provided with a thermistor 30d near the surface of the fixing roller 30a. The thermistor 30d detects the surface temperature of the fixing roller 30a and outputs the detected temperature to the control unit 70. The thermistor 30d may be either a contact type or a non-contact type that detects the temperature by contacting the surface of the fixing roller 30a.

  The power supply unit 80 is supplied with commercial external power (input power) PS via a power switch (not shown) of the image forming apparatus 1. The power supply unit 80 includes a rectifier such as an AC / DC converter, and performs processing such as AC / DC (alternating current / direct current) conversion, voltage conversion, and rectification on the external power supply power PS to each unit of the image forming apparatus 1. Supply AC and DC power.

  The power supply unit 80 includes a voltage detector 81, and the voltage detector 81 detects the voltage of the external power supply power PS and outputs the detected voltage to the control unit 70. The voltage detector 81 may directly detect the voltage of the AC external power supply power PS, or detects the DC voltage that the power supply unit 80 has converted into AC (AC) / DC (DC). It may be. Further, the voltage detector 81 does not need to be stored in the power supply unit 80, and may be disposed in front of the power supply unit 80, for example.

  The heater control unit 100 uses a triac or the like, and turns on and off the AC power (AC power) supplied from the power unit 80 in accordance with the control duty ratio from the control unit 70 to fix the heater. Control of the supply of heating power to the heater 30c is controlled. The heater control unit 100 is not limited to the triac.

  The paper feed / conveyance / printer unit 90 is a general term for the paper feed unit 10, the transport unit 20, and the printer unit 40, and is supplied with driving power from a power supply unit 80.

  The control unit 70 includes an arithmetic processing unit 71 and a ROM (Read Only Memory), a RAM (Random Access Memory), a nonvolatile memory, and the like (not shown). The arithmetic processing unit 71 is used by a CPU (Central Processing Unit) or the like. It has been. The ROM stores a basic program of the image forming apparatus 1, a program such as a program of the fixing control method of the present invention, system data, and the like, and the RAM is used as a work memory of the arithmetic processing unit 71.

  For example, NVRAM (Non Volatile RAM) is used as the nonvolatile memory, and data that needs to be stored even when the power supply of the image forming apparatus 1 is OFF is stored. In particular, the nonvolatile memory stores various data used in the fixing control process of the present invention, for example, the duty control range value of the heater control unit 100 that controls the temperature of the fixing heater 30c, the duty upper limit value used in the fixing control method of the present invention, and the like. Is stored.

  Here, the duty control range value is a value of a duty control range that is set in advance to duty-control the fixing heater 30c to a control temperature such as a fixing temperature. The duty upper limit value is an upper limit value of an on-duty control range in which the heater control unit 100 is duty-controlled.

  The arithmetic processing unit 71 uses the RAM as a work memory based on a program in the ROM, controls each unit of the image forming apparatus 1, executes basic processing as the image forming apparatus 1, and performs fixing control of the present invention. Execute the process.

  The arithmetic processing unit 71 controls the duty ratio of the heater control unit 100 in the on-duty control range based on the temperature of the fixing roller 30a detected by the thermistor 30d at the time of fixing, so that the fixing roller 30a is fixed by the fixing heater 30c. The heating temperature is controlled to a predetermined fixing temperature. Further, the arithmetic processing unit 71 is based on the voltage value of the external power supply power PS detected by the voltage detector 81 when the power supply to the fixing heater 30c is started, such as when the image forming apparatus 1 is turned on or when image formation is started. The on-tuty value of the heater control unit 100 is controlled. In particular, when the voltage of the external power supply PS detected by the voltage detector 81 falls below a predetermined voltage, the arithmetic processing unit 71 sets the upper limit of the on-duty ratio (on-duty control range) by the heater control unit 100 below a predetermined upper limit value. Set to.

  Further, the arithmetic processing unit 71 detects whether the voltage detector 81 is abnormal. That is, when the detection voltage of the voltage detector 81 is fixed at the upper limit or the lower limit, the arithmetic processing unit 71 determines that an abnormality (failure) such as a short circuit or an open (disconnection) has occurred in the voltage detector 81.

  If the arithmetic processing unit 71 determines that the abnormality is present, it stops the power supply to the fixing heater 30c by the operation of the heater control unit 100 and / or the output control of the power supply power of the power supply unit 80, and if necessary, Then, the power supply to the paper feed / conveyance / printer unit 90 is stopped.

  The control unit 70, the voltage detector 81, and the heater control unit 100 function as a fixing control unit (fixing control device) 110 as a whole.

  The fixing controller 110 includes a ROM, an EEPROM (Electrically Erasable and Programmable Read Only Memory), an EPROM, a flash memory, a flexible disk, a CD-ROM (Compact Disc Read Only Memory), a CD-RW (Compact Disc Rewritable), and a DVD (Digital ROM of the control unit 70 by reading a program for executing the fixing control method of the present invention recorded on a computer-readable recording medium such as Versatile Disk (SD), Secure Digital (SD) card, and Magneto-Optical Disc (MO) Is used to perform a fixing control method for improving the optimization of power supply at the start of supply of power to a fixing heater 30c, which is a heating means for heating a fixing roller 30a, which will be described later. The image forming apparatus 1 is constructed as a control apparatus, and the image forming apparatus 1 includes the fixing control apparatus. Is built as. The fixing control method program is a computer-executable program written in a legacy programming language such as assembler, C, C ++, C #, Java (registered trademark) or an object-oriented programming language, and is stored in the recording medium. And can be distributed.

  Then, the fixing control unit 110 constructs a functional block as shown in FIG. 3 by introducing the fixing control method program. That is, when the program is introduced, the fixing control unit 110 includes a voltage detection unit 121, a heating unit 122, a supply power amount control unit 123, an on-duty control unit 124, and an abnormality detection unit 125, as shown in FIG. Built.

  The voltage detection unit 121 is constructed by the voltage detector 81 and detects the voltage of the external power supply power PS that is input power supply power. The voltage detection unit 121 may directly detect AC external power supply power (input power supply power) PS, or may convert the external power supply power PS into direct current and detect the voltage of the DC power supply power. Therefore, the voltage detection unit 121 is constructed as a voltage detection unit.

  The heating unit 122 is constructed by the fixing heater 30c and generates heat according to the amount of supplied power to heat the fixing roller 30a that is a fixing member. Therefore, the heating unit 122 functions as a heating unit.

  The supply power amount control unit 123 is constructed by the heater control unit 100 and controls the amount of power supplied to the heating unit 122 by controlling the duty ratio for turning on / off the external power supply power (input power supply power) PS. Accordingly, the supplied power amount control unit 123 functions as a supplied power amount control unit. When there are a plurality of fixing heaters 30c, the power supply amount control unit 123 individually controls the power supply amount for the plurality of fixing heaters 30c.

  The on-duty control unit 124 is constructed by the arithmetic processing unit 71 of the control unit 70, and when the voltage of the external power supply (input power supply) PS detected by the voltage detection unit 121 falls below a predetermined voltage, the supplied power amount control unit 123. The upper limit of the on-duty ratio is set to a predetermined upper limit value or less. In addition, the on-duty control unit 124 sets the upper limit value of the on-duty ratio by the supplied power amount control unit 123 when the voltage value of the external power source power (input power source power) PS detected by the voltage detection unit 121 decreases. At the same time, the upper limit value is set low, and when the set upper limit value falls below a predetermined upper limit value, the supply of power to the heating unit 122 is stopped. Further, when the supply power amount control unit 123 individually controls the supply power amount for the plurality of fixing heaters 30c, the voltage of the external power supply power (input power supply power) PS detected by the voltage detection unit 121 has a predetermined voltage. If it falls below, the number of the fixing heaters 30c as the power supply destination by the power supply amount control unit 123 is reduced, and the upper limit of the on-duty ratio to the fixing heater 30c as the power supply destination is set to a predetermined upper limit value or less. Therefore, the on-duty control unit 124 functions as on-duty control means.

  The abnormality detection unit 125 is constructed by the arithmetic processing unit 71, and detects whether or not the voltage detection unit 121 (voltage detector 81) is abnormal. For example, the abnormality detection unit 125 detects the presence or absence of abnormality depending on whether or not the voltage detector 81 continues to detect an upper limit or lower limit voltage value due to an open failure, a short failure (short state), or the like. For example, if an open failure occurs in the voltage detection unit 121, the detection voltage is fixed at the upper limit or the lower limit by a pull-up resistor or a pull-down resistor.

  In this case, the on-duty control unit 124 stops the power supply to the fixing heater 30c when the abnormality detection unit 125 detects an abnormality in the voltage detection unit 121, that is, the voltage detector 81, and if necessary, The power supply to the paper feed / conveyance / printer unit 90 is stopped.

  Next, the operation of this embodiment will be described. In the image forming apparatus 1 according to the present exemplary embodiment, the fixing control unit 110 has a supply power at the start of supply of power to a heating unit (fixing heater 30c) that is a heating unit that heats the fixing roller 30a that is a fixing member. Improve optimization.

  That is, the image forming apparatus 1 starts supplying power to the fixing heater 30c of the fixing unit 30 when the power switch is turned on, when returning from the power saving mode, or the like. At the start of the supply of power to the fixing heater 30c, an inrush current flows if the external wiring status of the image forming apparatus 1 is a long wiring such as a saddle wiring or a reel cable. The voltage of the external power source power PS may decrease. When such a decrease in the external power supply power PS occurs, the power supplied to the fixing heater 30c decreases to cause a fixing failure or the fixing roller 30a does not rise to a predetermined fixing temperature. However, the image forming operation may be stopped because it is determined that the fixing is abnormal.

  Therefore, in the image forming apparatus 1 of the present embodiment, the fixing control unit 110 improves the optimization of the supply power at the start of the supply of power to the fixing heater 30c that heats the fixing roller 30a.

  That is, as shown in FIG. 4, when the fixing control unit 110 starts to supply power to the fixing heater 30c (step S101), the voltage detection unit 121 measures the voltage value of the external power source PS that is an AC power source. Is started (step S102).

  The on-duty control unit 124 checks whether the detection voltage of the voltage detection unit 121 is equal to or lower than a preset lower limit voltage (step S103). The set lower limit voltage is, for example, the lower limit value of the operation guarantee voltage of the image forming apparatus 1.

  When the detected voltage value exceeds the set lower limit voltage (NO in step S103), the on-duty control unit 124 normally sets the on-duty ratio of the fixing control without changing the on-duty control range of the fixing control. The on-duty control range. Then, the on-duty control unit 124 performs duty control of the supplied power amount control unit 123 within the determined on-duty control range (step S104), and the supplied power amount control unit 123 performs duty control on the external power supply power PS, Power is supplied to the heating unit 122.

  If the detected voltage value is equal to or lower than the set lower limit voltage (YES in step S103), the on-duty control unit 124 changes the on-duty control range of the fixing control to an on-duty control range in which the upper limit is lowered by a predetermined amount. To do. The on-duty control unit 124 starts duty control of the supplied power amount control unit 123 within the determined on-duty control range (step S105). For example, the on-duty control unit 124 changes the on-duty control range that was 80% to an on-duty control range that is lowered to 60%.

  The on-duty control unit 124 checks whether the detection voltage detected by the voltage detection unit 121 is equal to or lower than the set lower limit voltage (step S106).

  If the detected voltage is equal to or lower than the set lower limit voltage in step S106 (YES in step S106), the on-duty control unit 124 performs control to lower the upper limit of the on-duty control range by a predetermined amount (step S105). The on-duty control unit 124 repeatedly performs control to lower the upper limit of the on-duty range until the detected voltage becomes higher than the set lower limit voltage (steps S105 and S106).

  That is, when the power is turned on at the time indicated by the dashed circle in FIG. 5, the voltage of the external power supply PS (described as AC voltage in FIG. 5) decreases due to the inrush current. It falls below the set lower limit voltage. When the voltage of the external power supply power PS becomes equal to or lower than the set lower limit voltage, the fixing control unit 110 sets the upper limit of the on-duty control range of the duty control for the on-duty control unit 124 to turn on / off the supplied power amount control unit 123. Decrease the amount. By reducing the upper limit of the on-duty control range of the supply power amount control unit 123, the external power supply power Ps used for heating the heating unit 122 is reduced by that amount, and the voltage of the external power supply power PS is shown in FIG. Thus, it becomes higher than the set lower limit voltage. The fixing control unit 110 performs control to adjust the upper limit of the on-duty control range so that the voltage does not fall below the set lower limit voltage while monitoring the voltage of the external power supply power PS.

  If the detected voltage value exceeds the set lower limit voltage in step S106 (NO in step S106), the on-duty control unit 124 ends the control to lower the upper limit of the on-duty control range, Return to duty control.

  Therefore, when the supply of power to the fixing heater 30c is started, a voltage drop may occur in a situation where the voltage of the external power supply PS is not stable or in a long wiring such as a saddle wiring or a reel cable. In such a case, the power supply amount to the fixing heater 30c can be suppressed by lowering the upper limit of the on-duty control range of the power supply to the fixing heater 30c. As a result, even if there is no abnormality in the main body of the image forming apparatus 1 or the fixing unit 30 due to a voltage drop at a normal fixing control on-duty, it is determined that the fixing unit 30 is abnormal, and the image forming apparatus 1 itself It is possible to prevent the occurrence of time when the system is stopped and not operating. In addition, when the main body of the image forming apparatus 1 is stopped, it is possible to reduce costs such as service for restoration.

  Further, in the fixing control, when the voltage drop of the external power source power PS does not occur, the fixing control is not changed, and the on-duty control range of the normal control is set. Therefore, the warm-up time is extended and the productivity is increased. It is possible to prevent the decrease.

  In the suppression control of the power supply amount to the fixing heater 30c, not only the upper limit of the on-duty control range is lowered, but when there are a plurality of fixing heaters 30c, the number of fixing heaters 30c for supplying power is reduced. Control may also be performed.

  In this way, when there are a plurality of fixing heaters 30c, the amount of power supplied to the fixing heater 30c can be more effectively controlled, and supply at the start of supply of power to the fixing heater 30c. The optimization of electric power can be further improved.

  Further, the fixing control unit 110 may perform the fixing control process as shown in FIG. 6 in consideration of the presence / absence of an abnormality in the external power supply power PS. In FIG. 6, the same processing steps as those in FIG. 4 are given the same step numbers to simplify the description.

  In FIG. 6, when the fixing control unit 110 starts to supply power to the fixing heater 30c (step S101), the voltage detection unit 121 starts measuring the voltage value of the external power source PS that is AC power (step S101). S102).

  The on-duty control unit 124 checks whether the detection voltage of the voltage detection unit 121 is equal to or lower than a preset lower limit voltage (step S103).

  If the detected voltage value exceeds the set lower limit voltage, the on-duty control unit 124 sets the fixing control to the normal on-duty control range without changing the on-duty control range of the fixing control. Then, the on-duty control unit 124 performs duty control of the supplied power amount control unit 123 within the determined on-duty control range (step S104), and the supplied power amount control unit 123 performs duty control on the external power supply power PS, Power is supplied to the heating unit 122.

  When the detected voltage value is equal to or lower than the set lower limit voltage, the on-duty control unit 124 changes the on-duty control range of the fixing control to an on-duty control range in which the upper limit is lowered by a predetermined amount. The on-duty control unit 124 starts duty control of the supplied power amount control unit 123 within the determined on-duty control range (step S105).

  When the on-duty control unit 124 starts control to lower the upper limit of the on-duty control range, the on-duty control unit 124 checks whether the upper limit of the on-duty is equal to or less than a predetermined value (step S201). This fixed value is, for example, the upper limit value of the on-duty at which it is determined that the fixing heater 30c does not rise to the fixable temperature.

  In step S201, when the upper limit of the on-duty control range is higher than a certain value (NO in step S201), the on-duty control unit 124 detects the detected voltage detected by the voltage detecting unit 121 is equal to or lower than the set lower limit voltage. Is checked (step S106). If the detected voltage is equal to or lower than the set lower limit voltage in step S106, control is performed to lower the upper limit of the on-duty control range by a predetermined amount (step S105). The on-duty control unit 124 performs control to lower the upper limit of the on-duty range in a range where the upper limit of the on-duty does not become a certain value or less until the detection voltage becomes higher than the set lower limit voltage (steps S105, S201, S106). ).

  If the detected voltage exceeds the set lower limit voltage in step S106, the on-duty control unit 124 ends the control to lower the upper limit of the on-duty control range and returns to normal duty control.

  If the upper limit of the on-duty becomes equal to or less than a certain value in step S201 (YES in step S201), the on-duty control unit 124 determines that the external power supply power PS is abnormal (step S202). When the on-duty control unit 124 determines that the external power source power PS is abnormal, the on-duty control unit 124 stops the power supply to the fixing heater 30c and ends the fixing control process (step S203).

  Accordingly, the fixing control unit 110 performs control to lower the upper limit of the on-duty control range at the start of power supply to the fixing heater 30c, and the on-duty upper limit value drops to a value at which the fixing heater 30c does not rise to the fixing temperature. It is determined that the external power source power PS is abnormal. Then, the fixing control unit 110 can stop the supply of power to the fixing heater 30c without performing image formation.

  When the fixing control unit 110 determines that the external power source power PS is abnormal and stops supplying the power source power to the fixing heater 30c, the fixing control unit 110 displays that fact on the display of the operation display unit of the image forming apparatus 1. Notification may be made by sending e-mail to the user.

  In this way, the image formation is not performed, the user can be made to recognize the reason why the energization to the fixing heater 30c is stopped, and the user can be encouraged to take a countermeasure against the occurrence of the abnormality.

  Further, as shown in FIG. 7, the fixing control unit 110 may determine whether or not the voltage detection unit 121 is abnormal and perform a fixing control process.

  That is, in FIG. 7, the fixing control unit 110 determines whether or not there is an abnormality in the voltage detector 121 that detects the voltage of the external power supply power PS, that is, the voltage detector 81 before starting the fixing (step S301). Is detected by the abnormality detection unit 125 (step S302). The abnormality detection unit 125, that is, the arithmetic processing unit 71 determines whether there is an abnormality, that is, the external power supply power depending on whether or not the voltage detection unit 121 (voltage detector 81) continues to detect the upper limit or lower limit voltage value. It is detected whether or not the voltage detection function of the PS is out of order.

  In step S302, if there is no abnormality in voltage detection unit 121 (NO in step S302), on-duty control unit 124 determines whether the voltage value of external power supply power PS is equal to or lower than the set lower limit voltage as described above. The energization control to the fixing heater 30c is performed based on whether or not. That is, the on-duty control unit 124 determines whether the voltage value of the external power supply power PS detected by the voltage detection unit 121 is equal to or lower than the set lower limit voltage value (step S303). When the voltage value of the external power supply power PS is equal to or lower than the set lower limit voltage value, the on-duty control unit 124 performs energization control to the fixing heater 30c by duty control that lowers the upper limit of the on-duty control range (step S304).

  If the voltage detection unit 121 is abnormal in step S302 (YES in step S302), the on-duty control unit 124 changes the on-duty control range of the fixing heater 30c based on the detection voltage of the voltage detection unit 121. Control is stopped (step S305). In this case, the image forming apparatus 1 may stop the power supply to the paper feed / conveyance / printer unit 90 to stop the image forming operation, and the fixing temperature control function based on the thermistor 30d is normal. If so, the image forming operation including the fixing operation may be continued.

  Then, the fixing control unit 110 notifies the fact that there is an abnormality in the voltage detection of the external power supply power PS on the display of the operation display unit of the image forming apparatus 1 or by sending an e-mail to the user or service person. Then, the process ends (step S306).

  Therefore, it is possible to determine whether or not the voltage detector 121, that is, the voltage detector 81 is abnormal, and to appropriately cope with the decrease in the external power supply power PS, thereby improving the usability and safety. .

  As described above, in the image forming apparatus 1 according to the present exemplary embodiment, the fixing control unit 110 includes the voltage detection unit (voltage detection unit) 121 that detects the voltage of the external power supply power (input power supply power) PS and the supply power amount. Accordingly, the heating unit (heating unit) 122 that generates heat and heats the fixing roller (fixing member) 30a and the duty ratio for turning on / off the input power supply are controlled to control the amount of power supplied to the heating unit 122. When the voltage of the external power supply power PS detected by the supply power amount control unit (supply power amount control means) 123 and the voltage detection unit 121 falls below a predetermined voltage, the on-duty ratio of the supply power amount control unit 123 An on-duty control unit (on-duty control means) 124 for setting the upper limit to a predetermined upper limit value or less.

  Therefore, when the supply of the external power supply power PS to the heating unit 122, which is the fixing heater 30c, is started, if the voltage of the external power supply PS falls below a predetermined voltage such as an operation guarantee voltage of the image forming apparatus 1, the fixing heater 30c is supplied. The amount of power supply can be kept low. As a result, it is possible to improve the optimization of supply power at the start of supply.

  Further, in the image forming apparatus 1 of the present embodiment, the fixing control unit 110 detects a voltage of the external power source power (input power source power) PS, and the fixing heater 30c that generates heat according to the amount of supplied power. The heating unit 122 that heats the fixing member, which is the fixing roller 30a, and the duty ratio for turning on / off the external power supply power PS are controlled to control the amount of power supplied to the heating unit 122. When the voltage of the external power supply PS detected in the supply power amount control processing step and the voltage detection processing step falls below a predetermined voltage, the upper limit of the on-duty ratio in the supply power amount control processing step is less than or equal to a predetermined upper limit value An on-duty control processing step is set, and a fixing control method is executed.

  Therefore, when the supply of the external power supply power PS to the heating unit 122, which is the fixing heater 30c, is started, if the voltage of the external power supply PS falls below a predetermined voltage such as an operation guarantee voltage of the image forming apparatus 1, the fixing heater 30c is supplied. The amount of power supply can be kept low. As a result, it is possible to improve the optimization of supply power at the start of supply.

  Further, in the image forming apparatus 1 according to the present exemplary embodiment, the fixing control unit 110 fixes the control processor to the voltage detection process for detecting the voltage of the external power supply power PS and the heating unit 122 that generates heat according to the amount of power supplied. A heating process for heating the roller (fixing member) 30a; a supply power amount control process for controlling the supply power amount to the heating unit 122 by controlling a duty ratio for turning on / off the external power supply power PS; An on-duty control process for setting an upper limit of an on-duty ratio by the supplied power amount control process to be equal to or lower than a predetermined upper limit value when the voltage of the external power supply PS detected by the voltage detection process falls below a predetermined voltage. It has a program to let you.

  Therefore, when the supply of the external power supply power PS to the heating unit 122, which is the fixing heater 30c, is started, if the voltage of the external power supply PS falls below a predetermined voltage such as an operation guarantee voltage of the image forming apparatus 1, the fixing heater 30c is supplied. The amount of power supply can be kept low. As a result, it is possible to improve the optimization of supply power at the start of supply.

  Further, in the fixing control unit 110 of this embodiment, the on-duty control unit 124 detects the input power supply power that the voltage detection unit 121 detects the upper limit value of the on-duty ratio by the supply power amount control unit 123. As the voltage value decreases, the power value is set low, and when the set upper limit value falls below a predetermined upper limit value, the supply of power to the heating unit 122 is stopped.

  Accordingly, when the voltage value of the external power supply power PS drops to a voltage value at which the fixing heater 30c does not rise to the fixing temperature at the start of power supply to the fixing heater 30c, it is determined that the external power supply power PS is abnormal, and the fixing heater 30c. The supply of power to the power supply can be stopped. As a result, it is possible to further improve the optimization of the supply power at the start of the supply of the external power supply power PS to the heating unit 122 that is the fixing heater 30c.

  Further, in the fixing control unit 110 of this embodiment, the supply power amount control unit 123 individually controls the supply power amount for the plurality of heating units 122, and the on-duty control unit 124 includes the voltage detection unit. When the voltage of the external power source power PS detected by the power supply 121 falls below a predetermined voltage, the number of the heating units 122 as power supply destinations by the power supply amount control unit 123 is reduced and the heating unit 122 as a power supply destination is reduced. The upper limit of the on-duty ratio is set below a predetermined upper limit value.

  Therefore, when there are a plurality of fixing heaters 30c, the amount of power supplied to the fixing heater 30c can be controlled more effectively, and the appropriate power supply at the start of the supply of power to the fixing heater 30c can be controlled. Can be further improved.

  In the fixing control unit 110 of this embodiment, the voltage detection unit 121 converts the AC external power supply power PS into DC and detects the voltage of the DC power supply.

  Therefore, when the AC power source 80 converts the AC external power source power PS to DC, the voltage value converted to DC can be detected, and the voltage of the external power source PS can be detected easily and inexpensively.

  Further, the fixing control unit 110 according to the present embodiment further includes an abnormality detection unit (abnormality detection unit) 125 that detects whether or not the voltage detection unit 121 is abnormal, and the on-duty control unit 124 includes the abnormality detection unit. When 125 detects an abnormality in the voltage detection unit 121, the supply power amount control unit 123 stops the supply of power to the heating unit 122.

  Therefore, it is possible to determine whether or not the voltage detector 121, that is, the voltage detector 81 is abnormal, and to appropriately cope with the decrease in the external power supply power PS, thereby improving the usability and safety. .

  The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to that described in the above embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Main body housing | casing 3 Paper discharge tray 10 Paper feed part 11 Paper feed tray 12 Paper feed roller 20 Carrying part 21 Forward conveyance path 22 Double-sided conveyance path 23 Registration roller 24 Secondary transfer roller 25 Paper discharge roller 26 Both sides Roller 27 Registration sensor 28 Paper discharge sensor 29 Duplex sensor 30 Fixing unit 30a Fixing roller 30b Pressure roller 30c Fixing heater 30d Thermistor 40 Printer unit 41 Intermediate transfer unit 42C, 42M, 42Y, 42K Process cartridge 43 Exposure unit 44 Calibration sensor 45 Waste toner box 51 Intermediate transfer belt 52 Secondary transfer drive roller 53 Tension roller 54Y, 54M, 54C, 54K Transfer roller 61Y, 61M, 61C, 61K Photoconductor 62Y, 62M, 62C, 62K Charging roller 63 , 63M, 63C, 63K Development / toner storage section 64Y, 64M, 64C, 64K Cleaning section 70 Control section 71 Arithmetic processing section 80 Power supply section 81 Voltage detector 90 Paper feed / conveyance / printer section 30 Fixing section 100 Heater control section 110 Fixing control unit 121 Voltage detection unit 122 Heating unit 123 Supply power amount control unit 124 On-duty control unit 125 Abnormality detection unit P Paper PS External power supply power

JP2015-004891A

Claims (8)

Voltage detection means for detecting the voltage of the input power supply;
Heating means for heating the fixing member by generating heat according to the amount of supplied power;
Supply power amount control means for controlling the supply power amount to the heating means by controlling a duty ratio for turning on / off the input power supply power;
An on-duty control means for setting an upper limit of an on-duty ratio by the supplied power amount control means to be equal to or lower than a predetermined upper limit when the voltage of the input power source detected by the voltage detection means falls below a predetermined voltage;
A fixing control device comprising: The on-duty control means includes
The upper limit value of the on-duty ratio by the supply power amount control means is set to be lower as the voltage value of the input power supply power detected by the voltage detection means decreases, and the set upper limit value is The fixing control device according to claim 1, wherein when the value falls below a predetermined upper limit value, supply of electric power to the heating unit is stopped. The supplied power amount control means includes:
Individually controlling the amount of power supplied to the plurality of heating means,
The on-duty control means includes
When the voltage of the input power source detected by the voltage detection means falls below a predetermined voltage, the number of the heating means of the power supply destination by the supply power amount control means is reduced and the power supply destination to the heating means is reduced. The fixing control device according to claim 1, wherein an upper limit of the on-duty ratio is set to a predetermined upper limit value or less. The voltage detection means includes
4. The fixing control device according to claim 1, wherein the AC input power is converted into a direct current and the voltage of the DC power is detected. 5. The fixing control device includes:
An abnormality detection means for detecting the presence or absence of abnormality of the voltage detection means,
In addition,
The on-duty control means includes
5. The method according to claim 1, wherein when the abnormality detection unit detects an abnormality of the voltage detection unit, the supply power amount control unit stops supply of power to the heating unit. The fixing control device described. The recording agent image is transferred to the recording medium, and the recording medium image is heated by the heating unit whose temperature is controlled by controlling the amount of power supplied to the heating unit by the fixing control unit. An image forming apparatus for fixing to a recording medium,
An image forming apparatus comprising the fixing control device according to claim 1 as the fixing control unit. A voltage detection processing step for detecting the voltage of the input power supply;
A heat treatment step of heating the fixing member by a heating means that generates heat according to the amount of supplied power;
A supply power amount control processing step of controlling the supply power amount to the heating means by controlling a duty ratio for turning on / off the input power supply; and
An on-duty control processing step of setting an upper limit of an on-duty ratio in the supplied power amount control processing step to be equal to or lower than a predetermined upper limit value when the voltage of the input power supply detected in the voltage detection processing step is lower than a predetermined voltage; ,
A fixing control method characterized by comprising: To the control processor,
A voltage detection process for detecting the voltage of the input power supply;
A heat treatment for heating the fixing member by a heating means that generates heat according to the amount of power supplied;
A supply power amount control process for controlling the supply power amount to the heating means by controlling a duty ratio for turning on / off the input power supply; and
An on-duty control process for setting an upper limit of an on-duty ratio by the supplied power amount control process to be equal to or lower than a predetermined upper limit when the voltage of the input power supply detected by the voltage detection process is lower than a predetermined voltage;
A program characterized by having executed.

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