JP5206078B2 - Fixing device, printing device, and program - Google Patents

Description

  The present invention relates to a fixing device, a printing device, and a program.

  In a printing apparatus, a recording medium is sandwiched between a rotating body having a heat source for applying heat to the recording medium and a rotating body for pressurization arranged opposite to the rotating body, and the toner transferred to the recording medium, etc. Some have a fixing device for fixing an image forming material.

  In this fixing device, the heating member (or pressure member) may have a defect in which the recording medium is wound due to various factors such as static electricity of the recording medium, toner adhesion, oil supplied at the time of fixing, and the like. .

  For this reason, in order to detect the winding of the recording medium around one of the pair of rotating bodies, an optical sensor is arranged, and the winding of the recording medium is monitored based on the detection result of the optical sensor. Although it is conceivable, since the temperature around the fixing unit, the heating member, and the pressure member becomes high, the arrangement position is limited such as disposing the optical sensor at a distant position, which is unrealistic.

Also, a system that uses a temperature sensor to determine winding when the temperature falls below a predetermined temperature (see Patent Document 1), or a system that determines winding when the rate of change in temperature exceeds a reference ( Patent Document 2) has been proposed.
JP-A-11-296015 Japanese Patent Laid-Open No. 06-089067

    In consideration of the above-described facts, the present invention can prevent erroneous determination that a recording medium is wound around one of a pair of rotating bodies when the pair of rotating bodies are brought into contact with each other. It is an object to obtain a fixing device, a printing device, and a program.

The invention of claim 1 is sandwiched a pair of rotating bodies which rotate while sandwiching the recording medium conveyed by the image is formed using the image forming material by being contacted with each other, by the pair of rotating bodies the image on the recording medium conveyed Te so as to fix the movement of moving a heating means for heating at least one of the pair of rotating bodies, in a position apart from the position in contact with each other the pair of rotating bodies A temperature detection unit that detects at least one of the pair of rotating bodies as a detection target, and detects a surface temperature of the detection target rotating body in a non- contact manner, and according to conveyance of the recording medium to be fixed within the monitoring period is started, when judging whether or not the recording medium to the rotating body of the detection object is wound, the temperature reduction of the surface temperature issued RIKEN by said temperature detecting means is set in advance If it exceeds the reference value are, the said recording medium is wound occurrence determination unit determines that the attached-out winding on the rotating body to be detected, a predetermined time period immediately after contacting the pair of rotating bodies are in contact with each other, the The wrapping occurrence determining means includes an instruction means for instructing not to determine whether or not the wrapping is performed or to output a determination result of the determination whether or not the wrapping is performed .

According to a second aspect of the present invention, a pair of rotating bodies that rotate while sandwiching a recording medium on which an image is formed using an image forming material and conveyed by being in contact with each other, and the pair of rotating bodies are sandwiched between the pair of rotating bodies. Heating means for heating at least one of the pair of rotating bodies and movement for moving the pair of rotating bodies to a position where they are in contact with each other and to be separated from each other so as to fix the image on the recording medium conveyed A temperature detection unit that detects at least one of the pair of rotating bodies as a detection target, and detects a surface temperature of the detection target rotating body in a non-contact manner, and according to conveyance of the recording medium to be fixed When determining whether or not the recording medium is wound around the rotating body to be detected within the monitoring period to be started, the calculated value of the temperature decrease of the surface temperature detected by the temperature detecting means is previously If it exceeds the reference value that is constant for a predetermined time period immediately after contacting said rotating body on said recording medium is wound occurrence determination unit determines that the wound of the detection target, the pair of rotating bodies are in contact with each other, The winding occurrence determination means corrects the reference value so as not to determine that the recording medium has been wound around the detection target rotating body , or calculates the temperature decrease of the surface temperature so as not to determine that the recording medium has been wound. including a correcting means for correcting.

Invention according to claim 3, in the invention described in claim 2, wherein the correcting means, the reference value, the thickness of the recording medium, or, you corrected in accordance with the material.

According to a fourth aspect of the present invention, an image forming unit that forms an image using an image forming material on a recording medium, and an image is formed using the image forming material by the image forming unit by being brought into contact with each other and conveyed. At least one of the pair of rotating bodies is heated so that the image is fixed to the pair of rotating bodies that rotate while sandwiching the recording medium that is to be sandwiched, and the recording medium that is sandwiched and transported by the pair of rotating bodies. Heating means, moving means for moving the pair of rotating bodies between a position where they are in contact with each other and a position apart from each other, and at least one of the pair of rotating bodies as a detection target, the surface of the detection target rotating body The temperature detection means for detecting the temperature in a non-contact manner, and the recording medium is wound around the rotating body to be detected within a monitoring period started in response to the conveyance of the recording medium to be fixed. When determining whether or not the temperature drop of the surface temperature detected by the temperature detecting means exceeds a preset reference value, it is determined that the recording medium is wound around the rotating body to be detected. Whether or not the winding occurrence determination means does not determine whether or not the winding has occurred for a predetermined period immediately after the contact between the winding occurrence determination means and the pair of rotating bodies contact each other , or whether or not the winding has occurred. An instruction means for instructing not to output the determination result of the determination .

According to a fifth aspect of the present invention, an image forming unit that forms an image using an image forming material on a recording medium, and an image is formed by the image forming unit using the image forming material by being brought into contact with each other and conveyed. At least one of the pair of rotating bodies is heated so that the image is fixed to the pair of rotating bodies that rotate while sandwiching the recording medium that is to be sandwiched, and the recording medium that is sandwiched and transported by the pair of rotating bodies. Heating means, moving means for moving the pair of rotating bodies between a position where they are in contact with each other and a position apart from each other, and at least one of the pair of rotating bodies as a detection target, the surface of the detection target rotating body The temperature detection means for detecting the temperature in a non-contact manner, and the recording medium is wound around the rotating body to be detected within a monitoring period started in response to the conveyance of the recording medium to be fixed. Or when whether to determine the calculated value of the temperature drop of the surface temperature detected by said temperature detecting means, when it exceeds the reference value set in advance, the recording medium in the rotating body of the detection target The winding occurrence determination means for determining that the winding has been wound and the winding occurrence determination means do not determine that the recording medium has been wound around the detection target rotating body for a predetermined period immediately after the contact between the pair of rotating bodies. correcting the reference value as, or includes, a correction means for correcting the calculated value of the temperature drop of the surface temperature so as not to determine the wound.

The invention according to claim 6, a position where the pair of rotating bodies which rotate while sandwiching the recording medium on which an image is to be conveyed is formed using an image forming material, apart from the position in contact with each other upon contact with each other in a moving means for moving, so as to fix the image on the recording medium conveyed is sandwiched by the pair of rotating bodies, a heating means for heating at least one of the pair of rotating bodies, the rotation of the pair A temperature detecting means for detecting the surface temperature of the rotating body to be detected in a non- contact manner, with at least one rotating body of the body as a detection object, and within a monitoring period started in accordance with the conveyance of the recording medium to be fixed , when determining whether the recording medium to the rotating body of the detection object is wound, the calculated value of the temperature drop of the surface temperature detected at the temperature detector is set in advance based on Exceeding the value, wherein the recording medium to the rotating body and the winding occurrence determination unit determines that the attached-out winding, the predetermined time period immediately after contacting the pair of rotating bodies are in contact with each other of the detection target, the The wrapping occurrence determination means causes the computer to function as instruction means for instructing not to perform the determination as to whether or not the winding has been performed or to output the determination result of the determination as to whether or not the winding has occurred .

The invention according to claim 7, the position where the pair of rotating bodies which rotate while sandwiching the recording medium on which an image is to be conveyed is formed using an image forming material, apart from the position in contact with each other upon contact with each other in a moving means for moving, so as to fix the image on the recording medium conveyed is sandwiched by the pair of rotating bodies, a heating means for heating at least one of the pair of rotating bodies, the rotation of the pair A temperature detecting means for detecting the surface temperature of the rotating body to be detected in a non- contact manner, with at least one rotating body of the body as a detection object, and within a monitoring period started in accordance with the conveyance of the recording medium to be fixed , when determining whether the recording medium to the rotating body of the detection object is wound, the calculated value of the temperature drop of the surface temperature detected at the temperature detector is set in advance based on Exceeding the value, wherein the recording medium to the rotating body and the winding occurrence determination unit determines that the attached-out winding, the predetermined time period immediately after contacting the pair of rotating bodies are in contact with each other of the detection target, the The winding occurrence determination means corrects the reference value so as not to determine that the recording medium is wound around the detection target rotating body, or calculates the calculated value of the temperature decrease of the surface temperature so as not to determine that the recording medium is wound. and a correction to the correction means, Ru cause the computer to function with.

According to the present invention, it is possible to prevent erroneous determination that the recording medium has been wound around the rotation body to be detected when the pair of rotation bodies are brought into contact with each other from a separated state.

Further , according to the present invention, when the pair of rotators are brought into contact with each other from the separated state, the recording medium is detected while determining whether or not the recording medium is wound around the rotator to be detected. It is possible to prevent erroneous determination that the target rotator is wound.

According to the third aspect of the present invention, the recording medium is detected when the pair of rotating bodies comes into contact with each other regardless of the difference in the material of the recording medium or the thickness of the recording medium. It is possible to prevent erroneous determination that the target rotator is wound.

  FIG. 1 is a schematic configuration diagram of an image processing apparatus 10 according to the present embodiment.

  In the image processing apparatus 10, an image forming unit 14 is disposed so as to be adjacent to the paper transport unit 12.

(Image forming unit 14)
The image forming unit 14 is used as an example of an image forming unit. Further, as an example of the image forming material, toner is used, and a recording paper 30 as a recording medium is used.

  The image forming unit 14 forms an image on the recording paper 30 using toner. Specifically, the image forming unit 14 is provided with an endless loop-shaped transfer belt (image holding member) 16. The transfer belt 16 is wound around a plurality of rollers 18 and rotates in a substantially rectangular shape in the direction of arrow A in FIG. 1 (counterclockwise direction in FIG. 1) by a driving force of a driving motor (not shown). ing.

  On the upper side of the transfer belt 16 (upper side of the horizontal conveyance area), a charging device 20 is disposed on the upstream side in the conveyance direction of the transfer belt 16, and an optical scanning device 22 is disposed on the downstream side.

  In the charging device 20, the surface of the transfer belt 16 is uniformly charged.

  On the other hand, the optical scanning device 22 controls turning on / off of a laser as a light source based on input image data (hereinafter referred to as “lighting control”), and repeats the light beam whose lighting is controlled in one direction. Deflection to scan. This deflection direction is the main scanning direction, which is the depth direction in FIG. 1 (a direction perpendicular to the conveyance direction of the transfer belt 16).

  For this reason, the conveyance direction of the transfer belt 16 can be referred to as a sub-scanning direction with respect to the main scanning direction.

  That is, by rotating the transfer belt 16 uniformly charged by the charging device 20 at a predetermined conveyance speed, the main scanning light beam is output from the optical scanning device 22 (see arrow B in FIG. 1). An electrostatic image can be formed in a predetermined plane area on the transfer belt 16.

  A developing device 24 that develops toner by supplying toner as a developer to the electrostatic latent image is provided at the lower side of the transfer belt 16 (below the horizontal conveyance region).

  An image (toner image) developed and visualized by the developing device 24 is sent to the transfer unit 26 on the right side (on the right side of the vertical conveyance region) in accordance with the conveyance of the transfer belt 16. In the transfer unit 26, a toner image is transferred to a recording sheet 30 to be described later, and then the transfer belt 16 returns to the charging device 20 through a cleaning unit (not shown) (completion of one round).

  In the image forming unit 14, the image forming process is repeated by rotating the transfer belt 16.

(Paper transport unit 12)
As shown in FIG. 1, a two-stage tray 28A and a tray 28B are provided at the center of the sheet transport unit 12. In addition, a tray 28C having a paper storage capacity several times that of the tray 28A and the tray 28B is provided. Hereinafter, the tray 28A, the tray 28B, and the tray 28C are collectively referred to as “tray 28”.

  The tray 28 is accommodated, for example, in a state where recording sheets (mediums) 30 having different sizes are stacked.

  In addition, the tray 28 has a right side in FIG. 1 as a recording paper collecting side, and each has a tray sensor 32A-1 (for the tray 28A) for detecting the leading edge of the recording paper 30 immediately after being taken out. 32A-2 (for tray 28B) and 32A-3 (for tray 28C) are provided.

  The recording paper 30 taken out from the tray 28 is guided by a plurality of rollers 34 and is turned approximately 90 ° in the clockwise forward direction of FIG. 1 to be conveyed downward in FIG.

  Downward conveyance sensors 32B-1 and 32B-2 are provided at predetermined positions when the downward conveyance is performed. The downward conveyance sensor 32B-1 has a function of detecting the recording paper 30 conveyed from the trays 28A and 28B or a double-sided print conveyance unit 36 described later.

  A plurality of rollers 38 are provided on the downstream side of the downward conveyance sensors 32B-1 and 32B-2, and the recording paper 30 is guided by the plurality of rollers 38 to be approximately 90 ° in the clockwise forward direction in FIG. The direction is changed, and the sheet is conveyed substantially horizontally for a predetermined length.

  A transfer synchronization detection sensor 32C is provided on the downstream side of the horizontal conveyance region. The transfer synchronization detection sensor 32C has a function of synchronizing (timing) for normal transfer of the toner image to a predetermined area of the recording paper 30, and the recording paper 30 is transferred to the transfer synchronization detection sensor as necessary. It stops in a state where the tip is detected by 32C, and waits.

  A plurality of rollers 40 are provided on the downstream side of the transfer synchronization detection sensor 32C, and the recording paper 30 is guided by the plurality of rollers 40 and turned in the forward direction of about 90 ° in the clockwise direction in FIG. It will be transported upward.

  The transfer unit 26 described above is disposed in the middle of the upward conveyance path. In the transfer unit 26, the recording paper 30 is brought into close contact with the transfer belt 16 with a predetermined pressure, and toner is transferred from the transfer belt 16 to the recording paper 30 by electrostatic action. As a result, an image is transferred onto the recording paper 30. .

  A fixing unit 42 constituting a part of the image forming unit 14 is provided on the downstream side of the transfer unit 26 (upward in the upward conveyance direction). The recording sheet 30 onto which the image has been transferred in the transfer unit 26 is received, and is predetermined. The toner image is fixed on the surface of the recording paper 30 by performing a fixing process of applying heat and pressure.

  A pre-fixing detection sensor 32D is provided on the conveyance path between the fixing unit 40 and the transfer unit 26. The pre-fixing detection sensor 32D detects the leading edge of the recording paper 30 that is received by the fixing unit 42, and controls, for example, the temperature in the fixing unit 42 or the start timing of a mechanical operation for pressurization. I am doing so.

  A post-fixing detection sensor 32E is provided downstream of the fixing unit 42 in the recording paper conveyance direction. The post-fixing detection sensor 32E recognizes the end of the fixing process in the fixing unit 42.

  A plurality of rollers 44 are provided on the downstream side of the post-fixing detection sensor 32E, and the recording paper 30 is guided by the plurality of rollers 44 and is turned approximately 90 ° in the clockwise forward direction of FIG. It becomes a substantially horizontal conveyance.

  A print surface discrimination sensor 32F is provided on the transport path immediately after the substantially horizontal transport. This print surface discriminating sensor 32F has a role of detecting single-sided / double-sided print instruction information previously given to the recording paper 30. The detection result by the print surface discrimination sensor 32F is applied as a requirement for conveyance direction switching (point switching) at a branch portion of the conveyance path described later.

  The transport path for transporting the recording paper 30 in a substantially horizontal state by the transport roller 42 is provided with a first branch portion 46 on the downstream side of the print surface discrimination sensor 32F. The first branching unit 46 includes a plurality of transport rollers 48 and a switching point 50.

  Based on the information obtained by the print surface discriminating sensor 32F, the recording paper 30 currently being conveyed is (mode 1) a duplex printing instruction and printing on only one side has been completed (mode 2). ) It is classified as a case where a double-sided print instruction is given and double-sided printing is completed.

  In the case of (Mode 1), the recording paper 30 is turned approximately 90 ° by the conveyance roller 48 in the clockwise forward direction of FIG.

  In the case of (Mode 2), the recording paper 30 is maintained in substantially horizontal conveyance by the conveyance roller 48 by switching control of the point 50.

  The recording paper 30 whose direction has been changed by approximately 90 ° in the (mode 1) is sent to the duplex printing conveyance unit 36. The double-sided printing conveyance unit 36 is changed in direction by a plurality of conveyance rollers 49, and then the conveyance timing is controlled based on the double-sided printing recording paper detection sensor 32G. To join.

  A pass / fail judgment sensor 32H is provided in the transport path when substantially horizontal transport is maintained in the (mode 2). The pass / fail judgment sensor 32H reads the pass / fail judgment result related to the print processing.

  For example, when the amount of toner is not appropriate, when fixing is insufficient, when there is a problem in conveyance (diagonal conveyance, parallel movement, double feed, etc.), and when there is such a problem What is necessary is just to make it detect with the quality determination sensor 32H by marking. Alternatively, it may be a sensor unit having a control function for directly detecting and determining image density, paper position, and the like.

  A second branch portion 52 is provided in a substantially horizontal conveyance path on the downstream side of the quality determination sensor 32H. The second branch unit 52 includes a switching point 54.

  Based on the information obtained by the pass / fail judgment sensor 32H, the currently transported recording paper 30 is classified into (non-defective product judgment) and (defective product judgment).

  In the case of (non-defective product determination), the recording paper 30 is guided to the tray 56 on the upstream side in the conveyance direction (left side in FIG. 1) by switching control of the point 50. The number of recording sheets 30 discharged to the tray 56 is counted by a count sensor 32I.

In the case of (defective product determination), the recording paper 30 is guided to the tray 58 on the downstream side in the transport direction (right side in FIG. 1 ) by switching control of the point 50. The recording paper 30 discharged to the tray 58 is counted by the count sensor 32J.

(Configuration of control system of image processing apparatus 10)
As shown in FIG. 2, the image processing apparatus 10 is controlled by a controller 100.

  The control controller 100 includes an image forming main control unit 102 that performs overall management and controls all processes.

  The image forming main control unit 102 includes a CPU 104, a RAM 106, a ROM 108, an I / O (input / output unit) 110, and a bus 112 such as a data bus and a control bus for connecting them.

  The I / O 110 is connected to a conveyance control unit 114, an exposure control unit 116, a development control unit 118, a transfer control unit 120, and a fixing control unit 122.

  The CPU 101 reads out various programs for controlling the fixing unit stored in the ROM 108 and executes processing described later. It is also possible to provide the program by storing it in a transportable storage medium such as a CD-ROM.

  The transport control unit 114 performs control related to transport of the recording paper 30 in the paper transport unit 12. The exposure control unit 116 and the development control unit 118 perform control related to image forming processing in the image forming unit 14, respectively. The transfer control unit 120 performs image transfer control to the recording paper 30 at a contact point between the image forming unit 14 and the paper transport unit 12. The fixing control unit 122 performs control related to the fixing process of the recording paper 30 to which the image has been transferred.

  A GUI (graphic user interface) 124 is connected to the I / O 110. The GUI 124 has a function of receiving an input instruction from the user and notifying the user of information related to image processing.

  In the image processing apparatus 10 configured as described above, in the present embodiment, control relating to monitoring of conveyance failure during the fixing process of the recording paper 30 in the fixing unit 42 is performed. Before describing the conveyance failure monitoring control, the detailed configuration of the fixing unit 42 will be described.

(Detailed configuration of the fixing unit 42)
FIG. 3 shows a detailed configuration of the fixing unit 42 according to the present embodiment.

  The fixing unit 42 is covered with the casing 42A. A pair of rolls (a heating roll 42B and a pressure roll 42C) are disposed in the housing 42A. The pair of rolls (the heating roll 42B and the pressure roll 42C) conveys the recording paper while sandwiching the recording paper.

  A moving mechanism 42G is used as the moving means, and the heating roll 42B and the pressure roll 42C are moved between a position where they are in contact with each other and a position where they are separated from each other.

  The heating roll 42B, the pressure roll 42C, and the moving mechanism 42G are brought into contact with or separated from each other. In the present embodiment, only the pressure roll 42C is movable in the direction of arrow A in FIG.

  Strictly speaking, when the heating roll 42B and the pressure roll 42C are in contact with each other, they are in surface contact with each other by the elastic force of the surface, but in FIG. 3, they are illustrated in a state of line contact along the axial direction. When viewed from the front of FIG. 3, the heating roll 42B and the pressure roll 42C are in point contact.

  The housing 42A corresponding to the tangential direction of the contact point between the heating roll 42B and the pressure roll 42C is provided with through holes 42D and 42E, which serve as a passage space for the recording paper 30.

  The heating roll 42B is hollow, and a heat source (for example, a halogen lamp) 42F is accommodated therein. Thereby, the surface of the heating roll 42B is heated by the heat generated by the heat source 42F.

  In the present embodiment, a halogen lamp is used as an example of the heating means, but other heat sources such as a heat source using IH (Induction Heating) can also be used. In this embodiment, the heating roll 42B and the pressure roll 42C are used as an example of a pair of rotating bodies. However, an endless belt that performs pressure with the heating roll can also be used. As long as rotation is performed so as to be wound, fixing may be performed.

  In addition, a temperature sensor 126 that detects the surface temperature of the heating roll 42B is disposed around the heating roll 42B (in the radial direction) and at a predetermined distance.

  The temperature sensor 126 has a detection surface facing the surface of the heating roll 42B, and detects heat radiation (radiant heat, convection heat) from the heating roll 42B.

  The temperature sensor 126 is configured to detect infrared radiation due to heat and measure the surface temperature of the object.

  The temperature sensor 126 detects the surface temperature of at least one of the heating roll 42B and the pressure roll 42C in a non-contact manner. As a basic configuration, the temperature sensor 126 is connected to a temperature management control unit 128 that manages the temperature of the fixing unit 42 in the fixing control unit 122.

  The temperature management control unit 128 controls the temperature (surface temperature) of the heating roll 42B of the fixing unit 42 to be maintained at a predetermined temperature based on an instruction from the image forming main control unit 102 of the image processing apparatus 10.

  It should be noted that the fixing unit 42 is different in each of a pause mode in which processing is not executed for a long time, an image formation mode in which image formation processing is actually executed, and a standby mode in which the transition to the image formation processing mode can be performed in a relatively short period of time. The temperature is controlled at a temperature of. For example, there is a relationship of the temperature in the pause mode <the temperature in the standby mode <the temperature in the image forming processing mode.

  In the standby mode or the pause mode, the heating roll 42B and the pressure roll 42C are separated from each other, and in the image forming process mode, the heating roll 42B and the pressure roll 42C are brought into contact with each other.

  In the temperature management control unit 128, for example, when there is an image formation instruction in a standby mode in which the heating roll 42 </ b> B of the fixing unit 42 is controlled to a predetermined temperature and is separated from the pressure roll 42 </ b> C, the recording paper 30 is fixed to the fixing unit 42. The heating roll 42B and the pressure roll 42C are brought into contact with each other before reaching the temperature, and the temperature of the heating roll 42B taken away by the contact with the pressure roll 42C is controlled to be restored.

  In the fixing unit 42, in the image forming process mode, the recording paper 30 is fed from the lower part of FIG. 2 from the transfer unit 26 and is sandwiched between the heating roll 42B and the pressure roll 42C.

  At this time, the heating roll 42B is controlled to the optimum temperature for fixing by the temperature control of the temperature management control unit 128. The sandwiched recording paper 30 is conveyed upward in FIG. 2 while being subjected to heating and pressurizing processes.

  Here, during normal conveyance, the recording paper 30 passes through a contact point between the heating roll 42B and the pressure roll 42C and is linearly conveyed in a tangential direction between the heating roll 42B and the pressure roll 42C.

  On the other hand, the recording paper 30 may not be normally conveyed and the conveyance direction may be changed while being wound around the heating roll 42B (abnormal conveyance). In particular, winding easily occurs on the heating roll 42 </ b> B on the side where the toner is transferred. When this abnormal conveyance occurs, the function of the fixing unit 42 stops and the image forming process itself cannot be performed.

Therefore, in this embodiment, the winding monitoring control unit 130 of the fixing control unit 128 monitors the abnormal conveyance (winding failure) of the recording paper 30 based on the temperature data detected by the temperature sensor 126. Judgment is made. The winding monitoring control unit 130 is used as an example of a winding occurrence determination unit, and determines whether or not the recording paper has been wound around the heating roll 42B in accordance with the temperature drop of the surface temperature detected by the temperature sensor 126 in a non-contact manner. Judgment.

  In other words, the abnormal conveyance is monitored using the existing temperature sensor 126 without adding a new sensor for monitoring.

(Fixing part control system)
FIG. 4 is a functional block diagram of temperature control in the temperature management control unit 128 and abnormal conveyance monitoring control in the winding monitoring control unit 130 in the fixing control unit 122. In addition, this functional block diagram does not limit each hardware structure of the temperature management control part 128 and the winding monitoring control part 130, but is classified according to the function to the last.

(Temperature management controller 128)
Various signals are output from the image forming main control unit 102 to the signal analysis unit 132. The signal analyzer 132 analyzes these signals and outputs them appropriately.

  In the case of a mode change instruction such as an image formation instruction, a standby instruction, or a pause instruction in the signal analysis unit 132, these signals are output to the control temperature data determination unit 134.

  The control temperature data determining unit 134 is connected to the control temperature data reading unit 136. In the control temperature data reading unit 136, when the control temperature data information determined from the control temperature data determination unit 134 is input, reference control temperature data suitable for each mode is read from the control temperature data memory 138. ing.

  The read reference temperature control data is sent to the control temperature data temporary storage unit 140, and is temporarily stored in the control temperature data temporary storage unit 140 (while the mode is maintained).

  The control temperature data temporary storage unit 140 is connected to the temperature comparison unit 142.

  The temperature comparison unit 142 is connected to the sensor signal input unit 144. The sensor signal input unit 144 receives a detection signal from the temperature sensor 126, and the detection signal from the temperature sensor 126 is passed through the sensor signal input unit 144 (for example, A / D conversion is performed). It is sent to the temperature comparison unit 142.

  When the detected temperature data is input from the sensor signal input unit 144, the temperature comparison unit 142 reads the reference temperature data from the reference control temperature data temporary storage unit 140 and compares them.

  The comparison result in the temperature comparison unit 142 is sent to the heat source control unit 146. The heat source control unit 146 controls the heat source driver 148 based on the temperature comparison result to control the heating state of the heat source 42F. When the heat source 42F is a halogen lamp, power on / off control, PID control, or the like is executed. Further, when there are a plurality of halogen lamps, each may be controlled independently.

(Wrapping monitoring control unit 130)
The signal analysis unit 132 connected to the image forming main control unit 102 is connected to the transport system detection sensor signal extraction unit 150.

  A signal from the pre-fixing detection sensor 32D (see FIG. 1) and a signal from the post-fixing detection sensor 32E (see FIG. 1) are input to the transport system detection sensor signal extraction unit 150.

  The pre-fixing detection sensor 32D detects the leading edge of the recording paper 30 on the upstream side of the fixing unit 42 as described above, and starts monitoring abnormal conveyance from this detection time point.

  On the other hand, the post-fixing detection sensor 32E detects the leading edge of the recording paper 30 on the downstream side of the fixing unit 42 as described above, and ends the abnormal conveyance monitoring at the time of detection. That is, if the leading end of the recording paper 30 is detected by the post-fixing detection sensor 32E after a predetermined time has elapsed since the leading edge of the recording paper 30 is detected by the pre-fixing detection sensor 32D, the recording paper is normally conveyed (passes through the fixing unit 42). It can be judged that

  The conveyance system detection sensor signal extraction unit 150 is connected to the monitoring start / end instruction unit 152 and calculates to the temperature change calculation unit 154 based on the input signal source (pre-fixing detection sensor 32D or post-fixing detection sensor 32E). Send start or end instruction. This calculation start is the abnormality monitoring start, and the calculation end corresponds to the abnormality monitoring end.

  The temperature change amount calculation unit 154 is connected to the sensor signal input unit 144. During the activation (during the abnormality monitoring period), the temperature change amount calculation unit 154 inputs temperature data detected by the temperature sensor 126 at any time, and at least the absolute value of the temperature change amount based on the temperature data between two points at different times. Calculate the value.

  The temperature change amount calculation unit 154 is connected to the temperature change amount comparison unit 156 and the reference temperature change amount reading unit 158. The temperature change amount comparison unit 156 receives temperature change amount data as a calculation result from the temperature change amount calculation unit 154, and the reference temperature change amount reading unit 158 synchronizes with the calculation result transmission from the temperature change amount calculation unit 154. An instruction signal is sent out.

  In response to the input of the instruction signal, the reference temperature change amount reading unit 158 reads the absolute value of the reference temperature change amount from the reference temperature change amount data memory 160 and sends it to the temperature change amount comparison unit 156.

  Thereby, the absolute value | T '| of the actually calculated temperature change amount and the absolute value | T's | of the reference temperature change amount are input to the temperature change amount comparison unit 156. Are compared. The absolute value | T's | of the reference temperature change amount is used as an example of a preset reference value.

The comparison result in the temperature change amount comparison unit 156 is sent to the comparison result determination unit 162. In the comparison result determination unit 162, when the absolute value | T ′ | of the temperature change amount is an absolute value of the change amount exceeding the absolute value | T ′s | of the reference temperature change amount, the recording paper 30 on the heating roll 42B is detected. It is determined that winding has occurred, and an abnormality determination result is sent to the abnormal carrier signal output unit 164. As a result, the abnormal conveyance signal output unit 164 outputs an abnormal signal (winding defect) to the image formation control unit 102.

  In the image formation control unit 102, based on the abnormality signal from the winding monitoring control unit 130 of the fixing unit 42, abnormality notification is executed using the GUI 124, and a response to stop functions (image formation, conveyance, etc.) is executed. .

  By the way, when the signal from the pre-fixing detection sensor 32D is input, the fixing unit 42 performs an operation of bringing the heated roll 42B and the pressure roll 42C into contact with each other. For this reason, the surface temperature of the heating roll 42B is taken away by the pressure roll 42C, and as a result, the surface temperature of the heating roll 42B rapidly decreases (becomes an absolute value of a large temperature change amount).

  That is, immediately after the contact between the heating roll 42B and the pressure roll 42C, the same phenomenon as when the winding failure of the recording paper 30 occurs on the heating roll 42B may occur.

  Therefore, in the present embodiment, a period of a predetermined time (hereinafter referred to as “initial period”) immediately after the contact between the heating roll 42B and the pressure roll 42C is set to a period during which no abnormality determination is performed (see FIG. 5). did.

  This non-detection period may be set based on the contact direction movement start timing of the heating roll 42B and the pressure roll 42C based on the image forming processing instruction.

  That is, as shown in FIG. 4, the signal analysis unit 132 is connected to a period setting unit 166 that does not perform abnormality determination. Here, when an image formation instruction is input to the signal analysis unit 132, the image formation instruction signal is sent to the period setting unit 166 that does not perform abnormality determination.

  The period in which the abnormality determination is not performed by this signal is determined to be the start time of the initial period, and the timer 168 is used to start sending the initial period signal to the execution instruction unit 170 that does not perform the abnormality determination. (Start signal), timed by the timer 168, and the transmission ends when the initial period ends (stop signal).

  The period execution instruction unit 170 that does not perform abnormality determination sends a start signal and a stop signal to the comparison cancel execution unit 172 at the start and end of the initial period signal, respectively. The comparison cancel execution unit 172 sends a cancel signal to the temperature change amount comparison unit 156 during the period from the start signal to the stop signal. As a result, the comparison process in the temperature change amount comparison unit 156 is cancelled. In the present embodiment, the abnormality determination by the temperature change amount comparison unit 15 is not performed. However, the present invention is not limited to this, and abnormality determination is performed, but the determination result is sent to the image forming main control unit 102. You may comprise so that winding abnormality generation may not be output.

  The operation of the present embodiment will be described below with reference to the flowcharts of FIGS.

  FIG. 6 is a flowchart showing a temperature management control routine in the temperature management control unit 128 of the fixing control unit 122.

  In step 200, the mode is determined, and then a reference temperature corresponding to the mode determined in step 202 is set. In step 204, the temperature is detected by the temperature sensor, and then the process proceeds to step 206, where the detected temperature is compared with the reference temperature, and the process proceeds to step 208.

  In step 208, based on the comparison result, temperature control of the heat source 42F of the heating roll 42B is executed, and this routine ends.

  FIG. 7 is a flowchart illustrating a winding monitoring control routine in the winding monitoring control unit 130 of the fixing control unit 122.

  In step 220, it is determined whether or not the leading edge of the recording paper 30 is detected by the pre-fixing detection sensor 32D. If the determination is affirmative, the process proceeds to step 221. If a negative determination is made in step 220, this routine ends.

  In step 221, the temperature is detected by the temperature sensor 126, and the process proceeds to step 222. In step 222, the absolute value of the temperature change amount is calculated based on the temperature information detected this time and the temperature information detected so far.

  In the next step 224, it is determined whether or not the calculated absolute value of the temperature change amount indicates a rapid temperature decrease. If a negative determination (normal determination) is made in step 224, the process proceeds to step 226, the temperature information detected this time is stored, and the process proceeds to step 230.

In step 230, whether it has detected the leading end of the recording sheet 30 by the post-fixing sensor 32E is determined and if it is not constant determined returns to step 221 to repeat the above steps. If the determination in step 230 is affirmative, this routine ends to end the winding monitoring control.

  On the other hand, when an affirmative determination (abnormality determination) is made at step 224, the routine proceeds to step 228, where the occurrence of winding abnormality is output to the image forming main control unit 102, and this routine ends.

  The image forming main control unit 102 that has received the notification of the winding abnormality displays an abnormality using the GUI 124 or issues an alarm, and instructs each unit control unit to stop execution of the image forming process.

  FIG. 8 is a routine for controlling the execution timing of winding monitoring in the winding monitoring control unit 130 described with reference to the flowchart of FIG.

  In step 250, it is determined whether or not an image formation start instruction, that is, a processing mode has been entered. If a negative determination is made, this routine ends.

  If an affirmative determination is made in step 250, the process proceeds to step 254 where it is determined whether or not a predetermined time has elapsed (corresponding to the time when the recording paper 30 reaches the fixing unit 42 after entering the image forming processing mode). .

  If an affirmative determination is made in step 254, the process proceeds to step 256 to start a period in which no abnormality determination is performed.

  By the start of a period in which the abnormality determination is not performed, the winding monitoring control in FIG.

  In the next step 258, it is determined whether or not a predetermined time has elapsed. The predetermined time in step 258 is a time corresponding to a preset period during which no abnormality determination is performed, and varies depending on the process speed. The process speed refers to a processing time based on the conveyance speed of the recording paper 30, the optical scanning speed of the optical scanning device, and the like.

  If an affirmative determination is made in step 258, the period during which no abnormality determination is performed is stopped, and this routine ends. In other words, during the negative determination in step 258, the period during which no abnormality determination is performed continues.

The period in which the abnormality determination is not performed based on this signal is determined to be the start time of the initial period, and the timer 168 is used to start sending the initial period signal to the period execution instruction unit 170 in which the abnormality determination is not performed. At the same time (start signal), the time is counted by the timer 168, and the transmission is terminated at the end of the initial period (stop signal).

  In this embodiment, the start time of a period during which no abnormality determination is performed is set to a predetermined time from the instruction to start image formation processing, and the stop time during which no abnormality determination is performed is based on the time corresponding to the job (processing amount). However, the present invention is not particularly limited to this, and if the temperature drop caused by the contact between the heating roll 42B and the pressure roll 42C can be excluded from the wrapping monitoring, the abnormality determination is performed based on other timing. You may make it set the period which does not perform.

  Further, the wrapping monitoring control is performed from the image forming process start instruction timing to the leading edge detection timing of the recording paper 30 by the post-fixing detection sensor 32E, but monitoring may be performed throughout the image forming mode.

  Further, during the period when the abnormality determination is not performed, the abnormality determination is not performed completely. For example, the absolute value | T's of the reference temperature change compared with the absolute value | T '| The numerical value of | may be changed to such an extent that the abnormality is not determined during a predetermined period including the contact timing of the heating roll 42B and the pressure roll 42C (the abnormality determination may be blunted).

This will be described with reference to FIG. 9. Originally, the time in the chain line range in FIG. 9 is the contact time between the heating roll 42B and the pressure roll 42C, and a temperature drop (temperature change) should occur. When calculating the absolute value of the temperature change amount, so-called smoothing correction, that is, by adding a predetermined amount to the numerical value of the absolute value | T's |, the change amount that does not reach the absolute value of the reference temperature change amount It is suppressed to an absolute value. Thereby, it is prevented that the contact between the heating roll 42B and the pressure roll 42C is erroneously determined as the occurrence of winding. Instead of blunt detection data during the period ranging from a chain line in FIG. 9, sweeten the absolute value of the temperature variation, i.e., a predetermined amount subtracted from the absolute value of the temperature change amount (in the original any The level may be determined to be winding, but may be changed to a level that is not determined to be winding).

  In this case, the wrapping monitoring is performed for the predetermined period, but at least falls within the definition of the “non-detection period” in the present embodiment.

  Further, in this embodiment, the temperature decrease is determined based on the absolute value of the temperature change amount, but the temperature change rate of the temperature decrease is compared with a predetermined threshold value to determine the abnormal temperature decrease. Also good. In this case, during the contact period between the heating roll 42B and the pressure roll 42C, the temperature detection by the temperature sensor 126 may be canceled, or the comparison between the detected temperature and the threshold value may be canceled.

  Further, in the present embodiment, it is determined whether or not the recording paper 30 is wound around the heating roll 42B, but it is predicted that the recording paper 30 is rarely wound around the pressure roll 42C and is shown in FIG. As described above, a temperature sensor 126A corresponding to the pressure roll 42C may be disposed.

  In the present embodiment, the material, thickness, and the like of the recording paper 30 are not mentioned. However, when the recording paper 30 takes heat from the heating roll 42B, the material, the thickness, etc. of the recording paper 30 are taken into account. The reference value (threshold value) to be compared with the absolute value of the calculated temperature change amount or the detected temperature is corrected based on the material and thickness of the recording paper 30. Configured as follows.

  Specifically, in the ROM 108 and RAM 106, for each material of the recording medium 30, or for each thickness and material of the recording medium 30, the start / end timing of the non-detection period, the absolute value of the calculated temperature change, the detected temperature, A correction value for correcting a reference value (threshold value) to be compared is stored. This is acquired by an acquisition unit (not shown), and the correction value corresponding to the material of the recording medium 30 and the thickness of the recording medium 30 is corrected. Correct by part. That is, the thicker the recording medium or the higher the heat absorption rate, the greater the temperature drop that occurs when it is wound. In such a case, correction is made so that it is difficult to determine that the recording paper 30 has been wound. It will be. This correction unit is used as an example of a correction unit.

1 is a schematic configuration diagram of an image forming apparatus according to the present embodiment. 2 is a block diagram showing a hardware configuration of a control system of the image forming apparatus according to the present embodiment. FIG. FIG. 3 is an enlarged view showing a detailed configuration of a fixing unit. It is a functional block diagram for executing temperature control, winding monitoring control, and winding monitoring time management control in the fixing control unit according to the present embodiment. It is a timing chart for temperature control and winding start control concerning this embodiment. It is a flowchart which shows the temperature management control routine in the temperature management control part which concerns on this Embodiment. It is a flowchart which shows the winding monitoring control routine in the winding monitoring control part which concerns on this Embodiment. It is a flowchart which shows the routine which controls the execution time of the winding monitoring in the winding monitoring control part of FIG. It is a timing chart for temperature control and winding start control concerning a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image processing apparatus 12 Paper conveyance part 14 Image formation part 16 Transfer belt 18 Roller 20 Charging apparatus 22 Optical scanning device 24 Development apparatus 26 Transfer part 28 Tray 28A Tray 28B Tray 28C Tray 30 Recording paper 32 Sensor 32A-1 Tray sensor 32A- 2 Tray sensor 32A-3 Tray sensor 32B-1 Downward transport sensor 32B-2 Downward transport sensor 32C Transfer synchronization detection sensor 32D Pre-fixing detection sensor 32E Post-fixing detection sensor 32F Print surface discrimination sensor 32G Double-sided print recording paper detection sensor 32H Pass / fail Determination sensor 32I Count sensor 32J Count sensor 34 Roller 36 Double-sided printing transport section 38 Roller 40 Roller 42 Fixing section 42G Moving mechanism (moving means)
44 Roller 46 First Branch 48 Transport Roller 50 Switching Point 49 Transport Roller 52 Second Branch 54 Switching Point 56 Tray 58 Tray 100 Control Controller 102 Image Forming Main Control Unit 104 CPU
106 RAM
108 ROM
110 I / O
112 Bus 114 Transport Control Unit 116 Exposure Control Unit 118 Development Control Unit 120 Transfer Control Unit 122 Fixing Control Unit 124 GUI
42A Case 42B Heating roll (rotating body)
42C pressure roll (rotating body)
42D, 42E Through-hole 42F Heat source (heating means)
126 Temperature sensor (temperature detection means)
128 Temperature Management Control Unit 130 Winding Monitoring Control Unit 132 Signal Analysis Unit 134 Control Temperature Data Determination Unit 136 Control Temperature Data Reading Unit 138 Control Temperature Data Memory 140 Control Temperature Data Temporary Storage Unit 142 Temperature Comparison Unit 144 Sensor Signal Input Unit 146 Heat Source Control 148 Heat source driver 150 Conveyance system detection sensor signal extraction unit 152 Monitoring start / end instruction unit 154 Temperature change amount calculation unit 156 Temperature change amount comparison unit 158 Reference temperature change amount reading unit 160 Reference temperature change amount data memory 162 Comparison result determination unit (Winding occurrence determination means)
164 Abnormal carrier signal output unit 166 Period setting unit that does not perform abnormality determination 168 Timer 170 Period execution instruction unit that does not perform abnormality determination 172 Comparison cancel execution unit

Claims (7)

A pair of rotating bodies which rotate while sandwiching the recording medium on which an image is to be conveyed is formed using an image forming material by being in contact with each other,
Heating means for heating at least one of the pair of rotating bodies so as to fix the image on the recording medium conveyed while being sandwiched between the pair of rotating bodies;
Moving means for moving the pair of rotating bodies to a position in contact with each other and a position away from each other;
Temperature detection means for detecting at least one of the pair of rotating bodies as a detection target, and detecting a surface temperature of the detection target rotating body in a non- contact manner;
Within the monitoring period is started in response to the conveyance of the recording medium being the fixing, when determining whether the recording medium to the rotating body of the detection object is wound, by the said temperature detecting means Riken temperature drop out are surface temperature, and advance is exceeded the set reference value and, wherein the recording medium is wound occurrence determination unit determines that the attached-out winding on the rotating body of the detection object,
The winding occurrence determination means does not determine whether or not the winding has occurred or does not output the determination result of whether or not the winding has occurred for a predetermined period immediately after the pair of rotating bodies contact each other. Instruction means for instructing
Including a fixing device. A pair of rotating bodies that rotate while sandwiching a recording medium on which an image is formed using an image forming material and conveyed by being in contact with each other;
Heating means for heating at least one of the pair of rotating bodies so as to fix the image on the recording medium conveyed while being sandwiched between the pair of rotating bodies;
Moving means for moving the pair of rotating bodies to a position in contact with each other and a position away from each other;
Temperature detection means for detecting at least one of the pair of rotating bodies as a detection target, and detecting a surface temperature of the detection target rotating body in a non-contact manner;
When determining whether or not the recording medium is wound around the rotating body to be detected within a monitoring period started in response to conveyance of the recording medium to be fixed, the temperature detection unit detects the recording medium. When the calculated value of the temperature drop of the surface temperature exceeds a preset reference value, a winding occurrence determining means for determining that the recording medium is wound around the rotating body to be detected ;
Predetermined period immediately after contacting the pair of rotating bodies are in contact with each other, the winding occurrence determination means, corrects the recording said reference value so as not to determine the medium is wound around the rotating body of the detection target, or, Correction means for correcting the calculated value of the temperature drop of the surface temperature so as not to determine that it is wound;
Including a fixing device. The fixing device according to claim 2, wherein the correction unit corrects the reference value according to a thickness or a material of the recording medium . Image forming means for forming an image using an image forming material on a recording medium;
A pair of rotating bodies that rotate while sandwiching the recording medium on which an image is formed by using the image forming material by the image forming means by being brought into contact with each other; and
Heating means for heating at least one of the pair of rotating bodies so as to fix the image on the recording medium conveyed while being sandwiched between the pair of rotating bodies;
Moving means for moving the pair of rotating bodies between a position in contact with each other and a position away from each other;
Temperature detection means for detecting at least one of the pair of rotating bodies as a detection target, and detecting the surface temperature of the detection target rotating body in a non-contact manner;
When determining whether or not the recording medium is wound around the rotating body to be detected within a monitoring period started in response to conveyance of the recording medium to be fixed, the temperature detection unit detects the recording medium. When the temperature drop of the surface temperature exceeds a preset reference value, winding occurrence determination means for determining that the recording medium is wound around the rotating body to be detected;
The winding occurrence determination means does not determine whether or not the winding has occurred or does not output the determination result as to whether or not the winding has occurred for a predetermined period immediately after the pair of rotating bodies contact each other. Instruction means for instructing
Including printing device. Image forming means for forming an image using an image forming material on a recording medium;
A pair of rotating bodies that rotate while sandwiching the recording medium on which an image is formed by using the image forming material by the image forming means by being brought into contact with each other ; and
Heating means for heating at least one of the pair of rotating bodies so as to fix the image on the recording medium conveyed while being sandwiched between the pair of rotating bodies;
Moving means for moving the pair of rotating bodies between a position in contact with each other and a position away from each other;
Temperature detection means for detecting at least one of the pair of rotating bodies as a detection target, and detecting the surface temperature of the detection target rotating body in a non-contact manner;
When determining whether or not the recording medium is wound around the rotating body to be detected within a monitoring period started in response to conveyance of the recording medium to be fixed, the temperature detection unit detects the recording medium. calculated value of the temperature drop of the surface temperature, the advance is exceeded the set reference value and, the detection target of the rotating body to the recording winding occurrence determination unit determines that the medium is wound around,
The winding occurrence determination means corrects the reference value so as not to determine that the recording medium has been wound around the rotation body to be detected for a predetermined period immediately after the pair of rotating bodies contact each other , or Correction means for correcting the calculated value of the temperature drop of the surface temperature so as not to determine that it is wound;
Including printing device . A pair of rotating bodies which rotate while sandwiching the recording medium on which an image is to be conveyed is formed using an image forming material by contact with each other, and moving means for moving at a position away from the position in contact with each other,
Heating means for heating at least one of the pair of rotating bodies so as to fix the image on the recording medium conveyed while being sandwiched between the pair of rotating bodies;
As detected at least one rotating body of said pair of rotating bodies, a temperature detecting means for detecting the surface temperature of the rotating body to be detected without contact,
Within the monitoring period is started in response to the conveyance of the recording medium being the fixing, when determining whether the recording medium is wound around the rotating body of the detection object is detected in the temperature detecting means calculated value of the temperature drop of surface temperature, when it exceeds the reference value set in advance, and winding occurrence determination means for determining that said recording medium is attached-out winding on the rotating body of the detection object,
The winding occurrence determination means does not determine whether or not the winding has occurred or does not output the determination result as to whether or not the winding has occurred for a predetermined period immediately after the pair of rotating bodies contact each other. Instruction means for instructing
Program to make the computer function . A pair of rotating bodies which rotate while sandwiching the recording medium on which an image is to be conveyed is formed using an image forming material by contact with each other, and moving means for moving at a position away from the position in contact with each other,
Heating means for heating at least one of the pair of rotating bodies so as to fix the image on the recording medium conveyed while being sandwiched between the pair of rotating bodies;
As detected at least one rotating body of said pair of rotating bodies, a temperature detecting means for detecting the surface temperature of the rotating body to be detected without contact,
Within the monitoring period is started in response to the conveyance of the recording medium being the fixing, when determining whether the recording medium is wound around the rotating body of the detection object is detected in the temperature detecting means calculated value of the temperature drop of surface temperature, when it exceeds the reference value set in advance, and winding occurrence determination means for determining that said recording medium is attached-out winding on the rotating body of the detection object,
The winding occurrence determination means corrects the reference value so as not to determine that the recording medium has been wound around the rotation body to be detected for a predetermined period immediately after the pair of rotating bodies contact each other, or Correction means for correcting the calculated value of the temperature drop of the surface temperature so as not to determine that it is wound;
Program to make the computer function .

Images