JP2017024817A - Fixing device, image formation device and fixing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To derive thickness of a recording medium regardless of whether or not, a load of drive means for driving transport means in entry of the recording medium to the transport means has a peak value.SOLUTION: An image formation device 10 comprises: a positioning roll 68 for sandwiching a sheet P and transporting the sheet P; drive means for driving the positioning roll 68; and detection means for detecting a load of the drive means since the sheet P enters the positioning roll 68 until the sheet is discharged. A thickness of the sheet P is derived based on an integral amount of a load of the drive means in the period detected by the detection means.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a conveyance device, an image forming apparatus, and a conveyance program.

  In Patent Document 1, a heat fixing film or a heat fixing roller and a pressure roller that are pressed against each other are arranged to face each other, and an image is formed by heat fixing while moving a recording material by driving a DC motor. An image forming apparatus including the image forming unit is disclosed. In this image forming apparatus, the DC motor has a characteristic that the current increases due to an increase in load due to the thickness of the recording material, a detecting means for detecting the DC motor current, and a holding for holding a peak value of the detection signal. And a circuit having means for limiting temporary overvoltage of the output.

JP 2003-029555 A

  By the way, even if the load for transporting the medium is detected, the peak may not always be detected. The present invention relates to a conveying apparatus and an image forming apparatus capable of deriving the thickness of a recording medium regardless of whether or not the load of a driving unit that drives the conveying unit at the time of entering the medium conveying unit has a peak value. It is an object to provide a conveyance program.

  In order to achieve the above object, a transport apparatus according to claim 1 includes a transport unit that transports a recording medium, a driving unit that drives the transport unit, and the recording medium enters the transport unit. Detecting means for detecting the load of the driving means during a period from when the recording medium is discharged, and deriving means for deriving the thickness of the recording medium from the integrated amount of the load of the driving means detected during the period detected by the detecting means And.

  According to a second aspect of the present invention, in the first aspect of the present invention, the derivation unit has the load detected by the detection unit in the period and the recording medium is not conveyed by the conveyance unit. The integrated value of the difference from the load detected by the detecting means in the state is derived as the integration amount.

  On the other hand, in order to achieve the above object, an image forming apparatus according to claim 3 includes a conveying unit that conveys a recording medium, a driving unit that drives the conveying unit, and the recording medium is provided to the conveying unit. The thickness of the recording medium is derived from the detection means for detecting the load of the drive means in the period from the entry to the ejection, and the integrated amount of the load of the drive means in the period detected by the detection means. And a derivation unit that forms an image on the recording medium.

  On the other hand, in order to achieve the above object, according to a fourth aspect of the present invention, there is provided a conveyance program according to a fourth aspect of the present invention, in which a drive unit that drives a conveyance unit that conveys a computer with a recording medium interposed therebetween, In order to function as derivation means for deriving the thickness of the recording medium from the integrated amount of the load of the driving means during the period from the discharge to the discharge.

  According to the first, third, and fourth aspects of the present invention, the load of the driving unit that drives the conveying unit when the recording medium enters the conveying unit has a peak value. It is possible to derive the thickness of the recording medium.

  According to the second aspect of the present invention, it is possible to derive the thickness of the recording medium using the driving load of the conveying means in a state where the recording medium is not conveyed.

1 is a schematic configuration diagram illustrating a configuration of an image forming apparatus according to a first embodiment. 1 is a block diagram illustrating a main configuration of an electric system of an image forming apparatus according to a first embodiment. It is a graph which shows an example of the time series data of the detection result by the torque detection part which concerns on 1st Embodiment. It is a graph which shows an example of the time series data of the detection result by the torque detection part which concerns on 1st Embodiment. It is a schematic block diagram with which it uses for description of the timing which the paper which concerns on 1st Embodiment rushes into an alignment roll. FIG. 6 is a schematic configuration diagram for explaining a timing at which a sheet according to the first embodiment is discharged from an alignment roll. It is a graph which shows an example of the relationship between the integral amount and paper thickness which concern on each embodiment. It is a flowchart which shows the flow of a process of the thickness derivation processing program concerning each embodiment. It is the schematic which shows an example of the error notification screen which concerns on each embodiment. It is a schematic block diagram which shows the structure of the image forming apparatus which concerns on 2nd Embodiment. FIG. 5 is a block diagram illustrating a main configuration of an electrical system of an image forming apparatus according to a second embodiment. It is a graph which shows an example of the time series data of the detection result by the torque detection part which concerns on 2nd Embodiment. It is a graph which shows an example of the time series data of the detection result by the torque detection part which concerns on 2nd Embodiment. It is a graph which shows an example of the time series data of the detection result by the torque detection part which concerns on 2nd Embodiment. FIG. 6 is a schematic configuration diagram for explaining timing when a sheet according to a second embodiment enters a fixing device. FIG. 6 is a schematic configuration diagram for explaining timing when a sheet according to a second embodiment is discharged from a fixing device.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

[First Embodiment]
First, the configuration of the image forming apparatus 10 according to the present embodiment will be described with reference to FIG. In the following, yellow is indicated by Y, magenta color is indicated by M, cyan color is indicated by C, black is indicated by K, and each component and toner image (image) need to be distinguished for each color. The description will be made with the reference numerals (Y, M, C, K) corresponding to the colors at the end. Further, in the following, when the component parts and the toner image are collectively referred to without being distinguished for each color, the description of the color at the end of the code is omitted.

(overall structure)
As shown in FIG. 1, an image processing unit that performs image processing for converting input image data into four-color gradation data of Y, M, C, and K is provided inside the apparatus main body 10 </ b> A of the image forming apparatus 10. 12 is provided.

  Further, an image forming unit 16 that forms toner images of the respective colors is disposed at a central side of the apparatus main body 10A with an interval in a direction inclined with respect to the horizontal direction. Further, a primary transfer unit 18 is provided above the image forming unit 16 for each color in the vertical direction. The toner image formed by the image forming unit 16 for each color is transferred in multiple layers.

  Further, on the side of the primary transfer unit 18 (on the left side in FIG. 1), a sheet P as an example of a recording medium transported along a transport path 60 by a supply transport unit 30 described later is multiplexed on the primary transfer unit 18. A secondary transfer roll 22 is provided for transferring the toner image transferred to the toner image.

  A fixing device 24 is provided downstream of the secondary transfer roll 22 in the conveyance direction of the paper P (hereinafter referred to as “paper conveyance direction”). The fixing device 24 fixes the toner image transferred onto the paper P onto the paper P by heat and pressure.

  The fixing device 24 according to the present embodiment includes a heating belt 24A and a pressure roll 24B. The fixing device 24 is a so-called IH (Induction Heating) fixing device in which the heating belt 24A generates heat using electromagnetic induction. Further, the pressure roll 24B is driven (rotated) by a motor (not shown), and the heating belt 24A is driven to rotate as the pressure roll 24B rotates. Further, the surface of the pressure roll 24B is formed to include a sponge elastic layer such as foamed silicon rubber, for example.

  Further, on the downstream side of the fixing device 24 in the paper conveyance direction, a discharge roll 28 that discharges the paper P on which the toner image is fixed to a discharge portion 26 provided on the upper portion of the apparatus main body 10A of the image forming apparatus 10. Is provided.

  On the other hand, a supply transport unit 30 that supplies and transports the paper P is provided below and to the side of the vertical direction of the image forming unit 16. Also, above the primary transfer unit 18 in the vertical direction, there are four toner cartridges 14 that can be attached to and detached from the apparatus main body 10A from the front of the apparatus main body 10A and are filled with toner to be supplied to the developing device 38 by color. (14K to 14Y) are arranged side by side in the apparatus width direction. Each color toner cartridge 14 has a cylindrical shape extending in the depth direction of the apparatus, and is connected to each color developing device 38 via a supply pipe (not shown).

(Image forming unit)
As shown in FIG. 1, the image forming units 16 for the respective colors are all configured similarly. The image forming unit 16 includes a rotating columnar image carrier 34 and a charger 36 that charges the surface of the image carrier 34.

  Further, the image forming unit 16 includes an LED (Light Emitting Diode) head 32 that irradiates the surface of the charged image carrier 34 with exposure light. Further, the image forming unit 16 develops the electrostatic latent image formed by the exposure of the exposure light from the LED head 32 with a developer (in this embodiment, a toner charged on the negative electrode), and visualizes it as a toner image. A container 38 is provided. Further, the image forming unit 16 includes a cleaning blade (not shown) that cleans the surface of the image carrier 34.

  A developing roll 39 is disposed in the developing unit 38 so as to face the image holding member 34. The developing unit 38 uses the developing roll 39 to convert the electrostatic latent image formed on the image holding member 34 with a developer. Develop and visualize as a toner image.

  The charger 36, the LED head 32, the developing roll 39, and the cleaning blade are arranged in this order from the upstream side to the downstream side in the rotation direction of the image carrier 34 so as to face the surface of the image carrier 34. Has been.

(Transfer section (primary transfer unit, secondary transfer roll))
The primary transfer unit 18 includes an endless intermediate transfer belt 42 and a drive roll 46 around which the intermediate transfer belt 42 is wound and driven to rotate by a motor (not shown) to rotate the intermediate transfer belt 42 in the direction of arrow A. ing. In addition, the primary transfer unit 18 is wound around the intermediate transfer belt 42, is provided with a tension applying roll 48 that applies tension to the intermediate transfer belt 42, and is disposed vertically above the tension applying roll 48 and is driven by the intermediate transfer belt 42. And an auxiliary roll 50 that rotates. Further, the primary transfer unit 18 includes primary transfer rolls 52 disposed on the opposite sides of the image holders 34 of the respective colors with the intermediate transfer belt 42 interposed therebetween.

  With the above configuration, the toner images of each color Y, M, C, and K, which are sequentially formed on the image carrier 34 of the image forming unit 16 for each color, are transferred onto the intermediate transfer belt 42 by the primary transfer roll 52 for each color. Multiple transcriptions are made.

  Further, a cleaning blade 56 that contacts the surface of the intermediate transfer belt 42 and cleans the surface of the intermediate transfer belt 42 is disposed on the opposite side of the drive roll 46 with the intermediate transfer belt 42 interposed therebetween.

  Further, on the opposite side of the auxiliary roll 50 with the intermediate transfer belt 42 interposed therebetween, a secondary transfer roll 22 for transferring the toner image transferred onto the intermediate transfer belt 42 onto the conveyed paper P is provided. The secondary transfer roll 22 is grounded, the auxiliary roll 50 forms a counter electrode of the secondary transfer roll 22, and the secondary transfer voltage is applied to the auxiliary roll 50, whereby the paper P The toner image is transferred to the toner image. In this embodiment, the conveyance speed of the paper P by the secondary transfer roll 22 and the intermediate transfer belt 42 is higher than the conveyance speed of the paper P by the fixing device 24.

(Supply transport unit)
The supply conveyance unit 30 includes a sheet feeding member 62 on which a plurality of sheets P are stacked, which is disposed in the apparatus main body 10 </ b> A below the image forming unit 16 in the vertical direction.

  Further, the supply and transport unit 30 includes a paper feed roll 64 that feeds the paper P stacked on the paper feed member 62 to the transport path 60, and a separation roll 66 that separates the paper P sent by the paper feed roll 64 one by one. , And an alignment roll 68 for adjusting the conveyance timing of the paper P. And each roll is arrange | positioned in this order toward the downstream from the upstream in the paper conveyance direction. The alignment roll 68 is an example of a conveying unit that conveys the image P of the paper P across the image forming surface.

  The alignment roll 68 includes a drive roll 68A and a driven roll 68B. Then, the driving roll 68A is driven (rotated) by a motor 112 (see FIG. 2) as an example of a driving unit, and the driven roll 68B is driven to rotate as the driving roll 68A rotates. Further, the surface of the drive roll 68A is formed to include plastic or the like.

  With the above configuration, the paper P supplied from the paper supply member 62 is set at a timing determined by the rotating alignment roll 68 to the contact portion (secondary transfer position) between the intermediate transfer belt 42 and the secondary transfer roll 22. Sent out.

  The sheet P conveyed to the fixing device 24 is heated by the heating belt 24A and is pressed by the heating belt 24A and the pressure roll 24B, so that a toner image is formed on one surface (image forming surface) of the sheet P. It is fixed.

  Further, the supply / conveyance unit 30 forms the toner image on the other side without discharging the paper P, on which the toner image is fixed on one side by the fixing device 24, to the discharge unit 26 by the discharge roll 28 as it is. The double-sided conveyance device 70 used for the above is provided.

  The double-sided conveyance device 70 conveys the paper P along the double-sided conveyance path 72, and the double-sided conveyance path 72 where the paper P is conveyed by reversing the front and back of the paper P from the discharge roll 28 toward the alignment roll 68. A roll 74 and a transport roll 76 are provided.

(Other)
The image forming apparatus 10 includes a sheet detection sensor 80 provided on the upstream side in the sheet conveyance direction of the alignment roll 68 along the conveyance path 60 and a sheet detection sensor 82 provided on the downstream side. The sheet detection sensors 80 and 82 according to the present embodiment are, for example, reflection type sensors including a pair of light emitting elements and light receiving elements. The paper detection sensors 80 and 82 irradiate light from the light emitting element to the detection position on the transport path 60 corresponding to the installation position. Further, the paper detection sensors 80 and 82 output a signal having a signal level corresponding to the amount of light received by the light receiving element (hereinafter referred to as “detection signal”). During the period when the paper P is transported through the detection position, the light emitted from the light emitting element is reflected by the paper P. Accordingly, the sheet detection sensors 80 and 82 output detection signals having different signal levels depending on the period during which the sheet P is conveyed at the detection position and the period during which the sheet P is not conveyed.

  As described above, in the present embodiment, the reflection type sensors are applied as the paper detection sensors 80 and 82, but the present invention is not limited to this. For example, other sensors such as a transmission type sensor may be applied. Also good.

(Image formation process)
First, gradation data of each color is sequentially output from the image processing unit 12 to the LED head 32 of each color. The exposure light emitted from the LED head 32 in accordance with the gradation data is applied to the surface of the image carrier 34 charged by the charger 36. Thereby, an electrostatic latent image is formed on the surface of the image carrier 34. The electrostatic latent image formed on the image carrier 34 is developed by each color developer 38 and visualized as a toner image of each color of Y, M, C, K.

  Further, the primary transfer rolls 52 of the primary transfer unit 18 transfer the toner images of the respective colors formed on the image carrier 34 onto the rotating intermediate transfer belt 42 in a multiple manner.

  The toner images of the respective colors transferred in multiple on the intermediate transfer belt 42 are transferred onto the sheet P conveyed along the conveying path 60 from the sheet feeding member 62 by the sheet feeding roll 64, the separation roll 66, and the alignment roll 68. Secondary transfer is performed at the secondary transfer position by the secondary transfer roll 22.

  Further, the paper P on which the toner image is transferred is conveyed to the fixing device 24. Then, the toner image is fixed on the paper P by the fixing device 24. The paper P on which the toner image is fixed is discharged to the discharge unit 26 by the discharge roll 28.

  On the other hand, when images are formed on both sides of the paper P, the paper P on which the toner image is fixed on one side (front surface) by the fixing device 24 is not directly discharged to the discharge unit 26 by the discharge roll 28. The transport direction of the paper P is switched by the reverse rotation of the discharge roll 28. The sheet P is transported along the duplex transport path 72 by transport rollers 74 and 76.

  The sheet P transported along the duplex transport path 72 is transported again to the alignment roll 68 with its front and back reversed. Then, after the toner image is transferred and fixed on the other side (back side) of the sheet P, the sheet P is discharged to the discharge unit 26 by the discharge roll 28.

  Next, with reference to FIG. 2, the main configuration of the electrical system of the image forming apparatus 10 according to the present embodiment will be described.

  As shown in FIG. 2, an image forming apparatus 10 according to the present embodiment stores a CPU (Central Processing Unit) 100 that controls the overall operation of the image forming apparatus 10, and various programs, various parameters, and the like. A ROM (Read Only Memory) 102 is provided. The image forming apparatus 10 also includes a RAM (Random Access Memory) 104 that is used as a work area when the CPU 100 executes various programs, and a non-volatile storage unit 106 such as a flash memory.

  In addition, the image forming apparatus 10 includes a communication line I / F (Interface) unit 108 that transmits and receives communication data to and from an external device. In addition, the image forming apparatus 10 includes an operation display unit 110 that accepts an instruction from the user to the image forming apparatus 10 and displays various types of information regarding the operation status of the image forming apparatus 10 to the user. The operation display unit 110 includes, for example, a display button that realizes reception of an operation instruction by executing a program, a display provided with a touch panel on a display surface on which various information is displayed, and hardware keys such as a numeric keypad and a start button. including.

  Further, the image forming apparatus 10 includes a torque detection unit 114 as an example of a detection unit that detects a load (torque) of the motor 112 that rotationally drives the drive roll 68A. The torque detector 114 according to the present embodiment is connected to the motor 112, detects the torque of the motor 112 as a current value flowing through the motor 112, converts the current value into a voltage value, and outputs the voltage value.

  Note that the configuration of the torque detection unit 114 according to the present embodiment is not particularly limited as long as the torque of the motor 112 can be detected. For example, the torque detector 114 may be configured to detect a current by measuring a voltage between shunt resistors. Further, for example, as the torque detection unit 114, a configuration in which a resistor is provided on a path through which a current flows in the motor 112 and the current is detected by measuring a voltage between the resistors may be applied. Further, for example, the torque detection unit 114 may be configured to detect a current by providing a current sensor using a Hall element on a path through which a current flows in the motor 112. Furthermore, for example, a torque detector that detects the torque of the motor 112 may be applied as the torque detector 114.

  The CPU 100, the ROM 102, the RAM 104, the storage unit 106, the communication line I / F unit 108, the operation display unit 110, the motor 112, the torque detection unit 114, and the paper detection sensors 80 and 82 are each configured as an address bus, a data bus, and They are connected to each other via a bus 116 such as a control bus.

  With the above configuration, the image forming apparatus 10 according to the present embodiment allows the CPU 100 to access the ROM 102, the RAM 104, and the storage unit 106 and to communicate with an external device via the communication line I / F unit 108. Send and receive data each. In the image forming apparatus 10, the CPU 100 acquires various instruction information via the operation display unit 110 and displays various information on the operation display unit 110. In addition, the image forming apparatus 10 performs control of the motor 112 and acquisition of the voltage value output from the torque detection unit 114 by the CPU 100, respectively.

  Further, the image forming apparatus 10 acquires detection signals output from the paper detection sensors 80 and 82 by the CPU 100, respectively. Accordingly, in the image forming apparatus 10, the front end and the rear end of the paper P in the paper transport direction pass through the detection positions of the paper detection sensors 80 and 82 according to the change in the signal level of the detection signal acquired by the CPU 100. Detect the timing. Hereinafter, the leading edge and the trailing edge of the sheet P in the sheet conveyance direction are also simply referred to as the leading edge and the trailing edge of the sheet P.

  Incidentally, the image forming apparatus 10 according to the present embodiment is equipped with a detection function for detecting the thickness of the paper P.

The detection function will be described in detail with reference to FIGS. 3 and 4, the torque detection unit 114 is illustrated from the time when the leading edge of the paper P passes the detection position by the paper detection sensor 80 to the time when the rear edge of the paper P passes the detection position by the paper detection sensor 82. The time-series data of the voltage values output from is shown for the two types of paper P of thickness (basis weight). Further, FIG. 3 is basis weight showing an example of time-series data of the paper P of 256 g / m ^2, 4 basis weight shows an example of time-series data of the paper sheet P of 82 g / m ^2. FIGS. 5 and 6 are diagrams for explaining the time-series data of the voltage values shown in FIGS. 3 and 4 and show the transport position of the paper P. FIG.

  First, as shown in FIGS. 3 to 5, the voltage value output from the torque detection unit 114 starts to increase at the timing t <b> 1 when the leading edge of the paper P enters the alignment roll 68, and then the fluctuation amount is relatively small. Transition. 3, 4, and 6, the voltage value output from the torque detection unit 114 starts to decrease before the trailing edge of the paper P is discharged from the alignment roll 68, and the paper P After the timing t2 when the rear end of the rear end is discharged from the alignment roll 68, the fluctuation amount is relatively small.

  As shown in FIGS. 3 and 4, from the torque detection unit 114 in a period T <b> 1 from when the leading edge of the paper P enters the alignment roll 68 until the trailing edge of the paper P is discharged from the alignment roll 68. The output voltage value increases as the paper P becomes thicker.

  Therefore, the image forming apparatus 10 according to the present embodiment derives the thickness of the sheet P from the integral amount of the voltage value in the period T1 (period from timing t1 to timing t2). The integration amount corresponds to the area of the hatched portion in FIGS.

  Next, the integration amount derivation process will be described. First, the image forming apparatus 10 specifies the timing t1. Specifically, for example, by an experiment using an actual apparatus of the image forming apparatus 10, a period from when the leading edge of the paper P passes through the detection position by the paper detection sensor 80 until it enters the alignment roll 68 is measured in advance. Keep it. Then, the image forming apparatus 10 specifies the period measured in advance as the timing t1.

  The specifying process at the timing t1 is not limited to the example described above. For example, after the leading edge of the paper P passes the detection position by the paper detection sensor 80 and the detection by the torque detection unit 114 is started, the voltage value output from the torque detection unit 114 is the threshold value first. You may specify the timing beyond this as the timing t1. Further, for example, the image forming apparatus 10 increases the voltage value output from the torque detection unit 114 after the leading edge of the paper P passes the detection position by the paper detection sensor 80 and starts detection by the torque detection unit 114. The timing at which the amount (for example, the increase amount of the voltage value at each detection interval by the torque detection unit 114) first exceeds the threshold may be specified as the timing t1.

  Next, the image forming apparatus 10 specifies the timing t2. Specifically, for example, from an experiment using an actual apparatus of the image forming apparatus 10 until the trailing edge is discharged from the alignment roll 68 after the leading edge of the paper P passes the detection position by the paper detection sensor 80. The period is measured in advance. Then, the image forming apparatus 10 specifies the period measured in advance as the timing t2.

  Note that the identification process at the timing t2 is not limited to the example described above. For example, the image forming apparatus 10 may specify the timing at which the voltage value output from the torque detection unit 114 first falls below the threshold after the timing t1 as the timing t2. In addition, for example, the image forming apparatus 10 may decrease the amount of voltage value output from the torque detection unit 114 (for example, detection by the torque detection unit 114) after the voltage value output from the torque detection unit 114 increases after the timing t1. The timing at which the absolute value of the voltage value reduction amount for each interval is initially less than the threshold value may be specified as the timing t2.

  Next, the image forming apparatus 10 derives the integral amount of the voltage value in the period T1 from the timing t1 to the timing t2 specified by the above processing. First, the image forming apparatus 10 determines a reference value used for deriving an integration amount. Specifically, for example, the image forming apparatus 10 calculates the average value of the voltage values from the timing (left end in FIGS. 3 and 4) when the leading edge of the paper P passes the detection position by the paper detection sensor 80 to the timing t1. Derived as a reference value.

  Note that the reference value is not limited to this example. For example, the image forming apparatus 10 detects the torque of the motor 112 by the torque detection unit 114 while rotating the alignment roll 68 in a state where the paper P is not conveyed in advance, and the voltage value output from the torque detection unit 114 May be used as the reference value.

  Then, the image forming apparatus 10 derives the integration amount by integrating the difference between each of the voltage values output from the torque detection unit 114 and the reference value in the period T1.

  The integration amount derivation process is not limited to the example described above. For example, the image forming apparatus 10 approximates time-series data of voltage values in the period T1 to an arithmetic expression such as a quadratic expression. Then, the image forming apparatus 10 may derive the integration amount by integrating approximate arithmetic expressions. Further, the image forming apparatus 10 may derive the integration amount by integrating the voltage value output from the torque detection unit 114 in the period T1 without using the reference value.

  Next, a process for deriving the thickness of the paper P from the integral amount will be described with reference to FIG.

  As described above, the voltage value output from the torque detection unit 114 in the period T1 increases as the paper P becomes thicker. That is, the integral amount also increases as the paper P becomes thicker. Therefore, in the present embodiment, the voltage output from the torque detection unit 114 corresponding to the thickness of the plurality of types of paper P by experiments using the actual apparatus of the image forming apparatus 10 and the paper P of the plurality of types of thickness. The value is measured in advance. Further, the integration amount is derived from time-series data of voltage values measured in advance. Then, as shown in FIG. 7, the result obtained in advance is approximated to a linear line L by the least square method or the like. Further, an arithmetic expression representing the relationship between the thickness T of the paper P and the integral amount V of the voltage value output from the torque detection unit 114 in the period T1 corresponds to the linear straight line L represented by the following expression (1). A linear expression is derived in advance.

  Then, the image forming apparatus 10 derives the thickness T of the paper P from the integral amount V of the voltage value in the period T1 using the equation (1). However, the present invention is not limited to this, and the thickness T of the paper P may be derived from the integral V by using, for example, the relationship between the integral V and the thickness T of the paper P as an LUT (look-up table).

  Next, with reference to FIG. 8, the operation of the image forming apparatus 10 according to the present embodiment when the detection function is executed will be described. FIG. 8 is a flowchart showing the flow of the thickness derivation processing program executed by the CPU 100 each time an image formation instruction for the paper P is input. The thickness derivation program is preinstalled in the ROM 102. Here, in order to avoid complications, description of the process of forming an image on the paper P by the above-described image forming process is omitted. In the following description, it is assumed that the thickness of the paper P to be used is preset for the image forming apparatus 10 by the user.

  In step 150 of FIG. 8, the CPU 100 acquires the detection signal output from the paper detection sensor 80. In the next step 152, the CPU 100 determines whether or not the leading edge of the paper P has passed the detection position by the paper detection sensor 80 on the transport path 60 based on the detection signal acquired by the processing in step 150. . If the determination is negative, the CPU 100 returns to step 150. If the determination is affirmative, the CPU 100 proceeds to step 154.

  In step 154, the CPU 100 acquires the voltage value output from the torque detection unit 114. In the next step 156, the CPU 100 acquires the detection signal output from the paper detection sensor 82. In the next step 158, the CPU 100 determines whether or not the rear end of the paper P has passed the detection position by the paper detection sensor 82 on the transport path 60 based on the detection signal acquired by the processing in step 156. To do. If the determination is negative, the CPU 100 returns to step 154. If the determination is affirmative, the CPU 100 proceeds to step 160. The time series data of the voltage values shown in FIG. 3 and FIG. 4 are acquired by repeating the above-described steps 154 to 158.

  In step 160, as described above, the CPU 100 specifies the timings t <b> 1 and t <b> 2 from a period obtained by measurement in advance through an experiment using an actual apparatus of the image forming apparatus 10.

  In the next step 162, as described above, the CPU 100 derives, as the reference value, the average value of the voltage values output from the torque detection unit 114 until the timing t1 after the detection by the torque detection unit 114 is started. . In the next step 164, as described above, the CPU 100 integrates the difference between each of the voltage values output from the torque detection unit 114 and the reference value in the period T1 from the timing t1 to the timing t2, thereby integrating the integration. The quantity V is derived.

  In the next step 166, the CPU 100 derives the thickness T of the paper P from the integral amount V derived by the processing in step 164 using the above equation (1). In the next step 168, the CPU 100 determines whether or not the thickness T of the paper P derived by the processing in step 166 is outside the allowable range.

  Specifically, in this embodiment, as an example, the CPU 100 determines that the absolute value of the difference between the thickness T of the derived paper P and the thickness of the paper P preset by the user is the thickness of the thickness. When the ratio is equal to or greater than a predetermined ratio (for example, 10%), it is determined that it is out of the allowable range. If the determination at step 168 is affirmative, the CPU 100 proceeds to the process at step 170.

  In step 170, the CPU 100 displays an error notification screen indicating that the thickness T of the paper P derived by the processing in step 166 is outside the allowable range on the display of the operation display unit 110, and then derives the actual thickness. Terminate the processing program.

  FIG. 9 shows an example of an error notification screen according to the present embodiment. As shown in FIG. 9, on the error notification screen according to the present embodiment, information indicating that the thickness T of the derived paper P is out of the allowable range, and information indicating the thickness T of the derived paper P , And information indicating the thickness of the paper P preset by the user is displayed. Here, when ending the display of the error notification screen, the user designates an end button displayed at the bottom of the error notification screen.

  On the other hand, if the determination in step 168 is negative, the CPU 100 ends the thickness derivation processing program without executing the processing in step 170.

  As described above, in the present embodiment, the case where the error notification screen is displayed based on the derived thickness of the paper P has been described, but the present invention is not limited to this. For example, a configuration may be adopted in which members downstream of the transport path 60 are controlled based on the derived thickness of the paper P.

  In this case, a mode in which the voltage value of the secondary transfer voltage applied to the auxiliary roll 50 is changed according to the derived thickness of the paper P is exemplified. Further, according to the derived thickness of the paper P, a mode of changing the transport speed of the paper P in the transport path 60 downstream from the alignment roll 68 and a mode of changing the amount of heat heated by the heating belt 24A are also exemplified. Is done.

[Second Embodiment]
First, the configuration of the image forming apparatus 10 according to the present embodiment will be described with reference to FIGS. 10 and 11. In addition, about the component which has the same function as FIG. 1 in FIG. 10, the code | symbol same as FIG. 1 is attached | subjected and the description is abbreviate | omitted. Further, in FIG. 11, components having the same functions as those in FIG. 2 are denoted by the same reference numerals as those in FIG. 2, and description thereof is omitted.

  As shown in FIG. 10, in the present embodiment, the paper detection sensor 80 is provided on the upstream side of the fixing device 24 in the paper transport direction along the transport path 60, and the paper detection sensor 82 is the paper transport of the fixing device 24. It is provided downstream in the direction. In the present embodiment, the pressure roll 24B is driven (rotated) by a motor 118 (see FIG. 11) as an example of a driving unit, and the heating belt 24A is driven as the pressure roll 24B rotates. Then rotate. Further, as shown in FIG. 11, torque detection unit 114 according to the present embodiment detects the load of motor 118.

Next, the detection function according to the present embodiment will be described in detail with reference to FIGS. In FIGS. 12 to 14, the torque detection unit 114 is shown from the time when the leading edge of the paper P passes the detection position by the paper detection sensor 80 to the time when the rear edge of the paper P passes the detection position by the paper detection sensor 82. The time-series data of the voltage values output from is shown for the three types of thickness (basis weight) paper P. Further, FIG. 12 is a basis weight showing an example of time-series data of the paper P of 256 g / ^{m 2,} 13 basis weight showing an example of time-series data of the paper P of 157 g / ^{m 2,} 14 basis An example of time-series data of the paper P having an amount of 82 g / m ² is shown. 15 and 16 are diagrams for explaining the time-series data of the voltage values shown in FIGS. 12 to 14 and show the transport position of the paper P. FIG. In order to avoid complications, the intermediate transfer belt 42 is indicated by broken lines in FIGS. 15 and 16. Further, the waveform of the time series data is different from the waveform of the first embodiment (see FIGS. 3 and 4), because the material of the surface of the drive roll 68A and the material of the surface of the pressure roll 24B are different. It is inferred that this is due to various conditions such as a difference in nip force when the paper P is conveyed.

  First, as shown in FIGS. 12 to 14, the voltage value output from the torque detection unit 114 rapidly increases at the timing t <b> 1 and then decreases rapidly after reaching the upwardly convex peak value P <b> 1, and the timing t <b> 2. Thereafter, the fluctuation amount is relatively small. Thereafter, the voltage value sharply decreases and then increases rapidly after reaching a downwardly convex peak value P2.

  Next, with reference to FIG. 15 and FIG. 16, the principle of the time-series change of the voltage values shown in FIG. 12 to FIG. 14 will be described.

  As shown in FIG. 15, when the paper P enters the fixing device 24, a force in the direction opposite to the rotation direction of the pressure roll 24B (the force indicated by the arrow B in FIG. 15) acts on the pressure roll 24B. The torque of the motor 118 increases. Accordingly, the voltage value output by the torque detection unit 114 also increases and becomes the peak value P1. Thereafter, the paper P is conveyed while being sandwiched between the fixing devices 24, and the reverse force when the paper P enters the fixing device 24 does not work, so the voltage value decreases.

  Also, as shown in FIG. 16, when the paper P is discharged from the fixing device 24, a force in the same direction as the rotation direction of the pressure roll 24B is applied to the pressure roll 24B (the force indicated by the arrow C in FIG. 16). Works, and the torque of the motor 118 decreases. Therefore, the voltage value output by the torque detection unit 114 is also reduced to the peak value P2.

  On the other hand, as shown in FIGS. 12 to 14, also in this embodiment, in the period T <b> 1 from when the leading edge of the paper P enters the fixing device 24 until the trailing edge of the paper P is discharged from the fixing device 24. The voltage value output from the torque detector 114 increases as the paper P becomes thicker.

  Therefore, also in the present embodiment, as in the first embodiment, the thickness of the paper P is derived from the integrated amount of the voltage value in the period T1 (period from timing t1 to timing t2). Note that the integration amount corresponds to the area of the shaded portion in FIGS.

  The flow of the specific processing at timings t1 and t2, the derivation process of the integral amount V, the process of deriving the thickness T of the paper P from the integral amount V, and the process of the thickness derivation process program are the same as those in the first embodiment. Since it is the same as that of a form, description here is abbreviate | omitted.

  As described above, also in the present embodiment, the thickness of the paper P is derived from the integrated amount of the voltage value output by the torque detection unit 114 in the period T1, as in the first embodiment. .

  Although each embodiment has been described above, the technical scope of the present invention is not limited to the scope described in each embodiment. Various modifications or improvements can be added to the above-described embodiments without departing from the gist of the invention, and embodiments to which the modifications or improvements are added are also included in the technical scope of the present invention.

  In addition, each of the above embodiments does not limit the invention according to the claims (claims), and all combinations of features described in each embodiment are indispensable for solving means of the invention. Not necessarily. Each embodiment described above includes inventions at various stages, and various inventions are extracted by combining a plurality of disclosed constituent elements. Even if several constituent requirements are deleted from all the constituent requirements shown in the respective embodiments, the configuration from which these several constituent requirements are deleted can be extracted as an invention as long as the effect is obtained.

  For example, in each of the above embodiments, the case where the fixing device 24 or the alignment roll 68 is applied as the conveying unit of the present invention has been described, but the present invention is not limited to this. For example, as the conveying unit of the present invention, other conveying units that convey the image forming surface of the sheet P such as the intermediate transfer belt 42 and the secondary transfer roll 22 or the separation roll 66 may be applied. In this case as well, the thickness of the sheet P is derived from the integrated amount of the load of the driving unit that drives the conveying unit, as in the above embodiments.

  Further, although cases have been described with the above embodiment where the present invention is applied to an image forming apparatus, the present invention is not limited to this. For example, the present invention may be applied to another apparatus including a conveyance unit that conveys a recording medium such as an image reading apparatus or an ADF (Auto Document Feeder).

  Further, in each of the above embodiments, the case where the thickness derivation processing program is preinstalled in the ROM 102 has been described, but the present invention is not limited to this. For example, the thickness derivation processing program may be provided by being stored in a storage medium such as a CD-ROM (Compact Disk Read Only Memory) or provided via a network.

  Further, although cases have been described with the above embodiments where the thickness derivation process is implemented by a software configuration using a computer by executing a program, the present invention is not limited to this. For example, the thickness derivation process may be realized by a hardware configuration or a combination of a hardware configuration and a software configuration.

  In addition, the configuration of the image forming apparatus 10 described in the above embodiments (see FIGS. 1, 2, 10, and 11) is merely an example, and unnecessary portions are within the scope not departing from the gist of the present invention. Needless to say, it may be deleted or a new part may be added.

  Further, the flow of processing of the thickness derivation processing program described in the above embodiments (see FIG. 8) is also an example, and unnecessary steps can be deleted or new steps can be made without departing from the gist of the present invention. Needless to say, the processing order may be changed.

  Furthermore, the configuration of the error notification screen (see FIG. 9) shown in each of the above embodiments is also an example, and some information may be deleted or new information may be deleted without departing from the gist of the present invention. Needless to say, it is possible to add or change the display position.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 24 Fixing apparatus 24A Heating belt 24B Pressure roll 68 Positioning roll 68A Drive roll 68B Driven roll 100 CPU
112 Motor 114 Torque detector 118 Motor P Paper

The present invention relates to a fixing device, an image forming apparatus, and a fixing program.

According to the present invention, the thickness of the recording medium can be derived from the load during the period including the peak value of the load of the driving unit that drives the fixing unit when the recording medium enters the fixing unit and when the recording medium is discharged from the fixing unit. An object of the present invention is to provide a fixing device, an image forming apparatus, and a fixing program.

In order to achieve the above object, a fixing device according to claim 1 includes a fixing unit that conveys a recording medium on which an image is formed and fixes the image, a driving unit that drives the fixing unit, and a detecting means for the recording medium to detect a load of said driving means in a period until the discharged from the rush to the fixing unit, the recording medium loading of the drive means in the period detected by said detecting means Deriving means for deriving the thickness of the recording medium from an integral amount obtained by integrating the peak value when entering the fixing means and the peak value when discharging .

According to a second aspect of the present invention, in the first aspect of the present invention, the derivation unit has the load detected by the detection unit in the period, and the recording medium is not conveyed by the fixing unit. The integrated value of the difference from the load detected by the detecting means in the state is derived as the integration amount.

On the other hand, in order to achieve the above object, the image forming apparatus according to claim 3 includes a fixing unit that conveys a recording medium on which an image is formed and fixes the image, and a driving unit that drives the fixing unit. When a detection means for the recording medium to detect a load of said driving means in a period until the discharged from the rush to the fixing means, the load of the drive means in the period detected by said detecting means and the Deriving means for deriving the thickness of the recording medium from the integrated amount including the peak value when the recording medium enters the fixing means and the peak value when the recording medium is discharged , and forming an image on the recording medium Image forming means.

On the other hand, in order to achieve the above object, the fixing program according to claim 4 includes: a driving unit that drives a fixing unit that transports a computer across a recording medium on which an image is formed and fixes the image ; integration, including a peak value when the recording medium is the recording medium loading of the drive means in a period until the discharged from the rush to the fixing means is a peak value and the discharge at the time of rush to the fixing means This is to function as derivation means for deriving the thickness of the recording medium from the integrated amount.

According to the first, third, and fourth aspects of the invention, the peak value of the load of the driving unit that drives the fixing unit when the recording medium enters the fixing unit and when the recording medium is discharged from the fixing unit, respectively. The thickness of the recording medium can be derived from the load in a period including

According to the second aspect of the present invention, the thickness of the recording medium can be derived using the driving load of the fixing unit when the recording medium is not conveyed.

Claims (4)

Transport means for transporting the recording medium, and
Driving means for driving the conveying means;
Detecting means for detecting a load of the driving means in a period from when the recording medium enters the conveying means until it is discharged;
Deriving means for deriving the thickness of the recording medium from the integrated amount of the load of the driving means in the period detected by the detecting means;
Conveying device equipped with. The derivation means calculates an integrated value of a difference between a load detected by the detection means in the period and a load detected by the detection means in a state where the recording medium is not conveyed by the conveyance means. The transport device according to claim 1, wherein the transport device is derived as a quantity. Transport means for transporting the recording medium, and
Driving means for driving the conveying means;
Detecting means for detecting a load of the driving means in a period from when the recording medium enters the conveying means until it is discharged;
Deriving means for deriving the thickness of the recording medium from the integrated amount of the load of the driving means in the period detected by the detecting means;
Image forming means for forming an image on the recording medium;
An image forming apparatus.   With respect to the driving means for driving the conveying means for conveying the computer with the recording medium interposed therebetween, the recording medium is calculated from the integral amount of the load of the driving means in the period from when the recording medium enters the conveying means until it is discharged. A conveyance program for functioning as a deriving means for deriving the thickness of the sheet.

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