JP7294001B2 - Image forming apparatus, information processing system, and information processing method - Google Patents

Description

The present invention relates to an image forming apparatus, an information processing system, and an information processing method.

Electrophotographic image forming apparatuses have become widespread. An electrophotographic image forming apparatus includes, as printing processes, a process of forming a toner image corresponding to an input image on a photoreceptor, a process of primarily transferring the toner image on the photoreceptor onto a transfer belt, and a process of transferring the image onto the transfer belt. secondarily transfer the toner image onto the paper, and heat fix the toner image onto the paper by a fixing device.

Since the fixing device is a consumable item, in order to provide users with stable, high-quality printed images, it is necessary to predict the life of the fixing device and perform maintenance such as replacing the fixing device at the appropriate timing. be.

In the conventional determination of the life of a fixing device, a uniform running distance is determined based on a predetermined endurance evaluation result, etc., and the running distance is determined as the end of the life requiring maintenance. However, in this case, even a fixing device that can still be used is judged to have reached the end of its life, which is inefficient for the user.

Therefore, for example, as disclosed in Japanese Patent Application Laid-Open No. 2002-100000, two thresholds are set for the torque of the drive load of the fixing device, and when the torque is equal to or greater than the higher one of the two thresholds, the life of the fixing device is determined. is proposed. Further, Japanese Patent Application Laid-Open No. 2002-200000 discloses a technique for determining whether or not the life of a fixing device has reached the end based on the magnitude of a load detected by a current sensor.

JP 2017-138427 A JP 2018-155850 A

The sliding portion of the fixing device wears due to the sliding rotation of the fixing belt. Further, the fixing belt rotates following the pressure roller. Therefore, from the viewpoint of stable image formation, it is necessary to increase the rotational torque of the pressure roller in order to keep the number of rotations of the pressure roller constant.

However, even if the rotational torque of the pressure roller is increased, if the sliding load on the sliding portion of the fixing device becomes larger than the driving force transmitted from the pressure roller to the fixing belt, the pressure roller will and the fuser belt, and as a result, the paper tends to slip in the nip area of the fuser. In this case, the speed when the paper passes through the fixing device is lower than the speed when it passes through the transfer section located upstream of the fixing device. As a result, the output image (image after fixing) is degraded.

From the above point of view, it is conceivable to determine in advance the torque (torque of the pressure roller) at which paper slip is assumed to occur, and use this torque as the reference value (threshold) for life determination. However, the torque at which the paper slips also changes depending on the state of pressure (load) applied by the pressure roller. Therefore, it is difficult to uniquely determine the reference value.

Therefore, in the conventional technology, as a result, the end of life is determined at a considerably earlier stage than the actual end of life.

The present disclosure has been made in view of the above problems, and an object thereof is to provide an image forming cleaning device, an information processing system, and an information processing method capable of increasing the accuracy of life determination of a fixing device. That's what it is.

According to one aspect of the present invention, an image forming apparatus has a fixing device that fixes at least an unfixed image on a recording material, and forms an image on the recording material. The image forming apparatus forms a pressure member that rotates by a motor in a direction in which the recording material is conveyed to the downstream side of the conveying path in the fixing device, and a nip region that faces the pressure member to fix the unfixed image, A fixing belt that rotates following the rotation of a pressure member, and a fixing belt that is disposed inside the fixing belt and slidably supports the fixing belt at a position facing the pressure member so as to oppose the pressure applied by the pressure member. The fixing device reaches the end of its service life when the supporting member and the torque during driving of the motor are acquired each time a predetermined condition is satisfied, and the time-dependent change of the acquired torque turns from an upward change to a downward change. and a control unit that determines that

Preferably, the predetermined condition is that the running distance of the pressing member has increased by a predetermined distance. The control unit obtains the torque each time the traveling distance of the pressure member increases by a predetermined distance. The control unit determines that the life of the fixing device has expired when the acquired torque becomes smaller than the previously acquired torque.

Preferably, the predetermined condition is that the running distance of the pressing member has increased by a predetermined distance. The control unit obtains the torque a plurality of times each time the traveling distance of the pressure member increases by a predetermined distance, and calculates an average value of the torques obtained over the plurality of times. The control unit determines that the life of the fixing device has expired when the calculated average value is smaller than the average value calculated last time.

Preferably, the predetermined condition is that the running distance of the pressing member has increased by a predetermined distance. The control unit acquires the torque a plurality of times each time the traveling distance of the pressure member increases by a predetermined distance, and calculates the average value of the torques acquired over the plurality of times. The control unit calculates the moving average value using the calculated average value and at least the previous calculated average value. The control unit determines that the life of the fixing device has expired when the calculated moving average value becomes smaller than the moving average value calculated last time.

Preferably, the predetermined condition is that a predetermined period of time has passed. The control unit acquires the torque each time a predetermined period elapses. The control unit determines that the life of the fixing device has expired when the acquired torque becomes smaller than the previously acquired torque.

Preferably, the predetermined condition is that a predetermined period of time has passed. The control unit obtains the torque a plurality of times and calculates an average value of the torques obtained over the plurality of times each time the predetermined period elapses. The control unit determines that the life of the fixing device has expired when the calculated average value is smaller than the average value calculated last time.

Preferably, the predetermined condition is that a predetermined period of time has passed. The control unit obtains the torque a plurality of times and calculates an average value of the torques obtained over the plurality of times each time the predetermined period elapses. The control unit calculates the moving average value using the calculated average value and at least the previous calculated average value. The control unit determines that the life of the fixing device has expired when the calculated moving average value becomes smaller than the moving average value calculated last time.

Preferably, the control unit acquires information about the rotational speed of the pressing member. The controller calculates the travel distance by multiplying the rotation speed by the rotation time of the pressing member.

Preferably, the control unit acquires the idling torque when the paper is not passed as the torque every time the travel distance of the pressure member increases by a predetermined distance.

Preferably, the control unit acquires the idling torque when the paper is not fed as the torque every time the predetermined period elapses.

Preferably, the control unit acquires the torque detected after warming up the image forming apparatus or after fixing onto the recording material as the idling torque during non-feeding.

Preferably, the control unit determines that the life of the fixing device has expired on condition that the acquired torque is equal to or greater than a predetermined threshold value.

Preferably, the control unit determines that the life of the fixing device has expired on condition that the calculated average value is equal to or greater than a predetermined threshold value.

Preferably, the control unit determines that the life of the fixing device has expired on condition that the calculated moving average value is equal to or greater than a predetermined threshold value.

Preferably, when the acquired torque becomes smaller than the torque acquired last time, the control unit controls the fixing device to reach the end of its service life on condition that the torque acquired last time is smaller than the torque acquired two times before. It is determined that

Preferably, when the calculated average value becomes smaller than the average value calculated last time, the control unit provides that the average value calculated last time is smaller than the average value calculated two times before, It is determined that the fixing device has reached the end of its life.

Preferably, when the calculated moving average value becomes smaller than the moving average value calculated last time, the control unit determines that the moving average value calculated last time is smaller than the moving average value calculated last time before. condition, it is determined that the fixing device has reached the end of its life.

Preferably, when it is determined that the fixing device has reached the end of its service life, the control unit permits image formation using a sheet of the first sheet type and a second sheet having a basis weight smaller than that of the sheet of the first sheet type. Do not allow image formation using paper of the paper type.

Preferably, the image forming apparatus further includes an operation panel. When the control unit determines that the fixing device has reached the end of its life, it causes the operation panel to display a predetermined image.

According to another aspect of the present invention, an information processing system includes at least a fixing device for fixing an unfixed image on a recording material, an image forming apparatus for forming an image on the recording material, and an information processing apparatus. and The image forming apparatus forms a pressure member that rotates by a motor in a direction in which the recording material is conveyed to the downstream side of the conveying path in the fixing device, and a nip region that faces the pressure member to fix the unfixed image, A fixing belt that rotates following the rotation of a pressure member, and a fixing belt that is disposed inside the fixing belt and slidably supports the fixing belt at a position facing the pressure member so as to oppose the pressure applied by the pressure member. and a support member for The image forming apparatus detects torque when the motor is driven. The information processing apparatus acquires the torque during driving of the motor from the image forming apparatus each time a predetermined condition is satisfied. The information processing device determines that the fixing device has reached the end of its service life when the acquired torque changes over time from an upward change to a downward change.

According to still another aspect of the present invention, an information processing method is executed in an image forming apparatus that has a fixing device that fixes at least an unfixed image on a recording material and that forms an image on the recording material. . The image forming apparatus includes a control unit, a pressure member that is rotated by a motor in a direction in which the recording material is conveyed to the downstream side of the conveying path in the fixing device, and a nip area that faces the pressure member and fixes an unfixed image. and a fixing belt that rotates following the rotation of the pressure member; and a support member that movably supports. The information processing method comprises the step of obtaining the torque during driving of the motor by the control unit each time a predetermined condition is established, and and determining that the fixing device has reached the end of its life.

According to the present disclosure, it is possible to improve the accuracy of life determination of the fixing device.

1 is a diagram illustrating an example of the configuration of an image forming apparatus; FIG. 2 is a block diagram for explaining the hardware configuration of the image forming apparatus; FIG. 2 is a diagram for explaining the hardware configuration of a fixing device; FIG. 4 is a block diagram for explaining torque detection performed in the fixing device; FIG. It is a functional block diagram showing the functional composition of a control device. FIG. 4 is a diagram showing temporal changes in moving average torque; It is a figure showing the example of the warning screen displayed on an operation panel. 4 is a flowchart for explaining the flow of processing executed by the image forming apparatus; FIG. FIG. 9 is a flowchart for explaining the details of the processing in step S2 of FIG. 8; FIG. 10 is a flowchart for explaining the details of the processing in step S27 of FIG. 9; FIG. FIG. 4 is a diagram showing temporal changes in moving average torque; FIG. 10 is a flowchart for explaining the details of the process of step S27 in FIG. 9 in this modification. FIG. 4 is a diagram showing temporal changes in moving average torque; FIG. 10 is a flowchart for explaining the details of the processing in step S27 of FIG. 9; FIG. FIG. 4 is a diagram showing temporal changes in moving average torque; FIG. 10 is a flowchart for explaining the details of the processing in step S27 of FIG. 9; FIG. It is a functional block diagram showing the functional composition of a control device. FIG. 4 is a diagram showing temporal changes in moving average torque; FIG. 9 is a flowchart for explaining the details of the processing in step S2 of FIG. 8; FIG. 20 is a flowchart for explaining the details of the processing in step S27A of FIG. 19; 4 is a flowchart for explaining the flow of processing executed by the image forming apparatus; FIG. 1 is a diagram showing a network configuration of an information processing system; FIG.

An image processing apparatus according to an embodiment will be described below with reference to the drawings. In the embodiments described below, when referring to the number, amount, etc., the scope of the present disclosure is not necessarily limited to the number, amount, etc., unless otherwise specified. The same reference numbers are given to the same parts and equivalent parts, and redundant description may not be repeated.

In the drawings, there are portions that are not illustrated according to actual dimensional ratios, but are illustrated with changed ratios so as to clarify the structure in order to facilitate understanding of the structure. In addition, each embodiment and each modified example described below may be selectively combined as appropriate.

Further, although an image forming apparatus as a color printer will be described below, the image forming apparatus is not limited to a color printer. For example, the image forming apparatus may be a monochrome printer, a FAX, or a multi-function peripheral (MFP: Multi-Functional Peripheral) of monochrome printer, color printer and FAX.

Furthermore, hereinafter, each embodiment will be described using torque Tq, average torque Tav as an average value of torque Tq, and moving average torque Tmav as a moving average value of average torque Tav. Details of these torques will be described later.

For convenience of explanation, when the torque Tq, the average torque Tav, and the moving average torque Tmav are not distinguished, they are simply referred to as "torque Tg". That is, torque Tg is a concept that includes torque Tq, average torque Tav, and moving average torque Tmav.

[Embodiment 1]
<A. Overall configuration>
FIG. 1 is a diagram showing an example of the configuration of an image forming apparatus 100. As shown in FIG.

The image forming apparatus 100 includes imaging units 1Y, 1M, 1C, and 1K, an intermediate transfer belt 30 (transfer receiving material), a primary transfer roller 31, a secondary transfer roller 33, a cassette 37, a fixing device 40, A cleaning blade 53 and a control device 101 are provided.

The image forming apparatus 100 includes a toner bottle 15Y that supplies yellow (Y) toner, a toner bottle 15M that supplies magenta (M) toner, a toner bottle 15C that supplies cyan (C) toner, and a black toner bottle. A toner bottle 15B for supplying (BK) toner can be attached. The imaging unit 1Y receives toner supplied from the toner bottle 15Y and forms a yellow (Y) toner image. The imaging unit 1M receives supply of toner from the toner bottle 15M and forms a magenta (M) toner image. The imaging unit 1C receives supply of toner from the toner bottle 15C and forms a cyan (C) toner image. The imaging unit 1K receives supply of toner from the toner bottle 15K and forms a black (BK) toner image. The imaging units 1Y, 1M, 1C, and 1K are arranged in order along the rotation direction of the intermediate transfer belt 30, respectively.

Imaging units 1Y, 1M, 1C, and 1K each include a photoreceptor 10, a charging roller 11, an exposure section 12, a developing device 13, and a cleaning blade 17. As shown in FIG. Imaging units 1Y, 1M, 1C, and 1K are detachable from the main body of image forming apparatus 100 .

The photoreceptor 10 is an image carrier that carries a toner image. As an example, the photoreceptor 10 is a photoreceptor drum having a photosensitive layer formed on its surface.

The charging roller 11 uniformly charges the surface of the photoreceptor 10 . The exposure unit 12 irradiates the photoreceptor 10 with a laser according to a control signal from the control device 101, and exposes the surface of the photoreceptor 10 according to a designated image pattern. Thereby, an electrostatic latent image corresponding to the input image is formed on the photoreceptor 10 .

The developing device 13 develops the electrostatic latent image using developer containing toner, carrier, and external additives. Developer is supplied from a toner bottle. Developing device 13 includes a developing roller 14 . The developing device 13 applies a developing bias to the developing roller 14 to cause toner to adhere to the surface of the developing roller 14 . The developing device 13 rotates the developing roller 14 to transfer the toner from the developing roller 14 to the photoreceptor 10 . As a result, a toner image corresponding to the electrostatic latent image is developed on the surface of the photoreceptor 10 .

The photoreceptor 10 and the intermediate transfer belt 30 are in contact with each other at the portion where the primary transfer roller 31 is provided. A predetermined transfer bias is applied to the contact portion, and the toner image developed on the photoreceptor 10 is transferred to the intermediate transfer belt 30 by the transfer bias. At this time, a yellow (Y) toner image, a magenta (M) toner image, a cyan (C), and a black (BK) toner image are sequentially superimposed and transferred onto the intermediate transfer belt 30 . Thereby, a color toner image is formed on the intermediate transfer belt 30 .

The cleaning blade 17 is pressed against the photoreceptor 10 and collects toner remaining on the surface of the photoreceptor 10 after transfer to the intermediate transfer belt 30 .

Cassette 37 is provided, for example, in the lower portion of image forming apparatus 100 . A sheet S (transfer medium) as a recording material is set in the cassette 37 . Sheets S are fed one by one from cassette 37 to secondary transfer roller 33 . The secondary transfer roller 33 transfers the toner image transferred to the intermediate transfer belt 30 onto the sheet S. As shown in FIG. By synchronizing the timing of feeding and conveying the paper S with the position of the toner image on the intermediate transfer belt 30, the toner image is transferred to the appropriate position of the paper S. FIG. After that, the paper S is sent to the fixing device 40 .

The fixing device 40 fixes the unfixed image on the paper S onto the paper. Specifically, the fixing device 40 fuses the toner image on the paper S passing through the fixing device 40 to fix the toner image on the paper S. As shown in FIG. After that, the sheet S is discharged to the tray 48 . A specific configuration of the fixing device 40 will be described later.

The cleaning blade 53 is pressed against the intermediate transfer belt 30 and collects toner remaining on the intermediate transfer belt 30 after the toner image is transferred. The toner is transported by a transport screw (not shown) and collected in a waste toner container (not shown).

The control device 101 controls operations of the image forming apparatus 100 . The control device 101 controls, for example, a motor for controlling rotation of the photoreceptor 10, a motor for controlling rotation of the primary transfer roller 31, and the like. The control device 101 also controls the operation of the fixing device 40 . The motor is driven by PWM (Pulse Width Modulation) control, for example.

As described above, the image forming apparatus 100 has at least the fixing device 40 that fixes the unfixed image G on the sheet S (recording material) onto the sheet S, and forms an image on the sheet S. FIG.

FIG. 2 is a block diagram for explaining the hardware configuration of the image forming apparatus 100. As shown in FIG.
The image forming apparatus 100 includes at least a control device (control section) 101 , an operation panel 102 and a fixing device 40 .

Operation panel 102 includes a touch screen 120 . The touch screen 120 is composed of a display 122 and a touch panel 121 superimposed on the display 122 .

The control device 101 includes a CPU (Central Processing Unit) 131 that executes programs, a ROM (Read Only Memory) 132 that stores data in a nonvolatile manner, a RAM (Random Access Memory) 133 that stores data in a volatile manner, It has a flash memory 134 and a communication IF 135 . The control device 101 can communicate with the operation panel 102 via the communication IF 135 .

Flash memory 134 is a non-volatile semiconductor memory. The flash memory 134 stores an operating system and various programs executed by the CPU 131, various contents and data. The flash memory 134 volatilely stores various data such as data generated by the image forming apparatus 100 and data obtained from an external device of the image forming apparatus 100 .

<B. Fixing Device>
FIG. 3 is a diagram for explaining the hardware configuration of the fixing device 40. As shown in FIG.

The fixing device 40 typically includes a heating member 401, a fixing belt 402, a fixing member (supporting member) 490, a pressure roller (pressure member) 408, a motor 409, and a driving device (driving section). 410.

The fixing member 490 is arranged inside the fixing belt 402 and slidably supports the fixing belt 402 at a position facing the pressure roller 408 so as to resist the pressure of the pressure roller 408 . Specifically, the fixing member 490 includes a holding member 403 , a nip forming member 405 , a sliding sheet 406 and a curvature imparting member 407 . The nip forming member 405 has a connecting shaft 454 .

A heating member 401 is a heat source for warming the fixing belt 402 . Heating member 401 includes a halogen heater 451 and a housing 452 . A halogen heater 451 is installed in a housing 452 . The outer surface of the housing 452 is in contact with the fixing belt 402 . Heating member 401 transfers heat generated by halogen heater 451 to fixing belt 402 via housing 452 .

In this example, the halogen heater 451 is composed of two heaters with different heat generating regions. The housing 452 is a pipe made of aluminum or stainless steel and having a thickness of about 0.2 mm to 0.5 mm. The inner peripheral surface of the housing 452 is painted black in order to increase the absorption of light generated from the halogen heater 451 . In addition, the outer peripheral surface of the housing 452 is coated with fluorine to prevent contamination.

In this example, even if the fixing belt 402 rotates, the heating member 401 does not rotate. However, the present invention is not limited to this, and the heating member 401 may be configured to rotate following rotation of the fixing belt 402 .

The fixing belt 402 is an endless belt. The fixing belt 402 opposes the pressure roller 408 to form a nip area for fixing the unfixed image G, and rotates following the rotation of the pressure roller 408 . Specifically, the fixing belt 402 is supported by a fixing member 490 at a position facing the pressure roller 408 , and fixes an unfixed image on the sheet S between the fixing belt 402 and the pressure roller 408 . More specifically, fixing belt 402 is supported under tension by nip forming member 405 and heating member 401 , and rotates following the rotation of pressure roller 408 .

The fixing belt 402 has a base layer made of polyimide resin (PI) or nickel having a thickness of about 50 μm to 100 μm, an elastic layer made of silicon rubber having a thickness of about 100 μm to 300 μm, and a thickness of about 10 μm to 50 μm. It consists of a fluorine-based release layer.

Specifically, the fixing belt 402 has an elastic layer on the base layer and a release layer on the elastic layer. The base layer contacts the outer peripheral surface of the housing 452 of the heating member 401 . The release layer contacts the surface of the pressure roller 408 and the paper S. As shown in FIG. More specifically, the release layer contacts the unfixed image G on the paper S. As shown in FIG.

The holding member 403 holds the nip forming member 405 . The holding member 403 is made of U-shaped sheet metal with a thickness of about 2 mm. The holding member 403 has a hole at a position corresponding to the connecting shaft 454 of the nip forming member 405 so as to fit with the connecting shaft 454 .

Nip forming member 405 forms a nip area with pressure roller 408 . The nip forming member 405 is made of resin such as LCP (Liquid Crystal Plastic). Also, the connecting shaft 454 of the nip forming member 405 protrudes to the side opposite to the nip region. The nip forming member 405 is wrapped around the sliding sheet 406 .

A sliding sheet 406 as a sliding member is made of a glass cloth sheet or a PTFE (polytetrafluoroethylene) sheet covered with a fluororesin having excellent sliding properties. By sandwiching the sliding sheet 406 between the nip forming member 405 and the fixing belt 402 and rotating the fixing belt 402, resistance during sliding can be reduced. As a result, the fixing belt 402 can be stably rotated.

Further, the sliding sheet 406 has unevenness with a depth of about 50 μm to 200 μm on the surface that contacts the fixing belt 402 . As a result, the contact area with the fixing belt 402 can be reduced, so that the resistance during sliding can be reduced. Further, by applying grease as a lubricant between the fixing belt 402 and the sliding sheet 406, the resistance during sliding is reduced.

In order to fix the position of the sliding sheet 406 when the sliding sheet 406 is wound around the nip forming member 405 and fixed, the connecting shaft 454 between the upstream side and the downstream side of the sliding sheet 406 corresponds to the connecting shaft 454 . is perforated. The connecting shaft 454 passes through the through hole of the slide sheet 406 and the through hole of the holding member 403 . Further, in this state, the sliding sheet 406 is sandwiched between the nip forming member 405 and the holding member 403 by the pressing force of the pressure roller 408, and the position of the sliding sheet 406 is held. be.

The curvature imparting member 407 imparts curvature to the portion of the fixing belt 402 that has passed through the nip region. The curvature imparting member 407 is made of resin such as LCP, like the nip forming member 405 .

The pressure roller 408 is rotated by a motor 409 in a direction in which the sheet S is transported downstream of the transport path in the fixing device 40 . The pressure roller 408 is rotatable in the forward direction (direction of arrow Q in the drawing) for transporting the sheet S from the upstream side to the downstream side of the transport path, and in the reverse direction. When the pressure roller 408 rotates in the forward direction, the fixing belt 402 also rotates in the forward direction (direction of arrow R in the figure). In FIG. 3, the sheet S is transported from bottom to top along the transport path as indicated by an arrow 15, so the upstream side is the lower position and the downstream side is the upper position.

The pressure roller 408 is made of silicon rubber with a diameter of about 20 mm to 40 mm. In addition, the surface of the silicon rubber is covered with a fluorine-based tube in order to improve releasability.

Drive device 410 rotates motor 409 . Drive device 410 rotates motor 409 in forward and reverse directions according to commands from control device 101 .

Motor 409 rotates pressure roller 408 in the forward direction (the direction of arrow Q) and the reverse direction based on a command from drive device 410 . The motor 409 is connected to the rotating shaft of the pressure roller 408 via a gear (not shown).

Pressure roller 408 is moved to a position (position shown in FIG. 3) in contact with fixing belt 402 and a predetermined position (for example, position shown in FIG. position to the right of the position of the pressure roller 408). That is, pressure roller 408 moves between a position where fixing belt 402 is rotated (the position shown in FIG. 3) and a position where fixing belt 402 is not rotated.

Specifically, during image formation, the pressure roller 408 moves to a position in contact with the fixing belt 402 as shown in FIG. In this state, fixing member 490 is pressed by pressure roller 408 at the position where fixing belt 402 is supported. On the other hand, during non-image formation, the pressure roller 408 is separated from the fixing belt 402 .

At least after warm-up of the image forming apparatus 100 and after fixing onto the recording material, the pressure roller 408 is in contact with the fixing belt 402 as shown in FIG. The paper S does not pass through the fixing device 40 after the image forming apparatus 100 is warmed up and after the image is fixed on the paper S. In other words, the paper is not fed.

FIG. 4 is a block diagram for explaining torque detection performed in the fixing device 40. As shown in FIG.

The fixing device 40 includes a motor 409 , a driving device 410 and a rotary encoder 420 . The driving device 410 includes a motor control device 411 as a subordinate control device and a driver 412 as an electronic circuit. The driver 412 has a torque detector 413 .

Drive device 410 drives motor 409 so as to keep the rotational speed of pressure roller 408 constant based on a command from control device 101 as a higher control device.

Motor 409 is typically a three-phase AC motor. It rotates by applying a voltage (V) between each input terminal of three phases (U layer, V layer, and W layer). A control motor such as a servomotor can also be used as the motor 409 .

Motor control device 411 receives a rotation speed command from control device 101 . Upon receiving the rotation speed command, the motor control device 411 performs feedback control so that the rotation speed of the motor 409 becomes the rotation speed of the received rotation speed command (hereinafter also referred to as “command rotation speed”).

Upon receiving the rotation speed command, the motor control device 411 sends a torque command to the driver 412 in accordance with the rotation speed command.

The driver 412 controls switching operations of internal switching elements in order to apply a voltage based on the received torque command to each input terminal. This causes current to flow from the driver 412 to the motor 409 . The motor 409 is rotated by the current. A driver 412 acquires the current value of the current flowing through the motor 409 from a sensor (not shown).

A rotary encoder 420 detects the number of revolutions of the motor 409 . The detected number of revolutions (hereinafter also referred to as “actual number of revolutions”) is fed back to the motor controller 411 . Also, the actual number of rotations is notified to the driver 412 .

The motor control device 411 calculates the difference between the command rotation speed and the actual rotation speed. The motor controller 411 controls the torque command output to the driver 412 so that the difference approaches zero.

Torque detection unit 413 detects torque Tq (load torque) of motor 409 based on the actual number of rotations obtained from rotary encoder 420 and the current value detected by the sensor. Specifically, the driver 412 periodically calculates the torque Tq by dividing the product of the applied voltage (V) and the detected current value (I) by the actual rotation speed.

Each time a predetermined condition is satisfied, drive device 410 notifies control device 101 of torque Tq detected when the predetermined condition is satisfied, among the detected torques Tq. It is typically determined by control device 101 whether or not a predetermined condition has been established.

With such a configuration, control device 101 can acquire torque Tq detected by drive device 410 from drive device 410 each time a predetermined condition is satisfied. Specifically, control device 101 can acquire torque Tq detected by drive device 410 when a predetermined condition is established.

<C. Functional configuration>
FIG. 5 is a functional block diagram showing the functional configuration of the control device 101. As shown in FIG.

The image forming apparatus 100 includes a control device 101 , a drive device 410 and an operation panel 102 .

The control device 101 includes a torque acquisition section 151 , an average torque calculation section 152 , a moving average torque calculation section 153 , a life determination section 154 , a display control section 155 and a communication control section 156 .

Torque acquisition unit 151 acquires torque Tq (torque value) from drive device 410 . Specifically, torque acquisition unit 151 acquires torque Tq detected by drive device 410 from drive device 410 at predetermined intervals. In the following, a case where the predetermined period is set to "one day" will be described as an example. Note that the predetermined period is not limited to one day.

In this example, the torque acquisition unit 151 acquires the torque Tq from the driving device 410 up to five times a day. More specifically, torque acquisition unit 151 acquires torque Tq from drive device 410 when pressure roller 408 is in contact with fixing belt 402 as shown in FIG. That is, the torque acquisition unit 151 acquires from the driving device 410 the torque of the motor 409 when there is no load from the paper S (hereinafter also referred to as “idling torque”).

More specifically, torque acquisition unit 151 acquires torque Tq detected after image forming apparatus 100 warms up from driving device 410 . If the image forming apparatus 100 is warmed up five times in one day, the torque can be obtained five times. If the warm-up was performed only once a day, the controller 101 performs torque acquisition only once on that day. Note that the number of acquisitions of the torque Tq per day is not limited to five.

As described above, the "predetermined condition" in this example is "after one day" and "after warm-up of the image forming apparatus 100".

Below, the torques (torque values) for five times acquired from the driving device 410 by the torque acquisition unit 151 are Tq(n[1]), Tq(n[2]), Tq(n[3]), Tq( n[4]), Tq(n[5]). Note that n is a variable representing the day.

The torque acquisition unit 151 sends the acquired five torques to the average torque calculation unit 152 . It should be noted that when the torque can be obtained only four times, for example, the torque obtaining unit 151 typically transfers only Tq(n[1]) to Tq(n[4]) to the average torque calculating unit 152. send. Alternatively, torque acquisition unit 151 sends Tq(n[1]) to Tq(n[5]) and notifies average torque calculation unit 152 that the value of Tq(n[5]) is invalid. may

The average torque calculator 152 obtains the average value of torque for each day. Specifically, the average torque calculator 152 obtains an average value of five torques (hereinafter referred to as "average torque Tav") as shown in the following equation (1).

Tav(n)=(Tq(n[1])+Tq(n[2])+Tq(n[3])+Tq(n[4])+Tq(n[5]))÷5 (1)
The average torque calculator 152 sends the calculated average torque Tav(n) to the moving average torque calculator 153 .

The moving average torque calculator 153 calculates a moving average torque Tmav (moving average value) using the average torque Tav for five days. Specifically, the moving average torque calculation unit 153 calculates the average torque Tav(n) for the current day and the average torques for four days (Tav(n−4), Tav(n−3), Tav (n-2), Tav(n-1)) are used to calculate the moving average torque Tmav(n). Specifically, the moving average torque calculator 153 performs the calculation shown in the following equation (2).

Tmav(n)=(Tav(n−4)+Tav(n−3)+Tav(n−2)+Tav(n−1)+Tav(n))÷5 … (2)
Moving average torque calculation section 153 sends the calculated moving average torque Tmav(n) to life determination section 154 . In the above description, the moving average torque Tmav is calculated using the five-day (five) average torques Tav, but the number of average torques Tav is not limited to five.

Lifespan determination unit 154 determines whether fixing device 40 has reached the end of its lifespan. Specifically, the life determination unit 154 determines whether or not the fixing device 40 has reached the end of its life based on the moving average torque Tmav. More specifically, the life determination unit 154 determines that the fixing device 40 has reached the end of its life when the change over time of the moving average torque Tmav changes from an upward change to a downward change.

FIG. 6 is a diagram showing temporal changes in the moving average torque Tmav.
The horizontal axis of the graph (diagram) represents the date. The vertical axis of the graph represents the moving average torque Tmav. In the example of FIG. 6, moving average torques (Tmav(16) to Tmav(21)) from the 16th to the 21st of a month are plotted.

The moving average torque Tmav monotonously increases until the 20th day. However, the moving average torque Tmav(21) on the 21st is smaller than the moving average torque Tmav(20) on the 20th of the previous day. That is, the relationship "Tmav(n-1)>Tmav(n)" is established.

Therefore, the life determination unit 154 determines that the fixing device 40 has reached the end of its life on the 21st day (more specifically, when Tmav(21) is calculated). When the life determination unit 154 determines that the life has expired, the display control unit 155 is given a predetermined notification.

When the display control unit 155 receives a predetermined notification from the life determination unit 154, the display control unit 155 causes the operation panel 102 to display a predetermined warning screen.

FIG. 7 is a diagram showing an example of a warning screen displayed on the operation panel 102. As shown in FIG.
Typically, a predetermined warning screen 1201 pops up on the touch screen 120 of the operation panel 102 . Thereby, the user of the image forming apparatus 100 can know that it is time to replace the fixing device 40 .

Returning to FIG. 6 again, the lifespan determination unit 154 notifies the communication control unit 156 as well when predetermined settings have been made in the control device 101 . Communication control unit 156 is connected to an external network. Accordingly, the image forming apparatus 100 can notify the external device that the fixing device 40 has reached the end of its life.

In the above description, a configuration in which torque acquisition unit 151 acquires torque Tq detected after warm-up of image forming apparatus 100 from drive device 410 has been described as an example, but the configuration is not limited to this. For example, the control device 101 may be configured to acquire from the driving device 410 the torque Tq detected after fixing onto the recording material.

Further, the control device 101 typically stops subsequent image formation when determining that the fixing device 40 has reached the end of its life. However, the control is not limited to such control, and when it is determined that the fixing device 40 has reached the end of its life, image formation using paper of the first paper type is permitted, and moreover than paper of the first paper type The control device 101 may be configured so as not to permit image formation using paper of the second paper type having a low basis weight. This is because the sheet S having a large basis weight is less likely to slip in the nip region than the sheet S having a small basis weight.

<D. Summary>
The image forming apparatus 100 includes a control device 101 that controls the operation of the image forming apparatus, and a fixing device 40 that fixes an unfixed image on a sheet S (recording material).

The fixing device 40 includes a pressure roller 408 rotatable in the direction of conveying the recording material to the downstream side of the conveying path, a motor 409 that rotates the pressure roller 408, a driving device 410 that drives the motor 409, and a pressure roller. It includes an endless fixing belt 402 that rotates following the rotation of roller 408 and a fixing member 490 that slidably supports fixing belt 402 from the inner surface of fixing belt 402 . Fixing member 490 is pressed by pressure roller 408 at a position where fixing belt 402 is supported.

Drive device 410 drives motor 409 based on a command from control device 101 so as to keep the rotational speed of pressure roller 408 constant. Driving device 410 detects torque Tq when motor 409 is driven.

Control device 101 acquires detected torque Tq from drive device 410 . The control device 101 detects that the fixing device 40 has reached the end of its service life when the torque Tg (in this example, the moving average torque Tmav calculated based on the torque Tq) changes over time from an upward change to a downward change. I judge.

Specifically, the control device 101 acquires the torque Tq from the drive device 410 multiple times each time a predetermined period (one day in this example) elapses, and acquires the average value of the torque Tq acquired over the multiple times ( Average torque Tav) is calculated. Control device 101 calculates a moving average value (moving average torque Tmav) using the calculated average torque Tav and at least the previous calculated average torque Tav. The control device 101 determines that the life of the fixing device 40 has expired when the calculated moving average torque Tmav becomes smaller than the moving average torque Tmav calculated last time.

In the fixing device 40, as the fixing belt 402 rotates, the sliding sheet 406, which is a sliding portion, is gradually worn away, and the load between the fixing belt 402 and the sliding sheet 406 increases when the fixing belt 402 rotates. gradually increases. Therefore, in order to keep the speed of the pressure roller 408 constant, it is necessary to increase the torque Tq of the motor 409 that rotates the pressure roller 408 . Therefore, the value of torque Tq of pressure roller 408 gradually increases as the number of days of use elapses. As the value of torque Tq increases, the value of moving average torque Tmav also increases.

However, when the value of the torque Tq increases, a phenomenon occurs in which the sheet S slips in the fixing device 40 (specifically, the nip area).

When the paper S slips, the speed at which the pressure roller 408 feeds the paper S downstream decreases. Therefore, the speed at which the pressure roller 408 feeds the sheet S downstream is slower than the speed at which the secondary transfer roller 33 on the upstream side of the fixing device 40 feeds the sheet S to the fixing device 40 .

As a result, a phenomenon called “reverse loop” occurs between the secondary transfer roller 33 and the fixing device 40 . When a reverse loop occurs, the image deteriorates. A loop and a reverse loop refer to states in which the sheet S is bent. It should be noted that the "loop" is the bending of the sheet S that occurs in normal operation. A reverse loop is bending of the sheet S in a bending direction opposite to that at the time of looping.

As described above, when the paper S slips, the value of the detected torque Tq decreases. Therefore, the calculated moving average torque Tmav also becomes small.

Therefore, the image forming apparatus 100 determines that the fixing device 40 has reached the end of its service life when the moving average torque Tmav changes over time from an upward change to a downward change. With such a configuration, it is possible to determine the life of the fixing device 40 before a reverse loop occurs.

Moreover, according to the above configuration, the life of the fixing device 40 can be extended compared to a configuration in which the threshold value of the torque of the pressure roller 408 used for life determination is uniquely determined.

Furthermore, in this example, life determination is performed using the moving average torque Tmav. Therefore, even if noise is added to the torque, the influence of the noise can be reduced. That is, it is possible to determine the service life with higher accuracy than when the determination is simply based on the torque Tq.

Further, the control device 101 acquires the idling torque during non-passage of paper from the driving device 410 each time a predetermined period (one day in this example) elapses. Specifically, control device 101 acquires torque Tq detected after warm-up of image forming apparatus 100 or after fixing onto sheet S from drive device 410 .

At such timing, image formation is not performed. Therefore, the value of the torque Tq detected by the driving device 410 is not affected by the content of the unfixed image G on the paper S. Therefore, by acquiring the torque Tq at such timing, the control device 101 can determine the service life with high accuracy.

<E. Control structure>
FIG. 8 is a flowchart for explaining the flow of processing executed by the image forming apparatus 100. As shown in FIG.

In step S<b>1 , the control device 101 determines whether or not the torque determination permission mode is set as the life determination mode of the fixing device 40 . As described above, the torque determination permission mode is a mode in which the life of the fixing device 40 is determined based on the change over time of the torque Tg (moving average torque Tmav in this example). Note that the setting of the torque determination permission mode is typically performed by a service person.

When control device 101 determines that the torque determination permission mode is set (YES in step S1), in step S2, based on moving average torque Tmav, it determines whether fixing device 40 has reached the end of its life.

When control device 101 determines that the torque determination permission mode is not set (NO in step S1), in step S3, based on the number of prints in image forming apparatus 100 and the travel distance of pressure roller 408, the fixing device 40 is the lifespan or not. Typically, the control device 101 determines that the fixing device 40 has reached the end of its service life when the number of printed sheets exceeds a preset reference number of sheets, or when the traveling distance of the pressure roller 408 exceeds a preset distance. Determine that there is. That is, the control device 101 determines that the fixing device 40 has reached the end of its life when either one of the number of printed sheets and the traveling distance is satisfied.

FIG. 9 is a flowchart for explaining the details of the processing in step S2 of FIG.
In step S<b>21 , fixing device 40 sequentially detects torque Tq of pressure roller 408 . In step S22, the control device 101 acquires the torque Tq at a predetermined timing from the fixing device 40 on each day. As described above, control device 101 acquires torque Tq detected after warm-up of image forming apparatus 100 from drive device 410 , for example.

In step S23, the control device 101 calculates an average value (average torque Tav) of maximum five torques Tq on the same day. Specifically, the control device 101 executes the calculation of the formula (1) described above. In step S24, the control device 101 calculates the moving average torque Tmav using the five successive average values.

In step S25, control device 101 updates the current value (variable value) of moving average torque Tmav with the value calculated in step S24. In step S26, if the moving average torque Tmav is the maximum, the control device 101 updates the maximum value (variable value) of the moving average torque Tmav with the moving average torque Tmav. Note that the maximum value of the moving average torque Tmav is reset (typically set to zero) after the fixing device 40 is replaced. Therefore, the maximum value is the maximum value after the fixing device 40 is replaced.

In step S27, the control device 101 compares the calculated moving average torque Tmav with the previous day's moving average torque Tmav_old(1), and determines whether or not the fixing device 40 has reached the end of its life.

If the calculated moving average torque Tmav is Tmav(n) with reference to the equation (2), the previous day's moving average torque Tmav_old(1) is obtained by the following equation (3).

Tmav_old(1)=Tmav(n−1)=(Tav(n−5)+Tav(n−4)+Tav(n−3)+Tav(n−2)+Tav(n−1))÷5 … (3)
FIG. 10 is a flowchart for explaining the details of the process of step S27 in FIG.

In step S271, the control device 101 determines whether or not the moving average torque Tmav is smaller than the previous day's moving average torque Tmav_old(1). If control device 101 determines that it is small (YES in step S271), it determines that fixing device 40 has reached the end of its life in step S272. In step S273, control device 101 displays a warning screen on operation panel 102 as shown in FIG.

When control device 101 determines that it is not smaller (NO in step S271), in step S274, it determines that fixing device 40 has not reached its end of life yet.

<F. Variation>
A modified example of the life determination process of the control device 101 will be described below.

(f1. First modification)
FIG. 11 is a diagram showing temporal changes in moving average torque.

The control device 101 determines that the fixing device 40 has reached the end of its service life on the condition that the moving average torque Tmav is equal to or greater than a predetermined threshold value Th1 when the change over time of the moving average torque Tmav changes from an upward change to a downward change. I judge. That is, even if the change over time of the moving average torque Tmav changes from an increasing change to a decreasing change, the control device 101 controls the life of the fixing device 40 when the moving average torque Tmav is less than the predetermined threshold value Th1. I don't judge.

The reason for performing the above determination using the threshold value Th1 is that although the moving average torque Tmav is sufficiently smaller than the value (numerical range) at which slippage of the paper S occurs in the nip area, the moving average torque This is because the value of Tmav may turn downward.

FIG. 12 is a flowchart for explaining the details of the process of step S27 in FIG. 9 in this modification.

The flowchart of FIG. 12 differs from the flowchart shown in FIG. 10 in that step S275 is included. That is, when control device 101 determines that it is small in step S271 (YES in step S271), in step S275, it determines whether or not moving average torque Tmav is equal to or greater than threshold Th1. Note that the threshold Th1 is assumed to be a positive value.

When control device 101 determines that moving average torque Tmav is equal to or greater than threshold Th1 (YES in step S275), the process proceeds to step S272. When control device 101 determines that moving average torque Tmav is less than threshold Th1 (NO in step S275), the process proceeds to step S274.

(f2. Second modification)
FIG. 13 is a diagram showing temporal changes in moving average torque.

The control device 101 determines that the fixing device 40 has reached the end of its service life on condition that the amount of descent ΔTmav is equal to or greater than the threshold Th2 when the moving average torque Tmav changes over time from an upward change to a downward change. That is, even if the moving average torque Tmav changes over time from an upward change to a downward change, the control device 101 does not determine that the life of the fixing device 40 has expired when the amount of descent ΔTmav is less than or equal to the threshold Th2. .

The reason for performing the determination using the threshold Th2 is that the value of the moving average torque Tmav may turn downward due to noise or the like.

FIG. 14 is a flowchart for explaining the details of the process of step S27 in FIG.
The flowchart of FIG. 14 differs from the flowchart shown in FIG. 12 in that step S276 is included. That is, when control device 101 determines in step S275 that it is equal to or greater than threshold Th1 (YES in step S275), in step S276, the difference between moving average torque Tmav and moving average torque Tmav_old(1) (that is, moving average torque It is determined whether or not the decrease amount ΔTmav) of Tmav is equal to or greater than the threshold Th2. In addition, let the said difference be an absolute value. The threshold Th2 is assumed to be a positive value.

When control device 101 determines that amount of descent ΔTmav is equal to or greater than threshold Th2 (YES in step S276), the process proceeds to step S272. When control device 101 determines that amount of descent ΔTmav is less than threshold Th2 (NO in step S276), the process proceeds to step S274.

Note that the determination process in step S275 may be omitted. That is, when it is determined in step S271 that it is small (YES in step S271), control device 101 may advance the process directly to step S276.

(f3. Third modification)
FIG. 15 is a diagram showing temporal changes in moving average torque.

When the change over time of the moving average torque Tmav changes from an upward change to a downward change (that is, when the calculated moving average torque becomes smaller than the moving average torque calculated last time), the control device 101 changes the previous calculated On the condition that the calculated moving average torque is smaller than the moving average torque calculated last time, it is determined that the life of the fixing device 40 has expired. That is, the control device 101 determines that the life of the fixing device 40 has expired on condition that the moving average torque Tmav has decreased two times in succession. Such determination processing can improve the accuracy of life determination of the fixing device 40 .

FIG. 16 is a flowchart for explaining the details of the process of step S27 in FIG. 9 in this modification.

The flow chart of FIG. 16 differs from the flow chart shown in FIG. 10 in that step S277 is included. That is, when control device 101 determines that it is smaller in step S271 (YES in step S271), in step S277, whether moving average torque Tmav_old(1) on the previous day is smaller than moving average torque Tmav_old(2) on the day before last, in step S277. determine whether or not

When control device 101 determines that moving average torque Tmav_old(1) is smaller than moving average torque Tmav_old(2) (YES in step S277), the process proceeds to step S272. When control device 101 determines that moving average torque Tmav_old(1) is not smaller than moving average torque Tmav_old(2) (NO in step S277), the process proceeds to step S274.

(f4. Fourth modification)
In the above example, from the viewpoint of improving the accuracy of life determination, attention is paid to the change over time of the moving average torque Tmav. That is, the control device 101 determines that the fixing device 40 has reached the end of its life when the moving average torque Tmav changes over time from an upward change to a downward change.

However, the torque used for determination is not limited to the moving average torque Tmav. An average torque Tav may be used instead of the moving average torque Tmav. Alternatively, torque Tq may be used instead of moving average torque Tmav.

(1) Life Determination Based on Average Torque Tav The average torque calculator 152 of the control device 101 obtains the average value of five torques (average torque Tav) using the above-described formula (1).

In this modification, the life determination unit 154 of the control device 101 determines whether or not the fixing device 40 has reached the end of its life based on the torque Tg (average torque Tav in this example). Specifically, the life determination unit 154 determines that the fixing device 40 has reached the end of its life when the change over time of the average torque Tav changes from an upward change to a downward change.

More specifically, control device 101 acquires torque from driving device 410 multiple times each time a predetermined period (for example, one day) elapses, and calculates an average value of the torques acquired over the multiple times (average torque Tav ) is calculated. The control device 101 determines that the life of the fixing device 40 has expired when the calculated average torque Tav becomes smaller than the average torque Tav calculated last time.

As described above, even when the life span of the fixing device 40 is determined based on the change over time of the average torque Tav, the above-described first, second, and third modifications can be applied. Similar processing is applicable.

When the first modified example is applied to this example, it is as follows. When the change over time of the average torque Tav turns from an upward change to a downward change, the control device 101 determines that the fixing device 40 has reached the end of its service life on condition that the average torque Tav is equal to or greater than a predetermined threshold value Th1′. judge.

When the second modified example is applied to this example, it is as follows. The control device 101 determines that the fixing device 40 has reached the end of its service life on condition that the amount of decrease ΔTav is equal to or greater than the threshold Th2′ when the change over time of the average torque Tav changes from an upward change to a downward change. Note that the decrease amount ΔTav in this case is the difference between the average torque Tav and the previous day's average torque Tav_old(1).

When the third modified example is applied to this example, it is as follows. When the change over time of the average torque Tav changes from an upward change to a downward change (that is, when the calculated average torque Tav becomes smaller than the average torque Tav calculated last time), the control device 101 controls the previously calculated average torque Tav. It is determined that the life of the fixing device 40 has expired on the condition that the calculated average torque Tav is smaller than the average torque Tav calculated two previous times.

In the case of this example, since calculation of moving average torque Tmav is unnecessary, control device 101 does not need to include moving average torque calculation section 153 shown in FIG.

(2) Life Determination Based on Torque Tq In this modification, life determination unit 154 of control device 101 determines whether fixing device 40 has reached the end of its life based on torque Tg (torque Tq in this example). determine whether or not Specifically, the life determination unit 154 determines that the fixing device 40 has reached the end of its life when the change over time of the torque Tq changes from an upward change to a downward change.

More specifically, control device 101 acquires the torque once from drive device 410 each time a predetermined period (for example, one day) elapses. The control device 101 determines that the life of the fixing device 40 has expired when the torque Tq becomes smaller than the previous torque Tq (torque Tq on the previous day).

As described above, even when the life span of the fixing device 40 is determined based on the change in the torque Tq over time, it is the same as in the above-described first, second, and third modifications. is applicable.

When the first modified example is applied to this example, it is as follows. The control device 101 determines that the fixing device 40 has reached the end of its service life on condition that the torque Tq is equal to or greater than a predetermined threshold value Th1″ when the change over time of the torque Tq changes from an upward change to a downward change. .

When the second modified example is applied to this example, it is as follows. The control device 101 determines that the fixing device 40 has reached the end of its service life on the condition that the amount of decrease ΔTq is equal to or greater than the threshold value Th2″ when the change over time of the torque Tq changes from an upward change to a downward change. The decrease amount ΔTq in this case is the difference between the torque Tq and the previous day's torque Tq_old(1).

When the third modified example is applied to this example, it is as follows. When the torque Tq changes over time from an upward change to a downward change (that is, when the detected torque Tq becomes smaller than the previously acquired torque Tq), the control device 101 controls the previously acquired torque Tq is smaller than the torque Tq acquired before last, it is determined that the life of the fixing device 40 has expired.

In the case of this example, since it is not necessary to calculate the average torque Tav and the moving average torque Tmav, the control device 101 uses the average torque calculation unit 152 and the moving average torque calculation unit 153 shown in FIG. need not be provided.

[Embodiment 2]
The image forming apparatus according to the present embodiment will be described below with respect to the differences from the first embodiment. The image forming apparatus according to this embodiment has the same hardware configuration as the image forming apparatus 100 according to the first embodiment. Data processing executed by the control device 101 is different from the data processing of the first embodiment. Therefore, the data processing executed by the control device 101 will be described below.

In the first embodiment, control device 101 acquires torque Tq from drive device 410 multiple times each time a predetermined period (for example, one day) elapses, and averages torque Tq acquired over the multiple times. A value (average torque Tav) was calculated.

In the present embodiment, each time the running distance of pressure roller 408 increases by a predetermined distance, torque Tq is obtained from driving device 410 multiple times, and the average value of torques Tq obtained over the multiple times ( Also referred to as "average torque Tav").

The travel distance is calculated as follows. First, the control device 101 acquires information on the rotational speed of the pressure roller 408 from the driving device 410 . After that, the control device 101 calculates the traveling distance by multiplying the rotation speed by the rotation time of the pressure roller 408 .

<A. Functional configuration>
FIG. 17 is a functional block diagram showing the functional configuration of the control device 101. As shown in FIG.

The image forming apparatus 100 includes a control device 101 , a drive device 410 and an operation panel 102 .

The control device 101 includes a torque acquisition section 151A, an average torque calculation section 152A, a moving average torque calculation section 153A, a life determination section 154A, a display control section 155, and a communication control section 156.

Torque acquisition unit 151A acquires torque Tq (torque value) from drive device 410 . Specifically, torque acquisition unit 151A acquires from drive device 410 torque Tq detected by drive device 410 each time the running distance of pressure roller 408 increases by a predetermined distance. Below, the case where the predetermined distance is set to "10 km" will be described as an example.

Torque acquisition unit 151A acquires torque Tq from drive device 410, triggered by an increase in travel distance of 10 km. Typically, torque acquisition unit 151A acquires torque from driving device 410 up to 5 times within the day when it is detected that the traveling distance has increased by 10 km. Specifically, the torque acquisition unit 151A acquires the torque from the driving device 410 when the pressure roller 408 is in contact with the fixing belt 402 and the paper is not fed as shown in FIG.

More specifically, torque acquisition unit 151A acquires torque Tq detected after image forming apparatus 100 warms up from drive device 410, like torque acquisition unit 151 of the first embodiment.

As described above, in this example, the "predetermined condition" is "the traveling distance has increased by 10 km" and "after the warm-up of the image forming apparatus 100". As described in the first embodiment, instead of "after warm-up of the image forming apparatus 100", the control device 101 acquires from the driving device 410 the torque Tq detected after fixing onto the paper S. may be configured.

The five torques (torque values) acquired by the torque acquisition unit 151A from the driving device 410 are Tq(m[1]), Tq(m[2]), Tq(m[3]), Tq(m[4 ]), Tq(m[5]). It should be noted that m is a variable for distinguishing distances of 10 kilometers from each other. The value of m increases by 1 for every 10 km traveled.

151 A of torque acquisition parts send the acquired torque for 5 times to 152 A of average torque calculation parts.

The average torque calculator 152A obtains an average value of torque for each predetermined distance. Specifically, the average torque calculator 152 obtains an average value of five torques (hereinafter referred to as "average torque Tav'") as shown in the following equation (4).

Tav′(m)=(Tq(m[1])+Tq(m[2])+Tq(m[3])+Tq(m[4])+Tq(m[5]))÷5 (4)
The average torque calculator 152A sends the calculated average torque Tav'(m) to the moving average torque calculator 153A.

The moving average torque calculation unit 153A calculates a moving average torque Tmav' (moving average value) using the five average torques Tav'. Specifically, the moving average torque calculation unit 153A calculates the average torque Tav′(m) for the current day, the average torques for the most recent four times (Tav′(m−4), Tav′(m−3), Tav′(m −2), Tav′(m−1)) to calculate the moving average torque Tmav′(n). Specifically, the moving average torque calculator 153A performs the calculation shown in the following equation (5).

Tmav′(m)=(Tav′(m−4)+Tav′(m−3)+Tav′(m−2)+Tav′(m−1)+Tav′(m))÷5 … (5)
The moving average torque calculation unit 153A sends the calculated moving average torque Tmav'(m) to the life determination unit 154A. In the above description, the moving average torque Tmav' is calculated using five (five) average torques Tav', but the number of average torques Tav' is not limited to five.

The life determination unit 154A determines whether or not the fixing device 40 has reached the end of its life. Specifically, the life determination unit 154A determines whether or not the fixing device 40 has reached the end of its life based on the moving average torque Tmav'. More specifically, the life determination unit 154A determines that the fixing device 40 has reached the end of its life when the moving average torque Tmav' changes over time from an upward change to a downward change.

FIG. 18 is a diagram showing temporal changes in the moving average torque Tmav'.
The horizontal axis of the graph (figure) represents the running distance (km). The vertical axis of the graph represents the moving average torque Tmav'.

The moving average torque Tmav' monotonously increases up to the distance L(m-1). However, the moving average torque Tmav'(m) for the distance L(m) is smaller than the moving average torque Tmav'(m-1) for the previous distance L(m-1). That is, the relationship "Tmav'(m-1)>Tmav'(m)" is established.

Therefore, the life determination unit 154A determines that the fixing device 40 has reached the end of its life at the time when the distance L(m) (more specifically, when Tmav'(m) is calculated). When the lifespan determination unit 154A determines that the lifespan has expired, the display control unit 155 is given a predetermined notification.

Upon receiving a predetermined notification from the life determination unit 154, the display control unit 155 causes the operation panel 102 to display a predetermined warning screen (see FIG. 7).

<B. Summary>
Drive device 410 drives motor 409 based on a command from control device 101 so as to keep the rotational speed of pressure roller 408 constant. The driving device 410 detects torque when the motor 409 is driven.

Control device 101 acquires detected torque Tq from drive device 410 . The control device 101 determines that the fixing device 40 has reached the end of its service life when the torque Tg (moving average torque Tmav' in this example) changes over time from an upward change to a downward change.

Specifically, control device 101 acquires torque Tq from drive device 410 multiple times each time the running distance of pressure roller 408 increases by a predetermined distance (10 km in this example), and adjusts torque Tq acquired over the multiple times. (average torque Tav') is calculated. The control device 101 calculates a moving average value (moving average torque Tmav') using the calculated average torque Tav' and at least the previous calculated average torque Tav'. The control device 101 determines that the life of the fixing device 40 has expired when the calculated moving average torque Tmav' becomes smaller than the moving average torque Tmav' calculated last time.

According to such a configuration, the effect described in the first embodiment can be obtained also in this embodiment.

<C. Control structure>
Also in this embodiment, the processing shown in FIG. 8 is performed in the same manner as in the first embodiment.

FIG. 19 is a flowchart for explaining the details of the process of step S2 in FIG.
In step S<b>21 , fixing device 40 sequentially detects torque Tq of pressure roller 408 . In step S22A, control device 101 acquires torque Tq at a predetermined timing from fixing device 40 each time pressure roller 408 travels a predetermined distance. As described above, control device 101 acquires torque Tq detected after warm-up of image forming apparatus 100 from drive device 410 , for example.

In step S23A, the control device 101 calculates an average value (average torque Tav') of maximum five torques Tq on the same day. Specifically, the control device 101 executes the calculation of the formula (4) described above. In step S24A, the control device 101 calculates the moving average torque Tmav' using the five consecutive average values.

In step S25A, control device 101 updates the current value (variable value) of moving average torque Tmav' with the value calculated in step S24A. In step S26A, if the moving average torque Tmav' is the maximum, the control device 101 updates the maximum value (variable value) of the moving average torque Tmav' with the moving average torque Tmav'. Note that the maximum value of the moving average torque Tmav' is reset (typically set to zero) after the fixing device 40 is replaced. Therefore, the maximum value is the maximum value after the fixing device 40 is replaced.

In step S27A, the control device 101 compares the calculated moving average torque Tmav' with the previous moving average torque Tmav'_old(1) to determine whether the fixing device 40 has reached the end of its life.

If the calculated moving average torque Tmav' is Tmav'(m) with reference to the equation (5), the previous moving average torque Tmav'_old(1) is obtained by the following equation (6). be done.

Tmav′_old(1)=Tmav′(m−1)=(Tav′(m−5)+Tav′(m−4)+Tav′(m−3)+Tav′(m−2)+Tav′(m−1 ))÷5… (6)
FIG. 20 is a flowchart for explaining the details of the processing in step S27A of FIG.

In step S271A, control device 101 determines whether moving average torque Tmav' is smaller than previous moving average torque Tmav'_old(1). If control device 101 determines that it is small (YES in step S271A), it determines in step S272 that fixing device 40 has reached the end of its life. In step S273, control device 101 displays a warning screen on operation panel 102 as shown in FIG.

When control device 101 determines that it is not smaller (NO in step S271A), in step S274, it determines that fixing device 40 has not reached its end of life yet.

<D. Variation>
Each process (first to fourth modifications) shown in "<F. Modification>" of Embodiment 1 can also be applied to this embodiment.

For example, the application of "(f4. fourth modification)" is as follows.
The control device 101 may be configured to determine that the life of the fixing device 40 has expired when the calculated average value (average torque Tav′) is smaller than the average value calculated last time.

Alternatively, the control device 101 may be configured to determine that the fixing device 40 has reached the end of its service life when the torque Tq obtained last time becomes smaller than the torque Tq obtained last time.

[Embodiment 3]
In the present embodiment, life determination after it is determined that the torque determination permission mode is set is different from that in the first and second embodiments. This point will be described below.

FIG. 21 is a flowchart for explaining the flow of processing executed by the image forming apparatus 100. As shown in FIG.

In step S<b>1 , the control device 101 determines whether or not the torque determination permission mode is set as the life determination mode of the fixing device 40 .

When control device 101 determines that the torque determination permission mode is set (YES in step S1), in step S2A, the number of prints in image forming apparatus 100, the travel distance of pressure roller 408, and moving average torque Tmav ', it is determined whether or not the fixing device 40 has reached the end of its life.

When control device 101 determines that the torque determination permission mode is not set (NO in step S1), in step S3, based on the number of prints in image forming apparatus 100 and the travel distance of pressure roller 408, the fixing device 40 is the lifespan or not.

As shown in step S2A, in the present embodiment, when the torque determination permission mode is set, not only the moving average torque Tmav′ but also the number of prints and the travel distance of the pressure roller 408 are considered. , determination of the life of the fixing device 40 is performed. Therefore, the control device 101 can perform life determination with higher accuracy in the torque determination permission mode.

[Embodiment 4]
In the present embodiment, a configuration will be described in which an image forming apparatus and a server apparatus (information processing apparatus) work together to determine the life of the fixing device 40 .

FIG. 22 is a diagram showing the network configuration of the information processing system 1. As shown in FIG.
The information processing system 1 includes an image forming device 100 and a server device 900 . Image forming apparatus 100 and server apparatus 900 are communicably connected via network 901 . Image forming apparatus 100 communicates with server device 900 through communication control unit 156 (see FIG. 5).

In the information processing system 1 , the server device 900 acquires the torque Tq detected by the driving device 410 via the network 901 . The server device 900 also calculates the average torque Tav (or Tav') and the moving average torque Tmav (or Tmav'). Further, server device 900 determines the end of life of fixing device 40 based on moving average torque Tmav (or Tmav').

Even with such a configuration, the same effects as those described in the first to third embodiments can be obtained.

Information processing system 1 may be configured such that image forming apparatus 100 calculates moving average torque Tmav (or Tmav') and server apparatus 900 performs life determination.

[Embodiment 5]
In each of the first to fourth embodiments described above, drive device 410 detects torque when motor 409 is driven, but the present invention is not limited to this. For example, control device 101 may detect torque when motor 409 is driven. Alternatively, a device (not shown) in the image forming apparatus 100 may detect torque when the motor 409 is driven.

At least the image forming apparatus 100 needs to have a function of detecting torque when the motor 409 is driven. Specifically, the torque detection unit 413 shown in FIG. 4 may be provided anywhere in the image forming apparatus 100 . That is, the torque detection unit 413 may exist inside the fixing device 40 or may exist outside the fixing device 40 . It should be noted that such a function of detecting torque can be realized using, for example, at least one processor.

(1) Especially in the case of the first to third embodiments, the control device 101 acquires the torque during driving of the motor 409 each time a predetermined condition is satisfied, and the acquired torque over time. Any configuration may be employed as long as it is determined that the fixing device 40 has reached the end of its life when the change changes from an upward change to a downward change. Summarizing, it can be said that the image forming apparatus 100 has the following configuration.

The image forming apparatus 100 has at least a fixing device 40 that fixes an unfixed image G on a sheet S (recording material) onto the sheet S, and forms an image on the sheet S. As shown in FIG.

In the image forming apparatus 100, a motor 409 rotates a pressure roller (pressure member) 408 in the fixing device 40 in a direction in which the sheet S is transported downstream of the transport path. a fixing belt 402 that forms a nip area for fixing the image G and rotates following the rotation of the pressure roller 408; , a fixing member (supporting member) 490 that slidably supports the fixing belt 402 at a position facing the pressure roller 408, and a torque when the motor 409 is driven each time a predetermined condition is satisfied. and a control device (control unit) 101 that determines that the fixing device 40 has reached the end of its life when the acquired torque changes over time from an upward change to a downward change.

Even with such a configuration, the effects described above can be obtained. According to this configuration, it is possible to at least improve the accuracy of life determination of the fixing device 40 .

(2) Especially in the case of the fourth embodiment, the server device (information processing device) 900 acquires the driving torque of the motor 409 from the image forming device 100 each time a predetermined condition is satisfied, In addition, it is sufficient that it is determined that the fixing device 40 has reached the end of its life when the acquired torque changes over time from an upward change to a downward change. In summary, the image forming apparatus 100 can be said to have the following configuration.

The information processing system 1 has at least a fixing device 40 that fixes an unfixed image G on a sheet S (recording material) onto the sheet S, an image forming apparatus 100 that forms an image on the sheet S, and a server device (information processing device) 900.

In the image forming apparatus 100, a motor 409 rotates a pressure roller (pressure member) 408 in the fixing device 40 in a direction in which the sheet S is transported downstream of the transport path. a fixing belt 402 that forms a nip area for fixing the image G and rotates following the rotation of the pressure roller 408; , and a fixing member (supporting member) 490 that slidably supports the fixing belt 402 at a position facing the pressure roller 408 . The image forming apparatus 100 detects torque when the motor 409 is driven.

The server apparatus 900 acquires the torque during driving of the motor 409 from the image forming apparatus 100 each time a predetermined condition is satisfied. The server device 900 determines that the fixing device 40 has reached the end of its service life when the acquired torque changes over time from an upward change to a downward change.

Even with such a configuration, the effects described above can be obtained. According to this configuration, it is possible to at least improve the accuracy of life determination of the fixing device 40 .

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

1 Information Processing System 1C, 1K, 1M, 1Y Imaging Unit 10 Photoreceptor 11 Charging Roller 12 Exposure Unit 13 Developing Device 14 Developing Roller 15, 15B, 15C, 15K, 15M, 15Y Toner Bottle 17 , 53 cleaning blade, 30 intermediate transfer belt, 31 primary transfer roller, 33 secondary transfer roller, 37 cassette, 40 fixing device, 48 tray, 100 image forming device, 101 control device, 102 operation panel, 120 touch screen, 121 touch panel , 122 display, 134 flash memory, 151, 151A torque acquisition section, 152, 152A average torque calculation section, 153, 153A moving average torque calculation section, 154, 154A life determination section, 155 display control section, 156 communication control section, 401 Heating member 402 Fixing belt 403 Holding member 405 Nip forming member 406 Sliding sheet 407 Curvature imparting member 408 Pressure roller 409 Motor 410 Driving device 411 Motor control device 412 Driver 413 Torque detection Section 420 Rotary Encoder 451 Halogen Heater 452 Housing 454 Connecting Shaft 490 Fixing Member 900 Server Device 901 Network 1201 Warning Screen G Unfixed Image S Paper.

Claims (21)

An image forming apparatus having a fixing device for fixing at least an unfixed image on a recording material onto the recording material, and forming an image on the recording material,
a pressure member that is rotated by a motor in a direction in which the recording material is conveyed to the downstream side of the conveying path in the fixing device;
a fixing belt forming a nip area for fixing the unfixed image against the pressure member and rotating following the rotation of the pressure member;
a support member disposed inside the fixing belt and slidably supporting the fixing belt at a position facing the pressure member so as to oppose the pressure applied by the pressure member;
Each time a predetermined condition is satisfied, the torque during driving of the motor is acquired, and it is determined that the fixing device has reached the end of its service life when the time-dependent change in the acquired torque changes from an upward change to a downward change. an image forming apparatus comprising a control unit for the predetermined condition is that the traveling distance of the pressure member has increased by a predetermined distance;
The control unit
obtaining the torque each time the traveling distance of the pressure member increases by a predetermined distance;
2. The image forming apparatus according to claim 1, wherein it is determined that the fixing device has reached the end of its service life when the acquired torque becomes smaller than the previously acquired torque. the predetermined condition is that the traveling distance of the pressure member has increased by a predetermined distance;
The control unit
each time the travel distance of the pressure member increases by a predetermined distance, the torque is obtained a plurality of times and an average value of the torques obtained over the plurality of times is calculated;
2. The image forming apparatus according to claim 1, wherein when the calculated average value becomes smaller than the average value calculated last time, it is determined that the life of the fixing device has expired. the predetermined condition is that the traveling distance of the pressure member has increased by a predetermined distance;
The control unit
obtaining the torque a plurality of times each time the travel distance of the pressure member increases by a predetermined distance, and calculating an average value of the torques obtained over the plurality of times;
Calculate a moving average value using the calculated average value and at least the average value calculated last time,
2. The image forming apparatus according to claim 1, wherein when the calculated moving average value becomes smaller than the moving average value calculated last time, it is determined that the life of the fixing device has expired. The predetermined condition is that a predetermined period of time has elapsed,
The control unit
obtaining the torque each time the predetermined period elapses;
2. The image forming apparatus according to claim 1, wherein it is determined that the fixing device has reached the end of its service life when the acquired torque becomes smaller than the previously acquired torque. The predetermined condition is that a predetermined period of time has elapsed,
The control unit
each time the predetermined period elapses, the torque is obtained a plurality of times and an average value of the torques obtained over the plurality of times is calculated;
2. The image forming apparatus according to claim 1, wherein when the calculated average value becomes smaller than the average value calculated last time, it is determined that the life of the fixing device has expired. The predetermined condition is that a predetermined period of time has elapsed,
The control unit
each time the predetermined period elapses, the torque is obtained a plurality of times and an average value of the torques obtained over the plurality of times is calculated;
Calculate a moving average value using the calculated average value and at least the average value calculated last time,
2. The image forming apparatus according to claim 1, wherein when the calculated moving average value becomes smaller than the moving average value calculated last time, it is determined that the life of the fixing device has expired. The control unit
Acquiring information about the rotational speed of the pressure member;
5. The image forming apparatus according to claim 2, wherein the travel distance is calculated by multiplying the rotation speed by the rotation time of the pressing member. The image forming apparatus according to any one of claims 2 to 4, wherein the control unit acquires, as the torque, an idling torque during non-passing of paper each time the travel distance of the pressure member increases by a predetermined distance. . The image forming apparatus according to any one of claims 5 to 7, wherein the control unit acquires, as the torque, an idling torque when the paper is not fed each time the predetermined period elapses. 11. The image forming according to claim 9, wherein said control unit acquires a torque detected after warming up said image forming apparatus or after fixing onto said recording material as said idling torque during non-feeding of paper. Device. 6. The image forming apparatus according to claim 2, wherein the control unit determines that the fixing device has reached the end of its service life on condition that the acquired torque is equal to or greater than a predetermined threshold value. 7. The image forming apparatus according to claim 3, wherein said control unit determines that said fixing device has reached the end of its life on condition that said calculated average value is equal to or greater than a predetermined threshold value. 8. The image forming apparatus according to claim 4, wherein said control unit determines that said fixing device has reached the end of its life on condition that said calculated moving average value is equal to or greater than a predetermined threshold value. When the acquired torque becomes smaller than the torque acquired last time, the control unit controls the fixing process on the condition that the torque acquired last time is smaller than the torque acquired last time before last. 6. The image forming apparatus according to claim 2, wherein the life of the apparatus is determined. When the calculated average value is smaller than the previously calculated average value, the control unit is configured so that the previously calculated average value is smaller than the last calculated average value. 7. The image forming apparatus according to claim 3, further determining that said fixing device has reached the end of its life. When the calculated moving average value becomes smaller than the moving average value calculated last time, the control unit causes the moving average value calculated last time to become smaller than the moving average value calculated last time before. 8. The image forming apparatus according to claim 4, wherein it is determined that the fixing device has reached the end of its life on the condition that the fixing device has reached the end of its life. When determining that the fixing device has reached the end of its service life, the control unit permits image formation using a sheet of a first sheet type and a second sheet having a basis weight smaller than that of the sheet of the first sheet type. 18. The image forming apparatus according to any one of claims 1 to 17, wherein image formation using paper of the paper type of is not permitted. Equipped with an operation panel,
The image forming apparatus according to any one of claims 1 to 18, wherein the controller displays a predetermined image on the operation panel when determining that the fixing device has reached the end of its life. An information processing system comprising: an image forming apparatus for forming an image on the recording material;
The image forming device
a pressure member that is rotated by a motor in a direction in which the recording material is conveyed to the downstream side of the conveying path in the fixing device;
a fixing belt forming a nip area for fixing the unfixed image against the pressure member and rotating following the rotation of the pressure member;
a support member disposed inside the fixing belt and slidably supporting the fixing belt at a position facing the pressure member so as to oppose the pressure applied by the pressure member;
The image forming apparatus detects torque when the motor is driven,
The information processing device is
each time a predetermined condition is satisfied, the torque during driving of the motor is acquired from the image forming apparatus;
An information processing system that determines that the fixing device has reached the end of its life when the acquired torque changes over time from an upward change to a downward change. An information processing method in an image forming apparatus having a fixing device for fixing at least an unfixed image on a recording material and forming an image on the recording material, comprising:
The image forming apparatus includes a control unit, a pressure member that rotates in the fixing device in a direction in which the recording material is conveyed downstream of the conveying path by a motor, and the unfixed image that opposes the pressure member. and a fixing belt that rotates following the rotation of the pressure member, and the pressure member that is disposed inside the fixing belt and resists the pressure applied by the pressure member. a support member that slidably supports the fixing belt at a position facing the
The information processing method includes:
a step in which the control unit acquires the torque during driving of the motor each time a predetermined condition is satisfied;
and determining, by the control unit, that the fixing device has reached the end of its service life when the obtained change over time of the torque changes from an upward change to a downward change.

Images