JP2019156632A - Rotary body control device, conveyance device, image formation device, rotary body control method, and rotary body control program - Google Patents

Abstract

To reduce torque interference in a conveyance path.SOLUTION: This device includes: a plurality of driving parts which drive a plurality of rotary bodies for conveying a medium to be conveyed; and a speed setting part which sets rotary speed of a plurality of the driving parts, by referring to a storage part into which change rates of a value of driving torque of the driving part for rotary-driving a second rotary body adjacent to a first rotary body or a value having a proportional relationship with the value of the driving torque, at the time of varying the rotary speed of the first rotary body with a predetermined rotary body out of a plurality of the rotary bodies as the first rotary body, are stored for each of a plurality of the rotary bodies, and based on the value of the driving torque of a plurality of the driving parts or the value having the proportional relationship with the value of the driving torque and the change rates for each of a plurality of the rotary bodies.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a rotating body control device, a conveying device, an image forming apparatus, a rotating body control method, and a rotating body control program.

  In a conventional image forming apparatus, a mechanism is known in which a secondary transfer roller and an intermediate transfer belt are driven by a motor that rotates at a constant speed.

  In this mechanism, when the surface speed of the intermediate transfer belt is different from the surface speed of the secondary transfer roller, torque interference occurs between the intermediate transfer belt and the secondary transfer roller in order to keep the speed constant. Since this torque interference affects the driving of the intermediate transfer belt, it can be a factor such as color misregistration in image formation performed on the intermediate transfer belt.

  Therefore, conventionally, for example, torque information when the medium to be transported is transported only to the first transport rotating means and the medium to be transported are transported by both the first transport rotating means and the second transport rotating means. A technique for reducing the torque transfer between two rollers by controlling the rotational speed of the second rotating body driving means so as to reduce the comparison result with the torque information in this case is known.

  In the conventional technology described above, the pulling force or the pushing force with respect to the transported medium between the two rollers is reduced, and the interference of torque between the three or more rollers is not considered. For this reason, in the conventional technology, it is difficult to reduce the interference of the torque in the conveyance path formed by three or more rollers, and it is difficult to reduce the interference of the torque in the conveyance path.

  The present invention has been made in view of the above circumstances, and an object thereof is to reduce interference of torque in a conveyance path.

The disclosed technology includes a plurality of driving units that drive a plurality of rotating bodies that convey a medium to be conveyed;
A second rotating body adjacent to the first rotating body when the rotating speed of the first rotating body is changed with the predetermined rotating body as the first rotating body among the plurality of rotating bodies. A drive torque value of the drive unit to be rotationally driven or a change rate of a value proportional to the value of the drive torque is referred to a storage unit stored for each of the plurality of rotating bodies, and the plurality of drive units A drive torque value or a value having a proportional relationship with the drive torque value and the rate of change for each of the plurality of rotating bodies, a speed setting unit for setting the rotation speed of the plurality of drive units, It is the rotary body control apparatus which has.

  Torque interference in the transport path can be reduced.

It is a figure explaining the conveying apparatus of 1st embodiment. It is a figure explaining the interference torque by the difference of the surface speed of two rotary bodies. It is a figure explaining profile information. 1 is a diagram illustrating an outline of a configuration of an image forming apparatus according to a first embodiment. It is a figure explaining the motor control part of 1st embodiment. It is a figure explaining the function of the rotary body control processing part of 1st embodiment. It is a 1st flowchart explaining operation | movement of the rotary body control processing part of 1st embodiment. It is a 2nd flowchart explaining operation | movement of the rotary body control processing part of 1st embodiment. It is a figure explaining a motor control part in the case of using a current command value. It is a figure explaining a motor control part in the case of using current measurement value. It is a figure explaining the motor control part in the case of estimating a drive torque from PWM actual value. It is a figure explaining a motor control part in the case of using torque actual value. FIG. 5 is a schematic view illustrating the internal configuration of an inkjet image forming apparatus according to a third embodiment.

(First embodiment)
The first embodiment will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a transport apparatus according to the first embodiment.

  A transport apparatus 100 shown in FIG. 1 transports, for example, a sheet-shaped transport medium, and is mounted on an image forming apparatus or the like to be described later. 1A shows an outline of the configuration of the transport device, FIG. 1B shows the configuration of the periphery of the secondary transfer unit, and FIG. 1C shows the periphery of the transport unit. The configuration is shown.

  The conveyance device 100 of this embodiment includes an intermediate transfer belt 10, an intermediate transfer roller 11, a secondary transfer counter roller 12, a driven roller 13, a tension roller 14, a belt cleaning device 15, and a scale sensor 16. An encoder pattern 17 is formed on the intermediate transfer belt 10.

  Further, the transport apparatus 100 of the present embodiment includes an intermediate transfer motor 21, roller encoders 22, 33, 44, motor encoders 34, 45, a secondary transfer roller 31, a secondary transfer motor 32, a transport roller 41, a transport motor 42, A conveying counter roller 46 is provided.

  Furthermore, the transport apparatus 100 according to the present exemplary embodiment includes a motor control unit 200 that performs control for keeping the surface speed of the intermediate transfer belt 10 constant.

  In the conveyance device 100 of the present embodiment, the intermediate transfer belt 10 is stretched by a plurality of stretching rollers disposed in a belt loop, and is rotated by an intermediate transfer roller 11 that is one of the stretching rollers. It can be moved endlessly. The intermediate transfer roller 11 is connected to an intermediate transfer motor 21 as a drive source via a speed reduction mechanism. This reduction mechanism has a configuration in which a small-diameter gear on the rotation shaft of the intermediate transfer motor 21 and a large-diameter gear on the rotation shaft of the intermediate transfer roller 11 are meshed with each other.

  In the present embodiment, there is a belt encoder system as speed detection means for detecting the surface speed of the intermediate transfer belt 10. An encoder pattern 17 is engraved on the front surface or the back surface of the intermediate transfer belt 10 of this embodiment, and the surface speed of the intermediate transfer belt 10 is detected by reading the encoder pattern 17 with the scale sensor 16.

  In the example of FIG. 1, the scale sensor 16 is installed at the center of the driven roller 13 and the intermediate transfer roller 11, but the present invention is not limited to this. If the scale sensor 16 is installed on a flat portion, the surface speed of the intermediate transfer belt 10 can be correctly measured. For example, when the scale sensor 16 is installed on a non-flat rotating shaft or the like, the influence of the curvature of the shaft is exerted, and the interval between the encoder patterns 17 is changed due to a variation in the thickness of the intermediate transfer belt 10 due to manufacturing or a variation due to environmental changes. It must be avoided because it changes and is not the correct surface speed.

  The encoder pattern 17 may be manufactured by any method, such as attaching a sheet-like encoder pattern, patterning directly on the intermediate transfer belt 10, or integrally processing in the manufacturing process of the intermediate transfer belt 10.

  In the present embodiment, the scale sensor 16 is assumed to be a reflective optical sensor provided with equally spaced slits, but is not limited thereto. This sensor may be any sensor that can accurately detect the surface position of the intermediate transfer belt 10 from the encoder pattern 17. For example, a CCD camera or the like may be used to detect the surface position by image processing. In addition, the encoder pattern 17 can be eliminated by using a Doppler method or a sensor method that can detect the surface position by image processing from irregularities on the belt surface.

  As another speed detection means for detecting the surface speed of the intermediate transfer belt 10, there is a rotary encoder system. This method is a rotation detector provided on the rotation shaft of the driven roller 13. The driven roller 13 is a roller that rotates following the endless movement of the intermediate transfer belt 10, and can detect the surface speed of the intermediate transfer belt 10.

  In the conveyance device 100, the portion of the entire area in the circumferential direction of the intermediate transfer belt 10 that has passed through the position where the intermediate transfer roller 11 has been passed after passing through the position where the intermediate transfer roller 11 has been passed is M, C. , Y, and K are in contact with the photosensitive drum 19 to form primary transfer nips for M, C, Y, and K. The transfer rollers are in contact with the formation positions of the primary transfer nips for M, C, Y, and K on the intermediate transfer belt 10 from the back side of the intermediate transfer belt 10. In the transport device 100, a transfer bias is applied to each transfer roller by a power source, and a transfer electric field is formed between the intermediate transfer belt 10 and the photosensitive drum 19 in the primary transfer nip of each color.

  In the transport device 100, since a color image is formed at the primary transfer portion, it is preferable to detect and control the surface speed of the intermediate transfer belt 10 at this portion. Therefore, it is desirable to install a rotary encoder on the driven roller 13 or a scale sensor 16 between the driven roller 13 and the intermediate transfer roller 11.

  The tension roller 14 of this embodiment is pressed against the belt from the outside of the belt loop, and generates a constant belt tension. Due to the belt tension generated by the tension roller 14, the intermediate transfer belt 10 comes into contact with the surface of each stretching roller, and the intermediate transfer belt 10 is conveyed in the circumferential direction. In particular, the contact force between the surface of the driven roller 13 and the intermediate transfer belt 10 is important because there is a correlation with the belt conveyance friction force of the driven roller 13, and the conveyance friction force necessary for conveying the intermediate transfer belt 10 is large. The pressing force of the tension roller 14 is set so that it can be secured.

  Further, in the transport device 100, a secondary transfer roller 31 that contacts the surface of the intermediate transfer belt 10 is disposed at a position facing the secondary transfer counter roller 12. The secondary transfer roller 31 and the intermediate transfer belt 10 are arranged. By applying an electric charge to the surface, the recording paper is adsorbed on the surface.

In the transport device 100, the belt cleaning device 15 disposed downstream of the secondary transfer roller 31 in the belt transport direction outside the belt loop is in contact with the intermediate transfer belt 10. The belt cleaning device 15 collects foreign matters such as toner adhering to the surface of the intermediate transfer belt 10 from the surface of the intermediate transfer belt 10 due to a potential difference between the toner and itself.
Note that the transport apparatus 100 transports the medium to be transported in the transport direction indicated by the arrow Y. Therefore, in the transport apparatus 100, the transported medium is transported from the upstream of the transport roller 41 in the transport direction and is transported downstream of the secondary transfer roller 31 in the transport direction. That is, in this embodiment, the conveyance path of the medium to be conveyed is formed by a rotating body including the intermediate transfer belt 10, the secondary transfer roller 31, and the conveyance roller 41.

  The transport path of the present embodiment may include a rotating body other than the intermediate transfer belt 10, the secondary transfer roller 31, and the transport roller 41. The conveyance path of the present embodiment only needs to include a plurality of pairs of rotating bodies.

  The motor control unit 200 according to the present embodiment feedback-controls the intermediate transfer motor 21 in order to keep the surface speed of the intermediate transfer belt 10 constant.

  Specifically, the motor control unit 200 is based on the output signal S1 of the scale sensor 16 indicating the surface speed of the intermediate transfer belt 10 and the output signal S2 of the roller encoder 22 indicating the rotational speed of the intermediate transfer roller 11. A drive control signal S3 for the intermediate transfer motor 21 is output.

  Further, the motor control unit 200 feedback-controls the secondary transfer motor 32 and the transport motor 42 in order to suppress fluctuations in the surface speed of the intermediate transfer belt 10 due to the influence of the transported medium passing through the secondary transfer unit 50. . Specifically, the motor control unit 200 outputs a drive control signal S4 for the secondary transfer motor 32 based on the output signal S1 of the scale sensor 16 and the output signal S2 of the roller encoder 22.

  Next, a mechanism around the secondary transfer roller 31 will be described (see FIG. 1B). In addition to the intermediate transfer motor 21, the transport device 100 is provided with a secondary transfer motor 32. The secondary transfer motor 32 is rotated by a drive control signal S4 transmitted from the motor control unit 200.

  The secondary transfer motor 32 employs the same brushed DC motor or brushless DC motor as the intermediate transfer motor 21. The rotational speed of the secondary transfer motor 32 is reduced by a reduction mechanism (motor gear and secondary transfer roller 31 side reduction gear). Further, the secondary transfer roller 31 transports the transported medium transported to the secondary transfer unit 50 by its rotation.

  On the opposite side of the secondary transfer roller 31, there is a secondary transfer counter roller 12 that supports the intermediate transfer belt 10, and the secondary transfer roller 31 is placed on the secondary transfer counter roller 12 across the intermediate transfer belt 10. Abutted / separated. That is, the secondary transfer roller 31 and the secondary transfer counter roller 12 form a pair of rotating bodies arranged to face each other.

  The two rollers are brought into contact with each other by a spring. The secondary transfer roller 31 also has a cam mechanism that can move in the direction of the arrow Y in the figure for separating from the secondary transfer counter roller 12. Separation is switched.

  In the transport device 100 of the present embodiment, an elastic layer is provided on the surface portion of the secondary transfer roller 31 in order to improve the transferability of the secondary transfer unit 50. As an example of the secondary transfer roller 31, a low hardness rubber material roller portion (elastic rubber layer) such as silicon rubber is provided around a low inertia thin metal pipe, and a urethane coating layer is applied to the surface layer. .

  In the secondary transfer roller 31 of the present embodiment, the conductive rubber roller portion is composed of vulcanized rubber or silicon rubber having a rubber hardness of 40 ° (rubber hardness A scale) or less as a lower layer, and the surface layer has no viscosity. The urethane coating layer may be provided as a thin layer. In this embodiment, this makes it possible to expand the nip (pressure contact) region by contact deformation of the conductive rubber roller portion and to secure an appropriate transfer required pressure.

  In general, when trying to achieve a low hardness of 40 ° or less by a method other than the foam rubber structure, in the case of vulcanized rubber, the viscosity increases due to the addition of a plasticizer. Silicon rubber also has high viscosity. As a result, the movement failure of both the moving bodies occurs due to the adhesion at the pressure contact portion 51 where the intermediate transfer belt 10 and the secondary transfer roller 31 are in contact with each other or the adhesion with the portion in contact with the transported medium. In order to avoid this, the urethane coating applied to the surface layer described above is effective.

  The intermediate transfer motor 21 is controlled by the motor control unit 200 so that the surface speed of the intermediate transfer belt 10 is constant.

  Next, a configuration around the transport roller 41 will be described (see FIG. 1C).

  The transport roller 41 included in the transport apparatus 100 of the present embodiment is one of rotating bodies that form a transport path and transports a transported medium, and is rotated by a transport motor 42. When the conveyance motor 42 is driven, the rotation of the conveyance motor 42 is transmitted to the conveyance roller 41 via a gear and rotates. The medium to be transported is brought into pressure contact between the secondary transfer roller 31 and the secondary transfer counter roller 12 by a transport unit 60 formed by a transport roller 41 and a transport counter roller 46 disposed at a position facing the transport roller 41. It is conveyed to the part 51. That is, the conveyance roller 41 and the conveyance counter roller 46 of the present embodiment form a pair of rotating bodies.

  The transported medium transported to the pressure contact portion 51 is sandwiched and transported between the secondary transfer roller 31 and the intermediate transfer belt 10. In other words, the pressure contact portion 51 is a clamping portion where the transported medium is clamped between the secondary transfer roller 31 and the intermediate transfer belt 10.

  As described above, in the transport apparatus 100 of the present embodiment, the transported medium is transported from the transport unit 60 to the secondary transfer unit 50. The transport device 100 is in pressure contact with the secondary transfer roller 31 and the intermediate transfer belt 10 in the secondary transfer unit 50, and transfers the toner image to the transported medium.

  At this time, the surface speed of the rotating body forming the transport path of the transported medium varies depending on the type of transported medium, the tolerance of each roller, changes in contact pressure, the environment, the amount of deviation of the roller shape over time, and the like. .

  Further, this change causes the surface speed of the intermediate transfer belt 10 to change. In other words, fluctuations in the surface speed of the rotating body that forms the conveyance path of the medium to be conveyed generate interference torque that causes fluctuations in the driving torque of the intermediate transfer motor 21 that drives the intermediate transfer belt 10.

  Therefore, in this embodiment, in order to keep the surface speed of the intermediate transfer belt 10 constant, the rotational speed of the rotating body that forms the transport path of the transported medium is controlled. In other words, in this embodiment, the rotational speed of the rotating body that forms the transport path of the transported medium is controlled so as not to generate interference torque with respect to the driving torque of the intermediate transfer motor 21.

  In the present embodiment, the rotating body that forms the transport path of the transported medium includes, for example, a roller that is positioned upstream of the transport roller 41 and transports the transported medium to the transport roller 41. The rotating body that forms the transport path of the transported medium includes a roller that is positioned downstream of the press contact portion 51 in the transport path and transports the transported medium to the fixing device.

  The transported medium according to the present embodiment may be, for example, paper or a sheet-like film. The transported medium according to the present embodiment is capable of transferring an image, and is a transport device. Any material can be used as long as it can be conveyed at 100.

  Below, the interference torque by the difference of the surface speed of two adjacent rotary bodies in the conveyance path | route of the conveying apparatus 100 of this embodiment is demonstrated.

  FIG. 2 is a diagram illustrating the interference torque due to the difference in surface speed between the two rotating bodies.

  In the example of FIG. 2, the conveyance roller 41 and the secondary transfer roller 31 are shown as two adjacent rotating bodies in the conveyance path. In the example of FIG. 2, the transport roller 41 is an upstream rotating body in the transport direction, and the secondary transfer roller 31 is a downstream roller in the transport direction.

  In other words, in the example of FIG. 2, the pair of rotating bodies formed by the secondary transfer roller 31 and the secondary transfer counter roller 12 is a pair on the downstream side in the transport direction, and the transport roller 41 and the transport counter roller 46 include The pair of rotating bodies to be formed is a pair on the upstream side in the transport direction.

  FIG. 2A shows a case where the surface speed of the upstream roller is higher than the surface speed of the downstream roller. FIG. 2B shows a case where the surface speed of the upstream roller is slower than the surface speed of the downstream roller.

  In the present embodiment, the conveyance roller 41 that is the upstream roller is feedback-controlled based on the rotation speed obtained from the motor encoder 45, so the rotation speed Vr of the rotation shaft is always constant.

  Similarly, the secondary transfer roller 31, which is a downstream roller, is similarly feedback-controlled based on the rotational speed obtained from the motor encoder 34, so that the rotation shaft of the secondary transfer roller 31 rotates. The speed Vs is always constant.

  In the transport device 100, when the surface speed of the upstream roller and the surface speed of the downstream roller are different, interference torque is generated between the motors that drive these rollers. The interference torque here is generated when the downstream motor that drives the downstream roller is affected by pushing or pulling from the upstream roller through the medium to be transported when transporting the medium to be transported. Torque.

  In other words, in the example of FIG. 2, when the surface speed of the transport roller 41 (the rotational speed of the transport motor 42) and the surface speed of the intermediate transfer belt 10 are different, the transport motor 42 and the intermediate transfer motor 21 are not connected. Interference torque is generated.

  The interference torque described here is generated when the intermediate transfer motor 21 is affected by the pushing or pulling of the paper K in the transport roller 41 via the paper K as the transported medium. In order to measure this interference torque, the paper K straddles the secondary transfer roller 31 and the transport roller 41, and the paper K passes only through the secondary transfer roller 31 and does not pass through the transport roller 41. And the amount of change in the driving torque Tc of the intermediate transfer motor 21 at the above.

  FIG. 2A shows a state where the paper K is straddling both the transport roller 41 and the secondary transfer roller 31.

  In FIG. 2A, since the surface speed of the transport roller 41 is higher than the surface speed of the intermediate transfer belt 10, the transport roller 41 pushes the paper K toward the secondary transfer roller 31.

  In this state, the surface speed of the secondary transfer roller 31 is increased, and interference torque is generated between the surface of the paper K and the intermediate transfer belt 10. Here, the motor controller 200 reduces the driving torque Tc of the intermediate transfer motor 21 (secondary transfer motor 32) in order to control the surface speed of the intermediate transfer belt 10 to be a constant speed.

  In FIG. 2B, since the surface speed of the transport roller 41 that is the upstream roller is slower than the surface speed of the secondary transfer roller 31 that is the downstream roller, the transport roller 41 removes the paper K from the secondary. The transfer roller 31 is pulled.

  Then, the surface speed of the secondary transfer roller 31 becomes slow, and interference torque is generated between the paper K and the surface of the secondary transfer roller 31. Also at this time, the motor control unit 200 increases the drive torque Tc of the intermediate transfer motor 21 in order to control the surface speed of the secondary transfer roller 31 to be a constant speed.

  In the present embodiment, paying attention to this point, information indicating the relationship between the driving torque of the rotating body and the fluctuation in the rotational speed of another rotating body adjacent to the rotating body is held as profile information of the rotating body. In the present embodiment, torque interference between adjacent rotating bodies in the transport path is reduced by adjusting the rotation speed of the rotating bodies based on the profile information.

  FIG. 3 is a diagram for explaining profile information.

  In the example of FIG. 3, a pair of four rotating bodies is included in the transport path. Specifically, in the conveyance path shown in FIG. 3, a pair 521 formed by the roller 501 and the roller 511, a pair 522 formed by the roller 502 and the roller 512, and a pair formed by the roller 503 and the roller 513 are formed. 523 and a pair 524 formed by the roller 504 and the roller 514 are included. In the example of FIG. 3, the pair 524 is an upstream pair in the transport direction, and the pair 521 is a downstream pair in the transport direction.

  The pair 521 is adjacent to the pair 522, the pair 522 is adjacent to the pair 523, and the pair 523 is adjacent to the pair 524. That is, the roller 501 is adjacent to the roller 502, the roller 502 is adjacent to the roller 503, and the roller 503 is adjacent to the roller 504.

  In this case, in the present embodiment, for each of the rollers 501 to 504, the process of changing the rotation speed and acquiring the driving torque of the adjacent rollers is repeated. In the present embodiment, profile information indicating the relationship between the rotational speed and the amount of change in the driving torque of the adjacent roller can be acquired for each of the rollers 501 to 504 by this processing.

  Here, when the paper K is passing through each nip portion in the pairs 521 to 524, the driving torque of the motor that drives the roller 501 is T1, the driving torque of the motor that drives the roller 502 is T2, and the roller 503 is driven. The driving torque of the motor to be driven is T3, and the driving torque of the motor that drives the roller 504 is T4.

  Further, the torque change rate of the driving torque T2 with respect to the fluctuation of the rotation speed V1 of the roller 501 is T12. The torque change rate T12 indicates a ratio of the drive torque T2 after the rotation speed V1 is changed to the drive torque T2 before the rotation speed V1 is changed.

  The torque change rate of the drive torque T1 with respect to the fluctuation of the rotation speed V2 of the roller 502 is T21, and the torque change rate of the drive torque T3 with respect to the fluctuation of the rotation speed V2 of the roller 502 is T23. Further, the torque change rate of the drive torque T2 with respect to the fluctuation of the rotation speed V3 of the roller 503 is T32, and the torque change rate of the drive torque T4 with respect to the fluctuation of the rotation speed V3 of the roller 503 is T34. The torque change rate of the drive torque T3 with respect to the fluctuation of the rotational speed V4 of the roller 504 is T43.

  Here, for example, it is assumed that the value of the driving torque T1 when the value of the rotational speed V2 of the roller 502 is V2a is T1a. Assume that the value of the drive torque T1 when the rotational speed V2 of the roller 502 is V2a 'is T1a'.

  In this case, the fluctuation amount V2m of the rotational speed V2 of the roller 502 is V2a′−V2a, and the torque change rate T12 of the driving torque T1 with respect to the fluctuation of the rotational speed is T1a ′ / T1a.

  That is, in the present embodiment, the relationship among the drive torque T1, the fluctuation amount V2m, and the torque change rate T21 can be expressed by the following expression.

Driving torque T1 = variation amount V2m of rotational speed V2 × torque change rate T21
Therefore, in the present embodiment, in order to prevent the drive torque T1 from changing due to the fluctuation amount V2m,
Driving torque T1−variation amount V2m of rotational speed V2 × torque change rate T21 = 0 Formula (1)
The fluctuation amount V2m of the rotation speed V2 of the roller 502 may be adjusted so that In the present embodiment, by adjusting the rotation speed V2 of the roller 502 in this way, it is possible to suppress the occurrence of fluctuations in the drive torque T1 due to fluctuations in the rotation speed V2. In other words, it is possible to suppress the generation of interference torque with respect to the roller 501 due to fluctuations in the rotational speed V2.

  Similarly, the driving torques T2 to T4 are respectively expressed by the following equations.

Drive torque T2
= Variation amount V1m of rotation speed V1 × Torque change rate T12
+ Variation amount Vm3 of rotation speed V3 × Torque change rate T32
Therefore, in the present embodiment, when the interference torque generated for the roller 502 due to the rollers 501 and 503 is suppressed,
Driving torque T2− (variation amount V1m of rotational speed V1 × torque change rate T12
+ Variation amount Vm3 × torque change rate T32) of rotation speed V3 = 0 (2)
Thus, the fluctuation amount V1m of the rotation speed V1 of the roller 501 and the fluctuation amount V3m of the rotation speed V3 of the roller 503 may be adjusted.

Similarly, when suppressing the interference torque generated for the roller 503 due to the rollers 502 and 504,
Drive torque T3− (variation amount V2m of rotation speed V1 × torque change rate T23
+ Variation amount of rotation speed V4 V43 × torque change rate T43) = 0 Formula (3)
Thus, the fluctuation amount V2m of the rotation speed V2 of the roller 502 and the fluctuation amount V4m of the rotation speed V4 of the roller 504 may be adjusted. Similarly, when suppressing the interference torque generated for the roller 504 due to the roller 503,
Driving torque T4—variation amount Vm3 of rotational speed V3 × torque change rate T34 = 0 Formula (4)
The fluctuation amount V3m of the rotation speed V3 of the roller 503 may be adjusted so that

  Therefore, in the present embodiment, when the transporting path includes the rotating bodies (rollers 501 to 504) shown in FIG. 3, the torque change rates T21, T12, T32, T23 of the motors that drive these rotating bodies, T43 and T34 are held as profile information. In the present embodiment, the profile information may include formulas (1) to (4).

  That is, in this embodiment, the amount of fluctuation of one rotational speed (first rotating body) between adjacent rotating bodies and the other rotating body (second rotating body) according to the amount of fluctuation are driven. What is necessary is just to hold | maintain the change rate of the drive torque of a motor (drive part) as profile information.

  Note that the second rotating body includes a rotating body arranged on the upstream side in the transport direction and a rotating body arranged on the downstream side with respect to the first rotating body.

  Below, each apparatus of this embodiment is demonstrated. FIG. 4 is a diagram illustrating an outline of the configuration of the image forming apparatus according to the first embodiment.

  The image forming apparatus 300 according to the present embodiment is an electrophotographic system, is preferably a digital multi-function peripheral, and preferably has a copying function, a printer function, a facsimile function, and the like. However, the image forming apparatus 300 may be an ink jet method, a sublimation thermal transfer method, or a dot impact method that forms an image by ejecting ink droplets. The image forming apparatus 300 according to the present embodiment includes a transport device 100.

  The image forming apparatus 300 of this embodiment includes an image reading unit 301, an image writing unit 302, a photosensitive unit 303, a photosensitive drum 19, a developing unit 305, an intermediate transfer unit 306, an intermediate transfer belt 10, a secondary transfer unit 50, A conveyance unit 60, a tray 307, a conveyance unit 308, and a fixing unit 309 are included.

  The image forming apparatus 300 scans the document while irradiating the document with a light source by the image reading unit 301, and reads an image of reflected light from the document by a 3-line CCD (Charge Coupled Device) sensor. The read image is subjected to image processing such as scanner γ correction, color conversion, image separation, and gradation correction processing by the image processing unit, and then sent to the image writing unit 302.

  The image writing unit 302 modulates the driving of an LD (Laser Diode) according to the image data. In the photoconductor unit 303, an electrostatic latent image is written by a laser beam from the LD onto the uniformly charged rotating photoconductor drum 19, and toner is attached by the developing unit 305 to be visualized.

  The image formed on the photosensitive drum 19 is transferred onto the intermediate transfer belt 10 of the intermediate transfer unit of the intermediate transfer unit 306. When full-color copying is executed in the image forming apparatus 300, toner images of four colors (black, cyan, magenta, yellow) are sequentially superimposed on the intermediate transfer belt 10. At the time when image formation and transfer of all colors are completed, a transport medium is supplied from the tray 307 in synchronization with the intermediate transfer belt 10 by the transport unit 60, and transported from the intermediate transfer belt 10 by the secondary transfer unit 50. The toner image is secondarily transferred to the medium. The transported medium to which the toner image has been transferred is sent to the fixing unit 309 via the transport unit 308, and is discharged after the toner image is fixed on the transported medium by the fixing roller and the pressure roller.

  FIG. 5 is a diagram illustrating the motor control unit of the first embodiment.

  The motor control unit 200 according to the present embodiment is included in the conveyance device 100 and controls driving of the plurality of rotating bodies (the intermediate transfer roller 11, the secondary transfer roller 31, and the conveyance roller 41) illustrated in FIG. . In addition, the motor control unit 200 of the present embodiment controls the driving of the rotating body that forms the transport path.

  In the image forming apparatus 300 of the present embodiment, the motor control unit 200 is connected to a main control unit 310 that controls the entire image forming apparatus 300, and controls driving of a rotating body that forms a conveyance path.

  When an image data output instruction or the like is operated from the operation unit 320 of the image forming apparatus 300, the main control unit 310 instructs the motor control unit 200 to drive each motor. Specifically, when receiving an image data output instruction or the like, the main control unit 310 instructs the motor control unit 200 about a command value to each motor, a start / stop instruction, a target value of rotation speed, a rotation direction, and the like. Upon receiving this instruction, the motor control unit 200 controls driving of each motor. In addition, the main control unit 310 exchanges information regarding each motor with the motor control unit 200. Further, the main control unit 310 includes a memory 330 that stores information (motor information) regarding each motor. The information on the motor includes, for example, the rotational speed (set speed) of each motor, a PWM value corresponding to the command value, a drive current, an encoder value, and the like.

  In the motor control unit 200 of the present embodiment, the rotating body control processing unit 210 includes a driver corresponding to a motor that rotates each of a plurality of rollers that form a conveyance path, and an FET. In the example of FIG. 5, the intermediate transfer motor 21, the secondary transfer motor 32, and the transport motor 42 are shown as examples of motors that rotate a plurality of rollers forming the transport path.

  The drivers 221, 222, and 223 and the FETs 231, 232, and 233 included in the rotating body control processing unit 210 are drivers and FETs corresponding to the intermediate transfer motor 21, the secondary transfer motor 32, and the transport motor 42, respectively.

  As will be described in detail later, the rotating body control processing unit 210 first adjusts the target value of the rotational speed of the secondary transfer motor 32 and the target value of the rotational speed of the transport motor 42, and sets each adjusted target value. Store in the memory 330. The rotational speed of the secondary transfer motor 32 is synonymous with the rotational speed of the secondary transfer roller 31, and the rotational speed of the transport motor 42 is synonymous with the rotational speed of the transport roller 41.

  In addition, the rotating body control processing unit 210 acquires and holds profile information for each of a plurality of rollers that form the conveyance path. Further, the rotator control processing unit 210 refers to the profile information and controls the rotation speed of each of the plurality of rollers forming the conveyance path.

  Specifically, the rotator control processing unit 210 responds to the torque change rate of the intermediate transfer motor 21 according to the amount of change in the rotation speed of the intermediate transfer motor 21 and the amount of change in the rotation speed of the secondary transfer motor 32. The torque change rate of the secondary transfer motor 32 and the torque change rate of the carry motor 42 corresponding to the amount of change in the rotation speed of the carry motor 42 are acquired and held as profile information.

  The rotating body control processing unit 210 adjusts the rotation speeds of the intermediate transfer motor 21, the secondary transfer motor 32, and the transport motor 42 with reference to the profile.

  The driver 221 and the FET 231 have a function of supplying a constant drive current to the intermediate transfer motor 21. The driver 222 and the FET 232 have a function of supplying a constant drive current to the secondary transfer motor 32. The driver 223 and the FET 233 have a function of supplying a constant driving current to the transport motor 42.

  The rotating body control processing unit 210 acquires the surface speed of the intermediate transfer belt 10 and the rotation speed of the intermediate transfer motor 21 from the roller encoder 22 and the scale sensor 16 of the intermediate transfer roller 11. Further, the rotator control processing unit 210 acquires the rotation speeds of the secondary transfer motor 32 and the secondary transfer roller 31 from the motor encoder 34 and the roller encoder 33. Further, the rotating body control processing unit 210 acquires the rotation speeds of the transport motor 42 and the transport roller 41 from the motor encoder 45 and the roller encoder 44.

  Further, the rotating body control processing unit 210 acquires the drive currents of the intermediate transfer motor 21, the secondary transfer motor 32, and the transport motor 42, calculates the control output to each motor, and outputs the PWM command value corresponding to the control output. Output to each driver. In addition, the rotating body control processing unit 210 according to the present embodiment acquires a drive current for each motor that rotates each roller that forms the conveyance path, calculates a control output to each motor, and corresponds to the control output. The PWM command value is output to the driver of each motor.

  Specifically, the rotating body control processing unit 210 calculates the drive current of each motor based on the PWM command value. However, there is a possibility that an error may occur due to the influence of the fluctuation or response of the motor drive circuit including the driver. Therefore, in order to grasp the drive current of the motor with higher accuracy, the rotating body control processing unit 210 may grasp the drive current by measuring the current of the FET. Specifically, the rotator control processing unit 210 may grasp the drive current from the combined current value flowing through the shunt resistor connected to the FET.

  When the PWM command value is input, the drivers 221, 222, and 223 recognize the rotation angle of each motor (21, 32, 42) from the Hall element signal. Each driver converts the PWM signal generated according to the PWM command value into a motor three-phase output signal, and drives each motor via the FETs 231, 232, and 233.

  The rotating body control processing unit 210 of the present embodiment controls the rotation speed of the rotating body that forms the conveyance path based on the command value of each motor by the above operation.

  Further, the rotator control processing unit 210 calculates a drive torque from the acquired drive current. Specifically, the rotator control processing unit 210 obtains the rotation speed and drive current of the rotator (motor corresponding to the rotator) that forms the conveyance path, and converts the torque that indicates the relationship between the torque multiplier and the speed. The drive current is converted into torque using a table or the like.

  Further, the rotator control processing unit 210 stores the data acquired by the rotator control processing unit 210 or the calculated data in the memory 330 as necessary, or notifies the main control unit 310 of information such as an abnormality notification. To do. Incidentally, the memory 330 may also be included in the rotating body control processing unit 210.

  As described above, in this embodiment, the rotating body control processing unit 210 functions as a part of a rotating body control device that controls driving of a plurality of rotating bodies.

  Next, the function of the rotating body control processing unit 210 of this embodiment will be described with reference to FIG. FIG. 6 is a diagram illustrating the function of the rotating body control processing unit of the first embodiment.

  The rotating body control processing unit 210 of the present embodiment includes a condition setting unit 211, a sheet passing detection unit 212, a speed change instruction unit 213, a torque estimation unit 214, a change rate calculation unit 215, a profile storage unit 216, a speed calculation unit 217, A storage control unit 218 is included.

  In the condition setting unit 211, various conditions for acquiring profile information are set. Specifically, the condition setting unit 211 sets the motor for which the torque change rate is to be calculated, sets the fluctuation range of the rotation speed of the roller adjacent to the roller rotated by the specified motor, and changes the torque. In order to calculate the rate, the number of data to be acquired and the period for acquiring the data are set. The period for acquiring data is a period during which the medium to be transported passes through a pair of rollers included in the transport path.

  The data acquired for calculating the torque change rate indicates a set of the rotational speed of the roller adjacent to the roller driven by the designated motor and the drive torque of the designated motor.

  In addition, the condition setting unit 211 of the present embodiment may set the fluctuation range and fluctuation range of the rotation speed instead of the number of data.

  In the following description, a roller adjacent to a roller (second rotating body) driven by a designated motor (driving unit) is referred to as an adjacent roller (first rotating body). In the present embodiment, the rotation speed of the adjacent roller is synonymous with the rotation speed of the motor that drives the adjacent roller.

  The sheet passing detection unit 212 detects that each roller has reached or passed through the medium to be transported.

  The speed change instruction unit 213 instructs the motor that rotates each roller included in the transport path to change the rotation speed.

  The torque estimation unit 214 calculates an estimated value of the driving torque that rotates the roller specified by the condition setting unit 211. In other words, the torque estimation unit 214 of the present embodiment is an acquisition unit that acquires the driving torque of the roller specified by the condition setting unit 211.

  Hereinafter, as an example of a method for calculating the estimated value of the driving torque, a method for calculating the estimated value of the driving torque Tc of the intermediate transfer motor 21 will be described.

  The torque estimation unit 214 sets the load torque value calculated based on the PWM command value output to the driver 221 and the rotation speed of the intermediate transfer motor 21 obtained from the scale sensor 16 as the drive torque Tc. The estimated value of the drive torque Tc can be calculated from the current value supplied to the motor, the PWM command value, etc. in a state where each motor is accurately controlled at a constant speed or a predetermined speed.

  In the present embodiment, calculating the estimated value of the driving torque is synonymous with calculating the driving torque.

  The change rate calculation unit 215 calculates the change rate of the driving torque of the roller specified by the condition setting unit 211. Specifically, the change rate calculation unit 215 refers to a plurality of combinations of the rotation speed of the roller adjacent to the roller specified by the condition setting unit 211 and the specified drive torque, and changes the rotation speed according to the variation. Calculate the rate of change of the drive torque.

  The profile storage unit 216 holds the change rate for each roller calculated by the change rate calculation unit 215 as profile information 219.

  In the present embodiment, the rotating body control processing unit 210 includes the profile storage unit 216 and holds the profile information 219. However, the present invention is not limited to this. The profile information 219 may be stored in the memory 330 of the main control unit 310, for example. In that case, the rotator control processing unit 210 may not hold the profile storage unit 216.

  The speed calculation unit 217 refers to the profile information 219 and calculates a target value for the rotational speed of the motor that drives each roller included in the transport path.

  The storage control unit 218 stores the rotation speed (target value) calculated by the speed calculation unit 217 in the memory 330. That is, the speed calculation unit 217 and the storage control unit 218 of the present embodiment function as a speed setting unit that sets the rotation speed of the motor that drives the rotating body included in the conveyance path based on the profile information.

  Next, with reference to FIG.7 and FIG.8, operation | movement of the rotary body control process part 210 of this embodiment is demonstrated.

  FIG. 7 is a first flowchart for explaining the operation of the rotating body control processing unit of the first embodiment. FIG. 7 shows a process of acquiring profile information 219 by the rotating body control processing unit 210.

  The rotating body control processing unit 210 according to the present embodiment uses the condition setting unit 211 to specify a motor for which the rate of change in torque is to be calculated, to set the fluctuation width and fluctuation range of the rotation speed of the adjacent roller, and data. The period to obtain is set (step S701). In step S701, the rotation speed of the adjacent roller may be set to, for example, the slowest rotation speed or the fastest rotation speed in the rotation speed fluctuation range.

  Further, in the present embodiment, the fluctuation range of the rotation speed of the adjacent roller (first rotating body) is set so that the driving torque of the motor that rotationally drives the roller (second rotating body) is linear due to the fluctuation of the rotation speed. The width was changed.

  In this embodiment, by setting the fluctuation range of the rotation speed in this way, the correlation between the change in the drive torque and the fluctuation in the rotation speed can be strengthened, and the optimum fluctuation amount of the rotation speed can be obtained with high accuracy. Can be calculated.

  Subsequently, the rotating body control processing unit 210 detects that the medium to be transported has passed the roller driven by the designated motor by the sheet passing detection unit 212 (step S702).

  Subsequently, the rotator control processing unit 210 acquires the drive torque of the designated motor by the torque estimation unit 214 (step S703).

  Subsequently, the rotating body control processing unit 210 determines whether or not the drive torque is acquired by changing the rotation speed of the adjacent roller to the change range during the period set in step S701 (step S704). The driving torque referred to here is the average value of the driving torque of the motor driving the adjacent roller and the roller adjacent on the upstream side, and the average driving torque of the motor driving the roller adjacent to the adjacent roller on the downstream side. Value.

  In step S704, when all the corresponding drive torques are not acquired, the rotating body control processing unit 210 changes the rotation speed of the adjacent roller by the set fluctuation range by the speed change instruction unit 213 (step S705). The process returns to step S702.

  When all the corresponding drive torques are acquired in step S704, the rotator control processing unit 210 calculates the torque change rate of the drive torque according to the change in the rotation speed of the adjacent roller by the change rate calculation unit 215, and the profile The information is stored in the profile storage unit 216 as information 219 (step S706).

  Specifically, the change rate calculation unit 215 calculates the torque change rate of the designated motor drive torque from a plurality of sets including the designated motor drive torque and the rotation speed of the adjacent roller. Then, the change rate calculation unit 215 may store the calculated torque change rate in association with the specified motor in the profile storage unit 216 as the profile information 219 of the specified motor.

  Subsequently, the rotating body control processing unit 210 determines whether or not motor profile information has been acquired for all the rollers included in the transport path (step S707). Specifically, the rotating body control processing unit 210 determines whether all the rollers from the most upstream roller to the most downstream roller in the transport path are selected as adjacent rollers and the rotation speed is changed. Is judged.

  In step S707, when profile information has not been acquired for all corresponding motors, the rotating body control processing unit 210 returns to step S701.

  In step S707, when profile information is acquired for all corresponding motors, the rotating body control processing unit 210 ends the process.

  In FIG. 7, the rotation speed of the adjacent roller is a case where the notification of the medium to be transported is detected by the sheet passing detection unit 212, but is not limited thereto. In this embodiment, the rotation speed of the adjacent roller may be changed until the transported medium is sandwiched between the designated roller and the adjacent roller.

  FIG. 8 is a second flowchart for explaining the operation of the rotating body control processing unit of the first embodiment. In FIG. 8, the process which adjusts the rotational speed of a motor by the rotary body control process part 210 of this embodiment is shown.

  The rotating body control processing unit 210 according to the present embodiment starts transport of the transported medium (step S801). Subsequently, the rotating body control processing unit 210 acquires the driving torque of each motor that drives each roller through which the transported medium passes through the torque estimation unit 214 (step S802).

  Subsequently, the rotating body control processing unit 210 refers to the profile information 219 stored in the profile storage unit 216 by the speed calculation unit 217 and calculates a target value of the rotation speed of each motor (step S803).

  Step S803 will be further described. For example, assume that the rollers included in the transport path are rollers 501 to 504 (see FIG. 3). In this case, the profile information 219 stored in the profile storage unit 216 includes the torque change rate T21 of the drive torque T1 of the motor that drives the roller 501 and the torque change rates T12 and T32 of the drive torque T2 of the motor that drives the roller 502. Including. The profile information 219 includes torque change rates T23 and T43 of the drive torque T3 of the motor that drives the roller 503, and a torque change rate T34 of the drive torque T4 of the motor that drives the roller 504.

  Therefore, the speed calculation unit 217 refers to the profile information 219, and calculates the fluctuation amounts V1m, V2m, V3m, and V4m of the rotation speeds of the rollers 501 to 504 so that the expressions (1) to (4) are established. The rotational speed of the rollers 501 to 504 may be calculated according to the amount of change.

  In other words, the speed calculation unit 217 may calculate the rotation speed of each motor so that the amount of change in the drive torque of the motor that rotationally drives the rollers 501 to 504 approaches zero.

  For example, in order to bring the change amount of the drive torque T1 close to 0, the speed calculation unit 217 uses the formula (1) based on the drive torque T1 acquired in step S802 and the torque change rate T21 of the profile information 219. The fluctuation amount V2m of the rotation speed of the roller 502 may be calculated.

  Further, in order to bring the change amount of the drive torque T2 close to 0, the speed calculation unit 217 uses the fluctuation amount V1m based on the drive torque T2 and the torque change rates T12 and T32 of the profile information 219 from the equation (2). And the fluctuation amount V3m may be calculated.

  At this time, for example, the speed calculation unit 217 selects an arbitrary roller as the reference roller, and calculates the target value of the rotation speed in order from the rollers adjacent to the reference roller among the rollers 501 to 504 included in the transport path. May be.

  For example, when the roller 501 is selected as the reference roller among the rollers 501 to 504, the speed calculation unit 217 may calculate from the target value of the rotation speed of the roller 502 adjacent to the roller 501. In this case, the speed calculation unit 217 may calculate the target value of the rotation speed in the order of the rollers 502, 503, and 504.

  Subsequently, the rotating body control processing unit 210 causes the storage control unit 218 to store the rotation speed (target value) calculated by the speed calculation unit 217 in the memory 330.

  In the present embodiment, the profile information 219 is acquired in advance, but the present invention is not limited to this. In this embodiment, after the conveyance of the medium to be conveyed is started, the process shown in FIG. 7 may be executed to obtain the profile information 219, and the process may proceed to the process shown in FIG. In other words, in this embodiment, the process of acquiring the profile information 219 and the process of adjusting the rotation speed of the rotating body included in the transport path may be performed continuously.

  As described above, in the present embodiment, the profile information acquired from the rotational speed of one of the adjacent rotating bodies and the driving torque for driving the other rotating body is referred to, The generated interference torque can be reduced.

  Therefore, in the present embodiment, it is not necessary to set a specific reference in order to reduce the interference torque, and the interference torque can be reduced with a simple configuration.

  In the present embodiment, the example in which the rotation speed of the rotating body that forms the conveyance path is controlled has been described. However, the configuration to which the present embodiment is applied is not limited to this.

  The control method of this embodiment can be applied to an image forming apparatus having a photosensitive belt, for example. In this case, the interference torque for the photosensitive belt may be eliminated. In the present embodiment, the present invention can be applied to any apparatus as long as it has a plurality of pairs of rotating bodies and the medium to be transported is transported by the plurality of pairs.

(Second embodiment)
The second embodiment will be described below with reference to the drawings. The second embodiment is different from the first embodiment in that the estimated value of the drive torque is substituted with another value. Therefore, in the following description of the second embodiment, only differences from the first embodiment will be described, and those having the same functional configuration as the first embodiment will be described for the first embodiment. The same reference numerals as those used in FIG.

  In the image forming apparatus, a value other than the estimated value of the drive torque in a state where the rotating body forming the transport path such as the intermediate transfer motor 21, the secondary transfer motor 32, and the transport motor 42 is controlled at a constant rotational speed. Can be used instead of the driving torque of each motor.

  The reason is that the fluctuation of the interference torque due to the surface speed difference among the intermediate transfer belt 10, the secondary transfer roller 31, and the conveying roller 41 is a fluctuation in a frequency band included in the control band in the feedback control.

  If feedback control is performed on each motor, the rotation speed of each motor is reflected in the rotating body control processing unit. That is, the fluctuation of the driving torque of each motor is reflected in each signal upstream of each motor.

  Therefore, in this embodiment, instead of the driving torque of the intermediate transfer motor 21, the secondary transfer motor 32, the transport motor 42, and the like, the current command value, the driving current, the PWM actual value, and the torque actual value supplied to each motor. A case where the above is used will be described.

  In the present embodiment, each value such as a current command value, a drive current, a PWM actual measurement value, and a torque actual measurement value supplied to each motor is a value proportional to the drive torque.

  Since each value described above is used as a drive torque, the rotation speed of the rotating body that forms the conveyance path by the rotating body control processing unit in the present embodiment is controlled by the same method as in the first embodiment. .

  FIG. 9 is a diagram illustrating a motor control unit in the case of using a current command value. The image forming apparatus 300A of FIG. 9 includes a motor control unit 200BA, a rotating body control processing unit 210A, drivers 221A, 222A, and 223A, and FETs 231, 232, and 233.

  The rotating body control processing unit 210A outputs a current command value for instructing a current to be supplied to each motor to each driver.

  The rotating body control processing unit 210A of the present embodiment includes an acquisition unit that acquires the current command value, and uses the current command value acquired by the acquisition unit instead of the drive torque.

  FIG. 10 is a diagram for explaining a motor control unit in the case where an actual measured current value is used.

  The motor control unit 200B of the image forming apparatus 300B in FIG. 10 includes a rotating body control processing unit 210B, drivers 221, 222, and 223, and FETs 231, 232, and 233.

  The rotating body control processing unit 210B includes a current detection sensor that detects a current flowing through each motor included in the conveyance path, and an acquisition unit that acquires an actual measurement value of a current flowing through each motor. The measured value is used instead of the driving torque.

  FIG. 11 is a diagram for explaining the motor control unit in the case where the drive torque is estimated from the PWM actual measurement value.

  A motor control unit 200C of the image forming apparatus 300C in FIG. 11 includes a rotating body control processing unit 210C, drivers 221B, 222B, and 223B, and FETs 231, 232, and 233.

  The drivers 221B, 222B, and 223B of the present embodiment output the duty of the PWM signal generated according to the PWM command value supplied from the rotating body control processing unit 210C to the rotating body control processing unit 210C as a PWM actual measurement value. More specifically, for example, it has a clock counter or the like, and outputs the duty of the PWM signal obtained from the counted number of clocks to the rotating body control processing unit 210C.

  The rotating body control processing unit 210 </ b> C has an acquisition unit that acquires the PWM actual measurement value, and uses the PWM actual measurement value acquired by the acquisition unit instead of the driving torque of the intermediate transfer motor 21.

  FIG. 12 is a diagram for explaining a motor control unit in the case where an actual torque value is used.

  A motor control unit 200D of the image forming apparatus 300D in FIG. 12 includes a rotating body control processing unit 210D, drivers 221, 222, and 223, and FETs 231, 232, and 233.

  In the image forming apparatus 300 </ b> D, the intermediate transfer motor 21 is provided with a torque meter 90 that measures the driving torque of the intermediate transfer motor 21. Torque meter 90 outputs the measured drive torque to rotating body control processing unit 210D. In the image forming apparatus 300 </ b> D, the secondary transfer motor 32 is provided with a torque meter 91 that measures the drive torque of the secondary transfer motor 32. Torque meter 91 outputs the measured drive torque to rotating body control processing unit 210D. In the image forming apparatus 300 </ b> D, the transport motor 42 is provided with a torque meter 92 that measures the drive torque of the transport motor 42. Torque meter 92 outputs the measured drive torque to rotating body control processing unit 210D.

  The rotating body control processing unit 210D includes an acquisition unit that acquires the drive torque measured by the torque meters 90 to 92, and uses the drive torque acquired by the acquisition unit instead of the estimated value of the drive torque of each motor.

  As described above, according to the present embodiment, another value can be used instead of the driving torque of each motor that drives the rotating body included in the transport path, so that an estimated value of the driving torque need not be calculated. Also gets better.

(Third embodiment)
The third embodiment will be described below with reference to the drawings. The third embodiment is an embodiment in which the first embodiment is applied to an ink jet image forming apparatus.

  FIG. 13 is a schematic view illustrating the internal configuration of an inkjet image forming apparatus according to the third embodiment.

  In the image forming apparatus 300 </ b> E of the present embodiment, the head units 450 </ b> C, 450 </ b> M, 450 </ b> Y, and 410 </ b> K eject ink droplets to form an image on the outer peripheral surface of the transfer belt 420.

  Then, the drying mechanism 470 dries the image formed on the transfer belt 420 to form a film.

  The image formed on the transfer belt 420 is transferred onto the paper P at the transfer portion where the transfer belt 420 faces the transfer roller 430.

  The cleaning roller 423 cleans the surface of the transfer belt 420 after transfer.

  In the image forming apparatus 300E shown in FIG. 13, head units 450C, 450M, 450Y, and 450K, a drying mechanism 470, a cleaning roller 423, and a transfer roller 430 are provided around the transfer belt 420.

  In this configuration, the transfer belt 420 is stretched over a drive roller 421, a counter roller 422, four shape maintaining rollers 424, four support rollers 425C, 425M, 425Y, 425K, and the like, and is rotated by a transfer belt drive motor 427. Following the drive roller 421, it rotates in the direction of the arrow in the figure.

  Four support rollers 425C, 425M, 425Y, and 425K provided to face the head units 450C, 450M, 450Y, and 450K maintain the tension state of the transfer belt 420 when ink droplets are ejected from the head units 450. . The transfer motor 431 drives the transfer roller 430 to rotate.

  In the present embodiment shown in FIG. 13, the opposing roller 422 moves the transfer belt 420 to perform the contact / separation operation with respect to the transfer roller 430.

  The opposing roller 422 is moved by the contact / separation motor 461. The control board 440 is a board that outputs drive signals to the transfer belt drive motor 427, the contact / separation motor 461, and the transfer motor 431.

  In FIG. 13, the opposing roller performs the contact / separation operation, but the transfer roller may perform the contact / separation operation with respect to the transfer belt.

  In addition, the control board 440 of the image forming apparatus 300E of the present embodiment includes a rotating body control processing unit 210, and the target value of the rotational speed of the rotating body included in the transport path H is the same as that of the first embodiment. Find by technique. The rotating bodies included in the transport path H are a drive roller 421, a counter roller 422, four shape maintaining rollers 424, four support rollers 425C, 425M, 425Y, 425K, and the like.

  Therefore, also in this embodiment, the interference torque in the transport path can be reduced as in the first embodiment.

  As mentioned above, although this invention has been demonstrated based on each embodiment, this invention is not limited to the requirements shown in the said embodiment. With respect to these points, the gist of the present invention can be changed without departing from the scope of the present invention, and can be appropriately determined according to the application form.

DESCRIPTION OF SYMBOLS 11 Intermediate transfer roller 21 Intermediate transfer motor 31 Secondary transfer roller 32 Secondary transfer motor 41 Conveying roller 42 Conveying motor 100 Conveying device 200, 200A to 200D Motor control unit 210, 210A to 210D Rotating body control processing unit 211 Condition setting unit 212 Paper passing detection unit 213 Speed change instruction unit 214 Torque estimation unit 215 Change rate calculation unit 216 Profile storage unit 217 Speed calculation unit 218 Storage control unit 219 Profile information 300, 300A to 300E Image forming apparatus 310 Main control unit 320 Operation unit 330 Memory

Japanese Patent No. 5621383

Claims (12)

A plurality of drive units for driving a plurality of rotating bodies that convey a medium to be conveyed;
A second rotating body adjacent to the first rotating body when the rotating speed of the first rotating body is changed with the predetermined rotating body as the first rotating body among the plurality of rotating bodies. A drive torque value of the drive unit to be rotationally driven or a change rate of a value proportional to the value of the drive torque is referred to a storage unit stored for each of the plurality of rotating bodies, and the plurality of drive units A drive torque value or a value having a proportional relationship with the drive torque value and the rate of change for each of the plurality of rotating bodies, a speed setting unit for setting the rotation speed of the plurality of drive units,
Rotating body control device. A paper-passing detection unit that detects that the transported medium is passing through the first rotating body and the second rotating body;
A speed change instruction unit that varies the rotational speed of the first rotating body,
The speed change instruction unit
Changing the rotational speed of the drive unit that drives the first rotating body so as to be a predetermined speed until the transported medium is sandwiched between the first rotating body and the second rotating body, The rotating body control device according to claim 1, wherein the rotating speed of the first rotating body is changed. A change rate calculation unit for calculating the change rate;
The rate of change calculation unit
Before changing the rotational speed of the first rotating body, the value of the driving torque of the driving unit that rotationally drives the second rotating body or the value having a proportional relationship with the value of the driving torque,
Calculated based on the value of the drive torque of the drive unit that rotationally drives the second rotary body after changing the rotational speed of the first rotary body or a value proportional to the value of the drive torque The rotating body control device according to claim 2, wherein The second rotating body is
Including at least one of a rotating body arranged on the upstream side of the first rotating body and a rotating body arranged on the downstream side of the first rotating body in the transport direction of the transported medium. The rotating body control device according to claim 2 or 3.   The variation width of the first rotating body is a width in which the value of the driving torque of the driving unit that rotationally drives the second rotating body due to the variation of the rotation speed or the change in the value of the driving torque is linear. The rotating body control device according to any one of claims 2 to 4. The speed setting unit
A speed calculation unit that calculates a rotation speed of the plurality of drive units;
The speed calculation unit is configured to determine a driving torque value of each of the plurality of driving units while the sheet passing detection unit detects that the transported medium is passing through the plurality of rotating bodies. 6. The rotating body control device according to claim 2, wherein the rotational speed is calculated so that a change in a value proportional to the value of the driving torque approaches 0. 7. The speed calculator is
The rotator according to claim 6, wherein the second rotator is designated so that the first rotator is located on the most upstream side or the most downstream side among the rotators that sandwich the transported medium. Control device.   The value proportional to the driving torque is at least one of a driving current of the plurality of driving units, a current command value supplied to the plurality of driving units, and a PWM command value supplied to the plurality of driving units. The rotating body control device according to claim 1, wherein the number is one. A transport device that transports a medium to be transported by a plurality of rotating bodies,
The plurality of rotating bodies;
A rotating body control device,
The rotating body control device includes:
A plurality of drive units for driving a plurality of rotating bodies that convey a medium to be conveyed;
A second rotating body adjacent to the first rotating body when the rotating speed of the first rotating body is changed with the predetermined rotating body as the first rotating body among the plurality of rotating bodies. A drive torque value of the drive unit to be rotationally driven or a change rate of a value proportional to the value of the drive torque is referred to a storage unit stored for each of the plurality of rotating bodies, and the plurality of drive units A drive torque value or a value having a proportional relationship with the drive torque value and the rate of change for each of the plurality of rotating bodies, a speed setting unit for setting the rotation speed of the plurality of drive units,
Conveying device having An image forming apparatus having a conveying device that conveys a sheet by a plurality of rotating bodies,
The transfer device
The plurality of rotating bodies, and a rotating body control device,
The rotating body control device includes:
A plurality of drive units for driving a plurality of rotating bodies that convey a medium to be conveyed;
A second rotating body adjacent to the first rotating body when the rotating speed of the first rotating body is changed with the predetermined rotating body as the first rotating body among the plurality of rotating bodies. A drive torque value of the drive unit to be rotationally driven or a change rate of a value proportional to the value of the drive torque is referred to a storage unit stored for each of the plurality of rotating bodies, and the plurality of drive units A drive torque value or a value having a proportional relationship with the drive torque value and the rate of change for each of the plurality of rotating bodies, a speed setting unit for setting the rotation speed of the plurality of drive units,
An image forming apparatus. A rotating body control method by a rotating body control device that transports a medium to be transported by a plurality of rotating bodies, the rotating body control device comprising
Driving the plurality of rotating bodies by a plurality of driving units;
A second rotating body adjacent to the first rotating body when the rotating speed of the first rotating body is changed with the predetermined rotating body as the first rotating body among the plurality of rotating bodies. A drive torque value of the drive unit to be rotationally driven or a change rate of a value proportional to the value of the drive torque is referred to a storage unit stored for each of the plurality of rotating bodies, and the plurality of drive units Rotating body control method for setting the rotational speed of the plurality of driving units based on the driving torque value or a value proportional to the driving torque value and the rate of change for each of the plurality of rotating bodies . A rotating body control program executed in a computer that transports a medium to be transported by a plurality of rotating bodies,
Driving the plurality of rotating bodies by a plurality of driving units;
A second rotating body adjacent to the first rotating body when the rotating speed of the first rotating body is changed with the predetermined rotating body as the first rotating body among the plurality of rotating bodies. A drive torque value of the drive unit to be rotationally driven or a change rate of a value proportional to the value of the drive torque is referred to a storage unit stored for each of the plurality of rotating bodies, and the plurality of drive units The processing for setting the rotational speeds of the plurality of drive units based on the drive torque value or the value proportional to the drive torque value and the rate of change for each of the plurality of rotating bodies Rotating body control program to be executed.

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