JP5264461B2 - Belt drive device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve position accuracy of an image transferred to recording paper by preventing meandering control from being not performed normally because a belt runs over a contact, and to prevent damage to the intermediate transfer belt. <P>SOLUTION: An image forming apparatus 1 is provided with: the contact 202 which abuts on an end section in the width direction of the intermediate transfer belt 8 and is displaced according to the position in the width direction of the intermediate transfer belt 8; and a displacement sensor 403 for detecting the position of the contact 202, wherein the position in the width direction of the intermediate transfer belt 8 is controlled based on the detection result by the displacement sensor 403. Furthermore, when the output of the displacement sensor 403 is not varied even when control is carried out for moving the intermediate transfer belt 8 in the width direction, it is determined that the intermediate transfer belt is running over the contact 202. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a belt driving device that drives a belt such as an intermediate transfer belt, a fixing belt, and a recording paper conveyance belt, and an image forming apparatus having the belt driving device.

  Conventional image forming apparatuses are provided with various types of belts such as an intermediate transfer belt, a fixing belt, and a recording paper conveyance belt.

  These belts are driven to rotate by being suspended by a plurality of rollers. During the belt rotation process, the belt moves toward one end or the other end in the width direction (hereinafter referred to as meandering). Tend to. Due to the meandering of the belt, the belt may fall off from the roller that is suspending the belt, or the end of the belt may be damaged.

  Therefore, there is an edge sensor that detects an edge position in the width direction of the belt, and based on the detection result of the edge sensor, there is an apparatus that corrects the meandering of the belt by controlling the tilting operation of the steering roller that supports the belt. (For example, refer to Patent Document 1).

This edge sensor has a contactor that contacts one end of the belt and a displacement sensor that detects a positional variation of the contactor, and continuously detects meandering of the belt.
JP 2000-034031 A

  In an image forming apparatus having such an edge sensor, when an operator replaces the belt, the belt is mounted in a state where the contact does not come into contact with the end of the belt, for example, a state where the belt rides on the contact. There was a case.

  FIG. 10 is a diagram for explaining a state where the belt rides on the contact of the edge sensor.

  As shown by the dotted line in FIG. 10A, the intermediate transfer belt 8 is supported by a steering roller 10, a belt driving roller 11, and a rotating roller 21, and is applied with an appropriate tension. As shown in FIG. 4A, a contact 202 for detecting the amount of movement of the intermediate transfer belt 8 in the width direction is pressed against the end of the intermediate transfer belt 8 with an appropriate force. .

  Here, when the operator replaces the intermediate transfer belt 8, the intermediate transfer belt 8 is loosened as shown by the solid line by moving the steering roller 10 in the direction of the arrow in FIG. It becomes easy to exchange. At this time, since the looseness of the intermediate transfer belt 8 is large, the end of the intermediate transfer belt 8 is detached from the contactor 202.

  After the replacement of the intermediate transfer belt 8, when the steering roller 10 is returned again to apply tension to the intermediate transfer belt 8, the operator retracts the contact 202 to the end side of the intermediate transfer belt 8. If this evacuation is not performed well, as shown in FIGS. 4B and 10B, the contact 202 does not contact the end of the intermediate transfer belt 8, and the intermediate transfer belt 8 does not contact the contact 202. It will be in the state of riding on the tip of.

  In this case, since the normal belt meandering control is not performed, the positional accuracy of the image transferred onto the recording paper is lowered, or the contact 202 and the intermediate transfer belt 8 are rubbed due to long-term use. There was a problem that was damaged.

  Accordingly, the present invention prevents the meandering control from being performed normally by the belt running on the contact, thereby improving the positional accuracy of the image transferred to the recording paper and preventing the belt from being damaged. For the purpose.

In order to achieve the above object, a belt driving device according to the present invention is supported by a plurality of rollers and rotates in a predetermined direction, abutting on an end of the belt in a width direction perpendicular to the predetermined direction, A contact that is displaced according to the position of the belt in the width direction, a sensor that detects the position of the contact, a shaft of any one of the plurality of rollers based on a detection result of the sensor Control means for controlling the position of the belt in the width direction by tilting , and storage means for storing edge profile data indicating the shape data of the end of the belt on the side that contacts the contact. and said control means is a data for correcting the edge profile data stored in the storage means, the widthwise position of the belt by inclining the axis of the roller That based on the steering data, the belt is characterized in that to determine whether the ride on the contactor.

The belt drive device according to the present invention is in contact with a belt that is supported by a plurality of rollers and that rotates and moves in a predetermined direction, and an end of the belt in a width direction orthogonal to the predetermined direction, and the width of the belt By tilting the axis of any one of the plurality of rollers based on a contact that is displaced according to the position of the direction, a sensor that detects the position of the contact, and a detection result of the sensor, Control means for controlling the position of the belt in the width direction; and storage means for storing edge profile data indicating shape data of an end portion of the belt on the side on which the contact is in contact. Is based on the edge profile data stored in the storage means and the edge data obtained from the output of the sensor during the rotational movement of the belt. Characterized by determining whether a ride on contact. An image forming apparatus according to the present invention includes the belt driving device and an image forming unit that forms an image on recording paper. The belt is an intermediate transfer belt, a fixing belt, or a recording paper conveyance belt. It is characterized by being.

  According to the present invention, it is possible to prevent the meandering control from being performed normally due to the belt running on the contact, to improve the positional accuracy of the image transferred to the recording paper, and to prevent the intermediate transfer belt from being damaged. be able to.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view illustrating an overall configuration of an image forming apparatus including a belt driving device.

  The image forming apparatus 1 is an electrophotographic full-color printer that forms an image on recording paper. The image forming apparatus 1 includes four photosensitive drums 2a to 2d, chargers 3a to 3d, cleaners 4a to 4d, laser scanning units 5a to 5d, transfer blades 6a to 6d, developing units 7a to 7d, and an intermediate transfer belt 8. And a cleaner 12 are provided. Further, the image forming apparatus 1 is provided with a steering roller 10 that supports the intermediate transfer belt 8 and a belt driving roller 11 that rotates and moves the intermediate transfer belt 8 in a predetermined direction.

  A plurality of recording sheets S set on the manual feed tray 13 are separated into a single sheet by a pickup roller 14 and a separation roller 15 and fed. On the other hand, a plurality of recording sheets S stored in the sheet feeding cassette 17 are separated and fed by a pickup roller 18 and a separation roller 19 and then conveyed by a vertical path roller 20.

  The fed recording sheet S is conveyed to the secondary transfer roller 22 while the registration roller 16 sets the registration timing. Here, the rollers 14, 15, 16, 18, 19, and 20 for transporting the recording paper S are each driven by an independent stepping motor in order to realize a high-speed and stable transport operation.

  On the other hand, the chargers 3a to 3d uniformly charge the surfaces of the photosensitive drums 2a to 2d. Each of the laser scanning units 5a to 5d using the semiconductor laser as a light source irradiates the photosensitive drums 2a to 2d of the respective colors with lasers, thereby forming electrostatic latent images on the surfaces of the respective photosensitive drums 2a to 2d. . The developing devices 7a to 7d develop the electrostatic latent image as a toner image.

  Next, the transfer blades 6 a to 6 d transfer the color toner images developed on the photosensitive drums 2 a to 2 d to the intermediate transfer belt 8. The toner image on the intermediate transfer belt 8 is transferred to the recording paper at the nip portion between the rotating roller 21 and the secondary transfer roller 22. Then, heat is applied to the toner image transferred onto the recording paper by the fixing device 23 having a heating roller, and the toner image is fixed onto the recording paper.

  In double-sided printing, the recording paper S that has passed through the fixing unit 23 is guided in the direction of the double-sided reversing path 27 and then conveyed in the reverse direction so that the front and back are reversed and conveyed to the double-sided path 28. The recording paper S that has passed through the double-sided path 28 is conveyed again by the vertical path roller 20, forms an image on the second side as with the first side, and is discharged to the paper discharge tray 25 by the paper discharge roller 24.

  FIG. 2 is a diagram showing a schematic configuration for explaining the meandering correction control of the intermediate transfer belt 8.

  The belt driving motor 210 rotationally drives the belt driving roller 11 in order to convey the intermediate transfer belt 8 in the arrow direction shown in FIG. The steering roller 10 is a roller for correcting movement variation (meandering) in the width direction of the intermediate transfer belt 8. A belt HP sensor 205 and an edge sensor 203 are disposed downstream of the steering roller 10 in the belt conveyance direction.

  The belt HP sensor 205 detects a home position mark 204 attached to the back surface of the intermediate transfer belt 8 and generates a belt position reference signal (HP signal). The edge sensor 203 detects the amount of movement (displacement) of the contact 202 arranged so as to contact the end (edge) of the intermediate transfer belt 8 and outputs an output signal corresponding to the meandering of the intermediate transfer belt 8. Occur.

  A position variation in the width direction of the intermediate transfer belt 8 can be detected according to the detection result of the edge sensor 203, and the tilting operation of the steering roller 10 is controlled based on the position variation. Thereby, the meandering of the intermediate transfer belt 8 can be corrected.

  As the belt drive motor 210 and the steering motor 209, a stepping motor capable of controlling the rotation angle and rotation speed with high accuracy is used.

  FIG. 3 is a diagram for explaining the principle of meandering correction of the intermediate transfer belt.

  From the left of this figure, a front view of the eccentric cam 208, a side view of the eccentric cam 208 and the steering roller 10, and a front view of the steering roller 10 are shown.

  As shown in FIG. 3A, in the state where the eccentric cam 208 stops at a predetermined angle and the steering roller 10 is held substantially horizontal (tilt is almost zero) corresponding to the stop angle, the basic operation is basically performed. The intermediate transfer belt 8 does not move (meander) in the width direction.

  3B, when the eccentric cam 208 is rotated by driving the steering motor 209, the swing arm 206 swings in the θ1 direction according to the amount of eccentricity of the eccentric cam 208. Thereby, since one end of the steering roller 10 is lifted by the swing arm 206, the steering roller 10 is inclined according to the lift amount. At this time, the intermediate transfer belt 8 wound around the steering roller 10 moves to the roller end side lifted by the swing arm 206.

  On the other hand, as shown in FIG. 3C, when the eccentric cam 208 is rotated by driving the steering motor 209, the swing arm 206 swings in the θ2 direction according to the amount of eccentricity of the eccentric cam 208. . Thereby, since one end of the steering roller 10 is pushed down by the swing arm 206, the steering roller 10 is inclined according to the amount of the push-down. At this time, the intermediate transfer belt 8 wound around the steering roller 10 moves to the side opposite to the roller end pushed down by the swing arm 206.

  Therefore, the position variation in the width direction of the intermediate transfer belt 8 is continuously detected by the edge sensor 203, and the tilting operation of the steering roller 10 is controlled based on the detection result, whereby the meandering of the intermediate transfer belt 8 is performed. Can be corrected.

  FIG. 4 is a diagram illustrating a specific configuration of the edge sensor.

  Here, FIG. 4A shows a state in which the contact 202 is normally pressed against the end of the intermediate transfer belt 8. FIG. 4B shows a state in which the intermediate transfer belt 8 rides on the contact 202 without the contact 202 being pressed against the end of the intermediate transfer belt 8.

  As shown in FIG. 4A, one end of the contactor 202 is held in pressure contact with the end of the intermediate transfer belt 8 by receiving a pulling force from the spring 401. The pressing force of the contactor 202 by the spring 401 is set to an appropriate magnitude so as not to deform the intermediate transfer belt 8.

  Further, the intermediate portion of the contactor 202 is rotatably supported by the support shaft 402. The displacement sensor 403 is disposed to face the other end side of the contactor 202. The displacement sensor 403 is an optical sensor that irradiates the contactor 202 light, receives light reflected from the contactor 202, and detects the displacement of the contactor 202 according to the amount of received light.

  The edge sensor 203 replaces the movement amount in the width direction orthogonal to the traveling direction of the intermediate transfer belt 8 with the movement of the contactor 202 that presses against the end of the intermediate transfer belt 8. At this time, since the output level of the displacement sensor 403 varies according to the displacement of the contactor 202, the position variation of the end portion of the intermediate transfer belt 8 can be continuously detected based on the sensor output.

  On the other hand, as shown in FIG. 4B, when the contact 202 does not contact the end of the intermediate transfer belt 8 and the intermediate transfer belt 8 rides on the contact 202, the edge sensor 203 operates as the intermediate transfer belt. 8 position variation cannot be detected accurately.

  As in the example of this figure, the contactor 202 remains at an appropriate position where the output of the displacement sensor 403 indicates a normal value. This is because the intermediate transfer belt 8 is supported by the steering roller 10, the belt driving roller 11, and the rotating roller 21 with an appropriate tension, so that the force causes the force from the tip of the contactor 202 toward the support shaft 402. Because it is added.

  In this riding state, the edge sensor 203 cannot detect an abnormality, and the intermediate transfer belt 8 continues to be driven as usual.

  FIG. 5 is a control block diagram of the image forming apparatus.

  The control unit 501 includes a CPU 502, a ROM 503, and a RAM 504. The CPU 502 is a control circuit that controls the entire image forming apparatus 1. The ROM 503 stores a control program for controlling various processes executed by the image forming apparatus 1.

  A RAM 504 is a system work memory for the CPU 502 to operate, and also functions as an image memory for temporarily storing image data. A hard disk drive (HDD) 505 stores data such as system software and image data.

  In the HDD 505, the edge profile data P inherent to the intermediate transfer belt 8 is stored in order based on the position of the home position mark 204 in advance. The edge profile data P indicates the shape data of the end of the intermediate transfer belt 8 on the side where the contact 202 abuts.

  In the control unit 501, the CPU 502 accesses the HDD 505 and reads the edge profile data P based on the HP signal input from the belt HP sensor 205. Reading of the profile data P is sequentially performed at predetermined intervals.

  Further, the CPU 502 takes in the edge data E from the edge sensor 203 at the same interval as the edge profile data P based on the HP signal input from the belt HP sensor 205 during the rotational movement of the intermediate transfer belt 8. Then, the CPU 502 calculates a position change amount (hereinafter referred to as a displacement) corresponding to the meandering amount of the intermediate transfer belt 8 from the edge profile data P read sequentially and the edge data E taken in.

  Further, the CPU 502 outputs a steering control signal including a driving direction and a driving amount to the steering motor 209 so as to reduce meandering according to the calculated displacement of the intermediate transfer belt 8, thereby driving the steering motor 209. Further, the CPU 502 stores steering data S corresponding to the displacement of the intermediate transfer belt 8 in the RAM 504.

  The CPU 502 acquires the edge profile data P and the steering data S after a predetermined time in response to the input of the HP signal from the belt HP sensor 205, and performs a predetermined calculation using the edge profile data P and the steering data S. I do. The CPU 502 stores operation data in the RAM 504. This calculation and storage in the RAM 504 are sequentially performed at a predetermined interval similar to the interval at which the edge profile data P is read.

  When a new HP signal is input, the CPU 502 retrieves and calculates the calculation data for one rotation of the intermediate transfer belt 8 stored in the RAM 504, and determines whether the intermediate transfer belt 8 is riding on the contact 202. To do.

  In the case where it is running, the CPU 502 outputs a riding signal for the intermediate transfer belt 8 to the display unit 506. When the ride-up signal is input, the display unit 506 displays information indicating the belt ride-up to the user.

  FIG. 6 is a diagram for explaining belt riding detection according to the first embodiment.

  FIG. 6A shows the meandering correction characteristic when the edge of the intermediate transfer belt 8 is normally pressed against the contact 202 as shown in FIG. 4A. FIG. 6B shows meandering correction characteristics when the intermediate transfer belt 8 rides on the contactor 202 as shown in FIG. 4B.

  First, the meandering correction characteristic at normal time will be described. The upper part of FIG. 6A shows the characteristics of the edge profile data P for one turn of the intermediate transfer belt 8. The edge profile data P is unique edge shape data different for each intermediate transfer belt 8, and the shape data is measured in advance and stored in the HDD 505.

  When the meandering control is started simultaneously with the start of the driving of the intermediate transfer belt 8, the CPU 502 reads the edge profile data P from the HDD 505 in synchronization with the belt HP mark, and simultaneously acquires the edge data E from the edge sensor 203. The CPU 502 calculates a movement amount H (hereinafter referred to as displacement) of the intermediate transfer belt 8 from the edge profile data P and the edge data E. Here, the displacement H is represented by H = PE.

  Further, the CPU 502 calculates steering data S. The steering data S is expressed by S = α · H using the calculated displacement H. Here, α is a meandering correction gain for the belt displacement and is constant.

  The CPU 502 calculates a difference θn−θo between the eccentric cam rotational position θn corresponding to the calculated steering data S and the current cam rotational position θo (corresponding to the previously calculated steering data S). Then, the CPU 502 outputs a steering control signal to the steering motor 209 so as to rotate the eccentric cam 208 by θn−θo. In response to this, the steering motor 209 is controlled, the swing arm 206 moves in a direction in which the displacement H of the intermediate transfer belt 8 becomes 0, and the steering roller 10 tilts.

  By repeatedly controlling the steering motor 209 as described above at predetermined intervals, the displacement of the intermediate transfer belt 8 converges to zero. Finally, the edge data E has the characteristics shown in the middle part of FIG. 6A, and the steering data S has the characteristics shown in the lower part of FIG. 6A.

  Next, the meandering correction characteristic at the time of riding on the belt will be described. Acquisition of the edge profile data P and edge data E, calculation of the steering control signal, and control of the steering motor 209 are the same as in the normal state of FIG.

  The characteristics of the edge profile data P in the upper part of FIG. 6B are the same as the characteristics at the normal time, and are data stored in the HDD 505 in advance. When the belt is ridden, the characteristics of the middle edge data E in FIG. 6B and the lower steering data S in FIG. 6B are different from those in the normal state in FIG. 6A.

  When the belt rides on, the edge sensor 203 cannot accurately detect the edge of the intermediate transfer belt 8 and receives a force in the length direction of the contact 202 by the tension applied to the intermediate transfer belt 8. The movement of the flag centering on is restricted. Therefore, the amount of change in the edge data E is smaller than that in the normal state as shown in the middle part of FIG. The steering data S, on the other hand, has a larger amount of change than normal and has the same characteristics as the edge profile data P.

  FIG. 7 is a flowchart for explaining meandering correction control according to the first embodiment.

  A program for executing this flowchart is stored in the ROM 503 and is executed by being read by the CPU 502.

  First, the CPU 502 determines whether or not a belt HP signal is input from the belt HP sensor 205 (S701). When the belt HP signal is input, the CPU 502 initializes the address X to 1 (S702). On the other hand, when the belt HP signal is not input, the address X is not initialized.

Then, CPU 502 obtains edge data _{E X} corresponding to the address X from the edge sensor 203 (S703). Further, CPU 502 obtains an edge profile data _{P X} corresponding to the address X from HDD 505 (S704).

Based on the edge data E _X and the edge profile data P _X obtained here, the CPU 502 calculates steering data S _X (S705). Specifically, CPU 502 is a displacement _{H X} of the intermediate transfer belt 8 after having determined by equation _{H X =} P X -E X, the steering data _{S X} by equation _{S X} = _α · _{H X} Ask.

Then, the CPU 502 drives the steering motor 209 based on the calculated steering data S _X (S706). Specifically, the CPU 502 calculates the difference θn between the eccentric cam rotation position θn corresponding to the calculated steering data S _X and the current cam rotation position θo (the eccentric cam rotation position corresponding to the steering data S _X-1 ). -Θo is calculated. Then, the CPU 502 outputs a steering control signal to the steering motor 209 so as to rotate the eccentric cam 208 by θn−θo. In response to this, the steering motor 209 is controlled, the swing arm 206 moves in a direction in which the displacement H of the intermediate transfer belt 8 becomes 0, and the steering roller 10 tilts.

  Thereafter, the CPU 502 determines whether to stop meandering correction control when the image forming operation is finished (S707). When the meandering correction control is not stopped, the CPU 502 adds 1 to the address X (S708).

  Then, after waiting for the belt drive motor 210, which is a stepping motor, to rotate a predetermined number of steps (S709), the process returns to the above-described step S701. That is, the above control is repeated every time the belt drive motor 210 rotates a predetermined number of steps. On the other hand, when stopping the meandering correction control, the CPU 502 ends this control flow.

  FIG. 8 is a flowchart for explaining the belt running detection operation according to the first embodiment.

  A program for executing this flowchart is stored in the ROM 503 and is executed by being read by the CPU 502. This control flow is executed when there is a possibility that the intermediate transfer belt 8 gets on the contactor 202, such as when the intermediate transfer belt 8 is replaced.

  First, the CPU 502 determines whether or not a belt HP signal is input from the belt HP sensor 205 (S801). When the belt HP signal is input, the CPU 502 initializes the address X to 1 (S802). On the other hand, when the belt HP signal is not input, the address X is not initialized.

  Next, the CPU 502 determines whether the address X has reached 100 (S803). In order to sample a predetermined number (100 in this embodiment) of data, it is determined whether or not the predetermined number has been reached.

If the address X has not reached 100, CPU 502 obtains edge data _{E X} corresponding to the address X from the edge sensor 203 (S804). Further, CPU 502 obtains an edge profile data _{P X} corresponding to the address X from HDD 505 (S805).

Based on the edge data E _X and the edge profile data P _X obtained here, the CPU 502 calculates steering data S _X (S806). Since the specific calculation method has been described in step S705 described above, a description thereof will be omitted. Further, the CPU 502 drives the steering motor 209 based on the calculated steering data S _X (S807). Since the specific driving method has been described in step S706, the description thereof will be omitted.

Then, the CPU 502 calculates a ratio W _X between the steering data S _X and the edge profile data P _X (S808). Specifically, the ratio W _X is calculated by the following mathematical formula.

  Thereafter, the CPU 502 adds 1 to the address X (S809), and returns to the above-described step S801.

On the other hand, in step S803, if the address X is judged to have reached the 100, CPU 502 calculates the _{S AVE} is the average value of the absolute value of the steering data _{S X} (S810). The average value _SAVE represents the control accuracy of meandering correction, and the larger the average value _{SAVE, the} lower the control accuracy. Specifically, the average value _SAVE is calculated by the following mathematical formula.

Further, the CPU 502 calculates a deviation ε of the ratio W _X (S811). Deviation epsilon, represents the proportion of the edge profile data P _X and steering data S _X, indicating that strong proportional relationship as deviation epsilon is small. Specifically, the deviation ε of the ratio W _X is calculated by the following mathematical formula.

Next, the CPU 502 determines whether the contact 202 is not in contact with the end of the intermediate transfer belt 8 based on the calculated average value _SAVE and deviation ε, that is, the intermediate transfer belt 8 runs on the contact 202. It is determined whether or not (S812).

Here, when the intermediate transfer belt 8 rides on the contact 202, the fluctuation of the steering data S _X becomes large, so the average value S _AVE of the absolute value of the steering data S _X becomes a large value. On the other hand, since the edge profile data P _X and the steering data S _X have similar characteristics, the deviation ε of the ratio W _X is a small value. Therefore, for example, when S _AVE ≧ 3 and ε ≦ 0.3, the CPU 502 determines that the intermediate transfer belt 8 is riding on the contactor 202.

  If it is determined that the intermediate transfer belt 8 is riding on the contactor 202, the CPU 502 displays a message indicating that the intermediate transfer belt 8 is riding on the display unit 506 (S813), and ends this flow. To do.

  If it is determined in step S812 that the intermediate transfer belt 8 is not on the contactor 202, the CPU 502 ends this flow without displaying a message on the display unit 506.

  As described above, according to the present embodiment, the meandering control is normally performed when the intermediate transfer belt 8 rides on the contact 202 by notifying the user that the intermediate transfer belt 8 has been run and prompting maintenance. It can be prevented from being broken. As a result, it is possible to improve the positional accuracy of the image transferred to the recording paper and prevent the intermediate transfer belt from being damaged.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to the drawings.

In the first embodiment, the run-up detection of the intermediate transfer belt 8, had performed using the steering data S _X and the edge profile data P _X, in the second embodiment, the edge data E _X and edge profile data carried out using the P _X. In addition, the same code | symbol is attached | subjected to the member which is the same thru | or equivalent to 1st Embodiment, and the description shall be abbreviate | omitted.

  FIG. 9 is a flowchart for explaining a belt riding detection operation according to the second embodiment.

  A program for executing this flowchart is stored in the ROM 503 and is executed by being read by the CPU 502. This control flow is executed when there is a possibility that the intermediate transfer belt 8 gets on the contactor 202, such as when the intermediate transfer belt 8 is replaced.

In the second embodiment, instead of calculating the ratio W _X steering data S _X and the edge profile data P _X, and calculates the ratio Tx of the edge data E _X and edge profile data P _X. Steps S901 to S907 are the same as steps S801 to S807 described above, and a description thereof is omitted.

CPU502 After acquiring the edge data _{E X} and edge profile data _{P X,} calculates the ratio Tx of the edge data _{E X} and edge profile data _{P X} (S908). Specifically, the ratio Tx is calculated by the following mathematical formula.

  Thereafter, the CPU 502 adds 1 to the address X (S909), and returns to step S901.

On the other hand, if it is determined in step S903 that the address X has reached 100, the CPU ₅₀₂ calculates T _XAVE that is an average value of the ratio Tx (S910). The average value T _XAVE represents the reproducibility of the edge profile. The smaller the average value T _XAVE , the lower the reproducibility of the edge profile, and the meandering correction is not performed normally or the contact 202 is subject to restrictions. The case where it cannot move well is shown. Specifically, the average value T _XAVE is calculated by the following mathematical formula.

Further, CPU 502 calculates the deviation ε of the ratio _{T X} (S911). Deviation epsilon, represents the proportion of the edge profile data P _X and the edge data E _X, indicating that strong proportional relationship as deviation epsilon is small. Specifically, it calculates the deviation ε of the ratio T _X by the following equation.

Next, CPU 502, based on the ratio T _X and deviation ε the calculated whether the contactor 202 is not in contact with the end portion of the intermediate transfer belt 8, i.e., the intermediate transfer belt 8 is riding the contactor 202 It is determined whether or not (S912).

Here, when the intermediate transfer belt 8 is riding the contactor 202, since the spite edge data E _X is less variation no variation in the steering data S _X increases, the average value of the ratio Tx A certain T _XAVE is a large value. On the other hand, since the edge profile data P _X and the edge data E _X have different characteristics, the deviation ε of the ratio T _X is a small value. Therefore, for example, when T _XAVE ≦ 0.5 and ε ≧ 0.3, the CPU 502 determines that the intermediate transfer belt 8 is riding on the contactor 202.

  Since subsequent steps S912 to S913 are the same as steps S812 to S813 described above, description thereof will be omitted.

  As described above, according to the second embodiment, the same effect as that of the first embodiment can be obtained.

  In the above description, the intermediate transfer belt is described as an example of the belt, but is not limited thereto. For example, the present invention may be applied to meandering correction control and belt running detection operation of a fixing belt, a recording paper conveyance belt, and the like.

  In the above description, the method for notifying the belt riding state has been described by taking a message on the display unit as an example, but is not limited thereto. For example, the user may be notified by voice.

1 is a cross-sectional view illustrating an overall configuration of an image forming apparatus including a belt driving device. It is a figure which shows schematic structure for demonstrating the meandering correction | amendment control of an intermediate transfer belt. FIG. 6 is a diagram for explaining the principle of meandering correction of an intermediate transfer belt. It is a figure which shows the specific structure of an edge sensor. 2 is a control block diagram of the image forming apparatus. FIG. It is a figure for demonstrating the belt climbing detection which concerns on 1st Embodiment. It is a flowchart explaining the meandering correction control which concerns on 1st Embodiment. It is a flowchart explaining the belt climbing detection operation | movement which concerns on 1st Embodiment. It is a flowchart explaining meandering correction control concerning a 2nd embodiment. It is a figure for demonstrating the riding state of the belt to the contactor of an edge sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 8 Intermediate transfer belt 10 Steering roller 11 Belt drive roller 202 Contact 203 Edge sensor 205 Belt HP sensor 209 Steering motor 210 Belt drive motor 403 Displacement sensor 501 Control unit 502 CPU
503 ROM
504 RAM
505 HDD
506 Display

Claims (6)

A belt supported by a plurality of rollers and rotating in a predetermined direction;
A contact that abuts against an end of the belt in the width direction perpendicular to the predetermined direction and is displaced according to the position of the belt in the width direction;
A sensor for detecting the position of the contact;
Control means for controlling the position of the belt in the width direction by tilting the axis of any one of the plurality of rollers based on the detection result of the sensor ;
Storage means for storing edge profile data indicating shape data of an end portion of the belt on which the contact is in contact ;
Based on the edge profile data stored in the storage means and steering data which is data for correcting the position of the belt in the width direction by tilting the axis of the roller , the control means It is judged whether it has got on the said contactor, The belt drive device characterized by the above-mentioned. The control means performs a predetermined number of samplings of the steering data while rotating the belt, calculates an average value of absolute values of the predetermined number of the steering data, and calculates the steering data and the edge profile data. calculating a ratio deviation, calculated on the basis average value to said deviation, belt driving device according to claim 1, wherein said belt is characterized in that to determine whether the ride on the contactor. A belt supported by a plurality of rollers and rotating in a predetermined direction;
A contact that abuts against an end of the belt in the width direction perpendicular to the predetermined direction and is displaced according to the position of the belt in the width direction;
A sensor for detecting the position of the contact;
Control means for controlling the position of the belt in the width direction by tilting the axis of any one of the plurality of rollers based on the detection result of the sensor;
Anda storage means for the contactor of the belt for storing edge profile data indicating the shape data of the end portion of the abutting side,
The control means determines whether or not the belt is riding on the contact based on the edge profile data stored in the storage means and edge data obtained from the output of the sensor during the rotational movement of the belt. features and be behenate belt driving device to determine. The control means performs a predetermined number of samplings of the edge data while rotationally driving the belt, calculates an average value of a ratio of the predetermined number of the edge data and the edge profile data, and deviation of the average value 4. The belt driving apparatus according to claim 3 , wherein the belt driving device is configured to determine whether the belt is riding on the contact based on the calculated average value and the deviation. 5. The belt driving device according to claim 1, further comprising notification means for notifying a user to that effect when the control means determines that the belt is riding on the contact. A belt driving device according to any one of claims 1 to 5 ;
Image forming means for forming an image on a recording paper,
The image forming apparatus, wherein the belt is an intermediate transfer belt, a fixing belt, or a recording paper conveyance belt.

Images