JP2007163695A - Belt conveying device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a choice between speedy movement and highly accurate movement as necessary when moving a belt member in its widthwise direction. <P>SOLUTION: The image forming apparatus 100 includes a belt conveying device 10. The belt conveying device 10 has a first adjustment mechanism 14 and a second adjustment mechanism 15. By operating the first and second adjustment mechanisms 14 and 15, the position of a paper conveying belt 11 in its widthwise direction (the direction of x-axis) is adjusted. To speedily move the paper conveying belt 11, the belt conveying device 10 moves one end of a steering roll in the direction of y-axis by using the first adjustment mechanism 14. To correctly move the paper conveying belt 11, the belt conveying device 10 moves the one end of the steering roll in the direction of z-axis by using the second adjustment mechanism 15. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to conveyance control of an endless belt member, and more particularly to a technique for moving a belt member in the width direction.

There is known an image forming apparatus that uses an endless belt member as a sheet conveying member or an intermediate transfer member. In this type of image forming apparatus, the belt member may change its position in the width direction due to manufacturing errors such as the belt member and the transport roll. Such positional fluctuations cause color misregistration and must be corrected (see, for example, Patent Documents 1 and 2). In order to satisfactorily suppress color misregistration, it is desirable to perform position correction with high accuracy, that is, position correction with little position fluctuation per unit time.
Japanese Patent Laid-Open No. 9-110228 Japanese Patent Laid-Open No. 2004-211986

  On the other hand, for example, when the belt member is removed or attached along with the setup, the belt member needs to be moved largely in the width direction. In such a case, if the belt member is moved in the same manner as the position correction with little position fluctuation per unit time as described above, the time required for removal and removal increases more than necessary. It is inconvenient. In the technique described in Patent Document 2, attempts are made to eliminate the above-described disadvantages by changing parameters such as a correction cycle and a correction coefficient depending on the situation. However, since the technique described in Patent Document 2 has no difference in the method of moving the belt member itself, there is a problem in that a significant difference cannot be found in the correction accuracy and the required time even if the parameters are changed. is there.

  The present invention has been made in view of such circumstances, and an object thereof is to selectively perform rapid movement and high-precision movement as necessary when the belt member is moved in the width direction. It is to provide a technology that makes this possible.

  In order to achieve the above object, the present invention provides an endless belt member having a predetermined width and a plurality of roll members that stretch the belt member at different positions, respectively, in the width direction of the belt member. A plurality of roll members rotated about an extending shaft, at least one of the roll members, a driving means for rotating the belt member in a direction orthogonal to the width direction, and a plurality of the roll members. 1st adjustment means which adjusts the attitude | position of any one of these roll members, Comprising: One end of the axis | shaft of the said roll member is moved relatively to the 1st direction orthogonal to the said width direction with respect to the other end First adjusting means to be adjusted and second adjusting means for adjusting the posture of any one of the plurality of roll members, wherein one end of the shaft of the roll member is Different from the first direction And a belt position control means for operating the first or second adjusting means while operating the driving means, and a second adjusting means for relatively moving in a second direction orthogonal to the width direction. A belt conveyance device comprising: According to such a belt conveyance device, the position adjustment mode of the belt member can be made different between the first adjustment unit and the second adjustment unit.

In the belt conveyance device, the first direction is a direction substantially parallel to a direction of a tension applied to the belt member by a roll member whose posture is adjusted by the first adjusting unit. The direction is preferably a direction substantially orthogonal to the direction of tension applied to the belt member by the roll member whose posture is adjusted by the second adjusting means. In this way, the first adjusting means can quickly adjust the position of the belt member, and the second adjusting means can adjust the position of the belt member with high accuracy.
In this case, when operating the first adjusting means, it is more desirable to configure the belt member to move at a higher speed than when operating the second adjusting means.

The belt conveying device further includes a detecting unit that detects whether or not the belt member is at a predetermined position in the width direction, and the belt position control unit includes the belt member at the predetermined position. It is also possible to adopt a configuration in which the first or second adjusting means is operated when the detecting means detects that there is no.
Alternatively, it is possible to provide an input means for the user to input an instruction, and the belt position control means can operate the first or second adjusting means in accordance with the instruction input to the input means. is there.

  Moreover, in this belt conveying apparatus, the roll member from which the 1st adjustment means adjusts an attitude | position and the roll member from which the said 2nd adjustment means adjusts an attitude | position may be different. With such a configuration, posture control of each roll member can be facilitated.

  In this belt conveyance device, the roll member whose first adjusting means adjusts the posture and the roll member whose second adjusting means adjusts the posture may be the same roll member. In this case, the first adjustment unit may move the position of one end of the roll member, and the second adjustment unit may move the position of the other end of the roll member. If it does in this way, an adjustment means can be collected on one roll member.

  The roll member whose posture is adjusted by the first adjusting means is preferably a tension roll. Further, it may be configured to include a prohibiting unit that prohibits the operation of the other adjusting unit when either the first or second adjusting unit is operating. If it does in this way, control when a posture is adjusted and a roll member inclines can be made easy.

  The present invention is not limited to the belt conveyance device described above, and can also be specified as an image forming apparatus provided with this belt conveyance device.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, as one embodiment of the present invention, an electrophotographic image forming apparatus using a paper conveyance belt will be described with two types of embodiments. However, the following description is not intended to limit the implementation of the present invention to such an embodiment.

[1. First Embodiment]
FIG. 1 is a diagram illustrating a configuration of a main part of an image forming apparatus 100 according to the first embodiment of the present invention. In the figure, the right direction of the paper surface is defined as the positive direction of the y axis, the upward direction of the paper surface is defined as the positive direction of the z axis, and the direction from the back to the front of the paper surface is defined as the positive direction of the x axis. In the same figure, the arrow indicated by the broken line indicates the conveyance path of the recording paper.

  The configuration of the image forming apparatus 100 shown in the figure is roughly divided into a belt conveying device 10, a print engine 20, and a fixing device 30. The print engine 20 includes yellow, magenta, cyan, and black color print engines. These print engines further include a photosensitive drum, a charger, an exposure device, a developing device, and a transfer roll. The print engine 20 executes a known electrophotographic transfer process to transfer a toner image onto a recording sheet. The fixing device 30 heats and pressurizes the recording paper on which the toner image is transferred, and fixes the toner image on the recording paper.

  Next, the configuration of the belt conveyance device 10 will be described. The belt conveyance device 10 includes a paper conveyance belt 11, a plurality of support rolls 12a, 12b, 12c, and 12d, a position sensor 13, a first adjustment mechanism 14, and a second adjustment mechanism 15. The paper transport belt 11 is an endless belt member having a predetermined width, and is stretched between the plurality of support rolls 12a to 12d, the first adjustment mechanism 14 and the second adjustment mechanism 15 to maintain an appropriate tension. ing. The support rolls 12a to 12d are roll members that stretch the paper transport belt 11, and are provided so as to be rotatable about an axis extending in the x direction.

  The position sensor 13 is an optical sensor, and emits a signal for determining the presence or absence of the paper transport belt 11 by optically detecting the paper transport belt 11 at a predetermined position. As shown in FIG. 2, the position sensor 13 of the present embodiment includes a sensor 131 and a sensor 132 and is configured to detect the paper transport belt 11 at positions corresponding to both ends of the paper transport belt 11. If the position of the paper transport belt 11 is within an allowable range, both sensors detect the presence of the paper transport belt 11. In the present embodiment, the position sensor 13 is “0” when the sensors 131 and 132 detect the paper transport belt 11, “1” when only the sensor 131 detects the paper transport belt 11, and only the sensor 132. Is configured to emit a signal indicating “2” when the paper transport belt 11 is detected. For convenience of explanation, the position when the paper transport belt 11 is within the allowable range is hereinafter referred to as “fixed position”. That is, when the position sensor 13 issues a signal “0”, the paper transport belt 11 is in a fixed position.

  Note that at least one of the support rolls 12 a to 12 d has a function as a drive roll that is driven by a drive unit such as a motor (not shown) to rotate the paper transport belt 11. The drive roll moves the paper transport belt 11 in a direction orthogonal to the width direction thereof, that is, in the direction of arrow R in the figure. In addition, since it is arbitrary which support roll is made into a drive roll, this is called the "drive roll 12" for convenience of explanation below. The other support rolls are not directly driven by the drive unit, but are rotated by the movement of the sheet conveying belt 11 accompanying the rotation of the drive roll 12.

  Further, at least one of the support rolls 12a to 12d has a function as a tension roll. The tension roll is a roll member for applying an appropriate tension to the paper transport belt 11, and this tension roll biases the paper transport belt 11 in a direction in which a tension is applied to the paper transport belt 11. An example of a tension roll is shown in FIG. As shown in the figure, the tension roll 16 includes a roll member 161, a shaft 161 a, and urging members 162 and 163, and the urging members 162 and 163 are at the rotation center of the roll member 161. Is biased in the direction of arrow A in the figure.

  Next, the configuration of the first adjustment mechanism 14 will be described with reference to FIGS. 4 and 5. 4 is a view showing the first adjustment mechanism 14 from the positive direction of the x-axis, and FIG. 5 is a view showing the first adjustment mechanism 14 from the positive direction of the z-axis. The first adjustment mechanism 14 includes a steering roll 141, a motor 142, a shaft 143, and a bearing 144. The steering roll 141 is a roll member having a width equal to or greater than that of the paper transport belt 11 in the x-axis direction, and has a shaft 141a at the center thereof. The motor 142 is given a driving force to rotate the shaft 143. The motor 142 is preferably a servo motor or a stepping motor. The shaft 143 is a rod-shaped member in which a thread is formed, and corresponds to a male screw (male screw). The bearing 144 has a hole through which the shaft 143 passes, and a thread corresponding to a female thread (female thread) is formed on the inner wall of the hole.

  When the motor 142 rotates in the first adjusting mechanism 14, the screw threads formed on the shaft 143 and the bearing 144 convert this rotational motion into a reciprocating motion in the y-axis direction. As a result, one end of the steering roll 141 moves in the positive or negative direction of the y-axis. As shown in FIG. 5, the shaft 141a reciprocates only at one end, and the other end is fixed so as to perform only rotational motion.

  Next, the configuration of the second adjustment mechanism 15 will be described with reference to FIGS. 6 is a view showing the second adjustment mechanism 15 from the positive direction of the y-axis, and FIGS. 7 and 8 are views showing the second adjustment mechanism 15 from the positive direction of the z-axis. The second adjustment mechanism 15 includes a steering roll 151, a motor 152, an eccentric cam 153, an arm 154, and an urging member 155. The steering roll 151 is a roll member similar to the steering roll 141, and has a shaft 151a at the center thereof. The motor 152 is given a driving force to rotate the shaft 152a. The motor 152 is preferably a servo motor or a stepping motor. The eccentric cam 153 is an elliptical cam member fixed to the shaft 152a, and rotates with the shaft 152a about the shaft 152a. The arm 154 is a rod-like member having one end in contact with the eccentric cam 153 and the other end attached to the shaft 151a. The arm 154 has a pivot 154p at the middle point in the y-axis direction, and is provided so as to be swingable about the pivot 154p. The biasing member 155 is a spring and biases one end of the arm 154 in the direction of arrow B in the drawing.

  The second adjustment mechanism 15 moves the steering roll 151 up and down according to the rotation of the eccentric cam 153. Specifically, when the position shown in FIG. 7 is used as the reference position, the second adjustment mechanism 15 moves upward (in the positive direction of the z axis) or downward as shown in FIG. 8 (a) or (b). The steering roll 151 is moved in the direction (the negative direction of the z axis). In order to easily understand the contents shown in the drawing, in FIG. 8, the center line of the shaft 151a when the steering roll 151 is at the reference position is indicated by a one-dot chain line, and the vertical movement of the steering roll 151 is emphasized. Each part is shown as shown.

  Next, another configuration of the image forming apparatus 100 will be described with reference to the block diagram of FIG. As shown in FIG. 1, the image forming apparatus 100 includes a control unit 40, an operation unit 50, and a communication unit 60 in addition to the belt conveyance device 10, the print engine 20, and the fixing device 30 described above. The control unit 40 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and the operation of each part of the image forming apparatus 100 is executed by the CPU executing a program stored in the ROM. To control. The operation unit 50 is, for example, an input device including a touch panel display and various buttons, and receives an input instruction from a user. This input instruction is supplied to the control unit 30. The communication unit 60 is an interface device for exchanging data with an external device.

  Here, an example of a screen displayed on the display of the operation unit 50 will be described. FIG. 10 is a diagram illustrating a screen for allowing the user to select a function to be executed by the image forming apparatus 100. As shown in the figure, the image forming apparatus 100 has two functions of “setup mode” and “maintenance mode”. Here, the “setup mode” is a mode for executing a setup such as initial setting or parts replacement of the image forming apparatus 100, and the paper transport belt 11 can be attached or detached. The “maintenance mode” is a mode for performing fine position adjustment (maintenance) of the paper transport belt 11. In the figure, the button that triggers setup execution is B1, and the button that triggers maintenance execution is B2.

  Here, when the user selects the “setup mode”, a screen for selecting the details of the setup is displayed on the display of the operation unit 50 (see FIG. 11). As shown in the figure, on this screen, either “attachment of belt (paper conveyance belt 11)” or “removal of belt (paper conveyance belt 11)” can be selected. In the figure, the button that triggers the attachment of the paper transport belt 11 is B11, and the button that triggers the removal of the paper transport belt 11 is B12. Further, when attaching the belt, the user inserts the paper transport belt 11 to a certain position.

  Although not shown in the drawing, the image forming apparatus 100 has a casing that surrounds the main part described above. This housing has a door that can be opened and closed on the front surface thereof, that is, the side surface on the positive direction side of the x-axis, and the paper transport belt 11 can be attached and detached while the door is opened. . For convenience of explanation, in the following, the direction of the side surface with the door, that is, the positive direction side of the x-axis is referred to as “front side”, and the direction of the side surface facing the side surface with the door, that is, It is called “the back”.

  With the above configuration, the image forming apparatus 100 forms a toner image on the photosensitive drum, and transfers the image onto a recording sheet to fix it, thereby forming an image. In such a series of image forming processes, the paper transport belt 11 is deteriorated or a slight positional fluctuation occurs. Therefore, the user appropriately performs setup and maintenance to maintain the image forming apparatus 100 in a good state. The processing executed by the image forming apparatus 100 when performing this setup and maintenance is shown by the flowchart of FIG. Hereinafter, the operation of the image forming apparatus 100 will be described with reference to this flowchart. When starting this operation, the image forming apparatus 100 is assumed to display the screen shown in FIG. 10 in advance.

  First, the control unit 40 of the image forming apparatus 100 determines a mode based on information supplied from the operation unit 50 (step Sa1). The control unit 40 determines the mode selected by the user based on the information of the button pressed by the user. When the selected mode is the “setup mode”, the control unit 40 displays the screen shown in FIG. 11 on the operation unit 50 and determines the setup to be selected by the user (step Sa2).

  At this time, when the setup selected by the user is “attaching the belt”, the control unit 40 rotates the drive roll 12 and moves the end portion on the front side of the steering roll 141 via the first adjustment mechanism 14 to y. The axis is moved in the negative direction (step Sa3). Then, since the tension applied to the front side of the paper transport belt 11 becomes larger than the tension applied to the back thereof, the paper transport belt 11 is moved to the back. After that, when the paper transport belt 11 moves to an appropriate position (fixed position), the control unit 40 stops the drive roll 12 by returning the steering roll 141 to the original position, and stops the movement of the paper transport belt 11. Let In this way, the attachment of the sheet conveying belt 11 is completed.

  On the other hand, when the setup selected by the user is “removal of belt”, the control unit 40 rotates the drive roll 12 and moves the front end portion of the steering roll 141 to the y-axis via the first adjustment mechanism 14. Is moved in the positive direction (step Sa4). Then, since the tension applied to the back of the paper transport belt 11 becomes larger than the tension applied to the front of the paper transport belt 11, the paper transport belt 11 is moved forward. When the paper transport belt 11 is fed out in this way, the control unit 40 stops the drive roll 12 at an appropriate timing. In such a state, the user can easily take out the paper transport belt 11 from the door on the front surface of the housing. In this way, the removal of the sheet conveying belt 11 is completed.

  Next, a case where the mode selected by the user is “maintenance mode” will be described. If the mode selected in step Sa1 is the “maintenance mode”, the control unit 40 acquires a signal from the position sensor 13 and detects a positional variation in the width direction of the paper transport belt 11, that is, a positional variation in the x-axis direction. To do. Specifically, first, the control unit 40 determines whether or not the signal acquired from the position sensor 13 is “0” (step Sa5). When the signal from the position sensor 13 is “0”, it means that the paper transport belt 11 is in a fixed position. Therefore, the control unit 40 ends the process without doing anything at this time.

  On the other hand, if the signal from the position sensor 13 is not “0”, it means that the paper transport belt 11 is not in a fixed position, and some position adjustment is necessary. Therefore, the control unit 40 determines whether or not the signal from the position sensor 13 is “1” (step Sa6). When the signal from the position sensor 13 is “1”, it means that the paper transport belt 11 has moved to the back of the fixed position, and the control unit 40 moves this to the front. Specifically, the control unit 40 rotates the driving roll 12 and moves the front end of the steering roll 151 in the negative direction of the z-axis via the second adjustment mechanism 15 (step Sa7). Then, since the position when separating from the steering roll 151 moves in the positive direction with respect to the x axis, the paper transport belt 11 is gradually moved forward. After performing this operation for a certain time, the control unit 40 repeats the processing from step Sa5 again.

  Further, when the signal from the position sensor 13 is not “1”, that is, “2”, it means that the paper transport belt 11 has moved to the near side from the fixed position. Moves this back. Specifically, the controller 40 moves the front end of the steering roll 151 in the positive direction of the z-axis via the second adjustment mechanism 15 while rotating the drive roll 12 (step Sa8). Then, since the position when separating from the steering roll 151 moves in the negative direction with respect to the x axis, the paper transport belt 11 is gradually moved to the back. After performing this operation for a certain time, the control unit 40 repeats the processing from step Sa5 again.

  The control unit 40 repeats the processing from steps Sa5 to Sa8 until the signal from the position sensor 13 becomes “0”. That is, in other words, the control unit 40 moves the paper transport belt 11 to the back or front until the paper transport belt 11 moves to a fixed position. Then, the control unit 40 ends this processing when the paper transport belt 11 moves to a fixed position.

  By performing the series of processes described above, the image forming apparatus 100 can realize a function according to one of the “setup mode” and the “maintenance mode”. The image forming apparatus 100 can move the paper transport belt 11 relatively quickly by using the first adjustment mechanism 14 in the “setup mode”. For this reason, this operation is convenient in attaching and detaching the paper transport belt 11. On the other hand, in the “maintenance mode”, the image forming apparatus 100 can move the paper transport belt 11 relatively gently by using the second adjustment mechanism 15. For this reason, this operation is advantageous in fine work such as position adjustment of the paper transport belt 11. As described above, according to the image forming apparatus 100 of the present embodiment, it is possible to selectively perform the rapid movement and the high-precision movement of the sheet conveying belt 11 as necessary.

[2. Second Embodiment]
Subsequently, a second embodiment of the present invention will be described. In the first embodiment described above, the first adjustment mechanism 14 and the second adjustment mechanism 15 are provided on different roll members. However, in this embodiment, a mechanism equivalent to these is provided on the same roll member. It is. In the present embodiment, parts having the same configurations as those of the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted as appropriate.

  FIG. 13 is a diagram illustrating a configuration of a main part of the image forming apparatus 200 of the present embodiment. The main difference between the image forming apparatus 200 and the image forming apparatus 100 of FIG. 1 is that the belt conveying device includes an adjusting mechanism 17 instead of the first adjusting mechanism 14 and the second adjusting mechanism 15. There are three points: a point provided with the support roll 12 e and a point provided with a displacement sensor 18 instead of the position sensor 13. For convenience of explanation, this belt conveyance device is hereinafter referred to as “belt conveyance device 10a”. In addition, since the structure and function of the support roll 12e are substantially the same as the support rolls 12a-12d, the description is abbreviate | omitted here.

  FIG. 14 is a view showing the adjustment mechanism 17 from the positive direction of the z-axis. As shown in the figure, the adjustment mechanism 17 includes a steering roll 171, a first adjustment unit 172, and a second adjustment unit 173. The steering roll 171 is a roll member substantially similar to the steering rolls 141 and 151 described above, and has a shaft 171a at the center thereof. The first adjustment unit 172 has the same configuration as the motor 142, the shaft 143, and the bearing 144 of the first adjustment mechanism 14, and the second adjustment unit 173 includes the motor 152, the eccentric cam 153, and the arm of the second adjustment mechanism 15. 154 and the urging member 155 have the same configuration. That is, the adjustment mechanism 17 has a function similar to that of the second adjustment mechanism 15 at the end on the near side, and a function similar to that of the first adjustment mechanism 14 at the end on the back side.

  FIG. 15 is a diagram showing the displacement sensor 18 from the positive direction of the z-axis. As shown in the figure, the displacement sensor 18 is a line-shaped sensor capable of measuring the displacement of one end of the paper transport belt 11, and can measure a deviation of the paper transport belt 11 from a fixed position, that is, a displacement d. It is configured as follows. The displacement d is a numerical value that increases as the paper transport belt 11 moves from the fixed position in the positive direction of the x axis and decreases as the paper transport belt 11 moves in the negative direction of the x axis. The displacement d when in the position is “0”.

  The configuration of the image forming apparatus 200 is as described above. Next, processing executed by the image forming apparatus 200 will be described. The image forming apparatus 200 according to the present embodiment is different from the image forming apparatus 100 described above in the operation in the “maintenance mode”. Therefore, only the operation in the “maintenance mode” will be described below. However, of course, the image forming apparatus 200 can execute the same processing as in the “setup mode” described above.

  FIG. 16 is a flowchart illustrating processing performed by the image forming apparatus 200 in the “maintenance mode”. If it demonstrates along the figure, the control part 40 will acquire the displacement d which is the signal from the displacement sensor 18, and will judge whether this is 0 first (step Sb1). If this determination is affirmative, that is, if d = 0, the position of the conveyor belt 11 is a fixed position, and the control unit 40 ends this processing.

  On the other hand, if the determination in step Sb1 is negative, that is, if d ≠ 0, the control unit 40 determines whether or not the displacement d is a numerical value greater than 0 (step Sb2). That is, here, it is determined whether or not the moving direction of the paper transport belt 11 is the positive direction with respect to the fixed position. If this determination is affirmative, that is, if d> 0, the control unit 40 subsequently determines whether or not the displacement d is a numerical value greater than a predetermined threshold Th (step Sb3). The threshold value Th is an appropriate positive numerical value stored in the ROM of the control unit 40.

  If the determination in step Sb3 is affirmative, that is, if d> Th, the control unit 40 rotates the drive roll 12 and moves the rear end of the steering roll 171 through the first adjustment unit 172 of the adjustment mechanism 17. Move in the negative direction of the y-axis (step Sb4). Then, since the tension applied to the back of the paper transport belt 11 is smaller than the tension applied to the front of the paper transport belt 11, the paper transport belt 11 is moved to the back and approaches a fixed position.

  On the other hand, if the determination in step Sb3 is negative, that is, if 0 <d ≦ Th, the control unit 40 rotates the drive roll 12 and the front of the steering roll 171 via the second adjustment unit 173 of the adjustment mechanism 17. Is moved in the negative direction of the z-axis (step Sb5). Then, since the position when the paper conveying belt 11 is separated from the steering roll 171 moves in the negative direction with respect to the x-axis, the paper conveying belt 11 is gradually moved back to approach the fixed position.

  On the other hand, if the determination in step Sb2 is negative, that is, if d ≦ 0, the control unit 40 determines whether or not the displacement d is a value obtained by making the threshold Th negative, that is, a numerical value smaller than −Th. (Step Sb6). If this determination is affirmative, that is, if d <−Th, the control unit 40 rotates the drive roll 12 and moves the rear end portion of the steering roll 171 to y through the first adjustment unit 172 of the adjustment mechanism 17. The axis is moved in the positive direction (step Sb7). Then, since the tension applied to the back of the paper transport belt 11 becomes larger than the tension applied to the front side thereof, the paper transport belt 11 is moved to the front side and approaches a fixed position.

  On the other hand, if the determination in step Sb6 is negative, that is, if -Th ≦ d ≦ 0, the control unit 40 rotates the drive roll 12 and the steering roll 171 is rotated via the second adjustment unit 173 of the adjustment mechanism 17. The front end is moved in the positive z-axis direction (step Sb8). Then, since the position at which the paper transport belt 11 is separated from the steering roll 171 moves in the positive direction with respect to the x-axis, the paper transport belt 11 is gradually moved toward the home position.

  As described above, when the paper transport belt 11 is brought close to the fixed position, the control unit 40 acquires the displacement d again from the displacement sensor 18 and determines whether or not it is 0 (step Sb9). If the displacement d is 0, this means that the paper transport belt 11 has moved to a fixed position, and the control unit 40 ends this processing here. On the other hand, if the displacement d is not 0, the control unit 40 repeats the processing from step Sb2 until the displacement d becomes 0.

  The operation of the image forming apparatus 200 in the “maintenance mode” is as described above. That is, the image forming apparatus 200 according to the present embodiment varies the position adjustment mode according to the degree of displacement of the paper transport belt 11. Specifically, when the position fluctuation of the paper transport belt 11 is large, the image forming apparatus 200 performs position adjustment using the first adjustment unit 172 and corrects the position fluctuation of the paper transport belt 11 relatively quickly. . On the other hand, when the position fluctuation of the paper transport belt 11 is small, the image forming apparatus 200 performs position adjustment using the second adjustment unit 173, and the position fluctuation of the paper transport belt 11 is relatively moderate, that is, highly accurate. To correct. Such an image forming apparatus 200 can also achieve the same effects as those of the first embodiment described above. In addition, according to the image forming apparatus 200 of the present embodiment, since the configuration relating to the position adjustment can be concentrated around one roll member, the size of the apparatus can be reduced.

[3. Modified example]
In addition, this invention is not limited only to embodiment mentioned above, It is possible to implement in a various aspect. In the present invention, for example, the following modifications can be applied to the above-described embodiment. These modifications can be combined as appropriate.

  Although the above-described embodiment has a configuration including the position sensor 13 and the displacement sensor 18, such a detection means is not an essential component of the present invention. For example, in the setup of the paper transport belt 11, it is possible to adjust the position visually without using the detection means. In this case, the configuration may be such that the user can instruct the moving direction and mode of the sheet conveying belt 11 (whether the position adjustment is performed quickly or with high accuracy) via the display of the operation unit 50. desirable. The detection means is not limited to an optical sensor, and a contact type sensor or the like can also be used.

  Further, in the above-described embodiment, it has been described that one of the support rolls has the function of a tension roll. However, in such an aspect, the tension applied to both ends of the tension roll changes according to the inclination of the steering roll. Therefore, the tension roll is also inclined, and the position control of the paper transport belt 11 may be complicated. In order to eliminate such inconvenience, for example, a function of a tension roll may be added to the steering roll. 17 and 18 show the configuration of the steering roll end portion in this case. The configuration shown in FIG. 17 is a configuration in which an urging member 145 is added to the configuration shown in FIG. 4, and the other parts are almost the same as those in FIG. 4. 18 is a configuration in which an urging member 156 is added to the configuration shown in FIG. 6, and other portions are substantially the same as those in FIG. In addition, the arrow shown in these figures means the biasing direction of each biasing member.

  Note that, in some cases, the positional deviation of the paper transport belt 11 may occur. Such misalignment occurs, for example, when the circumferential length of the paper transport belt 11 is not constant in the width direction, or when there are attachment errors in various roll members. In such a case, even if the steering roll is parallel to the other roll members, the paper transport belt 11 gradually moves in the width direction. Therefore, in such a case, the steering roll may be tilted in advance in a non-parallel state, and the paper transport belt 11 may be rotated in this state. Hereinafter, a description will be given with reference to FIGS. In addition, the following description is an example at the time of applying to the above-mentioned 1st Embodiment.

  FIG. 19 is a graph showing an ideal rotation state of the paper transport belt 11. In the figure, the vertical axis indicates the amount of movement of the paper transport belt 11 in the width direction per unit time (hereinafter referred to as “movement rate Y”), with the positive direction moving to the back side and the negative direction being the front side. It means moving to the side. That is, the state of Y = 0 means that the positional deviation of the paper transport belt 11 is least likely to occur. Further, the horizontal axis in the figure represents the tilt angle X of the steering roll 141. If X = 0, the horizontal axis is parallel to the other roll members. It means moving in the negative direction of the axis.

In the state shown in FIG. 19, even if the steering roll 141 is kept parallel, the position fluctuation of the paper transport belt 11 hardly occurs. However, in reality, such a state is unlikely to occur, and a state in which some position fluctuations can occur as shown in FIG. In the state of the example in the figure, if the tilt angle D of the steering roll 141 is 0, the paper transport belt 11 moves to the back, and if it is not set to X ₁ (<0), the position fluctuates. It means to end. In such a case, the steering roll 141 may be tilted in advance so that the movement rate Y becomes substantially zero, and the second position adjustment mechanism 15 may be used to adjust fine position fluctuations. In this way, the steady positional deviation of the paper transport belt 11 is eliminated.

  Further, in the first embodiment described above, it has been described that the first adjustment mechanism 14 moves the steering roll 141 in the y-axis direction and the second adjustment mechanism 15 moves the steering roll 151 in the z-axis direction. This is because it is the most suitable direction for properly using the case where the paper transport belt 11 is moved quickly and the case where it is moved with high accuracy. However, of course, the moving direction is not necessarily this direction, and there may be a deviation from the y-axis direction / z-axis direction.

  In addition, the first adjustment mechanism 14 and the second adjustment mechanism 15 in the first embodiment described above can be operated at the same time, but if both are operated at the same time, the position control of the paper transport belt 11 becomes complicated. End up. Therefore, for example, it is desirable that the control unit 40 performs control to prohibit the operation of the other adjustment mechanism when one adjustment mechanism is operating.

  Further, in the above-described second embodiment, the aspect in which the configurations corresponding to the first adjustment mechanism 14 and the second adjustment mechanism 15 in the first embodiment are provided at the same end of the same roll member has been described. A configuration corresponding to the first adjustment mechanism 14 and the second adjustment mechanism 15 may be provided at each end of the same roll member.

  Note that the present invention is not applied only to the above-described image forming apparatus. For example, although the above-described embodiment is configured to include the paper transport belt, the present invention can also be implemented in an image forming apparatus configured to include a so-called intermediate transfer belt instead of the paper transport belt. Further, the present invention is not limited to these configurations, and can be applied to conveyance control of all endless belt members.

1 is a diagram illustrating a configuration of a main part of an image forming apparatus according to a first embodiment of the present invention. 2 is a diagram illustrating a configuration of a position sensor of the image forming apparatus. FIG. FIG. 3 is a diagram illustrating a configuration of a tension roll of the image forming apparatus. FIG. 3 is a diagram illustrating a configuration of a first adjustment mechanism of the image forming apparatus. FIG. 3 is a diagram illustrating a configuration of a first adjustment mechanism of the image forming apparatus. FIG. 6 is a diagram illustrating a configuration of a second adjustment mechanism of the image forming apparatus. FIG. 6 is a diagram illustrating a configuration of a second adjustment mechanism of the image forming apparatus. FIG. 6 is a diagram illustrating a configuration of a second adjustment mechanism of the image forming apparatus. FIG. 2 is a block diagram illustrating a configuration of the image forming apparatus. 6 is a diagram showing a screen displayed in the image forming apparatus. FIG. 6 is a diagram showing a screen displayed in the image forming apparatus. FIG. 3 is a flowchart illustrating processing executed by the image forming apparatus. FIG. 5 is a diagram illustrating a configuration of a main part of an image forming apparatus according to a second embodiment of the present invention. 2 is a diagram illustrating an adjustment mechanism of the image forming apparatus. FIG. It is the figure which showed the displacement sensor of the image forming apparatus. 3 is a flowchart illustrating processing executed by the image forming apparatus. It is the figure which showed the modification of an image forming apparatus. It is the figure which showed the modification of an image forming apparatus. FIG. 6 is a diagram illustrating a relationship between a tilt of a steering roll and a moving amount of a sheet conveying belt in a width direction per unit time. FIG. 6 is a diagram illustrating a relationship between a tilt of a steering roll and a moving amount of a sheet conveying belt in a width direction per unit time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100, 200 ... Image forming apparatus, 10 ... Belt conveyance apparatus, 11 ... Paper conveyance belt, 12a, 12b, 12c, 12d, 12e ... Support roll, 12 ... Drive roll, 13 ... Position sensor, 14 ... 1st adjustment mechanism, DESCRIPTION OF SYMBOLS 15 ... 2nd adjustment mechanism, 16 ... Tension roll, 17 ... Adjustment mechanism, 18 ... Displacement sensor, 20 ... Print engine, 30 ... Fixing device, 40 ... Control part, 50 ... Operation part, 60 ... Communication part

Claims (13)

An endless belt member having a predetermined width;
A plurality of roll members that stretch the belt member at different positions, and a plurality of roll members that are rotated around an axis extending in the width direction of the belt member;
Drive means for rotating at least one roll member and moving the belt member in a direction perpendicular to the width direction;
1st adjustment means which adjusts the attitude | position of one of the said roll members, Comprising: One end of the axis | shaft of the said roll member is 1st orthogonal to the said width direction with respect to the other end First adjusting means for moving relative to the direction;
A second adjusting means for adjusting the posture of any one of the plurality of roll members, wherein one end of the shaft of the roll member is different from the first direction with respect to the other end; And second adjusting means for relatively moving in a second direction orthogonal to the width direction;
And a belt position control means for operating the first or second adjusting means while operating the driving means. The first direction is a direction substantially parallel to a direction of tension applied to the belt member by a roll member whose posture is adjusted by the first adjusting means,
2. The belt conveyance according to claim 1, wherein the second direction is a direction substantially orthogonal to a direction of a tension applied to the belt member by a roll member whose posture is adjusted by the second adjustment unit. apparatus. The belt position control means is configured to perform the first or first operation in a first mode for quickly moving the belt member in the width direction, or in a second mode for moving the belt member gently in the width direction. 2 adjustment means are operated,
The belt conveyance device according to claim 2, wherein the first adjustment unit is operated in the first mode, and the second adjustment unit is operated in the second mode. The belt position control means operates the driving means so that the rotation speed of the roll member in the first mode is higher than the rotation speed in the second mode. The belt conveying apparatus as described. The belt position control means includes
The belt conveying apparatus according to claim 1, wherein the second adjusting unit is operated after the first adjusting unit is operated. Detecting means for detecting whether or not the belt member is at a predetermined position in the width direction;
The said belt position control means operates the said 1st or 2nd adjustment means, when the said detection means detects that the said belt member is not in the said predetermined position. Belt conveyor. An input means for a user to input an instruction;
The belt conveying apparatus according to claim 1, wherein the belt position control unit operates the first or second adjusting unit in accordance with the instruction input to the input unit. The belt conveyance device according to claim 1, wherein the roll member that adjusts the posture by the first adjustment unit and the roll member that adjusts the posture by the second adjustment unit are different roll members. The belt conveyance device according to claim 1, wherein the roll member that adjusts the posture by the first adjustment unit and the roll member that adjusts the posture by the second adjustment unit are the same roll member. . The belt according to claim 9, wherein the first adjustment unit moves a position of one end of the roll member, and the second adjustment unit moves a position of the other end of the roll member. Conveying device.   The belt conveying device according to claim 1, wherein the roll member whose posture is adjusted by the first adjusting means is a tension roll. The belt conveyance device according to claim 1, further comprising a prohibiting unit that prohibits the operation of the other adjusting unit when either the first or second adjusting unit is operating.   An image forming apparatus comprising the belt conveyance device according to claim 1.

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