JP2005298173A - Belt stretching device, and printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt stretching device, in which large-sizing or energy consumption increase in a drive system can be restricted, in which irregular belt move can be corrected by quick control, and in which irregular belt move correcting action can be finely controlled to eliminate the irregular belt move with high precision. <P>SOLUTION: This belt stretching device 100 is provided with a circular belt 101 stretched to run by means of a plurality of rollers 102, 103, and 104. It is provided with a tension providing member 121 to be applied to only a partial range along the width of the belt 101, and tension providing range changing means 122, 123, 124, 125, 126, and 105 to change the range of the belt 101 to which tension is provided by the tension providing member 121. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a belt erection device and a printing device, and more particularly to a structure of a belt erection device provided with means for correcting a deviation in the width direction of a belt.

  Conventionally, a belt erection device in which a belt is erected on a plurality of rollers has been used as a sheet feeding mechanism of a printing apparatus such as a printer. In particular, a sheet feeding mechanism using a belt is often used in a printing apparatus using a line type print head because a sheet can be horizontally conveyed.

  However, in the belt erection device as described above, the belt is displaced in the width direction during traveling, that is, is deviated due to the eccentricity of the roller for laying the belt and the parallel displacement between the plurality of rollers. There is a point. Accordingly, various deviation control mechanisms for preventing the deviation of the belt have been devised.

  For example, in Patent Document 1 below, one of a plurality of rollers for installing a belt is used as a bias control roller configured such that its shaft end portion can be displaced in a direction perpendicular to the roller axis. A belt driving device is described. In this belt driving device, the shaft end portion of the deflection control roller is displaced to give a biasing component in the opposite direction to the direction of belt tilting.

Further, in Patent Document 2 below, one of a plurality of rollers for laying a belt is provided as a steering roller having a rotation shaft configured to be rotatable around an intermediate position in the belt width direction. A printer belt meandering control device is described. This belt meandering control device corrects the deviation (meandering) of the running belt by inclining the rotating shaft of the steering roller.
Japanese Patent Laid-Open No. 11-263469 JP 2000-122509 A

  By the way, in the above-described conventional apparatus, the belt tension is biased in the width direction by inclining one of the plurality of rollers for constructing the belt, thereby moving the belt in the direction opposite to the direction of the bias. By doing so, the deviation of the belt is eliminated. For this reason, since it is necessary to change the posture of the roller that supports the belt in the entire width direction, a large driving force is required, which causes a problem that the drive system is enlarged and the energy consumption is increased. is there.

  In addition, since a large driving force is required as described above, it becomes difficult to quickly control the posture, and it is difficult to increase the response speed of the control. Depending on the control mode, there is also a problem that the deviation of the belt increases (the amplitude of the meandering state is amplified).

  Further, in the above method, since the control parameter for eliminating the belt deviation is only the roller axis angle, the controllability with respect to the belt deviation amount is not always sufficient, and the control necessary for the equipment such as a printer is required. There is also a problem that accuracy may not be obtained.

  Therefore, the present invention solves the above-mentioned problems, and its purpose is to reduce the driving force for correcting the belt deviation compared to the conventional method, thereby increasing the size of the drive system and reducing the energy consumption. An object of the present invention is to provide a belt erection device capable of suppressing the increase. Another object of the present invention is to provide a belt erection device capable of quickly controlling a belt deviation correcting operation as compared with the conventional method. Another object of the present invention is to provide a belt erection device capable of eliminating belt deviation with high accuracy by enabling fine control of the belt deviation correction operation.

  In order to solve the above-mentioned problems, a belt erection device according to the present invention is a belt erection device including an annular belt that is constructed so as to be able to run by a plurality of rollers, and is in a partial range in the width direction of the belt. And a tension applying member for applying a tension only by contacting the belt, and a tension applying range changing means for changing a range of the belt to which the tension is applied by the tension applying member.

  According to this invention, since the tension applying member abuts only on a partial range in the width direction of the belt to apply tension to the belt, the range in which the tension is applied by the tension applying member is changed. , The driving force required for the operation of the tension applying member can be reduced, so that the driving system can be downsized to reduce belt deviation, and the energy of the driving system can be reduced. Consumption can be reduced. Further, since the driving force can be reduced, the response speed of the belt deviation correcting operation can be increased, so that the belt deviation can be corrected quickly. Furthermore, since the tension distribution in the width direction of the belt is changed by changing the tension application range by the tension application member, a fine correction operation is also possible. It becomes possible to control with high accuracy.

  In this invention, it is preferable that the said tension | tensile_strength provision range change means is comprised so that the said tension | tensile_strength member in the state which provided the tension | tensile_strength to the said belt can be moved to the width direction of the said belt. According to this, since the tension applying range set in a part of the belt width direction can be moved in the width direction by moving the tension applying member in the belt width direction, the belt is biased in the belt width direction. Since a tension distribution can be formed, the belt can be moved in the width direction by this biased tension distribution. Further, since the tension applying member only needs to be moved while the tension is applied to the belt, a mechanism for operating the tension applying member can be easily configured.

  In this case, it is desirable that the tension applying range changing means is configured to move the tension applying member in the same direction as the direction of belt deflection. According to this, by moving the tension applying member in the same direction as the direction of the deviation in the width direction of the belt, the range subjected to the tension by the tension applying member is biased in the direction of the deviation of the belt. Since the belt can be moved in the direction opposite to the direction, it is possible to quickly and accurately eliminate the belt deviation.

  In this case, it is desirable that the tension applying range changing means includes a shaft supporting member that rotatably supports the tension applying member, and a moving mechanism that moves the shaft supporting member in the width direction of the belt. Here, for example, as the moving mechanism, a mechanism for moving the shaft support member by a feed screw mechanism such as a ball screw mechanism can be cited.

  In this invention, it is preferable to have a pair of said tension | tensile_strength provision member arrange | positioned in the position which each deviated near the both ends of the width direction of the said belt, and each comprised so that contact / separation was possible with respect to the said belt. According to this, since one of the pair of tension applying members is brought into contact with the belt and the tension is applied, the tension distribution in the width direction of the belt can be biased. It is possible to move the belt in the width direction as well. In addition, since it is only necessary to alternately operate the pair of tension applying members arranged on both sides in accordance with the direction of the belt deflection, a mechanism for operating the tension applying member can be easily configured. .

  In the present invention, the tension applying range changing means may apply the tension applied to the belt by one of the tension applying members arranged on the same side as the direction of deviation in the width direction of the belt by the other tension applying member. It is preferable that the tension is greater than the tension applied to the belt. According to this, by making the tension applied by one tension applying member arranged on the same side as the direction of deflection in the width direction of the belt larger than the tension applied by the other tension applying member, the belt This makes it possible to form a tension distribution that is biased to a large extent, and therefore, it is possible to quickly and accurately eliminate the belt deflection. In this configuration, the tension applying range changing means applies tension to the belt by one of the tension applying members arranged on the same side as the direction of deviation in the width direction of the belt, and applies the other tension. The case where it is comprised so that a member may be separated from a belt is also included.

  In the present invention, the tension application range changing means includes a deviation detector for detecting a deviation state of the belt, and an operation of the tension application member according to the deviation state detected by the deviation detector. It is preferable to have a control means for controlling the state. Here, examples of the detection target of the deviation detector include a position in the belt width direction, a deviation speed in the belt width direction, and the like. The tension application range changing means may change the position in the width direction of the tension application range, or may change the width of the tension application range.

  In the present invention, it further includes a position detector that detects a position of the belt in the traveling direction, and a recording unit that records the position of the belt in the traveling direction and the deviation state of the belt at the position in association with each other. The tension application range changing means corresponds to the position of the belt in the running direction recorded in the recording means in correspondence with the position of the belt in the running direction detected by the position detector. It is preferable to operate the tension applying member so as to reduce the state. According to this, by associating the belt deviation state with the position in the belt running direction in advance, a certain degree of belt deviation can be eliminated without detecting the belt deviation state. Also, it becomes possible to reduce the belt deviation more rapidly. In this case, the tension application range changing means is operated in accordance with both the recorded belt deviation state corresponding to the position in the traveling direction and the belt deviation state detected by the deviation detector. It doesn't matter.

  Next, a printing apparatus according to the present invention includes the belt laying device according to any one of the above as a transport mechanism for a sheet to be printed. According to this, since a sheet (paper or the like) to be printed can be transported by using the belt erection device as a transport device, deviation in the transport direction of the sheet can be reduced. It becomes possible to plan.

  ADVANTAGE OF THE INVENTION According to this invention, the drive system for reducing the belt deflection of a belt construction apparatus can be reduced in size, or the energy consumption of the said drive system can be reduced. In addition, the belt deviation correction control can be quickly performed as compared with the conventional method. Furthermore, it is possible to increase the accuracy of the belt deviation correcting operation.

  Next, an embodiment of a belt erection device according to the present invention will be described in detail with reference to the accompanying drawings. Each embodiment described below is a belt erection device mounted on a printing apparatus such as an ink jet printer. This belt erection device has an annular belt for conveying a sheet (for example, paper) to be printed in the printing device, and this belt is erected by a plurality of rollers. However, the present invention is not limited to the sheet erection belt mounting device mounted on the printing apparatus, and can be applied to any device as long as the belt is erected by a plurality of rollers.

[First embodiment]
FIG. 1 is a schematic plan view schematically showing a belt laying device according to a first embodiment of the present invention. FIG. 2 is a schematic longitudinal sectional view schematically showing a state cut along line II-II in FIG. FIG. 3 is a schematic partial front view schematically showing a state cut along line III-III in FIG. 1.

  The belt erection device 100 according to the first embodiment of the present invention includes an annular belt 101 and a plurality of erection rollers 102, 103, and 104 that erode the belt 101. The erection rollers 102, 103, and 104 are rotatably supported around mutually parallel axes, and erode the belt 101 so as to be able to travel in the X direction in the drawing. The belt 101 is made of a flexible material made of synthetic rubber or other synthetic resin. The belt 101 has a predetermined width in the width direction W orthogonal to the traveling direction X. The construction rollers 102, 103, 104 are configured to be slightly longer in the width direction than the belt 101, and are provided with flange portions 102 a, 103 a, 104 a that protrude radially outward with respect to the roller surface at both ends. These flange portions are for preventing the belt 101 from coming off from the construction rollers 102, 103, 104. A shaft support structure for rotatably supporting the construction rollers 102, 103, 104 is not shown.

  In the present embodiment, the erection roller 102 is configured to be rotationally driven by a belt driving mechanism 110. The belt drive mechanism 110 includes a motor drive circuit 111, a drive motor 112 driven by the motor drive circuit 111, and an output shaft 113 that transmits the output of the drive motor 112 to the installation roller 102. When the belt driving mechanism 110 is operated, the erection roller 102 is rotationally driven, and the erection roller 102 causes the belt 101 to travel in the traveling direction X. At this time, the other construction rollers 103 and 104 rotate as the belt 101 travels.

  A tab 101 a protruding sideways is provided on a side edge of the belt 101. The tab 101a is configured to be detectable by the sensor 146. By detecting the tab 101a by this sensor 146, the origin position of the belt 101 viewed in the running direction X can be detected. Furthermore, a scale 101b is provided on the side edge of the belt 101 (the side edge opposite to the side edge on which the tab 101a is formed). The scale 101b is configured to be detectable by the sensor 144. By detecting the scale 101b by the sensor 144, the relative position (movement amount) of the belt 101 in the traveling direction X can be measured. The absolute position of the belt 101 in the running direction can be specified by detecting the tab 101a and the scale 101b with the sensors 146 and 144.

  In this embodiment, a deflection control mechanism 120 is provided. The deflection control mechanism 120 supports a tension applying roller 121, a shaft member 122 that supports the tension applying roller 121 and extends in the width direction W of the belt 101, and a shaft member 122. A shaft support 123 is provided. Here, at least both ends of the shaft member 122 and the shaft support portion 123 are screwed together. A gear (for example, a worm gear) 124 meshes with the end of the shaft member 122, and the gear 124 is connected to a drive motor 125. The drive motor 125 is driven by a motor drive circuit 126. When the gear 124 is rotated by the drive motor 125, the shaft member 122 is rotated, and the shaft member 122 is moved in the axial direction (that is, the width direction W described above) with respect to the shaft support portion 123.

  In the tension applying roller 121, as shown in FIG. 4, the outer ring 121c is configured to be rotatable with respect to the inner ring 121a via a spherical or columnar rolling element 121b. That is, the tension applying roller 121 has a rolling bearing structure. The inner ring 121a is fixed to the shaft member 122. The outer ring 121 c constitutes a roller surface of the tension applying roller 121. As a result, the roller surface of the tension applying roller 121 is configured to be rotatable about the axis with respect to the shaft member 122, and is fixed to the shaft member 122 in the axial direction. The roller surface of the tension applying roller 121 is in contact with the surface of the belt 101 and applies tension to the belt 101 constructed by a plurality of construction rollers as described above. That is, the tension of the belt 101 in a state in which the tension applying roller 121 is in contact with the belt 101 is greater than the tension of the belt 101 when the tension applying roller 121 is not present.

  As shown in FIG. 2, in the case of this embodiment, the belt 101 is driven in the direction of the illustrated arrow by the erection roller 102, so the tension side (the upper surface in the figure) of the belt 101 conveys a conveyance object such as a sheet. It is a transfer surface 101A. At this time, the tension applying roller 121 abuts against the loose side of the belt 101 so that a predetermined tension is applied to the belt 101. By providing the tension applying roller 121 in contact with a portion other than the conveying surface 101A in this way, the flatness of the conveying surface 101A is impaired by providing the tension applying roller 121, or the conveying surface 101A is moved along an appropriate path. It is possible to avoid a situation where an arrangement space for an auxiliary erection roller (not shown) for erection cannot be secured. Further, the tension applying roller 121 is disposed inside the installation path of the belt 101 and is in contact with the inner surface of the belt 101. If it does in this way, belt erection device 100 can be constituted compactly.

  The length of the tension applying roller 121 in the axial direction is configured to be smaller than the width of the belt 101. The tension applying roller 121 abuts only on a partial range of the width of the belt 101 and applies tension only to the partial range. In this way, the tension applying roller 121 applies tension only to a partial range of the width of the belt 101, so that the tension distribution of the belt 101 is biased when viewed in the width direction. Here, when the tension applying roller 121 is moved in the axial direction (that is, the width direction W of the belt 101) by the operation of the deflection control mechanism 120 (drive motor 125), the tension distribution seen in the width direction W of the belt 101 is also obtained. It also changes. That is, in the illustrated example, the tension application range by the tension application roller 121 is the peak range of the tension distribution. Therefore, when the tension application roller 121 moves in the width direction W, the peak range of the tension distribution also changes in the width direction W. Move in the same direction. Note that the length of the tension applying roller 121 in the axial direction is preferably smaller than half of the width of the belt 101 in order to improve the controllability with respect to the deviation of the belt 101, and particularly 30% or less of the width of the belt 101. It is desirable to be. Further, the length of the tension applying roller 121 is 5% or more of the width of the belt 101 in order to apply a tension necessary for generating a sufficient correction force without damaging the belt 101. In particular, it is preferably 15% or more. In the illustrated example, the length of the tension applying roller 121 is about 20 to 25% of the belt 101.

  In the present embodiment, the control means 105 is configured to receive the detection values of the sensors 142, 144, 146 and to output control signals to the motor drive circuit 111 and the motor drive circuit 126. The control means 105 sends a control signal to the motor drive circuit 111, and the motor drive circuit 111 operates the drive motor 112, so that the belt 101 travels by the construction roller 102. At this time, the sensor 142 detects the deviation of the belt 101, and the control means 105 controls the motor drive circuit 126 according to the output. The motor drive circuit 126 is driven to change the rotation direction and rotation speed of the output shaft of the drive motor 125, thereby changing the position of the tension applying roller 121 in the width direction. Here, the sensor 142 is a deviation detector that detects the position in the width direction W of one side edge of the belt 101. For example, the sensor 142 can be configured by an optical sensor including a light emitting element such as an LED and a light receiving element such as a photodiode that detects light of the light emitting element in the vicinity of the side edge of the belt 101.

  FIG. 5 is a graph showing the relationship between the detection value of the sensor 142 and the position of the side edge of the belt 101. The detection range of the sensor 142 extends over both sides in the width direction of the reference position of the side edge portion of the belt 101 (the position in the width direction of the side edge portion when the belt 101 is disposed at the normal width direction position). Is set to When the side edge of the belt 101 is disposed at the reference position S, the detection value of the sensor 142 is set to the reference detection value P. When the belt 101 is deviated in the width direction W, the side edge portion thereof moves in the width direction W, so that the detection value of the sensor 142 increases or decreases with respect to the reference detection value P. In the example shown in FIG. 5, when the belt 101 is deflected to the left side, the left side edge portion shown in FIG. 1 moves to the left. The detection value is lower than the reference detection value P. Conversely, when the belt 101 is deflected to the right side, the left side edge is moved to the right, and accordingly, the range where light is blocked by the belt 101 is reduced. Therefore, the detection value of the sensor 142 is higher than the reference detection value P. Increase.

  In the present embodiment, the control means 105 controls the motor drive circuit 126 in a manner corresponding to the detection value shown in FIG. 5 of the sensor 142, so that the deviation in the width direction of the belt 101 is eliminated. Yes. The control mode is to move the tension applying roller 121 in the same direction as the movement direction of the belt 101 in the width direction W as shown in FIG. Normally, if the detection value of the sensor 142 is the reference detection value P, the belt 101 does not move in the width direction W, and therefore the tension applying roller 121 does not move. Is in contact with the substantially central portion in the width direction. However, the initial position of the tension applying roller 121 is the position at which the belt 101 has the smallest deviation width or the deviation of the belt 101 depending on the characteristics of the belt 101 and the arrangement state of the erection rollers 102, 103, 104. It is preferable to adjust to the center position of the moving range.

  In the above state, when the belt 101 is deviated leftward in the width direction, the detection value of the sensor 142 changes, and the motor drive circuit 126 drives the drive motor 125 in response to this, so that the tension applying roller 121 is deviated from the belt 101. Move to the left as the direction of movement. When the tension applying roller 121 moves to the left, the tension distribution of the belt 101 is also biased to the left side, and the tension is increased in the left side portion of the belt 101 and decreased in the right side portion. Therefore, the belt 101 is deviated.

  The control means 105 can be configured by a control circuit, an MPU (microprocessor unit), or the like. The control means 105 preferably performs feedback control so that the belt 101 is disposed at the reference position S, that is, the detection value of the sensor 142 becomes the reference detection value P. In this case, for example, the position in the width direction of the belt 101 can be converged to the reference position S by performing appropriate PID control using the deviation of the detected value with respect to the target value to be controlled. Here, examples of the control amount include a moving speed, a moving position, and a moving amount of the tension applying roller 121. This is because, as the position of the tension applying roller 121 is closer to the both side edges in the width direction of the belt 101, the bias in the tension distribution becomes larger, so the restoring force that moves the belt 101 in the width direction is considered to increase. It is. Normally, the deviation can be eliminated in a short time by increasing the moving speed of the tension applying roller 121 as the deviation increases. However, if the moving speed of the tension applying roller 121 is sufficiently high, the deviation of the belt 101 can be quickly eliminated by using the position and moving amount after the tension applying roller 121 is moved as a control amount.

  In the belt erection device 100 of the first embodiment, a tension applying roller 121 that is a tension applying member that applies tension by contacting only a partial range of the belt 101 in the width direction is provided. The tension applying range for the belt 101 is changed by a belt deflection control mechanism 120 which is a tension applying range changing means. Therefore, since the tension applying roller is not in contact with the belt 101 in the entire width direction, the driving force for the tension applying roller 101 is small, and the drive system of the belt deflection control mechanism 120 can be downsized. And energy consumption can be reduced. Further, since the driving force required for the belt deflection control mechanism 120 is reduced, the tension applying roller 121 can be operated quickly, and the response speed of the control can be improved. Further, since the tension applying range of the tension applying roller 121 is limited to a part in the width direction of the belt 101, the restoring force for eliminating the deviation of the belt 101 can be reduced. The control accuracy in the width direction of the belt 101 can be increased, and the deviation state of the belt 101 can be controlled with higher accuracy than in the past.

  Further, in this embodiment, the tension applying roller 121 is always in contact with the belt 101 to apply tension, and the tension applying roller 121 is moved in the width direction of the belt 101 according to the biased state of the belt 101. Thus, the tension applying range can be changed with a very simple mechanism, so that the apparatus can be reduced in size and the manufacturing cost thereof can be reduced.

[Second Embodiment]
Next, a second embodiment according to the present invention will be described with reference to FIG. Since the mechanical structure of the belt erection device of this embodiment is the same as that of the belt erection device 100 of the first embodiment, the same reference numerals of the first embodiment are used as they are for the same parts with reference to FIGS. These descriptions are omitted.

  In the present embodiment, instead of feedback control based on the detection value of the sensor 142 as in the first embodiment, a deviation state corresponding to the absolute position of the belt 101 viewed in the traveling direction X is measured in advance. The tension applying roller 121 is moved in the width direction in a manner suitable for the biased state, that is, so as to eliminate the biased state. That is, in the belt erection apparatus, the belt 101 is caused to travel due to the belt 101, the eccentricity of the erection rollers 102, 103, 104, the parallel displacement between the axes of the erection rollers 102, 103, 104, and the like. When this occurs, a biased state corresponding to the absolute position appears repeatedly. Therefore, by measuring the deviation state in advance and performing control corresponding to the deviation state, a delay in response of the deviation correction operation can be reduced or eliminated.

  In the present embodiment, the absolute position of the belt 101 in the traveling direction X is detected using the sensors 144 and 146 described above. Both the sensors 144 and 146 can be constituted by optical sensors, magnetic sensors, or the like.

  In the present embodiment, the control means 105 is provided with a recording means (not shown) such as a memory for storing the detection values of the sensors 142, 144, and 146. The recording means includes an absolute position in the running direction X of the belt specified by the detection value of the sensor 144 within one running cycle of the belt 101 from the time when the sensor 146 detects the tab 101a until the next detection. The state is recorded in a state in which the deviation state (the direction of deviation or the direction of deviation and the amount of deviation) specified by the detection value of the sensor 142 is associated. That is, the recording means records data representing the biased state for each absolute position of the belt 101. When the belt 101 travels, the biasing state corresponding to the absolute position of the belt 101 is sequentially read from the recording unit, and the tension applying roller 121 is moved according to the biasing state. For this reason, even when the belt 101 travels at a high speed, due to the delay in the belt deviation correction operation, the deviation state cannot be eliminated, or the deviation amount is amplified by the deviation of the deviation control timing. Can be prevented.

  In the belt laying apparatus described above, the above operation can be realized by operating the control means 105 in accordance with a predetermined operation program. In this case, it is preferable that the control means 105 is constituted by an MPU (microprocessor unit), the operation program is stored in a memory in the MPU, and is executed by a CPU (central processing unit) in the MPU. Further, this memory can be used as a recording place for the data of the absolute position and the deviation state.

  By executing the above-described operation program, the control unit 105 controls the belt erection device, for example, according to the procedure shown in FIG. First, a learning process is started, the drive motor 112 is operated by the motor drive circuit 111, and the belt 101 is caused to travel (S1). Next, it is determined whether or not the sensor 146 detects the tab 101a (S2). When the tab 101a is detected, the absolute position of the belt 101 is detected and taken into the recording means (S3), and the belt is in a biased state. Detection of (the direction of deviation of the belt 101, or the direction of deviation of the belt 101 and the amount of deviation) and the incorporation into the recording means (S4) are started. The absolute position detection and capture (S3) and the belt deviation state detection and capture (S4) are then repeated until the tab 101a is detected by the sensor 146 (S5). At this time, the absolute position and the belt deflection state corresponding to the absolute position are recorded in the recording unit in a state of being associated with each other. In this way, all the relationships between the absolute position of the belt 101 within one travel cycle and the belt deviation state are recorded.

  Next, the main drive process of the deflection control is started (S6). First, the absolute position of the belt 101 is detected by the sensors 144 and 146 (S7), the deflection direction of the belt 101 corresponding to the absolute position is read from the storage means (S8), and the tension applying roller 121 is operated (S9). ). For example, the tension applying roller 121 is moved in the same direction as the detected deflection direction, or the tension applying roller 121 is moved in the same direction as the detected deflection direction according to the detected amount of deviation. Move at speed or travel. In any case, the tension applying roller 121 is controlled so that the biased state corresponding to the absolute position of the belt 101 is reduced. Then, the above steps from S7 to S9 are repeated until the running of the belt 101 is completed (S10).

  In the second embodiment, the absolute position within one running circumference of the belt 101 detected by the sensors 142, 144, and 146 and the deviation state are recorded in association with each other. Since the tension applying roller 121 is operated according to the recorded deviation state corresponding to the absolute position 101, a delay in the deviation correcting operation can be reduced.

  In this embodiment, a learning process for associating and recording the absolute position of the belt 101 within one traveling cycle and the state of deviation is recorded when the belt 101 starts to travel. 101, the control unit 105 correlates the absolute position of the belt 101 within one traveling cycle and the state of deviation in advance before shipping the belt erection device or the equipment on which the belt is installed. For example, when the belt 101 travels, the deviation correction operation of the belt 101 may be performed from the beginning according to the recorded content.

[Third embodiment]
Next, with reference to FIG.8 and FIG.9, the belt construction apparatus 200 of 2nd Embodiment which concerns on this invention is demonstrated. FIG. 8 is a schematic plan view schematically showing the belt erection device 200 of the second embodiment. 9 is a schematic partial front view schematically showing a state cut along the line IX-IX in FIG. In this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. The belt erection device 200 includes the same belt 101, erection rollers 102, 103, and 104, a belt driving mechanism 110, and sensors 142, 144, and 146 as in the first embodiment.

  In the present embodiment, a belt deflection control mechanism 220 different from the first embodiment is provided. Here, in the belt deflection control mechanism 120 of the first embodiment, the tension applying roller 121 is configured to be able to reciprocate in the width direction of the belt 101. However, in the belt erection device 200, a pair of tension applying rollers is used. 221 and 221 'are configured to be able to contact and separate from the belt 101 (movable in the vertical direction in the figure). In the present embodiment, the pair of tension applying rollers 221 and 221 ′ are respectively arranged at positions deviated near both side edges in the width direction of the belt 101, that is, positions shifted from the center in the width direction toward both side edges. . The pair of tension applying rollers 221 and 221 ′ are configured to be movable between a position where they are separated from the belt 101 and a position where they are in contact with the belt 101 and apply tension.

  As shown in FIG. 9, the tension applying rollers 221 and 221 ′ are rotatably attached to shaft members 222 and 222 ′ extending in a direction perpendicular to the surface of the belt 101, respectively. The shaft core member extends in a direction orthogonal to each other and is rotatably supported. Here, the shaft core member that pivotally supports the tension applying members 221 and 221 ′ is a guide means (not shown) so that the tension applying rollers 221 and 221 ′ are always disposed on the belt 101 side around the shaft members 222 and 222 ′. Is regulated by. Screw shafts are formed in at least a part of these shaft members 222 and 222 ', and are screwed into the shaft support portions 223 and 223'. The shaft members 222 and 222 'mesh with gears 224 and 224', and the gears 224 and 224 'are connected to drive motors 225 and 225', respectively. These drive motors 225 and 225 ′ are driven by a motor drive circuit 226.

  Also in this embodiment, similarly to the first embodiment, the detection signals of the sensors 142, 144, and 146 are received, and the motor drive circuit 111 of the belt drive mechanism 110 and the motor drive circuit 226 of the belt deflection control mechanism 220 are controlled. Control means 205 is provided. This control means 205 controls the motor drive circuit 226, thereby driving the drive motors 225 and 225 'so that the tension applying rollers 221 and 221' can be appropriately moved with respect to the belt 101. It is configured.

  Here, the tension applying rollers 221 and 221 ′ are configured to be able to come into contact with the loose side of the belt 101 as in the first embodiment, and are disposed on the inner side of the construction path of the belt 101, on the inner surface of the belt 101. It is comprised so that contact | abutting is possible. Further, the tension applying rollers 221 and 221 ′ are configured to contact each other only in a partial range in the width direction of the belt 101 and apply tension. Specifically, the tension applying rollers 221 and 221 ′ each have a length in the axial direction that is smaller than the width of the belt 101.

  In the present embodiment, the tension applying rollers 221 and 221 ′ are configured to be movable so as to be able to abut against or separate from the belt 101. For example, in FIG. 9, the tension applying roller 221 on the left side in the drawing is in contact with the belt 101 to apply tension, and the tension applying roller 221 ′ on the right side in the drawing is separated from the belt 101. .

  In the present embodiment, the pair of tension applying rollers 221 and 221 ′ are not in contact with the belt 101 in the initial state, but when the running belt 101 is biased in the width direction under the control of the control means 205, One tension applying roller disposed on the same side as the direction of the deflection is configured to abut against the belt 101 to apply tension, and the other tension applying roller remains separated from the belt 101. As a result, the belt 101 has a large tension in the part on the same side as the direction of the deflection and a tension in the part on the opposite side, and thus the belt 101 moves in the direction opposite to the direction of the above-described deviation. The bias state is eliminated.

  In the initial state, the pair of tension applying rollers 221 and 221 ′ may both be brought into contact with the belt 101, and the pair of tension applying rollers may both apply tension to the belt 101. In this case, when the belt 101 is deflected in the width direction under the control of the control means 205, the tension applying roller disposed on the side opposite to the direction of the deviation is separated from the belt 101. Since a similar tension distribution is formed in the width direction of the belt, it is possible to eliminate the biased state as described above.

  In the initial state, the pair of tension applying rollers 221 and 221 ′ are both brought into contact with the belt 101, and the pair of tension applying rollers both apply tension to the belt 101. When the belt 101 is deviated in the width direction, the tension applying roller arranged on the same side as the direction of the deviation further moves to the belt 101 side, and the belt has a higher tension than the tension applying roller arranged on the opposite side. 101 may be provided. In this case, it is desirable that the tension applied to the belt 101 by the tension applying roller in the initial state is set to be extremely weak.

  In the present embodiment, the tension applied to the belt 101 by the tension applying rollers 221 and 221 ′ can be changed. In this case, when the deviation speed and deviation amount in the width direction of the belt 101 are large, the movement amount of the tension applying roller on the same side as the deviation direction after contacting the belt 101 is increased, and the tension is increased. By increasing the amount of tension applied to the belt 101 by the applying roller, it is possible to set a large cancellation speed and amount of deviation of the belt 101.

  In the present embodiment, the control unit 205 can perform the same feedback control as in the first embodiment. However, as described in the second embodiment, a deviation state corresponding to the absolute position of the belt 101 may be recorded in advance, and control according to the deviation state may be performed.

  In the third embodiment, since the biased state of the belt 101 can be eliminated simply by moving the tension applying rollers 221 and 221 'to and from the belt 101, the driving force of the tension applying rollers 221 and 221' is eliminated. As well as reducing the amount of movement, the amount of movement can be made extremely small, so that the deviation correcting operation can be performed more quickly and with high accuracy.

  Note that the belt erection device of the present invention is not limited to the illustrated examples described above, and it is needless to say that various modifications can be made without departing from the gist of the present invention. For example, in the above embodiment, a ball screw mechanism or other feed screw mechanism connected to an electric motor is used as a drive system for tension applying range changing means for operating the tension applying roller. Other drive sources may be used, and various transmission mechanisms such as a train wheel, a link mechanism, and a belt mechanism may be used.

  In each of the above embodiments, the tension applying member is a rotatably supported roller having a roller surface that contacts the belt. However, the present invention is not limited to such a configuration. Any member may be used as long as it applies a tension within a limited range by contacting a part of the belt in the width direction.

1 is a schematic plan view schematically showing a belt erection device according to a first embodiment of the present invention. The schematic longitudinal cross-sectional view which shows typically the cross section cut | disconnected along the II-II line | wire of FIG. 1 of 1st Embodiment. The schematic partial front view which shows typically the state cut | disconnected along the III-III line | wire of FIG. 1 of 1st Embodiment. The schematic longitudinal cross-sectional view which shows the structure of a tension | tensile_strength provision roller. The graph which shows the output characteristic of the sensor which comprises a deviation detector. The schematic plan view for demonstrating the deviation correction operation | movement of the belt of 1st Embodiment. The schematic flowchart which shows the operation | movement procedure of 2nd Embodiment. The schematic plan view which shows typically the belt construction apparatus of 3rd Embodiment. The schematic partial front view which shows typically the cross section cut | disconnected along the IX-IX line of FIG. 8 of 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100, 200 ... Belt installation apparatus, 101 ... Belt, 102, 103, 104 ... Installation roller, 105 ... Control means, 110 ... Belt drive mechanism, 120 ... Belt deflection control mechanism, 121 ... Tension applying roller, 122 ... Shaft member , 123 ... support structure, 124 ... gear, 125 ... drive motor, 126 ... motor drive circuit, 142, 144, 146 ... sensor

Claims (9)

A belt erection device comprising an annular belt constructed to be able to run by a plurality of rollers,
A tension applying member for applying tension by contacting only a partial range in the width direction of the belt, and tension applying range changing means for changing the range of the belt to which tension is applied by the tension applying member. A belt erection device comprising:   2. The belt erection device according to claim 1, wherein the tension application range changing unit is configured to be able to move the tension application member in a state of applying tension to the belt in a width direction of the belt. .   3. The belt erection device according to claim 2, wherein the tension applying range changing unit is configured to move the tension applying member in the same direction as the direction of deviation of the belt.   2. The belt according to claim 1, further comprising a pair of tension applying members that are arranged at positions deviated toward both ends of the belt in the width direction and configured to be able to contact and separate from the belt. Construction device.   The tension applying range changing means applies the tension applied to the belt by one of the tension applying members arranged on the same side as the direction of deviation in the width direction of the belt to the belt by the other tension applying member. The belt erection device according to claim 4, wherein the belt erection device is configured to be larger than a tension to be applied.   The tension applying member is a tension applying roller that is rotatably supported around a rotation axis parallel to the axis of the roller and is configured such that the length in the direction of the rotation axis is shorter than the width of the belt. The belt erection device according to any one of claims 1 to 5, characterized by the above-mentioned.   The tension applying range changing means controls the operation state of the tension applying member in accordance with the deviation detector for detecting the deviation state of the belt and the deviation state detected by the deviation detector. The belt erection device according to claim 1, further comprising a control unit. A position detector that detects a position of the belt in the traveling direction; and a recording unit that records the position of the belt in the traveling direction and the deviation state of the belt at the position in association with each other;
The tension applying range changing means corresponds to the position of the belt in the running direction recorded in the recording means, corresponding to the position in the running direction of the belt detected by the position detector. The belt erection device according to any one of claims 1 to 7, wherein the tension applying member is operated to reduce the tension. A printing apparatus comprising the belt laying device according to any one of claims 1 to 8 as a conveyance mechanism for a sheet to be printed.

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