JP2013025227A - Belt driving device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology which suppresses that a belt member after replacement is installed while running on a moving member of a belt position detecting device, when the belt member is replaced, in an image forming device equipped with the belt position detecting device which contacts with an edge of an endless belt member driven to circulate, and has the moving member moving in accordance with movement in a width direction of the belt member.SOLUTION: An image forming device (10) has: a belt module (140) having an endless belt member (141) driven to circulate; a belt position detecting means (200) provided on the belt module and having a moving member (202) which is contact with an edge of the belt member and moves in accordance with movement in a width direction of the belt member, for detecting a position in the width direction of the belt member according to the moving amount of the moving member; and a moving mechanism (300) for moving the moving member in a direction separating from the edge of the belt member, in response to preparation operation for replacing the belt member.

Description

  The present invention relates to a belt driving device and an image forming apparatus.

  In an image forming apparatus including a belt driving device having a belt member such as an intermediate transfer belt, a technique for correcting the meandering (or skewing) of the belt member is known. For example, Patent Document 1 discloses a belt position detection device that detects a change in the position of a conveyance belt (intermediate transfer belt) that conveys a toner image, and a position correction that corrects the position of the conveyance belt based on the output of the belt position detection device. An image forming apparatus having an apparatus is described. The position detection device includes a moving member that is pressed by the side end of the conveying belt and moves following the movement of the conveying belt when the conveying belt moves in a direction perpendicular to the conveying direction of the toner image. By detecting this, the position of the conveyor belt is detected.

  Patent Document 2 is provided with a contact that contacts the end of the intermediate transfer belt in the width direction and is displaced according to the position of the intermediate transfer belt in the width direction, and a displacement sensor that detects the position of the contact. In the image forming apparatus that controls the position of the intermediate transfer belt in the width direction based on the detection result of the sensor, the intermediate transfer belt is moved in the width direction and in the direction away from the contact according to the replacement of the intermediate transfer belt. The technology is described.

JP 2009-249145 A JP 2010-145654 A

  An object of the present invention is to provide a belt position that has a moving member that contacts the end of an endless belt member that is driven to rotate and moves with the movement of the belt member in the width direction, and detects the position in the width direction of the belt member. In the belt drive device provided with the detection device, when replacing the belt member, there is provided a technique for suppressing the belt member after replacement from being mounted on the moving member of the belt position detection device.

  In order to solve the above-described problem, a belt drive device according to claim 1 of the present application is provided with a belt module having an endless belt member that is supported by a plurality of belt support members and driven around, and the belt module. A belt position detecting means having a moving member that contacts the end of the belt member and moves in accordance with the movement of the belt member in the width direction, and the width of the belt member according to the amount of movement of the moving member; The belt position detecting means for detecting the position of the direction and the moving member of the belt position detecting means in a direction away from the end of the belt member in conjunction with a preparatory operation for replacing the belt member of the belt module. And a moving mechanism for moving.

  The belt drive device according to claim 2 of the present application is the belt drive device according to claim 1, wherein the preparatory operation for replacement of the belt member is a position where the belt module can be replaced with the belt member. It is an operation to move to a position.

  According to a third aspect of the present invention, there is provided a belt drive device according to the second aspect, further comprising: a housing that houses the belt module; and a module support unit that supports the belt module so that the belt module can be pulled out from the housing. The belt replacement position is a position where, after the belt module is pulled out from the housing, the downstream side in the pulling-out direction of the belt module is lifted with respect to the upstream side.

  According to a fourth aspect of the present invention, there is provided the belt driving device according to the third aspect, wherein the moving mechanism includes a fixing member fixed to the module support means, a support fixed to the belt module, and A shaft portion rotatably supported by the support, a first arm extending in a direction away from the moving member from one end of the shaft portion, and a second arm extending in a direction toward the moving member from the other end of the shaft portion When the belt module is moved to the belt replacement position, the first arm of the lever is pressed against the fixing member, so that the lever is centered on the shaft portion. Rotates, the second arm of the lever is caught by the moving member, moves the moving member in a direction away from the end of the belt member, and pushes against the fixing member of the first arm. Distance from devoted portion to the shaft portion is characterized by longer than the distance from the portion caught by the moving member of said second arm to said shaft portion.

  An image forming apparatus according to claim 5 of the present application includes an image forming unit that forms an image and the belt driving device according to any one of claims 1 to 4, wherein the belt member is formed by the image forming unit. The formed image or a sheet on which the image is transferred is conveyed.

  According to the structure of Claim 1 and 5, it has the moving mechanism which moves the moving member of a belt position detection means in the direction away from the end of a belt member in conjunction with the preparation operation for replacement | exchange of a belt member. Compared to the case where there is no belt member, when the belt member is replaced, it is possible to prevent the belt member after replacement from being mounted on the moving member of the belt position detecting device.

  According to the configuration of the second aspect, when the belt module is in the belt replacement position, the moving member of the belt position detecting means can be moved in a direction away from the end of the belt member.

  According to the structure of Claim 3, compared with the case where the downstream in the drawer direction of a belt module is not lifted with respect to an upstream, belt replacement | exchange operation | work is easy.

  According to the structure of Claim 4, the distance from the part pressed against the fixing member of the first arm to the shaft part is not longer than the distance from the part hooked on the moving member of the second arm to the shaft part. In comparison, the moving member can be easily moved away from the end of the belt member.

1 is a diagram schematically illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. It is a schematic diagram which shows the structure of a belt position detection apparatus. FIG. 4 is a perspective view showing a relationship between an intermediate transfer belt and a belt position detection device in a belt module. It is a figure which shows the drawer | drawing-out from the housing | casing of a belt module, and the movement to a belt exchange position. It is a perspective view which shows a retracting mechanism with a belt module and a module support part. It is a perspective view which shows the lever and support body of a evacuation mechanism. It is a figure which shows typically a motion of the retracting mechanism with respect to the movement to the belt exchange position of a belt module. It is a figure which shows typically the positional relationship of the edge part of a 2nd arm with respect to the movement to the belt replacement position of a belt module, and a contact part.

[Embodiment]
Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram schematically showing a configuration of an image forming apparatus 10 according to an embodiment of the present invention, and shows the image forming apparatus 10 viewed from the front side. For convenience of explanation, in FIG. 1, the left-right direction is the X-axis direction, the front-rear direction is the Y-axis direction, and the up-down direction is the Z-axis direction. Further, the left direction of the image forming apparatus 10 is the X (+) direction, the right direction is the X (−) direction, the rear direction of the image forming apparatus 10 is the Y (+) direction, the front direction is the Y (−) direction, and The upward direction of the image forming apparatus 10 is referred to as the Z (+) direction, and the downward direction is referred to as the Z (−) direction.

  The image forming apparatus 10 of the present embodiment is an electrophotographic printer, and, as shown in the figure, a paper feeding unit 110, a plurality of photosensitive units 120Y, 120M, 120C, and 120K, an exposure unit 130, A belt module 140, a fixing unit 150, and a belt position detection device 200 are provided. Note that the paper feeding unit 110, the photosensitive units 120Y, 120M, 120C, and 120K, the exposure unit 130, the belt module 140, and the fixing unit 150 have widths corresponding to the size of the recording medium in the front-rear direction (Y-axis direction) of the drawing. have.

  The paper feeding unit 110 supplies the stored recording medium. Here, the recording medium refers to a sheet-like medium on which an image is formed by the image forming apparatus 10, for example, so-called paper. The size and material of the recording medium are not particularly limited as long as they correspond to the image forming apparatus 10. The recording medium supplied from the paper supply unit 110 is conveyed along a path indicated by a broken-line arrow in the drawing, and an image is formed and discharged.

  The photoconductor units 120Y, 120M, 120C, and 120K correspond to yellow (Y), magenta (M), cyan (C), and black (K) colors, respectively, and images (hereinafter referred to as toner images) of the respective colors. Used to form and hold a toner image). These photoreceptor units 120Y, 120M, 120C, and 120K are arranged in the order of the photoreceptor units 120Y, 120M, 120C, and 120K from the upstream side to the downstream side with respect to the circumferential direction of the intermediate transfer belt 141. Here, the “downstream side” is, in other words, a side close to a position where secondary transfer described later is performed. Each of the photoconductor units 120Y, 120M, 120C, and 120K includes a rotating roll-shaped photoconductor drum, a charger, and a developer. The photoconductive drum is a cylindrical member having a photoconductive layer formed on the surface thereof, and an electrostatic latent image formed on the charged photoconductive layer or a toner image formed by developing the electrostatic latent image. Hold. The photosensitive drums of the respective colors are in contact with the intermediate transfer belt 141 at different positions.

  In the following, when it is not necessary to distinguish each of the photoconductor units 120Y, 120M, 120C, and 120K, these are collectively referred to as “photoconductor units 120”. The photoreceptor unit 120 may be configured to be detachable from the image forming apparatus 10 and replaceable. The photoconductor unit 120 is an example of an image forming unit according to the present invention.

  The exposure unit 130 irradiates each of the photoconductor units 120 with light and generates a potential difference in the photoconductive layer to form an electrostatic latent image. In the present embodiment, means for forming a toner image on the photosensitive drum is realized by the cooperation of the exposure unit 130 and the developing unit of the photosensitive unit 120. A direction in which the exposure unit 130 scans the photosensitive drum line by line is referred to as a main scanning direction. In this example, the main scanning direction coincides with the width direction (Y-axis direction) of the intermediate transfer belt 141.

  The belt module 140 includes an intermediate transfer belt 141, a plurality of primary transfer rolls 142Y, 142M, 142C, 142K, a plurality of support rolls 143, 144, 145, 146, 147, and a secondary transfer roll 148. The intermediate transfer belt 141 is an endless belt member to which the toner image of each color formed by the photoconductor unit 120 is transferred and conveys the transferred toner image. The intermediate transfer belt 141 is supported with tension by support rolls 143 to 147 and rotates in the direction of arrow A in the figure. The primary transfer rolls 142Y, 142M, 142C, and 142K correspond to the photoreceptor units 120Y, 120M, 120C, and 120K, and transfer the toner images formed on the opposing photoreceptor drums to the intermediate transfer belt 141. This transfer (primary transfer) is performed using a potential difference. The support rolls 143 to 147 are examples of a belt support member according to the present invention, and are roll-shaped members that support the intermediate transfer belt 141 in a rotatable state. At least one of the support rolls 143 to 147 is rotated by a driving force given by a driving unit (not shown) to rotate the intermediate transfer belt 141. The secondary transfer roll 148 faces the intermediate transfer belt 141 to form a nip region (a region in which toner or a recording medium is sandwiched), and transfers the toner image transferred to the intermediate transfer belt 141 to the recording medium in the nip region. . This transfer (secondary transfer) is also performed using a potential difference in the same manner as the primary transfer.

  The fixing unit 150 heats and pressurizes the recording medium by a pair of opposing members, and fixes the toner image transferred to the recording medium. The recording medium is fixed in a state where the toner images of the respective colors are superimposed, whereby an image that can be visually recognized by the user is formed and discharged.

  The belt position detection device 200 is provided at a predetermined position of the belt module 140 and detects a position variation in the direction perpendicular to the circumferential direction of the intermediate transfer belt 141 (position variation in the Y-axis direction in the figure). In this example, the belt position detection device 200 is disposed on the back side (Y (+) side) of the intermediate transfer belt 141 at a position between the photosensitive unit 120M and the photosensitive unit 120Y. Detects position fluctuation at the end of the upper traveling part.

  FIG. 2 is a schematic diagram showing an example of the configuration of the belt position detection device 200, and shows the belt position detection device 200 together with the end portion of the intermediate transfer belt 141. In this example, the belt position detection device 200 constitutes a device main body 201, a moving member 202 that is rotatably supported by the device main body 201 around a fulcrum 205, and a detection unit that detects a change in the position of the moving member 202. A light emitting unit 206 and a light receiving unit 207 are included. A recess 201A is formed on the side of the apparatus main body 201 facing the moving member 202, and the light emitting unit 206 and the light receiving unit 207 are disposed to face each other in the recess 201A. One end portion of the moving member 202 functions as a contact portion 203 that contacts the end of the intermediate transfer belt 141. The moving member 202 is urged by the spring member 208 in the direction of arrow a (counterclockwise) in FIG. 2, whereby the contact portion 203 is in contact with the intermediate transfer belt 141 while being pressed. The other end of the moving member 202 extends into the recess 201 </ b> A of the apparatus main body 201 and forms a light shielding portion 204. That is, part of the light emitted from the light emitting unit 206 provided in the recess 201 </ b> A toward the light receiving unit 207 is blocked by the light blocking unit 204, and the light that is not blocked is received by the light receiving unit 207. In such a configuration, when the position of the end of the intermediate transfer belt 141 in the width direction fluctuates, the contact portion 203 of the moving member 202 moves in the directions of arrows a and b around the fulcrum 205, and accordingly the light shielding portion 204 The amount of light that is blocked changes, and the amount of light received by the light receiving unit 207 changes. That is, the belt position detection device 200 detects a change in the position of the end of the intermediate transfer belt 141 as a change in the amount of light received by the light receiving unit 207.

  Further, since the moving member 202 is configured such that the contact portion 203 is urged in the direction of arrow a by the spring member 208, for example, when the intermediate transfer belt 141 is removed from the belt module 140 for replacement, the moving member 202 is retracted as will be described later. When the mechanism 300 is not provided, the contact portion 203 falls down in the arrow a direction. If the replacement intermediate transfer belt 141 is attached to the belt module 140 in a state where the contact portion 203 is tilted in the direction of the arrow a, the intermediate transfer belt 141 may run on the contact portion 203. In FIG. 2, the spring member 208 is described as a coil spring. However, any shape may be used as long as the spring urges the contact portion 203 in the direction of arrow a. For example, the spring member 208 is a torsion spring. May be.

  FIG. 3 is a perspective view showing the relationship between the intermediate transfer belt 141 and the belt position detecting device 200 in the belt module 140. As shown in FIG. 3, the belt position detection device 200 is attached to the inner side surface (the surface facing the intermediate transfer belt 141) of the plate body 140 </ b> A that forms the side surface of the belt module 140, and The contact portion 203 (moving member 202) of the position detection device 200 comes into contact. The upper end portion of the contact portion 203 protrudes above the upper end of the plate body 140A. The belt position detection device 200 has its device body 201 fixed to the plate body 140A by means such as screwing. In FIG. 3, the retraction mechanism 300 described later is omitted in order to clearly show the relationship between the intermediate transfer belt 141 and the belt position detection device 200.

  FIG. 4 is a diagram illustrating the drawing of the belt module 140 from the housing 1 of the image forming apparatus 10 and the movement to the belt replacement position. 4A shows a state in which the belt module 140 is pulled out from the housing 1 of the image forming apparatus 10, and FIG. 4B shows a state in which the belt module 140 is pulled out from the housing 1 and then moved to the belt replacement position. Indicates the state of the

  As shown in the drawing, the casing 1 forming the outer shape of the image forming apparatus 10 has a frame structure 2 that extends in the left-right, front-rear, and vertical (X, Y, Z-axis) directions. In the frame structure 2, the beam portion 3 that is located at an intermediate portion in the height direction (Z-axis) and extends in the front-rear direction (Y-axis direction) of the image forming apparatus 10 is a module support portion 4 that supports the belt module 140. Is supported so as to be slidable in the direction of arrow P (in this example, the forward direction of the image forming apparatus 10) and in the opposite direction, and forms a drawer mechanism together with the module support portion 4. The module support unit 4 has a lifting mechanism that moves the downstream side (Y (−) side) of the belt module 140 in the arrow U direction after being pulled out in the arrow P direction.

  During normal operation, the belt module 140 is accommodated in the casing 1 together with the module support 4 (the position of the belt module 140 at this time is referred to as an accommodation position). When the intermediate transfer belt 141 is replaced, as shown in FIG. 4A, the belt module 140 and the module support portion 4 are moved in the direction of the arrow P and pulled out from the housing 1 (the belt module 140 at this time). Further, as shown in FIG. 4B, the belt module 140 is lifted with respect to the upstream side in the pulling direction by the lifting mechanism (the front side in this example) with respect to the upstream side. Be changed. In the present embodiment, the intermediate transfer belt 141 can be replaced (removed) while the front side of the belt module 140 is lifted (that is, the belt module 140 is tilted rearward). The position of the belt module 140 where the intermediate transfer belt 141 can be replaced is called a belt replacement position, and the position of the belt module 140 shown in FIG. 4B is an example of the belt replacement position. The lifting mechanism that lifts the front side of the belt module 140 may be operable by an operator who replaces the intermediate transfer belt 141.

  FIG. 5 is a perspective view showing the retracting mechanism 300 according to the embodiment of the present invention together with the belt module 140 and the module support portion 4. 5A shows the retracting mechanism 300, the belt module 140, and the module support unit 4 in the pull-out position, and FIG. 5B shows the retracting mechanism 300, the belt module 140, and the module support unit 4 in the belt replacement position. Note that when moving between the storage position and the withdrawal position, the belt module 140 and the module support 4 are moved together and their relative positions do not change, so FIG. 5A shows the retraction mechanism 300 at the storage position. It can also be said that the belt module 140 and the module support part 4 are shown. When the intermediate transfer belt 141 is replaced, the retracting mechanism 300 moves the contact portion 203 (moving member 202) of the belt position detecting device 200 to the retracted position.

  As shown in FIG. 5, the retracting mechanism 300 includes a lever 301, a support body 305, and a fixing plate 310. The support body 305 is fixed to the outer surface (surface facing away from the intermediate transfer belt 141) of the plate body 140A forming the side surface of the belt module 140 by screws or the like, and the shaft portion 302 of the lever 301 described later can be rotated. To support. The fixed plate 310 is a plate that is fixed to the module support 4 and extends in the Z-axis direction. As shown in the perspective view of FIG. 6, the lever 301 extends in the direction away from the moving member 202 from the shaft portion 302 extending in the X-axis direction while being rotatably supported by the support body 305. It has the 1st arm 303 and the 2nd arm 304 extended in the direction which goes to the moving member 202 from the other end of the axial part 302. As shown in FIG. More specifically, the first arm 303 extends downward (Z (−) direction) and rearward (Y (+) direction) from one end of the shaft portion 302, and then further bends and extends downward. The second arm 304 extends upward (Z (+) direction) from the other end of the shaft portion 302, then bends and extends forward (Y (−) direction) beyond the plate body 140A. As will be described later, the end portion of the first arm 303 presses against the fixing plate 310 when the belt module 140 is moved to the belt replacement position (an example of a preparatory operation for replacing the belt member). The end portion of the second arm 304 extends in the X-axis direction on the front side (Y (−) side) of the contact portion 203 of the belt position detection device 200, and when the belt module 140 is in the drawing position (or accommodation position) ( FIG. 5A) is located away from the contact portion 203 in the Y-axis direction. The shaft 302 and the support body 305 of the lever 301 are provided with a torsion spring 306 that biases the lever 301 in the direction indicated by the arrow R in FIG. When the belt module 140 is in the pulled-out position (or housed position) (FIG. 5A), the vertically extending portion of the second arm 304 of the lever 301 hits the plate body 140A, and the rotation of the lever 301 in the R direction is performed. It is regulated.

  When the belt module 140 is tilted in the direction of the arrow U with respect to the module support portion 4 in order to move the belt module 140 from the pulled-out position to the belt replacement position (FIG. 5B), the belt module 140 is provided on the plate body 140A. As a result, the end of the first arm 303 of the lever 301 hits the fixing plate 310. As a result, the lever 301 rotates about the shaft 302, and the end of the second arm 304 of the lever 301 opposes the urging force of the torsion spring 306 (in the direction of arrow S in FIG. 8). Move to. At that time, the end portion of the second arm 304 is caught by the contact portion 203 (moving member 202) of the belt position detecting device 200, and the contact portion 203 is moved to the retracted position. In order to facilitate the movement of the contact portion 203 by the lever principle, the distance from the end portion of the first arm 303 that contacts the fixing plate 310 to the shaft portion 302 is from the end portion of the second arm 304 that is caught by the contact portion 203. It is longer than the distance to the shaft portion 302.

  The operation of the retraction mechanism 300 will be described in more detail with reference to FIGS. FIG. 7 is a view schematically showing the operation of the retracting mechanism 300 with respect to the movement of the belt module 140 to the belt replacement position. FIG. 8 is an end portion of the second arm 304 with respect to the movement of the belt module 140 to the belt replacement position. 2 is a diagram schematically showing the positional relationship between the contact portion 203 of the belt position detecting device 200 and FIG.

  FIG. 7A shows a state in which the belt module 140 is pulled out from the housing 1, and FIG. 7B shows a state in which the fixing plate 310 is attached to the lever 300 while the belt module 140 is being moved to the belt replacement position. FIG. 7C shows a state in which the arm 1 hits the arm 303, and a state in which the belt module 140 has been moved to the belt replacement position. FIGS. 8A to 8C correspond to FIGS. 7A to 7C, respectively. In these drawings, it is assumed that the intermediate transfer belt 141 is in a neutral position that is not displaced in the width direction.

  When the belt module 140 is in the pulled-out position, the fixing plate 310 and the end of the first arm 303 are separated from each other, and the retracting mechanism 300 does not act on the belt position detecting device 200. That is, as shown in FIG. 8A, the end of the second arm 304 of the retracting mechanism 300 and the contact portion 203 are separated by a gap Δa. As described above, since the relative positional relationship between the belt module 140 and the module support portion 4 does not change between the drawing position and the housing position, the gap Δa is also maintained at the housing position of the belt module 140. Therefore, even if the intermediate transfer belt 141 moves in the Y (−) direction from the neutral position at the retracted position, the retracting mechanism 300 moves the contact portion 203 (moving member) of the belt position detecting device 200 within the gap Δa. 202) and does not interfere with belt position detection.

  As described above, when the belt module 140 is pulled out of the housing 1 and then moved in the arrow U direction to move to the replacement position, the lever 301 provided on the belt module 140 also moves together. By this movement, the end of the first arm 303 of the lever 301 is pressed against the fixed plate 310, and the lever 301 is rotated in the direction of the arrow S about the shaft portion 302 supported by the support 305, as shown in FIG. As shown in b) and FIG. 8B, the second arm 304 of the lever 301 reaches the contact portion 203.

  Further, when the belt module 140 is tilted and moved to the belt replacement position, the lever 301 further rotates in the direction of the arrow S about the shaft portion 302 as shown in FIGS. 7 (c) and 8 (c). As a result, the end portion of the second arm 304 of the lever 301 is caught by the contact portion 203, and the contact portion 203 is rotated about the fulcrum 205 in the direction away from the end of the intermediate transfer belt 141 (clockwise in the figure). As a result, a gap Δb is formed between the contact portion 203 and the end of the intermediate transfer belt 141 at the neutral position. The position of the contact portion 203 (moving member 202) shown in FIGS. 7C and 8C is referred to as a retracted position. While the belt module 140 is in the belt replacement position, the state where the end portion of the first arm 303 of the lever 301 is pressed against the fixing plate 310 of the module support portion 4 is maintained. Therefore, the retracting mechanism 300 holds the contact portion 203 (the moving member 202) in the retracted position while the belt module 140 is in the belt replacement position.

  As described above, according to the present embodiment, in conjunction with the operation of moving the belt module 140 to the belt replacement position, the retracting mechanism 300 moves the contact portion 203 (the moving member 202) to the retracted position to the neutral position. A gap Δb is automatically formed between an intermediate transfer belt 141 and the contact portion 203 (moving member 202). This gap Δb is maintained during belt replacement work (that is, while the belt module 140 is in the belt replacement position). Therefore, when the intermediate transfer belt 141 is replaced, the intermediate transfer belt 141 after replacement is replaced with the belt position detection device. It is possible to suppress wearing in a state of riding on the contact portion 203 of 200.

[Modification]
As mentioned above, although embodiment of this invention was described, you may deform | transform the embodiment mentioned above as follows. Further, the following modifications may be combined.

(Modification 1)
In the above-described embodiment, the belt member is an intermediate transfer belt that transfers the toner images of the respective colors formed by the photosensitive unit and transfers the transferred toner images. However, the present invention is not limited to this. For example, the belt member may convey a recording medium on which the toner image is transferred, and the belt member may be modularized together with a support roll or the like that supports the recording medium and can be replaced.

(Modification 2)
In the embodiment described above, after the belt module 140 is pulled out of the housing, the retracting mechanism 300 is tilted by lifting the downstream side in the pulling direction with respect to the upstream side (that is, an operation for moving the belt module 140 from the pulling position to the belt replacement position). In conjunction with this, the moving member 202 of the belt position detecting device 200 is moved to the retracted position. However, the present invention is not limited to this. The retracting mechanism 300 may be configured to move the moving member 202 to the retracted position in conjunction with another preparation operation for replacing the belt member. For example, the retracting mechanism 300 may move the moving member 202 to the retracted position in conjunction with the operation of pulling out the belt module 140 from the housing 1. Alternatively, the retraction mechanism 300 is linked to an operation of moving at least one of the support rolls supporting the intermediate transfer belt 141 inward in order to weaken the tension of the intermediate transfer belt 141 before replacing the intermediate transfer belt 141. The moving member 202 may be moved to the retracted position. In order to move the belt module 140 to the belt replacement position, in addition to or in addition to the operation of lifting and tilting the front side of the belt module 140, when performing another posture changing operation, the retracting mechanism 300 is The moving member 202 may be moved to the retracted position in conjunction with another posture changing operation. In short, the moving member 202 only needs to be moved to the retracted position when the belt member is replaced.

(Modification 3)
In the above embodiment, the image forming apparatus 1 is described as a printer, but the image forming apparatus 1 may be a copier. In that case, the image forming apparatus 1 includes an image reading unit (scanner), and the image reading unit generates image data from the read image and sends the image data to the image data acquisition unit. The image forming apparatus 1 may have not only a printer function but also a facsimile communication function and a scanner function.

(Modification 4)
In the above embodiment, the belt module 140 is pulled out from the housing 1 to the front of the image forming apparatus 10, but the present invention is not limited to this. The belt module 140 may be pulled out to the back side of the image forming apparatus 10.

DESCRIPTION OF SYMBOLS 1 ... Case, 2 ... Frame structure, 3 ... Beam part, 4 ... Module support part, 10 ... Image forming apparatus, 110 ... Paper feed part, 120Y, 120M, 120C, 120K ... Photosensitive unit, 130 ... Exposure part, DESCRIPTION OF SYMBOLS 140 ... Belt module, 140A ... Plate body, 141 ... Intermediate transfer belt, 142Y, 142M, 142C, 142K ... Primary transfer roll, 143, 144, 145, 146, 147 ... Support roll, 148 ... Secondary transfer roll, 150 ... Fixing unit, 200 ... belt position detection device, 201 ... belt position detection device main body, 201A ... concave, 202 ... moving member, 203 ... contacting unit, 204 ... light shielding unit, 205 ... fulcrum, 206 ... light emitting unit, 207 ... light receiving unit , 208 ... Spring member, 300 ... Retraction mechanism, 301 ... Lever, 302 ... Shaft, 303 ... First arm, 304 ... Second arm, 305 Support, 306 ... torsion spring 310 ... fixing plate

Claims (5)

A belt module having an endless belt member that is supported by a plurality of belt support members and driven to circulate;
Belt position detection means provided in the belt module, comprising a moving member that contacts the end of the belt member and moves in accordance with the movement of the belt member in the width direction. In response, belt position detecting means for detecting the position of the belt member in the width direction;
A belt driving device comprising: a moving mechanism that moves the moving member of the belt position detecting means in a direction away from the end of the belt member in conjunction with a preparatory operation for replacing the belt member of the belt module.   2. The belt driving device according to claim 1, wherein the preparatory operation for exchanging the belt member is an operation of moving the belt module to a belt exchanging position where the belt member can be exchanged. . A housing for housing the belt module;
Module support means for supporting the belt module so that it can be pulled out from the housing;
The belt replacement position is a position where, after the belt module is pulled out from the housing, the downstream side in the pull-out direction of the belt module is lifted with respect to the upstream side. The belt drive device described in 1. The moving mechanism includes a fixing member fixed to the module support means;
A support fixed to the belt module;
A shaft portion rotatably supported by the support body, a first arm extending in a direction away from the moving member from one end of the shaft portion, and a second extending in a direction from the other end of the shaft portion toward the moving member. A lever having an arm, and
When the belt module is moved to the belt replacement position, the first arm of the lever is pressed against the fixing member, so that the lever rotates around the shaft portion, and the second of the lever An arm is caught by the moving member, and the moving member is moved away from the end of the belt member;
The distance from the part pressed against the fixing member of the first arm to the shaft part is longer than the distance from the part hooked on the moving member of the second arm to the shaft part. The belt drive device described in 1. An image forming unit for forming an image;
A belt drive device according to any one of claims 1 to 4,
The belt member is an image forming apparatus that conveys the image formed by the image forming unit or a sheet onto which the image is transferred.

Images