JP5870784B2 - Belt misalignment correction mechanism and image forming apparatus including the same - Google Patents

Description

  The present invention relates to a belt misalignment correcting mechanism and an image forming apparatus including the belt misalignment correcting mechanism, and in particular, a belt misalignment correcting mechanism that detects and restores a belt misalignment using only the mechanism without using electrical means such as a sensor or a motor. And an image forming apparatus including the same.

  Conventionally, in a belt driving device having an endless belt stretched over a plurality of rollers, the phenomenon of belt deviation in which the belt being driven is offset toward one of the two end portions of the roller is unavoidable. Is a problem.

  By the way, even with the same belt, it is necessary to suppress the load applied to the belt as much as possible in the relatively flexible conveyance belt and intermediate transfer belt used in the image forming apparatus. Then, it is necessary to incorporate a belt misalignment correction mechanism capable of stable belt travel.

  As such a belt misalignment correction mechanism, a method of inclining one of the rollers around the belt is generally used. For example, there has been proposed a method of detecting a shift using a sensor and tilting a roller by driving a motor. (For example, refer to Patent Document 1.)

Japanese Patent Laid-Open No. 2000-272772

  However, when the electric means of motor drive control based on the detection of the sensor as described above is used, precise and stable control is possible. There is a problem in terms of cost because it is necessary to prepare a different program for each.

  The present invention solves the above-described conventional problems, and includes a belt misalignment correction mechanism that detects and restores belt misalignment using only the mechanism without using electrical means such as a sensor and a motor, and the like. An object is to provide an image forming apparatus.

In order to solve the above-described problems, a belt misalignment correction mechanism according to the present invention is stretched over a tension roller supported by one shaft end as a fulcrum and the other shaft end in a swingable manner, and the tension roller. The belt is arranged in the vicinity of the swinging end of the tension roller and rotated in a direction crossing the belt surface of the belt depending on whether or not there is sliding contact with the end of the belt due to the offset. A belt-side interlocking member that is movably disposed, and one end of the belt-side interlocking member is engaged with the belt-side interlocking member, and the direction parallel to the belt surface corresponds to the rotation of the belt-side interlocking member in the cross direction. An interlocking lever that rotates to the other, a gear system that engages with or releases the other end of the interlocking lever, and a correction execution unit that holds the other shaft end of the tension roller. The belt is perpendicular to the running direction of the belt and is offset in a direction parallel to the belt surface. To correct the deviation of the belt, as configured.

  In order to solve the above-described problems, the image forming apparatus of the present invention is configured by including the belt misalignment correcting mechanism in the transfer belt.

  The present invention relates to a belt offset interlocking member that detects the deviation of the belt without using electrical means such as a sensor and a motor, an interlocking lever that interlocks with the belt offset interlocking member, and a gear system that engages with the interlocking lever. Thus, it is possible to provide a belt misalignment correction mechanism that detects and restores a belt misalignment using only a mechanism composed of the above-described combinations, and an image forming apparatus including the same.

1 is a cross-sectional view illustrating an internal configuration of a full-color image forming apparatus (printer, main body apparatus) including a belt misalignment correcting mechanism according to Embodiment 1 of the present invention. (a), (b), (c) is a figure which shows the structure of the belt deviation correction mechanism based on Example 1 with a driven roller. (a) is a perspective view of FIG. 2 (a) viewed in the direction of arrow b, and (b) is a correction of (a) with the correction execution unit lowered to the storage position of the execution unit storage frame and covered with a protective lid. It is the top view seen from the top of (a) in the state which removed the mechanism holding | maintenance part and the execution part accommodation frame. (a) is a perspective view of a belt offset interlocking member, (b) is a side view of (a) viewed in the direction of arrow c, (c) is a top view of (b), and (d) is a bottom view of (b). It is. (a), (b) is a figure explaining the engagement relationship between the cam part of a belt shift | linkage interlocking member, and the cam engagement lever of an interlocking lever, and its operation state. (a) is the top view which rotated 90 degree | times clockwise FIG.5 (b), (b) is the AA cross-sectional arrow view of (a).

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

  FIG. 1 is a cross-sectional view illustrating an internal configuration of a full-color image forming apparatus (hereinafter simply referred to as a printer or a main body apparatus) provided with a belt misalignment correcting mechanism according to Embodiment 1 of the present invention.

  A printer 1 shown in FIG. 1 is an electrophotographic secondary transfer tandem color image forming apparatus, and includes an image forming unit 2, a transfer belt unit 3, a toner supply unit 4, a paper feeding unit 5, and a belt type fixing device. It comprises a unit 6 and a transport unit 7 for duplex printing.

  The image forming unit 2 is in contact with the lower running portion surface 8a of the transfer belt 8 from right to left in FIG. Four image forming units 9 (9k, 9c, 9m, 9y) are arranged in a multistage manner.

  The image forming unit 2 is held by a frame of the printer 1 main body so as to be movable up and down from a printing execution position shown in FIG. 1 to a maintenance position below it. Of the four image forming units 9, three image forming units 9y, 9m, and 9c on the upstream side (the left side in the figure) are subtractive mixed primary colors yellow (Y), magenta (M), cyan ( A monocolor image is formed with the color toner of C).

  The image forming unit 9k forms a monochrome image using black (K) toner mainly used for characters and dark portions of images. Each of the image forming units 9 has the same configuration except for the color of the toner for developing the image. Accordingly, the configuration of the image forming unit 9y for yellow (Y) toner will be described below as an example.

  The image forming unit 9 includes a photosensitive drum 10 as an image carrier at the top. The photosensitive drum 10 has a peripheral surface made of, for example, an organic photoconductive material. A cleaner 11, a charging roller 12, an optical writing head 13, and a developing roller 15 of the developing device 14 are disposed in contact with or surrounding the periphery of the photosensitive drum 10.

  The developing device 14 includes a unit housing 16 that covers the outside, a partition wall 17 provided inside, a developing roller 15, a first stirring and conveying screw 18, and a second stirring and conveying screw 19. Although not specifically shown, the first and second agitating and conveying screws 18 and 19 include a screw shaft and a fin that is integrally formed with the screw shaft and rotates.

  The developing unit 14 includes a toner supply container 20 (20y, 20m, 20c, and 20k) of the toner supply unit 4, and yellow (Y) and magenta (M) as indicated by Y, M, C, and K in FIG. ), Cyan (C), or black (K) toner is supplied.

  The transfer belt unit 3 includes the above-described endless transfer belt 8 extending in a flat loop shape in the left-right direction in the figure at the approximate center of the main body device.

  The transfer belt 8 includes a driving roller 21, a driven roller 22, four primary transfer rollers 23, a secondary transfer auxiliary roller 24, which are pivotally supported by the frame of the transfer belt unit 3 and integrated with the transfer belt unit 3. A belt tension roller 25 and the like are stretched over.

  The transfer belt 8 is driven by a driving roller 21 and circulates in a counterclockwise direction indicated by an arrow a in the figure. The primary transfer roller 23 is pressed against the photosensitive drum 10 via the transfer belt 8 and directly transfers (primary transfer) the toner image to the lower running portion surface 8a of the transfer belt 8 that circulates downward.

  The transfer belt 8 conveys the primary-transferred toner image to the paper secondary transfer unit 26 for secondary transfer onto the paper. The secondary transfer unit 26 includes a transfer auxiliary roller 24 disposed on the downstream side (upward in the drawing) adjacent to the drive roller 21, and a secondary transfer roller 27 that presses the transfer auxiliary roller 24 via the transfer belt 8. And is formed.

  A belt cleaner 28 is disposed on the transfer belt 8. The belt cleaner 28 scrapes and removes the residual toner remaining on the surface of the transfer belt 8 by a cleaning blade that contacts the surface of the transfer belt 8 that is stretched around the driven roller 22.

  The removed waste toner is sent to a waste toner collection container 29 disposed adjacently from the left to the bottom of the belt cleaner 28 by a conveying screw (not shown) in the belt cleaner 28.

  The toner supply unit 4 includes four toner supply containers 20 (20y, 20m, 20c, and 20k) that are detachably disposed above the upper running unit of the transfer belt 8. As described above, the four toner supply containers 20 contain yellow (Y), magenta (M), cyan (C), and black (K) toners.

  These four toner replenishing containers 20 are hidden behind the opposite side of the transfer belt unit 3 in FIG. 1 but are not visible, but each corresponding image forming unit 9 via a toner supply path following the toner supply port of the mounting portion. The developing device 14 is connected.

  Although not particularly illustrated, the toner supply unit 4 is held on the frame of the main body of the printer 1 through a mounting unit so as to be movable up and down from a printing execution position shown in FIG. 1 to a maintenance position above it.

  The paper feed unit 5 includes two paper feed cassettes 30 (30a, 30b) arranged in two upper and lower stages. A paper take-out roller 31, a feed roller 32, a separating roller 33, and a standby conveyance roller pair 34 are disposed in the vicinity of the paper feed opening (right side in the figure) of the two paper feed cassettes 30, respectively.

  In the paper conveyance direction (vertical upward direction in the drawing) of the standby conveyance roller pair 34, the above-described secondary transfer portion 26 to the paper by the transfer belt 8, the transfer auxiliary roller 24, and the secondary transfer roller 27 is formed.

  The belt-type fixing unit 6 is disposed downstream (upward in the drawing) of the secondary transfer unit 26, and the fixed sheet is carried out of the belt-type fixing unit 6 further downstream of the belt-type fixing unit 6. A pair of carry-out rollers 36 and a pair of paper discharge rollers 38 that discharge the discharged paper to a paper discharge tray 37 formed on the upper surface of the apparatus are disposed.

  The conveyance unit 7 for double-sided printing also serves as an opening / closing member whose outer surface (right outer surface in the drawing) opens or shields the inside of the printer 1 from the side surface to the outside.

  This duplex printing transport unit 7 has a start return path 39a that branches rightward in the figure from just before the paper discharge roller pair 38, an intermediate return path 39b that bends downward, and a left lateral direction opposite to the above. Thus, a return path 39 including a terminal return path 39c for finally inverting the return sheet is provided.

  In the middle of the return path 39, five pairs of return rollers 41 (41a, 41b, 41c, 41d, 41e) are arranged. The exit of the end return path 39 c joins the conveyance path to the pair of standby conveyance rollers 34 corresponding to the sheet feeding cassette 30 b below the sheet feeding unit 5.

  2A, 2 </ b> B, and 2 </ b> C are views showing the configuration of the belt deviation correcting mechanism of this example together with the driven roller 22. FIG. 2A is a perspective view of the correction execution unit 42 that is lifted upward from the execution unit housing frame 44 of the correction mechanism holding unit 43 together with the shaft end side of the driven roller 22 for easy understanding.

  2B is a top view of the state in which the correction execution unit 42 is stored in the execution unit storage frame 44 and covered with the protective cover 45 from above, as viewed from the top of FIG. FIG. 2C is a side view of FIG. 2B viewed in the direction of arrow a. In FIG. 2B, the correction mechanism holding unit 43 and the execution unit storage frame 44 of FIG. 2A are removed.

  FIG. 3A is a perspective view of FIG. 2A viewed in the direction of the arrow b, and FIG. 3B is a diagram illustrating a state where the correction execution unit 42 is lowered to the storage position of the execution unit storage frame 44 and the protective lid 45 is used. It is the top view which looked at the state which covered the lid from the top of Drawing 3 (a). FIG. 3B shows a state in which the correction mechanism holding unit 43 and the execution unit storage frame 44 of FIG. 3A are removed.

  Note that the broken line 8 shown in FIGS. 2B and 3B indicates the end position of the transfer belt 8. As shown in FIGS. 2 (a), (b), (c) and FIGS. 3 (a), (b), the belt-side correction mechanism of this example includes a correction mechanism holding portion 43, a belt-side interlocking member 46, and interlocking. The lever 47, the correction execution unit 42, and the like are configured.

  The correction mechanism holding portion 43 is fixed to the frame on the main body side of the image forming apparatus 1 and is disposed in the vicinity of the shaft on the side surface of the driven roller 22. In this example, the driven roller 22 stretches the transfer belt 8 and provides a function of a stretch roller that corrects the deviation of the transfer belt 8 in the direction orthogonal to the traveling direction by tilting one of the shaft ends vertically. It has been.

  In FIG. 2C, the position of the transfer belt 8 indicated by a broken line appears to float above the peripheral surface of the driven roller 22 on the upstream side of the upper running surface of the transfer belt 8 in the running direction. This is because the belt tension roller 25 shown in FIG. 1 is lifted upward.

  As shown in FIG. 2 (c), the belt-shift interlocking member 46 is pivotally supported around a support shaft 48 so as to be rotatable in the arrow Z direction. The support shaft 48 is fixed to a frame (not shown) of the correction mechanism holding portion 43. The belt shift interlocking member 46 includes an upper surface portion 49, a vertical plate-like portion 51, and a cam portion 52. Here, the belt shift interlocking member 46 will be described in more detail.

  4 (a) is a perspective view of the belt-shifting interlocking member 46, FIG. 4 (b) is a side view of FIG. 4 (a) in the direction of arrow c, and FIG. 4 (c) is the same view (b). FIG. 4D is a bottom view of FIG. The upper surface of the upper surface portion 49 of the belt-shifting interlocking member 46 has a rectangular shape, and is formed on a flat surface with good slip so that the end portion of the transfer belt 8 can slide with little resistance.

  The entire belt-shifting interlocking member 46 is formed so that the rectangular longitudinal direction of the upper surface of the upper surface portion 49 is inclined upward from the inner side where the support shaft 48 is located to the outer side. A vertically extending vertical plate-like part 51 is formed integrally with the upper surface part 49 below the upper surface part 49.

  The lower surface of the lower edge of the vertical plate-like portion 51 forms a cam portion 52. The cam portion 52 forms a smooth inclined surface substantially parallel to the inclined surface of the upper surface portion 49, and a bent portion 52a whose inclination gradually changes in the vicinity of the outer end portion is formed.

  The description will return to FIGS. 2 (a), (b), (c) and FIGS. 3 (a), (b). The interlocking lever 47 is pivotally supported at the central portion 53 by a support shaft 54 so as to be rotatable in the horizontal direction. The support shaft 54 is fixed to the flat surface portion 55 of the correction mechanism holding portion 43.

  The cam engaging lever extends from one side surface of the central portion 53 (the left side surface in FIG. 2 (b) and the right side surface in FIGS. 3 (a) and 3 (b)) to the bottom of the cam portion 52 of the belt shift interlocking member 46. 56 extends. One end of a biasing member 57 is engaged in the vicinity of the center of the cam engagement lever 56.

  The other end of the urging member 56 is locked to a locking portion (not shown) of the correction mechanism holding portion 43. The biasing member 56 biases the entire interlocking lever 47 via the cam engagement lever 56 in the counterclockwise rotation direction when viewed from above.

  Further, from the other side surface of the central portion 53 of the interlocking lever 47 (the right side surface in FIG. 2B and the left side surface in FIGS. 3A and 3B), the outer side surface ( The rack lever 58 extends to the outer surface of the driven roller 22 as viewed in the axial extension direction.

  A rack 59 is formed in the lateral direction of the rack lever 58, that is, in the vertical direction, on the side surface of the end of the rack lever 58 that faces the correction execution unit 42. Here, the engagement relationship between the belt shift interlocking member 46 and the interlocking lever 47 will be described.

  FIGS. 5A and 5B are views for explaining the engagement relationship between the cam portion 52 of the belt-shifting interlocking member 46 and the cam engaging lever 56 of the interlocking lever 47 and its operating state. 5 (a) and 5 (b), the same components as those shown in FIGS. 2 to 4 are denoted by the same reference numerals as those in FIGS.

  FIG. 5A is a view of FIG. 3B viewed in the direction of the arrow d. In other words, FIGS. 5A and 5B are views of the driven roller 22 as viewed from the inside of the transfer belt unit 3 shown in FIG. Accordingly, the left side of the figure is the front side of the image forming apparatus main body, and the right side of the figure is the rear side of the image forming apparatus main body.

  As shown in FIGS. 5A and 5B, the upper edge portion 61 of the end portion of the cam engagement lever 56 of the interlocking lever 47 is always in sliding contact with the cam portion 52 of the belt shift interlocking member 46. In the state shown in FIG. 5A, the end portion of the transfer belt 8 is almost detached from the belt shift interlocking member 46. That is, a state in which the transfer belt 8 is close to the rear of the main body apparatus is shown.

  In this case, since the pressing from the end of the transfer belt 8 to the belt-shifting interlocking member 46 is eliminated, the cam engaging lever 56 of the interlocking lever 47 is pushed by the biasing force of the biasing member 57 and the upper edge 61 of the end. The cam engaging lever 56 rotates in the direction of the belt-shifting interlocking member 46 while sliding the cam portion 52 in sliding contact with the cam portion 52.

  Therefore, the rack lever 58 rotates counterclockwise as viewed from above with the support shaft 54 as a fulcrum. That is, the rack 59 of the rack lever 58 shown in FIGS. 2 (b) and 2 (c) and FIGS. 3 (a) and 3 (b) is separated from the pinion 62 of the correction execution unit 42.

  Since the engagement between the pinion 62 and the rack 59 is released, the correction execution unit 42 is largely hidden on the side facing the drawing depth direction of the support shaft 54 of the interlocking lever 47 and is not clearly visible. It is pushed upward together with the shaft end of the driven roller 22 by the biasing member 63.

  As a result, the driven roller 22 has a shape in which the front end is inclined upward with respect to the rear end on the right side of the figure, so that the transfer belt 8 is in the direction of the front end of the driven roller 22. And the state of the transfer belt 8 approaching the rear of the main body is corrected.

  5B, the end portion of the transfer belt 8 runs up to the vicinity of the outer end portion of the upper surface portion 49 of the belt shift interlocking member 46. That is, the transfer belt 8 is close to the front side of the main unit.

  In this case, the belt offset interlocking member 46 rotates downward about the support shaft 48 as a fulcrum by pressing from the end of the transfer belt 8. As a result, the cam portion 52 is also lowered, so that the upper edge portion 61 of the end portion of the cam engaging lever 56 of the interlocking lever 47 is pushed away from the belt-shifting interlocking member 46 along the inclination of the cam portion 52.

  As a result, the cam engagement lever 56 rotates in the clockwise direction in top view against the pressing force of the biasing member 57. Therefore, the rack lever 58 of the interlocking lever 47 is also rotated clockwise with the support shaft 54 as a fulcrum when viewed from above.

  That is, the rack 59 shown in FIGS. 2B and 2C and FIGS. 3A and 3B of the rack lever 58 is engaged with the pinion 62 of the correction execution unit 42.

  Since the pinion 62 and the rack 59 are engaged with each other, the correction execution unit 42 pushes and urges the pinion 62, that is, the entire correction execution unit 42, with the shaft end of the driven roller 22 as will be described in detail later. The member 63 descends against the pushing biasing force.

As a result, the driven roller 22 has a shape in which the front end is inclined downward relative to the rear end on the right side of the figure, so that the transfer belt 8 is in the rear end of the driven roller 22. The state of moving in the direction and approaching the front side of the main body of the transfer belt 8 is corrected. Here, the structure and operation of the correction execution unit 42 will be described.
FIG. 6A is a top view of FIG. 5B rotated 90 degrees to the right, and FIG. 6B is a cross-sectional view taken along the line AA in FIG. 6A. In order to avoid complicated illustrations, the correction mechanism holding portion 43 is not shown in the drawings other than FIGS. 2 (a) and 3 (a).

  Therefore, the correction mechanism holding part 43, the execution part storage frame 44 of the correction mechanism holding part 43, the internal space region 44a, the external opening part 44b, etc., which will be described below, are shown in FIGS. 2 (a) and 3 (a). The explanation will be continued assuming that

  As shown in FIGS. 2 (a), 3 (a), 6 (a), and 6 (b), the correction execution unit 42 is a bevel gear fixed vertically at the tip of the support shaft 64 of the driven roller 22. 65, an idle bevel gear 66 that is meshed with the bevel gear 65 and disposed horizontally, a bevel gear 67 that is meshed with the idle bevel gear 66 and disposed horizontally, and a lower surface of the bevel gear 67 that is integrally connected to the bottom. A cylindrical pinion 62 described above is provided.

  Each of the above members is housed in a casing 42a having a U-shaped flat cross section of the correction execution unit 42. As shown in FIGS. 6A and 6B, spiral teeth 68 formed on the cylindrical peripheral surface of the pinion 62 are exposed in the U-shaped opening of the casing 42a of the correction execution unit 42. doing.

  2 (a) and 3 (a) are shown in an easy-to-understand manner as described above, the correction execution unit 42 is moved from the execution unit storage frame 44 of the correction mechanism holding unit 43 together with the shaft end side of the driven roller 22. It is shown floating up.

  Actually, the correction execution unit 42 is arranged such that the housing 42 a falls into the internal space region 44 a of the execution unit storage frame 44 of the correction mechanism holding unit 43 as it is. The execution portion receiving frame 44 is formed with an external open portion 44b at a portion corresponding to the U-shaped opening of the housing 42a accommodated therein.

  As a result, when the interlocking lever 47 is rotated together with the rack lever 58 in the clockwise direction as described above, the rack 59 at the tip of the rack lever 58 causes the external opening 44b of the execution unit receiving frame 44 to be exposed from the outside. It penetrates inward and comes into close contact with the pinion 62 of the correction execution unit 42.

  The wall surface facing the U-shaped opening in which the pinion 62 of the correction execution unit 42 is disposed is a bearing portion that supports the support shaft 64 of the driven roller 22, and a bearing 69 is fitted therein. It is fixed.

  2 (a), (b), (c), FIG. 3 (a), (b), and FIG. 6 (a), the driven roller 22 always rotates in the direction indicated by the arrow e when the belt is driven. Yes. Accordingly, the support shaft 64 is always rotating together with the bevel gear 65 in the direction indicated by the arrow e as shown in FIG.

  The idle bevel gear 66 that meshes with the bevel gear 65 that rotates in the direction of arrow e rotates in the direction indicated by the direction of arrow f. A bevel gear 67 that meshes with an idle bevel gear 66 that rotates in the direction of arrow f rotates with the pinion 62 in the direction indicated by arrow g.

  The helical shape of the helical teeth 68 of the pinion 62 is formed such that the pinion 62 moves downward relative to the rack 59 when the teeth 68 mesh with the rack 59 and the pinion 62 rotates in the direction of the arrow g. Yes.

  The rack lever 58 having the rack 59, that is, the interlocking lever 47, is supported by the correction mechanism holding portion 43 via the support shaft 54, and can be rotated horizontally and prohibited from moving up and down. Therefore, the vertical position of the rack 59 is fixed with respect to the main body device 1, whereby the pinion 62 moves downward together with the correction execution unit 42 along with the support shaft 63 of the driven roller 22.

  That is, the state in which the rack 59 of the rack lever 58 is engaged with the pinion 62 of the correction execution unit 42 is the state shown in FIG. 5B, and as described in FIG. Since the front end is inclined downward relative to the rear end on the right side of the figure, the transfer belt 8 moves toward the rear end of the driven roller 22, and the transfer belt 8. The state close to the front side of the main unit is corrected.

  When the engagement between the pinion 62 and the rack 59 in FIG. 6B is released, the correction execution unit 42 is pushed up together with the support shaft 64 of the driven roller 22 by the pressing and urging member 63, so that FIG. As described in (a), the front end of the driven roller 22 is inclined upward and the transfer belt 8 moves in the direction of the front end of the driven roller 22, and the rear side of the main body of the transfer belt 8. The condition close to is corrected.

  In this way, the driven roller 22 corrects the deviation of the transfer belt 8 while constantly swinging the front shaft end up and down in the state of FIGS. 5 (a) and 5 (b).

Although several embodiments of the present invention have been described, the present invention is included in the invention described in the claims and the equivalents thereof. Hereinafter, the invention described in the scope of claims of the present application will be appended.
[Appendix 1]

A tension roller supported on one shaft end as a fulcrum and the other shaft end swingably;
A belt that runs around the stretch roller;
Arranged in the vicinity of the swinging side end of the tension roller, and arranged so as to be able to rotate in a direction intersecting the belt surface of the belt depending on whether or not there is sliding contact with the end of the belt due to the offset. A belt-side interlocking member;
An interlocking lever that engages with one end of the belt-side interlocking member and rotates in a direction parallel to the belt surface in response to the rotation of the belt-side interlocking member in the cross direction;
A gear system that engages or disengages the other end of the interlocking lever, and a correction execution unit that holds the one shaft end of the stretching roller;
Have
A belt misalignment correction mechanism that corrects a shift of the belt that is perpendicular to a running direction of the belt and that is offset in a direction parallel to the belt surface.
[Appendix 2]

The belt-sliding interlocking member includes an engaging portion that can slide-contact the end portion of the belt, a plate-like portion erected from the engaging portion, and a cam portion formed on an edge surface of the plate-like portion. And comprising
The one end of the interlocking lever is in sliding contact with the cam portion of the interlocking member near the belt, and a rack is formed at the other end.
The correction execution unit holds a pinion that engages or disengages the rack of the interlocking lever, and a shaft of the swing side end of the stretching roller that engages the pinion via a gear system. A bearing portion;
The belt offset correction mechanism according to Supplementary Note 1, wherein the belt offset correction mechanism is provided.
[Appendix 3]

The belt is displaced in the direction of the swinging side end of the stretching roller, and the swinging side end of the stretching roller is moved in the first direction, so that the end of the belt is corrected to be offset from the belt. When riding on the engagement part of the mechanism,
The belt-sliding interlocking member rotates, and the cam portion rotated in response to the rotation pushes the one end of the interlocking lever along the sliding surface of the cam portion, and rotates in response to the extrusion. The rack of the interlocking lever meshes with the pinion of the correction execution unit, and in response to the engagement, the pinion moves the swing execution of the stretching roller with respect to the rack via the gear system. Move in the opposite direction to the first direction along with the side edges,
The belt misalignment correcting mechanism according to appendix 2, wherein the belt offset correcting mechanism is configured as described above.
[Appendix 4]

The belt shifts away from the swinging end of the stretching roller, and the swinging end of the stretching roller moves in the second direction so that the end of the belt is offset from the belt. When it comes to run away from the engaging part of the correction mechanism,
The belt-sliding interlocking member rotates, and the cam portion rotated in accordance with the rotation pulls the one end of the interlocking lever along the sliding contact surface of the cam portion, and rotates in response to the pull-in. The rack of the interlocking lever releases the engagement of the correction execution unit with the pinion, and in response to the release, the pinion idles the gear system, and the correction execution unit applies the biasing force of the biasing member. With respect to the rack, it moves in the direction opposite to the second direction together with the swing side end of the stretching roller.
The belt misalignment correcting mechanism according to appendix 2, wherein the belt offset correcting mechanism is configured as described above.
[Appendix 5]

  An image forming apparatus comprising the transfer belt provided with the belt misalignment correcting mechanism according to any one of appendices 1 to 4.

  The present invention can be used for an image forming apparatus provided with a belt deviation correction mechanism.

1 Full-color image forming device (printer, main unit)
DESCRIPTION OF SYMBOLS 2 Image formation part 3 Transfer belt unit 4 Toner supply part 5 Paper feed part 6 Belt type fixing unit 7 Conveyance unit for double-sided printing 8 Transfer belt 8a Lower travel part surface 9 (9m, 9c, 9y, 9k) Image formation unit 10 Photosensitive Body drum 11 Cleaner 12 Charging roller 13 Optical writing head 14 Developer 15 Developing roller 16 Unit housing 17 Bulkhead 18 First agitating and conveying screw 19 Second agitating and conveying screw 20 (20y, 20m, 20c, 20k) Toner replenishment Container 21 Drive roller 22 Driven roller 23 Primary transfer roller 24 Secondary transfer auxiliary roller 25 Belt tension roller 26 Secondary transfer unit 27 Secondary transfer roller 28 Belt cleaner 29 Waste toner collection container 30 (30a, 30b) Paper feed cassette 31 Paper take-out roller 32 Feed roller 33 LA 34 Standby conveying roller pair 36 Unloading roller pair 37 Paper discharge tray 38 Paper discharge roller pair 39 Return path 39a Start return path 39b Intermediate return path 39c End return path 41 (41a, 41b, 41c, 41d, 41e) Return roller pair 42 Correction execution part 42a Case 43 Correction mechanism holding part 44 Execution part accommodating frame 44a Internal space area 44b External opening part 45 Protective lid 46 Belt shift interlocking member 47 Interlocking lever 48 Support shaft 49 Upper surface part 51 Vertical plate part 52 Cam part 53 Center part 54 Support shaft 55 Plane part 56 Cam engaging lever 57 Biasing member 58 Rack lever 59 Rack 61 End upper edge 62 Pinion 63 Pushing biasing member 64 Support shaft 65 Bevel gear 66 Idle bevel gear 67 Bevel gear 68 Spiral Tooth 69 bearing

Claims (5)

A tension roller supported on one shaft end as a fulcrum and the other shaft end swingably;
A belt that runs around the stretch roller;
Arranged in the vicinity of the swinging side end of the tension roller, and arranged so as to be able to rotate in a direction intersecting the belt surface of the belt depending on whether or not there is sliding contact with the end of the belt due to the offset. A belt-side interlocking member;
An interlocking lever that engages with one end of the belt-side interlocking member and rotates in a direction parallel to the belt surface in response to the rotation of the belt-side interlocking member in the cross direction;
A gear system that engages or disengages the other end of the interlocking lever, and a correction execution unit that holds the other shaft end of the stretching roller;
Have
A belt misalignment correction mechanism that corrects a shift of the belt that is perpendicular to a running direction of the belt and that is offset in a direction parallel to the belt surface. The belt-sliding interlocking member includes an engaging portion that can slide-contact the end portion of the belt, a plate-like portion erected from the engaging portion, and a cam portion formed on an edge surface of the plate-like portion. And comprising
The one end of the interlocking lever is in sliding contact with the cam portion of the interlocking member near the belt, and a rack is formed at the other end.
The correction execution unit holds a pinion that engages or disengages the rack of the interlocking lever, and a shaft of the swing side end of the stretching roller that engages the pinion via a gear system. A bearing portion;
The belt misalignment correcting mechanism according to claim 1. The belt is displaced in the direction of the swinging side end of the stretching roller, and the swinging side end of the stretching roller is moved in the first direction, so that the end of the belt is corrected to be offset from the belt. When riding on the engagement part of the mechanism,
The belt-sliding interlocking member rotates, and the cam portion rotated in response to the rotation pushes the one end of the interlocking lever along the sliding surface of the cam portion, and rotates in response to the extrusion. The rack of the interlocking lever meshes with the pinion of the correction execution unit, and in response to the engagement, the pinion moves the swing execution of the stretching roller with respect to the rack via the gear system. Move in the opposite direction to the first direction along with the side edges,
The belt misalignment correcting mechanism according to claim 2, wherein the belt offset correcting mechanism is configured as described above. The belt shifts away from the swinging end of the stretching roller, and the swinging end of the stretching roller moves in the second direction so that the end of the belt is offset from the belt. When it comes to run away from the engaging part of the correction mechanism,
The belt-sliding interlocking member rotates, and the cam portion rotated in accordance with the rotation pulls the one end of the interlocking lever along the sliding contact surface of the cam portion, and rotates in response to the pull-in. The rack of the interlocking lever releases the engagement of the correction execution unit with the pinion, and in response to the release, the pinion idles the gear system, and the correction execution unit applies the biasing force of the biasing member. With respect to the rack, it moves in the direction opposite to the second direction together with the swing side end of the stretching roller.
The belt misalignment correcting mechanism according to claim 2, wherein the belt offset correcting mechanism is configured as described above.   An image forming apparatus comprising the transfer belt provided with the belt misalignment correcting mechanism according to claim 1.