JP2010066302A - Belt conveying device and image forming apparatus using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress inclination of a belt end lug part even when having more or less deviation to stably detect a position when detecting a position along a circulating direction of an endless belt so as to detect an object to be detected provided on the belt end lug part protruded from a stretching member of the endless belt. <P>SOLUTION: A belt conveying device includes: the endless belt 2; a deviation amount regulation member 3 extended along the circulating direction of the endless belt 2 on the rear face of the belt end lug part 2a positioned on both the ends of the endless belt 2 and provided to be protruded in a thickness direction of the endless belt 2; the object to be detected 4 detected as a reference position of the circulating direction of the endless belt 2; a detector 5 for detecting the existence of the object to be detected 4 of the belt end lug part 2a; and an attitude adjustment member 7 connected with the deviation amount regulation member 3 in an allowable deviation amount of the endless belt 2 due to the deviation amount regulation member 3 and for adjusting inclination attitude along a width direction of the belt end lug part 2a so as to enable detection operation of the object to be detected 4 due to the detector 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a belt conveyance device and an image forming apparatus using the belt conveyance device.

  In an image forming apparatus such as an electrophotographic system that uses an intermediate transfer belt as an endless belt, a mark is written on the intermediate transfer belt as a method for detecting a reference position of the intermediate transfer belt, and this mark is an optical sensor. What is detected at is known. Patent Document 1 proposes a method in which a sensor backing is provided on the back side of the intermediate transfer belt facing the sensor to suppress fluctuations in the thickness direction of the intermediate transfer belt in order to improve the detection accuracy of the sensor. Has been.

  On the other hand, there is also known a method for restricting such an intermediate transfer belt from performing a belt walk such as meandering or slipping during its rotation. Patent Document 2 proposes a configuration in which a belt end ear portion protruding from the tension roll is provided with a shift regulation portion that prevents the belt from being offset, or a shift regulation portion is provided on the tension roll side. Yes. Further, Patent Document 3 proposes a configuration in which a guide member is provided that bends the belt by hitting the protruding belt end ear when the offset belt protrudes from the tension roll. Further, Patent Document 4 is provided with a guide member that is in contact with the inner surface side of the belt end ear portion that protrudes from one end of the tension roll due to the offset and is located only on the upstream side in the belt conveyance direction of the tension roll. A configuration has been proposed in which the belt end ear portion is lifted and restricted by a member.

JP 2004-318182 A (Best Mode for Carrying Out the Invention, FIG. 1) Japanese Patent Laying-Open No. 2003-267581 (Embodiment of the Invention, FIG. 5) JP 2003-267580 A (Embodiment 1, FIG. 5) JP 2004-51299 A (Embodiment 1, FIG. 5)

  The technical problem of the present invention is to detect the position along the circulation direction of an endless belt that is looped over a plurality of tension members, and is provided on a belt end ear portion that protrudes from the tension member of the endless belt. When the detection is performed by detecting the detection object, it is intended to enable stable position detection by suppressing the inclination at the belt end ear even if there is a slight deviation in the endless belt.

  The invention according to claim 1 is an endless belt which is arranged in a state of being stretched and circulated around a plurality of tension members and having end portions protruding from both ends of the tension members as belt end ears, and the endless belt. The endless belt circulates between the ends of at least one tension member provided on the back surface of the belt end ears located at both ends of the belt, extending along the circulating direction of the endless belt and protruding in the thickness direction of the endless belt. A deviation amount regulating member for regulating the deviation amount along the width direction intersecting the direction within the allowable deviation amount, and a reference position in the circulation direction of the endless belt provided on a part of the belt end ear surface of the endless belt The presence / absence of the detected object in the belt end ear part is arranged in a non-contact manner facing the surface of the belt end ear part of the endless belt at both ends of the at least one tension member. This detector and this Provided on the opposite side of the endless belt with respect to the intelligent device, engages with the deviation amount regulating member within the allowable deviation amount of the endless belt by the deviation amount regulating member, and detects the object to be detected by the detector It is a belt conveying apparatus provided with the attitude | position adjustment member which adjusts the inclination attitude | position in alignment with the width direction of the said belt end ear | edge part so that it becomes possible.

The invention according to claim 2 is the belt conveyance device according to claim 1, wherein the posture adjusting member is configured such that when the deviation amount of the belt end ear portion exceeds an intermediate value between zero and the maximum value of the allowable deviation amount. It is a belt conveying apparatus arrange | positioned so that the deviation | shift amount control member may contact.
According to a third aspect of the present invention, in the belt conveying device according to the first or second aspect, at least one of the posture adjusting member and the offset amount regulating member has an inclined surface, and the inclined surface is a piece of the belt end ear portion. The belt conveying apparatus is set so that the inclination posture of the belt end ear portion approaches the posture of the belt portion other than the belt end ear portion as the deviation amount increases.
According to a fourth aspect of the present invention, in the belt conveyance device according to the second or third aspect, the tension member is a rotating body that rotates about the rotation shaft body, and the posture adjustment member is a rotation shaft of the tension member. An annular member is provided on the body, and the inclined surface is formed along all or part of the outer peripheral surface of the annular member.
According to a fifth aspect of the present invention, in the belt conveying device according to the fourth aspect, the posture adjusting member is a belt conveying device that is rotatably provided on the rotating shaft of the stretching member.

The invention according to claim 6 is an endless belt that is arranged in a state in which it is looped over a plurality of stretching members and circulates and the end portions protrude from both ends of the at least one stretching member as belt end ears, A detection object provided on a part of the belt end ear surface of the endless belt and capable of being detected as a reference position in the circulation direction of the endless belt, and the belt of the endless belt at the outer end positions of at least one tension member A non-contact arrangement facing the end ear surface, a detector for detecting the presence or absence of a detection object at the belt end ear, and a detector on the opposite side of the endless belt with respect to this detector. And a posture adjusting member that adjusts an inclined posture along the width direction of the belt end ear portion so that a detection operation of a detection target can be performed.
According to a seventh aspect of the present invention, there is provided one or a plurality of image holding members for holding a toner image, and the toner image on the image holding member that is disposed opposite to the one or the plurality of image holding members directly or via a recording material. The image forming apparatus includes a belt conveyance device having an endless belt to be transferred, and uses the belt conveyance device according to any one of claims 1 to 6 as the belt conveyance device.

According to the first aspect of the present invention, the position detection along the circulation direction of the endless belt that circulates across the plurality of stretching members is provided on the belt end ear portion that protrudes from the stretching member of the endless belt. When the detection is performed by detecting the detected object, the inclination of the belt end ear portion is suppressed even if there is a slight deviation in the endless belt, and stable position detection can be performed.
According to the second aspect of the present invention, when the amount of deviation of the endless belt is small as compared with the case where this configuration is not provided, the deviation amount regulating member does not hit the posture adjusting member, and the endless belt can be conveyed. Is better secured.
According to the invention of claim 3, as compared with the case where the present configuration is not provided, the inclination posture of the belt end ear portion is brought closer to the posture of the belt portion other than the belt end ear portion as the deviation amount of the endless belt increases. Therefore, the detection accuracy by the detector can be maintained even when the deviation amount is large.
According to the invention of claim 4, the arrangement of the inclined surface is stabilized and the configuration is simplified as compared with the case where the present configuration is not provided, so that the inclined posture of the belt end ear portion can be kept good. become.
According to the fifth aspect of the present invention, even when the deviation amount adjusting member contacts the posture adjusting member, the frictional resistance between them can be reduced, and the endless belt can be circulated as compared with the case where this configuration is not provided. It will be done better.
According to the sixth aspect of the present invention, the position detection along the circulation direction of the endless belt that circulates across the plurality of tension members is provided at the belt end ear portion that protrudes from the tension member of the endless belt. When the detection is performed by detecting the detected object, the inclination of the belt end ear portion is suppressed even if there is a slight deviation in the endless belt, and stable position detection can be performed.
According to the seventh aspect of the present invention, the position detection along the circulation direction of the endless belt that circulates across the plurality of tension members is provided at the belt end ear portion that protrudes from the tension member of the endless belt. In the case where the detection is performed by detecting the detected object, the image forming apparatus can be provided which can suppress the inclination of the belt end ear portion and can detect the position stably even if there is a slight deviation in the endless belt.

First, an outline of an embodiment to which the present invention is applied will be described.
Outline of Embodiment FIGS. 1A to 1C show an outline of a belt conveying apparatus according to a representative model of an embodiment embodying the present invention. (B) and (c) are cross sections of the belt conveying device (a) as viewed from the A direction.
In the figure, the belt conveying device 1 is circulated and moved across a plurality of tension members 6 (specifically, 6A and 6B), and end portions from both ends of the tension members 6 are belt end ear portions 2a. An endless belt 2 disposed in a protruding state, and extends along the circulation direction of the endless belt 2 on the back surface of the belt end ear 2a located at both ends of the endless belt 2 and protrudes in the thickness direction of the endless belt 2. A deviation amount regulating member 3 that is provided and regulates the deviation amount along the width direction intersecting the circulation direction of the endless belt 2 between both ends of the at least one tension member 6 within an allowable deviation amount; A detected body 4 provided on a part of the surface of the belt end ear 2a of the belt 2 and capable of being detected as a reference position in the circulation direction of the endless belt 2, and at both ends of the at least one stretch member 6 Belt end ear 2a table of endless belt 2 Is disposed in a non-contact manner opposite to the sensor 5 and detects the presence / absence of the detected body 4 of the belt end ear portion 2a, and is provided at a position opposite to the detector 5 with the endless belt 2 interposed therebetween. The belt end ear portion 2a is engaged with the deviation amount regulating member 3 within the allowable deviation amount of the endless belt 2 by the amount regulating member 3 and can detect the detected body 4 by the detector 5. And an attitude adjusting member 7 that adjusts an inclination attitude along the width direction.

  Here, the tension member 6 may be in the form of a rotating body or may not be rotated as long as the endless belt 2 can be circulated and moved. Further, the deviation amount regulating member 3 may be affixed to the endless belt 2 so as to adhere a tape-like one, or may be configured integrally with the endless belt 2. The offset amount regulating member 3 provided near both ends of the endless belt 2 is hooked on the end of the tension member 6, whereby the offset amount of the endless belt 2 is regulated. The “at least one tension member 6” is the amount of deviation of the endless belt 2 between the tension member 6 using the tension member 6 of the plurality of tension members 6. Means that the deviation amount of the endless belt 2 may be regulated by the deviation amount regulating member 3 using a plurality of stretching members 6. To do.

  In addition, as a typical aspect of the detection target 4, a member having an optical reflection surface can be cited, and the detector 5 includes an optical sensor that emits and receives light, but is not limited thereto. Any method can be used as long as it can be detected apart from the detector 5, and for example, a magnet may be used as the detection target 4, and a method of detecting a magnetic flux change with respect to the annular coil as the detector 5 may be employed. The detected body 4 may be provided on the belt end ear portion 2a, and a part thereof may be provided over a region other than the belt end ear portion 2a.

  The posture adjusting member 7 is configured to come into contact with and engage with the offset amount regulating member 3 on the endless belt 2 side in a state where the endless belt 2 is largely offset. Therefore, there is no possibility that the circulating operation of the endless belt 2 is unnecessarily impaired.

  Furthermore, since the detector 5 is provided at a position corresponding to one tension member 6 (the tension member 6B in this example), the end of the belt end ear portion 2a at the position stretched by the tension member 6 is provided. The variation in the thickness direction of the belt 2 is less than the variation in the portion away from the stretching member 6 in the direction along the circulation direction of the endless belt 2, and the detection in the portion where the variation in the belt end ear portion 2a is smaller. Will be made. And judging from the rigidity of the endless belt 2, it is more preferable to provide the detector 5 at a position corresponding to the stretching member 6 where the winding angle of the endless belt 2 with respect to the stretching member 6 is large. If the wrapping angle is large, even if the endless belt 2 has the same thickness, the apparent rigidity becomes larger than that of the small wrapping angle, and the variation in the thickness direction at the belt end ear portion 2a is reduced. Tilt can be suppressed and detection accuracy is improved.

And as a specific aspect which controls the inclination posture of the belt end ear | edge part 2a, an aspect as shown to FIG.1 (b) (c) is mentioned. In other words, from the viewpoint of reducing the load on the endless belt 2, the posture adjusting member 7 has a deviation amount when the deviation amount of the belt end ear portion 2a exceeds an intermediate value between zero and the maximum allowable deviation amount. It is preferable that the regulating member 3 is arranged so as to come into contact. The intermediate value means an intermediate value from zero to the maximum allowable deviation amount.
At this time, the posture adjusting member 7 may be provided independently, or may be provided corresponding to the stretching member 6, for example. Further, from the viewpoint of maintaining a good inclination posture of the belt end ear portion 2a when the endless belt 2 is offset and improving the detection of the detected body 4 by the detector 5, the posture adjustment member 7 and the deviation amount regulation At least one of the members 3 has an inclined surface 8, and the inclined surface 8 has a belt portion other than the belt end ear portion 2a in which the inclined posture of the belt end ear portion 2a increases as the deviation amount of the belt end ear portion 2a increases. It is preferable that it is set to approach.

  At this time, the inclined surface 8 may be provided on the posture adjusting member 7 side as shown in (b), or may be provided on the deviation amount regulating member 3 side as shown in (c). In addition, both the posture adjusting member 7 and the deviation amount regulating member 3 may be provided with the inclined surfaces 8 respectively. Further, the inclined surface 8 may be a curved surface as well as a flat surface.

Here, the change in the inclined posture of the belt end ear portion 2a will be described with the configuration of FIG. 2A shows a case where the belt end ear portion 2a is at a predetermined offset amount, FIG. 2B shows a case where the belt end ear portion 2a exceeds a predetermined offset amount, and FIG. 2C shows a condition of (b). And the case where the attitude | position adjustment member 7 is not provided is each typically shown. Here, the detection method of the detection object 4 and the detector 5 will be described as using optical reflection.
First, as shown in (a), when the deviation amount of the endless belt 2 is regulated by the deviation amount regulating member 3, and the length of the belt end ear portion 2a protruding from the stretching member 6 of the endless belt 2 is small. The inclination at the belt end ear portion 2a (downward in the figure) is small, and the light emitted from the detector 5 is reflected as it is by the detection object 4 and reaches the detector 5 to be detected. The amount of light reflected from the detector 4 is large, and sufficient detection accuracy is ensured.

  Next, when the amount of deviation of the endless belt 2 is large, the belt end ear portion 2a is inclined downward in the figure. For example, as shown in FIG. Is reflected by the detection object 4, and the reflected light reaches outside the light receiving range of the detector 5. Therefore, the amount of reflected light from the detected body 4 to the detector 5 is reduced, and proper detection is not performed. Therefore, when the posture adjusting member 7 is provided as shown in (b), the deviation amount regulating member 3 on the endless belt 2 side contacts the inclined surface 8 of the posture adjusting member 7 and slides on the inclined surface 8, thereby moving the belt end. The inclination posture of the ear portion 2a is lifted as compared with the case where the posture adjusting member 7 is not provided, and the light emitted from the detector 5 is reflected by the detection object 4 so that the reflected light effectively reaches the detector 5. Become. Therefore, good detection by the detector 5 is maintained.

  Here, the posture adjusting member 7 may be provided integrally with the tension member 6 or may be provided separately from the tension member 6. Further, it does not matter whether or not the posture adjusting member 7 has the inclined surface 8. However, from the viewpoint of stabilizing the arrangement of the inclined surface 8 and simplifying the configuration of the posture adjusting member 7, in a mode in which the tension member 6 is a rotating body that rotates around the rotating shaft body, the posture adjusting member 7 is It is preferable that an annular member is provided on the rotary shaft of the tension member 6 and the inclined surface 8 is formed along all or part of the outer peripheral surface of the annular member. At this time, from the viewpoint of reducing the frictional resistance between the posture adjusting member 7 and the deviation amount regulating member 3, the posture adjusting member 7 is preferably provided rotatably on the rotating shaft body 6 a of the tension member 6. .

  Further, as the belt conveying device 1 that stabilizes the inclined posture of the belt end ear portion 2a of the endless belt 2, a device that does not have the deviation amount regulating member 3 in the endless belt 2 is possible. Like this. That is, an endless belt 2 that is looped over a plurality of stretching members 6 and circulates and is disposed with end portions protruding from both ends of the at least one stretching member 6 as belt end ears 2a, and an endless belt 2 is provided at a part of the surface of the belt end ear 2a and can be detected as a reference position in the circulation direction of the endless belt 2, and at least one end of the tension member 6 is endless at both ends. A detector 5 that is arranged in a non-contact manner facing the surface of the belt end ear 2a of the belt 2 and detects the presence or absence of the detection target 4 of the belt end ear 2a, and the endless belt 2 is sandwiched between the detector 5 Provided with an attitude adjustment member 7 that is provided at the opposite side part and adjusts the inclination attitude along the width direction of the belt end ear portion 2a so that the detector 5 can detect the detected object 4. Good. This aspect will be described in an embodiment described later.

  Such a belt conveyance device 1 can also be applied to an image forming apparatus. In this case, as shown in FIG. 1A, one or a plurality of image holding bodies 9 that hold a toner image, and the one or a plurality of image holding members. A belt conveyance device 1 having an endless belt 2 which is disposed opposite to the image carrier 9 and onto which a toner image on the image carrier 9 is transferred directly or via a recording material. The belt conveyance device 1 may be used. As such a belt conveyance device 1, an embodiment in which the endless belt 2 is used as an intermediate transfer member that temporarily holds and conveys the toner image on the image holding member 9, or for transferring the toner image on the image holding member 9. An embodiment in which the endless belt 2 is used as a recording material conveyance belt that holds and conveys the recording material is exemplified.

Hereinafter, the present invention will be described in more detail based on embodiments shown in the accompanying drawings.
Embodiment 1
FIG. 3 shows an outline of the image forming apparatus according to the present embodiment. In the figure, the image forming apparatus according to the present embodiment is provided with a photoconductor 20 as an image holding body for holding a toner image at a substantially center in the apparatus housing 10, and the photoconductor is opposed to the photoconductor 20. An intermediate transfer device 30 for transferring the toner image on 20 and temporarily holding and conveying the toner image is provided, and four multiple transfers are repeated on the intermediate transfer belt 31 of the intermediate transfer device 30 in order to obtain a four-color image. This is a so-called four-cycle image forming apparatus.

  Around the photosensitive member 20, a charging device 21 for charging the photosensitive layer formed on the surface of the photosensitive member 20, and each color component (for example, yellow, magenta, cyan, black) on the photosensitive layer of the charged photosensitive member 20 are provided. For example, a laser scanning type exposure device 22 for writing a latent image, a rotary developing device 23 for visualizing an electrostatic latent image for each color component formed on the photoconductor 20 with each color component toner, and a photoconductor A cleaning device 24 for cleaning the residual toner on 20 is disposed.

  Here, as the charging device 21, for example, a charging roll is used, but a corona charger such as a corotron may be used, and the exposure device 22 uses an LED array or the like instead of the laser scanning method. May be appropriately selected. Further, the rotary type developing device 23 has four developing devices 23a to 23d each containing respective color component toners rotatably mounted. For example, the potential of the photosensitive layer of the photoconductor 20 is lowered by exposure. Any toner may be used as long as each color component toner is selectively attached to the portion, and the toner to be used is not particularly limited, so long as the electrostatic latent image on the photoconductor 20 can be visualized. That's fine. Furthermore, the cleaning device 24 only needs to be able to clean the residual toner on the photoconductor 20, and may be appropriately selected such as a blade.

  The recording material conveyance system in such an image forming apparatus is as follows. A recording material accommodating portion 11 for accommodating the recording material to be supplied to a lower position in the apparatus housing 10, a supply roll 12 provided near the downstream end of the recording material accommodation direction in the recording material conveying direction, and Then, a single recording material is conveyed from the recording material accommodating portion 11 toward the recording material conveyance path 14 by a separating mechanism 13 constituted by a pair of roll members provided in the vicinity of the supply roll 12. The recording material conveyance path 14 is provided with a registration roll 15 that positions the recording material supplied from the recording material container 11 and conveys the recording material downstream at a predetermined timing. The registration roll 15 conveys the recording material at a predetermined timing. Multiplexed toner images on the intermediate transfer belt 31 are collectively transferred to the recording material by the intermediate transfer device 30. The recording material on which the toner images are collectively transferred is fixed by applying sufficient heat and pressure in a fixing device 16 composed of, for example, a heating roll 16a and a pressure roll 16b. After the fixing, the recording material is discharged from the discharge port opened in the apparatus housing 10 by the discharge roll 17 to the recording material discharge portion 10 a formed on the upper surface of the apparatus housing 10.

  On the other hand, the intermediate transfer device 30 includes a plurality of endless belts 31 (in this example, endless belts) in which a predetermined amount of a conductive agent such as carbon black is dispersed in polyimide resin to form a film having a thickness of about 50 to 100 μm. Four stretched rolls 32 to 35 are laid and rotated, for example, using the stretch roll 32 as a drive roll. A primary transfer device 25 such as a primary transfer roll is provided on the back surface side of the intermediate transfer belt 31 at a position facing the photoconductor 20, and a predetermined bias is applied between the photoconductor 20 and the primary transfer device 25. As a result, the toner image formed on the photoreceptor 20 is transferred onto the intermediate transfer belt 31.

  Further, a secondary transfer device 36 using the stretching roll 35 as a backup roll is disposed at a portion facing the stretching roll 35. The secondary transfer device 36 of the present embodiment includes a secondary transfer roll 36a and a holder 36b for positioning and supporting the secondary transfer roll 36a. The holder 36b is moved in the direction of the arrow in the drawing by a driving device (not shown). The secondary transfer roll 36a can be brought into and out of contact with the intermediate transfer belt 31 by reciprocating in the direction. Therefore, when the secondary transfer roll 36a comes into contact with the intermediate transfer belt 31, a predetermined transfer bias is applied between the secondary transfer roll 36a and the backup roll 35, so that the image is transferred onto the intermediate transfer belt 31. The multiplexed toner image is transferred onto the recording material by batch transfer. In this embodiment, since the primary transfer is repeated four times on the intermediate transfer belt 31, the secondary transfer roll 36 a is separated from the intermediate transfer belt 31 until batch transfer onto the recording material is performed. In the drawing, the position where the secondary transfer roll 36a contacts the intermediate transfer belt 31 is shown.

  Further, the intermediate transfer device 30 is provided with a belt cleaning device 40 for cleaning residual toner on the intermediate transfer belt 31 on the tension roll 32 side of the intermediate transfer belt 31. The belt cleaning device 40 is in contact with the intermediate transfer belt 31 to scrape residual toner, contacts the intermediate transfer belt 31 on the upstream side of the blade 41 in the rotational direction of the intermediate transfer belt 31, and the intermediate transfer belt. 31 is provided with a sealing film 42 for preventing residual toner from being scattered when the belt cleaning device 31 is cleaned. These members come into contact with the intermediate transfer belt 31 when the intermediate transfer belt 31 is cleaned. The belt cleaning device 40 is provided with a conveyance member 43 for conveying the collected toner scraped and collected by the blade 41 to a waste toner container (not shown).

  In the present embodiment, the object to be detected is affixed to the surface of the belt end ear that protrudes from the tension roll 32 of the intermediate transfer belt 31 at a position facing the tension roll 32 and spaced from the intermediate transfer belt 31. A sensor 37 for detecting a detection seal (described later) as a reference position information along the circulation direction of the intermediate transfer belt 31 by optically detecting the detection seal as the intermediate transfer belt 31 rotates. Is to be detected.

  The structure of both ends in the width direction of the intermediate transfer belt 31 in such an intermediate transfer device 30 is as shown in FIG. Ribs 311 as deviation amount regulating members that extend along the circulation direction of the intermediate transfer belt 31 and protrude in the thickness direction are provided at the belt end ears at both ends in the width direction on the back side of the intermediate transfer belt 31. Yes. The material of the rib 311 is preferably a thermosetting resin. For example, a single tape-like member made of polyurethane resin having a thickness of about 0.5 to 1.5 mm is attached to the back surface of the intermediate transfer belt 31. Thus, the tape-like member is affixed so as to have a slight gap at the end portion abutting position (position indicated by arrow B in the figure).

On the other hand, a reinforcing tape 312 that reinforces the intermediate transfer belt 31 is attached to the surface side of the intermediate transfer belt 31 at a position substantially corresponding to the rib 311 so as to cover the area of the rib 311. As the reinforcing tape 312, for example, a polyester tape having a thickness of about 50 to 100 μm is used. The polyester tape is applied over substantially the entire circumference of the intermediate transfer belt 31, and the attached end portions thereof are overlapped, for example (arrow C in the figure). The position indicated by It should be noted that the reinforcing tape 312 may be attached with a gap so as not to overlap, and may be attached so as to cover the gap with a tape having a stronger adhesive force.
Further, a detection seal 313 as a detected body is attached at an appropriate position on the reinforcing tape 312. The detection seal 313 of the present embodiment is made of a material having a different reflectance from the surface of the reinforcing tape 312. For example, a substantially square label tape is used, and its thickness and adhesive force are appropriately selected.
By sticking the detection seal 313 on the reinforcing tape 312 in this way, a large effective area that can be used for image formation on the intermediate transfer belt 31 can be secured. In FIG. 4, only one end in the width direction of the intermediate transfer belt 31 is shown, but the rib 311 and the reinforcing tape 312 are similarly attached to the other side.

  Further, in the intermediate transfer device 30 of the present embodiment, the posture adjusting member 50 is located on the opposite side of the tension roller 32 on which the sensor 37 is disposed, with the belt end ear on the side on which the sensor 37 is disposed. Is provided. As shown in FIG. 5, the posture adjusting member 50 is rotatably supported at a predetermined position of the rotating shaft 32 a of the stretching roll 32, and further toward the outer side in the width direction of the intermediate transfer belt 31. An inclined surface 51 that is inclined along the direction and from the belt back surface side toward the belt surface side is provided, and the end portion of the rib 311 can slide on the inclined surface 51. The posture adjusting member 50 is made of, for example, polyacetal resin having low friction with respect to the rib 311 or the rotating shaft 32a of the stretching roll 32, and the posture adjusting member 50 itself is smoothly rotated. Yes. Therefore, when the amount of outward displacement of the intermediate transfer belt 31 reaches a predetermined amount that is an intermediate value that reaches the maximum allowable displacement amount, the end of the rib 311 contacts the inclined surface 51 of the posture adjusting member 50. As the intermediate transfer belt 31 is further offset, the rib 311 slides on the inclined surface 51 without difficulty. In the present embodiment, the inclined surface 51 is provided along a part of the outer peripheral surface of the posture adjusting member 50. However, the inclined surface 51 may be provided along the entire outer peripheral surface.

  In this embodiment, the tension roll 32 side is also devised, and both ends of the tension roll 32 are provided with guide members 321 that can rotate independently of the rotation of the tension roll 32, The deviation amount of the intermediate transfer belt 31 is regulated by the end portion of the guide member 321 coming into contact with the rib 311. Here, as the guide member 321, a low friction material such as polyacetal resin is applied, for example, and the frictional resistance between the stretching roll 32 and the rib 311 is small, and good circulation rotation of the intermediate transfer belt 31 is maintained. It has become so. Here, the mode in which the guide members 321 are used at both ends of the tension roll 32 is shown. However, the present invention is not limited to this, and the guide member 321 is not used when it does not hinder the circulation rotation of the intermediate transfer belt 31. It may be.

Next, the detection operation of the reference position along the circulation direction of the intermediate transfer belt 31 in the present embodiment will be described with reference to FIG. Here, the reinforcing tape 312 is omitted for easy understanding.
First, when the intermediate transfer belt 31 is set on the tension roll 32, as shown in FIG. 6A, the gap between the guide member 321 on the tension roll 32 side and the rib 311 is totaled at both ends. There is a length of (d1 + d2), and the intermediate transfer belt 31 repeats the deviation in the width direction to any one of the lengths. Therefore, the position of the detection seal 313 with respect to the sensor 37 is only −d1 (indicating movement in the right direction in the figure) to + d2 (indicating movement in the left direction in the figure) when the center line c in the figure is a reference position. To move. At this time, it goes without saying that the lengths of d1 and d2 are within the effective detection range of the detection seal 313, so that even if they are deviated by this amount from the center line c, the detection by the sensor 37 can be performed satisfactorily. It has become.

When the intermediate transfer belt 31 is displaced in the minus direction, the length of the belt end ear portion from which the intermediate transfer belt 31 protrudes from the guide member 321 is short, and the belt end ear portion is kept substantially flat. Since the detection surface of the detection seal 313 is kept substantially parallel to the sensor 37, good detection can be performed when the deviation d is within the allowable range of the sensor 37.
On the other hand, as shown in FIG. 6B, when the direction is shifted in the + direction, the length of the belt end ear portion that the intermediate transfer belt 31 protrudes from the guide member 321 becomes longer, and the belt end ear portion is attached to the stretching roll 32. On the other hand, it tilts in the direction of stenosis. As a result, if the inclination angle θ at this time (deviation amount d = d1 + d2) is large, the reflected light from the detection seal 313 is not detected well by the sensor 37, and the position of the intermediate transfer belt 31 may not be detected. is there.

  Therefore, in the present embodiment, as shown in FIG. 6C, the posture adjustment member 50 is used to suppress the inclination of the belt end ear portion from becoming larger than necessary. The reflected light is sufficiently detected by the sensor 37. That is, when the amount of deviation in the + direction of the intermediate transfer belt 31 increases, the rib 311 slides on the inclined surface 51 in the direction of the arrow in the drawing after the rib 311 hits the inclined surface 51 of the posture adjusting member 50. Become. Therefore, the belt end ear portion is once lifted after the inclination angle θ (corresponding to the inclination angle from the horizontal position in the figure) is slightly increased, and the inclination angle θ is reduced. That is, as the inclination posture of the detection seal 313, the inclination angle θ once increases slightly until the rib 311 contacts the inclined surface 51, but gradually decreases after the rib 311 contacts the inclined surface 51. Posture changes occur.

  On the other hand, in order to detect the detection seal 313 by the sensor 37, it is only necessary that the reflected light from the detection seal 313 can be detected satisfactorily by the sensor 37. For example, detection is possible even if the detection seal 313 is slightly inclined at the center line c position. . As the deviation from the center line c position increases, the allowable inclination angle θ of the detection seal 313 decreases. In the present embodiment, the inclination angle θ of the detection seal 313 until the rib 311 comes into contact with the inclined surface 51 of the posture adjusting member 50 is ensured by the deviation amount d and the inclination angle θ that can be sufficiently detected by the sensor 37. Since the inclination angle θ is gradually reduced when the deviation amount d is further increased, the position of the intermediate transfer belt 31 by the sensor 37 can be detected satisfactorily.

  In order to reduce such inclination at the belt end ear, the gap (d1, d2) between the rib 311 and the guide member 321 when the intermediate transfer belt 31 is set on the tension roll 32 is narrowed. However, in consideration of the dimensional accuracy and mounting accuracy of each member, member deformation, and the like, it is necessary to consider a certain amount of offset d (amount offset further outward from the set position). Moreover, there is a concern that such a deviation amount d becomes particularly large when the environment changes or the installation status of the apparatus itself changes. In order to perform good detection with respect to such a deviation amount d, it is better to increase the size of the detection seal 313 and use a sensor 37 having a large light receiving area, but the apparatus configuration is large. It is not practical from the point of becoming. Here, an optical sensor (specifically, using a light emitting / receiving element) is used as the sensor 37. However, the present invention is not limited to this, and a sensor using a magnetic action may be applied. Is possible.

  In the present embodiment, the posture adjusting member 50 is formed of an annular member and is provided rotatably on the rotary shaft 32a of the tension roll 32. However, the position adjustment member 50 is located at a position separated from the tension roll 32. The posture adjusting member 50 having such an inclined surface 51 may be separately fixed and arranged.

Furthermore, in the present embodiment, the sensor 37 is installed at a position facing the stretching roll 32, but may be installed at a position facing another stretching roll. However, in that case, it is necessary to pay attention to the following points.
That is, in this embodiment, the winding angle of the intermediate transfer belt 31 with respect to the tension roll 32 is about 180 °, but for example, the tension roll 33 (see FIG. 3) is about 30 °. Therefore, when the sensor 37 is provided facing the tension roll 33 having a small winding angle, the amount of squeezing of the belt end ear portion is likely to be larger than that of the tension roll 32, and the inclination angle is accordingly increased. θ tends to increase. Therefore, when the sensor 37 is installed facing the tension roll 33 having a small winding angle, the posture adjusting member 50 is compared to the case where the sensor 37 is installed facing the tension roll 32 having a large winding angle. It is preferable that the arrangement of is installed on the inner side.
Further, instead of the intermediate transfer belt 31 used in the intermediate transfer device 30 of the present embodiment, a recording material conveyance belt that holds and conveys a recording material may be used. The reference position is easily detected.

Embodiment 2
FIG. 7 shows a second embodiment of the attitude adjustment member 50 of the intermediate transfer device 30. The posture adjusting member 50 of the present embodiment is configured in substantially the same manner as the posture adjusting member 50 (see FIG. 5) of the first embodiment, while the rib 311 also has a direction toward the outside in the width direction of the intermediate transfer belt 31. An inclined surface 311a that is inclined from the back surface side to the front surface side is provided, and the posture adjusting member 50 can slide on the inclined surface 311a. Components similar to those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted here.

  Further, in the present embodiment, a part of the inclined surface 51 provided on the posture adjusting member 50 comes into contact with the inclined surface 311 a of the rib 311. In other words, in this embodiment, when the amount of outward displacement of the intermediate transfer belt 31 reaches a predetermined amount, the inclined surface 311a of the rib 311 comes into contact with the inclined surface 51 of the posture adjusting member 50, and then further intermediate transfer is performed. When the belt 31 is offset, the inclined surface 311a of the rib 311 slides on the posture adjusting member 50, and the rib 311 is gradually lifted.

Therefore, also in the present embodiment, as in the first embodiment, the inclination angle of the belt end ear portion gradually increases until the deviation amount of the intermediate transfer belt 31 reaches a predetermined amount, and the inclined surface 311a of the rib 311 is increased. After the contact with the inclined surface 51 of the posture adjusting member 50, the inclination angle gradually decreases as the intermediate transfer belt 31 is offset. Therefore, there is no trouble in detection by the sensor 37.
Here, the posture adjusting member 50 is also provided with the inclined surface 51. However, for example, the posture adjusting member 50 does not have the inclined surface 51, and the rib 311 is formed at an end (for example, a corner) of the posture adjusting member 50. The inclined surface 311a may be lifted. Further, the inclined surface 51 may have a curved surface instead of a flat surface. Furthermore, the posture adjusting member 50 may not be provided on the rotary shaft body 32a of the stretching roll 32 but may be provided fixed to, for example, a bracket of the apparatus housing 10 or the like.

Embodiment 3
FIG. 8 shows a third embodiment of the attitude adjustment member of the intermediate transfer device 30. Unlike the first and second embodiments, the intermediate transfer device 30 of the present embodiment is configured such that the intermediate transfer belt 31 does not have a rib (for example, see FIG. 5) as a deviation amount regulating member. . Therefore, the posture adjusting member 60 has an inclined surface that changes the inclined posture by contact with the belt end ear portion of the intermediate transfer belt 31, and an abutting portion on which the end portion of the belt end ear portion abuts. ing. In other words, the posture adjusting member 60 of the present embodiment is rotatably provided on the rotating shaft 32a of the tension roll 32, and the outer peripheral surface of the posture adjusting member 60 is inclined to the intermediate transfer belt 31 along the outer peripheral surface. On the other hand, a flange 62 having an outer diameter larger than that of the inclined surface 61 is provided on the outer side of the outer peripheral surface. Between the flange 62 and the inclined surface 61, there is an intermediate in a direction substantially orthogonal to the rotary shaft body 32a. An abutting portion 63 against which the end of the transfer belt 31 abuts is provided. Components similar to those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted here.

  For this reason, in the present embodiment, when the intermediate transfer belt 31 is displaced to some extent, the belt end ear portion is inclined so that it first contacts the inclined surface 61 of the posture adjusting member 60. Due to the further deviation of the intermediate transfer belt 31, the end of the intermediate transfer belt 31 slides on the inclined surface 61, and the inclination of the belt end ear portion in the direction of the rotating shaft 32a gradually decreases. Further, the belt end ear portion whose inclination is suppressed is further restricted from being offset by the end portion being in contact with the abutting portion 63, and as a result, the amount of deviation of the intermediate transfer belt 31 itself is restricted.

  Here, the posture adjusting member 60 is shown as having a configuration including the inclined surface 61 and the abutting portion 63. However, for example, the member having the abutting portion 63 may be configured separately from the posture adjusting member. There is no problem. Further, the posture adjusting member 60 may be fixedly arranged separately from the rotating shaft body 32a. 8 shows the one-direction end portion side of the intermediate transfer belt 31, but a member having at least an abutting portion 63 is provided on the opposite side, and between the abutting portion 63 of the posture adjusting member 60. Thus, it goes without saying that the amount of deviation of the intermediate transfer belt 31 is regulated.

  In the present embodiment, the abutting portion 63 is provided on the posture adjusting member 60 and the amount of deviation of the intermediate transfer belt 31 is regulated by the abutting portion 63. However, as a modification, the intermediate transfer belt 31 itself is described. In the case where the amount of deviation is regulated by other methods, there may be a mode in which the abutting portion 63 is not provided.

  FIGS. 9 (a) and 9 (b) schematically show such a configuration. FIG. 9A shows the intermediate transfer device 30 having the intermediate transfer belt 31 that is looped over three tension rolls 71 to 73 and circulates with the tension roll 71 as a drive roll. As a roll, the meandering of the intermediate transfer belt 31 is regulated as the steering roll 73 swings in the arrow direction. Further, a belt end ear portion from which the intermediate transfer belt 31 protrudes is formed from the stretching rolls 71 and 72, and a sensor 37 is provided at a position corresponding to the belt end ear portion of the stretching roll 71. Further, a posture adjusting member 60 having an inclined surface 61 is provided on the rotating shaft body of the tension roll 71.

  In this case, the amount of deviation of the intermediate transfer belt 31 is regulated to the allowable amount of deviation by the swinging motion of the steering roll 73, and the inclined surface of the attitude adjusting member 60 provided corresponding to the stretching roll 71. 61, the inclination posture of the intermediate transfer belt 31 at the belt end ear portion changes, and the detection of a detection seal (not shown) by the sensor 37 is favorably performed.

9B differs from FIG. 9A in that both ends of the intermediate transfer belt 31 are used for the intermediate transfer belt 31 that is looped over the three stretching rolls 71 to 73 without using a steering roll. 2 shows a configuration in which the allowable deviation amount of the intermediate transfer belt 31 is regulated by regulating the position. In this aspect, a pair of end guides 81 that come into contact with both ends in the width direction of the intermediate transfer belt 31 are provided, and the end guides 81 are pressed against the end side of the intermediate transfer belt 31 by the biasing member 82, respectively. The deviation of the transfer belt 31 is regulated so that the deviation amount is within the allowable deviation amount.
Also in such an aspect, by providing the sensor 37 and the posture adjusting member 60 corresponding to the tension roll 71, a good detection of a detection seal (not shown) by the sensor 37 can be performed. Become. Here, the end guide 81 is disposed between the two stretching rolls 71 and 73. However, the present invention is not limited to this, and the end guide 81 may be provided at a position corresponding to the stretching rolls 71 to 73. Absent.

Example 1
In this embodiment, in order to confirm the effectiveness of the adjustment method of the inclination posture at the belt end ear portion of the present case, the deviation amount (the tension of the belt end ear portion of the intermediate transfer belt is not provided without the posture adjustment member. The specific output (SNR output) detected by the sensor changes with respect to the change in the inclination angle of the belt end ear (belt angle) and the change in the tilt angle of the belt end ear (belt angle). This is an evaluation check.

  The measurement was performed as follows using the measurement system of FIG. An endless belt 102 (intermediate transfer belt) is stretched over the tension roll 101, a rotatable support roll 103 is mounted on the rotary shaft 101a of the tension roll 101, and the end surface of the endless belt 102 is attached to the peripheral surface of the support roll 103. The angle of the endless belt 102 is changed by applying the rib 104 and changing the distance L from the end surface of the tension roll 101 to the tip of the support roll 103 and the diameter D of the support roll 103. The amount of deviation is the deviation between the center position of the 7 m square detection seal 105 on the endless belt 102 and the center position of the sensor 106, and the sensor 106 is matched to the position of the detection seal so as to be a predetermined deviation amount. Was moved. The belt angle was an angle in a direction in which the belt end ear portion of the intermediate transfer belt is narrowed, and was calculated as an average value of three times.

As a result, as shown in FIG. 11, when the deviation amount (axial deviation amount) is 0 mm, the sensor output (SNR output) changes to a uniform value up to an angle of 5 ° and then decreases. Became. Further, when the deviation amount is 1 mm, the sensor output has a uniform value until the angle is 1 °, but gradually decreases after 2 °, and the sensor output is a value that greatly decreases from the deviation amount 0 mm. became. Furthermore, when the amount of deviation was 2 mm, the sensor output was greatly reduced even at an angle of 1 °, and thereafter, the deviation remained almost unchanged.
Judging from this result, if the threshold value for determining the ON signal by the sensor is 2.5 V, the ON signal can be detected even if the belt angle changes by 9 ° when the deviation amount is 0 mm. However, it was expected that the belt angle was up to 5 ° when the deviation amount was 1 mm, and the belt angle was up to 0.5 ° when the deviation amount was 2 mm.

In general, when a rib is provided to prevent the belt from being displaced, a certain amount of deviation occurs in consideration of variations in the sensor mounting position and the detection sticking position, rib material and mounting variations, and the like. On the other hand, in order to stably detect the detection seal with the sensor, it is necessary to consider the detection size of the detection seal. For example, when a 7 mm square seal is used as the detection seal, the detection area on one side is 3.5 mm, so the amount that is not affected by the sensor is about 2 mm or less.
From FIG. 11, when the deviation amount is 1 mm, the belt angle is allowed up to 5 °. However, considering various margin factors, if the belt angle is set to 3 ° or less, there is no problem until the deviation amount is 1 mm. An area having no problem extends to an area exceeding 1 mm.

Therefore, by selecting the position of the posture adjusting member and the inclination angle of the inclined surface, good detection can be performed even if the deviation amount is 2 mm. FIG. 12 is a schematic diagram showing an example of this, in which the detection seal is 7 mm square and the reinforcing tape is omitted.
Now, when the center of the sensor and the detection seal is aligned with the position when the endless belt is set from the tension roll, and the endless belt is displaced 1 mm outward from it, it is assumed that it is inclined at an angle of 3 °. If the distance from the tension roll to the rib is 9 mm, the tip of the rib needs to contact the inclined surface of the posture adjusting member at this position. This position may be a position where the rib height is added to about 0.471 mm (9 × sin 3 °) from the peripheral surface of the stretch roll.
Next, the posture adjustment is performed so that the inclination angle of the detection seal becomes smaller when the endless belt is further displaced outward, and the inclination angle becomes about 0 ° when the displacement is 1 mm (2 mm in total). The angle of the inclined surface of the member may be about 25.2 ° so as to lift 0.471 mm with a displacement of 1 mm.

That is, it is set so that the inclined surface of the posture adjusting member hits in accordance with the rib position where the inclination angle is 3 °, shifted from the position of the endless belt at the time of setting by 1 mm. If the angle is set at 2 °, the rib hits the inclined surface of the posture adjusting member when the deviation amount is 1 mm, and the inclination angle gradually decreases with respect to the subsequent deviation, and is almost 0 ° when the deviation amount is 2 mm. It comes to be. By doing in this way, detection with a sensor comes to be made favorable.
Further, it goes without saying that such a method is similarly applied to the configurations of the second and third embodiments.

Example 2
This example uses the configuration of the first embodiment (see, for example, FIG. 6A), uses the posture adjustment member calculated as in Example 1, and shifts when the actual intermediate transfer belt is intentionally shifted. The relationship between the quantity and the output of the sensor (SNR output) is confirmed.
As a result, as shown in FIG. 13, the deviation amount was up to 2.5 mm. However, it was confirmed that it is effective to use the posture adjustment member of the present case without any problem when the threshold value is 2.5V.

It is explanatory drawing which shows the outline | summary of the belt conveying apparatus which concerns on embodiment model which embodies this invention. It is explanatory drawing which shows the relationship between the amount of slip of an endless belt in an embodiment model, and an inclination state, (a) is a case where deviation | shift amount is small, (b) is a case where the attitude | position adjustment member is acting, (c) Indicates a case where there is no posture adjusting member and the amount of deviation is large. 1 is an explanatory diagram illustrating an image forming apparatus according to Embodiment 1. FIG. 3 is an explanatory diagram illustrating an intermediate transfer belt according to Embodiment 1. FIG. 3 is an explanatory diagram illustrating a relationship between an intermediate transfer belt and a posture adjusting member according to Embodiment 1. FIG. 4A and 4B are explanatory diagrams showing the operation of the first embodiment, where FIG. 5A is a state where an intermediate transfer belt is set, FIG. 5B is a state where both a shift amount and a tilt angle are large, and FIG. Indicates a small state. FIG. 6 is an explanatory diagram illustrating a relationship between an intermediate transfer belt and a posture adjusting member according to a second embodiment. FIG. 10 is an explanatory diagram illustrating a relationship between an intermediate transfer belt and a posture adjusting member according to a third embodiment. (A) and (b) are explanatory views showing an intermediate transfer device as a modification of the third embodiment. 2 is an explanatory diagram showing a measurement system of Example 1. FIG. 3 is a graph showing the results of Example 1. It is explanatory drawing which shows an example of the attitude | position adjustment member calculated based on Example 1. FIG. 10 is a graph showing the results of Example 2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Belt conveying apparatus, 2 ... Endless belt, 2a ... Belt end ear | edge part, 3 ... Deviation amount control member, 4 ... Detected object, 5 ... Detector, 6 (6A, 6B) ... Stretch member, 6a ... Rotating shaft, 7 ... posture adjusting member, 8 ... inclined surface, 9 ... image carrier

Claims (7)

An endless belt arranged in a state of being stretched and circulated across a plurality of tension members and having end portions protruding from both ends of the tension members as belt end ears;
It is provided on the back surface of the belt end ear portion located at both ends of the endless belt, extending along the circulation direction of the endless belt and protruding in the thickness direction of the endless belt, and is endless between the ends of at least one stretch member. A deviation amount regulating member for regulating the deviation amount along the width direction intersecting the belt circulation direction within an allowable deviation amount;
A detected body provided on a part of the belt end ear surface of the endless belt and capable of being detected as a reference position in the circulation direction of the endless belt;
A non-contact arrangement facing the surface of the belt end ear portion of the endless belt at both ends outside the at least one tension member, and detecting the presence or absence of the detection object of the belt end ear portion;
Provided on the opposite side of the endless belt with respect to this detector, engages with the deviation amount regulating member within the allowable deviation amount of the endless belt by the deviation amount regulating member, and detects the object to be detected by the detector A belt conveying device comprising: a posture adjusting member that adjusts an inclined posture along the width direction of the belt end ear portion so as to be operable. In the belt conveyance device according to claim 1,
The posture adjusting member is arranged so that the deviation amount regulating member contacts when the deviation amount of the belt end ear part exceeds an intermediate value between zero and the maximum value of the allowable deviation amount. Belt conveyor. In the belt conveyance device according to claim 1 or 2,
At least one of the posture adjusting member and the deviation amount regulating member has an inclined surface, and this inclined surface has an inclined posture of the belt end ear portion other than the belt end ear portion as the deviation amount of the belt end ear portion increases. A belt conveying device, characterized in that it is set so as to approach the posture of the belt portion. In the aspect in which the tension member is a rotating body that rotates around the rotating shaft body in the belt conveyance device according to claim 2 or 3,
The posture adjusting member is a belt conveying device in which an annular member is provided on a rotating shaft of a stretching member, and the inclined surface is formed along all or a part of the outer peripheral surface of the annular member. In the belt conveyance device according to claim 4,
The posture adjusting member is rotatably provided on the rotating shaft of the stretching member. An endless belt which is arranged in a state where it is looped over a plurality of stretching members and circulates and the end portions protrude from both ends of the at least one stretching member as belt end ears,
A detected body provided on a part of the belt end ear surface of the endless belt and capable of being detected as a reference position in the circulation direction of the endless belt;
A non-contact arrangement facing the surface of the belt end ear portion of the endless belt at both ends outside the at least one tension member, and detecting the presence or absence of the detection object of the belt end ear portion;
A posture adjusting member that is provided on the opposite side of the endless belt with respect to the detector and adjusts the tilting posture along the width direction of the belt end ear portion so that the detection object can be detected by the detector. A belt conveying device comprising: One or a plurality of image carriers for holding a toner image;
A belt conveying device having an endless belt that is disposed opposite to the one or a plurality of image holding members and onto which a toner image on the image holding member is transferred directly or via a recording material;
An image forming apparatus using the belt conveyance device according to claim 1 as the belt conveyance device.

Images