Image forming apparatus

Abstract

To provide an image forming apparatus comprising a blade movement mechanism that, even if external force is applied thereto, can prevent a blade from moving from a retreat position to a contact position.SOLUTION: An image forming apparatus comprises: image carriers that carry developer images; a transfer belt to which the developer images are transferred from the image carriers; a blade that is in contact with the transfer belt to scrape off developer remaining on the transfer belt; a rotating member that rotates to act on the blade to move the blade between a contact position where the blade is in contact with the transfer belt and a retreat position where the blade is retreated in a direction to separate from the transfer belt; and regulation means that regulates the blade having moved from the contact position to the retreat position from returning from the retreat position to the contact position.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to an image forming apparatus.

Background Art

[0002] In an image forming apparatus in which a toner image is transferred onto a transfer belt, cleaning means for removing residual toner remaining on the transfer belt after being transferred onto a transfer material is provided. A rubber blade or the like is used as a member for removing this residual toner. The blade is pressed toward the transfer belt by a spring or the like and brought into contact with the surface of the transfer belt, and the residual toner on the transfer belt is removed by scraping off the toner on the transfer belt. The removed residual toner is once collected in a cleaner container provided in the cleaning means. The collected residual toner is conveyed by a conveying member provided in the cleaner container and discharged to an external container.

[0003] Since the blade is always under a force in the direction of contacting the transfer belt by a spring or the like, it may plastically deform due to the influence of external temperature and humidity when not used for a long time during transportation or storage. When the blade plastically deforms, the contact position with the transfer belt may deviate from the proper position, or the deflection direction of the blade itself may change, etc., and the removal performance of the residual toner may decrease.

[0004] Patent Document 1 describes a technique in which a moving member for moving a blade from a contact position where the blade contacts the transfer belt to a retracted position where the blade is separated from the transfer belt is provided, and the user can move the blade to the retracted position by operating the moving member. The moving member is composed of a rotating member having a cam capable of applying a force in a direction to separate the blade from the transfer belt against the force of a spring to a holding member that holds the blade, according to the rotation angle. When the user operates a lever provided on the rotating member to rotate the rotating member and bring the cam into contact with the holding member, the blade moves to the retracted position. By the user operating the lever to move the blade to the retracted position during transportation or storage, deformation of the blade can be suppressed. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2015-191104 [Overview of the project] [Problems that the invention aims to solve]

[0006] The rotating member described in Patent Document 1 is connected to a gear train to which the rotation of the tension roller that tensions the transfer belt is transmitted, and is configured so that the rotational driving force input to the tension roller when the image forming apparatus is in use is transmitted to the rotating member. As a result, when the image forming apparatus is in use, the rotating member rotates to a position where the cam does not come into contact with the holding member, and the blade automatically moves from the retracted position to the contact position. However, since an operating lever is integrally provided on the rotating member, there is a possibility that the blade may unintentionally move from the retracted position to the contact position if an external force is applied to the lever during transportation or handling of the apparatus. Therefore, the object of the present invention is to provide an image forming apparatus equipped with a blade movement mechanism that can suppress the blade from moving from the retracted position to the contact position even when an external force is applied. [Means for solving the problem]

[0007] The present invention An image carrier that holds the developer image, A transfer belt on which the developer image is transferred from the image carrier, A blade that contacts the transfer belt and scrapes off any developer remaining on the transfer belt, A rotating member that acts on the blade by rotating, moving the blade between a contact position in contact with the transfer belt and a retracted position in which it is moved away from the transfer belt, A tension roller for tensioning the aforementioned transfer belt, A drive transmission mechanism that connects the rotation axis of the tension roller and the rotation axis of the rotating member in a manner that enables the transmission of rotational force, Equipped with 、 The blade is configured such that the rotating member rotates in a first direction to move from the contact position to the retracted position, and the rotating member rotates further in the first direction to move from the retracted position to the contact position. The drive transmission mechanism is configured such that, when the blade is in the retracted position after moving from the contact position to the retracted position, the angle at which the rotating member can freely rotate in the first direction without the rotation axis of the tension roller rotating is smaller than the angle of rotation of the rotating member in the first direction required to move the blade from the retracted position to the contact position. This is an image forming apparatus characterized by the following: [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an image forming apparatus equipped with a blade movement mechanism that can suppress the blade from moving from the retracted position to the contact position even when an external force is applied. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic perspective view illustrating the external configuration of the image forming apparatus in Example 1. [Figure 2] This is a cross-sectional view illustrating the internal configuration of the image forming apparatus in Example 1. [Figure 3] This is a perspective view illustrating the configuration around the blade in the transfer means of Example 1. [Figure 4] This is a perspective view illustrating the configuration of the blade movement mechanism in Example 1. [Figure 5] This is a top view illustrating the blade movement mechanism of Example 1. [Figure 6] This is a side view illustrating the operation of the blade movement mechanism in Example 1. [Figure 7] This is a cross-sectional view illustrating the operation of the blade movement mechanism in Embodiment 1. [Figure 8] This is a cross-sectional view illustrating the lever lock in Example 1. [Figure 9] This is a cross-sectional view illustrating the configuration around the blade of Example 1. [Figure 10] These are side and top views illustrating a modified example of the lever in Example 1. [Figure 11] This is a side view illustrating a modified example of the blade movement mechanism of Example 1. [Modes for carrying out the invention]

[0010] Hereinafter, exemplary preferred embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the following embodiments should be appropriately changed according to the configuration of the apparatus to which the present invention is applied and various conditions. Therefore, unless otherwise specifically stated, it is not intended to limit the scope of the present invention. (Embodiment 1) [Configuration of Image Forming Apparatus]

[0011] FIG. 1 is a schematic perspective view for explaining the external configuration of the image forming apparatus 1 of the present embodiment, and FIG. 2 is a schematic cross-sectional view showing the internal configuration of the image forming apparatus 1. The image forming apparatus 1 of the present embodiment is a so-called tandem type image forming apparatus having a plurality of image forming units PY, PM, PC, and PK. The first image forming unit PY forms an image with yellow (Y) toner, the second image forming unit PM forms an image with magenta (M) toner, the third image forming unit PC forms an image with cyan (C) toner, and the fourth image forming unit PK forms an image with black (Bk) toner.

[0012] Further, the image forming apparatus 1 is of a process cartridge type, and the plurality of image forming units PY, PM, PC, and PK are each configured as a process cartridge and are detachable from the apparatus main body 2. The removal or attachment of each process cartridge is performed with the opening / closing door 3 provided in the image forming apparatus 1 open. As shown in FIG. 2, these four image forming units are arranged in a row at a certain interval, and the configurations of the respective image forming units have many substantially common parts except for the color of the toner to be accommodated. Therefore, in the following description, when no particular distinction is required, the suffixes Y, M, C, and K indicating elements for any color are omitted, and the elements are described collectively.

[0013] Further, in the following description, with respect to the image forming apparatus 1, the side provided with the opening / closing door 3 is defined as the front (front face), and the face opposite to the front is defined as the back (rear face). Also, when viewing the image forming apparatus 1 from the front The right side is referred to as the drive side, and the left side as the non-drive side. In the drawing, the direction from the back to the front of the device body 2 is defined as the X-axis direction, the direction from the non-drive side to the drive side is defined as the Y-axis direction, and the direction from the bottom to the top of the device body 2 is defined as the Z-axis direction.

[0014] As shown in Figure 2, each image forming unit P is arranged horizontally with respect to the bottom surface of the main body 2 of the apparatus. Each image forming unit P has an electrophotographic process mechanism, and rotational driving force is transmitted from a cartridge drive transmission unit (not shown) provided in the main body 2 of the apparatus. Each image forming unit P includes a photosensitive drum 40 as an image carrier that holds a toner image (developer image), a charging means (not shown), and a developing means (not shown).

[0015] Furthermore, an exposure means LS is provided above the image forming unit P in the Z-axis direction, and the exposure means LS outputs laser light in response to image information received by a controller (not shown). The laser light W output from the exposure means LS passes through the exposure window of the image forming unit P and scans and exposes the surface of the photosensitive drum 40.

[0016] Furthermore, a transfer means 11 is provided below the image forming unit P in the Z-axis direction. The transfer means 11 includes a movable endless intermediate transfer belt 12, a primary transfer roller 16, a drive roller 13, a tension roller 17, an assist roller 15, a recovery means 19, and a storage container 18. The drive roller 13 rotates under driving force, moving the intermediate transfer belt 12 in the direction of arrow B in the figure, and is a tension roller that tensions the intermediate transfer belt 12 together with the tension roller 17 and the assist roller 15. The recovery means 19 recovers the toner remaining on the intermediate transfer belt 12 (hereinafter referred to as residual transfer toner). The residual transfer toner recovered by the recovery means 19 is stored in a storage container 18 provided in the area on the inner circumferential surface side of the intermediate transfer belt 12.

[0017] The primary transfer roller 16 is a transfer means for transferring the toner image supported on the photosensitive drum 40 from the photosensitive drum 40 to the intermediate transfer belt 12, and is in contact with the inner circumferential surface of the intermediate transfer belt 12. Each primary transfer roller 16Y, 16M, 16C, and 16K is provided corresponding to each photosensitive drum 40Y, 40M, 40C, and 40K via the intermediate transfer belt 12. Each primary transfer roller 16 is provided extending in a direction perpendicular to the direction of movement of the intermediate transfer belt 12 (indicated by arrow B) (Y-axis direction). Each primary transfer roller 16 biases the intermediate transfer belt 12 toward each photosensitive drum 40, forming a primary transfer section where the photosensitive drum 40 and the intermediate transfer belt 12 are in contact.

[0018] In this embodiment, as shown in Figure 2, each primary transfer roller 16 is positioned offset in the direction of movement of the intermediate transfer belt 12 from the position of each primary transfer section where each photosensitive drum 40 and the intermediate transfer belt 12 come into contact. More specifically, each primary transfer roller 16 is positioned shifted downstream of the position of each primary transfer section with respect to the direction of movement of the intermediate transfer belt 12. Alternatively, each primary transfer roller 16 may be shifted upstream of the position of each primary transfer section with respect to the direction of movement of the intermediate transfer belt 12.

[0019] The recovery means 19 is located on the rear side of the image forming unit P and near the rear door 60 for accessing the interior of the image forming apparatus 1 from the rear side. The recovery means 19 includes a frame 191 and a cleaning blade 192 (hereinafter referred to as the blade) provided inside the frame 191 and extending in the Y-axis direction. The blade 192 is positioned to contact the outer circumferential surface of the intermediate transfer belt 12 in a counter-direction opposite to the movement direction B of the intermediate transfer belt 12. The blade 192 removes residual transfer toner remaining on the intermediate transfer belt 12 by scraping it off, and recovers the removed residual transfer toner into the frame 191. The configuration of the blade 192 will be described in detail later.

[0020] A secondary transfer roller 14 is positioned opposite the drive roller 13 (drive rotating body) via an intermediate transfer belt 12, and a secondary transfer section is formed at the position where the secondary transfer roller 14 and the intermediate transfer belt 12 come into contact. Furthermore, with respect to the transport direction of the transfer material S, a feeding means 50 is provided upstream of the secondary transfer section, which includes a paper feed cassette 51 for containing the transfer material S and a paper feed roller 52 for feeding the transfer material S from the paper feed cassette 51 toward the secondary transfer section.

[0021] With respect to the direction of movement of the transfer material S, downstream of the secondary transfer section, there is a fixing means 31 for fixing a toner image onto the transfer material S, and a pair of discharge rollers 32 for discharging the transfer material S with the toner image fixed onto it from the main body 2 of the device. The transfer material S discharged from the main body 2 by the pair of discharge rollers 32 is loaded onto the paper output tray 33. [Image Formation Process]

[0022] Next, the image forming operation of the image forming apparatus 1 of the present invention will be described. When a control means (not shown), such as a controller, receives an image signal, the image forming operation is started, and the photosensitive drum 40 and drive rollers 13, etc., start rotating at a predetermined peripheral speed (process speed) due to the driving force from a drive source (not shown).

[0023] The photosensitive drum 40 is uniformly charged on its surface by a charging means (not shown) to the same polarity as the normal charging polarity of the toner (negative polarity in this embodiment). Subsequently, an electrostatic latent image according to the image information is formed on the photosensitive drum 40 by irradiation with laser light W from an exposure means LS. Then, the electrostatic latent image formed on the photosensitive drum 40 is developed by the toner contained in a developing means (not shown), and a toner image corresponding to the image information is carried on the surface of the photosensitive drum 40. At this time, each photosensitive drum 40Y, 40M, 40C, and 40K is carried with a toner image corresponding to the image components of yellow, magenta, cyan, and black, respectively.

[0024] Subsequently, the toner images of each color carried on each photosensitive drum 40 reach each primary transfer section as each photosensitive drum 40 rotates. Then, by applying voltage from a power supply (not shown) to each primary transfer roller 16, the toner images of each color carried on each photosensitive drum 40 are sequentially transferred onto the intermediate transfer belt 12 in each primary transfer section. As a result, four toner images corresponding to the desired color image are formed on the intermediate transfer belt 12.

[0025] Subsequently, the four toner images supported on the intermediate transfer belt 12 reach the secondary transfer section as the intermediate transfer belt 12 moves, and are transferred simultaneously to the surface of the transfer material S, such as paper or an OHP sheet, as they pass through the secondary transfer section. At this time, a voltage with the opposite polarity to the normal charging polarity of the toner is applied to the secondary transfer roller 14 from a secondary transfer power supply (not shown).

[0026] The transfer material S, contained in the paper feed cassette 51, is fed from the paper feed cassette 51 by the paper feed roller 52 at a predetermined timing and transported toward the secondary transfer section. In the secondary transfer section, the transfer material S onto which the four-color toner images have been transferred is heated and pressurized in the fixing means 31, causing the four colors of toner to melt and mix, and fix to the transfer material S. After that, the transfer material S is discharged from the main body 2 by the discharge roller pair 32 and loaded onto the paper discharge tray 33, which serves as a loading section. In this embodiment of the image forming apparatus 1, a full-color print image is formed by the above operations.

[0027] In this embodiment, the image forming apparatus 1 is equipped with a controller (not shown) for controlling the operation of each part of the image forming apparatus, and a memory (not shown) as a storage means for storing various control information. The controller performs control related to the transport of the transfer material S, control related to the driving of the intermediate transfer belt 12 and each image forming unit P as a process cartridge, and control related to image formation. [Configuration of the drive transmission mechanism and cleaning mechanism in the transfer means]

[0028] Figures 3 and 6 show the configuration of the drive transmission mechanism and cleaning mechanism in the transfer means 11 of the present invention. As shown in Figures 3(a) and 6(a), a driving force from a drive source (not shown) is input from the drive side end 13a of the drive roller 13, and this driving force drives the drive roller 13 and its non-drive side end 13b. A through hole is provided in the non-drive side end 13b of the drive roller 13 in a direction intersecting the axial direction, and a drive transmission pin 20 is inserted into this through hole, and the driving force is transmitted by the drive transmission pin 20 to the drive gear 21 provided on the non-drive side end 13b. The drive gear 21 is provided with a contacted portion 21b in the circumferential direction that the drive transmission pin 20 can contact, and the part other than the contacted portion 21b is a space 21c. When the drive transmission pin 20 is in the space 21c, there is a section of free travel (play) between the time the driving force is input to the drive roller 13 and the time the drive transmission pin 20 contacts the contacted portion 21b. When the image forming apparatus 1 is in use, the drive roller 13 rotates in the forward direction B, and after passing through a free-running section, the contact surface 20a of the drive transmission pin 20 comes into contact with the drive transmission surface 21a of the contacted portion 21b, thereby transmitting the driving force input to the drive roller 13 to the drive gear 21. The driving force transmitted to the drive gear 21 is transmitted in the order of idler gear 22, stirring gear 23a, and screw gear 25a, and a separation gear 26 is provided at the downstream position from the screw gear 25a to which the driving force can be transmitted. Near the vicinity of the above gear train, a blade shaft 24a (non-driven side) that rotatably supports the blade 192 is provided. This drive transmission mechanism connects the rotation axis of the drive roller 13, which is a tensioned roller, and the separation gear 26, which is a rotating member, in a manner that enables the transmission of rotational force.

[0029] Figure 3(b) shows the cleaning mechanism using the above drive transmission mechanism. Figure 3(b) shows the internal state with the frame 191 removed in Figure 3(a). The blade 192 has a blade portion 192a made of a flexible elastic rubber material and a sheet metal portion 192b to which the blade portion 192a is bonded and which supports the blade portion 192a. Blade springs 28a, 28b are stretched between the sheet metal portion 192b and the frame 191 at both ends in the Y direction. The blade springs 28a, 28b apply a pressing force to the blade portion 192a toward the intermediate transfer belt 12, causing the blade portion 192a to bend and come into contact with the intermediate transfer belt 12. By coming into contact with the rotating intermediate transfer belt 12, the blade portion 192a scrapes off the remaining toner on the intermediate transfer belt 12, and the scraped-off remaining toner is collected inside the frame 191. Inside the frame 191, there is an agitation shaft 23b mounted coaxially with the agitation gear 23a, and an agitation sheet 23c fixed to the agitation shaft 23b. As the agitation shaft 23b rotates in the direction of arrow C in Figure 3(b) (clockwise when viewed in the +Y direction), the agitation sheet 23c rotates inside the frame 191 along the inner wall of the frame 191. As a result, the transfer residue toner inside the frame 191 is transported to the screw 25b. The screw 25b is mounted coaxially with the screw gear 25a, and as the screw 25b rotates in the direction of arrow D in Figure 3(b) (counterclockwise when viewed in the +Y direction), the transfer residue toner is transported in the +Y direction. The transported transfer residue toner is stored in the storage container 18. [Blade movement mechanism]

[0030] Since the blade 192 is constantly subjected to a force in the direction of being pressed against the intermediate transfer belt 12 by the blade springs 28a and 28b, if appropriate measures are not taken, the blade 192 may undergo plastic deformation due to the influence of ambient temperature and humidity during transportation or storage. If the blade 192 undergoes plastic deformation, there is a concern that the contact position between the intermediate transfer belt 12 and the blade 192 may deviate from the proper position, or the way the blade 192 deflects may change, making it impossible to adequately remove residual toner from the intermediate transfer belt 12.

[0031] Therefore, in this embodiment, a blade movement mechanism is provided that allows the blade 192 to be moved from a contact position where residual toner can be appropriately removed from the intermediate transfer belt 12, to a retracted position where the pressing force on the intermediate transfer belt 12 is smaller than that at the contact position. During transport or storage, the user can operate the blade movement mechanism to move the blade 192 from the contact position to the retracted position. By doing so, the plastic deformation of the blade 192 can be suppressed.

[0032] Figure 4 shows the configuration of the blade movement mechanism. As described above based on Figures 3 and 6, a separation gear 26 is provided at the downstream end of the drive transmission mechanism. The separation gear 26 is a rotating member that acts on the blade 192 by rotating, moving the blade 192 between a contact position in contact with the intermediate transfer belt 12 and a retracted position in which it is moved away from the intermediate transfer belt 12.

[0033] The blade movement mechanism is equipped with a lever 27 that can rotate the separation gear 26 around the Y axis. The lever 27 is an operating member that allows the user to perform an operation to rotate the separation gear 26 by applying force to the rotating member, the separation gear 26. The lever 27 is separate from the separation gear 26 and is not connected to the separation gear 2. The lever 27 is also detachable from the image forming apparatus 1. Further details will be described later. In the blade movement mechanism of this embodiment, when the blade 192 is in the contact position, the user can rotate the separation gear 26 by operating the lever 27, thereby moving the blade 192 to the retracted position. Also, when a driving force is input to the drive roller 13 while the blade 192 is in the retracted position, that driving force is transmitted to the separation gear 26 by the above-mentioned drive transmission mechanism, causing the separation gear 26 to rotate, and the blade 192 automatically moves from the retracted position to the contact position.

[0034] The separation gear 26 has support portions 26a and 26e at both ends in the Y-axis direction, with a separation portion 26b, a lever receiving portion 26c, and a gear portion 26d between them. The separation gear 26 is rotatably supported by the frame 191 at support portion 26a and by a cover 112 provided on part of the transfer means 11 at support portion 26e. When the blade 192 is in the retracted position, the separation portion 26b contacts the sheet metal portion 192b and the frame 191, supporting the sheet metal portion 192b against the frame 191 against the pressing force of the blade springs 28a and 28b (see also Figure 7(b)). Figures 4(a) and 4(b) show the blade 192 in the contact position.

[0035] The lever receiving portion 26c contacts the tip portion 27a of the lever 27, and a linear operation of the lever 27 in the +X direction (pushing operation) rotates the separation gear 26 by approximately 90° in the E direction (clockwise when viewed in the +Y direction, the first direction). This allows the blade 192 to be moved from the contact position to the retracted position shown in Figure 4(b). The operation of pushing the lever 27 in the +X direction is a user operation oriented along the first direction, which is the rotation direction of the separation gear 26. The lever 27 contacts the lever receiving portion 26c of the separation gear 26 when operated along the first direction, and applies a force to the separation gear 26 that rotates it in the first direction. The lever 27 is configured to move away from the separation gear 26 and not apply force to the separation gear 26 when operated along the second direction, which is the opposite direction to the first direction (counterclockwise when viewed in the +Y direction). In detail, the tip 27a of the lever 27 contacts the lever receiving portion 26c in the +X direction, but the two are separate and not connected. That is, the separation gear 26, which is the rotating member that moves the blade 192, and the lever 27, which is the operating member operated by the user, are independent of each other. Only pushing the lever 27 in the +X direction affects the separation gear 26, while pulling it in the -X direction does not affect the separation gear 26. Therefore, even if the user pushes the lever 27 to move the blade 192 to the retracted position and then pulls the lever 27 in the -X direction, the blade 192 will not move from the retracted position. The lever 27 configured in this way is an example of a restricting means that restricts the rotation of the separation gear 26 in the second direction. Thus, it offers excellent stability in the retracted position of the blade 192 during work inside the main body of the device or when handling the image forming apparatus. The lever 27 has a protrusion 27b that projects in the +Y direction, and is configured so that the protrusion 27b can be engaged with the groove 191a of the frame 191. When the user operates the lever 27, the protrusion 27b engages with the groove 191a, which prevents the lever 27 from falling off and improves work efficiency. In addition, the lever 27 is provided with a gripping portion 27c for the user to grasp, which also contributes to improving the user's work efficiency.

[0036] As will be described in detail later, when the blade 192 is in the retracted position, the gear section 26d is engaged with the screw gear 25a (see also Figure 6(b)). Therefore, when the image forming apparatus 1 is used with the blade 192 in the retracted position, the driving force input to the drive roller 13 is transmitted to the separation gear 26 by the drive transmission mechanism described above. The separation gear 26 then rotates approximately 90° in the E direction (clockwise when viewed in the +Y direction, the first direction) (see also Figure 6(c)). As a result, the separation section 26b is released from supporting the sheet metal section 192b relative to the frame 191 (see also Figure 7(c)), and the blade 192 moves from the retracted position to the contact position. The blade 192 is configured to move from the contact position to the retracted position when the separation gear 26 rotates in the first direction, and to return from the retracted position to the contact position when the separation gear 26 rotates further in the first direction. Furthermore, the blade 192 can move from the contact position to the retracted position by the rotation of the separation gear 26 in a first direction, and then return from the retracted position to the contact position by the rotation of the separation gear 26 in a second direction. However, in this embodiment, after the blade 192 has moved from the contact position to the retracted position, a restricting means is provided to restrict the rotation of the separation gear 26 in the first direction. In addition, in this embodiment, a restricting means is provided to restrict the rotation of the separation gear 26 in a second direction after the blade 192 has moved from the contact position to the retracted position. This restricts the blade 192, which has moved from the contact position to the retracted position, from returning from the retracted position to the contact position. When a driving force is input to the drive roller 13 upon the start of use of the image forming apparatus 1, the restriction of the rotation of the separation gear 26 in the first direction by the restricting means is released, and the blade 192 moves from the retracted position to the contact position. Details will be described later.

[0037] Fig. 5 shows the configuration of the blade movement mechanism as viewed from above in the Z direction. As shown in Fig. 5(a) and Fig. 5(b), the driving-side blade spring 28a that stretches the frame body 191 and the sheet metal part 192b is inclined at an angle F in the -Y direction with respect to the X axis, and the non-driving-side blade spring 28b is inclined at an angle G in the +Y direction with respect to the X axis. The Y-direction component of the tensile force of the driving-side blade spring 28a is directed in the +Y direction, and the Y-direction component of the tensile force of the non-driving-side blade spring 28b is directed in the -Y direction. In this embodiment, since it is configured such that F < G, the resultant force of the Y-direction components of the tensile forces of the blade springs 28a and 28b is directed in the -Y direction. Therefore, a force that presses the blade 192 in the -Y direction (non-driving side) acts, and it is shifted in the -Y direction. As a result, the amount L of engagement in the Y direction between the disengaging portion 26b of the disengaging gear 26 provided on the non-driving side and the sheet metal part 192b can be maximized, and the variation in the amount L of engagement can be reduced, improving the operating stability of the blade movement mechanism. [Operation of Blade Movement Mechanism]

[0038] Figure 6 shows the operation of the blade movement mechanism and drive transmission mechanism when the blade 192 automatically moves from the contact position to the separation position and then to the contact position. Figure 6(a) shows the state in which the blade 192 is in the contact position before the retraction operation. During inspections and operational checks performed before the shipment of the image forming apparatus, the blade 192 is in the contact position. Figure 6(a) shows the state after the drive roller 13 and intermediate transfer belt 12, which have received driving force from the drive source, have rotated in direction B (forward direction when the image forming apparatus is in use). The contact surface 20a of the drive transmission pin 20 inserted into the non-driven end 13b of the drive roller 13 is in contact with the drive transmission surface 21a of the contacted portion 21b of the drive gear 21, which is opposite to the forward rotation direction B. At this time, the space 21c between the contact surface 20b opposite to the contact surface 20a used for drive transmission of the drive transmission pin 20 during forward rotation B, and the non-drive transmission surface 21d on the side of the contacted portion 21b of the drive gear 21 that is not used for drive transmission, becomes the free-running section H. In addition, the separation gear 26 has teeth on a part of its circumferential direction that engage with the screw gear 25a, and when the blade 192 is in contact position, the teeth of the separation gear 26 do not engage with the screw gear 25a, and no driving force is transmitted to the separation gear 26. The tip portion 27a of the lever 27 is in a pushed-in position that leads the separation gear 26 in the X direction.

[0039] From the state shown in Figure 6(a), perform a linear motion operation by pulling lever 27 in the -X direction and pushing it in the +X direction. As a result, the blade 192 moves to the retracted position shown in Figure 6(b). More specifically, the tip 27a of the lever 27 contacts the lever receiving portion 26c of the separation gear 26, causing the separation gear 26 to rotate approximately 90° in the E direction (clockwise when viewed in the +Y direction, the first direction). As the separation gear 26 rotates, the gear portion 26d rotates until its teeth engage with the screw gear 25a. In the process of the blade 192 moving to the retracted position, the gear portion 26d rotates the screw gear 25a. At this point, the stirring gear 23a, idler gear 22, and drive gear 21 also rotate along with the screw gear 25a. There is a free-running section H with the blade 192 in the contact position shown in Figure 6(a). Therefore, the drive gear 21 can be rotated even when the drive roller 13 is connected to the drive source, until the non-drive transmission surface 21d of the contacted portion 21b of the drive gear 21 contacts the contact surface 20b of the drive transmission pin 20. The free-running section H' when the blade 192 has moved from the contact position in Figure 6(a) to the retracted position in Figure 6(b) is smaller than the free-running section H at the contact position, as shown in Figure 6(b). The angle of the free-running section H' remaining at the retracted position in Figure 6(b) is smaller than the angle required for the separation gear 26 to rotate further in the E direction from the retracted position in Figure 6(b) so that the blade 192 can reach the contact position. Therefore, even if a force is applied to rotate the separation gear 26 in the E direction (clockwise) due to transportation or handling, the drive transmission pin 20 and the drive gear 21 will come into contact and lock the rotation of the separation gear 26. This prevents the blade 192 from moving from its retracted position even when an external force is applied, improving the stability of the blade 192 in its retracted position.

[0040] When the image forming apparatus 1 is used in the state shown in Figure 6(b), and driving force is input to the drive roller 13, the driving force is transmitted to the drive transmission mechanism via the drive transmission pin 20. As a result, the contact surface 20a of the drive transmission pin 20 contacts the drive transmission surface 21a of the contacted portion 21b of the drive gear 21, causing the drive gear 21 to rotate in direction B. This rotational force is transmitted to the separation gear 26 by the drive transmission mechanism, causing the separation gear 26 to rotate in direction E (first direction). As the separation gear 26 rotates approximately 90° in direction E (first direction), the blade 192 moves to the contact position.

[0041] Thus, the drive transmission mechanism is configured to allow the drive gear 21 to spin freely without the drive roller 13 rotating for at least the angle necessary for the blade 192 to move from the contact position to the retracted position, and therefore the separation gear 26 to spin freely in the first direction. Furthermore, after the blade 192 has moved from the contact position to the retracted position, the angle by which the separation gear 26 can spin freely in the first direction without the drive roller 13 rotating corresponds to the free-running section H' of the drive gear 21. This angle is set to be smaller than the rotation angle in the first direction (corresponding to the free-running section H of the drive gear 21) necessary for the blade 192 to move from the retracted position to the contact position. The drive transmission mechanism configured in this way is an example of a restricting means for restricting the rotation of the separation gear 26 in the first direction after the blade 192 has moved from the contact position to the retracted position.

[0042] Figure 7 shows the operation of the blade movement mechanism and drive transmission mechanism when the blade 192 automatically moves from the contact position to the separation position and then to the contact position. Figure 7 shows a cross-section of the plane indicated by line II in Figure 5(b). Figure 7(a) shows the state in which the blade 192 is in the contact position. When the rotational position of the separation portion 26b is in the phase shown in Figure 7(a), the separation portion 26b does not contact the frame 191. The blade 192, which is subjected to the force of the blade spring 28, receives a moment around the blade axis 24a that rotates counterclockwise in the +Y direction (indicated by arrow K), and as a result the blade portion 192a is pressed toward the intermediate transfer belt 12, bending and coming into contact with it.

[0043] By performing the aforementioned movement operation from this state, the separation gear 26 rotates approximately 90° clockwise, and the blade 192 moves to the retracted position shown in Figure 7(b). In the retracted position, the rotational position of the separation part 26b is in the phase shown in Figure 7(b), and the separation part 26b contacts both the sheet metal part 192b and the sheet metal part 192b of the blade 192, supporting the sheet metal part 192b against the frame 191 against the tensile force of the blade spring 28. At this time, the blade spring 28 vibrates The force acting on blade 192 is received by the frame 191 via the separation portion 26b. In the retracted position shown in Figure 7(b), the blade 192 is rotated clockwise (indicated by arrow J) in the +Y direction relative to its position in the contact position shown in Figure 7(a), and the amount of deflection of the blade portion 192a is smaller compared to when it is in the contact position. By moving the blade 192 to the retracted position, the amount of deflection of the blade portion 192a is reduced, and the pressing force that contacts the intermediate transfer belt 12 is reduced. Therefore, by moving the blade 192 to the retracted position during transport or storage, creep and impact on the blade portion 192a can be mitigated even when subjected to heat or external forces, and the impact on the removal performance of residual toner can be reduced. Note that even when the blade 192 is in the retracted position, the blade portion 192a is configured to be in contact with the intermediate transfer belt 12. This prevents residual toner from leaking out of the frame 191 when the blade 192 is in the retracted position. In addition, the portion of the separated section 26b that contacts the sheet metal section 192b and the frame 191 is made of a flat surface, so that the blade 192 can be stably kept in the retracted position against impacts and the like.

[0044] When the image forming apparatus 1 is used with the blade 192 in the retracted position as shown in Figure 7(b), and driving force is input to the drive roller 13, the separation gear 26 rotates approximately 90° clockwise in the +Y direction in response to the driving force transmitted via the drive transmission mechanism. In detail, as the separation gear 26 rotates clockwise, after a certain angle of rotation, the teeth of the separation gear 26 and the screw gear 25a no longer engage. However, the separation gear 26 continues to rotate due to the force acting from the sheet metal portion 192b, and the blade 192 moves to the contact position shown in Figure 7(c). In the contact position in Figure 7(c), the blade portion 192a flexes and contacts the intermediate transfer belt 12 with a predetermined pressing force, similar to Figure 7(a), making it possible to properly remove the remaining toner from the intermediate transfer belt 12. [Lever locking mechanism]

[0045] Figure 8 shows the positional relationship between the lever 27 and the lever receiving portion 26c of the separation gear 26 when the lever 27 is pushed in the +X direction and the blade 192 is in the retracted position. Figure 8 shows a cross-section of the plane indicated by the KK line in Figure 5(b). As shown in Figure 8, when the lever 27 is pushed in, the bottom surface 27d of the tip portion 27a abuts against the upper end of the lever receiving portion 26 in the Z direction, thereby restricting the counterclockwise rotation of the separation gear 26 when viewed in the +Y direction. That is, the lever 27 is configured to abut the separation gear 26 in a second direction (counterclockwise) after the user operation to move the blade 192 from the contact position to the retracted position has been performed. The lever 27 and separation gear 26 configured in this way are an example of a restricting means that restricts the rotation of the separation gear 26 in the second direction after the blade 192 has moved from the contact position to the retracted position. This improves the stability of the blade 192 in the retracted position. Furthermore, the convex portion 27b of the lever 27 engages with the groove portion 191a of the frame 191, restricting the movement of the lever 27 in the +Z direction (see also Figure 4(b)). In addition, the frame 191 is located near the rear door 60 of the image forming apparatus 1 (see Figure 2), and the gripping portion 27c is restricted by the rear door 60, restricting the movement of the lever 27 in the -X direction. Due to these positional relationships, when the lever 27 is pushed in the +X direction to move the blade 192 to the retracted position, the counterclockwise rotation of the separation gear 26 is suppressed. Also, as explained with reference to Figure 6(b), the clockwise rotation of the separation gear 26 is restricted by the small free-running section H between the drive transmission pin 20 and the drive gear 21 after the blade 192 has been moved to the retracted position. In this way, the state in which the lever 27 is pushed in the +X direction to move the blade 192 to the retracted position is stably maintained against rotation of the separation gear 26 in both directions. [Improved precision of the blade movement mechanism]

[0046] Figure 9 shows the configuration around the blade. Figure 9 shows a cross-section of the plane indicated by line AA in Figure 3(a). The blade 192 is rotatably supported on a blade shaft 24a provided on a transfer frame 111, which is a frame constituting the transfer means 11, and receives a force in the -X direction due to the tensile force of the blade spring 28. On the other hand, the frame 191 is provided on the transfer frame 111. The blade 192 is supported with the hole 111a as the center of rotation, and the groove 111b acts as a rotation stopper, positioning it on the transfer frame 111. The frame 191 also receives the tensile force of the blade spring 28, and is positioned relative to the transfer frame 111 so as to abut against it in the +X direction within the hole 111a and in the -Z direction within the groove 111b. In this way, the blade 192 and the frame 191 are positioned relative to the transfer frame 111 by the blade spring 28 being stretched between them. Furthermore, in the retracted position of the blade 192, the blade 192 and the frame 191 are directly supported by a separation gear 26 provided between the two members of the blade 192 and the frame 191, thereby positioning the blade 192 and the frame 191 in the retracted position of the blade 192. This reduces the variation in the amount of movement of the blade 192 between the retracted position and the contact position, and allows the blade 192 to be moved accurately to the target retracted position.

[0047] Furthermore, in this configuration, the outer diameter of the drive roller 13 is smaller than the outer diameter of the assist roller 15. If the configuration from the surface of the intermediate transfer belt 12 to the separation gear 26 is the same, the smaller the radius of the drive roller 13, the shorter the distance from the center of the drive roller 13 to the center of the separation gear 26. Therefore, by reducing the outer diameter of the drive roller 13, the size of the gears and other components of the drive transmission mechanism described above, which automatically moves the blade 192 from the retracted position to the contact position when the image forming apparatus 1 is put into use, can be reduced. This contributes to cost reduction through simplification.

[0048] Furthermore, to improve the stability of the retracted position of the blade 192, it is desirable that the outer diameter (φDr) of the drive roller 13 be smaller than the outer diameter (φAs) of the assist roller 15. Details are shown in Figure 9(b). Figure 9(b) shows the case where φDr < φAs, and the shafts at both ends of the drive roller 13 are shown as 13a and 13b, and the holes at both ends of the assist roller 15 are shown as 15a and 15b. Unlike the drive roller 13, the assist roller 15 is configured to rotatably support a shaft member provided at a position that becomes the rotation center 111d in the transfer frame 111 by a hole provided on the assist roller 15 side. The shafts 13a and 13b at both ends of the drive roller 13 are rotatably supported by a hole 111c provided in the transfer frame 111. The transfer means 11 is rotatably supported on the side plate of the main body via bearings on the shafts 13a and 13b at both ends of the drive roller 13.

[0049] Let T1 be the belt tension from the drive roller 13 to the tension roller 17 (see Figure 2), T2 be the belt tension from the drive roller 13 to the assist roller 15, and T3 be the belt tension from the assist roller 15 to the tension roller 17. Each tension acts on the shafts 13a and 13b of the drive roller 13, the holes 111c and 111d of the transfer frame 111, and the holes 15a and 15b of the assist roller 15. Considering the moment acting on the transfer frame 111 with the shafts 13a and 13b at both ends of the drive roller 13, which is supported by the side plate, as the center of rotation, the resultant force T23 of the tensions in the assist roller 15 acts as a counterclockwise moment indicated by arrow A. Now, let's consider the case where the belt tensions T2 and T3 fluctuate due to impacts during transport, for example, when T3 becomes smaller due to an impact in the -X direction (T3'). In this case, the moment due to the resultant force T23' of tensions T2 and T3' acts counterclockwise with respect to the rotation center of axes 13a and 13b, as indicated by arrow A, similar to the moment due to the resultant force T23 of tensions T2 and T3. Therefore, the direction in which the axes 13a and 13b of the drive roller 13 approach the hole 111c of the transfer frame 111 does not change within the play. Consequently, the positional relationship between the blade 192, which has its rotation center (blade axis 24a) in the transfer frame 111, and the drive roller 13 remains unchanged, and the blade 192 has high stability in its retracted position against the action of external forces during transport.

[0050] On the other hand, Figure 9(c) shows the situation where φDr > φAs. With the axes 13a and 13b at both ends of the drive roller 13 supported by the side plate as the centers of rotation, the moment due to the resultant force T23 of the tensions of the assist roller 15 acts counterclockwise as indicated by arrow A. On the other hand, consider the case where the belt tensions T2 and T3 fluctuate due to impacts during transport, for example, when T3 becomes smaller due to an impact in the -X direction (T3'). In this case, the moment due to the resultant force T23' of the tensions T2 and T3' The drive roller 13 acts clockwise, as indicated by arrow B, with its axis 13a and 13b as the center of rotation. As a result, the direction in which the axis 13a and 13b of the drive roller 13 approach the hole 111c of the transfer frame 111 changes within the play. Consequently, the positional relationship between the blade 192, which has its center of rotation (blade axis 24a) in the transfer frame 111, and the drive roller 13 may change. This causes fluctuations in the amount of movement between the contact position and the retracted position, which may reduce the stability of the blade 192 in the retracted position against external forces during transport. [Improved blade movement accuracy through T2 separation section configuration]

[0051] Furthermore, the drive connection configuration to the transfer means 11 includes a drive connection to the drive roller 13 and a drive connection to the T2 separation section, which increases the support portion of the transfer means 11, improving stability during transport and enhancing the stability of the blade 192 in its retracted position. Details are shown in Figures 5, 6, and 7.

[0052] As shown in Figure 5(a), the transfer means 11 is connected to the drive source on the main body side via the shaft 13a of the drive roller 13 provided on the drive side, and is also connected to the fixing drive source (not shown) on the main body side via the T2 separation input gear 34 provided on the non-drive side. As shown in Figure 6(b), the T2 separation input gear 34, which is connected to the gear train from the fixing drive source, has a coupling shape on the gear itself, and during transport, the coupling shape is oriented in the X direction. At this time, the coupling surface 34a of the T2 separation input gear 34 is positioned vertically in the Z direction, so the transfer means 11 is held even if an external force in the Z direction acts on the device body. The transfer means 11 is positioned in the Z direction relative to the main body side plate in the vicinity of the tension roller 17, with the shafts 13a and 13b on the drive side and non-drive side of the drive roller 13 as its centers of rotation. In this embodiment, the movement in the Z direction is further restricted at the T2 separation input gear 34 located between the drive roller 13 and the tension roller 17 in the X direction. This suppresses the movement and deformation of the transfer means 11 in response to external forces during transport. In the Y direction, the T2 separation input gear 34 is located on the non-driven side, similar to the separation gear 26, and the T2 separation input gear 34, which restricts the movement of the transfer means 11, is close to the blade movement mechanism. In the X direction, the rotation center of the blade 192 (blade axis 24a) is located between the non-driven side axis 13b of the drive roller 13 and the T2 separation input gear 34. This reduces the displacement of the blade 192 due to deformation and rotation of the transfer means 11, resulting in high stability of the blade movement mechanism.

[0053] Furthermore, downstream from the T2 separation input gear 34, as shown in Figure 7(b), a T2 separation cam gear 36 is provided coaxially with the T2 separation idler gear 35 and the drive roller 13, and the secondary transfer roller 14 is moved into contact with and separated by the phase of the T2 separation cam gear 36. The gear phase is detected by a sensor (not shown) provided in the middle of the fixing gear train. [Variations of the blade movement mechanism]

[0054] Next, a modified example of the blade movement mechanism in this embodiment will be described using Figures 10 and 11. As shown in Figure 10(a), the lever 27 may be configured to be removable from the image forming apparatus 1. In this case, for example, the lever 27 can be operated in a pre-shipment process to move the blade 192 to the retracted position, and then the image forming apparatus 1 can be shipped without the lever 27 attached. This reduces the number of components in the image forming apparatus 1 itself. In addition, it is prevented from moving the blade 192 from the retracted position to the contact position due to erroneous operation by the handling company or end user of the image forming apparatus 1 after shipment from the factory, thus improving the stability of the blade 192 in the retracted position. In this case, since the lever 27 is removed after the blade 192 moves to the retracted position by lever operation, the counterclockwise rotation of the separation gear 26 described in Figure 8 is not restricted. Therefore, as shown in Figure 10(a), a hook 26f may be provided on the separation gear 26 as a projection, and an engaging portion 112a may be provided on the cover 112 that engages with the hook 26f after the blade 192 moves from the contact position to the retracted position. This allows the blade 192 to move from the retracted position This prevents the blade 192 from unintentionally moving to the contact position, improving its stability in the retracted position. The hook 26f and engaging portion 112a configured in this way are an example of a restricting means that restricts the rotation of the separation gear 26 in the second direction (counterclockwise) after the blade 192 has moved from the contact position to the retracted position.

[0055] As shown in Figure 10(b), an operated portion 26g is provided at the tip of the support portion 26e of the separation gear 26, formed by making a part of the outer circumferential surface planar. The separation gear 26 may be configured to be rotatable by a rotating operating member 29 having an engaging portion 29a that engages with the operated portion 26g. With this configuration, by engaging the engaging portion 29a of the rotating operating member 29 with the operated portion 26g and rotating the rotating operating member 29, the separation gear 26 can be rotated, and the blade 192 can be moved between the contact position and the retracted position. With this configuration, there is no need to provide the lever 27 above the separation gear 26, which contributes to reducing the size of the image forming apparatus 1 in the Z direction and enables space saving of the main body. Furthermore, since the lever 27 is not required, the member positioned above the transfer means 11 can be positioned lower in the Z direction compared to a configuration with a lever 27. Such a member arrangement suppresses inadvertent access to the separation portion 26b by the end user and helps prevent erroneous operation. Furthermore, by making the rotation operating member 29 removable, as in the case of Figure 10(a) described above, it is possible to suppress the blade 192 from unintentionally moving from the retracted position to the contact position due to erroneous operation, and the stability of the blade 192 in the retracted position is improved. Also, as in Figure 10(a), in order to restrict the rotation of the separation gear 26 in the counterclockwise direction, a hook 26f and an engaging portion 112a may be provided in the configuration of Figure 10(b) as in Figure 10(a).

[0056] Furthermore, as shown in Figure 11, the gear portion 26d of the separation gear 26 can also be made of a flexible material. Figure 11 shows the state in which the separation gear 26 is rotated clockwise by pushing the lever 27 in the +X direction, moving the blade 192 from the contact position to the retracted position. At this time, if the gear portion 26d is a rigid body, the teeth of the gear portion 26d engage with the screw gear 25a, and when the separation gear 26 is rotated clockwise by operating the lever 27, the rotation is transmitted to the drive gear 21 via the drive transmission mechanism. This causes the drive gear 21 to rotate in direction B (see Figure 6(b)). In order to allow this rotation (free spinning) of the drive gear 21, a free spin section H was set for the drive gear 21 as described above (see Figure 6(a)). On the other hand, if the gear portion 26d is made of a flexible material, some of the teeth of the gear portion 26d engage with the screw gear 25a, and when the separation gear 26 rotates clockwise due to the operation of the lever 27, the gear portion 26d deforms to absorb this rotational force. Therefore, since the rotational force is not transmitted to the drive transmission mechanism, there is no need to provide a free-running section H between the drive gear 21 and the drive transmission pin 20 to allow the drive gear 21 to rotate (slip). As explained in Figure 6(b), after moving the blade 192 from the contact position to the retracted position, it was necessary to set a free-running section H' that was smaller than the angle required to move it further to the contact position, but still sufficient to account for variations in parts, etc. In this respect, if the gear portion 26d is made of a flexible material, the free-running section H at the contact position is also unnecessary, so the locking of the separation gear 26 in the clockwise direction becomes more reliable, and the stability of the blade 192 at the retracted position is improved. In this drive transmission mechanism, there is a flexible gear connected to the rotation axis of the separation gear 26, which is a rotating member, and the flexible gear deforms. Then, the separation gear 26 can rotate in the first direction (clockwise) by at least the angle necessary for the blade 192 to move from the contact position to the retracted position without the drive roller 13 rotating and without the separation gear 26 and therefore the drive gear 21 slipping. As a result, the drive transmission mechanism can be set so as not to allow the separation gear 26 to slip in the first direction without the rotation axis of the drive roller 13 rotating, that is, to eliminate the free-running section H.The drive transmission mechanism configured in this way is an example of a restricting means that restricts the rotation of the separation gear 26 in the first direction after the blade 192 moves from the contact position to the retracted position. Although the deformation of the gear portion 26d causes a force to act on the separation gear 26 in a counterclockwise direction, the lever 27 in Figure 8 and Figure 10(a) are examples of this. A configuration that restricts rotation, such as the 26f hook, can be applied.

[0057] The configurations of the embodiments described above can be combined as much as possible within the scope of the present invention to implement the present invention.

[0058] This embodiment includes the following configurations and methods. (Composition 1) An image carrier that holds the developer image, A transfer belt on which the developer image is transferred from the image carrier, A blade that contacts the transfer belt and scrapes off any developer remaining on the transfer belt, A rotating member that acts on the blade by rotating, moving the blade between a contact position in contact with the transfer belt and a retracted position in which it is moved away from the transfer belt, A restricting means for restricting the blade, which has moved from the contact position to the retracted position, from returning from the retracted position to the contact position, An image forming apparatus characterized by comprising: (Configuration 2) The blade is configured such that the rotating member rotates in a first direction to move from the contact position to the retracted position, and the rotating member rotates further in the first direction or in a second direction opposite to the first direction to return from the retracted position to the contact position. The image forming apparatus according to configuration 1, wherein the restricting means restricts the rotation of the rotating member in the first direction after the blade moves from the contact position to the retracted position. (Composition 3) A tension roller for tensioning the aforementioned transfer belt, A drive transmission mechanism that connects the rotation axis of the tension roller and the rotation axis of the rotating member in a manner that enables the transmission of rotational force, Furthermore, The image forming apparatus according to configuration 2, wherein the drive transmission mechanism is configured to allow the rotating member to rotate freely in the first direction without the rotation axis of the tension roller rotating by at least the angle necessary for the blade to move from the contact position to the retracted position. (Composition 4) In the drive transmission mechanism, after the blade moves from the contact position to the retracted position, the angle at which the rotating member can further rotate freely in the first direction without the rotation axis of the tension roller rotating is set to be smaller than the angle of rotation of the rotating member in the first direction required for the blade to move from the retracted position to the contact position. The image forming apparatus according to configuration 3, wherein the restricting means restricts the rotation of the rotating member in the first direction by the configured drive transmission mechanism. (Composition 5) A tension roller for tensioning the aforementioned transfer belt, A drive transmission mechanism that connects the rotation axis of the tension roller and the rotation axis of the rotating member in a manner that enables the transmission of rotational force, Furthermore, The image forming apparatus according to configuration 2, wherein the drive transmission mechanism has a flexible gear connected to the rotation shaft of the rotating member, and the gear deforms so that the rotating member rotates in the first direction without the rotation shaft of the tension roller rotating and without the rotating member free-spinning, by at least the angle necessary for the blade to move from the contact position to the retracted position. (Composition 6) In the drive transmission mechanism, the rotational member is not allowed to rotate freely in the first direction without the rotational shaft of the tension roller rotating. The regulating means, by the configured drive transmission mechanism, controls the first direction of the rotating member The image forming apparatus according to configuration 5, which restricts rotation in the direction. (Composition 7) The image forming apparatus according to any one of the configurations 3 to 6, wherein when a driving force is applied to rotate the tension roller while the blade is in the retracted position, the driving force is transmitted to the rotating member by the drive transmission mechanism, causing the rotating member to rotate in the first direction and the blade to move from the retracted position to the contact position. (Composition 8) The system further includes an operating member that allows a user to perform an operation to rotate the rotating member by applying force to it. The image forming apparatus according to any one of configurations 1 to 7, wherein the operating member is separate from the rotating member and is not connected to the rotating member. (Composition 9) The image forming apparatus according to configuration 8, wherein the operating member is detachable from the image forming apparatus. (Composition 10) The blade is configured such that the rotating member rotates in a first direction to move from the contact position to the retracted position, and the rotating member rotates further in the first direction or in a second direction opposite to the first direction to return from the retracted position to the contact position. The image forming apparatus according to any one of configurations 1 to 9, wherein the restricting means restricts the rotation of the rotating member in the second direction after the blade has moved from the contact position to the retracted position. (Composition 11) The system further includes an operating member that allows a user to perform an operation to rotate the rotating member by applying force to it. The image forming apparatus according to configuration 10, wherein the operating member is separate from the rotating member and is not connected to the rotating member. (Composition 12) The image forming apparatus according to configuration 11, wherein the operating member is detachable from the image forming apparatus. (Composition 13) The operating member is configured to contact the rotating member and apply a force to rotate the rotating member in the first direction when operated by a user in the direction of the first direction, and to move away from the rotating member and not apply a force to the rotating member when operated by a user in the direction of the second direction. The image forming apparatus according to configuration 11 or 12, wherein the restricting means restricts the rotation of the rotating member in the second direction by the operating member configured as described above. (Composition 14) The operating member is configured to contact the rotating member in the second direction after a user operation has been performed to move the blade from the contact position to the retracted position. The image forming apparatus according to configuration 11 or 12, wherein the restricting means restricts the rotation of the rotating member in the second direction by the operating member and the rotating member configured as described above. (Composition 15) The rotating member has a projection, The image forming apparatus has an engaging portion that engages with the projection of the rotating member after the blade moves from the contact position to the retracted position. The image forming apparatus according to any one of the configurations 10 to 12, wherein the restricting means restricts the rotation of the rotating member in the second direction by the projection and the engaging portion. (Composition 16) A tension roller for tensioning the aforementioned transfer belt, A drive transmission mechanism that connects the rotation axis of the tension roller and the rotation axis of the rotating member in a manner that enables the transmission of rotational force, Furthermore, The image forming apparatus according to any one of the configurations 10 to 15, wherein when a driving force is applied to rotate the tension roller while the blade is in the retracted position, the driving force is transmitted to the rotating member by the drive transmission mechanism, causing the rotating member to rotate in the first direction and the blade to move from the retracted position to the contact position. [Explanation of symbols]

[0059] 1: Image forming apparatus, 12: Intermediate transfer belt, 192: Cleaning blade, 26: Separation gear, 26c: Lever receiver, 26f: Hook, 27: Lever, 27d: Bottom surface, 40: Photosensitive drum, 112a: Engaging part

Claims

1. An image carrier that holds the developer image, A transfer belt on which the developer image is transferred from the image carrier, A blade that contacts the transfer belt and scrapes off any developer remaining on the transfer belt, A rotating member that acts on the blade by rotating, moving the blade between a contact position in contact with the transfer belt and a retracted position in which it is moved away from the transfer belt, A tension roller for tensioning the aforementioned transfer belt, A drive transmission mechanism that connects the rotation axis of the tension roller and the rotation axis of the rotating member in a manner that enables the transmission of rotational force, Equipped with, The blade is configured such that the rotating member rotates in a first direction to move from the contact position to the retracted position, and the rotating member rotates further in the first direction to move from the retracted position to the contact position. The drive transmission mechanism is configured such that, when the blade is in the retracted position after it has moved from the contact position to the retracted position, the angle at which the rotating member can freely rotate in the first direction without the rotation axis of the tension roller rotating is smaller than the angle of rotation of the rotating member in the first direction required to move the blade from the retracted position to the contact position.

2. The image forming apparatus according to claim 1, characterized in that when a driving force to rotate the tension roller is input while the blade is in the retracted position, the driving force is transmitted to the rotating member by the drive transmission mechanism, causing the rotating member to rotate in the first direction, and the blade moves from the retracted position to the contact position.

3. The operating member further comprises a user operation that allows the user to perform an operation to rotate the rotating member by applying force to the rotating member, The operating member is separate from the rotating member, A user operation in a direction along the first direction causes contact with the rotating member and applies a force to the rotating member that rotates it in the first direction. By user operation in a direction opposite to the first direction, the rotating member is moved away from the rotating member. The image forming apparatus according to claim 1 or 2, characterized in that no force is applied to the rotating member.

4. The image forming apparatus according to claim 3, characterized in that the operating member is detachable from the image forming apparatus.

5. The blade is configured to move from the retracted position to the contact position even when the rotating member rotates in a second direction opposite to the first direction, The operating member is configured to contact the rotating member in the second direction after a user operation has been performed to move the blade from the contact position to the retracted position. The image forming apparatus according to claim 3, characterized in that the rotation of the rotating member in the second direction is restricted by the operating member and the rotating member.

6. The blade is configured to move from the retracted position to the contact position even when the rotating member rotates in a second direction opposite to the first direction, The rotating member has a projection, The image forming apparatus has an engaging portion that engages with the projection of the rotating member after the blade moves from the contact position to the retracted position. The image forming apparatus according to claim 1 or 2, characterized in that the rotation of the rotating member in the second direction is restricted by the projection and the engaging portion.

Images