Contact / separation device and image forming apparatus

Abstract

To perform contact and separation operations between a contact target member and a roller member with a simple configuration without using a drive gear, and prevent unintended contact and separation operations between the contact target member and the roller member.SOLUTION: A contact and separation device 45 has: a separation member 24 that rotates in a first direction centered on a rotation axis parallel to a rotation axis of a secondary transfer outer roller 20 to release engagement with a bearing member 22 and move the bearing member 22 from a separation position to a contact position by an urging force of a transfer coil spring 21; and the bearing member 22 that, at the separation position, applies a turning force in a second direction being the opposite direction to the first direction to the separation member 24. The separation member 24 has a regulation part 24c that is in contact with a device body 45c to regulate rotation in the second direction to inhibit movement of the bearing member 22 to the contact position.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an image forming apparatus such as a separating device and a multifunction machine having an electrophotographic FAX and a printer equipped with the separating device.

Background Art

[0002] Conventionally, as an electrophotographic image forming apparatus, an apparatus using an intermediate transfer belt and a transfer roller that is pressed against the intermediate transfer belt is widely known. Such an image forming apparatus is not used for a long period from the time of shipment until it reaches the end user, and particularly during transportation, it is often placed in a harsh environment such as a high-temperature and high-humidity environment.

[0003] When the image forming apparatus is not used for a long period in such an environment, the transfer roller is left in a state of being pressed against the intermediate transfer belt for a long time, and there is a risk that substances exuded on the surface of the intermediate transfer belt adhere and disturb the image. In addition, the transfer roller may be locally deformed and cause transfer failure. Therefore, a shipping form may be adopted in which a sheet-like member is sandwiched between the intermediate transfer belt and the transfer roller, or a separating member that separates the transfer roller and the intermediate transfer belt is inserted on the transfer roller side to bring the intermediate transfer belt and the transfer roller into a light pressure state or a separated state.

[0004] Patent Document 1 discloses an image forming apparatus that releases the separation between the intermediate transfer belt and the transfer roller by using a drive gear that transmits a driving force to the secondary transfer outer roller at the time of initial startup from the viewpoints of improving serviceability and preventing malfunction due to forgetting to remove a sheet-like member. In the image forming apparatus of Patent Document 1, since the secondary transfer roller and the secondary transfer outer roller, which have the role of conveying paper, need to be easily separated by the user's hand when a paper jam occurs, the secondary transfer roller and the secondary transfer outer roller are in the vicinity of a place that the user touches.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2006-113283 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, Patent Document 1 has the problem that the configuration for transmitting driving force to the drive gear during initial startup becomes complex. Also, in Patent Document 1, since the secondary transfer outer roller is located near the area touched by the user, the drive gear that transmits driving force to the secondary transfer outer roller is also located near the area touched by the user, which has the problem that the drive gear is easily damaged. Furthermore, in Patent Document 1, there is room for improvement in preventing contact and separation movements between the intermediate transfer belt and the transfer roller when unpredictable external forces are applied during logistics, etc.

[0007] The object of the present invention is to provide a contact / separation device and an image forming apparatus that can perform the contact / separation operation between a member to be contacted and a roller member with a simple configuration without using a drive gear, and can suppress unintended contact / separation operations between the member to be contacted and the roller member. [Means for solving the problem]

[0008] The contact / separation device according to the present invention comprises: a rotatable roller member; a bearing member that rotatably holds the roller member and is movable between a contact position in which the roller member is in contact with a member to be contacted and a separation position in which the roller member is separated; a biasing member that biases the bearing member to the contact position; and a separation member that engages with the bearing member to hold the bearing member to the separation position against the biasing force of the biasing member, and rotates in a first direction about a rotation axis parallel to the rotation axis of the roller member to release the engagement with the bearing member and move the bearing member from the separation position to the contact position by the biasing force of the biasing member, wherein the bearing member applies a rotational force to the separation member in a second direction opposite to the first direction at the separation position, and the separation member is provided with a restricting part that abuts against the device body and restricts rotation in the second direction, thereby preventing the bearing member from moving to the contact position. [Effects of the Invention]

[0009] According to the present invention, the contact and separation movements between the contacted member and the roller member can be performed with a simple configuration without using a drive gear, and unintended contact and separation movements between the contacted member and the roller member can be suppressed. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of an image forming apparatus according to an embodiment of the present invention. [Figure 2] This is a schematic diagram showing a partial removal of the contact / separation device according to an embodiment of the present invention. [Figure 3] A schematic diagram of a contact / separation device according to an embodiment of the present invention. [Figure 4] This is a schematic diagram illustrating the operation of a contact / separation device according to an embodiment of the present invention. [Figure 5] This figure shows the relationship between the bearing member and the separation member of the connecting / separating device according to an embodiment of the present invention. [Figure 6] This is an enlarged view showing the relationship between the bearing member and the separation member of a connecting / separating device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0011] The embodiments will be described in detail below with reference to the drawings.

[0012] <Configuration of an image forming apparatus> The configuration of the image forming apparatus 100 according to an embodiment of the present invention will be described in detail with reference to Figure 1.

[0013] The image forming apparatus 100 performs image formation operations in response to input image information from an external host device (not shown), such as a computer or image reader, which is communicatively connected to a control unit (not shown), and forms and outputs a full-color image on the recording material P. Here, the image forming apparatus 100 is exemplified as an image forming apparatus such as an intermediate transfer type tandem full-color digital printer.

[0014] Specifically, the image forming apparatus 100 includes image forming sections 1Y, 1M, 1C, and 1Bk, a paper discharge roller 5, a discharge tray 6, an intermediate transfer belt unit 9, a switching member 10, and a reversing roller 11. The image forming apparatus 100 also includes a paper feeding section 28, a laser exposure device 32, a resist roller 34, a fixing device 36, a contact / separation device 45, and a transport section 52.

[0015] The image forming units 1Y, 1M, 1C, and 1Bk are located in the central part of the apparatus body 100a. The image forming units 1Y, 1M, 1C, and 1Bk are arranged in a line at predetermined intervals along the rotational direction of the intermediate transfer belt 8 below the intermediate transfer belt 8 of the intermediate transfer belt unit 9. Each of the image forming units 1Y, 1M, 1C, and 1Bk is composed of a laser exposure type electrophotographic process mechanism. The image forming units 1Y, 1M, 1C, and 1Bk perform image formation operations based on a color separation image signal input from an external host device (not shown) under the control of a control unit (not shown).

[0016] Each of the image forming units 1Y, 1M, 1C, and 1Bk includes a photosensitive drum 18, a charging roller 19, a developing device 26, and a drum cleaner device 27.

[0017] The photosensitive drum 18 is a drum-type electrophotographic photoreceptor on which a toner image is formed at a predetermined control timing according to the electrophotographic imaging principle and process. The photosensitive drum 18 is rotationally driven at a predetermined speed in the clockwise direction in FIG. 1 to form a toner image. A yellow toner image is formed on the photosensitive drum 18 of the image forming unit 1Y. A magenta toner image is formed on the photosensitive drum 18 of the image forming unit 1M. A cyan toner image is formed on the photosensitive drum 18 of the image forming unit 1C. A black toner image is formed on the photosensitive drum 18 of the image forming unit 1Bk.

[0018] The charging roller 19 uniformly charges the photosensitive drum 18.

[0019] The developing device 26 attaches toner to the exposed portion on the photosensitive drum 18 exposed by the laser exposure device 32.

[0020] The drum cleaner device 27 removes and recovers the primary transfer residual toner remaining on the photosensitive drum 18 without being transferred to the intermediate transfer belt 8 during primary transfer by the primary transfer roller 16 of the intermediate transfer belt unit 9 from the photosensitive drum 18.

[0021] The paper discharge roller 5 discharges the recording material P that is conveyed through the conveyance path 37 by the fixing device 36 and whose conveyance path is switched by the switching member 10 onto the discharge tray 6 as a full-color image formation.

[0022] The discharge tray 6 is provided above the apparatus main body 100a. The discharge tray 6 stacks the recording material P discharged from the paper discharge roller 5.

[0023] The intermediate transfer belt unit 9 is located above the image forming sections 1Y, 1M, 1C, and 1Bk. The intermediate transfer belt unit 9 comprises a secondary transfer roller 7, an intermediate transfer belt 8, a tension roller 14, a tension roller 15, and a primary transfer roller 16.

[0024] The secondary transfer roller 7, together with the tension roller 14 and tension roller 15, tensions the intermediate transfer belt 8. The secondary transfer roller 7 is driven by a drive motor (not shown) to rotate the intermediate transfer belt 8 counterclockwise (arrow E direction) in Figure 1 at a predetermined speed.

[0025] The intermediate transfer belt 8 is an endless and flexible belt member. The intermediate transfer belt 8 is wrapped around the secondary transfer internal roller 7, the tension roller 14, and the tension roller 15. The intermediate transfer belt 8 is driven to rotate in the direction of rotation of each photosensitive drum 18 and in the forward direction, at a speed corresponding to the rotational speed of each photosensitive drum 18. The intermediate transfer belt 8 constitutes the primary transfer section 29 by the contact portion that abuts against each photosensitive drum 18. The intermediate transfer belt 8 is cleaned by a belt cleaning device (not shown) positioned opposite the tension roller 14 to remove residual deposits such as secondary transfer toner that remain on the recording material P in the secondary transfer section 17 and is used for repeated imaging.

[0026] The primary transfer unit 29 sequentially superimposes the toner images formed on each photosensitive drum 18 onto the outer surface of the intermediate transfer belt 8, thereby synthesizing and forming an unfixed full-color toner image on the outer surface of the intermediate transfer belt 8 by superimposing the four toner images.

[0027] The tension roller 14, together with the secondary transfer inner roller 7 and the tension roller 15, tensions the intermediate transfer belt 8.

[0028] The tension roller 15, together with the secondary transfer inner roller 7 and the tension roller 14, tensions the intermediate transfer belt 8.

[0029] The primary transfer roller 16 is positioned inside the intermediate transfer belt 8. The primary transfer roller 16 is in contact with the photosensitive drum 18 via the intermediate transfer belt 8.

[0030] The switching member 10 switches the transport path by transporting the recording material P, which is transported from the fixing device 36 via the transport path 37, to the paper discharge roller 5 or to the reversing roller 11.

[0031] In the case of double-sided image formation, the reversing roller 11 rotates and transports the recording material P that is being transported after the transport path is switched by the switching member 10. The reversing roller 11 reverses rotation immediately after the rear end of the transport direction of the transported recording material P passes a predetermined branching point, and switches back transports the recording material P to the transport roller 38 via the double-sided transport path 12.

[0032] The paper feeding unit 28 is located at the bottom of the main body 100a of the device and feeds the recording material P to the transport roller 13. The paper feeding unit 28 comprises a paper feeding cassette 1 and paper feeding rollers 2.

[0033] The paper feed cassette 1 stores and holds recording materials P of various widths and sizes.

[0034] The paper feed roller 2 is positioned in accordance with the paper feed cassette 1 and, by rotating, separates and feeds the recording material P stored in the paper feed cassette 1 one sheet at a predetermined feeding timing, and transports it to the register roller 34 via the vertical transport path 33 of the transport unit 52.

[0035] The laser exposure apparatus 32 is provided below the image forming sections 1Y, 1M, 1C, and 1Bk, corresponding to each of the photosensitive drums 18 of the image forming sections 1Y, 1M, 1C, and 1Bk. The laser exposure apparatus 32 consists of a laser light-emitting means that emits light corresponding to the time-series electrical digital pixel signals of the given image information, a polygon mirror, a reflective mirror, and the like. The laser exposure apparatus 32 exposes each photosensitive drum 18 by irradiating it with a laser and scanning it, thereby forming an exposed area on each photosensitive drum 18.

[0036] The registration roller 34 transports the recording material P, which is being transported by the paper feed roller 2, so that the leading edge of the recording material P reaches the secondary transfer section 17 at the same time that the leading edge of the full-color toner image on the rotating intermediate transfer belt 8 reaches the secondary transfer section 17.

[0037] The fixing device 36 melts and mixes the full-color toner image that has been secondarily transferred to the recording material P, which has passed through the secondary transfer section 17 and been separated from the intermediate transfer belt 8, and fixes it as a fixed image on the surface of the recording material P. The fixing device 36 then transports the recording material P, on which the full-color toner image has been fixed, to the paper discharge roller 5 via the transport path 37.

[0038] The contact / separation device 45 is equipped with a secondary transfer outer roller 20 as a roller member, and moves the secondary transfer outer roller 20 and the intermediate transfer belt 8 as a contact member. The contact / separation device 45 forms a secondary transfer section 17 by bringing the secondary transfer outer roller 20 into contact with the intermediate transfer belt 8. The contact / separation device 45 sequentially transfers the full-color toner image, which has been primary transferred onto the intermediate transfer belt 8 by the primary transfer roller 16, to the recording material P in one go in the secondary transfer section 17. The contact / separation device 45 transports the recording material P, on which the toner image has been secondary transferred, to the fixing device 36 via the vertical guide 35 of the transport section 52. Details of the configuration of the contact / separation device 45 will be described later.

[0039] The transport unit 52 transports the recording material P transported from the paper feed roller 2 to the paper discharge roller 5 or the reversing roller 11. The transport unit 52 also transports the recording material P transported from the reversing roller 11 to the paper discharge roller 5. The transport unit 52 includes a transport roller 13, a transport roller 38, and a transport roller 39.

[0040] The transport roller 13 transports the recording material P, which is being transported by the transport roller 38, toward the transport roller 39.

[0041] The transport roller 38 transports the recording material P, which is being transported from the reversing roller 11 via the double-sided transport path 12, toward the transport roller 13.

[0042] The transport roller 39 transports the recording material P, which is transported by the paper feed roller 2 or the transport roller 38, to the register roller 34 via the vertical transport path 33.

[0043] <Configuration of the contact / separation device> The configuration of the contact / separation device 45 according to an embodiment of the present invention will be described in detail with reference to Figures 1 to 6.

[0044] In Figure 2, Figure 2(a) shows the bearing member 22 in a separated position with a portion of the separating member 24 omitted, and Figure 2(b) shows the bearing member 22 in a contact position with a portion of the separating member 24 omitted.

[0045] In Figure 3, Figure 3(a) shows the bearing member 22 in a separated position with a portion of the separating member 24 omitted, and Figure 3(b) shows the bearing member 22 in a contact position with a portion of the separating member 24 omitted.

[0046] In Figure 4, Figure 4(a) shows the bearing member 22 in a contact position, and Figure 4(b) shows the bearing member 22 in a separated position.

[0047] In Figure 5, Figure 5(a) shows the bearing member 22 in a separated position with a portion of the separating member 24 omitted, and Figure 5(b) shows the bearing member 22 and the separating member 24 disengaged with a portion of the separating member 24 omitted.

[0048] The contact / separation device 45 includes a secondary transfer outer roller 20, a transfer coil spring 21, a bearing member 22, and a separation member 24.

[0049] The secondary transfer outer roller 20 faces the secondary transfer inner roller 7 across the intermediate transfer belt 8 and is positioned to be able to move toward and away from the intermediate transfer belt 8. The secondary transfer outer roller 20 is constructed using an iron metal core (not shown) and a semiconducting sponge mainly composed of NBR hydrin rubber as an elastic layer covering the metal core. The secondary transfer outer roller 20, together with the secondary transfer inner roller 7, secondary transfers the toner image transferred to the intermediate transfer belt 8 to the recording material P.

[0050] The transfer coil spring 21, acting as a biasing member, is provided between the bearing member 22 and the main body 45c of the contact / separation device 45. The transfer coil spring 21 biases the secondary transfer outer roller 20, which is rotatably supported by the bearing member 22, to the intermediate transfer belt 8 and the secondary transfer inner roller 7 via the bearing member 22, so that a predetermined contact pressure is applied. The main body 45c constitutes a part of the main body 100a.

[0051] As shown in Figure 2(a), the bearing member 22 is held by the bearing support portion 46a and bearing support portion 46b of the device body 45c so as to be movable in the direction of contact with and separation from the intermediate transfer belt 8 together with the secondary transfer outer roller 20, while rotatably holding the secondary transfer outer roller 20. The bearing member 22 is movable between the contact position shown in Figure 3(b), where the secondary transfer outer roller 20 is in contact with the intermediate transfer belt 8, and the separated position shown in Figure 3(a), where the secondary transfer outer roller 20 is separated. The bearing member 22 is biased to the contact position by the transfer coil spring 21.

[0052] Here, Figures 2(a), 3(a), 4(b), 5(a), and 6 are views from the same direction and show the bearing member 22 in a spaced-out position. Also, Figures 2(b), 3(b), and 4(a) are views from the same direction and show the bearing member 22 in a contact position. Figure 5(b) is a view from the same direction as Figures 2(a), 3(a), 4(b), 5(a), and 6.

[0053] The bearing member 22 comprises a bearing holding portion 22a and a bearing contact portion 22c.

[0054] The bearing holder portion 22a engages with the rotating shaft portion (not shown) of the secondary transfer outer roller 20, thereby rotatably holding the secondary transfer outer roller 20.

[0055] The bearing contact portion 22c is key-shaped and engages with the lower right side of the rotating cylindrical portion 24b of the separating member 24 in Figure 5(a). The bearing contact portion 22c is formed in an arc shape with approximately the same curvature as the outer surface curvature of the rotating cylindrical portion 24b.

[0056] The separating member 24 rotates along a plane parallel to the plane of paper in Figures 2 to 5 by rotating around an axis of rotation parallel to the axis of rotation of the secondary transfer outer roller 20 (the axis of rotation parallel to the direction perpendicular to the plane of paper in Figure 2).

[0057] The separating member 24 includes a notch 24a, a rotating cylindrical portion 24b, a restricting portion 24c, an engaging piece 24f, and an engagement release portion 24g. Note that the restricting portion 24c is omitted in Figure 2. Also, the restricting portion 24c, the engaging piece 24f, and the engagement release portion 24g are omitted in Figures 3, 5, and 6.

[0058] As shown in Figures 5 and 6, the notch 24a is cut radially from the outer circumferential surface of the rotating cylindrical portion 24b.

[0059] The rotating cylindrical portion 24b is cylindrical in shape and is rotatably supported by the main body 45c of the device. The rotating cylindrical portion 24b is provided with a regulating portion 24c.

[0060] The restricting portion 24c is rotatable in the Z direction in Figure 4(a) as the rotating cylindrical portion 24b rotates, and is biased in a clockwise direction, which is the first direction in Figure 4(a), by an elastic body (not shown). The restricting portion 24c is biased in a clockwise direction in Figure 4(a) by a biasing force smaller than the biasing force of the transfer coil spring 21.

[0061] The restricting portion 24c contacts the abutment portion 45b of the device body 45c when a rotational force in the counterclockwise direction, which is the second direction in Figure 4, is applied to the rotating cylindrical portion 24b by the biasing force of the transfer coil spring 21 from the bearing member 22 which is at a separated position. By contacting the abutment portion 45b, the restricting portion 24c restricts the rotation of the rotating cylindrical portion 24b in the counterclockwise direction in Figure 4. By contacting the abutment portion 45b and restricting the rotation of the rotating cylindrical portion 24b, the restricting portion 24c prevents the bearing member 22 from moving to the contact position.

[0062] When the engagement between the rotating cylindrical portion 24b and the bearing member 22 is released, the restricting portion 24c comes into contact with the abutment portion 45a of the device body 45c by the biasing force of an elastic body (not shown), thereby restricting the rotation of the rotating cylindrical portion 24b in the clockwise direction in Figure 4.

[0063] The engaging piece 24f extends outward from the outer circumferential surface of the rotating cylindrical portion 24b in an arc shape in a counterclockwise direction in Figure 2, and is elastically deformable inward. By engaging with the engaging projection 46c of the device body 45c, the engaging piece 24f prevents the rotating cylindrical portion 24b from rotating clockwise in Figure 2(a) by the biasing force of an elastic body (not shown), thereby holding the bearing member 22 in a separated position. When the engagement of the engaging piece 24f with the engaging projection 46c is released, the engaging piece 24f allows the rotating cylindrical portion 24b to rotate clockwise in Figure 2(a) by the biasing force of an elastic body (not shown), enabling the bearing member 22 to move to the contact position.

[0064] The disengagement portion 24g is provided on the rotating cylindrical portion 24b and engages with a disengagement member (not shown), causing the disengagement member to rotate the rotating cylindrical portion 24b in a clockwise direction in Figure 2(a) when driven.

[0065] The separating member 24 having the above configuration is provided with respect to the rotating cylindrical portion 24b in the order of restricting portion 24c, engaging piece portion 24f, notch portion 24a, and release portion 24g from top to bottom, when the front direction is oriented upward with respect to the plane of the paper in Figures 2 to 5. Note that the positions in which the restricting portion 24c, engaging piece portion 24f, notch portion 24a, and release portion 24g are provided with respect to the rotating cylindrical portion 24b are not limited to the above order and can be provided at any position.

[0066] <Operation of the contact / separation device> The operation of the contact / separation device 45 according to an embodiment of the present invention will be described in detail with reference to Figures 1 to 6.

[0067] During transportation, the bearing member 22 is held in a separated position by the separating member 24. At this time, the rotating cylindrical portion 24b is subjected to a rotational force in the counterclockwise direction (arrow Y direction in Figure 5(a)) in Figures 2 to 5 by engaging with the bearing contact portion 22c. In addition, the rotation of the rotating cylindrical portion 24b in the direction of arrow Y is restricted by the contact portion 24e of the restricting portion 24c contacting the abutment portion 45b. Furthermore, the rotation of the rotating cylindrical portion 24b in the opposite direction to arrow Y due to the biasing force of an elastic body (not shown) is also restricted by the engagement piece 24f engaging with the engagement projection 46c. As a result, the bearing member 22 is held in a separated position by the separating member 24, which restricts its movement toward the intermediate transfer belt 8.

[0068] Furthermore, even when the bearing member 22 is held in a separated position, if an unpredictable external force is applied to the bearing member 22 toward the contact position, a rotational force in the direction of arrow Y is applied to the rotating cylindrical portion 24b by engaging with the bearing contact portion 22c. At this time, the rotation of the rotating cylindrical portion 24b in the direction of arrow Y is restricted as described above, by the contact portion 24e of the restricting portion 24c contacting the abutment portion 45b. As a result, the bearing member 22 is restricted from moving toward the intermediate transfer belt 8 by the separating member 24 and is held in the separated position. Therefore, the contact / separation device 45 can withstand unpredictable forces such as those encountered during logistics.

[0069] Next, when the secondary transfer outer roller 20 and the intermediate transfer belt 8 are separated, and the secondary transfer outer roller 20 is brought into contact with the intermediate transfer belt 8, the release member (not shown) rotates the release portion 24g clockwise in Figure 2(a). As a result, the engaging piece 24f elastically deforms inward and overcomes the engaging projection 46c, and the rotating cylindrical portion 24b rotates clockwise in Figure 5(a) due to the biasing force of an elastic body (not shown).

[0070] The separating member 24 rotates 90 degrees clockwise from the state shown in Figure 5(a) to the state shown in Figure 5(b), where the notch 24a and the bearing contact portion 22c face each other. As a result, the bearing member 22 is released from engagement with the separating member 24 and moves towards the intermediate transfer belt 8 by the biasing force of the transfer coil spring 21, passing through the notch 24a without contacting the rotating cylindrical portion 24b.

[0071] Then, the bearing member 22 moves to the contact position and presses the secondary transfer outer roller 20 against the secondary transfer inner roller 7 and the intermediate transfer belt 8 with a predetermined contact pressure, and the separating member 24 has the contact portion 24d of the regulating portion 24c come into contact with the abutment portion 45a of the device body 45c.

[0072] In this embodiment, there is a separating member 24 that rotates in the opposite direction to the Y direction, thereby disengaging from the bearing member 22 and moving the bearing member 22 from a separated position to a contact position by the biasing force of the transfer coil spring 21. There is also a bearing member 22 that applies a rotational force in the Y direction to the separating member 24 at the separated position. The separating member 24 is equipped with a restricting part 24c that contacts the main body 45c of the device and restricts rotation in the Y direction, thereby preventing the bearing member 22 from moving to the contact position. As a result, the contact and separation operation between the intermediate transfer belt 8 and the secondary transfer outer roller 20 can be performed with a simple configuration without using a drive gear, and unintended contact and separation operation between the intermediate transfer belt 8 and the secondary transfer outer roller 20 can be suppressed.

[0073] The present invention is not limited to the embodiments described above, and it goes without saying that various modifications are possible without departing from the spirit of the invention.

[0074] Specifically, in the above embodiment, the intermediate transfer belt 8 and the secondary transfer outer roller 20 were brought into contact and separated by the contact / separation device 45. However, the invention is not limited to this, and can be applied to a contact / separation device that brings into contact and separates a photosensitive drum 18 as a contacted member and a charging roller 19 as a roller member.

[0075] Furthermore, in the above embodiment, the bearing member 22 applies a rotational force in the Y direction as shown in Figure 5(b) to the separating member 24. However, the bearing member 22 may also apply a rotational force in the opposite direction to the Y direction to the separating member 24. In this case, the bearing contact portion 22c is configured to engage with the rotating cylindrical portion 24b on the lower left side as shown in Figure 5(a). The bearing member 22 is configured to be able to move from the separated position to the contact position when the separating member 24 rotates in the Y direction, thereby releasing its engagement with the separating member 24. [Explanation of symbols]

[0076] 7. Secondary transfer inner roller 8. Intermediate transfer belt 9. Intermediate transfer belt unit 17 Secondary transfer section 18 Photosensitive drum 19. Electrostatic roller 20 Secondary transfer outer roller 21 Transfer coil spring 22 Bearing member 22a Bearing retaining part 22c bearing contact area 24 Separating member 24a Notch 24b Rotating cylinder section 24c Regulatory Department 24d Contact part 24e Contact part 24f Engagement piece 24g Disengagement part 45 Contact / Disconnection Device 45a Buttocks 45b Buttocks 45c Device body 46a Bearing support part 46b Shaft Support Section 46c is a protruding part 100 image forming device 100a device body

Claims

1. A rotatable roller member, A bearing member that rotatably holds the roller member and is movable between a contact position in which the roller member is in contact with the member to be contacted and a separation position in which the roller member is separated from the member to be contacted, A biasing member that biases the bearing member to the contact position, A separating member that, by engaging with the bearing member, holds the bearing member in the separated position against the biasing force of the biasing member, and rotates in a first direction about a rotation axis parallel to the rotation axis of the roller member, thereby disengaging from the bearing member and moving the bearing member from the separated position to the contact position by the biasing force of the biasing member, It has, The bearing member is At the separated position, a rotational force is applied to the separating member in a second direction opposite to the first direction. The separation member is, The device includes a restricting part that contacts the main body of the device and restricts rotation in the second direction, thereby preventing the bearing member from moving to the contact position. A device for approaching and separating, characterized by the following features.

2. The separation member is, It comprises a rotating cylindrical portion having a notch cut radially from the outer circumferential surface, The bearing member is As the rotating cylindrical portion rotates in the first direction, the engagement with the separating member is released by the notch, and the member moves through the notch to the contact position. The contact / separation device according to feature 1.

3. The approach / disconnection device according to claim 1 or claim 2, An image forming unit that forms an image on the recording material, An image forming apparatus characterized by having the following features.

Images