IMAGE FORMING APPARATUS

An image forming apparatus includes an image bearing member, a transfer member movably provided between a contact position and a separated position, first and second bearings, a supporting member, first and second urging members for urging the first and second bearings respectively, and a moving member provided with first and second engaging portions engaging with the first and second bearings respectively. At least a part of the moving member is disposed on the same side as the transfer member with respect to the supporting member in a moving direction. As viewed in a recording material conveyance direction, the moving member and the transfer member are overlapped with each other in a state in which the transfer member is positioned in the separated position.

FIELD OF THE INVENTION AND RELATED ART

The present invention relates to an image forming apparatus for forming an image on a recording material.

In the image forming apparatus of an electrophotographic method, a toner image formed on an image bearing member such as photosensitive drum is transferred to the recording material by a transfer member. According to Japanese Patent Application Laid-open No. 2015-090402, it is disclosed that in order to avoid adverse effects such as deformation of a transfer roller due to long-term pressure contact between the transfer roller and the photosensitive drum, the transfer roller is held in a separated position in which the transfer roller is separated from the photosensitive drum by a lock member, which engages a bearing of the transfer roller.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided an image forming apparatus comprising: a rotatable image bearing member configured to bear an image; a rotatable transfer member configured to form a transfer portion between itself and the image bearing member and to transfer the image from the bearing member to a recording material in the transfer portion, the transfer member being movable between a contact position in contact with the image bearing member and a separated position separated from the image bearing member in a moving direction crossing both a rotational axis direction of the transfer member and a recording material conveyance direction in the transfer portion; a first bearing configured to rotatably support a first end portion of the transfer member in the rotational axis direction and movably provided in the moving direction; a second bearing configured to rotatably support a second end portion of the transfer member in the rotational axis direction and movably provided in the moving direction; a supporting member opposing the first bearing and the second bearing with respect to the moving direction; a first urging member of which one end is supported by the supporting member and the other end is connected to the first bearing and configured to urge the first bearing in a direction from the separated position toward the contact position of the transfer member; a second urging member of which one end is supported by the supporting member and the other end is connected to the second bearing and configured to urge the second bearing in the direction from the separated position toward the contact position of the transfer member; and a moving member provided with a first engaging portion engaging with the first bearing and a second engaging portion engaging the second bearing and movably provided in a direction along the rotational axis direction between a first position where the first engaging portion engages with the first bearing and the second engaging portion engages with the second bearing so as to hold the transfer member at the separated position and a second position where the first engaging portion is disengaged from the first bearing and the second engaging portion is disengaged from the second bearing so as to permit the transfer member to move from the separated position to the contact position, wherein at least a part of the moving member is disposed on the same side as the transfer member with respect to the supporting member in the moving direction, and wherein as viewed in the recording material conveyance direction, the moving member and the transfer member are overlapped with each other in a state in which the transfer member is positioned in the separated position.

DESCRIPTION OF THE EMBODIMENTS

In the following, embodiments of the present invention will be specifically described with reference to Figures.

FIG.1is a schematic view illustrating a cross-sectional configuration of an image forming apparatus1according to an Embodiment 1. The image forming apparatus1is a laser beam printer which forms an image on a recording material P based on image information received from an external device. Incidentally, in the present disclosure, the “image forming apparatus” is not limited to a single-function printer, but may also be a copy machine, a multifunction machine, a commercial printing machine, etc. In addition, as the recording material (recording medium) P, a variety of sheet materials of different sizes and materials can be used, for example, a paper such as a plain paper and a thick paper, a sheet material with a surface treatment such as a coated paper, a special shaped sheet material such as an envelope and an index paper, a plastic film, a cloth, etc.

The image forming apparatus1is provided with a process unit1A (image forming unit), which forms an image (toner image) on the recording material P by an electrophotographic process, and a fixing unit10to fix the image onto the recording material P. The process unit1A includes a photosensitive drum2as an image bearing member, a charging roller3as a charging means, a laser scanner4as an exposure means, and a developing roller5as a developing means, and a transfer roller9as a transfer member. A part or all of the process unit1A may be a process cartridge, which is attachable to and detachable from an apparatus main body1B of the image forming apparatus1. In the present Embodiment, the apparatus main body1B refers to a part which is the image forming apparatus1minus the process unit1A.

The photosensitive drum2is an electrophotographic photosensitive member formed in a drum shape (cylindrical shape). In addition, in the process unit1A, toner as a developer is accommodated. The transfer roller9is disposed opposing the photosensitive drum2. As a nip portion between the photosensitive drum2and the transfer roller9, a transfer portion Nt, in which a transfer of the image (toner image) from the image bearing member to the recording material P is performed, is formed.

The fixing unit10is a device of a thermal fixing method, which fixes the image to the recording material P by heating the image (toner image). The fixing unit10is provided with, for example, a roller pair, which is constituted by a pressing roller10aand a fixing roller10b, and a heating means such as a halogen lamp, which heats the fixing roller10b.

In addition, the image forming apparatus1is provided with a feeding tray15, a pickup roller6, a feeding roller pair7, a conveyance roller pair8aand8b, a discharging roller pair11, a discharge tray12and a double side roller pair13. The feeding tray15is an example of an accommodating portion in which the recording material P used for an image formation is accommodated. The pickup roller6and the feeding roller pair7are examples of a feeding means, which feeds the recording material P one sheet at a time. The discharging roller pair11is an example of a discharging means, which discharges the recording material P, on which the image formation has completed, outside the apparatus. The discharge tray12is an example of a stacking portion, on which the recording material P discharged out of the apparatus is stacked.

Furthermore, the image forming apparatus1is provided with a conveyance path of the recording material P including a first conveyance path100and a second conveyance path110. The first conveyance path100is a conveyance path from the conveyance roller pair8b, through the transfer portion Nt and the fixing unit10, to the discharging roller pair11. The second conveyance path110is a conveyance path from the discharging roller pair11through the double side roller pair13and merges with the first conveyance path100on upstream of the conveyance roller pair8b. The first conveyance path100is a conveyance path where the image formation is performed on the recording material P, and the second conveyance path110is a conveyance path where the recording material once passed the first conveyance path100is conveyed again toward the first conveyance path100.

A series of operations in which the image forming apparatus1forms an image on the recording material P (image forming operation) will be described. When the image forming apparatus1receives the image information, the image forming operation is initiated. First, the recording material P is fed from the feeding tray15by the pickup roller6, and one sheet of the recording material P is fed in a separated state by the feeding roller pair7. The recording material P is conveyed by the conveyance roller pairs8aand8bto the transfer portion Nt.

In parallel with the feeding and the conveyance of the recording material P, the process unit1A forms the toner image. The photosensitive drum2is rotationally driven, and the charging roller3uniformly charges a surface of the photosensitive drum2. The laser scanner4performs an exposure process by irradiating the photosensitive drum2with a laser beam, which is modulated according to a video signal generated based on the image information, to form an electrostatic latent image on the surface of the photosensitive drum2. The developing roller5bears the toner as a developer and supplies the toner to the photosensitive drum2to develop the electrostatic latent image into the toner image. And when the recording material P, which is conveyed from the conveyance roller pair8b, passes through the transfer portion Nt, the transfer roller9transfers the toner image from the photosensitive drum2to the recording material P.

After passing through the transfer portion Nt, the recording material P is conveyed to the fixing unit10. The fixing unit10fixes the toner image on the recording material P by heating and pressuring the toner image on the recording material P while nipping and conveying the recording material P with a nip portion (fixing nip) between the pressing roller10aand the fixing roller10b. As such, while the recording material P is conveyed through the first conveyance path100, the image is formed on one side of the recording material P.

In a case of a single-side image formation (single-side printing), the recording material P, of which the image is formed on the first surface while being conveyed through the first conveyance path100, is discharged out of the apparatus by the discharging roller pair11and stacked on the discharge tray12. In a case of a double-side image formation (double-side printing), the recording material P, of which the image is formed on the first surface while being conveyed through the first conveyance path100, is reversely conveyed (switched back) and is sent to the second conveyance path110. The recording material P sent to the second conveyance path110is conveyed to the conveyance roller pair8bof the first conveyance path100via the double side roller pair13. And the recording material P, of which the image is formed on a second surface opposite to the first surface while being conveyed through the first conveyance path100again, is discharged out of the apparatus by the discharging roller pair11and stacked on the discharge tray12.

(Holding Configuration of the Transfer Roller)

A holding configuration of the transfer roller9, a mechanism for holding the transfer roller9in a separated position from the photosensitive drum2(hereinafter referred to as a transfer separating mechanism90), and a mechanism for releasing the holding by the transfer separating mechanism90(hereinafter referred to as a releasing unit60) will be described.

In the following description and Figures, a direction along a rotational axis of the photosensitive drum2is referred to as a rotational axis direction D1. A direction perpendicular to the rotational axis direction D1and along a moving direction of the recording material P in the transfer portion Nt is referred to as a recording material conveyance direction D2. A direction crossing both the rotational axis direction D1and the recording material conveyance direction D2, and in which the transfer roller9is pressed toward the photosensitive drum2, is referred to as a pressing direction D3. The rotational axis direction D1, the recording material conveyance direction D2and the pressing direction D3are preferably perpendicular to each other. In addition, in the present Embodiment, the rotational axis direction D1is substantially parallel to a rotational axis direction of the transfer roller9.

FIG.2is a perspective view of the transfer separating mechanism90, the releasing unit60, the transfer roller9and the photosensitive drum2, and an enlarged view of a portion thereof. Part (a) and part (c) ofFIG.3are views of the transfer separating mechanism90, the releasing unit60, the transfer roller9and the photosensitive drum2as viewed from one side of the rotational axis direction D1(lower right side ofFIG.2). Part (b) and part (d) ofFIG.3are views of the transfer separating mechanism90, the releasing unit60and the transfer roller9as viewed from one side of the pressing direction D3(upper side of part (a) ofFIG.3, etc.).FIG.4is a cross-sectional view illustrating a cross-section of the apparatus at a line A-A in part (d) ofFIG.3.

As shown inFIG.2, one end portion (first end portion) of the transfer roller9in the rotational axis direction D1is rotatably supported by a first bearing20. The other end portion (second end portion) of the transfer roller9in the rotational axis direction D1is rotatably supported by a second bearing21. The first bearing20is urged in the pressing direction D3by a first pressing spring30. The second bearing21is urged in the pressing direction D3by the second pressing spring31. As a result, the transfer roller9is urged in the pressing direction D3toward the photosensitive drum2.

Each of the first bearing20and the second bearing21is movably provided in a direction crossing both the rotational axis direction D1and the recording material conveyance direction D2with respect to a frame member of the image forming apparatus1. Thus, the transfer roller9is movable between a contact position (part (a) ofFIG.3), in which the transfer roller9is in contact with the photosensitive drum2, and a separated position (part (c) ofFIG.3), in which the transfer roller9is separated from the photosensitive drum2. In the present Embodiment, a moving direction of the transfer roller9substantially coincides with the pressing direction D3.

The first pressing spring30is an example of a first urging member, which urges the first bearing20in a direction in which the transfer member (transfer roller9) is moved from the separated position toward the contact position. The second pressing spring31is an example of a second urging member which urges the second bearing21in the direction in which the transfer member (transfer roller9) is moved from the separated position toward the contact position.

As shown inFIG.2, the transfer separating mechanism90is provided with a separation holding member40, a slider member50and an urging member43.

The separation holding member40is a moving member movable in a moving direction E1and a moving direction E2, which are along the rotational axis direction D1. The separation holding member40of the present Embodiment is a rod-shaped or a plate-shaped member (separating rod) elongated in a direction along the rotational axis direction D1. The separation holding member40is urged in the predetermined moving direction E2by the urging member43.

The slider member50is a second moving member movable in a moving direction F1and a moving direction F2crossing the rotational axis direction D1. In the present Embodiment, the moving direction F1and the moving direction F2of the slider member50are directions substantially perpendicularly crossing with respect to the rotational axis direction D1and along the recording material conveyance direction D2. In addition, the slider member50is movably provided by an assembly work of the image forming apparatus1or by being driven by the releasing unit60, which will be described below.

The separation holding member40includes a first engaging portion41, a second engaging portion42, a slider contacting portion44, a first main body contacting portion45and a second main body contacting portion46.

The first engaging portion41is provided on one side (lower right side ofFIG.2. Hereinafter, the side is referred to as a first end side) of the separation holding member40in the rotational axis direction D1. The second engaging portion42is provided on the other side (upper left side ofFIG.2. Hereinafter, the side is referred to as a second end side) of the separation holding member40in the rotational axis direction D1.

The first bearing20includes a first hook portion22as a first engaged portion, which is engaged with the first engaging portion41of the separation holding member40. The second bearing21includes a second hook portion23as a second engaged portion, which is engaged with the second engaging portion42of the separation holding member40. The first hook portion22and the second hook portion23are formed so as to project in a direction crossing both the rotational axis direction D1and the pressing direction D3. By this, as described below, it is easily realized that a configuration, which makes the separation holding member40engage the first hook portion22and the second hook portion23, while disposing the separation holding member40side-by-side with respect to the transfer roller9. The first hook portion22and the second hook portion23in the present Embodiment extend toward a direction along the recording material conveyance direction D2(upstream of the recording material conveyance direction D2).

The separation holding member40is movable between an engaging position (holding position, part (d) ofFIG.3), in which the separation holding member40engages the first bearing20and the second bearing21, and a releasing position (disengaged position, part (b) ofFIG.3), in which the separation holding member40disengages from the first bearing20and the second bearing21. The engaging position is a first position in which the first engaging portion41of the separation holding member40engages the first hook portion22of the first bearing20and the second engaging portion42engages the second hook portion23of the second bearing21. The releasing position is a second position in which the first engaging portion41of the separation holding member40is disengaged from the first hook portion22of the first bearing20and the second engaging portion42is disengaged from the second hook portion23of the second bearing21.

When the separation holding member40is positioned in the engaging position, the movement of the first bearing20and the movement of the second bearing21in the pressing direction is restricted by the separation holding member40. Therefore, the transfer roller9is held in the separated position against the urging force of the first pressing spring30and the second pressing spring31.

When the separation holding member40is positioned in the releasing position, the movement restriction of the first bearing20and the second bearing21by the separation holding member40is released. Therefore, the transfer roller9is permitted to move from the separated position to the contact position according to the urging force of the first pressing spring30and the second pressing spring31.

Thus, in the present Embodiment, both end portions of the transfer roller9is held in the separated position by the one separation holding member40(moving member) engaging both the first bearing20and the second bearing21. In addition, the holding of both end portions of the transfer roller9is released by the one separation holding member40(moving member) being moved in the moving direction E2along the rotational axis direction D1and being disengaged from both the first bearing20and the second bearing21. By this configuration, it becomes possible to downsize the configuration of the transfer separating mechanism90compared to, for example, a case in which a moving member, which engages the second bearing21and moves in a second direction different from a first direction, is provided separately from a moving member, which engages the first bearing20and moves in the first direction.

In addition, it is possible to restrict and release the movement restriction of both the first bearing20and the second bearing21by restricting and releasing the restriction of the one separation holding member40(moving member) in the moving direction E2. In other words, since the movement of both end portions of the transfer roller9can be restricted simultaneously by restricting only the movement of the one separation holding member40(moving member) in the moving direction E2, it becomes possible to increase degree of design freedom of the image forming apparatus1. Incidentally, in the present Embodiment 1, as a restricting means for restricting the movement of the one separation holding member40(moving member) in the moving direction E2, the slider member50is used.

As shown inFIG.4, the first main body contacting portion45of the separation holding member40is provided on a surface opposite to a surface, with which the first engaging portion41is in contact, with respect to the pressing direction D3in the separation holding member. Similarly, the second main body contacting portion46of the separation holding member40is provided on a surface opposite to a surface, with which the second engaging portion42is in contact, with respect to the pressing direction D3in the separation holding member. In other words, the first engaging portion41and the second engaging portion42are provided on upstream of the separation holding member40in the pressing direction D3, and the first main body contacting portion45and the second main body contacting portion46are provided on downstream of the separation holding member40in the pressing direction D3.

The first main body contacting portion45is facing to a first restricting surface145, which is provided on a member fixed to the frame member of the apparatus main body1B (hereinafter, referred to as a main body frame101. SeeFIG.7), in the pressing direction D3. Similarly, the second main body contacting portion46is facing a second restricting surface, which is provided on the main body frame101, in the pressing direction D3. When the separation holding member40is positioned in the engaging position, the urging force of the first pressing spring30and the second pressing spring31are received by the main body frame101by the first main body contacting portion45and the second main body contacting portion46being in contact with the main body frame101.

The first main body contacting portion45and the second main body contacting portion46may be configured to have a rib shape. The first main body contacting portion45and the second main body contacting portion46in the present Embodiment have rib shapes having a cross-section of a projecting shape projecting in the pressing direction D3and extending in a direction along a longitudinal direction of the separation holding member40. By configuring the first main body contacting portion45and the second main body contacting portion46to have rib shapes, it becomes easier to determine a contact position of the separation holding member40(end surface of the rib shape) with respect to the main body frame101with high accuracy. By this, it becomes possible to increase accuracy of the position of the separation holding member40in the pressing direction D3, and thus accuracy of the position of the first bearing20, the second bearing21and the transfer roller9in the pressing direction D3, in the state in which the separation holding member40is positioned in the engaging position.

The separation holding member40is urged in the moving direction E1from the engaging position to the releasing position by the urging member43. The urging member43in the present Embodiment is a compression spring provided between a spring receiving portion48(see lower right ofFIG.2), which is provided on a first end portion side of the separation holding member40with respect to the rotational axis direction D1, and a spring receiving portion148(seeFIG.6), which is provided in the main body frame101. As the urging member43, an elastic member other than the compression spring may be used.

The slider contacting portion44of the separation holding member40is a portion in contact with a first holding portion51or a second holding portion52of the slider member50. When the slider contacting portion44is in contact with the first holding portion51, the separation holding member40is held in the releasing position (part (b) ofFIG.3). When the slider contacting portion44is in contact with the second holding portion52, the separation holding member40is held in the engaging position (part (d) ofFIG.3). In other words, the slider member50functions as a restricting means to restrict a movement of the separation holding member40from the engaging position.

The first holding portion51of the slider member50has a concave shape, which is concave toward the moving direction E2(first end side of the rotational axis direction D1) when the separation holding member40moves from the releasing position to the engaging position. The second holding portion52of the slider member50is disposed upstream of the moving direction E2(second end side of the rotational axis direction D1) compared to the first holding portion51. The first holding portion51and the second holding portion52are connected by an inclined surface53, which is inclined to the moving direction E1and the moving direction E2. The inclined surface53is a guide surface, which guides the slider contacting portion44of the separation holding member40from the second holding portion52to the first holding portion51when the slider member50is driven in the moving direction F2by the releasing unit60(part (d) ofFIG.3), which will be described below.

As shown inFIG.2, the separation holding member40further includes a main body hook portion49and a retaining portion47. In the present Embodiment, three main body hook portions49and one retaining portion47are disposed spaced apart from each other along the rotational axis direction D1, however, a number and a disposition can be changed as needed.

The main body hook portion49is formed so as to project in a direction crossing with the rotational axis direction D1from an extending portion400extending in the rotational axis direction D1between the first engaging portion41and the second engaging portion42. In the present Embodiment, the extending portion400of the separation holding member40has an elongated plate shape along the rotational axis direction D1, and a projecting direction of the main body hook portion49with respect to the extending portion400is a direction along the pressing direction D3. The main body hook portion49is an example of an engaging portion (third engaging portion) configured to make the separation holding member40be held by the main body frame101by engaging the engaged portion149provided in the main body frame101(frame member).

As shown inFIG.6, the main body hook portion49has a hook shape opened toward one side of the rotational axis direction D1. The main body frame101of the image forming apparatus1includes the engaged portions149(third engaged portions) which are engaged with the main body hook portions49of the separation holding member40, respectively.

The retaining portion47has a projecting shape formed so as to project from the extending portion400in a direction crossing with the rotational axis direction D1. The retaining portion47is disposed so as to oppose to a stopper portion147, which is provided in the main body frame101of the image forming apparatus1, in the rotational axis direction D1. A function of the main body hook portion49and the retaining portion47will be described below.

The releasing unit60will be described. The releasing unit60is configured to release the movement restriction of the separation holding member40by the slider member50.

As shown inFIG.2and part (a) through part (d) ofFIG.3, the releasing unit60of the present Embodiment is provided with a motor61and a driving gear62. The motor61is an example of a driving source, and as a driving source, for example, a solenoid may be used. In addition, the driving gear62is an example of a driving member which moves the slider member50as a restricting means by driving force of the driving source, and other transmission mechanisms may be used.

The driving gear62meshes with a rack portion54of the slider member50. The driving gear62is driven in a rotational direction R1by the driving force of the motor61being input. The slider member50is movable in the moving direction F2described above by receiving the driving force from the motor61via the meshing of the driving gear62and the rack portion54. By this, the slider member50is moved from a position, where the slider contacting portion44of the separation holding member40is held by the second holding portion52of the slider member (third position. Part (b) ofFIG.3) to a position, where the slider contacting portion44is held by the first holding portion51(fourth position. Part (d) ofFIG.3).

(Operation of the Transfer Separating Mechanism During Assembly)

An operation of the transfer separating mechanism90and the releasing unit60upon assembling the image forming apparatus1will be described. Hereinafter, it is assumed that the transfer roller9, the first bearing20and the second bearing21are attached to the apparatus main assembly1B in advance.

First, as shown inFIG.6, an operator attaches the separation holding member40to the main body frame101. In attaching the separation holding member40, the operator moves the separation holding member40with respect to the main body frame101along the rotational axis direction D1and engages the main body hook portion49with the engaged portion149of the main body frame101. By the engagement of the main body hook portion49and the engaged portion149, the separation holding member40is held by the main body frame101in a state movable in the moving direction E1and the moving direction E2, which are along the rotational axis direction D1.

The retaining portion47is in contact with the stopper portion147in a case in which the main body hook portion49is moved in the moving direction E2by the urging force of the urging member43in a state in which the hook portion49is engaged with the engaged portion149. As a result, the movement of the separation holding member40in the moving direction E2to the position disengaged from the engaged portion149is restricted, and it becomes possible to prevent the separation holding member40from falling off the main body frame101.

In a state immediately after the separation holding member40is held by the main body frame101, the separation holding member40is positioned in the releasing position as shown in part (b) ofFIG.3. The slider contacting portion44of the separation holding member40is held by the first holding portion51of the slider member50. In addition, the transfer roller9is positioned in the contact position (part (a) ofFIG.3).

Next, the operator presses the first bearing20and the second bearing21in the opposite direction of the pressing direction D3to move the transfer roller9from the contact position to the separated position. As a result, the separation holding member40is in a state in which the movement thereof from the releasing position to the engaging position is permitted. In this state, the operator moves the slider member50in the moving direction F1. Then, the separation holding member40is moved in the moving direction E1from the releasing position to the engaging portion (see also part (a) ofFIG.5) by the slider contacting portion44of the separation holding member40being guided by the inclined surface53of the slider member50.

When the separation holding member40reaches the engaging position (part (d) ofFIG.3), the operator removes his or her hand from the slider member50. In this state, the first engaging portion41and the second engaging portion42of the separation holding member40engage the first hook portion22of the first bearing20and the second hook portion23of the second bearing21, respectively (part (c) ofFIG.3,FIG.4and part (b) ofFIG.5). By this, the movement of the first bearing20and the second bearing21in the pressing direction D3is restricted, and the transfer roller9is held in the separated position.

In addition, the first main body contacting portion45and the second main body contacting portion46of the separation holding member40is in contact with the first restricting surface145and the second restricting surface of the main body frame101, respectively. As a result, the urging force of the first pressing spring30and the second pressing spring31, which the separation holding member40receives from the first bearing20and the second bearing21, is received by the main body frame101.

Thereafter, the transfer roller9is held in the separated position until the separation holding member40is moved from the engaging position to the releasing position by the releasing unit60.

In a case in which the transfer roller9is in contact with the photosensitive drum2during storage or transportation of the image forming apparatus1, the following adverse effects may occur. For example, in a case in which the transfer roller9includes an elastic layer, plastic deformation of the elastic layer caused by the transfer roller9being pressed against the photosensitive drum2over a long period of time may occur. In addition, the transfer roller9or the surface of the photosensitive drum2may be damaged by being rubbed due to vibration during the transportation. In addition, chemical substances contained in the transfer roller9may seep out and adhere to the surface of the photosensitive drum2, causing image defects. It becomes possible to reduce possibility that these adverse effects occur by having the transfer roller9held in the separated position by the transfer separating mechanism90at a time of shipment from a factory.

(Operation of the Releasing Unit)

Next, the operation in which the releasing unit60releases the holding of the transfer roller9by the transfer separating mechanism90will be described. The following operation is performed automatically or by an operation by a support representative as a part of an initial setup of the image forming apparatus1after the image forming apparatus1is installed in a place of use of a user.

As shown in part (c) ofFIG.3, the motor61is actuated and the driving gear62is rotationally driven in the rotational direction R1. Then, via the meshing of the rack portion54and the driving gear62, the slider member50receives the driving force of the motor61, and the slider member50moves in the moving direction F2. As a result, the slider contacting portion44of the separation holding member40is guided from the second holding portion52to the first holding portion51along the inclined surface53. In other words, the slider member50releases the movement restriction of the separation holding member40and permits the separation holding member40to move from the engaging position (part (d) ofFIG.3) to the releasing position (part (b) ofFIG.3) in the moving direction E2in accordance with the urging force of the urging member43.

By the separation holding member40being moved to the releasing position (part (b) ofFIG.3), the engagement between the first engaging portion41and the first hook portion22of the first bearing20is released, and the engagement between the second engaging portion42and the second hook portion23of the second bearing21is released. As a result, the first bearing20and the second bearing21move in the pressing direction D3in accordance with the urging force of the first pressing spring30and the second pressing spring31. And the transfer roller9moves from the separated position to the contact position (part (a) ofFIG.3) due to the movement of the first bearing20and the second bearing21.

Thus, in the present Embodiment, it is possible to easily move the transfer roller9from the separated position to the contact position, since it is configured that the separation holding member40is moved from the engaging position to the releasing position by using the driving force of the motor61.

Incidentally, when the slider member50is moved to the position in part (b) ofFIG.3, the motor61is stopped. Thereafter, throughout a use period of the image forming apparatus1, the slider member50is held in the position shown in part (b) ofFIG.3and the separation holding member40is held in the releasing position (part (b) ofFIG.3).

In addition, in the present Embodiment, the separation holding member40is unmovable from the releasing position to the engaging position after the separation holding member40is moved from the engaging position to the releasing position and the transfer roller9is moved from the separated position to the contact position. In other words, the moving member is unmovable from the second position to the first position after the moving member has moved from the first position to the second position and the transfer member moves from the separated position to the contact position. For example, even if the separation holding member40is to be moved in the moving direction E1from the releasing position to the engaging position in the state ofFIG.2, the first engaging portion41or the second engaging portion42abuts a side surface of the first hook portion22or the second hook portion23, and the separation holding member40does not move in the moving direction E1.

(Disposition of the Separation Holding Member)

Next, disposition of the separation holding member40in the present Embodiment will be described. Part (a) and part (b) ofFIG.5are views schematically illustrating a state in which a portion of the transfer roller9, a portion of the first bearing20and the separation holding member40are viewed from upstream of the recording material conveyance direction D2.FIG.6is a view in which the photosensitive drum2, the transfer roller9, the transfer separation mechanism90and the releasing unit60are viewed from upstream of the recording material conveyance direction D2.FIG.7is a view schematically illustrating a cross-section of a portion of the image forming apparatus1sectioned by a virtual plane perpendicular to the rotational axis direction D1.

In part (a) and part (b) ofFIG.5andFIG.6, the transfer roller9is positioned in the separated position. In part (a) ofFIG.5, outlines of the transfer roller9and the first bearing20are illustrated as broken lines when the transfer roller9is positioned in the contact position, and inFIG.7, an outline of the transfer roller9is illustrated as a broken line when the transfer roller9is positioned in the separated position. In addition, in part (a) ofFIG.5andFIG.6, the separation holding member40is positioned in the releasing position, and in part (b) ofFIG.5, the separation holding member40is positioned in the engaging position.

As shown inFIG.6, the main body frame101includes a supporting surface70(attaching surface of the spring) for supporting the first pressing spring30and the second pressing spring31. One ends of the first pressing spring30and the second pressing spring31are supported by the supporting surface70and the other ends of the first pressing spring30and the second pressing spring31are connected to the first bearing20and the second bearing21, respectively. The main body frame101as a supporting member for the first pressing spring30and the second pressing spring31is disposed so as to be opposite to the first bearing20and the second bearing21in the pressing direction D3.

As shown inFIG.6andFIG.7, at least a part of the separation holding member40is disposed on the same side (upper side in Figures) as the transfer roller9with respect to the main body frame101in the pressing direction D3. In addition, as shown in part (a) and part (b) ofFIG.5, andFIG.6, as viewed in the recording material conveyance direction D2, the separation holding member40and the transfer roller9are overlapped with each other in a state in which the transfer roller9is positioned in the separated position. However, by two elements “are overlapped with each other as viewed in a predetermined direction”, it means that a projected area of one element at least partially overlaps a projected area of the other element when each element is vertically projected onto a virtual plane perpendicular to the predetermined direction.

In other words, in the present Embodiment, it is configured that the transfer roller9and the separation holding member40are not aligned in the pressing direction D3, but the transfer roller9and the separation holding member40are aligned side-by-side in a direction crossing with the pressing direction D3.

Advantages of the above configuration will be described. As mentioned above, in the present Embodiment, it is configured that the one separation holding member40(moving member) engages both the first bearing20and the second bearing21and disengages from both the first bearing20and the second bearing21by moving in the moving direction E2along the rotational axis direction D1. By this configuration, it becomes possible to make the mechanism (transfer separation mechanism90) for holding the transfer roller9in the separated position be compact. On the other hand, the disposition of the separation holding member40, which extends in the rotation axial direction D1so as to engage both the first bearing20and the second bearing21positioned at both ends of the rotation axial direction D1, needs to be considered.

In a case of a configuration in which the transfer roller9and the separation holding member40are aligned in the pressing direction D3(as a comparative example), the separation holding member40has to be disposed between the transfer roller9and the main body frame101in the pressing direction D3. However, considering the movement of the transfer roller9, in the D3pressing direction, the separation holding member40has to be disposed between the transfer roller9positioned in the separated position (broken line inFIG.7) and the main body frame101. In other words, a space for movement of the transfer roller9in the pressing direction D3and the separation holding member40are disposed linearly in the pressing direction D3. Therefore, a distance between the photosensitive drum2and the main body frame101increases in the pressing direction D3, leading to an increase in the size of the image forming apparatus1in the pressing direction D3.

In contrast, in the present Embodiment, since it is configured that the separation holding member40and the transfer roller9are disposed side by side in the direction crossing the pressing direction D3, the main body frame101can be disposed in a position closer to the photosensitive drum2in the pressing direction D3than in the configuration of the comparative example. By this, it becomes possible to downsize the image forming apparatus1in the direction (pressing direction D3) crossing both the rotational axis direction D1and the recording material conveyance direction D2.

In other words, according to the present Embodiment, it becomes possible to provide the image forming apparatus which can be downsized.

In addition, in the present Embodiment, as shown inFIG.7, in the pressing direction D3, a back surface of the supporting surface70of the main body frame101, which supports the first pressing spring30and the second pressing spring31, is a guide surface71, which forms the second conveyance path110. In other words, the supporting surface70is a surface opposite to the guide surface71with respect to the pressing direction D3(moving direction of the transfer roller9) in the main body frame101(supporting member). Incidentally, on the guide surface71, ribs may be formed to guide the recording material more smoothly.

According to this configuration, a distance between the first conveyance path100(conveyance path which includes the transfer portion Nt) and the second conveyance path110in the pressing direction D3can be narrowed, and it becomes possible to downsize the image forming apparatus1in the pressing direction D3.

Incidentally, in order to narrow the distance between the first conveyance path100and the second conveyance path110in the pressing direction D3, at least an inner part of a passing region W of the recording material (sheet passing area, seeFIG.6) in the separation holding member40should be disposed on the same side as the transfer roller9with respect to the supporting surface70in the pressing direction D3. For example, outside the passing region W of the recording material, a part of the separation holding member40may projected toward the opposite side of the transfer roller9(downward side inFIG.7) against the supporting surface70.

The passing region W of the recording material is a range of the recording material in the rotational axis direction when the recording material with a maximum length in the rotational axis direction D1(recording material widthwise direction), among the recording materials for which the image forming apparatus1can form the image, passes through the transfer portion Nt. In addition, in the present Embodiment, the passing region W shall be defined based on a state in which a center of the recording material in the rotational axis direction D1coincides with a center of the transfer portion Nt in the rotational axis direction D1.

In addition, in the present Embodiment, the feeding tray15(accommodating portion), in which the recording material to be fed to the transfer portion Nt is accommodated, is positioned below the conveyance path (second conveyance path110) formed by the guide surface71of the main body frame101. In addition, the transfer portion Nt is positioned above the conveyance path (second conveyance path110).

According to this configuration, a distance between the feeding tray152(accommodating portion) and the transfer portion Nt in the vertical direction can be reduced, and the size of the image forming apparatus1(height of the image forming apparatus1) in the vertical direction can be reduced.

A position of the separation holding member40in the recording material conveyance direction D2will be described using part (a) and part (b) ofFIG.8. Part (a) ofFIG.8is a view schematically illustrating an example of a configuration in which a distance from the separation holding member40to the first bearing20and the second bearing21in the recording material conveyance direction D2is long. Part (b) ofFIG.8is a view schematically illustrating an example of a configuration in which the distance from the separation holding member40to the first bearing20and the second bearing21in the recording material conveyance direction D2is short.

In part (a) and part (b) ofFIG.8, it is assumed that the transfer roller9is held in the separated position by the transfer separating mechanism90. An engaging position, at which the first engaging portion41of the separation holding member40engages the first hook portion22of the first bearing20, is defined as P1. A point where force applied, at which the first bearing20receives the urging force from the first pressing spring30in the pressing direction D3, is defined as P2. The engaging position P1is a point where force applied, at which the first hook portion22receives force from the separation holding member40in the opposite direction to the pressing direction D3.

In the present Embodiment, since the separation holding member40and the transfer roller9are disposed to align in the direction crossing the pressing direction D3, the engaging position P1and the point where force applied P2are separated from each other in the recording material conveyance direction D2. Therefore, the first hook portion22is to deform so that the point where force applied P2moves in the pressing direction D3, with the engaging portion P1functioning as a fulcrum.

Here, as shown by the broken line in part (a) ofFIG.8, in the case in which the distance from the engaging position P1to the point where force applied P2is long, a deformation amount A of the first hook portion22is likely to be large. When the first hook portion22is deformed, the transfer roller9will move in the pressing direction D3even though the first engaging portion41of the separation holding member40engages the first hook portion22of the first bearing20at the certain engaging position P1. As a result, the distance between the transfer roller9and the photosensitive drum2becomes smaller, which may cause the aforementioned adverse effects caused by the contact between the transfer roller9and the photosensitive drum2.

As shown in part (b) ofFIG.8, if the distance from the engaging position P1to the point where force applied P2is short, then it becomes possible to reduce the deformation amount A of the first hook portion22. Similarly, if a distance from an engaging position, where the second engaging portion42of the separation holding member40engages the second hook portion23of the second bearing21, to a point, where the second bearing21receives the urging force in the pressing direction D3from the second pressing spring31, is short, then it becomes possible to reduce the deformation amount of the second hook portion23.

Therefore, as shown inFIG.7, in the present Embodiment, the separation holding member40is disposed directly below a pre-transfer guide80, which is provided just before the transfer portion Nt. The pre-transfer guide80is disposed upstream of the transfer portion Nt in the recording material conveyance direction D2and is a guide member configured to guide the recording material to the transfer portion Nt. As viewed in the pressing direction D3(moving direction of the transfer roller9), the separation holding member40(moving member) and the pre-transfer guide80(guide member) are overlapped with each other.

Thus, by disposing the separation holding member40using a space directly below the pre-transfer guide80, it becomes possible to reduce the deformation amount of the first hook portion22and the second hook portion23, and to reduce possibility of the contact between the transfer roller9and the photosensitive drum2. In addition, since the separated position of the transfer roller9does not need to be positioned farther away from the photosensitive drum2in consideration of the deformation of the first hook portion22and the second hook portion23, it becomes possible to make the space for movement of the transfer roller9smaller, which is advantageous for downsizing the image forming apparatus1.

In addition, in the present Embodiment, after the transfer roller9moves from the separated position to the contact position, the separation holding member40becomes unmovable from the releasing position to the engaging position, and no operation is performed to drive the transfer roller9from the contact position to the separated position via the separation holding member40. In a case in which the transfer roller9is configured to be capable of being driven from the contact position to the separated portion by providing a cam surface, which engages the first hook portion22and the second hook portion23, to the separation holding member40, it is required for the separation holding member40to be rigid enough to withstand force received at the cam surface. In contrast, in the present Embodiment, no operation is performed to drive the transfer roller9from the contact position to the separated position via the separation holding member40. Therefore, it is sufficient for the separation holding member40to have sufficient rigidity in vicinities of the engaging positions with the first hook portion22and the second hook portion23and in a vicinity of the contact position with the main body frame101.

Specifically, the first engaging portion41of the separation holding member40, which engages the first bearing20, and the first main body contacting portion45(first contacting portion) of the separation holding member40, which is in contact with the main body frame101, are disposed on one side with respect to the passing region W (FIG.6) of the recording material in the rotational axis direction D1. In addition, the second engaging portion42of the separation holding member40, which engages the second bearing21, and the second main body contacting portion46(second contacting portion) of the separation holding member40, which is in contact with the main body frame101, are disposed on the other side with respect to the passing region W (FIG.6) of the recording material in the rotational axis direction D1.

According to this configuration, the separation holding member40has only to have rigidity to withstand the urging force from the first pressing spring30and the second pressing spring31at both end portions in the rotational axis direction D1. On the other hand, for the extending portion400(FIG.2) of the separation holding member40, which extends in the rotational axis direction D1between the first engaging portion41and the second engaging portion42, less rigidity is required than both end portions of the separation holding member40in the rotational axis direction D1, therefore it becomes possible to reduce, for example, a thickness of the plate.

Incidentally, as shown inFIG.2andFIG.4, it is preferable that the first engaging portion41and the first main body contacting portion45be adjacent in the recording material conveyance direction D2, and the second engaging portion42and the second main body contacting portion46be adjacent in the recording material conveyance direction D2. The first engaging portion41and the first main body contacting portion45may be overlapped with each other in the pressing direction D3, and the second engaging portion42and the second main body contacting portion46may be overlapped with each other in the pressing direction D3.

In addition, in the present Embodiment, in the state in which the transfer roller9is positioned in the separated position indicated by the broken line, as viewed in the recording material conveyance direction D2(FIG.6), the urging member43(third urging member), which urges the separation holding member40(moving member), and the transfer roller9are overlapped with each other. By this configuration, it becomes possible to further downsize the image forming apparatus1by being able to dispose the urging member43(third urging member) for urging the separation holding member40by using a space which is overlapped with the transfer roller9as viewed in the recording material conveyance direction D2.

In addition, in the present Embodiment, in the state in which the transfer roller9is positioned in the separated position indicated by the broken line, as viewed in the recording material conveyance direction D2(FIG.6), the main body hook portion49(third engaging portion) of the separation holding member40(moving member) and the transfer roller9are overlapped with each other. By this configuration, it becomes possible to dispose the main body hook portion49(third engaging portion) for holding the separation holding member40to the main body frame101by using the space which is overlapped with the transfer roller9as viewed in the recording material conveyance direction D2. Thus, it becomes possible to further downsize the image forming apparatus1.

Furthermore, in the present Embodiment, in the case in which the transfer roller9is positioned in the separated position indicated by the broken line, as viewed in the recording material conveyance direction D2(FIG.6), the retaining portion47(projecting shape) of the separation holding member40(moving member) and the transfer roller9are overlapped with each other. By this configuration, it becomes possible to dispose the retaining portion47(projecting shape) for restricting the falling off of the separation holding member40from the main body frame101by using the space which is overlapped with the transfer roller9as viewed in the recording material conveyance direction D2. Thus, it becomes possible to further downsize the image forming apparatus1.

A configuration of an image forming apparatus according to an Embodiment 2 will be described usingFIG.9. In the present Embodiment, the disposition of the separation holding member40is different from the Embodiment 1. Hereinafter, elements with a common reference numeral with the Embodiment 1 are assumed to be provided with substantially the same configuration and action as those described in the Embodiment 1 unless otherwise mentioned, and parts which differ from the Embodiment 1 will be mainly described.

As shown inFIG.9, the separation holding member40in the present Embodiment is disposed downstream of the transfer roller9with respect to the recording material conveyance direction D2. At least a part of the separation holding member40is disposed on the same side (upper side in Figure) of the transfer roller9with respect to the main body frame101in the pressing direction D3. In addition, in the state in which the transfer roller9is positioned in the separated position, as viewed in the recording material conveyance direction D2, the separation holding member40and the transfer roller9are overlapped with each other.

Therefore, it becomes possible to downsize the image forming apparatus1in the direction (pressing direction D3) crossing both with the rotational axis direction D1and the recording material conveyance direction D2. In other words, according to the present Embodiment, it becomes possible to provide the image forming apparatus which can be downsized.

In addition, in the pressing direction D3, the back surface of the supporting surface70of the main body frame101, which supports the first pressing spring30and the second pressing spring31, is the guide surface71, which forms the second conveyance path110. In other words, the supporting surface70is a surface opposite to the guide surface71with respect to the pressing direction D3(moving direction of the transfer roller9) in the main body frame101(supporting member).

According to this configuration, the distance between the first conveyance path100(conveyance path which includes the transfer portion Nt) and the second conveyance path110in the pressing direction D3can be narrowed, and it becomes possible to downsize the image forming apparatus1in the pressing direction D3.

In the present Embodiment, a static eliminating needle190is disposed downstream of the transfer portion Nt in the recording material conveyance direction D2. The static eliminating needle190is conductive and electrically grounded via a conductive path provided in the main body frame101. The static eliminating needle190has a function of reducing an occurrence of an image defect due to excess charge by removing excess charge (electrically discharging) from the recording material by being in contact with the recording material which has passed through the transfer portion Nt.

In the present Embodiment, the separation holding member40is disposed directly below the static eliminating needle190, which is provided immediately after the transfer portion Nt. The static eliminating needle190is disposed downstream of the transfer portion Nt in the recording material conveyance direction D2, and is an example of an electrically discharging member configured to electrically discharge the recording material in the transfer portion Nt. As viewed in the pressing direction D3(moving direction of the transfer roller9), the separation holding member40(moving member) and the static eliminating needle190(electrically discharging member) are overlapped with each other.

Thus, by disposing the separation holding member40using a space directly below the static eliminating needle190, it becomes possible to reduce the deformation amount of the first hook portion22and the second hook portion23, and to reduce the possibility of the contact between the transfer roller9and the photosensitive drum2. In addition, since the separated position of the transfer roller9does not need to be positioned farther away from the photosensitive drum2in consideration of the deformation of the first hook portion22and the second hook portion23, it becomes possible to make the space for movement of the transfer roller9smaller, which is advantageous for downsizing the image forming apparatus1.

A configuration of an image forming apparatus according to an Embodiment 3 will be described usingFIG.10. In the present Embodiment, the configuration for releasing the holding of the transfer roller9by the transfer separating mechanism90is different from the Embodiment 1. Hereinafter, elements with a common reference numeral with the Embodiment 1 are assumed to be provided with substantially the same configuration and action as those described in the Embodiment 1 unless otherwise mentioned, and parts which differ from the Embodiment 1 will be mainly described.

FIG.10is a view illustrating a state in which the transfer roller9, the first bearing20and the transfer separating mechanism90are viewed toward the opposite side of the pressing direction D3. The transfer separation mechanism90is provided with the separation holding member40, the urging member43, and a stopper member160. As in the Embodiment 1, the one separation holding member40engages both the first bearing20and the second bearing21. The movement of the transfer roller9from the separated position to the contact position is permitted by the separation holding member40moving in the moving direction E2along the rotational axis direction D1from the engaging position (position viewed inFIG.10) to the releasing position.

In the present Embodiment, the stopper member160is used instead of the slider member50of the Embodiment 1 as a mechanism (restricting means) for holding the separation holding member40in the engaging position. The stopper member160includes a contacting surface161, which is in contact with an end portion144of the separation holding member40in the moving direction E2, and holds the separation holding member40in the engaging position against the urging force of the urging member43in the moving direction E2.

The stopper member160is mounted on a mounting portion101bof the apparatus main body1B (main body frame101) in a demountable state during the assembly of the image forming apparatus1. The stopper member160is then removed before a use of the image forming apparatus1is begun. As a result, since the movement of the separation holding member40in the moving direction E2is permitted, the separation holding member40moves from the engaging position to the releasing position according to the force of the urging member43. And by the first engaging portion41and the second engaging portion42of the separation holding member40being disengaged from the first hook portion22of the first bearing20and the second hook portion23of the second bearing21, the transfer roller9moves from the separated position to the contact position.

Thus, in the present Embodiment, the stopper member160is used as the restricting means and a restriction releasing means of the movement in the moving direction E2of the separation holding member40. As in the Embodiment 1, in the configuration in which the one separation holding member40engages both the first bearing20and the second bearing21, by restricting the position of the separation holding member40, the positions of both the first bearing20and the second bearing21can be simultaneously restricted. By taking advantage of this high degree of design freedom, the positions of the first bearing20and the second bearing21can be restricted with a simpler and more compact configuration than the releasing unit60of the Embodiment 1.

Incidentally, in the present Embodiment, the configuration in which the stopper member160is removable from the apparatus main body1B, however, the stopper member160may be configured to remain in the state mounted on the apparatus main body1B and to be moved to a position permitting the movement of the separation holding member40.

OTHER EMBODIMENTS

In the Embodiments described above, it is described by exemplifying the mono-color image forming apparatus using a single process cartridge, however, the present disclosure is not limited to this configuration, but can be applied to a full-color image forming apparatus using multiple process cartridges. In addition, in the Embodiments described above, the image forming apparatus of a direct transfer method, in which an image is transferred directly from the photosensitive drum as the image bearing member to the recording material, is exemplified, however, the configurations of the present disclosure may be applied to an image forming apparatus of an intermediary transfer method. In this case, an image formed on a photosensitive drum is primarily transferred to an image bearing member (intermediary transfer member), and then secondarily transferred from the image bearing member (intermediary transfer member) to the recording material by a transfer member.

In addition, in the Embodiments described above, it is described by exemplifying the image forming apparatus capable of double-side printing by being provided with the second conveyance path110, however, the configurations of the present disclosure may be applied to an image forming apparatus only capable of single-side printing without the second conveyance path110. Even in this case, it is possible to downsize the image forming apparatus with respect to the moving direction of the transfer member.

In addition, in the Embodiments described above, it is described by exemplifying the image forming apparatus of a so-called S-path configuration. The S-path configuration is a configuration in which the recording material is fed from the feeding tray15toward one side of the horizontal direction, the recording material is conveyed through the transfer portion Nt above the feeding tray15toward the other side of the horizontal direction, and the recording material is discharged above the transfer portion Nt toward the one side of the horizontal direction. Not limited to this configuration, the configurations of the present disclosure may be applied to an image forming apparatus of a so-called C-path configuration. The C-path configuration is a configuration in which the recording material is fed from the feeding tray15toward one side of the horizontal direction, the recording material passes through the transfer portion Nt while being conveyed toward upper direction, and the recording material is discharged toward the other side of the horizontal direction. In a case of the image forming apparatus of the C-pass configuration, there is a case in which it is possible to downsize the image forming apparatus in the horizontal direction as viewed in the rotational axis direction of the transfer roller9by the configurations of the present disclosure.

In addition, in the Embodiments described above, a printer is exemplified as the image forming apparatus, however, the present disclosure is not limited thereto. For example, the image forming apparatus may be another image forming apparatus such as a copy machine and facsimile device, or another image forming apparatus such as a multifunction machine combining these functions. The configurations of the present disclosure may be applied to a transfer separating mechanism used in these image forming apparatuses.

SUMMARY OF THE DISCLOSURE

The present disclosure includes at least the following structures.

An image forming apparatus comprising:a rotatable image bearing member configured to bear an image;a rotatable transfer member configured to form a transfer portion between itself and the image bearing member and to transfer the image from the bearing member to a recording material in the transfer portion, the transfer member being movable between a contact position in contact with the image bearing member and a separated position separated from the image bearing member in a moving direction crossing both a rotational axis direction of the transfer member and a recording material conveyance direction in the transfer portion;a first bearing configured to rotatably support a first end portion of the transfer member in the rotational axis direction and movably provided in the moving direction;a second bearing configured to rotatably support a second end portion of the transfer member in the rotational axis direction and movably provided in the moving direction;a supporting member opposing the first bearing and the second bearing with respect to the moving direction;a first urging member of which one end is supported by the supporting member and the other end is connected to the first bearing and configured to urge the first bearing in a direction from the separated position toward the contact position of the transfer member;a second urging member of which one end is supported by the supporting member and the other end is connected to the second bearing and configured to urge the second bearing in the direction from the separated position toward the contact position of the transfer member; anda moving member provided with a first engaging portion engaging with the first bearing and a second engaging portion engaging the second bearing and movably provided in a direction along the rotational axis direction between a first position where the first engaging portion engages with the first bearing and the second engaging portion engages with the second bearing so as to hold the transfer member at the separated position and a second position where the first engaging portion is disengaged from the first bearing and the second engaging portion is disengaged from the second bearing so as to permit the transfer member to move from the separated position to the contact position,wherein at least a part of the moving member is disposed on the same side as the transfer member with respect to the supporting member in the moving direction, andwherein as viewed in the recording material conveyance direction, the moving member and the transfer member are overlapped with each other in a state in which the transfer member is positioned in the separated position.

An image forming apparatus according to Structure 1, further comprising a guide member disposed upstream of the transfer member in the recording material conveyance direction and configured to guide the recording material to the transfer portion,wherein as viewed in the moving direction, the moving member and the guide member are overlapped with each other.

An image forming apparatus according to Structure 1, further comprising an electrically discharging member disposed downstream of the transfer portion in the recording material conveyance direction and configured to electrically discharge the recording material,wherein as viewed in the moving direction, the moving member and the electrically discharging member are overlapped with each other.

An image forming apparatus according to Structure 2 or 3, wherein the first bearing includes a first engaged portion engaged with the first engaging portion,wherein the second bearing includes a second engaged portion engaged with the second engaging portion, andwherein the first engaged portion and the second engaged portion are formed so as to project in a direction crossing both the rotational axis direction and the moving direction.

An image forming apparatus according to any one of Structures 1 to 3, wherein the supporting member includes a supporting surface for supporting the first urging member and the second urging member, and a guide surface for forming a conveyance path along which the recording material, of which a first side is transferred with the image in the transfer portion, is again conveyed toward the transfer portion in order to. transfer an image to a second side thereof opposite to the first side, andwherein the supporting surface is a surface opposite to the guide surface with respect to the moving direction.

An image forming apparatus according to Structure 5, wherein of the moving member, an inner part of a passing region where the recording material passes through the transfer portion in the rotational axis direction is disposed on the same side as the transfer member with respect to a position of the supporting surface in the moving direction.

An image forming apparatus according to Structure 5 or 6, further comprising an accommodating portion configured to accommodate the recording material fed toward the transfer portion,wherein the accommodating portion is positioned below the conveyance path and the transfer portion is positioned above the conveyance path.

An image forming apparatus according to any one of Structures 1 to 7, further comprising a third urging member configured to urge the moving member from the first position toward the second position. andrestricting means for restricting movement of the moving member from the first position toward the second position.

An image forming apparatus according to Structure 8, further comprising a releasing unit configured to release restriction by the restricting means,wherein the restricting means is movable in a direction crossing to the rotational axis between a third position where the restricting means restricts the movement of the moving member from the first position to the second position and a fourth position where the restricting means permits the movement of the moving member from the first position to the second position, andwherein the releasing unit includes a driving source and a driving member configured to cause the restricting means to move the third position to the fourth position by a driving force of the driving source.

An image forming apparatus according to any one of Structures 1 to 9, wherein the moving member is constituted so as to be unmovable from the second position to the first position after the moving member has moved from the first position to the second position and the transfer member moves from the separated position to the contact position.

An image forming apparatus according to Structure 10, wherein the moving member includes an extending portion extending in the rotational axis direction between the first engaging portion and the second engaging portion, and a first contacting member and a second contacting member contacting a frame member of the image forming apparatus, respectively,wherein in a case in which the moving member is positioned in the first position, each urging forces of the first urging member and the second urging member is received by the frame member by contacting of the first contacting portion and the second contacting portion with the frame member,wherein the first engaging portion and the first contacting portion are disposed on one side with respect to a passing region where the recording material passes through the transfer portion in the rotational axis direction, andwherein the second engaging portion and the second contacting portion are disposed on the other side with respect to the passing region in the rotational axis direction.

An image forming apparatus according to any one of Structures 1 to 11, further comprising a third urging member configured to urge the moving member in a direction from the first position toward the second position,wherein in a state in which the transfer member is positioned in the separated position, as viewed in the recording material conveyance direction, the third urging member and the transfer member are overlapped with each other.

An image forming apparatus according to any one of Structures 1 to 12, wherein the moving member includes an extending portion extending in the rotational axis direction between the first engaging portion and the second engaging portion, and a third engaging portion configured to engage with a third engaged portion provided on a frame member of the image forming apparatus, and is held by the frame member by engaging of the third engaging portion with the third engaged portion, andwherein in a state in which the transfer member is positioned in the separated position, as viewed in the recording material conveyance direction, the third engaging portion and the transfer member are overlapped with each other.

An image forming apparatus according to Structure 13, wherein the moving member includes a projecting shape projecting from the extending portion in a direction crossing to the rotational axis direction and configured to restrict falling of the moving member from the frame member,wherein in a state in which the transfer member is positioned in the separated position, as viewed in the recording material conveyance direction, the projecting shape and the transfer member are overlapped with each other.

This application claims the benefit of Japanese Patent Application No. 2023-010974 filed on Jan. 27, 2023, which is hereby incorporated by reference herein in its entirety.