Image forming apparatus

Abstract

To provide an image forming apparatus that suppresses the increase in size of the apparatus and can form a power supply path to the driven unit that is inserted into and removed from the housing. [Solution] The image forming apparatus comprises a fixing unit 5b that is removable from the insertion / removal section 1b, an output engaging section 63 provided on the insertion / removal section 1b and rotating in response to the driving force of a drive source 61, and an input engaging section 571 provided on the fixing unit 5b and engaging with the output engaging section 53. The output engaging section 63 and the input engaging section 571 are supported so as not to move along the insertion direction D12, and the output engaging section 63 rotates until it comes into contact with the input engaging section 571 and engages with the input engaging section 571 when it is not facing the input engaging section 571 in an engageable manner during insertion of the fixing unit 5b into the insertion / removal section 1b.

Description

Technical Field

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

Background Art

[0002] An image forming apparatus including a driven part such as a photosensitive drum driven by the driving force of a driving source provided in a housing and provided with a driven unit that can be inserted into and removed from the housing is known as a related art (see Patent Document 1).

[0003] The image forming apparatus according to the above related art includes an output engagement part, an input engagement part, and a biasing part. The output engagement part is provided rotatably about an axis along the insertion direction at an end on the downstream side in the insertion direction of the driven unit in the insertion part of the housing where the driven unit is inserted and removed, is supported movably along the insertion direction, and rotates receiving the driving force. The input engagement part is provided rotatably about an axis along the insertion direction at an end on the downstream side in the insertion direction of the driven unit in the driven unit, engages with the output engagement part, and transmits the driving force transmitted from the output engagement part to the driven part. The biasing part biases the output engagement part upstream in the insertion direction.

[0004] In the image forming apparatus according to the above related art, when the output engagement part and the input engagement part do not face each other so as to be engageable during insertion of the driven unit into the insertion part, the output engagement part and the input engagement part come into contact and the output engagement part is pressed downstream in the insertion direction. Then, the output engagement part rotates until it faces the input engagement part so as to be engageable receiving the driving force, and the output engagement part moves upstream in the insertion direction by the biasing force of the biasing part, and the output engagement part and the input engagement part engage with each other.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] However, in the image forming apparatus relating to the above-mentioned related technologies, it is necessary to secure space that allows the output engaging portion to move along the insertion direction in order to engage the output engaging portion with the input engaging portion, which increases the size of the apparatus.

[0007] The object of the present invention is to provide an image forming apparatus that can suppress the increase in size of the apparatus and create a supply path for driving force to a driven unit that is inserted into and removed from the housing. [Means for solving the problem]

[0008] An image forming apparatus according to one aspect of the present invention comprises a housing, a drive source, a driven unit, an output engagement portion, and an input engagement portion. The drive source is provided in the housing. The driven unit includes a driven portion driven by the driving force of the drive source and is provided in the housing so as to be insertable and removable. The output engagement portion is provided at the downstream end of the insertion portion of the housing where the driven unit is inserted and removed, so as to be rotatable about an axis along the insertion direction, and rotates upon receiving the driving force. The input engagement portion is provided at the downstream end of the driven unit so as to be rotatable about an axis along the insertion direction, and engages with the output engagement portion to transmit the driving force transmitted from the output engagement portion to the driven portion. In the image forming apparatus, the output engagement portion has a first ratchet tooth formed along the rotation direction and is supported so as to be immovable along the insertion direction. The input engagement portion has a second ratchet tooth that engages with the first ratchet tooth and is supported so as to be immovable along the insertion direction. Furthermore, if either the output engaging portion or the input engaging portion is not facing the other in a way that allows it to engage with the other during insertion of the driven unit into the insertion / removal portion, it will rotate due to the force received through the contact portion with the other until it engages with the other. [Effects of the Invention]

[0009] According to the present invention, it is possible to suppress the increase in size of the device and to form a supply path for driving force to the driven unit that is inserted into and removed from the housing. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a configuration diagram of an image forming apparatus according to an embodiment. [Figure 2] Figure 2 shows the configuration of the main part of the fixing device in the image forming apparatus according to the embodiment. [Figure 3] Figure 3 is a front view of the fixing device in the image forming apparatus according to the embodiment. [Figure 4] Figure 4 is a perspective view of the fixing unit in the image forming apparatus according to this embodiment. [Figure 5] Figure 5 is a perspective view of the support unit and the movable unit in the image forming apparatus according to the embodiment. [Figure 6] Figure 6 is a plan view of the drive mechanism and reciprocating mechanism in an image forming apparatus according to an embodiment. [Figure 7] Figure 7 is a perspective view of the output engagement section in the image forming apparatus according to this embodiment. [Figure 8] Figure 8 is a perspective view of the input engagement portion in the image forming apparatus according to the embodiment. [Figure 9] Figure 9 is a plan view of an output engagement portion and an input engagement portion that are not engaged with each other in an image forming apparatus according to an embodiment. [Figure 10] Figure 10 is a plan view of a modified example of the output engagement portion in an image forming apparatus according to an embodiment. [Modes for carrying out the invention]

[0011] The embodiments of the present invention will be described below with reference to the drawings. Note that the following embodiments are merely examples of the present invention and do not limit the technical scope of the present invention.

[0012] [Configuration of Image Forming Apparatus 10] The image forming apparatus 10 according to the embodiment executes print processing by an electrophotographic method. The print processing is processing for forming an image on the sheet SH.

[0013] As shown in FIG. 1, the image forming apparatus 10 includes a sheet storage unit 2, a sheet conveyance device 3, and a print device 4. The sheet conveyance device 3 and the print device 4 are housed in a main body portion 1 (see FIG. 1) that is a housing.

[0014] The sheet storage unit 2 can store a plurality of sheets SH.

[0015] The sheet conveyance device 3 includes a sheet feeding device 30 and a plurality of sets of conveyance roller pairs 31.

[0016] The sheet feeding device 30 feeds the sheets SH in the sheet storage unit 2 one by one to the conveyance path 300. The conveyance path 300 is a passage for the sheet SH.

[0017] The plurality of sets of conveyance roller pairs 31 convey the sheet SH along the conveyance path 300. One of the plurality of sets of conveyance roller pairs 31 discharges the sheet SH on which an image is formed from the conveyance path 300 onto the discharge tray 1a (see FIG. 1).

[0018] The print device 4 executes the print processing on the sheet SH conveyed along the conveyance path 300. The image formed on the sheet SH is a toner image.

[0019] The print device 4 includes an optical scanning unit 40, one or more image forming units 4x, a transfer device 45, and a fixing device 5.

[0020] The image forming unit 4x includes a photoreceptor 41, a charging device 42, a developing device 43, and a drum cleaning device 44.

[0021] The charging device 42 charges the surface of the photoreceptor 41. The optical scanning unit 40 scans the charged surface of the photoreceptor 41 with a beam of light. As a result, the optical scanning unit 40 forms an electrostatic latent image on the surface of the photoreceptor 41.

[0022] The developing device 43 develops the electrostatic latent image into a toner image by supplying toner to the surface of the photoreceptor 41. The transfer device 45 transfers the toner image formed on the surface of the photoreceptor 41 to the sheet SH.

[0023] The transfer device 45 transfers the toner image to the sheet SH at the transfer position P1 (see Figure 1) in the transport path 300.

[0024] In this embodiment, the printing apparatus 4 is a tandem-type color printing apparatus equipped with a plurality of image forming units 4x. The transfer apparatus 45 includes an intermediate transfer belt 450, a plurality of primary transfer devices 451, a secondary transfer device 452, and a belt cleaning device 453.

[0025] In the example shown in Figure 1, the printing device 4 comprises four image forming units 4x corresponding to four toner colors: yellow, magenta, cyan, and black. The transfer device 45 comprises four primary transfer units 451 corresponding to the four image forming units 4x.

[0026] The intermediate transfer belt 450 is rotatably supported by a plurality of support rollers 454. One of the support rollers 454 is rotated by a belt drive device (not shown), thereby causing the intermediate transfer belt 450 to rotate.

[0027] Each primary transfer device 451 transfers the toner image formed on the surface of the photoreceptor 41 in each image forming unit 4x to the surface of the intermediate transfer belt 450. As a result, a composite toner image, formed by combining the four toner images, is created on the surface of the intermediate transfer belt 450.

[0028] The intermediate transfer belt 450 rotates while carrying the synthetic toner image. The secondary transfer device 452 transfers the synthetic toner image formed on the surface of the intermediate transfer belt 450 to the sheet SH at the transfer position P1.

[0029] The drum cleaning device 44 removes primary waste toner from the surface of the photoreceptor 41. The primary waste toner is the toner remaining on the surface of the photoreceptor 41 that has passed through the primary transfer device 451.

[0030] The belt cleaning device 453 removes secondary waste toner from the surface of the intermediate transfer belt 450. The secondary waste toner is the toner remaining on the surface of the intermediate transfer belt 450 that has passed through the secondary transfer device 452.

[0031] The fixing device 5 heats and pressurizes the synthesized toner image on the sheet SH at the fixing position P2 (see Figure 1) in the transport path 300. This fixes the synthesized toner image to the sheet SH. The fixing position P2 is located downstream of the transfer position P1 in the transport direction D4 (see Figure 1) of the sheet SH.

[0032] As shown in Figure 2, the fixing device 5 includes a heater 51, a fixing belt 52, a fixing roller 520, a pressure roller 53, and a sheet separating member 5200.

[0033] The fixing belt 52 is a flexible cylindrical member that encloses the fixing roller 520. The fixing belt 52 is heated by the heater 51.

[0034] The fixing roller 520 is a cylindrical member that supports the fixing belt 52 from the inside of the fixing belt 52. The fixing roller 520 has a cylindrical core metal portion 521 and an elastic portion 522 formed on the outer circumference of the core metal portion 521.

[0035] The fixing roller 520 is rotatably supported. The fixing belt 52 is rotatable together with the fixing roller 520.

[0036] The fixing belt 52 comprises a conductive base material, an elastic layer formed on the outer periphery of the base material, and a release layer formed on the outer periphery of the elastic layer. The base material is made of nickel. The elastic layer is made of silicone rubber. The release layer is made of PFA tubing.

[0037] The heater 51 is positioned opposite the outer circumferential surface of the fixing belt 52. In this embodiment, the heater 51 is an electromagnetic induction heating device. The heater 51 primarily heats the base material of the fixing belt 52 by electromagnetic induction.

[0038] The pressure roller 53 is rotatably supported. Like the fixing roller 520, the pressure roller 53 also has a cylindrical core portion 531 and an elastic portion 532 formed on the outer circumference of the core portion 531.

[0039] The pressure roller 53 is driven and rotated by a drive device (not shown). The fixing belt 52 and the fixing roller 520 rotate in conjunction with the pressure roller 53.

[0040] The fixing belt 52 heats the synthetic toner image formed on the sheet SH. The pressure roller 53 applies pressure to the synthetic toner image toward the sheet SH.

[0041] The fixing belt 52 and the pressure roller 53 transport the sheet SH onto which the synthetic toner image has been transferred, and form a fixing nip section that fixes the synthetic toner image to the sheet SH. Fixing position P2 is the position where the fixing nip section is formed. The fixing belt 52 and the pressure roller 53 are arranged side by side along a horizontal plane (see Figure 1). The heater 51 heats the fixing belt 52 on the side opposite to the pressure roller 53.

[0042] The sheet separation member 5200 separates the sheet SH from the fixing belt 52 when the sheet SH adheres to the fixing belt 52.

[0043] In this embodiment, the fixing device 5 is divided into a heating unit 5a and a fixing unit 5b (see Figure 3). The heating unit 5a has a heater 51. The fixing unit 5b has a fixing belt 52, a fixing roller 520, and a pressure roller 53.

[0044] By moving the heating unit 5a to a position away from the fixing unit 5b, the fixing unit 5b can be pulled out from the main body 1 in the withdrawal direction D11 (see Figure 6) along the first direction D1. The first direction D1 is the direction along the centerlines of rotation of the fixing belt 52 and the pressure roller 53. In this embodiment, the first direction D1 is the depth direction of the image forming apparatus 10.

[0045] [Configuration of heating unit 5a and fixing unit 5b] The heating unit 5a includes a heater 51 and a support 54 (see Figure 3). The support 54 is a member that supports the heater 51.

[0046] The fixing unit 5b includes a support unit 55 and a movable unit 56 (see Figures 3 and 4). The movable unit 56 includes a fixing belt 52, a fixing roller 520, and a pressure roller 53.

[0047] The support unit 55 supports the movable unit 56 from below.

[0048] As shown in Figures 4 and 5, the support unit 55 comprises a support surface portion 551, an opening 552, a protruding portion 553, and a side wall portion 554.

[0049] The support surface 551 forms a support surface that supports the movable unit 56. The support surface 551 is formed in a flat plate shape perpendicular to the vertical direction D3. The vertical direction D3 is the up and down direction. The first direction D1 is also a direction perpendicular to the vertical direction D3. The support surface 551 is formed in an elongated shape in the first direction D1. Figure 5 shows the movable unit 56 lifted from the support surface 551.

[0050] The opening 552 is provided in the support surface 551. The sheet SH being transported to the anchoring position P2 passes through the inside of the opening 552.

[0051] The protruding portion 553 is provided so as to protrude from the support surface of the support surface portion 551 toward the movable unit 56. Specifically, the protruding portion 553 protrudes upward from the support surface portion 551. The protruding portion 553 is formed in a cylindrical shape. However, the protruding portion 553 may be formed in a rectangular prism shape. As shown in Figure 5, the support unit 55 includes two protruding portions 553 arranged at an interval in the first direction D1.

[0052] The side wall portion 554 is erected along one end of the support surface portion 551 in the first direction D1. Specifically, the side wall portion 554 is erected along the upstream end of the support surface portion 551 in the pull-out direction D11.

[0053] The movable unit 56 rotatably supports the fixing roller 520 and the pressure roller 53. The fixing roller 520 supports the fixing belt 52. That is, the fixing belt 52 is supported by the movable unit 56 via the fixing roller 520.

[0054] As shown in Figures 4 and 5, the movable unit 56 includes a bottom portion 561 and a guide portion 562.

[0055] The bottom surface 561 forms the bottom surface of the movable unit 56. The bottom surface 561 is formed in a flat plate shape perpendicular to the vertical direction D3. The bottom surface 561 is formed in an elongated shape in the first direction D1. The bottom surface 561 is placed on the support surface 551 of the support unit 55. The bottom surface 561 has an opening (not shown) for passing the sheet SH to the fixing position P2. A fixing belt 52, fixing roller 520, and pressure roller 53 are provided on the upper side of the bottom surface 561.

[0056] The guide portion 562 is provided on the bottom portion 561. The guide portion 562 is formed so that the protrusions 553 of the support unit 55 can be inserted into it. Specifically, the guide portion 562 is a hole formed in the bottom portion 561. The guide portion 562 is formed to be elongated in the first direction D1. The guide portion 562 is provided in correspondence with the two protrusions 553 provided on the support unit 55. In other words, the movable unit 56 has two guide portions 562 that are spaced apart in the first direction D1. When the movable unit 56 is attached to the support unit 55, the two protrusions 553 are inserted into the two guide portions 562.

[0057] The fixing unit 5b is provided so as to be able to be integrally inserted into and removed from the main body 1, which is the housing of the image forming apparatus 10, along the first direction D1.

[0058] Incidentally, in the image forming apparatus 10, as the sheet SH repeatedly passes through the fixing nip section, wear progresses more rapidly at the contact points between the fixing belt 52 and the side edges of the sheet SH than at other points. As wear progresses at the contact points between the fixing belt 52 and the side edges of the sheet SH, streaky scratches are formed on the fixing belt 52 along the transport direction D4, and these scratches cause streaky abnormal images to appear in the output image.

[0059] In contrast, in the image forming apparatus 10, the movable unit 56 is moved along the width direction of the sheet SH. The width direction is the same direction as the first direction D1.

[0060] The fixing unit 5b further includes a reciprocating mechanism 57 that moves the movable unit 56 back and forth along the first direction D1 (see Figure 6).

[0061] The image forming apparatus 10 further includes a drive mechanism 6 located within the main body 1 (see Figure 6). The drive mechanism 6 is fixed to the main body frame of the main body 1.

[0062] The drive mechanism 6 comprises a drive source 61, a reduction gear mechanism 62, and an output engagement part 63.

[0063] For example, the drive source 61 is a motor.

[0064] The reduction gear mechanism 62 includes an output gear 621 (see Figure 6). The reduction gear mechanism 62 transmits the driving force of the drive source 61 to the output gear 621 while reducing its speed.

[0065] The output engagement portion 63 is formed integrally with the output gear 621. The output engagement portion 63 rotates at the same speed as the output gear 621. The output engagement portion 63 is a rotating body that transmits rotational driving force to the movable unit 56 of the fixing unit 5b.

[0066] Specifically, the output engagement portion 63 is rotatably mounted on an axis along the insertion direction D12 at the downstream end of the insertion / removal portion 1b (see Figure 6) of the main body portion 1, where the fixing unit 5b is inserted and removed. The insertion direction D12 is the opposite direction to the removal direction D11. The output engagement portion 63 rotates in response to the driving force of the drive source 61. The insertion / removal portion 1b is the part of the main body portion 1 that forms the housing space for the fixing unit 5b. The insertion / removal portion 1b is formed in an elongated shape along the first direction D1.

[0067] The reciprocating mechanism 57 includes an input engagement portion 571 and a cylindrical cam 572.

[0068] The input engagement portion 571 is provided at the downstream end of the fixing unit 5b in the insertion direction D12, so as to be rotatable about an axis along the insertion direction D12. The input engagement portion 571 is provided so as to protrude in the insertion direction D12 from the side wall portion 554 of the support unit 55. The input engagement portion 571 engages with the output engagement portion 63. Figure 6 shows the state in which the output engagement portion 63 and the input engagement portion 571 are engaged. The input engagement portion 571 transmits the driving force transmitted from the output engagement portion 63 to the movable unit 56 via the cylindrical cam 572. The input engagement portion 571 and the cylindrical cam 572 are provided at both ends of a shaft member extending in the first direction D1. The shaft member is rotatably supported by the side wall portion 554.

[0069] The movable unit 56 of the fixing unit 5b has a cam engaging portion 563 that engages with the cylindrical cam 572. As the cylindrical cam 572 rotates, the cam engaging portion 563 reciprocates along the first direction D1.

[0070] As the cam engagement portion 563 reciprocates along the first direction D1, the entire movable unit 56 reciprocates along the first direction D1. That is, the reciprocating mechanism 57 converts the rotational motion of the output engagement portion 63 into the reciprocating motion of the movable unit 56. The movable unit 56 is driven (reciprocates) by the driving force of the drive source 61. The movable unit 56 is an example of a driven part of the present invention. The fixing unit 5b is also an example of a driven part of the present invention.

[0071] The guide portion 562 of the movable unit 56 guides the protruding portion 553 of the support unit 55, which swings relative to the movable unit 56, along the first direction D1. The guide portion 562, which is reciprocated by the reciprocating mechanism 57, is restricted from moving in the second direction D2, which is perpendicular to the first direction D1, by the protruding portion 553. In other words, the movement of the movable unit 56, which is reciprocated by the reciprocating mechanism 57, in the second direction D2 is restricted by the protruding portion 553. The second direction D2 is the lateral direction of the image forming apparatus 10. Also, the second direction D2 is perpendicular to the vertical direction D3.

[0072] Incidentally, an image forming apparatus is known as a related technology that includes an output engagement portion 63 which is supported so as to be movable along the insertion direction D12 and is biased toward the upstream side of the insertion direction D12 by a biasing portion.

[0073] In the image forming apparatus relating to the above-mentioned related technology, if the output engagement portion 63 and the input engagement portion 571 are not facing each other in an engageable manner during insertion of the fixing unit 5b into the insertion / removal portion 1b, the output engagement portion 63 and the input engagement portion 571 come into contact and the output engagement portion 63 is pressed downstream in the insertion direction D12. Subsequently, the output engagement portion 63 rotates under the driving force of the drive source 61 until it faces the input engagement portion 571 in an engageable manner, causing the output engagement portion 63 to move upstream in the insertion direction D12 due to the biasing force of the biasing portion, and the output engagement portion 63 and the input engagement portion 571 engage.

[0074] However, in the image forming apparatus relating to the above-mentioned related technologies, it is necessary to secure space that allows movement of the output engaging portion 63 along the insertion direction D12 in order to engage the output engaging portion 63 with the input engaging portion 571, which increases the size of the apparatus.

[0075] In contrast, the image forming apparatus 10 according to an embodiment of the present invention, as described below, suppresses the increase in size of the apparatus and makes it possible to form a supply path for driving force to the fixing unit 5b that is inserted into and removed from the main body 1.

[0076] Specifically, in the image forming apparatus 10, the output engagement portion 63 is supported so as not to move along the insertion direction D12. The input engagement portion 571 is also supported so as not to move along the insertion direction D12.

[0077] As shown in Figure 7, the output engagement portion 63 comprises a disc-shaped portion 63a and a plurality of ratchet teeth 63b. The disc-shaped portion 63a has thickness in the insertion direction D12 and has a circular first opening in its center. The output engagement portion 63 is fixed to the shaft of the output gear 621 by a screw inserted through the first opening of the disc-shaped portion 63a. The plurality of ratchet teeth 63b (an example of the first ratchet teeth of the present invention) are formed along the edge on the upstream surface of the disc-shaped portion 63a in the insertion direction D12. In other words, the plurality of ratchet teeth 63b are formed along the rotational direction of the output engagement portion 63. For example, as shown in Figure 7, the output engagement portion 63 comprises four ratchet teeth 63b.

[0078] As shown in Figure 8, the input engagement portion 571 comprises a disc-shaped portion 571a and a plurality of ratchet teeth 571b. The disc-shaped portion 571a has thickness in the insertion direction D12 and has a circular second opening in its center. The input engagement portion 571 is fixed to the shaft member by a screw inserted through the second opening of the disc-shaped portion 571a. The plurality of ratchet teeth 571b (an example of the second ratchet teeth of the present invention) engage with the plurality of ratchet teeth 63b of the output engagement portion 63. The plurality of ratchet teeth 571b are formed along the edge on the downstream surface of the disc-shaped portion 571a in the insertion direction D12. In other words, the plurality of ratchet teeth 571b are formed along the rotational direction of the input engagement portion 571. For example, as shown in Figure 8, the input engagement portion 571 comprises four ratchet teeth 571b.

[0079] For example, the input engagement portion 571 has the same shape as the output engagement portion 63.

[0080] If the output engaging portion 63 is not facing the input engaging portion 571 in an engageable manner during insertion of the fixing unit 5b into the insertion / removal portion 1b (see Figure 9), it will come into contact with the input engaging portion 571 and rotate until it engages with the input engaging portion 571 due to the force of the person inserting the fixing unit 5b, which is received through the contact portion with the input engaging portion 571. When the output engaging portion 63 and the input engaging portion 571 are facing each other in an engageable manner, the tips of the four ratchet teeth 63b of the output engaging portion 63 and the roots of the four ratchet teeth 571b of the input engaging portion 571 face each other (see Figure 6).

[0081] Specifically, in the image forming apparatus 10, if the output engagement portion 63 and the input engagement portion 571 are not facing each other in an engageable manner during insertion of the fixing unit 5b into the insertion / removal portion 1b, the inclined surface 63c of the ratchet teeth 63b of the output engagement portion 63 (see Figures 7 and 9) and the inclined surface 571c of the ratchet teeth 571b of the input engagement portion 571 (see Figures 8 and 9) come into contact. As a result, a portion of the force applied to the fixing unit 5b in the insertion direction D12 by the person inserting the fixing unit 5b is converted into a force along the rotation direction of the output engagement portion 63. Therefore, the output engagement portion 63 rotates until the driving force transmission surface 63d of the ratchet teeth 63b of the output engagement portion 63 (see Figure 7) and the driving force receiving surface 571d of the ratchet teeth 571b of the input engagement portion 571 (see Figure 8) come into contact. The driving force transmission surface 63d is a plane substantially perpendicular to the rotational direction of the output engagement portion 63, and together with the inclined surface 63c, forms the ratchet teeth 63b. The driving force receiving surface 571d is a plane substantially perpendicular to the rotational direction of the input engagement portion 571, and together with the inclined surface 571c, forms the ratchet teeth 571b. The state in which the driving force transmission surface 63d and the driving force receiving surface 571d are in contact is the state in which the output engagement portion 63 and the input engagement portion 571 are engaged, and driving force can be transmitted from the output engagement portion 63 to the input engagement portion 571.

[0082] Thus, in the image forming apparatus 10, the output engagement portion 63 is supported so as not to move along the insertion direction D12, and the input engagement portion 571 is also supported so as not to move along the insertion direction D12. As a result, it is not necessary to secure space that allows movement of the output engagement portion 63 or the input engagement portion 571 along the insertion direction D12, thereby suppressing the increase in size of the apparatus.

[0083] Furthermore, in the image forming apparatus 10, if the output engaging portion 63 and the input engaging portion 571 are not facing each other in an engageable manner during insertion of the fixing unit 5b into the insertion / removal portion 1b, the output engaging portion 63 rotates until it engages with the input engaging portion 571. This makes it possible to form a supply path for driving force to the fixing unit 5b that is inserted into and removed from the main body portion 1.

[0084] In addition, instead of the output engagement portion 63, if the input engagement portion 571 is not facing the output engagement portion 63 in a way that allows it to engage with the output engagement portion 63 during insertion of the fixing unit 5b into the insertion / removal portion 1b, the input engagement portion 571 may come into contact with the output engagement portion 63 and rotate until it engages with the output engagement portion 63 due to the force of the person inserting the fixing unit 5b, received through the contact portion with the output engagement portion 63.

[0085] Furthermore, the image forming unit 4x may be provided so as to be insertable and removable from the main body 1. In this case, the driven unit of the present invention may be the image forming unit 4x. Alternatively, the driven unit of the present invention may be the photoreceptor 41.

[0086] [Differentiation] The output engagement portion 63 may have a different shape from the input engagement portion 571.

[0087] For example, as shown in Figure 10, the corners of the ratchet teeth 63b of the output engagement portion 63 may be rounder than the corners of the ratchet teeth 571b of the input engagement portion 571.

[0088] This makes it easier to rotate the output engaging portion 63 or the input engaging portion 571 if the tip of the ratchet teeth 63b of the output engaging portion 63 and the tip of the ratchet teeth 571b of the input engaging portion 571 collide during insertion of the fixing unit 5b into the insertion / removal portion 1b.

[0089] Furthermore, by rounding the tip of only one of the ratchet teeth 63b of the output engagement portion 63 and the ratchet teeth 571b of the input engagement portion 571, it is possible to avoid the contact area between the driving force transmission surface 63d of the ratchet teeth 63b (see Figure 10) and the driving force receiving surface 571d of the ratchet teeth 571b (see Figure 10) becoming excessively small. Therefore, it is possible to suppress instability in the transmission of driving force from the drive source 61 from the output engagement portion 63 to the input engagement portion 571.

[0090] Furthermore, the corners of the ratchet teeth 571b of the input engagement portion 571 may be rounder than the corners of the ratchet teeth 63b of the output engagement portion 63.

[0091] [Notes on the invention] The following is an overview of the invention extracted from the above-described embodiments. Note that each configuration and processing function described below can be selected and combined as desired.

[0092] <Note 1> A housing, a drive source provided in the housing, a driven unit including a driven part driven by the driving force of the drive source, which is inserted into and removed from the housing, an output engaging part provided at the downstream end of the driven unit in the insertion direction of the inserted unit in the insertion / removal part of the housing into which the driven unit is inserted into and removed, so as to be rotatable about an axis along the insertion direction, and which rotates upon receiving the driving force, and a component provided at the downstream end of the driven unit in the insertion direction, so as to be rotatable about an axis along the insertion direction, which engages with the output engaging part and transmits from the output engaging part An image forming apparatus comprising: an input engaging portion that transmits the driving force to the driven portion, wherein the output engaging portion has a first ratchet tooth formed along the rotational direction and is supported so as not to move along the insertion direction, and the input engaging portion has a second ratchet tooth that engages with the first ratchet tooth and is supported so as not to move along the insertion direction, and if either the output engaging portion or the input engaging portion is not facing the other in an engageable manner during insertion of the driven unit into the insertion / removal portion, it rotates until it engages with the other due to a force received through a contact portion with the other.

[0093] <Note 2> The image forming apparatus according to Appendix 1, wherein the output engaging portion rotates until it engages with the input engaging portion due to a force received via the contact portion with the input engaging portion when the driven unit is not facing the input engaging portion in an engageable manner during insertion of the driven unit into the insertion / removal portion.

[0094] <Note 3> The image forming apparatus according to Appendix 1 or 2, wherein the corner of the tip of either the first ratchet tooth or the second ratchet tooth is rounder than the corner of the tip of the other tooth. [Explanation of Symbols]

[0095] 1: Main body 1b: Insertion / extraction part 2: Seat storage section 3: Sheet conveying device 4: Printing device 4x: Image forming section 5: Fixing device 5a: Heating unit 5b: Fixing unit 6: Drive mechanism 10: Image forming apparatus 51: Heater 52: Fixing belt 53: Pressure roller 54:Support 55: Support Unit 56: Movable Unit 57: Reciprocating mechanism 61: Power source 62: Reduction gear mechanism 63: Output engagement part 63b: Ratchet teeth 563; Cam engagement part 571: Input engagement part 571b: Ratchet teeth 572: Cylindrical cam 621: Output gear

Claims

1. The casing and A drive source provided in the housing, A driven unit includes a driven part that is driven by the driving force of the aforementioned drive source, and is provided in a manner that allows it to be inserted into or removed from the housing, An output engaging portion is provided at the downstream end of the insertion portion of the housing through which the driven unit is inserted and removed, so as to be rotatable about an axis along the insertion direction, and which rotates upon receiving the driving force, An input engaging portion is provided at the downstream end of the driven unit in the insertion direction so as to be rotatable about an axis along the insertion direction, and engages with the output engaging portion to transmit the driving force transmitted from the output engaging portion to the driven unit, Equipped with, The output engagement portion has a first ratchet tooth formed along the rotational direction and is supported so as to be immovable along the insertion direction. The input engagement portion has a second ratchet tooth that engages with the first ratchet tooth, and is supported so as not to move along the insertion direction. If either the output engaging portion or the input engaging portion is not facing the other in a way that allows it to engage with the other during insertion of the driven unit into the insertion / removal portion, it rotates until it engages with the other due to the force received through the contact portion with the other. Image forming apparatus.

2. If the output engaging portion is not facing the input engaging portion in an engageable manner during insertion of the driven unit into the insertion / removal portion, it rotates until it engages with the input engaging portion due to the force received through the contact portion with the input engaging portion. The image forming apparatus according to claim 1.

3. The corner of the tip of either the first ratchet tooth or the second ratchet tooth is rounder than the corner of the tip of the other tooth. The image forming apparatus according to claim 1 or 2.

Images