Image forming device

Abstract

To reliably attach a fixation device.SOLUTION: When a fixation device is inserted through an opening provided on a stacker before being attached to an apparatus housing, a part of the fixation device is exposed from the opening provided on the stacker so as to form a part of the stacker, and a connector of the fixation device engages with a connector of the apparatus housing. The fixation device includes: a handle that is provided on the exposed part from the opening, and can switch between a standing state in which it stands with respect to the exposed part and a tilted state in which it is tilted with respect to the exposed part; and a tilt holding detent mechanism that, when the handle is switched from the standing state to the tilted state by applying predetermined force or more to the handle, switches the handle to the titled state and holds it in the tilted state.SELECTED DRAWING: Figure 14

Description

[Technical field]

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

[0002] 2. Description of the Related Art In image forming apparatuses such as copying machines, printers, and facsimiles that form images by electrophotography, an image transferred onto a medium using a developer is fixed onto the medium by a fixing device.

[0003] Conventionally, such image forming devices include a device housing having a stacker on the outer periphery into which media with fixed images are ejected, and a fixing unit that can be attached to and detached from the device housing through an opening provided in the stacker, and when the fixing unit is attached to the device housing, part of the fixing unit is exposed through the opening provided in the stacker to form part of the stacker (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-38242 A Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional image forming devices, the fixing unit can be easily attached and detached because it can be directly attached and detached from the device housing without opening the cover of the device housing. However, there was a problem in that when inserting the fixing unit through the opening of the device housing, if the insertion force is insufficient, the connector on the fixing unit and the connector on the device housing do not fit together, resulting in incomplete installation of the fixing unit.

[0006] The present invention has been made in consideration of the above points, and aims to propose an image forming apparatus in which a fixing unit can be securely attached. [Means for solving the problem]

[0007] The image forming apparatus of the present invention includes a device housing having a stacker on an outer periphery thereof for stacking media, the stacker being provided with an opening, an image forming unit provided in the device housing for forming an image on the media, and a fuser that is detachably provided on the device housing and can be attached to the device housing via the opening, and fuses the image formed on the medium by the image forming unit to the medium, wherein when the fuser is inserted through the opening and attached to the device housing, a part of the fuser is exposed from the opening provided in the stacker to form a part of the stacker, and a connector of the fuser is fitted to a connector of the device housing, and the fuser has a handle on an exposed part exposed from the opening that can be transitioned between an upright state in which it stands against the exposed part and a tilted state in which it tilts against the exposed part, and further includes a tilt retention detent mechanism that transitions the handle to the tilted state and retains it in the tilted state when a force of a predetermined value or more is applied to the handle when transitioning the handle from the upright state to the tilted state. The handle is held by the fixing device so as to be rotatable about a rotation axis between the upright state and the tilted state, and the tilt-holding detent mechanism is located below the rotation axis when the handle is in the tilted state. I made it so that.

[0008] In this way, for example, after grasping the handle in an upright position and inserting the fixing unit through the opening, a force greater than or equal to a predetermined value set in the tilt retention detent mechanism is applied to the handle to transition the handle from the upright position to a tilted position, and this force ensures that the connector of the fixing unit and the connector of the device housing are securely engaged. Effect of the Invention

[0009] Thus, the present invention can realize an image forming apparatus in which the fixing unit can be securely attached. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing an external configuration of an image forming apparatus. [Diagram 2] 1 is a side cross-sectional view showing an internal configuration of an image forming apparatus. [Diagram 3]FIG. 2 is a perspective view showing the external configuration of the image forming apparatus when the apparatus cover is open. [Figure 4] FIG. 2 is a perspective view showing the external configuration of the image forming apparatus when the fixing unit is removed. [Diagram 5] FIG. 2 is an enlarged cross-sectional view showing the configuration of a fixing unit and its surrounding area. [Figure 6] FIG. 2 is a perspective view showing the external configuration of the fixing unit as viewed from the front. [Figure 7] FIG. 2 is a perspective view showing the external configuration of the fixing unit when viewed obliquely from above and on the front side. [Figure 8] FIG. 2 is an enlarged perspective view showing the external configuration of a left handle and its surrounding area. [Figure 9] FIG. 2 is an enlarged perspective view showing the internal configuration of the left handle and its surrounding area. [Figure 10] 10 is a cross-sectional view showing a cross section taken along the line AA shown in FIG. 9. [Figure 11] 10 is a cross-sectional view showing a cross section taken along line BB shown in FIG. 9. [Figure 12] 4 is an enlarged perspective view showing a left portion of the fixing unit housing when it is accommodated in the fixing unit accommodating section; FIG. [Figure 13] FIG. 4 is a partial cross-sectional view showing the configuration of a link member. [Figure 14] 11 is a cross-sectional view showing a cross section of a handle located immediately before being tilted. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, modes for carrying out the invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.

[0012] [1. Configuration of image forming device] 1 and 2 show the configuration of an image forming apparatus 1 according to the present embodiment. This image forming apparatus 1 is a color printer that forms (i.e., prints) an image on paper by an electrophotographic method. Note that FIG. 1 is a perspective view showing the external configuration of the image forming apparatus 1, and FIG. 2 is a side cross-sectional view showing the internal configuration of the image forming apparatus 1.

[0013] First, the external configuration of the image forming device 1 will be described. As shown in Fig. 1, the image forming device 1 has a device housing 2 having a substantially rectangular parallelepiped shape as an exterior. Here, the direction from the front surface 2f to the rear surface 2b of the device housing 2 is defined as the rear direction, the direction from the rear surface 2b to the front surface 2f is defined as the front direction, the direction from the lower side to the upper side of the device housing 2 is defined as the upper direction, the direction from the upper side to the lower side of the device housing 2 is defined as the lower direction, the direction from the right side to the left side of the device housing 2 is defined as the left direction, and the direction from the left side to the right side of the device housing 2 is defined as the right direction.

[0014] The device housing 2 is composed of a substantially box-shaped housing main body 2m with an opening 3 (see the perspective view of FIG. 3) on the top surface, and a lid-shaped device cover 2c that forms the top surface of the device housing 2 and covers the opening (hereinafter, referred to as the body-side opening) 3 of the housing main body 2m. As shown in FIG. 2, the device cover 2c has a device cover rotation shaft 4 extending in the left-right direction provided at the rear end, which is rotatably supported by a bearing portion (not shown) provided at the upper end of the rear end of the housing main body 2m. As a result, as shown in FIG. 3, the device cover 2c can be opened by rotating the front side in a direction away from the housing main body 2m around the device cover rotation shaft 4 (not shown in FIG. 3), and can be closed by rotating the front side in a direction toward the housing main body 2m. When the device cover 2c is opened, the inside of the image forming device 1 is exposed from the body-side opening 3 of the housing main body 2m, allowing access to the inside.

[0015] In this regard, the state of the device cover 2c will be referred to as the closed state when it is completely closed, covering the opening 3 on the main body side, as shown in FIG. 1, and as the open state when it is fully open, exposing the inside from the opening 3 on the main body side, as shown in FIG. 3.

[0016] 1 and 2, the device cover 2c has a recessed portion on its top surface, and this recessed portion forms a stacker 5 for stacking (accumulating) paper. In other words, the device cover 2c has the stacker 5 on its top surface, which is the outer periphery. The stacker 5 has a stack surface (i.e., bottom surface) 5s, which is the surface on which paper is stacked, that slopes gently upward from the rear end to the front end. The image forming device 1 is configured to stack paper discharged forward from a paper discharge port 6 provided on the rear wall surface 5b of the stacker 5 on the stack surface 5s of the stacker 5.

[0017] Furthermore, the device cover 2c is provided with a cover-side opening 7 at the rear of the stacker 5. The cover-side opening 7 is a hole that is long in the left-right direction and opens the rear of the stacker 5 and both the left and right outer parts thereof.

[0018] In the image forming apparatus 1, the top surface of the fixing unit 8, which is detachably attached to the housing main body 2m, is exposed to the outside from the cover side opening 7. The fixing unit 8 will be described in detail later. The top surface of the fixing unit 8 closes the cover side opening 7 and is shaped to form the rear part of the stacker 5 (i.e., the rear parts of the stacking surface 5s and the left and right side wall surfaces 5w of the stacker 5) and both the left and right outer parts thereof. The rear wall surface 5b of the stacker 5 is a part of the housing main body 2m. In other words, the stacking surface 5s and the side wall surfaces 5w of the stacker 5 are formed by the device cover 2c and the fixing unit 8, and the rear wall surface 5b is formed by the housing main body 2m.

[0019] Furthermore, handles 9 are provided on the top surface of the fixing unit 8 on both the left and right outer parts of the stacker 5. As shown in the perspective view of Fig. 4, the image forming apparatus 1 is configured so that the fixing unit 8 attached to the housing main body 2m can be removed from the housing main body 2m through the cover side opening 7 of the apparatus cover 2c by grasping the handle 9 exposed from the cover side opening 7 of the apparatus cover 2c and pulling it upward while the apparatus cover 2c is kept in the closed state. The image forming apparatus 1 is also configured so that the fixing unit 8 can be attached to the housing main body 2m through the cover side opening 7 of the apparatus cover 2c by grasping the handle 9 to lift the fixing unit 8 and inserting it through the cover side opening 7 of the apparatus cover 2c.

[0020] A control unit 10 that controls the entire image forming apparatus 1 is provided at a predetermined position inside the housing main body 2m. Although omitted in Fig. 1, a display panel that can be touched and displays various information, various operation buttons, and the like are provided at predetermined positions on the housing main body 2m or the device cover 2c.

[0021] Next, the internal configuration of the image forming apparatus 1 will be described. As shown in Fig. 2, inside the apparatus housing 2, various parts are arranged along a transport path R along which paper M is transported. That is, inside the apparatus housing 2, approximately at the center in the vertical direction, four image forming units 20 (20K, 20Y, 20M, 20C) corresponding to each color of developer (for example, four colors of toner: black (K), yellow (Y), magenta (M), and cyan (C)) handled by the image forming apparatus 1 are arranged in a line in the front-rear direction along the transport path R.

[0022] Each image forming unit 20 (20K, 20Y, 20M, 20C) has an LED head 21 (21K, 21Y, 21M, 21C), a photoconductor drum 22 (22K, 22Y, 22M, 22C), and a toner storage section 23 (23K, 23Y, 23M, 23C). Each image forming unit 20 is hardware that forms a toner image on the surface of the photoconductor drum 22 by irradiating and exposing the surface of the photoconductor drum 22 with light using the LED head 21, and then causes toner supplied from the toner storage section 23 to adhere to the electrostatic latent image.

[0023] Furthermore, inside the device housing 2, a transfer unit 24 is provided below the four image forming units 20. The transfer unit 24 has a circular conveyor belt 25 that is provided so as to be able to move freely in the front-rear direction along the conveyor path R, and transfer rollers 26 (26K, 26Y, 26M, 26C) that are disposed below the photoconductor drums 22 (22K, 22Y, 22M, 22C) facing each other with the conveyor belt 25 in between.

[0024] Each transfer roller 26 is a member that transfers the toner image of each color formed on the photosensitive drum 22 to the paper M by charging the paper M with a polarity opposite to that of the toner when the paper M passes between the photosensitive drum 22 and the conveyor belt 25.

[0025] Further, inside the device housing 2, below the transfer unit 24 (i.e., at the bottom of the device housing 2), a paper tray 27 for storing paper M is provided. Further, inside the device housing 2, a pair of transport rollers for transporting paper M is provided on a transport path R between the paper tray 27 and the transfer unit 24.

[0026] Furthermore, inside the device housing 2, a fixing unit 8 is provided downstream in the paper transport direction (i.e., rearward) of the transfer unit 24. The fixing unit 8 includes a heating roller 28 and a backup roller 29 disposed below the heating roller 28 and facing it with the transport path R in between, and is a device that fixes the toner image transferred to the paper M by the transfer unit 24 onto the paper M by applying heat and pressure to the toner image by the heating roller 28 and the backup roller 29.

[0027] Furthermore, inside the device housing 2, a pair of discharge rollers that discharges the paper M from the paper discharge port 6 to the stacker 5 is provided on the transport path R between the fixing unit 8 and the paper discharge port 6. The internal configuration of the image forming device 1 is as described above.

[0028] 2, the image forming apparatus 1 is arranged with the portions other than the paper tray 27 tilted with respect to the bottom surface of the apparatus housing 2. For example, the four image forming units 20 and the fuser 8 are each tilted toward the front side of the apparatus housing 2 with respect to the bottom surface of the apparatus housing 2, and are arranged with their positions in the up-down direction shifted. This allows the length of the apparatus housing 2 in the front-to-rear direction to be shorter than in the case where the portions other than the paper tray 27 of the image forming apparatus 1 are arranged parallel to the bottom surface of the apparatus housing 2.

[0029] [2. Configuration of the fixing unit and its surrounding parts] Next, the configuration of the fixing unit 8 and its surrounding parts will be described in more detail. Note that, here, only the configuration of the parts related to the attachment and detachment of the fixing unit 8 will be mainly described among the configuration of the fixing unit 8 and its surrounding parts.

[0030] Fig. 5 shows the configuration of the fixing unit 8 and its surrounding parts. Note that Fig. 5 is an enlarged cross-sectional view showing the configuration of the fixing unit 8 and its surrounding parts, with the device cover 2c in a closed state and the fixing unit 8 attached to the housing main body 2m.

[0031] As shown in FIG. 5, the housing main body 2m is provided with a fixing unit housing section 30 for detachably housing the fixing unit 8 below the cover side opening 7 of the device cover 2c in the closed state.

[0032] As shown in Fig. 4 as well as Fig. 5, the fuser unit 8 has an exterior fuser unit housing 40 in the shape of a substantially rectangular parallelepiped that is long in the left-right direction. The fuser unit housing 40 is accommodated in the fuser unit housing section 30 of the housing main body 2m with the top surface exposed to the outside from the cover side opening 7. The fuser unit housing section 30 is adapted to accommodate the fuser unit housing 40 in a state in which it is tilted forward. For this reason, in the image forming apparatus 1, when the fuser unit 8 is removed, the fuser unit housing 40 is pulled out obliquely upward and forward, and when the fuser unit 8 is installed, the fuser unit housing 40 is inserted obliquely downward and rearward.

[0033] The fuser housing 40 has an exposed top surface that is long in the left-right direction and is formed by the fuser cover 40c. The fuser cover 40c has a recess in the center in the left-right direction, and this recess forms the rear of the stacker 5 (i.e., the rears of the stack surface 5s and the left and right side wall surfaces 5w).

[0034] Here, of the entire fuser cover 40c, the portion 40s that forms the stack surface 5s of the stacker 5 is referred to as the stack surface forming portion 40s, and the portion 40w that forms the side wall surface 5w is referred to as the side wall surface forming portion 40w. In contrast, of the entire device cover 2c, the portion 50s that forms the front portion of the stack surface 5s of the stacker 5 is referred to as the stack surface forming portion 50s, and the portions 50w that form the front portions of the left and right side wall surfaces 5w of the stacker 5 are referred to as the side wall surface forming portions 50w.

[0035] The stack surface forming portion 40s and the side wall surface forming portion 40w of the fuser cover 40c are surfaces that are extensions of the stack surface forming portion 50s and the side wall surface forming portion 50w of the device cover 2c, and a stacker 5 is formed by the stack surface forming portion 40s and the side wall surface forming portion 40w of the fuser cover 40c and the stack surface forming portion 50s and the side wall surface forming portion 50w of the device cover 2c.

[0036] Furthermore, the fuser cover 40c is provided with a handle 9 (FIG. 1) on each of the left and right outer parts of the stacker 5. The left and right handles 9 can be rotated between an upright state in which they stand up and protrude upward from the fuser cover 40c as shown in FIG. 4, and a tilted state in which they are tilted toward the center in the left-right direction (toward the inside in the longitudinal direction of the top surface of the fuser housing 40) so as to be accommodated in the fuser cover 40c as shown in FIG. 1. When attaching or detaching the fuser 8, the user can hold the left and right handles 9 in the upright state. The configuration of the handles 9 and their surroundings will be described in detail later.

[0037] Further, on the upper surface of the fuser housing 40, a sub-cover 41 is attached separately from the fuser cover 40c, to cover the gap Sp1 between the front end of the stack surface forming portion 40s of the fuser housing 40 housed in the fuser housing portion 30 and the rear end of the stack surface forming portion 50s of the device cover 2c in the closed state. The sub-cover 41 is attached to the fuser cover 40c so as to cover the front part of the fuser cover 40c. In other words, the front part of the upper surface of the fuser housing 40 has a double structure of the fuser cover 40c and the sub-cover 41, and the fuser cover 40c and the sub-cover 41 form the rear part of the stacker 5. Here, of the entire sub-cover 41, the part 41s that forms the stack surface 5s of the stacker 5 is called the stack surface forming part 41s, and the part 41w that forms the side wall surface 5w is called the side wall surface forming part 41w.

[0038] The sub-cover 41 has a sub-cover rotation shaft 42 extending in the left-right direction provided at the rear ends of the left and right side wall surface forming portions 41w, which is rotatably supported by a bearing portion (not shown) provided at the rear of the side wall surface forming portion 40w of the fuser cover 40c. As a result, the sub-cover 41 can be opened by rotating the stack surface forming portion 41s of the sub-cover 41 in a direction away from the stack surface forming portion 40s of the fuser cover 40c (counterclockwise in FIG. 5) around the sub-cover rotation shaft 42, and can be closed by rotating the stack surface forming portion 41s of the sub-cover 41 in a direction approaching the stack surface forming portion 40s of the fuser cover 40c (clockwise in FIG. 5).

[0039] Furthermore, the sub-cover 41 is biased by a biasing member (not shown) in a direction in which the stack surface forming portion 41s of the sub-cover 41 approaches the stack surface forming portion 40s of the fixing unit cover 40c (that is, in a closing direction).

[0040] In addition, since the front end of the stack surface forming portion 41s of the sub-cover 41 overlaps with the stack surface forming portion 50s of the device cover 2c, when the device cover 2c is opened, the stack surface forming portion 41s of the sub-cover 41 is pushed upward by the stack surface forming portion 50s of the device cover 2c, and the sub-cover 41 opens together with the device cover 2c. Furthermore, when the device cover 2c is closed, the sub-cover 41 closes together with the device cover 2c due to the biasing force of the biasing member. In this way, the sub-cover 41 covers the gap Sp1 and opens and closes in accordance with the opening and closing of the device cover 2c.

[0041] 6(A) shows an external perspective view of the fuser 8 seen from the front, and a connector 43 is provided at the lower end of the fuser housing 40 on one end side (e.g., the left end side) in the longitudinal direction (left-right direction) so as to protrude downward. A gear portion 44 is provided at the lower end of the fuser housing 40 on the other end side (e.g., the right end side) in the longitudinal direction so as to protrude downward.

[0042] As shown in FIG. 6B, when the fuser housing 40 is housed in the fuser housing 30, the connector 43 of the fuser housing 40 is adapted to be fitted from above into the connector 31 provided at the bottom of the fuser housing 30. When the connector 43 is fitted into the connector 31, the fuser 8 can receive power from the image forming apparatus 1 and can transmit and receive various signals to and from the image forming apparatus 1. When the fuser housing 40 is housed in the fuser housing 30, the gear portion 44 of the fuser housing 40 is adapted to be engaged from above into the gear portion 32 provided at the bottom of the fuser housing 30. When the gear portion 44 is engaged with the gear portion 32, the fuser 8 can receive driving force from the image forming apparatus 1.

[0043] [3. Structure of the handle and its surrounding parts] Next, the handle 9 of the fixing unit 8 and the configuration of the surrounding area will be described in detail. As shown in Figs. 7(A) and (B) which are external perspective views of the fixing unit 8 as viewed diagonally from above and ahead, the handles 9 are provided on both the left and right sides of the fixing unit cover 40c (i.e., on both the left and right sides of the upper end of the fixing unit housing 40). The handle 9 shown in Fig. 7(A) is in an upright position, while the handle 9 shown in Fig. 7(B) is in a tilted position. The left and right handles 9 are symmetrical and have the same basic configuration, so here, the left handle 9 will be mainly described.

[0044] 8(A) and (B) show the external configuration of the handle 9 and the external configuration of the surrounding area, and Fig. 9(A) and (B) show the external configuration of the handle 9 and the internal configuration of the surrounding area. Note that the handle 9 shown in Fig. 8(A) and Fig. 9(A) is in an upright state, and the handle 9 shown in Fig. 8(B) and Fig. 9(B) is in a tilted state.

[0045] 8(A), (B), 9(A), and (B), the handle 9 is made up of a roughly U-shaped gripping portion 60 which is the portion that the user grips, and an attachment portion 61 which extends from one end of the U-shape of the gripping portion 60 to the other end and is the portion that is attached to the fuser housing 40, and is generally in a roughly D-shaped ring shape. The handle 9 is also provided with a rotating shaft 62 which extends along the extension direction of the attachment portion 61 on the attachment portion 61, and the rotating shaft 62 protrudes from one end and the other end of the attachment portion 61 in the extension direction.

[0046] As shown in Figs. 8A and 8B, the handle 9 is attached to the left end of a recess 70, which is provided in the left portion of the upper end of the fuser housing 40 and has approximately the same size as the handle 9, with the mounting portion 61 attached in a direction such that the rotation shaft 62 (see Figs. 9A and 9B) is in the front-rear direction. Here, as shown in Figs. 9A and 9B, the rotation shaft 62 protruding from each of the front and rear ends of the mounting portion 61 is inserted into shaft holes 71h located on the front and rear sides of the recess 70, which are provided in the frame 71 of the fuser housing 40. In this way, the mounting portion 61 of the handle 9 is supported by the frame 71 of the fuser housing 40 so as to be rotatable about the rotation shaft 62 extending in the front-rear direction.

[0047] The handle 9 can transition between an upright state and a tilted state by rotating about the rotation shaft 62. As shown in FIG. 8A, the upright state is a state in which the handle 9 stands up almost vertically with respect to the bottom surface 70b of the recess 70 (i.e., with respect to the upper surface of the fuser housing 40) so that the grip portion 60 is located above the mounting portion 61. As shown in FIG. 8B, the tilted state is a state in which the handle 9 is tilted almost parallel to the bottom surface 70b of the recess 70 and almost the entire handle 9 is housed in the recess 70 so that the grip portion 60 is located on the right side of the mounting portion 61.

[0048] 9B, the handle 9 and the frame 71 of the fuser housing 40 have a detent mechanism 80 for holding the handle 9 in an upright position, and a detent mechanism 90 for holding the handle 9 in a tilted position. The upright detent mechanism 80 and the tilt detent mechanism 90 will be described below in order.

[0049] In addition to Figure 9(B), as shown in Figure 10(A), which is a cross-sectional view of the handle 9 and frame 71 cut along the AA cutting line in Figure 9(A), the upright retention detent mechanism 80 is composed of an upright retention arm portion 81 provided on the mounting portion 61 of the handle 9, and an upright retention arm engagement portion 82 provided on the frame 71 of the fixation unit housing 40.

[0050] Two standing support arms 81 are provided at a distance in the axial direction in the central portion of the attachment part 61. The two standing support arms 81 are provided to be located at the lower end of the attachment part 61 (below the rotation shaft 62) when the handle 9 is in an upright state, and are cantilever leaf springs extending from the left end side to the right end side of the lower end of the attachment part 61 (from the outside to the inside in the longitudinal direction of the fixation unit housing 40 (FIG. 7)).

[0051] In other words, the two upright retaining arm portions 81 are arranged to be positioned at the lower end of the mounting portion 61 when the handle 9 is in an upright state, and are cantilevered leaf spring members extending from the left end side of the lower end of the mounting portion 61 in the opposite direction to the rotational direction (clockwise direction indicated by arrow Ar1 in Figure 10(A)) when the handle 9 rotates from an upright state to a tilted state.

[0052] The tip of the standing support arm portion 81 is located to the right of the center P of the rotation shaft 62 (inner in the longitudinal direction of the top surface of the fixing unit housing 40). Furthermore, the tip of the standing support arm portion 81 is provided with a protrusion 81p that protrudes downward.

[0053] In contrast to this, two standing support arm engaging portions 82 are provided axially spaced apart below the axial center of the mounting portion 61. The two standing support arm engaging portions 82 are provided so as to be located below the two standing support arm portions 81 when the handle 9 is in an upright state, and form flat portions that form part of the bottom surface 70b of the recess 70.

[0054] 10(A), when the handle 9 is in an upright state, the upright holding arm 81 is maintained in the upright state by the protrusion 81p abutting against the upright holding arm engaging portion 82. That is, at this time, the upright holding arm engaging portion 82 is positioned within the movement trajectory of the protrusion 81p shown by the dotted line in the figure (the side closer to the rotation shaft 62), so that the handle 9 is restricted from rotating in the clockwise direction indicated by the arrow Ar1 in the figure, and is maintained in the upright state.

[0055] Here, for example, suppose that a user applies a force of a predetermined magnitude or more to the handle 9 in the tilting direction indicated by the arrow Ar2 in an attempt to rotate the handle 9 from an upright state to a tilted state. Then, as shown in FIG. 10B, the upright support arm 81 bends in a direction in which the tip side approaches the rotation axis 62. As a result, the upright support arm engaging portion 82 of the handle 9 is positioned outside the movement trajectory of the protrusion 81p, and the protrusion 81p rotates in the clockwise direction in the figure while sliding on the upright support arm engaging portion 82. At this time, the elastic force of the upright support arm 81 presses the protrusion 81p against the upright support arm engaging portion 82 below, so that a force is applied to the upright support arm engaging portion 82 to push it downward as indicated by the arrow Ar3.

[0056] Then, the protrusion 81p of the standing support arm 81 moves to the left of the center P of the rotation shaft 62 and climbs over the standing support arm engagement portion 82, whereby the handle 9 is released from the standing state and continues to rotate in the clockwise direction in the figure. Specifically, the handle 9 is released from the standing state when it rotates about 10 degrees in the clockwise direction in the figure from the standing state.

[0057] In this way, the upright retention detent mechanism 80 retains the handle 9 in an upright position, and when a force of a predetermined magnitude or greater is applied in a direction tilting the handle 9 (i.e., a force sufficient to move the protrusion 81p to the left side of the rotation axis 62), it releases the upright position and allows the handle 9 to be rotated to a tilted position.

[0058] When the handle 9 is transitioned from the tilted state to the upright state, the operation of the upright holding detent mechanism 80 is the opposite to that when the handle 9 is transitioned from the upright state to the tilted state. That is, when the handle 9 rotates in the upright direction and reaches just before the upright state, the upright holding arm portion 81 abuts against the upright holding arm engagement portion 82. When the user applies a force of a predetermined magnitude or more to the handle 9 in the upright direction, the tip side of the upright holding arm portion 81 bends in the direction approaching the rotation shaft 62. As a result, the upright holding arm engagement portion 82 of the handle 9 is positioned outside the movement trajectory of the protrusion 81p, and the protrusion 81p rotates while sliding on the upright holding arm engagement portion 82. At this time, the elastic force of the upright holding arm portion 81 presses the protrusion 81p against the upright holding arm engagement portion 82 below, so that the force pressing downward as indicated by the arrow Ar3 is applied to the upright holding arm engagement portion 82.

[0059] When the protrusion 81p of the upright holding arm portion 81 moves to the right of the center P of the rotation shaft 62 and reaches an upright state, the upright holding arm portion 81 overcomes the upright holding arm engagement portion 82 and returns to its original shape, thereby maintaining the handle 9 in an upright state.

[0060] In this way, when a force of a predetermined magnitude or more is applied in the direction of raising the handle 9 just before it reaches the raised state (i.e., a force capable of moving the protrusion 81p to the right side of the rotation shaft 62), the upright retention detent mechanism 80 rotates the handle 9 into the raised state and maintains it in the raised state.

[0061] Next, a description will be given of the tilt-retaining detent mechanism 90. As shown in Fig. 9(B) and Fig. 11(A), which is a cross-sectional view of the handle 9 and the frame 71 taken along the line BB in Fig. 9(B), the tilt-retaining detent mechanism 90 is made up of a tilt-retaining arm portion 91 provided on the mounting portion 61 of the handle 9, and a tilt-retaining arm engagement portion 92 provided on the frame 71 of the fixing unit housing 40.

[0062] Two tilting support arms 91 are provided at one end and the other end (i.e., axially outward of the upright support arm 81) of the attachment part 61. The two tilting support arms 91 are provided so as to be located at the lower end of the attachment part 61 (below the rotation shaft 62) when the handle 9 is in a tilted state, and are cantilever leaf springs extending from the right end side to the left end side of the lower end of the attachment part 61 (from the inside to the outside in the longitudinal direction of the fixation unit housing 40).

[0063] In other words, the two tilting retaining arm portions 91 are arranged to be positioned at the lower end of the mounting portion 61 when the handle 9 is in a tilted state, and are cantilevered leaf spring members extending from the right end side of the lower end of the mounting portion 61 in the opposite direction to the rotational direction when the handle 9 rotates from the tilted state to the upright state (the counterclockwise direction indicated by arrow Ar4 in Figure 11(A)).

[0064] The tip of the inclined support arm 91 is located to the left of the center P of the rotation shaft 62 (outside in the longitudinal direction of the top surface of the fixing unit housing 40). Furthermore, the tip of the inclined support arm 91 is provided with a protrusion 91p that protrudes downward.

[0065] In contrast to this, two tilt-retaining arm engaging portions 92 are provided below one end side and the other end side of the attachment portion 61 in the axial direction. The two tilt-retaining arm engaging portions 92 are provided so as to be located below the two tilt-retaining arm portions 91 when the handle 9 is in the tilted state, and are composed of a flat portion 92s that forms part of the bottom surface 70b of the recess 70 (see FIG. 8(B)) and a recess 92c formed in the flat portion 92s.

[0066] 11(A), when the handle 9 is in the tilted state, the tilt-retaining arm 91 maintains the tilted state by fitting the protrusion 91p into the recess 92c of the tilt-retaining arm engagement part 92. In other words, at this time, the right end wall of the recess 92c of the tilt-retaining arm engagement part 92 is located within the movement trajectory of the protrusion 91p shown by the dotted line in the figure (the side closer to the rotation shaft 62), so that the handle 9 is restricted from rotating in the counterclockwise direction indicated by the arrow Ar4 in the figure, and is maintained in the tilted state.

[0067] Here, for example, suppose that a user applies a force of a certain level or more to the handle 9 in the upright direction indicated by the arrow Ar5 in order to rotate the handle 9 from the tilted state to the upright state. Then, as shown in FIG. 11B, the tilt-holding arm 91 bends in the direction in which the tip side approaches the rotation axis 62. Then, the handle 9 rotates until the protrusion 91p of the tilt-holding arm 91 overcomes the right end wall of the recess 92c of the tilt-holding arm engagement portion 92, and the tilted state is released, and the handle 9 continues to rotate in the counterclockwise direction in the figure. Specifically, the tilted state of the handle 9 is released when it rotates about 10 degrees counterclockwise from the tilted state. At this time, the elastic force of the tilt-holding arm 91 presses the protrusion 91p against the tilt-holding arm engagement portion 92 below, so that the tilt-holding arm engagement portion 92 is subjected to a force pressing downward indicated by the arrow Ar6.

[0068] In this way, the tilted detent mechanism 90 holds the handle 9 in a tilted state, and when a force of a predetermined magnitude or more is applied in a direction to raise the handle 9 upright (i.e., a force sufficient to remove the protrusion 91p from the recess 92c), the tilted state is released and the handle 9 can be rotated to an upright state.

[0069] When the handle 9 is transitioned from the upright state to the tilted state, the operation of the tilt-retaining detent mechanism 90 is the opposite to that when the handle 9 is transitioned from the tilted state to the upright state. That is, when the handle 9 rotates in the tilting direction and reaches a position immediately before the tilted state, the tilt-retaining arm portion 91 abuts against the flat portion 92s of the tilt-retaining arm engagement portion 92. When the user applies a force of a predetermined magnitude or more to the handle 9 in the tilting direction, the handle 9 rotates further while the tip side of the tilt-retaining arm portion 91 bends in a direction approaching the rotation axis 62. At this time, the elastic force of the tilt-retaining arm portion 91 presses the protrusion portion 91p against the tilt-retaining arm engagement portion 92 below, so that the tilt-retaining arm engagement portion 92 is subjected to a force pressing downward as indicated by the arrow Ar6. When the handle 9 reaches the tilted state, the protrusion 91p climbs over the flat portion 92s of the tilt-retaining arm engagement portion 92 and enters the recess 92c, causing the tilt-retaining arm portion 91 to return to its original shape, thereby retaining the handle 9 in the tilted state.

[0070] In this way, when a force greater than a predetermined value (i.e., a force capable of fitting the protrusion 91p into the recess 92c) is applied in a direction tilting the handle 9 just before it is in the tilted state, the tilt retention detent mechanism 90 rotates the handle 9 into a tilted state and retains it in the tilted state.

[0071] 8A and 8B, the fixing unit housing 40 is provided with a lever 100 that protrudes from an opening 40h provided in the left side surface 40L of the fixing unit housing 40 when the left handle 9 is in an upright position. The lever 100 is linked to the rotation of the handle 9, and protrudes from the opening 40h when the handle 9 is tilted from the upright position.

[0072] 12A and 12B show the left side of the fuser housing 40 when it is housed in the fuser housing 30. In addition, in FIG. 12A, the handle 9 is in an upright position, and in FIG. 12B, the handle 9 is in a tilted position.

[0073] The fuser housing 30 has a lever fitting hole 30h at a position facing an opening 40h provided on the left side surface 40L of the housed fuser housing 40. When the handle 9 is tilted from the upright position while the fuser housing 40 is housed in the fuser housing 30, a lever 100 protruding from the opening 40h of the fuser housing 40 fits into the lever fitting hole 30h. Although not shown, a lever is also provided on the right side surface of the fuser housing 40, which protrudes from the opening when the right handle 9 is in the upright position, and this lever fits into the lever fitting hole of the fuser housing 30.

[0074] In this way, when the handle 9 is tilted down from the upright position while the fuser housing 40 is housed in the fuser housing section 30, the lever 100 protruding from the fuser housing 40 fits into the lever fitting hole 30h of the fuser housing section 30, thereby fixing the fuser housing 40 to the fuser housing 40.

[0075] Incidentally, the lever 100 does not protrude from the fuser unit housing 40 during the section in which the handle 9 rotates (i.e., from the upright state to the tilted state) where the upright state is maintained by the upright retention detent mechanism 80 (i.e., while rotating about 10 degrees from the upright state), but protrudes from the fuser unit housing 40 during the other sections. In other words, the fuser 8 cannot be removed from the image forming apparatus 1 unless the handle 9 is in the upright state.

[0076] 12(A) and (B), the fixing unit housing 30 is provided with a lock switch 101 that is turned on when pressed by the tip of the lever 100 when the lever 100 is fitted into the lever fitting hole 30h. Although not shown, a similar lock switch is also provided on the right side of the fixing unit housing 30. In the image forming apparatus 1, the control unit 10 recognizes that the fixing unit 8 is completely installed when both the left and right lock switches 101 are on. Furthermore, if at least one of the left and right lock switches 101 is turned off during printing, for example, the control unit 10 recognizes that the fixing unit 8 has been removed and stops printing.

[0077] Next, a brief description will be given of the link member 102 that links the handle 9 and the lever 100 with each other using Figures 9(A), (B) and 13(A)-(C). Note that Figures 13(A)-(C) are plan views of the link member 102 as seen from the front, and are cross-sectional views of the handle 9.

[0078] The link member 102 is a rod-shaped member that is long in the vertical direction and is located between the center of the axial direction (front-rear direction) of the attachment part 61 of the handle 9 and the lever 100 that is located below it and extends in the left-right direction. The lower end of this link member 102 is connected to the lever 100, and the upper end is supported by the attachment part 61 of the handle 9 so as to be rotatable about a rotation shaft 62. In other words, the link member 102 rotates about the rotation shaft 62 to move the lever 100 in a direction protruding from the fuser housing 40 and in a direction retracting into the fuser housing 40.

[0079] Furthermore, the mounting portion 61 of the handle 9 is provided with a lever abutment portion 63 in the axial center portion (between the two upright holding arms 81) that abuts against the upper end portion of the link member 102. This lever abutment portion 63 abuts against the upper end portion of the link member 102 (the portion below the rotation shaft 62) just before the handle 9 reaches the upright state, and by pushing the link member 102 when the handle 9 rotates to the upright state, the link member 102 is rotated in the same direction as the handle 9.

[0080] Furthermore, the lever 100 is biased in a direction protruding from the fixing unit housing 40 by a biasing member 103 such as a spring.

[0081] Here, the operations of the handle 9, lever 100, and link member 102 will be briefly described with reference to Figures 13(A) to (C). As shown in Figure 13(A), when the handle 9 is in a tilted state, the lever abutment portion 63 of the handle 9 is separated from the upper end of the link member 102. At this time, the lever 100 is in a state of protruding from the fuser housing 40, as indicated by the dotted line in the figure, due to the biasing force of the biasing member 103.

[0082] When the handle 9 is raised from this state, as shown in Fig. 13(B), just before the handle 9 reaches the raised state, the lever abutment portion 63 of the handle 9 abuts against the upper end of the link member 102. At this point, the lever 100 still protrudes from the fuser housing 40.

[0083] 13C, when the handle 9 is further raised, the lever abutment portion 63 of the handle 9 presses the upper end of the link member 102 to the right (the inner side in the longitudinal direction of the fuser housing 40), causing the link member 102 to rotate counterclockwise around the rotation shaft 62 as indicated by the arrow Ar7 in the figure. At this time, the lower end of the link member 102 moves to the right, which is the direction in which the lever 100 is accommodated in the fuser housing 40. As a result, the lever 100 connected to the lower end of the link member 102 moves to the right against the biasing force and is accommodated in the fuser housing 40.

[0084] In this way, when the handle 9 is raised, the link member 102 stores the lever 100 in the fuser housing 40. In other words, when the handle 9 is tilted from the raised state, the link member 102 causes the lever 100 to protrude from the fuser housing 40. This concludes the description of the configuration of the handle 9 and its surrounding parts.

[0085] [4. Operation when installing the fixing unit] Next, a description will be given of the operation when the fixing unit 8 is attached to the image forming apparatus 1. As described above, when attaching the fixing unit 8 to the image forming apparatus 1, the user grasps the handle 9 in an upright state to lift the fixing unit 8, and inserts it through the cover-side opening 7 provided in the apparatus cover 2c of the image forming apparatus 1. Then, the user inserts the fixing unit 8 until the entire fixing unit 8 fits into the apparatus housing 2 of the image forming apparatus 1.

[0086] As a result, the fixing unit 8 is accommodated in the fixing unit accommodating section 30 provided in the device housing 2, the connector 43 provided on the fixing unit 8 is engaged with the connector 31 provided on the fixing unit accommodating section 30, and the gear portion 44 provided on the fixing unit 8 is engaged with the gear portion 32 provided on the fixing unit accommodating section 30.

[0087] Incidentally, in order to reliably fit the connector 43 of the fixing unit 8 to the connector 31 of the fixing unit housing 30, a force set as a standard value of the connectors 43, 31 is required. In the image forming apparatus 1 of the present embodiment, this standard value is set to 2 kgf. In other words, a force of at least 2 kgf is required to reliably fit the connector 43 and the connector 31.

[0088] On the other hand, in the image forming apparatus 1 of the present embodiment, the weight of the fixing unit 8 is 1.5 kgf. Therefore, if the fixing unit 8 is inserted from the cover side opening 7 and then further inserted downward by its own weight alone, the force (1.5 kgf) due to the weight of the fixing unit 8 is smaller than the force (2 kgf) required to securely fit the connector 43 to the connector 31, and therefore the connector 43 of the fixing unit 8 cannot be securely fitted to the connector 31 of the fixing unit housing part 30.

[0089] In other words, when inserting the fixing unit 8 through the cover side opening 7 to attach the fixing unit 8 to the image forming device 1, if the insertion force is too weak, the connector 43 of the fixing unit 8 cannot be securely engaged with the connector 31 of the fixing unit accommodating section 30, and the fixing unit 8 may not be securely attached to the image forming device 1.

[0090] Therefore, in the image forming apparatus 1 of this embodiment, the fixing unit 8 is provided with a tilt retention detent mechanism 90 for retaining the handle 9 in a tilted state, and when the user transitions the handle 9 to the tilted state, a force equal to or greater than a predetermined value set in the tilt retention detent mechanism 90 is applied to the handle 9, and this force is used to securely engage the connector 43 of the fixing unit 8 with the connector 31 of the fixing unit accommodating section 30.

[0091] That is, the user grasps the handle 9 in an upright state, lifts the fixing unit 8, and inserts it through the cover-side opening 7 provided in the device cover 2c of the image forming device 1. Then, the user inserts the fixing unit 8 downward until the entire fixing unit 8 is accommodated in the device housing 2.

[0092] After inserting the fixing unit 8, the user tilts the handle 9 from the upright state to transition to the tilted state. At this time, the user rotates the handle 9 from the upright state to just before the tilted state, and then applies a force to the handle 9 that is equal to or greater than the predetermined force set in the tilt retention detent mechanism 90, thereby rotating the handle 9 to the tilted state.

[0093] 14, the elastic force of the tilting support arm portion 91 presses the protrusion 91p against the tilting support arm engagement portion 92 below, so that the tilting support arm engagement portion 92 receives a downward pressing force, as indicated by arrow Ar6, from the tilting support arm portion 91. This force of the tilting support arm portion 91 pressing the tilting support arm engagement portion 92 downward is used as a force for fitting the connector 43 of the fixation unit 8 into the connector 31 of the fixation unit housing portion 30 located below.

[0094] In other words, if the force with which the tilting support arm portion 91 presses the tilting support arm engagement portion 92 downward is Fa, the force required to securely engage the connector 43 with the lower connector 31 is Fc (2kgf), and the weight of the fixing unit 8 is Ff (1.5kgf), then if Fa+Ff>Fc, the connector 43 can be securely engaged with the lower connector 31.

[0095] In this case, if the force Fa with which the tilting support arm portion 91 presses the tilting support arm engagement portion 92 downward is greater than 0.5kgf obtained by subtracting Ff (1.5kgf) from Fc (2kgf), the connector 43 can be securely fitted into the lower connector 31.

[0096] For this reason, the tilt-retaining detent mechanism 90 has an appropriate displacement amount of the tip end of the tilt-retaining arm portion 91 when it bends, a thickness of the tilt-retaining arm portion 91, and the like selected so that Fa>0.5 kgf.

[0097] In fact, when the fixing unit 8 is accommodated in the fixing unit accommodating section 30, the fixing unit 8 comes into contact with the fixing unit accommodating section 30 and receives a certain reaction force from the fixing unit accommodating section 30. For this reason, it is preferable to set the force Fa with which the tilting support arm portion 91 presses the tilting support arm engagement portion 92 downward, taking this reaction force into consideration.

[0098] That is, if the maximum value of the reaction force that the fixing unit 8 receives from the fixing unit accommodating portion 30 is Fo, then if Fa+Ff>Fc+Fo, the connector 43 can be reliably fitted into the lower connector 31.

[0099] In this case, if the force Fa with which the tilting support arm portion 91 presses the tilting support arm engagement portion 92 downward is greater than 0.74kgf, which is the sum of Fc (2kgf) and Fo (e.g., 0.24kgf) minus Ff (1.5kgf), then the connector 43 can be securely fitted into the lower connector 31.

[0100] For this reason, in the tilt-retaining detent mechanism 90 of this embodiment, the amount of displacement of the tip of the tilt-retaining arm portion 91 when it bends and the thickness of the tilt-retaining arm portion 91 are appropriately selected so that Fa>0.74 kgf. Specifically, the amount of displacement is set to 0.6 mm±0.2 mm, and the thickness is set to 2.5 mm.

[0101] By doing so, in the image forming apparatus 1 of the present embodiment, when the fixing unit 8 is attached to the image forming apparatus 1, the connector 43 of the fixing unit 8 can be reliably fitted into the connector 31 of the fixing unit accommodating section 30, and the fixing unit 8 can be reliably attached to the image forming apparatus 1. This completes the description of the operation when the fixing unit 8 is attached to the image forming apparatus 1.

[0102] [5. Summary and Effects] As described so far, the image forming device 1 of this embodiment has a stacker 5 on its outer periphery for stacking paper sheets M as a medium, and is equipped with a device housing 2 in which the stacker 5 is provided with a cover side opening 7, an image forming unit 20 as an image forming section provided in the device housing 2 for forming an image on the paper sheets M, and a fuser 8 which is detachably provided in the device housing 2 and can be attached to the device housing 2 via the cover side opening 7 as an opening, and fuses the image formed on the paper sheets M by the image forming unit 20 to the paper sheets M, and when the fuser 8 is attached to the device housing 2, a part (upper end) of the fuser 8 is exposed from the cover side opening 7 provided in the stacker 5 to form part of the stacker 5, and a connector 43 of the fuser 8 and a connector 31 of the device housing 2 are fitted together.

[0103] Furthermore, the fixing unit 8 has a handle 9 at an exposed portion (upper end portion) exposed from the cover-side opening 7, which can be moved between an upright state in which it stands relative to the exposed portion and a tilted state in which it tilts relative to the exposed portion.

[0104] Furthermore, the image forming apparatus 1 is provided with a tilted state retention detent mechanism 90 that transitions the handle 9 to a tilted state and retains it in the tilted state when a predetermined or greater force is applied to the handle 9 when the handle 9 is transitioned to the tilted state.

[0105] More specifically, the tilt-retaining detent mechanism 90 has a tilt-retaining arm portion 91 as a tilt-retaining elastic member and a tilt-retaining arm engaging portion 92 as a tilt-retaining abutment member, and when the handle 9 is rotated from an upright state to a tilted state, a protrusion 91p of the tilt-retaining arm portion 91 abuts against a flat portion 92s of the tilt-retaining arm engaging portion 92 before the handle 9 reaches the tilted state. When a force of a predetermined level or more is applied to the handle 9 in a direction to rotate the handle 9 to the tilted state, the tilt-retaining arm portion 91 abuts against the tilt-retaining arm engaging portion 92 and bends as the handle 9 rotates, and when the handle 9 reaches the tilted state, the protrusion 91p of the tilt-retaining arm portion 91 gets over the flat portion 92s of the tilt-retaining arm engaging portion 92 and enters the recess 92c, and the tilt-retaining arm portion 91 returns to its original shape, thereby retaining the tilted state. When the tilting support arm portion 91 comes into contact with the tilting support arm engagement portion 92 and bends while the handle 9 rotates, the elastic force of the tilting support arm portion 91 pushes the fixing unit 8 in a direction in which the connector 43 of the fixing unit 8 fits into the connector 31 of the device housing 2.

[0106] By doing so, in the image forming apparatus 1, for example, after a user grasps the handle 9 in an upright position and inserts the fixing unit 8 through the cover-side opening 7, a force equal to or greater than a predetermined value set in the tilt retention detent mechanism 90 is applied to the handle 9 in order to transition the handle 9 from the upright position to the tilted position, and this force can be used to reliably engage the connector 43 of the fixing unit 8 with the connector 31 of the device housing 2. Thus, the image forming apparatus 1 can reliably mount the fixing unit 8 in the device housing 2.

[0107] In addition, the image forming apparatus 1 is provided with an upright retention detent mechanism 80 that transitions the handle 9 to the upright state and retains it in the upright state when a predetermined or greater force is applied to the handle 9 when the handle 9 is transitioned to the upright state.

[0108] More specifically, the upright retention detent mechanism 80 has an upright retention arm portion 81 as an upright retention elastic member and an upright retention arm engaging portion 82 as an upright retention abutment member, and when the handle 9 is rotated from the inclined state to the upright state, the protrusion 81p of the upright retention arm portion 81 abuts against the upright retention arm engaging portion 82 just before the handle 9 reaches the upright state. When a force of a predetermined magnitude or more is applied to the handle 9 in a direction to rotate the handle 9 to the upright state, the upright retention arm portion 81 abuts against the upright retention arm engaging portion 82 and bends as the handle 9 rotates, and when the handle 9 reaches the upright state, the protrusion 81p of the upright retention arm portion 81 overcomes the upright retention arm engaging portion 82 and the upright retention arm portion 81 returns to its original shape, thereby maintaining the upright state.

[0109] This allows the handle 9 to be held upright, for example, when attaching or detaching the fixing unit 8 to or from the device housing 2, so that the user can easily perform the attachment or detachment operation by grasping the handle 9.

[0110] Furthermore, when the handle 9 of the image forming device 1 is held in an upright position by the upright holding detent mechanism 80, it is housed in the fuser housing 40 of the fuser 8, and in other cases, it is provided with a lever 100 that protrudes from both the left and right side surfaces of the fuser housing 40 (the housing portion housed inside the device housing 2), and the lever 100 protruding from the fuser housing 40 fits into the fuser housing section 30 of the device housing 2, thereby fixing the fuser housing 40 to the fuser housing section 30.

[0111] Furthermore, the image forming device 1 is provided with a lock switch 101 as a detection unit for detecting a lever 100 protruding from the fixing unit housing 40 housed in the fixing unit housing 30, and when the lock switch 101 detects the lever 100, the control unit 10 determines that the fixing unit 8 is attached to the device housing 2.

[0112] In this way, in the image forming device 1, for example, after the fixing unit 8 is attached to the device housing 2, even if a user tries to pick up paper M discharged into the stacker 5 and their hand or the like hits the handle 9, the handle 9 will not transition from a tilted state to an upright state, and it is possible to avoid a situation in which the handle 9 unintentionally stands up and the fixing unit 8 is released from its fixed position, or the fixing unit 8 is determined to have been removed from the device housing 2 and printing is stopped.

[0113] Furthermore, in the image forming apparatus 1, when the handle 9 is held in an upright state by the upright holding detent mechanism 80, the lever 100 is accommodated in the fuser housing 40, and by raising the handle 9, the lever 100 can be held in a state in which it does not protrude from the fuser housing 40. This makes it possible to avoid a situation in which, for example, when attaching the fuser 8 to the device housing 2, the lever 100 protrudes from the fuser housing 40 and hits the device housing 2, resulting in damage.

[0114] [6. Other embodiments] [6-1. Another embodiment 1] In the above-described embodiment, the standing-holding detent mechanism 80 is configured by the standing-holding arm portion 81 formed of a leaf spring member and the standing-holding arm engagement portion 82 formed of a flat portion that engages (abuts) with the standing-holding arm portion 81. Here, for example, the standing-holding arm portion 81 may be provided on the side of the fixing unit housing 40, and the standing-holding arm engagement portion 82 may be provided on the side of the handle 9. In addition, without being limited to this, another detent mechanism may be used instead of the standing-holding detent mechanism 80 as long as the mechanism transitions the handle 9 to the standing state and maintains the standing state when a force of a predetermined level or more is applied to the handle 9 when the handle 9 transitions to the standing state. For example, a detent mechanism using a latch structure or a detent mechanism using a rotation stop structure using an elastic member such as a spring may be used.

[0115] Similarly, with respect to the tilt retention detent mechanism 90, for example, the tilt retention arm portion 91 may be provided on the fixation unit housing 40 side and the tilt retention arm engagement portion 92 may be provided on the handle 9 side, or a different detent mechanism may be used as long as it transitions the handle 9 to a tilted state and maintains it in the tilted state when a force of a predetermined level or more is applied to the handle 9 when the handle 9 is transitioned to a tilted state.

[0116] [6-2. Other embodiment 2] In the above-described embodiment, the fixing unit 8 is provided with an upright retention detent mechanism 80 that holds the handle 9 in an upright position, and a tilted retention detent mechanism 90 that holds it in a tilted position, but this is not limited to the above. For example, the upright retention detent mechanism 80 may be omitted, and only the tilted retention detent mechanism 90 may be provided.

[0117] [6-3. Other embodiment 3] Furthermore, in the above-described embodiment, the lever 100 is accommodated in the fuser housing 40 of the fuser 8 when the handle 9 is held in the upright state by the upright holding detent mechanism 80, and protrudes from the fuser housing 40 in other cases. However, without being limited thereto, for example, the lever 100 may protrude from the fuser housing 40 only when the handle 9 is held in the tilted state by the tilted holding detent mechanism 90.

[0118] [6-4. Other embodiment 4] Furthermore, in the above-described embodiment, one lock switch 101 for detecting the lever 100 protruding from each of the left and right sides of the fixing unit housing 40 is provided on each of the left and right sides of the fixing unit housing 30, but this is not limited to the above, and the lock switch 101 may be provided only on either the left or right side.

[0119] [6-5. Other embodiment 5] Furthermore, in the above-described embodiment, the sub-cover 41 is provided on the fixing unit 8, but this is not limiting, and the sub-cover 41 may be omitted.

[0120] [6-6. Other embodiment 6] Furthermore, in the above-described embodiment, the present invention is applied to the image forming apparatus 1, which is an electrophotographic color printer, but the present invention is not limited to this, and can be applied to an image forming apparatus having a different configuration from the image forming apparatus 1, as long as it is an image forming apparatus equipped with a fixing device. For example, the present invention may be applied to an image forming apparatus configured to transfer a toner image formed by an image forming unit to an intermediate transfer belt and then to a medium. The present invention may also be applied to a monochrome image forming apparatus having one image forming unit, or a color image forming apparatus having four or more image forming units. Furthermore, the present invention may be applied to an image forming apparatus that forms an image on a medium other than paper. Furthermore, the present invention may be applied to an image forming apparatus such as an electrophotographic copier, facsimile, or multifunction machine.

[0121] [6-7. Other embodiment 7] Furthermore, the present invention is not limited to the above-described embodiments, and the scope of application of the present invention extends to embodiments in which some or all of the above-described embodiments are combined in any manner, or in which some of the embodiments are extracted. [Industrial Applicability]

[0122] The present invention can be widely used in image forming apparatuses such as electrophotographic printers equipped with a fixing unit, copiers, facsimiles, and multifunction machines. [Explanation of symbols]

[0123] 1...image forming apparatus, 2...apparatus housing, 2m...housing main body, 2c...apparatus cover, 5...stacker, 7...cover side opening, 8...fuser, 9...handle, 20...image forming unit, 30...fuser housing, 30h...lever fitting hole, 31...connector, 32...gear portion, 40...fuser housing, 40c...fuser cover, 40h...opening, 43...connector, 44...gear portion, 80...standing hold detent mechanism, 81...standing hold arm portion, 81p...projection portion, 82...standing hold arm engagement portion, 90...tilting hold detent mechanism, 91...tilting hold arm portion, 91p...projection portion, 92...tilting hold arm engagement portion, 92s...flat portion, 92c...recess, 100...lever, 101...lock switch, 102...link member, M...paper.

Claims

1. a device housing having a stacker on an outer periphery thereof for stacking media, the stacker having an opening; an image forming unit provided in the device housing and configured to form an image on a medium; a fixing unit that is detachably provided in the device housing and can be attached to and detached from the device housing through the opening, and fixes an image formed on a medium by the image forming unit to the medium; Equipped with when the fixing unit is inserted through the opening and attached to the device housing, a part of the fixing unit is exposed through the opening provided in the stacker to form a part of the stacker, and a connector of the fixing unit and a connector of the device housing are fitted together, the fixing unit has a handle at an exposed portion exposed through the opening, the handle being capable of transitioning between an upright state in which the handle stands with respect to the exposed portion and an inclined state in which the handle inclines with respect to the exposed portion; Further, a tilted state holding detent mechanism is provided which, when a predetermined force or more is applied to the handle when the handle is transitioned from the upright state to the tilted state, transitions the handle to the tilted state and holds the handle in the tilted state, the handle is held by the fixing device so as to be rotatable about a rotation axis between the upright state and the tilted state, The tilt-retaining detent mechanism is located below the rotation axis when the handle is in the tilted state. Image forming device.

2. After the fixing unit is inserted through the opening, when the handle is transitioned from the upright state to the tilted state, if a force equal to or greater than the predetermined value set in the tilt-retaining detent mechanism is applied to the handle, the force pushes the fixing unit in a direction in which a connector of the fixing unit is fitted into a connector of the device housing. The image forming apparatus according to claim 1 .

3. The tilt-retaining detent mechanism has a tilt-retaining elastic member and a tilt-retaining abutment member, and when the handle is rotated from the upright state to the tilted state, the tilt-retaining elastic member and the tilt-retaining abutment member abut each other just before the handle reaches the tilted state, and when a force equal to or greater than the predetermined value is applied to the handle in a direction to rotate the handle to the tilted state, the tilt-retaining elastic member abuts against the tilt-retaining abutment member and deforms as the handle rotates, and when the handle reaches the tilted state, the tilt-retaining elastic member overcomes the tilt-retaining abutment member and returns to its original shape, thereby retaining the tilted state. The image forming apparatus according to claim 2 .

4. When the handle rotates while the tilt-retaining elastic member abuts against the tilt-retaining abutment member and deforms, the fixing unit is pushed by the elastic force of the tilt-retaining elastic member in a direction in which the connector of the fixing unit is fitted into the connector of the device housing. The image forming apparatus according to claim 3 .

5. The device further includes an upright holding detent mechanism that, when a predetermined force or more is applied to the handle when the handle is transitioned from the inclined state to the upright state, transitions the handle to the upright state and holds the handle in the upright state.

5. The image forming apparatus according to claim 1.

6. The upright retention detent mechanism has an upright retention elastic member and an upright retention abutment member, and when the handle is rotated from the inclined state to the upright state, the upright retention elastic member and the upright retention abutment member come into contact with each other just before the handle reaches the upright state, and when a force equal to or greater than the predetermined value is applied to the handle in a direction to rotate the handle to the upright state, the upright retention elastic member abuts against the upright retention abutment member and deforms as the handle rotates, and when the handle reaches the upright state, the upright retention elastic member overcomes the upright retention abutment member and returns to its original shape, thereby maintaining the upright state. The image forming apparatus according to claim 5 .

7. the fixing unit has a lever that protrudes from a housing portion that is housed inside the device housing when the handle is in the tilted state, When the handle transitions from the upright state to the tilted state with the fixing unit attached to the device housing, the lever projects from the housing portion and fits into the device housing.

7. The image forming apparatus according to claim 1.

8. The lever does not protrude from the storage portion when the handle is in the upright state, and protrudes from the storage portion when the handle is in the reclined state and when the handle is between the upright state and the reclined state. The image forming apparatus according to claim 7.

9. a detection unit provided in the device housing for detecting the lever protruding from the housing portion of the fixing unit; 9. The image forming apparatus according to claim 7 or 8.

Images