Image forming device

Abstract

To provide an image forming apparatus that can prevent a transfer belt from contacting a table.SOLUTION: An image forming apparatus comprises: a housing 80; a transfer unit 20 that is detachably attached to the housing 80; and lock levers 70 that are attached to the transfer unit 20 and lock the transfer unit 20 and the housing 80 to each other. The lock lever 70 is configured to be transitioned to a lock state for locking the transfer unit 20 and the housing 80 to each other and a release state for releasing the locking between the transfer unit 20 and the housing 80, and when it is transitioned to the release state, a tip of a leg part projecting downward is located below a bottom face of the transfer unit.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus including a transfer unit that is detachable from a housing. [Background technology]

[0002] Conventionally, in electrophotographic image forming apparatuses, a toner image is formed on an image carrier, the toner image is transferred to paper, and the toner image is fixed to the paper by a fixing device to form an image. In recent years, in consideration of the ease of assembly and maintenance, image forming apparatuses have been proposed that include multiple internal devices, such as a transfer belt unit, an image forming unit, and a fixing unit, that are detachably attached to a housing (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-167788 A [Patent Document 2] JP 2017-068039 A Summary of the Invention [Problem to be solved by the invention]

[0004] The image forming device described in Patent Document 1 comprises an apparatus housing, a number of photosensitive drums arranged side by side in an easily attachable and detachable manner in the apparatus housing, a transfer belt stretched across a number of rollers, a belt displacement control mechanism for controlling displacement of the belt posture of the transfer belt, an opening / closing member that is opened and closed when the photosensitive drums are attached to or detached from the apparatus housing, a lock lever that locks the opening / closing member, and a linkage mechanism that engages with the lock lever on one side and with the belt displacement control mechanism on the other side, and controls displacement of the posture of the transfer belt when the lock lever is rotated.

[0005] Incidentally, when the transfer belt unit is detached from the device housing and placed on a stand, the distance between the stand and the transfer belt is short, and there is a risk that foreign matter on the stand may come into contact with and damage the transfer belt.

[0006] The image forming apparatus described in Patent Document 2 includes an intermediate transfer unit that is attached to an apparatus main body that includes multiple photosensitive drums so as to be adjacent to the multiple photosensitive drums. The intermediate transfer unit has an intermediate transfer belt that carries a toner image, a transfer roller that is arranged opposite the photosensitive drum, a pair of side walls that support the intermediate transfer belt so that it can rotate, and legs that are arranged at the lower ends of the side walls and abut against a predetermined installation surface. One of the side walls has a protruding shaft, and the legs are movable legs that are rotatable around the shaft and can change their position.

[0007] In the above-mentioned image forming apparatus, gears, coil springs, and the like are provided to rotate the movable leg, and a complex mechanism is required.

[0008] The present invention has been made to solve the above-mentioned problems, and has an object to provide an image forming apparatus that can prevent the transfer belt from contacting the base without providing a complex mechanism. [Means for solving the problem]

[0009] The image forming apparatus of the present invention is an image forming apparatus comprising a housing, a transfer unit that is detachable from the housing, and a lock lever that is attached to the transfer unit and engages the transfer unit with the housing, wherein the transfer unit has a transfer belt suspended on a plurality of rollers, and the lock lever is configured to transition between a locked state in which the transfer unit engages the housing and a released state in which the transfer unit releases the engagement between the transfer unit and the housing, and when in the released state, the tip of the leg that protrudes downward is positioned below the bottom surface of the transfer unit.

[0010] In the image forming apparatus according to the present invention, the lock lever may be configured so that, when in the locked state, a tip of the leg portion is positioned above a bottom surface of the transfer unit.

[0011] In the image forming device of the present invention, the housing may have a storage space below the transfer unit for accommodating an attachment unit attached to the housing, and the transfer unit attached to the housing may be configured such that the tip of the leg of the lock lever in the released state overlaps a portion of the storage space.

[0012] In the image forming apparatus according to the present invention, the transfer unit may have a pair of transfer frames supporting both ends of the roller, and the transfer frames may be configured to have a protrusion on their bottom surface that protrudes downward beyond the surrounding area.

[0013] In the image forming apparatus of the present invention, the lock lever may be attached to the transfer frame on the front side in the insertion direction of the transfer unit into the housing, and the protrusion may be provided on the transfer frame on the rear side in the insertion direction.

[0014] In the image forming apparatus according to the present invention, the lock lever may be attached to the transfer unit via a regulating mechanism, and the regulating mechanism may be configured to regulate the movement of the lock lever to maintain the released state or the locked state.

[0015] In the image forming apparatus of the present invention, the regulating mechanism may be configured to regulate the transition of the lock lever from the released state to the locked state when the transfer unit is removed from the housing, and to allow the transition from the released state to the locked state when the transfer unit is attached to the housing.

[0016] In the image forming apparatus of the present invention, the lock lever may be attached to the transfer unit via a rotating shaft, the leg extending in a direction away from the rotating shaft, and configured to rotate around the rotating shaft as a fulcrum and transition between the released state and the locked state.

[0017] In the image forming apparatus according to the present invention, the lock lever may be configured to slide relative to the transfer unit to transition between the released state and the locked state. Effect of the Invention

[0018] According to the present invention, the lock lever that locks the transfer unit in the released state itself serves as a leg that supports the transfer unit, so that when the transfer unit is removed from the housing and placed on a stand, the transfer belt can be prevented from contacting the stand. [Brief description of the drawings]

[0019] [Figure 1] 1 is a schematic side view of an image forming apparatus according to a first embodiment of the present invention. [Diagram 2] FIG. 4 is a schematic side view showing a part of the housing and a transfer unit. [Diagram 3] FIG. 2 is a perspective view showing a transfer unit. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] 13 is an enlarged side view showing an end portion of the front side transfer frame. FIG. [Figure 7] FIG. 2 is an enlarged perspective view showing a part of a housing. [Figure 8] 11 is an enlarged side view showing the positional relationship between the housing and the lock lever in the released state. FIG. [Figure 9] 11 is an enlarged side view showing the positional relationship between the housing and the lock lever in a locked state. FIG. [Figure 10]FIG. 11 is a schematic side view showing the positional relationship between a housing and a lock lever in an unlocked state in the second embodiment of the present invention. [Figure 11] FIG. 11 is a schematic side view showing the positional relationship between a housing and a lock lever in a locked state in a second embodiment of the present invention. [Figure 12] FIG. 11 is an enlarged side view showing an end portion of a front side transfer frame in a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] (First embodiment) An image forming apparatus according to a first embodiment of the present invention will now be described with reference to the drawings.

[0021] FIG. 1 is a schematic side view of an image forming apparatus according to a first embodiment of the present invention.

[0022] The image forming apparatus 1 according to the first embodiment of the present invention includes a main body section that performs image formation, a document reading section 44 and a document transport section 45 provided at an upper portion, and a paper feeder 50 provided at a lower portion. The paper feeder 50 is composed of an apparatus main body 52 and a paper feed cassette 51 that is inserted into the apparatus main body 52.

[0023] Document reading unit 44 has document placement table 43 on its upper surface on which a document is placed, reads the image of the document on document placement table 43, creates image data, and transmits the image data to image forming apparatus 1. Document transport unit 45 automatically transports the document onto document placement table 43. Document transport unit 45 is rotatably attached to image forming apparatus 1, and can be rotated to open the top of document placement table 43, allowing the document to be placed manually.

[0024] The main body of the image forming apparatus 1 is provided with an exposure device 11, a developing device 12, a photosensitive drum 13, a cleaning device 14, a charger 15, a transfer unit 20, a fixing device 17, a paper output tray 39, and a paper transport path R1, and forms multi-color and monochrome images on a specified paper sheet according to image data transmitted from the outside or from a document reading unit 44.

[0025] Image data handled by the image forming apparatus 1 corresponds to a color image using each of the colors black (K), cyan (C), magenta (M), and yellow (Y). Therefore, four developing devices 12, photoconductor drums 13, chargers 15, and cleaning devices 14 are provided so as to form four types of latent images corresponding to each color, and are set to black, cyan, magenta, and yellow, respectively, to form four image stations Pa, Pb, Pc, and Pd.

[0026] The photoconductor drum 13 is disposed approximately in the center of the image forming apparatus 1. The charger 15 uniformly charges the surface (circumferential surface) of the photoconductor drum 13 to a predetermined potential. The exposure device 11 exposes the surface of the photoconductor drum 13 to light to form an electrostatic latent image. The development device 12 develops the electrostatic latent image on the surface of the photoconductor drum 13 to form a toner image on the surface of the photoconductor drum 13. Through the series of operations described above, a toner image of each color is formed on the surface of each photoconductor drum 13. The cleaning device 14 removes and collects residual toner on the surface of the photoconductor drum 13 after development and image transfer.

[0027] The transfer unit 20 includes a transfer driving roller 22, a transfer driven roller 23, and an intermediate transfer belt 21 (an example of a transfer belt). The intermediate transfer belt 21 is suspended between the transfer driving roller 22, which is rotated by a connected drive source, and the transfer driven roller 23, and is driven together with the transfer driven roller 23 in response to the rotation of the transfer driving roller 22. The intermediate transfer belt 21 moves in a circular movement in the direction of the arrow C, and residual toner is removed and collected by an intermediate transfer belt cleaning device 25. The toner images of each color formed on the surface of each photoconductor drum 13 are transferred and superimposed in sequence, forming a color toner image on the surface of the intermediate transfer belt 21. The detailed structure of the transfer unit 20 will be described later with reference to FIGS. 3 and 4.

[0028] The image forming apparatus 1 further includes a secondary transfer device 26 including a transfer roller 26a. A nip area is formed between the transfer roller 26a and the intermediate transfer belt 21, and the paper conveyed through the paper conveying path S is sandwiched in the nip area and conveyed. When the paper passes through the nip area, the toner image on the surface of the intermediate transfer belt 21 is transferred to the paper.

[0029] The image forming apparatus 1 forms an image using paper sheets stored in a paper feed cassette 51. The paper feed device 50 is provided below the exposure device 11. The paper discharge tray 39 is provided below the document reading unit 44, and is a tray for placing paper sheets on which an image has been formed.

[0030] The paper is pulled out from the paper feed cassette 51 by the paper feed roller 33 and fed to the S-shaped paper transport path R1. Further arranged along the paper transport path R1 are a transport roller 35, a registration roller 34, a secondary transfer device 26, a fixing device 17, and a paper discharge roller 36.

[0031] The registration roller 34 temporarily holds the paper being transported from the paper feed cassette 51, and transports the paper to the transfer roller 26a at a timing when the leading edge of the toner image on the photosensitive drum 13 and the leading edge of the paper are aligned. The transport roller 35 is a small roller for assisting in the transport of the paper.

[0032] The fixing device 17 receives a sheet of paper on which an unfixed toner image has been formed, and fixes the toner image on the sheet by sandwiching the sheet between a heating roller 31 and a pressure roller 32 and applying heat and pressure to the sheet. After the fixing, the sheet is discharged onto a discharge tray 39 by a discharge roller 36.

[0033] Furthermore, when forming an image on the back side of the paper as well as the front side, the paper is transported in the reverse direction from the discharge rollers 36 to the reversal path Rr to turn the paper over, and the paper is guided again to the registration rollers 34, where an image is formed on the back side in the same manner as on the front side, and the paper is then discharged to the discharge tray 39.

[0034] In the image forming apparatus 1, the transfer unit 20 is detachably attached to a housing 80 provided in the main body. Next, the relationship between a part of the housing 80 and the transfer unit 20 will be described with reference to FIG.

[0035] FIG. 2 is a schematic side view showing a part of the housing and a transfer unit.

[0036] FIG. 2 shows a part of the housing 80 provided on the front side of the image forming apparatus 1, and shows a state in which the transfer unit 20 is attached to this housing 80. The housing 80 is provided with a space for accommodating the transfer unit 20 and an opening corresponding to the space, and is structured so that the transfer unit 20 is inserted through the opening. When the transfer unit 20 is inserted into the opening of the housing 80 from the front side toward the back side in the insertion direction to the back of the space to be accommodated, the housing 80 and the front end of the transfer unit 20 shown in FIG. 2 are adjacent to each other. A lock lever 70 is attached to the front end of the transfer unit 20. When the transfer unit 20 is accommodated in the housing 80, the transfer unit 20 and the housing 80 are locked by transitioning the lock lever 70 from the release state to the lock state.

[0037] In addition, the housing 80 is provided with an accommodation space SA below the space that accommodates the transfer unit 20, which accommodates an attachment unit different from the transfer unit 20. The relationship between the accommodation space SA and the transfer unit 20 will be described together with the structure of the transfer unit 20, which will be described later.

[0038] FIG. 3 is a perspective view showing the transfer unit, and FIG. 4 is a side view showing the transfer unit.

[0039] 3 shows the transfer unit 20 as viewed from the bottom side, and FIG. 4 shows the transfer unit 20 as viewed from the side on the front side. The transfer unit 20 has a pair of transfer frames that support both ends of the transfer drive roller 22 and the transfer driven roller 23. Note that the transfer unit 20 may be provided with rollers other than the transfer drive roller 22 and the transfer driven roller 23, and may be configured to support other rollers by the transfer frames. In the following, in order to distinguish between the pair of transfer frames, the transfer frame on the front side in the insertion direction may be referred to as the front transfer frame 60, and the transfer frame on the rear side in the insertion direction may be referred to as the rear transfer frame 90.

[0040] The bottom surface of the transfer frame is provided with protruding portions that protrude downward from the surroundings. Specifically, the front transfer frame 60 is provided with front protruding portions 61 at several positions spaced apart in the left-right direction, and the rear transfer frame 90 is provided with rear protruding portions 91 at several positions spaced apart in the left-right direction. The front protruding portions 61 and the rear protruding portions 91 protrude downward from the intermediate transfer belt 21 suspended on the transfer driving roller 22 and the transfer driven roller 23. In this way, by providing the protruding portions on the transfer frame, it is possible to prevent the intermediate transfer belt 21 from contacting the platform.

[0041] The above-mentioned lock lever 70 is attached to the front transfer frame 60. In this embodiment, two lock levers 70 are attached to both ends in the left-right direction of the front transfer frame 60. In the transfer unit 20 shown in Figs. 3 and 4, the lock lever 70 is in a released state. When the lock lever 70 is in a released state, the tip of the leg 71 protruding downward is positioned below the bottom surface of the transfer unit 20 (for example, the front protruding portion 61 and the rear protruding portion 91).

[0042] When the transfer unit 20 is removed from the housing 80, the lock lever 70 is released. In the released state, the lock lever 70 itself that locks the transfer unit 20 becomes a leg that supports the transfer unit 20. Therefore, when the transfer unit 20 removed from the housing 80 is placed on a stand, the intermediate transfer belt 21 can be prevented from contacting the stand. In addition, since the lock lever 70 is attached to the front transfer frame 60, the operability when operating the lock lever 70 can be improved. Furthermore, when the transfer unit 20 is removed from the housing 80, the intermediate transfer belt 21 is lifted by the lock lever 70 and the rear protrusion 91 that are separated in the insertion direction, so that the intermediate transfer belt 21 can be reliably prevented from contacting the stand.

[0043] FIG. 5 is a perspective view showing a lock lever.

[0044] 5 shows the lock lever 70 removed from the transfer unit 20, as viewed from the side facing the front transfer frame 60. A shaft engaging portion 72 that engages with the front transfer frame 60 is provided approximately in the center of the lock lever 70. A leg portion 71 is provided at an end extending from the shaft engaging portion 72, and a lock portion 73 that engages with the housing 80 is provided at an end opposite to the leg portion 71. In this embodiment, the shaft engaging portion 72 is a boss having a hole.

[0045] The lock lever 70 has a claw portion 74 that protrudes from the surrounding area on the side facing the front transfer frame 60. The lock lever 70, including the claw portion 74, is made of an elastic material and is elastically deformed when pressed. A gap is provided around the claw portion 74, and the claw portion 74 is configured to be pushed into the inside of the lock lever 70 when pressed by the front transfer frame 60.

[0046] FIG. 6 is an enlarged side view showing an end portion of the front side transfer frame.

[0047] 6 shows an enlarged view of the end portion of the front transfer frame 60 to which the lock lever 70 is attached, with the lock lever 70 removed from the transfer unit 20. Note that while Fig. 6 shows an enlarged view of the left end portion in Fig. 4, the right end portion may have substantially the same structure with the left and right sides reversed, and detailed description thereof will be omitted.

[0048] The front side transfer frame 60 is provided with a shaft support portion 62 corresponding to the shaft engagement portion 72 and a restriction groove 63 corresponding to the claw portion 74. The shaft engagement portion 72 and the shaft support portion 62 combined together form a rotation axis that serves as a fulcrum when rotating the lock lever 70. In this embodiment, the shaft support portion 62 is a protrusion that is inserted into a hole provided in the shaft engagement portion 72.

[0049] The claw portion 74 and the restricting groove 63, when combined, constitute a restricting mechanism that restricts the movement of the lock lever 70. The restricting groove 63 is provided along a path that the claw portion 74 follows when the lock lever 70 is rotated. The restricting groove 63 has a release locking portion 63a provided at one end at a position corresponding to the claw portion 74 in the released state, a lock locking portion 63c provided at the other end at a position corresponding to the claw portion 74 in the locked state, and a shallow groove portion 63b provided between the release locking portion 63a and the lock locking portion 63c. The release locking portion 63a and the lock locking portion 63c are deep enough to accommodate the claw portion 74. The shallow groove portion 63b is formed shallower than the release locking portion 63a and the lock locking portion 63c, and presses the claw portion 74 in such a way that it is pushed in. The bottom surface of the restricting groove 63 may be inclined so that the depth gradually changes at the boundary between the release engaging portion 63a and the lock engaging portion 63c and the shallow groove portion 63b. In the shallow groove portion 63b, the claw portion 74 is pressed and a load is applied so that the lock lever 70 moves to the release engaging portion 63a or the lock engaging portion 63c. As a result, the lock lever 70 is restricted to maintain the release state or the lock state and not to stop in an incomplete state that does not fall into either of these states. In this way, the restricting mechanism temporarily determines the position of the lock lever 70, thereby restricting the transition to an unstable state between the release state and the lock state.

[0050] FIG. 7 is an enlarged perspective view showing a part of the housing.

[0051] 7 shows an enlarged view of a portion of the housing 80 shown in FIG. 2 that faces the lock lever 70. The housing 80 is provided with a lever insertion portion 81 into which the lock portion 73 of the lock lever 70 is inserted. Note that the lever insertion portion 81 does not have to be a hole that penetrates the housing 80, and may be a recess according to the size of the lock portion 73. The relationship between the lever insertion portion 81 and the lock portion 73 will be described with reference to FIGS. 8 and 9, which will be described later.

[0052] FIG. 8 is an enlarged side view showing the positional relationship between the housing and the lock lever in the released state, and FIG. 9 is an enlarged side view showing the positional relationship between the housing and the lock lever in the locked state.

[0053] 8 and 9 show an enlarged view of one of the lock levers 70 (the left side in FIG. 2) in the state where the transfer unit 20 is inserted into the housing 80. As shown in FIG. 8, in the released state, the lock portion 73 of the lock lever 70 does not protrude further toward the housing 80 than the end of the front transfer frame 60, so it does not prevent the transfer unit 20 from being inserted into the housing 80. In addition, the tip of the leg portion 71 overlaps with a part of the accommodation space SA (see FIG. 2) located below the transfer unit 20. When the transfer unit 20 is attached to the housing 80, if the lock lever 70 is left released, the leg portion 71 will prevent the attachment unit from being attached, so it is possible to prevent forgetting to lock it.

[0054] After the transfer unit 20 is inserted into the housing 80, as shown in Fig. 9, when the lock lever 70 is rotated around the rotation axis (shaft engagement portion 72) as a fulcrum and transitioned to a locked state, the lock portion 73 enters the lever insertion portion 81. In this state, the lock portion 73 is caught in the lever insertion portion 81, preventing the transfer unit 20 from being pulled out of the housing 80. Also, in the locked state, the tip of the leg portion 71 is positioned above the bottom surface of the transfer unit 20, so that the space below the transfer unit 20 can be effectively utilized.

[0055] Second embodiment Next, an image forming apparatus according to a second embodiment of the present invention will be described with reference to the drawings.

[0056] The second embodiment is different from the first embodiment in the structure near the end of the transfer unit 20. Note that the second embodiment has a configuration substantially similar to that of the first embodiment shown in Figures 1 to 9, so a description thereof will be omitted and only the differences will be described.

[0057] FIG. 10 is a schematic side view showing the positional relationship between the housing and the lock lever in an unlocked state in the second embodiment of the present invention, and FIG. 11 is a schematic side view showing the positional relationship between the housing and the lock lever in a locked state in the second embodiment of the present invention.

[0058] In the second embodiment, the structure of the portion where the lock lever 70 is attached to the front transfer frame 60 is different from that of the first embodiment, and the lock lever 70 is slid relative to the transfer unit 20 to transition between the unlocked state and the locked state. Specifically, the lock lever 70 has an engagement protrusion 75 instead of the shaft engagement portion 72, and the front transfer frame 60 has a slide hole 64 instead of the shaft support portion 62. The slide hole 64 is an elongated hole formed long in the vertical direction. The engagement protrusion 75 is fitted into the slide hole 64 and moves up and down along the slide hole 64. In the lock lever 70 in the first embodiment, the lock portion 73, the shaft engagement portion 72, and the leg portion 71 are arranged in a straight line, whereas in the lock lever 70 in the second embodiment, the lock portion 73 and the leg portion 71 extend in a direction intersecting each other, starting from the engagement protrusion 75. That is, the leg portion 71 extends downward, and the lock portion 73 extends toward the housing 80 side (to the left in FIG. 10).

[0059] As shown in Fig. 10, in the released state, the leg portion 71 protrudes downward beyond the front protrusion 61. The housing 80 is recessed so as not to overlap with the lock portion 73 in the released state, and a lever insertion portion 81 is provided above the lock portion 73. The lever insertion portion 81 is a groove that corresponds to the lock portion 73. When the lock lever 70 is slid upward from the released state shown in Fig. 10, it transitions to the locked state shown in Fig. 11.

[0060] 11, in the locked state, the leg portion 71 is located above the front protrusion 61, and the lock portion 73 is inserted into the lever insertion portion 81. In the present embodiment as well, in the locked state, the lock portion 73 is caught in the lever insertion portion 81, so that the transfer unit 20 is prevented from being pulled out from the housing 80.

[0061] Third embodiment Next, an image forming apparatus according to a third embodiment of the present invention will be described with reference to the drawings.

[0062] The third embodiment is different from the first embodiment in the structure near the end of the transfer unit 20. Note that the third embodiment has substantially the same configuration as the first and second embodiments shown in Figures 1 to 11, so a description thereof will be omitted and only the differences will be described.

[0063] FIG. 12 is an enlarged side view showing an end portion of a front side transfer frame in the third embodiment of the present invention.

[0064] 12 shows an enlarged view of the end of the front transfer frame 60 to which the lock lever 70 is attached, with the lock lever 70 removed from the transfer unit 20. The restricting groove 63 of the front transfer frame 60 has a restricting hole 63d that is open at a position corresponding to the release locking portion 63a. In the released state, when the claw portion 74 enters the restricting hole 63d, the claw portion 74 gets caught on the edge of the restricting hole 63d, so that the lock lever 70 is restricted from rotating.

[0065] The housing 80 is provided with a frame receiving portion 82 that faces the back surface of the front transfer frame 60 when the transfer unit 20 is attached. The frame receiving portion 82 has a restricting protrusion 83 that is provided at a position corresponding to the restricting hole 63d. When the transfer unit 20 is attached, the claw portion 74 is pressed by the restricting protrusion 83 that has entered the restricting hole 63d. When the claw portion 74 is pressed and rises out of the restricting hole 63d, the restriction of the lock lever 70 is released, and the lock lever 70 can be rotated to transition to the locked state.

[0066] As described above, when the printer is removed from the housing 80, the lock lever 70 is regulated to maintain the locked state, so that it is possible to prevent the lock lever 70 from moving unintentionally due to an impact or the like, causing the intermediate transfer belt 21 to come into contact with the base.

[0067] It should be noted that the embodiments disclosed herein are illustrative in all respects and are not intended to provide a basis for a restrictive interpretation. Therefore, the technical scope of the present invention is not interpreted solely by the above-described embodiments, but is defined by the claims. Furthermore, all modifications within the scope and meaning equivalent to the claims are included. [Explanation of symbols]

[0068] 1. Image forming device 20 Transcription Unit 60 Front transfer frame 61 Front protrusion 70 Lock lever 71 Legs 72 Shaft engagement part 73 Rock Club 74 Claw part 75 Engagement protrusion 80 Case 81 Lever insertion part 82 Frame support 83 Regulating protrusion 90 Rear transfer frame 91 Back protrusion

Claims

1. A housing and a transfer unit that is detachable from the housing; an image forming apparatus including a lock lever attached to the transfer unit and configured to lock the transfer unit and the housing, The transfer unit has a transfer belt suspended on a plurality of rollers, The lock lever is a lock state in which the transfer unit and the housing are locked, and a release state in which the transfer unit and the housing are released from the locked state, and when the transfer unit is in the release state, a tip of a leg protruding downward is positioned below a bottom surface of the transfer unit, The transfer unit is attached to the transfer unit via a regulating mechanism. The regulating mechanism is The movement of the lock lever is restricted to maintain the released state or the locked state, When the transfer unit is removed from the housing, the lock lever is restricted from transitioning from the release state to the lock state, and when the transfer unit is attached to the housing, the lock lever is permitted to transition from the release state to the lock state. An image forming apparatus comprising:

2. 2. The image forming apparatus according to claim 1, When the lock lever is in the locked state, the tip of the leg is positioned above the bottom surface of the transfer unit. An image forming apparatus comprising:

3. 3. The image forming apparatus according to claim 2, the housing has an accommodation space below the transfer unit for accommodating an attachment unit attached to the housing; The transfer unit attached to the housing has a tip of the leg of the lock lever in the released state overlapping a part of the accommodation space. An image forming apparatus comprising:

4. 4. The image forming apparatus according to claim 1, The transfer unit has a pair of transfer frames supporting both ends of the roller, The transfer frame has a protruding portion on the bottom surface that protrudes downward from the surrounding area. An image forming apparatus comprising:

5. 5. The image forming apparatus according to claim 4, the lock lever is attached to the transfer frame on the front side in an insertion direction of the transfer unit into the housing, The protrusion is provided on the transfer frame on the rear side in the insertion direction. An image forming apparatus comprising:

6. 6. The image forming apparatus according to claim 1, The lock lever is attached to the transfer unit via a rotation shaft, the leg portion extends in a direction away from the rotation shaft, and is configured to rotate about the rotation shaft as a fulcrum and transition between the release state and the lock state. An image forming apparatus comprising:

7. 6. The image forming apparatus according to claim 1, The lock lever is configured to slide relative to the transfer unit to transition between the released state and the locked state. An image forming apparatus comprising:

Images