Image forming apparatus

Abstract

To provide an image forming apparatus that allows easy replacement of a toner container even when the height of an apparatus body is lowered.SOLUTION: An image forming apparatus comprises: a plurality of container groups comprising a plurality of toner containers in which toners in different colors are stored; and a storage unit to which the toner containers are removably attached. The storage unit comprises: a side plate 51 that is provided with opening rows in which openings 53 are horizontally arranged through which the toner containers are taken in and out, side by side in a vertical direction for the respective container groups; a cover 61 that rotates to be in an opening posture for opening the openings 53 and a closing posture for closing the openings; a lock device that fixes the cover 61 rotating to be in the closing posture to the side plate; and a first stopper 105 that, when the cover 61 rotates to be in the opening posture, holds the cover at an opening angle of 90° or less relative to the side plate 53, and a second stopper 103 that holds the cover at an opening angle larger than 90°.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus equipped with a detachable toner container. [Background technology]

[0002] Conventional electrophotographic image forming devices are provided with a toner container for each color, and toner is supplied from each toner container to the corresponding developing device. When a toner container becomes empty, the image forming device is temporarily stopped and the toner container is replaced.

[0003] On the other hand, the image forming apparatus of Patent Document 1 includes an upper container group and a lower container group each consisting of four toner containers that contain toner of four colors (yellow, cyan, magenta, and black). The upper container group and the lower container group are housed in the toner storage section along upper and lower rows that run in the left-right direction. In this way, two toner containers are provided for each color. Even if one toner container becomes empty, toner can be supplied from the other toner container, thereby reducing the downtime of the image forming apparatus.

[0004] The toner container is attached to and detached from the container housing through openings formed in the side panels of the main body of the apparatus, and each opening is closed and opened by a cover to prevent toner leakage. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-22444 Summary of the Invention [Problem to be solved by the invention]

[0006] In the image forming apparatus described in Patent Document 1, the height of the apparatus body is somewhat high in order to accommodate the upper and lower container groups. Therefore, there is a demand for reducing the height of the apparatus body as much as possible. Lowering the height of the apparatus body in this way also shortens the distance between the upper and lower covers. This causes the rotation range of the cover to overlap with the space for pulling out the toner container, which causes the toner container pulled out through the opening to interfere with the open cover when replacing the toner container. Furthermore, since the number of toner containers increases, it is preferable that the cover can be easily opened and closed when replacing the toner container.

[0007] SUMMARY OF THE INVENTION In consideration of the above circumstances, an object of the present invention is to provide an image forming apparatus in which the toner container can be easily replaced even when the height of the apparatus main body is reduced. [Means for solving the problem]

[0008] In order to solve the above problem, the image forming apparatus of the present invention comprises a plurality of container groups consisting of a plurality of toner containers each containing toner of a different color, and a storage section to which the toner containers are attached and detached, the storage section comprising: a side plate having rows of openings in which the openings through which the toner containers are inserted and removed arranged horizontally, aligned in the vertical direction for each container group; a cover supported by a pivot provided at the lower end of each opening of the side plate and rotating between an open position that opens the opening and a closed position that closes the opening; a locking device that fixes the cover rotated to the closed position to the side plate; a first stopper that holds the cover at an opening angle relative to the side plate of 90° or less when the cover is rotated to the open position; and a second stopper that holds the cover at an opening angle greater than 90°.

[0009] In the present invention, the first stopper and the second stopper may be arranged to be spaced apart in a circumferential direction of the rotation shaft, and the first stopper may be rotatable in the up-down direction by elastic deformation.

[0010] In the present invention, the cover may have a first protrusion and a second protrusion arranged at a distance from each other in the circumferential direction of the pivot shaft, and when the cover is released from its fixation by the locking device, the cover rotates under its own weight until the first protrusion engages with the first stopper, and then by pushing down on the cover, the first protrusion pushes the first stopper, causing the first stopper to elastically deform and rotate, and the cover may rotate until the second protrusion engages with the second stopper.

[0011] In the present invention, when the cover is pressed down and then released, the first stopper elastically returns to its original position, and the cover rotates until the first protrusion is engaged by the first stopper.

[0012] In the present invention, the first stopper and the second stopper may be integral with each other.

[0013] In the present invention, the cover may be pressed down by the toner container being pulled out from the opening.

[0014] In the present invention, the cover may have a recess recessed in the thickness direction of the cover, and when the cover is rotated to the open position, the upper end of the cover below the cover may fit into the recess.

[0015] In the present invention, when the cover is rotated to the closed position, the center of gravity of the cover may be located outside the side plate with respect to the rotation shaft.

[0016] The present invention may be characterized in that it further includes a sensor that detects that the toner container is empty, and when the sensor detects that the toner container is empty, the locking device of the cover that opens and closes the opening corresponding to the toner container is released from its locking. [Effects of the Invention]

[0017] According to the present invention, even when the rotation range of the upper cover and the rotation range of the lower cover overlap, the upper and lower toner containers can be smoothly attached and detached without interfering with the cover in the open position. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a front view schematically illustrating an internal structure of an image forming apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a side view showing a toner container in the image forming apparatus according to the embodiment of the present invention. [Figure 3] FIG. 2 is a front view showing a front side plate in the image forming apparatus according to the embodiment of the present invention. [Figure 4] 1 is a front view showing an inner cover rotated to a closed position in an image forming apparatus according to an embodiment of the present invention; [Figure 5] 1 is a front view showing an inner cover rotated to an open position in an image forming apparatus according to an embodiment of the present invention; [Figure 6] 4 is a side cross-sectional view showing the inner cover and the outer cover rotated to a closed position in the image forming apparatus according to the embodiment of the present invention. FIG. [Figure 7] FIG. 2 is a perspective view showing an inner cover in the image forming apparatus according to the embodiment of the present invention. [Figure 8] FIG. 2 is a side view showing an inner cover in the image forming apparatus according to the embodiment of the present invention. [Figure 9] FIG. 2 is a perspective view showing a stopper member in the image forming apparatus according to the embodiment of the present invention. [Figure 10] 10 is a cross-sectional view showing a stopper member supported by a front side plate in an image forming apparatus according to one embodiment of the present invention. FIG. [Figure 11] FIG. 2 is a plan view showing a locking device in the image forming apparatus according to the embodiment of the present invention. [Figure 12]1 is a side view showing an inner cover rotated to an open position (opening angle 90°) in an image forming apparatus according to one embodiment of the present invention. [Figure 13] 1 is a side view showing an inner cover rotated to an open position (opening angle 120°) in an image forming apparatus according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] An image forming apparatus according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

[0020] The overall configuration of the image forming apparatus 1 will be described with reference to Fig. 1. Fig. 1 is a front view schematically showing the internal configuration of the image forming apparatus 1. Fr, Rr, L, and R shown in each figure indicate the front, rear, left, and right sides of the image forming apparatus 1, respectively.

[0021] The image forming apparatus 1 includes a device main body 3 having a box-shaped housing structure. The device main body 3 includes a paper feed unit 5 that feeds sheets, an image forming unit 7 that forms a toner image to be transferred onto the sheet, a fixing unit 9 that fixes the toner image onto the sheet, and a discharge unit 11 that discharges the sheet with the fixed toner image. In addition, a discharge tray 13 is provided on the top surface of the device main body 3.

[0022] The paper feed unit 5 is disposed at the bottom of the device main body 3. The paper feed unit 5 includes a paper feed cassette 15 that stores sheets, and a paper feed device 17 that feeds the sheets stored in the paper feed cassette 15.

[0023] The image forming unit 7 is disposed above the paper feed unit 5. The image forming unit 7 includes four image forming units 21 corresponding to four colors of toner (yellow, cyan, magenta, and black), an intermediate transfer belt 23, primary transfer rollers 25 corresponding to the four image forming units 21, secondary transfer rollers 27, and an exposure device 29. Each image forming unit 21 includes a rotatable photosensitive drum 31, a charging device 33 arranged around the photosensitive drum 31, a developing device 35, and a cleaning device 37. The four image forming units 21 are disposed side by side in the left-right direction. Each developing device 35 is connected to a toner container 39 containing toner of the corresponding color.

[0024] The toner container 39 is housed in a container housing portion 41 provided above the image forming unit 7. The toner container 39 and the container housing portion 41 will be described later.

[0025] The intermediate transfer belt 23 is disposed above the four image forming units 21, is wound around a drive roller and a driven roller spaced apart in the left-right direction, and travels in the direction indicated by the arrow in FIG. 1. The outer surface of the lower track of the intermediate transfer belt 23 faces the photosensitive drums 31 of the four image forming units 21, forming a primary transfer nip between the photosensitive drums 31 and the intermediate transfer belt 23. The four primary transfer rollers 25 are disposed in the hollow portion of the intermediate transfer belt 23, and face the photosensitive drums 31 of the four image forming units 21, with the intermediate transfer belt 23 sandwiched between them. The secondary transfer roller 27 faces the drive roller, with the intermediate transfer belt 23 sandwiched between them, forming a secondary transfer nip between the secondary transfer roller 27 and the intermediate transfer belt 23.

[0026] The fixing unit 9 is disposed above the image forming unit 7. The fixing unit 9 includes a heating roller and a pressure roller, and a fixing nip is formed between the two rollers. The discharge unit 11 is disposed above the fixing unit 9. The discharge unit 11 includes a pair of discharge rollers.

[0027] Furthermore, the apparatus main body 3 is formed with a sheet transport path 43 that runs from the paper feed device 17 of the paper feed section 5 through the secondary transfer nip and the fixing nip toward a pair of discharge rollers of the discharge section 11. A pair of registration rollers 47 is provided on the transport path 43 upstream of the secondary transfer nip in the sheet transport direction.

[0028] The image forming operation will be briefly described. In each image forming unit 21 of the image forming section 7, the charging device 33 charges the photosensitive drum 31 to a predetermined potential. The photosensitive drum 31 is then exposed by the exposure device 29 based on image data to form an electrostatic latent image. The electrostatic latent image is developed into a toner image by the developing device 35. The toner image is transferred from the photosensitive drum 31 to the intermediate transfer belt 23 at the primary transfer nip by the primary transfer roller 25 to which a transfer bias is applied. In each of the four image forming units 21, a toner image is transferred to the intermediate transfer belt 23, thereby forming a full-color toner image on the intermediate transfer belt 23.

[0029] Meanwhile, in the paper feeding unit 5, a sheet is fed from a paper feeding cassette 15 to a conveying path 43 by a paper feeding device 17. The sheet is conveyed along the conveying path 43, and after skew is corrected by a pair of registration rollers 47, the sheet is conveyed to a secondary transfer nip. At the secondary transfer nip, a full-color toner image is transferred from the intermediate transfer belt 23 to the sheet by a secondary transfer roller 27 to which a transfer bias is applied. The sheet is then conveyed to a fixing unit 9, where the toner image is heated and pressurized at the fixing nip to be fixed to the sheet. The sheet is conveyed to a discharge unit 11 and discharged onto a discharge tray 13 by a pair of discharge rollers.

[0030] Next, the toner container 39 will be described with reference to Figure 2. Figure 2 is a side view of the toner container 39. The toner container 39 is formed in a cylindrical shape with a hollow portion in which toner is stored. A small-diameter protrusion 39a is provided on one longitudinal end face of the toner container 39, and an outlet 39b is provided on the other longitudinal end face. A spiral protrusion 39c is formed on the inner peripheral surface of the toner container 39 along the longitudinal direction.

[0031] The toner containers 39 that store yellow, cyan, and magenta toner have the same shape and capacity, while the toner container 39 that stores black toner has a larger capacity than these toner containers 39. Each toner container 39 has a memory chip (not shown) attached that stores various information.

[0032] Next, the container storage section 41 will be described with reference to Fig. 1 and Fig. 3 to Fig. 6. Fig. 3 is a front view showing the front side plate 51 of the device main body 3, Fig. 4 is a front view showing the inner cover 61 rotated to the closed position, Fig. 5 is a front view showing the inner cover 61 rotated to the open position, and Fig. 6 is a side cross-sectional view showing the inner cover 61 and outer cover 63 rotated to the closed position.

[0033] 1, the container storage section 41 houses an upper container group 39A and a lower container group 39B, each of which consists of four toner containers 39, each of which houses toner of four colors (yellow, cyan, magenta, and black). In other words, two toner containers 39 are provided for each color. As a result, as described above, even if one toner container 39 becomes empty, toner can be supplied from the other toner container 39, thereby reducing the downtime of the image forming apparatus 1 due to toner container replacement.

[0034] The container housing section 41 is formed between a front side plate 51 and a rear side plate (not shown) of the apparatus main body 3. As shown in FIG. 3, the front side plate 51 has upper and lower opening rows 53A and 53B formed therein corresponding to the upper and lower container groups 39A and 39B. Each opening row includes four openings 53 aligned in the horizontal direction (left-right direction). Each opening 53 in the upper opening row 53A and each opening 53 in the lower opening row 53B are shifted left-right by the distance between adjacent openings 53 in the left-right direction. The toner container 39 is inserted into and removed from the container housing section 41 through the openings 53.

[0035] In each row of openings, the four openings 53 correspond, from left to right, to the yellow, magenta, cyan, and black toner containers 39. The openings 53 corresponding to yellow, magenta, and cyan have approximately the same size and shape, and the opening 53 corresponding to black is larger than these openings 53.

[0036] Furthermore, the container housing section 41 is provided with a toner supply mechanism (not shown) for each opening 53, which supplies toner from the toner container 39 to the developing device 35. The toner supply mechanism includes a rotation mechanism for rotating the toner container 39, a pipe extending in the vertical direction and disposed between the toner container 39 and the developing device 35, and a toner sensor 55 (see FIG. 1) for detecting when the toner container 39 is empty. The pipe is formed of a transparent material. As described above, the openings 53 in each opening row are disposed with a lateral offset, so that the pipe corresponding to an upper opening 53 can be disposed between the pipes of the toner supply mechanism corresponding to the adjacent opening 53 in the lower opening row.

[0037] The toner sensor 55 is a magnetic permeability sensor that detects the presence or absence of toner in the pipe. The toner sensor 55 is electrically connected to a control unit (not shown). The detection result of the toner sensor 55 is sent to the control unit.

[0038] In addition, the front side plate 51 rotatably supports an inner cover 61 (see Figures 4 and 5) that opens and closes each opening 53, and an outer cover 63 (see Figure 6) that covers the outside of all of the inner covers 61.

[0039] As shown in Fig. 3, left and right inner pivot shafts 65 that pivotally support the inner cover 61 are provided on both left and right sides of the lower end of each opening 53. The inner cover 61 can pivot about the left and right inner pivot shafts 65 between a closed position (see Fig. 4) in which the opening 53 is closed and an open position (see Fig. 5) in which the opening 53 is opened. Furthermore, as shown in Fig. 3, left and right outer pivot shafts 67 that pivotally support the outer cover 63 are provided at the left and right lower corners of the front side panel 51. The outer cover 63 can pivot about the left and right outer pivot shafts 67 between a closed position (see Fig. 6) in which the outside of all of the inner covers 61 is covered and an open position in which all of the inner covers 61 are exposed.

[0040] Next, the inner cover 61 will be described with reference to Figures 7 and 8. Figure 7 is a perspective view showing the inner cover 61, and Figure 8 is a side view showing the inner cover 61.

[0041] All of the inner covers 61 are formed to have the same dimensions (vertical length, horizontal length) and the same structure (see FIG. 4). However, depending on the position of the inner cover 61, a notch or recess may be provided to avoid interference with other components. For example, the inner cover 61 that opens and closes the opening 53 for the upper yellow toner container has a notch formed in the upper left corner, and the inner cover 61 that opens and closes the opening 53 for the lower black toner container has a recess formed.

[0042] 7 and 8, the inner cover 61 has a rectangular cover plate 71 having a predetermined height (length in the vertical direction) and width (length in the horizontal direction). A mark indicating the corresponding toner color is printed on the outer surface of the cover plate 71. Also, as shown in FIG. 8, the cover plate 71 is formed so that a lower portion 71a is recessed relative to an upper portion 71b in the thickness direction (front-to-back direction) via an inclined portion 71c.

[0043] As shown in Figure 7, the inner surface of the cover plate 71 is formed with an upper wall 73U that protrudes in the thickness direction along the upper edge, and left and right walls 73S that protrude in the thickness direction along the left and right side edges. The left and right walls 73S have a predetermined width in the left-right direction. A protrusion 75 that further protrudes in the thickness direction is formed in the center of the left and right walls 73S. As shown in Figure 8, the upper outer corners of the cover plate 71 and the upper and lower outer corners of the protrusion 75 are rounded.

[0044] 7, a plurality of ribs 77 extending in the vertical and horizontal directions are provided between the upper wall 73U and the left and right walls 73S on the inner surface of the cover plate 71. Furthermore, a hook 79 is provided at the upper end of one of the left and right walls 73S. The hook 79 is engaged with the front plate 51 by a locking device 93 (described later with reference to FIG. 11).

[0045] Cylindrical left and right bearing portions 81 that fit onto the left and right inner pivot shafts 65 of the front side plate 51 are provided at the lower end portions of the left and right walls 73S. A first protrusion 83 and a second protrusion 85 are formed on the outer peripheral surface of each bearing portion 81 and spaced apart in the circumferential direction. In this example, the first protrusion 83 and the second protrusion 85 are disposed at a central angle of approximately 90° with respect to the center of the bearing portion 81. The first protrusion 83 and the second protrusion 85 each have a predetermined width in the left-right direction. The first protrusion 83 has a tapered claw shape that extends in a direction parallel to the tangent direction of the bearing portion 81 along an extension of the outer surface of the lower portion 71a of the cover plate 71. The second protrusion 85 is disposed more inward than the first protrusion 83 and protrudes in the radial direction of the bearing portion 81. The height of the second protrusion 85 (the length in the radial direction from the surface of the bearing portion 81) is shorter than the height of the first protrusion 83.

[0046] With this configuration, the center of gravity of the inner cover 61 in the closed position is located outside (in front of) the front side plate 51 relative to the left and right inner rotation shafts 65. This allows the inner cover 61 to automatically rotate to the open position.

[0047] Furthermore, the front side plate 51 is provided with a stopper member 91 that holds the inner cover 61, which has been rotated to the open position, at at least two opening angles relative to the front side plate 51, and a locking device 93 that fixes the inner cover 61, which has been rotated to the closed position, to the front side plate 51.

[0048] First, the stopper member 91 will be described with reference to Figures 9 and 10. Figure 9 is a perspective view showing the stopper member 91, and Figure 10 is a side view showing the stopper member 91 supported by the front side plate 51. The stopper member 91 holds the inner cover 61 at an open angle of 90° and 120°, which is greater than 90°, relative to the front side plate 51. The stopper member 91 has left and right side plates 101 that face each other in the left-right direction, and upper and lower stopper pieces 103 and 105 that are supported in a cantilevered manner by the left and right side plates 101. The stopper member 91 is made of, for example, resin.

[0049] The left and right side plates 101 are rectangular when viewed from the left and right. Upper and lower protrusions 111 are formed on the rear end of the upper end surface and the rear end of the lower end surface of each side plate 101. In addition, outer protrusions 113 are formed on the outer surface of each side plate 101 in the horizontal direction.

[0050] The upper stopper piece 103 has a main body 121, left and right fixing portions 123, and a locking portion 125. The main body 121 is a rectangular plate piece having a predetermined width in the left-right direction, a predetermined length in the front-rear direction, and a predetermined thickness. The left and right fixing portions 123 protrude in opposite directions from the rear end portions of the left and right side surfaces of the main body 121. The left and right fixing portions 123 are fixed to the rear end portions of the inner surfaces of the left and right side plates 101.

[0051] The locking portion 125 is provided at the front end of the main body 121. The locking portion 125 is thicker than the main body 121 and is trapezoidal when viewed from the left and right. The locking portion 125 has flat upper and lower surfaces, a downwardly sloping front end surface, and a rear end surface that extends in the up and down direction. The front end of the locking portion 125 protrudes forward beyond the left and right side plates 101. The top surface of the locking portion 125 is formed at the same height as the top surfaces of the left and right side plates 101.

[0052] The lower stopper piece 105 has a main body portion 131, left and right fixing portions, and a locking portion 135. The main body portion 131 is a rectangular plate piece having the same width, length, and thickness as the main body portion 121 of the upper stopper piece 103. The left and right fixing portions protrude in opposite directions from the rear ends of the left and right sides of the main body portion 131. The left and right fixing portions are fixed to the rear ends of the inner surfaces of the left and right side plates 101 below the upper stopper piece 103. In other words, there is space above the lower stopper piece 105. The locking portion 135 has the same thickness as the main body portion 131 and has an inclined portion bent diagonally downward from the tip of the main body portion 131 and a bent portion bent downward from the tip of the inclined portion. The locking portion 135 protrudes forward and downward beyond the left and right side plates 101.

[0053] As shown in Figure 10, the stopper member 91 is supported in a storage space 139 formed in the front side plate 51 of the device body 3. The storage space 139 is a substantially rectangular parallelepiped space formed behind the left and right inner rotation shafts 65 and surrounded by left, right, top, and bottom walls. The stopper member 91 is attached to the storage space 139 by inserting the stopper member 91 into the storage space 139 from behind the front side plate 51 and bringing the top and bottom protrusions 111 of the left and right side plates 101 into contact with the front side plate 51. The outer protrusions 113 of the left and right side plates 101 come into contact with the left and right wall surfaces of the storage space 139.

[0054] The front end of the locking portion 125 of the upper stopper piece 103 protrudes forward from the accommodation space 139. The locking portion 135 of the lower stopper piece 105 protrudes forward and downward from the accommodation space 139. The front end of the protruding locking portion 125 of the upper stopper piece 103 and the locking portion 135 of the lower stopper piece 105 are spaced apart in the circumferential direction of the bearing portion 81 around the bearing portion 81 of the inner cover 61 fitted onto the inner rotating shaft 65. A predetermined gap is provided between the locking portion 135 of the lower stopper piece 105 and the bearing portion 81. The front end of the locking portion 125 of the upper stopper piece 103 is in substantial contact with the bearing portion 81.

[0055] Additionally, the upper surface of the locking portion 125 of the upper stopper piece 103 contacts the upper wall surface of the accommodation space 139. This restricts the upward rotation of the upper stopper piece 103. On the other hand, because there is space above the lower stopper piece 105, the lower stopper piece 105 can elastically rotate upward around the left and right fixing portions.

[0056] Next, the locking device 93 will be described with reference to Fig. 11. Fig. 11 is a plan view illustrating the locking device 93. The locking device 93 is provided on the front side plate 51 and engages with hooks 79 provided on the inner cover 61, thereby fixing the inner cover 61, which has been rotated to the closed position, to the front side plate 51. The locking device 93 is supported by horizontal fixing plates 51a provided on the front side plate 51 in correspondence with each opening 53. The locking device 93 includes hook members 141 that can rotate to engage with the hooks 79 of the inner cover 61, and a solenoid 143 that rotates the hook members 141.

[0057] The hook member 141 has a base end formed with a shaft hole 141a and a tip end provided with a hook piece 141b and a pressing piece 141c. A rotation shaft 51b provided on the fixed plate 51a is inserted into the shaft hole 141a. This allows the hook member 141 to rotate on the fixed plate 51a around the rotation shaft 51b. The hook piece 141b and the pressing piece 141c are arranged at a predetermined interval along a rotation trajectory centered on the shaft hole 141a. The hook member 141 is biased by a torsion coil spring 145 provided in the shaft hole 141a so that the hook piece 141b rotates in an engagement direction A in which it engages with the hook 79 of the inner cover 61. The rotation of the hook piece 141b in the engagement direction A is restricted by a pin 51c provided on the fixed plate 51a.

[0058] When the hook member 141 is biased by the torsion coil spring 145 and rotates in the engagement direction A, the hook piece 141b becomes able to engage with the hook 79 of the inner cover 61. On the other hand, when the hook member 141 rotates in the release direction B opposite to the engagement direction A (see the two-dot chain line in FIG. 11), the engagement between the hook piece 141b and the hook 79 is released, and the hook 79 is pressed by the pressing piece 141c, so that the inner cover 61 is biased to rotate to the open position.

[0059] A movable member 143a is supported on the solenoid 143 so as to be movable back and forth in the front-rear direction. A tip of the movable member 143a is rotatably connected to the hook member 141. More specifically, a shaft 143b is provided at the tip of the movable member 143a, and an opening 141d into which the shaft 143b is inserted is formed in the hook member 141. The diameter of the opening 141d is larger than the diameter of the shaft 143b. As the movable member 143a moves back and forth in the front-rear direction, the hook member 141 rotates about the rotation shaft 51b via the shaft 143b and the opening 141d. More specifically, when the movable member 143a extends, the hook member 141 rotates in the engagement direction A, and when the movable member 143a retracts, the hook member 141 rotates in the release direction B.

[0060] The solenoid 143 is electrically connected to the control unit, and the solenoid 143 is switched between a conducting state and a non-conducting state by the control unit.

[0061] Next, the outer cover 63 will be described with reference to Figure 6. The outer cover 63 has a rectangular shape with approximately the same dimensions as the front side plate 51. A plurality of ribs are provided on the inner surface of the outer cover 63 along the up-down and left-right directions. The outer cover 63 is rotatably supported by left and right outer rotation shafts 67 provided on the front side plate 51. The outer cover 63 rotates between a closed position in which it covers the front side plate 51 and an open position in which it opens the front side plate 51.

[0062] The outer cover 63 and the front plate 51 are fixed in the open position by a locking device (not shown) that engages with each other. In the open position, the opening angle of the outer cover 63 relative to the front plate 51 is approximately 90°. In addition, the front plate 51 is provided with an open / closed detection switch 151 for detecting whether the outer cover 63 is open or closed. The open / closed detection switch 151 switches from on to off when the outer cover 63 is slightly opened from the position in FIG. 6 (closed position). The open / closed detection switch 151 is electrically connected to the control unit.

[0063] The opening and closing operation of the inner cover 61 in the image forming apparatus 1 having the above configuration will be described with reference to Figures 12 and 13. Figure 12 is a side view showing the inner cover 61 rotated to the open position (opening angle 90°), and Figure 13 is a side view showing the inner cover 61 rotated to the open position (opening angle 120°).

[0064] During image formation, the outer cover 63 and the inner cover 61 rotate to the closed position and are each fixed in the closed position by a locking device. When the inner cover 61 rotates to the closed position, the upper wall 73U, the left and right walls 73S, and the protrusions 75 abut against the front side plates 51 on both sides of the opening 53, and the opening 53 is closed by the cover plates 71. Furthermore, as shown in Figure 4, when all the inner covers 61 rotate to the closed position, there is almost no gap between the inner covers 61 in the left-right direction, and the gap between the inner covers 61 in the up-down direction is also made as narrow as possible.

[0065] When the control unit determines that a specific toner container 39 is empty based on the detection result of the toner sensor 55, it displays a message on a display unit (not shown) or the like indicating that the toner container 39 needs to be replaced. After checking the message, the user rotates the outer cover 63 to the open position. This switches the open / close detection switch 151 from on to off, and the control unit switches the solenoid 143 of the locking device 93 provided in the corresponding opening 53 from a non-energized state to a powered state for a predetermined period of time.

[0066] As a result, the movable member 143a moves backward (see arrow C in FIG. 11), and the hook member 141 rotates in the release direction B, moving away from the hook 79 of the inner cover 61. Furthermore, the pressing piece 141c of the hook member 141 presses the hook 79. As described above, in the closed position, the center of gravity of the inner cover 61 is located outside the front side plate 51 with respect to the left and right inner rotation shafts 65. In addition to this configuration, the pressing piece 141c of the hook member 141 presses the hook 79, so that when the corresponding toner container 39 is emptied, the inner cover 61 automatically and reliably becomes rotatable to the open position.

[0067] Therefore, when the outer cover 63 is opened, the inner cover 61 leans against the outer cover 63 and automatically rotates to the open position.

[0068] As shown in Fig. 12, the inner cover 61 rotates until the first protrusion 83 formed on the bearing portion 81 is locked by the locking portion 135 of the lower stopper piece 105 of the stopper member 91. At this time, the opening angle of the inner cover 61 with respect to the front side plate 51 is 90° in this example. As such, the lower stopper piece 105 is an example of a first stopper in the present invention that holds the inner cover 61 at an opening angle of 90° or less. Note that the height of the second protrusion piece 85 is lower than the height of the first protrusion piece 83, and therefore the second protrusion piece 85 passes between the lower stopper piece 105 and the bearing portion 81 while the inner cover 61 is rotating.

[0069] When the inner cover 61 is rotated to the open position in this manner, the opening 53 of the front side plate 51 is exposed. However, in this state, the protrusion 75 of the inner cover 61 is located in front of the opening 53, i.e., in front of the toner container 39.

[0070] 13, the user pulls the toner container 39 forward through the opening 53. At this time, the toner container 39 hits the protrusion 75 of the inner cover 61. The protrusion 75 is then pushed by the toner container 39, causing the inner cover 61 to rotate further downward. At this time, the first protrusion 83 of the inner cover 61 pushes up the lower stopper piece 105, causing the lower stopper piece 105 to elastically rotate upward.

[0071] The inner cover 61 rotates until the second protrusion 85 abuts against the locking portion 125 of the upper stopper piece 103 (see the arrow in FIG. 13). At this time, the opening angle of the inner cover 61 is 120°. By rotating the inner cover 61 in this manner, it becomes possible to pull out the toner container 39 through the opening 53. The upper stopper piece 103 is an example of a second stopper in the present invention that holds the inner cover 61 at an opening angle greater than 90°.

[0072] Furthermore, when the inner cover 61 rotates in this manner, the upper corner of the lower inner cover 61 fits into the corner between the lower portion 71a and the inclined portion 71c of the cover plate 71 of the inner cover 61. In this way, the lower portion 71a of the cover plate 71 is an example of a recess in the present invention into which the upper end of the lower inner cover 61 fits when the inner cover 61 rotates to the open position. As a result, even when the upper inner cover 61 and the lower inner cover 61 are so close to each other in the vertical direction that the rotation range of the upper inner cover 61 and the rotation range of the lower inner cover 61 partially overlap, the upper inner cover 61 can be rotated to an open angle of 120°.

[0073] When the toner container 39 is completely pulled out, the lower stopper piece 105 elastically returns to its original position and urges the inner cover 61 upward, thereby returning the inner cover 61 to the open position with an opening angle of 90° (see FIG. 12).

[0074] The user removes the empty toner container 39 and installs a new toner container 39 into the container holder 41 through the opening 53. Each toner container 39 is installed in the container holder 41 in the installation / removal direction along the front-to-rear direction, with the end with the discharge outlet 39b facing forward (rear). This detects the installation and reads various pieces of information from the memory chip and transmits them to a control unit (not shown). The control unit stores the detection results of the toner sensor 55 and the various pieces of information read from the toner container 39 in association with each other.

[0075] After the toner container 39 is installed, the inner cover 61 is rotated upward. This causes the hook 79 of the inner cover 61 to press the hook piece 141b of the hook member 141 of the locking device 93. As described above, there is play between the shaft 143b provided at the tip of the movable member 143a and the opening 141d provided in the hook member 141, so the hook member 141 rotates in the release direction B. After the inner cover 61 has rotated to the completely closed position, it is biased by the torsion coil spring 145 to rotate in the engagement direction A, and the hook piece 141b engages with the hook 79 of the inner cover 61. In other words, the inner cover 61 is fixed to the front side plate 51 by the locking device 93.

[0076] Furthermore, when the inner cover 61 is rotated to the closed position in this manner, the toner container 39 is pushed in by the inner cover 61. This allows the toner container 39 to be securely attached to the container accommodating portion 41. Furthermore, if the toner container 39 rotates when toner is replenished from the toner container 39 to the developing device 35, the toner container 39 may move in the front-to-rear direction. In this case, the inner cover 61 restricts the forward movement of the toner container 39.

[0077] The user then rotates the outer cover 63 to the closed position. The control unit then drives the rotation mechanism of the toner supply mechanism in response to detection of the installation of the toner container 39 and the closed position of the outer cover 63. This causes the toner container 39 to rotate, and the stored toner is transported toward the discharge port 39b by the spiral protrusion 39c. The toner is discharged from the discharge port 39b into a pipe, and is replenished to a specified developing device 35 through the pipe.

[0078] When the toner sensor 55 detects toner, it stops the rotation of the toner container 39. If the toner sensor 55 does not detect toner within a predetermined time, it determines that the toner container is empty and stops the rotation of the toner container 39. Therefore, when the outer cover 63 is opened, the solenoid 143 is energized again, and the inner cover 61 opens.

[0079] When replacing the toner containers 39, it is possible to replace only one of the toner containers 39 that has become empty, or to replace both toner containers 39 at the same time after both toner containers 39 have become empty. When replacing one of the toner containers 39, the replacement is performed as described above.

[0080] When replacing two toner containers 39 simultaneously, when the user rotates the outer cover 63 to the open position, the upper and lower inner covers 61 automatically rotate to the open position at the same time. At this time, both the upper and lower inner covers 61 rotate to an open angle of 90°. When removing the toner containers 39, as described above, the toner container 39 pushes the inner cover 61, causing it to rotate further downward, allowing the toner container 39 to be removed. When removing the upper toner container 39, as described above, the inner cover 61 rotates to an open angle of 120°. After removal, the lower stopper piece 105 elastically returns, causing the inner cover 61 to rotate to an open angle of 90°. Therefore, when removing the lower toner container 39, the inner cover 61 is not present in the space in front of it. Therefore, the lower toner container 39 can be removed without interfering with the upper inner cover 61, which has been rotated to the open position.

[0081] When the toner container 39 is pulled out, the rounded upper corners of the inner cover 61 slide against the toner container 39, so that the toner container 39 can be smoothly removed without being caught on the inner cover 61.

[0082] As is clear from the above explanation, according to the image forming apparatus 1 of the present invention, even when the inner covers 61 are arranged in the vertical and horizontal directions with almost no gaps between them and the rotation range of the upper inner cover 61 overlaps with the rotation range of the lower inner cover 61, the upper and lower toner containers 39 can be smoothly attached and detached without interfering with the inner covers 61 in the open position.

[0083] Specifically, when the locking device 93 releases the inner cover 61, the inner cover 61 automatically rotates to an open angle of 90° and is held there. Furthermore, when the inner cover 61 is pressed down to pull out the toner container 39, the inner cover 61 rotates to an open angle of 120°, but after the toner container 39 is pulled out, the inner cover 61 automatically rotates to an open angle of 90°. Therefore, when pulling out a toner container 39 below an already pulled-out toner container 39, the toner container 39 does not interfere with the upper inner cover 61.

[0084] Furthermore, when the upper inner cover 61 is rotated to the open position, the upper corner of the lower inner cover 61 fits into the lower part 71a of the cover plate 71 of the inner cover 61, so that the upper inner cover 61 can also be rotated to an opening angle of 90° or more.

[0085] Furthermore, when the toner sensor 55 detects that the toner container 39 is empty, the locking device 93 of the inner cover 61, which opens and closes the opening 53 corresponding to the toner container 39 when the outer cover 63 is opened, releases the inner cover 61 from its locking position. When the inner cover 61 is rotated to the closed position, the center of gravity of the inner cover 61 is located outside the front side plate 51 with respect to the inner rotation shaft 65. Therefore, when the locking device 93 releases the inner cover 61 from its locking position, the inner cover 61 automatically rotates to the open position, improving the workability of installing and removing the toner container 39.

[0086] Additionally, the upper and lower stopper pieces 103, 105 are supported in a cantilevered manner by the left and right side plates 101 and are integrally formed as the stopper member 91. This makes it easy to position both pieces and to attach them to the accommodation space 139. Furthermore, because the upper stopper piece 103 is restricted from rotating upward, after the inner cover 61 has rotated until the second protruding piece 85 is engaged with the upper stopper piece 103, further rotation of the inner cover 61 is restricted. This makes it possible to restrict excessive rotation of the inner cover 61.

[0087] The opening angles of the inner cover 61 are not limited to 90° and 120°. One opening angle may be smaller than 90°, and the other opening angle may be larger than 90°. The inner cover 61 may also be rotated to two or more opening angles.

[0088] The container storage section 41 may be provided so as to be able to store a group of three or more containers. The openings in the upper and lower opening rows do not need to be arranged offset in the left-right direction.

[0089] Although the present invention has been described with reference to specific embodiments, the present invention is not limited to the above embodiments, and those skilled in the art may modify the above embodiments without departing from the scope and spirit of the present invention. [Explanation of symbols]

[0090] 1. Image forming device 39 Toner container 39A, 39B container group 41 Container storage area 51 Side panel 53 Aperture 53A, 53B opening row 55 Toner sensor 61 Cover 65 Rotating shaft 71b Lower part (recess) 81 Bearing section 83 First Projection 85 Second projection 93 Locking device 103 Upper stopper piece (second stopper) 105 Lower stopper piece (first stopper)

Claims

1. a plurality of container groups each including a plurality of toner containers each containing a toner of a different color; a storage section to which the toner container is detachably attached, The storage section is a side plate on which rows of openings for inserting and removing the toner containers are arranged horizontally, the rows being aligned in the vertical direction for each container group; a cover supported by a pivot provided at a lower end of each opening of the side plate and pivotable between an open position for opening the opening and a closed position for closing the opening; a locking device that fixes the cover, which has been rotated to the closed position, to the side plate; an image forming apparatus comprising: a first stopper that holds the cover at an opening angle of 90° or less relative to the side plate when the cover is rotated to the open position; and a second stopper that holds the cover at an opening angle greater than 90°.

2. 2. The image forming apparatus according to claim 1, wherein the first stopper and the second stopper are arranged at a distance from each other in a circumferential direction of the rotation shaft, and the first stopper is rotatable in the vertical direction by elastic deformation.

3. the cover has a first protrusion and a second protrusion arranged apart from each other in a circumferential direction of the rotation shaft, The image forming apparatus described in claim 2, characterized in that when the cover is released from its locking device, the cover rotates under its own weight until the first protrusion engages with the first stopper, and then by pushing down on the cover, the first protrusion pushes the first stopper, causing the first stopper to elastically deform and rotate, and the cover rotates until the second protrusion engages with the second stopper.

4. 3. The image forming apparatus according to claim 2, wherein when the cover is released after being pressed down, the first stopper elastically returns to its original position, and the cover rotates until the first protrusion is locked by the first stopper.

5. 2. The image forming apparatus according to claim 1, wherein the first stopper and the second stopper are integral.

6. 2. The image forming apparatus according to claim 1, wherein the cover is pushed down by the toner container being pulled out from the opening.

7. 2. The image forming apparatus according to claim 1, wherein the cover has a recess recessed in the thickness direction of the cover, and when the cover is rotated to the open position, the upper end of the cover below the cover fits into the recess.

8. 2. The image forming apparatus according to claim 1, wherein the center of gravity of the cover is located outside the side plate with respect to the rotation shaft when the cover is rotated to the closed position.

9. a sensor for detecting when the toner container is empty; 2. The image forming apparatus according to claim 1, wherein when the sensor detects that the toner container is empty, the locking device of the cover that opens and closes the opening corresponding to the toner container is released from the locking of the cover.

Images