JPH04335672A - Loading structure for developing device - Google Patents

Abstract

PURPOSE:To offer the loading structure of a developing device whose installing area can be remarkably reduced and whose reliability is improved. CONSTITUTION:The developing device 17 is inserted between the front wall 46 and the back wall 47 of a frame 3 from the upper part so that a pair of guide pins 48 and 49 arranged on the frame 3 are engaged with a guide groove 56 which is formed on the side part of the device 17 and which extends in an upper and lower direction. Under such a state that the device 17 is inserted in the frame 3 and a pair of guide pins 48 and 49 of the frame 3 arrives at the terminating position of the upper side of the groove 56 of the device 17, the lock pins 64 and 65 of the device 17 are engaged with supporting pieces 68a and 68b mounted on the frame 3. Thereafter, the loading of the device 17 in the frame 3 is finished by angularly displacing the pieces 68a and 68b along a mark shown by an arrow A and circularly moving the device 17.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for a developing device used in an electrophotographic apparatus, when the developing device is mounted/removed from above.

0002

2. Description of the Related Art In recent years, a wide variety of electrophotographic apparatuses have been used, and their uses are wide-ranging. On the other hand, as a ticketing machine that issues airline boarding passes, the content printed is not limited to Arabic numerals or English alphabets, but can also print any character design, etc., and uses laser light to form an optical image on a photosensitive drum. Electrophotographic equipment is preferred. However, such ticket issuing machines are required to be miniaturized because they are installed within an extremely limited area within a crowded ticket counter in an airport. In particular, a reduction in the installation area is required. Furthermore, in the event of a malfunction such as a breakdown, interruptions in ticketing operations must be minimized, and maintenance work must therefore be easy to perform even for ticketing staff who are inexperienced with ticketing machine mechanisms. be.

0003

[Problems to be Solved by the Invention] When an electrophotographic device that occupies an extremely limited area is required, such as the aforementioned ticket issuing machine that issues boarding passes for an aircraft, current devices require a relatively large footprint and are difficult to maintain. The problem is that the work is time-consuming.

An object of the present invention is to solve the above-mentioned technical problems and provide a mounting structure for a developing device that can significantly reduce the installation area, facilitate maintenance work, and improve reliability. That's true.

[0005]

[Means for Solving the Problems] The present invention provides a structure in which a developing device is installed in a frame having a front wall and a rear wall, in which the developing device protrudes from the lower side in a direction intersecting the longitudinal direction of the frame. a guide groove formed on a side corresponding to one of the longitudinal directions of the frame, the lower end of which is open, and which extends in the vertical direction; The frame includes an engagement groove extending obliquely upward in the opposite direction, and a pair of lock pins protruding in the front-rear direction near the lower end, and a developing device protruding inward from either the front wall or the rear wall of the frame. When the developing device is attached to the frame, the pair of lock pins are engaged with a guide pin that is placed at a position where it slides inside the guide groove, and when the guide pin reaches the upper end position of the guide groove of the developing device, The developing device mounting structure is characterized in that it includes a support member that can be angularly displaced around an axis in the front-rear direction.

The present invention also provides a structure in which a developing device is installed in a frame having a front wall and a rear wall, in which the developing device has a protrusion on the lower side thereof that protrudes in a direction intersecting the longitudinal direction of the frame; a first gear provided on at least one side of the protrusion in the front-rear direction, and a second gear meshed with the first gear at a position where the developing device is completely attached to the frame. The first gear approaches the second gear along an arcuate trajectory by being displaced along an arcuate trajectory in the direction in which the protrusion of the developing device protrudes, and In the completed state, the developing device mounting structure is characterized in that the developing device meshes with the second gear from an oblique direction that intersects with the normal direction at the meshing position with the second gear.

The present invention also provides a structure in which a developing device is installed in a frame having a front wall and a rear wall, in which the developing device has a protrusion on the lower side thereof that protrudes in a direction intersecting the longitudinal direction of the frame. The frame is provided with a drive gear that is rotationally driven by a drive source, and the developing device includes a stirring member that stirs the developer stored therein, and a stirring member that is connected to the stirring member and is disposed on the rear side and outside of the developing device. a driven gear which is interposed between the driving gear and the driven gear when the developing device is attached to the frame, and which transmits power, and which is swingable in the vertical direction behind the developing device; This is a mounting structure for a developing device characterized by being provided with an idle gear that is resiliently biased toward the developing device.

[0008]

[Operation] According to the present invention, the developing device is mounted on the front wall of the frame so that the guide pin provided on the frame fits into the vertically extending guide groove formed on the side of the developing device. and the rear wall from above. When the developing device is inserted into the frame and the guide pin of the frame reaches the upper end position of the guide groove of the developing device through relative movement, a pair of locks protrudes in the front and back direction near the lower end of the developing device. A pin engages a support member mounted to the frame. Thereafter, the supporting member is angularly displaced around the longitudinal axis, and the developing device is moved in an arc toward the protruding side of the protrusion protruding in a direction intersecting the longitudinal direction on the lower side thereof. At this time, the guide pin relatively moves along an engagement groove extending obliquely upward in a direction opposite to the protrusion direction of the protrusion from at least the upper end of the guide groove formed in the developing device.

[0009] In this way, the developing device is first inserted into the frame from above, and then moves in an arc to reach the fully installed state. In other words, if the developing device is inserted into the frame from above toward the installation completion position, even if other components that collide with the protrusion are arranged in the frame, this can be avoided. It is possible to insert the protrusion from above at the position, and then move the protrusion under the other component by an arcuate movement to complete the installation. This increases the degree of freedom in arranging the developing device in the fully installed state within the frame, making it possible to reduce the installation area.

Furthermore, when the first gear provided on the protrusion of the developing device and the second gear provided on the photosensitive means approach each other and mesh with each other, they approach each other in an arc shape, so that the peaks of both gears Even when the ridges face each other, angular displacement easily occurs and engagement becomes easy. This greatly improves operational reliability.

Further, when the developing device is mounted on the frame, the frame is provided with a drive gear that is rotationally driven by a drive source. A stirring member provided inside the developing device is connected to a driven gear disposed outside the rear side of the developing device. The developing device is provided with an idle gear that transmits power between the driving gear and the driven gear when the developing device is fully installed. The idle gear is vertically swingable behind the developing device and is elastically biased downward. In other words, when the idle gear comes into contact with the drive gear when the developing device is attached to the frame, if the peaks of the two gears face each other, the drive gear pushes the idle gear upward, and the contact between the two can cause mechanical damage. This will prevent the situation from occurring. Further, the idle gear is elastically biased downward, and when the installation is completed, it is in a state of meshing with the drive gear, and power can be transmitted to the driven gear.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view of an electrophotographic apparatus 1 according to an embodiment of the present invention, and FIG. 2 is a perspective view of a frame 3 viewed from the front side. The electrophotographic apparatus 1 of this embodiment is used, for example, in a ticket issuing apparatus 2 that prints and issues necessary information on an airplane boarding pass. As explained in the conventional technology,
Such a ticket issuing device 2 is installed within an extremely limited area occupied by a ticket issuing counter in an airport. The frame 3 of the electrophotographic device 1 of this embodiment is the ticket issuing device 2.
The entire body can be attached to and detached from the frame 4 in the front-rear direction in the drawing. That is, it slides on a pair of guide rails 5 fixed to the frame 4 in the front-rear direction in the drawing.

A pair of support frames 6 and 7 are arranged on the frame 3 near the inner center position of the frame 3, and the tip of the support frame 6 and the support frame 7 support the photosensitive unit 8.
A housing 9 is supported so as to be slidable in the front-rear direction in the drawing. Inside the photosensitive unit 8, there are a photosensitive drum 10 that is rotatable in the direction of arrow A1 around an axis in the front-rear direction of the paper, a cleaning device 11 that removes the developer on the photosensitive drum 10 after transfer, and a main charger 12. Placed.

Above the photosensitive unit 8 are a contact pin 13 fixed to the frame 3 and a front wall 4 of the frame 3.
The light source device 15, which is attached and detached upward, is arranged by the positioning grooves 14a formed at the upper ends of the light source device 6 and the rear wall 47, respectively. The light source device 15 includes a contact member 15a on the bottom surface that contacts the contact pin 13, and a positioning pin 14b that engages with the positioning groove 14a. The light source device 15 generates laser light in a state corresponding to the content printed on the face of the boarding pass 16 in response to an input using a keyboard (not shown) of the ticket issuing device 2, and irradiates the laser light onto the photosensitive drum 10. Regarding the light source device 15, a developing unit 17 is installed on the upstream side in the direction A2 in which the boarding pass 16 is conveyed to the electrophotographic apparatus 1. An opening 150 into which the photosensitive unit 8 is inserted is formed in the front wall 46 of the frame 3, and positioning pins 131 and 132 are provided at the periphery of the opening 150.

The developing unit 17 is supplied with toner through a toner storage section 20 that includes toner scraping members 18 and 19 that are angularly displaced at predetermined angles, and a replenishment roller 21 that rotates intermittently from the toner storage section 20. The image forming apparatus includes a stirring section 24 including a stirring roller 23 that stirs and mixes the toner and carrier and supplies the toner and carrier to the developing roller 22 side.

When the developing unit 17 is completely attached to the frame 3, the developing roller 22 is set to maintain a predetermined minute distance from the photosensitive drum 10 by a configuration described later. Further, when the developing unit 17 is attached to the frame 3, as will be described later, it is first inserted into the frame 3 from above, and then the photosensitive unit 8 is moved in an arc as described later.
A configuration approaching that is adopted. Furthermore, the developing unit 17
A plurality of terminal boards 52 are provided facing downward and are electrically connected to connection pins 53 of a connector 54 fixed to the frame 3.

A transfer discharger 2 is provided below the photosensitive unit 8.
5 and a transformer 26 that generates high voltage for discharge. Transfer unit 2
7 is supported by a support shaft 28 so as to be freely angularly displaceable with respect to the frame 3 near the upstream end in the transport direction A2. A transport roller 2 is provided near the support shaft 28 of the transfer unit 27.
A conveyance roller 30 is rotatably fixed to the frame 3 and faces the conveyance roller 29 to sandwich the boarding pass 16 and convey it to the photosensitive drum 10 side.

Further, at the free end of the transfer unit 27 opposite to the support shaft 28, a pressure spring 31 and a guide 32 for guiding the transferred boarding pass 16 toward the fixing unit 33 are provided. Further, supply rollers 98 and 99 are provided for supplying the boarding pass 16 to the conveyance rollers 29 and 30.

A fixing unit 33 is arranged downstream of the photosensitive unit 8 in the transport direction A2. The fixing unit 33 includes a pair of support rails 34 hanging from the support frame 6,
35, and is slidably displaced in the front-rear direction in the plane of the drawing to be attached and detached. The fixing unit 33 includes a first housing 39 having engagement pieces 36 that engage with the support rails 34 and 35, a heating roller 37 housed therein, and a paper guide 38 provided near the lower end. An opening 151 into which the fixing unit 33 is inserted is formed in the front wall 46 of the frame 3, and the peripheral edge of the opening 151 engages with the positioning holes 136 and 137 of the end plate 134 on the front side of the photosensitive unit 8 when installed. Positioning pins 133a and 133b are provided.

A bracket 40 is provided at the lower end of the first housing 39, and a second housing 42 in which a pressure roller 41 is housed is supported via a pivot 139 so as to be freely angularly displaceable. A paper guide 43 and a pressure spring 31 of the transfer unit 27 contact the lower surface of the second housing 42 near the upper end of the portion facing the photosensitive unit 8, and the transfer unit 27 is in the horizontal state shown by the solid line in FIG. The pressing piece 4 is pressed upward by a spring force when installed.
4 is provided to protrude outward.

The frame 3 is equipped with the support frames 6, 7, the abutment pin 13, the support rails 34, 35, the support shaft 28, etc. as described above. Further, the frame 3 is provided with a storage section 45 having an upper opening and into which the developing unit 17 is inserted and stored from above, as will be described later. Inside the front wall 46 of the frame 3 that defines the storage section 45, a pair of guide pins 48, 4 are provided with an interval L1 in the vertical direction.
9 is arranged and a developing unit 17 is housed inside.
A pair of leaf springs 50 are provided that elastically press the front plate 46 from the rear plate 47 side. Further, a lever 51, which constitutes a component to be described later, is arranged at the front end of a rotating shaft 66 extending in the front-rear direction.

FIG. 3 is a perspective view of the developing unit 17. A side portion 55 of the frame 3 of the developing unit 17 facing the front wall 46 has a guide groove 56 extending in the vertical direction and opening on the lower side, and the guide pin 4 in the guide groove 56.
The protrusion 57 where the developing roller 22 of the developing unit 17 is located from the end positions P1 and P2 in the moving direction of 8 and 49
A pair of engagement grooves 58 and 59 are formed, respectively, extending obliquely upward on the opposite side to the protruding direction.

A toner replenishment hole 60 and a developer (a mixture of toner and carrier) replenishment hole 61 are provided at the ends of the toner storage section 20 and stirring section 24 of the developing unit 17 in the projecting direction, respectively. Lid 62, respectively.
63 is installed. A pair of lock pins 64 and 65 are provided near the lower protrusion 57 of the developing unit 17, respectively, and protrude in the front-rear direction of the frame 3. Further, the support shaft 74 of the developing roller 22 is connected to the developing unit 17.
It penetrates the front-rear side wall of the housing 7a.

FIG. 4 shows the lock pin 6 of the developing unit 17.
FIG.
2 is a perspective view illustrating the structure of a developing roller 22 and a photosensitive drum 10. FIG. Please refer to FIG. 2 as well. The lever 51
A rotating shaft 66 passing through the front wall 46 and rear wall 47 of the frame 3 is fixed to the frame 3 . The developing unit 17 is located near the inner wall surfaces of the front wall 46 and the rear wall 47 of the rotating shaft 66.
support recesses 67a into which the pair of lock pins 64 and 65 of the developing unit 17 fit respectively when inserted into the frame 3;
, 67b, substantially U-shaped support pieces 68a, 68b,
Each is fixed at its proximal end.

As described above, when the developing unit 17 is inserted into the frame 3 from above and has finished moving downward, that is, when the lock pins 64 and 65 are fitted with the support pieces 68a and 68b, the apparatus is operated. The operator moves lever 51 to arrow A in Figure 4.
Rotate in 3 directions. As a result, the developing unit 17 moves towards the photosensitive unit 8 along an arcuate trajectory along the direction of arrow A3.
In particular, the developing roller 22 approaches the photosensitive drum 10 along an arcuate trajectory.

As shown in FIG. 5, the photosensitive drum 10 includes a pair of support shafts 70 protruding from both ends of a right cylindrical body 69 in the axial direction, which is formed by engaging flanges made of stainless steel or the like at both ends of an aluminum pipe, for example. A photosensitive layer 71 is formed in an inward range spaced a predetermined distance from both ends of the right cylindrical body 69 in the axial direction. The exposed portions 72 and 73 near both ends of the right cylindrical body 69 on which the photosensitive layer 71 is not formed are provided at both ends in the axial direction of the developing roller 22, which is rotatably supported by a support shaft 74 within the developing unit 17. A pair of spacer rollers 75 and 76 are in contact with each other.

The radius R1 of the spacer rollers 75 and 76 is smaller than the radius R2 of the developing roller 22 by a predetermined degree d1.
Therefore, the photosensitive drum 10 and the developing roller 22 are arranged to be separated by this distance d1. A helical gear 77 is installed behind the spacer rollers 75 and 76 of the developing roller 22, and a similar helical gear 78 is installed at the end of the photosensitive drum 10 in the same direction.

FIG. 6 is a rear view of the developing unit 17. The scraping members 18, 1 are provided on the back side of the developing unit 17.
Gears 79 and 80 are driven gears for rotationally driving the gears 9 and 9.
are provided between them, and two idle gears 81,
82 is placed. The shaft 8 of this idle gear 81, 82
3 and 84 are formed on the back surface of the developing unit 17 and are slidably fitted into elongated holes 85 and 86 that extend in the vertical direction or in the direction connecting the starting point position and the ending point position regarding the arcuate movement of the developing unit 17. .

Further, the other end of a torsion spring 88, which is wound around a shaft 89 and whose one end is locked by a pin 87, is in contact with the shaft 84 of the idle gear 82, which is the upper one of the idle gears 81 and 82. The spring force elastically pushes the idle gears 81 and 82 along the long holes 85 and 86 toward the lower right in FIG. When the developing unit 17 is completely installed in the frame 3, a drive gear 90 provided on the rear wall of the frame 3 and to which power from the motor is transmitted meshes with the idle gear 81. Further, a gear 92 for rotationally driving the replenishment roller 21 is connected to the gear 79 via a gear 91 . Therefore, the driving force from the drive gear 90 is transmitted to the idle gears 81 and 8.
Two systems are set: one in the transmission direction shown by arrow B1, which is transmitted to gear 80 via idle gear 81 and gears 79 and 91, and the other in the direction shown by arrow B2, which is transmitted to gear 92 via idle gear 81 and gears 79 and 91. There is.

The helical gear 77 connected to the developing roller 22 is connected to the helical gear 78 connected to the photosensitive drum 10.
The helical gear 77 meshes with a first gear 93 having a relatively small diameter, and a second gear 77 is coaxially and integrally formed with the first gear 93 and has a larger diameter than the first gear 93. It meshes with a helical gear 95 coaxially fixed to the stirring roller 23 via a gear 94 . Here, the reason why the helical gears 77 and 78 are used is to prevent the smooth rotation of the developing roller 22 and the photosensitive drum 10 from being disturbed due to intermittent meshing between the peaks of the spur gears. .

FIG. 7 shows the developing unit 1 of the electrophotographic apparatus 1.
7 and the photosensitive unit 8 in a non-attached state, FIG. 8 is a sectional view when the developing unit 17 is in a completely attached state, and FIG. 9 is a front view showing the procedure for attaching the developing unit 17. FIG. 10 is a rear view showing the positional relationship of each gear in the developing unit 17. In order to house the developing device 17 in the frame 3 in this embodiment, the developing unit 17 is first housed from above the frame 3 into the housing part 45 so as to face downward. FIG. 7 shows this state.

At this time, the guide pins 48 and 49 are in the guide groove 56.
The developing unit 17 is positioned in the direction intersecting the insertion direction of the developing unit 17, that is, in the left-right direction in FIG. With the developing unit 17 inserted downward and the lock pins 64 and 65 fitted to the support pieces 68a and 68b, the guide pins 48 and
49 are located at the end positions P1 and P2 of the guide groove 56 in the moving direction, as shown in FIG. 9(1). At this time, developing unit 1
Gears 79 and 80 and idle gears 81 and 82, which are arranged on the rear side of gear 7, are spaced apart from drive gear 90. Further, the helical gear 78 coaxial with the photosensitive drum 10 is
It is spaced apart from a helical gear 77 coaxial with the developing unit roller 22 .

After that, when the lever 51 is rotated in the direction of arrow A3, the lever 51 is rotated through the lock pins 64 and 65 that are fitted with the support pieces 68a and 68b that are fixed to the lever 51 through the rotation shaft 66. The developing unit 17 approaches the photosensitive unit 8 along an arcuate trajectory. At this time, as shown in FIG. 9(2), the guide pins 48 and 49 enter and engage the engagement grooves 58 and 59 from the terminal positions P1 and P2 of the guide groove 56 in the moving direction. The lock pins 64 and 65 are in contact with the receiving surface 97 of the receiving member 96, and the spacer rollers 75 and 76 coaxially attached to the developing roller 22 are in contact with the photosensitive drum 1.
0, the distance between the photosensitive drum 10 and the developing roller 22 can be set with high precision. Further, as shown in FIG. 10(2), the idle gear 81 of the developing unit 17 meshes with the drive gear 90. Further, the helical gears 77 and 78 also mesh with each other, and power is transmitted to the developing roller 22 and stirring roller 23.

In this manner, the developing unit 17 is inserted into the frame 3 from above at a position away from the light source device 15, as shown in FIG. 7, and then moved in an arc to approach the photosensitive unit 10. That's what I do. In this way, the positioning of the developing unit 17 when it is attached to the frame 3 can be carried out without difficulty.

On the other hand, the developing unit 17 shown in FIG.
With respect to the connection between the terminal plate 52 and the connecting pin 53, the developing unit 17 reaches the mounting completion position through circular arc movement as described above. At this time, the connecting pin 53 slides on the terminal plate 52 by a distance L2 by a length corresponding to the horizontal direction component in FIG. 1 of the circular arc movement. As a result, the terminal board 52 and the connecting pin 53
Ensures electrical connection with the

[0036]

As described above, according to the present invention, the developing device is arranged such that the guide pin provided on the frame fits into the guide groove extending in the vertical direction formed on the side of the developing device. The device is inserted from above between the front and rear walls of the frame. When the developing device is inserted into the frame and the guide pin of the frame reaches the upper end position of the guide groove of the developing device through relative movement, a pair of locks protrudes in the front and back direction near the lower end of the developing device. A pin engages a support member mounted to the frame. Thereafter, the supporting member is angularly displaced around the longitudinal axis, and the developing device is moved in an arc toward the protruding side of the protrusion protruding in a direction intersecting the longitudinal direction on the lower side thereof. At this time, the guide pin relatively moves along an engagement groove extending obliquely upward in a direction opposite to the protrusion direction of the protrusion from at least the upper end of the guide groove formed in the developing device.

In this manner, the developing device is first inserted into the frame from above, and then moves in an arc to reach the fully installed state. In other words, if the developing device is inserted into the frame from above toward the installation completion position, even if other components that collide with the protrusion are arranged in the frame, this can be avoided. It is possible to insert the protrusion from above at the position, and then move the protrusion under the other component by an arcuate movement to complete the installation. This increases the degree of freedom in arranging the developing device in the fully installed state within the frame, making it possible to reduce the installation area.

Furthermore, when the first gear provided on the protrusion of the developing device and the second gear provided on the photosensitive means approach each other and mesh with each other, they approach each other in an arc shape, so that the peaks of both gears Even when the ridges face each other, angular displacement easily occurs and engagement becomes easy. This greatly improves operational reliability.

[Brief explanation of drawings]

FIG. 1 is a sectional view of one embodiment of the present invention.

FIG. 2 is a perspective view of the frame 3.

FIG. 3 is a perspective view of the developing unit 17.

FIG. 4 is a perspective view related to support pieces 68a and 68b.

FIG. 5 is a perspective view of the developing roller 22 and the photosensitive drum 10.

FIG. 6 is a rear view of the developing unit 17.

FIG. 7 is a sectional view illustrating the mounting operation of the developing unit 17.

FIG. 8 is a sectional view illustrating the mounting operation of the developing unit 17.

FIG. 9 is a front view illustrating the mounting operation of the developing unit 17.

FIG. 10 is a rear view illustrating the mounting operation of the developing unit 17.

FIG. 11 is a perspective view of a terminal plate 52 and a connecting pin 53.

[Explanation of symbols] 1 Electrophotographic equipment 3 Frame 8 Photosensitive unit 10 Photosensitive drum 15 Light source device 16 Boarding pass 17 Developing unit 33 Fusing unit 46 Front wall 47 Rear wall 48, 49 Guide pin 51 Lever 52 Terminal board 53 Connection pin 56 Guide groove 58, 59 Engagement groove

Claims (3)

[Claims] Claim 1: In a structure in which a developing device is installed in a frame having a front wall and a rear wall, the developing device has a protrusion on its lower side that protrudes in a direction intersecting the front-rear direction of the frame, and a guide groove formed on a side corresponding to one of the directions, having an open lower end and extending in the vertical direction; and a locking groove extending obliquely upward in a direction opposite to the protruding direction of the protrusion from at least the upper end of the guide groove. A matching groove and a pair of lock pins protruding in the front-back direction near the lower end, and a guide groove protruding inward on either the front wall or the rear wall of the frame when the developing device is attached to the frame. The pair of lock pins engage with each other when the guide pin reaches the upper end position of the guide groove of the developing device, causing angular displacement around the longitudinal axis. and a support member that is capable of being angularly displaced in the direction in which the protrusion protrudes, and that moves the developing device along an arcuate trajectory to a position where attachment to the frame is completed when the angularly displacing operation is completed. The mounting structure of the developing device. 2. In a structure in which a developing device is installed in a frame having a front wall and a rear wall, the developing device has a protrusion that protrudes in a direction intersecting the front-rear direction of the frame on a lower side thereof, and a protrusion that a first gear provided on at least one side in the front and back direction of the photosensitive means, and a second gear provided in the frame that meshes with the first gear when the developing device is completely attached to the frame. The first gear approaches the second gear along an arcuate trajectory by being displaced along an arcuate trajectory in the direction in which the protrusion of the developing device protrudes, and when the developing device has completed the displacement, the first gear approaches the second gear in an arcuate trajectory. A mounting structure for a developing device, characterized in that the second gear meshes with the second gear from an oblique direction that intersects with the normal direction at the meshing position with the second gear. 3. In a structure in which the developing device is installed in a frame having a front wall and a rear wall, the developing device has a protrusion on the lower side that protrudes in a direction intersecting the front-rear direction of the frame. is provided with a driving gear that is rotationally driven by a drive source, and the developing device includes a stirring member that stirs the developer stored inside, and a driven member that is connected to the stirring member and disposed outside the rear side of the developing device. The gear is interposed between the driving gear and the driven gear when the developing device is attached to the frame, and transmits power, and is movable in the vertical direction behind the developing device, and has an elastic force directed downward. A mounting structure for a developing device, characterized in that it is provided with an idle gear that is actively energized.