JPH1138721A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily replace a first and a second developing means without providing a support base by concurrently extracting the second developing means by the action of a coupling means when the first developing means is extracted, and supporting the first developing means with the second developing means in the state. SOLUTION: When a developing door 25 is opened and a second hook lever is rotated to this side, a second coupling pin is lowered, and the coupling between the second coupling pin provided on a first developing means 51 and the groove 33 of a second device main body 30 is released. The second hook lever is held and pulled to the front side of a device, and the hanging member of the first developing means 51 is extracted along a guide groove. Since the front coupling pin is coupled with a groove provided on the first developing means 51, a second developing means 55 is extracted concurrently with the extraction of the first developing means 51. The hanging member of the first developing means 51 is released from the guide groove at the final stage of the extraction, and the second developing means 55 is supported on a support face 251 of the developing door 25. When only the first developing means 51 is lifted, the first coupling pin is released from the groove of the first developing means 51, and only the first developing means 51 is lifted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly, to at least an image carrier for forming an electrostatic latent image and an electrostatic latent image formed on the image carrier using a developer. The present invention relates to an image forming apparatus having a developing means for developing.

[0002]

[Prior art]

(Prior Art 1) Since the life cycle of a developing unit used in an image forming apparatus is generally shorter than the life cycle of an image forming apparatus, the developing unit must be replaced after a predetermined period of use. Therefore, it is necessary to determine the structure of the image forming apparatus so that the image forming apparatus can be most easily performed in consideration of the replacement of the developing unit, and various types of replacement have been considered.

(Prior Art 2) There is known an image forming apparatus in which a transfer unit or the like can be opened in order to facilitate processing of a paper jam occurring inside the apparatus and easy replacement of a developing unit by a consumable method.

[0004]

However, the problem of (Prior Art 1) is that a color image in which yellow, magenta, cyan, and black developing means are arranged in parallel from the top in the image forming apparatus. Considering the forming apparatus, the yellow and magenta developing means are used as a single unit because they are used less frequently than the black developing means and have almost the same life cycle (hereinafter referred to as a color developing unit). Some of them are exchanged together.

[0005] The color developing unit has a considerable weight, and it is impossible to carry out the replacement work by holding the color developing unit with a stable force unless the structure has the top of the color developing unit when replacing. . Therefore, when replacing the color developing unit, an image forming apparatus that is opened so as to hold the upper part of the color developing unit is considered, but a document table, a toner supply unit, and the like are installed on the installed color developing unit. For this reason, it is not preferable that the original platen is configured to hold the upper portion of the color developing unit because the accuracy with respect to the apparatus main body is required and the toner replenishing unit and the like spill toner.

Therefore, it is preferable to replace the developing means such as the color developing unit by pulling it out to the front side of the apparatus in terms of easiness of the replacing work and the structure of the apparatus. However, since the replacing work is performed by holding the upper part of the color developing unit. In addition, the color developing unit must be supported at the position where the color developing unit is pulled out. It is conceivable to provide a support for supporting the color developing unit and the like at the position where the color developing unit and the like are pulled out. However, if a support is separately provided in the apparatus main body, the size of the apparatus is increased, which is not preferable.

As a problem of (Prior Art 2), in order to open a transfer section and the like, the second apparatus main body is connected to a first main body which is a main part of the main body.
2. Description of the Related Art There has been known an image forming apparatus which can be pulled out from an apparatus main body and divided into two parts (Japanese Patent Application No. 6-277978).
Considering the internal structure of the image forming apparatus, since the driving sources of the developing unit, the image carrier, and the like are electric components, it is desirable to install the power supply in the first apparatus main body where the power supply is arranged in consideration of wiring and the like. . On the other hand, it is desirable that the image carrier and the developing means be pulled out together with the second apparatus main body in order to open the transfer section and the like.

However, since it is necessary to stably supply the driving force from the driving source to the image carrier and to perform good image formation while minimizing the rotation unevenness, the second apparatus main body is connected to the first apparatus main body.
When set in the apparatus main body, it is desirable that the drive source is supported by the installed first apparatus main body and the distance to the drive source be set accurately.

Further, the developing means which requires delicate positional accuracy with respect to the image carrier is also supported by the first device main body when the second device main body is set in the first device main body, and the driving source, the image carrier and It is desirable to set the distance accurately. As described above, since the developing unit supported by the first apparatus main body is pulled out together with the second apparatus main body, an image forming apparatus having a structure that does not increase the size of the apparatus and is easy to operate has been desired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a first object of the present invention is to easily replace a heavy developing means without providing a support stand for supporting the developing means in a pulled-out state. An object of the present invention is to provide an image forming apparatus. As a second object, a plurality of developing means are pulled out in conjunction with a pulling-out device of the second apparatus main body, a transfer section of the image forming apparatus is largely opened, and consumable replacement of a paper jam and developing means is facilitated. It is an object of the present invention to provide an image forming apparatus which can be used in a computer.

[0011]

The above object is achieved by the following means.

(1) An image forming apparatus having at least an image carrier for forming an electrostatic latent image and a plurality of developing means for visualizing the electrostatic latent image formed on the image carrier with a developer. In the instep developing means, the instep developing means provided below the instep developing means, and engaging means for engaging the instep developing means and the instep developing means, the instep developing means is The second developing means can be pulled out to the image forming apparatus, and when the first developing means is pulled out, the second developing means is simultaneously pulled out by the action of the engaging means, and the first developing means is pulled out in a state where the first developing means is pulled out. An image forming apparatus, wherein the developing means supports the image forming apparatus.

Alternatively, (2) an image having at least an image carrier for forming an electrostatic latent image and a plurality of developing means for visualizing the electrostatic latent image formed on the image carrier with a developer. In the forming apparatus, a first apparatus main body in which a driving source is installed, a second apparatus main body that can be pulled out with respect to the first apparatus main body, an instep developing means in the plurality of developing means, and Second developing means; first engaging means for engaging the first developing means with the second developing means;
The apparatus main body includes a second engaging means for engaging the upper developing means, and the first developing means and the second developing means are in a state where the second apparatus main body is not pulled out with respect to the first apparatus main body. The second device main body is supported by a support portion provided on the first device main body. When the second device main body is pulled out from the first device main body, the support is performed by the action of the upper engaging means and the second engaging means. The image forming apparatus is characterized in that the support by the unit is released, and the instep developing means and the second developing means are pulled out at the same time.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the description of an embodiment of the present invention, an apparatus suitable for adopting the image forming apparatus of the present invention will be described. FIG. 1 is a side view of an apparatus suitable for adopting the image forming apparatus of the present invention, and more specifically, a side view of a color printer which is an image forming apparatus.

In this color printer, each color toner image sequentially formed on the image carrier is superimposed, and then transferred once onto a transfer paper P at a transfer section to form a color image. Is a color image forming apparatus that separates from an image forming surface.

In the figure, an image carrier 42 is a photosensitive drum,
A photoconductor formed by applying a PC photoreceptor to a drum substrate. The scorotron charger 61 is provided with uniform charging of a high potential to the peripheral surface of the photosensitive drum by a grid maintained at a grid potential and a corona discharge wire. After the photosensitive drum is uniformly charged, the image exposure unit 63 performs image exposure based on the image signal. The image exposure means 63 includes a polygon mirror 64, an fθ lens 65, and a cylindrical lens 6
The main scanning is performed by bending the optical path by the reflection mirror 67 through 6, and a latent image is formed by rotation of the photosensitive drum. Around the periphery of the photoconductor drum 42, a Y developing device 52 composed of yellow (Y), magenta (M), cyan (C), and black (K) toners and a carrier, and two-component developers are respectively incorporated. Device 53, C developing device 54, K
There is a developing device 56.

First, development of the first color yellow is performed by a developing sleeve which is a developer carrying member which contains a magnet and rotates while holding the developer. The developer is composed of a carrier and a toner. The developer is conveyed to the developing area while being regulated to a predetermined developer layer thickness on the developing sleeve 69. The distance between the developing sleeve 69 and the image carrier 42 in the developing area is maintained at a predetermined value larger than the thickness of the developer layer.

After the visualization of the first color is completed, a magenta image forming process for a two-color surface is started. Further, the same image formation is performed for cyan and black, and four-color visible images are formed on the photosensitive drum. On the other hand, one sheet of transfer paper P discharged from the paper supply cassette 72 via the half-moon roller 70 is temporarily stopped near the registration roller 74 via the paper supply roller 71, and when the transfer timing is adjusted, the registration roller 7 is stopped.
By the rotation operation of No. 4, the paper is fed to the transfer area.

In the transfer area, the transfer means 62 is pressed against the peripheral surface of the photosensitive drum 42 in synchronization with the transfer timing, and the multicolor image is collectively transferred onto the fed transfer paper P. Next, the transfer paper P is separated from the peripheral surface of the photosensitive drum and conveyed to the fixing device 76. After the toner is welded by heating and pressing, the toner is discharged to a discharge tray 78 outside the apparatus via a discharge roller 77. On the other hand, the photosensitive drum 42 from which the transfer paper P has been separated is subjected to static elimination by the static eliminator, and then the residual toner is removed by pressure contact of the blade of the cleaning device 79. Enter the process.

Next, an embodiment of the image forming apparatus of the present invention will be described, but the present invention is not limited to this. FIG. 2 is a side view of the image forming apparatus of the embodiment, and FIG. 3 is a perspective view of the instep developing means and the developing means of the image forming apparatus in the embodiment. More specifically, FIG. FIG. 3B shows a state in which the developing means is stored in the image forming apparatus, FIG. 3B shows a state in which the developing means is pulled out from the image forming apparatus, and FIGS. 3C and 3D show a state in which the developing means is engaged. It is operation | movement explanatory drawing of a means. FIG. 4 is a front view of the instep developing means and the developing means of the embodiment, FIG. 5 is a side view of the image forming apparatus of the embodiment in which the instep developing means and the developing means are drawn out, and FIG. FIG. 6 is a side view of a state in which a second apparatus main body, a developing unit, and a photosensitive drum unit are pulled out from the image forming apparatus of FIG.

2, 3 and 4, the image forming apparatus comprises a first apparatus main body 20 and a second apparatus main body 30. The first apparatus main body 20 includes a driving source (not shown) for driving the developing unit 50, the first apparatus main body rail 21, the roller 23, and the developing door 2.
5, a support plate 24 and the like.

The first apparatus main body rail 21 is the second apparatus main body 3
A second device main body arm 31, which will be described later, moves along the rail, which serves as a guide when pulling out 0. The roller 23 is connected to the second device main body arm 31.
Is spinning on.

The developing door 25 is rotatable about a shaft 26, and is opened when the second apparatus main body 30 is pulled out from the first apparatus main body 20. Second device main body 30
The developing door 25 is supported by the support surface 251 in a state where the upper developing means 51 and the second developing means 55 are overlapped in a state where the developing door 25 is pulled out with respect to the first apparatus main body 20. Also, Developing means 5
5 is pulled out, the developing door 25 is connected to the developing means 5
5 is supported on the support surface 251. Also, the first device main body 20
The support plate 22 fixed to the
The shaft 43 of the image carrier 42 is engaged with and supports the image carrier 42.

Next, the second apparatus main body 30 can be pulled out substantially horizontally on the front side of the first apparatus main body 20 where the operation section of the image forming apparatus is installed. The second device main body 30 is provided with a second device main body arm 31, a groove 33, and the like.

The second device main body arm 31 has a roller 23
, And the roller 32 provided on the second apparatus main body arm 31 moves along the first apparatus main body rail 21 so that the second apparatus main body 30 is pulled out to the front side of the apparatus. . A projection 311 for moving the photosensitive drum unit 41 is provided on the second apparatus main body arm 31.
Is provided. The groove 33 is a groove fixedly provided in the second apparatus main body 30, and is adapted to engage with a second engagement pin 571 of a second engagement means described later.

Next, the developing means 50 visualizes the electrostatic latent image formed on the image carrier 42 with a developer. The developing means 50 includes an instep developing means 51 and a developing means 55 provided below the instep developing means.

The first developing means 51 includes a developing device frame 59, a Y developing device 52, an M developing device 53, a C developing device 54, and a second engaging device 57.
It is composed of The developing device frame 59 is a frame having a Y developing device 52, an M developing device 53, a C developing device 54, a second engaging means 57, and the like. The instep developing means 51 is a developing device for a color, and can replace the developing device other than the black developing device together. Further, when the upper developing means 51 is not pulled out with respect to the second apparatus main body 30, the hanging member 51 of the upper developing means 51 is not used.
1 is slidably supported in the guide groove 80 of the second apparatus main body (FIG. 4).

The Y developing device 52 in the developing device frame 59 has a structure in which the Y developing device support portion 524 provided in the first apparatus main body 20 is sandwiched between the Y developing projecting upper portion 522 and the Y developing device projecting lower portion 523. It is supported by the first device main body 20. Each developing unit other than the Y developing unit 52 is also supported by the first apparatus main body.

The second engaging means 57 is capable of connecting and separating the second apparatus main body 30 and the instep developing means 51. As shown in FIGS. A second engagement pin 571 is fixed to the second engagement lever 572 provided. Further, the second engagement pin 571 is connected to the bearing portion 57.
4 so as to be rotatable and move in the vertical direction. The upper end of the second engagement pin 571 is adapted to engage with the groove 33 of the second apparatus main body 30. The compression spring 573 is inserted into and incorporated into the second engagement pin 571 and urges the second engagement lever 572 downward. Also,
The instep developing means 51 has L-shaped depressions 513 and 514,
The second engagement lever 572 is inserted. In addition, when the tip of the second engagement pin 571 protrudes as shown in FIG. 3A, the second engagement lever 572 is in the recess 513 side, while the tip of the second engagement pin 571 is FIG. 3 (b)
When it does not protrude as in the above, the second engagement lever 572 enters the recess 514 side. FIG. 3 (c),
When the user engages the lever 572 in the direction of arrow 575 as shown in FIG. 4D, the lever 572 is disengaged from the L-shaped recess 513, and the compression spring 573 biases the arrow 5 to move the arrow 575.
It moves in the direction of 76. Then, the second engagement pin 571 is lowered and comes out of the groove 33 (FIG. 2) of the second device main body 30. Next, in order to protrude the tip of the second engagement pin 571, the second engagement lever 572 is lifted in a direction opposite to the arrow 576 against the compression spring 573, and furthermore, an arrow 575
When it is rotated in the opposite direction to the direction of FIG. Keeps the tip protruding.

Next, the second developing means 55 comprises a K developing device 56 for black developer and an instep engaging means 58 and the like. The K developing device 56 is provided alone since the consumption of the black developer is larger than the consumption of the other developers.

The instep engaging means 58 is adapted to engage and disengage the instep developing means 51 and the second developing means 55. The instep engaging means 58 is mechanically and functionally similar to the above-mentioned second engaging means 57, and detailed description is omitted. The instep engaging pin 581 can be engaged with and separated from the groove 512 provided in the instep developing means 51.

Next, in FIG. 6, the photosensitive drum unit 41 is a detachable unit having an image carrier 42. The photosensitive drum unit 41 has an image carrier 42 fixed to a support plate 44, and the image carrier 42 is a shaft. 43 is rotated. The support plate 44 has a locking portion 441 which is engaged with the projection 311 of the second device main body arm 31. When the second device main body arm 31 moves to the front side of the device, a projection 311 provided on the second device main body arm 31 pushes the locking portion 441 in the same direction. When the support plate 44 moves, the photosensitive drum unit 41 supported by the support plate 44 also moves in the same direction. When the second apparatus main body 30 is not pulled out with respect to the first apparatus main body 20, the photosensitive drum unit 41
The shaft 43 enters the support plate 22 of the first apparatus main body 30 and is supported. Further, the second device main body 30 is connected to the first device main body 20.
When the photosensitive drum unit 41 is pulled out, the engaging portion 441 is supported by the projection 311 and pulled out.

Here, each of the actual drawing operations will be described.

(A) Pull-out operation of the developing means (first and second developing means) 50 In FIGS. 3 and 5, the developing door 25 is opened in the direction of arrow 27, and the second locking lever 572 is rotated forward (arrow 575 in FIG. 3). Direction), the biasing force of the compression spring 573 causes the engagement pin 57
1 goes down. Then, the engagement between the second engagement pin 571 provided on the instep developing means 51 and the groove 33 of the second apparatus main body 30 is released. Here, the user lock lever 572 is gripped and pulled toward the front side of the apparatus, and the suspension member 511 of the instep developing means 51 is pulled out along the guide groove 80. At this time, the instep engaging pin 581
Is engaged with the groove 512 provided in the instep developing means 51, so that the developing means 55 is also pulled out at the same time as the instep developing means 51 is pulled out. At the end of the drawer, the suspending member 511 of the instep developing means 51 is disengaged from the guide groove 80, and the instep developing means 51 is placed on the support surface 251 of the developing door 25 so as to overlap the developing means 55. When only the instep developing means 51 is lifted, the instep engaging pin 581 is disengaged from the groove 512 of the instep developing means 51 and only the instep developing means 51 is lifted.

(B) Pulling-out operation of the second developing means 55 When the developing door 25 is opened in FIGS. 2 and 3 and the upper lock lever 582 is rotated forward in the same manner as the second lock lever 572, the urging force of the compression spring is obtained. As a result, the instep engaging pin 581 is lowered. Then, the engagement between the instep engaging pin 581 and the groove 512 (FIG. 4) of the instep developing means 51 is released. Here, the upper lock lever 582
, And slide it out on the support surface 251 of the developing door 25 toward the front side of the apparatus. Note that the instep developing means 51 includes the hanging member 5.
11 enters the guide groove 80 so that no load is applied to the developing means 55.

(C) The second apparatus main body 30 and the developing means (A,
6, the developing door 25 is opened in the direction of arrow 27, and the second apparatus main body 30 is pulled out toward the front side of the apparatus (in the direction of arrow 28). Then, the second device main body arm 3 integrated with the second device main body 30
1 is also drawn out to the front side of the apparatus. Specifically, the second device main body arm 31 moves on the roller 23, and the roller 32 provided on the second device main body arm 31 rotates and moves along the first device main body rail 21, and the second device main body arm 31 moves. Body 3
0 is drawn to the front side of the apparatus. At this time, when the second apparatus main body moves to the front side of the apparatus, the groove 33 fixed to the second apparatus main body also moves, and the groove 33 pushes the second engagement pin 571 in the same direction. Then, the upper developing means 51 moves, and when the upper developing means 51 moves, the groove 512 of the upper developing means 51 pushes the upper engaging pin 581 in the same direction, and the developing means 55 is also pulled out. It is supported on the support surface 251 of the developing door 25 as described in the description (A).

As for the support of the developing device, since the upper portion 522 of the Y developing device projection and the lower portion 523 of the Y developing device projection are disengaged from the Y developing device support portion 524 provided in the first apparatus main body 30, the Y developing device 52 is supported. Support is released. The support of each developing device other than the Y developing device 52 is similarly released.

(D) Pull-out operation of the second apparatus main body 30 and the photosensitive drum unit 41 In FIG. 6, the developing door 25 is opened in the direction of arrow 27, and the second apparatus main body 30 is pulled out to the front side of the apparatus (in the direction of arrow 28). . Then, the second device main body arm 3 integrated with the second device main body 30
1 is also drawn out to the front side of the apparatus. Specifically, the second device main body arm 31 moves on the roller 23, and the roller 32 provided on the second device main body arm 31 rotates and moves along the first device main body rail 21, and the second device main body arm 31 moves. Body 3
0 is drawn to the front side of the apparatus. At this time, when the second device main body arm 31 moves to the front side of the device, the projection 311 provided on the second device main body arm 31 pushes the locking portion 441 provided on the support plate 44 in the same direction. Then the support plate 4
4 moves, and the image carrier 42 supported by the support plate 44
Is also moved and pulled out in the same direction. Note that the shaft 43 of the photosensitive drum unit 41 enters the groove 221 of the support plate 22 of the first device main body 30 when the second device main body 30 is not pulled out with respect to the first device main body 20. Supported. When the second apparatus main body 30 is pulled out from the first apparatus main body 20, the photosensitive drum unit 41 is pulled out with the locking portion 441 provided on the photosensitive drum unit 41 supported by the projection 311.

[0039]

According to the structure described above, the following effects can be obtained.

According to the first aspect of the present invention, when the developing means includes, for example, a color developing means and a black and white developing means, when the developing means is pulled out, the developing means is also drawn out at the same time. Also, it is not necessary to newly install a member for supporting the instep developing means, so that the instep developing means can be supported, and the developing means can be easily gripped and exchanged.

According to the second aspect of the present invention, only the developing means out of the plurality of developing means can be pulled out alone, which is convenient.

According to the third aspect of the present invention, the developing means can be supported without the necessity of separately providing a support base on the apparatus main body, so that the structure is simple and the cost can be reduced.

According to the fourth aspect of the present invention, since the image forming apparatus can be pulled out to the front side, the replacement operation becomes easy.

According to the fifth aspect of the present invention, since the developing means supported by the first apparatus main body is pulled out together with the second apparatus main body, the image forming apparatus has a structure which does not increase the size of the apparatus and is easy to operate. become.

According to the sixth aspect of the present invention, there is no need to separately provide a support base in the apparatus main body, and the structure can be simplified and the cost can be reduced.

According to the seventh aspect of the present invention, since the image carrier needs to receive the driving force from the driving source and perform image formation while minimizing rotation unevenness, the second apparatus main body is replaced with the first apparatus main body. In this state, the drive source is supported by the installed first device main body, and the distance to the drive source can be set accurately.

According to the eighth aspect of the present invention, since the image forming apparatus can be pulled out to the front side, the replacement operation becomes easy.

[Brief description of the drawings]

FIG. 1 is a side view of an apparatus suitable for adopting an image forming apparatus of the present invention.

FIG. 2 is a side view of the image forming apparatus according to the embodiment.

FIG. 3 is a perspective view of instep developing means and second developing means of the image forming apparatus of the embodiment.

FIG. 4 is a front view of the instep developing means and the second developing means of the embodiment.

FIG. 5 is a side view of the image forming apparatus according to the exemplary embodiment in a state in which the instep developing means and the second developing means are drawn out;

FIG. 6 is a side view showing a state where a second apparatus main body, a developing unit, and a photosensitive drum unit are pulled out from the image forming apparatus of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 20 1st apparatus main body 21 1st apparatus main body rail 221 groove 22 support plate 25 developing door 251 support surface 26 axis 30 2nd apparatus main body 31 2nd apparatus main body arm 41 photosensitive drum unit 42 image carrier 441 locking plate 50 developing means 51 Instep developing means (color developing unit) 511 Suspension member 512 Groove 52 Y developing unit 522 Y developing unit protrusion upper part 523 Y developing unit protrusion lower part 524 Y developing unit support part 53 M developing unit 54 C developing unit 55 O developing unit 56 K Developing device 57 Party engaging means 571 Party engaging pin 572 Party locking lever 58 Party engaging means 581 Party engaging pin 582 Party locking lever

Claims (8)

[Claims] 1. An image forming apparatus having at least an image carrier for forming an electrostatic latent image and a plurality of developing means for visualizing the electrostatic latent image formed on the image carrier with a developer. Developing means, a developing means provided below the developing means, and an engaging means for engaging the developing means with the developing means, wherein the developing means The second developing means is withdrawn by the action of the engaging means when the first developing means is pulled out, and the first developing means is pulled out in a state where the first developing means is pulled out. An image forming apparatus supported by a developing means. 2. The image forming apparatus according to claim 1, wherein only the developing means can be pulled out by releasing the function of the engaging means. 3. A developing door installed in the apparatus body is opened when the developing means or the developing means is pulled out, and when the developing means is pulled out, the developing door connects the developing means with the developing means. The image forming apparatus according to claim 1, wherein the image forming apparatus supports the image forming apparatus. 4. The image forming apparatus according to claim 1, wherein said first developing means and said second developing means are capable of being pulled out to the front side of the image forming apparatus on which an operation section of the image forming apparatus is installed. 4. The image forming apparatus according to 2 or 3. 5. An image forming apparatus having at least an image carrier for forming an electrostatic latent image and a plurality of developing means for visualizing the electrostatic latent image formed on the image carrier with a developer. A first apparatus main body in which a driving source is installed, a second apparatus main body that can be pulled out with respect to the first apparatus main body, instep developing means in the plurality of developing means, and second developing means in the plurality of developing means. And an upper engaging means for engaging the upper developing means and the second developing means; and a second engaging means for engaging the second apparatus body with the upper developing means. The developing unit is configured to, when the second device main body is not pulled out from the first device main body, to the first device main body.
The second device main body is supported by a support portion provided on the device main body, and is supported by the support portion by the action of the instep engaging means and the second engaging means when the second device main body is pulled out from the first device main body. Is released, and the instep developing means and the second developing means are simultaneously drawn out. 6. A developing door is provided in the image forming apparatus, and when the second apparatus main body is pulled out from the first apparatus main body, the developing door is opened, and the second apparatus main body is opened. 6. The image forming apparatus according to claim 5, wherein the developing door supports the developing means and the developing means in a state where the developing door is pulled out with respect to the first apparatus main body. 7. The image carrier is supported by the first apparatus main body in a state where the second apparatus main body is not pulled out with respect to the first apparatus main body, and the second apparatus main body is connected to the first apparatus main body. The image forming apparatus according to claim 5, wherein the image forming apparatus is supported by the second apparatus main body when being pulled out from one apparatus main body. 8. The image forming apparatus according to claim 5, wherein the second apparatus main body can be pulled out to the apparatus front side where the operation unit of the image forming apparatus is installed with respect to the first apparatus main body. An image forming apparatus according to claim 1.