JPS63273878A - Process cartridge and image forming device - Google Patents

Abstract

PURPOSE:To prevent the surfaces of an image carrier and a developer conveying means from being damaged by holding a developing device at a 2nd position as a nondevelopment position distant from the image carrier by a spacer member when a process cartridge (PC cartridge) is unused and brand-new. CONSTITUTION:While the PC cartridge 100 is unused and brand-new, a spacer block 43 is interposed between a photosensitive drum 1 and a developing device 3. The developing device is therefore held stably against a pressure spring 40 at the 2nd position as the nondevelopment position where a developing sleeve 32 leaves the photosensitive drum 1. Here, even if a oscillatory swing is caused, the development part gap between the photosensitive drum 1 and the developing sleeve 32 on the side of the developing device 3 is held at a 2nd interval gap alpha2 larger than a 1st prescribed narrow interval gap alpha1 which enables develop ment, so the photosensitive body 1 and developing sleeve 32 neither contact nor interfere with each other and the damage to the both 1 and 32 is prevented.

Description

Detailed Description of the Invention A. Object of the Invention [Industrial Application Field] The present invention includes at least an image bearing member and a developing device for developing a latent image formed on the surface of the image bearing member. The present invention relates to a process cartridge (hereinafter referred to as a PC cartridge) that is detachably attached to an apparatus main body.

[Conventional technology]

A removable IJ-type image forming device is generally used for multiple process devices such as an image carrier, a developing device, a cleaning device, a charging device, etc. out of all the process devices for image formation. The entire cartridge is assembled into a common cartridge housing so that it can be attached to and detached from the main body of the image forming apparatus.

A predetermined amount (
For example, when the amount of developer (equivalent to 2,000 copies) is used up, the cartridge is replaced with a new PC cartridge.

By making the image forming apparatus removable with a PC cartridge as described above, the maintainability and serviceability of the image forming apparatus is improved, and users can use multiple PC cartridges with different functions such as developing colors. Jam handling and equipment that allows the same image forming apparatus to be used for multiple functions by replacing and installing PC cartridges with functions that match the purpose on the image forming apparatus. This method has advantages such as easy maintenance, and is already in practical use as one of the configuration methods for, for example, a personal type small and lightweight image forming apparatus.

The developing device assembled into the PC cartridge as described above uses an l-component type magnetic toner developer or non-magnetic toner as a developer, and coats the surface of the developer conveying means in a thin layer with it. One that is applied to the surface of an image carrier by magnetically or electrostatically adhering it to the surface of the image carrier (one-component developing device)
There are various types of developing devices, such as those using a two-component developer consisting of a mixture of magnetic carrier particles and toner particles, which is carried on the surface of a developer conveying means and applied to the surface of an image carrier (two-component magnetic brush developing device). This method is in practical use.

[Problem that the invention seeks to solve]

In a conventional PC cartridge that includes at least an image bearing member and a developing device that develops a latent image formed on the image bearing member, the developing device faces the image bearing member and conveys a developer that develops the surface of the image bearing member. The means is fixedly disposed within the cartridge housing with a gap (hereinafter referred to as a developing section gap) facing the image carrier surface set to a predetermined very small gap that allows development from the beginning.

In practice, the developing section gap that allows development is, for example, about several hundred μm in a one-component developing device, and for example, 1 to 5 μm in a general magnetic brush developing device, which is a two-component developing device.
There is a two-component developing device in which a thin layer of two-component developer is applied to the surface of the developer transporting means, and an alternating electric field is applied between the developer transporting means and the image carrier to increase development efficiency. For example, it is about 0.2 to 0.8 mm, which is extremely small.

For this reason, if a packaged new, unused PC cartridge is subjected to fairly severe vibrations or shocks during distribution, resulting in bending of the PC cartridge or vibrations in the built-in equipment, it is necessary to Since the developer conveyance means and the image carrier on the apparatus side are in contact with each other or interfere with each other because the developing section gap between them is extremely small as described above, or if the developer conveyance means is not used for one-component development in advance. If a two-component developer containing a developer or a carrier is coated, there is a possibility that they will be strongly pressed against each other via the coated developer layer. If contact, interference, or pressure as described above occurs, the surface of the image carrier and the surface of the developer conveying means will be damaged.

Also, even after the use of PC cartridges has started,
Opening the inside of the image forming apparatus or inserting/removing the PC cartridge when removing jammed paper from the image forming apparatus, maintaining the apparatus, replacing with another PC cartridge, etc. In this case, or in other cases where the PC cartridge is roughly handled and subjected to severe vibrations or shocks, mutual contact between the image carrier surface and the developer conveying means on the developing device side will occur in the same way as described above.
May cause interference/pressure.

It is an object of the present invention to solve the above-mentioned problems in PC cartridges and image forming apparatuses in which a PC cartridge is removable.

Summary: Structure of the Invention [Means for Solving the Problems] The first invention of the present invention includes at least an image bearing member and a developing device for developing a latent image formed on the surface of the image bearing member. In a process cartridge of an image forming apparatus that is used and is detachably attached to the main body of the forming apparatus, the developing apparatus is arranged at a predetermined first interval that allows the developer conveying means of the apparatus to perform development on the surface of the image carrier. a first position where the two faces face each other;
The developing device is arranged so as to be swingable between second positions facing each other with a second gap larger than the second gap, and at least when the cartridge is in a new, unused state, the developing device is moved to the second position. The present invention provides a process cartridge characterized in that the process cartridge is equipped with a spacer member that can be moved or removed to hold the process cartridge.

The second invention also provides a cartridge support means that can be opened and closed with respect to the main body of an image forming apparatus and that supports a process cartridge in a detachable manner; The developing device includes a first position in which the developer conveying means on the device side faces the surface of the image carrier with a predetermined first gap therebetween so that development can be performed. , a process cartridge disposed so as to be swingable between second positions facing each other with a second gap larger than the first gap; and a developing device normally placed in the second position. a movable spacer member that holds the developing device in the second position, and a movable spacer member that holds the developing device in the second position when the cartridge supporting means with the process cartridge mounted thereon is closed relative to the image forming device. The gist of the present invention is an image forming apparatus comprising: a spacer release member provided on the image forming apparatus main body side for swinging the spacer member to allow the developing device to move to a first position.

[For production]

In the case of the first invention, when the PC cartridge is in a new, unused state, the developing device is held in the second position, which is the non-developing position, separated from the image carrier by the spacer member. During the distribution of new PC cartridges, quite severe vibrations and shocks occur, resulting in damage to the P.
Even if the C cartridge is bent or vibrations occur in the built-in equipment, mutual contact, interference, or pressure between the developer conveyance means on the developing device side and the image carrier is prevented, and the image carrier Damage to the surface of the developer transport means is strictly prevented. When in use, the spacer member that holds the developing device in the second position is moved to the first developing position.
Images can be produced by releasing or removing the material so as to move it to a new position.

Further, in the case of the second invention, the developing device is held at the first position where it can produce an image only when the cartridge support means with the PC cartridge attached is closed with respect to the image forming apparatus, and the cartridge with the PC cartridge attached When the support means is opened from the image forming apparatus main body or
When the C cartridge is taken out from the cartridge support means, it is held in the second position, which is a non-developing position, separated from the image carrier by the intervention of the spacer member. Even if vibrations or shocks are applied, mutual contact, interference, or pressure between the developer conveying means on the developing device side and the image carrier is prevented, and damage to both is strictly prevented.

〔Example〕

Embodiment 1 (Figs. 1 to 5) Fig. 4 is an external perspective view of an example of a PC cartridge 100 according to the present invention, and the cartridge housing 101 thereof is
As shown in FIG. 5, at least a photosensitive drum 1 as an image carrier and a developing device 3 are incorporated therein. In general, a cartridge is often constructed including a charger 2 for uniformly charging the circumferential surface of the photosensitive drum and a cleaning device 4 for cleaning the surface of the photosensitive drum after image transfer.

The image forming apparatus main body 200 of the PC cartridge 100 (
In the case of this embodiment, the attachment to the device main body 2 (Fig. 5) is
00, an upper frame that can be opened and closed diagonally upward to the main body of the device as shown by the solid line around the support shaft 201, and can be closed flat against the main body of the device as shown by the two-dot chain line. body 202 (cartridge support means).

That is, when a locking member (not shown) is released, the upper frame body 202 is opened around the support shaft 201 by an opening biasing member (not shown), and is held in the diagonally upward open position shown by the solid line. Insert the PC cartridge 100 from the front side of the upper frame into the PC cartridge insertion/removal section inside the upper frame in the open state and push it in sufficiently, then open the upper frame 202 with respect to the apparatus main body 200 and urge it. It resists the member and is trapped like the two-dot chain line water. When it is fully closed, the locking member works to stably maintain the closed state. That is, the PC cartridge 100 is built into the main body 200 of the apparatus. When the upper frame body 202 is closed, the built-in PC cartridge 100 is mechanically and electrically connected to a mechanism on the device main body 100 side via a mutual coupling member (not shown).

The built-in PC cartridge 100 can be removed by opening and raising the upper frame 202 from the apparatus main body 200, contrary to the above, and removing the PC cartridge from the PC cartridge insertion/removal section inside the upper frame.

FIG. 5 is a perspective view of the developing device 3, and FIG. 1 is a cross-sectional view thereof.

The developing device 3 of this embodiment is a two-component magnetic brush developing device, and a non-rotating magnet roller 3 serves as a magnetic field generating means.
A developing container 31 is provided with a non-magnetic developing sleeve 32 as a developer conveying means into which a developing sleeve 3 is inserted and built-in, a non-magnetic or magnetic blade member 34 as a developer layer thickness regulating member for the developing sleeve, and the like. It consists of a replenishment toner storage container 35 that is integrally attached to the developer container.

In a new, unused state, the developer container 31 contains a predetermined amount of starting developer T, which is a mixture of magnetic carrier C and toner T. The externally exposed surface of the developing sleeve 32 is also coated with a thin layer of developer T. This applied developer is magnetically restrained and held on the surface of the sleeve 32 by the magnetic field of the magnet roller 33 within the developing sleeve 32. Further, the replenishment toner storage container 35 is separated from the developing container 31 via a sealing member 36 that can be pulled out and removed, and the replenishment toner t is hermetically stored in the container 35.

A handle member 37 is attached to the end of the seal member 36, and the handle member 37 is fitted onto and supported by a protrusion 38 provided at the front end of the developing device (Fig. 3, 2 points). (dashed line). The handle member 37 is connected to the front end plate 10 of the housing 101 of the PC cartridge 100 as shown in FIG.
It protrudes outward from a slit hole 103 provided in 2. By pinching the protruding handle member 37, removing it from the protruding piece 38, and pulling it in the direction of arrow M, the seal member 36
is peeled off from the opening 351 of the replenishment toner storage container and extracted out of the cartridge, and the container 35 is opened. As a result, the toner t in the container 35 is supplied into the developing container 1 in which the starting developer T is already accommodated (FIG. 2). The sealing member 36 is, for example, a tape-shaped plastic film such as PUT-PP, A Bunji having tensile strength, or the like.

The developing device 3 has a predetermined first gap (developing section gap) α1 within the cartridge housing 101 around a support shaft 39, as shown in FIG. A first position where they face each other and a second position where they face each other with a second gap α2 larger than the first gap α1 as shown in FIG. It is arranged so that it can swing. The developing device 3 is always biased toward the first position by a pressure spring 40 (FIG. 5).

Reference numeral 41 denotes a lever provided on the developing device 3 so as to be freely rotatable about a support shaft 42, and on the other hand, a spacer block 43 made of rubber, plastic, etc. is attached to the tip of an arm portion 411.

When the PC cartridge 100 is new and unused, the spacer block 43 is interposed between the photosensitive drum 1 and the developing device 3 as shown in the first figure.

As a result, the developing device 3 is moved to a second position, which is a non-developing position away from the photosensitive drum 1, where the developing sleeve 32 faces the photosensitive drum 1 with the second gap α2. It is held stably against the pressure spring 40.

Therefore, even if the PC cartridge 100 is deflected due to fairly strong vibrations and shocks during the transportation of unused new PC cartridge packages, or vibrations are caused to the built-in equipment, the photosensitive drum l and the developing device 3 Since the developing section gap with the developing sleeve 32 on the side is maintained at the second gap α2 which is larger than the predetermined narrow first gap α1 that allows development, the gap between the photosensitive drum 1 and the developing sleeve 32 is maintained. mutual contact and interference are prevented, and both l
・32 damage troubles are strictly prevented.

The pressure spring 40 and lever 41 described above are located inside the end plate 102 of the housing 101 of the PC cartridge 100 and are hidden.

As described above, the unpacked, new, unused PC cartridge lOO is opened diagonally upward to the image forming apparatus main body 200, and is then inserted into the insertion/removal section inside the upper frame body 202 (the Figure 5).

Before closing the upper frame body 202 against the apparatus main body 200, pinch the pull-out removal handle member 37 protruding outward from the front end plate 102 of the PC cartridge lOO and pull out the seal member 36 to remove it. As a result, the replenishment toner storage container 35 is opened. As a result, the toner t in the container 35 is supplied to the side of the developing container 31 in which the starting developer T is already accommodated, as shown in the second figure.

Next, the upper frame body 202 is closed into the image forming apparatus main body 200 (double-dashed line in FIG. 5). Shortly before the upper lever body 202 is completely closed, the arm portion 4 of the lever 41 on the developing device 3 side is located on the side opposite to the spacer block 43 side.
12 hits the upward protruding member 203 on the device main body 200 side, and the receiver is stopped. Then, as the upper frame body 202 continues to move in the closing direction, the lever 41 rotates counterclockwise around the support shaft 42 due to the stop of the projection member 203, and the spacer block 43 moves the photosensitive drum 1 and the developing device. The removal unit 202 automatically moves downward from between the
Until the spacer block 43 is completely closed with respect to 0, the spacer block 43 is completely pulled out from between the photosensitive drum 1 and the developing device 3 downward and escapes, as shown in the second figure.

When this spacer block 43 is removed, the developing device 3
The developing sleeve 32 is oscillatedly displaced by the force of the pressurized spring to the first position, which is the developing position where the developing sleeve 32 faces the photosensitive drum 1 with a predetermined first interval αl that allows development.
Figure 1 → Figure 2).

In the case of the developing device of this example, spacers 032a and 032a having a diameter larger than that of the developing sleeve 32 are provided on both end sides of the developing sleeve 32.
32a (Fig. 3), and this spacer roller 32a.3
2a comes into contact with the circumferential surface of both ends of the photosensitive drum l, the receiver is stopped, and this contact is always maintained by the force of the pressure spring 40, so that the first contact between the photosensitive drum l and the developing sleeve 32 is stopped.
The interval gap α1 is defined.

Thus, as described above, the replenishment toner storage container 35 of the developing device i3 is opened, and the PC cartridge 100 is inserted into the apparatus main body 200 with the developing device 3 being displaced and held in the first position where development can be performed with respect to the photosensitive drum 1. By being built in, the apparatus main body 200 becomes ready to perform image formation. That is, in the state shown in FIG. 2, the developing sleeve 32 is driven to rotate in the direction of the arrow, and a part of the developer T in the developing container 31 is adhered and held as a magnetic adsorption layer on the circumferential surface of the rotating developing sleeve 32, and the blade member In the process of passing through position 34, the layer thickness is regulated to a predetermined value, and the layer is carried out from inside the developing container l to the outside, and in the developing section A facing the photosensitive drum 1, it stands up with the developing pole S1 and is applied to the surface of the photosensitive drum 1. It acts on Due to this and the action of the developing bias (alternating electric field), the latent image on the surface of the photosensitive drum is sequentially developed with toner. The residual developer layer that has passed through the developing section A is held on the developing sleeve surface by the magnetic force of the magnetic poles N2 and S2, and returns to the developing container 1 again.

31 is a magnetic sealing member attached to the inner bottom of the developer container 1, which prevents the developer in the container 1 from leaking out from the lower part of the container.

In the case of this embodiment, the lever 41 cannot be restored once it is rotated counterclockwise as described above and the spacer block 43 escapes downward from between the photosensitive drum 1 and the developing device 3. connects the PC cartridge 100 to the device main body 20
Even if the developing device 3 is taken out from zero, the developing device 3 remains displaced to the first position in FIG. 2, where it can perform development with respect to the photosensitive drum 1. Therefore, the scattering of developer from the developing sleeve 32 when the PC cartridge 100 is repeatedly inserted into and removed from the apparatus main body 200 is also reduced.

In the case of this embodiment, the blade member 34 of the developing device 3 is made of non-magnetic SUS with a plate thickness of 1 cm. The developer layer applied to the peripheral surface is a thin layer (the spike height of the developer layer is approximately 0.8 to 1.5 mm), and accordingly, the first developing section gap α1 is approximately 200 to 800 pLm. Preferably 300~
It is designed to be 500 ILm. Regarding the second developing section gap α2, the deflection between the photosensitive drum 1 and the developing sleeve 32 due to vibrations and impacts during transportation is generally 3.
．． Since it is considered to be within 5mmmm, it should be set to 2IIIIII+ or more.

Generally, if α2 is set to 211I11 or more, there will be no mutual contact or interference between the photosensitive drum 1 and the developing sleeve 32 during distribution, which will prevent damage to both 1 and 32.

Embodiment 2 (FIG. 6) In this embodiment, a knob 5 is provided between the photosensitive drum 1 and the developing device 3.
A freely removable spacer block 43a is engaged with a drawstring 51 with a 0.0-tight string, and the developing device 3 is moved to a second position in which a second gap α2 exists between the developing sleeve 32 on the device side and the photosensitive drum l. This is what was held. Knob 5
0 hangs down from the bottom side of the PC cartridge,
By pulling this knob 50 and removing the spacer block 43a from between the photosensitive drum 1 and the developing device 3, the developing device 3 is displaced to the first position where development is possible, as in FIG. 2 described above.

In addition, the spacer block 43 (Figs. 1 and 2) - 43a (6th
Figure) shows two of the non-image areas of the photosensitive drum between the photosensitive drum 1 and the developing device 3 on both end sides (front side and back side).
It is preferable to leave it in place.

Embodiment 3 (Figures 7 to 9) This embodiment differs from the embodiment 1 in that the lever 41 to which the spacer block 43 is attached is constantly actively rotated clockwise around the support shaft 42 by the spring member 44. It is dynamically energized. This rotating direction is a direction in which the spacer block 43 is wedged between the photosensitive drum 1 and the developing device 3. The clockwise rotational force of the lever 41 by the spring member 44 is applied to the spacer block 43 in the free state by the urging force of the pressure spring 40 (FIG. 5) toward the photosensitive drum 1 about the support shaft 39 of the developing device 3. The developing device 3 is automatically pushed into the space between the photosensitive drum 1 and the developing device 3 or in tension with the surface of the photosensitive drum 1 to move the developing device 3 to the second position (developing unit gap α2). or a position close to that (α2) with sufficient force.

When the PC cartridge 100 is new and unused, a spacer block 43 is interposed between the photosensitive drum 1 and the developing device 3 as shown in FIG. 7 in the same manner as in FIG. 1 of the first embodiment. It is in good condition.

As a result, the developing device 3 is stably held at the second position, which is a non-developing position away from the photosensitive drum 1.

Then, as in the case of the first embodiment, the unused PC cartridge 100 is opened to the main body 200 of the image forming apparatus and then attached to the upper frame body 202 (FIG. 5).
After opening the refill toner storage container 35 by pulling the handle member 37 and removing the seal member 36,
The upper frame body 202 is closed to the image forming apparatus main body 200. Due to this confinement, the upward protruding member 203 on the apparatus main body side contacts the arm 412 of the lever 41 from below, and the lever 41 rotates counterclockwise against the spring member 44, and the spacer block 43 is moved as shown in FIG. The extraction moves downward from between the photosensitive drum 1 and the developing device 3 as shown in FIG. Dynamic displacement. When the lever 41 is rotated in the counterclockwise direction, the upper frame body 202 is
As long as the projection member 203 remains closed, the projection member 203 holds the projection member 203 as it is.

In addition, the upper frame body 202, which is closed in, is opened from the image forming apparatus main body 200 for removing jammed paper that has occurred in the image forming apparatus, during apparatus maintenance, or for converting to another PC cartridge. (Fig. 5) Then, the lever 41
The contact of the projection member 203 with respect to the projection member 203 is released. Then, the lever 41 becomes free and rotates clockwise around the support shaft 42 by the spring member 44, and is actively and automatically wedged between the photosensitive drum 1 and the developing device 3 or onto the surface of the photosensitive drum 1. By contacting them in a tensile manner, the developing device 3 is oscillated to the second position or a position close to the second position against the pressure spring 40, as shown in FIG. 9, and is held at that position.

Therefore, when opening/closing the upper frame body 202 or attaching/detaching the PC cartridge 100 to/from the upper frame body 202, other PC
Even if severe vibration or shock is applied to the PC cartridge 100 when handling the cartridge, the developing device 3 is moved and held at or near the second position, which is the non-developing position, relative to the photosensitive drum 1, as shown in Figure 9. Therefore, damage troubles due to mutual contact, interference, and pressure between the photosensitive drum 1 and the developing sleeve 32 are not caused. Further, wasteful adhesion of toner to the photosensitive drum 1 is also prevented.

When the upper body 202 is closed in the device main body 200 again, the eighth
As shown in the figure, the protruding member 203 abuts against the lever 41, the lever 41 is rotated counterclockwise against the spring member 44, and the spacer block 43 escapes and moves, and the developing device 3
is oscillated again to the first position, which is the developing position, with respect to the photosensitive drum 1, and is held at that position.

In both the first and second inventions, the first position of the developing device 3 is a contact development position with respect to the photosensitive drum 1 serving as an image carrier;
When the second position is a non-contact position, the effects of the present invention can be maximized.

Furthermore, it is preferable that the spacer member has slight elasticity so that a minimum amount of spacer can be secured, and when moving the spacer member, an eccentric cam is used to move the spacer. It is better to make contact gradually.

In the developing device 3, the developing sleeve 32 serving as a developer conveying means is non-rotating, and by rotating the sleeve internal magnetic roller 33, the developer layer is transferred to the developing section A along the circumferential surface of the non-rotating developing sleeve. It is also possible to adopt a configuration system in which the developer is transported to the developer container 31, and further transported and transported back into the developer container 31. The developing sleeve 32 may be an endless rotating belt member. Further, the developer conveying means itself may be a rotating magnet roller or a rotating magnetic belt member having a magnetic field generating section. The developing device is the same as in Example 2.
The developing method is not limited to the component magnetic brush development method, but may be a one-component development method or other methods.

C. Effects of the Invention As described above, according to the present invention, the image carrier and the developer conveying means are damaged by vibrations and shocks during the distribution of new, unused PC cartridges or when handling PC cartridges after they have been used. It is possible to strictly prevent mutual contact, interference, pressure, and resulting damage to both, and the intended purpose is well achieved.

[Brief explanation of the drawing]

The drawings show an embodiment, and FIG. 1 is a cross-sectional view of the developing device before the package is opened and is held in the second position by the spacer block. FIG. A cross-sectional view of the developing device held in the first position, FIG. 3 is a perspective view of the developing device, and FIG. 4 is a PC
A perspective view of the cartridge; FIG. 5 is a diagram showing the PC cartridge inserted into the upper frame of the image forming apparatus in an open state;
FIG. 6 is a cross-sectional view of another embodiment of the developing device, and FIGS. 7 to 9 are diagrams showing various states of the developing device of still other embodiments. 100 is a PC cartridge, l is a photosensitive drum as an image carrier, 3 is a developing device, 43 and 43a are spacer blocks,
αl and α2 are the first and second developing section gaps and

Claims (5)

[Claims] (1) In a process cartridge of an image forming apparatus, which includes at least an image bearing member and a developing device for developing a latent image formed on the surface of the image bearing member, and is used and is detachably attached to the main body of the image forming apparatus. The device is installed at a predetermined first location where the developer conveying means on the device side can perform development on the surface of the image carrier.
It is possible to swing between a first position where they face each other with a gap between them and a second position where they face each other with a second gap that is larger than the first gap. A process cartridge, comprising: a spacer member which is disposed and is movable or removable for holding the developing device in the second position at least when the cartridge is in a new, unused state. (2) The process cartridge according to claim 1, wherein developer is preliminarily supported on the surface of the developer conveyance means on the image carrier side of the developing device when the cartridge is new and unused. (3) The process cartridge according to claim 1, wherein the developing device is always oscillatedly biased toward the first position. (4) The process cartridge according to claim 1, wherein the second gap is set to 2 mm or more. (5) Includes a cartridge support means that can be opened and closed with respect to the image forming apparatus main body and that supports the process cartridge in a detachable manner; and at least an image carrier and a developing device that develops a latent image formed on the surface of the image carrier. The developing device has a first position where the developer conveying means on the device side faces the surface of the image carrier with a predetermined first interval that allows development, and a second position in the first position. a process cartridge disposed so as to be swingable between second positions facing each other with a second gap larger than the gap; and a movable process cartridge that normally holds the developing device in the second position. a spacer member; and the movable spacer member, which is provided on the image forming apparatus main body side and holds the developing device at the second position when the cartridge support means in which the process cartridge is mounted is closed with respect to the image forming apparatus. An image forming apparatus comprising: a spacer release member that interferes with the spacer member to swing the spacer member to allow the developing device to move to the first position.